JP2007211748A - Heat exchanger and thermoelectric generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger and a thermoelectric generator capable of suppressing change of fin intervals due to thermal deformation of fins. <P>SOLUTION: A high temperature side heat exchanger 12 constructing an exhaust thermoelectric generator 10 is provided with a high temperature side heat exchanger case 18 forming a passage of exhaust gas and a fin heat collection part 20 having a plurality of fins 48 arranged in parallel with an exhaust gas flow direction in a high temperature side heat exchanger case 18. At least part of an outer surface of a circumference wall of the high temperature side heat exchanger case 18 is used as an upper side heat transmission surface 12A and a lower side heat transmission surface 12B touching each heat power generation module 16. A plurality of heat collection fin 48 is formed in a corrugated plate shape to make thermal deformation direction consistent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat exchanger for transferring heat of a heat exchange medium that passes through a shell to a heat transfer object in contact with a heat transfer surface of the shell, and a thermoelectric generator including the heat exchanger.

Some vehicles, such as automobiles, are equipped with an automobile exhaust heat power generation device that generates electric power using exhaust heat of an engine (see, for example, Patent Document 1). The heat exchanger constituting the automobile exhaust heat power generation apparatus is configured to transmit heat of exhaust gas to the power generation module, and is configured by connecting the rectangular cross-section facing surfaces in the short direction with a plurality of fins. ing.
JP 2001-12240 A JP 2002-199762 A

  However, in the conventional technology as described above, since the direction of thermal deformation of the fins is different for each fin, there is a concern that the fin interval, that is, the exhaust gas flow rate between the plurality of fins becomes uneven and the heat recovery efficiency decreases. The In particular, when a large number of fins are arranged at a narrow interval, the rate of change in fin interval due to thermal deformation with respect to the fin interval before thermal deformation becomes large, so the above problem becomes significant.

  In view of the above fact, an object of the present invention is to obtain a heat exchanger and a thermoelectric generator that can suppress changes in fin spacing due to thermal deformation of fins.

  In order to achieve the above object, the heat exchanger according to the first aspect of the present invention forms a heat exchange medium flow path, and at least a part of the outer surface of the peripheral wall is a heat transfer surface in contact with the heat transfer object. A shell, a plurality of fins standing from the back surface side of the heat transfer surface on the peripheral wall of the shell, and parallel to the flow direction of the heat exchange medium, and fin deformation for matching the heat deformation direction of the plurality of fins Direction regulating means.

  In the heat exchanger according to the first aspect, the heat of the heat exchange medium flowing through the shell is collected by a plurality of fins and transmitted from the heat transfer surface of the shell to the heat transfer target. At this time, each fin is thermally deformed by heat exchange with the heat exchange medium. Here, the present heat exchanger is provided with fin deformation direction regulating means that substantially matches the direction in which each fin is thermally deformed (the shape after deformation). The change of is suppressed. Thereby, a fin space | interval is kept substantially constant and required heat exchange performance is ensured.

  Thus, in the heat exchanger according to the first aspect, changes in the fin interval due to thermal deformation of the fins can be suppressed.

  The heat exchanger according to a second aspect of the present invention is the heat exchanger according to the first aspect, wherein the plurality of fins are provided on each of a back surface of the heat transfer surface and a surface facing the back surface of the peripheral wall of the shell. The fin deformation direction restricting means is a bent shape formed by bending an intermediate portion in the fin standing direction to the same side so that the plurality of fins connect the opposing surfaces of the shell with curves.

  In the heat exchanger according to claim 2, both ends of the plurality of fins in the standing direction from the back surface of the heat transfer surface are constrained by connection with the shell, and at the intermediate portion in the standing direction, They are pre-curved and juxtaposed so as to project in the direction intersecting (right angle) with the flow direction. For this reason, each fin deform | transforms into the preset bending direction by heat exchange with a heat exchange medium. Thus, the fin deformation restricting means is realized with a simple structure.

