thermoelectric conversion module

Abstract

The purpose of the present disclosure is to provide a sheet-like thermoelectric conversion module having excellent thermoelectric conversion characteristics. A thermoelectric conversion module (100) of the present disclosure is formed as a sheet and is disposed in contact with or in proximity to a heat source to generate electric power on the basis of a temperature difference between a portion in the vicinity of the heat source and a portion spaced apart from the heat source, the thermoelectric conversion module (100) having an incision penetrating through the sheet in a thickness direction thereof. The thermoelectric conversion module (100) is characterized by, when extended in a predetermined direction to separate opposite ends of the incision away from each other, deforming from a sheet-like form A to a three-dimensionally structured form B protruding in the sheet thickness direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority based on Japanese Patent Application No. 2021-62105, filed on March 31, 2021, the entire specification of which is incorporated herein by reference. [Technical Field]

[0002] The present disclosure relates to a thermoelectric conversion module. [Background technology]

[0003] In recent years, flexible, thin, and lightweight sheet-type thermoelectric conversion modules using sheet-type thermoelectric conversion elements have been proposed. For example, Patent Document 1 discloses a thermoelectric conversion element in which flexible film-like substrates made of materials with different thermal conductivities are provided on both sides of the thermoelectric conversion module, and the material with higher thermal conductivity is located on part of the outer surface of the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3981738 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Document 1, the temperature gradient in the thickness direction of the substrate is converted into a temperature gradient in the in-plane direction of the substrate, so it is difficult to obtain the temperature difference necessary for power generation unless the area of ​​the thermoelectric conversion element is large. Also, it is difficult to flexibly respond to heat sources with various shapes and temperature difference directions, so there is room for improvement in these respects.

[0006] Therefore, an object of the present disclosure is to solve the above-mentioned problems and provide a sheet-shaped thermoelectric conversion module with excellent thermoelectric conversion properties. [Means for solving the problem]

[0007] The present disclosure aims to advantageously solve the above-mentioned problems, and the thermoelectric conversion module of the present disclosure is a sheet-shaped thermoelectric conversion module that is placed in contact with or close to a heat source and generates electricity based on the temperature difference between a portion near the heat source and a portion remote from the heat source, and has cuts that penetrate the sheet in the thickness direction, and the thermoelectric conversion module is characterized in that, when stretched in a predetermined direction, opposing edges of the cuts are separated from each other and the thermoelectric conversion module is transformed from sheet-shaped form A to three-dimensional structure form B that protrudes in the sheet thickness direction. By adopting such a configuration, the sheet-shaped thermoelectric conversion module can be transformed into a three-dimensional structure by the simple method of stretching it in a predetermined direction and brought close to a heat source, thereby increasing the temperature difference within the sheet-shaped thermoelectric conversion module and improving the thermoelectric conversion characteristics.

[0008] Here, the thermoelectric conversion module of the present disclosure preferably includes a sheet-like substrate and an element main body formed on the substrate. By adopting such a configuration, only the portions of the thermoelectric conversion module that protrude in the thickness direction of the sheet can be formed with thermoelectric conversion elements, thereby improving the thermoelectric conversion characteristics using a smaller amount of thermoelectric conversion material.

[0009] Here, in the thermoelectric conversion module of the present disclosure, it is preferable that the element main body includes an element body formed in an elongated shape, and that the element body is arranged so that both longitudinal ends of the element body are spaced apart from each other in the protruding direction of the sheet in the state of Form B. By employing such a configuration, the rear surface of the sheet is brought close to a heat source, thereby efficiently creating a temperature difference in the longitudinal direction of the element body and improving the thermoelectric conversion characteristics.

[0010] In the thermoelectric conversion module of the present disclosure, the element body preferably includes a plurality of elongated element bodies, and adjacent element bodies are electrically connected in series at longitudinal ends of the plurality of element bodies. By adopting such a configuration, the thermoelectromotive force generated within the element bodies can be increased and output by the series connection.

[0011] In the thermoelectric conversion module of the present disclosure, the element body preferably contains carbon nanotubes. By adopting such a configuration, the Seebeck coefficient of the element body itself can be increased by stretching the thermoelectric conversion module, thereby improving the thermoelectric conversion characteristics. Furthermore, the mechanical strength of the thermoelectric conversion module can be further improved and the weight can be reduced.

[0012] In the thermoelectric conversion module according to the present disclosure, the longitudinal length of the element body is preferably 30 mm or more. By adopting such a configuration, it is possible to easily ensure a temperature difference within the element body and improve the thermoelectric conversion characteristics.

[0013] In the thermoelectric conversion module of the present disclosure, the longitudinal length of the element body is preferably 5 mm or more and 12 mm or less. By adopting such a configuration, it is possible to increase the electromotive force generated by the thermoelectric conversion module for the same amount of carbon nanotubes used.

[0014] In the thermoelectric conversion module according to the present disclosure, the thermal conductivity of the substrate is preferably 5.0 W / (m K) or less. By adopting such a configuration, heat conduction in the longitudinal direction of the element body can be suppressed, making it easier to ensure a temperature difference and improving the thermoelectric conversion characteristics.

[0015] Here, in the thermoelectric conversion module of the present disclosure, the thermoelectric conversion module preferably comprises, in the state of Form B, the element body as a power generation section, a heat absorption section in contact with or close to a heat source, and a heat dissipation section in contact with or close to a heat dissipation body having a temperature lower than that of the heat source and disposed on the opposite side of the heat absorption section in the protruding direction of the sheet. By employing such a configuration, it is possible to increase the temperature difference in the longitudinal direction of the element body, thereby improving the thermoelectric conversion characteristics.

[0016] Here, the thermoelectric conversion module of the present disclosure preferably has a plurality of the notches. By adopting such a configuration, it is possible to easily ensure a temperature difference between the plurality of element bodies and improve the thermoelectric conversion characteristics.

[0017] Here, in the thermoelectric conversion module of the present disclosure, the predetermined direction is preferably a direction approximately perpendicular to the extending direction of the cutout portion in the thermoelectric conversion module in the state of Form A. By employing such a configuration, the thermoelectric conversion module is stretched in the predetermined direction, thereby increasing the deflection around the cutout portion and causing it to protrude in the thickness direction of the sheet, thereby effectively creating a temperature difference within the element body.

[0018] Here, in the thermoelectric conversion module of the present disclosure, the predetermined direction is preferably a direction approximately perpendicular to the extending direction of the notch in the in-plane direction of the thermoelectric conversion module in the state of Form A. By employing such a configuration, the thermoelectric conversion module is stretched in the predetermined direction, thereby increasing the deflection around the notch and causing it to protrude in the thickness direction of the sheet, thereby effectively creating a temperature difference within the element body.

[0019] In the thermoelectric conversion module of the present disclosure, the cutouts preferably include a first cutout disposed at a substantially central position in a direction perpendicular to the predetermined direction in a region between the plurality of element bodies arranged in the predetermined direction, and second cutouts extending from both sides of the element body in a direction perpendicular to the predetermined direction to both ends of the thermoelectric conversion module, the first cutouts and the second cutouts being alternately arranged in the predetermined direction. By employing such a configuration, the spacing of the edges of the first cutouts makes it easier for the end portions of the element body in the predetermined direction to displace in a direction perpendicular to the sheet thickness, and the spacing of the edges of the second cutouts can further reduce the rigidity of the element body in the standing direction.

[0020] Here, in the thermoelectric conversion module of the present disclosure, it is preferable that the predetermined direction is a direction approximately perpendicular to the in-plane direction of the sheet-like thermoelectric conversion module of Form A. By adopting such a configuration, the direction in which the stretching means pulls the thermoelectric conversion module coincides with the stretching direction of the thermoelectric conversion module, so that the thermoelectric conversion module can be reliably stretched by the amount of stretching required for desired power generation.

[0021] Here, in the thermoelectric conversion module of the present disclosure, it is preferable that the notches extend spirally from the inner periphery of the thermoelectric conversion module in the state of Form A toward the outer periphery provided concentrically with the inner periphery, and that in the state of Form B, the inner periphery protrudes in the thickness direction of the thermoelectric conversion module, and either the inner periphery or the outer periphery is disposed in contact with or in proximity to a heat source. By employing such a configuration, the thermoelectric conversion module has an axisymmetric structure, and each element body can generate stable power corresponding to the amount of protrusion of the inner periphery.

[0022] In the thermoelectric conversion module of the present disclosure, a plurality of the notches extending in substantially the same direction in an in-plane direction of the thermoelectric conversion module in the state of Form A are spaced apart in a direction substantially perpendicular to the extending direction of the notches, Preferably, the stretching means alternately penetrates the thermoelectric conversion module through the plurality of cuts from the front to the back and from the back to the front, thereby transforming the thermoelectric conversion module into a state of Form B in which the regions between adjacent cuts alternately protrude from the front and back of the thermoelectric conversion module. By adopting such a configuration, a rod-shaped member alternately penetrates the cuts from the front to the back and from the back to the front of the thermoelectric conversion module, causing a portion of the substrate to stably protrude in the thickness direction of the sheet, thereby reliably creating a temperature difference in the element body. This improves the thermoelectric conversion characteristics.

