Thermoelectric power generation device and installation method for the same

Abstract

To provide a thermoelectric power generation device that generates power more efficiently.SOLUTION: A thermoelectric power generation device 1 includes a steam tank 10 into which steam flows, and a thermoelectric conversion module 12 that generates power by a thermoelectric conversion element using the steam flowing into the steam tank 10. The thermoelectric conversion module 12 is in contact with an outer wall surface of the steam tank 10, and an inner wall surface of the steam tank 10 is inclined in a region of the steam tank 10 with which the thermoelectric conversion module 12 is in contact. The thermoelectric power generation device 1 further includes a cooling water tank 14 into which cooling water for cooling the thermoelectric conversion module 12 flows. An outer wall surface of the steam tank 10 with which the thermoelectric conversion module 12 is in contact is a plane, and an angle defined by the outer wall surface of the steam tank 10 in contact with the thermoelectric conversion module 12 and a horizontal plane is less than 90 degrees.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a thermoelectric power generation device and a method for installing the thermoelectric power generation device.

Background Art

[0002] For example, in Patent Document 1, a cooling unit is provided on the low-temperature side of a thermoelectric conversion element, a heating unit for supplying steam of a heat medium is provided on the high-temperature side, and a plurality of thermoelectric power generation units configured to generate power by the temperature difference between the low-temperature side and the high-temperature side are arranged in a matrix direction. A thermoelectric power generation device in which a plurality of thermoelectric conversion elements are connected in a planar shape, wherein the heating unit of the thermoelectric power generation unit is provided along the surface on the high-temperature side of the thermoelectric conversion element, and includes a plate-shaped space member that forms a plate-shaped space inside, and a tubular space that is formed at a position away from the plate-shaped space member and has both open ends connected to communicate with the plate-shaped space, and is composed of a tubular member that is heated by a high-temperature fluid from the outside. A thermoelectric power generation device is disclosed, characterized in that a circulation path for the heat medium filled in the space is formed by the plate-shaped space and the tubular space.

[0003] In addition, Patent Document 2 discloses a thermoelectric power generation device including a thermoelectric conversion module that performs thermoelectric power generation according to the temperature difference between a high-temperature part and a low-temperature part. The device includes an exhaust gas introduction part that introduces exhaust gas discharged from an internal combustion engine into the high-temperature part, and a vapor circulation part that introduces vapor of a refrigerant heated by the heat of the exhaust gas into the low-temperature part. The thermoelectric conversion module is composed of a first thermoelectric conversion module having a high operating temperature range and a second thermoelectric conversion module having an operating temperature range lower than that of the first thermoelectric conversion module. The vapor circulation part is composed of a first vapor circulation part and a second vapor circulation part communicating with the first vapor circulation part. The device further includes a main body case that houses the first thermoelectric conversion module, the exhaust gas introduction part provided on the main body case and facing the high-temperature part of the first thermoelectric conversion module, the first vapor circulation part attached outside the main body case and facing the low-temperature part of the first thermoelectric conversion module, the second vapor circulation part provided on the upper part of the main body case, the second thermoelectric conversion module provided on the upper part of the second vapor circulation part such that the high-temperature part faces the second vapor circulation part, and a cooling water circulation part provided on the upper part of the second thermoelectric conversion module so as to face the low-temperature part of the second thermoelectric conversion module.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a thermoelectric power generation device that generates electricity more efficiently.

Means for Solving the Problems

[0006] The thermoelectric power generation device according to the present invention includes a steam tank into which steam flows, and a thermoelectric conversion module that generates electricity by a thermoelectric conversion element using the steam that has flowed into the steam tank. The thermoelectric conversion module is in contact with the outer wall surface of the steam tank, and in the region of the steam tank with which the thermoelectric conversion module is in contact, the inner wall surface of the steam tank is inclined.

[0007] Preferably, it further includes a cooling water tank into which cooling water for cooling the thermoelectric conversion module flows. The outer wall surface of the steam tank in contact with the thermoelectric conversion module is flat, and the angle formed between the outer wall surface of the steam tank in contact with the thermoelectric conversion module and the horizontal plane is less than 90 degrees.

