Thermoelectric generator and method for using the thermoelectric generator

Abstract

Provided is a thermoelectric generation device comprising piping through which a fluid flows and a thermoelectric unit connected to the piping, the thermoelectric unit comprising a heat collection member having a plurality of flow channels through which the fluid passes, and a thermoelectric conversion module attached to a surface of the heat collection member, the thermoelectric conversion module facing the surface of the heat collection member and including a first surface heated by the fluid, and a second surface on the opposite side from the first surface, and the thermoelectric conversion module being configured so that a temperature difference occurs between the first surface and the second surface.

Description

[Technical Field]

[0001] The present invention relates to a thermoelectric generator and a method for using the same. [Background technology]

[0002] Patent Document 1 discloses an example of a thermoelectric power generation device. This thermoelectric power generation device includes an exhaust pipe and multiple thermoelectric units that generate electricity by utilizing the heat of exhaust gas flowing through the exhaust pipe. The multiple thermoelectric units include a heat exchanger, a thermoelectric conversion module attached to the heat exchanger, and a cooling water case attached to the thermoelectric conversion module. The heat exchanger has multiple heat exchange fins that recover heat from the exhaust gas flowing through the exhaust pipe. In this thermoelectric power generation device, a first surface of the thermoelectric conversion module that comes into contact with the heat exchanger is heated by the heat recovered by the heat exchange fins, and a second surface to which the cooling water case is attached is cooled by the cooling water. An electromotive force is generated due to the Seebeck effect in response to the temperature difference between the first and second surfaces, allowing the thermal energy of the exhaust gas flowing through the exhaust pipe to be converted into electrical energy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-214350 Summary of the Invention [Problem to be solved by the invention]

[0004] In a thermoelectric power generation device, it is preferable to be able to control the conversion rate from the thermal energy of exhaust gas to electrical energy depending on the application. For example, when the heat of the exhaust gas is not used as thermal energy, it is preferable that as much heat as possible be recovered from the exhaust gas by the heat exchange fins. On the other hand, when a portion of the heat of the exhaust gas is used as thermal energy, it is necessary to control the amount of heat recovered by the heat exchange fins. In the above-mentioned thermoelectric power generation device, controlling the conversion rate from thermal energy to electrical energy is complicated because it is necessary to change the shape and dimensions of the heat exchange fins. Note that this problem also occurs in a thermoelectric power generation device that converts the thermal energy of a liquid into electrical energy.

[0005] An object of the present invention is to provide a thermoelectric power generating device that can easily control the conversion rate from thermal energy of a fluid to electrical energy, and a method for using the same. [Means for solving the problem]

[0006] A thermoelectric power generation device according to a first aspect of the present invention is a thermoelectric power generation device comprising a pipe through which a fluid flows and a thermoelectric unit connected to the pipe, wherein the thermoelectric unit comprises a heat collecting member having a plurality of flow paths through which the fluid passes, and a thermoelectric conversion module attached to a surface of the heat collecting member, and the thermoelectric conversion module includes a first surface facing the surface of the heat collecting member and heated by the fluid, and a second surface opposite the first surface, and is configured so that a temperature difference occurs between the first surface and the second surface.

[0007] A thermoelectric power generation device according to a second aspect of the present invention is the thermoelectric power generation device according to the first aspect, and includes a cooling member configured to cool the thermoelectric conversion module from the second surface, and the cooling member is connected to the heat collecting member.

[0008] A thermoelectric generator according to a third aspect of the present invention is the thermoelectric generator according to the first or second aspect, wherein the heat collecting member is prismatic.

[0009] A thermoelectric generator according to a fourth aspect of the present invention is the thermoelectric generator according to any one of the first to third aspects, further comprising a closing member that closes some of the plurality of flow paths.

[0010] A thermoelectric power generation device according to a fifth aspect of the present invention is the thermoelectric power generation device according to the fourth aspect, wherein the flow path has an inlet for the fluid, an outlet for the fluid, and an intermediate portion between the inlet and the outlet, and the blocking member is configured to block at least one of the inlet, the outlet, and the intermediate portion.

[0011] A thermoelectric power generation device according to a sixth aspect of the present invention is the thermoelectric power generation device according to any one of the first to fifth aspects, wherein the thermoelectric conversion module includes a p-type thermoelectric conversion element and an n-type thermoelectric conversion element, and the p-type thermoelectric conversion element is Ca 3-p Bi p Co4O q (1) (wherein p and q are numbers satisfying 0≦p≦1 and 8.5≦q≦10), or Bi2Sr 2-r Ca r Co2O t (2) (where r and t are numbers that satisfy 0.0≦r≦2.0 and 8.5≦t≦10), and the n-type thermoelectric conversion element is composed of a layered cobalt-based oxide that satisfies the composition formula represented by CaMn 1-X M x O y (3) In formula (3), M is at least one element selected from the group consisting of Nb, Ta, Mo, and W, and x and y are numbers that satisfy 0≦x≦0.1 and 2.8≦y≦3.2, respectively. a B b The alloy is made of a half-Heusler alloy that satisfies the composition formula expressed by NiSn···(4) (in formula (4), A is Ti or Zr, B is at least one of Hf and Zr when A is Ti, and at least one of Hf and Ti when A is Zr, and 0.5≦a≦1, 0≦b≦0.5).

[0012] A thermoelectric generator according to a seventh aspect of the present invention is the thermoelectric generator according to any one of the third to sixth aspects which cites the second aspect, wherein the cooling member includes a heat dissipation fin.

[0013] A thermoelectric generator according to an eighth aspect of the present invention is the thermoelectric generator according to any one of the third to seventh aspects which cites the second aspect, wherein the cooling member includes a circulating or stagnating liquid.

[0014] A thermoelectric generator according to a ninth aspect of the present invention is the thermoelectric generator according to the eighth aspect, wherein the liquid is cooling water.

[0015] A thermoelectric power generation device according to a tenth aspect of the present invention is the thermoelectric power generation device according to any one of the third to ninth aspects which cites the second aspect, wherein the cooling member includes a heat pipe which cools using the latent heat of the working liquid.

[0016] A method for using a thermoelectric power generation device according to an eleventh aspect of the present invention is a method for using a thermoelectric power generation device comprising a pipe through which a fluid flows and a thermoelectric unit connected to the pipe, wherein the thermoelectric unit comprises a heat collecting member having a plurality of flow paths through which the fluid passes, and a thermoelectric conversion module attached to a surface of the heat collecting member, the thermoelectric conversion module including a first surface facing the surface of the heat collecting member and heated by the fluid, and a second surface opposite to the first surface, and configured such that a temperature difference occurs between the first surface and the second surface, and the method includes a step of closing some of the plurality of flow paths with a blocking member depending on a desired conversion rate from thermal energy to electrical energy. [Effects of the Invention]

[0017] According to the thermoelectric power generating device of the present invention, the conversion rate from the thermal energy of the fluid to electrical energy can be easily controlled. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view of a combustion burner equipped with a thermoelectric power generation device according to a first embodiment. [Figure 2] FIG. 2 is a front view of the thermoelectric unit of FIG. 1. [Figure 3] Rear view of the thermoelectric unit in Figure 1. [Figure 4] FIG. 2 is a plan view of the thermoelectric unit of FIG. 1. [Figure 5] Bottom view of the thermoelectric unit in Figure 1. [Figure 6] FIG. 2 is a left side view of the thermoelectric unit in FIG. 1. [Figure 7] FIG. 2 is a right side view of the thermoelectric unit in FIG. 1. [Figure 8] 2 is a diagram showing an example of attaching a blocking member to the heat collecting member of the thermoelectric unit of FIG. 1. FIG. [Figure 9] 1. FIG. 4 is a diagram showing another example of attaching a blocking member to the heat collecting member of the thermoelectric unit of FIG. [Figure 10] 1. FIG. 4 is a diagram showing another example of attaching a blocking member to the heat collecting member of the thermoelectric unit of FIG. [Figure 11] 1. FIG. 4 is a diagram showing another example of attaching a blocking member to the heat collecting member of the thermoelectric unit of FIG. [Figure 12] FIG. 2 is a front view of a thermoelectric conversion module of the thermoelectric unit of FIG. 1. [Figure 13] FIG. 13 is a plan view of the thermoelectric conversion module of FIG. 12 as viewed from above. [Figure 14] FIG. 13 is a right side view of the thermoelectric conversion module of FIG. 12. [Figure 15] FIG. 13 is a left side view of the thermoelectric conversion module of FIG. 12. [Figure 16] 13 is a plan view of the thermoelectric conversion module of FIG. 12 in which the thermoelectric conversion elements and upper electrodes are omitted. [Figure 17] FIG. 13 is a plan view of the thermoelectric conversion module of FIG. 12 with the upper electrodes omitted. [Figure 18] FIG. 13 is a plan view showing a state in which the thermoelectric conversion modules of FIG. 12 are connected in series. [Figure 19] FIG. 13 is a plan view showing a state in which the thermoelectric conversion modules of FIG. 12 are connected in parallel. [Figure 20] FIG. 2 is a plan view of a cooling member of the thermoelectric unit of FIG. 1. [Figure 21] FIG. 21 is a right side view of the cooling member of FIG. 20. [Figure 22] FIG. 2 is a front view of a thermoelectric unit included in the thermoelectric power generation device of the first embodiment. [Figure 23] FIG. 10 is a front view of a thermoelectric unit included in a thermoelectric power generation device according to a second embodiment. [Figure 24] FIG. 11 is a front view of a thermoelectric unit included in a thermoelectric power generation device according to a third embodiment. [Figure 25] FIG. 2 is a front view of a thermoelectric unit included in a thermoelectric power generation device of Comparative Example 1. [Figure 26] FIG. 26 is a plan view of the thermoelectric unit of FIG. 25. [Figure 27] 1 is a table showing test results of the thermoelectric power generation units of Examples 1 to 3 and Comparative Example 1. [Figure 28] FIG. 10 is a perspective view of a hot water circulator including a thermoelectric power generation device according to a second embodiment. [Figure 29] FIG. 29 is a left side view of the thermoelectric unit of FIG. 28. [Figure 30] FIG. 30 is a front view of the thermoelectric unit of FIG. 29. [Figure 31] FIG. 29 is a rear view of the thermoelectric unit of FIG. [Figure 32] FIG. 10 is a front view of a thermoelectric unit included in a thermoelectric power generation device according to a fourth embodiment. [Figure 33] FIG. 10 is a front view of a thermoelectric unit included in a thermoelectric power generation device according to a fifth embodiment. [Figure 34] FIG. 13 is a front view of a thermoelectric unit included in a thermoelectric power generation device according to a sixth embodiment. [Figure 35] FIG. 13 is a front view of a thermoelectric unit included in a thermoelectric power generation device according to a seventh embodiment. [Figure 36] FIG. 10 is a front view of a thermoelectric unit included in a thermoelectric power generation device of Comparative Example 2. [Figure 37] 1 is a table showing test results of the thermoelectric power generation units of Examples 4 to 7 and Comparative Example 2. [Figure 38] FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. [Figure 39] FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. [Figure 40] FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. [Figure 41]FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. [Figure 42] FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. [Figure 43] FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. [Figure 44] FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. [Figure 45] FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. [Figure 46] FIG. 10 is a diagram showing the arrangement of cooling members included in a thermoelectric power generation device according to a modified example of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, a combustion burner equipped with a thermoelectric power generation device according to one embodiment of the present invention will be described with reference to the drawings.

