Thermoelectric conversion device

Abstract

To provide a thermoelectric conversion device having a simpler structure than before and capable of reducing a manufacturing cost.SOLUTION: A thermoelectric conversion device comprises a honeycomb structure 10, one or more thermoelectric conversion modules 20, and a heat radiation unit 30. The honeycomb structure 10 has an outer peripheral wall 11, and partition walls 15 arranged inside the outer peripheral wall 11 and defining a plurality of cells 14 which serve as fluid flow paths extending from a first end surface 12 to a second end surface 13. The thermoelectric conversion module 20 is arranged on the outer peripheral wall 11. The heat radiation unit 30 is arranged on the thermoelectric conversion module 20.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] The present invention relates to a thermoelectric conversion device.

Background Art

[0002] In various factories such as metal factories, ceramic factories, pulp and paper factories, chemical factories, and food factories, from the viewpoints of carbon neutral CO 2 reduction and energy saving measures, it is required to effectively utilize the thermal energy contained in exhaust gas, hot water, steam, etc. For the effective utilization of thermal energy, it is necessary not only to construct the method but also to optimize the amount of heat used, and a sensor for measuring the amount of heat with high accuracy is required. As a sensor, from the viewpoint of measurement accuracy, using a sensor equipped with a thermoelectric conversion module has been considered.

[0003] On the other hand, in automobiles as well, from the viewpoint of improving fuel efficiency, a thermoelectric conversion device that converts the thermal energy contained in automobile exhaust gas, etc. into electrical energy is required. For example, in Patent Document 1, an outer peripheral side wall having one or more planar outer peripheral side surfaces, and a plurality of cells disposed inside the outer peripheral side wall and penetrating from a first bottom surface to a second bottom surface to form a flow path for a first fluid are partitioned and formed. A plurality of partition walls; one or more thermoelectric conversion modules disposed facing each other on one or more planar outer peripheral side surfaces; a cylindrical member that circumferentially covers the outer peripheral side surface of the honeycomb structure including one or more thermoelectric conversion modules; and a casing that circumferentially covers the cylindrical member. The plurality of partition walls are mainly composed of ceramics, the casing has an inlet and an outlet for a second fluid having a lower temperature than the first fluid, and a flow path for the second fluid is formed between the inner surface of the casing and the outer surface of the cylindrical member so as to surround the cylindrical member. A heat recovery device has been proposed. This heat recovery device can improve fuel efficiency by converting the thermal energy of automobile exhaust gas into electrical energy by a thermoelectric conversion module, recovering it, and effectively using it as electric power for charging a battery or driving electrical components.

Prior Art Documents

Patent Document

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The heat recovery device of Patent Document 1 requires a structure for circulating a second fluid (cooling water) on the outer peripheral side of the thermoelectric conversion module. Therefore, this heat recovery device has a complex structure as a thermoelectric conversion device, and the manufacturing cost increases. In particular, since this heat recovery device has a complex structure, it is also difficult to use as a sensor.

[0006] The present invention has been made to solve the above problems, and an object thereof is to provide a thermoelectric conversion device having a simpler structure than conventional ones and capable of reducing the manufacturing cost.

Means for Solving the Problems

[0007] As a result of intensive research on thermoelectric conversion devices, the present inventors have found that the above problems can be solved by providing a heat radiating portion capable of radiating heat into the air on the thermoelectric conversion module, and have completed the present invention. That is, the present invention is exemplified as follows.

[0008] [1] A honeycomb structure having an outer peripheral wall and a partition wall disposed inside the outer peripheral wall and partitioning and forming a plurality of cells serving as a flow path for a fluid extending from a first end face to a second end face, One or more thermoelectric conversion modules disposed on the outer peripheral wall, and A heat radiating portion disposed on the thermoelectric conversion module and capable of radiating heat into the air A thermoelectric conversion device comprising.

[0009] [2] The thermoelectric conversion device according to [1], wherein the outer peripheral wall has one or more planar outer peripheral surfaces, and the thermoelectric conversion module is disposed on the outer peripheral surface.

[0010] [3] The thermoelectric conversion device according to [1] or [2], wherein the thermoelectric conversion module is flexible.

