Note: Descriptions are shown in the official language in which they were submitted.
Field
This invention relates to devices and improved methods for converting
thermal energy into mechanical energy. In particular, this invention relates
to improving the efficiency of a heat engine over a wider range of
temperatures and enabling an energy storage synergy.
Background
Thermal energy exists in all environments and is often produced as a by-
product in industrial and commercial processes. Natural and waste thermal
energy may be used as an input to a heat engine to produce mechanical
energy; for instance, as an input to an electrical generator or hydraulic
motor. The efficiency of the heat engine is an important factor in
determining the economic viability of building a heat engine to use naturally
existing, or waste thermal energy as an input. Efficiency is not only defined
as
thermodynamic efficiency, but as capital cost per Kwh.
Existing thermal engines such as Organic Rankine Cycles are not capable of
reaching the lower heat sink temperatures and making use of their thermal
benefits as they are impeded by change of state working fluids. Likewise,
Stirling engines have only novelty value at low temperature differentials.
A second factor affecting heat engines is that due to daily consumption
patterns, it is economically advantageous to not produce and use electricity
during periods of low consumption and to make electricity available during
periods of high consumption when electricity prices and demand are high.
Many generating sources generate during times when the demand is not
aligned with the supply. For example, wind generation can be most
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productive at night, but demand may be highest in the day, particularly on
hot summer days when air-conditioning demand is high but there may not be
any wind. Solar power generation is at the mercy of daylight hours and even
then, cloud cover often interferes with its output.
Due to these impediments which hinder the use of more renewable energy,
there have been a number of technologies developed to store the energy
produced during inconvenient hours, relative to demand.
Some examples of storage include batteries, hydrogen, flywheels, pumped-
hydro, compressed air, and gravity.
Generally, the cost of storing energy is much higher than the cost to produce
it; and necessitates its use when the hourly market price per Kwh is at its
highest, and the cost of storing it at its lowest.
It is therefore desirable to develop storage and generation technologies that
minimize the gap between the cost to produce and the cost of storage.
The present invention describes a dual output thermal engine that utilizes a
heat engine in combination with a liquid nitrogen or liquid natural gas
expander engine which operate synergistically to produce electricity
economically during periods of high demand, thereby reducing the cost of
producing backup energy in times of peak demand. Additionally, to provide a
method of providing liquid nitrogen or hydrogen from naturally occurring
thermal differentials or wasted industrial heat by means of benign electricity
production, which is then used to produce hydrogen or facilitate other
storage methods.
Brief Description of the Drawings
In drawings which illustrate by way of example only a preferred embodiment
of the invention,
Figure 1 is a schematic illustration of a preferred embodiment of the present
invention including the dual output combined cycle
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Figure 2 shows the dual acting hydraulic accumulator arrangement, valves,
transmission, and generator configuration of the present invention;
Figure 3 shows the dual acting hydraulic accumulator arrangement in valve
position 1;
Figure 4 shows the dual acting hydraulic accumulator arrangement in valve
position 2;
Figure 5 is a schematic illustration of the liquid nitrogen or liquid natural
gas
expander engine or 300;
Figure 6 shows the hydraulic accumulator arrangement in valve position 1 of
the expander engine process;
Figure 7 shows the hydraulic accumulator arrangement in position 2 of the
expander engine process
Detailed Description
In an implementation, a Heat Engine is provided that is operable to extract
thermal energy between a first thermal source and a second thermal source
and converting this energy into mechanical energy that can be used to
generate electrical energy or drive compressors for energy storage, or direct
use, or to feed into a power grid. The thermal sources are put in fluid
communication with two vessels containing a gas under pressure. The
thermal sources have thermal values that are different than the thermal
values of the vessels. The thermal sources are used to alternately increase
the temperature and pressure in one of the vessels and decrease the
temperature and pressure in the other vessel. A pressure driven pair of
hydraulic accumulators are activated in a single direction by the resulting
pressure and mass released by the first vessel and the suction from the
second vessel. During the process a partial re-distribution of the mass in the
heated vessel to the cooled vessel takes place. A reversal of the heating and
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cooling cycle causes the pair of hydraulic accumulators to move in the
opposite direction. The motions of both actions drive a hydraulic motor
which in turn drives a generator or compressor.