[0020] First Embodiment <1. Overall configuration of combustion burner> 1 is a perspective view of a combustion burner 500 including a thermoelectric power generation device 10 according to this embodiment. The combustion burner 500 includes a combustion section 510 and the thermoelectric power generation device 10.

[0021] The combustion unit 510 is hollow and box-shaped, and generates high-temperature gas, for example, at 80°C or higher, by burning the fuel supplied thereto. The fuel for the combustion burner 500 includes gaseous fuel, liquid fuel, or solid fuel. The gaseous fuel is, for example, natural gas. The liquid fuel is, for example, kerosene, diesel, or gasoline. The solid fuel is, for example, fossil fuel or biomass fuel. The fossil fuel is, for example, coal. The biomass fuel is rice husks, wheat waste, or waste wood. The thermoelectric power generation device 10 converts the thermal energy of the high-temperature gas discharged from the combustion unit 510 into electrical energy. Note that, hereinafter, the high-temperature gas generated in the combustion unit 510 may be simply referred to as a fluid.

[0022] <2. Thermoelectric power generation device configuration> The thermoelectric power generation device 10 is connected to a combustion section 510. The thermoelectric power generation device 10 includes an upstream pipe 20, an upstream connecting section 30, a thermoelectric unit 40, a downstream connecting section 50, and a downstream pipe 60. The fluid flows through the upstream pipe 20, the upstream connecting section 30, the thermoelectric unit 40, the downstream connecting section 50, and the downstream pipe 60 in this order, and is supplied to, for example, a furnace.

[0023] The upstream pipe 20 is disposed at the most upstream position among the elements constituting the thermoelectric power generation device 10 in the direction of fluid flow. The upstream pipe 20 is connected to the combustion section 510. The shape of the upstream pipe 20 can be selected arbitrarily as long as it allows fluid to flow through it. In this embodiment, the upstream pipe 20 is a hollow cylinder.

[0024] The upstream connecting part 30 is disposed downstream of the upstream pipe 20 in the fluid flow direction. The upstream connecting part 30 connects the upstream pipe 20 and the thermoelectric unit 40. The upstream connecting part 30 has two metal plates 31A and 31B and a flange 32. The metal plate 31A is welded to the upstream pipe 20. A through hole (not shown) through which the fluid passes is formed in the metal plate 31A. The through hole of the metal plate 31A communicates with the end of the upstream pipe 20. The metal plate 31B is welded to the flange 32. A through hole (not shown) through which the fluid passes is formed in the metal plate 31B. The through hole of the metal plate 31B communicates with the through hole of the metal plate 31A. The metal plates 31A and 31B are connected by a plurality of bolts 33.

[0025] The flange 32 connects the metal plate 31B and the thermoelectric unit 40. The flange 32 is made of, for example, a metal material. The flange 32 has, for example, a hollow rectangular parallelepiped shape. The flange 32 is connected to a front surface 74 (see FIG. 2) of the heat collecting member 70 with screws.

[0026] The thermoelectric unit 40 is disposed downstream of the upstream connecting portion 30 in the direction of fluid flow. The detailed configuration of the thermoelectric unit 40 will be described later.

[0027] The downstream connecting portion 50 is disposed downstream of the thermoelectric unit 40 in the fluid flow direction. The downstream connecting portion 50 connects the thermoelectric unit 40 and the downstream piping 60. The downstream connecting portion 50 has two metal plates 51A and 51B and a flange 52. The metal plate 51A is welded to the downstream piping 60. A through hole (not shown) through which the fluid passes is formed in the metal plate 51A. The through hole of the metal plate 51A communicates with an end of the downstream piping 60. The metal plate 51B is welded to the flange 52. A through hole (not shown) through which the fluid passes is formed in the metal plate 51B. The through hole of the metal plate 51B communicates with the through hole of the metal plate 51A. The metal plates 51A and 51B are connected by a plurality of bolts 53.

[0028] The flange 52 connects the metal plate 51B and the thermoelectric unit 40. The flange 52 is made of, for example, a metal material. The flange 52 has, for example, a hollow rectangular parallelepiped shape. The flange 52 is connected to the rear surface 75 (see FIG. 3) of the heat collecting member 70 with screws.

[0029] The downstream pipe 60 is disposed at the most downstream position among the elements constituting the thermoelectric power generation device 10 in the direction of fluid flow. The downstream pipe 60 is connected to, for example, a furnace. The shape of the downstream pipe 60 can be selected arbitrarily as long as it allows fluid to flow through it. In this embodiment, the downstream pipe 60 is a hollow cylinder.

[0030] <3. Thermoelectric unit configuration> FIG. 2 is a front view of the thermoelectric unit 40. FIG. 3 is a rear view of the thermoelectric unit 40. FIG. 4 is a plan view of the thermoelectric unit 40. FIG. 5 is a bottom view of the thermoelectric unit 40. FIG. 6 is a right side view of the thermoelectric unit 40. FIG. 7 is a left side view of the thermoelectric unit 40. The thermoelectric unit 40 includes a heat collecting member 70, a blocking member 80, and three power generation units 90. The thermoelectric unit 40 is configured so that a temperature difference occurs between a first surface 90A and a second surface 90B of the thermoelectric conversion module 100 of the power generation unit 90.

[0031] <4. Configuration of heat collection element> The heat collecting member 70 absorbs heat from a fluid at, for example, 80°C or higher, and heats the thermoelectric conversion module 100 of the power generating unit 90 attached to its outer circumferential surface. The heat collecting member 70 has a plurality of flow paths 70A through which the fluid passes. The plurality of flow paths 70A penetrate the heat collecting member 70.

[0032] The material constituting the heat collecting member 70 is preferably one that does not melt or deform even at the temperature of the fluid, and that does not significantly impair heat absorption and heat transfer to the thermoelectric conversion module 100 by reacting with components contained in the fluid (for example, by reacting with oxygen and becoming oxidized). The material constituting the heat collecting member 70 is preferably a material with high thermal conductivity so as to facilitate the transport of heat absorbed from the fluid to the thermoelectric conversion module 100. From this perspective, the material constituting the heat collecting member 70 is preferably, for example, metals such as copper, aluminum, iron, alloys containing these, stainless steel, or ceramics such as alumina, zirconia, or silicon nitride. In order to form the multiple flow paths 70A, from the perspective of processability, the material constituting the heat collecting member 70 is preferably metal, which is easier to process than ceramics.

[0033] The shape of the heat collecting member 70 can be selected arbitrarily as long as it can accommodate the power generation units 90. The heat collecting member 70 preferably has three or more surfaces to which the power generation units 90 are attached. In this embodiment, the heat collecting member 70 is a rectangular prism. The heat collecting member 70 has a first side surface 71, a second side surface 72, a third side surface 73, a front surface 74, a back surface 75, and a bottom surface 76. The power generation units 90 are attached to the first side surface 71, the second side surface 72, and the third side surface 73, respectively. The front surface 74 faces the flange 32 of the upstream connecting portion 30. The front surface 74 is formed with holes 74A into which screws for coupling to the flange 32 are inserted and inlets 70X of the multiple flow paths 70A. The back surface 75 faces the flange 52 of the downstream connecting portion 50. The back surface 75 is formed with holes 75A into which screws for coupling to the flange 52 are inserted and outlets 70Y of the multiple flow paths 70A. The multiple flow paths 70A are formed to penetrate the front surface 74 and the back surface 75 of the heat collecting member 70. The area of ​​the front surface 74 may be larger or smaller than the area of ​​the opening of the upstream pipe 20, as long as the flange 32 can seal the inlets 70X of all of the flow paths 70A. The area of ​​the back surface 75 may be larger or smaller than the area of ​​the opening of the downstream pipe 60, as long as the flange 52 can seal the outlets 70Y of all of the flow paths 70A.

[0034] The lengths of the first side surface 71, the second side surface 72, and the third side surface 73 in the fluid flow direction can be selected arbitrarily as long as they are long enough to form a flow path 70A that can sufficiently absorb heat from the fluid. The areas of the first side surface 71, the second side surface 72, and the third side surface 73 can be selected arbitrarily as long as they are large enough to accommodate enough thermoelectric conversion modules 100 to obtain the desired power. In this embodiment, the areas of the first side surface 71, the second side surface 72, and the third side surface 73 are each large enough to accommodate four thermoelectric conversion modules 100.

