JPH10136672A - Thermoelectric generation unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable uniform pressurization superior in thermal contact in a thermoelectric module, a heat exchanger for heating and a heat exchanger for cooling by filling the gaps among the heat exchanger for heating, the thermoelectric module and the heat exchanger for cooling with helium gas, and using a pressurizing means which uses fluid as the pressurizing medium. SOLUTION: A thermoelectric power generation unit 1 is provided with a nine-layered laminate, constituted of plate fin type heat exchangers 3 for heating, thermoelectric power generating modules 2 and plate fin type heat exchangers 4 for cooling. These apparatuses are encapsulated in a box-type sealing material, which is filled with helium gas. As a pressuring means, air pressure in a bellows is changed, and the pressure applied to the nine-layered laminate encapsulated in the seal material is adjusted. As a result, thermal contact (thermal efficiency) among the heat exchangers 3, the thermoelectric modules 2 and the heat exchangers 4 is improved. These apparatuses are pressurized by using a pressurizing means 9 which uses fluid such as air for the pressurizing medium, so that uniform pressurization is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric generator unit, and more particularly to a thermoelectric generator unit of a cogeneration system utilizing waste heat.

[0002]

2. Description of the Related Art As shown in FIG. 4, a semiconductor thermoelectric element 41 for converting heat energy of a certain form directly into electric energy utilizing the Seebeck effect is replaced with a p-type semiconductor 42 and an n-type semiconductor 42 instead of two kinds of metals. A device in which a pair of semiconductors 43 are connected as a device is used. In FIG. 4, reference numeral 44 denotes a ceramic insulating plate, reference numeral 45 denotes a heating plate fin type heat exchanger, and reference numeral 46 denotes a cooling plate fin type heat exchanger. Since the electromotive force is small in such a pair of semiconductor thermoelectric elements 41, a thermoelectric power generation module in which a large number of pairs are unitized in series is used.

[0003] There is a cogeneration system that uses the thermoelectric generation module having the above-described configuration and recovers and uses heat of an engine-driven generator and exhaust gas and cooling water thereof. An example of this is shown in FIG. That is, the thermoelectric generation unit 51 is provided between the gas engine 52 and the exhaust gas heat exchanger 53. The jacket water heat exchanger 54 is connected to the gas engine 52 and the thermoelectric generation unit 51, respectively. The hot water heat exchanger 55 is provided with the exhaust gas heat exchanger 5.
3 is connected. The cooling heat exchanger 56 is connected to the hot water heat exchanger 55. The cooling tower 57 is connected to the cooling heat exchanger 56. In such a cogeneration system, the thermoelectric generation unit 51 plays a role of converting exhaust heat of the engine into electric power.

FIG. 6 shows the thermoelectric power generation unit. The thermoelectric generation unit 60 includes a thermoelectric generation module 61. The two ceramic insulating plates 62a and 62b are bonded to both surfaces of the thermoelectric power generation module 61 with grease 63 having good thermal conductivity and high viscosity. Thermoelectric power generation module 61 and two ceramic insulating plates 62
Two inserts 64a and 64b for improving the thermal contact between the a and 62b are adhered to the outer surface of the five-layer laminate by grease 63. The heating plate fin type heat exchanger 65 is adhered to the upper surface of the insert material 64a with grease 63. The cooling plate fin type heat exchanger 66 is bonded to the lower surface of the insert material 64b with grease 63.

Since the electric output depends on the quality of heat dissipation from the high-temperature side of the thermoelectric power generation module 61, the surface accuracy of the contact surface in the 13-layer laminate having such a structure is set in advance to about 10 μm or less. I have. Upper plate 67 and lower plate 68
Are located on the outer surface of the 13-layer laminate and
9 and a nut (not shown). Due to the sandwiching by the upper plate 67 and the lower plate 68, a load of, for example, 10 kg / cm ² is applied to the 13-layer laminate.

[0006] The thermoelectric power generation unit 60 having such a structure.
Heats one surface of the thermoelectric generation module 61 with the heat exchanger 65 for heating, and cools (radiates) the other surface with the heat exchanger 66 for cooling. By generating a temperature difference between the surface of the module with the heating heat exchanger 65) and the surface of the module with the thermoelectric generation module 61 and the cooling body (the heat exchanger 66 for cooling), the electric output can be increased. I'm taking it out.

