Note: Descriptions are shown in the official language in which they were submitted.
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GENERATOR
FIELD OF THE DISCLOSED SUBJECT MATTER
This subject matter of the present application relates to energy generating
systems, more particularly, systems adapted for the generation of electrical
energy
utilizing heating/cooling and corresponding expansion/compression of a
material.
BACKGROUND OF THE DISCLOSED SUBJECT MATTER
Generation of electrical power is a process in which one form of energy is
converted into electricity, and a great plurality of processes is known and
used today for
performing the same. Some of these processes involve turning one form of
energy into
mechanical energy allowing the movement/rotation of a mechanical element
within a
to magnetic field for the generation of electricity.
Some of these processes are as follows:
- burning coal in order to turn water into steam and allowing the
steam to
expand within and revolve a turbine, the turbine being the mechanical
element;
- using solar energy in order to turn water into steam and implementing the
same;
- using the power of a waterfall for driving a turbine;
- burning gas within a combustion chamber to drive a piston (for
example in
an internal combustion engine);
In addition, there also exist processes for the generation of electricity
which rely
on the compression/expansion of a medium, entailing reciprocation/movement of
a
mechanical element. In some of these processes, compression/expansion of the
medium
is performed by heating/cooling thereof.
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Such systems are disclosed, for example, in the following publications:
GB1536437, W02009064378A2, US2008236166A1,
US2005198960A1,
US2006059912A1 etc.
SUMMARY OF THE DISCLOSED SUBJECT MATTER
According to the subject matter of the present application, there is provided
a
generator configured for extracting heat from and medium, and utilizing said
heat in a
process for the generation electrical energy. In particular, said heat can be
utilized for
reciprocating/rotating a mechanical element for the generation of said
electricity.
According to one aspect of the subject matter of the present application,
there is
provided a generator comprising a heat differential module configured for
providing a
first reservoir and a second reservoir having a temperature difference
therebetween, a
pressure module containing a pressure medium configured for performing an
alternate
heat exchange process with the reservoirs of the heat differential module so
as to
fluctuate its temperature, and a conversion module configured to utilize the
fluctuation
of the pressure module for the generation of energy.
In particular, said generator can comprise:
- a heat differential module comprising at least:
o a first, high temperature reservoir configured for containing a work
medium at high temperature and being in selective thermal
communication with the pressure medium of said pressure module;
o a second, low temperature reservoir configured for containing a work
medium at low temperature Sand being in selective thermal
communication with the pressure medium of said pressure module;
and
o a heat mechanism configured for maintaining a temperature
difference between the reservoirs;
- a pressure module comprising a pressure medium configured for
alternately
performing a heat exchange process with the high/low temperature work
medium so as to fluctuate its temperature between a minimal operative
temperature and a maximal operative temperature corresponding to the high
and low temperature of the reservoirs; the pressure medium being in
mechanical communication with the conversion module so as to operate it
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- a conversion module configured for converting temperature
fluctuation of
the pressure medium into output energy; and
- a heat recovery arrangement configured transferring heat from the
pressure
module back to the heat differential module or to the pressure module.
It is appreciated that the term 'medium' is used herein to describe any of the
following: solids, fluids ¨ liquids and gasses. For example, the pressure
medium can
even be a solid, or, for example, even a substance which solidifies under
pressure.
It is also appreciated that the terms 'high' and 'low' temperature refer to
two
different temperatures, TH and Tc (can also be referred to herein as TO, so
that TH > TC-
According to different examples, the temperatures TH and Tc can vary as
follows:
- both TH and Tc are above ambient temperature;
- both TH and Tc are below ambient temperature; and
- TH is above ambient temperature and Tc is below ambient temperature.
The term 'ambient' is used herein to define the average temperature of the
external environment in which at least the heat differential module of the
generator is
located. In particular, while in general this environment is simply ambient
air, the
generator can also be configured to be immersed in any desired medium, whereby
the
term 'ambient' will refer to the average temperature of that medium.
The heat differential module can be constituted by a work medium sub-system
comprising the high temperature reservoir and the low temperature reservoir.
In
particular, each of the high/low temperature reservoirs can be provided with
an inlet line
configured for providing selective fluid communication between the reservoirs
and an
inlet access end of the pressure module, and an outlet line configured for
providing
selective fluid communication between an outlet access end of the pressure
module and
the reservoirs.
The respective inlet/outlet lines of the heat differential module are
configured
for alternately providing high/low temperature work medium to the pressure
module so
as to perform a heat exchange process with the pressure medium.
The work medium sub-system can comprise a heat pump having an evaporator
end and a condenser end, the heat pump being configured for withdrawing an
amount of
heat Q from the evaporator end towards the condenser end under the provision
thereto
of input power W. As a result of operation of the heat pump, the condenser end
is
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constantly provided with heat, so that the temperature of the condenser end
exceeds that
of the evaporator end.
The arrangement is such that at least one of the high temperature reservoir
and
the low temperature reservoir is thermally associated with one of said
evaporator end
and condenser end of the heat pump. For example, the high temperature
reservoir can be
thermally associated with the condenser end of the heat pump and/or the low
temperature reservoir can be associated with the evaporator end of the heat
pump. Thus,
the heat pump can operate as a cooling unit to maintain the low temperature
reservoir at
a desired 'low' temperature, while heat expelled from the air heat pump during
cooling
is used to maintain the high temperature reservoir at a desired 'high'
temperature.
Thermal association between the evaporator/condenser end of the heat pump and
the high/low temperature reservoir can be achieved via direct/indirect contact
between
the evaporator/condenser end of the heat pump and the work medium contained
within
the high/low temperature reservoir, allowing for a heat exchange process
between the
former and the latter. According to a specific example, such contact is
achieved via
emersion of the evaporator/condenser end of the heat pump within the high/low
work
medium.
According to one specific design, the high temperature reservoir is in direct
thermal communication with the condenser side of the heat pump while the low
temperature reservoir is associated with the outside environment (i.e. exposed
to
ambient temperature). According to a specific example of this design, the low
temperature reservoir, though exposed to the outside environment can also be
fitted with
an element providing thermal association of the low temperature reservoir with
the
evaporator end of the heat pump.
According to another design, the high temperature reservoir is in direct
thermal
communication with the condenser side of the heat pump while the low
temperature
reservoir is in direct thermal communication with the evaporator side of the
heat pump.
The pressure module can comprise a vessel containing the pressure medium and
at least one conduit (referred herein as 'conduit' or 'core') having an inlet
end and an
outlet end, constituting the respective inlet and outlet access ends of the
pressure
module. Thus, said conduit can be configured for being in selective fluid
communication with said high/low temperature reservoirs, to allow passage of
high/low
temperature work medium therethrough.
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The generator is configured such that high/low temperature work medium can be
alternatively passed through the conduit of the vessel (using selective fluid
communication with the reservoirs) so as to perform a heat-exchange process
with the
pressure medium. Thus, the high temperature work medium is used to bring the
pressure
medium to said maximal operative temperature and said low temperature work
medium
is used to bring said pressure medium to said minimal operative temperature.
As a result, the pressure medium is configured to fluctuate between a maximal
operative temperature and a minimum operative temperature thereof, said
fluctuation
causing a respective increase/decrease of the volume of said pressure medium,
which
can be utilized by the conversion module for the production of energy.
With respect to the pressure module, the following features can be used
(individually or in combination with one another):
? the vessel can be a pressure vessel in which the pressure medium is pre-
loaded to constitute a high-pressure medium. The advantages of pre-loading
the pressure medium will become apparent when discussing the operation of
the generator in further detail;
? the vessel can comprise more than one cores passing therethrough, each
being configured for selective fluid communication with reservoirs of the
heat differential module;
? the cores can be in selective fluid communication with one another, so as to
allow them to assume at least a first, linear configuration in which the cores
form a long single flow path for the work medium and a second, parallel
configuration in which the cores are configured for simultaneous flow of
work medium therein;
? the core/s can be made of materials having high resistance to
compression/pressure forces, a low heat capacity and high heat transfer
coefficient. For example, such materials can be Silicon Carbide, Tungsten
Carbide, Titanium etc.;
? the length L of the pressure vessel can be considerably longer than a
diameter D thereof, whereby several supports may be require within the
pressure vessel to support the cores passing therethrough;
? the pressure vessel can comprise one or more cores which are co-aligned,
having connection points at the supports;
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? at least one of the cores can be fitted with a dissipation
arrangement being in
contact with the pressure medium and configured for increasing the
efficiency of heat transfer into the pressure medium, consequently increasing
the efficiency of the heat exchange process between the work medium and
the pressure medium;
? the dissipation arrangement can be integral with the core or can
be a separate
arrangement fitted thereto. In the former case, the core can be formed with
increased surface area in the form of ribs/spikes or the like, and in the
latter
case the core can be fitted with at least one dissipation member mounted
thereon (e.g. ribs/wings/blades etc.);
? one or more cores can be configured for revolving about their own
axis, or
all the cores can be configured to revolve about a mutual axis (e.g. a central
axis of the pressure vessel;
? the separate dissipation arrangement can also be configured to
revolve about
the cores on which it is mounted;
? the separate dissipation arrangement can be configured to be driven by a
motor. The arrangement may also be such that the dissipation arrangements
of several cores are simultaneously driven by a single motor;
? the motor driving the dissipation arrangement can be located outside the
pressure vessel;
? a drive shaft of the motor can be configured to extend from both
sides of the
pressure vessel, and even be driven by two motors, one engaged with the
drive shaft at each end. It is appreciated that is the drive shaft only
protrudes
from one end of the pressure vessel, i.e. having its second end within the
pressure vessel, the pressure within the vessel can apply a great load on the
drive shaft attempting to push it out of the pressure vessel. This effect may
be so severe that the drive shaft is in danger of being 'shot out' of the
vessel;
? each core can also be fitted with an inner arrangement configured for
increasing heat transfer within the work medium, thereby increasing the
efficiency of the heat exchange process between the pressure medium and
the work medium;
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? according to one example, the inner arrangement can be a static
arrangement, i.e. simply located within the core. According to another
example, the inner arrangement can be a dynamic arrangement configured
for displacing/revolving within the core so as to circulate the work medium
passing through the core;
? the inner arrangement can also be configured for actively displacing the
work medium along the core (e.g. similar to an Archimedes' screw);
? for relatively long pressure vessels, the pressure vessel can
comprise two or
more cores which are co-linearly connected with one another, and also be
provided with sealed supports at the junction points between two adjacent
cores;
? the pressure medium within said vessel can be pre-loaded and contained
under pressure in the range of 2000-8000 atm., more particularly of 3000-
7500 atm., even more particularly of 4000-7000 atm. and ever more
particularly of 5000-6500 atm. It is appreciated that providing suitable
materials from which the pressure vessel is made, even higher pre-loading of
the pressure medium is possivle;
? the pressure medium can have a heat expansion coefficient in the range of
100-1200, more particularly of 250-1100, even more particularly of 500-
1000 and ever more particularly of 600-900; and
? the pressure medium can be selected from a group of: Ethyl
Bromide, water,
N-Pentene, Diethyl ether, Methanol, Ethanol, Mercury and acids.
In addition, at least one or more of the components of the generator through
which a heat transfer process takes place (e.g. cylinders, tubes, surfaces
etc.) can be
formed with a heat transferring surface which has an increased surface area.
Specifically, said surface can be formed with a plurality of elements
increasing its
surface area, e.g. bulges, protrusions etc. According to one particular
example, the
elements can be micro-structures having geometric shapes such as cubes,
pyramids,
cones etc. According to another example, the elements can be ridges (either
parallel or
spiraling).
In the latter case, such ridge elements yield that in cross-section of the
pipes
taken along a central axis thereof, the surface appears undulating (between
peaks and
troughs). In case the ridges are formed both on the internal and on the
external surface
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of the pipe, the arrangement can be such that a peak on the inner surface
faces a trough
on the outer surface and vise verse, thereby maintaining a generally constant
material
thickness in each cross-section perpendicular to the central axis.
It is appreciated that whereas pre-forming an outer surface of a cylindrical
component (as mentioned above) with said micro-structures is fairly simple,
pre-
forming an inner surface of said cylindrical component poses a more complex
problem.
For this purpose, the steps of a method for pre-forming an inner surface of a
cylindrical
component with micro-structures are presented below:
(a) providing a generally planar plate having a first face and an opposite
second
face;
(b) pre-forming said micro-structures on said first face;
(c) providing a mold formed with a non-through going cavity corresponding in
size and shape to said plate, said cavity having a base surface and an opening
at a surface of the mold;
(d) placing said plate in said cavity such that said second face is mated
against
said base surface and said first faces facing the opening of the cavity, such
that there remains a space between said first face and said opening;
(e) introducing a filler material into the cavity so as to fill said space,
including
spaced formed between the micro-structures;
(f) letting said filler material solidify so as to form a single plate
constituted by
said plate and solidified filler material, having a first face constituted by
said
filler material and a second face constituted by the second face of the
original plate;
(g) deforming said single plate to obtain at least a partially cylindrical
shape,
such that the second face of said single plate constitutes and outer surface
of
said cylinder and the first face of said single plate constituted an inner
surface of said cylinder;
(h) removing said filler material from said single plate, thereby resulting in
the
original plate having micro-structures formed on the inner surface thereof;
and
(i) performing a final finish on the inner surface with the micro-structures.
The conversion module of the generator can comprise a dynamic arrangement
being in mechanical communication with the pressure medium so as to be driven
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thereby. In particular, the dynamic arrangement can comprise a movable member
configured to reciprocate in correspondence with the fluctuation of the
pressure medium
from said maximal operative temperature and said minimal operative
temperature.
According to a specific example, the dynamic arrangement can be constituted by
a piston assembly, comprising a housing with a piston located therein, the
piston
sealingly dividing the housing into a first, input chamber being in mechanical
communication with the pressure medium and the second, output chamber being in
mechanical communication with a motor assembly configured for generating
output
energy.
The piston of the conversion module can be configured for reciprocating within
the housing respective to volumetric fluctuations of the pressure medium.
Specifically,
as the temperature of the pressure medium increases, its volume increases
correspondingly, thereby displacing the piston so that the volume of the input
chamber
increases and the volume of the output chamber decreases. Respectively, as the
temperature of the pressure medium decreases, its volume decreases
correspondingly,
thereby displacing the piston so that the volume of the input chamber
decreases and the
volume of the output chamber increases. This reciprocation can be used by the
motor
assembly for the production of output energy.
According to one example, the motor assembly comprises a crank shaft
arrangement so that reciprocation of the piston is configured for generating
revolution
of the crank shaft about is axis. This revolution can be converted, by known
means, for
the production of output energy.
According to another example, the piston can be associated with a linear shaft
which is configured to be meshed with a gear assembly, which in turn is
configured for
converting the linear reciprocation of the shaft into rotational movement.
This rotational
movement can be converted, by known means, for the production of output
energy.
According to a specific design embodiment, there can be provided an
intermediary device between the piston and the motor, for example, the piston
can be
adapted to drive a utility piston via pressure on an intermediary substance
such as oil.
The generator of the present application can further comprise at least one
auxiliary heat exchanger which is in thermal communication at least with one
of the
outlet lines of the high temperature reservoir and the low temperature
reservoir. The
heat exchanger can be configured for performing a heat exchange process
between the
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work medium within said outlet lines and the outside environment and/or a
medium in
which the heat exchanger is immersed.
Thus, the heat exchanger can be configured to respectively cool down / heat up
the work medium heated up / cooled down during the heat exchange process with
the
pressure medium of the pressure module, upon its exit from the pressure
vessel.
Several examples of various constructional configurations of the generator, as
well as methods for operation of each configuration will now be described, in
some of
which configurations the generator may comprise additional elements, members,
modules and/or arrangements. It should be appreciated that while each
configuration
may be used independently, different features of the various configurations
can also be
combined together to produce new configurations of the generator.
Basic configuration
According to a basic configuration of the above described generator, the heat
differential module comprises a high temperature reservoir which is in thermal
communication with a condenser end of a heat pump, and a low temperature
reservoir
which is in thermal communication with the outside environment.
It is appreciated that under this configuration, the evaporator end of the
heat
pump is also exposed to the outside environment, so that, in operation, the
evaporator
end constantly withdrawn heat from the environment, and the heat pump
constantly
withdrawn heat from the evaporator end to the condenser end.
The pressure module comprises a single pressure vessel containing therein a
pressure medium which is pre-loaded to high pressure (approx. 6000 atm.), and
having
at least one conduit passing therethrough. The pressure vessel is further
provided with
an inlet valve associated with an inlet end of the conduit and an outlet valve
associated
with an outlet end of the conduit. The pressure vessel can also be provided
with an
output line which is in fluid communication with a dynamic arrangement of the
conversion module.
Each of the high/low temperature reservoirs comprises an inlet line providing
selective fluid communication between the reservoir and the inlet valve and an
outlet
line providing selective fluid communication between the reservoir and the
outlet valve.
There is thus provided a method for generating output energy using the
generator of the above example, said method comprising the steps of:
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a) selectively opening the inlet and outlet valve to provide fluid
communication
between the high temperature reservoir and the pressure vessel and passing
high temperature work medium from the high temperature reservoir into
inlet valve, through the conduit and out of the outlet valve back into the
high
temperature reservoir. As a result of a heat exchange process between the
high temperature work medium and the pressure medium, the former cools
down while the latter heats up to a maximal operative temperature thereof.
When heating up, the pressure medium increases its volume and causes
displacement of the piston in one direction; and
b) selectively opening the inlet and outlet valve to provide fluid
communication
between the low temperature reservoir and the pressure vessel and passing
low temperature work medium from the low temperature reservoir into inlet
valve, through conduit and out of the outlet valve back into the low
temperature reservoir. As a result of a heat exchange process between the
low temperature work medium and the pressure medium, the former heats up
while the latter cools down to a minimal operative temperature. When
cooling down, the pressure medium decreases in volume and causes
displacement of the piston in an opposite direction.
Performing the above steps repeatedly provides reciprocation of the piston
back
and forth, thereby allowing generation of electricity by the generator.
It is pointed out that higher the pressure of the high-pressure medium, the
more
efficient the thermodynamic operation of the generator (providing that
mechanical
integrity of the generator is maintained). More specifically, the piston has a
predetermined resistance which requires a predetermined threshold pressure of
the high-
pressure medium to overcome this resistance and displace the piston. In the
event a low-
pressure medium is used, heating thereof will first result in a pressure
increase of the
low-pressure medium to the threshold pressure and only then displacement of
the
piston.
In light of the above, pre-loading the medium within the pressure vessel to a
high pressure (exceeding that of the threshold pressure) ensures that upon
heating of the
pressure medium will directly entail displacement of the piston and will not
go to waste
for pressuring the medium to the threshold pressure.
The following should also be noted:
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- when returning to the high temperature reservoir, the cooled down high
temperature work medium can be free to absorb further heat from the
condenser end of the heat pump so as to bring it back to its original high
temperature;
- when returning to the low temperature reservoir, the heated up low
temperature work medium can emit at least some heat into the outside
environment so as to cool down and bring its temperature back to its original
low temperature;
- when
switching from step (a) to step (b) and depending on the length of the
conduit, it can be beneficial, after the selective switching of the position
of
inlet valve to provide fluid communication with the low temperature
reservoir, to delay selective switching of the position of the outlet valve to
provide fluid communication with the low temperature reservoir. In this
way, upon beginning the performing of step (b), the high temperature work
medium contained within the conduit can be first be pushed through its
outlet line into the high temperature reservoir, and only then will the outlet
valve be selectively switched to provide fluid communication with the low
temperature reservoir. The same holds true when switching from step (b) to
step (a);
The above method can further include an additional step (c) in which the
heated
up low temperature work medium is passed through the auxiliary heat exchanger
in
order to allow more efficient emission of heat from the work medium to the
outside
environment.
Direct recovery configuration
According to the above configuration, the outlet line of the low temperature
reservoir is not returned directly back into the low temperature reservoir
upon exiting
the pressure vessel, but rather is first passed through the evaporator end of
the heat
pump. In this manner, instead of its heat being emitted to the environment and
re-
absorbed by the heat pump at the evaporator end, it is directly returned to
the evaporator
end of the heat pump, thereby increasing the efficiency of the operation of
the
generator.
Cooled reservoir configuration
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According to the above configuration of the generator is shown demonstrating a
cooled reservoir arrangement in which the first, high temperature reservoir is
in thermal
communication with the condenser end of the heat pump (as in previous
examples),
while the low temperature reservoir is in thermal communication with the
evaporator
end of the heat pump.
Under the above arrangement, the low temperature work medium recovers a
partial amount of heat from the pressure medium upon a heat exchange process
therewith, and a remaining amount of heat from the environment to provide an
overall
amount of heat from the evaporator end to the condenser end of the heat pump
HP.
Dual operation
The generator can comprise two pressure vessels, each of which is connected to
the high and the low temperature reservoir via corresponding inlet/outlet
valves. In
addition, the pressure medium of each of the pressure vessels is in fluid
mechanical
communication with a respective piston.
Using two pressure vessels allows for at least two modes of operation of the
generator:
a) simultaneous cycle ¨ both the pressure vessels perform steps (a) and
(b) above in parallel. In other words, at any time point throughout the
generator cycle, the temperature of the pressure medium in one
pressure vessel is similar to that of the pressure medium in the other
pressure vessel, i.e. both pressure mediums heat up simultaneously
and cool down simultaneously. Under this arrangement, the generator
can be provided with two motor assemblies, each being driven by its
respective piston;
b) alternating
cycle ¨ the pressure vessels perform steps (a) and (b) at
an offset, e.g. when one pressure vessel performs step (a) of the cycle,
the other pressure vessel performs step (b) of the cycle. In other
words, when the pressure medium in one pressure vessel undergoes
heating, the pressure medium in the other pressure vessel undergoes
cooling and vise versa. Under this arrangement, the generator can be
provided with one motor assembly, which is driven by two pistons
(i.e. both pistons can reciprocate in synchronization with one another).
Intermediate reservoir configuration
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Under the above configuration, the generator can comprise three reservoirs: a
high temperature reservoir, a low temperature reservoir and an intermediate
temperature
reservoir. This arrangement is based on the cooled reservoir configuration,
wherein an
additional intermediate reservoir is added containing intermediate temperature
work
medium. The intermediate temperature reservoir is configured to contain an
intermediate temperature work medium, the term 'intermediate' referring to a
temperature between said high temperature and said low temperature. Each of
the
high/intermediate/low temperature reservoirs is in selective fluid
communication with
the pressure vessel.
Under this arrangement, two additional steps (a') and (b') are performed on
top
of steps (a) and (b) described with respect to the basic configuration, as
follows:
(a') [performed after step (a)] passing intermediate temperature work medium
from the intermediate temperature reservoir through the conduit of the
pressure vessel,
thereby reducing the temperature of the pressure medium (via heat exchange
process
therewith) from the maximal operative temperature to an intermediate operative
temperature (between the maximal operative temperature and the minimal
operative
temperature); and
(b') [performed after step (b)] passing intermediate temperature work medium
from the intermediate temperature reservoir is passed through the conduit of
the
pressure vessel, thereby increasing the temperature of the pressure medium
(via heat
exchange process therewith) from the minimal operative temperature to an
intermediate
operative temperature (between the maximal operative temperature and the
minimal
operative temperature).
