JP2011187669A - Heat transfer structure of power generation unit - Google Patents

Abstract

The present invention provides a heat transfer structure for a power generation unit that increases the heating / cooling efficiency of a thermoelectric module.
In a heat transfer structure of a power generation unit in which a thermoelectric module is sandwiched between a heat receiving panel and a cooling unit, a part of a heating-side facing surface is projected in a plate shape so that the thermoelectric A heating side pedestal 20a formed substantially in the same shape as the module 11, a cooling side pedestal 30a formed substantially in the same shape as the thermoelectric module 11 by projecting a part of the cooling side facing surface 30c in a plate shape, and a heating side pedestal Heating side heat transfer sheet 41 sandwiched between 20a and thermoelectric module 11, cooling side heat transfer sheet 42 sandwiched between cooling side pedestal 30a and thermoelectric module 11, heating side pedestal 20a, heating side The heat transfer sheet 41, the thermoelectric module 11, the cooling side heat transfer sheet 42, and the heat insulating material 12 interposed between the heating side facing surface 20c and the cooling side facing surface 30c around the cooling side pedestal 30a.
[Selection] Figure 9

Description

  The present invention relates to a heat transfer structure of a water-cooled power generation unit that generates power by using a temperature difference of a thermoelectric module constituted by a plurality of thermoelectric elements.

  A phenomenon in which a so-called electromotive force is generated when a temperature difference is generated between both ends of a thermoelectric module configured by electrically connecting a plurality of thermoelectric elements is known as the Seebeck effect.

  For example, Patent Document 1 discloses a power generation device that utilizes this phenomenon.

  In this device, a water cooling jacket is provided outside the heat insulating material covering the heating chamber via a gap, and a thermoelectric module is attached to the inner wall surface of the water cooling jacket so as not to be in contact with the heat insulating material. . The thermoelectric module is configured by alternately arranging P-type semiconductors and n-type semiconductors, and the side facing the heat insulating material is the high temperature side, while the cooling jacket side is the low temperature side, and generates an electromotive force therebetween. It is like that.

  Since this power generator employs a water-cooling type using a water-cooling jacket, it can cool more efficiently than the air-cooled type and can increase the thermoelectric conversion efficiency.

JP 2002-171776 A

  However, in order to put into practical use a power generation device using thermoelectric conversion, it is required to increase the heating and cooling efficiency of the thermoelectric module to obtain higher thermoelectric conversion efficiency.

  This invention is made | formed in view of the situation mentioned above, and it aims at providing the heat-transfer structure of the electric power generation unit which raised the heating and cooling efficiency of the thermoelectric module.

  The invention according to claim 1 is a plate-like thermoelectric module configured by electrically connecting a plurality of thermoelectric elements, and includes a heating side facing surface and a cooling side facing surface that face each other between the heat receiving plate and the cooling unit. In the heat transfer structure of the power generation unit configured to be sandwiched between, a heating side pedestal formed substantially in the same shape as the thermoelectric module by projecting a part of the heating side facing surface in a plate shape, and the cooling side facing A cooling side pedestal formed substantially in the same shape as the thermoelectric module by projecting a part of the surface in a plate shape, and sandwiched between the heating side pedestal and the thermoelectric module formed substantially in the same shape as the thermoelectric module A heating side heat transfer sheet, a cooling side heat transfer sheet formed in substantially the same shape as the thermoelectric module and sandwiched between the cooling side base and the thermoelectric module, the heating side base, and the heating side heat transfer sheet. Thermal sheet, thermoelectric module The cooling side heat transfer sheet, at the periphery of the cooling-side seat, and a heat insulating material interposed between the heating side facing surface and the cooling side facing surface, it is characterized.

  The invention according to claim 2 is the heat transfer structure of the power generation unit according to claim 1, further comprising a fastening member that penetrates the heat insulating material and connects the heat receiving plate and the cooling unit, and the fastening member is It is made of synthetic resin.

  The invention according to claim 3 is the heat transfer structure of the power generation unit according to claim 1 or 2, wherein the thickness of the heating side pedestal is the heating side thickness, and the thickness of the cooling side pedestal is the cooling side thickness. In addition, when the heat capacity of the heat receiving plate is larger than the heat capacity of the cooling unit, the heating side thickness is made thicker than the cooling side thickness, and the heat capacity of the heat receiving plate is smaller than the heat capacity of the cooling unit. Is characterized in that the heating side thickness is made thinner than the cooling side thickness.

  According to a fourth aspect of the present invention, in the heat transfer structure of the power generation unit according to any one of the first to third aspects, the heat insulating material is engaged and positioned around the heating side pedestal and the cooling side pedestal. The groove part to be formed is formed.

  According to the invention of claim 1, since the heat insulating material is disposed around the heating side pedestal on the heating side facing surface of the heat receiving plate, that is, the portion other than the heating side pedestal, the heat of the heat receiving plate is concentrated on the heating side pedestal. Then, it passes through the heating side heat transfer sheet and is efficiently transmitted to the thermoelectric module. Similarly, since the heat insulating material is disposed around the cooling side pedestal on the cooling side facing surface of the cooling unit, that is, the part other than the cooling side pedestal, the cooling unit is interposed via the cooling side pedestal and the cooling side heat transfer sheet. The thermoelectric module can be efficiently cooled. Further, since the thermoelectric module is sandwiched between the heat receiving plate and the cooling unit via the heating side heat transfer sheet and the cooling side heat transfer sheet, the adhesion is improved by these sheets and the heat transfer efficiency is increased. In addition, since these sheets act as cushioning materials, damage during assembly can be prevented.

