JP2015138792A - Thermoelectric conversion power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoelectric conversion power generator in which damage on a thermoelectric conversion element can be suppressed effectively, by reducing a stress applied to the thermoelectric conversion element, while holding enhancement of power generation efficiency by a fin in a tube body.SOLUTION: In a power generator generating power by providing a cooling jacket 3 on the outer surface side of a tube body 25, disposing a thermoelectric conversion module 4 while sandwiching between the main plate 251 of the tube body 25 and the cooling jacket 3, and then giving a temperature difference to the thermoelectric conversion module 4 by means of the tube body 25 heated by heating fluid H and the cooling jacket 3, a heat collection fin 7 disposed in the tube body 253 has flexibility and less likely to give rigidity to the main plate 251, and the main plate 251 is deformable and less likely to damage the thermoelectric conversion element 41 of the thermoelectric conversion module 4.

Description

  The present invention relates to a thermoelectric power generation apparatus that converts a thermal energy into an electrical energy by giving a temperature difference to a thermoelectric conversion module.

  A power generation technique for converting thermal energy into electrical energy using a thermoelectric conversion element is known. The thermoelectric conversion element uses a Seebeck effect that causes a potential difference between a high temperature part and a low temperature part by giving a temperature difference to a separated part, and the power generation amount increases as the temperature difference increases. Such a thermoelectric conversion element is used in the form of a thermoelectric conversion element module in which a plurality are joined by electrodes. For example, by laminating a thermoelectric conversion module and a cooling part on the outer surface of the pipe body and introducing a heating fluid into the pipe body, the space between the heated pipe body (high temperature part) and the cooling part (low temperature part) 2. Description of the Related Art A thermoelectric conversion power generator having a configuration in which electricity is extracted by causing a temperature difference in a thermoelectric conversion module sandwiched between two is known (Patent Document 1).

JP 2006-217756 A

  In the thermoelectric conversion power generation device having the above configuration, the fin is joined to the inner surface of the tubular body, the heat of the heating fluid is collected by the fin and transferred to the tubular body, and the temperature of the high temperature part is further increased, Power generation efficiency is improved. By the way, the thermal stress by a thermal expansion difference arises in the thermoelectric conversion element of the thermoelectric conversion module to which a temperature difference is given by a high temperature part and a low temperature part. Since the thermoelectric conversion element is joined to the tubular body via the high temperature side electrode, the thermal stress generated in the thermoelectric conversion element is transmitted to the tubular body and tries to deform the tubular body. However, the tube body is hard to be deformed because the rigidity is increased by the fins being joined, and therefore, the thermoelectric conversion element receives stress from the tube body, and as a result, the thermoelectric conversion element In some cases, cracks or breakage occurred.

  The present invention has been made in view of the above circumstances, and the main problem is that while maintaining the improvement in power generation efficiency by the fins inside the tube body, the stress applied to the thermoelectric conversion element is reduced to effectively damage the thermoelectric conversion element. An object of the present invention is to provide a thermoelectric conversion power generation device that can be suppressed.

  The thermoelectric conversion power generation device of the present invention includes at least a pair of opposed heating plates on one side and the other side, a tubular body through which a heating fluid that heats the heating plate is flowed, and the heating plate A cooling unit disposed on the outer surface side, a thermoelectric conversion module having a thermoelectric conversion element disposed between the heating plate unit and the cooling unit, and disposed in the tube, the heating fluid In the thermoelectric conversion power generator that generates power when a temperature difference is given to the thermoelectric conversion module by the heating plate portion and the cooling portion, the fin includes: And a flexible portion that is joined to the pair of heating plate portions and allows the pair of heating plate portions to be deformed in the joined state.

