JP2005310823A - Thermophotovoltaic power generation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a thermophotovoltaic power generation device, having high combustion efficiency and high power generation efficiency, even if the combustion chamber is small in volume. <P>SOLUTION: The thermophotovoltaic power generation device has an emitter 5 for radiating infrared light by heating at a high temperature, a plurality of photocells 6 arranged adjacently by making the light reception surface to face one surface of the emitter 5, a first combustion chamber 3 for generating combustion gas for heating one surface of the emitter 5, and a channel 14 for guiding the combustion gas generated in the first combustion chamber 3 to one surface of the emitter 5. A space is provided among a plurality of photocells 6, by forming one surface of the emitter 5 in a dome shape for composing a second combustion chamber 4, and non-burned content in the combustion gas generated in the first combustion chamber 3 is burned in the second combustion chamber 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermophotoelectric generator for converting infrared light emitted from a high heat source into electrical energy and outputting the same.

  A thermophotovoltaic power generation device (thermophotovoltaic-system) is a power generation device that mainly generates infrared light by heating an object called an emitter to a high temperature, receives the light with a photovoltaic cell, and extracts it as electric energy. In this apparatus, by adjusting the heating temperature of the emitter, it is possible to generate radiation with a spectrum corresponding to the high sensitivity region of the photovoltaic cell, thereby expecting high energy conversion efficiency, that is, power generation efficiency. it can. In addition, since there is no moving part, it is possible to realize a low noise and low vibration device, and the future is expected as a long-life, distributed power generation device.

  The currently developed thermophotoelectric generator has a structure in which a large number of photovoltaic cells are arranged around the light emitting surface of an emitter heated by a high-temperature combustion gas. In this case, in order to increase the power generation efficiency of the apparatus, it is necessary to efficiently transmit the combustion energy of the fuel to the emitter and raise the emitter temperature. For this purpose, it is desirable to cause a high-temperature combustion reaction immediately before the emitter. In that case, a sufficient volume combustion chamber must be secured between the emitter and the photovoltaic cell in order to cause complete combustion. As a result, there is a problem in that the distance between the emitter and the photovoltaic cell is increased, and the emitted light from the emitter is not efficiently transmitted to the photovoltaic cell, and many leaks to the outside as heat, reducing the power generation efficiency of the apparatus.

  In order to solve this problem, a structure is provided in which a combustion chamber is provided in a part different from between the emitter and the photovoltaic cell, and gas that has been burned and heated to the emitter's light emitting surface is supplied to the emitter and the photovoltaic cell. The distance between them is made as small as possible to prevent radiation leakage. However, in this case, since a high-temperature combustion reaction occurs in a combustion chamber that is away from the emitter, heat radiation from the combustion chamber is large, and combustion energy is not efficiently transmitted to the emitter.

Techniques related to the present invention are described in the following Patent Documents 1 to 5.
JP 2000-106001 A JP 2000-106452 A JP 2002-315371 A Japanese Patent Laid-Open No. 2002-319693 JP 2003-46106 A

  The present invention has been made in order to solve the above-described problems in the conventional thermophotovoltaic power generation apparatus, and enables complete combustion of the fuel while maintaining a small amount of heat released from the combustion chamber and effectively leaking radiant light. It is an object of the present invention to provide a thermoluminescent power generation device having a novel structure that can be prevented.

  In order to solve the above problems, a first thermophotovoltaic power generator of the present invention has an emitter that emits infrared light when heated to a high temperature, and a light receiving surface facing the one surface of the emitter. A plurality of photovoltaic cells arranged; a first combustion chamber for generating combustion gas for heating the one surface of the emitter; and the combustion gas generated in the first combustion chamber for supplying one surface of the emitter In the thermophotovoltaic power generation device including the flow path for guiding the first to the second, a space is provided between the plurality of photovoltaic cells to form a second combustion chamber by forming the one surface of the emitter into a dome shape. The unburned portion in the combustion gas generated in the first combustion chamber is combusted in the second combustion chamber.

  According to the above apparatus, since the surface heated by the combustion gas of the emitter, that is, the light emitting surface is formed in a dome shape so as to surround the photovoltaic cell, a space is formed between the emitter emitting surface and the photovoltaic cell. Operates as a second combustion chamber (sub-combustion chamber) to completely burn the unburned portion in the first combustion chamber (main combustion chamber). Therefore, it is not necessary to achieve complete combustion of the fuel in the first combustion chamber, and the temperature of the combustion gas can be lowered by reducing the combustion amount. This reduces the amount of heat released from the first combustion chamber. In addition, by making the light emitting surface of the emitter a dome shape and surrounding the light receiving surface of the photovoltaic cell, the emitted light from the emitter is collected on the light receiving surface of the photovoltaic cell, and is less likely to leak to parts other than the photovoltaic cell, The power generation efficiency of the device is improved.