[0023] In the thermoelectric conversion module of the present disclosure, Preferably, the thermoelectric conversion module in the form A has a central portion provided at approximately the center in the in-plane direction and partitioned from the outer peripheral portion by the cutouts, connected to the outer peripheral portion via arm portions partitioned from the outer peripheral portion by the cutouts, and an extension means is disposed between the back surface of the central portion and the surface of the outer peripheral portion, thereby transforming the thermoelectric conversion module into the form B in which the central portion protrudes toward the front side. By adopting such a configuration, a portion of the substrate can be stably protruded in the thickness direction of the sheet, thereby reliably creating a temperature difference in the element body. Therefore, the thermoelectric conversion characteristics can be improved. [Effects of the Invention]

[0024] According to the present disclosure, it is possible to provide a sheet-shaped thermoelectric conversion module with excellent thermoelectric conversion properties. [Brief explanation of the drawings]

[0025] [Figure 1A] 1 is a plan view showing a state of Form A of a thermoelectric conversion module (an element body having a plurality of element bodies) according to a first embodiment of the present disclosure. [Figure 1B] FIG. 1 is a plan view showing a state of Form A of a thermoelectric conversion module (having an element body having a single element body) according to a first embodiment of the present disclosure. [Figure 2A]FIG. 2 is a perspective view showing a state of Form B of the thermoelectric conversion module (the element body having a plurality of element bodies) according to the first embodiment of the present disclosure. [Figure 2B] FIG. 2 is a perspective view showing a state of Form B of the thermoelectric conversion module (having a single element body as an element body) according to the first embodiment of the present disclosure. [Figure 3A] FIG. 2 is a diagram showing the configuration of an element body (uni-leg type) in a thermoelectric conversion module (the element body having a plurality of element bodies) according to the first embodiment of the present disclosure. [Figure 3B] 10A and 10B are diagrams illustrating modified examples of the configuration of the element body in the thermoelectric conversion module (the element body having a plurality of element bodies) according to the first embodiment of the present disclosure. [Figure 3C] FIG. 2 is a diagram showing a modified example of the configuration (π-type) of the element body in the thermoelectric conversion module (the element body having a plurality of element bodies) according to the first embodiment of the present disclosure. [Figure 3D] FIG. 2 is a diagram showing a modified example of the configuration (uni-leg type) of the element body in the thermoelectric conversion module (the element body having a single element body) according to the first embodiment of the present disclosure. [Figure 3E] FIG. 2 is a diagram showing a modified example of the configuration (π-type) of the element body in the thermoelectric conversion module (the element body having a single element body) according to the first embodiment of the present disclosure. [Figure 4A] FIG. 10 is a diagram showing the relationship between the extension distance and the output voltage and output current when the thermoelectric conversion module is extended in the longitudinal direction. [Figure 4B] FIG. 10 is a diagram showing the relationship between the stretching distance and the output power when the thermoelectric conversion module is stretched in the longitudinal direction. [Figure 4C] FIG. 10 is a diagram showing the relationship between the stretching distance and the tensile stress when a thermoelectric conversion module is stretched in the longitudinal direction. [Figure 4D] FIG. 10 is a diagram showing the relationship between the stretching distance and the Seebeck coefficient when a thermoelectric conversion module is stretched in the longitudinal direction. [Figure 5A] FIG. 10 is a diagram showing the relationship between the longitudinal length of the element body and the temperature difference occurring in the longitudinal direction of the element body. [Figure 5B]FIG. 10 is a diagram showing the relationship between the longitudinal length of the element body and the generated electromotive force. [Figure 6] FIG. 10 is a plan view showing a state of form A of a first modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. [Figure 7] FIG. 10 is a perspective view showing a state of form B of a first modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. [Figure 8] 10 is a plan view showing a state of form A of a second modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. FIG. [Figure 9] FIG. 10 is a perspective view showing a state of form B of a second modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. [Figure 10] 10 is a plan view showing a state of form A of a third modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. FIG. [Figure 11] FIG. 10 is a plan view showing a state of form A of a fourth modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. [Figure 12] FIG. 10 is a plan view showing a state of form A of a fifth modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. [Figure 13] FIG. 10 is a perspective view showing a state of form B of a fifth modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. [Figure 14] FIG. 13 is a plan view showing a state of form A of a sixth modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. [Figure 15] 13 is a plan view showing a state of form A of a seventh modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure. FIG. [Figure 16] FIG. 10 is a plan view illustrating a state of Form A of a thermoelectric conversion module according to a second embodiment of the present disclosure. [Figure 17] FIG. 10 is a perspective view showing a state of Form B of a thermoelectric conversion module according to a second embodiment of the present disclosure. [Figure 18] FIG. 10 is a plan view illustrating a state of Form A of a thermoelectric conversion module according to a third embodiment of the present disclosure. [Figure 19] FIG. 10 is a perspective view showing a state of Form B of a thermoelectric conversion module according to a third embodiment of the present disclosure. [Figure 20] It is a plan view showing the state of Form A of the first modification of the thermoelectric conversion module according to the third embodiment of the present disclosure. [Figure 21] It is a perspective view showing the state of Form B of the first modification of the thermoelectric conversion module according to the third embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0026] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The same reference numerals are given to common components in each figure.

[0027] [First Embodiment] Figures 1A to 3E are diagrams showing the configuration of the thermoelectric conversion modules 100 and 101 according to the first embodiment of the present disclosure. The thermoelectric conversion module 100 includes a base material 10 formed in a sheet shape, and an element body 20 formed on the base material 10 that generates electricity based on the temperature difference within the thermoelectric conversion module 100.

[0028] In the specification, claims, and drawings of the present application, the left - right direction in Figure 1A is the X - axis direction, and the up - down direction in Figure 1A is the Y - axis direction. Also, the direction perpendicular to the plane of Figure 1A is the Z - axis direction, the plus side in the Z - axis direction is the front side of the thermoelectric conversion module 100, and the minus side in the Z - axis direction is the back side of the thermoelectric conversion module 100.

[0029] The base material 10 has a rectangular shape with the X - axis direction being the longitudinal direction in the plan view shown in Figure 1A. In the present embodiment, a plurality of element bodies 20 for performing thermoelectric conversion are arranged at equal intervals in the longitudinal direction (X - axis direction) of the base material 10.

[0030] As shown in FIG. 3A, the element body 20 can be configured such that a plurality of elongated element bodies 21-23, which are p-type thermoelectric conversion elements, are electrically connected in series at their longitudinal ends to adjacent element bodies 21-23 via wiring 25. In the example of FIG. 3A, the element body 20 includes three element bodies 21-23 aligned in the Y-axis direction. In the example of FIG. 3A, the element bodies 21-23 can be configured, for example, of carbon nanotubes (CNTs), which are p-type thermoelectric conversion elements. Note that the element body 20 may also be configured to include a single element body 21, as shown in FIGS. 1B and 3D.

[0031] 1A, in a region between a plurality of element bodies 20 arranged in the X-axis direction, the substrate 10 has first cutouts 11 that extend in the Y-axis direction and are located at approximately the center of the substrate 10 in the Y-axis direction, and second cutouts 13 that extend from both sides of the element bodies 20 in the Y-axis direction to both ends of the substrate 10 in the Y-axis direction. The first cutouts 11 and second cutouts 13 are cutouts that penetrate the substrate 10 in the thickness direction, and are provided alternately at approximately equal intervals in the longitudinal direction (X-axis direction) of the substrate 10.

[0032] The first cutout 11 extends beyond the element body 20 in the lateral direction (Y-axis direction) of the substrate 10, and is disposed at approximately the center in the lateral direction (Y-axis direction) of the substrate 10. In the example of Fig. 1A, the first cutout 11 has a length equal to or greater than half the lateral length of the substrate 10, and both ends of the first cutout 11 terminate inside both ends of the lateral direction of the substrate 10.

[0033] 1A, the element body 20 is disposed at approximately the center of the substrate 10 in the short-side direction (Y-axis direction), and the second cutouts 13 extend from both sides of the element body 20 in the Y-axis direction to both ends of the substrate 10 in the Y-axis direction. The first cutouts 11 and the second cutouts 13 extend parallel to each other in the Y-axis direction and are alternately disposed at approximately equal intervals in the X-axis direction.