Specifically, during steps (a') and (b') above, the intermediate temperature
work
medium is used for cooling/heating of the pressure medium between the
cooling/heating
thereof by high/low temperature work medium respectively. Thus, each
cooling/heating
step is divided into two stages, the first being performed by intermediate
work medium
and the second being performed by high/low work medium.
Under the above arrangement, it is appreciated that the high/low temperature
work medium is practically used to provide heating/cooling within a reduced
temperature range (i.e. between intermediate and high and/or between
intermediate and
low), thereby making the operation of the generator more effective.
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With respect to the above arrangement, it is appreciated that the intermediate
temperature reservoir can be in thermal communication with the outside
environment,
while the high/low temperature reservoirs are in thermal communication with
the
condenser/evaporator ends of the heat pump respectively.
In addition, any one of the outlet lines of the high/intermediate/low
temperature
reservoirs can be passed through the auxiliary heat exchanger upon exiting the
pressure
vessel. According to a particular example of this arrangement, the
intermediate outlet
line can pass through the auxiliary heat exchanger so as to respectively
convey
to/absorb from the atmosphere the required amount of heat gained/lost during
the heat
exchange process with the pressure medium before returning to its reservoir.
To the
contrary, the outlet lines of the high/low temperature reservoirs can return
the work
medium directly to its respective reservoir without necessarily passing
through the heat
exchanger.
Cross-over configuration
According to the above configuration, the generator comprises two pressure
vessels (similar to the dual operation arrangement), and each of the outlet
valve is also
in selective fluid communication with the inlet valves.
Specifically, each outlet valve 0 is also provided with a cross-over line COL
which provides fluid communication between the outlet valve of one pressure
vessel
and the inlet valve of the other pressure vessel. Under this arrangement, it
is possible to
perform additional cross-over steps as explained below:
(a") [performed after step (a')] in which the intermediate work medium WM,
upon exiting the conduit of one pressure vessel PV is provided, via cross-over
line COL
to the inlet valve of the other pressure vessel PV in order to begin heating
the pressure
medium therein and only then back to the intermediate temperature reservoir
via the
other outlet valve; and
(b") [performed after step (b')] in which the intermediate work medium WM,
upon exiting the conduit of one pressure vessel PV is provided, via cross-over
line COL
to the inlet valve of the other pressure vessel PV in order to begin cooling
the pressure
medium therein and only then back to the intermediate temperature reservoir
via the
other outlet valve.
The above arrangement provides for a more significant heat recovery from the
pressure medium. More specifically, instead of emitting/withdrawing a certain
amount
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of heat to/from the environment during its return to the intermediate
temperature
reservoir, the intermediate temperature work medium now emits/withdraws a
portion of
that amount of heat in a heat exchange with the pressure medium, thereby
increasing the
efficiency of the generator.
Heat gradient recovery configuration
Under the above configuration, the generator also comprises one pressure
vessel
(similar to the basic arrangement), and at least one gradient tank associated
with the
outlet valve.
The gradient tank can comprise an arrangement configured for preventing
mixing of portions of work medium contained therein, thereby considerably
reducing
heat transfer between the portions and the speed with which these portions
reach a
thermal equilibrium. In particular, the gradient tank, when used in the
present generator,
can contain a first portion of work medium at a temperature Ti, a second
portion of
work medium at temperature T2 and so forth so that Ti T2 and so forth.
Specifically, under operation of the generator as will now be explained, the
gradient tank allows for maintaining the work medium contained therein at a
temperature gradient so that Ti > T2> > Tn, or alternatively, Ti <T2 < <
Tn.
Thus, the portions of the heated/cooled intermediate temperature work medium
entering the gradient tank have different temperatures, and, as will be
explained in detail
later, it can be beneficial to maintain a temperature gradient between these
portions
within the gradient tanks. For this purpose, the gradient tank can further
comprise a
non-mix mechanism, configured for maintaining a temperature gradient within
the
reservoir by preventing different portions of the work medium from mixing with
one
another. In other words, the non-mix mechanism is configured for slowing down
the
work medium received within the gradient tank from reaching a uniform
temperature.
The non-mix mechanism can be any mechanism formed with a flow path such
that the cross-sectional area for heat transfer between consecutive portions
of the work
medium entering the gradient tank is small enough to considerably slow down
the heat
transfer. The term 'small enough' refers to a cross-sectional area defined by
a nominal
cross-sectional dimension D which is considerably smaller than the length L of
the path.
Examples of such a non-mix mechanism can be:
- a long tube of length L and cross-sectional D <<L;
- a spiraling tube having similar characteristics;
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- a
spiraling surface located within the reservoir so as to form a flow path of
the above properties; and
- a confining labyrinth formed with a plurality of flow paths, each
adhering to
the above properties.
In all of the above examples, the flow path can be made out of a material
having
isolating properties, i.e. having poor heat conduction. One example for such a
material
can be plastic.
In operation, several additional steps are added to the basic operation steps
(a)
and (b) as explained with respect to the basic configuration, as follows:
(b") [performed before step (b)] in which low temperature work medium is
passed through the conduit of the pressure vessel to be heated via a heat
exchange
process with the pressure medium, but instead of being returned to the low
temperature
reservoir is introduced into the gradient tank. It is appreciated that the
first portion of
the low temperature work medium to exit the pressure vessel with reach the
gradient at
a higher temperature than the last portion (as the pressure medium gradually
cools down
during this heat exchange process). The design of the gradient tank allows
maintaining
these portions each at their own respective temperature, so that eventually,
the upper-
most portion in the gradient tank is the of the highest temperature while the
lower-most
portion in the gradient tank is the of the lowest temperature.
(b") [performed after step (b)] in which the work medium in the gradient tank
is re-circulated back through the pressure vessel in a LIFO (Last In First
Out) order,
thereby gradually heating up the pressure medium to an intermediate
temperature, and
only then commencing step (a) of the operation.
In essence, these steps of the operation of the generator describe a "stall"
operation in which the work medium WM in the gradient tank is held therein
(stalled)
until the right time, and then released into the piping of the generator to
perform the
required heat exchange process.
It is appreciated that each portion of the intermediate temperature work
medium
passing through the heated/cooled pressure vessel is emitted therefrom having
a
different temperature. For example, if operation of the system is observed in
a
quantified manner, when the intermediate temperature work medium of
temperature
TENTERMEDIATE begins circulating through the heated pressure vessel containing
the
pressure medium at the high temperature THOT> TINTERMEDIATE, the first portion
of the
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intermediate temperature work medium will be emitted from the pressure vessel
at a
temperature 'Nur' such that TINTERMEDIATE < THOT' < THOT, the second portion
of the
work medium will be emitted from the pressure vessel at a temperature THOT",
such that
TINTERMEDIATE < THOT" < -NOT' < THOT etc. A similar process occurs with the
intermediate temperature work medium passing through the cooled pressure
vessel, only
TINTERMEDIATE TCOLD" TCOLD' TCOLD. The temperatures THOT, TINTERMEDIATE and
TCOLD correspond to the high/intermediate/low temperature of the work medium
in the
respective high/intermediate/low temperature reservoirs.
The above arrangement provide for another way of performing heat recovery in
the generator, thereby further increasing its efficiency. It is also
appreciated that the use
of the LIFO configuration allows the pressure medium to be gradually heated
(starting
from the lowest temperature portion first), making better use of the amount of
heat of
each portion of the work medium.
It is also appreciated that the gradient tank can be used both for the heated
low
temperature work medium and the cooled high temperature work medium. According
to
specific examples as will be described in detail later, the generator can
comprise more
than one gradient tank. For example, each pressure vessel can be provided with
its own
gradient tank and/or gradient tanks are provided for high/low temperature work
medium.
According to a specific arrangement, the heat gradient recovery configuration
can be combined with the dual operation configuration, wherein the operation
of the
generator can be described as follows:
At a first stage, similar to the previously described example (without
gradient
tanks), high temperature work medium at temperature 'Nur is passed through one
pressure vessel to heat up the pressure medium contained therein, while,
simultaneously, low temperature work medium at temperature TCOLD is passed
through
the other pressure vessel to cool down the pressure medium contained therein.
After this
stage, the pressure medium in one pressure vessel is heated up to a
temperature THOT' <
THOT and the pressure medium in the other pressure vessel is cooled down to a
temperature TCOLD' > TCOLD.
Thereafter, a return step is performed, during which intermediate temperature
work medium at temperature TINTERMEDIATE is passed through both pressure
vessels in
order to cool down / heat up the pressure medium therein. Specifically, the
intermediate
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temperature work medium passing through the heated pressure vessel performs a
heat
transfer process with the latter and cools it down to a temperature closer to
TINTERMEDIATE, while the intermediate temperature work medium passing through
the
cooled pressure vessel performs a heat transfer process with the latter and
heats it up to
a temperature closer to TINTERMEDIATE (however, not reaching TINTERMEDIATE)-
However, contrary to the previous example in which the intermediate
temperature work medium, after passing through the pressure vessels was
returned back
to the intermediate reservoir via the radiator, in the present example, the
intermediate
temperature work medium flows into the gradient tanks in a two-beat sequence.
During the first beat of the sequence, the first portion of the heated
intermediate
temperature work medium to exit the pressure vessel is at a temperature
THEATED such
that TINTERMEDIATE < THEATED < THOTT, the second portion of the work medium
will be
emitted from the pressure vessel at a temperature THOT1 such that
TINTERMEDIATE <
THEATED' < THEATED < 'NOT' etc. The heated work medium is passed into the
gradient
tank of its respective pressure vessel such that the gradient tank contains
therein the
different portions of the heated work medium and maintains a temperature
gradient
therebetween.
Simultaneously, the first portion of the cooled intermediate temperature work
medium to exit the pressure vessel is at a temperature TCOOLED such that
TINTERMEDIATE
> TCOOLED > TCOOLI, the second portion of the work medium will be emitted from
the
pressure vessel at a temperature TCOOLED' such that TINTERMEDIATE > TCOOLED' >
TCOOLED
> TcOOLI etc. The cooled work medium is passed into the gradient tank of its
respective
pressure vessel such that the gradient tank contains therein the different
portions of the
cooled work medium and maintains a temperature gradient therebetween.
In any case, it is important to note that since the heated pressure medium
within
the heated pressure vessel never reaches TINTERMEDIATE during this step, the
intermediate
temperature work medium passing therethrough also never leaves the pressure
vessel at
a temperature TINTERMEDIATE, but rather always slightly hotter. In other
words, each
portion of the heated intermediate temperature work medium is at a temperature
THEATEDn such that TINTERMEDIATE < THEATEDn < THOT. At the same time, since
the cooled
pressure medium within the cooled pressure vessel also never reaches
TINTERMEDIATE
during this step, the intermediate temperature work medium passing
therethrough also
never leaves the pressure vessel at a temperature TINTERMEDIATE, but rather
always
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slightly cooler. In other words, each portion of the cooled intermediate
temperature
work medium is at a temperature TCOOLEDn such that TINTERMEDIATE TCOOLEDn
TCOOL=
Due to the non-mix mechanism in each of the gradient tanks, the work medium
in each of the gradient tanks is maintained with a temperature gradient,
slowing down
mixing between the different portions of the heated/cooled intermediate
temperature
work medium.
When the first beat of the sequence is complete, the majority of each of the
gradient tanks is filled with a heated/cooled intermediate temperature work
medium at a
varying temperature across the reservoir. At this point, the second beat of
the sequence
is performed, also referred to as the cross-over step:
work medium from the gradient tank of the heated pressure vessel (i.e. the
gradient tank containing the heated intermediate temperature work medium used
during
the first beat) is passed through the opposite (cooled) pressure vessel
containing the
pressure medium previously cooled down by the low temperature work medium to a
temperature TCOLD', and work medium from the gradient tank of the cooled
pressure
vessel (i.e. the gradient tank containing the cooled intermediate temperature
work
medium used during the first beat) is passed through the opposite pressure
vessel
containing the pressure medium previously heated up by the high temperature
work
medium to a temperature THOT'=
In addition, the work medium from the gradient tanks flows to the opposite
pressure vessels in a First In Last Out (FILO) order, i.e. the last portion of
the heated up
intermediate temperature work medium to enter the gradient tank (which is also
the
coolest portion of the heated intermediate temperature work medium) will be
the first
portion to be passed through the opposite pressure vessel. In this way, the
temperature
of the work medium passed through the now low/high temperature pressure vessel
during the cross-over step constantly and gradually increases/decreases.
It is noted that the even the coolest portion of the heated up work medium is
at a
temperature THOT> TINTERMEDIATE > TCOLD', and even the hottest portion of the
cooled
down intermediate temperature work medium is at a temperature TCOLDn <
TINTERMEDIATE < THOT'. Therefore, it is appreciated that the temperature
difference
between the cooled/heated pressure medium TcouPTH0T1 and the coolest/hottest
portion
of the heated/cooled intermediate temperature work medium THurnacown is much
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greater than the previous temperature difference between the former and the
intermediate temperature work medium at TINTERMEDIATE.
It is also noted that one of the reason for performing the cross-over step at
a
LIFO order is that if a First In First Out (FIFO) order were used, the
hottest/coolest
portion of the heated/cooled intermediate temperature work medium would
perform
such an intense heat transfer process with the pressure medium that the
coolest/hottest
portion of the heated/cooled intermediate temperature work medium would have
little
effect on the heat transfer process. Using LIFO order allows better
utilization of each
portion of the work medium.
During the above step (switch step), a heat transfer takes place between the
heated up intermediate temperature work medium and the cooled pressure medium
resulting in an average temperature of the cooled down pressure medium which
is
relatively TANT_C = (TCOLD' THEATEDn)/2. Simultaneously, a heat transfer takes
place
between the cooled down intermediate temperature work medium and the heated
pressure medium resulting in an average temperature of the cooled down
pressure
medium which is relatively TAV_H = (THOTI TCOOLEDn)/2.
It should be noted that due to the temperature difference discussed above
(i.e.
TINTERMEDIATE < THEATEDn < THOT' and TINTERMEDIATE > TCOOLEDn > TCOLDI), the
temperatures TAN/s and TAILH are hotter/cooler than a corresponding average
temperature TAN'S' and TAN/ that would have been achieved if only intermediate
temperature work medium at TENTERMEDIATE was used to cool/heat the pressure
medium.
After the pressure mediums of both pressure vessels finish the heat transfer
process and reach the temperatures of TAvs and TAN/ J-1, the main cycle (steps
(I) and
(III)) repeats itself but with high temperature work medium now flowing to the
previously cooled pressure vessel and the low temperature work medium now
flowing
to the previously heated pressure vessel.
The switch step thus provides an improvement over the previously described
example of the generator allowing for a more efficient heat transfer process
with the
pressure medium, so that the heated/cooled pressure medium returns, after
heating/cooling to a temperature much closer to TINTERMEDIATE, and can even
reach a
temperature which is lower/higher than TrNTERMEDIATE.
In both beats of the sequence, intermediate temperature work medium (although
not necessarily at temperature TINTERMEDIATE) is passed through the radiator,
allowing it
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to perform a heat transfer process with the outside environment (usually
ambient air but
can be any other medium in which the radiator is immersed).
Throughout the operation of the generator, due to thermodynamic performance
of the work medium and pressure medium, the generator constantly produces
heat,
which is, in turn, emitted to the ambient environment through the radiator.
More
particularly, the arrangement is such that the increase in temperature of the
heated
intermediate temperature work medium is slightly greater than the decrease in
temperature of the cooled intermediate temperature work medium. This
difference in
increase/decrease is expressed by slight overheating of the intermediate
temperature
work medium, i.e. excess heat being generated. However, it is compensated by
the
eviction of the excess heat via the radiator.
It should also be noted that the entire generator, and more particularly, all
the
piping of the generator configured for passing high/low/intermediate
temperature work
medium is always under constant pressure (i.e. there is always work medium
present in
each section of the pipe, whether circulating or not). Thus, in an initial
position of the
system, the gradient tanks contain therein intermediate temperature water
(i.e. water at
temperature TINTERMEDIATE). During the first beat of the sequence, when
heated/cooled
intermediate temperature work medium enters the gradient tanks, the work
medium
previously contained therein is emitted and re-circulated back into the
auxiliary storage
reservoir containing intermediate temperature work medium at temperature
TINTERMEDIATE.
During the switch step (second beat of the sequence), in order to pump the
work
medium contained in the gradient tanks into the proper pressure vessels,
intermediate
temperature work medium is circulated into the gradient tanks, thus pushing
the
heated/cooled intermediate temperature work medium out of the reservoir and
into the
desired pressure vessel. It is noted that during the second beat of the
sequence, the
reservoirs (high/low/intermediate) are shut off from the circulating fluid so
that, in fact,
only intermediate temperature work medium is circulated through the piping of
the
generator.
The generator can also comprise one or more thermostats configure for
providing control over high/low/intermediate temperature work medium as well
as
heated/cooled pressure medium. For example, the thermostat/s can be configured
for
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maintaining the intermediate temperature work medium at a temperature
generally
equal to that of the ambient environment (air, water etc.) the generator is
surrounded by.
Accumulator configuration
According to the above configuration, the generator can further comprise an
accumulator unit containing a storage work medium. The accumulator unit is
provided
with a heating arrangement which is configured to be operated by output power
provided by the generator.
The accumulator unit can be in selective fluid communication with the pressure
vessel via corresponding inlet and outlet lines which are connected to the
inlet and
outlet valve respectively.
In operation, a portion of the output power of the generator can be used to
operate the heating arrangement, so that it heats up the work medium contained
within
the accumulator unit. Thus, at a required moment, the high temperature
reservoir can be
shut-off, and the accumulator unit can provide the necessary high temperature
work
medium. Under this arrangement, any excess output power which is not used can
be
provided to the accumulator unit, thereby operating, de facto, as an
accumulator.
According to a specific example, the heating element can be a heating coil or
any other element which is configured to be heated so as to heat the storage
work
medium. Alternatively, the heating arrangement can be constituted by an
auxiliary heat
pump (not shown), and the accumulator unit can comprise two compartments, one
being
in thermal communication with the evaporator side of the auxiliary heat pump
and the
other in thermal communication with the condenser side of the auxiliary heat
pump.
In particular, each of the compartments can have a respective inlet to which
corresponding inlet and outlet lines are attached respectively. The
arrangement can be
such that the outlet is located at a top end of the high temperature
compartment, while
the inlet is located at a bottom end of the high compartment. In contrast, the
outlet of the
low temperature compartment can be located at a bottom end of the compartment
while
the inlet thereof can be located at a top end of the compartment.
The above arrangement allows for withdrawing high temperature work medium
from a high temperature zone of the high temperature compartment, and
returning the
work medium to a low temperature zone of the high temperature compartment.
Correspondingly, this arrangement allows withdrawing low temperature work
medium
from a low temperature zone of the low temperature compartment, and returning
the
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temperature work medium to a high temperature zone of the low temperature
compartment.
In operation, once the auxiliary work medium in the compartments and reaches
temperatures which are similar to those of the high/low temperature reservoirs
respectively, it can be used in operation of the generator while the main heat
pump
temporarily ceases its operation.
It is appreciated that the accumulator can comprise both a heat pump and
direct
heating elements (e.g. coil), and work in combination with both. Specifically,
the high
temperature compartment can be provided with heaters which are configured for
directly heating the storage fluid contained within the compartment. It is
appreciated
that during operation of the auxiliary heat pump, the storage medium within
the
high/low temperature compartment can reach a heating/cooling limit (i.e.
reaching a
maximal/minimal temperature limit). In such an event, the operation of the
auxiliary
heat pump can be interrupted, and the heaters are then used to further heat
the storage
medium in the high temperature compartment.
Under the above arrangement, once the auxiliary heat pump is interrupted, the
work medium in the high temperature compartment can be used as a high
temperature
work medium, while the work medium in the low temperature compartment is used
as
the low/intermediate work medium.
In all of the above aspects of the subject matter of the present application,
the
A/C unit used for generating the heat/cold source for the respective high/low
temperature reservoir can be in the form of a cascade arrangement, comprising
several
grades, each of which operates as a basic A/C compression/expansion manner.
In particular, the cascade arrangement can comprise a first end-grade
configured
for providing the heat for the high temperature reservoir and a second end-
grade
configured for providing the necessary cold for the low temperature reservoir.
Each of the grades comprises an evaporator section, a compressor, an expansion
member and a condenser section, and contains a fluid (gas or liquid)
configured for
undergoing corresponding compression and expansion to provide a high
temperature
source at the condenser and a low temperature source at the evaporator as
known per se.
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Specifically, the fluid in each of the grades is configured to have an
evaporator
temperature TEVAP(n) and a condenser temperature TcoND(n), where TcoND(n) >
TEvAp(n),
and n denotes the number of the grade.
The cascade arrangement is designed such that the condenser section of one
grade is configured for performing a heat exchange process with the evaporator
section
of the subsequent grade. In particular, the design can be such that the
temperature of
compressed fluid in the condenser of the one grade is higher than the
temperature of the
expanded fluid in the evaporator of the subsequent grade with which the heat
exchange
process takes place.
Each of the grades can operate in a closed-loop, i.e. the fluid of each grade
does
not come in contact with the fluid of a subsequent grade. Specifically, the
heat exchange
process between two subsequent grades can be performed via an intermediate
member,
e.g. a heat conducting surface.
According to a specific example, the heat exchange process between two
subsequent grades takes place in a heat exchanger comprising an inner tube of
diameter
DI passing through an outer tube of diameter D2 <D1. The inner tube
constitutes the
condenser of the one grade while the outer tube constitutes the evaporator of
the
subsequent grade.
Thus, in operation, compressed fluid of one grade, heated due to compression
thereof to a temperature TcoND(1), flows through the inner tube an expanded
fluid of the
subsequent grade, cooled due to expansion thereof to a temperature TEVAP(n+1)
<
TcoND(n), flows through the outer tube (so as to flow around the inner tube).
As a result,
a heat exchange process takes place via the wall of the inner tube ¨ the
heated fluid
coming in contact with an inner surface of the inner tube and the cooled fluid
coming in
contact with an outer surface of the inner tube. In this heat exchange
process, heat is
emitted from the fluid flowing within the inner tube to the fluid flowing in
the outer
tube.
It should be noted that the design of the heat exchanger can be such that the
volume defined by the inner tube is smaller than the volume defined between
the
external surface of the inner tube and the internal surface of the outer tube.
In particular,
while the inner surface of the outer tube is essentially round in cross-
section taken
perpendicular to a longitudinal axis of the tube, while the inner and/or outer
surfaces of
the inner tube can be of a more convoluted shape in the same cross-section.
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The flow direction within the condensing portion and evaporator portion can
either be parallel, i.e. both the compressed fluid and the expanded fluid flow
in the same
direction (as in a parallel heat exchanger). Alternatively, the flow direction
can be
opposite, i.e. i.e. the compressed fluid and the expanded fluid flow in
opposite
directions (as in a counterflow heat exchanger).
Each of the grades can contain a different fluid, and is configured for
operation
at a different temperature range. In particular, within the same grade the
difference
between the high temperature TCOND of the fluid in the condenser and the low
temperature TEVAp of the fluid in the evaporator can be generally similar
between all the
grades. For example, the temperature difference can be about 30 C.
