WO2018143185A1

WO2018143185A1 - Thermoelectric conversion module

Info

Publication number: WO2018143185A1
Application number: PCT/JP2018/002943
Authority: WO
Inventors: 内田　秀樹; 聡阿部
Original assignee: 日本ゼオン株式会社
Priority date: 2017-01-31
Filing date: 2018-01-30
Publication date: 2018-08-09
Also published as: JPWO2018143185A1

Abstract

The thermoelectric conversion module 102 according to the present invention comprises: a film-type thermoelectric conversion element body 10 having p-type thermoelectric conversion elements 1 and n-type thermoelectric conversion elements 2 joined in one direction in a plane; and heat conductors 4 joined to where the p-type thermoelectric conversion elements 1 and the n-type thermoelectric conversion elements 2 are joined on one surface of the thermoelectric conversion element body. Insulation regions 5 are disposed adjoining both sides of the heat conductors 4 in said one direction and, if disposed on the heat source, have radiation reflecting bodies 21 and/or radiation prevention bodies 22 closer to the heat source than the thermoelectric conversion element body 10.

Description

Thermoelectric conversion module

The present invention relates to a thermoelectric conversion module.

In recent years, thermoelectric conversion modules that convert heat into electricity using temperature differences have attracted attention. In particular, as a thermoelectric conversion module, a thermoelectric conversion module including a joined body formed by joining a p (Positive) type semiconductor material and an n (Negative) type semiconductor material has attracted attention because of its large electromotive force. ing. And the thermoelectric conversion module is anticipated as an effective means for utilizing an unused thermal energy.

Here, as the thermoelectric conversion module, a thermoelectric conversion module configured by a thin film p-type element and an n-type element in which film-like substrates are arranged on both upper and lower surfaces in the thickness direction has been proposed (for example, Patent Documents). 1). The film-like substrate of the thermoelectric conversion module described in Patent Document 1 has flexibility and is made of two or more types of materials having different thermal conductivities. Further, such a substrate is configured such that a material with high thermal conductivity is located on a portion of the outer surface of the substrate. For this reason, the thermoelectric conversion module described in Patent Document 1 can efficiently convert the temperature gradient in the thickness direction into the temperature gradient in the surface direction.

JP 2006-186255 A

Here, the thermoelectric conversion module is required to further improve the thermoelectric conversion efficiency. However, as described in Patent Document 1, a thin-film thermoelectric conversion module in which a temperature gradient is formed in the surface direction of the thin film is said to increase the temperature gradient in the surface direction of the module and increase the thermoelectric conversion efficiency. There was room for improvement.

Therefore, an object of the present invention is to provide a thermoelectric conversion module having high thermoelectric conversion efficiency.

An object of the present invention is to advantageously solve the above-described problems, and a thermoelectric conversion module according to the present invention includes a p-type thermoelectric conversion element and an n-type thermoelectric conversion joined along one in-plane direction. A film-like thermoelectric conversion element body having an element; a thermal conductor coupled to a junction of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element on one surface of the thermoelectric conversion element body; A heat insulating region adjacent to both sides of the heat conductor in the direction, and when installed on a heat source, a radiation reflector and / or a radiation preventer on the heat source side of the thermoelectric conversion element body It is characterized by having. Thus, if the thermoelectric conversion module has a radiation reflector and / or a radiation prevention body arranged at a predetermined position, the temperature gradient in the surface direction of the thermoelectric conversion element body is large, and the thermoelectric conversion efficiency is excellent.

Here, it is preferable that the thermoelectric conversion module of the present invention includes the radiation reflector and the radiation prevention body, and the radiation prevention body is disposed at a position closer to the heat source than the radiation reflector. If the thermoelectric conversion module includes a radiation preventer disposed closer to the heat source than the radiation reflector, the temperature gradient in the surface direction of the thermoelectric conversion element body is further increased, and the thermoelectric conversion efficiency is further improved.

Moreover, the thermoelectric conversion module of the present invention that can advantageously solve the above-described problem is a film-like thermoelectric element having a p-type thermoelectric conversion element and an n-type thermoelectric conversion element joined along one in-plane direction. A conversion element body; a thermal conductor coupled to a junction of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element on one surface of the thermoelectric conversion element body; and both sides of the thermal conductor in the one direction And having a foam material on the heat source side of the thermoelectric conversion element body when installed on a heat source. If the thermoelectric conversion module has a foam material at a specific position, the temperature gradient in the surface direction of the thermoelectric conversion element body is large, and the thermoelectric conversion efficiency is excellent.

Moreover, the thermoelectric conversion module of the present invention that can advantageously solve the above-described problem is a film-like thermoelectric element having a p-type thermoelectric conversion element and an n-type thermoelectric conversion element joined along one in-plane direction. A conversion element body; a thermal conductor coupled to a junction of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element on one surface of the thermoelectric conversion element body; and both sides of the thermal conductor in the one direction And a heat insulating region adjacent to the heat source, and when it is installed on a heat source, contacts the heat conductor on the heat source side with respect to the thermoelectric conversion element body and is not in contact with the thermoelectric conversion element body. It is characterized by having a heat storage material. If the thermoelectric conversion module has a heat storage material at a specific position, the temperature gradient in the surface direction of the thermoelectric conversion element body is large, and the thermoelectric conversion efficiency is excellent.