  A heat exchanger according to a third aspect of the present invention is the heat exchanger according to the first aspect, wherein the shell forms the flow path having a rectangular cross section and the outer surfaces of the portions facing each other on the peripheral wall are each The plurality of fins are respectively connected to back surfaces of the respective heat transfer surfaces of the peripheral wall of the shell facing each other, and the fin deformation direction regulating means is configured such that the plurality of fins are It is a bent shape formed by bending the intermediate portion in the fin erection direction to the same side so as to connect the opposing surfaces of the shell with a curve.

  4. The heat exchanger according to claim 3, wherein the heat of the heat exchange medium flowing through the shell is collected by a plurality of fins and is in contact with each heat transfer surface, which is the outer surface of the opposing peripheral wall of the shell. Communicated to the subject. The plurality of fins are constrained at both ends in the standing direction by connection to the back surface of each heat transfer surface, and project in a direction intersecting (at a right angle) with the flow direction of the heat exchange medium at an intermediate portion of the standing direction. As described above, they are bent or curved in parallel. For this reason, each fin deform | transforms into the preset bending direction by heat exchange with a heat exchange medium. Thus, the fin deformation restricting means is realized with a simple structure in the structure in which the heat transfer object is arranged on both sides of the shell.

  A heat exchanger according to a fourth aspect of the present invention is the heat exchanger according to any one of the first to third aspects, wherein the plurality of fins are arranged in parallel along the flow direction of the heat exchange medium. The unit heat collecting portions thus arranged were arranged at predetermined intervals in the flow direction of the heat exchange medium.

  In the heat exchanger according to claim 4, since the plurality of unit heat collecting portions are arranged in the heat exchange medium at predetermined intervals in the flow direction, in other words, a gap is set between the unit heat collecting portions. The heat exchange medium is diffused in the gaps, so that the temperature (distribution) of the heat exchange medium is made uniform, and the heat exchange medium having the uniform temperature flows into the unit heat collecting section on the downstream side. For this reason, in each part of each unit heat collection part arrange | positioned along the flow direction of a heat exchange medium, heat exchange performance can be improved using a fin area as an effective heat collection surface. In addition, in this heat exchanger, when the amount of thermal deformation between the upstream unit heat collection unit and the downstream unit heat collection unit is different due to the temperature difference between the upstream side and the downstream side of the heat exchange medium, the unit collection is performed. Since the fins are not distorted (not continuous) due to the difference in the amount of thermal deformation due to the gaps between the hot portions, the fin interval is kept substantially constant. The predetermined interval between the unit heat collecting units may be a fixed interval or an indefinite interval.

  In order to achieve the above object, a heat exchanger according to a fifth aspect of the present invention forms a flow path of a heat exchange medium, and at least a part of the outer surface of the peripheral wall is a heat transfer surface in contact with a heat transfer target. A plurality of fins configured in parallel with the shell and in the flow direction of the heat exchange medium and connected to the back surface of the heat transfer surface and the opposing surface of the back surface of the peripheral wall of the shell. And a heat collecting part configured by arranging unit heat collecting parts at predetermined intervals in the flow direction of the heat exchange medium.

  In the heat exchanger according to the fifth aspect, the heat of the heat exchange medium flowing through the shell is collected by the fins constituting the heat collecting section, and is transmitted from the heat transfer surface of the shell to the heat transfer target. At this time, each fin is thermally deformed by heat exchange with the heat exchange medium. Here, since the plurality of unit heat collecting portions are arranged in the heat exchange medium at predetermined intervals in the flow direction, in other words, since a gap is set between the unit heat collecting portions, heat exchange is performed in the gap. When the medium is diffused, the temperature (distribution) of the heat exchange medium is made uniform, and the heat exchange medium with the temperature made uniform flows into the unit heat collecting section on the downstream side. For this reason, in each part of each unit heat collection part arrange | positioned along the flow direction of a heat exchange medium, heat exchange performance can be improved using a fin area as an effective heat collection surface. In addition, in this heat exchanger, when the amount of thermal deformation between the upstream unit heat collection unit and the downstream unit heat collection unit is different due to the temperature difference between the upstream side and the downstream side of the heat exchange medium, the unit collection is performed. Since the fins are not distorted (not continuous) due to the difference in the amount of thermal deformation due to the gaps between the hot portions, the fin interval is kept substantially constant.

