JP2015177050A - Thermoelectric conversion module - Google Patents

Abstract

A thermoelectric conversion module is provided with improved durability by suppressing breakage of a thermoelectric semiconductor and suppressing peeling at a joint surface between a thermoelectric semiconductor and an electrode. A plurality of p-type thermoelectric semiconductors (11) and n-type thermoelectric semiconductors (12); 12 are electrically connected in series, and the p-type thermoelectric semiconductor 11 and the n-type thermoelectric semiconductor 12 are installed on the surface of the low-temperature heat source side of the p-type thermoelectric semiconductor 11 and the n-type thermoelectric semiconductor 12. are electrically connected in series, the thermoelectric conversion module 10 is divided into a plurality of blocks, and the plurality of blocks are electrically connected by electrode members 17. connected in series. [Selection drawing] Fig. 1

Description

  The present invention relates to a thermoelectric conversion module using, for example, waste heat from various industrial equipment and automobiles as a heat source.

  A conventional thermoelectric conversion module (hereinafter sometimes abbreviated as “module”) has electrodes arranged on the upper and lower surfaces of a plurality of p-type thermoelectric semiconductors and n-type thermoelectric semiconductors, that is, the surface on the high-temperature heat source side and the surface on the low-temperature heat source side. In general, a structure is provided that includes an electric circuit and a case member that accommodates the thermoelectric semiconductor and the electrode on both outer sides of the electrode via an electric insulating plate such as ceramics (Patent Document 1).

  Since the thermoelectric conversion module generates power by applying a temperature difference between the upper and lower surfaces of the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor that are electrically connected to each other and paired with each other, the degree of thermal expansion of the electrode on the high temperature side Is greater than the degree of thermal expansion of the low temperature side electrode. For this reason, shear stress, tensile stress, and compressive stress act on the thermoelectric semiconductor and the upper and lower electrodes, and the fragile thermoelectric semiconductor may be destroyed or peeling may occur at the joint surface between the thermoelectric semiconductor and the electrode. .

  Such a problem is particularly serious in a high-temperature thermoelectric conversion module having a use temperature of 500 ° C. or higher assuming automobiles and industrial waste heat.

JP 2006-49872 A

  An object of the present invention is to improve durability by destroying a thermoelectric semiconductor in a thermoelectric conversion module or suppressing peeling at a joint surface between the thermoelectric semiconductor and an electrode.

In order to achieve the above object, the present invention provides:
A plurality of p-type thermoelectric semiconductors and n-type thermoelectric semiconductors are installed on the surface of the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor on the high-temperature heat source side, and the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor are electrically connected in series. A plurality of high-temperature side electrode portions connected to the low-temperature heat source side of the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor, and electrically connecting the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor in series A thermoelectric conversion module comprising a plurality of low temperature side electrode parts,
The thermoelectric conversion module is divided into a plurality of blocks, and the plurality of blocks are electrically connected in series with each other with an electrode member.

  According to the present invention, the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor are installed on the surface of the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor on the high temperature heat source side, and the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor are electrically connected in series. A high temperature side electrode portion connected to the low temperature heat source side surface of the p type thermoelectric semiconductor and the n type thermoelectric semiconductor, and a low temperature side electrode portion electrically connecting the p type thermoelectric semiconductor and the n type thermoelectric semiconductor in series In such a thermoelectric conversion module, the thermoelectric conversion module is divided into a plurality of blocks, and the plurality of blocks are electrically connected to each other in series by electrode members.

  Therefore, when the thermoelectric conversion module is operated to generate power by giving a temperature difference between the upper and lower surfaces of the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor, the thermoelectric conversion module as a whole has a high temperature side electrode (high temperature side electrode portion). ), The degree of thermal expansion of the high temperature side electrode portion can be suppressed in each block unit even if the degree of thermal expansion is sufficiently larger than that of the low temperature side electrode (low temperature side electrode portion). it can.

  For this reason, in the entire thermoelectric conversion module, shear stress, tensile stress, and compressive stress act on the thermoelectric semiconductor and the upper and lower electrodes, thereby destroying the fragile thermoelectric semiconductor and peeling off at the joint surface between the thermoelectric semiconductor and the electrode. Even in the case of generating a block, it is possible to suppress the shearing force, tensile stress, and compressive stress generated in the thermoelectric semiconductor and its upper and lower electrodes in a block unit, destroying the fragile thermoelectric semiconductor, and bonding between the thermoelectric semiconductor and the electrode No peeling occurs on the surface. As a result, even in the entire thermoelectric conversion module, the above-described destruction of the thermoelectric semiconductor and peeling at the joint surface between the thermoelectric semiconductor and the electrode can be suppressed.