[0035] The cross-sectional shape of the multiple flow paths 70A perpendicular to the fluid flow direction in a front view (hereinafter referred to as the "cross-sectional shape of the flow paths 70A") can be selected arbitrarily. The cross-sectional shape of the flow paths 70A is, for example, a circle, an ellipse, a triangle, or a polygon with four or more sides. From the viewpoint of easily processing the flow paths 70A, the cross-sectional shape of the flow paths 70A is preferably a circle or an ellipse. In this embodiment, the cross-sectional shape of the flow paths 70A is a circle. The sizes of the inlets 70X and the outlets 70Y of the flow paths 70A can be selected arbitrarily. In this embodiment, the diameters of the inlets 70X and 70Y of the flow paths 70A are 10 mm. The positions at which the flow paths 70A are formed in the heat collecting member 70 can be selected arbitrarily. In this embodiment, the vertical distance between the centers of the inlets 70X and the outlets 70Y on the front surface 74 and the rear surface 75 is 20 mm, and the diagonal distance is 12.5 mm.

[0036] The number of flow paths 70A formed in the heat collecting member 70 and the length of the flow paths 70A are not particularly limited as long as the heat collecting member 70 has a structure that satisfies the heat transfer area in contact with the fluid, the ability to store heat sufficient to heat the thermoelectric conversion module 100, and the strength to maintain the shape of the heat collecting member 70. In this embodiment, 91 flow paths 70A are formed in the heat collecting member 70.

[0037] In the thermoelectric power generation device 10, it is preferable that the conversion rate from the thermal energy of the fluid to electrical energy can be controlled depending on the application. For example, when the heat of the fluid is not used as thermal energy, it is preferable that a larger amount of heat is recovered from the fluid by the thermoelectric conversion module 100. On the other hand, when a portion of the heat of the fluid is used as thermal energy, it is necessary to control the amount of heat recovered by the thermoelectric conversion module 100. The thermoelectric power generation device 10 of this embodiment is configured to easily control the conversion rate from the thermal energy of the fluid to electrical energy by closing a portion of the multiple flow paths 70A with a closing member 80. The closing member 80 is arranged to close the inlet 70X, the outlet 70Y, or an intermediate portion 70Z between the inlet 70X and the outlet 70Y of the flow path 70A.

[0038] <5. Configuration of the Closing Member> Fig. 8 is a schematic diagram showing an example in which a closing member 80 is arranged to close an inlet 70X of a flow channel 70A. In the example shown in Fig. 8, the closing member 80 is a screw. The closing member 80 is inserted into the flow channel 70A from the inlet 70X of the flow channel 70A.

[0039] Fig. 9 is a schematic diagram showing an example in which a blocking member 80 is arranged to close an outlet 70Y of a flow path 70A. In the example shown in Fig. 9, the blocking member 80 is a screw. When the blocking member 80 is arranged at the outlet 70Y, it is preferable that a female screw 70YA that engages with the blocking member 80 be formed in the flow path 70A near the outlet 70Y so that the blocking member 80 does not come off the outlet 70Y.

[0040] Fig. 10 is a schematic diagram showing an example in which a blocking member 80 is arranged to close an inlet 70X of a flow path 70A. In the example shown in Fig. 10, the blocking member 80 is a metal foil. The blocking member 80 is adhered to the front surface 74 of the heat collecting member 70 so as to close the inlet 70X of the flow path 70A.

[0041] 11 is a schematic diagram showing an example in which a blocking member 80 is arranged to close an intermediate portion 70Z of a flow path 70A. In the example shown in FIG. 11, the blocking member 80 is made of clay. The blocking member is arranged in the intermediate portion 70Z by, for example, inserting it into the flow path 70A from the inlet 70X or the outlet 70Y and pushing it into the intermediate portion 70Z.

[0042] The heat collecting member 70 can control the location and flow rate of the fluid flowing through the heat collecting member 70 by closing some of the multiple flow paths 70A with the blocking member 80. This makes it easy to control the conversion rate of the thermal energy of the fluid into electrical energy.

[0043] <6. Configuration of the power generation unit> The power generating unit 90 includes a thermoelectric conversion module 100 and a cooling member 200. The power generating unit 90 is configured to generate a temperature difference between the first surface 100A and the second surface 100B of the thermoelectric conversion module 100. The number of power generating units 90 included in the thermoelectric unit 40 can be selected arbitrarily. In this embodiment, the thermoelectric unit 40 includes a first power generating unit 91, a second power generating unit 92, and a third power generating unit 93. That is, in this embodiment, the thermoelectric unit 40 includes three power generating units 91, 92, and 93. The thermoelectric unit 40 may include one, two, or four or more power generating units 90. The first power generating unit 91 is attached to the first side surface 71 of the heat collecting member 70. The second power generating unit 92 is attached to the second side surface 72 of the heat collecting member 70. The third power generating unit 93 is attached to the third side surface 73 of the heat collecting member 70. The first power generating unit 91, the second power generating unit 92, and the third power generating unit 93 have the same configuration, and therefore, hereinafter, when no particular distinction is made between them, they may be simply referred to as power generating units 90.

[0044] 7. Thermoelectric conversion module configuration Fig. 12 is a front view of the thermoelectric conversion module 100. Fig. 13 is a plan view of the thermoelectric conversion module 100 viewed from above. Fig. 14 is a right side view of the thermoelectric conversion module 100. Fig. 15 is a left side view of the thermoelectric conversion module 100.

[0045] The thermoelectric conversion module 100 converts the thermal energy of a fluid into electrical energy. The thermoelectric conversion module 100 includes a substrate 110, a lower electrode 120, a current lead 130, a thermoelectric conversion element 140, and an upper electrode 150.

[0046] The substrate 110 is disposed to insulate the lower electrode 120 from the heat collecting member 70, for example, when the heat collecting member 70 is made of metal. The substrate 110 also functions to stabilize the shape of the thermoelectric conversion module 100. The substrate 110 has a front surface 110A and a back surface 110B. The front surface 110A contacts the first side surface 71, the second side surface 72, and the third side surface 73 of the heat collecting member 70. The lower electrode 120 is disposed on the back surface 110B. The material and dimensions of the substrate 110 can be selected arbitrarily. The substrate 110 is preferably attached in close contact with the surface of the heat collecting member 70 to enhance heat transfer with the heat collecting member 70. For this reason, the substrate 110 preferably has a shape corresponding to the surface shapes of the first side surface 71, the second side surface 72, and the third side surface 73 of the heat collecting member 70. For example, in this embodiment, the first side surface 71, the second side surface 72, and the third side surface 73 of the heat collecting member 70 are flat, so the substrate 110 does not need to be flexible. Therefore, the material constituting the substrate 110 can be an inorganic material such as alumina, zirconia, titania, or silicon nitride, which has high thermal conductivity and electrical insulation. The material constituting the substrate 110 may be a resin film such as polyethylene terephthalate (PET) or polyimide (Kapton). The thickness of the substrate 110 is preferably thin to optimize heat transfer. The thickness of the substrate 110 is, for example, 1 mm or less, preferably 0.8 mm or less, and more preferably 0.1 mm or less. It is preferable that the surface 110A in contact with the first side surface 71, the second side surface 72, and the third side surface 73 of the heat collecting member 70 be highly smooth. However, to maintain high heat transfer, thermally conductive grease may be applied to the surface 110A to enhance smoothness.

[0047] When an electrical insulating film is formed on the surface of the heat collecting member 70, the substrate 110 is not necessary. The electrical insulating film can be formed, for example, by applying a paint containing an insulating resin and a pigment. The electrical insulating film can be formed, for example, by forming a thin film by sputtering an oxide such as titania, alumina, or zirconia, or by forming a thick film by thermal spraying. Even if the thermoelectric conversion module 100 does not have a substrate 110, in order to efficiently transfer heat from the heat collecting member 70 to the thermoelectric conversion module 100, it is preferable that the thickness of the electrical insulating film be thin as long as electrical insulation between the heat collecting member 70 and the lower electrode 120 can be maintained.

[0048] The bottom electrode 120 and the top electrode 150 electrically connect the p-type thermoelectric conversion element 140P and the n-type thermoelectric conversion element 140N of the thermoelectric conversion element 140. The materials constituting the bottom electrode 120 and the top electrode 150 can be selected from any electrically conductive material. From the viewpoints of high thermal conductivity, high electrical conductivity, and ease of processing, the material constituting the bottom electrode 120 and the top electrode 150 is preferably a flexible, crack-resistant sheet metal. Examples of the sheet metal include copper, silver, gold, or platinum. From the viewpoints of low cost, high thermal conductivity, and high electrical conductivity, copper or silver is preferred as the sheet metal, and from the viewpoint of durability, silver is most preferred. The dimensions of the bottom electrode 120 and the top electrode 150, such as length, width, and thickness, are determined based on the size, electrical resistivity, thermal conductivity, etc. of the thermoelectric conversion element 140. High thermal conductivity is necessary to efficiently transfer heat from the heat collecting member 70 to the high-temperature portion of the thermoelectric conversion element 140 and to efficiently dissipate heat from the low-temperature portion. For this reason, it is preferable that the thickness of the lower electrode 120 and the upper electrode 150 be as thin as possible. The thickness of the lower electrode 120 and the upper electrode 150 is, for example, 0.01 to 3 mm.

[0049] The lower electrode 120 is joined to the first surface 100A of the thermoelectric conversion element 140 via a joint 161. The upper electrode 150 is joined to the second surface 100B of the thermoelectric conversion element 140 via a joint 162. The materials constituting the joints 161 and 162 are preferably materials that can be joined with low electrical resistance. Examples of materials constituting the joints 161 and 162 include solder and silver solder. However, as described below, the materials constituting the thermoelectric conversion element of this embodiment are oxides or half-Heusler alloys. Therefore, solder and silver solder may have weak bonding strength and may not provide good durability. Furthermore, they may increase the electrical resistance (junction resistance) between the lower electrode 120 and the upper electrode 150 and the thermoelectric conversion element 140. For this reason, the materials constituting the joints 161 and 162 are preferably conductive metal pastes such as silver, gold, platinum, or copper. Metal pastes provide good bonding strength with the thermoelectric conversion element of this embodiment. For example, when a silver sheet is used as the material forming the lower electrode 120 and the upper electrode 150, the bonding strength between the thermoelectric conversion element and the lower electrode 120 and the upper electrode 150 can be sufficiently increased by using silver paste as the material forming the joints 161 and 162. Furthermore, by adding a predetermined amount of a specific additive such as an oxide or silver oxide to the silver paste forming the joints 161 and 162, the durability and bonding resistance of the thermoelectric conversion module 100 can be improved.