An apparatus for converting a differential in thermal energy between a first
thermal source having a thermal conducting fluid and a second thermal
source having a thermal conducting fluid, the apparatus comprising:
= a first vessel for containing a gas under pressure, the first
vessel being in fluid communication with said first and second
thermal sources;
= a second vessel for containing gas under pressure, the second
vessel being in fluid communication with said first and second
thermal sources;
= a multiple of two vessel modules in series which comprises a
preferred embodiment
A plurality of cooperating valves for alternately regulating a flow of thermal
conducting fluid from the first and second thermal sources to the first and
second
vessels, the plurality of cooperating valves alternating between the first and
second
operating positions, the plurality of cooperating valves permitting a flow of
thermal
conducting fluid from the first thermal source to the first vessel and from
the second
vessel in first operating position, the plurality of cooperating valves
preventing a
flow of thermal conducting fluid from the first thermal source to the second
vessel
and from the second thermal source to the first vessel in the first operating
position,
the plurality of cooperating valves permitting a flow of thermal conducting
fluid
from the first thermal source to the second vessel and from the second thermal
source to the first vessel in the second operating position, the plurality of
cooperating valves preventing a flow of thermal conducting fluid from the
first
thermal source to the first vessel and from the second thermal source to the
second
vessel.
Date Recue/Date Received 2020-08-31
A pressure driven pair of hydraulic accumulators in fluid communication
with the first and second vessels whereby the hydraulic accumulators are
driven
into reciprocating motion between a first position and a second position by
alternating positive pressure and negative pressure from the first and second
vessels wherein positive pressure from the first vessel coupled with negative
pressure from the second vessel when the plurality of cooperating valves is in
the
first operating position drives the accumulators to the first position and
negative
pressure from the first vessel coupled with positive pressure from the second
vessel
when the plurality of cooperating valves is in the second operating position
drives
the actuator or hydraulic accumulators to the second position.
According to another aspect there is provided a method for converting a
differential in thermal energy to mechanical energy comprising the following
steps:
= providing first and second vessels containing a gas under pressure,
the gas under pressure being of a temperature T;
= providing a first thermal source and a second thermal source, the first
thermal source housing a thermal transfer fluid of a temperature above T and
the
second thermal source housing a thermal transfer fluid of a temperature below
T.
= delivering the thermal transfer fluid from the first thermal source to
the first vessel thereby raising the pressure of the gas in the first vessel;
= delivering the thermal transfer fluid from the second thermal source
to the second vessel thereby lowering the pressure of the gas in the second
vessel;
= delivering gas under pressure from the first vessel to a pressure
activated pair of hydraulic accumulators and applying suction from the second
vessel to the pressure activated piston or hydraulic accumulators thereby
causing
the pressure activated piston or hydraulic accumulators to move in a first
direction.
The hydraulic accumulator embodiment/arrangement of the nitrogen or LNG
expander engine provides a method for extracting the heat from the heat sink
of the
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heat engine and using it in the process of returning the liquid nitrogen or
LNG to the
gaseous state and harnessing the expansion that occurs in the process.
The integration of both parts provide a novel integrated system that creates a
synergy of two power generation methods that increases the overall efficiency
of
the two methods compared to the sum of the individual efficiencies on their
own
without being integrated.
In an implementation, a thermal engine is implemented in combination with
a liquid nitrogen or liquid natural gas (LNG) expander engine. The heat engine
and
the expander engine are combined by using the liquid nitrogen or LNG source of
the
expander engine as a heat sink for the heat engine, allowing the system to use
a
lower temperature heat source and improve the Carnot efficiency of the system
as a
whole.
In an implementation, the liquid nitrogen source may be re-supplied using
low cost energy during off-peak periods and may be expanded through the
expander engine at another time during periods of high energy consumption,
improving the economics of the system. Accordingly, the liquid nitrogen source
further provides for an energy storage that allows for improved energy
generation
efficiency during peak periods of consumption.
In an implementation, natural gas that has been liquified can be used as the
heat sink for the heat engine and expanded through the expander engine to
generate
electricity thereby recovering much of the cost of the liquefaction process.
