WO2016093238A1

WO2016093238A1 - Thermoelectric conversion device

Info

Publication number: WO2016093238A1
Application number: PCT/JP2015/084419
Authority: WO
Inventors: 孝広地主; 征央根岸; 昌尚冨永; 石島　善三; 亮大谷; 森　正芳; 寛治松本; 松本　学
Original assignee: 日立化成株式会社; 本田技研工業株式会社
Priority date: 2014-12-10
Filing date: 2015-12-08
Publication date: 2016-06-16

Abstract

The purpose of the invention is to increase the amount of power generation by increasing the amount of heat supplied to a thermoelectric conversion module via sheet parts, even when high-temperature-side and low-temperature-side sheet parts that sandwich the thermoelectric conversion module are made of a metal having low thermal conductivity, such as stainless steel. Disclosed is a thermoelectric conversion device comprising a high-temperature-side sheet part 12 and a low-temperature-side sheet part 22 that are arranged in opposition to one another, and a thermoelectric conversion module 40 that is arranged between these sheet parts 12, 22 and to which a temperature difference is imparted, wherein: a thermally conductive sheet 60 that collects the heat of the sheet part(s) and supplies the heat to the thermoelectric conversion module 40 is provided between the high-temperature-side sheet part 12 and the thermoelectric conversion module 40 and/or between the low-temperature-side sheet part 22 and the thermoelectric conversion module 40. Thus, heat loss in the sheet parts is suppressed, and the temperature difference occurring at the thermoelectric conversion module 40 is further increased.

Description

Thermoelectric converter

The present invention relates to a thermoelectric conversion device such as a thermoelectric conversion power generation device that converts a thermal energy into an electric energy by giving a temperature difference to a thermoelectric conversion module, for example.

The thermoelectric conversion power generation device converts thermal energy into electrical energy using the Seebeck effect such as causing a potential difference between the high temperature part and the low temperature part by giving a temperature difference to the separated parts. It is known that the amount of power generation increases as the temperature difference increases. Such a thermoelectric conversion element is used in the form of a thermoelectric conversion module in which a plurality are joined by electrodes. For example, a thermoelectric module and a low temperature part are laminated on the outer surface of the pipe body, and a heating fluid is introduced into the pipe body, so that a thermoelectric element sandwiched between the heated pipe body (high temperature part) and the low temperature part. There is known a thermoelectric conversion power generator configured to generate electricity by generating a temperature difference in a conversion module (Patent Document 1).

JP 2006-217756 A

The above-mentioned tube body into which the heated fluid is introduced is required to have heat resistance, and stainless steel is mainly used in consideration of workability and economy. However, since stainless steel has low thermal conductivity, it is disadvantageous in terms of efficiently transmitting the high heat temperature of the heating fluid to the thermoelectric conversion module. When the heating fluid to be used is, for example, exhaust gas, the temperature is almost constant and it is difficult to raise the temperature. Therefore, more heat loss of the heating fluid is taken into the thermoelectric conversion module to minimize heat loss. Countermeasures such as reduction are required.

The present invention has been made in view of the above circumstances, and its main problem is that even if the high-temperature side plate portion and the low-temperature side plate portion that are arranged to face each other are made of a metal having low thermal conductivity such as stainless steel, the plate An object of the present invention is to provide a thermoelectric conversion device that can efficiently supply the heat amount on the high temperature side or the low temperature side flowing to the thermoelectric conversion module through the unit to the thermoelectric conversion module, thereby improving the power generation amount.

The thermoelectric conversion device of the present invention is disposed between a high-temperature side plate portion and a low-temperature side plate portion that are arranged opposite to each other, and the high-temperature-side plate portion and the low-temperature-side plate portion. And a thermoelectric conversion module to which a temperature difference is given by the low temperature side plate portion, between the high temperature side plate portion and the thermoelectric conversion module, or the low temperature side plate portion And a thermoconductive plate that is in close contact with the plate portion and supplies heat of the plate portion to the thermoelectric conversion module.

In the present invention, at least one of the amount of heat transmitted to the high temperature side plate (heat amount on the heating side) or the amount of heat transmitted to the low temperature side plate (the amount of heat on the cooling side) is in close contact with the heat conducting plate. Heat is collected from the plate portion to the heat conducting plate and transmitted to the thermoelectric conversion module. Even if the plate part is a low heat conductive metal such as stainless steel, the amount of heat is collected on the heat conduction plate through the plate part, so that the heat loss of the plate part is suppressed and the amount of heat efficiently passes through the heat conduction plate. Is transmitted to the thermoelectric conversion module. As a result, the amount of heat supplied to the thermoelectric conversion module increases and the temperature difference generated in the thermoelectric conversion module increases, thereby improving the amount of power generation.

