Thermoelectric conversion module

Abstract

A first thermoelectric material (110) and a second thermoelectric material (120) are arranged with a spacing therebetween in arrangement directions. A first one-end portion (111) of the first thermoelectric material corresponding to one of extension directions is electrically and thermally connected to a first junction portion (113) corresponding to one of the arrangement directions on a heat dissipation surface (131) of a two-phase thermoelectric material (130). A second one-end portion (121) of the second thermoelectric material corresponding to one of the extension directions is electrically and thermally connected to a second junction portion (123) corresponding to the other of the arrangement directions on the heat dissipation surface of the two-phase thermoelectric material. The two-phase thermoelectric material has a temperature gradient portion (133) that generates a temperature difference in the extension directions between the first junction portion and the second junction portion, and generates a thermoelectromotive force based on the temperature difference.

Description

Thermoelectric conversion module Cross-reference to related applications

[0001] This application is based on Japanese Patent Application No. 2024-189726 filed on October 29, 2024, the contents of which are incorporated herein by reference.

[0002] This disclosure relates to a thermoelectric conversion module.

[0003] Conventionally, a π-type thermoelectric module in which a P-type thermoelectric material and an N-type thermoelectric material are electrically connected in series and thermally connected in parallel has been proposed, for example, in Patent Document 1. The P-type thermoelectric material has holes as carriers. The N-type thermoelectric material has electrons as carriers.

[0004] The potential difference generated between the P-type thermoelectric material and the N-type thermoelectric material due to the temperature difference, that is, the direction of the current is reversed. Therefore, in the π-type thermoelectric module, a temperature difference is generated in each thermoelectric material by heating one end side of each thermoelectric material to a high temperature. Further, the P-type thermoelectric material and the N-type thermoelectric material are electrically connected in series. For this reason, the potential difference between the P-type thermoelectric material and the N-type thermoelectric material increases and it becomes possible to flow a current through an external resistor.

[0005] In such a π-type thermoelectric module, inside the P-type thermoelectric material and the N-type thermoelectric material, the direction of heat transfer and the direction of the current are the same or opposite. That is, the direction of the current is not inclined with respect to the direction of heat transfer.

[0006] On the other hand, it is known, for example, from Non-Patent Document 1 that a high electromotive force can be generated by applying a unique temperature gradient to a thermoelectric material having a structure that undergoes a phase transition when heated. Specifically, a part of the thermoelectric material is heated to a temperature above the phase transition temperature so that the temperature gradient between two electrodes provided on the thermoelectric material becomes oblique. Thereby, a state in which the direction of the current is inclined with respect to the direction of heat transfer is created inside the thermoelectric material.

[0007] Japanese Patent Application Laid-Open No. 2008-277404

[0008] Dogyun Byeon Dogyun Byeon, et al., Discovery of colossal Seebeck effect in metallic Cu2Se, Nature Communications, [online], <URL: https: / / www.nature.com / articles / s41467-018-07877-5>

[0009] As described in Non-Patent Document 1 above, a thermoelectric material that exhibits high thermoelectric performance by achieving both a high Seebeck coefficient and low electrical conductivity when a phase transition occurs from a phase with a high Seebeck coefficient (insulator-like) to a phase with a low electrical conductivity (metallic-like), creating a two-phase coexistence state within the material, is defined as a two-phase thermoelectric material.

[0010] However, two-phase thermoelectric materials require heating in two directions: a first heating to generate the temperature gradient necessary for power generation, and a second heating to generate a temperature gradient in a direction opposite to the first heating to promote a phase transition in the material. The first heating is used for power generation, but the second heating is wasted because heat is released from the opposite side of the heating in the two-phase thermoelectric material. As a result, heat loss occurs due to the second heating, which could reduce the power generation efficiency of the two-phase thermoelectric material.

[0011] In view of the above, this disclosure aims to provide a thermoelectric conversion module that can suppress heat loss of two-phase thermoelectric materials and improve power generation efficiency.

[0012] To achieve the above objective, according to one aspect of the present disclosure, a thermoelectric conversion module includes: a two-phase thermoelectric material having a structure that undergoes a phase transition when heat is applied and a heat dissipation surface that releases internal heat; a first thermoelectric material having a shape along the stretching direction and of a first conductivity type; and a second thermoelectric material having a shape along the stretching direction and of a second conductivity type.