Moreover, the thermoelectric conversion module of the present invention that can advantageously solve the above-described problem is a film-like thermoelectric element having a p-type thermoelectric conversion element and an n-type thermoelectric conversion element joined along one in-plane direction. A conversion element body; a thermal conductor coupled to a junction of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element on one surface of the thermoelectric conversion element body; and both sides of the thermal conductor in the one direction And the heat conductor has a connection surface connected to the film-like thermoelectric conversion element body and a bottom surface opposite to the connection surface, and the area of the bottom surface Is larger than the area of the connection surface. If the bottom surface of the heat conductor of the thermoelectric conversion module is larger than the connection surface, the temperature gradient in the surface direction of the thermoelectric conversion element body is large and the thermoelectric conversion efficiency is excellent.

Here, in the thermoelectric conversion module of the present invention, the thermal conductor preferably has a thermal conductivity of 10 W / m · K or more. When the thermal conductivity of the thermal conductor is 10 W / m · K or more, the temperature gradient in the surface direction of the thermoelectric conversion element can be further increased, and the thermoelectric conversion efficiency can be further increased.
In the present specification, “thermal conductivity” is a value that can be measured for a measurement object such as a thermal conductor, for example, using a laser flash method.

Moreover, it is preferable that the thermoelectric conversion module of the present invention further includes at least one substrate, and the thermal conductor connects the at least one substrate and the film-like thermoelectric conversion element body. If at least one board | substrate connected via a thermoelectric conversion element body and a heat conductor is provided, the mechanical strength of a thermoelectric conversion module can be improved. Further, the at least one substrate can also have a function of protecting the components inside the module from the external environment.

In the thermoelectric conversion module of the present invention, it is preferable that the at least one substrate comprises a resin material. If the substrate connected to the thermoelectric conversion element body and the thermal conductor is a substrate containing a resin material, flexibility can be given to the thermoelectric conversion module, and the installation ease of the thermoelectric conversion module is improved. Because it can. The installation location of the thermoelectric conversion module is not necessarily flat, so if flexibility can be given to the thermoelectric conversion module, the thermoelectric conversion module can be freely deformed according to the shape of the installation location, and power generation efficiency Can be raised.

In the thermoelectric conversion module of the present invention, it is preferable that the at least one substrate includes a metal material. If the thermoelectric conversion element body and the substrate connected via the heat conductor include a metal material, the temperature gradient in the surface direction of the thermoelectric conversion element body can be further increased, and the thermoelectric conversion efficiency can be further increased.

In the thermoelectric conversion module of the present invention, it is preferable that the at least one substrate disposed on the opposite side of the heat source when the thermoelectric conversion module is installed on the heat source is a heat sink. If the substrate disposed on the side farther from the heat source when disposed on the heat source is a heat sink, the temperature gradient in the surface direction of the thermoelectric conversion element body can be further increased to further increase the thermoelectric conversion efficiency.

In the thermoelectric conversion module of the present invention, the thermal conductor is an anisotropic thermal conductor, and the thermal conductivity in the thickness direction of the thermal conductor is transverse to the thickness direction of the thermal conductor. It is preferably higher than the thermal conductivity. This is because, if the heat conductor is an anisotropic heat conductor rich in heat conductivity in the thickness direction, loss that can occur when conducting heat can be reduced, and thermoelectric conversion efficiency can be further improved.

In the thermoelectric conversion module of the present invention, the at least one substrate is an anisotropic heat conductive substrate, and the heat conductivity in the transverse direction with respect to the thickness direction of the substrate is the heat conductivity in the thickness direction of the substrate. Higher than that. This is because if the substrate is an anisotropic heat conductive substrate having a high thermal conductivity in the plane direction, the temperature gradient in the plane direction of the thermoelectric conversion element can be further increased, and the thermoelectric conversion efficiency can be further improved.

According to the present invention, a thermoelectric conversion module with high thermoelectric conversion efficiency can be provided.

It is sectional drawing for demonstrating the structure used as the base of the thermoelectric conversion module of this invention. It is sectional drawing which shows schematic structure of an example of the thermoelectric conversion module provided with a heat sink as an upper board | substrate. It is sectional drawing which shows schematic structure of the thermoelectric conversion module concerning 1st Embodiment of this invention. It is sectional drawing which shows schematic structure of the thermoelectric conversion module concerning 2nd Embodiment of this invention. It is sectional drawing which shows schematic structure of the thermoelectric conversion module concerning 3rd Embodiment of this invention. It is sectional drawing which shows schematic structure of the thermoelectric conversion module concerning 4th Embodiment of this invention.

Hereinafter, a structure serving as a base of the thermoelectric conversion module of the present invention and an embodiment of the present invention will be described in detail with reference to the drawings. In addition, in each figure, what attached | subjected the same code | symbol shall show the same component.