According to a specific example, the cascade arrangement can comprise seven
grades, each operating at a temperature range A of about 30 C, with the
temperature of
the fluid at the evaporator of the first grade TEVAP(1) is as low as 0 C, and
the
temperature of the fluid at the condenser of the seventh grade TEvAp(7) is as
high as
245 C.
It is noted that in all the grades, the temperature of the expanded fluid in
the
evaporator of one grade is always lower than the condensation temperature of
compressed fluid in the condenser of the subsequent grade. In other words,
TEVAP(n) <
TCOND(n+1)=
The generator can also comprise a controller configured for regulating the
operation of the compressor and/or the expansion valve of each grade so as to
maintain
a desired difference between the compression temperature of a fluid in one
grade and
the expansion temperature of fluid in a subsequent grade.
As previously described, each grade can comprise a compressor configured for
compressing the fluid circulating in the grade during its progression between
the
evaporator to the condenser. In order to maintain a generally similar
temperature range
between the condenser and the evaporator in each grade, the compressors of the
grades
can have different power consumptions so that each grade is configured for
operating at
a different COP.
The reasoning for this is that the COP for heating/cooling is calculated as
the
temperature difference divided by the high/low temperature. Therefore, a grade
having a
30 C condenser/evaporator difference between 27 C and 57 C yields a COP which
is
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different than that of a grade having a 30 C condenser/evaporator difference
between
90 C and 120 C.
Alternatively, each grade can be fitted with the same compressor (i.e.
providing
the same power). However, under this arrangement, the temperature difference
between
the condenser/evaporator in each grade (from low to high) will gradually be
reduced.
For example, the A for the first grade can be 30 C for the first grade, 24 C
for the
second grade, 20 C for the third grade and so forth.
It is appreciated that by using a cascade arrangement having several grades,
each
contributing to the overall temperature difference between THicir of the high
temperature
reservoir and TCOLD of the low temperature reservoir. As in the above example,
each of
the seven grades can contribute about 30 C, thereby yielding a temperature
difference of
240 C.
It should be understood that a single compression/expansion cycle having a
temperature difference of 240 C has a COP which is much lower than that of
seven
compressors, each contributing to its own compression/expansion cycle. As a
result, the
energy going to waste in the single compression/expansion cycle is greater
than that of
the cascade arrangement, making the latter more efficient for the presently
described
generator.
As previously described, the generator can comprise a radiator configured for
allowing the work medium to perform a heat exchange process with the
environment
after heating/cooling the pressure fluid within the pressure vessels.
According to a particular design, the high work medium, after heating the
pressure fluid (and subsequently cooling down) is provided directly back into
the high
temperature reservoir, while the low temperature work medium, after cooling
the
pressure fluid (and subsequently heating up) passes through the radiator in
order to be
cooled down by the environment.
The radiator unit can be configured for being controlled according to the
temperature of the environment and the resulting temperature of the low
temperature
work medium, so that the low temperature work medium leaves the radiator unit
at a
generally constant and predetermined temperature.
More particularly, the radiator unit can comprise a control element configured
for determining the cooling rate provided by the radiator, and a sensing unit
configured,
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on the one hand, for measuring the temperature of the low temperature work
medium
leaving the radiator unit, and, on the other hand, providing the data to the
control unit.
For example, if it is desired that the low temperature work medium leaves the
radiator unit and enters the low temperature reservoir at a predetermined
temperature T,
the sensing unit measures the temperature T, of the low temperature work
medium
leaving the radiator unit and:
(a) if T, > T, the sensing unit provides this reading to the control unit,
which, in
turn, increases the cooling rate of the radiator unit (for example by
increasing the revolution speed of a cooling fan), to reduce the temperature
I"- and
(b) if T, <T, the sensing unit provides this reading to the control unit,
which, in
turn, decreases the cooling rate of the radiator unit (for example by
decreasing the revolution speed of a cooling fan), to increase the temperature
V.
With reference to the above, when using the cascade arrangement, the
configuration is such that the heat exchange process within the radiator takes
place with
the low temperature work medium entering the first grade of the cascade
arrangement
associated with the low temperature reservoir. In particular, this heat
exchange process
brings the low temperature work medium (which is now heated after passing
through
the pressure vessel) to a temperature V TENv, while TcOND > TENV > TEVAp,
where
TcoND is the high temperature of the compressed fluid at the condenser of the
first grade
and TEVAP is the low temperature of the expanded fluid at the evaporator of
the first
grade.
It should be noted that each grade (depending on its compressor) is designed
for
a predetermined temperature range, i.e. it is configured to remove a
predetermined
amount of heat from the cold end (evaporator). If the evaporator is located at
an
environment providing it with more heat than the compressor can withdraw in
the
compression/expansion cycle of the grade, the grade becomes less efficient
(i.e. the
compressor can't cope with removing heat from the evaporator).
Thus, the cascade arrangement can further be configured for adjusting its
operation, and its overall temperature range, in accordance with the
temperature of the
environment. More particularly, if the temperature of the environment
increases such
that TENv > TCOND > TEvAp, and the first grade of the cascade arrangement
becomes less
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efficient (as described above), the cascade arrangement can be configured for
bypassing
the first grade and connecting the low temperature reservoir to the second
grade.
Under the above arrangement, instead of operating between a low temperature
of TEVAP(1) and a high temperature of TCOND(7), the cascade arrangement now
operates
between as low temperature of TEVAP(2) and a high temperature of TCOND(7).
Thus, the
overall temperature difference between the high and low temperature reservoir
decreases, but the efficiency of the cascade arrangement remains generally the
same.
In order to perform the above adjustment, the cascade arrangement can have a
bypass module comprising an evaporator associated to the second grade and
located
to within the low temperature reservoir. The bypass module can further
comprise valves
allowing shutting off the first grade completely, and directing the compressed
fluid of
the second grade to expand within the evaporator of the bypass module instead
of in the
original evaporator of the second grade.
According to a specific design of the generator, it can include the following
features:
- Multiple pressure vessels ¨ each side (left/right) of the generator
comprises
four pressure vessels, each being of similar structure to the pressure vessels
described with respect to previous examples;
- Linear core connection ¨ each vessels comprises six cores, but contrary
to
previous examples, the cores are connected linearly to one another so as to
form a long work medium flow path (six times as long in comparison to a
parallel connection as previously disclosed);
- Linear vessel connection (work medium) ¨ the cores of the four pressure
vessels of each side are linearly connected to one another so as to form an
even longer work medium flow path;
- Linear vessel connection (pressure medium) ¨ the compartments of
the four
pressure vessels on each side containing the high pressure medium are also
in fluid communication with one another via high-pressure connections,
thereby forming a long pressure medium flow path;
- External low temperature reservoir ¨ the low temperature reservoir
constituted by the evaporator of the A/C unit is exposed to the environment
and is not used for circulation of work medium therethrough.
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In operation, a full cycle of one side of the generator can include the
following
steps (taking into account that the opposite side undergoes the same steps
only at a
shift):
a) High temperature work medium is passed from the condenser end of the A/C
unit along the length of twenty four cores (six cores in each of the four
pressure vessels), thereby increasing the temperature of the pressure medium
to its maximal operating temperature, and simultaneously being cooled down
to a lower temperature;
b) From the last core of the fourth pressure vessel, the cooled down high
temperature work medium is returned to the condenser end of the A/C unit
after passing through a radiator for expelling therefrom at least an
additional
part of the heat remained therein;
c) Intermediate temperature work medium at an ambient temperature from the
intermediate reservoir is passed through all twenty four cores of the four
pressure vessels, thereby lowering the temperature of the pressure medium
below the maximal operating temperature, and simultaneously being heated
to a higher temperature;
d) From the last core, the intermediate work medium flows into the gradient
tanks to be stored there, so that the first portion of intermediate
temperature
work medium to enter the gradient tank is at the highest temperature and the
last portion to enter the gradient tank is at the lowest temperature;
e) Intermediate temperature work medium at an ambient temperature from the
intermediate reservoir is passed through all twenty four cores of the four
pressure vessels, thereby further lowering the temperature of the pressure
medium to the minimal operative temperature, and simultaneously being
heated to a higher temperature;
f) From the last core, the intermediate work medium flows back into the
intermediate work reservoir, passing through the radiator to expel any
additional heat to the environment;
g) Heated intermediate temperature work medium from the gradient tank is
passed through the cores of the four pressure vessels, thereby gradually
heating the pressure medium to a temperature above the minimal operative
temperature yet still below the maximal operative temperature. Gradual
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heating is achieved by using a LIFO arrangement where the last portion to
enter the gradient tank (which is also of the lowest temperature) is first to
flow through the cores;
h) From the last core, the intermediate temperature work medium flows into the
intermediate reservoir while passing through the radiator unit to expel any
additional heat to the environment;
i) Repeating from step (a).
In particular, steps (a) and (b), and (e) and (f) can last for a first period
of time
and steps (c) and (d), and (g) and (h) can last for a second period of time
which is
greater than the first period of time. Specifically, the second period of time
can be twice
as long as the first period of time. Under a particular example, the first
period of time
can be about 5 seconds and the second period of time can be about 10 seconds.
The generator can be utilized in a variety of power-requiring systems, e.g.
households, vehicles (for example cars, boats, plains, submarines etc.),
industrial
systems etc. In particular, in the example of systems configured for operation
when at
least partially submerged in a medium other than ambient air, the generator
can be
configured to use this particular medium as the work medium. For example, in
case the
generator is used on a boat for sailing at sea, the work medium can be sea
water.
With respect to the pressure medium, the following should be noted:
- When pre-loading the pressure medium, the heat transfer coefficient thereof
increases;
- When pre-loading the pressure medium, the volumetric expansion
coefficient of the pressure medium decreases;
- When pre-loading the pressure medium, the density of the pressure medium
increases;
- The higher the density of the pressure medium, the lower is its
susceptibility
to volumetric changes under pressure;
- When pre-loading the pressure medium, the density of the pressure medium
increases;
- When pre-loading the pressure medium, the heat capacity decreases; and
- When pre-loading the pressure medium, the viscosity of the pressure
medium increases.
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In addition to the above, the generator of the present application can
incorporate
the following features:
- During operation of the generator, when switching from one step of
operation to the subsequent step, it can be beneficial to delay the selective
opening of the outlet valves with respect to the selective opening of the
inlet
valves. For example, during step (a), high temperature work medium is
passed through the cores so that both the inlet and the outlet valve are in
fluid communication with the high temperature reservoir, and during step
(b), low temperature work medium is passed through the cores so that both
the inlet and the outlet valve are in fluid communication with the low
temperature reservoir. When switching from (a) to (b), it can be beneficial to
delay selective switching of the outlet valve so that it remains in fluid
communication with the high temperature reservoir until all the high
temperature work medium contained within the core is first fully returned to
the high temperature reservoir, and only then switching the outlet valve to be
in fluid communication with the low temperature reservoir;
- The static spiral within the core can be made of a material having very
low
heat transfer coefficient, so as not to absorb heat from the work medium.
Example of such a material can be fiberglass, having a heat transfer
coefficient of about 0.1;
- The generator can comprise several gradient tanks, some being designated
for use solely with high temperature work medium while others are
designated for use solely with low temperature work medium;
- The core can be formed with strengthening ribs, providing the core with
increased resistance to pressure. Increased resistance can allow for reducing
the thickness of the core wall, thereby increasing heat transfer between the
work medium and the pressure medium;
- The accumulator can also be pre-loaded, so as to raise the boiling point
of
the work medium contained therein, thereby allowing it to absorb more heat;
- The accumulator can itself be used as a backup for the work medium sub-
system;
- The generator can comprise a controller configured for performing
optimization of the operation of the generator, including control of the
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compressor and thereby control of the COP of the air conditioning unit,
operation of the valves etc.;
- The accumulator can comprise two compartments, one for containing
high
temperature storage medium and the other for containing low temperature
storage medium;
- The compartment of the accumulator can have a vertical orientation, so as
to
allow a heat gradient therein, similar to the gradient tanks;
- A generator for producing about 1MW can have a weight of about 30 ton.
And occupy an area of about 100 square meters;
- The accumulator can be used as a direct source of hot/cold water supply for
houses/offices/factories etc.;
- The use of an accumulator unit can reduce the overall power capacity of
the
generator by as much as 66% (when the accumulator operates using a heat
pump), thereby allowing to reduce the dimensions of the generator system
by as much as a 2/3.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to understand the invention and to see how it can be carried out in
practice, embodiments will now be described, by way of non-limiting examples
only,
with reference to the accompanying drawings, in which:
Figs. A to H are schematic diagrams of examples of different variations of the
generator according to the subject matter of the present application;
Figs. lA to ID are respective schematic isometric, front, side and cross-
section
views of the generator of the disclosed subject matter;
Fig. 2A is a schematic isometric view of the generator shown in Fig. 1A,
without the mechanical power units and the energy generation unit;
Fig. 2B is a schematic enlarged view of detail A shown in Fig. 2A;
Fig. 3A is a schematic isometric view of the pressure vessels and energy
generation units of the generator of Fig. 1A;
Fig. 3B is a schematic cross-section of the pressure vessels shown in Fig. 3A;
Fig. 3C is a schematic enlarged view of detail B shown in Fig. 3B;
Fig. 3D is a schematic enlarged view of detail C shown in Fig. 3B;
Fig. 3E is a schematic front view of the cross-section shown in Fig. 3B;
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Fig. 4A is a schematic isometric view of a pressure vessel of the generator
shown in Fig. 1A;
Fig. 4B is a schematic enlarged view of detail D shown in Fig. 4A;
Fig. 4C is a schematic isometric view of detail D shown in Fig. 4A, with the
shell of the pressure vessel being stripped away;
Fig. 4D is a schematic isometric view of the pressure vessel shown in Fig. 4A
with the shell being stripped away;
Fig. 4E is a schematic enlarged view of detail E with several other components
being stripped away;
Fig. 4F is a schematic enlarged view of detail F. shown in Fig. 4A;
Fig. 5A is a schematic isometric cross-section view of the pressure vessel;
Fig. 5B is a schematic isometric view of a segment of the core of the pressure
vessel;
Fig. 5C is an additional isometric cross-sectional view of the pressure
vessel;
Figs. 6A to 6C are respective schematic isometric view of the power generation
unit of the generator shown in Fig. 1A;
Figs. 7A to 7C are respective schematic front views of heat dissipation units
used in the pressure vessel;
Figs. 8A to 8F are respective schematic diagrams of analysis of operation of
the
generator;
Fig. 9 is a schematic isometric view of the generator of Fig. 1A when used in
conjunction with an accumulator arrangement;
Fig. 10 is an additional schematic diagram of analysis of operation of the
generator;
Fig. 11A is a front schematic isometric view of another example of the
generator
shown in Figs. lA to 1D;
Fig. 11B is a schematic rear isometric view of the generator shown in Fig.
11A;
Fig. 12A is a schematic isometric view of a gradient system used in the
generator shown in Figs. 11A and 11B;
Fig. 12B is a schematic enlarged view of the gradient system shown in Fig.
12A;
Fig. 12C is a schematic isometric view of the gradient system shown in Fig.
12A, with several components thereof being removed;
Fig. 12D is a schematic side view of the generator as shown in Fig. 12C;
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Fig. 13A is a schematic isometric view of a radiator section used in the
generator shown in Figs. 11A and 11B;
Fig. 13B is a schematic isometric view of a work medium reservoir used in the
generator shown in Figs. 11A and 11B, with the casing thereof being
transparent;
Fig. 14A is a schematic isometric view of a mixing mechanism used in the
generator shown in Figs. 11A and 11B;
Fig. 14B is a schematic isometric view of the mixing mechanism shown in Fig.
14A, with the several components of the generator being removed;
Fig. 14C is a schematic enlarged view of detail G shown in Fig. 14B;
Fig. 14D is a schematic cross-sectional view of a pressure vessel used in the
generator shown in Figs. 11A and 11B, taken along a plane perpendicular to the
central
axis of the pressure vessel;
Figs. 14E and 14F are respective schematic isometric and isometric cross-
sectional views of a drive screw used in the generator shown in Figs. 11A and
11B;
Fig. 15A is a schematic isometric view of a flow regulator used in the
generator
shown in Figs. 11A and 11B;
Fig. 15B is a schematic enlarged view of the regulator shown in Fig. 15A, with
the cover thereof being transparent;
Fig. 15C is a schematic view of the flow regulator shown in Fig. 15B;
Fig. 16A is a schematic isometric view of an accumulator arrangement used in
the generator shown in Figs. 11A and 11B;
Fig. 16B is a schematic rear isometric view of an accumulator arrangement
shown in Fig. 16A;
Figs. 17A to 17D are respective schematic isometric views of piping junctions
of the generator shown in Figs. 11A and 11B;
Fig. 17E and 17E' are a schematic charts of the temperature of the work
medium of the generator shown in Figs. 11A and 11B;
Fig. 18A is a schematic isometric view of a vehicle comprising the generator
shown in Figs. 11A and 11B;
Fig. 18B is a schematic isometric view of the vehicle shown in Fig. 18A, with
several components thereof being removed;
Fig. 18C is a schematic isometric view of the vehicle shown in Fig. 18B, with
further components thereof being removed;
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Figs. 18D and 18E are respective schematic top and bottom views of the vehicle
shown in Fig. 18C;
Figs. 18F and 18G are respective schematic enlarged views of details H and I
shown in Fig. 18C respectively;
Fig. 19A is a schematic isometric view of a marine vessel comprising the
generator shown in Figs. 11A and 11B;
Fig. 19B is a schematic isometric view of the marine vessel shown in Fig. 19A,
with several components thereof being removed;
Fig. 19C is a schematic isometric view of the marine vessel shown in Fig. 19B,
with further components thereof being removed;
Figs. 19D to 19F are respective schematic enlarged views of details J, K and L
shown in Fig. 19C respectively;
Figs. 20A and 20B are respective schematic cross-sectional views of a
cylindrical component of the generator shown in Figs. 11A and 11B;
Fig. 20C is a schematic isometric partial cross-sectional view of the
cylindrical
component shown in Fig. 20A, with a spiral element located therein;
Fig. 20D is a schematic isometric view of another example for a cylindrical
component to be used in the generator of the present application;
Fig. 20E is a schematic cross-sectional view of the cylindrical component
shown in Fig. 20D taken along a central axis thereof;
Figs. 21A to 21G are respective schematic isometric views of various stages of
producing the cylindrical component shown in Figs. 20A and 20B;
Figs. 22A and 22B are respective schematic front and rear isometric views of a
generator according to another example of the present application;
Fig. 22C is a schematic enlarged view of detail M shown in Fig. 22A;
Fig. 22D is a schematic enlarged view of detail N shown in Fig. 22B;
Fig. 23A is a schematic isometric view of a work medium sub-system used in
the generator shown in Fig. 22A;
Fig. 23B is a schematic isometric view of the work medium sub-system shown
in Fig. 23A, with the housing thereof being removed for clearer view;
Fig. 23C is a schematic right-side view of the work medium sub-system shown
in Fig. 23B;
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Fig. 23D is a schematic cross-sectional view of the work medium sub-system
shown in Fig. 23A, taken along a plane I-I shown in Fig. 23B;
Fig. 23E is a schematic enlarged view of detail 0 shown in Fig. 23D;
Fig. 23F is a schematic cross-sectional view of the work medium sub-system
shown in Fig. 23A, taken along a plane II-II shown in Fig. 23B;
Figs. 24A and 24B are respective schematic front and rear isometric views of
another example of a work medium sub-system used in the generator of the
subject
matter of the present application;
Figs. 24C and 24D are respective schematic enlarged views of details P and Q
taken from Figs. 24A and 24B respectively;
Fig. 25A is a schematic isometric view of another example of a work medium
sub-system used in the generator of the subject matter of the present
application;
Fig. 25B is a schematic enlarged view of detail R taken from Fig. 25A;
Figs. 26A and 26B are respective schematic tables showing the properties of
two
materials which can be used in construction of the generator shown in the
above figures;
Fig. 27A is a schematic isometric view of a generator according to another
example of the subject matter of the present application;
Fig. 27B is a schematic isometric view of the generator shown in Fig. 27A,
with
the supporting structure being removed for a clearer view;
Figs. 27C to 27E are respective schematic front, rear and side views of the
generator shown in Fig. 27B;
Fig. 28A is a schematic isometric view of the piping junctions of the front of
the
generator shown in Figs. 27A to 27E;
Fig. 28B is a schematic enlarged view of the piping junctions shown in Fig.
28A;
Fig. 29A is a schematic isometric view of the pressure system used in the
generator shown in Figs. 27A to 27E;
Figs. 29B and 29C are respective schematic isometric and front views of a
front
portion of a single cylinder of the pressure system shown in Fig. 29A;
Figs. 30A to 30C are respective schematic top-isometric, bottom-isometric and
side views of a mid portion of the pressure system shown in Fig. 29A;
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Figs. 31A and 31B are respective schematic rear-isometric and side views of
the
pressure system shown in Fig. 29A, with some of the cylinders removed for a
clearer
view;
Figs. 32A and 32B are two schematic isometric views of gradient tanks used in
the generator shown in Figs. 27A to 27E;
Fig. 33A is a schematic isometric view of an accumulator arrangement used in
the generator shown in Figs. 27A to 27E when connected to reservoirs of the
generator;
Fig. 33B is a schematic isometric view of the accumulator arrangement shown
in Fig. 33B;
Fig. 33C is a schematic isometric view of the accumulator arrangement shown
in Fig. 33B;
Fig. 34 is a schematic isometric view of a heat pump used in the generator
shown in Figs. 27A to 27E;
Fig. 35A is a schematic isometric view of a gear assembly used in the
generator
shown in Figs. 27A to 27E;
Fig. 35B is a schematic isometric view of the gear assembly shown in Fig. 35A,
with a casing thereof being removed;
Figs. 35C to 35E are respective schematic enlarged isometric, side and top
views of a mechanism of the gear assembly shown in Figs. 35A and 35B;
Figs. 36A and 36B are respective schematic isometric and side views of a
generator according to still another example of the subject matter of the
present
application;
Fig. 36C is a schematic enlarged isometric view of the generator shown in
Figs.
36A and 36B;
Fig. 36D is a schematic isometric view of the generator shown in Figs. 36A and
36B, with the pressure vessels thereof being removed for clearer view;
Fig. 37A is a schematic enlarged isometric view of the piping junction shown
in
Fig. 36D;
Fig. 37B is a schematic further enlarged isometric view of a front right side
of
the piping junction shown in Fig. 37A
Fig. 37C is a schematic further enlarged isometric view of a front left side
of the
piping junction shown in Fig. 37A;
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Fig. 3'7D is a schematic isometric view of a rear-end of the generator shown
in
Figs. 36A and 36B;
Fig. 37E is a schematic enlarged isometric view of the piping junction shown
in
Fig. 37C;
Fig. 38 is a schematic isometric view of the pressure system used in the
generator shown in Figs. 36A and 36B;
Fig. 39 is a schematic isometric view of a heat pump used in the generator
shown in Figs. 36A and 36B;
Fig. 40A is a schematic isometric view of an accumulator arrangement used in
the generator shown in Figs. 36A to 36D;
Fig. 40B is an enlarged view of a piping system of the accumulator arrangement
shown in Fig. 40A;
Figs. 40C and 40D are schematic enlarged isometric views of compartments of
the accumulator arrangement shown in Fig. 40A;
Fig. 41A is a schematic isometric view of a single cylinder used in the
generator
shown in Figs. 36A and 36B;
Fig. 41B is a schematic isometric enlarged view of a front end of the cylinder
shown in Fig. 41A;
Fig. 41C is a schematic isometric view of the single cylinder shown in Fig.
