Tube-type heat exchanger with thermoelectric power generation function

Abstract

This tubular heat exchanger with a thermoelectric power generation function comprises: a thermoelectric power generation module 2 that is mounted on the outer peripheral surface of an exhaust heat tube 1; and a cooling pipe 3 that is mounted on the outer peripheral surface of the thermoelectric power generation module 2 and through which coolant flows. The thermoelectric power generation module 2 generates thermoelectric power using the outer peripheral surface of the exhaust heat tube 1 as a high temperature source and the inner peripheral surface of the cooling pipe 3 as a low temperature source. The cooling pipe 3 is in close contact with the outer peripheral surface of the thermoelectric power generation module 2.

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger having a function of generating thermoelectric power using heat from a heat exhaust tube. [Background technology]

[0002] In modern industrial society, a huge amount of waste heat, more than 60% of the total primary energy supply, is emitted into the global environment, particularly from factories, power plants, steel mills, automobiles, buildings, lighting, ships, etc. It is estimated that more than 75% of this waste heat is discharged as wastewater or exhaust at temperatures below 250°C.

[0003] This waste heat is generally transported through a heat exhaust tube. In a tubular heat exchanger, which exchanges the heat of high-temperature gas flowing inside the heat exhaust tube with cold water flowing outside the tube, the high-temperature gas can be cooled, but it is difficult to reuse the heat exchanged with the cold water, which is an issue in terms of energy conservation.

[0004] Patent Document 1 discloses a tubular heat exchanger with a thermoelectric power generation function, in which a flexible thermoelectric power generation module 110 is attached between the outside of a drainage pipe 100 through which high-temperature gas 100A and the like flows and a cooling water pipe 120 through which cooling water 120A flows, as shown in Figure 4, and generates electricity by utilizing the temperature difference. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-267316 Summary of the Invention [Problem to be solved by the invention]

[0006] In the tubular heat exchanger with thermoelectric power generation function disclosed in Patent Document 1, the thermoelectric power generation module 110 is directly water-cooled, so it is necessary to provide a waterproofing means, such as a waterproof sheet, on the outside of the thermoelectric power generation module 110. However, providing a waterproofing means such as a waterproof sheet causes heat loss, which causes a problem of reducing the power generation efficiency of the thermoelectric power generation module 110.

[0007] The present invention has been made in view of the above points, and its main object is to provide a tubular heat exchanger with a thermoelectric power generation function that has little heat loss and high power generation efficiency. [Means for solving the problem]

[0008] The tubular heat exchanger with thermoelectric power generation function according to the present invention comprises a thermoelectric power generation module attached to the outer surface of a heat exhaust tube, and a cooling pipe attached to the outer surface of the thermoelectric power generation module and through which a coolant flows. The thermoelectric power generation module generates thermoelectric power using the outer surface of the heat exhaust tube as a high-temperature source and the inner surface of the cooling pipe as a low-temperature source, and the cooling pipe is in close contact with the outer surface of the thermoelectric power generation module. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a tubular heat exchanger with a thermoelectric power generation function that has little heat loss and high power generation efficiency. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is an external perspective view showing the configuration of a tubular heat exchanger with a thermoelectric power generation function according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the tubular heat exchanger with thermoelectric power generation function shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view of a tube-type heat exchanger with a thermoelectric power generation function according to a modified example of the present invention. [Figure 4] FIG. 4 is a perspective view of the appearance of a conventional tubular heat exchanger with a thermoelectric power generation function. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the following embodiment. Furthermore, appropriate modifications are possible within the scope of the effects of the present invention.

[0012] 1 and 2 are diagrams showing the schematic configuration of a tubular heat exchanger with a thermoelectric power generation function (hereinafter simply referred to as "heat exchanger") according to one embodiment of the present invention. FIG. 1 is an external perspective view of the heat exchanger, with some parts removed to reveal the internal structure. FIG. 2 is a cross-sectional view perpendicular to the axial direction of the heat exchanger. Here, "axial direction" refers to the direction of the central axis of the heat exhaust tube 1.

[0013] 1 and 2, the tubular heat exchanger of this embodiment includes a flexible thermoelectric power generation module 2 attached to the outer peripheral surface of a heat exhaust tube 1, and a cooling pipe 3 attached to the outer peripheral surface of the thermoelectric power generation module 2 and through which a coolant 4, such as cooling water, flows. The thermoelectric power generation module 2 generates thermoelectric power using the outer peripheral surface of the heat exhaust tube 1 as a high-temperature source and the inner peripheral surface of the cooling pipe 3 as a low-temperature source.

[0014] The thermoelectric power generation module 2 has a gap 8 extending along the axial direction in a portion of its circumferential direction. The cooling pipe 3 is a double cooling pipe consisting of an inner pipe 3a and an outer pipe 3b. The inner pipe 3a and the outer pipe 3b are welded at their axial ends. Reference numeral 5 in the figure indicates the welded portion. Alternatively, the axial ends of the inner pipe 3a and the outer pipe 3b may be sealed with resin 6.

[0015] The inner pipe 3a is tightly wound around the outer circumferential surface of the thermoelectric power generation module 2. This means that the cooling pipe 3 is tightly attached to the outer circumferential surface of the thermoelectric power generation module 2. As a result, heat loss in the thermoelectric power generation module 2 is reduced and the temperature difference can be increased, thereby increasing the power generation efficiency.

[0016] Both circumferential ends of the inner pipe 3a are welded along the axial direction at the position of the gap 8. This makes it possible to avoid adverse effects on the thermoelectric power generation module 2 due to heat generated when welding the inner pipe 3a.