[0034] The thermoelectric conversion module 100 shown in FIG. 1A is in an initial sheet-like state. This sheet-like form will be referred to as "Form A" in the specification and claims of the present application. When the thermoelectric conversion module 100 in Form A is stretched in the left-right direction of FIG. 1A and both longitudinal ends of the thermoelectric conversion module 100 are attached to a mounting unit 40, which serves as a stretching means, as shown in FIG. 2A. The opposing edges 11a, 11b of the first cutout 11 and the opposing edges 13a, 13b of the second cutout 13 are separated from each other in the left-right direction of FIGS. 1A and 2A, which is the predetermined stretching direction. As a result, the right-side edges 11b, 13b in FIG. 2A are flexed upward, and the left-side edges 11a, 13a in FIG. 1A are flexed downward. 1A, the left end of the element body 20 protrudes upward (toward the front side) in the thickness direction of the sheet due to the flexural deformation of the edges of the first cut portion 11 and the second cut portion 13. Also, the right end of the element body 20 protrudes downward (toward the back side) in the thickness direction of the sheet (see FIG. 2A).

[0035] In this embodiment, the thermoelectric conversion module 100 is stretched from the state of Form A in a predetermined direction, that is, the left-right direction in FIG. 1A, so that it protrudes in the thickness direction of the sheet and assumes a three-dimensional structure as shown in FIG. 2A. In the specification and claims of this application, this three-dimensional structure will be referred to as "Form B." Form B will also be identified by a different reference numeral, such as "thermoelectric conversion module 101."

[0036] In this embodiment, the thermoelectric conversion module 101 in the form B is disposed above the heat source 30 as shown in FIG. 2A. As a result, the region around the right longitudinal end of each of the plurality of element bodies 21-23 (see FIG. 3A) constituting the element body 20 functions as a heat absorption section disposed adjacent to the heat source 30. Furthermore, the region at the left longitudinal end of each of the plurality of element bodies 21-23, located opposite the heat source 30, functions as a heat dissipation section cooled by natural convection of air. Note that a heat sink having a lower temperature than the heat source 30 may be disposed above the thermoelectric conversion module 101 in FIG. 2A, and the heat dissipation section may be actively cooled by the heat sink to increase the temperature difference in the longitudinal direction of the plurality of element bodies 21-23. Note that FIG. 2B shows the configuration of form B when the element body 20 has a single element body as shown in FIG. 1B.

[0037] 3A shows an example (a so-called "uni-leg type") in which an element body 20 is formed from a plurality of elongated element bodies 21-23 that are p-type thermoelectric conversion elements. The region marked with the reference numeral 20 in FIG. 1A corresponds to the region marked with the reference numeral 20 in FIG. 3A. The white arrows in the figure indicate the heat flux from the high-temperature side to the low-temperature side of the element bodies 21-23, and the black arrows indicate the direction of the current flowing through the element bodies 21-23. When a temperature difference occurs within the element bodies 21-23, holes move from the high-temperature side to the low-temperature side, generating a thermoelectric power in which the low-temperature side is positive. Therefore, as shown in Figure 3A, by connecting the high-temperature side ends of multiple element bodies 21-23 in series with the low-temperature side ends of adjacent element bodies 21-23 by wiring 25, and by connecting the low-temperature side ends in series with the high-temperature side ends of adjacent element bodies 21-23 by wiring 25, the element body 20 can obtain a large thermoelectric power corresponding to the number of element bodies 21-23 connected.

[0038] 1B, the element body 20 can be configured by a single long element body 21 that is a p-type thermoelectric conversion element, as shown in, for example, Fig. 3D. In this case, the high-temperature end of the element body 21 is connected in series to the low-temperature end of the adjacent element body 21 by wiring 25, and the low-temperature end of the element body 21 is connected in series to the high-temperature end of the adjacent element body 21 by wiring 25.

[0039] The wiring 25 can be made of various metals such as silver paste, gold, copper, aluminum, nickel, etc. In the example of Fig. 3A, the description is given on the assumption that p-type thermoelectric conversion elements are used for the element bodies 21-23, but n-type thermoelectric conversion elements may be used instead.

[0040] 3B shows a modified example in which the element body 20 is constituted by a plurality of elongated element bodies 21, 22A, and 23 including p-type thermoelectric conversion elements and n-type thermoelectric conversion elements. The region marked with reference numeral 20 in FIG. 1A corresponds to the region marked with reference numeral 20 in FIG. 3B. As described above, when a temperature difference occurs within the element bodies 21 and 23, holes move from the high-temperature side to the low-temperature side, generating a thermoelectromotive force in which the low-temperature side is positive. Furthermore, when a temperature difference occurs within the n-type thermoelectric conversion element 22A, electrons move from the high-temperature side to the low-temperature side, generating a thermoelectromotive force in which the high-temperature side is positive. Therefore, as shown in FIG. 3B, by connecting the high-temperature side ends of the p-type thermoelectric conversion elements 21 and 23 in series with the high-temperature side end of the adjacent n-type thermoelectric conversion element 22A or the low-temperature side end of the adjacent p-type thermoelectric conversion element 21 and 23 by wiring 25, and by connecting the low-temperature side ends of the p-type thermoelectric conversion elements 21 and 23 in series with the low-temperature side end of the adjacent n-type thermoelectric conversion element 22A or the high-temperature side end of the adjacent p-type thermoelectric conversion element 21 and 23 by wiring 25, the element body 20 can obtain a large thermoelectric power corresponding to the number of element bodies 21, 22A, and 23 connected together.

[0041] FIG. 3C shows a modified example (so-called "π-type") in which the element body 20 is configured by a plurality of elongated element bodies 21, 22A, 23, or element bodies 21A, 22, 23A, including p-type thermoelectric conversion elements and n-type thermoelectric conversion elements. The region marked with reference numeral 20 in FIG. 1A corresponds to the region marked with reference numeral 20 in FIG. 3C. As described above, when a temperature difference occurs within the element bodies 21, 22, 23, holes move from the high-temperature side to the low-temperature side, generating a thermoelectric power in which the low-temperature side is positive. Similarly, when a temperature difference occurs within the element bodies 21A, 22A, 23A, electrons move from the high-temperature side to the low-temperature side, generating a thermoelectric power in which the high-temperature side is positive. Therefore, as shown in FIG. 3C, by connecting the high-temperature side ends of the p-type thermoelectric conversion elements 21, 22, and 23 in series with the high-temperature side ends of the adjacent n-type thermoelectric conversion elements 21A, 22A, and 23A by wiring 25, and by connecting the low-temperature side ends of the p-type thermoelectric conversion elements 21, 22, and 23 in series with the low-temperature side ends of the adjacent n-type thermoelectric conversion elements 21A, 22A, and 23A by wiring 25, the element body 20 can obtain a large thermoelectric power corresponding to the number of connected element bodies 21, 21A, 22, 22A, 23, and 23A.

[0042] 1B, the element body 20 can be configured by a long element body 21 that is a p-type thermoelectric conversion element and a long element body 21A that is an n-type thermoelectric conversion element, as shown in, for example, Fig. 3E. In this case, the high-temperature end of the element body 21 is connected in series with the high-temperature end of the adjacent element body 21A by wiring 25, and the low-temperature end of the element body 21 is connected in series with the low-temperature end of the adjacent element body 21A by wiring 25.

[0043] In the examples of FIGS. 3A to 3E , the thermoelectric conversion materials for forming the p-type and n-type thermoelectric conversion elements constituting the element bodies 21-23 are not particularly limited, and examples include bismuth tellurium-based compounds, antimony-based compounds, silicon-based compounds, metal oxide-based compounds, Heusler alloy-based compounds, conductive polymer compounds, conductive fibers, and composite materials thereof. Among these, conductive fibers are preferred, and fibrous carbon nanostructures such as carbon nanotubes (hereinafter also referred to as CNTs) are more preferred. The use of CNTs not only further improves the mechanical strength and weight of the thermoelectric conversion module 100 of the present disclosure, but also increases the Seebeck coefficient of the element bodies 21-23 by stretching the thermoelectric conversion module 100, as described below. Furthermore, the CNTs are not particularly limited, and single-walled CNTs and / or multi-walled CNTs can be used. However, single-walled CNTs are preferred. This is because single-walled CNTs tend to have superior thermoelectric properties (Seebeck coefficient). Single-walled carbon nanotubes can be produced using a method (see International Publication No. WO 2006 / 011655) in which raw material compounds and a carrier gas are supplied to a substrate bearing a catalyst layer on its surface to synthesize CNTs by chemical vapor deposition (CVD). The presence of a trace amount of oxidizing agent (catalytic activator) in the system dramatically improves the catalytic activity of the catalyst layer. (Hereinafter, CNTs produced using this method may be referred to as "SGCNTs"). Furthermore, SGCNTs are characterized by frequent bending. While CNTs have high thermal conductivity due to electron transfer, they are also thought to have a high thermal conductivity reduction effect due to phonon vibrations. However, because SGCNTs have more bending than CNTs produced using other common methods, their structure makes them less susceptible to phonon vibration amplification, thereby suppressing the reduction in thermal conductivity due to phonon vibrations. Therefore, SGCNTs can be a more advantageous material as a thermoelectric conversion material than other common CNTs.