[0013] If the direction perpendicular to the extension direction is defined as the alignment direction, then the first thermoelectric material and the second thermoelectric material are arranged with a gap between them in the alignment direction.

[0014] The first thermoelectric material has a first end corresponding to one of its stretching directions that is electrically and thermally connected to a first joint corresponding to one of its arrangement directions on the heat dissipation surface of the two-phase thermoelectric material.

[0015] The second thermoelectric material has a second end corresponding to one of its stretching directions that is electrically and thermally connected to a second junction on the heat dissipation surface of the two-phase thermoelectric material that corresponds to the other of its arrangement directions.

[0016] The two-phase thermoelectric material has a temperature gradient section that generates a temperature difference in the stretching direction between the first joint and the second joint, and generates a thermoelectric voltage based on the temperature difference.

[0017] According to this configuration, heat emitted from the heat-dissipating surface of the two-phase thermoelectric material is transferred to the first thermoelectric material via the first joint and to the second thermoelectric material via the second joint. As a result, a temperature difference in the stretching direction can be generated between the first and second thermoelectric materials, as well as a potential difference between them. Furthermore, since the first thermoelectric material, the two-phase thermoelectric material, and the second thermoelectric material are connected in series, not only the potential difference between the two-phase thermoelectric material but also the potential difference between the first and second thermoelectric materials can be extracted. Therefore, heat loss in the two-phase thermoelectric material can be suppressed, and the power generation efficiency of the thermoelectric conversion module can be improved.

[0018] The above and other purposes, features and advantages of this disclosure will become clearer from the following detailed description with reference to the attached drawings. In the attached drawings, Figure 1 is a cross-sectional view of a thermoelectric conversion module according to the first embodiment, Figure 2 is a cross-sectional view of a thermoelectric conversion module according to the second embodiment, and Figure 3 is a cross-sectional view of a thermoelectric conversion module according to the third embodiment.

[0019] The following describes several embodiments for implementing this disclosure with reference to the drawings. In each embodiment, parts corresponding to matters described in a preceding embodiment may be denoted by the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, other embodiments described in a preceding embodiment may be applied to the remaining parts of the configuration.

[0020] It is possible to combine parts that are explicitly shown as being combinable in each embodiment. Furthermore, as long as there are no particular problems with the combination, it is also possible to partially combine embodiments with each other, embodiments with modifications, and modifications with each other, even if it is not explicitly shown that they are combinable.

[0021] Furthermore, the N-type shown in each of the following embodiments corresponds to the first conductivity type of this disclosure, and the P-type corresponds to the second conductivity type of this disclosure. Of course, it is also possible to assume that the P-type corresponds to the first conductivity type and the N-type corresponds to the second conductivity type.

[0022] (First Embodiment) The thermoelectric conversion module generates an electromotive force by applying a temperature gradient to a thermoelectric element. As shown in Figure 1, the thermoelectric conversion module 100 includes a first thermoelectric material 110, a second thermoelectric material 120, a two-phase thermoelectric material 130, a conductive material 140, an electrode 150, a first insulating plate 160, and a second insulating plate 170.

[0023] The first thermoelectric material 110 and the second thermoelectric material 120 are semiconductor elements having a substantially rectangular parallelepiped shape along the stretching direction. The first thermoelectric material 110 and the second thermoelectric material 120 are formed from, for example, a Bi-Te compound. The first thermoelectric material 110 and the second thermoelectric material 120 are, for example, Bi ２ Te ３ The first thermoelectric material 110 has N-type conductivity. The second thermoelectric material 120 is, for example, Bi ２ Te ３ It has P-type conductivity due to being doped with antimony.

[0024] The first thermoelectric material 110 and the second thermoelectric material 120 are arranged alternately with spacing between them in an arrangement direction perpendicular to the stretching direction.

[0025] The two-phase thermoelectric material 130 generates an electromotive force when heat is applied to it. The two-phase thermoelectric material 130 has a structure that undergoes a phase transition when heated. The two-phase thermoelectric material 130 is, for example, Cu ２ Se, Ag ２ The answer is S. The two-phase thermoelectric material 130 can be any chalcogenite-type transition metal that undergoes a phase transition when heated.

[0026] The two-phase thermoelectric material 130 includes a heat dissipation surface 131, an end face 132, and a temperature gradient section 133.