  The plurality of blocks are electrically connected in series by electrode members. Therefore, each block to which the thermoelectric semiconductors 11, 12, etc. belong constitutes a thermoelectric conversion module element, and a plurality of blocks also constitute a thermoelectric conversion module as a whole. As a result, the thermoelectric conversion module of the present invention secures its function.

  In one example of the present invention, the electrode member can be composed of a bridge-type electrode member. Since the bridge-type electrode member can be easily expanded and contracted by heating and cooling and deformed, when the thermoelectric conversion module is operated to generate electric power, the high-temperature side electrode portion in each block expands thermally, and the thermoelectric When the operation of the conversion module is stopped, the thermal expansion and thermal contraction can be easily followed even when the high temperature side electrode portion in each block is thermally contracted. Therefore, electrical connection between the blocks constituting the thermoelectric conversion module can be more reliably performed.

  The bridge-type electrode member can be composed of a plurality of film bodies. In this case, for example, even when the expansion and contraction of the high temperature side electrode part belonging to each block is large and some film bodies are divided, some of the film bodies remain without being divided, and the conductivity is reduced. The function as an electrode member can be fulfilled. When the film body is not divided, the same effects as the above-described bridge-type electrode member are obtained.

  In one example of the present invention, the electrode member can be at least partially composed of a porous metal body. In this case, the density of the portion composed of the porous metal body of the electrode member is lower than that of the portion composed of another non-porous metal body. Therefore, since such a porous metal body can be easily expanded and contracted by heating and cooling and deformed, when the thermoelectric conversion module is operated to generate electric power, the high temperature side electrode portion in each block is heated. When the operation of the thermoelectric conversion module is expanded and the high temperature side electrode portion in each block is thermally contracted, the thermal expansion and contraction can be easily followed. Therefore, electrical connection between the blocks constituting the thermoelectric conversion module can be more reliably performed.

  In addition, when comprising an electrode member from a porous metal body, it is preferable to set it as the nonporous metal body formed by crushing the said porous metal body in a contact part with the electrode part which belongs to each block. In this case, the contact resistance with the electrode part belonging to each block can be reduced.

  In addition, when the electrode member is composed of a porous metal body, a bulk metal body is formed at the contact portion with the electrode portion belonging to each block, and the metal bodies extending from each block are joined to each other. It is also possible to dispose a porous metal body. Also in this case, the contact resistance with the electrode part belonging to each block can be reduced.

  The electrode member may be joined to either the high temperature side electrode part or the low temperature side electrode part belonging to each block, but is preferably joined to the high temperature side electrode part. As described above, when the thermoelectric conversion module is operated and stopped, it is the high temperature side electrode section that causes larger thermal expansion and contraction. Therefore, by selecting and bonding the electrode member in accordance with the degree of thermal expansion and contraction of the high temperature side electrode part, the electrode member can sufficiently follow the thermal expansion and thermal contraction of the high temperature side electrode part. It is possible to make electrical connection between the blocks more reliable.

  In addition, when selecting and joining the electrode member in accordance with the degree of thermal expansion and thermal contraction of the low temperature side electrode part, the low temperature side electrode part is pulled by the thermal expansion and thermal contraction of the high temperature side electrode part. The electrode member joined to the low temperature side electrode part may peel off from the joining surface, or the electrode member itself may break.

  As described above, according to the present invention, in the thermoelectric conversion module, the thermoelectric semiconductor can be broken, or peeling can be suppressed at the joint surface between the thermoelectric semiconductor and the electrode, thereby improving durability.

It is a perspective view which shows schematic structure of the thermoelectric conversion module in 1st Embodiment. It is a perspective view which shows schematic structure of the thermoelectric conversion module in 2nd Embodiment. It is a perspective view which shows schematic structure of the thermoelectric conversion module in 3rd Embodiment.

  Hereinafter, details and other characteristics of the thermoelectric conversion module with an airtight case of the present invention will be described based on embodiments.