[0011] [4] The thermoelectric conversion device according to any one of [1] to [3], further comprising a cylindrical member fitted to the outer peripheral surface of the outer peripheral wall between the honeycomb structure and the thermoelectric conversion module.

[0012] [5] The thermoelectric conversion device according to [4], wherein the cylindrical member is made of a metal material.

[0013] [6] The thermoelectric conversion device according to any one of [1] to [5], wherein the heat radiating part has a plurality of heat radiating fins.

[0014] [7] The thermoelectric conversion device according to any one of [1] to [6], further comprising a substance for reducing contact thermal resistance between the thermoelectric conversion module and the honeycomb structure and / or between the thermoelectric conversion module and the heat radiating part. [Advantages of the Invention]

[0015] According to the present invention, it is possible to provide a thermoelectric conversion device having a simpler structure than conventional ones and capable of reducing manufacturing costs. [Brief Description of the Drawings]

[0016]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 4

Figure 5A

Figure 5B

DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications and improvements can be appropriately made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention, and such modified and improved embodiments also fall within the scope of the present invention.

[0018] FIG. 1A is a cross-sectional view parallel to the axial direction (the direction in which the cells extend) of the honeycomb structure of the thermoelectric conversion device according to an embodiment of the present invention. Further, FIG. 1B is a cross-sectional view taken along line a-a' of the thermoelectric conversion device of FIG. 1A (a cross-sectional view orthogonal to the axial direction of the honeycomb structure). As shown in FIGS. 1A and 1B, a thermoelectric conversion device according to an embodiment of the present invention includes a honeycomb structure 10, one or more thermoelectric conversion modules 20, and a heat radiating part 30. The honeycomb structure 10 has an outer peripheral wall 11 and partition walls 15 disposed inside the outer peripheral wall 11 and partitioning a plurality of cells 14 that serve as fluid flow paths extending from a first end face 12 to a second end face 13. The thermoelectric conversion module 20 is disposed on the outer peripheral wall 11 of the honeycomb structure 10. The heat radiating part 30 can radiate heat into the air and is disposed on the thermoelectric conversion module 20. Since the thermoelectric conversion device having such a structure has a simpler structure than the conventional one, the manufacturing cost can be reduced.

[0019] <Honeycomb structure 10> The honeycomb structure 10 has an outer peripheral wall 11 and partition walls 15 disposed inside the outer peripheral wall 11 and partitioning a plurality of cells 14 that serve as fluid flow paths extending from a first end face 12 to a second end face 13. By using the honeycomb structure 10 having such a structure, the heat of the fluid flowing through the cells 14 of the honeycomb structure 10 can be efficiently collected and transferred to the outer peripheral wall 11. The flow direction of the fluid is not particularly limited. For example, it can flow from the first end face 12 toward the second end face 13, that is, in the direction of the arrow in FIG. 1A (from the left side to the right side of the paper surface), and in the direction from the front to the back of the paper surface in FIG. 1B. The fluid is not particularly limited, and various liquids and gases can be used. For example, it can be exhaust gas, hot water, steam, etc. Specifically, when the thermoelectric conversion device is installed in the exhaust line of a combustion engine or a combustion device, it can be exhaust gas. In particular, when the thermoelectric conversion device is installed in the exhaust line of an automobile, it can be the exhaust from the engine.

[0020] As shown in FIG. 1B, the outer peripheral wall 11 of the honeycomb structure 10 has one or more planar outer peripheral surfaces, and the thermoelectric conversion module 20 can be disposed on the outer peripheral surface. Here, the outer peripheral surface of the outer peripheral wall 11 means the surface of the outer peripheral wall 11 parallel to the direction in which the cell 14 extends. Since the thermoelectric conversion module 20 is often flat-plate-shaped, the flat-plate-shaped thermoelectric conversion module 20 can be easily arranged face-to-face by the outer peripheral wall 11 of the honeycomb structure 10 having a planar outer peripheral surface. Also, an improvement in heat transfer efficiency can be expected by the face-to-face arrangement. The number of planar outer peripheral surfaces in the outer peripheral wall 11 is not particularly limited as long as it is one or more. However, from the viewpoint of enabling installation of a plurality of thermoelectric conversion modules 20, the outer peripheral wall 11 of the honeycomb structure 10 preferably has a plurality (two or more) of planar outer peripheral surfaces, and more preferably has three or more planar outer peripheral surfaces. When having three or more planar outer peripheral surfaces, for example, the outer shape of the honeycomb structure 10 may be a prismatic shape. In this case, all of the three or more outer peripheral surfaces of the outer peripheral wall 11 can be planar.