In an aspect, the expansion engine comprises at least one pressure vessel for
receiving the liquid nitrogen or liquid natural gas and storing them in a
gaseous
state, and releasing the stored nitrogen or liquid natural gas in a gaseous
state and
releasing the stored gas as a second working fluid into a second pressure
driven set
of hydraulic accumulators which drive the hydraulic motor connected to an
electrical generator or compressor.
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An apparatus is provided for converting a differential in thermal energy
between two thermal sources into mechanical energy that can be used for a wide
range of applications known to a person skilled in the art including the
generation
and storage of electrical energy, or storing the means to enable the
production of
electrical energy in the form of liquid nitrogen or liquid natural gas as a
heat sink
enhancer.
An embodiment is shown in Figure 1. Part A, 200 includes a first vessel 2 and
a second vessel 4. Each of the two vessels is preferably a sealed container
that
defines a chamber therein for containing a gas under pressure. As shown in
Figure
1, the first vessel 2 defines a chamber 3 and the second vessel 4 defines a
chamber 5.
The vessels contain the gas under pressure in the chambers.
The vessels are shown in longitudinal cross-section in Figure 1. Each of the
vessels preferably has an insulating jacket 72 for preventing thermal exchange
with
the ambient environment.
The first vessel 2 has a heat exchange conduit 10 located in the chamber 3.
The conduit is preferably a tube bundle consisting of stainless steel tubing
that is
adapted to conduct a fluid. Other conduits known in the art to have favourable
heat
exchanging properties may also be employed in alternate embodiments. The
conduit 10 has a first end 30 that communicates with the exterior of the
vessel 2
through an opening 31 defined by vessel 2. The conduit 10 has a second end 32
that
communicates with the exterior of the vessel 2 through an opening 33 defined
by
the vessel 2. Similarly, the second vessel 4 has a heat exchange conduit 12
located in
the chamber 5. The conduit 12 is also preferably a tube bundle consisting of
stainless steel tubing that is adapted to conduct a fluid. Again, other
conduits known
in the art to have favourable heat exchanging properties may also be employed
in
alternate embodiments. The conduit 12 has a first end 34 that communicates
with
the exterior of the vessel 4 through an opening 35 defined by the vessel 4.
The
conduit 12 has a second end 36 that communicates with the exterior of the
vessel 4
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through an opening 37 defined by the vessel 12. Vessel 2 has a pressure sensor
102.
Vessel 4 has a pressure sensor 104.
The heat engine assembly 1, in Figure 1 further includes a thermal heat
source 6 and a thermal heat sink 8. The thermal source and sink are shown in
Figure
1. Preferably, the thermal source and thermal sink define an interchanger
conduit
running through them for passage of the thermal conducting fluid and to
transfer
the heat to or from the heat source or sink. The thermal delivery fluid is
preferably
an environmentally suitable fluid that can operate between temperatures of -
100oC
and +250oC or various other temperature differentials.
The thermal sources can be any medium that is capable of storing or
transferring thermal energy to or from the thermal conducting fluid. Among the
examples of possible thermal sources include ambient outside air, outside
soil,
water heated by energy produced by natural gas combustion, wood combustion,
solar energy or geothermal energy, or industrial waste heat. Sample examples
of
thermal sinks include ambient outside air, water, liquid nitrogen, or
liquified natural
gas.
A thermal fluid-conducting heat supply conduit 42 communicates between
the thermal source 6 and the first vessel 2. The conduit 42 further
communicates
between thermal source 6 and the second vessel 4. A fork 43 in the conduit 42
separates the conduit into a first branch leading to the first vessel 2 and a
second
branch leading to the second vessel 4.
A thermal fluid-conducting conduit 44 communicates between thermal sink
8 and vessels 2 and 4. A fork 45 in the conduit 44 separates the conduit into
a first
branch leading to the first vessel 2 and a second branch leading to the second
vessel
4.
A thermal fluid-conducting heat sink supply conduit 38a communicates
between liquid nitrogen or liquid natural gas heat sink reservoir 170 and heat
sink
8.