Here, the thermoelectric conversion module of the present invention is not particularly limited, and is a temperature control element that can be used in a cold storage or the like, a power generation element for waste heat power generation or snow ice power generation, and a lithium ion battery or the like. Can be used as an electrode. Moreover, it does not specifically limit as a heat source of the thermoelectric conversion module of this invention, For example, it can be heat sources, such as an electric equipment, and cold heat sources, such as liquefied natural gas, snow, and ice. In the following description, for the sake of clarity, it is assumed that the temperature of the heat source is higher than the temperature on the high temperature side of the temperature gradient to be formed in the thermoelectric conversion element, that is, the heat source is a heat source other than the cold heat source. I will explain.

FIG. 1 is a cross-sectional view for explaining a structure serving as a base of the thermoelectric conversion module 100 of the present invention. One surface of the thermoelectric conversion module 100 may be disposed adjacent to the heat source. In FIG. 1, the thermoelectric conversion module 100 is illustrated as being disposed on a heat source, and in the drawing, the lower side is illustrated as the heat source side and the upper side is illustrated as the heat dissipation side.

The thermoelectric conversion module 100 includes a film-like thermoelectric conversion element body 10 in which a p-type thermoelectric conversion element 1 and an n-type thermoelectric conversion element 2 are joined along one direction in the plane. In the figure, the thermoelectric conversion element body 10 is shown as having three pairs of p-type thermoelectric conversion elements 1 and n-type thermoelectric conversion elements 2. However, the thermoelectric conversion element body 10 is not limited to this, It is only necessary to have a pair of p-type thermoelectric conversion elements 1 and n-type thermoelectric conversion elements 2. And the thermoelectric conversion element body 10 is provided with the heat conductor 4 couple | bonded with the junction part of the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2 in the at least one surface. And the heat insulation area | region 5 is arrange | positioned adjacent to the both sides of the heat conductor 4 along the connection direction of the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2.

Here, the heat insulating region 5 adjacent to the heat conductor 4 can be configured by a material having a lower thermal conductivity than the heat conductor 4 or by a vacuum. Further, the substance having a lower thermal conductivity than the thermal conductor 4 is preferably a substance having a lower thermal conductivity than thermoelectric

conversion element substrates

11 and 12 described later, and more preferably a heat insulating substance. Specifically, such a substance is not particularly limited, and has a thermal conductivity of less than 0.1 W / m · K, such as an inorganic fiber-based heat insulating material, a foamed plastic-based heat insulating material, and air, Preferably, a heat insulating material of less than 0.06 W / m · K is used. Among these, it is preferable that the heat insulating material is air. This is because the heat insulation effect is enhanced by the fluidity of the air, and the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be increased. Hereinafter, description will be made assuming that air is contained in the heat insulating region 5 adjacent to the heat conductor 4.

A schematic scheme of power generation by the thermoelectric conversion module 100 is as follows. First, the heat released from the heat source is transmitted to each end of the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2 joined at the joint 3 via the heat conductor 4. Thereby, a temperature gradient in the surface direction of the thermoelectric conversion module 100 is generated in each of the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2. An electromotive force is generated by the Seebeck effect resulting from the temperature gradient, and the thermoelectric conversion module 100 generates power. If the temperature gradient is large, the electromotive force generated increases, and the thermoelectric conversion efficiency of the thermoelectric conversion module 100 can be improved.

The thermoelectric conversion material for forming the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2 constituting the thermoelectric conversion element body 10 is not particularly limited, and is a bismuth tellurium compound, antimony compound, silicon-based material. A compound, a metal oxide compound, a Heusler alloy compound, a conductive polymer compound, a conductive fiber, a composite material thereof, and the like can be used. Among these, it is preferable to use conductive fibers, and it is more preferable to use fibrous carbon nanostructures such as carbon nanotubes (hereinafter also referred to as CNT). This is because if CNTs are used, the mechanical strength of the thermoelectric conversion module 100 of the present invention can be further improved and the weight can be reduced. Furthermore, the CNT is not particularly limited, and single-wall CNT and / or multi-wall CNT can be used, and the CNT is preferably single-wall CNT. This is because single-walled CNTs tend to have superior thermoelectric properties (Seebeck coefficient). As single-walled carbon nanotubes, when a raw material compound and a carrier gas are supplied onto a substrate having a catalyst layer for producing CNTs on the surface, CNTs are synthesized by chemical vapor deposition (CVD). In addition, according to the method of dramatically improving the catalytic activity of the catalyst layer by making a small amount of oxidizing agent (catalyst activating substance) present in the system (super growth method; see International Publication No. 2006/011655). The produced CNT can be used (hereinafter, the CNT produced according to such a method may be referred to as “SGCNT”). Furthermore, SGCNT has a feature that it is bent a lot. Here, although CNT has high thermal conductivity due to electron transfer, it is considered that the effect of lowering thermal conductivity due to phonon vibration is also high. However, SGCNT is more bent than CNTs manufactured according to other general methods, and thus has a structure in which phonon vibration is less likely to be amplified, and can suppress a decrease in thermal conductivity due to phonon vibration. . Therefore, SGCNT can be a material more advantageous as a thermoelectric conversion material than other general CNTs.

