Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION OF PRIOR ART
There is a thermionic generator known, containing an exterior case, inside of
which
a source of heat and a battery of thermionic elements, connected consecutively
by means
of a key plug wire are located, the exterior case being entirely heat-isolated
from the
environment, and each of the thermionic elements is made in the form of
separated from
each other by spacers emitter and collector, separated from the case with a
heat insulation
layer. Spacers are made of a high heat conduction material, providing the
opportunity of
heat transfer between emitter and collector. Thermionic elements are tightly
packed inside
the thermal screen located on the exterior case. The battery of thermionic
elements is
made in the form of a set of parallel bars, one surface of which is made in
the form of
emitter, and the opposite surface is made in the form of collector of the
adjacent thermionic
element. All the bars are connected to each other by a common thermal
conduction
element - spacer (SU, author's certificate No1822505; H01J45/00, published in
1993).
Useful work of the known thermionic generator is accomplished at the expense
of
temperature difference between emitter and collector. The method consists in
conversion
the heat of a spot source into electrical energy.
The heat is transferred from its source through a solid thermal conduction
element
by means of contacting the thermionic elements, contacting the thermal
conduction
element and located along the length of the latter. Temperature difference
between
emitters and collectors is set up at the expense of the descent of the
temperature along the
length of the thermal conduction element while the heat is being extracted
from it. While
the emitters are being heated in the batch of thermionic elements to emission
temperature,
the eduction of electrons into the interelectrode intervals and sedimentation
of them on the
collectors follows.
The obtained current is transferred from thermionic elements connected
consecutively into an external electrical circuit. Application of the method
allows the use of
the heat, having moved through each of the thermionic elements, in the sequent
thermionic
elements, thus resulting in increasing the efficiency of transformation of
thermal energy into
electrical one and raising the efficiency of thermionic generator to 40 per
cent.
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Heat transmission through a solid thermal conduction element, having thermal
resistance, is accompanied by highly unjustifiable temperature decrease along
the length
of the thermal conduction element.
The temperature decrease also takes place while the heat is transferred from
contact spots located along the bars, forming the surfaces of emitters and
collectors. Low
temperature flow can't be used effectively for conversion into electrical
energy.
Therefore, the efficiency of conversion of elements planes which are far from
the
source in the known generator is low. Application of high heat conduction
spacers,
reserved for acceleration of heat transfer between emitters and collectors, to
a certain
extent improves admission of heat to the planes of elements, distanced from
the heat
source. However, the efficiency of the generator conversion can't be high,
because
spacers also have thermal resistance, causing temperature decrease of the
thermal flow
being transferred.
There is also a method of direct conversion of thermal energy into electrical
one and
thermionic generator for its realization. This method has been adopted as
prototype for the
method claimed. In the known method thermal transfer is accomplished through
the flow of
the moving media, advanced to the thermionic elements, the latter being placed
in the
hermetically sealed case of the thermionic generator in the form of a multi-
level battery,
thus enabling the spiral trajectory of the heat media passage through the
levels of the
battery divided from each other by horizontal channels. Thermionic elements
cathodes
function as emitters and anodes function as collectors the heat media flow
being passed
along the first channel warming up the thermionic element emitters of the
first storey at
least as high as the temperature of the thermal emission of electrons. At the
channel
output the heat media flow is advanced though the channel of the bypass main
to the input
of the next channel in the same direction with the heat media flow of the
previous channel,
one and the same heat media flow being used simultaneously as a coolant for
thermionic
element collectors of the previous storey of the battery and as heat media
flow for warming
up thermionic element emitters of the next storey of the battery, the
operational cycle being
repeated as long as the temperature of the waste flow becomes lower than the
temperature of the thermal emission of electrons. Thermionic elements are
connected with
one another into a single electrical circuit (RU, Patent # 2144241, HOW5/00,
published in
1998). Any known devices for utilization of useful heat, e.g. heat exchangers
can be
installed for achieving additional effect of the energy use.
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There is a thermionic generator known from the same source in the form of a
hermetically sealed case with a device of heat media flow input from an outer
source and
an exhaust of the waste heat media flow. Inside the case there are thermionic
elements
placed connected with one another into a single electrical circuit, the
thermionic elements
arranged in the form of a multi-level battery, the gaps between the levels
forming heat
media passage channels thus enabling the advance of the heat to the thermionic
element
emitters and cooling the collectors of the thermionic elements, the output of
the previous
channel being connected to the input of the subsequent channel through the
bypass main,
the whole complex determining a spiral form of the heat media advance
trajectory through
the battery of the thermionic elements. The thermionic elements emitters,
placed at the end
of the heat media flow trajectory, are provided with a more developed surface
then the
thermionic elements emitters, placed at the beginning of the trajectory.