[0027] The heat dissipation surface 131 is a surface that releases heat from inside the two-phase thermoelectric material 130 in the stretching direction. The first end 111 of the first thermoelectric material 110 and the second end 121 of the second thermoelectric material 120 are joined to the heat dissipation surface 131 by solder or the like. Each end 111, 121 corresponds to one side in the stretching direction of the first thermoelectric material 110 and the second thermoelectric material 120, i.e., the side of the two-phase thermoelectric material 130. The other side in the stretching direction of the first thermoelectric material 110 is the first other end 112. The other side in the stretching direction of the second thermoelectric material 120 is the second other end 122.

[0028] The first end portion 111 of the first thermoelectric material 110 is electrically and thermally connected to a first joint portion 113 on the heat dissipation surface 131 that corresponds to one of the arrangement directions. The second end portion 121 of the second thermoelectric material 120 is electrically and thermally connected to a second joint portion 123 on the heat dissipation surface 131 that corresponds to the other of the arrangement directions.

[0029] In this embodiment, a pair consists of a first thermoelectric material 110, a two-phase thermoelectric material 130, and a second thermoelectric material 120. In this embodiment, two such pairs are provided. In each pair, the two-phase thermoelectric material 130 can be said to be a connection part that electrically connects the first thermoelectric material 110 and the second thermoelectric material 120. Furthermore, the first thermoelectric material 110 and the second thermoelectric material 120 can be said to be electrodes of the two-phase thermoelectric material 130.

[0030] The end face 132 is the side of the two-phase thermoelectric material 130 opposite to the heat dissipation surface 131. The end face 132 is, for example, a flat surface. The end face 132 is fixed to the second insulating plate 170.

[0031] The temperature gradient section 133 generates a temperature difference in the stretching direction between the first joint 113 and the second joint 123, and also generates a thermoelectric voltage based on the temperature difference. In this embodiment, the temperature gradient section 133 generates a temperature difference between the first joint 113 and the second joint 123 due to the difference in thickness of the two-phase thermoelectric material 130 in the stretching direction.

[0032] Specifically, in the stretching direction, the first thickness of the two-phase thermoelectric material 130 between the first joint 113 and the end face 132 of the heat dissipation surface 131 is different from the second thickness of the two-phase thermoelectric material 130 between the second joint 123 and the end face 132 of the heat dissipation surface 131. That is, in the stretching direction, the first distance from the end face 132 to the first joint 113 is different from the second distance from the end face 132 to the second joint 123.

[0033] In this embodiment, the first thickness (first distance) > the second thickness (second distance). Consequently, the intermediate region 134 between the region on the first joint 113 side and the region on the second joint 123 side of the heat dissipation surface 131 is an inclined surface with respect to the end face 132. In other words, the intermediate region 134 forms a structural gradient.

[0034] The conductive material 140 is a plate-shaped wiring component that electrically connects the sets of the first thermoelectric material 110, the two-phase thermoelectric material 130, and the second thermoelectric material 120. The conductive material 140 is joined to the first other end 112 of the first thermoelectric material 110 of one set and to the second other end 122 of the second thermoelectric material 120 of the other set by solder or the like.

[0035] The electrode 150 is a plate-shaped wiring component for extracting the thermoelectric voltage from the first thermoelectric material 110, the two-phase thermoelectric material, and the second thermoelectric material 120 to the outside. One electrode 150 is electrically connected to the second other end 122 of the second thermoelectric material 120 of one set with solder or the like. The other electrode 150 is electrically connected to the first other end 112 of the first thermoelectric material 110 of the other set with solder or the like.

[0036] For example, metallic materials such as Cu, Al, Ni, or alloys thereof can be used as the conductive material 140 and the electrode 150.

[0037] The first insulating plate 160 is a plate-shaped insulating component that electrically insulates and thermally connects the conductive material 140 and electrode 150 with the low-temperature heat source 200. The second insulating plate 170 is a plate-shaped insulating component that electrically insulates and thermally connects the two-phase thermoelectric material 130 with the high-temperature heat source 300. For each insulating plate 160, 170, for example, SiO ２ Insulating materials such as AlN and ceramic materials are used.

[0038] Note that each of the insulating plates 160 and 170 is not limited to being configured as a single plate, and may only be provided at portions that come into contact with the conductive material 140 and the electrodes 150. That is, each of the insulating plates 160 and 170 may be composed of a plurality of plates. Alternatively, if the low-temperature heat source 200 and the high-temperature heat source 300 are electrically insulated from the conductive material 140 and the two-phase thermoelectric material 130, the insulating plates 160 and 170 are unnecessary.