And in using CNT as the thermoelectric conversion material for comprising the thermoelectric conversion element body 10, it is necessary to make the Seebeck coefficients of the CNT constituting the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2 different from each other. is there. Here, CNTs have characteristics as p-type thermoelectric conversion elements as they are. Therefore, it is necessary to apply a process for obtaining the n-type thermoelectric conversion element 2 (hereinafter also referred to as “n-treatment”) to the CNTs. Specifically, for example, a bucky paper, which is a CNT formed into a thin film, which is produced by a known method or is commercially available, is described in a general method, for example, as described in International Publication No. 2015/198980. By performing n-treatment according to the method, a bucky paper that can function as the n-type thermoelectric conversion element 2 can be obtained.

In addition, it is preferable that the thickness of the thermoelectric conversion module 100 provided with the thermoelectric conversion element body 10 is 10 mm or less, and it is more preferable that it is 6 mm or less. This is because the ease of attachment of the thermoelectric conversion module 100 can be improved.

Furthermore, as a thermoelectric conversion material for forming the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2 constituting the thermoelectric conversion element body 10, it is preferable to use a thermoelectric conversion material having a structure having a void inside. Examples of the thermoelectric conversion material having a structure having voids therein include a conductive structure having a density of 0.1 g / cm ³ or less and a fibrous network structure. Such a conductive structure can be specifically composed of a fibrous carbon nanostructure such as CNT. If a thermoelectric conversion material having a void inside is used as the thermoelectric conversion material for forming the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2, the thermal conductivity of the thermoelectric conversion element body 10 is lowered. Thus, the temperature gradient in the surface direction of the thermoelectric conversion element can be further increased, and the thermoelectric conversion efficiency can be further improved.

In addition, the thermoelectric conversion material having a structure having voids therein is not particularly limited, and can be formed by using, for example, a fibrous carbon nanostructure containing CNTs and unexpanded expanded particles in combination. In the thermoelectric conversion material having a structure having voids inside, the respective thermal conductivities in two directions orthogonal (crossing) to each other may be different. Therefore, the direction in which the thermal conductivity is high can be formed so as to coincide with the thickness direction of the thermoelectric conversion module 100. Specifically, for example, a sheet containing a non-foamed expanded particle and a fibrous carbon nanostructure containing CNTs is formed, and the obtained sheet is sandwiched between upper and lower or left and right molds, It can be produced by foaming.

The junction 3 that electrically connects the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2 is not particularly limited, and can be formed of a metal having conductivity and thermal conductivity. Examples of the metal having conductivity and thermal conductivity include a metal material having an electrical conductivity (JIS K 0130: 2008) of 10 S / m or more and a thermal conductivity of 10 W / m · K or more, more specifically. , Ag, Cu and the like. Among these, Ag is preferable from the viewpoint that there is an easily available paste-like material, the cost of the process can be reduced, and the ease of the process can be imparted. Alternatively, if the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2 can be electrically connected to each other without interposing a conductive material at the interface, the above-described conductive material is not interposed. It may be a junction.
For example, the junction 3 can be formed by connecting the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2 using a paste-like resin material containing Ag as a conductive material. The resin material is not particularly limited, and is a general resin such as (meth) acrylic resin, epoxy resin, fluorine resin, silicone resin, olefin resin, polyamide resin, and polyimide resin. Materials can be used. Preferably, a polyimide resin having high flexibility and high heat resistance is used as the resin material. In the present specification, (meth) acryl means “acryl” or “methacryl”.

The heat conductor 4 connected to the thermoelectric conversion element body 10 is coupled to the joint 3 as described above. Here, it is preferable that the heat conductor 4 is disposed so that the heat insulating regions 5 adjacent to the heat conductor 4 communicate with each other. This is because air flows between the heat insulating regions 5 to further enhance the heat insulating properties of the heat insulating regions 5 and to increase the temperature gradient in the surface direction of the thermoelectric conversion element body 10. Further, in the heat conductor 4, the heat insulating regions 5 adjacent to the heat conductor 4 communicate with each other, and each of the plurality of heat insulating regions 5 communicates directly or indirectly with the outside atmosphere of the thermoelectric conversion module 100. It is preferable to arrange so as to. It is because the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be further increased by further increasing the heat insulating property of the heat insulating region 5.

The heat conductor 4 can be formed of a heat conductive material including a heat conductive inorganic material such as Al and Cu, and a heat conductive organic material such as a heat conductive resin without any particular limitation. Among these, Al is preferable from the viewpoint of lightness. The thermal conductivity of the heat conductor 4 is preferably 10 W / m · K or more, more preferably 50 W / m · K or more, further preferably 100 W / m · K or more, and 200 W / m Particularly preferred is m · K or more. Moreover, it is preferable that the heat conductor 4 has the thickness direction length of the thermoelectric conversion module 100 of 1 mm or more. This is because the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be further increased. Furthermore, the heat conductor 4 is in contact with the thermoelectric conversion element body 10 in a region that is 1/5 or less of the length in each plane direction of the junction 3 and the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2. Is preferred.

FIG. 1 exemplifies a configuration in which the heat conductor 4 is disposed on both sides of the thermoelectric conversion element body 10. However, in the thermoelectric conversion module 100, it is only necessary that the heat conductor 4 is connected to at least the heat source side surface of the thermoelectric conversion element body 10. This is because a temperature gradient can be generated if heat is input to one end of each p-type thermoelectric conversion element 1 and n-type thermoelectric conversion element 2 that are continuously joined. If the heat conductor 4 is also connected to the side opposite to the heat source side, that is, the heat radiating side, each p-type thermoelectric conversion is performed in a region near the end opposite to the heated end. Heat may be released from the element 1 and the n-type thermoelectric conversion element 2, and the temperature gradient in the surface direction of the thermoelectric conversion element body 10 may be further increased.