(First embodiment)
FIG. 1 is a perspective view showing a schematic configuration of a thermoelectric conversion module in the present embodiment.
As shown in FIG. 1, the thermoelectric conversion module 10 of this embodiment includes a plurality of p-type thermoelectric semiconductors 11 and n-type thermoelectric semiconductors 12 arranged alternately in a matrix, and p-type thermoelectric semiconductors 11 and n-type thermoelectric semiconductors. 12 is installed on the surface of the high-temperature heat source side, and is installed on the surface of the p-type thermoelectric semiconductor 11 and the n-type thermoelectric semiconductor 12 on the low-temperature heat source side that connects these thermoelectric semiconductors 11 and 12 in series. It has the low temperature side electrode part 14 which connects these thermoelectric semiconductors 11 and 12 in series.

  The thermoelectric conversion module 10 is divided into four blocks A, B, C, and D, and 7 × 4 thermoelectric semiconductors 11 and 12 belong to each block. Furthermore, the edge part of adjacent blocks is electrically joined by the bridge-type electrode member 17 which consists of a single film body between the opposing high temperature side electrode parts 13 located in the edge part of the said block. As a result, the four blocks A, B, C, and D are connected in series in the order of A → B → C → D. Therefore, each block to which the thermoelectric semiconductors 11, 12, etc. belong constitutes a thermoelectric conversion module element, and the four blocks A, B, C, D constitute a thermoelectric conversion module as a whole, and the thermoelectric conversion module 10 has its function. Will be secured.

  In addition, the location joined by the bridge-type electrode member 17 is not limited between the high temperature side electrode portions 13 located at the ends of adjacent blocks, and can be joined at any location.

  In the present embodiment, the thermoelectric conversion module 10 is divided into four blocks A, B, C, and D, but the number of blocks to be divided is not limited to four, for example, in the range of 4 to 120. Can be set. Moreover, although the number of thermoelectric semiconductors 11 and 12 belonging to each block is 7 × 4, the number of thermoelectric semiconductors 11 and 12 belonging to each block can be any number as necessary. It can be 36. Further, the width, length, height, and the like that define the shape of the thermoelectric semiconductors 11 and 12 can be set to, for example, 1 to 3 mm.

  According to the thermoelectric conversion module 10 of the present embodiment, the thermoelectric conversion module 10 is divided into four blocks A, B, C, and D, and these four blocks are electrically connected in series with each other by a bridge-type electrode member 17. Like to do.

  Therefore, when the thermoelectric conversion module 10 is operated to generate power by giving a temperature difference between the upper and lower surfaces of the p-type thermoelectric semiconductor 11 and the n-type thermoelectric semiconductor 12, the thermoelectric conversion module 10 as a whole has the high-temperature side electrode portion 13. Even if the degree of thermal expansion is sufficiently greater than the degree of thermal expansion of the low temperature side electrode part 14, the degree of thermal expansion of the high temperature side electrode part 13 can be suppressed in each block unit.

  For this reason, in the thermoelectric conversion module 10 as a whole, the thermoelectric semiconductors 11 and 12 and the upper and lower electrodes 13 and 14 are subjected to shear stress, tensile stress, and compressive stress, and the fragile thermoelectric semiconductors 11 and 12 are destroyed. Even when peeling occurs at the joint surface between the thermoelectric semiconductors 11 and 12 and the electrodes 13 and 14, the shearing force, tensile stress, and compressive stress generated in the thermoelectric semiconductors 11 and 12 and the electrodes 13 and 14 above and below the block unit. Therefore, the fragile thermoelectric semiconductors 11 and 12 are not destroyed, and no peeling occurs at the joint surface between the thermoelectric semiconductors 11 and 12 and the electrodes 13 and 14. As a result, even in the entire thermoelectric conversion module 10, it is possible to suppress the above-described destruction of the thermoelectric semiconductors 11 and 12 and peeling at the joint surface between the thermoelectric semiconductors 11 and 12 and the electrodes 13 and 14.

  In the present embodiment, the blocks A, B, C, and D are electrically connected in series by the bridge-type electrode member 17. Since the bridge-type electrode member 17 can be easily expanded and contracted by heating and cooling and deformed, when the thermoelectric conversion module 10 is operated to generate electric power, the high temperature side electrode portion 13 in each block is thermally expanded. And when operation | movement of the thermoelectric conversion module 10 is stopped, also when the high temperature side electrode part 13 in each block heat-shrinks, it can follow these thermal expansion and thermal shrinkage easily. Therefore, electrical connection between the blocks A, B, C, and D constituting the thermoelectric conversion module 10 can be more reliably performed.