  In the present invention, the heating plate portion is heated by the heating fluid flowing inside the tube, and the heat is transferred to the inner surface side (tube body side) of the thermoelectric conversion module and heated. On the other hand, the outer surface side of the thermoelectric conversion module is cooled by the cooling unit, thereby generating a temperature difference in the thermoelectric conversion module and generating power. The heat of the heating fluid flowing inside the tube is collected by the fins and transmitted to the pair of heating plate portions, and the heating plate portions are increased in temperature and the power generation efficiency is improved. Since the fin joined to the pair of heating plate portions has a flexible portion that allows the heating plate portion to be deformed, when the heating plate portion is to be deformed, the flexible portion of the fin is deformed following that, The heating plate can be deformed. That is, even if the fins are joined, the heating plate portion is restrained from increasing in rigidity. Therefore, the heating plate portion is deformed in accordance with the thermal stress applied to the thermoelectric conversion element. The stress received from the part is reduced compared to the conventional case. As a result, damage to the thermoelectric conversion element can be effectively suppressed.

The present invention includes the following forms.
The flexible part is an elastic deformation part in which the fin is elastically deformed. Further, the fin is composed of a single plate material. Moreover, the said fin is comprised with the corrugated board.

  According to the present invention, while maintaining improvement in power generation efficiency by the fins inside the tubular body, it is possible to reduce the stress applied to the thermoelectric conversion element and effectively suppress breakage of the thermoelectric conversion element.

1 is an overall perspective view of a thermoelectric conversion power generator according to an embodiment of the present invention. It is an II directional arrow line view of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is IV-IV sectional drawing of FIG. It is a perspective view which shows the structure of the housing | casing of the airtight container with which the same electric power generating apparatus is provided. FIG. 5 is a partially enlarged view of FIG. 4, and is a cross-sectional view illustrating a configuration of a thermoelectric conversion module and fins. It is a partial cross section figure of the power generator showing the composition of the fin of other embodiments.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[1] Configuration of Thermoelectric Conversion Power Generation Device FIGS. 1 to 4 show a thermoelectric conversion power generation device (hereinafter referred to as a power generation device) 1 according to an embodiment. FIG. 1 is an overall perspective view, and FIG. II direction view, FIG. 3 and FIG. 4 are a III-III sectional view and an IV-IV sectional view of FIG. 2, respectively. This power generator 1 is formed in a flat rectangular parallelepiped shape (the X direction is the longitudinal direction in FIGS. 1, 3, and 4), and is housed in a water cooling jacket (cooling portion) 3 and the water cooling jacket 3. A sealed container 2 is provided.

  The sealed container 2 has a double tube structure in which a flat tubular tube 25 is housed in the center of the flat tubular housing 20, and the space between the housing 20 and the tubular body 25 is decompressed. The opening at both ends in the X direction of the decompression space 29 is hermetically closed by the sealing cover 26. The water-cooling jacket 3 is formed in a flat tubular shape substantially along the outer shape of the sealed container 2, and the sealed container 2 housed therein has both end portions on the opening side projecting from both end openings of the water-cooled jacket 3.

  As shown in FIG. 5, the housing 20 is composed of a rigid portion 21 as a main body and a rectangular thin plate 22 joined to the rigid portion 21. The rigid portion 21 includes a pair of frames having a rectangular outer frame plate portion 211 and an inner frame plate portion 212 that partitions the inside of the outer frame plate portion 211 into two rectangular holes 213 divided in the longitudinal direction (X direction). The plates 210 face each other in parallel in the vertical direction (Z direction), the edges along the longitudinal direction of the outer frame plate portion 211 are connected by the side plate portions 215, and open at both ends in the longitudinal direction. It has the opening pipe part 217 which forms 218. FIG.

  The thin plate 22 is formed in a rectangular shape having a size that covers the two holes 213 of the rigid portion 21 with a flexible elastically deformable plate material. The thin plate 22 is joined to the periphery of the hole 213 on the outer surface of each frame plate 210 by a joining means such as brazing, whereby the two holes 213 are closed by the single thin plate 22. As a material of the thin plate 22, a metal plate having heat resistance and oxidation resistance such as stainless steel such as SUS444 or aluminum is preferable, and a thickness of about 0.1 mm is used, for example.

  As shown in FIGS. 3 and 4, the tubular body 25 accommodated in the housing 20 is formed in a longitudinal direction of a pair of upper and lower flat rectangular main plate portions 251 parallel to the upper and lower frame plates 210 of the housing 20. Are connected by a side plate portion 252 parallel to the side plate portion 215 of the housing 20, and the outer surfaces of both end opening edges are on the inner surface of the opening tube portion 217 of the rigid portion 21 of the housing 20. The cross section is U-shaped with a concave inward, and is joined through an oval sealing cover 26 as a whole.