[0008] Preferably, it further includes a thermoelectric conversion module fixing plate provided with an arrangement hole for arranging the thermoelectric conversion module. The thermoelectric conversion module is arranged in the arrangement hole of the thermoelectric conversion module fixing plate laminated on the steam tank.

[0009] Preferably, the thermoelectric conversion module fixing plate further has a plurality of protrusions for fixing the thermoelectric conversion module fixing plate on the steam tank, and the thermoelectric conversion module fixing plate is supported by the plurality of protrusions.

[0010] Preferably, it further includes a steam shielding plate for blocking the flow path of the steam in the steam tank. The steam shielding plate is installed on the downstream side of the flow path of the steam in the steam tank, and the steam shielding plate is provided with an opening as the flow path of the drain water flowing in the steam tank.

[0011] Preferably, the steam tank has a tubular structure with a square cross-section, and the thermoelectric conversion module and the cooling water tank are respectively laminated on adjacent side surfaces in the long side direction of the steam tank.

[0012] The installation method of the thermoelectric power generation device according to the present invention includes a stacking step of stacking a thermoelectric conversion module that generates power by a thermoelectric conversion element using the steam flowing into a steam tank into which steam flows, and an inclination step of inclining the surface on which the steam tank and the thermoelectric conversion module are stacked with respect to a horizontal plane. In the stacking step, the thermoelectric conversion module is stacked in contact with the outer wall surface of the steam tank, which is a flat surface. In the inclination step, in the region of the outer wall surface of the steam tank that contacts the thermoelectric conversion module, the inner wall surface of the steam tank is inclined at an angle less than 90 degrees with respect to the horizontal plane.

Effect of the Invention

[0013] According to the present invention, power generation can be performed more efficiently.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0015] First, the background of the present invention will be described. As illustrated in FIG. 1(a), conventional thermoelectric power generation devices had a structure in which a unit, which is an assembly of a cooling water tank and a thermoelectric conversion module, was inserted into a steam tank. The thermoelectric power generation device 1 in the present invention was changed from the conventional structure to the structure illustrated in FIG. 1(b), in which the thermoelectric conversion module 12 and the cooling water tank 14 are laminated in the steam tank 10, enabling cost reduction and miniaturization compared to conventional thermoelectric power generation devices.

[0016] Hereinafter, embodiments according to the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the illustrated examples. The thermoelectric power generation device 1 is a power generation device that utilizes the heat of steam generated in production facilities such as industrial wastewater to extract electric power generated by creating a temperature difference on both sides of a thermoelectric conversion module. As illustrated in FIG. 1(b), the thermoelectric power generation device 1 includes a steam tank 10, a thermoelectric conversion module 12, and a cooling water tank 14. The thermoelectric power generation device 1 is arranged such that the steam tank 10 is thermally in contact with one side surface of the thermoelectric conversion module 12 and the cooling water tank 14 is thermally in contact with the other side surface. Specifically, in the thermoelectric power generation device 1, the thermoelectric conversion module 12 is sandwiched between the steam tank 10 and the cooling water tank 14, and the steam tank 10, the thermoelectric conversion module 12, and the cooling water tank 14 are laminated in this order. The thermoelectric power generation device 1 generates electricity when the heat of the steam flowing into the steam tank 10 causes one side surface of the thermoelectric conversion module 12 to become high temperature and the other side surface of the thermoelectric conversion module 12 to be cooled by the cooling water tank 14 and become low temperature. Note that the thermoelectric power generation device 1 uses steam in an atmospheric pressure atmosphere.