  According to invention of Claim 2, since the fastening member which penetrates a heat insulating material and fastens a heat receiving board and a cooling unit was made from the synthetic resin, it heat-insulated compared with the case where a fastening member is a general steel material. Therefore, the amount of heat leaking from the heat receiving panel side to the cooling unit side through the fastening member can be reduced. Furthermore, since the fastening member is made of a synthetic resin, damage to the thermoelectric module caused by the fastening force being too strong can be reduced as compared with the case of steel. For this reason, the workability | operativity at the time of an assembly improves.

  According to the invention of claim 3, since the thermoelectric module can be arranged at a position where it is easy to achieve thermal equilibrium, the cooling efficiency of the thermoelectric module can be increased.

  According to the fourth aspect of the present invention, the heat insulating material can be easily positioned by engaging a part of the heat insulating material with the groove, and it is possible to prevent unnecessary movement after positioning.

(A) is a top view of the power generation unit 1, (b) is a cross-sectional view taken along the line AA in (a), and (c) is a bottom view. It is sectional drawing cut | disconnected and shown along the arrow BB line in FIG.1 (b). It is a figure explaining the cooling state of the electric power generation unit. It is a figure explaining the thermoelectric module 11, (a) is a front view, (b) is a bottom view, (c) is a right view. It is a figure explaining the electric power generation unit 2 using the several thermoelectric module 11, (a) is a front view, (b) is sectional drawing cut | disconnected and shown by the CC line in (a), (c) is It is a top view. It is a figure explaining the cooling fin 33 of the electric power generation unit 2, (a) is a front view, (b) is a bottom view, (c) is a right view. FIGS. 7A and 7B are diagrams illustrating the casing 31 of the power generation unit 2, where FIG. 7A is a front view, FIG. 7B is a bottom view, and FIG. 7C is a right side view. 2 is an exploded perspective view of a thermoelectric module 3. FIG. FIG. 9 is a cross-sectional view schematically shown by cutting along the line CC in FIG. 8 in a state where the heat receiving board 20 and the cooling unit 30 are combined.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each drawing, the member etc. which attached | subjected the same code | symbol are the same structures, The duplication description about these shall be abbreviate | omitted suitably. Moreover, in each drawing, members and the like that are not necessary for the description are omitted as appropriate.
<Embodiment 1>

  With reference to FIGS. 1-4, the fundamental structure of the electric power generation unit which can apply the heat insulation structure of the electric power generation unit which concerns on this invention is demonstrated. Here, FIG. 1A is a top view of the power generation unit 1, FIG. 1B is a cross-sectional view taken along the line AA in FIG. 1A, and FIG. FIG. 2 is a cross-sectional view taken along the line BB in FIG. FIG. 3 is a diagram illustrating a cooling state of the power generation unit 1. 4A and 4B are diagrams for explaining the thermoelectric module 11, where FIG. 4A is a front view, FIG. 4B is a bottom view, and FIG. 4C is a right side view.

  The power generation unit 1 includes a thermoelectric unit 10, a heat receiving plate 20 as a heating unit, and a cooling unit 30 as a cooling unit. The power generation unit 1 is formed in a rectangular parallelepiped shape as a whole. 20 and the cooling unit 30 are configured to be sandwiched.

  The thermoelectric unit 10 includes a thermoelectric module 11, a heat insulating material 12, heat transfer sheets 41 and 42, which will be described in detail later with reference to FIGS. 8 and 9, and bolts 43 and 44 as fastening members. . Among these, the thermoelectric module 11 utilizes the so-called Seebeck effect that electromotive force is generated when two different metals or semiconductors are joined together and a temperature difference is generated between the two ends. In the power generation unit 1, in order to obtain a large potential difference, as shown in FIGS. 4A to 4C, a thermoelectric element (Beltier element) configured by combining a p-type semiconductor and an n-type semiconductor as the thermoelectric module 11. A large number of 11a are arranged vertically and horizontally and the front and back are sandwiched between insulating plates 11b. The thermoelectric module 11 uses, for example, a structure in which 254 thermoelectric elements 11a are arranged in a state where they are aligned vertically and two adjacent thermoelectric elements 11a are connected one after another.