  Heated fluid H (see FIGS. 3 and 4) flows through the inside 253 of the tube body 25 along the pipe line direction from one opening to the other opening. Inside the tubular body 253, fins 7 that collect the heat of the heating fluid H and transmit it to the tubular body 25 are disposed.

  As shown in FIG. 6, the fin 7 is formed by bending a single plate material so that a large number of “V” -shaped horizontal V-shaped portions 71 are parallel to each other with gaps 72 at equal intervals. The horizontal V-shaped portion 71 is composed of a substantially bellows-like corrugated plate in which the upper and lower ends in the drawing are joined together. The fin 7 is disposed in the tubular body 253 with both ends of the gap 72 between the horizontal V-shaped portions 71 facing both ends of the tubular body 25, and the upper and lower end connecting portions 73 are connected to the tubular body 25. By being joined to the main plate portion 251 by a joining means such as brazing, it is fixed to the tube body interior 253. A large number of gaps 72 between the horizontal V-shaped parts 71 of the fins 7 extend in parallel with the pipe line direction of the pipe body inside 253, and the heating fluid H passes through these gaps 72 while contacting the main plate part 251 and the fins 7. To do.

  The fins 7 are formed of a flexible and elastically deformable plate material. For example, similar to the thin plate 22, it is manufactured using a metal plate having heat resistance and oxidation resistance such as stainless steel such as SUS444 or aluminum and having a thickness of, for example, about 0.1 mm. The fin 7 can be elastically deformed by changing the angle of the tip portion (flexible portion, elastic deformation portion) 74 bent at an acute angle in the center in the thickness direction. In a state of being joined to the portion 251, the pair of opposed main plate portions 251 can be deformed so as to bend in the outer surface direction or the inner surface direction.

  The same material as that of the thin plate 22 is used for the rigid portion 21, the tubular body 25, and the sealing cover 26 of the casing 20 that constitute the sealed container 2. Between the thin plate 22 of the casing 20 and the main plate portion 251 of the tubular body 25 of the sealed container 2, the thermoelectric conversion modules 4 are respectively disposed.

  As shown in FIG. 6, the thermoelectric conversion module 4 includes an electrode 42 made of a metal plate such as a rectangular copper plate on one side and the other side of a plurality of thermoelectric conversion elements 41 arranged in a plane. Thus, the electrode 42 on one surface side is joined to the outer surface of the main plate portion 251 of the tubular body 25 by a joining means such as brazing. The electrode 42 on the other side faces the inner surface of the thin plate 22 of the housing 20, and the buffer material 5 is held between the thin plate 22 and the electrode 42. The thin plate 22 and the buffer material 5 and the buffer material 5 and the electrode 42 are not joined, but are in contact with each other so as to be slidable. The electrode 42 is insulated from the tube body 25 and the buffer material 5.

  The buffer material 5 is preferably a flexible sheet-like material such as a thin carbon sheet. In the present embodiment, the buffer material 5 is sandwiched between the thin plate 22 and the thermoelectric conversion module 4. However, the buffer material 5 is used as necessary, and the thin plate 22 directly contacts the thermoelectric conversion module 4. Can be selected.

  As the thermoelectric conversion element 41 constituting the thermoelectric conversion module 4, a type having a high heat-resistant temperature is used. For example, a silicon-germanium system, a magnesium-silicon system, a manganese-silicon system, an iron silicide system, or the like is preferably used. The decompression space 29 of the sealed container 2 in which the thermoelectric conversion module 4 is housed is hermetically sealed by a casing 20, a tubular body 25, and a sealing cover 26 that are formed of the rigid portion 21 and the thin plate 22. As shown in FIG. 4, the fin 7 has a size corresponding to the thermoelectric conversion module 4, and the thermoelectric conversion module 4 is disposed on both sides of the fin 7.