[0021] When the honeycomb structure 10 is prismatic, examples of the prism include, but are not limited to, a triangular prism, a quadrangular prism, a pentagonal prism, a hexagonal prism, a heptagonal prism, an octagonal prism, or other prisms. Among these, from the viewpoint of facilitating assembly, it is preferable that the opposing outer peripheral surfaces are parallel to each other, and it is more preferable that the number of outer peripheral surfaces is an even number (for example, 4, 6, 8). Note that FIGS. 1A and 1B show an example in which the outer shape of the honeycomb structure 10 is a regular octagonal prism.

[0022] Further, the outer peripheral wall 11 of the honeycomb structure 10 may have a structure in which a planar outer peripheral surface is formed on a part of the curved outer peripheral surface. Examples of the thermoelectric conversion device including the honeycomb structure 10 having such a structure are shown in FIGS. 2A and 2B. Note that FIGS. 2A and 2B are cross-sectional views orthogonal to the axial direction of the honeycomb structure of the thermoelectric conversion device. The honeycomb structure 10 used in the thermoelectric conversion device shown in FIGS. 2A and 2B has a structure in which a planar outer peripheral surface is formed on a part of the outer peripheral wall 11 of the columnar honeycomb structure 10. By adopting such a structure, the thermoelectric conversion modules 20 can be easily arranged facing each other.

[0023] Furthermore, the outer peripheral wall 11 of the honeycomb structure 10 does not necessarily have a planar outer peripheral surface. That is, the outer peripheral wall 11 of the honeycomb structure 10 may have only a curved outer peripheral surface. Examples of the thermoelectric conversion device including the honeycomb structure 10 having such a structure are shown in FIGS. 3A and 3B. FIGS. 3A and 3B are cross-sectional views perpendicular to the axial direction of the honeycomb structure of the thermoelectric conversion device. The honeycomb structure 10 used in the thermoelectric conversion device shown in FIGS. 3A and 3B is columnar. Note that the honeycomb structure 10 may be elliptical columnar or the like in addition to being columnar. In recent years, since flexible thermoelectric conversion modules 20 have been manufactured and sold, by using such flexible thermoelectric conversion modules 20, the thermoelectric conversion modules 20 can be easily arranged facing each other on the outer peripheral wall 11. Also, by using a columnar honeycomb structure 10, special bases and processing for forming a planar outer peripheral surface are not required, so that the manufacturing cost can be suppressed.

[0024] The shape of the inner peripheral surface of the outer peripheral wall 11 of the honeycomb structure 10 is not particularly limited. For example, the shape of the inner peripheral surface of the outer peripheral wall 11 may be a shape corresponding to the outer peripheral surface of the outer peripheral wall 11, or may be a shape not corresponding to the outer peripheral surface of the outer peripheral wall 11. In FIG. 1B, in a cross-section perpendicular to the axial direction of the honeycomb structure 10, the case where the outer peripheral surface of the outer peripheral wall 11 is a regular octagon and the inner peripheral surface of the outer peripheral wall 11 is a circle is shown as an example. Also, in FIGS. 2A, 2B, 3A, and 3B, the case where the shapes of the outer peripheral surface and the inner peripheral surface of the outer peripheral wall 11 are the same in a cross-section perpendicular to the axial direction of the honeycomb structure 10 is shown.

[0025] Further, although not shown, the honeycomb structure 10 may be a hollow type. In this case, the hollow honeycomb structure 10 has a hollow portion that penetrates from the central portion of the first end face 12 to the central portion of the second end face 13 in a cross section orthogonal to the axial direction of the honeycomb structure 10 and serves as a flow path for the first fluid, and a plurality of cells 14 are arranged on the outer peripheral side of the hollow portion. In addition, an inner cylinder member having a branch path that branches into a path passing through the hollow portion and a path passing through the plurality of cells 14 can be disposed in the hollow portion of the honeycomb structure 10. Further, a flow rate control valve is disposed on one or both of the upstream side of the first end face 12 or the downstream side of the second end face 13 of the honeycomb structure 10, in the middle of one or both of the path passing through the hollow portion and the path passing through the plurality of cells 14, whereby the flow rate ratio of the first fluid passing through the hollow portion and the first fluid passing through the plurality of cells 14 can be adjusted. The flow rate control valve can have any known structure. For example, a gate valve, a butterfly valve, a ball valve, etc. can be used. The flow rate control valve may be manually opened and closed, but can also be automatically opened and closed by an air-type or electric actuator or the like. Further, it may be opened and closed using an actuator (such as a thermo actuator or a thermostat) that utilizes the volume change of a temperature-dependent material (such as wax).