[0044] Here, we will explain the thermoelectric conversion characteristics of a thermoelectric conversion module when CNTs are used as the thermoelectric conversion elements. Fig. 4A shows the output voltage and output current of the thermoelectric conversion elements when a thermoelectric conversion module (where the entire shape of the substrate 10 in Fig. 1A is composed of thermoelectric conversion elements) is stretched while placed close to a heat source, and Fig. 4B shows the output power of the thermoelectric conversion elements when the thermoelectric conversion module is stretched. Figs. 4A and 4B show that stretching the thermoelectric conversion module in the longitudinal direction increases the thermoelectromotive force in the thermoelectric conversion elements, and accordingly, the output current and output power tend to increase. This can be explained by the following two reasons.

[0045] First, by stretching the thermoelectric conversion module in the longitudinal direction, the angle between the longitudinal direction of the thermoelectric conversion element and the surface of the heat source increases, which is thought to increase the temperature difference within the thermoelectric conversion element and, accordingly, increase the thermoelectromotive force in the thermoelectric conversion element.

[0046] Second, by stretching the thermoelectric conversion module in the longitudinal direction, the tensile stress applied to the thermoelectric conversion module increases as shown in Figure 4C, and as a result, the Seebeck coefficient of the thermoelectric conversion element itself increases as shown in Figure 4D, which is thought to increase the thermoelectric conversion efficiency.

[0047] Furthermore, quantum calculation results have shown that the increase in the Seebeck coefficient itself due to the stretching of the thermoelectric conversion module is caused by a change in the electronic structure when a single CNT undergoes a structural change such as bending. In other words, it is thought that the bending of the CNT changes the electrical properties, resulting in an increase in the Seebeck coefficient.

[0048] When the Seebeck coefficient itself is increased by stretching the thermoelectric conversion module in the longitudinal direction, CNT alone may be used as the material for the thermoelectric conversion element, but a material in which CNT is blended with a copolymer of vinylidene fluoride and trifluoroethylene (VDF-TrFE) may also be used. When the Seebeck coefficient is increased by mixing CNT with another material and stretching it, the other material is not limited to those mentioned above and may be any material that enhances the electronic state change of CNT, and is particularly preferably a ferroelectric material with spontaneous polarization in the molecule.

[0049] The longitudinal length of the elongated element 21-23 is preferably 30 mm or more, more preferably 40 mm or more, and most preferably 60 mm or more. When the element includes CNTs, the element thickness is 80 μm, the element's surface thermal conductivity is 10 W / (m·K), the element's thickness direction thermal conductivity is 0.1 W / (m·K), and the temperature difference between the heat source temperature and the ambient temperature is 100 K. The simulation results for the temperature difference within the element installed on the surface of the heat source are shown in FIG. 5A. That is, if the element length is at least 30 mm or more, it is easy to ensure the temperature difference within the element. Furthermore, the simulation results showed that when the element's longitudinal length exceeds 10 mm, the thickness of the substrate, whose thermal conductivity is two orders of magnitude smaller than that of CNTs, does not significantly affect the temperature difference within the element.

[0050] Since CNT is an expensive material, the applicant investigated what strip size each element 21-23 should be to improve the thermoelectric conversion efficiency when the amount of CNT used (total area of ​​element 21-23) is the same.

[0051] In this embodiment, as shown in Figure 3A etc., multiple long element bodies 21-23 are connected together. Assuming that the total area of ​​the element bodies 21-23 is constant, if the width of one element body (Y-direction width in Figure 3A) is fixed, the product of the longitudinal length (X-direction length in Figure 3A) and the number of element bodies will be constant.

[0052] For example, if the element width is d, the longitudinal length L is L1, and the number of elements is n:n1, then the total element area S is S = d × L1 × n1. If the longitudinal length L is L2 and the number of elements is n:n2, ​​then S = d × L2 × n2. Doubling the longitudinal length L halves the number of elements n. In this case, a longer longitudinal length L allows for a larger temperature difference between the two longitudinal ends, increasing the electromotive force per element, but reducing the number of elements n. The final electromotive force obtained from a thermoelectric conversion module is the electromotive force per element multiplied by the number of elements n. Therefore, assuming a constant total element area S, the final electromotive force obtained will differ depending on whether the longitudinal length L of the element is increased to increase the temperature difference per element, or whether the longitudinal length L is decreased to increase the number of elements n. It is believed that there is an optimal value for the longitudinal length L of the element that will maximize the electromotive force. The results of a simulation study of this are shown in Figure 5B, which show that the largest electromotive force is obtained when the longitudinal length L of the element body is 6 mm. Figure 5B shows that the electromotive force decreases significantly when the longitudinal length L of the element body is 5 mm or less, whereas the electromotive force decreases gradually when the longitudinal length L of the element body is increased. From this perspective, the longitudinal length L of the element body is preferably 5 mm or more and 12 mm or less, and more preferably 5 mm or more and 8 mm or less.

[0053] The thermal conductivity of the substrate is preferably smaller than that of the thermoelectric conversion element. When CNTs are used for the thermoelectric conversion element, the thermal conductivity is preferably 5.0 W / (m·K) or less. Furthermore, the thermal conductivity of the substrate is more preferably 1.0 W / (m·K) or less, and most preferably 0.1 W / (m·K) or less. Materials that can be used for the substrate include paper (thermal conductivity: 0.06 W / (m·K)), wood (0.2 W / (m·K)), polyethylene (0.3 W / (m·K)), rubber (0.15 W / (m·K)), and polyimide (0.3 W / (m·K)).

[0054] [First Modification of the First Embodiment] Next, a first modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure will be described with reference to FIGS.

[0055] As shown in FIG. 6, the thermoelectric conversion module 110 according to the first modified example of the first embodiment includes a sheet-like substrate 10 formed in a circular ring shape, and an element body 20 formed on the substrate 10 and generating electricity based on a temperature difference.

[0056] The substrate 10 is a sheet-like member having an annular shape in the plan view shown in Fig. 6. As shown in Fig. 6, the substrate 10 has first cutouts 11 extending radially in a region between a plurality of element bodies 20 arranged in the circumferential direction and disposed at an approximately central position in the radial direction of the substrate 10, and second cutouts 13 extending from both radial sides of the element bodies 20 to both radial ends of the substrate 10. The first cutouts 11 and the second cutouts 13 are cutouts that penetrate the substrate 10 in the thickness direction and are provided alternately in the circumferential direction of the substrate 10.

[0057] The first cutout 11 extends beyond the element body 20 in the radial direction of the substrate 10, and is located at approximately the center of the radial direction of the substrate 10. The first cutout 11 has a length equal to or greater than half the radial length of the substrate 10, and both ends of the first cutout 11 terminate more inward than both ends of the radial direction of the substrate 10.

[0058] 6, the element body 20 is disposed at approximately the center in the radial direction of the substrate 10, and the second cutouts 13 extend from both radial sides of the element body 20 to both radial ends of the substrate 10. The first cutouts 11 and the second cutouts 13 both extend in the radial direction and are alternately disposed at approximately equal intervals in the circumferential direction.

[0059] The thermoelectric conversion module 110 shown in Fig. 6 is in a sheet-like initial state (form A). When the thermoelectric conversion module 110 of form A is deformed so that the radial direction is oriented in the up-down direction and attached to the outer peripheral surface of a substantially cylindrical heat source 41, which serves as an extension means and is shown in Fig. 7, the opposing edges 11a, 11b of the first cut portion 11 and the opposing edges 13a, 13b of the second cut portion 13 are spaced apart in the circumferential direction of the cylindrical heat source 41, which is the predetermined extension direction. As a result, one edge 11b, 13b of the first cut portion 11 and one edge 11b, 13b of the second cut portion 13 are flexibly deformed radially outward from the heat source 41, and the other edge 11a, 13a is flexibly deformed radially inward from the heat source 41. 7, due to the bending deformation of the edges of the first cut portion 11 and the second cut portion 13, the left end portion of the element body 20 protrudes radially outward from the heat source 41 in the thickness direction of the sheet, and the right end portion of the element body 20 protrudes radially inward from the heat source 41 in the thickness direction of the sheet (see FIG. 7).

[0060] In this embodiment, the thermoelectric conversion module 110 extends from the state of Form A in the circumferential direction of the heat source 41, which is a predetermined direction, and protrudes in the thickness direction of the sheet, resulting in a three-dimensional structure (Form B) as shown in Fig. 7. Form B will be identified by a different reference symbol from Form A, such as "thermoelectric conversion module 111."

[0061] In this embodiment, the thermoelectric conversion module 111 in the form B state is disposed on the outer peripheral surface of the heat source 41 as shown in Fig. 7. As a result, the peripheral region of the right end in the longitudinal direction of the multiple element bodies constituting the element body 20 in Fig. 7 serves as a heat absorption portion disposed close to the heat source 41. In addition, the region of the left end in the longitudinal direction of the multiple element bodies located on the opposite side from the heat source 41 functions as a heat dissipation portion that is cooled by natural convection of air.