  At this time, the 254 thermoelectric elements 11a are divided into a plurality of groups, and for the plurality of thermoelectric elements 11a in the group, two adjacent thermoelectric elements 11a are connected at one end side, and then adjacent to each other. The two thermoelectric elements 11a are connected in series so as to be connected on the other end side. The groups are connected in parallel. When all the thermoelectric elements 11a are connected in series, the internal resistance increases. Therefore, when the power is increased, the internal resistance increases accordingly. For this reason, in order to reduce the electric current of the electric heating module 11, the serial connection and the parallel connection are used in combination as described above. According to this method, redundancy for operation can be obtained, so that power generation operation can be greatly improved. That is, it is possible to prevent a power generation stop due to a failure of a part of systems in parallel with respect to the failure of the thermoelectric module 11. Even if a part of the system stops due to this failure, the function as the thermoelectric module 11 does not stop. However, although the function is reduced, the operation rate can be dramatically improved by restoring the function by preventive maintenance. In addition, about the connection of the thermoelectric element 11a, the number of series connection and parallel connection shall be suitably set according to the electromotive force as a single unit of the thermoelectric element 11a, the electromotive force as a whole, etc. The electromotive force generated in the thermoelectric module 11 can be taken out from the output terminal 11c. As shown in FIG. 1, the thermoelectric module 11 has a heat transfer sheet 41, which will be described in detail later, on the front surface 13 a side (the heat receiving panel 20 side, the right side in FIG. 1) which is the high temperature side and the rear surface 13 b side which is the low temperature side. 42 (not shown in FIG. 1), and the other four surfaces, that is, the upper surface 13c, the lower surface 13d, the left surface 13e, and the right surface 13f are covered with the heat insulating material 12.

  The heat receiving board 20 as a heating unit is a part that receives heat, and is made of, for example, a metal having excellent thermal conductivity. As a heat source for heating the heat receiving board 20, for example, geothermal heat from a hot spring resort or a high temperature hot spring can be used. Further, waste heat generated when incineration of garbage can be used in a garbage incineration plant or the like. In other words, a heat source that can effectively use heat that is normally discarded is preferable. As shown in FIG. 1, the heat receiving panel 20 is disposed so as to be in close contact with the front surface 13 a of the thermoelectric module 11 via a heat transfer sheet 41 described later, and transmits high heat to the thermoelectric module 11.

  The cooling unit 30 as a cooling unit includes a housing 31 and a plurality of cooling fins 33 disposed inside the housing 31.

  As shown in FIGS. 1 and 2, the casing 31 is formed in a substantially rectangular parallelepiped shape and has six wall portions. The six wall parts are a bottom part (lower wall part) 32a, a ceiling part (upper wall part) 32b, a front wall part 32c, a rear wall part 32d, a left wall part 32e, and a right wall part 32f. Of these six wall portions, the front wall portion 32c becomes a wall portion (second wall portion) close to the thermoelectric module 11, and contacts the rear surface 13b of the thermoelectric module 11 via a heat transfer sheet 42 described later. Are arranged to be. Further, the rear wall portion 32d becomes a wall portion (first wall portion) far from the thermoelectric module 11, and also supports a plurality of cooling fins 33, which will be described later, and an integral support plate. That is, the rear wall portion 32 d is formed by the support plate that supports the base end portions 33 a of the plurality of cooling fins 33. Of the six wall portions described above, the housing 31 has a rear wall portion 32d formed of a support plate formed of the same aluminum material (aluminum material) as the cooling fins 33, and the remaining five wall portions, That is, the bottom part 32a, the ceiling part 32b, the front wall part 32c, the left wall part 32e, and the right wall part 23f are made of copper having a high thermal conductivity among metals. Also for the rear wall portion 32d described above, copper is preferable from the viewpoint of thermal conductivity, but the rear wall portion 32d is formed integrally with the plurality of cooling fins 33 in order to reduce the cost of the cooling fins 33. The rear wall portion 32b is formed of an aluminum material. Note that the material of the casing 31 is not limited to the above-described materials, and it is preferable to appropriately set the size, weight, strength, thermal conductivity, cost, and the like. A substantially rectangular parallelepiped cooling chamber R is formed in a portion surrounded by the six wall portions described above, that is, inside the housing 31. The cooling chamber R is filled with cooling water W.

  Three water inlets 31 a are formed in the bottom 32 a of the housing 31. As shown in FIG. 1, the three water injection ports 31 a are all disposed at the same position in the front-rear direction, and are disposed at positions corresponding to inclined portions 33 b of the cooling fins 33 described later. . On the other hand, the positions of the three water inlets 31a in the left-right direction are arranged at substantially the same positions as the three drain outlets 31b described below.

  Three drain ports 31b are formed in the ceiling portion 32b of the casing 31. As shown in FIGS. 1 and 2, the three drain outlets 31 b are all arranged at the same position in the front-rear direction, and are the frontmost of the inclined portions 33 b of the cooling fins 33 described later. It arrange | positions in the position corresponding to the part near the wall part 32c. This position is in front of the water injection port 31a. On the other hand, the left and right positions of the three drain ports 31b are arranged at substantially the same positions as the three water inlets 31a. Cooling water W is injected from the water injection port 31a of the bottom portion 32a, and the injected cooling water W cools the cooling chamber R and the cooling fins 33 and is discharged from the drain port 31b of the ceiling portion 32b. As the cooling water W, for example, when the power generation unit 1 is installed in a hot spring resort, ground water or river water can be used, and when installed in a garbage incineration plant, tap water is used. Can be used.