However, the air conductivity and the solid matter are mixed in the grease 63 layer at the time of application, so that the thermal conductivity is significantly reduced. Further, the heat exchangers 65 and 66 of the thermoelectric generation unit 60, the ceramic insulating plates 62a and 62b
In addition, the surfaces of the inserts 64a and 64b have irregularities. As a result, the contact thermal resistance between the thermoelectric generation module 61, the heating element (on the side of the heating heat exchanger 65) and the cooling element (on the side of the cooling heat exchanger 66) significantly increases, and the thermal efficiency decreases. This leads to a decrease in power generation efficiency. The thermoelectric power generation module 61 and the ceramic insulating plates 62a, 62
FIG. 7 shows a state in which the air 70 is mixed in the grease layer 63 existing between b.

As described above, when the 13-layer laminate including the thermoelectric power generation module 61 is pressed by sandwiching it between the upper plate 68 and the lower plate 67, the upper plate 68 and the lower plate 67 are deformed, and Since the applied load becomes non-uniform, the contact thermal resistance between the thermoelectric power generation module 61 and the heat exchangers 62 and 63 locally increases, so that the thermal efficiency is reduced and the power generation efficiency is reduced. In addition, if the weight becomes uneven, the output of each module varies, and in extreme cases, the ceramic insulating plates 62a and 62b and the thermoelectric generation module 61 may be broken. When the grease 63 is removed during maintenance, the grease is removed from the ceramic insulating plate 6.
Since the ceramic insulating plates 62a, 62b, etc. are taken out, they may be damaged because they adhere to the 2a, 62b, etc. In addition, there is a problem that it takes time to remove grease during maintenance.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a thermoelectric power generation unit in which a thermoelectric power generation module, a heat exchanger for heating and a heat exchanger for cooling have good thermal contact and these are uniformly pressurized. It is intended to provide.

[0010]

A thermoelectric generation unit according to the present invention comprises a thermoelectric generation module, a heating heat exchanger disposed on one surface of the thermoelectric generation module, and the other surface of the thermoelectric generation module. A cooling heat exchanger disposed in the helium gas present between the heating heat exchanger and the thermoelectric generator module and between the cooling heat exchanger and the thermoelectric generator module, the heating heat exchanger, And a pressurizing means for pressurizing the thermoelectric power generation module and the cooling heat exchanger and including a fluid as a pressurizing medium.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
A fluid is used as a pressurizing medium used for pressurizing means for pressurizing the thermoelectric power generation module, the heating heat exchanger, and the cooling heat exchanger. Examples of the fluid include a gas such as air and nitrogen, and a liquid such as silicone oil.

According to the thermoelectric power generation unit of the present invention, helium gas is present between the heat exchanger for heating and the thermoelectric power generation module and between the heat exchanger for cooling and the thermoelectric power generation module (thermal interface). The gas is an inert gas whose thermal conductivity is several tens of times higher than that of air.It does not contain impurities like when a grease layer is provided, and has no thickness like a grease layer. Since the heaters can be arranged close to each other, it is possible to improve the thermal contact (thermal efficiency) between the heating heat exchanger, the module, and the cooling heat exchanger. Also,
By making the pressurizing medium of the means for pressurizing (pressing) the thermoelectric power generation module, the heating heat exchanger, and the cooling heat exchanger into a fluid, they can be uniformly pressurized. It is possible to avoid a local increase. Therefore, it is possible to provide a thermoelectric power generation unit with significantly improved power generation efficiency.

[0013] Further, since pressure for pressing the grease layer is not required, the pressing means can be downsized.
The weight of the thermoelectric generation unit can be reduced. Furthermore,
Since problems that occur when removing grease can be solved, maintenance of the thermoelectric power generation unit can be easily performed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is a perspective view showing the thermoelectric power generation unit according to the present invention with a part cut away, FIG. 2 is a front view of the thermoelectric power generation unit of FIG. 1, and FIG. FIG. 2 shows a schematic view of the thermal contact interface in the module.