[0026] The shape of the cell 14 in a cross section orthogonal to the axial direction of the honeycomb structure 10 is not particularly limited, and for example, a desired shape may be appropriately selected from among a circular shape, an elliptical shape, a triangular shape, a quadrangular shape, a hexagonal shape, or other polygonal shapes. Note that FIGS. 1B, 2A, 2B, 3A, and 3B show the case where the cross-sectional shape of the cell 14 is a quadrangle. Further, the cell 14 may have a shape surrounded by a partition wall 15 extending in the circumferential direction and a partition wall 15 extending in the radial direction (radial direction). By adopting such a shape, the thermal conductivity in the radial direction can be increased, so that the heat of the fluid flowing through the cell 14 can be efficiently transmitted to the outer peripheral wall 11.

[0027] The outer peripheral wall 11 and the partition wall 15 can be mainly composed of ceramics. "Mainly composed of ceramics" means that the mass ratio of ceramics in the total mass of all components of the outer peripheral wall 11 and the partition wall 15 is 50% by mass or more.

[0028] The porosity of the outer peripheral wall 11 and the partition wall 15 is not particularly limited, but is preferably 10% or less, more preferably 5% or less, and still more preferably 3% or less. The porosity of the outer peripheral wall 11 and the partition wall 15 can also be 0%. By setting the porosity of the outer peripheral wall 11 and the partition wall 15 to 10% or less, the thermal conductivity can be improved.

[0029] The outer peripheral wall 11 and the partition wall 15 preferably contain SiC (silicon carbide) having high thermal conductivity as a main component. "Containing SiC (silicon carbide) as a main component" means that the mass ratio of SiC (silicon carbide) in the total mass of all components of the outer peripheral wall 11 and the partition wall 15 is 50% by mass or more. Examples of such materials include Si-impregnated SiC, (Si + Al)-impregnated SiC, metal composite SiC, recrystallized SiC, Si 3 N 4 , and SiC, etc. Among these, it is preferable to use Si-impregnated SiC and (Si + Al)-impregnated SiC because they can be manufactured at low cost and have high thermal conductivity.

[0030] There is no particular limitation on the cell density (that is, the number of cells per unit area) in the cross section orthogonal to the axial direction of the honeycomb structure 10. The cell density can be appropriately designed, but is preferably in the range of 4 to 320 cells / cm 2 . By setting the cell density to 4 cells / cm 2 or more, the strength of the partition wall 15, and thus the strength of the honeycomb structure 10 itself and the effective GSA (geometric surface area) can be ensured. Also, by setting the cell density to 320 cells / cm 2 or less, an increase in the pressure loss when the fluid flows can be suppressed.

[0031] The isostatic strength of the honeycomb structure 10 is not particularly limited, but is preferably 1 MPa or more, more preferably 5 MPa or more. When the isostatic strength of the honeycomb structure 10 is 1 MPa or more, the durability of the honeycomb structure 10 can be ensured. The upper limit of the isostatic strength of the honeycomb structure 10 is about 100 MPa. The isostatic strength of the honeycomb structure 10 can be measured according to the measurement method of the isostatic fracture strength specified in JASO standard M505-87, which is an automotive standard issued by the Society of Automotive Engineers of Japan.

[0032] The diameter of the honeycomb structure 10 in the cross section orthogonal to the axial direction of the honeycomb structure 10 is not particularly limited, but is preferably 20 to 900 mm, more preferably 30 to 700 mm. By setting the diameter in this way, the thermoelectric conversion efficiency can be improved. In this specification, when the outer shape in the cross section orthogonal to the axial direction of the honeycomb structure 10 is a shape other than a circular shape (for example, a polygon, etc.), the diameter of the maximum inscribed circle inscribed in the outer peripheral surface of the outer peripheral wall 11 of the honeycomb structure 10 is defined as the diameter of the honeycomb structure 10.