[0039] The high-temperature heat source 300 and the low-temperature heat source 200 are heat sources for generating a temperature gradient in the stretching direction in the thermoelectric conversion module 100. The high-temperature heat source 300 is, for example, a high-temperature gas, a high-temperature liquid, a device that emits high temperature, high-temperature waste heat, or the like. The low-temperature heat source 200 is, for example, a low-temperature gas, a low-temperature liquid, a device that emits low temperature, or the like. For each of the heat sources 200 and 300, pipes, ducts, the housing of the device, etc. will come into contact with the insulating plates 160 and 170. In the case of a gas such as air, the gas itself may directly contact the insulating plates 160 and 170.

[0040] It is not necessary to install both the high-temperature heat source 300 and the low-temperature heat source 200 with respect to the thermoelectric conversion module 100. For example, only the high-temperature heat source 300 may be installed with respect to the thermoelectric conversion module 100. Alternatively, only the low-temperature heat source 200 may be installed with respect to the thermoelectric conversion module 100. The high-temperature heat source 300 and the low-temperature heat source 200 are not essential, and a heat source using the environment around the thermoelectric conversion module 100 may be used. The above is the overall configuration of the thermoelectric conversion module 100.

[0041] Next, the thermoelectric power generation of the thermoelectric conversion module 100 will be described. First, when the high-temperature heat source 300 and the second insulating plate 170 are thermally joined, high-temperature heat is transmitted to the two-phase thermoelectric material 130 through the second insulating plate 170. At the same time, a part of the two-phase thermoelectric material 130 is heated to a temperature not lower than the phase transition temperature. Therefore, a temperature distribution occurs inside the two-phase thermoelectric material 130.

[0042] Here, the temperature gradient section 133 of the two-phase thermoelectric material 130 makes the first thickness on the side of the first joint section 113 and the second thickness on the side of the second joint section 123 different in the stretching direction. Thereby, the temperature gradient section 133 generates a temperature difference in the stretching direction between the first joint section 113 and the second joint section 123.

[0043] In the present embodiment, since the first thickness > the second thickness, in the stretching direction, the second distance from the end face 132 of the two-phase thermoelectric material 130 to the second joint section 123 is shorter than the first distance from the end face 132 to the first joint section 113. Therefore, the vicinity of the second joint section 123 becomes relatively higher in temperature than the first joint section 113, and the vicinity of the first joint section 113 becomes relatively lower in temperature than the second joint section 123. Thus, a temperature difference in the stretching direction occurs between the first joint section 113 and the second joint section 123.

[0044] Also, the portion near the end face 132 of the two-phase thermoelectric material 130 rises to a temperature equal to or higher than the phase transition temperature and becomes a high-temperature phase in a state of phase transition. At that time, the portion near the first joint section 113 can be maintained in the low-temperature phase in the state before the phase transition. In the high-temperature phase in which phase transition occurs near the end face 132 of the two-phase thermoelectric material 130, the electrical resistivity is low, so electrons are transmitted and move through the high-temperature phase portion. Therefore, the electrical resistivity between the first joint section 113 and the second joint section 123 decreases. Near the first joint section 113, since the portion of the low-temperature phase before phase transition with a high thermoelectromotive force (high Seebeck) remains, a high thermoelectromotive voltage can be maintained. Note that between the low-temperature phase and the high-temperature phase, a mixed phase in which the low-temperature phase and the high-temperature phase are mixed is formed.

[0045] The heat from the high-temperature heat source 300 is transmitted through the interior of the two-phase thermoelectric material 130 in the stretching direction and dissipated from the heat dissipation surface 131. However, since the first thermoelectric material 110 and the second thermoelectric material 120 are thermally joined to the heat dissipation surface 131, some of the heat that would normally be dissipated from the heat dissipation surface 131 is transferred to the first thermoelectric material 110 and the second thermoelectric material 120. As a result, the ends 111 and 121 of the first thermoelectric material 110 and the second thermoelectric material 120 become relatively hotter than the other ends 112 and 122. Therefore, a temperature difference in the stretching direction is created between the first end 111 and the first other end 112 of the first thermoelectric material 110, and a temperature difference in the stretching direction is created between the second end 121 and the second other end 122 of the second thermoelectric material 120.