  In the present embodiment, the bridge-type electrode member 17 is joined to the high temperature side electrode portion 13. When the thermoelectric conversion module 10 is operated and stopped, it is the high temperature side electrode portion 13 that causes greater thermal expansion and contraction. Therefore, the bridge-type electrode member 17 is selected and bonded in accordance with the degree of thermal expansion and contraction of the high temperature side electrode portion 13, so that the electrode member 17 is thermally expanded and contracted by the high temperature side electrode portion 13. The electrical connection between the blocks can be made more reliable.

  On the other hand, when the bridge-type electrode member 17 is selected and bonded in accordance with the degree of thermal expansion and contraction of the low temperature side electrode portion 14, the low temperature side electrode portion 14 is caused by the thermal expansion and contraction of the high temperature side electrode portion 13. As a result, the bridge-type electrode member 17 bonded to the low-temperature side electrode portion 14 may be peeled off from the bonding surface, or the electrode member 17 itself may be broken.

  The p-type thermoelectric semiconductor 11 and the n-type thermoelectric semiconductor 12 are preferably made of a material having low thermal conductivity, obtaining a large temperature difference between the high temperature side and the low temperature side, and generating a large potential difference by thermoelectric conversion (Seebeck effect). For example, it is made of a semiconductor material such as Bi—Te, Pb—Te, Si—Ge, Mg—Si, or Mn—Si.

  The high temperature side electrode part 13, the low temperature side electrode part 14, and the bridge-type electrode member 17 are required to exhibit excellent heat resistance and mechanical strength and relatively high conductivity. For example, Mo, Cu, W, It can be composed of Ti, Ni and their alloys or stainless steel.

(Second Embodiment)
FIG. 2 is a perspective view showing a schematic configuration of the thermoelectric conversion module in the present embodiment. In addition, the same code | symbol is used about the same or similar component as the thermoelectric conversion module 10 shown in FIG.

  The thermoelectric conversion module 20 of the present embodiment is the same as the thermoelectric conversion module 10 of the first embodiment shown in FIG. 1, except that the bridge-type electrode member 17 made of a single film body is replaced with a bridge made of a plurality of film bodies. The same configuration is adopted except that a mold electrode member 27 is used. Therefore, in the following, the configuration of the electrode member 27 that is a feature of the thermoelectric conversion module 20 of the present embodiment and the function and effect thereof will be described.

  In the thermoelectric conversion module 20 of the present embodiment, a plurality of bridge-type electrode members 27 that are joined to the high temperature side electrode portions 13 of the blocks A, B, C, and D and electrically connect these blocks in series are formed. It consists of film bodies 27-1, 27-2, 27-3, 27-4.

  In this case, for example, even when the expansion and contraction of the high temperature side electrode portion 13 belonging to each block is large and the film bodies 27-1 and 27-3 are divided, the remaining film bodies 27-2 and 27-4 The conductivity can be ensured, and the function as the electrode member 27 can be achieved.

  When the film body 27-1 and the like are not divided, the same effects as the bridge-type electrode member 17 are obtained. That is, since the plurality of film bodies 27-1 to 27-4 can be easily expanded and contracted by heating and cooling and deformed, when the thermoelectric conversion module 20 is operated to generate electric power, When the side electrode section 13 is thermally expanded and the operation of the thermoelectric conversion module 20 is stopped, the thermal expansion and contraction of the high temperature side electrode section 13 in each block can easily follow the thermal expansion and contraction. Can do. Therefore, electrical connection between the blocks A, B, C, and D constituting the thermoelectric conversion module 20 can be more reliably performed.

  Moreover, the effect by dividing | segmenting the thermoelectric semiconductors 11 and 12 which comprise the thermoelectric conversion module 20 into four blocks A, B, C, and D is the same as that of the thermoelectric conversion module 10 in 1st Embodiment. That is, when the thermoelectric conversion module 20 is operated by generating a temperature difference between the upper and lower surfaces of the p-type thermoelectric semiconductor 11 and the n-type thermoelectric semiconductor 12 to generate power, the entire thermoelectric conversion module 20 Even if the degree of thermal expansion is sufficiently greater than the degree of thermal expansion of the low temperature side electrode part 14, the degree of thermal expansion of the high temperature side electrode part 13 can be suppressed in each block unit.