[0062] In this modified example, as shown in Fig. 6, third cut portions 11A that intersect with each other are provided at four locations in the circumferential direction. By providing these intersecting cuts intermittently in the circumferential direction in this manner, when transforming from the annular shape of Configuration A in Fig. 6 to Configuration B shown in Fig. 7, one side can be turned over at the third cut portion 11A to swap the inner and outer sides. With this configuration, when transforming from Configuration A to Configuration B, it is possible to prevent the inner side, which has a shorter circumferential length, from being significantly distorted in the circumferential direction.

[0063] 6 has a shape in which the thermoelectric conversion module 100 extending in the left-right direction in FIG. 1A is extended in the circumferential direction. Therefore, the configuration of the element body 20 can be, for example, the configurations shown in FIGS. 3A to 3E.

[0064] [Second Modification of the First Embodiment] Next, a second modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure will be described with reference to FIGS. 8 and 9. FIG.

[0065] As shown in FIG. 8, the thermoelectric conversion module 120 according to the second modification of the first embodiment includes a sheet-like substrate 10 formed in a rectangular shape, and an element body 20 formed on the substrate 10 and generating electricity based on a temperature difference.

[0066] The substrate 10 is a sheet-like member having a rectangular shape in a plan view shown in FIG. 8. As shown in FIG. 8, the substrate 10 has a total of four element bodies (element bodies surrounded by dashed lines indicated by reference numeral 20 in FIG. 8) arranged in the longitudinal direction of the substrate 10, two in the lateral direction (Y-axis direction) and two in the longitudinal direction (X-axis direction), as one unit (element body 20). A plurality of these are arranged in the longitudinal direction of the substrate 10. In the region between the plurality of element bodies 20 in the X-axis direction, the substrate 10 has first cutouts 12 that are arranged at approximately the center of the substrate 10 in the Y-axis direction and cross each other, and second cutouts 13 that extend from both sides of the element body 20 in the Y-axis direction to both ends of the substrate 10 in the Y-axis direction. The first cutouts 12 and the second cutouts 13 are cutouts that penetrate the substrate 10 in the thickness direction.

[0067] The thermoelectric conversion module 120 shown in FIG. 8 shows a sheet-like initial state "Form A." When the thermoelectric conversion module 120 of Form A is stretched in the left-right direction (X-axis direction) in FIG. 8 and both longitudinal ends of the thermoelectric conversion module 120 are attached to a stretching means (not shown) that serves as a stretching unit, the opposing edges 12a, 12b of the first cutout 12 and the opposing edges 13a, 13b of the second cutout 13 are separated from each other in the left-right direction in FIGS. 8 and 9, which is the predetermined stretching direction. As a result, the spear-point-shaped portion surrounded by the first cutout 12 and the second cutout 13 that connects the element bodies 20 in FIG. 8 is stretched in the X-axis direction. This stretching of the spear-point-shaped portion pulls both ends of the substrate 10 in the Y-axis direction toward the center in the Y-axis direction, and the region where the element bodies 20 are provided protrudes in the Z-axis direction, as shown in FIG. 9, and the region is transformed into a three-dimensional structure "Form B."

[0068] When the thermoelectric conversion module 121 of form B shown in Fig. 9 is placed on a heat source (not shown), the spear-shaped portion extending in the X-axis direction described above functions as a heat absorption portion by being close to the heat source, and raises the temperature of both ends of the element body 20 in the Y-axis direction in Fig. 8. In this way, both ends of the element body 20 in the Y-axis direction become the high temperature side, and the center of the element body 20 in the Y-axis direction becomes the low temperature side, and a temperature difference occurs in the longitudinal direction of the element body.

[0069] In this modified example, as in Figure 3A, the high-temperature side ends of the element bodies, which are multiple p-type thermoelectric conversion elements, are connected in series with the low-temperature side ends of adjacent element bodies by wiring, and the low-temperature side ends are connected in series with the high-temperature side ends of adjacent element bodies by wiring, so that the element body 20 can obtain a large thermoelectric power corresponding to the number of connected element bodies.

[0070] Furthermore, in this modified example, as in Figure 3B, the high-temperature end of the element body, which is a p-type thermoelectric conversion element, is connected in series by wiring to the high-temperature end of the element body, which is an adjacent n-type thermoelectric conversion element, or the low-temperature end of the element body, which is an adjacent p-type thermoelectric conversion element, and the low-temperature end of the element body, which is a p-type thermoelectric conversion element, is connected in series by wiring to the low-temperature end of the element body, which is an adjacent n-type thermoelectric conversion element, or the high-temperature end of the element body, which is an adjacent p-type thermoelectric conversion element, thereby allowing the element body 20 to obtain a large thermoelectric power corresponding to the number of connected element bodies.

[0071] Furthermore, in this modified example, as in Figure 3C, the high temperature end of the element body, which is a p-type thermoelectric conversion element, is connected in series with the high temperature end of the element body, which is an adjacent n-type thermoelectric conversion element, by wiring, and the low temperature end of the element body, which is a p-type thermoelectric conversion element, is connected in series with the low temperature end of the element body, which is an adjacent n-type thermoelectric conversion element, by wiring, so that the element body 20 can obtain a large thermoelectric power corresponding to the number of connected element bodies.

[0072] [Third and fourth modified examples of the first embodiment] Next, third and fourth modified examples of the thermoelectric conversion module according to the first embodiment of the present disclosure will be described with reference to FIGS.

[0073] As shown in Figures 10 and 11, a thermoelectric conversion module 130 according to a third variant of the first embodiment and a thermoelectric conversion module 140 according to a fourth variant include a sheet-like substrate 10 formed in a rectangular shape and an element body 20 formed on the substrate 10 and generating electricity based on a temperature difference.

[0074] The thermoelectric conversion module 130 according to the third modification is similar to the first embodiment, except that the second cutouts 13, which are arranged in line symmetry with respect to the first cutouts 11 oriented in the Y-axis direction, extend at an angle relative to the Y-axis direction. The fourth modification shown in FIG. 11 is also similar to the configuration of the third modification, except that the pitch of the cutouts in the X-axis direction is different from that of the third modification. Therefore, detailed description thereof will be omitted here.

[0075] [Fifth Modification of the First Embodiment] Next, a fifth modified example of the thermoelectric conversion module according to the first embodiment of the present disclosure will be described with reference to FIGS.

[0076] As shown in FIG. 12, a thermoelectric conversion module 150 according to the fifth modification of the first embodiment includes a sheet-like substrate 10 formed in a rectangular shape, and an element body 20 formed on the substrate 10 and generating electricity based on a temperature difference.

[0077] The substrate 10 is a sheet-like member having a rectangular shape in the plan view shown in FIG. 12. The substrate 10 is provided with an element body 20 in which three element bodies are arranged in a direction toward the positive side in the X-axis direction and the negative side in the Y-axis direction. The element bodies 20 are arranged at approximately equal intervals in the X-axis direction. A first cutout 14 extending in the arrangement direction of the element bodies is provided on the outer side of the longitudinal end of each element body in the element body 20. The first cutout 14 is arranged at an angle with respect to the Y-axis direction at approximately the center position of the substrate 10 in the Y-axis direction, and terminates in a region inside both ends of the substrate 10 in the Y-axis direction.

[0078] The substrate 10 also has second cutouts 13 that extend to both ends of the substrate 10 in the Y-axis direction, excluding the region of the element body 20. The first cutouts 12 and second cutouts 13 are cutouts that penetrate the substrate 10 in the thickness direction.

[0079] The thermoelectric conversion module 150 shown in FIG. 12 is in a sheet-like initial state (form A). When the thermoelectric conversion module 150 of form A is stretched in the left-right direction in FIG. 12 and both longitudinal ends of the thermoelectric conversion module 150 are attached to a stretching means (not shown) on a fitting portion, as shown in FIG. 13, the opposing edges 14a, 14b of the first cutout 14 and the opposing edges 13a, 13b of the second cutout 13 are separated from each other in the left-right direction in FIGS. 12 and 13, which is the predetermined stretching direction. As a result, the left edges 14a, 13a in FIG. 13 are flexed upward, and the right edges 14b, 13b in FIG. 13 are flexed downward. Due to this flexural deformation of the edges of the first cutout 14 and the second cutout 13, in the example of FIG. 13, the right end of the element body 20 protrudes upward (toward the front side) in the thickness direction of the sheet. Furthermore, the left end of the element body 20 protrudes downward (to the back side) in the thickness direction of the sheet (see FIG. 13).

[0080] In this embodiment, the thermoelectric conversion module 150 is stretched from the state of Form A in a predetermined direction, that is, the left-right direction in FIG. 12, so that it protrudes in the thickness direction of the sheet, resulting in a three-dimensional structure (Form B) as shown in FIG. 13. As a result, the right end of each element body in the longitudinal direction that constitutes the element main body 20 protrudes upward, and the left end of each element body in the longitudinal direction protrudes downward. Therefore, by placing the thermoelectric conversion module 150 shown in FIG. 13 on a heat source, a temperature difference can be created in the longitudinal direction of each element body that constitutes the element main body 20. This can improve the thermoelectric conversion characteristics.