[0046] Consequently, in the N-type first thermoelectric material 110, electrons move from the two-phase thermoelectric material 130 side to the conductive material 140 or electrode 150 side. Therefore, a thermoelectric voltage is generated in the first thermoelectric material 110 such that current flows from the conductive material 140 or electrode 150 side to the two-phase thermoelectric material 130 side.

[0047] In contrast, in the P-type second thermoelectric material 120, holes move from the conductive material 140 or electrode 150 side to the two-phase thermoelectric material 130 side. Therefore, a thermoelectric voltage is generated in the second thermoelectric material 120 such that current flows from the two-phase thermoelectric material 130 side to the conductive material 140 or electrode 150 side.

[0048] Thus, the N-type first thermoelectric material 110 and the P-type second thermoelectric material 120 have opposite directions of potential difference, i.e., current, due to the temperature difference. Since the first thermoelectric material 110 and the second thermoelectric material 120 are joined to the two-phase thermoelectric material 130, the thermoelectric forces generated in the first thermoelectric material 110, the second thermoelectric material 120, and the two-phase thermoelectric material 130 are added together. Furthermore, the voltage difference becomes larger by the number of pairs. Therefore, a high power generation capacity (high voltage) can be secured for the thermoelectric conversion module 100.

[0049] As described above, in this embodiment, since the first thermoelectric material 110 and the second thermoelectric material 120 are joined to the heat dissipation surface 131 of the two-phase thermoelectric material 130, a portion of the heat released from the heat dissipation surface 131 is transferred to the first thermoelectric material 110 and the second thermoelectric material 120 via the respective joints 113 and 123. This makes it possible to generate a temperature difference in the stretching direction between the first thermoelectric material 110 and the second thermoelectric material 120, as well as a potential difference between the first thermoelectric material 110 and the second thermoelectric material 120. In other words, the thermoelectric voltage of the two-phase thermoelectric material 130 and the first thermoelectric material 110 and the second thermoelectric material 120 can be extracted. Therefore, the power generation efficiency of the thermoelectric conversion module 100 can be improved while suppressing the heat loss of the two-phase thermoelectric material 130.

[0050] As another example, the intermediate region 134 of the two-phase thermoelectric material 130 does not have to be an inclined surface. That is, as long as there is a difference between the first thickness and the second thickness of the two-phase thermoelectric material 130 in the stretching direction, the intermediate region 134 may be formed in a staircase shape, for example. The staircase may have one step or two or more steps.

[0051] (Second Embodiment) In this embodiment, the main differences from the first embodiment will be described. As shown in Figure 2, the heat dissipation surface 131 of the two-phase thermoelectric material 130 is a flat surface.

[0052] Furthermore, the temperature gradient portion 133 of the two-phase thermoelectric material 130 generates a temperature difference in the stretching direction between the first joint portion 113 and the second joint portion 123 because the second end portion 121 of the second thermoelectric material 120 is inserted from the heat dissipation surface 131 towards the end surface 132.

[0053] Specifically, the two-phase thermoelectric material 130 has a groove 135. The groove 135 is provided along the extension direction in the region of the heat dissipation surface 131 on the side of the second thermoelectric material 120 (second joint portion 123). The second end portion 121 of the second thermoelectric material 120 is inserted into the groove 135. Therefore, the second insertion depth of the second end portion 121 of the second thermoelectric material 120 is the depth of the groove 135 relative to the heat dissipation surface 131.

[0054] In contrast, in this embodiment, the first end portion 111 of the first thermoelectric material 110 is not inserted into the two-phase thermoelectric material 130. Therefore, the first insertion depth of the first end portion 111 of the first thermoelectric material 110 is 0.

[0055] Therefore, in the stretching direction, the first insertion depth of the first thermoelectric material 110 and the second insertion depth of the second thermoelectric material 120 are different, with reference to the heat dissipation surface 131 of the two-phase thermoelectric material 130. As a result, the second end 121 of the second thermoelectric material 120 is closer to the high-temperature heat source 300 than the first end 111 of the first thermoelectric material 110. That is, the second end 121 of the second thermoelectric material 120 is closer to the high-temperature heat source 300 in the shortest distance and becomes hotter than the first end 111 of the first thermoelectric material 110. Thus, the temperature gradient portion 133 can generate a temperature difference in the stretching direction between the first joint portion 113 and the second joint portion 123.