[0050] FIG. 16 is a plan view of the thermoelectric conversion module 100 on the substrate surface, with the thermoelectric conversion elements 140, upper electrodes 150, and joints 162 omitted. FIG. 17 is a plan view of the thermoelectric conversion module 100, with the upper electrodes 150 and joints 162 omitted. The shape of the thermoelectric conversion module 100 can be selected arbitrarily. In order to closely contact the thermoelectric conversion module 100 with the first side surface 71, the second side surface 72, and the third side surface 73 of the heat collecting member 70, the thermoelectric conversion module 100 is preferably plate-shaped overall. From the viewpoint of easily manufacturing the thermoelectric conversion module 100, the thermoelectric conversion module 100 is preferably a square or rectangular flat plate in plan view.

[0051] In the thermoelectric conversion module 100, the thermoelectric conversion elements 140 include p-type thermoelectric conversion elements 140P and n-type thermoelectric conversion elements 140N. The p-type thermoelectric conversion elements 140P and the n-type thermoelectric conversion elements 140N are arranged alternately. The p-type thermoelectric conversion elements 140P and the n-type thermoelectric conversion elements 140N are connected in series. One of the two current leads 130 is electrically connected to the p-type thermoelectric conversion elements 140P. The other of the two current leads 130 is electrically connected to the n-type thermoelectric conversion elements 140N. The thermoelectric conversion module 100 of this embodiment is composed of 64 pairs of elements. Each element pair is composed of two p-type thermoelectric conversion elements 140P and two n-type thermoelectric conversion elements 140N.

[0052] The material constituting the thermoelectric conversion element 140 can be selected arbitrarily. The material constituting the thermoelectric conversion element 140 is preferably determined based on, for example, the temperatures of the first side surface 71, the second side surface 72, and the third side surface 73 of the heat collecting member 70 (hereinafter referred to as the "temperature of the outer peripheral surface of the heat collecting member 70"). If the temperature of the outer peripheral surface of the heat collecting member 70 is about 200°C or less, a Bi2Te3-based conversion element can be used; if it is about 400°C or less, a skutterudite, half-Heusler alloy, or silicide-based conversion element can be used; and if it is about 400°C or more, a thermoelectric conversion element using a metal oxide thermoelectric material can be used. When the material constituting the thermoelectric conversion element 140 is determined based on durability, safety, such as not containing toxic elements, regardless of the temperature of the outer peripheral surface of the heat collecting member 70, it is preferable to use a thermoelectric conversion element made of a metal oxide or half-Heusler alloy.

[0053] The material constituting the p-type thermoelectric conversion element 140P of this embodiment is made of a layered cobalt-based oxide that satisfies the composition formula represented by formula (1) or formula (2).

[0054] Ca 3-p Bi p Co4O q ···(1) In formula (1), p and q are numbers that satisfy 0≦p≦1 and 8.5≦q≦10. Bi2Sr 2-r Car Co2O t ···(2) In formula (2), r and t are numbers that satisfy 0.0≦r≦2.0 and 8.5≦t≦10.

[0055] The material constituting the n-type thermoelectric conversion element 140N of this embodiment is a perovskite-type calcium manganese oxide satisfying the composition formula expressed by formula (3), or a half-Heusler alloy constituted by formula (4).

[0056] CaMn 1-X M x O y ···(3) In formula (3), M is at least one element selected from the group consisting of Nb, Ta, Mo, and W, and x and y are numbers that satisfy 0≦x≦0.1 and 2.8≦y≦3.2.

[0057] A a B b NiSn···(4) In formula (4), A is Ti or Zr, and B is at least one of Hf and Zr when A is Ti, and at least one of Hf and Ti when A is Zr, and 0.5≦a≦1, 0≦b≦0.5.

[0058] The composition formula used for p-type thermoelectric conversion element 140P is Ca 3-p Bi p Co4O q and Bi2Sr 2-r Ca r Co2O t The composite oxides shown in the figure have a structure in which layers with a rock-salt structure with composition ratios of (Ca,Bi)2CoO3 and Bi2(Sr,Ca)2O4 are alternately stacked with CoO2 layers in which six O atoms are octahedrally coordinated to one Co atom and the octahedra are arranged two-dimensionally so that they share edges with each other.As a p-type thermoelectric conversion element, they have a high Seebeck coefficient and good electrical conductivity.

[0059] The composition formula used for the n-type thermoelectric conversion element 140N is CaMn1-x M x O y The oxide represented by the formula (1) has a perovskite structure, with Mn or M located at the center of the body-centered cubic lattice structure and eight Ca atoms at the vertices. Furthermore, Mn or M is at the center, with six O atoms located around it in a face-centered cubic lattice structure. As an n-type thermoelectric conversion element 140N, it exhibits a negative Seebeck coefficient at temperatures above room temperature and has good electrical conductivity.

[0060] The composition formula used for the n-type thermoelectric conversion element 140N is A a B b The half-Heusler alloy represented by NiSn has a basic body-centered cubic lattice structure with Ni at the center and A (or B) and Sn at the vertices, with eight body-centered cubic elements forming a cube, four of which are deficient in Ni. Half-Heusler alloys composed of this composition formula exhibit a negative Seebeck coefficient and good electrical conductivity at temperatures above room temperature.

[0061] The composite oxides represented by the composition formulas (1), (2), and (3) can be produced by known methods such as single crystal production, powder production, and thin film production. Examples of single crystal production methods include the flux method, zone melting method, pulling method, and glass annealing method via a glass precursor. Powder production methods include the solid-state reaction method and the sol-gel method. Thin film production methods include the sputtering method, laser ablation method, and chemical vapor deposition method.

[0062] Among these manufacturing methods, the method for manufacturing oxides by the solid-state reaction method will be described in more detail. The oxides represented by formulas (1), (2), and (3) are manufactured by mixing raw materials so that the elemental component ratio is similar to the metal element ratio of the target oxide, and then calcining the mixture. The calcination temperature and calcination time are not particularly limited as long as they are conditions under which the target oxide is formed, but for example, calcination may be performed at a temperature in the range of about 700 to 1300°C for about 10 to 40 hours.

[0063] The raw materials are not particularly limited as long as they can form oxides upon firing, and include simple metals, oxides, and various compounds (carbonates, etc.). Alkoxide compounds can be used as the Ca source and Co source. Examples of alkoxide compounds used as the Ca source include calcium oxide (CaO), calcium chloride (CaCl2), calcium carbonate (CaCO3), calcium nitrate (Ca(NO3)2), calcium hydroxide (Ca(OH)2), dimethoxycalcium (Ca(OCH3)2), diethoxycalcium (Ca(OC2H5)2), and dipropoxycalcium (Ca(OC3H7)2).

[0064] Alkoxide compounds used as Co sources include cobalt oxide (CoO, Co2O3, Co3O4), cobalt chloride (CoCl2), cobalt carbonate (CoCO3), cobalt nitrate (Co(NO3)2), cobalt hydroxide (Co(OH)2), and dipropoxycobalt (Co(OC3H7)2). Similarly, manganese sources include manganese oxide (MnO, MnO2, Mn3O4), manganese chloride (MnCl2), manganese carbonate (MnCO3), manganese nitrate (Mn(NO3)2·6H2O), and diisopropoxymanganese (Mn[OCH(CH3)2]2).

[0065] When carbonates or organic compounds are used as raw materials, it is preferable to calcinate the raw materials in advance to decompose them, and then calcinate them to form the desired oxide. For example, when carbonates are used as raw materials, calcination is performed at about 700 to 900°C for about 10 hours, followed by calcination under the above conditions.

[0066] The calcination method is not particularly limited, and any method such as an electric heating furnace or a gas heating furnace can be used. The calcination atmosphere is usually an oxidizing atmosphere. Examples of oxidizing atmospheres include an oxygen stream and air. If the raw materials contain a sufficient amount of oxygen, calcination can be carried out in an inert atmosphere such as nitrogen or argon. The amount of oxygen in the oxide produced can be controlled by the oxygen partial pressure during calcination, the calcination temperature, the calcination time, etc. The higher the oxygen partial pressure, the higher the oxygen ratio in formulas (1), (2), and (3).

[0067] To produce the desired oxide by solid-state reaction, it is preferable to sinter the raw material powder as a pressed compact to efficiently promote the solid-state reaction. The resulting sintered compact is then cut, ground, and polished to form the thermoelectric conversion element 140 to be used in the thermoelectric conversion module 100. The dimensions of the thermoelectric conversion element 140 can be determined based on the dimensions of the thermoelectric conversion module 100 and the required power generation amount, but generally, it is sufficient to form a rectangular prism with a cross-sectional side of approximately 0.5 to 10 mm and a length of approximately 0.5 to 50 mm parallel to the direction of the temperature difference, or a cylinder with a diameter of approximately 0.5 to 10 mm and a length of approximately 0.5 to 50 mm. Alternatively, to obtain the desired shape without further processing after sintering, the pre-sintered powder may be pre-formed to a shape and dimensions that will yield the desired material after sintering, and then sintered. Similarly, for the other elements of the oxide thermoelectric conversion elements of formulas (1), (2), and (3), simple elements, oxides, chlorides, carbonates, nitrates, hydroxides, alkoxide compounds, etc. can be used.

[0068] A compound containing two or more of the constituent elements of the composite oxide that constitutes the thermoelectric conversion element 140 may also be used. There are no particular limitations on the method for producing the alloy having the half-Heusler structure of formula (4), but for example, raw materials are first blended so that the element ratio is the same as the element ratio of the target alloy, and then melted at a high temperature, reacted, and then cooled. The raw materials are not particularly limited as long as they can be used to form the alloy having the half-Heusler structure of formula (4) by firing, and simple metals or compounds containing two or more constituent elements may be used.