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The conduit 38b communicates between vessels 2 and 4 and the thermal sink
8. A fork 39 in the conduit 38b separates the conduit into a branch leading
from the
first vessel 2 and another branch leading from the second vessel 4.
A thermal fluid-conducting conduit 40 communicates between the first
vessel 2 and the thermal source 6. The conduit 40 further communicates between
the second vessel 4 and the thermal source 6. A fork 41 in the conduit 40
separates
the conduit into a branch leading from the first vessel 2 and another branch
leading
from the second vessel 4.
A first valve 14 controls the flow of fluid from the thermal unit 6 to the
conduit 10. A second valve 26 controls the flow of fluid from the thermal unit
6 to
the conduit 12. A third valve 22 controls the flow of fluid from the thermal
unit 8 to
the conduit 10. A fourth valve 18 controls the flow of fluid from the thermal
unit 8 to
the conduit 12. A fifth valve 16 controls the flow of fluid from the conduit
10 to the
thermal unit 6. A sixth valve 24 controls the flow of fluid from the conduit
10 to the
thermal unit 8. A seventh valve 28 controls the flow of fluid from the conduit
12 to
the thermal unit 6. An eighth valve 20 controls the flow of fluid from the
conduit 12
to the thermal unit 8. Preferably the valves are electronically operated ball
or piston
valves although other valves known in the art may also be employed. In an
alternate
embodiment, cam or linear actuator operated piston valves may be used,
particularly in a multi-module engine, in order to ensure synchronization of
the
pistons and valves. Controller 70 is operatively connected to the valves for
opening
and closing the valves as required. The eight valves described herein together
with
the controller comprise a plurality of cooperating valves for alternately
regulating a
flow of thermal energy from the heat source and heat sink to the first and
second
vessels.
To avoid unnecessary heat loss during cycling between the two pressure
vessels in each module, the in valve and out valves are timed to allow the
return of
the respective heating and cooling fluids to their source before the incoming
fluid
reaches the out port of the respective vessel.
Date Recue/Date Received 2020-08-31
Preferably, pump 46 and pump 48 pump the thermal fluids through the
thermal fluid conducting conduits. The pumps 46, 48 are preferably circulating
pumps.
Vessel 2 further defines an opening 53. A pressure conduit 54 is received in
the opening 53 and communicates between the chamber 3 and the exterior of the
vessel 2 for delivering gas from the chamber 3 to the exterior and vice versa.
Similarly, vessel 4 further defines an opening 55. A pressure conduit 56
communicates between the chamber 5 and the exterior of the vessel 4 for
delivering
gas from the chamber to the exterior and vice versa.
As shown in Figure 2, the hydraulic accumulators 58a and 58b have
hydraulic fluid chambers 74 moveably received therein. The hydraulic
accumulators
58a and 58b define chambers 106 and 108 respectively. Each of the pressure
conduits 130 and 134 preferably communicate with the first chamber 106 of
hydraulic accumulator 58a. Similarly, each of the pressure conduits 132 and
136
communicate with the second chamber 108 of hydraulic accumulator 58b. The
chambers 74 are connected to a diversionary valve 79 as shown in Figure 2, and
the
diversionary valve 79 is connected to a hydrostatic transmission or hydraulic
gearmotor 80 connected to a generator or compressor. A valve 50 is located at
the
junction of conduits 130, 132, and 54 leading from vessel 2 and the hydraulic
accumulators 58a and 58b for regulating gas flow. Similarly, valve 52 is
located at
the junction of conduits 136, 134, and 56 leading from vessel 4 and the
hydraulic
accumulators 58a and 58b for regulating gas flow. A valve 138 is located in
the
pressure conduit 134 between the vessel 4 and the hydraulic accumulator 58a
for
regulating gas flow. Similarly, valve 140 is located in the pressure conduit
132
between vessel 2 and the hydraulic accumulator 58b.
Hydrostatic transmission 80 is preferably coupled to the diversionary valve
79. The transmission can be coupled to a flywheel and generator combination.
Vessel 2 is connected to the pressure conduit 54. Pressure conduit 54 feeds
into pressure conduits 130 and 132. Valve 50 is located between conduit 54 and
the
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Date Recue/Date Received 2020-08-31
conduits 130 and 132. Similarly, vessel 4 is connected to the pressure conduit
56.