[0056] As another example, the first end 111 of the first thermoelectric material 110 may be embedded in the two-phase thermoelectric material 130. In this case, the thickness of the two-phase thermoelectric material 130 in the stretching direction may be set so that the first thickness > the second thickness, as shown in Figure 1. Alternatively, both the first end 111 of the first thermoelectric material 110 and the second end 121 of the second thermoelectric material 120 may be embedded in the two-phase thermoelectric material 130. Of course, even when the respective ends 111 and 121 of the first thermoelectric material 110 and the second thermoelectric material 120 are embedded in the two-phase thermoelectric material 130, the first and second thicknesses of the two-phase thermoelectric material 130 may be adjusted.

[0057] As another example, the first thickness > second thickness of the two-phase thermoelectric material 130 shown in the first embodiment may be combined with the insertion depth according to this embodiment.

[0058] (Third Embodiment) In this embodiment, the differences from the first and second embodiments will be mainly described. As shown in Figure 3, the temperature gradient section 133 generates a temperature difference in the stretching direction between the first joint 113 and the second joint 123 by adjusting the density per unit volume inside the two-phase thermoelectric material 130.

[0059] Specifically, the two-phase thermoelectric material 130 has a plurality of holes 136. The holes 136 are provided on the first thermoelectric material 110 side of the two-phase thermoelectric material 130. The size of each hole 136 is, for example, the same. In the stretching direction, there are more holes 136 on the second insulating plate 170 side than on the first thermoelectric material 110 side.

[0060] The size of the holes 136 may vary depending on their location. Furthermore, the holes 136 are not limited to grooves; they may be through-holes penetrating the two-phase thermoelectric material 130. Alternatively, the holes 136 may be provided throughout the entire two-phase thermoelectric material 130.

[0061] As a result, the material density on the side of the first joint 113 and the material density on the side of the second joint 123 are different in the two-phase thermoelectric material 130. Therefore, the heat transferred from the high-temperature heat source 300 to the first joint 113 via the second insulating plate 170 can be reduced compared to the heat transferred to the second joint 123. Thus, the temperature gradient section 133 can generate a temperature difference in the stretching direction between the first joint 113 and the second joint 123.

[0062] As another example, the means for adjusting the material density per unit volume of the two-phase thermoelectric material 130 is not limited to the holes 136, and other means may be used.

[0063] As another example, the first thickness > second thickness of the two-phase thermoelectric material 130 shown in the first embodiment may be combined with the adjustment of the material density according to this embodiment. Alternatively, the insertion depth of the first thermoelectric material 110 and the second thermoelectric material 120 shown in the second embodiment may be combined with the adjustment of the material density according to this embodiment. Alternatively, both the first and second embodiments may be combined with the adjustment of the material density according to this embodiment.

[0064] This disclosure is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit of this disclosure, as follows.

[0065] For example, multiple sets of a first thermoelectric material 110, a two-phase thermoelectric material 130, and a second thermoelectric material 120 may be connected in series. This makes it possible to obtain a thermoelectric voltage equal to the number of sets connected.

[0066] In each of the above embodiments, N-type Ag is used as the two-phase thermoelectric material 130. ２ Although S is used, P-type materials may also be used. If the thermoelectric properties of the two-phase thermoelectric material 130 are P-type, the second thermoelectric material 120 will be electrically and thermally joined to the low-temperature junction of the two-phase thermoelectric material 130, and the first thermoelectric material 110 will be joined to the high-temperature junction. As a result, the thermoelectric forces generated in the P-type two-phase thermoelectric material 130, the first thermoelectric material 110, and the second thermoelectric material 120 will be electrically connected in series and will have the same direction of electromotive force, making it possible to achieve a high electromotive force.