[0081] [Sixth and Seventh Modifications of the First Embodiment] Next, sixth and seventh modified examples of the thermoelectric conversion module according to the first embodiment of the present disclosure will be described with reference to FIGS.

[0082] As shown in Figures 14 and 15, a thermoelectric conversion module 160 according to the sixth variant of the first embodiment and a thermoelectric conversion module 170 according to the seventh variant include a sheet-shaped substrate 10 and an element body 20 formed on the substrate 10 and generating electricity based on a temperature difference.

[0083] The thermoelectric conversion module 160 according to the sixth modification is similar to the first embodiment, except that the plurality of first notches 11 oriented in the Y-axis direction and arranged at equal intervals in the X-axis direction are gradually offset in the negative Y-axis direction toward the positive X-axis direction. The seventh modification shown in FIG. 15 is similar to the configuration of the first embodiment, except that the outer shape of the substrate 10 is rhombic, and the element body 20 and notches are not provided in the center in the X-axis direction. Therefore, detailed description thereof will be omitted here.

[0084] As described above, this embodiment relates to a sheet-shaped thermoelectric conversion module 100 that is placed in contact with or close to a heat source and generates electricity based on the temperature difference between a portion near the heat source and a portion away from the heat source, and has cuts that penetrate the sheet in the thickness direction, and the thermoelectric conversion module 100 is configured so that, when stretched in a predetermined direction, opposing edges of the cuts separate from each other, and the thermoelectric conversion module 100 transforms from sheet-shaped form A to three-dimensional structure form B that protrudes in the sheet thickness direction. By employing such a configuration, the sheet-shaped thermoelectric conversion module 100 can be transformed into a three-dimensional structure by the simple method of stretching it in a predetermined direction and then brought close to a heat source, thereby increasing the temperature difference within the sheet-shaped thermoelectric conversion module and improving the thermoelectric conversion characteristics.

[0085] Furthermore, this embodiment is configured to include a sheet-like substrate 10 and an element body 20 formed on the substrate 10. By adopting such a configuration, only the portions protruding in the thickness direction of the sheet within the thermoelectric conversion module 100 can be formed with thermoelectric conversion elements, thereby improving the thermoelectric conversion characteristics using a smaller amount of thermoelectric conversion material.

[0086] In this embodiment, the element body 20 includes element bodies 21-23 formed in an elongated shape, and the element bodies 21-23 are preferably arranged so that both longitudinal ends of the element bodies are spaced apart from each other in the protruding direction of the sheet in the state of Form B. By employing such a configuration, the rear surface of the sheet is brought close to the heat source, thereby efficiently creating a temperature difference in the longitudinal direction of the element bodies and improving the thermoelectric conversion characteristics.

[0087] In this embodiment, the element body 20 includes a plurality of element bodies 21-23 formed in a long shape, and it is preferable that adjacent element bodies 21-23 are electrically connected in series at the longitudinal ends of the plurality of element bodies 21-23. By adopting such a configuration, the thermoelectromotive force generated within the element bodies can be increased and output by the series connection.

[0088] In this embodiment, the element bodies 21-23 are configured to include carbon nanotubes. By adopting such a configuration, the Seebeck coefficient of the element bodies 21-23 can be increased by stretching the thermoelectric conversion module 100, thereby improving the thermoelectric conversion characteristics. Furthermore, the mechanical strength of the thermoelectric conversion module 100 can be further improved and the weight can be reduced.

[0089] In this embodiment, the element bodies 21-23 are configured to have a longitudinal length of 30 mm or more. By adopting such a configuration, it is possible to easily ensure a temperature difference within the element bodies 21-23 and improve the thermoelectric conversion characteristics.

[0090] In this embodiment, the longitudinal length of the element bodies 21-23 is set to be 5 mm or more and 12 mm or less. By adopting such a configuration, it is possible to increase the electromotive force generated by the thermoelectric conversion module 100 for the same amount of carbon nanotubes used.

[0091] In this embodiment, the thermal conductivity of the substrate is set to 5.0 [W / (m K)] or less. By adopting such a configuration, the thermal conduction in the longitudinal direction of the element bodies 21-23 is suppressed, making it easier to ensure a temperature difference and improving the thermoelectric conversion characteristics.

[0092] Furthermore, in this embodiment, the thermoelectric conversion module 100 may, in the state of form B, include an element body 20 as a power generation section, a heat absorption section in contact with or close to the heat source 30, and a heat dissipation section in contact with or close to a heat dissipation body having a lower temperature than the heat source 30 and disposed on the opposite side of the heat absorption section in the protruding direction of the sheet. By employing such a configuration, the temperature difference in the longitudinal direction of the element bodies 21-23 can be increased, thereby improving the thermoelectric conversion characteristics.

[0093] In this embodiment, the element bodies 20 are configured to have a plurality of notches. By adopting such a configuration, it is possible to easily ensure a temperature difference between the plurality of element bodies 20, thereby improving the thermoelectric conversion characteristics.

[0094] In this embodiment, the predetermined direction is configured to be a direction approximately perpendicular to the extension direction of the notch in the in-plane direction of the thermoelectric conversion module 100 in the state of Form A. By adopting such a configuration, the thermoelectric conversion module 100 is stretched in the predetermined direction, thereby increasing the deflection around the notch and causing it to protrude in the thickness direction of the sheet, and effectively creating a temperature difference within the element body 20.

[0095] In this embodiment, the cutouts include a first cutout 11 disposed at approximately the center of a region between a plurality of element bodies 20 arranged in a predetermined direction in a direction perpendicular to the predetermined direction, and a second cutout 13 extending from both sides of the element body 20 in a direction perpendicular to the predetermined direction to both ends of the thermoelectric conversion module 100, and the first cutouts 11 and the second cutouts 13 are arranged alternately in the predetermined direction. By employing such a configuration, the separation of the edge portions 11a, 11b of the first cutout 11 makes it easier for the end of the element body 20 in the predetermined direction to displace in a direction perpendicular to the sheet thickness, and the separation of the edge portions 13a, 13b of the second cutout 13 can further reduce the rigidity of the element body 20 in the standing direction.

[0096] [Second embodiment] 16 and 17 are diagrams showing the configurations of thermoelectric conversion modules 200, 201 according to a second embodiment of the present disclosure. As shown in Fig. 16, the thermoelectric conversion module 200 includes a sheet-shaped substrate 10 and an element body 20 formed on the substrate 10 and generating electricity based on a temperature difference within the thermoelectric conversion module 200.

[0097] The substrate 10 has a substantially square shape in a plan view shown in FIG. 16. In this embodiment, the substrate 10 has a notch 15 that extends spirally from an annular inner peripheral portion 10b having an opening 10a toward an outer peripheral portion 10c that is concentric with the inner peripheral portion 10b. A plurality of notches 15 are formed at substantially equal intervals in the circumferential direction. Then, as shown in FIG. 16, an element body 20 that performs thermoelectric conversion is disposed in the region between the notches 15 that are adjacent in the circumferential direction.

[0098] The thermoelectric conversion module 200 shown in Fig. 16 is in a sheet-like initial state (form A). When the inner circumferential portion 10b of the thermoelectric conversion module 200 of form A is stretched in the thickness direction of the sheet in Fig. 16 and attached to a mounting portion (not shown) that serves as a stretching means, the inner circumferential portion 10b rotates clockwise in a plan view, and the opposing edges 15a, 15b of the cutout portion 15 move apart in the approximately horizontal direction, as shown in Fig. 17. Then, the inner end of the element body 20 is displaced upward (toward the front side) in the thickness direction of the sheet (see Fig. 17).

[0099] In this embodiment, the thermoelectric conversion module 200 is stretched from the state of Form A in a predetermined direction, that is, perpendicular to the plane of the paper of Fig. 16, so that it protrudes in the thickness direction of the sheet, resulting in a three-dimensional structure (Form B) as shown in Fig. 17. Form B will be identified by a different reference numeral, such as "thermoelectric conversion module 201."

[0100] In this embodiment, the thermoelectric conversion module 201 in the form B state can be placed on a heat source (not shown). As a result, the outer circumferential side in the longitudinal direction of the element body constituting the element main body 20 serves as a heat absorption part located close to the heat source 30. In addition, the inner circumferential side in the longitudinal direction of the element body located on the opposite side to the heat source functions as a heat dissipation part that is cooled by natural convection of air.

[0101] When a p-type thermoelectric conversion element is used for the element body constituting the element body 20, as in the configuration of Figure 3A, the high temperature side end of the element body (the radially outer end in the example of Figure 17) is connected in series with the low temperature side end of one circumferentially adjacent element body (the radially inner end in the example of Figure 17) by wiring, and the low temperature side end is connected in series with the high temperature side end of the other circumferentially adjacent element body by wiring, thereby allowing the element body 20 to obtain a large thermoelectric power corresponding to the number of connected element bodies.