[0069] The method for melting the raw materials is not particularly limited. For example, methods such as arc melting or induction heating can be used to heat the raw materials to a temperature above their melting point. To avoid oxidation, the melting atmosphere is preferably an inert gas atmosphere such as helium or argon, or a non-oxidizing atmosphere such as a reduced pressure atmosphere or vacuum. If necessary, heat treatment of the resulting alloy having a half-Heusler structure can be performed to produce a more homogeneous alloy and improve its performance as a thermoelectric conversion material. The heat treatment conditions are not particularly limited and vary depending on the type and amount of metal elements contained, but heat treatment at a temperature of approximately 1000 to 1300°C is preferred. Even more preferably, prior to heat treatment, the molten alloy is pulverized and mixed, and the powder is pressure-molded into a disk or other desired shape, followed by sintering. This promotes solid-state reactions and allows for the production of a more homogeneous sintered body in a short time. Furthermore, by applying uniaxial pressure during heating during firing, such as by hot pressing or electric current sintering (so-called SPS sintering), a sintered body with high sintering density can be obtained, resulting in a sintered body with low electrical resistivity and high fracture strength. Regarding the atmosphere during heat treatment, it is preferable to use a non-oxidizing atmosphere, similar to that during melting, in order to avoid oxidation of the alloy having a half-Heusler structure.

[0070] The resulting fused and solidified material or sintered compact is cut, ground, and polished to form a thermoelectric conversion element 140 to be used in the thermoelectric conversion module 100. The size of the thermoelectric conversion element 140 is determined based on the size of the thermoelectric conversion module 100, the amount of power generation, and other factors. The dimensions of the thermoelectric conversion element 140 are determined based on the dimensions of the thermoelectric conversion module 100, the required amount of power generation, and other factors. The dimensions of the thermoelectric conversion element 140 are preferably, for example, a square prism with a cross-sectional side of approximately 0.5 to 10 mm and a length of approximately 0.5 to 50 mm, or a cylinder with a diameter of approximately 0.5 to 10 mm and a length of approximately 0.5 to 50 mm. Alternatively, to obtain the desired shape without undergoing processing and molding after sintering, the pre-sintered powder may be pressure-molded into a shape and dimensions that will result in the element shape after sintering, and then sintered.

[0071] The p-type thermoelectric conversion elements 140P and the n-type thermoelectric conversion elements 140N do not need to have the same dimensions, but it is preferable that they have the same length in order to ensure good adhesion with the heat collecting member 70 and the cooling member 200. The cross-sectional dimensions are determined based on the electrical resistivity and thermal conductivity so as to obtain the desired power generation output, current, and voltage values.

[0072] Although the specific method for electrically connecting one end of the p-type thermoelectric conversion element 140P and one end of the n-type thermoelectric conversion element 140N is not particularly limited, it is preferable that a good thermoelectric power can be obtained when they are joined and that the electrical resistance is low. One example of a method for electrically connecting one end of the p-type thermoelectric conversion element 140P and one end of the n-type thermoelectric conversion element 140N is to bond one end of the p-type thermoelectric conversion element 140P and one end of the n-type thermoelectric conversion element 140N to a conductive material (electrode) using a bonding material. Another example of a method for electrically connecting one end of the p-type thermoelectric conversion element 140P and one end of the n-type thermoelectric conversion element 140N is to press-bond or sinter one end of the p-type thermoelectric conversion element 140P and one end of the n-type thermoelectric conversion element 140N directly or via a conductive material. Another example of a method for electrically connecting one end of the p-type thermoelectric conversion element 140P and one end of the n-type thermoelectric conversion element 140N is to electrically contact the p-type thermoelectric conversion element 140P and the n-type thermoelectric conversion element 140N using a conductive material.

[0073] The number of thermoelectric conversion modules 100 included in one power generation unit 90 can be selected arbitrarily. In this embodiment, one power generation unit 90 has four thermoelectric conversion modules 100. The number of thermoelectric conversion modules 100 included in one power generation unit 90 may be one to three, or five or more.

[0074] FIG. 18 is a schematic diagram showing an example in which four thermoelectric conversion modules 100 are connected in series in one power generation unit 90. In FIG. 18, the upper electrodes 150 and joints 162 of the four thermoelectric conversion modules are not shown. When four thermoelectric conversion modules 100 are connected in series, the current leads 130 of adjacent thermoelectric conversion modules 100 alternately connect the p-type thermoelectric conversion elements 140P and the n-type thermoelectric conversion elements 140N. When four thermoelectric conversion modules 100 are connected in series, the resulting voltage is the sum of the voltages of the four thermoelectric conversion modules 100. This allows for a high-voltage, low-current output.

[0075] 19 is a schematic diagram showing an example in which four thermoelectric conversion modules 100 are connected in parallel in one power generation unit 90. In FIG. 19, the upper electrodes 150 and joints 162 of the four thermoelectric conversion modules are not shown. When four thermoelectric conversion modules 100 are connected in parallel, adjacent p-type thermoelectric conversion elements 140P are connected to each other by current lead wires 130, and adjacent n-type thermoelectric conversion elements 140N are connected to each other. When four thermoelectric conversion modules 100 are connected in parallel, the obtained current is the sum of the currents from the four thermoelectric conversion modules 100, so a high current output can be obtained at a low voltage.

[0076] <8. Cooling component configuration> FIG. 20 is a plan view of the cooling member 200. FIG. 21 is a side view of the cooling member 200. The cooling member 200 cools the thermoelectric conversion module 100 from the second surface 100B. The cooling member 200 is connected to the heat collecting member 70 by any connecting means. In other words, the cooling member 200 is structurally connected to the heat collecting member 70 via the connecting means. For example, if an external force using a weight, a spring, or the like is used to press the cooling member 200 against the heat collecting member 70 from the upper surface of the cooling member 200 via the thermoelectric conversion module 100, the thermoelectric power generation device 10 will become large. In this embodiment, the cooling member 200 and the heat collecting member 70 are connected by connecting means such as screws. This makes it possible to easily attach the cooling member 200 to any surface of the heat collecting member 70, particularly the first side surface 71 and the third side surface 73, while preventing the thermoelectric power generation device 10 from becoming large. The specific configuration of the cooling member 200 can be selected arbitrarily as long as it is capable of cooling the thermoelectric conversion module 100. In this embodiment, the cooling member 200 includes a water tank 210 and a liquid (not shown) circulating within the water tank 210. The liquid is, for example, cooling water. The material constituting the water tank 210 is, for example, an aluminum alloy. In this embodiment, one power generation unit 90 has one cooling member 200. In other words, one cooling member 200 cools four thermoelectric conversion modules 100. The water tank 210 is formed with a cooling surface 211, holes 212, a cooling water inlet 213, and a cooling water outlet 214. The cooling surface 211 is in direct or indirect contact with the thermoelectric conversion module 100. In this embodiment, a heat-conductive sheet (not shown) made of an electrically insulating and highly thermally conductive material is disposed between the cooling surface 211 and the thermoelectric conversion module 100. The thickness of the heat-conductive sheet is, for example, 1.0 mm. Screws are inserted into the holes 212 as connecting means for fixing the heat-collecting member 70.

[0077] <9. How to use the thermoelectric generator> Depending on the desired conversion rate from thermal energy to electrical energy, some of the multiple flow paths 70A of the heat collecting member 70 are closed by the closing member 80. The upstream piping 20 and the downstream piping 60 are connected to the thermoelectric unit 40, some of the multiple flow paths 70A being closed, via the upstream connecting portion 30 and the downstream connecting portion 50.

[0078] <10. Function of thermoelectric generator> The high-temperature fluid discharged from the combustion section 510 passes through the upstream pipe 20 and the flange 52 of the upstream connecting section 30, in that order, before reaching the inlet 70X of the flow path 70A of the heat collecting member 70. The fluid that reaches the inlet 70X passes through the flow path 70A that is not closed by the blocking member 80. The heat collecting member 70 absorbs heat from the fluid passing through the flow path 70A and heats the thermoelectric conversion module 100 of the power generating unit 90 attached to the first side surface 71, the second side surface 72, and the third side surface 73. This causes the temperature of the first surface 100A of the thermoelectric conversion module 100 to rise. Meanwhile, the second surface 100B of the thermoelectric conversion module 100 is cooled by the cooling member 200. This causes a temperature difference between the first surface 100A and the second surface 100B of the thermoelectric conversion module 100. An electromotive force is generated in the thermoelectric conversion module 100 due to the Seebeck effect, converting the thermal energy of the fluid into electrical energy. By attaching an output wire to the thermoelectric conversion module 100 and connecting an external resistor to the output wire, a current flows, and the converted electrical energy can be extracted.

[0079] <11. Features of Thermoelectric Generator> In the thermoelectric power generation device 10 of this embodiment, a portion of the multiple flow paths 70A can be closed by the blocking member 80. Therefore, the conversion rate from the thermal energy of the fluid to electrical energy can be easily controlled without requiring complicated work such as replacing the heat collection fins.

[0080] <12. Cold and Heat Applications> The thermoelectric conversion module 100 and the thermoelectric power generation device 10 of this embodiment can also be applied to cold energy power generation using a low-temperature fluid such as liquefied gas by appropriately selecting the heat collecting member 70 and the thermoelectric conversion element 140 to be used. In this case, the cooling member 200 of this embodiment is selected as a heating member, and the cooling liquid is selected as a heating liquid.

[0081] 13. Working Example The inventor(s) of the present application manufactured thermoelectric power generation devices of Examples 1 to 3 and Comparative Example 1, and conducted tests to confirm the conversion rate from thermal energy of a fluid to electrical energy. For ease of explanation, the following description will be given by assigning the same reference numerals as in the first embodiment to the elements constituting the thermoelectric power generation devices of Examples 1 to 3 and Comparative Example 1 that are the same as in the first embodiment.

[0082] <13-1. Manufacture of thermoelectric conversion modules of Examples 1 to 3> The thermoelectric conversion modules 100 of Examples 1 to 3 were manufactured as follows. A rectangular column of Ca with a cross section of 3.5 x 3.5 mm and a height of 5 mm 2.7 Bi 0.3 p-type thermoelectric conversion element 140P made of Co4O9 sintered body and CaMn 0.98 Mo 0.02 128 n-type thermoelectric conversion elements 140N each made of O3 sintered body were manufactured. Each element pair of the thermoelectric conversion module 100 was composed of two p-type thermoelectric conversion elements 140P and two n-type thermoelectric conversion elements 140N, so that even if one element were to break, electrical conduction would not be completely cut off.