  The sealed container 2 is stored in a water-cooled jacket 3. As shown in FIGS. 3 and 4, the water-cooling jacket 3 has a sealing frame portion 31 that is bent inward and formed on the opening edges at both ends, on the outer surface of the outer frame plate portion 211 of the rigid portion 21 in the sealed container 2. And airtightly joined by means such as brazing. A space in the water cooling jacket 3, that is, a space formed between the rigid portion 21 and the water cooling jacket 3 is a cooling space 32 for cooling the thin plate 22 by supplying cooling water. A cooling water inlet / outlet 33 is provided at a central portion of the water cooling jacket 3 corresponding to each side plate portion 215 of the housing 20.

  A total of four thermoelectric conversion modules 4 are accommodated in the sealed container 2, and these thermoelectric conversion modules 4 are connected in series. Then, electricity is taken out from the two lead wires 49 of + • − shown in FIGS. The lead wire 49 passes through the side plate portion 215 and the water cooling jacket 3 of the sealed container 2 and is drawn to the outside, and the lead wire through hole of the side plate portion 215 and the water cooling jacket 3 is hermetically closed.

  The heat exchange means 6 is joined to the thin plate 22 at a location corresponding to the thermoelectric conversion module 4 in the cooling space 32. The heat exchange means 6 is provided in a state in which the cooling of the thin plate 22 is not hindered by the cooling water supplied to the cooling space 32 being brought into contact to dissipate the thin plate 22 to promote cooling.

  Examples of the heat exchanging means 6 include a heat exchanging member such as a fin having flexibility that does not hinder the flexibility of the thin plate 22. Moreover, even if it is a heat exchange member such as a hard fin, a plurality of independent heat exchange members are provided in contact with the thin plate 22 in a scattered manner so as not to hinder the flexibility of the thin plate 22. Also good.

  The sealed container 2 sucks air in the decompression space 29 from a decompression sealing port (not shown) formed at a predetermined location to decompress the decompression space 29 to a predetermined pressure (for example, about 1 to 100 Pa). Are hermetically sealed by welding or the like. As a result, in the sealed container 2, a pressure difference is generated in which the pressure in the decompression space 29 is lower than that in the outside atmosphere, and the force that pressurizes the thin plate 22 of the housing 20 toward the thermoelectric conversion module 4 due to the pressure difference. Receive.

[2] Action of power generator In power generator 1 having the above-described configuration, high-temperature heating fluid H is flowed from one opening to the other opening in tube body 253 to heat tube body 25. In addition, the cooling water is introduced into the cooling space 32 from one introduction outlet 33 of the water cooling jacket 3, the cooling water is discharged from the other introduction outlet 33, and the cooling space 32 is filled with the cooling water to be sealed. The thin plate 22 of the container 2 is cooled.

  The heat of the heating fluid H that flows in the tube body 253 directly heats the pair of opposing main plate portions 251, and is collected by the fins 7 and transmitted to the main plate portions 251, so that the temperature of the main plate portions 251 is increased. Is done. Heat of the main plate portion 251 of the heated tube body 25 is transmitted to the inner surface side of the thermoelectric conversion module 4, and the inner surface side of the thermoelectric conversion module 4 is heated. On the other hand, the cooling of the thin plate 22 is promoted by the heat exchange means 6 that is cooled by cooling water. The heat of the cooled thin plate 22 is transmitted to the outer surface side of the thermoelectric conversion module 4, and the outer surface side of the thermoelectric conversion module 4 is cooled. Thereby, a temperature difference is given to the thermoelectric conversion element 41 of the thermoelectric conversion module 4 so that the inner surface side is high temperature and the outer surface side is low temperature.

  In the hermetic container 2, the internal decompression space 29 is decompressed as described above to generate a pressure difference with the outside, whereby the thin plate 22 of the housing 20 is pressurized toward the thermoelectric conversion module 4. Thereby, the thin plate 22 of the housing | casing 20 is pressurized and closely_contact | adhered to the shock absorbing material 5, and the shock absorbing material 5 closely_contact | adheres in the state pressurized to the thermoelectric conversion module 4 side.