  The cooling fins 33 are formed in a plate shape extending in the front-rear direction and the up-down direction, and a plurality of cooling fins 33 are aligned with a predetermined gap along the left-right direction. As shown in FIG. 1, each cooling fin 33 has a base end portion 33a located on the rear end side coupled to a support plate constituting the rear wall portion 32d, and a tip end portion extending toward the front wall portion 32c. Yes. An inclined portion 33b is formed at the tip portion. The inclined portion 33b is inclined so as to approach the front wall portion 32c from the lower end side toward the upper end side. The position in the front-rear direction of the water injection port 31a described above is set to a position corresponding to between the lower end and the upper end of the inclined portion 33b. Moreover, the position of the above-described drain port 31b in the front-rear direction is set to a position corresponding to the vicinity of the upper end of the inclined portion 33b. Further, in the cooling chamber R, between the inclined portion 33b of the cooling fin 33 and the inner surface of the front wall portion 32c, the cooling water W injected from the water injection port 31a and discharged from the drain port 31b flows smoothly. An appropriate space is formed. That is, the cooling water W flows smoothly between the inclined portion 33b and the front wall portion 32c, that is, on the front side in the cooling chamber R, while adjacent to each other between the left wall portion 32e and the cooling fins 33. Between the two cooling fins 33 and between the right wall portion 32f and the cooling fins 33, the cooling fins 33 and the like can be sufficiently cooled by staying appropriately. As described above, the plurality of cooling fins 33 are erected on the support plate constituting the rear wall portion 32d, and are formed integrally as a whole. The cooling fins 33 and the support plate are made of aluminum (made of aluminum) in order to reduce costs from the viewpoint of good heat conduction.

  An arrow a1 to an arrow a10 in FIG. 1B and an arrow b1 to an arrow b10 in FIG. 2 schematically indicate the moving direction of heat moving from the high temperature side to the low temperature side. As shown in these drawings, the heat transferred to the heat receiving board 20 heats the surface 13a side of the electric heating module 11 to a high temperature (arrows a1, b1). This heat is transmitted to the rear surface 13 b side of the thermoelectric module 11 and is transmitted to the front wall portion 32 c of the housing 31, and most of the heat is taken away by the cooling water W. As described above, the cooling water W injected into the cooling chamber R from the water injection port 31a flows toward the front wall portion 32c toward the downstream side (upper side) by the inclined portion 32b of the cooling fin 33, and in the vicinity of the front wall portion 32c. Then, since it becomes a smooth flow, most of the heat transmitted to the front wall portion 32c is efficiently exchanged by the cooling water W flowing smoothly through the front wall portion 32c. Further, as shown in FIG. 1, a part of the heat transmitted to the front wall portion 32c is transmitted from the front wall portion 32c to the cooling fins 33 via the ceiling portion 32b and the rear wall portion 32d (arrows a3 to a6). ) Or from the front wall portion 32c to the cooling fin 33 via the bottom portion 32a and the rear wall portion 32d (arrows a7 to a10). Further, as shown in FIG. 2, another part of the heat transferred to the front wall portion 32c is transferred from the front wall portion 32c to the cooling fins 33 via the left wall portion 32e and the rear wall portion 32d (arrows). b3 to b6), or transmitted from the front wall portion 32c to the cooling fin 33 via the right wall portion 32f and the rear wall portion 32d (arrows b7 to b10). As described above, the heat transferred to the front wall portion 32c is transferred to the cooling water while passing through the respective wall portions, that is, the ceiling portion 32b, the bottom portion 32a, the left wall portion 32e, and the right wall portion 32f, or the cooling fins. Is transmitted to the cooling water W from the surface of the cooling fin 33. The heat transmitted to the cooling water W is released to the outside as the cooling water W is discharged from the drain port 31b. As described above, since the heat transmitted to the low temperature side of the thermoelectric module 11 can be discharged together with the cooling water W, the low temperature side of the thermoelectric module 11 can be kept at a predetermined temperature.

  FIG. 3 shows a thermal gradient in the power generation unit 1. The heat receiving board 20 receives heat from the heat source and becomes a high heat temperature tHi. This heat is transferred to the thermoelectric module 11. In the thermoelectric module 11, the temperature of the front surface 13a (see FIG. 1) is substantially the high heat temperature tHi. The temperature of the thermoelectric module 11 decreases as it approaches the rear surface 13b (see FIG. 1), and at the rear surface 13b, the chilled water temperature tLw is substantially the same as that of the cooling unit 30. Here, the low temperature maintenance temperature tLo is set to a temperature higher than the cold water temperature tLw, and the difference between the low temperature maintenance temperature tLo and the cold water temperature tLw becomes a heat loss discharged to the outside together with the discharge of the cooling water W. . And the heat | fever corresponding to the temperature difference which deducted the low temperature maintenance temperature tLo from the high heat temperature tHi is converted into electricity. That is, a thermoelectric conversion amount proportional to the above temperature difference can be obtained.

  According to the power generation unit 1 described above, since the cooling unit 30 is water-cooled and has the cooling fins 33 in the cooling chamber R, the low temperature side of the thermoelectric module 11 can be cooled stably and efficiently. it can.

  Further, since there is no cooling fin 33 in the vicinity of the front wall portion 32c of the casing 31, the flow of the cooling water W is smooth in this vicinity, and the front wall portion 32c is directly connected to the cooling water W by this smooth flow. It can be cooled efficiently.

  Further, since the water supply port 31a and the drain port 31b are provided on the front wall portion 32c side at a position where the cooling fins 33 are substantially removed, the flow of the cooling water W in the vicinity of the front wall portion 32c is also smoothed. Can be.