[0083] An alumina plate measuring 65 × 65 mm and 0.8 mm thick was used as the substrate 110, and 56 lower electrodes 120 (silver electrodes) measuring 7.5 × 7.5 mm and 0.1 mm thick, seven lower electrodes 120 (silver electrodes) measuring 15.5 × 3.5 mm and 0.1 mm thick, and two current leads 130 (silver current leads) measuring 7.5 × 150 mm and 0.1 mm thick were arranged at 0.5 mm intervals on the substrate 110, as shown in Fig. 13. Silver paste was applied to the electrode surfaces of the thermoelectric conversion elements 140, and p-type thermoelectric conversion elements 140P and n-type thermoelectric conversion elements 140N were arranged so that they were alternately connected in series to the lower electrodes 120 on the substrate 110, as shown in Fig. 17. Furthermore, as shown in FIG. 13, 64 7 x 7 mm, 0.1 mm thick top electrodes 150 (silver electrodes) were placed on the other electrode surface of the thermoelectric conversion element 140 coated with silver paste, with p-type thermoelectric conversion elements 140P and n-type thermoelectric conversion elements 140N alternately connected in series. The precursor of the thermoelectric conversion module 100 thus manufactured was placed in a hot press furnace, and a pressure of 1.6 MPa was applied perpendicular to the electrode surface. The temperature was raised to 200°C over one hour and held at 200°C for one hour. The pressure was then increased to 3.2 MPa, the temperature was raised to 450°C over one hour, and held at 450°C for one hour. The temperature was then raised to 860°C over two hours, and the pressure was increased to 6.4 MPa one hour after the temperature increase. The mixture was further heated at 860°C for six hours, and then naturally cooled in the furnace to manufacture the thermoelectric conversion module 100. All firing was performed in air. A total of 12 thermoelectric conversion modules 100 were manufactured using the same method and conditions.

[0084] <13-2. Manufacture of thermoelectric power generation devices of Examples 1 to 3> Four thermoelectric conversion modules 100 per side were arranged on a first side 71, a second side 72, and a third side 73 of a heat collecting member 70 made of SS400 steel, with the substrate 110 in contact with the heat collecting member 70. Nothing was inserted between the substrate 110 and the heat collecting member 70. An electrically insulating heat transfer film (Lambdagel COH-4000LVC) measuring 65 x 65 mm and 1 mm thick was placed on the electrode surface of each thermoelectric conversion module 100, and the cooling member 200 was stacked on top of it and fixed to the heat collecting member 70 with five screws. The high-potential and low-potential ends of four adjacent thermoelectric conversion modules 100 in each power generation unit 90 were alternately connected in series.

[0085] <13-3. Closure of Flow Channels in Thermoelectric Power Generation Devices of Examples 1 to 3> The thermoelectric generators 10 of Examples 1 to 3 have the same configuration except for the positions and number of flow paths 70A closed by the closure member 80. The closure member 80 is a screw. The portion of the flow path 70A to which the closure member 80 is attached is the inlet 70X. The dimensions of the screw are: head 11.5 mm, outer diameter of the threaded portion 6 mm, and length of the threaded portion 20 mm.

[0086] 22 is a front view of the thermoelectric generator 10 of Example 1. In the thermoelectric generator 10 of Example 1, the flow paths 70A are not closed by the closing member 80. That is, in the thermoelectric generator 10 of Example 1, fluid flows through all of the flow paths 70A.

[0087] 23 is a front view of the thermoelectric generator 10 of Example 2. In the thermoelectric generator 10 of Example 2, 27 flow paths 70A near the bottom surface 76 are closed by closing members 80.

[0088] 24 is a front view of the thermoelectric power generation device 10 of Example 3. In the thermoelectric power generation device 10 of Example 3, 39 flow paths 70A near the bottom surface 76 and near the first side surface 71 are closed by the closing members 80. In FIGS. 23 and 24, the portions of the inlets 70X of the flow paths 70A that are filled in black are the flow paths 70A that are closed by the closing members 80.

[0089] <13-4. Thermoelectric power generation device of comparative example 1> FIG. 25 is a front view of a thermoelectric unit 440 included in the thermoelectric power generation device of Comparative Example 1. FIG. 26 is a plan view of the thermoelectric unit 440. The thermoelectric unit 440 includes two power generation units 90 and a fin-shaped heat collecting member 470 made of SS400 steel. The thermoelectric unit 440 was fabricated by closely contacting the substrates 110 of the four thermoelectric conversion modules 100, the same as those fabricated in Examples 1 to 3, with the heat collecting member 470. Nothing was inserted between the substrates 110 and the heat collecting member 470. A 65 × 65 mm, 1 mm thick, electrically insulating heat transfer film (Lambdagel COH-4000LVC) was placed on the other electrode surface of the thermoelectric conversion module 100, and the cooling member 200 was stacked and fixed to the heat collecting member 470 with five screws, thereby fabricating a thermoelectric unit 440 with a heat collecting member 470. The high potential ends and low potential ends of four adjacent thermoelectric conversion modules 100 in each power generation unit 90 were alternately connected in series. Flanges 480 were attached to the two power generation units 90, and they were connected to the combustion section 510 of the combustion burner 500 in the same manner as in Examples 1 to 3.

[0090] <13-5. Test methods and conditions> The thermoelectric generators 10 of Examples 1 to 3 and Comparative Example 1 were connected to the combustion section 510 of a combustion burner 500. The fuel for the combustion burner 500 was kerosene. The temperature of the fluid immediately before passing through the heat collecting member 70 was approximately 830°C to 840°C. A water pump was used to flow cooling water at a temperature immediately before the inlet 213 of the cooling member 200 of approximately 75°C to 77°C. The flow rate of the cooling water was 6.2 L / min. In Examples 1 to 3, the cooling water was flowed in the order of the first power generating unit 91, the second power generating unit 92, and the third power generating unit 93. In Comparative Example 1, the cooling water was flowed in the order of the power generating unit 91 and the power generating unit 92. For the thermoelectric generators 10 of Examples 1 to 3 and Comparative Example 1, the temperature of the fluid after passing through the heat collecting member 70, the temperature of the cooling water near the outlet 214, and the power generated by the power generating unit 90 were measured. The power generation output was measured for each power generating unit 90 in which four thermoelectric conversion modules 100 were connected in series, and the maximum values ​​were added together. The current lead wires 130 at both ends of the four thermoelectric conversion modules 100 connected in series were connected to the voltage and current terminals of the electronic load device, and the load resistance value within the electronic load device was scanned to measure the current and voltage values, and the power generation output was obtained by multiplying the current and voltage.

[0091] <13-6. Test Results> FIG. 27 is a table showing the test results. In the thermoelectric power generation device of Comparative Example 1, only two heat-receiving surfaces are formed due to spatial interference between the fins. Therefore, even if the area of ​​the opening through which the fluid passes is the same, the number of locations where the thermoelectric conversion module 100 is efficiently heated is fewer than when the heat collecting member 70 of the Example is used. Furthermore, since the temperature change of the fluid before and after passing through the upstream pipe 20 and the downstream pipe 60 is small, and the temperature change of the cooling water is also small, it can be seen that the amount of heat flowing into the thermoelectric conversion module 100 is small. As a result, the thermoelectric power generation device 10 of Comparative Example 1 had a lower maximum output than the thermoelectric power generation devices 10 of Examples 1 to 3. This shows that the block-shaped heat collecting member 70 used in the thermoelectric power generation devices 10 of Examples 1 to 3 is effective for increasing power generation output.

[0092] It can be seen that in the thermoelectric generators 10 of Examples 1 to 3, the power generation output, fluid temperature, and cooling water temperature can be freely controlled by changing the locations and number of blocked flow paths 70A. If flow paths 70A are formed near the bottom surface 76 of the heat collecting member 70 where the power generating units 90 are not attached, heat will be released from the bottom surface 76. By blocking the flow paths 70A around the bottom surface 76 with blocking members 80, the heat flow is distributed to the first side surface 71, second side surface 72, and third side surface 73 of the heat collecting member 70 where the power generating units 90 are attached. Therefore, in the thermoelectric generators 10 of Examples 2 and 3, the amount of heat passing through the thermoelectric conversion module 100 is higher than in the thermoelectric generator 10 of Example 1, resulting in higher power generation output and greater temperature change in the cooling water.

[0093] In the thermoelectric generator 10 of Example 3, the first side surface 71, in other words, the flow path 70A near the first power generating unit 91, is blocked by the blocking member 80, so the power generation output from the first power generating unit 91 is reduced, and the overall power generation output is lower than that of the thermoelectric generators 10 of Examples 1 and 2. On the other hand, in the thermoelectric generator 10 of Example 3, the temperature change of the fluid and the cooling water is smaller than that of the thermoelectric generators 10 of Examples 1 and 2, because the amount of heat passing through the power generating unit 90 is reduced.

[0094] Second Embodiment A hot water circulation system 600 including a thermoelectric power generation system 300 according to the second embodiment will be described with reference to FIGS.

[0095] <14. Overall configuration of hot water circulation system> FIG. 28 is a perspective view of the hot water circulation device 600. The hot water circulation device 600 includes an apparatus main body 610, a pipe 620, and a thermoelectric power generation device 300. The apparatus main body 610 includes, for example, a heater and a pump. The apparatus main body 610 sends hot water to the thermoelectric power generation device 300 and heats the coolant from which heat has been removed by the thermoelectric power generation device 300. Hereinafter, the hot water sent to the thermoelectric power generation device 300 by the apparatus main body 610 may be simply referred to as a fluid. The pipe 620 connects the apparatus main body 610 and the thermoelectric power generation device 300. The pipe 620 includes a first pipe 621 and a second pipe 622. The first pipe 621 connects the apparatus main body 610 and the upstream side of the thermoelectric power generation device 300. The second pipe 622 connects the apparatus main body 610 and the downstream side of the thermoelectric power generation device 300.