41A,
with a housing thereof being removed;
Fig. 41D is a schematic isometric enlarged view of a front end of the cylinder
shown in Fig. 41C;
Fig. 41E is a schematic isometric enlarged view of a mid-portion of the
cylinder
shown in Fig. 41C;
Fig. 42A is a schematic isometric view of a portion of a core used in a
pressure
vessel of the generator shown in Figs. 36A and 36B according to another
example of the
subject matter of the present application;
Fig. 42B is a schematic enlarged isometric view of a front portion of the core
shown in Fig. 42A;
Fig. 42C is a schematic enlarged isometric view of a rear portion of the core
shown in Fig. 42A;
Fig. 42D is a schematic rear view of the core shown in Fig. 42A;
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Fig. 42E is a schematic enlarged isometric view of a rear portion of the core
shown in Fig. 42C;
Fig. 43 is a schematic isometric view of a portion of a core used in a
pressure
vessel of the generator shown in Figs. 36A and 36B according to yet another
example of
the subject matter of the present application;
Fig. 44A is a schematic isometric view of a portion of a core used in a
pressure
vessel of the generator shown in Figs. 36A and 36B according to still another
example
of the subject matter of the present application;
Fig. 44B is a schematic enlarged isometric view of a front portion of the core
shown in Fig. 44A;
Fig. 44C is a schematic enlarged isometric view of a rear portion of the core
shown in Fig. 44A;
Fig. 45A is a schematic isometric view of a portion of a core used in a
pressure
vessel of the generator shown in Figs. 36A and 36B according to still another
example
of the subject matter of the present application;
Fig. 45B is a schematic enlarged isometric view of a rear portion of the core
shown in Fig. 44A;
Fig. 45C is a schematic enlarged isometric view of a front portion of the core
shown in Fig. 44A;
Fig. 46A is a schematic isometric exploded view of a pressure vessel used in
the
generator shown in Figs. 36A and 36B;
Figs. 46B to 46D are schematic enlarged isometric views of portions of the
pressure vessel shown in Fig. 46A;
Fig. 47 is a schematic isometric view of a mechanism of a gear arrangement
used in the generator shown in Figs. 36A and 36B, according to another example
of the
subject matter of the present application;
Fig. 48A is a schematic isometric view of a work medium sub-system used in
the generator of the subject matter of the present application;
Figs. 48B and 48C are schematic respective isometric lateral and longitudinal
cross-sectional views of the sub-system shown in Fig. 49A, taken along planes
A-A and
B-B respectively;
Fig. 49A is a schematic isometric view of a pressure vessel used in the
generator
shown in Figs. 36A to 36D;
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Figs. 49B to 49E are schematic enlarged views of details shown in Fig. 49A;
Fig. 49F is a schematic isometric view of a bracing arrangement used in the
pressure vessel shown in Fig. 49A and holding a single core thereof;
Fig. 49G is a schematic isometric view of the bracing arrangement shown in
Fig. 49F; and
Fig. 49H is a schematic isometric enlarged view of a detail shown in Fig. 49G.
DETAILED DESCRIPTION OF EMBODIMENTS
With reference to Fig. A, a schematic diagram is shown demonstrating a basic
arrangement of the generator of the present invention comprising a heat
differential
module, a pressure module and a conversion module.
The heat differential module comprises a first, high temperature reservoir and
a
second, low temperature reservoir, each containing therein a work medium WM
(not
shown) at a respective high/low temperature. The first, high temperature
reservoir is
thermally associated with a condenser end CE of a heat pump HP, so that
operation of
the heat pump HP (under provision of power W1) provides heat Q to the
condenser end
so as to maintain the work medium WM in the first reservoir at high
temperature. The
second, low temperature reservoir is thermally associated with the
environment.
Each of the reservoirs is provided with an inlet line IL which is in selective
fluid
communication with an inlet of the pressure vessel PV of the pressure module
via an
inlet valve I and an outlet line OL which is in selective fluid communication
with an
outlet of the pressure vessel PV via an outlet valve 0.
The pressure vessel PV contains therein a pressure medium PM and is formed
with a central conduit C passing therethrough which is in fluid communication
with the
inlet valve I and with an outlet valve 0, allowing the passage therethrough of
the work
medium WM from the reservoirs.
The pressure vessel PV is provided with a pressure line PL being in fluid
communication with the pressure medium PM, which is in fluid communication
with
the conversion module. The conversion module, in turn, comprises a piston P
which is
in fluid communication with the pressure line PL, and with a generator. The
piston in
configured for reciprocation which is utilized by the generator for the
generation of
output power W2.
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In operation, high/low temperature work medium WM is selectively provided
into the pressure vessel, entailing expansion and shrinkage of the pressure
medium PM,
consequently entailing reciprocation of the piston P. Specifically, the
following steps
are performed:
a) passing high temperature work medium WM from the high temperature
reservoir into inlet valve I, through conduit C and out of outlet valve 0 back
into the high temperature reservoir. As a result of a heat exchange process
between the high temperature work medium WM and the pressure medium
PM, the former cools down while the latter heats up to a maximal operative
temperature. When heating up, the pressure medium PM increases its
volume and causes displacement of the piston P to the right; and
b) passing low temperature work medium WM from the low temperature
reservoir into inlet valve I, through conduit C and out of outlet valve 0 back
into the low temperature reservoir. As a result of a heat exchange process
between the low temperature work medium WM and the pressure medium
PM, the former heats up while the latter cools down to a minimal operative
temperature. When cooling down, the pressure medium PM decreases in
volume and causes displacement of the piston P to the left.
Performing the above steps repeatedly will provide reciprocation of the piston
P
back and forth, thereby allowing generation of electricity by the generator.
The following should be noted:
- when returning to the high temperature reservoir, the cooled down high
temperature work medium WM is free to absorb further heat from the
condenser end of the heat pump so as to bring it back to its original high
temperature;
- when returning to the low temperature reservoir, the heated up low
temperature work medium WM emits at least some heat into the outside
environment so as to cool down and bring its temperature back to its original
low temperature;
- depending on the length of the conduit C, it can be beneficial, after the
selective switching of the position of inlet valve I to provide fluid
communication with the low temperature reservoir, to delay selective
switching of the position of the outlet valve 0 to provide fluid
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communication with the low temperature reservoir. In this way, upon
beginning the performing of step (b), the high temperature work medium
WM contained within the conduit C will first be pushed through its outlet
line OL into the high temperature reservoir, and only then will the outlet
valve 0 be selectively switched to provide fluid communication with the low
temperature reservoir. The same holds true when switching from step (b) to
step (a);
In terms of the thermodynamic operation, the heat pump HP withdraws an
amount of heat Q (heat absorbed from the environment with which the evaporator
is in
thermal communication) from the evaporator end thereof into the condenser end
by
applying an amount of work W1. Thus, the amount of heat Q contained within the
high
temperature work medium WM of the high temperature reservoir Q = Q + WI.
In operation, the amount of heat Q is provided to the pressure medium PM via
the heat exchange process, so that a portion Qi of the amount Q of heat is
used for
displacing the piston P, and at least a portion amount Q2 of heat is absorbed
by the low
temperature work medium WM via heat exchange with the pressure medium PM.
An amount of heat Q2 is released back to the outside environment during
passage of the heated low temperature work medium WM via outlet line OL, and
from
the environment, is free to be re-drawn into the evaporator end of the heat
pump HP.
Such an arrangement provides for a certain amount of heat Q2 to be recovered
by the
generator (i.e. a recovery arrangement).
It is appreciated that the amount of heat Q2 is less than the amount of heat
Q'
participating in the thermodynamic process of the heat pump HP, and thus the
heat
pump constantly withdraws additional heat from the environment (on top of Q2)
to
allow provision of a full amount Q' to the condenser end.
The amount of output work W2 provided by the generator of the conversion unit
depends on the amount Qi of heat which is converted into energy thereby. The
arrangement is such that the amount Qi of heat is greater than the amount Q' +
Wi, so
that the output energy W2 produced is greater than WI.
Specifically, since a heat pump HP is used in order to circulate heat within
the
generator, it is appreciated that an amount of input work W1 is sufficient for
displacing
an amount of heat Q'> Wi, depending on the COP (Coefficient of performance) of
the
heat pump. For example, under COP = 3, the heat pump will withdrawn Q' = 2KW
of
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heat from the evaporator to the condenser under the application of W1 = 1KW.
Thus, the
amount of heat Q1 can be greater than WI, thereby producing an output energy
W2
Wi.
Turning now to Fig. B, an alternative arrangement is shown, demonstrating
direct heat recovery arrangement. Under this arrangement, the outlet line LO
of the low
temperature reservoir is not returned directly back into the low temperature
reservoir
upon exiting the pressure vessel, but rather is first passed through the
evaporator end of
the heat pump HP. In this manner, instead of the heat Q2 being emitted to the
environment and re-absorbed by the heat pump from the evaporator end, it is
directly
returned to the evaporator end of the heat pump HP, thereby increasing the
efficiency of
the operation of the generator.
Turning now to Fig. C, yet another alternative arrangement of the generator is
shown demonstrating a cooled reservoir arrangement in which the first, high
temperature reservoir is in thermal communication with the condenser end of
the heat
pump HP (as in previous examples), while the low temperature reservoir is in
thermal
communication with the evaporator end of the heat pump HP.
Under the above arrangement, the low temperature work medium WM recovers
a partial amount of heat Q2 from the pressure medium PM upon a heat exchange
process
therewith, and a remaining amount of heat q from the environment to provide an
amount of heat Q' form the evaporator end to the condenser end of the heat
pump HP.
Turning now to Fig. D, another arrangement of the generator is shown,
demonstrating dual operation of pressure vessels. In particular, it is
observed that the
pressure module comprises two pressure vessels, each being in selective fluid
communication with the high/low temperature reservoirs on the one hand, and on
the
other hand being in fluid communication with its own piston arrangement. The
arrangement is further such that each of the pistons is in mechanical
connection with the
generator, so that reciprocation of both pistons is used by the generator for
the
generation of output power.
Under the above arrangement, when one pressure vessel is in fluid
communication with the high temperature reservoir, the other pressure vessel
is in fluid
communication with the low temperature reservoir and vise versa. Thus, when
the
pressure medium PM in one pressure vessel is heated, the pressure medium PM in
the
other pressure vessel is cooled down and vise verse.
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Under the above arrangement, reciprocation of the pistons is coordinated so
that
when both pistons displace generally in the same direction generally at the
same time.
In other words, when the pressure medium PM of the bottom pressure vessel
increases
its volume and pushes its piston to the right, the pressure medium PM of the
top
pressure vessel decreases it volume, displacing the piston to the left and
vise versa. It is
noted that the terms 'top' and 'bottom' are used solely for descriptive
purposes ¨ as it will
be shown in later arrangements, the pistons can also be positioned side-by-
side. It is
also appreciated that the above arrangement provides for the use of a
plurality of
pressure vessels (not only two) which are interconnected with each other.
Attention is now drawn to Fig. E, in which yet another example of the
generator
is shown demonstrating an intermediate reservoir arrangement in which the
generator
comprises three reservoirs: a high/intermediate/low temperature reservoir.
This
arrangement is a combination of the cooled reservoir arrangement shown in Fig.
C,
wherein an additional intermediate reservoir has been added containing
intermediate
temperature work medium. Each of the high/intermediate/low temperature
reservoirs is
in selective fluid communication with the pressure vessel.
Under this arrangement, two additional steps (a') and (b') are performed on
top
of steps (a) and (b) described with respect to Fig. A as follows:
(a') [performed after step (a)] during which intermediate temperature work
medium WM from the intermediate temperature reservoir is passed through the
conduit
of the pressure vessel, thereby reducing the temperature of the pressure
medium PM
(via heat exchange process therewith) from the maximal operative temperature
to an
intermediate operative temperature (between the maximal operative temperature
and the
minimal operative temperature); and
(b') [performed after step (b)] during which intermediate temperature work
medium WM from the intermediate temperature reservoir is passed through the
conduit
of the pressure vessel, thereby increasing the temperature of the pressure
medium PM
(via heat exchange process therewith) from the minimal operative temperature
to an
intermediate operative temperature (between the maximal operative temperature
and the
minimal operative temperature).
With respect to the above arrangement, it is appreciated that the intermediate
temperature reservoir can be in thermal communication with the outside
environment,
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while the high/low temperature reservoirs are in thermal communication with
the
condenser/evaporator ends of the heat pump HP respectively.
Turning now to Fig. F, still another example of the generator is shown
demonstrating a cross-over arrangement in which the generator comprises two
pressure
vessels (similar to the dual operation arrangement), and each of the outlet
valve is also
in selective fluid communication with the inlet valves.
Specifically, each outlet valve 0 is also provided with a cross-over line COL
which provides fluid communication between the outlet valve of one pressure
vessel
and the inlet valve of the other pressure vessel. Under this arrangement, it
is possible to
perform additional cross-over steps as explained below:
(a") [performed after step (a')] in which the intermediate work medium WM,
upon exiting the conduit of one pressure vessel PV is provided, via cross-over
line COL
to the inlet valve of the other pressure vessel PV in order to begin heating
the pressure
medium therein and only then back to the intermediate temperature reservoir
via the
other outlet valve; and
(b") [performed after step (b')] in which the intermediate work medium WM,
upon exiting the conduit of one pressure vessel PV is provided, via cross-over
line COL
to the inlet valve of the other pressure vessel PV in order to begin cooling
the pressure
medium therein and only then back to the intermediate temperature reservoir
via the
other outlet valve.
The above arrangement provides for a more significant heat recovery from the
pressure medium PM. More specifically, instead of emitting/withdrawing a
certain
amount of heat to/from the environment during it return to the intermediate
temperature
reservoir, the intermediate temperature work medium WM now emits/withdraws a
portion of that amount in a heat exchange with the pressure medium PM, thereby
increasing the efficiency of the generator.
Turning now to Fig. G, still a further example of the generator is shown
demonstrating a heat gradient arrangement in which the generator comprises one
pressure vessel (similar to the basic arrangement), and a gradient tank
associated with
the outlet valve 0.
The gradient tank comprises an arrangement configured for preventing mixing
of portions of work medium contained therein, thereby considerably reducing
heat
transfer between the portions and the speed with which these portions reach a
thermal
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equilibrium. In particular, the gradient tank, when used in the present
generator, can
contain a first portion of work medium at a temperature Ti, a second portion
of work
medium at temperature T2 and so forth so that Ti T2 t and so forth.
Specifically, under operation of the generator as will now be explained, the
gradient tank allows for maintaining the work medium contained therein at a
temperature gradient so that Ti > T2> > Tn, or alternatively, Ti <T2 < <
Tn.
In operation, several additional steps are added to the basic operation steps
(a)
and (b) as explained with respect to Fig. A, as follows:
(b") [performed before step (b)] in which low temperature work medium WM
is passed through the conduit of the pressure vessel PV to be heated via a
heat exchange
process with the pressure medium, but instead of being returned to the low
temperature
reservoir is introduced into the gradient tank. It is appreciated that the
first portion of
the low temperature work medium to exit the pressure vessel with reach the
gradient at
a higher temperature than the last portion (as the pressure medium PM
gradually cools
down during this heat exchange process). The design of the gradient tank
allows
maintaining these portions each at their own respective temperature, so that
eventually,
the upper-most portion in the gradient tank is the of the highest temperature
while the
lower-most portion in the gradient tank is the of the lowest temperature.
(b") [performed after step (b)] in which the work medium in the gradient tank
is re-circulated back through the pressure vessel in a LIFO (Last In First
Out) order,
thereby gradually heating up the pressure medium to an intermediate
temperature, and
only then commencing step (a) of the operation.
In essence, these steps of the operation of the generator describe a "stall"
operation in which the work medium WM in the gradient tank is held therein
(stalled)
until the right time, and then released into the piping of the generator to
perform the
required heat exchange process.
The above arrangement provide for another way of performing heat recovery in
the generator, thereby further increasing its efficiency. It is also
appreciated that the use
of the LIFO configuration allows the pressure medium to be gradually heated
(starting
from the lowest temperature portion first), making better use of the amount of
heat of
each portion of the work medium.
It is also appreciated that the gradient tank can be used both for the heated
low
temperature work medium WM and the cooled high temperature work medium WM.
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According to specific examples as will be described in detail later, the
generator can
comprise more than one gradient tank. For example, each pressure vessel can be
provided with its own gradient tank and/or gradient tanks are provided for
high/low
temperature work medium.
Turning now to Fig. H, still a further example of the generator is shown
demonstrating an accumulator (green battery) arrangement in which the
generator
further comprises an accumulator unit containing a storage work medium. The
accumulator unit is provided with a heating arrangement which is configured to
be
operated by output power W2 provided by the generator.
The accumulator unit is in selective fluid communication with the pressure
vessel PV via corresponding inlet and outlet lines which are connected to the
inlet and
outlet valve respectively.
In operation, a portion of the output power of the generator is used to
operate the
heating arrangement, so that it heats up the work medium contained within the
accumulator unit. Thus, at a required moment, the high temperature reservoir
can be
shut-off, and the accumulator unit can provide the necessary high temperature
work
medium.
Under the above arrangement, any excess output power which is not used can be
provided to the accumulator unit, thereby operating, de facto, as an
accumulator.
According to a specific example, the heating element can be a heating coil or
any other element which is configured to be heated so as to heat the storage
work
medium. Alternatively, the heating arrangement can be constituted by an
auxiliary heat
pump (not shown), and the accumulator unit can comprise two compartments, one
being
in thermal communication with the evaporator side of the auxiliary heat pump
and the
other in thermal communication with the condenser side of the auxiliary heat
pump.
With reference to Fig. 1A, there is shown a generator generally designated 1,
comprising an air conditioning unit 10 connected to a work medium sub-system
100,
two pressure vessels 200, a mechanical power assembly 300, a radiator unit
400, a
power generator unit 500, an accumulator unit 50 and output.
In general, each of the vessels 200 contains a pressurized fluid, and the
generator
operates on the principle of periodic increase/decrease of the volume of the
pressurized
liquid to be used for mechanical back and forth displacement of a piston for
generating
electricity.
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With further reference to Fig. 3C, the pressure vessel 200 has a hollow
cylinder
body 210, and a hollow central core 240 passing therethrough, such that there
is formed
a cavity between the outer surface 242 of the central core 240 and the inner
surface 214
of the cylinder body 210, which is adapted to contain the pressurized fluid.
The inner
space 243 of the hollow central core 240 is adapted to received therethrough a
high/intermediate/low temperature work medium from the work medium sub-system
100, in order to manipulate the temperature of the pressurize fluid.
With reference to Figs. lA to 1D, the work medium sub-system 100 comprises a
high temperature reservoir 110, a low temperature reservoir 120 and a
reservoir 130 of
intermediate temperature water at room temperature. The terms 'high', 'low'
and
'intermediate' refer in this specific example to the corresponding
temperatures: about
40 C, about 10 C and about 25 C. The work medium sub-system is in fluid
communication on one side with an air conditioning unit 10, and on the other
side with
the pressure vessels 200.
Each of the reservoirs 110, 120 and 130 is connected to both of the pressure
vessels 200 via distribution valves 140. Since the generator 1 comprises two
pressure
vessels 200, and is generally symmetric about a central plane passing
therethrough, left
(L) and right (R) designations are used where applicable. The manner of
connection
between the work medium sub-system 100 and the right pressure vessels 200R
will now
be explained in detail (it should be noted that the manner of connection to
the second
pressure vessel 200 is essentially similar):
The high temperature reservoir 110 is connected to the distribution valve 140R
via inlet 111R and to the outlet of the pressure vessel 200R via line 112R.
Correspondingly, low temperature reservoir 120 is connected to the
distribution valve
140R via inlet 121R and to the outlet of the pressure vessel 200R via line
122R. The
reservoir 130 is connected to the distribution valve 140R via inlet 131R and
to the
outlet of the pressure vessel 200R via line 132R. The line 132R is then
connected to a
cooling element 410R of the radiator unit 400, and the outlet of the cooling
element 410
is connected back to the reservoir 130 via line 133R.
The reservoirs 110 and 120 as well as the piping connecting them to the
pressure
vessels 200L, 200R, and the radiator unit 400 can be applied with thermal
insulation in
order to prevent heat losses to the piping itself. Similarly, the distribution
valves 140L,
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140R can also be made of low conductivity materials (e.g. Titanium or plastic)
or
covered with thermal insulation.
To the contrary, the piping connecting the reservoir 130 to the pressure
vessels
200L, 200R, and the radiator unit 400 can be made of materials having high
heat
transfer coefficients (for example copper) and be exposed to the environment,
allowing
the temperature of the 'intermediate' water to be as equalized as possible
with that of the
surrounding environment.
In general, the piping described above can be constructed such that it has an
in-
built water pressure (and no air), that is maintained throughout the operation
of the
generator 1. Furthermore, the intermediate temperature water reservoir 130 can
be
connected to the household water pressure (consumer pressure) via faucet 135
(Fig.
IC), such that in case of a drop of pressure in the system, additional water
can be
provided to the system to re-build the pressure.
The general operation of the generator 1 will now be described (it should be
noted that operation is described herein with respect to the vessel 200R,
however, a
similar operation takes place simultaneously in the vessel 200L).
At an initial position, the vessels 200 are filled with the pressure medium,
which
is pressurized to about 5000 Atm. The cores 240 as well as all of the above
connecting
lines are filled with the work medium at a standard household pressure
(consumer
pressure). In this position, the temperature of the pressure medium is equal
to the room
temperature (e.g. about 25 C), and correspondingly, the piston of the motor is
at an
intermediary position.
At a first stage of operation, the distribution valve 140R opens the port for
line
111R, and high temperature water from the high temperature reservoir begins
circulating through the core 240 of the vessel 200R. While passing through the
core
240, a heat exchange process takes place between the high temperature water
(at about
40 C) and the pressure medium (at about 25 C), causing the pressure medium to
be
heated up. As a result of heating, the pressure medium increases its volume
(expands),
consequently displacing the piston towards a first end point thereof.
The high temperature water, now of slightly reduced temperature, now exits the
pressure vessel 200R via line 112R, and is returned to the high temperature
reservoir.
This process takes place until the pressure medium is heated (and expanded) to
a
desired/sufficient amount, i.e. until the piston is displaced to its desired
first end
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position. Typically, the pressure medium is not heated to be the same
temperature as the
high temperature water, but rather several degrees below, e.g. 32-35 C.
Thereafter, the distribution valve 140R closes the port for the high
temperature
water inlet, and opens the port for line 131R of the intermediate temperature
water
reservoir. Intermediate temperature water (i.e. at 25 C) then flow through the
pressure
vessel 200R, causing a reverse heat transfer process to take place, in which
the heated
pressure medium (at about 32-35 C) gives away its heat to the intermediate
temperature
water. As a result, the pressure medium is cooled and the intermediate
temperature
water is heated.
