JPH07123758A - Thermoelectric power generator - Google Patents

Abstract

PURPOSE:To provide a thermoelectric power generator which is constituted by combining a combustor and thermoelectric conversion modules and is contrived to efficiently heat the heated surfaces of the modules and to prevent the thermal destruction of the modules. CONSTITUTION:A variable conductance type heating heat pipe 2 is installed, with its heat receiving section 2c facing a combustor 1, and, at the same time, multiple thermoelectric conversion modules 3 are arranged on the peripheral surface of the heat radiating section 2d of the pipe 2 in a heat transferring state. In addition, a gas reservoir section 2e in which a non-condensable gas is enclosed and which is equipped with heat radiating fins 2f is continuously provided on the heat radiating section 2d of the pipe 2 and the heated surfaces (on a high-temperature interface side) of the modules 3 are uniformly heated by supplying the combustion heat of the combustor 1 to the modules 3 by using the pipe 2 as a heat carrying means. At the same time, the abnormal overheating of module elements is prevented when the inputted quantity of heat increases by using the variable conductance function of the pipe 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric generator which is constructed by combining a combustor and a thermoelectric conversion module.

[0002]

2. Description of the Related Art As a thermoelectric power generator applying the Seebeck effect, a method in which a combustor is used as a heat source and a large number of semiconductor thermoelectric conversion elements are connected in series and in parallel as shown in the preceding paragraph. Are well known. Here, in the conventional thermoelectric power generation device, a plurality of thermoelectric conversion modules are heat-conductively coupled on the outer peripheral surface of the combustion cylinder with respect to the combustor in which the burner and the combustion cylinder are combined, and the surface to be heated of the module is heated. While heating (the high temperature junction point of the thermoelectric conversion element), a radiation fin is attached to the surface to be cooled (the low temperature junction point of the thermoelectric conversion element) opposite to the surface to be heated and forced air cooling is performed by a cooling fan. It is configured to provide a temperature difference between the hot junction and the cold junction of the conversion module to obtain an electrical output (thermoelectromotive force).

[0003]

By the way, the above-mentioned conventional thermoelectric generator has the following problems in terms of performance and reliability. (1) When the burner and the combustion cylinder of the combustor are arranged on the horizontal axis, the flame blown out from the burner into the combustion cylinder turns upward due to the effect of thermal convection in the cylinder, and is biased upward. The upper half and the lower half are not heated uniformly. Further, when the burner and the combustion cylinder are arranged vertically, the flame blows up vertically from the burner, so that the upper region and the lower region of the combustion cylinder are not heated uniformly. For this reason, the heating temperature of the surface to be heated for each thermoelectric conversion module dispersedly arranged on the peripheral surface of the combustion cylinder is different, and as a result, there is a difference in output voltage between the modules, and high power generation efficiency cannot be obtained. . Moreover, in the thermoelectric conversion module arranged in the region where the combustion temperature is high, the element may be overheated to the allowable temperature or higher and may be thermally destroyed when abnormal combustion occurs in the burner.

(2) Further, in the cooling system in which the cooling air is blown from the cooling fan toward the radiating fins mounted on the surface to be cooled of the thermoelectric conversion module, the modules arranged in the upstream side of the cooling air flow and the modules arranged in the downstream side of the cooling air flow. The modules and the modules are not uniformly cooled, and this causes a difference in cooling temperature between the modules, which causes variations in the output voltage. The present invention has been made in view of the above points, and is intended for the above-mentioned thermoelectric power generation device in which a combustor and a thermoelectric conversion module are combined, the object of which is to solve the above problems and to provide a heated surface of the thermoelectric conversion module. In addition, it is to provide a thermoelectric power generation device capable of uniformly and efficiently heating and cooling the surface to be cooled to improve the power generation efficiency.

[0005]

In order to achieve the above object, the thermoelectric generator of the present invention is constructed as follows. (1) A variable-conductance-type heat pipe for heating is installed in the combustor so that the heat receiving part faces it, and a plurality of thermoelectric conversion modules are arranged in a heat transfer manner on the peripheral surface of the heat radiating part of the heat pipe. .