Furthermore, the heat conductor 4 is preferably an anisotropic heat conductor. In the anisotropic thermal conductor, the thermal conductivity in the thickness direction is higher than the thermal conductivity in the transverse direction with respect to the thickness direction. If the heat conductor 4 is an anisotropic heat conductor rich in heat conductivity in the thickness direction, loss that may occur when the heat conductor 4 conducts heat is reduced, and the thermoelectric conversion efficiency of the thermoelectric conversion module 100 is reduced. It is because it can improve further. And when the heat conductor 4 is an anisotropic heat conductor, it is preferable that the thermal conductivity of the thickness direction of this anisotropic heat conductor is 10 W / m * K or more, and is 50 W / m *. It is more preferably K or higher, more preferably 100 W / m · K or higher, and particularly preferably 200 W / m · K or higher.

The anisotropic heat conductor is not particularly limited, and is formed using, for example, a graphite sheet, an organic anisotropic heat conductive material such as CNT, and an inorganic anisotropic heat conductive material such as flat metal particles. can do. The flat metal particles mean, for example, flat metal particles having an aspect ratio of 3 or more. It is preferable to use an organic anisotropic heat conductive material from the viewpoint of imparting flexibility to the thermoelectric conversion element body 10 and reducing the weight. Furthermore, from the viewpoint of further improving the thermoelectric conversion efficiency of the thermoelectric conversion module 100, it is preferable to form the anisotropic heat conductor constituting the heat conductor 4 using CNTs.
The anisotropic heat conductor is not particularly limited, and is formed by using these anisotropic heat conductive materials and a general resin material that can also be used for forming the joint portion 3. Can do. The anisotropic heat conductor includes a coating process, a pressurizing process, and the like so that the direction of high thermal conductivity of the anisotropic heat conductive material matches the thickness direction of the thermoelectric conversion module 100 using these. It can be produced by a known production method.

Further, when the thermoelectric conversion module 100 has a structure as shown in the figure having the heat conductors 4 on both sides of the thermoelectric conversion element body 10, the thermoelectric conversion modules 100 are arranged on the heat source side with a plurality of heat conductors 4 arranged on the heat dissipation side. The plurality of heat conductors 4 are arranged so that the heat radiation side and the heat source side are alternately arranged at every other junction 3 of the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2. It is preferable.

Furthermore, it is preferable that the thermoelectric conversion module 100 has at least one substrate. The heat conductor 4 preferably connects at least one substrate and the film-like thermoelectric conversion element body 10. If at least one board | substrate connected through the thermoelectric conversion element body 10 and the heat conductor 4 is provided, the mechanical strength of the thermoelectric conversion module 100 can be improved. Further, the at least one substrate can also have a function of protecting the components inside the module from the external environment.

In FIG. 1, the thermoelectric conversion module 100 includes a lower substrate 6 disposed on the heat source side and an upper substrate 7 disposed on the heat dissipation side. These lower substrate 6 and upper substrate 7 are preferably a resin substrate and / or a metal substrate. As the resin substrate, a so-called flexible substrate, which is a substrate including a flexible resin material, can be used. Examples of such a flexible substrate include a substrate formed using a resin having low thermal conductivity and excellent heat resistance and flexibility, and specifically, a polyimide substrate. Moreover, as a metal substrate, the board | substrate which comprises metal materials with high heat conductivity, such as aluminum, copper, and silver, is mentioned. In addition, although a resin substrate and a metal substrate can each be used independently, both can be laminated | stacked and used together.

When a resin substrate is employed as the lower substrate 6 or the upper substrate 7, flexibility can be imparted to the thermoelectric conversion module, and the ease of installation of the thermoelectric conversion module can be improved. This is because the installation location of the thermoelectric conversion module is not necessarily a flat place, so if flexibility can be given to the thermoelectric conversion module, the thermoelectric conversion module can be freely deformed according to the shape of the installation location, This is because the power generation efficiency can be increased.
On the other hand, when a metal substrate is used as the lower substrate 6 or the upper substrate 7, the temperature gradient in the surface direction of the thermoelectric conversion element can be further increased, and the thermoelectric conversion efficiency can be further increased.

The lower substrate 6 and the upper substrate 7 do not need to be formed of the same material. For example, the lower substrate 6 may be a resin substrate and the upper substrate 7 may be a metal substrate. In this case, the heat dissipation effect in the upper substrate can be improved, the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be further increased, and the thermoelectric conversion efficiency of the thermoelectric conversion module 100 can be further increased.
In addition, when the temperature of the heat source is not uniform, a metal substrate may be used for the lower substrate 6 in order to distribute heat uniformly throughout the thermoelectric conversion module. In that case, the upper substrate 7 may be a metal substrate or a resin substrate.