  Further, the cooling fin 33 has an inclined portion 33 b at the tip, and the inclined portion 33 b is inclined so that the area of the cooling fin 33 becomes wider toward the downstream side along the cooling water W. In other words, since the cooling fin 33 is formed so that the surface area of the cooling fin 33 is increased on the downstream side where the temperature of the cooling water W tends to be higher than the upstream side, the cooling fin 33 can be uniformly cooled.

  Further, since the rear wall portion 32d is configured by a support plate that integrally supports the plurality of cooling fins 33, the configuration can be simplified correspondingly.

  Next, the power generation unit 2 including a plurality of the thermoelectric modules 11 will be described with reference to FIGS. Here, FIG. 5 is a figure explaining the electric power generation unit 2 using the some thermoelectric module 11, (a) is a rear view, (b) is cut and shown by the CC line in (a). Sectional drawing and (c) are top views. 6A and 6B are diagrams for explaining the cooling fins 33 of the power generation unit 2, in which FIG. 6A is a rear view, FIG. 6B is a left side view, and FIG. FIGS. 7A and 7B are diagrams illustrating the casing 31 of the power generation unit 2, where FIG. 7A is a rear view, FIG. 7B is a left side view, and FIG. 7C is a top view. In these drawings, members similar to those described above are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

The power generation unit 2 is greatly different in that the power generation unit 1 has one (1) thermoelectric module 11 but a plurality (5) of thermoelectric modules 11.
As shown in FIG. 5, a plurality (five) of thermoelectric modules 11 are arranged in the vertical direction on the rear surface side (the upper side in FIG. 5B) of the heat receiving plate 20 so as to be in close contact with the heat receiving plate 20. Has been. A heat insulating material 12 is attached to the upper, lower, left, and right sides of each thermoelectric module 11. As shown in FIGS. 5 and 7, the casing 31 includes a front wall portion 32c that is long in the vertical direction, a bottom portion 32a having three water inlets 31a, a ceiling portion 32b having three drain ports 31b, and a left wall portion. 32e, the right wall part 32f, and the rear wall part 32d which covers these rear surfaces. As shown in FIGS. 5 and 6, a plurality of cooling fins 33 extending in the vertical direction are provided on the rear wall portion 32 d so as to protrude toward the front side. Each cooling fin 33 has an inclined portion 33 b that is inclined similarly to the power generation unit 1. The rear wall portion 32d and the plurality of cooling fins 33 are integrally formed, and are made of, for example, aluminum. As shown in FIG. 5, the rear wall portion 32d is set to have a vertical dimension larger than that of the front wall portion 32c, and has protruding portions on the upper side and the lower side. Bolts 35 are passed through the protruding portions from the rear surface side, and the ends of the bolts 35 are screwed into the rear surface of the heat receiving plate 20 to fix the entire housing 31 to the heat receiving plate 20. A heat insulating material 34 is wound around the bolt 35.

  Although the basic configuration of the power generation unit 2 is substantially the same as that of the power generation unit 1 described above, a plurality (five) of thermoelectric modules 11 are arranged to individually extract electromotive forces from these thermoelectric modules 11. In addition, it is possible to extract a large electromotive force by connecting a plurality of these.

  In the power generation unit 2, the example in which the five thermoelectric modules 11 are arranged in a line in the vertical direction has been described, but this number is not limited to five and may be other numbers. Further, a plurality of thermoelectric modules 11 can be arranged in the horizontal direction, and the number of thermoelectric modules 11 can be further increased. Even in this case, the basic configuration of the power generation unit other than the thermoelectric module 11 can be substantially the same.

  Next, the heat transfer structure of the power generation unit according to the present invention will be described in detail with reference to the power generation unit 3 shown in FIGS. The heat transfer structure is a structure for efficiently heating the thermoelectric module 11 by the heat receiving panel 20 and for efficiently cooling the thermoelectric module 11 by the cooling unit 30, and also has a heat insulating structure for preventing unnecessary heat leakage. include.

  Since the basic configuration of the power generation unit 3 is the same as that of the power generation unit 1 and the power generation unit 2 described above, description thereof is omitted. In the power generation unit 3, the heat transfer structure will be described in detail. The power generation unit 3 shown in the figure is configured using four thermoelectric modules 11.

  Here, FIG. 8 is an exploded perspective view of the power generation unit 3. FIG. 9 is a cross-sectional view schematically shown by cutting along the arrow CC line in FIG. 8 in a state in which the heat receiving panel 20 and the cooling unit 30 are combined. In FIG. 8, the dimensions of each member and the like are exaggerated as appropriate in order to facilitate understanding of the heat transfer structure. For example, the thermoelectric module 11, the heating side heat transfer sheet 41, the cooling side heat insulating sheet 42, the heat insulating material 12 and the like are illustrated with exaggerated thicknesses and sizes.

  As shown in FIGS. 8 and 9, the heat transfer structure of the power generation unit includes a heating side heat transfer sheet 41, a cooling side heat transfer sheet 42, a bolt 43 as a fastening member, a heat insulating material 12, and the like. .