[0102] In this embodiment, one p-type thermoelectric conversion element is arranged on the upper surface (surface) of each spiral arm 15c defined by the cutouts 15, but this is not limited to this configuration. An n-type thermoelectric conversion element may be arranged instead of the p-type thermoelectric conversion element. Furthermore, the entire spiral arm 15c may be formed of thermoelectric conversion elements. Alternatively, one p-type thermoelectric conversion element and one n-type thermoelectric conversion element may be arranged on the front and back of each spiral arm 15c, with the high-temperature end of the p-type thermoelectric conversion element connected in series with the high-temperature end of the n-type thermoelectric conversion element on the opposite surface of the spiral arm 15c by wiring, and the low-temperature end of the p-type thermoelectric conversion element connected in series with the low-temperature end of the adjacent n-type thermoelectric conversion element by wiring.

[0103] As described above, in this embodiment, the predetermined direction is configured to be a direction approximately perpendicular to the in-plane direction of the sheet-like thermoelectric conversion module 200 of Form A. By adopting such a configuration, the direction in which the stretching means pulls the thermoelectric conversion module 200 coincides with the stretching direction of the thermoelectric conversion module 200, so that the thermoelectric conversion module 200 can be reliably stretched by the amount of stretching required for the desired power generation.

[0104] In this embodiment, the notches 15 extend spirally from the inner circumferential portion 10b of the thermoelectric conversion module 200 in the state of Form A toward the outer circumferential portion 10c provided concentrically with the inner circumferential portion 10b, and in the state of Form B, the inner circumferential portion 10b protrudes in the thickness direction of the thermoelectric conversion module 200, and either the inner circumferential portion 10b or the outer circumferential portion 10c is arranged in contact with or in proximity to the heat source. By adopting such a configuration, the thermoelectric conversion module 200 has an axisymmetric structure, and each element body can generate stable power corresponding to the amount of protrusion of the inner circumferential portion 10b.

[0105] [Third embodiment] 18 and 19 are diagrams showing the configurations of thermoelectric conversion modules 300, 301 according to a third embodiment of the present disclosure. As shown in Fig. 18, the thermoelectric conversion module 300 includes a sheet-shaped substrate 10 and an element body 20 formed on the substrate 10 and generating electricity based on a temperature difference within the thermoelectric conversion module 300.

[0106] The substrate 10 has a rectangular shape elongated in the Y-axis direction in the plan view shown in FIG. 18 . In this embodiment, the substrate 10 is provided with element bodies 20 that perform thermoelectric conversion and are composed of a total of six element bodies, two arranged in the X-axis direction and three arranged in the Y-axis direction. In this embodiment, four element bodies 20 are arranged at predetermined intervals in the Y-axis direction as shown in FIG. 18 , and on both sides of each element body 20 in the Y-axis direction, a notch 16 is provided that extends in the X-axis direction and terminates inside both ends of the substrate 10 in the X-axis direction. Therefore, two parallel notches 16 are provided between each element body 20 as shown in FIG. 18 . In this embodiment, the notches 16 extend in approximately the same direction (X-axis direction) in the in-plane direction of the thermoelectric conversion module 300 and are spaced apart in the Y-axis direction.

[0107] The thermoelectric conversion module 300 shown in FIG. 18 is in a sheet-like initial state (Configuration A). As shown in FIG. 19, rod-shaped members 43, which serve as extension means, are attached to this Configuration A thermoelectric conversion module 300 so that the rod-shaped members 43 alternately penetrate the cutouts 16 from the front surface of the thermoelectric conversion module 300 (the surface on which the element bodies 20 are arranged in FIG. 18) to the back surface and from the back surface to the front surface. As a result, as shown in FIG. 19, the opposing edges 16a, 16b of the cutouts 16 are separated in the thickness direction of the sheet, and the central position of the element bodies 20 in the X-axis direction protrudes upward in the thickness direction of the sheet (to the front side) from the Configuration A thermoelectric conversion module 300, thereby transforming it into a three-dimensional structure (Configuration B). As a result, of the regions between the cutouts 16, the regions where the element bodies 20 are arranged protrude toward the front side of the thermoelectric conversion module 300, and the regions between the element bodies 20 in the Y-axis direction protrude toward the back side of the thermoelectric conversion module 300.

[0108] In this embodiment, the thermoelectric conversion module 301 in the form B state can be placed on a heat source (not shown) so that, for example, the back surface of the thermoelectric conversion module 301 is close to the heat source. This allows the outer longitudinal side of the element body constituting the element main body 20 to serve as a heat absorption part located close to the heat source 30. Also, the inner longitudinal side of the element body located opposite the heat source functions as a heat dissipation part that is cooled by natural convection of air.

[0109] When, for example, a p-type thermoelectric conversion element is used as the element constituting the element body 20, the high temperature end of the element body (the outer end in the example of FIG. 19) is connected in series with the low temperature end of the adjacent element body (the inner end in the example of FIG. 19) by wiring, as in the configuration of FIG. 3A, and the low temperature end is connected in series with the high temperature end of the adjacent element body by wiring, thereby allowing the element body 20 to obtain a large thermoelectric power corresponding to the number of connected element bodies.

[0110] For example, when p-type thermoelectric elements and n-type thermoelectric elements are used as the elements constituting the element body 20, the high-temperature end of a p-type thermoelectric element may be connected in series with the high-temperature end of an adjacent n-type thermoelectric element or the low-temperature end of an adjacent p-type thermoelectric element by wiring, as in the configuration of Figure 3B, and the low-temperature end may be connected in series with the low-temperature end of an adjacent n-type thermoelectric element or the high-temperature end of an adjacent p-type thermoelectric element by wiring, thereby enabling the element body 20 to generate a large thermoelectric power corresponding to the number of connected elements. Furthermore, the high-temperature end of a p-type thermoelectric element may be connected in series with the high-temperature end of an adjacent n-type thermoelectric element by wiring, as in the configuration of Figure 3C, and the low-temperature end may be connected in series with the low-temperature end of an adjacent n-type thermoelectric element by wiring, thereby enabling the element body 20 to generate a large thermoelectric power corresponding to the number of connected elements.

[0111] [First Modification of the Third Embodiment] Next, a first modified example of the thermoelectric conversion module according to the third embodiment of the present disclosure will be described with reference to FIGS. 20 and 21. FIG.

[0112] As shown in FIG. 20, the thermoelectric conversion module 310 includes a substrate 10 formed in a sheet shape and an element body 20 formed on the substrate 10 and generating electricity based on the temperature difference within the thermoelectric conversion module 310.

[0113] The substrate 10 has a substantially square shape in the plan view shown in Fig. 20. In this embodiment, the substrate 10 is provided with a central notch 17 for defining a central portion 17c of the substrate 10 into a substantially square shape, and arm notches 18 for defining arm portions 18c extending radially from the central portion 17c toward the corners of the substrate 10. The arm portions 18c are defined relative to the outer periphery 10e by the arm notches 18. An element body 20 extending in the longitudinal direction of the arm portions 18c is disposed on each of the four arm portions 18c extending from the central portion 17c toward the corners of the substrate 10.

[0114] The thermoelectric conversion module 310 shown in Fig. 20 is in a sheet-like initial state (form A). When a rectangular parallelepiped corner member 45, which serves as an extension means, is placed between the back surface of the central portion 17c and the front surface of the outer peripheral portion 10e of this thermoelectric conversion module 310 in form A with the central portion 17c lifted upward as shown in Fig. 21, the opposing edges 17a, 17b of the central cutout 17 move apart in the thickness direction of the sheet, and the opposing edges 18a, 18b of the arm cutouts 18 move apart in the thickness direction of the sheet. As a result, the central portion 17c protrudes upward (toward the front side) from the thermoelectric conversion module 310 in form A in the thickness direction of the sheet, and the thermoelectric conversion module 310 is transformed into a three-dimensional structure (form B).

[0115] In this embodiment, the thermoelectric conversion module 311 in the form B state can be placed on a heat source (not shown) so that, for example, the back surface of the thermoelectric conversion module 311 is close to the heat source. This allows the outer longitudinal side of the element body constituting the element main body 20 to function as a heat absorption part located close to the heat source 30. Also, the inner longitudinal side of the element body located opposite the heat source functions as a heat dissipation part that is cooled by natural convection of air.

[0116] When, for example, a p-type thermoelectric conversion element is used as the element body constituting the element body 20, the high temperature side end of the element body (the outer end in the example of FIG. 21) is connected in series with the low temperature side end of another element body (the inner end in the example of FIG. 21) by wiring, as in the configuration of FIG. 3A, and the low temperature side end is connected in series with the high temperature side end of another element body by wiring, thereby allowing the element body 20 to obtain a large thermoelectric power corresponding to the number of connected element bodies.