[0067] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

[0068] The technical features of the thermoelectric conversion module disclosed herein are as follows: (Item 1) A two-phase thermoelectric material (130) having a structure that undergoes a phase transition when heat is applied and a heat dissipation surface (131) that releases internal heat; a first thermoelectric material (110) having a shape along the stretching direction and of a first conductivity type; a second thermoelectric material (120) having a shape along the stretching direction and of a second conductivity type; wherein, if the direction perpendicular to the stretching direction is defined as the arrangement direction, the first thermoelectric material and the second thermoelectric material are spaced apart in the arrangement direction; the first thermoelectric material has a first end portion (111) corresponding to one of the stretching directions that is electrically and thermally connected to a first joint portion (113) on the heat dissipation surface of the two-phase thermoelectric material that corresponds to one of the arrangement directions. A thermoelectric conversion module wherein the second thermoelectric material has a second end portion (121) corresponding to one of the stretching directions that is electrically and thermally connected to a second joint portion (123) on the heat dissipation surface of the two-phase thermoelectric material that corresponds to the other of the arrangement directions, and the two-phase thermoelectric material has a temperature gradient portion (133) that generates a temperature difference in the stretching direction between the first joint portion and the second joint portion and generates a thermoelectric voltage based on the temperature difference. (Item 2) The thermoelectric conversion module according to Item 1, wherein the temperature gradient portion generates the temperature difference in the stretching direction between the first joint portion and the second joint portion, by having a first thickness of the two-phase thermoelectric material between the end portion and the first joint portion on the heat dissipation surface and a second thickness of the two-phase thermoelectric material between the end portion and the second joint portion on the heat dissipation surface, with reference to the end portion (132) of the two-phase thermoelectric material opposite to the heat dissipation surface in the stretching direction.(Item 3) The thermoelectric conversion module according to Item 1 or 2, wherein the two-phase thermoelectric material has an end face (132) opposite to the heat dissipation surface in the stretching direction, and the temperature gradient portion is such that one or both of the first end of the first thermoelectric material and the second end of the second thermoelectric material are inserted from the heat dissipation surface toward the end face, so that in the stretching direction, the first insertion depth of the first end of the first thermoelectric material toward the heat dissipation surface and the second insertion depth of the second end of the second thermoelectric material toward the heat dissipation surface are different, thereby generating the temperature difference in the stretching direction between the first joint and the second joint. (Item 4) The thermoelectric conversion module according to any one of items 1 to 3, wherein the temperature gradient portion generates the temperature difference in the stretching direction between the first joint and the second joint, by adjusting the density inside the two-phase thermoelectric material so that the density on the side of the first joint and the density on the side of the second joint are different in the direction of arrangement.

Claims

1. A two-phase thermoelectric material (130) having a structure that undergoes a phase transition when heat is applied and a heat dissipation surface (131) that releases internal heat; a first thermoelectric material (110) having a shape along the stretching direction and being of a first conductivity type; and a second thermoelectric material (120) having a shape along the stretching direction and being of a second conductivity type, wherein, when the direction perpendicular to the stretching direction is defined as the arrangement direction, the first thermoelectric material and the second thermoelectric material are arranged with a gap between them in the arrangement direction, and the first thermoelectric material has a first end portion (111) corresponding to one of the stretching directions electrically and thermally connected to a first joint portion (113) on the heat dissipation surface of the two-phase thermoelectric material corresponding to one of the arrangement directions. A thermoelectric conversion module wherein the second thermoelectric material has a second end portion (121) corresponding to one of the stretching directions electrically and thermally connected to a second joint portion (123) corresponding to the other of the arrangement directions on the heat dissipation surface of the two-phase thermoelectric material, and the two-phase thermoelectric material has a temperature gradient portion (133) that generates a temperature difference in the stretching direction between the first joint portion and the second joint portion and generates a thermoelectric voltage based on the temperature difference.

2. The thermoelectric conversion module according to claim 1, wherein, in the stretching direction, the temperature gradient portion generates the temperature difference in the stretching direction between the first joint and the second joint, by having a first thickness of the two-phase thermoelectric material between the end face (132) of the two-phase thermoelectric material opposite to the heat dissipation surface and the first joint of the heat dissipation surface differ in the stretching direction.

3. The thermoelectric conversion module according to claim 1 or 2, wherein the two-phase thermoelectric material has an end face (132) opposite to the heat dissipation surface in the stretching direction, and the temperature gradient portion is such that one or both of the first end of the first thermoelectric material and the second end of the second thermoelectric material are inserted from the heat dissipation surface toward the end face, so that in the stretching direction, the first insertion depth of the first end of the first thermoelectric material relative to the heat dissipation surface and the second insertion depth of the second end of the second thermoelectric material relative to the heat dissipation surface are different, thereby generating the temperature difference in the stretching direction between the first joint and the second joint.

4. The thermoelectric conversion module according to claim 1 or 2, wherein the temperature gradient portion is configured such that the density inside the two-phase thermoelectric material is adjusted so that the density on the side of the first joint and the density on the side of the second joint are different in the direction of arrangement, thereby generating the temperature difference in the stretching direction between the first joint and the second joint.

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