As shown in FIGS. 1 and 2, a thermoelectric power generation unit 1 includes a four-layer thermoelectric power generation module 2, a three-layer heating plate fin heat exchanger 3, and a two-layer cooling plate fin heat exchanger. 4 comprising a nine-layer laminate. In this 9-layer laminate, the first, fifth and ninth layers are plate heat exchangers 3 for heating, the second, fourth, sixth and eighth layers are thermoelectric generator modules 2 and the third and seventh layers are cooling plates. This is a fin type heat exchanger 4. The three exhaust gas supply pipes 5 are respectively connected to the side surfaces of the three-layer heating plate fin heat exchanger 3. The three exhaust gas discharge tubes 6 are respectively connected to side surfaces of the heating plate fin heat exchangers 3 opposite to the side surfaces to which the exhaust gas supply tubes 5 are connected. The two cooling water supply pipes 7 are respectively connected to the side surfaces of the plate fin type heat exchanger 4 for cooling. The two cooling water discharge tubes (not shown) are respectively connected to side surfaces of the cooling plate fin heat exchangers 4 opposite to the side surfaces to which the cooling water supply tubes 7 are connected. The thermoelectric power generation module 2, the heating plate fin heat exchanger 3, and the cooling plate fin type heat exchanger 4 in such a nine-layer laminate are sealed in a box-shaped sealing material (not shown). . Helium gas is filled in the sealing material. The two heat insulating plates 8a and 8b are arranged on the upper and lower surfaces of the nine-layer laminated structure enclosing the sealing material. An SUS single-shaped bellows 9 as a pressurizing means is disposed on the heat insulating plate 8a, and has an air pressure adjusting hole 10 at an upper portion. By supplying or discharging air into the bellows 9 from the adjustment hole 10 to change the air pressure in the bellows 9 and expand and contract the bellows 9,
The pressure applied to the sealing material enclosing 9-layer laminate is adjusted.
The upper plate 11 is arranged on the upper surface of the heat insulating plate 8a. The ribbed holding plate 12 reinforced by ribs is arranged on the lower surface of the heat insulating plate 8b. The upper plate 11 and the holding plate 12 with plate ribs are fixed by bolts 13 and nuts 14, and sandwich the two heat insulating plates 8a and 8b and the nine-layer laminate enclosing a sealing material. Note that a pressure of 10 kgf / cm ² was uniformly applied to the nine-layer laminate containing the sealing material.

According to the thermoelectric generation unit 1 according to the above embodiment, as shown in FIG. 3, for example, between the thermoelectric generation module 2 and the heating heat exchanger 3 and between the thermoelectric generation module 2 and the cooling heat exchange. Since the helium gas 15 exists between the heat exchangers 4, the thermal contact (thermal efficiency) between the heat exchanger 3, the thermoelectric power generation module 2, and the heat exchanger 4 can be improved. The pressurization of the heat exchanger 3, the thermoelectric power generation module 2, and the heat exchanger 4 is performed by pressurizing means 9 using a fluid such as air as a pressurized medium, so that the heat exchanger 3, The thermoelectric power generation module 2 and the heat exchanger 4 can be uniformly pressurized,
The contact heat resistance can be prevented from locally increasing. Therefore, a sufficient temperature difference can be generated between the junction between the heat exchanger 3 and the thermoelectric generation module 2 and the junction between the heat exchanger 4 and the thermoelectric generation module 2, and the power generation efficiency is reduced. Can be improved.

[0017]

As described above in detail, according to the thermoelectric generator module according to the present invention, good heat contact between the heating heat exchanger, the thermoelectric generator module and the cooling heat exchanger can be achieved. , The contact thermal resistance can be prevented from partially increasing, the power generation efficiency can be improved, and the output can be prevented from varying for each module.
It has remarkable effects such as easy maintenance and light weight.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a thermoelectric power generation unit according to one embodiment of the present invention.

FIG. 2 is a schematic front view of FIG.

FIG. 3 is an enlarged view of a boundary surface between a thermoelectric generation module and a heat exchanger of the thermoelectric generation unit in FIG. 1;

FIG. 4 is a principle diagram of a thermoelectric power generation system.

FIG. 5 is a system diagram of a thermoelectric power generation system.

FIG. 6 is a schematic front view of a conventional thermoelectric generation unit.

FIG. 7 is an enlarged view of a boundary surface between a thermoelectric generation module of a conventional thermoelectric generation unit and a ceramic insulating plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Thermoelectric power generation unit, 2 ... Thermoelectric power generation module, 3 ... Heating plate fin type heat exchanger, 4 ... Cooling plate fin type heat exchanger, 9 ... Pressurizing means, 11 ... Upper plate, 12 ... Holder with rib Board.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichi Tada 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Hitoshi Nishino 4-chome, Hirano-cho, Chuo-ku, Osaka, Osaka No. 1-2 in Osaka Gas Co., Ltd.

Claims (1)

[Claims] A thermoelectric power module; a heating heat exchanger disposed on one surface of the thermoelectric power module; a cooling heat exchanger disposed on the other surface of the thermoelectric power module; Helium gas existing between the heat exchanger for heat and the thermoelectric generator module and between the heat exchanger for cooling and the thermoelectric generator module; and the heat exchanger for heating, the thermoelectric generator module and the heat exchanger for cooling. And a pressurizing unit that pressurizes and includes a fluid as a pressurizing medium.