The cooling down of the pressure medium causes its volume to consequently be
reduced, entailing mechanical displacement of the piston towards its initial
position.
This process continues until the pressure medium is cooled to a
desired/sufficient
amount, i.e. until the piston is displaced back to its initial (intermediary)
position.
The heated intermediate temperature water leaves the pressure vessel 200R via
line 132R, and enters the cooling element 410R of the radiator unit 400. In
the cooling
element 410R, the heated intermediate temperature water undergoes another heat
exchange process in which it emits to the surrounding atmosphere the heat
absorbed
from the heated pressure medium. Thus, the intermediate temperature water
returns to
the intermediate temperature water reservoir 130 via line 133R at a
temperature close to
its initial temperature within the reservoir (at about 25 C).
The above concludes the first part of the generator cycle.
Following the first part of the cycle, the second part takes place, in which a
similar operation is performed using the low temperature water as follows: the
distribution valve 140R shuts off the water from the intermediate temperature
water
reservoir 130, and opens for fluid communication with line 121R incoming from
the
low temperature reservoir. Low temperature water is then passed through the
core 240
of the vessel 200R. While passing through the core 240, a heat exchange
process takes
place between the low temperature water (at about 10 C) and the pressure
medium
(which is now, after the first part of the cycle, back to about 25 C), causing
the pressure
medium to be cooled down. As a result of cooling, the pressure medium
decreases its
volume (compresses), consequently displacing the piston towards a second end
point
thereof.
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The low temperature water, now of slightly elevated temperature, exits the
pressure vessel 200R via line 122R, and is returned to the low temperature
reservoir.
This process takes place until the pressure medium is cooled (and compressed)
to a
desired/sufficient amount, i.e. until the piston is displaced to its desired
second end
position. Typically, the pressure medium is not cooled down to be the same
temperature
as the low temperature water, but rather several degrees below, e.g. 15-18 C.
Thereafter, the distribution valve 140R closes the port for the low
temperature
water inlet, and re-opens the port for line 131R of the intermediate
temperature water
reservoir. Intermediate temperature water (i.e. at 25 C) then flows through
the pressure
vessel 200R, causing a reverse heat transfer process to take place, in which
the cooled
pressure medium (at about 15-18 C) absorbs heat from the intermediate
temperature
water. As a result, the pressure medium is heated up and the intermediate
temperature
water is cooled down.
The heating of the pressure medium causes its volume to consequently be
increased, entailing mechanical displacement of the piston towards its initial
position.
This process continues until the pressure medium is heated to a
desired/sufficient
amount, i.e. until the piston is displaced back to its initial (intermediary)
position.
The cooled intermediate temperature water leaves the pressure vessel 200R via
line 132R, and enters the cooling element 410R of the radiator unit 400. In
the cooling
element 410R, the cooled intermediate temperature water undergoes another heat
exchange process in which it absorbs from the surrounding atmosphere the heat
lost to
the heated pressure medium. Thus, the intermediate temperature water returns
to the
intermediate temperature water reservoir 130 via line 133R at a temperature
close to its
initial temperature within the reservoir (at about 25 C).
This concludes the second part of the generator cycle.
In summary, during the full generator cycle can be described as follows:
I) the pressure medium is first heated up (by high temperature water
from the high temperature reservoir 110) from about 25 C to about 32-
C, displacing the piston from its initial position to a first end
30 position;
II) the pressure medium is cooled back down (by intermediate
temperature water from the intermediate temperature water reservoir
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130) from 32-35 C to about 25 C, displacing the piston back to its
initial position;
III) the pressure medium is cooled down (by low temperature water from
the low temperature reservoir 120) from about 25 C to about 15-18 C,
displacing the piston from its initial position to a second end position;
IV) the pressure medium is heated back up (by intermediate temperature
water from the intermediate temperature water reservoir 130) from 15-
18 C to about 25 C, displacing the piston back to its initial position;
It should be noted that while the low/high temperature water, after passing
to through
the pressure vessel 200R, is returned directly to their respective reservoirs
120,
110, the intermediate temperature water, after passing through the pressure
vessel 200R,
is passed through the cooling element 410 of the radiator unit 400, in order
to
respectively convey to/absorb from the atmosphere the required amount of heat
gained/lost during the heat exchange process with the pressure medium.
In construction, the high temperature reservoir 110 and the low temperature
reservoir 120 constitute part of the air conditioning unit 10, as is observed
from Fig. 1D.
Each of the reservoirs 110, 120 has fully immersed therein a tube array
adapted to
receive an operating fluid of the air conditioning unit 10, e.g. Freon gas.
In particular, the air conditioning unit 10 has a compressor (not shown)
adapted
to compress the Freon gas into the tubes of the high temperature reservoir 110
through
line 12, such that the heated Freon gas conveys the heat to the water of the
high
temperature reservoir. The cooled Freon gas then leaves the high temperature
reservoir
110 via line 14 back to the air conditioning unit 10. The cooled Freon gas is
then
provided to the low temperature reservoir 120 via inlet 22, in the tubes of
which it is
allowed to expand, thereby cooling the water of the low temperature reservoir
120, and
leaving it via line 24 back into the air conditioning unit 10. This process
takes place
repeatedly in order to provide a high temperature water reservoir in the high
temperature reservoir 110, and a low temperature water reservoir in the low
temperature
reservoir 120.
It is appreciated that the above operation was described with respect only to
the
right pressure vessel 200R, however, a similar operation can be simultaneously
performed on the left pressure vessel 200L. Thus, two main operational cycles
can be
performed as follows:
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a) simultaneous cycle ¨ both the left and the right pressure vessel 200L,
200R perform steps (I) to (IV) above in parallel. In other words, at
any time point throughout the generator cycle, the temperature of the
pressure medium in the right pressure vessel 200R is similar to that of
the pressure medium in the left pressure vessel 200L, i.e. both
pressure mediums heat up simultaneously and cool simultaneously;
b) alternating cycle ¨ the pressure vessels 200L, 200R perform steps (I)
to (IV) at an offset, e.g. when the right pressure vessel 200R performs
step (I) of the cycle, the left pressure vessel 200L performs step (III)
of the cycle. In other words, when the pressure medium in the right
pressure vessel 200R undergoes heating, the pressure medium in the
left pressure vessel 200L undergoes cooling and vise versa.
In general, the pressurized fluid within the pressure vessels 200L, 200R
should
be chosen such that it has good heat expansion properties (expands
considerably under
heating), as well as sufficient heat transfer capabilities. Examples of
materials used for
the pressurized fluid can be (yet not limited to): water, N-Pentene, Diethyl
ether, Ethyl
Bromide, Methanol, Ethanol, Mercury, acids and others. It should also be
understood
that the pressurized fluid is not limited to a liquid medium and can be
constituted also
by a gas material.
The work medium passing through the core 240 should be chosen such that it
has sufficient heat transfer properties and a density allowing easy propulsion
thereof
through the generator 1. Examples of materials used for the pressurized fluid
can be (yet
not limited to): water, Mercury, Freon and others. It should also be
understood that the
work medium is not limited to a liquid medium and can be constituted also by a
gas
material (e.g. Freon in gas form).
Turning now to Figs. 2A to 4A to 4F, unique construction of the pressure
vessels
200 and the cores 240 will be described in detail.
Each of the pressure vessel 200L, 200R comprises an external shell 210 made of
a material which is both strong enough and thick enough to sufficiently
withstand the
pressure of the pressurized fluid, i.e. about 5000 atm. An example of such a
material can
be steel.
Within the pressure vessel 200L, 200R, there passes a core 240 through which
the work medium is adapted to pass. The core 240 can be made, on the one hand
of a
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material which is also able to withstand the high pressure within the pressure
vessel
200L, 200R, and on the other hand has sufficient heat capacity and heat
transfer
properties in order to provide an effective heat transfer process between the
work
medium and the pressurized fluid. Examples of such a material can be Copper-
Beryllium, 4340 steel etc.
Particular reference is drawn to Fig. 4B, in which a segment of the core 240
is
shown. It is observed that the inner and outer surfaces of the core are formed
with
surface elements 247 in the form of pyramids. The purpose of the surface
elements 247
is to increase the contact area with the work medium and the pressurized
fluid, thereby
increasing the effectiveness of the heat transfer between the core 240 and the
work
medium / pressurized fluid. Forming of the elements 247 can be performed by
gradual
sand spraying on the outside, and on the inside using a designated finishing
head (not
shown). In this manner, the surface area of the core 240 can be increased by
almost 20
times (compared to a smooth inner/outer surface).
With particular reference to Fig. 4F, on the core there is mounted a mixing
unit
220 adapted for mixing the pressurized fluid during operation of the generator
in order
to increase its effectiveness. The mixing unit 220 has a central axis X
extending in the
direction of the core 240 and comprises a plurality of fan blades 224 spread
about the
central axis X, connected to one another using rings 225. The mixing unit 220
is
delimited on each side by a limit ring 223. The fan blades 224 can be made of
a material
having sufficient insulation properties so as to reduce heat losses to the
blades 224
themselves, having low heat capacity to reduce heat absorption and lightweight
to
minimize the required drive power. Such a material can be, for example,
Titanium.
The limit ring 223 is fitted with a spur-gear 229 adapted to mesh with a gear
228a mounted on a driving rod 226. The driving rod 226 is driven by an
external motor
205L, 250R, the connection being between a gear 228b mounted on the driving
rod 226
and a corresponding gear 254 of the driving motor 250R.
It should be noted that according to a particular design, the motor can be
located
within the pressure vessel, not necessarily outside the vessel ¨ saves on
energy required
for overcoming dynamic resistance of the shaft and the forces acting in
conjunction with
the seal. Another option is revolving the shaft using a magnetic mechanism ¨
eliminating the need for complex dynamic seals.
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As an alternative to the mixing unit 220 described above, attention is drawn
to
Figs. 7A to 7C, where three variations of passive heat dissipation units 280,
290 and
290' are shown. The heat dissipation unit 280 is in the form of a sleeve 282
from which
a plurality of heat dissipating elements 284 extend radially, adapted for
increasing the
heat transfer between the core 240 and the pressurized fluid. The heat
dissipation unit
290 has a central sleeve 292 with radial heat dissipation elements 294
extending
therefrom. The heat dissipation unit 290' is generally similar with the
difference being
in that each of the heat dissipation elements 294' is formed with additional
extension
296' for increased heat transfer.
The heat dissipation units 280, 290 and 290' are firmly attached to the core
240
so as to have a maximal surface contact therewith, allowing for better
conduction heat
transfer.
With particular reference being drawn to Fig. 5A, the pressure vessel 200L,
200R further comprises an inner shell 230 having a diameter smaller than that
of the
inner surface 214 of the shell 210, and greater than that of the mixing unit
220. Thus,
the shell 230 divides the inner space of the pressure vessel 200L, 200R into
an inner
chamber 232 between the shell 230 and the mixing unit 220, and an outer
chamber 234
between the shell 230 and the inner surface 214 of the pressure vessel 200L,
200R. The
shell 230 can be made of a material having sufficient insulation properties so
as to
reduce heat losses to the shell 230 itself, for example, Titanium.
It should be noted that the inner chamber 232 and the outer chamber 234 are in
fluid communication with one another since the shell 230 is open at both ends.
In
operation of the generator 1, separation to an inner chamber 232 and an outer
chamber
234 facilitates insulation of the pressurized fluid of the inner chamber 232
by the
pressurized fluid in the outer chamber 234 (despite the face they are in fluid
communication with one another). Insulation of the pressurized fluid increases
the
efficiency of the generator 1 by reducing the heat losses to the external
steel shell 210. It
should also be noted that the circulation created by the mixing unit 240
hardly effects
that pressurized fluid contained between the shell 230 and the inner surface
of shell 210.
Reverting to Fig. 4F, the core 240 is fitted therein with a drive-screw 248
adapted to revolve about itself in order to propel the work medium through the
core 240
(working on a principle similar to the Archemedes screw). The drive-screw 248
is
driven by an external motor 260L, 260R, and is connected thereto via meshing
of the
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gear 246 with the gear 264 of the motor 260L, 260R. The drive-screw 248 can be
made
of a material having sufficient insulation properties so as to reduce heat
losses to the
drive-screw 248 itself. Examples of such a material can be Titanium or high-
strength
plastic. It is noted that over variations of the drive screw 248 can be used,
as will be
evident from Figs. 14F and 14G to be later discussed.
With reference to Figs. 3C and 4E, each of the pressure vessels 200R, 200L is
fitted at both ends thereof with a sealing assembly 270, comprising a head
seal 272
fastened by bolts, a main seal body 273 onto which three sealing members 274
are
mounted, an auxiliary seal assembly 276 and a soft sealing member 278. In
addition,
there are provided two seals 276', 278' of similar design (shown Fig. 3C),
used for
sealing the space between the main seal body 273 and the core 240.
Turning now to Figs. 3A to 3E, the mechanical power assembly 300 and the
power generator unit 500 will now be described in detail. Each of the pressure
vessels
200L, 200R is fitted at one end thereof with a mechanical power assembly 300L,
300R.
Since both mechanical power assemblies 300L, 300R are essentially similar,
only one
of them will now be described in detail, understanding that the description
holds true for
the other assembly as well.
The mechanical power assembly 300R is in maintained in fluid communication
with the pressure vessel 200R via an outlet port 216R. The mechanical power
assembly
300R comprises a piston unit 320R, and a pressure regulator 340R.
The piston unit 320R has a hollow housing 322 and a neck portion 324
articulated to the port 216 of the pressure vessel 200R. The neck portion 324
is formed
with an inlet orifice 326 providing fluid communication between the pressure
vessel
200R and the neck portion 324.
Within the housing 322 there is contained a displaceable piston 330 having a
head portion 332 snugly and sealingly received within the housing 322 by o-
rings 333,
and a neck portion 334 snugly received within the neck portion 324. Thus, the
housing
322 is divided into an inlet chamber 3231 being in fluid communication with
the
pressure vessel 200R to receive therein the pressure medium, and an outlet
chamber
3230, the chambers being isolated from one another by the heat portion 332.
The design of the piston unit 320 is such that the inlet chamber 3231 is
adapted
to contain therein some of the pressure medium and the outlet chamber 3230 is
adapted
to contain therein an auxiliary work medium, adapted for operating the
generator unit
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500. Such a fluid can be, for example, machine oil or the like. The housing
322 is
further formed with an outlet port 325 through which the auxiliary fluid can
leave the
piston unit towards the generator unit 500.
In operation, during stage (I) of the generator cycle, the pressure medium
heat
up and its volume increases, thereby flowing into the inlet chamber 323k,
pushing the
head portion 332 of the piston 330 towards the bottom 328 of the housing 322.
As a
result, the auxiliary work medium contained within the outlet chamber 3230 is
pressured out through the outlet port 325 and into line 302.
During stages (II) and (III) of the cycle, the pressure medium cools down and
its
volume decreases, thereby flowing from the inlet chamber 3231 back into the
pressure
vessel 200R, pulling the head portion 332 of the piston 330 towards the neck
portion
324 of the housing 322. As a result, the auxiliary work medium is sucked back
into the
outlet chamber 323o.
The piston 330 is designed such that the cross-sectional area of the head
portion
322 is 20 times greater than that of the cross-sectional area of the neck
portion 324,
thereby reducing the pressure in the outlet chamber 3230 from 5000 atm. to
about 250
atm. The back and forth movement of the auxiliary fluid is used for operating
a piston
of the motor 520 (Figs. 6A and 6B), which is in turn used for the generation
of
electricity.
In addition, the auxiliary work medium is also in fluid communication with the
pressure regulator 340 situated between the piston unit 320 and the generator
unit 500.
The pressure regulator 340 is formed with a housing 342 holding therein a
piston 350
biased by a compression spring 360. According to alternative examples the
piston 350
can be biased by a compresses gas, e.g. Nitrogen. The pressure regulator 340
is formed
with a T-junction member 343 having an inlet port 345 adapted to receive line
302, a
housing inlet 346 and an outlet port 347 connected to line 304.
In operation, most of the auxiliary fluid leaving the outlet chamber 3230 of
the
piston unit 320 via line 302 flows directly, through the T-junction 343 into
line 304 via
outlet 345, while the remainder of the auxiliary fluid flows into the pressure
regulator
340. Thus, upon an undesired increase of pressure, the piston 350 of the
pressure
regulator 340 is pushed against the biasing force of the spring 360, whereby
the pressure
of the auxiliary fluid within line 304 leading to the generator unit 500 is
maintained at a
desire pressure.
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The pressure regulator also functions as a synchronizer of the piston movement
in the following manner: if the expansion of the pressure medium in one
pressure vessel
is too great, and the piston of the other pressure vessel has no room to
"retreat", the gas
piston will absorb the additional pressure, and will return it upon
reciprocation of the
mechanism. More particularly, any additional pressure provided to the piston
which
should not be expressed in movement of the opposite piton is absorbed by the
gas piston
340, and alternatively, upon a shortage of pressure, the gas piston 340
compensates for
the above shortage.
Turning now to Figs. 6A and 6C, the generator unit 500 will now be described
in
detail. The generator unit 500 comprises a motion converter 520 and a power
unit 540.
The motion converter 520 comprises a base housing 510, and two piston housings
522R, 522L, each connected at one end to the main conversion unit and at the
other end
to line 304.
The base housing is formed of a top member 512 and a bottom member 514 (of
similar design), each member being formed with a channel 516 such that when
the two
members are attached, there is formed a space 518 (not shown) in which a
center plate
513 is adapted to reciprocate.
The center plate 513 is fitted with a cam follower 517 via stud 515. The cam
follower 517 is adapted to revolve about a second stud 519 under reciprocation
of the
center plate 513. The cam follower 517 is fixedly attached to plate 511, such
that
revolution of the cam follower 517 about the stud 519 entails revolution of
the plate 511
about its central axis X. A fly wheel (not shown) can also be provided between
the gear
and the generator in order to overcome top/bottom "dead points".
The housing 522R (only one will be described since they are both of similar
design), comprises a piston 530R adapted to reciprocate therein, forming in
the housing
522R an inlet chamber 524R. The housing 522R is formed with an inlet 526R
providing fluid communication between the inlet chamber 524R and the auxiliary
work
medium incoming from line 304. The pistons 530R and 530L are formed at one end
with a head portion 532R, 532L, located closer to the inlets 526R, 526L
respectively,
and at the other, opposite end, are integrally formed with the center plate
513.
In operation, for example under an alternating cycle as described above,
during
stage I of the cycle, the pressurized fluid in the right chamber 200R heats up
and
increases in volume, the pressurized fluid in the left chamber 200L cools down
and
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decreases in volume. As a result, the auxiliary work medium in the right
piston unit
320R is urged towards the piston 530R pushing on it, while the auxiliary work
medium
in the left piston unit 320R is sucked in, pulling on the piston 530L. During
this stage,
the movement of the pistons 530R, 530L displaced the center plate 513 in one
direction.
Thereafter, during stages II and III of the cycle, a reverse operation takes
place,
i.e. the pressurized fluid in the left chamber 200L heats up and increases in
volume, the
pressurized fluid in the right chamber 200R cools down and decreases in
volume. As a
result, the auxiliary work medium in the left piston unit 320R is urged
towards the
piston 530L, pushing on it. The movement of the pistons 530R, 530L displaced
the
center plate 513 in the other direction, as seen in Figs. 6B and 6C.
Reciprocation of the center plate 513 entails revolution of the cam follower
517
resulting in revolution of the plate 511 about its central axis. This
rotational movement
is converted into electrical energy by the power unit 540.
Reverting to Fig. 1B, a part of the electrical power generated by the power
unit
540 is provided to the output, a part for the air conditioning unit 10, and
the remainder
is provided to a battery 50. The battery 50 can be used for jump starting the
system.
It is appreciated, that the above described system 1 can produce at least up
to 4
times the amount of electricity used for its operation, i.e. if the generator
1 requires
1 kwh (kilowatts per hour) for its operation, it can produce at least up to
4kwh of
electricity. It should also be understood that this profit in electricity is
gained by
performing a heat exchange process with the environment, i.e. using the
surrounding
medium (air, water) to absorb/convey heat to the water running through the
radiator
400.
In particular, the use of an air conditioning unit 10 allows for the
significant gain
in electricity production. As opposed to intermediate air conditioning systems
in which,
the heat produced during cooling of a space (e.g. a room) is expelled to the
outside
environment (heat emitted to the outside of the room by the air conditioning
system), in
the present generator, this heat does not go to waste and is used for heating
the water in
the high temperature reservoir.
Experimental analysis of the generator 1 are disclosed in Figs. 8A to 8F,
showing diagrams of the temperature fluctuation of the work medium and of the
pressurized fluid under different cycle times.
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Turning to Fig. 9 The generator 1 can also comprise an accumulator
arrangement 590 filled with a storage medium, e.g. water, where, in the event
that an
excess amount of electricity is produced by the generator 1, this excess
amount will be
diverted to a heating body used for heating the water within the accumulator
arrangement 590. In this manner, the accumulator arrangement 590 can function
as a
battery.
For example, when the water in the accumulator arrangement 590 is heated to a
desired degree, e.g. to a temperature similar to the temperature of the high
temperature
reservoir 110, the high temperature water for the operation of the generator 1
can be
provided by the accumulator arrangement 590 instead of by the high temperature
reservoir 110. As a result, the operation of the air conditioning unit 10 can
be reduced
(or even be completely interrupted), allowing it to consume less electricity.
Once the amount of electricity produced by the generator 1 is commensurate to
the desired consumption, the air conditioning unit 10 returns to normal
operation and
the water in the accumulator arrangement 590 will gradually be cooled down. In
addition, increased pressure within the accumulator arrangement can allow
heating it
above the boiling point of the work medium, in order to accumulate more heat.
For
example: water at 5atm (standard household pressure) can boil at 150 C.
Furthermore, the accumulator arrangement 590 can comprise a heating element
configured for directly heating up the water in the accumulator arrangement in
order to
maintain therein a desired temperature.
The generator 1 can also comprise a controller (not shown) adapted to monitor
the temperature of the pressurized fluid, the work medium, the temperature of
the water
in the accumulator arrangement 590, the displacement of the pistons 330R,
330L,
530R, 530L, the pressure within the pressure regulator 340, the displacement
of the
center plate 513 etc. The controller can be used to control the operation of
the
distribution valves 140, the operation of the motors 250, 260, the
displacement of the
pistons etc.
Turning now to Figs. 11A and 11B, another example of the generator is shown,
generally designated as 1', and comprising an air conditioning unit 10
connected to a
work medium sub-system 100', two pressure vessels 200', a mechanical power
assembly 300, a radiator unit 400, a power generator unit 500, a gradient
assembly 600,
an accumulator unit 50 and output.
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In principle, the generator 1' is similar in design to the generator 1
previously
described, with the difference being in the design and number of the cores
passing
through the pressure vessels 200', a different design of the radiator unit
400', the
additional gradient assembly 600, and corresponding valves and piping
associating
various components of the generator to one another.