  As shown in FIG. 4, the thermoelectric module 11 shown in FIGS. 8 and 9 has a large number of thermoelectric elements (Beltier elements) 11a formed by combining p-type semiconductors and n-type semiconductors arranged vertically and insulate the front and back sides. It is sandwiched between the plates 11b and formed into a rectangular thin plate as a whole. The thermoelectric module 11 is provided with output terminals 11c in the vicinity of both corners of one side of the rectangle shown in FIG. 4, and lead wires 11d are drawn from these output terminals 11c as shown in FIG. The thermoelectric element 11a, which is a main component of the thermoelectric module 11, is generally fragile and often uses Bi (bismuth) -Te (tellurium) material, and therefore requires careful handling.

  As shown in FIG. 9, the heat receiving board 20 has a heating side pedestal 20 a protruding therefrom. The heating side pedestal 20a projects a rear surface of the heat receiving board 20, that is, a part of the heating side facing surface (rear surface) 20c facing the cooling unit 30 in the heat receiving plate 20 into a rectangular shape substantially the same shape as the thermoelectric module 11. It is formed by that. Around the heating side pedestal 20a, a groove 20h for engaging a part (part 12c) of a heat insulating material 12 described later is formed. Here, a distance L1 from the bottom of the groove 20h to the rear surface 20d of the heating side pedestal 20a is defined as the height (thickness) of the heating side pedestal 20a. As shown in FIG. 9, the front surface 20e of the heat receiving panel 20 is formed with a recess 20b in which a head 43a of a bolt 43 described later is accommodated at a position removed from the thermoelectric module 11, and at the bottom of the recess 20b. A through hole 20f that penetrates the heat receiving board 20 in the front-rear direction is formed.

  A heating side heat transfer sheet 41 is interposed between the heating side pedestal 20 a and the thermoelectric module 11. The heating-side heat transfer sheet 41 is formed in a rectangular shape that is substantially the same shape as the thermoelectric module 11, and is sandwiched between the rear surface 20 d of the heating-side base 20 a and the front surface 13 a of the thermoelectric module 11. Here, as the heating-side heat transfer sheet 41, in order to efficiently transfer the heat of the heat receiving panel 20 to the thermoelectric module 11, a sheet having excellent thermal conductivity is preferable. In the present embodiment, it is preferable that the heating side heat transfer sheet 41 has appropriate elasticity (softness). The heating-side heat transfer sheet 41 has appropriate elasticity, so that when the heating-side heat transfer sheet 41 is sandwiched between the rear surface 20d of the heating-side pedestal 20a of the heat receiving board 20 and the front surface 13a of the thermoelectric module 11, the adhesion between them is increased. As a result, the heat transfer efficiency is improved as compared with the case where the rear surface 20d of the heating side base 20a and the front surface 13a of the thermoelectric module 11 are brought into direct contact with each other. Further, the heating-side heat transfer sheet 41 has moderate elasticity, and thus acts as a buffer material for the thermoelectric module 11, and can prevent the thermoelectric module 11 from being damaged during assembly. Thus, as the heating side heat transfer sheet 41 which is excellent in thermal conductivity and also acts as a buffer material, for example, a silicone rubber having a thickness of about 0.5 to 1.5 mm can be suitably used. . In addition, the heating side heat transfer sheet 41 increases the fastening force by the bolts 43 to be described later, and the adhesion to the heat receiving board 20 and the thermoelectric module 11 increases, so that the heat of the heat receiving board 20 passes through the heating side heat transfer sheet 41. Thus, it is easy to be transmitted to the thermoelectric module 11. Furthermore, when, for example, silicone cream or the like is applied to the surface of the heat receiving plate 20 that is in close contact with the heating side heat transfer sheet 41, that is, the rear surface 20d of the heating side pedestal 20a, the adhesion is further improved and the heat transfer effect is improved. Can be increased.

  Similar to the power receiving panel 20 described above, the cooling unit 30 is provided with a cooling side pedestal 30a. The cooling side pedestal 30a is formed by projecting a front surface of the cooling unit 30, that is, a part of the cooling side facing surface 30c facing the heat receiving board 20 in the cooling unit 30, into a rectangular shape substantially the same shape as the thermoelectric module 11. Has been. Around the cooling side pedestal 30a, a groove 30h for engaging a part (part 12c) of the heat insulating material 12 described later is formed. Here, a distance L2 from the bottom of the groove 30h to the front surface 30d of the cooling side pedestal 30a is defined as the height (thickness) of the cooling side pedestal 30a. On the cooling side facing surface (front surface) 30c of the cooling unit 30, a female screw portion 30e into which a male screw portion 43b of a bolt 43 described later is screwed at a position corresponding to the concave portion 20b and the through hole 20f of the heat receiving plate 20 is screwed. It is engraved.

  A cooling side heat transfer sheet 42 is interposed between the cooling side pedestal 30 a and the thermoelectric module 11. The cooling side heat transfer sheet 42 is formed in a rectangular shape substantially the same as the thermoelectric module 11, and is sandwiched between the front surface 30 d of the cooling side pedestal 30 a and the rear surface 13 b of the thermoelectric module 11. As the cooling-side heat transfer sheet 42, the same one as the above-described heating-side heat transfer sheet 41, that is, a sheet having excellent heat conductivity and having appropriate elasticity (softness) can be used. As a result, when sandwiched between the cooling side pedestal 30a and the thermoelectric module 11, they are in close contact with each other, so that the cooling efficiency of the thermoelectric module 11 is increased compared to the case where there is no cooling side heat transfer sheet 42. At the same time, the thermoelectric module 11 can be damaged by acting as a buffer material.