  As described above, a temperature difference is given between the outer surface side and the inner surface side of the thermoelectric conversion module 4, so that the thermoelectric conversion module 4 generates power and electricity is extracted from the lead wire 49.

  In the power generation apparatus 1 of this embodiment, for example, exhaust heat gas generated in a factory or a garbage incinerator, automobile exhaust gas, or the like is used as the heating fluid H.

[3] Effects of One Embodiment In the power generation apparatus 1 of the above-described embodiment, thermal stress due to a difference in thermal expansion is generated in the thermoelectric conversion element 41 of the thermoelectric conversion module 4 to which a temperature difference is given. The main plate portion 251 is deformed by being transmitted to the 25 main plate portions 251. Here, conventionally, the tubular body to which the fins are joined has increased in rigidity and is difficult to be deformed. For this reason, there is a problem that the thermoelectric conversion element receives a stress from the tubular body and is cracked or broken.

  However, in the fin 7 according to the present embodiment, the upper and lower flat portions 75 are separated from or close to each other around the tip 74 at the center in the thickness direction of the horizontal V-shaped portion 71 even in a state where the fin 7 is joined to the main plate portion 251 of the tube body 25. The pair of opposing main plate portions 251 can be deformed. That is, even if the fins 7 are joined, the main plate portion 251 is suppressed from increasing in rigidity. Therefore, the main plate portion 251 is deformed in accordance with the thermal stress applied to the thermoelectric conversion element 41, and therefore, the thermoelectric conversion element 41 is less likely to be stressed from the main plate portion 251 than before, and as a result, the thermoelectric conversion element is damaged. The risk is reduced.

[4] Other Embodiments The shape of the fin according to the present invention is not limited to the above embodiment, and the heating plate portion is deformed while being joined to the heating plate portion (main plate portion 251 in the above embodiment). Any form may be used as long as it has a flexible part to be enabled.

  For example, as in the fin 8 shown in FIG. 7, a corrugated plate in which curved portions (flexible portions, elastically deformable portions) 81 having an Ω cross section are alternately formed on the top and bottom can be used. The fin 8 is disposed in a state in which the hollow portion 82 inside the bending portion 81 extends in parallel with the pipe line direction of the tube body inside 253, and the outer surface of the bending portion 81 is joined to the main plate portion 251. 81 and the space between the fin 8 and the main plate portion 251 are caused to flow the heating fluid H. The fin 8 is bent and elastically deformed so that the curved portion 81 is crushed, whereby the main plate portion 251 is suppressed from increasing in rigidity, and the main plate portion 251 can be deformed.

  DESCRIPTION OF SYMBOLS 1 ... Thermoelectric conversion type electric power generating apparatus, 25 ... Tube, 251 ... Main plate part (heating plate part), 253 ... Inside pipe body, 3 ... Water cooling jacket (cooling part), 4 ... Thermoelectric conversion module, 41 ... Thermoelectric conversion element, 7, 8 ... fins, 74 ... tip parts (flexible parts, elastic deformation parts), 81 ... bending parts (flexible parts, elastic deformation parts), H ... heating fluid.

Claims (4)

A pipe body that includes at least a pair of opposed heating plate portions on one side and the other side, and in which a heating fluid that heats the heating plate portion is caused to flow;
A cooling part disposed on the outer surface side of the heating plate part;
A thermoelectric conversion module disposed between the heating plate portion and the cooling portion and having a thermoelectric conversion element;
A fin disposed in the tube and transmitting heat of the heating fluid to the heating plate;
With
In the thermoelectric conversion power generator that generates power by giving a temperature difference to the thermoelectric conversion module by the heating plate part and the cooling part,
The fin is joined to the pair of heating plate portions, and has a flexible portion that allows the pair of heating plate portions to be deformed in the joined state. apparatus.   The thermoelectric conversion power generation apparatus according to claim 1, wherein the flexible portion is an elastically deformable portion in which the fin is elastically deformed.   The thermoelectric conversion power generator according to claim 1, wherein the fin is formed of a single plate material.   The thermoelectric conversion power generator according to any one of claims 1 to 3, wherein the fin is formed of a corrugated plate.

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