Furthermore, as the lower substrate 6 and / or the upper substrate 7, an anisotropic heat conductive substrate formed using an anisotropic heat conductive material similar to the heat conductor 4 can be used. In the anisotropic thermal conductive substrate, the thermal conductivity in the transverse direction with respect to the thickness direction of the substrate is higher than the thermal conductivity in the thickness direction of the substrate. Therefore, if at least the lower substrate 6 is an anisotropic heat conductive substrate having a high thermal conductivity in the plane direction, the heat collection efficiency from the heat source is increased and the heat is input to the thermoelectric conversion element body 10 via the heat conductor 4. The amount of heat generated can be increased. Thereby, the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be further increased, and the thermoelectric conversion efficiency can be further improved. Furthermore, if the upper substrate 7 is also an anisotropic heat conductive substrate rich in surface direction heat conductivity in addition to the lower substrate 6, the heat radiation efficiency from the upper substrate 7 can be improved. Also by this, the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be further increased, and the thermoelectric conversion efficiency of the thermoelectric conversion module 100 can be further improved. In the case where the lower substrate 6 and / or the upper substrate 7 is an anisotropic heat conductive substrate, an organic anisotropic heat conductive material is used from the viewpoint of flexibility and weight reduction in the same manner as the heat conductor 4. It is preferable to use it.

The film-like thermoelectric conversion element body 10 may include at least one thermoelectric conversion element substrate that supports the thermoelectric conversion element body 10. In FIG. 1, the thermoelectric conversion element body 10 is supported on both surfaces by thermoelectric

conversion element substrates

11 and 12. If the thermoelectric conversion element includes at least one thermoelectric conversion element substrate, the mechanical strength of the thermoelectric conversion module 100 can be further improved. The thermoelectric

conversion element substrates

11 and 12 are not particularly limited as long as the materials have low thermal conductivity, and are formed of a resin material similar to the resin material that can be used for forming the lower substrate 6 and / or the upper substrate 7. Can do.

Although not shown in FIG. 1, the thermoelectric conversion module 100 is configured such that conductive wires are connected to both ends of the thermoelectric conversion element body 10, and electric power generated by the thermoelectric conversion element body 10 can be taken out.

FIG. 2 shows a schematic structure of an example of a thermoelectric conversion module including a heat sink as an upper substrate. In the thermoelectric conversion module 101 shown in FIG. 2, when installed on a heat source, it is preferable that the upper substrate 7 'disposed on the opposite side of the heat source, that is, on the heat dissipation side shown in FIG. If the upper substrate 7 ′ arranged on the side far from the heat source when arranged on the heat source, that is, the heat radiating side shown in FIG. Thus, the thermoelectric conversion efficiency can be further increased.

The heat sink that can constitute the upper substrate 7 'is not particularly limited, and is a plate having a plurality of plate-like or rod-like fins on the surface, which is made of a highly thermally conductive metal material such as Al, Fe, and Cu. A state body is mentioned. Such a heat sink is excellent in heat dissipation because of its high thermal conductivity and large surface area. Optionally, a fan or the like can be attached to the heat sink to further improve heat dissipation.
The structure serving as the base of the thermoelectric conversion module of the present invention follows the above description. Hereinafter, although each thermoelectric conversion module according to each embodiment of the present invention will be described in detail, also in these embodiments, each component described as an essential or optional configuration in the above description may be provided as an essential or optional. .

(First embodiment)
FIG. 3 shows a schematic structure of the thermoelectric conversion module according to the first embodiment of the present invention. The thermoelectric conversion module 102 according to the first embodiment of the present invention includes a radiation reflector 21 and / or a radiation prevention body 22 on the heat source side of the thermoelectric conversion element body 10 when installed on a heat source. Here, the region closer to the heat source than the thermoelectric conversion element body 10 is, for example, an air gap that is partitioned by the two heat conductors 4, the lower substrate 6, and the heat source side surfaces of the thermoelectric conversion element body 10. Such voids can coincide with the heat insulating region 5. As long as the radiation reflector 21 is not in contact with the lower substrate 6, it can be disposed at any position within the gap. According to the radiation reflector 21 having such a specific arrangement, the radiation from the heat source is reflected and the direct heating of the thermoelectric conversion element without passing through the heat conductor 4 is suppressed, whereby the surface direction of the thermoelectric conversion element The temperature gradient in can be further increased, and the thermoelectric conversion efficiency of the thermoelectric conversion module can be further increased. Preferably, the radiation reflector 21 may have a radiation reflectance of 90% or more. More preferably, from the viewpoint of maximizing the radiation reflection effect, the radiation reflector 21 is disposed adjacent to the surface of the thermoelectric conversion element body 10 facing the heat source, and the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element. The two end portions in the connecting direction of the two can be arranged so as to be in contact with the two heat conductors 4 defining the gap.
When the thermoelectric conversion module 102 does not include the lower substrate 6, the radiation reflector 21 has two heat conductors 4, a heat source, and a heat source side surface of the thermoelectric conversion element body 10 as long as it is not in contact with the heat source. Can be arranged at any position within the gap defined by the four sides.

The radiation reflector 21 is not particularly limited, and may be, for example, a sheet-like structure formed by blending flat metal particles with a general resin as described above. In such a sheet-like structure, the flat metal particles are preferably oriented so as to be substantially parallel to the surface direction.