The thermionic element of the above generator is made in the form of a flat
hermetically sealed case containing an emitter, a collector and a device for
transferring
electrons through the interelectrode intervals. The method of conversion of
thermal energy
into electrical one and the generator for accomplishing it increase the
efficiency of the
usage of heat flow energy at the expense of advancing the flow through the
thermionic
elements. The efficiency of thermionic generator can reach 60 per cent. A high
temperature
in the first (upper) channel of the thermionic generator, formed by the
thermionic elements
and the upper part of the case, as well as in the heat-isolated bypass
channels leads to
unjustifiable heat losses of the heat media thermal energy through the walls
of the case
and the channels all this decreasing the efficiency of the known generator.
Thickening heat
insulation in order to cut down thermal losses leads to increasing it in size,
and the
generator comes out to be very bulky.
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THE BEST EMBODIMENT OF THE INVENTION
According to the present invention the method of direct conversion of thermal
energy into electrical energy consists in advancing the heat of the moving
heat media to
the thermionic elements placed in a hermetically sealed case and connected
with one
another into a single electrical circuit, the cathodes of the thermionic
elements being
warmed up at least as high as the temperature of the thermal emission of
electrons,
anodes of the thermionic elements being cooled, and the obtained electrical
current is
advanced to the load.
The heat transfer is put into effect through the walls of the channel from the
heat
media moving along the channel and from the same heat media advancing from the
channel output and moving in the reverse direction, the thermionic elements
being
arranged in ring rows composed of separate segments perpendicularly to the
walls of the
case embracing the channel with the warmed heat media, the space between the
walls of
the case and the channel being divided into separate sections with gaps
between ring rows
and gaps between segments for providing an opportunity for the flow to move
along a
helical trajectory, the segments of the thermionic elements being arranged in
such a way
that both sides of every gap join either the anodes or the cathodes of the
thermionic
elements.
The heat media flow is advanced through the gap, which is the first from the
end, to
which the cathodes of the thermionic elements adjoin, and the flow moving
circularly
warms up the gap cathodes and having been cooled through the gap between the
segments of the second ring row, advances into the next gap and makes one more
turn. In
this gap the heat media flow is used as a coolant for anodes, from the second
gap the flow
is advanced to a section of the space between the channel and the case, the
section under
the second and the third gaps where the flow is warmed up through the wall of
the channel
gaining heat from a section of the flow moving along the channel and passes
into the third
gap befringed with cathodes, the operational cycle being repeated as long as
the
temperature of the waste flow becomes lower than the temperature of the
thermal emission
of electrons.
There is a new method suggested for providing heat exchange between thermal
flows in the thermionic generator. In the claimed method the thermal energy of
the moving
heat media is used for conversing into electrical energy with simultaneous
warming of the
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moving heat media from the section of the heat media, having a higher
temperature. Thus,
an opportunity is provided to keep the temperature range at the level of
maximum
efficiency value of conversion and of minimal volume of the conversing
elements
consequently making the generator more compact. Besides that advancing the
hottest part
of the flow in the middle of the generator and blowing air warm up at the
expense of heat
tap from the neighboring area of the generator provides cutting losses of
thermal energy
through the walls of the case and reducing the bulk of thermal insulation
material within the
case.
The present method is performed by a thermionic generator consisting of a
hermetically sealed case with a device for directing the heat media flow from
an exterior
source and with a device for the used heat media flow output. Inside the case
there are
thermionic elements, made as separate segments forming rows with gaps for
passing the
heat media flow and connected with one another into a single electrical
circuit, the case
having a cylindrical shape, the device for directing the heat media flow
mounted in the
middle of the above case along its longitudinal axis and the row of separate
segments of
thermionic elements make ring rows perpendicularly to the walls with gaps for
passing the
heat flow thus making it possible to advance the heat to the thermionic
element cathodes
and to cool the anodes of these elements with gaps in the segment for passing
the heat
media flow along a helical trajectory.
Application of the claimed method and the thermionic generator for
accomplishing it
increase the efficiency of heat flow energy conversion into electrical energy
at the expense
of its rational use and increase the efficiency of the thermionic generator to
as high as 70-
80 per cent. In the sources of information known to us there is no data about
the claimed
technique of heat flow advancing through the thermionic elements of the
thermionic
generator with simultaneous warm up of the flow. Application of this technique
allows a
substantial increase of thermal energy conversion efficiency without any
additional
expenditure for thermal insulation of the generator case.
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INDUSTRIAL APPLICATION
The present invention is applicable in industry, because known technologies
used
now in production of generators are used for its embodiment. All the
structural components
of the claimed thermionic generator can be produced with known equipment using
known
industrial technologies. The claimed method can be used at any thermal power
station and
in other heat generation processes in power plants.