[0117] For example, when p-type thermoelectric elements and n-type thermoelectric elements are used as the elements constituting the element body 20, the high-temperature end of a p-type thermoelectric element may be connected in series with the high-temperature end of another n-type thermoelectric element or the low-temperature end of another p-type thermoelectric element by wiring, and the low-temperature end may be connected in series with the low-temperature end of another n-type thermoelectric element or the high-temperature end of another p-type thermoelectric element by wiring, as in the configuration of Fig. 3B. This allows the element body 20 to generate a large thermoelectric power corresponding to the number of connected elements. Furthermore, the high-temperature end of a p-type thermoelectric element may be connected in series with the high-temperature end of another n-type thermoelectric element by wiring, and the low-temperature end may be connected in series with the low-temperature end of another n-type thermoelectric element by wiring, as in the configuration of Fig. 3C. This allows the element body 20 to generate a large thermoelectric power corresponding to the number of connected elements.

[0118] As described above, in this embodiment, the thermoelectric conversion module 300 in Form A has multiple notches 16 extending in approximately the same in-plane direction, spaced apart in a direction approximately perpendicular to the notch extension direction. The stretching means alternately penetrates the multiple notches 16 from the front to the back of the thermoelectric conversion module 300 and from the back to the front, thereby transforming the thermoelectric conversion module into Form B, in which regions between adjacent notches 16 alternately protrude from the front and back sides of the thermoelectric conversion module. By adopting this configuration, a rod-shaped member alternately penetrates the notches 16 from the front to the back of the thermoelectric conversion module 300 and from the back to the front, causing portions of the substrate 10 to stably protrude in the thickness direction of the sheet, thereby reliably creating a temperature difference in the element body 20. This improves the thermoelectric conversion characteristics.

[0119] In this embodiment, the thermoelectric conversion module 310 in the form A state has a central portion 17c, which is provided at a substantially central position in the in-plane direction and is partitioned from the outer peripheral portion 10e by a central notch 17. The central portion 17c is connected to the outer peripheral portion 10e via arm portions 18c, which are partitioned from the outer peripheral portion 10e by arm notches 18. A stretching means is disposed between the back surface of the central portion 17c and the front surface of the outer peripheral portion 10e, so that the thermoelectric conversion module 310 is transformed into the form B state in which the central portion 17c protrudes toward the front side. By adopting such a configuration, a portion of the substrate 10 is stably protruded in the thickness direction of the sheet, thereby reliably creating a temperature difference in the element body 20. This improves the thermoelectric conversion characteristics.

[0120] Although the present disclosure has been described based on various drawings and examples, it should be noted that those skilled in the art can easily make various modifications and alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included in the scope of the present invention. For example, the functions included in each component can be rearranged so as not to cause logical inconsistencies, and multiple components can be combined into one or divided. It should be understood that these modifications and alterations are also included in the scope of the present invention.

[0121] For example, in the first to third embodiments, the thermoelectric conversion module is configured to include the substrate 10 and the element body 20 formed on the substrate 10, but is not limited to this. The thermoelectric conversion module may be configured so that the entire module is formed by the thermoelectric conversion element without providing the substrate 10.

[0122] Furthermore, in the first to third embodiments, the thermoelectric conversion module is configured to stretch in a predetermined direction by being attached to an attachment portion at the end in the stretching direction, but this is not limited to this. For example, the thermoelectric conversion module may be configured to stretch in a predetermined direction by a user wearing clothing or the like to which the thermoelectric conversion module is sewn, or the user may stretch the thermoelectric conversion module by manually pulling it in a predetermined direction. The stretching means of the present disclosure encompasses a broad concept that can stretch a thermoelectric conversion module in a predetermined direction. [Industrial Applicability]

[0123] According to the present disclosure, it is possible to provide a sheet-like thermoelectric conversion module 100 with excellent thermoelectric conversion properties. [Explanation of symbols]

[0124] 10 Base material 10a opening 10b Inner circumference 10c outer periphery 10e Outer periphery 11 First cut 11a,11b Edge 12 First cut 12a,12b Edge 13 Second cut 13a,13b Edge 14 First cut 14a,14b Edge 15 Notch 15a,15b Edge 15c Spiral Arm 16 Notch 16a,16b Edge 17 Central notch 17a,17b Edge 17c central part 18 Arm notch 18a,18b Edge 18c Arm 20 Element body 21, 21A, 22, 22A, 23, 23A Element body 25 Wiring 30 Heat source 40 Mounting section (extension means) 41 Heat source (stretching means) 43 Rod-shaped member (extension means) 45 Corner member (extension means) 100, 110, 120, 130, 140, 150, 160, 170, 200, 300, 310 Thermoelectric conversion module (type A) 101, 111, 121, 151, 201, 301, 311 Thermoelectric conversion module (type B)

Claims

1. A sheet-shaped thermoelectric conversion module that is disposed in contact with or in the vicinity of a heat source and generates electricity based on the temperature difference between a portion near the heat source and a portion distant from the heat source, The sheet has a cut portion that penetrates in the thickness direction, When the thermoelectric conversion module is stretched in a predetermined direction, the opposing edges of the cut portions are separated from each other, and the thermoelectric conversion module is transformed from a sheet-like form A to a three-dimensional structure form B that protrudes in the sheet thickness direction.

2. The thermoelectric conversion module according to claim 1 , comprising: a sheet-like substrate; and an element body formed on the substrate.

3. The element body includes an element body formed in an elongated shape, The thermoelectric conversion module according to claim 2 , wherein the element bodies are arranged such that both longitudinal ends of the element bodies are spaced apart from each other in the protruding direction of the sheet in the state of form B.

4. The element body includes a plurality of element bodies formed in an elongated shape, The thermoelectric conversion module according to claim 2 or 3, wherein adjacent elements of the plurality of element bodies are electrically connected in series at longitudinal ends.

5. The thermoelectric conversion module according to claim 3 , wherein the element body includes carbon nanotubes.

6. The thermoelectric conversion module according to claim 5 , wherein the element body has a length in the longitudinal direction of 30 mm or more.

7. The thermoelectric conversion module according to claim 5 , wherein the element body has a length in the longitudinal direction of 5 mm or more and 12 mm or less.

8. The thermoelectric conversion module according to claim 2 , wherein the thermal conductivity of the base material is 5.0 W / (m·K) or less.

9. 9. The thermoelectric conversion module according to claim 2, wherein, in the state of form B, the thermoelectric conversion module comprises the element main body as a power generation unit, a heat absorption unit in contact with or close to a heat source, and a heat dissipation unit in contact with or close to a heat dissipation body having a temperature lower than that of the heat source and arranged on the opposite side of the heat absorption unit in the protruding direction of the sheet.

10. The thermoelectric conversion module according to claim 1 , comprising a plurality of the notches.

11. The thermoelectric conversion module according to claim 1 , wherein the predetermined direction is a direction substantially perpendicular to an extension direction of the cutout portion in the thermoelectric conversion module in the form A state.

12. The thermoelectric conversion module according to claim 11 , wherein the predetermined direction is a direction substantially perpendicular to an extension direction of the notch in an in-plane direction of the thermoelectric conversion module in the form A state.

13. The thermoelectric conversion module described in claim 12 when dependent on claim 2, wherein the notches include a first notch that is positioned at approximately the center in a direction perpendicular to the predetermined direction in a region between the plurality of element bodies arranged in the predetermined direction, and a second notch that extends from both sides of the element body in a direction perpendicular to the predetermined direction to both ends of the thermoelectric conversion module, and the first notch and the second notch are arranged alternately in the predetermined direction.

14. The thermoelectric conversion module according to claim 11 , wherein the predetermined direction is a direction substantially perpendicular to an in-plane direction of the sheet-like thermoelectric conversion module of form A.

15. The thermoelectric conversion module described in claim 14, wherein the notch extends spirally from an inner periphery of the thermoelectric conversion module in the state of form A toward an outer periphery arranged concentrically with the inner periphery, and in the state of form B, the inner periphery protrudes in the thickness direction of the thermoelectric conversion module, and either the inner periphery or the outer periphery is positioned in contact with or adjacent to a heat source.

16. a plurality of the notches extending in substantially the same direction in an in-plane direction of the thermoelectric conversion module in the state of Form A are spaced apart in a direction substantially perpendicular to the extending direction of the notches, The thermoelectric conversion module described in claim 14, wherein the stretching means alternately penetrates the plurality of cut portions from the front surface to the back surface and from the back surface to the front surface of the thermoelectric conversion module, thereby deforming the thermoelectric conversion module into a state of form B in which the areas between adjacent cut portions alternately protrude to the front and back sides of the thermoelectric conversion module.

17. a central portion that is provided at a substantially central position in an in-plane direction of the thermoelectric conversion module in the state of Form A and that is partitioned from the outer peripheral portion by the notch portion is connected to the outer peripheral portion via an arm portion that is partitioned from the outer peripheral portion by the notch portion, The thermoelectric conversion module according to claim 14, wherein an extension means is disposed between the rear surface of the central portion and the surface of the peripheral portion, thereby deforming the central portion into a state of form B in which the central portion protrudes toward the front side of the thermoelectric conversion module.

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