  Thus, in the heat exchanger according to claim 5, it is possible to suppress changes in the fin interval due to thermal deformation of the fins. The predetermined interval between the unit heat collecting units may be a fixed interval or an indefinite interval.

  A heat exchanger according to a sixth aspect of the present invention is the heat exchanger according to any one of the first to fifth aspects, wherein the heat exchange medium is supplied to an inlet side of the heat exchange medium in the shell. A connecting channel forming part connected to the pipe while gradually changing the channel cross-sectional shape is provided, and the connecting channel forming part includes a part of the heat exchange medium in the center of the shell in the shell. Guide means for guiding in a direction away from the vehicle is provided.

  In the heat exchanger according to claim 6, the heat exchange medium is introduced from the supply pipe into the shell via the connection flow path forming portion. In the connected flow path forming section that gradually changes the shape of the flow path cross section, the guide means guides the heat exchange medium in the direction away from the center of the shell (toward the peripheral edge). It is possible to prevent the medium flow from being biased toward the center of the shell. As a result, the flow (flow rate) of the heat exchange medium introduced into the shell is made uniform, that is, the amount of heat exchange between the fins and the heat exchange medium is made uniform, and the change in the fin interval due to thermal deformation is more effective. Is suppressed.

  A heat exchanger according to a seventh aspect of the present invention is the heat exchanger according to the sixth aspect, wherein the connecting flow path forming portion exchanges the heat in a first predetermined direction perpendicular to the flow direction of the heat exchange medium. The flow path of the medium is narrowed, and the flow path of the heat exchange medium is widened in a second predetermined direction perpendicular to the flow direction of the heat exchange medium and the first predetermined direction. The medium flow is configured to be distributed in the second predetermined direction.

  In the heat exchanger according to claim 7, the guide means disperses and expands the flow of the heat exchange medium contracted in the first predetermined direction in the second predetermined direction. Thereby, the flow of the heat exchange medium introduced into the shell is made uniform.

  The thermoelectric generator according to claim 8 is a thermoelectric generator that generates electromotive force due to a temperature difference between a high temperature side and a low temperature side, a cooling unit for cooling the low temperature side of the thermoelectric generator, and the thermoelectric generator A thermoelectric generator having a heating unit for heating the high temperature side, wherein the heating unit uses exhaust gas as the heat exchange medium and the heat transfer target is the high temperature side of the thermoelectric generator. The heat exchanger according to any one of claims 1 to 7.

  In the thermoelectric generator according to claim 8, the thermoelectric generator is generated (maintained) when the high temperature side (heat absorption side) is heated by the heating unit and the low temperature side (heat dissipation side) is cooled by the cooling unit. An electromotive force is generated by the temperature difference between the high temperature side and the low temperature side. Here, since the heat exchanger according to any one of claims 1 to 8 is used as the heating unit, the heat recovery efficiency from the exhaust gas by the heat exchanger is high, and the power generation efficiency is improved.

  As described above, the heat exchanger and the thermoelectric generator according to the present invention have an excellent effect of being able to suppress changes in the fin interval due to thermal deformation of the fins.

  An exhaust heat power generation apparatus 10 to which a high temperature side heat exchanger 12 that is a heat exchanger according to an embodiment of the present invention is applied will be described with reference to FIGS. 1 to 7. In the following description, for the sake of convenience, the direction indicated by the arrow U is the upward direction, the direction indicated by the arrow W is the width direction, and the direction indicated by the arrow F is the exhaust gas flow direction. First, the schematic overall configuration of the exhaust heat power generation apparatus 10 will be described, and then the fin structure and exhaust gas guide structure of the high temperature side heat exchanger 12 which are the main parts of the present invention will be described in detail.