Pressure conduit 56 feeds into pressure conduits 134 and 136. Valve 52 is
located
between conduit 56 and conduits 134 and 136. Valve 138 is located between
conduit 134 and the hydraulic accumulator 58a leading to chamber 106.
Similarly,
valve 140 is located between conduit 132 and hydraulic accumulator 58b leading
to
chamber 108.
In its operation, the apparatus reciprocates between a first valve position as
shown in Figure 3 and a second valve position as shown in Figure 4 thereby
driving
the hydrostatic transmission. The reciprocal motion can be transformed into
mechanical energy, which in turn can drive a generator or compressor for
example.
The controller 70 controls the opening and closing of the valves of the
plurality of co-operating valves. To begin the cycle whereby the apparatus
moves to
the first operating position, the controller opens valve 14 and closes valve
26 so that
warm or hot thermal transfer fluid from the heat source 6 flows through
thermal
fluid conduit 42 to opening 31 and into the heat exchange conduit 10 of the
vessel 2.
As the heated thermal transfer fluid flows through conduit 10 in the chamber
3, heat
is transferred from the conduit to the surrounding gas in the chamber 3. This
causes
the pressure of the gas to increase. An acceptable pressure range of the gas
for the
purposes of the invention is approximately 150 psi to 5000 psi. The controller
opens
valve 16 and closes valve 24 so that the thermal transfer fluid can flow
through the
opening 33 through thermal fluid conduit 40 and back to the heat source 6
where
the thermal transfer fluid is re-heated.
In addition to opening valve 14 and closing valve 26, the controller
simultaneously opens valve 18 and closes valve 22 so that cool thermal
transfer
fluid from the heat sink 8 flows through conduit 44 to opening 35 and into
heat
exchange conduit 12 of vessel 4. As the cool thermal transfer fluid flows
through the
conduit 12 in the chamber 5, heat is transferred from the surrounding gas in
the
chamber 5 to the conduit. This causes the pressure of the gas to decrease. The
controller opens valve 20 and closes valve 28 so that the thermal transfer
fluid can
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flow through the opening 37. The thermal transfer fluid flows through thermal
fluid
conduit 38b and back to heat sink 8 where the fluid is re-cooled.
When maximum thermal transfer has occurred in the two vessels, the
controller 70 will open the pressure valves 50 and 52. In valve position 1,
Figure 3,
the increased pressure in the vessel 2 will cause the gas from the chamber 3
to flow
through the pressure conduit 54 to valve 50 and through conduit 130 to chamber
106 of the hydraulic accumulator 58a. At the same time, the decreased pressure
in
the vessel 4 will cause the gas from the second chamber 108 of the hydraulic
accumulator 58b to flow through the pressure conduit 136 and into the chamber
5
of the vessel 4.
The movement of the hydraulic fluid 74 through the diversionary valve 79
drives hydrostatic transmission 80 and engages the generator or compressor.
When the fluid 74 from accumulator 58a has reached its maximum discharge,
a sensor will cause the valves 110 and 112 to close.
In valve position 2 Figure 4, when valves 110 and 112 are closed, the
controller will open valves 140 and 138 causing the working fluid 74 to move
in the
opposite direction forcing the gas from chamber 106 through conduit 134 and
into
chamber 5 of vessel 4. The cycle will repeat until the working fluid pressure
in
vessels 2 and 4 are at their minimum achievable differential.
During this multi-stroke operation, part of the mass of the working fluid
contained in the vessels is re-distributed to the lower pressure or cooled
vessel of
the stage. This results in higher-pressure differentials than would normally
be
achieved if no mass transfer occurred. When the pressure achieves its minimum
achievable differential in both vessels and no additional cycles can be
obtained, the
process will revert to the second stage. Pressure vessel 4 will then become
the
heated and therefore high-pressure source and vessel 2 will become the cooled
and
therefore low-pressure receiver of the working fluid.