Furthermore, the radiation preventing body 22 can be arranged at any position in the gap as long as it is not in contact with the thermoelectric conversion element body 10 and the radiation reflector 21. When the thermoelectric conversion module 102 includes the above-described radiation reflector 21, the radiation preventing body 22 is arranged on the heat source side of the radiation reflector 21 (that is, the radiation reflector 21 with the thermoelectric conversion element body 10 as a standard). Rather than a position farther in the thickness direction of the thermoelectric conversion module). The radiation preventing body 22 prevents radiation from the heat source and suppresses the direct heating of the thermoelectric conversion element body 10 without passing through the heat conductor 4, thereby the surface direction of the thermoelectric conversion element body 10. The temperature gradient in can be further increased, and the thermoelectric conversion efficiency of the thermoelectric conversion module 102 can be further increased. Preferably, from the viewpoint of maximizing the radiation prevention effect, the radiation prevention body 22 is disposed adjacent to the lower substrate 6 and both ends of the radiation prevention body 22 in the connection direction of the p-type thermoelectric conversion element 1 and the n-type thermoelectric conversion element 2. The part can be arranged so as to be in contact with the two heat conductors 4 that define the gap. In the case where the thermoelectric conversion module 102 does not include the lower substrate 6, the radiation preventing body 22 can be disposed directly adjacent to the heat source.

The radiation preventing body 22 is not particularly limited, and is the same material as the radiation reflecting body 21 or, for example, a commercially available heat shielding film (manufactured by Nippon Shokubai Co., Ltd. “Top Heat Barrier (registered trademark) THB-WBE1”). ) And a general material with low radiation.

(Second Embodiment)
FIG. 4 shows a schematic structure of a thermoelectric conversion module according to the second embodiment of the present invention. The thermoelectric conversion module 103 according to the second embodiment of the present invention preferably has the foam material 23 on the heat source side of the thermoelectric conversion element body 10 when installed on the heat source. Due to the heat insulating effect and the radiation preventing effect of the foam material 23, it is possible to suppress the thermoelectric conversion element body 10 from being heated in a region where the heat conductor 4 is not connected. Thereby, the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be further increased, and the thermoelectric conversion efficiency of the thermoelectric conversion module 103 can be further increased.

Here, the foam material 23 is divided into four sides by the heat source side surfaces of the two heat conductors 4, the lower substrate 6, and the thermoelectric conversion element body 10, for example, similarly to the radiation reflector 21 and the radiation prevention body 22 described above. Can be disposed within the gap. And unlike the radiation reflector 21 and the radiation prevention body 22 which were mentioned above, the foaming material 23 needs to be non-contact with the two heat conductors 4 which divide the said space | gap from a viewpoint of hold | maintaining a heat insulation effect. is there. Moreover, the foam material 23 may be in contact with at least one of the thermoelectric conversion element body 10 and the arbitrary lower substrate 6, or may be in non-contact with both. The foam material 23 is not particularly limited, and examples thereof include a foam resin material such as foam plastic. The thermal conductivity of the foam material 23 can be, for example, less than 0.1 W / m · K.

(Third embodiment)
FIG. 5 shows a schematic structure of a thermoelectric conversion module according to the third embodiment of the present invention. When the thermoelectric conversion module 104 according to the third embodiment of the present invention is installed on a heat source, the thermoelectric conversion element body 10 is in contact with the heat conductor 4 on the heat source side of the thermoelectric conversion element body 10 and is not separated from the thermoelectric conversion element body 10. It is preferable to have a contact heat storage material 24. The heat storage effect of the heat storage material 24 can reduce radiant heat from the heat source and can supply heat to the thermoelectric conversion element body 10 even when the heat source is not in operation. From the viewpoint of further improving the heat storage effect and further improving the thermoelectric conversion efficiency of the thermoelectric conversion module 104, the heat storage material 24 is disposed adjacent to the lower substrate 6, and two heat conductors 4 in which both end portions in the plane direction partition the gap. It is preferable to arrange so that it contacts. When the thermoelectric conversion module 104 does not include the lower substrate 6, the heat storage material 24 can be disposed directly adjacent to the heat source.

The heat storage material 24 is not particularly limited, and examples thereof include a phase change material whose phase changes according to a temperature change. Such phase change materials include hydrocarbons including paraffin, organic phase change materials such as fatty acids including stearic acid and acetic acid, and MgCl ₂ (H ₂ O) ₆ , Ba (OH) ₂ (H ₂ O ) ₈ , and inorganic phase change substances including CaCl ₂ (H ₂ O) _{6 and the} like.