  In the second combustion chamber, the combustion gas having a high temperature in the first combustion chamber is further burned, so that the gas reaches the maximum temperature immediately before the second combustion chamber, that is, the emitter. Therefore, the emitter temperature rises and the amount of radiation to the photovoltaic cell increases. In addition, since the radiation amount in thermal radiation is proportional to the fourth power of the absolute temperature, even a slight increase in temperature has a great influence on the radiation amount increase. Furthermore, when the emitter becomes high temperature, the peak wavelength of the emitted light spectrum shifts to the short wavelength side, but since the photovoltaic cell has high power generation efficiency on the short wavelength side, the ratio of the wavelength effective for photoelectric conversion in the emission spectrum, That is, the effective wavelength ratio is improved. As a result, the power generation efficiency of the device is improved.

  In the present invention, in the first thermoelectric generator, the flow path of the combustion gas from the first combustion chamber toward the second combustion chamber so that a swirl flow is formed by the combustion gas in the second combustion chamber. Is formed at an angle with respect to the inflow surface into the second combustion chamber.

  By causing a swirl flow in the second combustion chamber, the mixing of fuel and air is promoted and a combustion reaction is likely to occur. Therefore, the combustion gas temperature is further increased, and the power generation efficiency of the apparatus is improved. In addition, since the combustion reaction is promoted even if the volume of the combustion chamber is small, it is possible to reduce the size of the apparatus by reducing the size of the second combustion chamber. Furthermore, since the amount of heat released from the combustion chamber is reduced by reducing the size of the second combustion chamber, there is an effect that the heating efficiency of the emitter is increased and the emitter is further heated.

  Further, by causing the swirl flow, there is an effect that the flow of the combustion gas is stabilized and the emitter temperature distribution can be easily predicted.

  According to the present invention, in the first device, a reflector is provided opposite to the surface other than the one surface of the emitter, so that light radiated in a direction other than the direction of the photovoltaic cell of the emitter is emitted by the reflector in the emitter direction. And is collected by the emitter. This further heats the emitter to a high temperature, improving the power generation efficiency of the device.

  The second thermophotovoltaic power generator of the present invention has a columnar emitter that emits infrared light when heated to a high temperature, a light receiving surface facing the side wall in the axial direction of the columnar emitter, and surrounds the side wall. A plurality of photovoltaic cells, a first combustion chamber for generating a combustion gas for heating the sidewall of the emitter, and the combustion gas generated in the first combustion chamber for the sidewall of the emitter In the thermophotovoltaic power generation device comprising a flow path for leading to the first and second photovoltaic cells, a space is provided between a side wall of the columnar emitter and the plurality of photovoltaic cells to form a second combustion chamber, which is generated in the first combustion chamber. In this case, unburned components in the combustion gas are combusted in the second combustion chamber.

  In the second thermoelectric generator, the flow path of the combustion gas to the second combustion chamber is formed so that a swirl flow of the combustion gas surrounding the columnar emitter side wall is formed in the second combustion chamber. An angle is provided with respect to the inflow surface.

  With the above configuration, a thermophotoelectric generator having the same effect as described for the first thermophotoelectric generator can be obtained.

[Example 1]
FIG. 1 is a cross-sectional view showing a schematic configuration of a thermophotovoltaic power generator according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view of a main part showing structures of a main combustion chamber and a sub-combustion chamber shown in FIG. . The thermophotovoltaic power generator according to this embodiment includes a main combustion chamber (first combustion chamber) 3 composed of wall surfaces 1 and 2 made of heat insulating material, and a sub-combustion chamber for recombusting the gas burned in the main combustion chamber 3. (Second combustion chamber) 4 is provided. The sub-combustion chamber 4 is configured by forming the bottom surface of the selective wavelength light emitting emitter 5 in a dome shape and disposing the photovoltaic module 6 below it. As is well known, the photovoltaic module 6 is configured by connecting a plurality of photovoltaic cells in series or in series-parallel. A filter 7 is made of quartz or the like, and is used to prevent unnecessary heating of the photovoltaic cell by cutting the wavelength component that does not contribute to photoelectric conversion in the photovoltaic cell from the emitted light of the emitter 5. is there.

Reference numeral 8 denotes a cooling block for the photovoltaic module 6, which is cooled by the outside air introduced from the air inlet 9 and cools the photovoltaic module 6. The emitter 5 is made of a porous ceramic made of SiC, Yb ₂ O ₃ or the like, and emits infrared light efficiently by being heated to about 1500 ° C., for example. The gas burned in the auxiliary combustion chamber 4 passes through the emitter 5 which is a porous ceramic, is introduced into the heat exchanger 10, and is then discharged from the exhaust port 11 to the outside of the apparatus.