[0033] The thickness of the outer peripheral wall 11 of the honeycomb structure 10 is not particularly limited, but is preferably larger than the thickness of the partition wall 15. By adopting such a configuration, it is possible to suppress the honeycomb structure 10 from being damaged by impact or thermal stress. For example, the thickness of the outer peripheral wall 11 is preferably 0.2 mm to 30 mm, more preferably 0.5 mm to 20 mm, and still more preferably 1 mm to 10 mm.

[0034] The thickness of the partition wall 15 of the honeycomb structure 10 may be appropriately designed according to the purpose and is not particularly limited. The thickness of the partition wall 15 is preferably 0.1 to 1 mm, more preferably 0.2 to 0.6 mm. By setting the thickness of the partition wall 15 to 0.1 mm or more, the mechanical strength can be ensured and the honeycomb structure 10 can be prevented from being damaged by impact or thermal stress. Also, by setting the thickness of the partition wall 15 to 1 mm or less, problems such as an increase in the pressure loss of the fluid or a decrease in the thermoelectric conversion efficiency can be suppressed.

[0035] The density of the partition wall 15 is preferably 0.5 to 5 g / cm 3 . By setting the density of the partition wall 15 to 0.5 g / cm 3 or more, the partition wall 15 can have sufficient strength, and damage to the partition wall 15 due to the resistance when the fluid passes through the flow path (inside the cell 14) can be suppressed. Also, by setting the density of the partition wall 15 to 5 g / cm 3 or less, the honeycomb structure 10 can be lightened. By setting the density within the above range, the honeycomb structure 10 can be strengthened, and the effect of improving the thermal conductivity can also be obtained. The density of the partition wall 15 is a value measured by the Archimedes method.

[0036] The thermal conductivity of the honeycomb structure 10 is not particularly limited, but at 25°C, it is preferably 50 W / (m·K) or more, more preferably 100 to 300 W / (m·K), and even more preferably 120 to 300 W / (m·K). By setting the thermal conductivity of the honeycomb structure 10 within such a range, the thermal conductivity becomes good, and the heat inside the honeycomb structure 10 can be efficiently transmitted to the thermoelectric conversion module 20. The value of the thermal conductivity is a value measured by the laser flash method (JIS R1611-1997).

[0037] When exhaust gas from an engine or the like is caused to flow as a fluid through the cells 14 of the honeycomb structure 10, a catalyst may be supported on the partition walls 15 of the honeycomb structure 10. When a catalyst is supported on the partition walls 15, it becomes possible to convert CO, NOx, HC, etc. in the exhaust gas into harmless substances by a catalytic reaction. In addition to this, it becomes possible to use the heat of reaction generated during the catalytic reaction for heat exchange. As the catalyst, it is preferable that it contains at least one kind of element selected from the group consisting of noble metals (platinum, rhodium, palladium, ruthenium, indium, silver, and gold), aluminum, nickel, zirconium, titanium, cerium, cobalt, manganese, zinc, copper, tin, iron, niobium, magnesium, lanthanum, samarium, bismuth, and barium. The above elements may be contained as a simple metal, a metal oxide, and other metal compounds.

[0038] The supported amount of the catalyst (catalyst metal + support) is not particularly limited, but it is preferably 10 to 400 g / L. Also, in the case of a catalyst containing a noble metal, the supported amount is preferably 0.1 to 5 g / L. When the supported amount of the catalyst (catalyst metal + support) is 10 g / L or more, the catalytic action is likely to be exhibited. The support is a carrier on which the catalyst metal is supported. As the support, it is preferable that it contains at least one kind selected from the group consisting of alumina, ceria, and zirconia.

[0039] <Thermoelectric conversion module 20> The thermoelectric conversion module 20 is disposed on the outer peripheral wall 11 of the honeycomb structure 10. The thermoelectric conversion module 20 is an element capable of converting heat into electricity by the Seebeck effect when there is a temperature difference between both surfaces on which the thermoelectric conversion module 20 is disposed. The electricity generated by the thermoelectric conversion module 20 can be supplied to various electronic devices via, for example, an electric wire 21, or stored in a battery. Also, the thermoelectric conversion module 20 may be a component of a sensor module that measures the amount of heat.