The foregoing description represents a single operating module of an
embodiment. In an embodiment, multiple pairs of vessels and hydraulic
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Date Recue/Date Received 2020-08-31
accumulators, which will comprise a module, may be used to attain a consistent
output to the generator. In the embodiment, the modules are connected to a
common driveshaft to develop higher rpms and torque to the transmission and to
drive larger generators as required. The modules consisting of one pair of
vessels
and one assembly of hydraulic accumulators can be added as needed. They can
also
be of different capacities to deliver versatility to the installation,
depending on the
demand of the application.
In this multiple module embodiment, the valves controlling the cycles
between each module in valve positions 1 and 2, can be operated by a
synchronized
camshaft or linear actuator.
In a second aspect, or part B 300, the output efficiency of the process
described in part A is enhanced by using liquid nitrogen or liquid natural gas
to cool
the heat sink transfer fluid thereby allowing the system to use a heat source
with a
much lower ambient temperature while maintaining a similar temperature
differential efficiency or Carnot efficiency between the heat source and the
heat
sink. The integrated thermal heat engine 200, comprised of heat engine 1 and
the
liquid nitrogen or LNG expansion engine 300, provides for a system that can
synergistically operate with a greater overall efficiency than either
component
alone.
In addition, regardless of the heat source, the maximum realizable efficiency,
or theoretical efficiency, will increase exponentially because of the
increased
temperature between the heat source and heat sink.
The second aspect, or part B, describes a novel expander engine to capture
the energy of the conversion process of the liquid nitrogen or LNG to a gas as
the
liquid nitrogen or liquid natural gas absorbs heat from part A heat sink 8.
Whereas storing liquid nitrogen and capturing its expansion on its own is an
established process, the current prevailing method of using a turbine to
capture the
expansion does not achieve acceptable round-trip conversion efficiency to
attain
economic viability.
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Figure 5 illustrates a method of capturing the expansion of the liquid
nitrogen or liquid natural gas and allowing it to:
First expand to a prescribed pressure in insulated pressure vessels and,
Second, the pressurized nitrogen or liquid natural gas, which is now a gas, is
released to a modified hydraulic accumulator assembly and process similar to
the
assembly described above for the heat engine and illustrated in more detail in
Figures 2, 3, and 4. Alternately, the expanded gas can be stored in
independent
pressure vessels for release at a later time when demand is higher. This
illustrates
the versatility of the present invention over straight liquid nitrogen or
liquid natural
gas expansion through an expander/generator system.
In Figure 1, a vessel containing liquid nitrogen or liquid natural gas 170
provides a second, lower, heat sink for the heat engine 1. The liquid nitrogen
or LNG
supply 170 reduces the temperature of the heat exchange fluid circulating
through
heat sink supply conduit 38a. The pump 171 maintains a sufficient flow rate to
ensure the heat transfer fluid does not cool below its freezing point. As the
heat
transfer fluid passes through interchanger 190, it gives up enough heat to
lower the
temperature of the working fluid to its low temperature working limit but not
the
point at which it freezes. This provides the maximum temperature differential
for
thermal efficiency of the heat engine 1, while causing the liquid nitrogen, or
LNG
contained in the supply 170 to expand through supply conduit 150 to the
expansion
engine 300.
Referring to Figure 5, the liquid nitrogen or LNG expansion engine 300 is
illustrated in more detail. The nitrogen expansion engine 300 includes a
separate
hydraulic accumulator and hydraulic motor assembly. The nitrogen or LNG supply
conduit 150 supplies manifold 152 which supplies insulated pressure vessels
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Date Recue/Date Received 2020-08-31
through control valves 153 in each of the vessels. Control valves 153 are of
the type
through which the rate of flow of the liquid nitrogen or LNG can be regulated.
The liquid nitrogen or LNG is then received by dispersion nozzles 154 in each
of the pressure vessels, at which point the liquid nitrogen or LNG expands
into
gaseous form. The gaseous nitrogen or natural gas is allowed to expand to a
prescribed pressure.
Heat source return conduit 40 is diverted through the pressure vessels 155
to add secondary heat to the gaseous nitrogen or natural gas thereby
maintaining
and increasing the pressure as prescribed for storage or immediate use through
the
expander and transmission/generator assembly 157. As will be appreciated from
Figure 1, thermal fluid conducting heat return conduit 40 comprises the return
path
of the thermal fluid from the first vessel 2 and the second vessel 4.