(2) In the above item (1), the heat receiving portion of the cooling heat pipe is attached to the surface to be cooled of the thermoelectric conversion module in a heat conductive manner, and the heat radiating portion of the heat pipe is forcibly cooled. (3) In the above item (1) or (2), a gas reservoir portion with a heat radiating fin in which a non-condensable gas is sealed is provided in series with the heat radiating portion of the heating heat pipe.

(4) The heat radiating portion of the cooling heat pipe in the preceding paragraph (2) and the gas reservoir portion of the heating heat pipe in the preceding paragraph (3) are arranged side by side in the air passage of the cooling fan.

[0008]

In the above structure, the heating heat pipe operates as follows. That is, the combustion heat generated in the combustor heats the heat receiving portion of the heating heat pipe and evaporates the working fluid sealed in the heat pipe. Further, the vapor of the working fluid diffuses in the heat pipe, is condensed in the heat radiating portion, and then repeats the evaporation / condensing cycle so as to be returned to the heat receiving portion, and in this process, the thermoelectric conversion module heat-transfer coupled to the heat radiating portion. The heated surface of is heated. In this case, if there is a portion with a low wall surface temperature in the heat radiation part, the vapor of the hydraulic fluid will condense much in that portion, so the wall surface temperature throughout the heat radiation part will always be uniform, so that it will be dispersed on the peripheral surface of the heat radiation part. The heated surface of each thermoelectric conversion module arranged is also heated to a uniform temperature.

Here, as a well-known heat pipe for heating, by adopting a variable conductance type heat pipe in which a non-condensable gas is enclosed together with a working liquid in the pipe, as well known, The effective area that functions as a heat radiating unit increases / decreases in response to the increase / decrease in heat input (self-control function). Therefore, even if the heat input to the heat pipe fluctuates due to changes in the combustion state in the combustor, the amount of heat given to the thermoelectric conversion module placed in the peripheral region of the heat pipe heat-dissipation section is kept almost constant, so It is possible to avoid a troubled situation in which the surface to be heated of the module is abnormally overheated due to abnormal combustion or the like and the thermoelectric conversion element of the module is thermally destroyed. In particular, by providing a gas reservoir with a radiation fin for connecting the non-condensable gas to the radiation portion of the heating heat pipe, the variable conductance function can be effectively operated.

The cooling heat pipe attached to the surface to be cooled of the thermoelectric conversion module operates as follows. That is, when heat is transferred from the heated surface side to the cooled surface side through the thermoelectric conversion module itself, the cooling heat pipe receives the heat and the working liquid evaporates. While taking heat from the cooling surface, the vapor of the working liquid moves to the heat radiating section and is condensed, and the condensed heat is radiated to the outside through the heat radiating section of the heat pipe. Moreover, the evaporation of the working liquid is performed in proportion to the amount of heat input to the heat receiving portion, so that the surface temperature of the heat receiving portion, and thus the surface to be cooled of each thermoelectric conversion module, is also cooled to a uniform temperature.

As a result, the temperature of the heated surface and the cooled surface of each thermoelectric conversion module becomes uniform, and there is no voltage difference in the electrical output (thermoelectromotive force) between the modules, so that the power generator High power generation efficiency can be obtained as a whole, and heat damage to the thermoelectric conversion module element due to local overheating can be prevented.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 shows an embodiment corresponding to claims 1 and 3, in which 1 is a combustor, 2 is a heating heat pipe, 3 is a thermoelectric conversion module, and 4 is a cooling fan. As the heating heat pipe 2, a gravity-type variable conductance heat pipe in which a non-condensable gas 2b is enclosed together with a working fluid 2a is adopted.
The heat pipe 2 is arranged above the combustor 1 with the heat receiving portion (evaporating portion) 2c facing down, and the heat radiating portion (condensing portion) 2d.
A plurality of thermoelectric conversion modules 3 are installed on the upper peripheral surface of the heat pipe that functions as a heat transfer surface by superimposing the surface to be heated on the wall surface of the heat dissipation portion, and the surface to be cooled of the thermoelectric conversion module 3 ( A block fin 5 for heat radiation is attached to the surface opposite to the surface to be heated. Further, the top of the heat pipe 2 is provided with a radiation fin 2e on its outer peripheral surface as a gas reservoir 2e for the non-condensable gas 2b. The cooling fan 4 is disposed so as to face the heat radiation fins 2f and the heat radiation fins (block fins) 5.