Included in the present invention is a configuration in which the thermal conductivity of the thermal conductive plate is made of a material having a thermal conductivity of 50 W / m · k or more. In this embodiment, the heat collecting effect is further increased by the heat conducting plate having a relatively high heat conductivity, and the amount of heat supplied from the plate portion to the thermoelectric conversion module through the heat conducting plate can be further increased.

Further, the present invention includes a form in which the heat conducting plate is disposed in a decompression chamber that is a negative pressure space. In this embodiment, by reducing the pressure in the decompression chamber to a negative pressure space, it is possible to obtain a state in which the heat conduction plate is difficult to be oxidized without being exposed to the oxidizing atmosphere. Therefore, it is effective when the heat conductive plate is a metal that is easily oxidized such as copper.

According to the thermoelectric conversion device of the present invention, the high-temperature side plate portion and the low-temperature side plate portion that are arranged to face each other flow through the plate portion to the thermoelectric conversion module even if the metal has low thermal conductivity such as stainless steel. The amount of heat on the high temperature side or the low temperature side can be efficiently supplied to the thermoelectric conversion module, thereby producing an effect of improving the amount of power generation.

It is sectional drawing of the thermoelectric conversion type electric power generating apparatus which concerns on one Embodiment of this invention. It is a perspective view which shows the thermoelectric conversion module mounted on the pipe body of the same electric power generating apparatus, and the heat conductive board of this invention. (A): Partial enlarged view of FIG. 1, (b): The b section enlarged view of (a). It is sectional drawing which shows other embodiment which changed the arrangement | positioning position of a heat conductive board.

1. Power generation device (thermoelectric conversion device)
12 ... High temperature side plate 20 ... Module room (decompression room)
22 ... Low temperature side plate part 40 ... Thermoelectric conversion module 60 ... Thermal conduction plate

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[1] Configuration of Thermoelectric Conversion Power Generation Device FIG. 1 shows a thermoelectric conversion power generation device 1 to which the thermoelectric conversion device of the present invention is applied. The power generation device 1 has a flat rectangular parallelepiped shape as a whole, and a tubular body 11 made of a flat tube passes through the center. A module chamber (decompression chamber) 20, a cold chamber 30, and Are formed symmetrically in the vertical direction.

Inside the pipe body 11, a pipe line 10 is formed that penetrates in the left-right direction in FIG. 1 and through which the heating fluid H flows along the penetration direction. The tubular body 11 has flat plate portions 12 that are arranged in parallel in the vertical direction and face each other. These plate portions 12 are heated by the heating fluid H flowing through the pipe line 10. Hereinafter, these plate portions 12 are referred to as high-temperature side plate portions 12. A flat tubular inner case 21 is disposed around the tube body 11, and an outer case 31 is disposed further around the inner case 21.

The inner case 21 has a flat plate portion 22 that is parallel to the upper and lower high-temperature plate portions 12 of the tube body 11 and faces the plate portions 12. The module chamber 20 is formed by a tube body 11 and an inner case 21, and the module chamber 20 is hermetically sealed by a sealing cover 23 that seals both end openings between the tube body 11 and the inner case 21. Yes. The module chamber 20 has a predetermined pressure (for example, about 1 to 100 Pa) by sucking air from a decompression sealing port (not shown) formed in the sealing cover 23 and the like and then sealing the decompression sealing port. ).

The inner case 21 and the outer case 31 are airtightly joined, and a low temperature chamber 30 is formed between the

cases

21 and 31. A cooling medium such as cooling water is supplied to the low greenhouse 30, and the plate portion 22 of the inner case 21 is cooled by the cooling medium. Hereinafter, the plate portion 22 is referred to as a low temperature side plate portion 22. The pipe 10 and the low temperature chamber 30 inside the tube body 11 can be provided with fins for improving the efficiency of heat conduction to the

plate portions

12 and 22 on the high temperature side and the low temperature side.

The tubular body 11, the inner case 21, the outer case 31, and the sealing cover 23 are made of a metal such as stainless steel having heat resistance and oxidation resistance, such as SUS444, and the joint portion is fixed by fixing means such as brazing. The

In the module room 20, a plurality of thermoelectric conversion modules 40 are arranged. 2 and 3, the thermoelectric conversion module 40 includes a plurality of rectangular parallelepiped thermoelectric conversion elements 41 arranged in a matrix and a plurality of electrodes 45 that connect these thermoelectric conversion elements 41 in series. Is done. As the thermoelectric conversion element 41, a type having a high heat-resistant temperature is used. For example, a silicon-germanium system, a magnesium-silicon system, a manganese-silicon system, an iron silicide system, or the like is preferably used.