  12 is a mixing chamber of air and fuel, and 13 is a fuel pipe. The air introduced from the air inlet 9 is introduced into the heat exchanger 10 through the outer periphery of the side wall of the main combustion chamber 4 and heated by absorbing the heat generated by the combustion gas, and then into the mixing chamber 12. It is sent here, mixed with fuel and supplied to the main combustion chamber 3 to burn the fuel.

  As described above, in this embodiment, a two-stage combustion structure is provided in which the auxiliary combustion chamber 4 is provided immediately before the emitter with respect to the main combustion chamber 3, and the unburned portion in the main combustion chamber 3 is completely removed in the auxiliary combustion chamber 4. It is made to burn and the emitter is efficiently heated with a high-temperature combustion gas. Therefore, it is not necessary to perform complete combustion in the main combustion chamber 3, and combustion can be performed at a lower combustion temperature. Accordingly, the amount of heat released from the main combustion chamber 3 is greatly reduced. The combustion gas that has been completely burned in the auxiliary combustion chamber 4 and has reached a high temperature heats the emitter 5 by heat conduction while passing through the emitter 5 that is a porous body, and raises the temperature. As a result, the emitter 5 emits infrared light. Infrared light from the emitter 5 is received by the photovoltaic module 6 and converted into electrical energy.

  The emitter 5 should have a large volume in order to absorb the thermal energy of the combustion gas as much as possible. In the apparatus of FIG. 1, the emitter 5 has a structure divided into two stages. This is because heat conduction through the emitter material is once interrupted by dividing the emitter, and light emitted from the lower emitter is reflected and recovered by the upper emitter, thereby raising the temperature of the emitter further. is there.

  In the present embodiment, as shown in FIG. 2, the combustion gas flow path 14 from the main combustion chamber 3 to the sub-combustion chamber 4 is provided with an angle, so that the swirl is introduced into the sub-combustion chamber 4 by the inflowing combustion gas. It is characterized by causing a flow. This swirl flow promotes mixing of fuel and air in the auxiliary combustion chamber 4 and facilitates complete combustion. Therefore, the space of the main combustion chamber 3 and the auxiliary combustion chamber 4 can be further reduced, and the entire apparatus can be reduced in size and weight. Further, since the flow of the combustion gas is stabilized by causing the swirl flow, the temperature distribution of the emitter can be easily predicted.

[Example 2]
FIG. 3 is a cross-sectional view illustrating a schematic configuration of the thermophotovoltaic power generator according to the second embodiment of the present invention. The apparatus of the present embodiment is the thermophotovoltaic power generation apparatus shown in FIGS. 1 and 2, in which the reflective surface 17 is provided on the heat insulating casing member 16 facing the surface 51 other than the surface facing the photovoltaic module 6 of the emitter 50. Of the infrared light emitted from the emitter 50 heated to, the light emitted in the direction other than the direction of the photovoltaic module 6 is reflected and returned to the emitter 50 again. In addition, 18 is quartz glass, and is provided in order to isolate combustion gas and the reflective surface 17, and to prevent the heat transfer to a reflective surface and to protect the reflective surface 17.

  The emitter 50 is further heated to a high temperature by collecting the light reflected by the reflecting surface 17, so that the amount of radiation in the direction of the photovoltaic module 6 increases and the emission wavelength shifts to the short wavelength side. There is an effect that the effective wavelength ratio contributing to the conversion is improved and the power generation efficiency is improved.

  Also in this embodiment, by providing an angle in the flow path of the combustion gas from the main combustion chamber 3 to the sub-combustion chamber 4, it is possible to cause a swirl flow in the sub-combustion chamber 4 and promote combustion. is there.

  In FIG. 3, the same reference numerals as those shown in FIGS. 1 and 2 indicate the same or similar constituent members, and therefore redundant description thereof is omitted.

[Example 3]
FIG. 4 is a cross-sectional view illustrating a schematic configuration of the thermophotovoltaic power generator according to Embodiment 3 of the present invention. In the present embodiment, a thermo-electric power generation device having a vertically long structure as a whole is provided by providing a main combustion chamber at the bottom of the device and providing a sub-combustion chamber on the side surface of the cylindrical emitter.

  In FIG. 4, 20 is a main combustion chamber composed of a heat insulating member 21, 22 is a fuel supply pipe, and 23 is an air fuel mixing chamber. Reference numeral 24 denotes a columnar selective wavelength light emitting emitter, 25 denotes a quartz filter, 26 denotes a photovoltaic module, 27 denotes a cooling block of the photovoltaic module 26, and 28 denotes a sub-combustion chamber constituted by the columnar side surface of the emitter 26 and the photovoltaic module 26. In the present embodiment, the side surface of the columnar emitter 24 is formed in a dome shape, that is, a concave shape, and a space is formed between the columnar emitter 24 and the photovoltaic cell module 26, thereby forming the auxiliary combustion chamber 28.