  For this reason, in the whole thermoelectric conversion module 20, shear stress, tensile stress, and compressive stress act on the thermoelectric semiconductors 11 and 12 and the upper and lower electrodes 13 and 14, and the fragile thermoelectric semiconductors 11 and 12 are destroyed. Even when peeling occurs at the joint surface between the thermoelectric semiconductors 11 and 12 and the electrodes 13 and 14, the shearing force, tensile stress, and compressive stress generated in the thermoelectric semiconductors 11 and 12 and the electrodes 13 and 14 above and below the block unit. Therefore, the fragile thermoelectric semiconductors 11 and 12 are not destroyed, and no peeling occurs at the joint surface between the thermoelectric semiconductors 11 and 12 and the electrodes 13 and 14. As a result, even in the entire thermoelectric conversion module 20, it is possible to suppress the above-described destruction of the thermoelectric semiconductors 11 and 12 and peeling at the joint surface between the thermoelectric semiconductors 11 and 12 and the electrodes 13 and 14.

  In the present embodiment, the number of film bodies is four, but can be any number as necessary. Moreover, although the thickness of a film body can be set to arbitrary values as needed, it can be 0.002 mm-0.2 mm, for example.

  Since other features and operational effects are the same as those in the first embodiment, description thereof will be omitted.

(Third embodiment)
FIG. 3 is a perspective view showing a schematic configuration of the thermoelectric conversion module in the present embodiment. In addition, the same code | symbol is used about the same or similar component as the thermoelectric conversion module 10 shown in FIG.

  The thermoelectric conversion module 30 of this embodiment is an electrode made of a porous metal body in place of the bridge-type electrode member 17 made of a single film body in the thermoelectric conversion module 10 of the first embodiment shown in FIG. The same configuration is adopted except that the member 37 is used. Therefore, in the following, the configuration of the electrode member 37 that is a feature of the thermoelectric conversion module 30 of the present embodiment and the function and effect thereof will be described.

  In the thermoelectric conversion module 30 of this embodiment, the electrode member 37 is comprised from the porous metal body. The density of the porous metal body is lower than that of the non-porous metal body made of the same material. Therefore, since such a porous metal body can be easily expanded and contracted by heating and cooling and deformed, when the thermoelectric conversion module 30 is operated to generate electric power, the high temperature side electrode portion 13 in each block. When the high temperature side electrode portion 13 in each block thermally contracts when the thermal expansion of the thermoelectric conversion module 30 stops, the thermal expansion and the thermal contraction can be easily followed. Therefore, electrical connection between the blocks constituting the thermoelectric conversion module 30 can be more reliably performed.

  In the present embodiment, the porous metal body is a non-porous metal body that is crushed at the contact portion 37A of the electrode member 37 with the high temperature side electrode portion 13 belonging to each block. Therefore, contact resistance with the high temperature side electrode part 13 which belongs to each block can be reduced.

  When the electrode member 37 is made of a porous metal body, for example, the porosity can be 50% to 95%.

  Since other features and operational effects are the same as those in the first embodiment, description thereof will be omitted.

  While the present invention has been described in detail based on the above specific examples, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

  For example, in the third embodiment, when the electrode member is composed of a porous metal body, a bulk metal body is formed at the contact portion with the high temperature side electrode portion belonging to each block, and extends from each block. A porous metal body may be disposed so as to join the metal bodies. Also in this case, the contact resistance with the electrode part belonging to each block can be reduced.

DESCRIPTION OF SYMBOLS 10, 20, 30 Thermoelectric conversion module 11 P-type thermoelectric semiconductor 12 N-type thermoelectric semiconductor 13 High temperature side electrode part 14 Low temperature side electrode part 15 1st insulating member 16 2nd insulating member 17, 27, 37 Electrode member

Claims (4)

A plurality of p-type thermoelectric semiconductors and n-type thermoelectric semiconductors are installed on the surface of the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor on the high-temperature heat source side, and the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor are electrically connected in series. A plurality of high-temperature side electrode portions connected to the low-temperature heat source side of the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor, and electrically connecting the p-type thermoelectric semiconductor and the n-type thermoelectric semiconductor in series A thermoelectric conversion module comprising a plurality of low temperature side electrode parts,
The thermoelectric conversion module, wherein the thermoelectric conversion module is divided into a plurality of blocks, and the plurality of blocks are electrically connected to each other in series with electrode members.   The thermoelectric conversion module according to claim 1, wherein the electrode member is a bridge-type electrode member.   The thermoelectric conversion module according to claim 2, wherein the electrode member includes a plurality of film bodies.   The thermoelectric conversion module according to claim 1, wherein at least a part of the electrode member is made of a porous metal body.

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