[0040] The thermoelectric conversion module 20 is not particularly limited, and a commercially available one can be used. For example, the thermoelectric conversion module 20 has a heat receiving substrate made of insulating ceramics and a heat radiating substrate made of insulating ceramics, and between them, N-type thermoelectric conversion elements and P-type thermoelectric conversion elements that are alternately connected in series via electrodes are arranged. Adjacent thermoelectric conversion modules 20 may be electrically connected via wiring. Since the thermoelectric conversion module 20 having such a structure is generally flat (not flexible), it is arranged on the planar outer peripheral wall 11 (outer peripheral surface) of the honeycomb structure 10. When using the thermoelectric conversion module 20 having such a structure, it is arranged such that the heat receiving substrate is on the honeycomb structure 10 side and the heat radiating substrate is on the heat radiating portion 30 side.

[0041] Also, the thermoelectric conversion module 20 may be flexible. By using the flexible thermoelectric conversion module 20, it can be arranged on the curved outer peripheral wall 11 (outer peripheral surface) of the honeycomb structure 10. Note that the flexible thermoelectric conversion module 20 may also be arranged on the planar outer peripheral wall 11 (outer peripheral surface) of the honeycomb structure 10. The flexible thermoelectric conversion module 20 has, for example, a structure in which thermoelectric element chips (N-type thermoelectric conversion elements and P-type thermoelectric conversion elements) are arranged on a flexible substrate made of a resin film. When using the thermoelectric conversion module 20 having such a structure, it is arranged such that the substrate is on the honeycomb structure 10 side. Note that the shape of the thermoelectric conversion module 20 is not particularly limited as long as it can be arranged on the outer peripheral wall 11 of the honeycomb structure 10.

[0042] The number of thermoelectric conversion modules 20 arranged on the outer peripheral wall 11 of the honeycomb structure 10 may be adjusted according to the size of the thermoelectric conversion module 20, the purpose of using the thermoelectric conversion device, etc., and is not particularly limited. For example, when the main purpose of the thermoelectric conversion device is to store the electricity generated by the thermoelectric conversion module 20 in a battery, it is required to increase the thermoelectric conversion amount. Therefore, it is preferable to arrange as many thermoelectric conversion modules 20 as possible on the outer peripheral wall 11 of the honeycomb structure 10. Specifically, as shown in FIG. 4, the thermoelectric conversion modules 20 may be arranged on the entire outer peripheral wall 11 of the honeycomb structure 10. Note that FIG. 4 is a cross-sectional view perpendicular to the axial direction of the honeycomb structure 10 of the thermoelectric conversion device. In the case of this purpose of use, the number of thermoelectric conversion modules 20 arranged on the outer peripheral wall 11 of the honeycomb structure 10 is typically 1 to 20.

[0043] On the other hand, when the thermoelectric conversion device is used as a sensor for measuring the amount of heat, the number of thermoelectric conversion modules 20 arranged on the outer peripheral wall 11 of the honeycomb structure 10 does not have to be large. That is, as shown in FIG. 1B, etc., the thermoelectric conversion modules 20 may be arranged on a part of the outer peripheral wall 11 of the honeycomb structure 10. In the case of this purpose of use, the number of thermoelectric conversion modules 20 arranged on the outer peripheral wall 11 of the honeycomb structure 10 is typically 1 to 5.

[0044] <Heat dissipation part 30> The heat dissipation part 30 is arranged on the thermoelectric conversion module 20. The heat dissipation part 30 is not particularly limited as long as it can dissipate heat into the air, and known heat dissipation parts can be used. For example, examples of known heat dissipation parts include heat spreaders, heat sinks, heat pipes, vapor chambers, etc. Among these, the heat dissipation part 30 is preferably a heat sink with a simple structure and good heat dissipation performance.

[0045] The heat sink as the heat dissipation part 30 has a plurality of heat dissipation fins. Specifically, the heat sink as the heat dissipation part 30 has a flat part in contact with the thermoelectric conversion module 20 and a plurality of heat dissipation fins arranged on the flat part. The plurality of heat dissipation fins can increase the surface area in contact with air, so the heat dissipation performance is improved. Note that the shape of the heat dissipation fins is not particularly limited and can be various shapes. Further, a fan for forcibly flowing air may be attached to the heat sink as needed.