(Fourth embodiment)
FIG. 6 shows a schematic structure of a thermoelectric conversion module according to the fourth embodiment of the present invention. In the thermoelectric conversion module 105 according to the fourth embodiment of the present invention, the heat conductor 4 ′ has the connection surface 25 connected to the film-like thermoelectric conversion element body 10 and the bottom surface 26 opposite to the connection surface 25. It is preferable that the area of the bottom surface 26 is larger than the area of the connection surface 25. If the bottom surface 26 of the heat conductor 4 ′ connected to the lower substrate 6 is larger than the connection surface 25, the heat collection efficiency from the heat source can be increased. Further, if the bottom surface 26 of the heat conductor 4 ′ connected to the upper substrate 7 is larger than the connection surface 25, the heat dissipation efficiency through the upper substrate 7 can be increased. This is because, according to such a structure, the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be further increased, and the thermoelectric conversion efficiency of the thermoelectric conversion module 105 can be further improved. Furthermore, although not shown, it is preferable to provide the radiation reflector 21 and / or the radiation preventer 22 as described in the first embodiment in the thermoelectric conversion module 105 according to the fourth embodiment. If the thermoelectric conversion module 105 includes the radiation reflector 21 and / or the radiation preventing body 22, the thermoelectric conversion element body 10 is heated via the portion other than the connection surface 25 by radiation that can be emitted from the surface of the heat conductor 4 ′. Can be suppressed. Thereby, the temperature gradient in the surface direction of the thermoelectric conversion element body 10 can be further increased, and the thermoelectric conversion efficiency of the thermoelectric conversion module 105 can be further increased.

The heat conductor 4 ′ can be formed using the same heat conductive material as that of the heat conductor 4.

As described above, according to the present invention, a thermoelectric conversion module having high thermoelectric conversion efficiency can be provided.

DESCRIPTION OF SYMBOLS 1 p-type thermoelectric conversion element 2 n-type thermoelectric conversion element 3 Junction part 4, 4 'Thermal conductor 5 Thermal insulation area | region 6 Lower board | substrate 7, 7' Upper board | substrate 10 Thermoelectric

conversion element body

11, 12 Thermoelectric conversion element board | substrate 21 Radiation reflector 22 radiation prevention body 23 foam material 24 heat storage material 25 connection surface 26 bottom surface 100 to 105 thermoelectric conversion module

Claims

A film-like thermoelectric conversion element body having a p-type thermoelectric conversion element and an n-type thermoelectric conversion element bonded along one direction in the plane;
On one surface of the thermoelectric conversion element body, a thermal conductor coupled to a joint portion of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element;
A heat insulating region adjacent to both sides of the heat conductor in the one direction, and
A thermoelectric conversion module having a radiation reflector and / or a radiation prevention body on a side closer to the heat source than the thermoelectric conversion element body when installed on a heat source.
Comprising the radiation reflector and the radiation preventer;
The thermoelectric conversion module according to claim 1, wherein the radiation prevention body is disposed at a position closer to the heat source than the radiation reflector.
A film-like thermoelectric conversion element body having a p-type thermoelectric conversion element and an n-type thermoelectric conversion element bonded along one direction in the plane;
On one surface of the thermoelectric conversion element body, a thermal conductor coupled to a joint portion of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element;
A heat insulating region adjacent to both sides of the heat conductor in the one direction, and
The thermoelectric conversion module which has a foam material in the said heat source side rather than the said thermoelectric conversion element body, when it installs on a heat source.
A film-like thermoelectric conversion element body having a p-type thermoelectric conversion element and an n-type thermoelectric conversion element bonded along one direction in the plane;
On one surface of the thermoelectric conversion element body, a thermal conductor coupled to a joint portion of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element;
A heat insulating region adjacent to both sides of the heat conductor in the one direction, and
A thermoelectric conversion module having a heat storage material that is in contact with the heat conductor and is not in contact with the thermoelectric conversion element body, closer to the heat source side than the thermoelectric conversion element body when installed on a heat source.
A film-like thermoelectric conversion element body having a p-type thermoelectric conversion element and an n-type thermoelectric conversion element bonded along one direction in the plane;
On one surface of the thermoelectric conversion element body, a thermal conductor coupled to a joint portion of the p-type thermoelectric conversion element and the n-type thermoelectric conversion element;
A heat insulating region adjacent to both sides of the heat conductor in the one direction, and
The thermoelectric conversion module, wherein the thermal conductor has a connection surface connected to the film-shaped thermoelectric conversion element body and a bottom surface opposite to the connection surface, and an area of the bottom surface is larger than an area of the connection surface. .
The thermoelectric conversion module according to any one of claims 1 to 5, wherein the thermal conductivity of the thermal conductor is 10 W / m · K or more.
And having at least one substrate,
The thermoelectric conversion module according to any one of claims 1 to 6, wherein the heat conductor connects the at least one substrate and the film-like thermoelectric conversion element body.
The thermoelectric conversion module according to claim 7, wherein the at least one substrate includes a resin material.
The thermoelectric conversion module according to claim 7 or 8, wherein the at least one substrate comprises a metal material.
10. The thermoelectric conversion module according to claim 7, wherein the at least one substrate disposed on the opposite side of the heat source when installed on the heat source is a heat sink.
The thermal conductor is an anisotropic thermal conductor, and the thermal conductivity in the thickness direction of the thermal conductor is higher than the thermal conductivity in a direction transverse to the thickness direction of the thermal conductor. The thermoelectric conversion module according to any one of 1 to 10.
The at least one substrate is an anisotropic thermal conductive substrate, and the thermal conductivity in a direction transverse to the thickness direction of the substrate is higher than the thermal conductivity in the thickness direction of the substrate. The thermoelectric conversion module in any one.