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Below there is an example of an embodiment of the thermionic generator. Case 1
(Fig. 1, 2) of the thermionic generator has the form of a cylinder. The case
walls are directly
attached to a double insulation layer 2. Between the insulation layers there
are gaps, along
which a gaseous heat media is moving (air). In the middle of the case
coaxially with it there
is a cooled furnace 3. There is case 4 around the furnace and the space
between the
furnace and the case is divided into separate sections by partitions 5. Fuel
is advanced to
the furnace through nozzle 6, and hot blowing air passes from the gap between
insulation
layers through branch pipe 7. The operational zone, placed between case 4 and
the inner
insulation layer is divided into sections by segment thermionic elements 8
with apertures 9
and communication pins 10, the segments arranged in such a way that in every
section
either anodes A or cathodes K placed inside the segments join the opposite
surfaces. In
Unit A (Fig. 5) we can see reciprocal disposition of cathodes and anodes in
the segments.
The furnace output is connected by passage 11 with the gap, which is the first
from the end
of and is formed by thermionic elements. There are apertures 12 in the case
for passing of
the moving heat carrier. There is the form of the gaps between the segments of
the
thermionic elements depicted in Fig. 4, and partitions 5 are marked by dashed
lines. Heat
exchanger 13 is for warming up blowing air and heat exchanger 14 is for
warming up water
side the case. Smoke passage trajectories are marked with arrowed continuous
lines.
Thermionic elements 8 are connected into a single electrical circuit and
connected to the
load with communication wires 15 (Fig. 3).
The process of conversion of thermal energy into electrical one within the
thermionic
generator takes place in the following way. Fuel and hot air are fed to the
furnace through
nozzle 6. Fuel burns with emission of thermal energy and hot gas (smoke) in
the cylindrical
part of the furnace. Fuel is advanced to the operational area through the
walls of the
furnace and while moving along the furnace its temperature decreases. The
pattern of
temperature variation in the function of furnace length is shown in Fig. 6 and
as it is seen
from the chart the temperature of the smoke reaches as high as 1650 degrees
Celsius, and
at the output it is equal to 900 degrees. At the temperature of 900 degrees
smoke passes
to the last section of the operational zone through passage 11 where it is
directed circularly
and bathes the surfaces of segments joined with cathodes K. In the process of
circular
movement the smoke returns part of its thermal energy to the cathodes, where
it is
conversed into electricity and partly warms the anodes of these segments.
Having passed
this circle, smoke cooled down as low as 700 degrees passes in to the last but
one section
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where it warms up a little, tapping heat from anodes. The temperature of smoke
at the
output of this section is about 750 degrees Celsius, which is much higher than
in the
neighboring section befringed with cathodes. That is why smoke is directed
from the anode
section though apertures 12 into the space, limited by cylindrical surfaces of
the fumace
with case and tabular partitions, where it is warmed up once more as high as
900 degrees
Celsius. This part of the chart is marked with an erratic in Fig.6. Heating is
achieved at the
expense of heat passing through the furnace wall, the flow of smoke inside of
which being
cooled down. Then the warmed smoke advances into the next cathode section, and
the
process of heat exchange will be repeated while moving from the end to the
beginning of
the case as it is shown at Fig.6 in the chart of smoke temperature variation
of the
operational area. According to the chart, the temperature in the anode
sections is set up
much lower than in the cathode ones. This provides the required difference of
temperatures between cathodes and anodes in the thermionic elements. According
to this
pattern of smoke advance in the operational zone constant temperature of the
thermionic
elements is set up and its value 700-900 degrees Celsius with the average of
800 degrees
Celsius is optimal for conversion of heat into electricity and for reliability
and durability of
the material the thermionic elements are made of. Cooling of side segments
joining the
case (Fig. 2) is accomplished through cooled insulated walls.
At temperature level 300 degrees smoke advances from the first left section to
heat
exchanger 13 through the end of the isolating gap, and flowing directly gives
its heat to the
blowing air; the temperature of the smoke is decreasing as low as 150 degrees
Celsius and
the temperature of the blowing air is increasing approximately as high as 150
degrees
Celsius. Further increase of the temperature as high as 300 degrees takes
place in the air-
cooled area. Variation of air temperature is shown in Fig. 6 with thin arrowed
lines. The
temperature of the smoke decreases as low as 40 degrees Celsius in heat
exchanger 12,
which is possible in the process of contra-directorial heat exchange between
smoke and
heat carrier advanced through heat exchanger 14. Thermionic elements 8 form a
single
electrical circuit and are connected to generator load pins with communication
wires 15
(Fig. 3). The process of heat exchange in the thermionic generator, mentioned
here,
provides economy and compactness of the generator.
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