[0046] The thermoelectric conversion device according to the embodiment of the present invention may further include a cylindrical member fitted to the outer peripheral surface of the outer peripheral wall 11 between the honeycomb structure 10 and the thermoelectric conversion module 20. Here, a cross-sectional view parallel to the axial direction of the honeycomb structure (the direction in which the cells extend) of the thermoelectric conversion device including the cylindrical member is shown in FIG. 5A, and a cross-sectional view taken along line b-b' of the thermoelectric conversion device in FIG. 5A (a cross-sectional view perpendicular to the axial direction of the honeycomb structure) is shown in FIG. 5B. The thermoelectric conversion devices shown in FIGS. 5A and 5B further include a cylindrical member 40 between the honeycomb structure 10 and the thermoelectric conversion module 20. By providing the cylindrical member 40, damage to the honeycomb structure 10 due to external impacts and the like, and the outflow of the fluid flowing through the cells 14 of the honeycomb structure 10 to the outside can be suppressed.

[0047] The cylindrical member 40 is fitted to the outer peripheral surface of the outer peripheral wall 11. Here, "fitted" in this specification means being fixed in a state of fitting with each other. For this reason, fitting includes not only fixing methods by fitting such as clearance fit, interference fit, and shrink fit, but also cases where it is fixed by brazing, welding, diffusion bonding, and the like.

[0048] From the perspective of increasing the thermoelectric conversion efficiency, it is preferable that the ratio of the area of the portion of the outer peripheral surface of the outer peripheral wall 11 circumferentially covered by the cylindrical member 40 to the total area of the outer peripheral surface of the outer peripheral wall 11 is higher. Specifically, it is preferably 80% or more, more preferably 90% or more, and even more preferably 100% (that is, the entire outer peripheral surface of the outer peripheral wall 11 is circumferentially covered by the cylindrical member 40).

[0049] The material of the cylindrical member 40 is not particularly limited as long as the above effects can be achieved, and it can be formed from a metal material, ceramics, etc. Among them, the cylindrical member 40 is preferably composed of a metal material from the perspective of manufacturability (ease of assembly). As the metal material, for example, stainless steel, titanium alloy, copper alloy, aluminum alloy, brass, nickel alloy, steel, lead, lead alloy, etc. can be used, but stainless steel is preferred for the reason of high durability and reliability. Further, from the perspective of improving corrosion resistance, surface treatment such as fluororesin lining or FRP lining may be applied to the cylindrical member 40.

[0050] The thickness of the cylindrical member 40 is preferably 0.1 mm or more, more preferably 0.3 mm or more, and even more preferably 0.5 mm or more from the perspective of durability and reliability. The thickness of the cylindrical member 40 is preferably 50 mm or less, more preferably 40 mm or less, and even more preferably 30 mm or less from the perspective of reducing thermal resistance.

[0051] The thermoelectric conversion device according to the embodiment of the present invention may further include a substance for reducing contact thermal resistance between the thermoelectric conversion module 20 and the honeycomb structure 10 and / or between the thermoelectric conversion module 20 and the heat dissipation part 30. By arranging a substance for reducing contact thermal resistance at such a position, the thermoelectric conversion efficiency can be increased. Examples of the substance for reducing contact thermal resistance include a metal plate, a carbon (graphite) sheet, a thermal sheet, thermal grease, etc. Specific examples of the metal constituting the metal plate include soft metals such as aluminum, copper, and lead, and alloys such as solder.