[0096] 15. Thermoelectric power generation device configuration The thermoelectric power generation device 300 includes an upstream pipe 310, a thermoelectric unit 320, and a downstream pipe 330. The upstream pipe 310 connects a first pipe 621 and the thermoelectric unit 320. The downstream pipe 330 connects the thermoelectric unit 320 and a second pipe 622. The basic configuration of the thermoelectric unit 320 is similar to that of the thermoelectric unit 40 of the first embodiment. The following describes the thermoelectric unit 320, focusing on the differences from the thermoelectric unit 40 of the first embodiment.

[0097] <16. Thermoelectric unit configuration> Fig. 29 is a side view of the thermoelectric power generation device 300. Fig. 30 is a front view of the upstream side of the thermoelectric power generation device 300. Fig. 31 is a rear view of the downstream side of the thermoelectric power generation device 300. Note that Fig. 30 omits illustration of the upstream piping 310, and Fig. 31 omits illustration of the downstream piping 330.

[0098] The thermoelectric unit 320 includes a heat collecting member 340 and three power generating units 350. The three power generating units 350 are the same as the power generating unit 90 of the first embodiment except for the numbers of p-type thermoelectric conversion elements 140P and n-type thermoelectric conversion elements 140N and the configuration of the cooling member 370.

[0099] 17. Heat collection component configuration The heat collecting member 340 absorbs heat from a fluid at, for example, 80°C or higher, and heats the thermoelectric conversion module 100 of the power generating unit 350 attached to its outer circumferential surface. The heat collecting member 340 has a plurality of flow paths 340A through which the fluid passes. The plurality of flow paths 340A penetrate the heat collecting member 340. In this embodiment, 21 flow paths 340A are formed in the heat collecting member 340.

[0100] The heat collecting member 340 has a first side surface 341, a second side surface 342, a third side surface 343, a front surface 344, a back surface 345, and a bottom surface 346. A power generating unit 350 is attached to each of the first side surface 341, the second side surface 342, and the third side surface 343. The upstream pipe 310 is attached to the front surface 344, for example, via a screw. Inlets 340X of the multiple flow paths 340A are formed in the front surface 344. Outlets 340Y of the multiple flow paths 340A are formed in the back surface 345. The multiple flow paths 340A are formed to penetrate the front surface 344 and the back surface 345 of the heat collecting member 340. The blocking member 80 of the first embodiment can be attached to the inlets 340X or outlets 340Y of the multiple flow paths 340A, or to an intermediate portion (not shown) between the inlets 340X and the outlets 340Y.

[0101] <18. Configuration of power generation unit> The power generating unit 350 includes a thermoelectric conversion module 100 and a cooling member 370. The power generating unit 350 is configured to generate a temperature difference between the first surface 100A (see FIG. 12) and the second surface 100B (see FIG. 12) of the thermoelectric conversion module 100. The number of power generating units 350 included in the thermoelectric unit 320 can be selected arbitrarily. In this embodiment, the thermoelectric unit 320 includes a first power generating unit 351, a second power generating unit 352, and a third power generating unit 353. That is, in this embodiment, the thermoelectric unit 320 includes three power generating units 351, 352, and 353. The thermoelectric unit 320 may include one, two, or four or more power generating units 350. The first power generating unit 351 is attached to a first side surface 341 of the heat collecting member 340. The second power generating unit 352 is attached to a second side surface 342 of the heat collecting member 340. The third power generation unit 353 is attached to the third side surface 343 of the heat collecting member 340. Since the first power generation unit 351, the second power generation unit 352, and the third power generation unit 353 have the same configuration, they may be simply referred to as power generation unit 350 below when no particular distinction is made between them.

[0102] 19. Cooling component configuration The cooling member 370 is a heat pipe that cools using the latent heat of a working liquid (not shown). The cooling member 370 has an evaporation section 371 where the working liquid evaporates, a condensation section 372 where the working liquid condenses, and heat dissipation fins 373 attached to the condensation section 372. In the power generation unit 350, the cooling member 370 is arranged so that the condensation section 372 is located above the evaporation section 371.

[0103] <20. How to use the thermoelectric generator> Depending on the desired conversion rate from thermal energy to electrical energy, some of the multiple flow paths 340A of the heat collecting member 340 are closed by the closing member 80. The upstream pipe 310 and the downstream pipe 330 are connected to the thermoelectric unit 320 in which some of the multiple flow paths 340A are closed.

[0104] 21. Function of Thermoelectric Generator A high-temperature fluid sent from the device main body 610 passes through the first pipe 621 and the upstream pipe 310 in this order, and reaches the inlet 340X of the flow path 340A of the heat collecting member 340. The fluid that reaches the inlet 340X passes through the flow path 340A that is not closed by the blocking member 80. The heat collecting member 340 absorbs heat from the fluid passing through the flow path 340A and heats the thermoelectric conversion module 100 of the power generating unit 350 attached to the first side surface 341, the second side surface 342, and the third side surface 343. This causes the temperature of the first surface 100A of the thermoelectric conversion module 100 to rise. Meanwhile, the second surface 100B of the thermoelectric conversion module 100 is cooled by the cooling member 370. This causes a temperature difference to occur between the first surface 100A and the second surface 100B of the thermoelectric conversion module 100. The Seebeck effect generates an electromotive force in the thermoelectric conversion module 100, converting the thermal energy of the fluid into electrical energy. By attaching an extraction wire to the thermoelectric conversion module 100 and connecting an external resistor to the extraction wire, a current flows, and the converted electrical energy can be extracted.

[0105] <22. Features of Thermoelectric Generator> In the thermoelectric power generation device 300 of this embodiment, a portion of the multiple flow paths 340A can be closed by the closing member 80. This makes it possible to easily control the conversion rate from the thermal energy of the fluid to electrical energy without requiring complicated work such as replacing the heat collection fins.

[0106] 23. Example The inventor(s) of the present application manufactured thermoelectric power generation devices of Examples 4 to 7 and Comparative Example 2, and conducted tests to confirm the conversion rate from thermal energy of the fluid to electrical energy. For ease of explanation, the following description will be given by assigning the same reference numerals as in the second embodiment to the elements constituting the thermoelectric power generation devices of Examples 4 to 7 and Comparative Example 2 that are the same as in the second embodiment.

[0107] <23-1. Manufacture of thermoelectric conversion modules of Examples 4 to 7> The thermoelectric conversion modules 100 of Examples 4 to 7 were manufactured as follows. A rectangular column of Ca with a cross section of 2.0 x 2.0 mm and a height of 5 mm 2.7 Bi 0.3 p-type thermoelectric conversion element 140P made of Co4O9 sintered body and CaMn 0.98 Mo 0.02 112 n-type thermoelectric conversion elements 140N each made of O3 sintered compact were manufactured. Each element pair of the thermoelectric conversion module 100 is composed of one p-type thermoelectric conversion element 140P and one n-type thermoelectric conversion element 140N.

[0108] On a PET film measuring 60 mm in length, 20 mm in width, and 0.8 mm in thickness, 111 lower electrodes 120 (silver electrodes) measuring 2.0 × 4.5 mm and 0.1 mm in thickness and two current lead wires 130 (silver current lead wires) measuring 2.0 × 28 mm and 0.1 mm in thickness were arranged at 0.5 mm intervals on the substrate 110. P-type thermoelectric conversion elements 140P and n-type thermoelectric conversion elements 140N were arranged on top of the lower electrodes 120 so as to be alternately connected in series. Furthermore, 112 upper electrodes 150 (silver electrodes) measuring 2.0 × 4.5 mm and 0.1 mm in thickness were placed on the other electrode surface of the thermoelectric conversion element 140, on which silver paste had been applied, so as to be alternately connected in series with the p-type thermoelectric conversion elements 140P and n-type thermoelectric conversion elements 140N. The precursor of the thermoelectric conversion module 100 thus manufactured was placed in a hot press furnace, and a pressure of 1.6 MPa was applied perpendicular to the electrode surface. The temperature was raised to 200°C over one hour and held at 200°C for one hour. The pressure was then increased to 3.2 MPa, the temperature was raised to 450°C over one hour, and the temperature was held at 450°C for one hour. The temperature was then raised to 860°C over two hours, and the pressure was increased to 6.4 MPa one hour after the temperature increase. The precursor was further heated at 860°C for six hours, and then naturally cooled in the furnace to manufacture the thermoelectric conversion module 100. All firing was performed in the air. A total of three thermoelectric conversion modules 100 were manufactured using the same method and conditions.

[0109] <23-2. Manufacture of thermoelectric power generation devices of Examples 4 to 7> One thermoelectric conversion module 100 was placed on each of the first side surface 341, second side surface 342, and third side surface 343 of the heat collecting member 340, with the substrate 110 in contact with the heat collecting member 340. An electrically insulating heat transfer film measuring 60 × 20 mm and 0.5 mm thick was inserted between the substrate 110 and the heat collecting member 340. An electrically insulating heat transfer film measuring 60 × 20 mm and 0.5 mm thick was placed on the electrode surface of each thermoelectric conversion module 100, and the cooling member 370 was stacked on top of it and fixed to the heat collecting member 340 with six screws.

[0110] <23-3. Closure of flow paths in thermoelectric power generation devices of Examples 4 to 7> The thermoelectric generators 300 of Examples 4 to 7 have the same configuration except for the position and number of flow paths 340A closed by the closing member 80. The closing member 80 is a screw. The portion of the flow path 70A to which the closing member 80 is attached is the outlet 340Y. The outlet 340Y is formed with a female thread that mates with a screw. The screw is M2.5.

[0111] Fig. 32 is a rear view of the thermoelectric generator 300 of Example 4. In the thermoelectric generator 300 of Example 4, the flow paths 340A are not closed by the closing member 80. That is, in the thermoelectric generator 300 of Example 4, fluid flows through all of the flow paths 340A. Note that the power generation unit 350 is not shown in Figs. 32 to 36.