[0017] FIG. 2(a) is a front view of the thermoelectric power generation device 1, and (b) is a cross-sectional view taken along line A - A of the thermoelectric power generation device 1. As illustrated in Fig. 2(a), the steam tank 10 is a flow path for high-temperature steam and has a steam inlet 100 which is an inlet for steam, a steam outlet 102 which is an exhaust port for steam, and a drain outlet 104 which is an outlet for drain water. The steam tank 10 has a tubular structure with a square cross-section. Inside the steam tank 10, the high-temperature steam flowing in from the steam inlet 100 passes through the upper part of the steam tank 10 as a flow path and is exhausted from the steam outlet 102. Also, the drain water formed by the high-temperature steam flowing in from the steam inlet 100 being cooled and condensed flows out of the steam tank 10 from the drain outlet 104 through the lower part of the steam tank 10 as a flow path. The steam tank 10 is composed of a metal plate, preferably stainless steel. Specifically, for the steam tank 10, stainless steel mainly composed of chromium and nickel is used, which is excellent in heat resistance and corrosion resistance. SUS304 is used for the steam tank 10 in this example. The thermoelectric conversion module 12 is laminated on the outer wall surface which is a plane of the steam tank 10. Specifically, as illustrated in Fig. 2(b), the thermoelectric conversion module 12 is arranged on two adjacent side surfaces of the tubular structure with a square cross-section of the steam tank 10. Also, in the region of the steam tank 10 where the thermoelectric conversion module 12 is in contact, the inner wall surface is inclined.

[0018] The thermoelectric conversion module 12 is in contact with the outer wall surface of the steam tank 10. Specifically, the thermoelectric conversion module 12 is located between the steam tank 10 and the cooling water tank 14 and is arranged in a state of being thermally in contact with both the steam tank 10 and the cooling water tank 14. More specifically, the thermoelectric conversion module 12 is arranged with one surface in contact with the steam tank 10 and the other surface of the thermoelectric conversion module 12 in contact with the cooling water tank 14. The surface of the thermoelectric conversion module 12 in contact with the cooling water tank 14 is the low-temperature side, and the surface in contact with the steam tank 10 is the high-temperature side. The thermoelectric conversion module 12 is a module in which a plurality of thermoelectric conversion elements that generate electricity by thermoelectric conversion elements and mutually convert heat and electrical energy are arranged on a substrate, and the arranged thermoelectric conversion elements are electrically connected. The thermoelectric conversion module 12 may be a bismuth telluride (Bi-Te) system, a lead telluride (Pb-Te) system, a magnesium system (Mg-Si system, Mg-Si-Sn system, Mg-Ag-Sb system), a silicide system (Mn-Si, Fe-Si), or a silicon germanium (Si-Ge) system thermoelectric conversion element as long as it is a module including a thermoelectric conversion element that enables power generation using a temperature difference.

[0019] The cooling water tank 14 is a flow path for cooling water that is laminated so as to contact the other surface of the thermoelectric conversion module 12 that is in contact with the steam tank 10 and through which a medium for cooling the thermoelectric conversion module 12 passes. The cooling water tank 14 has a tubular structure with a square cross-section and has a cooling water inlet 140 that is an inlet for cooling water and a cooling water outlet 142 that is an outlet for cooling water. In the cooling water tank 14, cooling water flows from the cooling water inlet 140 toward the cooling water outlet 142 inside the cooling water tank 14. That is, the cooling water flowing through the cooling water tank 14 cools the low-temperature side surface of the thermoelectric conversion module 12 with which the cooling water tank 14 is in contact and is then discharged from the cooling water outlet 142. Here, the cooling medium may be a liquid or a gas. In the case of a liquid, it is cooling water (water), and in the case of a gas, it is air. Note that the cooling medium in this example is liquid cooling water. The cooling water tank 14 is composed of a metal plate, like the steam tank 10, and preferably stainless steel, and is excellent in heat resistance and corrosion resistance. SUS304 is used for the cooling water tank 14 in this example.