[0052] The thermoelectric conversion device according to an embodiment of the present invention can be manufactured according to a known method. Hereinafter, a method for manufacturing a thermoelectric conversion device according to an embodiment of the present invention will be exemplarily described. First, a green compact containing ceramic powder is extruded into a desired shape to produce a honeycomb formed body. At this time, by selecting an appropriate form of die and jig, the shape and density of the cell 14, the shape and thickness of the partition wall 15 and the outer peripheral wall 11, etc. can be controlled. Further, as the material of the honeycomb formed body, the above-mentioned ceramics can be used. For example, when manufacturing a honeycomb formed body mainly composed of Si-impregnated SiC, a binder and water or an organic solvent are added to a predetermined amount of SiC powder, the obtained mixture is kneaded to form a green compact, and then molded to obtain a honeycomb formed body having a desired shape. Then, the obtained honeycomb formed body is dried, and the honeycomb structure 10 can be obtained by impregnating and firing metallic Si into the honeycomb formed body in an inert gas or vacuum under reduced pressure. In addition, when forming the outer peripheral wall 11 having one or more planar outer peripheral surfaces, the outer peripheral wall 11 having a predetermined shape may be obtained during extrusion molding, or an outer peripheral coat may be performed after obtaining the cylindrical honeycomb structure 10 to form the outer peripheral wall 11 having a planar outer peripheral surface. Further, after polishing the side surface of the cylindrical honeycomb structure 10 to produce a polygonal columnar honeycomb structure 10, an outer peripheral coat may be performed to form the outer peripheral wall 11 having a planar outer peripheral surface.

[0053] Next, when disposing the cylindrical member 40 between the honeycomb structure 10 and the thermoelectric conversion module 20, the honeycomb structure 10 obtained above is inserted into the cylindrical member 40 and fitted. As the fitting method, the method described above may be used. Next, a desired number of thermoelectric conversion modules 20 are arranged and fixed on the outer peripheral surface of the honeycomb structure 10 (or the cylindrical member 40). The fixing method of the thermoelectric conversion module 20 is not particularly limited. For example, it may be fixed using an adhesive or the like. Further, when a substance for reducing the contact thermal resistance is arranged between the thermoelectric conversion module 20 and the honeycomb structure 10 (or the cylindrical member 40), the substance for reducing the contact thermal resistance may be arranged on the honeycomb structure 10 (or the cylindrical member 40) before arranging and fixing the thermoelectric conversion module 20.

[0054] Next, the heat dissipation part 30 is arranged and fixed on the thermoelectric conversion module 20. The fixing method of the heat dissipation part 30 is not particularly limited. For example, it may be fixed using an adhesive or the like. Further, when a substance for reducing the contact thermal resistance is arranged between the thermoelectric conversion module 20 and the heat dissipation part 30, the substance for reducing the contact thermal resistance may be arranged on the thermoelectric conversion module 20 before arranging and fixing the heat dissipation part 30.

[0055] The thermoelectric conversion device according to the embodiment of the present invention has a simpler structure than before and can reduce the manufacturing cost. Therefore, this thermoelectric conversion device can be used as a heat recovery device that converts thermal energy contained in exhaust gas, hot water, steam, etc. in various factories and exhaust gas of automobiles into electric energy and recovers it. Further, this thermoelectric conversion device can also be used as a sensor that measures the amount of heat by converting thermal energy into electric energy.

Explanation of Signs

[0056] 10 Honeycomb structure 11 Outer peripheral wall 12 First end face 13 Second end face 14 Cell 15 Partition wall 20 Thermoelectric conversion module 21 Electric wire 30 Heat dissipation part 40 Cylindrical member

Claims

1. A honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that serve as fluid flow paths extending from a first end face to a second end face; One or more thermoelectric conversion modules disposed on the outer circumferential wall; and a heat dissipation section that is disposed on the thermoelectric conversion module and is capable of dissipating heat into the air; A thermoelectric conversion device comprising:

2. The thermoelectric conversion device according to claim 1 , wherein the outer peripheral wall has one or more planar outer peripheral surfaces, and the thermoelectric conversion module is disposed on the outer peripheral surfaces.

3. The thermoelectric conversion device of claim 1 , wherein the thermoelectric conversion module is flexible.

4. The thermoelectric conversion device according to any one of claims 1 to 3, further comprising a tubular member fitted to an outer peripheral surface of the outer peripheral wall between the honeycomb structure and the thermoelectric conversion module.

5. The thermoelectric conversion device according to claim 4 , wherein the cylindrical member is made of a metal material.

6. The thermoelectric conversion device according to any one of claims 1 to 3, wherein the heat dissipation portion has a plurality of heat dissipation fins.

7. The thermoelectric conversion device according to any one of claims 1 to 3, further comprising a material that reduces contact thermal resistance between the thermoelectric conversion module and the honeycomb structure and / or between the thermoelectric conversion module and the heat dissipation portion.

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