With this structure, when fuel is supplied to the combustor 1 for combustion, the heat receiving portion 2c of the heat pipe 2 is heated by the combustion heat of the flame 1a blown out from the combustor 1, and the working fluid 2 is discharged.
As a vaporizes, the vapor 2g diffuses inside the heat pipe and pushes the non-condensable gas 2b toward the gas reservoir 2e at the top due to the vapor pressure (P in the figure is the vapor 2g of the working fluid). Along with the boundary surface with the non-condensable gas 2e), it condenses on the wall surface of the heat dissipation portion 2d and heats the heated surface of the thermoelectric conversion module 3. The surface to be cooled of the thermoelectric conversion module 3 and the gas reservoir 2e of the heat pipe 2 are forcedly cooled by the air blown by the cooling fan 4. As a result, a temperature difference occurs between the high temperature junction and the low temperature junction of the thermoelectric conversion module 3, and a thermoelectromotive force is generated in the module 3 due to the Seebeck effect.

Further, in this state, when the heat of combustion in the combustor 1 increases and the amount of heat input to the heat receiving portion 2a of the heat pipe 2 increases, the vapor pressure of the working fluid 2a also increases accordingly. The volume of the condensable gas 2b decreases and the boundary surface P moves upward. As a result, the effective area length of the heat radiating portion increases, and the amount of heat radiated in the entire heat pipe increases so that the working liquid vapor 2g radiates heat to the outside through the wall surface and the heat radiation fins 2f even in the area of the gas reservoir 2e. . On the contrary, when the heat input amount of the heat receiving portion 2a decreases, the vapor pressure of the working fluid decreases, the non-condensable gas expands, and the effective area length of the heat radiating portion decreases. Therefore, by optimizing the enclosed amount of the non-condensable gas 2b in advance, even if the heat input amount increases or decreases, the temperature of the surface to be heated of the thermoelectric conversion module 3 does not significantly change, and the heat input amount increases. However, the module is not overheated abnormally.

Embodiment 2 FIG. 2 shows an application example of Embodiment 1, wherein the heating heat pipe 2 has a flat structure, the bottom surface side thereof is the heat receiving portion 2c, and the top surface side thereof is the heat radiating portion 2d.
Further, a gas reservoir 2e of the non-condensable gas 2b standing upward is provided in the central portion on the upper surface side so as to be continuous with the heat radiating portion 2d. Then, the thermoelectric conversion modules 3 are dispersed and mounted on the upper surface side heat radiation portion 2d of the heat pipe 2. A cooling fan 4 is provided so as to face the heat radiation fins 2f provided on the peripheral surface of the gas reservoir 2e.

The operation and operation of this structure are the same as in the first embodiment. Embodiment 3 FIG. 3 shows an embodiment corresponding to claims 2 and 4, and a thermoelectric conversion module 3 in which a heated surface is superposed on the peripheral surface of the heat radiating portion 2d of the heating heat pipe 2 is arranged. On the other hand, the heat receiving portion (evaporating portion) of the gravity type heat pipe 6 for cooling is heat-transferably coupled to the surface to be cooled in place of the heat radiation fins 5 in the above-described first and second embodiments. In addition, a radiation fin 6a is provided in the heat radiation portion (condensing portion) on the upper side of the cooling heat pipe 6 and is arranged at the same height as the gas reservoir portion 2e of the variable conductance type heating heat pipe 2, and is arranged on the side thereof. Cooling heat pipe 6 with cooling fan 4 arranged oppositely
Radiating portion of the gas and the gas reservoir 2e of the heating heat pipe 2
Is forced to cool.