Firstly, the gradient assembly 600 and its utilization in the generator 1'
will be
described in detail with respect to Figs. 12A to 12D:
At an initial position of the generator (when the generator is at rest), the
piping
of the generator are filled with work medium at a predetermined pressure, the
work
medium being at an intermediate temperature. Consequently, the pressure medium
is
also at the intermediate temperature.
During a first stage of operation of the generator, the air conditioning unit
AC
begins its operation, heating up the work medium in the high reservoir 110'
and cooling
down the work medium in the low temperature reservoir 120'. The intermediate
reservoir 130' has working medium remaining at intermediate temperature. Once
the
work medium in the high/low temperature reservoirs 110', 120' respectively has
reached its desired temperature, the driving mechanisms 250', 260' begin their
operation as follows:
(a) (i) high temperature work medium from the high reservoir 110' is passed
through the right pressure vessel 200R so as to heat up the pressure medium,
and is re-circulated through lines PHR back into the high temperature
reservoir 110' (lines LI, L2);
(ii) simultaneously, low temperature work medium from the high
temperature reservoir 120' is passed through the left pressure vessel 200L so
as to cool down the pressure medium, and is re-circulated through lines PR
back into the low temperature reservoir 120' (lines L1, L3);
(iii) step (a) continues until the pressure medium in each pressure vessel
200R', 200L' reaches a desired high temperature THoTacoLD respectively;
(b) (i) work medium at intermediate temperature from the intermediate
reservoir
130' is passed through pressure vessel 200R' so as to be heated up by the hot
pressure medium, thereby removing heat therefrom;
(ii) simultaneously, work medium at intermediate temperature from the
intermediate reservoir 130' is passed through pressure vessel 200L' so as to
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be cooled down by the cold pressure medium, thereby providing heat
thereto;
(c) (i) the heated intermediate temperature work medium is passed into the
gradient tank 600R (lines L1, 1,4), having a temperature gradient therein, so
that the top portion of the gradient tank 600R contains a hotter heated
intermediate temperature work medium than the bottom portion of the
gradient tank 600R;
(ii) simultaneously, the cooled intermediate temperature work medium is
passed into the gradient tank 600L (lines L1, L4), having a temperature
gradient therein, so that the top portion of the gradient tank 600R contains a
cooler cooled intermediate temperature work medium than the bottom
portion of the gradient tank 600L;
(iii) this stage continues until the intermediate temperature work medium
reaches a desired temperature in each of the gradient tanks 600R, 600L;
(d) (i) heated intermediate temperature work medium is passed from the
gradient tank 600R to the front of the generator, where it re-enters the left
pressure vessel 200L' (see lines L611, L7c in Fig. 17A), thereby further
providing heat to the cold pressure medium and heating it up back to a
temperature close to TINTERMEDIATE;
(ii) Simultaneously, cooled intermediate temperature work medium is passed
from the gradient tank 600L to the front of the generator, where it re-enters
the right pressure vessel 200R' (lines L6C, L7H in Fig. 17A) thereby further
removing heat from the hot pressure medium and cooling it down back to a
temperature close to TENTERMEDIATE;
(iii) this step continues until the pressure medium in both pressure vessels
200R' and 200L' is at a temperature of TINTERMEDIATE;
Steps (a) to (d) then repeat themselves but in an opposite manner, i.e. high
temperature work medium is now passed through the left pressure vessel 200L'
and low
temperature work medium is passed through the right pressure vessel 200R', and
so on.
It is appreciated that the first portion of the heated intermediate
temperature
work medium entering the gradient tank 600R is the hotter than the next
portion of
intermediate temperature work medium passing into the gradient tank 600R, and
respectively, the first portion of the cooled intermediate temperature work
medium
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entering the gradient tank 600L is the cooler than the next portion of
intermediate
temperature work medium passing into the gradient tank 600L.
This cross-over step provides for many advantages, one of which is a better
heat
transfer process with the pressure medium. In particular, it is noted that in
each vessel,
the pressure medium first performs a heat transfer process with intermediate
temperature work medium at temperature TINTERMEDIATE (steps (b)(i) and
(b)(ii)), and
thereafter an additional heat transfer process with a heated/cooled
intermediate
temperature work medium (steps (c)(i) and (c)(ii)).
It is noted that during steps (b)(i) and (b)(ii), the intermediate temperature
work
medium contained in the gradient tanks 600R, 600L, flows through lines L5R,
L51, and L5
into the radiator, where any accumulated heat of the generator can be removed
via a
heat transfer process with the outside environment.
With particular reference being drawn to Fig. 12C, the gradient tanks 600R,
600L are formed with a spiral structure 620R, 620L, configured for preventing
the
different portions of the heated/cooled intermediate work medium from
performing a
heat exchange process therebetween, and thus maintaining a temperature
gradient
within the reservoirs 600R, 600L.
Turning now to Fig. 13A, further piping arrangements of the generator are
shown, in particular:
L3 ¨ leading low temperature water which has passed through the pressure
vessel back to the low temperature reservoir 120';
L5', L5R% L51; ¨ leading intermediate temperature water after passing through
the radiator back into the intermediate reservoir 130';
L8 ¨ leading intermediate temperature work medium back to the intermediate
reservoir 130; and
L9 ¨ leading intermediate temperature water back to the rear of the generator
towards the gradient tanks 600R, 600L.
With reference to Fig. 13B, it is observed that the low temperature reservoir
120' comprises a heat transfer element 124' configured for cooling the work
medium in
the reservoir 120' by constituting a condenser of the air conditioning unit
AC. The
reservoir 120' further comprises a fan 128' driven by an external motor 126',
configured for maintaining a uniform temperature within the reservoir 120'.
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Turning now to Figs. 14A to 14D, the driving mechanism of the work medium
and the cores of the pressure vessels 200R', 200L' will be described:
It is observed that, whereas the previously described generator 1 only has one
core 240 per vessel, the presently described generator 1' has six cores 240'
per vessel,
each having a design similar to that of the previously described core 240.
In order to circulate the work medium through all cores 240 simultaneously, a
motor 250' is provided, configured for driving a gear 254' meshing with a gear
256',
which in turn drives a mutual gear 259', meshing with the respective gears
242' of each
of the cores 240. The gears 242' are responsible for the rotation of the drive
screw (not
shown) which propels the work medium through the entire generator piping
system.
In addition, there is provided a secondary drive motor 260', configured for
revolving the cores 240' the fan arrangement 220' of each of the cores 240'
about the
axis of the cores (it is noted that in some application, even the cores
themselves can
revolve about their axis). The drive motor 260' is configured to be meshed
with the
mutual drive wheel 269', which, in turn, meshes with the gears 222' of the fan
arrangement 220'.
It is noted that the generator further comprises an additional array of
driving
motors 250', 260' located at a rear side of the generator, i.e. at the other
end of the
pressure vessels 200R', 200L'. In this manner, the driving load is distributed
between
the front array and the rear array of motors.
With particular reference being drawn to Figs. 14E and 14F, the drive screw
used in the presently described generator can be of a different design, the
difference
lying in the pitch angle of the screw (70 deg.), which further contributes to
circulation
of the work medium through the core 240' and to pushing the work medium
towards the
inner surface of the core 240'.
Turning now to Figs. 15A to 15C, a controller of the generator 1' is shown,
generally designated as 700. The controller 700 is positioned so as to
interject between
line Lo exiting the pressure vessel 200' and line L1 leading to the valve
140'. The
purpose of the controller 700 is to regulate the flow rate Q from the pressure
vessel
200', by controlling the cross-sectional area through which the work medium is
passed.
With particular reference to Fig. 15C, the controller 700 comprises a casing
720
formed with an inlet hole 722 in fluid communication with line Lo, and an
outlet hole
724 in fluid communication with line L1. The controller 700 further comprises
a plunger
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740 formed with a top portion 742, a neck portion 744 and a main block 746.
The main
block 746 is formed with a passageway 748, and a spring is mounted onto the
neck
portion 744, pressing against the casing, so as to bias the plunger 740
downwards.
Thus, when the passageway 748 is aligned with the inlet/outlet holes 722, 744,
a
maximal cross-sectional flow area is provided. When the plunger is shifted,
and the
passageway 748 is misaligned, the cross-sectional flow area reduces. By
controlling the
load of the spring, e.g. by any conventional means such as screws (not shown),
it can be
possible to regulate the flow rate through the generator 1'.
Turning now to Figs. 16A and 16B, the accumulator arrangement 590 is shown
when used in the generator 1' described above. The reservoir 590 has two lines
Llo
leading thereto, one from each pressure vessel 200'. In addition, the
accumulator
arrangement 590 further has lines L11 leading thereto from the rear side of
the generator
1'. The storage reservoirs also have an outlet line 592 leading to a user port
(not
shown). The accumulator arrangement 590 may, as previously described, comprise
a
heating element therein, configured for heating up the work medium contained
therein.
In general, the accumulator arrangement 590 can be used to accumulate excess
energy produced by the generator 1'. More specifically, any additional energy
generated
by the generator 1' (i.e. energy not consumed by a user) can be diverted to
heating up
the work medium contained in the accumulator arrangement 590. The heated work
medium of the accumulator arrangement 590 can later be used instead of the
high
temperature work medium produced in the high temperature reservoir 110' by the
air
conditioning unit AC, thereby saving on the power of the AC.
Alternatively, the pressure of the work medium in the accumulator arrangement
590 can be increased (greater than that required to the end user of line 592)
so that the
boiling point of the work medium increases, thereby allowing the work medium
in the
accumulator arrangement to absorb more energy.
Turning now to Figs. 17A to 17D, the valves and piping system of the generator
1' are displayed:
¨ main front valve, having inlets/outlets to the following lines:
LH - outlet pipe from the high temperature reservoir 110';
Lc ¨ outlet pipe from the low temperature reservoir 120';
L10 ¨ outlet pipe leading to the accumulator arrangement 590;
L ¨ main core line leading work medium into the pressure vessels 200'; and
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L6c, L611 ¨ cross-over lines, leading work medium from a gradient tank 600 to
an opposite pressure vessel 200'.
V2 ¨ auxiliary front valve, having inlets/outlets to the following lines:
L5e, L5H9 (splitting from L5') ¨ lines leading intermediate temperature work
medium at intermediate temperature from the gradient tanks 600;
L8 ¨ leading intermediate temperature work medium back to the intermediate
reservoir 130'; and
L9 ¨ leading intermediate temperature work medium to the rear of the generator
1' to provide pressure.
V3 ¨ main rear valve, having inlets/outlets to the following lines:
L1 ¨ leading work medium from the core of the pressure vessels 200';
L2 ¨ leading high temperature work medium back to the high temperature
reservoir 110';
L3 ¨ leading low temperature work medium back to the low temperature
reservoir 120';
L4 ¨ leading intermediate temperature work medium to the gradient tank 600;
and
L9 ¨ leading intermediate temperature work medium to the rear of the generator
1' to provide pressure.
V4 ¨ auxiliary rear valve, having inlets/outlets to the following lines:
L4 ¨ leading intermediate temperature work medium to the gradient tank 600;
L5 ¨ leading intermediate temperature work medium to the gradient tank 600;
and
L6c, L6H ¨ cross-over lines, leading work medium from a gradient tank 600 to
an opposite pressure vessel 200'.
Turning now to Fig. 17E, a schematic chart of the temperature of the work
medium passing through the core is shown, one for each of the pressure vessels
200R',
200L'. The chart can be divided into the following sections:
Si ¨ equivalent to step (a)(i) of a first half-cycle described above ¨ high
temperature work medium at temperature 'Nix of 15 C is passed through the core
from
t lOsec tot = 15sec;
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S2 ¨ equivalent to step (b)(i) of a first half-cycle described above ¨
intermediate
temperature work medium at temperature TINTERmEDIATE are passed through the
core
from t = 15sec tot 20sec;
S3 ¨ equivalent to step (d)(i) of a first half-cycle described above ¨ cooled
intermediate temperature work medium at a gradient temperature from the
gradient tank
600 of the opposite pressure vessel 200' is passed through the core from t
20sec to t
25sec;
S4 ¨ equivalent to step (a)(i) of a second half-cycle described above, where
the
pressure vessels trade place ¨ low temperature work medium at TCOLD is passed
through the core from t 25sec to t 30sec;
S5 ¨ equivalent to step (b)(i) of a second half-cycle described above ¨
intermediate temperature work medium at TINTERMEDIATE is passed through the
pressure
vessels 200' from t 30sec to t 35sec; and
S6 ¨ equivalent to step (d)(i) of a second half-cycle described above ¨ heated
intermediate temperature work medium at a gradient temperature from the
gradient tank
600 of the opposite pressure vessel 200' is passed through the core from t
35sec to t
40sec;
This concludes a full cycle of the generator 1'. It is appreciated that the
lower
chart depicts the temperature of the work medium passing through the core of
the
opposite pressure vessel. Thus, the above stages are applicable to the lower
chart, with
the changing of the index from (i) to (ii), e.g. step (b)(ii) instead of step
(b)(i).
Turning now to Figs. 18A to 18G, a vehicle is shown, generally designated as
800, in which a modified version of generator 1' is employed, generally
designated as
1". It is observed that the containers of the work medium are disposed at the
front F of
the vehicle 800 while all the movement generating mechanisms are located at
the rear R
of the vehicle 800. The pressure vessels 200' are disposed horizontally along
the chassis
820 of the vehicle, connecting between the front F and the rear R.
Unlike the generator 1' described above, in the present generator, the
gradient
tanks 600 are located on the same side f the pressure vessels 200' as the work
medium
reservoirs 110', 120' and 130'.
It is also appreciated that the disposition of the pressure vessels 200'
provides
the vehicle 800 with extra stability due to the weight of the pressure vessels
200'. It is
also appreciated that since the vehicle 800 is usually in movement when the
generator
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1' is active, the efficiency of the operation of the radiator 400 can be
considerably
improved due to the increase in the heat transfer coefficient between the
moving vehicle
800 and the ambient air.
Turning now to Figs. 19A to 19F. a marine vessel generally designated 900 is
shown comprising a modified version of the previously described generator 1',
generally designated as 1".
It is noted that in the generator 1", the intermediate reservoir 130' is
missing.
The reason for this is that the generator 1" uses the water it is submerged in
as its main
work medium, and therefore, the reservoir holding the water in which it is
submerged
(lake, ocean, pool) replaces the reservoir 130'. In order to utilize the
medium, two lines
L9' are provided, allowing the generator to withdraw water from the above
medium into
the generator 1".
Turning now to Figs. 20A and 20B, there is shown a cross-section of a core of
the pressure vessel 200' when without pressure and when pressure is applied
thereto
respectively. It is observed that the inner surface of the core is lined with
an inner layer
1000 having an increased surface area due to micro-structures 1100 formed
thereon.
Increasing the surface area is desired in order to increase the heat transfer
coefficient
between the inner layer and the work medium flowing through the core.
Fig. 20C shows the core of the vessel 200' with the spiral 240' passing
therein,
configured for causing progression of the work medium through the pressure
vessel
200' and the entire generator system 1.
Turning now to Figs. 21A to 21G, a method for producing the inner layer is
shown, including the following steps:
(a) providing a generally planar plate 1000' having a first face F1 and an
opposite second face F2;
(b) pre-forming the micro-structures 1100 on the first face F1 using two
pressing
wheels W1, W2 one of which is formed with a corresponding surface MS for
forming the micro-structures 1100;
(c) providing a mold M formed with a non-through going cavity C
corresponding in size and shape to the plate 1000', the cavity C having a
base surface and an opening at a surface of the mold M;
(d) placing the plate 1000' in the cavity such that the second face F2 is
mated
against the base surface and the first face F1 is facing the opening of the
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cavity C, such that there remains a space between the first face F1 and the
opening;
(e) introducing a filler material F into the cavity C so as to fill the space,
including spaces formed between the micro-structures MS;
(f) letting the filler material F solidify so as to form a single plate
constituted by
the plate 1000' and solidified filler material F, having a first face
constituted
by the filler material and a second face F2 constituted by the second face of
the original plate 1000';
(g) deforming the single plate by a pressure block PB and a deformation mold
D, to obtain at least a partially cylindrical shape of diameter Dm, such that
the second face F2 of the single plate 1000' constitutes and outer surface of
the cylinder and the first face of the single plate constituted an inner
surface
of the cylinder;
(h) removing the filler material F from the single plate 1000', thereby
resulting
in the original plate 1000 having micro-structures MS formed on the inner
surface thereof; and
(i) performing a final finish on the inner surface with the micro-structures.
With reference to Figs. 20D and 20E, another example of a core is shown
generally designated as 240", which formed, both on its inner surface and on
its outer
surface, with ridges 246" and 247" respectively. This core 240" can be made of
tungsten or other materials (see Figs. 26A, 26B), and its design provides for
a more
robust core 240".
It is noted that the ridges 246" and 247" are designed such that the peak of
one
is opposite the trough of another and vise versa, so that the thickness in
each point along
the central axis X is generally the same (N).
The ridges 246", 247" can be parallel as in the present example, or,
alternatively, be in the form of one spiraling ridge (as in a thread). One
advantage of the
latter example is the simplicity of production ¨ the external ridges 247" can
be made by
turning and the internal ridges 246" can be formed by a tap.
Turning now to Figs. 22A and 22B, still another example of the generator is
shown, generally designated as 2000 which is generally similar in construction
to the
generator 1 previously described, but differs from it mainly by the design of
the work
medium sub-system 2100 (as opposed to the work medium sub-system 100).
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The work medium subs-system 2100 is in the form of a cascade arrangement
2150 which comprises a high temperature reservoir 2110 and a low temperature
reservoir 2120, without an intermediate work medium reservoir as in the
previous
examples.
Each of the pressure vessels 2200R, 2200L is provided at its inlet end with a
respective inlet line 2136R, 2136L, regulated by respective valves 2140B and
2140A,
and at its outlet end with a respective inlet line 2146R, 2146L, regulated by
respective
valves 2140D and 2140C.
An outlet end of the high temperature reservoir 2110 is connected to the
valves
2140B and 2140A via respective lines 2134R, 2134L, and an inlet end of the
high
temperature reservoir 2110 is connected to the valves 2140D and 2140C via
respective
lines 2144R, 2144L.
An outlet end of the low temperature reservoir 2120 is connected to the valves
2140B and 2140A via respective lines 2132R, 2132L, and an inlet end of the low
temperature reservoir 2120 is connected to the valves 2140D and 2140C via
respective
lines 2142R, 2142L.
In the present generator (as in previously described examples), in the initial
position, the pressure fluid within the pressure vessel is at the temperature
TENv which
is roughly the temperature of the environment. The initial steps of the
operation cycle of
the presently described generator can be described as follows:
(a) passing high temperature water from the high temperature reservoir 2110,
at
a temperature TH through the pressure vessel so as to heat up the pressure
fluid contained therein. This results in heating the pressure fluid to a
temperature of Thot > TENv (however Thot < TH) and simultaneously in
cooling of the high temperature work medium to a temperature TH-cooied <
TH;
(b) passing low temperature work medium from the low temperature reservoir
2120, at a temperature Tc < TENv through the pressure vessel so as to cool
down the heated pressure fluid contained therein. This results in cooling the
pressure fluid from a temperature of Thot to a temperature 'I'm(' > Tc, and
simultaneously in heating the low temperature water to a temperature Tc_
Heated > Tc.
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Thereafter, steps (a) and (b) repeat themselves, with the difference being
that the
pressure fluid now constantly fluctuates between the temperatures Thot and Tem-
Simultaneously with the performance of step (a), the heated low temperature
work medium, which is now at a temperature of TC-Heated Tc, is cooled down by
performing a heat exchange process with the environment which is at a
temperature
TENV < TC-Heated= This process is regulated by a radiator unit 2400 (shown
Figs. 22A,
22B). In addition, simultaneously with the performance of step (b), the cooled
high
temperature work medium, which is now at a temperature of Tx-cooled < TH, is
heated up
by the A/C system, bringing it back to the temperature TH.
It is appreciated that while step (a) takes place in one pressure vessel (for
example vessel 2200R), the second pressure vessel 2200L undergoes step (b).
Thus, the
pressure vessels keep alternating ¨ while the pressure fluid in one heats up,
the pressure
fluid in the other is cooled down and vise versa.
Turning now to Figs. 23A to 23F, the main difference in the design of the work
medium sub-system 2100 is that the A/C previously used to provide the high/low
temperature reservoirs at the respective condenser/evaporator sections of the
A/C is now
replaced by a cascade arrangement 2150, having several grades G1 to G7, each
operating
as a basic A/C compression/expansion mechanism as will now be explained. The
arrangement is such that the cascade 2150 has a first end-grade G1 which
provides the
'low' for the low temperature reservoir 2120 and a second end-grade G7 which
provides
the heat for the high temperature reservoir 2110.
Each of the grades Goo comprises a compressor C(n), a condenser section
2152(n),
an expansion valve 2154(fl), an evaporator section 2156(n) and a return pipe
2158(n) to the
compressor C(), where (n) denotes the number of the grade G.
Each of the grades G1 to G7 comprises a compressible fluid (gas or liquid),
and
is designed to operate between a high fluid temperature TH() at the respective
condenser
section 2152(n) and a low temperature Tcoo at the respective evaporator
section 2156(n).
The arrangement is such that the condenser section 2152(n) of one grade G()
and
the evaporator section 2156(n) of a subsequent grade G(n+i) are thermally
coupled to
provide a heat exchange process. Specifically, the arrangement is of
concentric tubes
where the condenser section 2152(n) is constituted by the inner tube and the
evaporator
section 2156(fl) is constituted by the outer tube.
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Under this arrangement, compressed fluid from one grade Goo flows within the
inner tube and performs a heat exchange process with the expanded fluid from
the
subsequent grade G(+1) which flows between the inner surface of the outer tube
and the
outer surface of the inner tube (see Fig. 23E).
The cascade arrangement 2150 is designed such that the temperature Tcoo of the
fluid in the evaporator section 2156(n) of one grade Goo is lower than the
condensation
temperature of the fluid flowing in the subsequent grade G(n+i), and
necessarily lower
than the temperature TH(n+i) of the fluid in the condenser section 2152(n+1)
of that grade
G(+1). As a result, a heat exchange process takes place where the expanded
fluid of one
grade Goo takes up the heat from the compressed fluid of the subsequent grade
G(n+i).
However, it is appreciated that the temperature Tc(n+1) of the cooled-down
fluid
of the subsequent grade G(n+i)
An example of the temperatures Tc(n), TH(n) and TcOND are shown below:
(n) TH(n) TC(n) TCOND
1 27 0
2 57 27 30
3 90 57 60
4 116 90 93
5 155 116 119
6 197 155 158
7 245 197 200
In practice, the evaporator section 21561 of the first grade G1 is submerged
within the low temperature reservoir 2120 bringing the low temperature water
to a
temperature of about 3 C, and the condenser section 21527 of the seventh grade
is
submerged within the high temperature reservoir 2110 bringing the high
temperature
water to a temperature of about 242 C. It is appreciated that the high/low
temperatures
of the high/low temperature reservoirs 2110, 2120 never reach the temperature
of the
respective condenser/evaporator sections 21527, 21561, and are always slightly
lower/higher respectively.