The electrode 45 is divided into a high temperature side electrode 451 disposed opposite to the high temperature side plate portion 12 and a low temperature side electrode 452 disposed opposite to the low temperature side plate portion 22. A thermoelectric conversion element 41 is disposed between the side electrode 452. One electrode 45 is disposed between adjacent thermoelectric conversion elements 41 and is fixed to the upper and lower surfaces of the thermoelectric conversion elements 41.

In the present embodiment, as shown in FIG. 2, a plurality of sets (in this case, four sets) of thermoelectric conversion modules 40 are arranged in a vertical and horizontal manner in the module chamber 20, and each set of thermoelectric conversions. Modules 40 are connected in series by connecting terminals 46.

As shown in FIG. 3, the low temperature side electrode 452 of the thermoelectric conversion module 40 is fixed to the low temperature side plate portion 22 via an insulating material 50 such as ceramic, whereby the low temperature side electrode 452 is attached to the low temperature side electrode 452. It is insulated from the plate part 22. On the other hand, as shown in FIG. 2 and FIG. 3, a heat conduction plate 60 is provided in close contact with the outer surface side (module chamber 20 side) where the thermoelectric conversion module 40 is disposed in the plate portion 12 on the high temperature side. The high temperature side electrode 451 of the thermoelectric conversion module 40 is fixed onto the heat conducting plate 60 via an insulating material 50 such as ceramic. Therefore, the high temperature side electrode 451 is also insulated from the high temperature side plate portion 12.

The heat conductive plate 60 is formed of a metal having a thermal conductivity of 50 W / m · k or more, such as copper or copper alloy, nickel or nickel alloy, molybdenum or molybdenum alloy, aluminum or aluminum alloy, for example. The type of metal constituting the heat conductive plate 60 is preferably as high as possible, but is appropriately selected in view of other factors such as cost. The heat conducting plate 60 is a thin plate made of such a metal, and is provided by a technique such as brazing and closely contacting the plate portion 12 on the high temperature side.

The heat conductive plate 60 can be formed on the high temperature side plate portion 12 by, for example, thermal spraying or plating, in addition to the method of attaching a metal plate to the high temperature side plate portion 12, but is not limited to these methods. . The thickness of the heat conductive plate 60 is about 5 μm to 2 mm, and the thickness of the plate portion 12 on the high temperature side where the heat conductive plate 60 is provided is about 0.5 mm, for example.

As shown in FIG. 2, one heat conduction plate 60 is provided for each set of thermoelectric conversion modules 40, and a plate portion on the high temperature side is provided by the plurality of heat conduction plates 60. It is large enough to cover most of the 12 surfaces. The connection terminal 46 is considered so as not to contact the heat conductive plate 60 and short circuit. In addition, although one heat conductive plate having a size capable of covering all the thermoelectric conversion modules 40 may be provided on the high-temperature side plate portion 12, each thermoelectric conversion module 40 as in the heat conductive plate 60 is provided. By dividing, problems such as deformation and peeling are suppressed by distortion generated between the plate portion 12 on the high temperature side due to a difference in thermal expansion, and therefore, a form divided into a plurality of parts is preferable.

[2] Power Generation Action of Power Generation Device In the power generation device 1 having the above-described configuration, the high-temperature side plate portion 12 is heated by flowing a high-temperature heating fluid H through the pipe line 10 of the tube body 11. Further, a cooling medium is flowed into the low temperature chamber 30 to cool the plate portion 22 on the low temperature side. The plate 12 on the high temperature side is heated by the heat of the heating fluid H flowing through the pipe 10, and the heat of the heated plate 12 on the high temperature side passes through the high temperature side electrode 451 of the thermoelectric conversion module 40 from the heat conduction plate 60. And is transmitted to the thermoelectric conversion element 41. On the other hand, the heat of the low temperature side plate portion 22 cooled by the cooling medium is transmitted to the thermoelectric conversion element 41 through the low temperature side electrode 452 of the thermoelectric conversion module 40. As a result, a temperature difference is given to the thermoelectric conversion element 41 such that the temperature of the tube body 11 is high and the temperature of the low temperature chamber 30 is low, and the thermoelectric conversion element 41 generates electric power from an unshown terminal connected to the electrode 45. Is taken out.

In the power generation apparatus 1 of the present embodiment, for example, exhaust heat gas generated in a factory or a garbage incinerator, automobile exhaust gas, or the like can be used as the heating fluid H.