  The heat insulating material 12 includes a heating side facing surface 20c and a cooling side facing surface 30c around the heating side pedestal 20a, the heating side heat transfer sheet 41, the thermoelectric module 11, the cooling side heat transfer sheet 42, and the cooling side pedestal 30a. It is pinched (interposed) between. That is, the heat insulating material 12 is interposed between the heat receiving panel 20 and the cooling unit 30 in substantially the entire portion where the thermoelectric module 11 is not provided. As shown in FIG. 8, the heat insulating material 12 covers the substantially entire surface of the rear surface of the heat receiving board 20 (the surface facing upward in FIG. 8) other than the portion where the thermoelectric module 11 is arranged in a frame shape. 12A and a heat insulating material 12B that covers the entire front surface of the cooling unit 30 (the surface facing upward in FIG. 8) except for the portion where the thermoelectric module 11 is disposed in a frame shape, The heat insulating material 12 whole is comprised by combining these heat insulating materials 12A and 12B. When the heat receiving board 20 and the cooling unit 30 are combined to form the power generation unit 3, the heat insulating material 12A on the heat receiving board 20 side is located on the lower part 12a, the upper part 12b, and on the left side. 12h in the left-right direction so that the left-side part 12e and the right-side part 12f are connected between the upper and lower adjacent thermoelectric modules 11, 11. Is provided. In the right portion 12f, a notch 12g for taking out the lead wire 11d connected to the thermoelectric module 11 is formed. From another point of view, the heat insulating material 12A on the heat receiving board 20 side is a plate-like heat insulating material having substantially the same shape as the power receiving board 20, and the heating side thermoelectric sheet 41 and the thermoelectric module 11 are arranged. It can be said that a notch 12g that communicates with the outside is formed at two locations on the left side of the recess. Further, as shown in FIG. 9, the heat insulating material 12A has a portion 12c that can be engaged with a groove portion 20h formed around the heating side base 20a of the heat receiving board 20, and this portion 12c is engaged with the groove portion 20h. By combining them, the heat insulating material 12 </ b> A can be easily positioned with respect to the heat receiving board 20. The heat insulating material 12A has a through hole 12k through which a bolt 43 described later passes.

  The heat insulating material 12B on the cooling unit 30 side is the same as the heat insulating material 12A on the heat receiving panel 20 described above. That is, the heat insulating material 12B includes the lower portion 12a, the upper portion 12b, and the left portion 12e when the heat receiving panel 20 and the cooling unit 30 are combined to form the power generation unit 3. The left portion 12h and the right portion 12f are connected between the thermoelectric modules 11 and 11 adjacent to each other in the left and right direction. ing. In the right part 12e, a notch 12g for taking out the lead wire 11d connected to the thermoelectric module 11 is formed. Further, as shown in FIG. 9, the heat insulating material 12B has a portion 12c that can be engaged with a groove 30h formed around the heating side pedestal 30a of the cooling unit 30, and this portion 12c is engaged with the groove 30h. By combining, the heat insulating material 12B can be easily positioned with respect to the cooling unit 30. The heat insulating material 12B has a through hole 12k through which a bolt 43 described later passes.

  As shown in FIG. 9, the heat insulating materials 12 </ b> A and 12 </ b> B having the above-described configuration are sandwiched (interposed) so as to overlap between the heat receiving plate 20 and the cooling unit 30, and are tightened by bolts 43 described below.

  The bolt 43 as a fastening member has a head portion 43a on the proximal end side (lower side in FIG. 9), and a male screw portion 43b is screwed on the distal end side. The bolt 43 has its head portion 43a accommodated in the recess 20b of the front surface 20e of the heat receiving board 20, and the intermediate portion passes through the through hole 20f, the through hole 12k of the heat insulating material 12A, and the through hole 12k of the heat insulating material 12B to cool it. The unit 30 is screwed into the female screw portion 30e of the front surface 30c. The bolts 43 are provided so as to penetrate the numerous through holes 12k of the heat insulating materials 12A and 12B shown in FIG. That is, the bolts 43 are provided at one place on each of the left and right sides of each thermoelectric module 11, and at three places on each of the upper side of the uppermost thermoelectric module 11 and the lower side of the lowermost thermoelectric module 11. Yes.

  Here, in this embodiment, the bolt 43 is not made of general steel but is made of synthetic resin. Since the synthetic resin bolt 43 has a lower thermal conductivity than the steel bolt and heat is not easily transmitted, the heat escaped from the heat receiving plate 20 side to the cooling unit 30 via the bolt 43 can be suppressed. Further, since the synthetic resin bolt 43 is more easily elastically deformed than the steel bolt, when the heat receiving plate 20 and the cooling unit 30 are fastened, the fastening force is excessive, unlike the steel bolt. Therefore, there is little possibility of damaging the thermoelectric module 11. As a material of such a synthetic resin bolt 43, for example, thermoplastic polyimide or the like is suitable.