[0112] 33 is a rear view of the thermoelectric generator 300 of Example 5. In the thermoelectric generator 300 of Example 5, four flow paths 340A near the bottom surface 346 are closed by the closing member 80.

[0113] 34 is a rear view of the thermoelectric generator 300 of Example 6. In the thermoelectric generator 300 of Example 6, nine flow paths 340A near the bottom surface 346 and near the third side surface 343 are closed by the closing member 80.

[0114] 35 is a rear view of the thermoelectric power generation device 300 of Example 7. In the thermoelectric power generation device 300 of Example 7, eight flow paths 340A near the bottom surface 346 and near the second side surface 342 are closed by the closing member 80. In FIGS. 33, 34, and 35, the portions of the outlets 340Y of the flow paths 340A that are filled in black are the flow paths 340A that are closed by the closing member 80.

[0115] <23-4. Thermoelectric power generation device of comparative example 2> 36 is a rear view of the thermoelectric generator 300 of Comparative Example 2. In the thermoelectric generator of Comparative Example 2, the heat collecting member 340 has one flow path 340A. In other words, in the thermoelectric generator 300 of Comparative Example 2, the inside of the heat collecting member 340 is hollow.

[0116] <23-5. Test methods and conditions> The thermoelectric generators 300 of Examples 4 to 7 and Comparative Example 2 were connected to the device main body 610. The temperature of the fluid immediately before passing through the heat collecting member 340 was approximately 80°C. The flow rate of the fluid sent by the device main body 610 was 4.8 L / min. For the thermoelectric generators 300 of Examples 4 to 7 and Comparative Example 2, the temperature of the fluid after passing through the heat collecting member 340 and the power generated by the power generating unit 350 were measured. The power generation output was measured for each power generating unit 350, and the maximum values ​​were added together. The current lead wires 130 at both ends of the thermoelectric conversion module 100 were connected to the voltage and current terminals of the electronic load device, and the load resistance value within the electronic load device was scanned to measure the current and voltage values. The current and voltage were then multiplied to obtain the power generation output.

[0117] <23-6. Test Results> FIG. 37 is a table showing the test results. The thermoelectric power generation device 300 of Comparative Example 2 had a lower power output than the thermoelectric power generation devices 300 of Examples 4 to 6. This is because the amount of heat flowing from the hot water to the thermoelectric conversion module 100 was less than when the hot water passed through the flow path 340A. The temperature change of the fluid in the thermoelectric power generation device 300 of Comparative Example 2 was also smaller than that in the thermoelectric power generation devices 300 of Examples 4 to 7. In the thermoelectric power generation devices 300 of Examples 4 to 7, which have a flow path 340A through which a fluid flows, closing the flow path 340A with the blocking member 80 blocks the flow of heat to the outer peripheral surface of the surrounding heat collecting member 340, and it can be seen that the amount of power generated by the power generation unit 350 and the temperature change of the hot water can be controlled as desired.

[0118] <24. Variation> The above-described embodiments are examples of possible forms of the thermoelectric generator and method of using the thermoelectric generator according to the present invention, and are not intended to limit the forms. The thermoelectric generator and thermoelectric generator according to the present invention may take forms different from those exemplified in the embodiments. Examples of such forms include forms in which part of the configuration of each embodiment is replaced, modified, or omitted, or forms in which a new configuration is added to each embodiment. Below are some examples of modified forms of each embodiment. Note that the following modified forms can be combined as long as they do not cause technical contradictions.

[0119] <24-1> In the first embodiment, an example in which the thermoelectric power generation device 10 is applied to the combustion burner 500 has been described, but the application of the thermoelectric power generation device 10 is not limited to this. For example, the thermoelectric power generation device 10 can also be used to convert heat contained in gas discharged from an industrial furnace or an incinerator, or in automobile exhaust gas, into electricity.

[0120] <24-2> In the second embodiment, an example in which the thermoelectric power generation device 300 is applied to the hot water circulation device 600 has been described, but the application of the thermoelectric power generation device 300 is not limited to this. For example, the thermoelectric power generation device 300 can also be used to convert heat contained in hot water discharged from a heat exchanger into electricity.

[0121] <24-3> In the first embodiment, the cooling member 200 is configured to circulate cooling water in the water tank 210. However, the cooling water may remain in the water tank 210. A heat pipe may also be used as the cooling member 200, as in the cooling member 370 of the second embodiment. FIGS. 38 to 40 are diagrams showing the arrangement of a cooling member 370 according to a modified example when the thermoelectric conversion module 100 is attached to the second side surface 72 of the heat collecting member 70. FIG. 41 is a diagram showing the arrangement of a cooling member 370 according to a modified example when the thermoelectric conversion module 100 is attached to the bottom surface 76 of the heat collecting member 70. FIG. 42 is a diagram showing the arrangement of a cooling member 370 according to a modified example when the thermoelectric conversion module 100 is attached to the first side surface 71 or the third side surface 73 of the heat collecting member 70. FIGS. 44 to 46 are diagrams showing the arrangement of a cooling member 370 according to a modified example when the surface of the heat collecting member 70 on which the thermoelectric conversion module 100 is attached is inclined. In any of the modified examples, the cooling member 370 is disposed so that the condensation section 372 of the cooling member 370 is located above the evaporation section 371. [Explanation of symbols]

[0122] 10: Thermoelectric power generation device 20: Upstream piping (piping) 40: Thermoelectric unit 60: Downstream piping (piping) 70: Heat collecting member 70A: Flow path 70X: Entrance 70Y: Exit 70Z: Middle part 80: Closure member 90: Power generation unit 100: Thermoelectric conversion module 100A: Side 1 100B: 2nd side 140: Thermoelectric conversion element 140P: p-type thermoelectric conversion element 140N: n-type thermoelectric conversion element 200: Cooling member 300: Thermoelectric power generation device 310: Upstream piping 320: Thermoelectric unit 330: Downstream piping 340: Heat collecting member 340A: Flow path 340X: Entrance 340Y:Exit 350: Power generation unit 360: Thermoelectric conversion module 370: Cooling member 371: Evaporation section 372: Condenser section 373: Heat dissipation fin

Claims

1. A thermoelectric power generation device including a pipe through which a fluid flows and a thermoelectric unit connected to the pipe, The thermoelectric unit comprises: a heat collecting member having a plurality of flow paths formed therein through which the fluid passes; a blocking member that closes some of the flow paths; a thermoelectric conversion module attached to a surface of the heat collecting member, the thermoelectric conversion module includes a first surface facing the surface of the heat collecting member and heated by the fluid via the heat collecting member, and a second surface opposite to the first surface; A temperature difference is generated between the first surface and the second surface, the heat collecting member has a front surface on which an inlet of the flow path is formed and a back surface on which an outlet of the flow path is formed, the thermoelectric conversion module is attached to the outside of the flow path and to an outer surface of the heat collecting member other than the front surface and the back surface, the flow path has the inlet, the outlet, and an intermediate portion between the inlet and the outlet; The blocking member is configured to be inserted at least partially into the flow path; or configured to be joined to the heat collecting member to close the inlet or the outlet Thermoelectric generator.

2. a cooling member configured to cool the thermoelectric conversion module from the second surface, The cooling member is connected to the heat collecting member. The thermoelectric power generating device according to claim 1 .

3. The heat collecting member is prismatic. The thermoelectric power generating device according to claim 1 or 2.

4. the thermoelectric conversion module includes a p-type thermoelectric conversion element and an n-type thermoelectric conversion element, The p-type thermoelectric conversion element is Ca 3-p Bi p Co 4 O q ・・・(1) (In formula (1), p and q are numbers that satisfy 0≦p≦1 and 8.5≦q≦10.) Or, Bi 2 Sr 2-r Ca r Co 2 O t ・・・(2) (wherein r and t are numbers satisfying 0.0≦r≦2.0 and 8.5≦t≦10), The n-type thermoelectric conversion element is CaMn 1-X M x O y ・・・(3) (In formula (3), M is at least one element selected from the group consisting of Nb, Ta, Mo, and W, and x and y are numbers satisfying 0≦x≦0.1 and 2.8≦y≦3.2.) A perovskite-type calcium manganese oxide satisfying the composition formula represented by: A a B b NiSn・・・(4) (In formula (4), A is Ti or Zr, B is at least one of Hf and Zr when A is Ti, and at least one of Hf and Ti when A is Zr, and 0.5≦a≦1, 0≦b≦0.5.) It is composed of a half-Heusler alloy that satisfies the composition formula The thermoelectric power generating device according to claim 1 or 2.

5. The cooling member includes a heat dissipation fin. A thermoelectric power generating device according to claim 3 which relies on claim 2.

6. The cooling element includes a circulating or stagnant liquid. A thermoelectric power generating device according to claim 3 which relies on claim 2.

7. The liquid is cooling water The thermoelectric power generating device according to claim 6 .

8. The cooling member includes a heat pipe that cools using the latent heat of a working liquid. A thermoelectric power generating device according to claim 3 which relies on claim 2.

9. A method of using a thermoelectric power generation device including a pipe through which a fluid flows and a thermoelectric unit connected to the pipe, comprising: The thermoelectric unit comprises: a heat collecting member having a plurality of flow paths formed therein through which the fluid passes; a blocking member that closes some of the flow paths; a thermoelectric conversion module attached to a surface of the heat collecting member, the thermoelectric conversion module includes a first surface facing the surface of the heat collecting member and heated by the fluid via the heat collecting member, and a second surface opposite to the first surface; A temperature difference is generated between the first surface and the second surface, the heat collecting member has a front surface on which an inlet of the flow path is formed and a back surface on which an outlet of the flow path is formed, the thermoelectric conversion module is attached to the outside of the flow path and to an outer surface of the heat collecting member other than the front surface and the back surface, the flow path has the inlet, the outlet, and an intermediate portion between the inlet and the outlet; The blocking member is configured to be inserted at least partially into the flow path; or configured to be joined to the heat collecting member so as to close the inlet or the outlet; and closing some of the plurality of flow paths with a blocking member in accordance with a desired conversion rate of thermal energy to electrical energy. How to use a thermoelectric generator.

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