[3] Effects of Embodiment In the power generation apparatus 1 of the present embodiment, the heat amount of the high-temperature side plate portion 12 heated by the heating fluid H (heat amount on the heating side) is collected by the heat conduction plate 60, and the thermoelectric conversion module. 40. When the tube 11, that is, the high-temperature side plate portion 12 is stainless steel as described above, the stainless steel is a metal having low thermal conductivity, but the amount of heat of the high-temperature side plate portion 12 around the thermoelectric conversion module 40 is heat conduction. Since heat is collected by the plate 60, heat loss of the plate portion 12 on the high temperature side is suppressed and the amount of heat is efficiently transmitted to the thermoelectric conversion module 40 via the heat conductive plate 60. As a result, the amount of heating supplied to the thermoelectric conversion module 40 increases and the temperature difference generated in the thermoelectric conversion module 40 increases, thereby improving the amount of power generation.

Further, the heat conductive plate 60 is made of a metal having a high heat conductivity of 50 W / m · k or more, and the region where the thermoelectric conversion module 40 is not mounted on the plate portion 12 on the high temperature side. Is substantially covered over the entire region of the plate portion 12 on the high temperature side. For this reason, the amount of heating reaching the thermoelectric conversion element 41 from the plate portion 12 on the high temperature side can be further increased.

Further, since the heat conductive plate 60 is disposed in the module chamber 20 which is a negative pressure space, it is possible to obtain a state in which the heat conductive plate 60 is not easily oxidized without being exposed to the oxidizing atmosphere. Therefore, even if the heat conductive plate 60 is a metal that is easily oxidized, such as copper, the oxidation is suppressed, and the problem that the high thermal conductivity is impaired by the oxidation does not occur.

[4] Other Embodiments In the above embodiment, the heat conduction plate 60 is provided between the high temperature side plate portion 12 and the thermoelectric conversion module 40, and the heat conduction plate 60 is used to control the amount of heating of the high temperature side plate portion 12. By taking in more by the conversion module 40, the temperature difference is increased. In the present invention, the arrangement position of the heat conductive plate 60 is not limited to this, and it is between the high temperature side plate portion 12 and the thermoelectric conversion module 40 or the low temperature side plate portion 22 and the thermoelectric conversion as in the above embodiment. A heat conductive plate 60 is provided on at least one side of the module 40.

That is, as shown in FIG. 4A, instead of providing the heat conduction plate 60 on the high temperature side plate portion 12, the heat conduction plate 60 is provided on the inner surface facing the module chamber 20 side of the low temperature side plate portion 22. Other forms can also be employed. In this embodiment, a large amount of heat (heat amount for cooling) of the low-temperature side plate portion 22 cooled by the cooling medium is collected by the heat conduction plate 60, thereby improving the cooling efficiency of the thermoelectric conversion module 40 and thermoelectric power. The temperature difference of the conversion module 40 is increased.

Further, as shown in FIG. 4B, a heat conduction plate 60 may be provided on the module chamber 20 side surfaces of both the high temperature side plate portion 12 and the low temperature side plate portion 22. In this embodiment, the high-temperature heat amount of the high-temperature side plate portion 12 heated by the heating fluid H is collected by the heat conduction plate 60 to further heat the thermoelectric conversion module 40 and is cooled by the cooling medium. The low-temperature calorie | heat amount of the board part 22 is heat-collected with the heat conductive board 60, and the thermoelectric conversion module 40 is cooled more. Accordingly, the temperature difference generated in the thermoelectric conversion module 40 is further expanded, and the improvement in the amount of power generation is further promoted as compared with the case where the heat conduction plate 60 is provided on one of the high temperature side plate portion 12 and the low temperature side plate portion 22. The

Claims

A plate portion on the high temperature side and a plate portion on the low temperature side which are arranged opposite to each other;
A thermoelectric conversion device comprising: a thermoelectric conversion module disposed between the high temperature side plate portion and the low temperature side plate portion, and provided with a temperature difference by the high temperature side plate portion and the low temperature side plate portion. In
At least one of the high temperature side plate portion and the thermoelectric conversion module, or at least one of the low temperature side plate portion and the thermoelectric conversion module, is brought into close contact with the plate portion to transfer the heat of the plate portion. A thermoelectric conversion device provided with a heat conduction plate to be supplied to the conversion module.
The thermoelectric conversion device according to claim 1, wherein the heat conduction plate is made of a material having a thermal conductivity of 50 W / m · k or more.
The thermoelectric conversion device according to claim 1 or 2, wherein the heat conducting plate is disposed in a decompression chamber that is a negative pressure space.