It is observed from Figs. 22A and 22B, that the generator 2000 is fitted with
a
front and a rear driving motor 2250F and 2250R respectively configured for
driving the
cores of the pressure vessels 2200, and with a front and a rear driving motor
2260F and
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2260R configured for driving the spiral for circulating the work medium within
the
generator 2000.
The use of front and rear motors for driving the same element facilitates
lower
loads exerted on the revolved element (core or spiral) which are positioned
within a
high pressure environment. Should only one motor be used, the core and/or
spiral will
tend to bend within the pressure vessel, which can lead to damage of the
mechanical
integrity of the system.
Reverting now to Fig. 22D, the radiator unit 2400 is shown positioned along
the
lines 2146R, 2146L leading from the pressure vessels 2200R, 2200L to the low
temperature reservoir 2120. The purpose of the radiator unit 2400 is to
provide for a
heat exchange process between the heated low temperature water flowing in
these lines
(at a temperature of TC-Heated) and the ambient air of the environment.
The radiator unit is fitted with a fan (not shown) and control unit (not
shown)
configured for regulating the operation of the fan, so that the low
temperature water
leaving the radiator remain essentially at a constant temperature. For
example, if Tc_
Heated is about 50 C, it is required to lower this temperature down to about
20 C to allow
the first grade G1 to perform efficiently. Thus, the control unit is used to
maintain the
low temperature water leaving the radiator at a temperature of about 20 C.
The control unit can comprise a sensor associated with line 2149 of the low
temperature water emitted from the radiator and configured for measuring its
temperature. Should this temperature exceed the predetermined temperature (in
this
particular example 20 C), the control unit will cause the fan to revolve
faster in order to
increase the heat-exchange rate within the radiator unit 2400. Alternatively,
should this
temperature be lower than the predetermined temperature (in this particular
example
20 C), the control unit will cause the fan to revolve slower in order to
decrease the heat-
exchange rate within the radiator unit 2400.
Turning now to Figs. 24A to 24D, another example of a cascade arrangement is
shown generally designated as 2150', and configured for adjusting its
operation mode to
the ambient temperature of the outside environment.
The difference between the currently described cascade arrangement 2150' and
the cascade arrangement 2150 previously described with respect to Figs. 23A to
23F
lies in the design of the first and second grade GI, G2, and in particular, in
the bypass
arrangement 2170 associated therewith.
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In general, it can be that at different times, the ambient temperature of the
environment increases to an extent when it exceeds the temperature of the
compressed
fluid in the condensation section 21522 of the second grade G2. In such case,
the low
temperature water emitted from the radiator unit after performing a heat
exchange
process therewith will also be at a temperature exceeding that of the
compressed fluid in
the condensation section 21522 of the second grade G2=
As a result, the evaporator section 21561 of the first grade G1 will be
submerged
in a very hot environment. Since each grade is fitted with a compressor of
predetermined power and is design for a predetermined temperature difference
A, the
compressor C1 simply will not be able to remove so much heat from the
evaporator
section 21561 rendering the operation of the first grade G1 inefficient.
In order to overcome this, a bypass arrangement 2170 is used, configured to
bypass the first grade G1 and connect the low temperature reservoir 2120 with
the
evaporator of the second grade G2=
Specifically, the bypass arrangement 2170 comprises two valves 2172A, 217213
associated with the evaporator section of the second grade G2 and the
compressor C2 of
the second grade respectively. The bypass arrangement 2170 has an expansion
valve
2174 leading to an evaporator section 2176 which is in the form of a tube
leading into
the low temperature reservoir 2120, and an outlet lien 2178 leading out of the
low
temperature reservoir 2120.
Under a normal operation mode, when the temperature of the environment is
lower than the temperature of the compressed fluid in the second grade G2,
ports A1 and
B1 are open and ports A2 and B2 are closed, and the cascade arrangement 2150
operates
in a manner identical to that of the cascade arrangement 2150.
Once the temperature of the ambient air of the outside environment rises
beyond
the temperature of the compressed fluid in the second grade G2, ports A1 and
B1 are
closed and ports A2 and B2 are open to allow the following:
Compressed fluid from the condenser section 21522 of the second grade G2
passes to the expansion valve 2174 allowing the fluid to expand and cool down.
After
passing through the expansion valve 2174, the expanded fluid progresses along
the line
2176 to pass into the low temperature reservoir 2120 where it cools down the
water and
is emitted (slightly heated) through line 2178 leading to the compressor C2=
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It is appreciated that whereas in the normal operation mode the temperature
= difference between the low temperature reservoir 2120 and the high
temperature
reservoir 2110 was about 240 C (between 3 C provided by the 0 C of the first
grade
evaporator 21561 and 242 C provided by the 242 C of the seventh grade
condenser
21527), the temperature difference now is about 210 C between 30 C provided by
the
27 C of the second grade evaporator 21562 and 242 C provided by the 242 C of
the
seventh grade condenser 21527.
In other words, while reducing the overall temperature difference of the
cascade
arrangement 2150', the efficiency remains generally the same, on account of
eliminating
from the process the operation of the first grade GI of the cascade
arrangement 2150'.\
Turning now to Figs. 25A and 25B, another example of a cascade arrangement
is shown generally designated as 2150", which is similar to the previously
described
cascade arrangement 2150, with the difference being in that the flow of the
fluids in the
heat exchanger of each grade is now in opposite directions (as opposed to
parallel flow
in the previously described example).
Specifically, compressed fluid of the first grade G1 flows through its
respective
condenser section 21521" in one direction, while expanded fluid of the second
grade G2
flows through its respective evaporator section 21562" in the opposite
direction. As well
known, counterflow heat exchangers provide for higher efficiency of the heat
exchanger
and consequently for a more efficient operation of the cascade arrangement
2150".
It is also noted that while the present example of the cascade arrangement
2150"
is shown without a bypass arrangement 2170 (see Figs. 24A to 24D) as in the
previous
example of cascade arrangement 2150', such a bypass arrangement 2170 can be
fitted to
the presently described cascade arrangement 2150".
Turning now to Figs. 27A to 27E, yet another example of a generator is shown,
generally designated as 3000. In general, the structure of the generator 3000
is generally
similar to that of the previously described generators, however, with the
following
differences:
-
Multiple pressure vessels ¨ each side (left/right) of the generator comprises
four pressure vessels, each being of similar structure to the pressure vessels
described with respect to previous examples;
- Linear core connection ¨ each vessels comprises six cores, but
contrary to
previous examples, the cores are connected linearly to one another so as to
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form a long work medium flow path (six times as long in comparison to a
parallel connection as previously disclosed);
- Linear vessel connection (work medium) ¨ the cores of the four
pressure
vessels of each side are linearly connected to one another so as to form an
even longer work medium flow path;
- Linear vessel connection (pressure medium) ¨ the compartments of
the
four pressure vessels on each side containing the high pressure medium are
also in fluid communication with one another via high-pressure connections,
thereby forming a long pressure medium flow path;
- External low temperature reservoir ¨ the low temperature reservoir
constituted by the evaporator of the A/C unit is exposed to the environment
and is not used for circulation of work medium therethrough.
In operation, a full cycle of one side of the generator can include the
following
steps (taking into account that the opposite side undergoes the same steps
only at a
shift):
a) High temperature work medium is passed from the condenser end of the A/C
unit along the length of twenty four cores (six cores in each of the four
pressure vessels), thereby increasing the temperature of the pressure medium
to its maximal operating temperature, and simultaneously being cooled down
to a lower temperature;
b) From the last core of the fourth pressure vessel, the cooled down high
temperature work medium is returned to the condenser end of the A/C unit
after passing through a radiator for expelling therefrom at least an
additional
part of the heat remained therein;
c) Intermediate temperature work medium at an ambient temperature from the
intermediate reservoir is passed through all twenty four cores of the four
pressure vessels, thereby lowering the temperature of the pressure medium
below the maximal operating temperature, and simultaneously being heated
to a higher temperature;
d) From the last core, the intermediate work medium flows into the gradient
tanks to be stored there, so that the first portion of intermediate
temperature
work medium to enter the gradient tank is at the highest temperature and the
last portion to enter the gradient tank is at the lowest temperature;
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e) Intermediate temperature work medium at an ambient temperature from the
intermediate reservoir is passed through all twenty four cores of the four
pressure vessels, thereby further lowering the temperature of the pressure
medium to the minimal operative temperature, and simultaneously being
heated to a higher temperature;
0 From the last core, the intermediate work medium flows back into the
intermediate work reservoir, passing through the radiator to expel any
additional heat to the environment;
g) Heated intermediate temperature work medium from the gradient tank is
passed through the cores of the four pressure vessels, thereby gradually
heating the pressure medium to a temperature above the minimal operative
temperature yet still below the maximal operative temperature. Gradual
heating is achieved by using a LIFO arrangement where the last portion to
enter the gradient tank (which is also of the lowest temperature) is first to
flow through the cores;
h) From the last core, the intermediate temperature work medium flows into the
intermediate reservoir while passing through the radiator unit to expel any
additional heat to the environment;
i) Repeating from step (a).
In particular, steps (a) and (b), and (e) and (0 can last for a first period
of time
and steps (c) and (d), and (g) and (h) can last for a second period of time
which is
greater than the first period of time. Specifically, the second period of time
can be twice
as long as the first period of time. Under a particular example, the first
period of time
can be about 5 seconds and the second period of time can be about 10 secnods.
With particular reference being made to Figs. 28A and 28B, the steps are
carried
out as follows:
Steps (a) and (b): High temperature work medium flows from the high
temperature reservoir into valve E: enter via E2, exit via E and line LE =>
line 42 into
valve B: enter via B2, exit via B and line LIZ! => exit cores via line LIZ
and into valve
D: enter via D, exit via D3 and line LD3 => line LF into valve F: enter via F,
exit via Fl
and line LF1 back to the high temperature water reservoir.
Steps (c) and (d): Intermediate temperature work medium flows from the
intermediate temperature reservoir via line Lm into valve B: enter via B3,
exit via B and
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line LIZI => exit cores via line L110 and into valve D: enter via D, exit via
D1 and line
Lin => line LH into valve H: enter via H1, exit via H into the gradient tank.
Water
previously stored in the gradient tank will be pushed through line Lp (shown
Fig. 27A)
and the radiator 3400 and back into the intermediate reservoir.
Steps (e) and (f): Intermediate temperature work medium flows from the
intermediate temperature reservoir via line Lm into valve B: enter via B3,
exit via B and
line Liti => exit cores via line LI20 and into valve D: enter via D, exit via
D2 and line
LE12 => line LN into the radiator unit 3400 and back to the intermediate
reservoir.
Steps (g) and (h): Intermediate temperature work medium flows from the
gradient tank into valve H: enter via H, exit via 112 and line 1431 into valve
B: enter via
Bl, exit via B and line LR1=> exit cores via line L120 and into valve D: enter
via D,
exit via D2 and line 4.2 => line LN into the radiator unit 3400 and back to
the
intermediate reservoir.
It is appreciated that valve A is equivalent to valve B, valve C is equivalent
to
D, and valve G is equivalent to H. Valves E and F are not equivalent, and are
each
responsible for a different reservoir ¨ valve E for the high temperature work
medium
reservoir and valve F for the intermediate temperature work medium reservoir.
With reference being drawn to Figs. 29A to 29C, it is observed that the
generator 3000 comprises four pressure vessels 3200, each comprising six cores
C1
through C6. It is also noted that the cores are inter-connected so as to form
a single flow
path. In particular, the cores are connected as follows:
- At the front end of the pressure vessel 3200, the cores C1 and C2 are
in fluid
communication via connector CC1_2, cores C3 and C4 are in fluid
communication via connector CC34 and cores C5 and C6 are in fluid
communication via connector CC5_6;
- At the rear end of the pressure vessel 3200, the cores are oppositely
connected: cores C2 and C3 are in fluid communication via connector CC2-3,
cores C4 and C5 are in fluid communication via connector CCa_5 and cores C6
and C1 are in fluid communication via connector CC64 (shown Fig. 30A);
Turning now to Figs. 30A to 30C, the generator 3000 is shown to have a middle-
point feed, i.e. the work medium enters the pressure vessels at the area
between two
consecutive pressure vessels 3200 rather than at the front of the first
pressure vessels
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3200 as in the previously described examples. It is also observed that all
four cores
32001 to 3200iv are inter-connected via pipes W1-29 W2_3 and W.
In particular, the line Liu is connected to the first core C1 of the first
pressure
vessels 3200.1 As a result, the flow path of the work medium is as follows:
- entering the
first core C1 of the first pressure vessel 32001, passing through
all the cores C1 through C6 thereof and exiting the sixth core C6 into
connector pipe W1-2;
- entering the first core C1 of the second pressure vessel 3200,11
passing
through all the cores C1 through C6 thereof and exiting the sixth core C6 into
connector pipe W2-3;
- entering the first core C1 of the third pressure vessel 3200m,
passing through
all the cores Ci through C6 thereof and exiting the sixth core C6 into
connector pipe W34; and
-
entering the first core C1 of the fourth pressure vessel 32001v, passing
through all the cores C1 through C6 thereof and exiting the sixth core C6 into
line L120-
Under the above arrangement, all twenty four cores of the pressure vessels
32001
to 32001v are in fluid communication with each other, forming a long flow
path.
Turning now to Figs. 31A and 31B, it is observed that the pressure vessels
32001
to 3200v are also in fluid communication with one another, i.e. the pressure
fluid within
each one of these vessels is in fluid communication with the pressure fluid in
the other
vessels. Fluid communication is provided by high-pressure connectors P1-29 P2-
3 and P1.
Oneof the four pressure vessels is fitted with an outlet high-pressure
connector PEND,
through which the high pressure medium is provided to the piston units 3270R,
3270L.
Turning now to Figs. 32A and 32B, the generator 3000 is shown to comprise
two gradient tanks 3600L, 3600R, each being in fluid communication with
pressure
vessels 3200 via appropriate piping. In particular, each of the gradient tanks
3600R,
3600L is fitted with a corresponding valve H, G respectively, configured for
providing
the gradient tanks 3600R, 3600L with heated/cooled work medium as previously
described with respect to steps (c) and (d) above.
Each of the gradient tanks 3600L, 3600R is of generally similar construction
to
the gradient tanks 600, 1600 and 2600 previously described. In particular, it
is formed
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with a flow labyrinth 3610 configured for maintaining a temperature difference
between
consecutive portions of work medium entering the gradient tank.
In addition, it is observed that each of the gradient tanks 3600R, 3600L is
connected at the top to a pipeline L00, configured for allowing a medium
contained
within the gradient tank to be pushed out when work medium enters the gradient
tanks
via valves H and G.
With reference being made to Figs. 33A and 33B, an accumulator arrangement
is disclosed generally designated as 3900, configured for storing some of the
energy
produced by the above generator. The accumulator arrangement 3900 comprises a
casing 3910 which contains a storing medium (not shown) configured for being
heated
by heating elements 3920 located within the casing 3910. Specifically, the
heating
elements 3920 are operated using some of the electrical power generated by the
generator 3000, so as to heat the storing medium.
As a result, throughout a given amount of time, the storing medium within the
casing 3910 is gradually heated to a temperature similar to that of the high
temperature
work medium within the high temperature reservoir 3110. Upon reaching such a
temperature, the valves A to G of the generator 3000 are selectively switched
so that
high temperature storing medium from the casing 3910 is circulated through the
generator 3000 instead of high temperature work medium from the high
temperature
reservoir 3110, defining an auxiliary operation mode.
In particular, the arrangement is such that in the auxiliary mode, steps (a)
and (b)
are performed thereby as follows:
Steps (a) and (b): high temperature storing medium flows from outlet GBouT of
the casing 3910 of the accumulator arrangement 3900 into valve E: enter via
El, exit
via E and line LK => line 1432 into valve B: enter via B2, exit via B and line
IA => exit
cores via line Lilo and into valve D: enter via D, exit via D3 and line L03
==> line LF
into valve F: enter via F, exit via Fl and line LF3 back to the casing 3910
through GBDI.
It is appreciated that while the generator 3000 operates in the auxiliary
mode,
the high temperature reservoir 3110 is circumvented by the piping as described
above,
and therefore does not take part in the operation of the generator 3000. This
allows
temporarily shutting down the A/C unit and thereby reducing overall power
consumption of the generator 3000.
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Turning now to Fig. 34, the A/C unit is in the form of a work medium sub-
system 3100 having a condenser end 3112, an evaporator end 3122, a compressor
arrangement CP and an expansion valve arrangement EV. The evaporator end 3122
is
exposed to the environment so as to be in thermal communication therewith and
absorb
heat therefrom. The condenser end 3112 is located within a housing
constituting the
high temperature reservoir 3110 containing the high temperature work medium
(not
shown).
The compressor arrangement CP and the expansion valve arrangement EV are
in fluid communication with both the condenser end 3112 and the evaporator end
3122,
and operate to generate a standard cooling cycle in which a carrier medium
(not shown)
is compressed by the compressor arrangement CP, passes through the condenser
end
3112 and expands via the expansion valve arrangement EV into the evaporator
end
3122.
It is observed that the compressor arrangement CP comprises four compressors
(CPI to CP4), and the expansion valve arrangement EV comprises corresponding
four
expansion valves (EVi to EV4), to form four working couplets CP1-EVI, CP2-EV2,
CP3-EV3 and CP4-EV4. Each of the compressors CPi to CP4 has a different power
consumption and provides a different compression ratio, and each of the
expansion
valves EVI to EV4 are respectively configured for providing a different
expansion
degree.
The arrangement is such that the work medium sub-system 3100 is operated by
at least one couplet at a time, the couplet being chosen according to the
required
temperature difference between the high temperature reservoir and the cold
temperature
reservoir, and according to the temperature of the outside environment.
The CP-EV couplets can be configured for operation during specific times of
day/year. More specifically, one couplet can be configured for operation
during summer
days, another for summer nights, a third for winder days and a fourth for
winter nights,
providing for a more efficient operation of the generator 3000.
In addition, the above arrangement provides at least three backup compressors
when one of the four compressors malfunctions. For example, if the summer
night
compressor malfunctions, the winter day compressor can be used while the
summer
night compressor is being repaired.
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Turning now to Figs. 35A to 35E, a linear gear mechanism generally designated
as 3300 is shown, replacing the previously described power assembly 300. The
linear
gear 3300 comprises a housing 3310 within which a rack 3320 is configured for
engagement with pinion arrangements 3340R, 3340L of the gear mechanism 3300.
Each of the ends 3310R, 3310L is formed with a corresponding opening 3312R,
3312L respectively, being in fluid communication with an auxiliary work medium
pumped into and out of the housing 3310 during operation of the generator 300
owing
to pressure changes in the pressure medium contained in the pressure vessels
3200R,
3200L. As a result, the rack 3320 is caused to reciprocate under alternating
pressure
between a first end 3310R and a second end 3310L of the housing 3310.
Due to the engagement of the threaded portion 3324 of the rack 3320 with the
pinions 3348R, 3348L of the pinion arrangements 3340R, 3340L, reciprocation of
the
rack 3320 within the housing 3310 entails revolution of the pinions 3348R,
3348L
about their axis, thereby converting linear movement into rotational movement,
which is
eventually transferred to a drive shaft 3332.
It is observed that each of the shafts 3342L, 3342R carrying the pinions
3348R,
3348L is also fitted with bearings 3345L, 3345R at both ends thereof, so that
rotation of
the pinions 3348R, 3348L is uni-directional only. Specifically, and with
particular
reference to Fig. 35C, when the rack 3320 displaces to the left, the shaft
3342R on
which the pinion 3348R is mounted, revolves about its axis, entailing
revolution of the
pinion 3348R. However, at the same time, while shaft 3342L on which the pinion
3348L is mounted also revolves about its axis, the pinion 3348L itself remains
stationary due to the bearing 3345L. Similarly, during displacement of the
rack 3320 in
the opposite direction, the pinion 3348L revolves while the pinion 3348R
remains
stationary.
In order to stabilize the shafts 3342L, 3342R, yet still allow them to freely
rotate
during displacement of the rack 3320, additional bearings 3344L, 3344R are
fitted to
each of the shafts 3342L, 3342R.
Thus, since both pinions 3348R, 3348L are engaged with a gear 3338 of the
generator shaft, any displacement of the rack 3320, in any of the two
directions, will
entail revolution of the gear 3338 and consequently of the shaft 3332.
Revolution of the
shaft 3332 can be converted to electricity in any known manner.
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In addition, in order to stabilize the rack 3320 in its reciprocating movement
within the housing, the gear mechanism 3300 is provided with two delimiting
rollers
3350R, 3350L, each being positioned in front of a respective pinion
arrangement
3340L, 3340R respectively. The rollers 3350R, 3350L, are configured for
engaging the
rack so as to delimit its movement only to the axial direction.
Each of the delimiting rollers 3350R, 3350L comprises a shaft 3352R, 3352L
respectively, on which a roller member 3356R, 3356L is mounted. In addition,
each end
of the shaft 3352R, 3352L is fitted with bearings 3354R, 3354L respectively,
which are
similar to the bearings 3344L, 3344R of the pinion arrangements 3340R, 3340L.
In
assembly, the roller members 3356R, 3356L are engaged with a non-threaded
portion
3322 of the rack 3320, so as to allow only axial movement thereof.
It is also noted that the drive shaft 3332 itself, is also provided with a
bearing
3335, allowing it to freely rotate by inertia, even if the rack 3320 has
already stopped
reciprocating.
It is appreciated that the rack and pinion arrangement of the linear gear
assembly
3300 provides for several significant advantages:
- any displacement of the rack 3320 entails revolution of the drive
shaft 3332,
even if a stroke in one direction is not similar in length to the stroke in
the
opposite direction;
- Due to the bearing 3335 of the drive shaft 3332, upon a single stroke of the
rack 3320 in one direction, and after the rack as finished its movement in
that direction, the drive shaft continues to further revolve, thus allowing to
generate additional power even within movement of the rack;
- The linear gear arrangement 3300 is more accurate than the previously
described power assembly due to its simple constructions and use of a single
rack 3320;
- It provides a much higher transmission ratio than the previously
described
power assembly; and
Turning now to Figs. 36A to 36D, yet another example of a generator is shown
generally designated as 4000. In essence, the generator 4000 is similar to the
previously
described generator 3000, however with several differences, some of which are
as
follows:
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- Comprises only two pressure vessels 4200R, 4200L (not eight), each being
longer that the pressure vessels 3200;
- Operates on front feed and rear egress, i.e. work medium enters the
pressure
vessels 4200R, 4200L from a front end thereof and exits at a rear end
thereof;
- Propulsion of the work medium through the generator is performed by
pumps;
- Provided with a combined valve 4140R, 4140L configured for having two
operational modes;
- Comprises an accumulator arrangement 4900 divided into two compartments
and having a heat pump operating therebetween; and
- The gear mechanism 4300 thereof comprises roller-gears instead of
regular
gears.
With reference to Fig. 36A, it is observed that the generator 4000 comprises a
work medium sub-system 4100, pressure vessels 4200, a generator assembly 4300,
a
radiator 4400, gradient tanks 4600L, 4600R and an accumulator arrangement
4900.