[0020] Figure 3 is a diagram illustrating a method of installing the thermoelectric power generation device 1. As illustrated in FIG. 3(a), when the thermoelectric power generation device 1 is installed such that the surface of the steam tank 10 on which the thermoelectric conversion modules 12 are stacked is parallel to the horizontal plane h, droplets of drain water formed by the condensation of steam remain on the side surface 10a that serves as the ceiling surface inside the steam tank 10, impeding the condensation of the steam and inhibiting heat transfer to the thermoelectric conversion modules 12. Further, on the side surface 10b inside the steam tank 10, heat is transferred from the drain water rather than the steam to the thermoelectric conversion modules 12, resulting in a decrease in the amount of heat transfer and a reduction in the power generation amount. Therefore, as illustrated in FIG. 3(b), the thermoelectric power generation device 1 is installed in an inclined manner so that the two side surfaces (side surface 10a and side surface 10b) on which the thermoelectric conversion modules 12 are disposed do not come into contact with the drain water stored at the lower part of the steam tank 10. Specifically, the thermoelectric power generation device 1 is inclined at an inclination angle X with respect to the horizontal plane h. In this example, the inclination angle X is 45 degrees. By installing the thermoelectric power generation device 1 in an inclined manner, the droplets slide along the inner wall surface of the steam tank 10 on which the thermoelectric conversion modules 12 are stacked and fall to the lower part of the inclined steam tank 10. This prevents the droplets from remaining on the inner wall surface of the steam tank 10 and inhibits heat transfer from being impeded. Further, by being installed in an inclined manner, the drain water accumulates in the lower part of the inclined steam tank 10, and since the drain water does not come into contact with the side surfaces 10a and 10b on which the thermoelectric conversion modules 12 are stacked, heat from the steam rather than the drain water is transferred to the thermoelectric conversion modules 12, preventing a reduction in the power generation amount. Although the inclination angle X of the thermoelectric power generation device 1 in this example is 45 degrees, the inclination angle X is not limited to this as long as it is an angle at which the drain water can smoothly move along the inner wall surface of the steam tank 10 in which the thermoelectric conversion modules 12 are stacked and reach the lower part of the steam tank 10. Further, since the droplets of drain water travel along the inner wall surface of the steam tank 10, it is desirable that the inner wall surface of the steam tank 10 be a smooth surface without irregularities.

[0021] FIG. 4 is a diagram illustrating a thermoelectric conversion module fixing plate 16 for fixing the thermoelectric conversion modules 12 to the steam tank 10. The position of the thermoelectric conversion module 12 disposed on the steam tank 10 is fixed by the thermoelectric conversion module fixing plate 16. As illustrated in FIGS. 4(a) and (b), the thermoelectric conversion module fixing plate 16 is a plate-shaped member, and a plurality of arrangement holes 160, which are rectangular through-holes for arranging the thermoelectric conversion module 12, are provided. Specifically, the arrangement holes 160 are provided at equal intervals in the longitudinal direction of the thermoelectric conversion module fixing plate 16. The thermoelectric conversion module fixing plate 16 in this example has 5 to 8 arrangement holes 160, and the thermoelectric power generation device 1 has 5 to 8 thermoelectric conversion modules 12 arranged in the arrangement holes 160. The thermoelectric conversion module fixing plate 16 is placed on the steam tank 10, the thermoelectric conversion module 12 is arranged in the arrangement hole 160 of the thermoelectric conversion module fixing plate 16, and the mounting surface of the thermoelectric conversion module 12 arranged in the arrangement hole 160 is in contact with and fixed to the steam tank 10. Also, as illustrated in FIG. 4(c), the thickness of the thermoelectric conversion module fixing plate 16 is thinner than the thickness of the substrate of the thermoelectric conversion module 12. Specifically, it is about 0.5 mm to 1 mm thick. By making the thickness thinner than that of the substrate of the thermoelectric conversion module 12, it is possible to prevent the power generation amount from decreasing due to heat transfer from the steam tank 10 to the thermoelectric conversion module fixing plate 16. By arranging the thermoelectric conversion module 12 on the thermoelectric conversion module fixing plate 16, it is possible to prevent the displacement of the position of the thermoelectric conversion module 12 on the steam tank 10 and realize efficient power generation.

[0022] In this example, the material of the thermoelectric conversion module fixing plate 16 is the same SUS304 as that of the steam tank 10 and the cooling water tank 14. This is because when using a metal different from that of the steam tank 10 and the cooling water tank 14, there is a risk of electrolytic corrosion and the cost may increase, so the same material as that of the steam tank 10 and the cooling water tank 14 is used. However, it is not limited to this. As long as the material has poor heat conduction from the steam tank 10 and does not cause a shape change at 100 °C because the temperature of the steam tank 10 reaches 100 °C, and does not cause electrolytic corrosion, for example, rubber or plastic may be used.