Accordingly, after the heat flow from the heat source 6 has been used in the
heat engine 1, it is directed to the expansion engine 300 to heat the expanded
gas in
the pressure vessels 155, and accordingly transfer further energy to the
expanded
gas. The thermal fluid may then be directed through the thermal fluid
conducting
heat return conduit 40 to return to the heat source 6 to be re-heated and
supplied
again to the heat engine 1.
In Figure 5, valves 160 are used to equalize the pressure between pressure
vessels 155 as needed. Sensors 158 in each of the pressure vessels 155
communicate with the control module 70 to regulate the expander engine
operation. Valves 159 control the release of the expanded gas to conduit 156
and
thenceforth to the expander module 183.
In Figure 6, a hydraulic accumulator assembly is shown in position 1. The
gaseous nitrogen or natural gas flowing from conduit 156 is received by
distribution
junction 177 and flows through conduit 176.
Valves 179 and 180 are open and valves 178 and 181 are closed, causing the
gaseous nitrogen or natural gas flowing through conduit 176 to push the
hydraulic
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Date Recue/Date Received 2020-08-31
fluid 183 in one direction which in turn forces the gaseous nitrogen or
natural gas in
chamber 184 to exit through valve 180.
During the operation of the expander engine in valve position 1, hydraulic
motor 186 is caused to rotate, transferring the mechanical energy created by
the
conversion of the liquid nitrogen or LNG, to connecting driveshaft 187, which
in turn
will drive a generator, compressor, or hydraulic pump.
Similarly, in valve position 2, Figure 7, the gaseous nitrogen or natural gas
flowing from conduit 156 is received by distribution junction 177 and flows
through
conduit 175. Valves 178 and 181 are open and valves 179 and 180 are closed,
causing the gaseous nitrogen or natural gas flowing through conduit 175 to
push the
hydraulic fluid 183 in the opposite direction which in turn forces the gaseous
nitrogen in chamber 185 to exit through valve 181.
During the operation of the expander engine in valve position 2, hydraulic
motor 186 is caused to rotate, transferring the mechanical energy created by
the
conversion of the liquid nitrogen or LNG, to connecting driveshaft 187, which
in turn
drives the transmission and generator 186.
Multiple hydraulic assemblies are synchronized on a common driveshaft to
enhance the steady delivery of power to the generator or compressor or a
hydraulic
pump, and facilitate the use of larger units.
In some aspects, the expander engine 300, may be selectively enabled so as
to operate the heat engine 1 with the greater thermal differential during
periods of
low electricity demand when electricity prices are low.
The foregoing embodiments describe preferred embodiments only.
While various embodiments and particular applications of this invention
have been shown and described, it is apparent to those skilled in the art that
many
other modifications and applications of this invention are possible without
departing from the inventive concepts herein. It is, therefore, to be
understood that
within the scope of the appended claims, this invention may be practiced
otherwise
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Date Recue/Date Received 2020-08-31
than as specifically described, and the invention is not to be restricted
except by the
scope of the claims.
Claims:
I/we hereby claim:
1. An apparatus for converting a differential in thermal energy temperatures
between a heat source having a thermal conducting fluid and a heat sink
having a cooling thermal conducting fluid, the apparatus comprising:
a heat engine comprising:
a pair of gas filled vessels in communication with said heat
source and said heat sink;
a pressure driven reciprocating arrangement of hydraulic
accumulators defining a first and second chamber separated by
at least one hydraulic motor, said first chamber and said
second chamber in fluid communication with said gas filled
vessels;
said pair of gas filled vessels supplying a gas comprising a
working fluid to said first chamber and second chamber of said
pressure driven arrangement of reciprocating hydraulic
accumulators; and,
a controller for alternating flow of the thermal energy from
heat source and heat sink between each of the pair of gas-filled
vessels to alternately raise and lower pressure of said gas in
the vessels to alternately transfer gas from one vessel to the
first and second chamber of the hydraulic accumulator
assembly and drive the assembly into reciprocating motion;
and,
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Date Recue/Date Received 2020-08-31