With this configuration, the thermoelectric conversion module 3
The heat transferred from the heated surface side to the cooled surface side is transferred to the heat receiving portion of the cooling heat pipe 6, and is dissipated through the radiation fins 6a of the heat radiation portion by the evaporation / condensation cycle operation of the heat pipe. . In this case, the working liquid in the cooling heat pipe 6 is evaporated in accordance with the amount of heat input to the heat receiving portion, so that the surface to be cooled of each thermoelectric conversion module 3 is maintained at a uniform temperature. Further, even if the heat input amount from the combustor 1 to the heating heat pipe 2 increases in this state, the first embodiment
As described above, the variable conductance function of the heat pipe does not cause the surface to be heated of the thermoelectric conversion module 5 to be abnormally overheated, and the surface is heated to a uniform temperature. In this case, by arranging the gas reservoir 2e of the heating heat pipe 2 and the heat radiating portion of the cooling heat pipe 6 side by side in the ventilation path of the cooling fan 4, both can be cooled by the cooling fan 4 at the same time. .

[0018]

As described above, the structure of the present invention has the following effects. (1) According to the constitutions of claims 1 and 3, the combustion heat of the combustor is applied to the thermoelectric conversion modules by using the heating heat pipe as a heat transport means to heat the heated surfaces of the thermoelectric conversion modules to a uniform temperature. In addition to being able to do, the heat pipe for heating is a variable conductance type heat pipe,
Even if the amount of heat generated by the heat source is abnormally increased, thermal destruction of the module element can be safely prevented without abnormally overheating the surface to be heated of the thermoelectric conversion module. Thereby, the output voltage of each thermoelectric conversion module can be made constant, and the power generation efficiency of the entire power generation device can be improved. Further, in particular, by providing a gas reservoir with a radiation fin for enclosing the non-condensable gas in the heating heat pipe, the variable conductance function can be effectively functioned as the heat input from the heat source increases. .

(2) By combining the constitutions of claims 1 and 3 with the constitutions of claims 2 and 4, the surface to be cooled of the thermoelectric conversion module can be efficiently cooled to a uniform temperature via the cooling heat pipe. In addition to arranging the heat radiation part of the cooling heat pipe and the gas reservoir part of the heating heat pipe side by side in the air passage of the cooling fan, it is possible to cool the heat radiation part of the cooling heat pipe with the same cooling fan. At the same time, the gas reservoir of the heating heat pipe can also be cooled, which simplifies the structure.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a thermoelectric generator according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a thermoelectric power generator according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a thermoelectric generator according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustor 2 Heating heat pipe 2a Hydraulic fluid 2b Non-condensable gas 2c Heat receiving part 2d Radiating part 2e Gas storage part 2f Radiating fin 2g Steam of working fluid 3 Thermoelectric conversion module 4 Cooling fan 5 Radiating fin 6 Cooling heat pipe 6a Radiation fin

Claims (4)

[Claims] 1. A thermoelectric power generator for generating power by a thermoelectric conversion module using a combustor as a heat source, wherein a heat receiving pipe of variable conductance type is installed with a heat receiving portion facing the combustor, and heat radiation of the heat pipe is performed. A thermoelectric power generation device comprising a plurality of thermoelectric conversion modules arranged in a heat transfer manner on a peripheral surface. 2. The thermoelectric generator according to claim 1, wherein the heat receiving portion of the cooling heat pipe is attached to the surface to be cooled of the thermoelectric conversion module in a heat conductive manner, and the heat radiating portion of the heat pipe is forcibly cooled. And a thermoelectric generator. 3. The thermoelectric generator according to claim 1 or 2, further comprising: a gas reservoir portion with a radiation fin filled with a non-condensable gas, which is connected to the heat radiation portion of the heating heat pipe. apparatus. 4. The heat radiating portion of the cooling heat pipe according to claim 2 and the gas reservoir portion of the heating heat pipe according to claim 3 are arranged side by side in the air passage of the cooling fan. Thermoelectric generator.