[0023] Next, the protrusion 106 for preventing displacement of the thermoelectric conversion module fixing plate 16 placed on the steam tank 10 will be described. The steam tank 10 has a plurality of protruding members, the protrusions 106, which are fixed to the steam tank 10. As illustrated in FIGS. 4(b) and (c), the protrusions 106 are fixed by welding to the steam tank 10. Specifically, the protrusions 106 include a protrusion 106a that supports the short side direction of the thermoelectric conversion module fixing plate 16 placed on the steam tank 10 and a protrusion 106b that supports the long side direction. The height of the protrusion 106 reaches the cooling water tank 14 laminated on the thermoelectric conversion module 12, supports the thermoelectric conversion module fixing plate 16 with the cooling water tank 14 interposed therebetween, prevents displacement of the thermoelectric conversion module fixing plate 16, and also prevents displacement of the cooling water tank 14. The protrusion 106 is made of stainless steel, like the steam tank 10, and in this example, SUS304 is used.

[0024] FIG. 5 is a diagram for explaining the steam shielding plate 108 provided in the steam tank 10. The steam that has flowed into the steam tank 10 passes through the upper part of the steam tank 10 and is discharged from the steam exhaust port 102, and the drain water passes through the lower part of the steam tank 10 and is discharged from the drain water outlet 104. At this time, if the pressure of the steam flowing into the steam tank 10 is high, the introduced steam does not contact the inner wall surface on the side of the thermoelectric conversion module 12 in the steam tank 10, passes through, and escapes to the outside through the steam exhaust port 102 and the drain water outlet 104, and sufficient power generation does not occur. Therefore, the thermoelectric power generation device 1 prevents the passage of steam by the steam shielding plate 108 in the steam tank 10. The steam shielding plate 108 is a plate-shaped metal that blocks the steam flow path. Specifically, as illustrated in FIG. 5(a), it is installed on the downstream side of the steam flow path and in front of the steam exhaust port 102 in the steam flow path. By being installed at this position, the steam that passes through the upper part of the steam tank 10 and flows to the steam exhaust port 102 has its flow path blocked by the steam shielding plate 108, the steam undergoes convection, stays in the steam tank 10 for a longer time, and can efficiently transfer heat to the thermoelectric conversion module 12.

[0025] In addition, the steam shielding plate 108 is installed to cover the square cross-section of the steam tank 10 while securing a flow path for the drain water. Specifically, as illustrated in FIG. 5(b), the steam shielding plate 108 has substantially the same shape as the square shape of the cross-section of the steam tank 10 and is provided with an opening in part. The area of the opening is larger than the opening of the drain water outlet 104. When the amount of drain water to be discharged is large, if the opening of the steam shielding plate 108 is small, the steam shielding plate 108 may block the discharge of the drain water, and there is a risk that the drain water will be clogged. To avoid this, the opening of the steam shielding plate 108 is made larger than the drain water outlet 104. In addition, the steam drain that flows in the steam tank 10 in a state where the vapor of the gas and the drain water of the liquid are mixed can be vapor-liquid separated by the steam shielding plate 108 into the steam that flows in the upper part of the steam tank 10 and the drain water that flows in the lower part of the steam tank 10.

[0026] Next, in the inclined thermoelectric power generation device 1, the installation positions of the steam inlet 100, the steam exhaust port 102, and the cooling water outlet 142 will be described. As illustrated in FIG. 6(a), the drain water outlet 104 is a cylindrical opening provided on the side surface in the short side direction of the steam tank 10 on the downstream side of the steam flow path in the steam tank 10. Further, the drain water outlet 104 is provided below the center of the side surface in the short side direction of the inclined steam tank 10 so that the drain water flowing through the lower part of the steam tank 10 can be easily discharged in the inclined thermoelectric power generation device 1. In addition, as illustrated in FIG. 6(b), the steam inlet 100 is an inlet for steam flowing into the steam tank 10 and is provided on the other side surface in the short side direction of the steam tank 10 of the surface where the drain water outlet 104 is provided. The steam inlet 100 is a cylindrical opening provided at the center of the side surface of the steam tank 10. Furthermore, the installation position of the steam inlet 100 may be provided at the upper part of the side surface in the short side direction in the inclined steam tank 10. Thereby, when steam with high pressure flows into the steam inlet 100, the steam is likely to hit the steam shielding plate 108, and it is possible to prevent the steam from escaping. Then, as illustrated in FIG. 6(a), the steam exhaust port 102, which is the steam exhaust port of the steam tank 10, is a cylindrical opening provided on the downstream side in the steam flow path within the steam tank 10. In this example, so that steam can be easily exhausted, in the inclined steam tank 10, an opening in the direction opposite to the gravitational direction is provided on the downstream side of the steam flow path between the side surface 10a and the side surface 10b on the steam tank 10.