The selective wavelength light emitting emitter 24 is a porous ceramic made of SiC, Yb ₂ O ₃ or the like, and allows the combustion gas completely burned in the sub-combustion chamber 28 to pass through and absorbs the heat energy of the combustion gas by heat conduction during that time Then it heats itself. The combustion gas is introduced into the heat exchanger 30 through the opening 29, where it is cooled by exchanging heat with the air introduced through the air pipe 31, and is discharged from the discharge port 32 to the outside of the apparatus. Produced.

  Although not clearly shown in FIG. 4, also in this embodiment, the combustion gas flow path 33 from the main combustion chamber 20 to the sub-combustion chamber 28 is angled with respect to the inflow surface to the sub-combustion chamber 28. As a result, a swirl flow 34 is generated in the auxiliary combustion chamber 28. Combustion is promoted in the sub-combustion chamber 28 by the swirl flow 34, and the flow of the combustion gas is stabilized, so that the emitter temperature distribution can be easily predicted. Further, the volume of the auxiliary combustion chamber 28 can be reduced, and the apparatus can be reduced in size and weight.

  As described above, in the thermophotovoltaic power generator of the present invention, the light emitting surface of the emitter facing the photovoltaic cell is formed in a dome shape to prevent the radiated light from leaking from the periphery of the emitter to a portion other than the photovoltaic cell, and between the emitter and the photovoltaic cell. The sub-combustion chamber is secured, and unburned fuel is completely burned immediately before the emitter in the main combustion chamber. Thereby, the heating efficiency of the emitter by the fuel is improved, and further, the leakage of the emitted light from the emitter to the direction other than the direction of the photovoltaic cell is reduced, so that the power generation efficiency of the apparatus is greatly improved.

Sectional drawing which shows schematic structure of the thermophotovoltaic power generating apparatus concerning Example 1 of this invention. Sectional drawing which shows the structure of the principal part of the apparatus shown in FIG. Sectional drawing which shows schematic structure of the thermophotovoltaic power generating apparatus concerning Example 2 of this invention. Sectional drawing which shows schematic structure of the thermophotovoltaic power generating apparatus concerning Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 ... Wall surface 3 made of heat insulating material ... Main combustion chamber 4 ... Subcombustion chamber 5 ... Selected wavelength light emission emitter 6 ... Photovoltaic module 7 ... Quartz filter 8 ... Cooling block 10 ... Heat exchanger 11 ... Exhaust port 14 ... Gas flow path

Claims (5)

An emitter that emits infrared light by being heated to a high temperature, a plurality of photovoltaic cells that are arranged close to each other with its light-receiving surface facing one surface of the emitter, and combustion for heating the one surface of the emitter In a thermophotovoltaic power generation device comprising: a first combustion chamber for generating gas; and a flow path for guiding the combustion gas generated in the first combustion chamber to one surface of the emitter.
By forming the one surface of the emitter into a dome shape, a space is provided between the plurality of photovoltaic cells to form a second combustion chamber, and in the combustion gas generated in the first combustion chamber An unburned portion is combusted in the second combustion chamber.   2. The thermophotoelectric generator according to claim 1, wherein a flow path of the combustion gas is formed with respect to an inflow surface to the second combustion chamber so that a swirl flow is formed by the combustion gas in the second combustion chamber. A thermophotovoltaic power generation device characterized by being formed at an angle.   The thermophotoelectric generator according to claim 1, wherein a reflector is provided to face a surface other than the one surface of the emitter. A columnar emitter that emits infrared light when heated to a high temperature, a plurality of photovoltaic cells disposed so as to oppose a light receiving surface to and surround the side wall in the axial direction of the columnar emitter, and the emitter Thermoelectric power generation comprising: a first combustion chamber that generates combustion gas for heating the side wall of the first gas; and a flow path for guiding the combustion gas generated in the first combustion chamber to the side wall of the emitter In the device
A space is provided between the side wall of the columnar emitter and the plurality of photovoltaic cells to form a second combustion chamber, and unburned components in the combustion gas generated in the first combustion chamber are removed from the second combustion chamber. A thermoelectric power generator characterized by being burned in   5. The thermophotoelectric generator according to claim 4, wherein the flow path of the combustion gas is formed in the second combustion chamber so that a swirl flow of the combustion gas surrounding the columnar emitter side wall is formed in the second combustion chamber. A thermophotovoltaic power generation device characterized in that it is formed at an angle with respect to the inflow surface.

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