  Regarding the magnitude relationship between the height L1 of the heating side pedestal 20a on the heat receiving board 20 side and the height L2 of the cooling side pedestal 30a on the cooling unit 30 side, for example, the heat capacity of the heat receiving board 20 and the cooling unit 30 When comparing the heat capacity, if the former heat receiving panel 20 is larger, L1> L2, and conversely if the latter cooling unit 30 is larger, L1 <L2. In the present embodiment, between the heating side pedestal 20a (or the heating side heat transfer sheet 41) of the heat receiving panel 20 and the thermoelectric module 11, and the cooling side pedestal 30a (or the cooling side heat transfer sheet 42) of the cooling unit 30. When the state where there is no movement of heat with the thermoelectric module 11 is assumed to be thermal equilibrium, the power generation efficiency of the thermoelectric module 11 is highest when the thermoelectric module 11 is in thermal equilibrium. This thermal equilibrium can be achieved by changing the position of the thermoelectric module 11 in the front-rear direction, that is, the heights L1 and L2. In the present embodiment, the heights L1 and L2 are in a relationship such that when one increases, the other decreases.

  In the present embodiment, the magnitude relationship between the heights L1 and L2 is determined as described above, that is, when the heat receiving plate 20 is larger by comparing the heat capacities, L1> L2, and conversely the cooling unit. When 30 is larger, it is possible to maintain the thermoelectric module 11 in a state close to thermal equilibrium by setting L1 <L2. It should be noted that specific numerical values and the like of the heights L1 and L2 may be set based on an experiment with an actual power generation unit 3 or the like.

As described above, according to the present embodiment, the following effects can be obtained.
-By providing the heating side base 20a and the cooling side base 30a on the heat receiving board 20 and the cooling unit 30, respectively, heat can be concentrated on them.
By interposing (clamping) the heating side heat transfer sheet 41 and the cooling side heat transfer sheet 42 between the thermoelectric module 11 and the heating side pedestal 20a and the cooling side pedestal 30a, Heat transfer efficiency can be increased.
Furthermore, since the heating side heat transfer sheet 41 and the cooling side heat transfer sheet 42 act as cushioning materials, breakage of the fragile thermoelectric module 11 can be suppressed during assembly.
Since the bolt (fastening member) 43 that fastens the heat receiving board 20 and the cooling unit 30 is made of synthetic resin, the thermal conductivity can be made lower than that of a general steel bolt. It is possible to reduce the heat leaking through.
Furthermore, since the bolt 43 is made of a synthetic resin and easily stretches with respect to the steel bolt, damage to the thermoelectric module 11 due to excessive fastening force can be reduced.
The thermoelectric module 11 is brought close to thermal equilibrium by setting the magnitude relationship between the height L1 of the heating side pedestal 20a and the height L2 of the cooling side pedestal 30a in accordance with the magnitude relationship between the heat capacities of the heat receiving board 20 and the cooling unit 30. Therefore, the heat transfer efficiency can be further increased.

1, 2, 3 Power generation unit 10 Thermoelectric unit 11 Thermoelectric module 11a Thermoelectric element 12 Heat insulating material 20 Heat receiving panel (heating side)
20a Heating side base 20c Heating side facing surface 20h Groove 30 Cooling unit (cooling side)
30a Cooling side pedestal 30c Cooling side facing surface 30h Groove part 41 Heating side heat transfer sheet 42 Cooling side heat transfer sheet 43 Bolt (fastening member)
L1 Heating side pedestal height (thickness)
L2 Cooling side pedestal height (thickness)

Claims (4)

Power generation configured by sandwiching a plate-shaped thermoelectric module configured by electrically connecting a plurality of thermoelectric elements between a heating side facing surface and a cooling side facing surface that face each other between the heat receiving panel and the cooling unit. In the heat transfer structure of the unit,
A heating side pedestal formed substantially in the same shape as the thermoelectric module by protruding a part of the heating side facing surface in a plate shape;
A cooling side pedestal formed substantially in the same shape as the thermoelectric module by projecting a part of the cooling side facing surface into a plate shape;
A heating side heat transfer sheet formed in substantially the same shape as the thermoelectric module and sandwiched between the heating side pedestal and the thermoelectric module;
A cooling side heat transfer sheet formed in substantially the same shape as the thermoelectric module and sandwiched between the cooling side pedestal and the thermoelectric module;
The heating side pedestal, the heating side heat transfer sheet, the thermoelectric module, the cooling side heat transfer sheet, and the cooling side pedestal are interposed between the heating side facing surface and the cooling side facing surface. An insulation material,
A heat transfer structure of a power generation unit characterized by that. A fastening member that penetrates through the heat insulating material and connects the heat receiving plate and the cooling unit;
The fastening member is made of synthetic resin;
The heat transfer structure for a power generation unit according to claim 1. When the thickness of the heating side pedestal is the heating side thickness and the thickness of the cooling side pedestal is the cooling side thickness, if the heat capacity of the heat receiving plate is larger than the heat capacity of the cooling unit, the heating side pedestal When the thickness is made thicker than the cooling side thickness and the heat capacity of the heat receiving plate is smaller than the heat capacity of the cooling unit, the heating side thickness is made thinner than the cooling side thickness,
The heat transfer structure for a power generation unit according to claim 1 or 2. A groove portion is formed around the heating side pedestal and the cooling side pedestal so that the heat insulating material is engaged and positioned.
The heat transfer structure for a power generation unit according to claim 1, wherein the heat transfer structure is a heat transfer structure.

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