[0027] As described above, according to the thermoelectric power generation device 1 in the present embodiment, by separating the steam tank 10 and the cooling water tank 14 and sandwiching the thermoelectric conversion module 12 therebetween, miniaturization of the thermoelectric power generation device is achieved. Further, by installing the thermoelectric power generation device 1 having a laminated structure of the steam tank 10, the thermoelectric conversion module 12, and the cooling water tank 14 in an inclined manner, droplets do not remain on the wall surface within the steam tank 10 and slide down to the drain water flow path, enabling efficient heat transfer to the thermoelectric conversion module 12. Furthermore, in order to realize the thermoelectric conversion module fixing plate 16 and the protrusion 106, which are configurations for maintaining the laminated structure, with a simple structure, cost reduction is made possible. Also, the thermoelectric power generation device 1 provides efficient heat transfer to the thermoelectric conversion module 12 by providing the steam shielding plate 108 in consideration of the steam pressure and flow path, or by providing an opening in the steam shielding plate 108 to secure a flow path for the drain water.

Explanation of Reference Numerals

[0028] 1... Thermoelectric power generation device 10... Steam tank 12... Thermoelectric conversion module 14... Cooling water tank 16... Thermoelectric conversion module fixing plate 100... Steam inlet 102... Steam exhaust port 104... Drain water outlet 106... Protrusion 108... Steam shielding plate 140... Cooling water inlet 142... Cooling water outlet 160... Arrangement hole

Claims

1. A steam tank into which steam flows, a thermoelectric conversion module that generates electricity by a thermoelectric conversion element using the steam that has flowed into the steam tank, and having, the thermoelectric conversion module is in contact with the outer wall surface of the steam tank, in the region of the steam tank with which the thermoelectric conversion module is in contact, the inner wall surface of the steam tank is inclined, A thermoelectric power generation device.

2. A cooling water tank into which cooling water for cooling the thermoelectric conversion module flows, further having, the outer wall surface of the steam tank with which the thermoelectric conversion module is in contact is flat, the angle formed by the outer wall surface of the steam tank in contact with the thermoelectric conversion module and the horizontal plane is less than 90 degrees, The thermoelectric power generation device according to claim 1.

3. A thermoelectric conversion module fixing plate provided with an arrangement hole for arranging the thermoelectric conversion module, further having, the thermoelectric conversion module is arranged in the arrangement hole of the thermoelectric conversion module fixing plate laminated on the steam tank, The thermoelectric power generation device according to claim 1.

4. A plurality of protrusions for fixing the thermoelectric conversion module fixing plate on the steam tank, further having, the thermoelectric conversion module fixing plate is supported by the plurality of protrusions, The thermoelectric power generation device according to claim 3.

5. A steam shielding plate for blocking the flow path of steam in the steam tank, further having, the steam shielding plate is installed on the downstream side of the flow path of steam in the steam tank, the steam shielding plate is provided with an opening as the flow path of drain water flowing in the steam tank, The thermoelectric power generation device according to claim 1.

6. the steam tank has a tubular structure with a square cross section, the thermoelectric conversion module and the cooling water tank are respectively laminated on adjacent side surfaces in the long side direction of the steam tank, The thermoelectric power generation device according to claim 1.

7. A lamination step of laminating a thermoelectric conversion module that generates electricity by a thermoelectric conversion element using the steam flowing into the steam tank on the steam tank into which the steam flows, an inclination step of inclining the surface on which the steam tank and the thermoelectric conversion module are laminated with respect to the horizontal plane, and having, in the step of laminating, the thermoelectric conversion module is laminated in contact with the flat outer wall surface of the steam tank, in the inclination step, in the region of the outer wall surface of the steam tank in contact with the thermoelectric conversion module, the inner wall surface of the steam tank is inclined with respect to the horizontal plane by less than 90 degrees, A method for installing a thermoelectric power generation device.

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