Turning now to Figs. 37A to 37D, the generator 4000 comprises four core
distribution arrangements 4140L, 4140R (two of each), each pressure vessel
4200 being
fitted with a core distribution arrangement 4140L, 4140R at each end thereof.
It is noted
that each of the pressure vessels 4200L, 4200R comprises five cores 4220, and
each of
the valves 4140L, 4140R is connected to the cores 4220 via five distribution
lines (e.g.
LA6 to LAio for the front end of the left pressure vessel 4200L as shown in
Fig. 37B),
and five corresponding regulator valves (e.g. A6 to A10).
It is also noted that the cores 4220 of each pressure vessel 4200L, 4200R are
inter-connected to form a single flow path via connectors (e.g. LAC7-8 and
LAC9-10 for the
front end of the left pressure vessel 4200L as shown in Fig. 37B and LDC8-9
and LDC10-6
for the rear end of the left pressure vessel 4200L).
The distribution arrangements 4140L, 4140R and the regulator valves are design
to allow selective parallel/linear flow through the cores 4220. In other
words, the cores
4200 can operate in parallel, i.e. unidirectional flow of work medium through
all cores
4220 from one end of the pressure vessel 4200 to the other, or alternatively,
form a
single (and considerably long) flow path through which the work medium
progresses.
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As will become apparent with respect to operation of the generator 4000, it
can
be beneficial, at certain stages of operation thereof to use a parallel flow
configuration,
while during other stage is can be beneficial to use a linear flow
configuration.
The different stages of operation of the generator will now be described with
reference to Figs. 37A to 37D. The steps are provided below starting from an
initial
position of the pressure vessels 4200L, 4200R in which the pressure medium
within the
right pressure vessel 4200R has reached its maximal temperature (e.g. 42.5 C),
while
the pressure medium within the left pressure vessel 4200L has reached its
minimal
temperature (e.g. 7.5 C). The stages will be described below with respect to
the right
pressure vessel 4200R, understanding that the same applies to the left
pressure vessel
4200L at a phase shift:
High temperature energy absorption and storage: Intermediate temperature work
medium (e.g. 25 C) flows from the intermediate temperature reservoir via line
LH into
valve B: enter via B2, exit via B into pump 4150R and through there to the
distribution
arrangement 4140R into line LB6 => pass through all cores (linear flow
configuration)
=> exit cores via line Lcio and into valve C: enter via C, exit via Cl and
line La. =>
into valve G: enter via G2 into the gradient tank. Water previously stored in
the
gradient tank will be pushed through line LBGL (shown Fig. 37D) and back into
the
intermediate reservoir 4130 through the radiator 4400. At this point, the
hottest portion
of the intermediate work medium in the gradient tank 4600R (top of the tank)
can be
about 40 C and the coldest portion of the intermediate work medium in the
gradient
tank 4600R (bottom of the tank) can be about 27.5 C. The temperature of the
pressure
medium at this point can be about 30 C.
High temperature energy recovery: Intermediate temperature work medium
flows from the gradient tank 4600R into valve G: enter via G, exit via G1 and
line LGI
(LAO into valve A: enter via Al, exit via A and into pump 4150L and through
there to
the distribution arrangement 4140L into line LA6 => pass through all cores
(linear flow
configuration) => exit cores via line Lino and into valve D: enter via D, exit
via D2 and
line LB2 => into the radiator unit and back to the gradient tank 4600L. During
this step,
the work medium in the right gradient tank 4600R gradually heats the pressure
medium
in the left pressure vessel 4200L while the intermediate work medium in the
left
gradient tank 4600L (ranging between about 22.5 C to 10 C) gradually cools the
pressure medium in the right pressure vessel 4200R to about 15 C.
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Substantial cooling: low temperature work medium (e.g. 0 C) flows from the
low temperature reservoir via line La into valve B: enter via B4, exit via B
into pump
4150R and through there to the distribution arrangement 4140R into line LB6 =>
pass
through all cores simultaneously (parallel flow configuration) => exit cores
via all line
LC6-10 and into valve C: enter via C, exit via C3 and line Lc3 => back into
the low
temperature reservoir 4120, optionally through the radiator 4400 (even
partly). This can
reduce the temperature of the pressure medium in the right pressure vessel
4200R to
about 7.5 C.
low temperature energy absorption and storage: Intermediate temperature work
medium (e.g. 25 C) flows from the intermediate temperature reservoir via line
LH into
valve B: enter via B2, exit via B into pump 4150R and through there to the
distribution
arrangement 4140R into line LB6 => pass through all cores (linear flow
configuration)
=> exit cores via line Lcio and into valve C: enter via C, exit via Cl and
line Li =>
into valve G: enter via G2 into the gradient tank. Water previously stored in
the
gradient tank will be pushed through line L0GL (shown Fig. 37C) and back into
the
intermediate reservoir 4130 through the radiator 4400. At this point, the
coldest portion
of the intermediate work medium in the gradient tank 4600R (top of the tank)
can be
about 10 C and the hottest portion of the intermediate work medium in the
gradient tank
4600R (bottom of the tank) can be about 22.5 C. The temperature of the
pressure
medium at this point can be about 20 C.
low temperature energy recovery: Intermediate temperature work medium flows
from the gradient tank 4600R into valve G: enter via G, exit via G1 and line
LG1 (LA!)
into valve A: enter via Al, exit via A and into pump 4150L and through there
to the
distribution arrangement 4140L into line LA6 => pass through all cores (linear
flow
configuration) => exit cores via line L06-10 and into valve D: enter via D,
exit via D2
and line L02 => line LI0 into the radiator unit and back to the gradient tank
4600L.
During this step, the work medium in the left gradient tank 4600L gradually
heats the
pressure medium in the right pressure vessel 4200R to about 35 C while the
intermediate work medium in the right gradient tank 4600R (ranging between
about
22.5 C to 10 C) gradually cools the pressure medium in the left pressure
vessel 4200L
to about 15 C.
Substantial heating: high temperature work medium (e.g. 50 C) flows from the
high temperature reservoir 4110 via line L111 into valve B: enter via B3, exit
via B into
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pump 4150R and through there to the distribution arrangement 4140R into line
LB6 =>
pass through all cores simultaneously (parallel flow configuration) => exit
cores via line
Lcio and into valve C: enter via C, exit via C4 and line LC4 => back into the
high
temperature reservoir 4110 optionally through the radiator 4400 (even partly).
This can
increase the temperature of the pressure medium in the right pressure vessel
4200R to
about 42.5 C.
Each of the above described six steps can last for a predetermined amount of
time, e.g. five seconds. However, under other arrangements, it can be
beneficial that
each steps lasts for a different period of time.
In order to control the operation of the generator, a controller can be
provided
which is configured to monitor any one of the following:
- Flow rate through the piping of the generator 4000;
- The operational mode of the valve (which are open/closed, parallel/linear
configuration etc.); and
- The duration of each step.
With reference being drawn to Fig. 38, the generator 4000 comprises a pressure
system which is similar to that previously described with respect to the
generator 3000.
Each pressure vessel 4200L, 4200R is fitted with a work piston 4270L, 4270R
and a
compensation piston 4280L, 4280R respectively. Each of the work pistons 4270L,
4270R is attached via lines 4274L, 4274R to the housing of the gear mechanism
4300,
so as to eventually cause reciprocation of the rack 4320 (shown Fig.47)
therein.
Turning to Fig. 39, a work medium sub-system 4100 is shown being in the form
of a heat pump which is generally similar to the sub-system 3100 previously
described,
with the difference being that it does not make use of four different
compressors but
rather a single screw compressor which can operate under varying compression
ratios
and power consumption, and being thus able to adjust its operation to the
conditions of
the environment.
Turning now to Figs. 40A to 40D, the generator 4200 further comprises an
accumulator arrangement 4900, which is similar in purpose to the accumulator
arrangement 3900 previously described. However, it is observed that the
accumulator
arrangement 4900 comprises a high temperature compartment 4910H and a low
temperature compartment 4910c, and is connected to an auxiliary heat pump 4930
of
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which the condenser end 4932 is located in the first compartment 4910H and the
evaporator end 4934 is located in the first compartment 4910c.
In particular, each of the compartments 4910H, 4910c, has a respective inlet
GHI, GCI and outlet GHO, GCO, to which corresponding inlet and outlet lines
LGHI,
LGCI, LGHO, LGco are attached respectively. It is observed that the outlet GHO
is
located at a top end of the compartment 4910H, while the inlet Gill is located
at a
bottom end of the compartment 4910H. In contrast, the outlet GCO is located at
a
bottom end of the compartment 4910c, while the inlet GCI is located at a top
end of the
compartment 4910c.
The above arrangement allows for withdrawing high temperature work medium
from a high temperature zone of the high temperature compartment 4910H, and
returning the work medium to a low temperature zone of the high temperature
compartment 4910H. Correspondingly, this arrangement allows withdrawing low
temperature work medium from a low temperature zone of the low temperature
compartment 4910c, and returning the temperature work medium to a high
temperature
zone of the low temperature compartment 4910c.
Thus, some of the energy provided by the generator can selectively be provided
to the auxiliary heat pump 4930 instead of simple heaters (as in the
previously described
example), thereby providing not only an auxiliary high temperature reservoir
at 4910H,
but also yielding a low temperature reservoir at 4910c.
In operation, once the auxiliary work medium in the compartments 4910H and
4910c reaches temperatures which are similar to those of the high/low
temperature
reservoirs respectively, it can be used in operation of the generator while
the main heat
pump temporarily, ceases its operation.
In addition, the high temperature compartment 4910H is provided with heaters
which are configured for directly heating the storage fluid contained within
the
compartment 4910H. It is appreciated that during operation of the auxiliary
heat pump
4930, the storage medium within the high/low temperature compartment can reach
a
heating/cooling limit (i.e. reaching a maximal/minimal temperature limit). In
such an
event, the operation of the auxiliary heat pump 4930 can be interrupted, and
heater are
then used to further heat the storage medium in the high temperature
compartment
4910H.
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Under the above arrangement, once the auxiliary heat pump 4930 is interrupted,
the work medium in the high temperature compartment 4910H can be used as a
high
temperature work medium, while the work medium in the low temperature
compartment 4910c is used as the low/intermediate work medium.
Turning now to Figs. 41A to 41E, the structure of the pressure vessel 4200 and
the cores therein will be described. The pressure vessel 4200 comprises and
external
housing 4222 accommodating therein the five cores 4220. The pressure vessel
4200 is
also provided with a sealing arrangement comprising seals 4242, 4244 and 4246,
configured for preventing leaks from the pressure vessel 4200, and maintaining
a high
pressure of the pressure medium.
Each core 4220 is fitted, within the pressure vessel 4200 with a stirring
assembly
4230, configured for revolving about the core 4220 for providing better mixing
of the
pressure medium and thereby a more efficient heat transfer between the
pressure
medium and the work medium flowing within the cores 4220 during operation of
the
generator 4200.
The stirring assemblies 4230 are generally similar to those previously
described,
and comprise a drive gear 4234 engaged with a center gear 4232 mounted on a
central
shaft 4235 and driven by an external motor.
It is also observed that since the pressure vessel 4200 is considerably long
(its
length is much greater than its nominal diameter), support arrangements 4290
are
provided along the pressure vessel 4200 configured for supporting the cores
4220. In
essence, these support arrangements 4290 comprise support discs 4293 formed
with
holes for receiving therethrough the cores 4220. Each such support arrangement
4290 is
also fitted with sealing members 4295, 4297 for preventing any undesired
leakage.
Reference is now made to Figs. 42A to 45C, in which various examples of core
structures are shown. It is noted that these examples show the structure of
the front end
of the core.
With particular reference being made to Figs. 42A to 42E, a core 4220' is
shown
comprising a core body 4221' and a central core cavity 4222' accommodating a
static
flow axle.
It is observed that closer to the front end, the first portion 4223' of the
flow axle
is smooth and does not occupy the entire cross-section of the cavity 4222'. In
addition, it
is observed that the core body 4221' at the front portion is formed with a
roughened
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surface 4226' only on an inner side thereof To the contrary, the second
portion 4224' of
the flow axle is formed as a spiral occupying the entire cross-section of the
cavity 4222'.
In addition, it is observed that the core body 4221' at the second portion is
formed with
a roughened surface 4226' both on an inner and on an outer side thereof It is
also
observed that the flow axle is hollow and is formed with inner channels 4223o.
It is noted that the ridges formed with the roughened surface 4226' both on an
inner and on an outer side thereof are aligned with one another, so that a
peak of a ridge
on the outer surface is aligned against a trough on the inner surface. This
provides the
core with a uniform thickness at any given cross-section taken perpendicular
to an axis
of the core.
One reason for the above design lies in the location of the first portion
within the
pressure vessel. As can be observed from Figs. 41A to 41E, the first portion
of the core
is located at the area of the seals 4242, 4244, 4246, thereby not taking place
in the heat
exchange process with the pressure medium. As such, it is not required to have
the same
structure as the second portion, and costs can be reduced by maintaining it in
a
simplified design as shown.
With particular reference being drawn to Fig. 42D, it is observed that the
roughened surface 4226' is in the form of teeth which do not extend completely
radially
from the center of the core. Rather, the teeth extend at a slight angle, so
that the work
medium flowing through the core 4220 is swirled by the direction of the teeth
and
penetrates in between the teeth, allowing for a better heat exchange process.
Attention is now drawn to Fig. 43, in which a core 4220" is shown having a
similar design to that shown in Figs. 42A to 42E, with the difference being
that the first
portion of the core 4220" is isolated using an isolating sleeve 4227", so that
work
medium passing through the first portion doesn't waste its energy on
heating/cooling
that portion of the core which does not participate in the heat exchange
process.
Turning now to Figs. 44A to 45C, two additional cores 4220" and 42201v are
shown, being of similar design to that of the previously described cores 4220'
and 4220"
(similar elements have been designated with similar reference numerals with
the
addition of corresponding primes). The main difference between the cores 4220"
and
4220I' and the previously describe cores lies in the design of the roughened
surface,
which is in the form of rings rather than in the form of conical/pyramidal
protrusions.
Such a design is slightly easier and less costly to manufacture.
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Turning now to Figs. 46A to 46D, an assembly of the pressure vessel 4200 is
shown. It can be observed that the cores 4220 and all the mechanical elements
relating
thereto (fan arrangements, gears, drive-shaft etc., herein 'core assembly')
are all
enclosed by sleeve members 4200s. The sleeve members 1200s are formed of a
rigid
material and have a sufficient thickness to provide mechanical support to the
entire core
assembly. For example, the sleeve member 4200s can be made of steel and have a
thickness of several millimeters.
Under the above arrangement, it is possible to first fully assembly the entire
core
assembly and enclose it with the sleeve members 4200s and only then slide the
enclosed
assembly into the pressure vessel casing 4200. In addition, for servicing and
maintenance purposes, it is possible to remove the enclosed core assembly from
the
pressure vessel 4200 (for example by sliding it out), remove the appropriate
sleeve
member 4200s and perform the required maintenance.
It is also observed that the sleeve members 4200s have a semi-circular cross
section (i.e. have a half-pipe shape), and when two such members enclose a
section of
the core assembly, there remains a gap G therebetween (see Figs. 46C, 46D).
The gap G
provides fluid communication of the pressure medium between an inner zone
defined
between the sleeve members 4200S and the core assembly, and an outer zone
between
the sleeve members 4200S and casing 4222 of the pressure vessel 4200.
It is also noted that the seal arrangement comprises seals 4244 which are
essentially made of three separate pieces, and once inserted into the sleeve
4220s and
mounted onto the cores 4220, these are pressed closer to one another to
provide the
necessary seal for the pressure vessel 4200.
Turning now to Fig. 47, an improvement of the gear mechanism 4300 is shown,
in which the gear mechanism 4300 comprises roller-pin pinions 4348R, 4348L
which
are engaged with the rack 4320, and gears 3349R, 3349L which are engaged with
the
drive shaft 4332. Roller-pin pinions 3348R, 3348L provide a much higher
efficiency
over regular gear engagement due to an increased contact surface and
simplified teeth
shape. In all other aspects, the gear mechanism 4300 operates much the same
way.
However, the roller-pin pinions 4348R, 4348L provide the gear with the
advantage of reduced friction, since the roller-pin pinions 4348R, 4348L are
free to
revolve about their own axis.
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Turning to Figs. 48A to 48C, another example of a work medium sub-system
4100' is shown in which each of the high/low temperature reservoirs 4110, 4120
respectively, has been divided into several compartments. The compartments are
in
fluid communication with one another, yet they still delay mixing between the
work
medium exiting the sub-system 4100 towards the pressure vessels 4200L, 4200R,
and
work medium entering the sub-system 4100 after performing its heat exchange
process.
Such an arrangement can provide a more efficient configuration of the
generator.
Turning now to Figs. 49A to 49H, a pressure vessel 4200' is shown having a
length L which is much greater than the diameter D thereof The pressure vessel
4200'
also comprises support assemblies 4920' as described previously with respect
to Figs.
41A to 41D, however, contrary thereto, in the present example each core 4220'
is not a
single core, but rather is formed of core segments. Each two consecutive
segments are
adjoined with one another at the support assembly 4290' located therebetween.
In order to adjoin two core segments, an insert is introduced between the
segments and is respectively received within the cores so as to provide fluid
communication therebetween. It is also observed from Fig. 49B that the core
segments
are fully contained within the pressure vessel and that at the ends of the
pressure vessel,
only the inserts are protruding. The insert 4299' itself can be made of a
material not
requiring high heat transfer coefficients, e.g. plastic.
When adjoined at the support assembly 4290' by the insert, two consecutive
core
segments have a certain degree of freedom for movement with respect to one
another. In
order to reduce the displacement of the cores with respect to one another, the
support
assembly 4290' comprises bearings 4293' which allow the fan arrangements of
the cores
to freely revolve about themselves.
With particular reference being drawn to Fig. 49D, the bearings 4293' are of a
self-aligning type, in which the housing 4294' of the bearing balls 4295' is
of a curved
shape, providing the cores, and the fan arrangements mounted thereon, with a
certain,
yet controllable, degree of freedom.
With reference being made to Figs. 49F and 49G, the support assembly 4290' is
more clearly shown having the shape of a disc formed with several openings,
corresponding in number to the number of the cores and the drive shaft DS.
Attention is now drawn to Fig. 49H, in which the sleeve member 4200s' is
shown attached to the core assembly by bolts 4285 via an opening 4287. It is
observed
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that the opening 4287 is not circular, but rather slightly prolonged. It
should be
understood that the enclosed core assembly is first introduced into the
pressure vessel
4200', and only then is the pressure vessel pre-loaded with the high pressure
(e.g. 6000
atm.). Under such pressure, the pressure vessel may elongate slightly, and
therefore the
openings holding the bolts should provide for a certain degree of freedom.
This
arrangement holds true not only for bolts of the sleeve member 4200s' but for
other
bolted elements within the pressure vessel.
In addition, at least for a majority of bolt attachments within the pressure
vessel
(i.e. attachments having a bolt or screw threaded into a threaded hole), it
can be
beneficial to form a hole within the thread which provides fluid communication
between the portion of the threaded hole not occupied by the bolt, so as to
equalize the
load on both sides of the bolt (its head and it end), in order to reduce sheer
forces.
With respect to all of the above examples, configurations and arrangements of
the generator of the present application, the following calculations can
apply:
Basic data:
- in general, the generator 4000 can be configured to provide
approx. 2.24
times the input power, i.e. WOUTPUT = 2.24WHOUT. Naturally, if some of the
output power is provided back to the operation of the generator, the net
output power is about 1.24WiNpuT (2.24WINPuT - WINPUT);
- the average efficiency of standard heat pumps can be in the range of 50-
70%, i.e. for a COP 10 which should theoretically provide WOUTPUT =
lOWINpuT, the actual output is in the range of 5-7WINpuT. For purpose of this
calculation, an efficiency of 55% will be assumed;
- the COP chosen for the present calculation is 8 and the temperature
difference between the high temperature work medium and the low
temperature work medium is about 40 C;
- ;
- the generator can convert approx. 30% of the heat provided to the
pressure
medium into output energy via the motor assembly, i.e. for an amount of
heat Q provided to the pressure medium, approx. 0.3Q is converted to actual
output (based on the properties of Ethyl Bromide under a pre-loading of
about 6000 atm.);
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- the
energy recovery arrangement provides for a recovery of approx. 50-66%
of the remainder of the amount of heat within the pressure medium;
Under the above parameters, the generator can operate as follows:
Providing 1.00 kWh of electrical energy in the heat pump of the generator (to
generate the 40 C difference between the high and the low temperature
reservoir) will
provide for 4.40 kWh of heat energy, which is the amount of heat provided to
the
pressure medium. Theoretically a 40 C temperature range at appropriate
temperatures
and a COP 8 should yield more power, however, due to the 55% efficiency of the
heat
pump the output is lkWh x 8 x 55% = 4.40 kWh.
Since only 30% of the heat provided to the pressure medium is eventually
converted to output energy, the above calculation yields approx. 1.32 kWh of
electrical
energy. This yields that the remainder of the heat within the pressure medium
is about
4.40 ¨ 1.40 = 3.00 kWh (1.4 is used instead of 1.32 to take into account
various heat
losses within the system).
Recovering 60% of the remainder of the amount of heat within the pressure
medium yields a recovery of 1.80 kWh (3.00x0.6 = 1.80 kWh). Therefore, is out
of 4.40
kWh provided to the pressure medium 1.80 is recovered, this yields that the
additional
heat that should be provided to the pressure medium with each operation cycle
of the
generator is 4.40 - 1.80 = 2.60.
In other words, in each cycle, an amount of heat of approx. 2.60 kWh is
provided by the heat differential module and an amount of heat of approx. 1.80
is
provided by the recovery arrangement, yielding the amount of heat of 4.40 kWh
which
is required for operation of the generator at a production of 1.32 kWh.
Under the above arrangement, in order to provide the required 2.60 kWh of
heat,
the heat pump of the heat differential module now requires only 0.59 kWh
(rather than 1
kWh), under the COP = 8 as suggested above. This yields that at startup of the
operation
of the generator, i.e. at the first cycles of operation thereof, 1 kWh is
provided as input
power, but is quickly reduced to 0.59 kWh during continuous operation of the
generator
once the recovery arrangement takes effect.
In summary, in continuous operation of the generator (after startup), in order
to
provide a 1.32 kWh output energy, the generator requires a constant feed of
0.59 kWh,
thereby yielding the input/output ratio of 1.32/0.59 = 2.24:1.
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It should be noted that it is possible to operate the generator under a lower
temperature range, for example 30 C rather than 40 C, thereby possibly
increasing the
net output for each operation cycle of the generator (1.67 kWh instead of 1.32
kWh).
However, this may also yield a lower number of cycles per hour, thereby
reducing the
overall energy production of the generator.
The above calculations are provided with respect to specific parameters which
depend on materials, COP, temperature range etc., and taking into account
various
losses, heat leaks, compensation factors etc.. These parameters can be varied
to achieve
different end results by the operation of the generator which may exceed (and
also
possible be lower than) the results presented above.
Those skilled in the art to which subject matter of the present application
pertains will readily appreciate that numerous changes, variations, and
modification can
be made without departing from the scope of the subject matter of the present
application, mutatis mutandis.