[0017] For example, when three 10 cm square thermoelectric power generation modules 2 are wrapped around a heat exhaust tube 1 with an outer circumference of 34 cm, a gap 8 of 3 cm is created. An inner tube 3a made of a 0.1 mm thick stainless steel plate is tightly wrapped around the outer circumference of the thermoelectric power generation module 2, and laser welding is performed above the gap 8. An outer tube 3b made of a 0.1 mm thick stainless steel plate is wrapped around the outer circumference of the inner tube 3a with a gap of 2 cm, or an existing tube is inserted, and the axial ends of the inner tube 3a and outer tube 3b are welded or resin sealed. This forms a double cooling pipe 3.

[0018] According to this embodiment, a tubular heat exchanger with a thermoelectric power generation function can be realized, which has little heat loss and high power generation efficiency. Furthermore, when the cooling pipe 3 is configured as a double cooling pipe consisting of an inner pipe 3a and an outer pipe 3b, by welding both wound ends of the inner pipe 3a at the positions of the gaps 8 provided in the thermoelectric power generation module 2, it is possible to prevent adverse effects on the thermoelectric power generation module 2 caused by heat generated when welding the inner pipe 3a.

[0019] Although the present invention has been described above with reference to preferred embodiments, such description is not intended to be limiting and various modifications are possible.

[0020] For example, the thermoelectric power generation module 2 may be attached to the outer peripheral surface of the heat exhaust tube 1 by inserting a heat dissipation sheet (not shown). Furthermore, as shown in FIG. 2, a heat transfer sheet 7 may be provided between the thermoelectric power generation module 2 and the cooling pipe 3. This further reduces heat loss associated with the attachment of the thermoelectric power generation module from the heat exhaust tube 1 to the cooling pipe 3. As a result, the temperature difference in the thermoelectric power generation module 2 can be further increased, thereby further increasing power generation efficiency.

[0021] The heat dissipation sheet can be, for example, a silicone sheet with a thermal conductivity of 10 W / mK and a thickness of 0.1 mm. The heat transfer sheet 7 can be, for example, a flexible carbon sheet with a thermal conductivity of 30 W / mK and a thickness of 0.1 mm. Alternatively, a flexible porous metal film, a metal-plated fabric, or the like can be used as the heat transfer sheet 7. The heat dissipation sheet and heat transfer sheet 7 also function as cushioning materials for the thermoelectric power generation module 2 when the thermoelectric power generation module 2 is attached and the inner tube 3a is tightly wrapped around it.

[0022] 3, the thermoelectric power generation module 2 may be attached by inserting a heat collector 9 into the outer peripheral surface of the heat exhaust tube 1. This improves the efficiency of heat collection from the heat exhaust tube 1, and further increases the temperature at the high-temperature source of the thermoelectric power generation module. As a result, the temperature difference in the thermoelectric power generation module 2 can be further increased, thereby further increasing the power generation efficiency. The heat collector 9 can be, for example, a copper plate with a thickness of 0.2 mm.

[0023] Alternatively, the thermoelectric power generation module 2 may be attached to the outer circumferential surface of the heat exhaust tube 1 by inserting a heat transfer sheet therebetween. The heat transfer sheet may be, for example, a flexible carbon sheet with a thermal conductivity of 30 W / mK and a thickness of 0.1 mm. The heat collector 9 and the heat transfer sheet may be used together. [Explanation of symbols]

[0024] 1 Heat exhaust tube 2 Thermoelectric power generation module 3 Cooling pipe 3a inner tube 3b Outer tube 5 Welded parts 4 Coolant 6. Resin 7. Heat transfer sheet 8 Gap 9 Heat collector

Claims

1. a thermoelectric power generation module attached to an outer peripheral surface of the heat exhaust tube; a cooling pipe attached to the outer peripheral surface of the thermoelectric power generation module through which a coolant flows; A tube-type heat exchanger comprising: the thermoelectric power generation module generates thermoelectric power using an outer circumferential surface of the heat exhaust tube as a high temperature source and an inner circumferential surface of the cooling tube as a low temperature source; The thermoelectric power generation module has a gap extending along an axial direction in a part of a circumferential direction, The cooling pipe is a double cooling pipe consisting of an inner pipe and an outer pipe, the inner tube is wound around an outer circumferential surface of the thermoelectric power generation module, Both circumferential winding ends of the inner pipe are welded along the axial direction at the position of the gap, The inner tube is in close contact with the outer circumferential surface of the thermoelectric power generation module, forming a tubular heat exchanger with a thermoelectric power generation function.

2. 2. The tubular heat exchanger with thermoelectric power generation function according to claim 1, further comprising a heat transfer sheet provided between an outer circumferential surface of the thermoelectric power generation module and an inner circumferential surface of the cooling pipe.

3. 3. The tubular heat exchanger with thermoelectric generating function according to claim 2, wherein the heat transfer sheet is made of a flexible porous metal film.

4. 3. The tubular heat exchanger with thermoelectric power generation function according to claim 2, wherein the heat transfer sheet is made of a metal-plated woven fabric.

5. 3. The tubular heat exchanger with thermoelectric power generation function according to claim 2, wherein the heat transfer sheet is made of a flexible carbon sheet.

6. 3. The tubular heat exchanger with thermoelectric power generation function according to claim 1, further comprising a heat collector provided between an outer circumferential surface of the heat exhaust tube and an inner circumferential surface of the thermoelectric power generation module.

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