(Overall configuration of exhaust heat generator)
4 shows a schematic overall configuration of the exhaust thermoelectric generator 10 in a side view, and FIG. 1 shows a cross-sectional view taken along line 1-1 of FIG. 2 is a side sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a plan sectional view taken along line 3-3 in FIG. As shown in FIGS. 1 to 4, the exhaust thermoelectric generator 10 includes a high temperature side heat exchanger 12 as a heat exchanger (heat recovery device) in the present invention and a low temperature side heat exchanger 14 as a cooling unit. A plurality of thermoelectric generator modules 16 as thermoelectric generators are sandwiched therebetween. Each thermoelectric generation module 16 is formed in a rectangular shape in plan view that is flattened in the vertical direction.

  As shown in FIG. 1, the high temperature side heat exchanger 12 is formed in a flat rectangular shape whose vertical height is smaller than the width, and between the upper heat transfer surface 12 </ b> A and the upper low temperature side heat exchanger 14. A plurality of thermoelectric modules 16 are sandwiched and held, and the same number of thermoelectric modules 16 are sandwiched and held between the lower heat transfer surface 12B and the lower low-temperature heat exchanger 14. In this embodiment, the exhaust thermoelectric generator 10 holds four thermoelectric generator modules 16 in the exhaust gas flow direction and two in the width direction on one side of the high temperature side heat exchanger 12. A total of 16 thermoelectric generator modules 16 are provided.

  As shown in FIG. 1, the high temperature side heat exchanger 12 is a high temperature side heat exchanger case as a shell that forms a flat rectangular exhaust gas passage in a cross-sectional view along a plane orthogonal to the flow direction of the exhaust gas. A fin heat collecting portion 20 as a heat collecting portion is disposed in the heat sink 18. As shown in FIGS. 2 to 4, the high temperature side heat exchanger case 18 has an upstream end 18A as a connecting flow path forming portion at the downstream end of the catalytic converter 22 for purifying exhaust gas of an internal combustion engine of an automobile. The downstream end 18B is connected to the upstream end of the exhaust pipe connecting portion 24 via the downstream connection duct 26.

  At the upstream end of the catalytic converter 22, a flange 22 </ b> A connected to an unillustrated exhaust manifold assembly or an exhaust pipe is provided. At the downstream end of the exhaust pipe connecting portion 24, a muffler (not shown) or a flange 24A connected to the exhaust pipe is provided. As a result, the high temperature side heat exchanger case 18 allows the exhaust gas introduced from the internal combustion engine through the catalytic converter 22 to pass through and is discharged to the muffler or the like via the exhaust pipe connecting portion 24. Yes. In this embodiment, the catalytic converter 22 corresponds to a “heat exchange medium supply pipe”.

  As shown in FIG. 3, each side wall 28 constituting both ends in the width direction of the high temperature side heat exchanger case 18 has a double structure, and a heat insulating air layer 28C is provided between the inner side wall 28A and the outer side wall 28B. Is formed. The fin heat collector 20 disposed in the high temperature side heat exchanger case 18 receives heat received from the exhaust gas flowing in the high temperature side heat exchanger case 18 in the direction of arrow F in the high temperature side heat exchanger case 18. The outer surface (upper surface) is transmitted to the top plate 30 having the upper heat transfer surface 12A, and the outer surface (lower surface) is transmitted to the bottom plate 32 having the lower heat transfer surface 12B. The detailed structure of these fin heat collecting parts 20 will be described later.

  Each of the plurality of thermoelectric generation modules 16 is configured by modularizing a large number of thermoelectric generation elements (not shown), and is formed in a flat rectangular shape as described above. Each thermoelectric module 16 generates an electromotive force due to a temperature difference between the high temperature side and the low temperature side. Therefore, each thermoelectric generation module 16 has the high temperature side surface 16A in contact with the high temperature side heat exchanger 12 (the top plate 30 or the bottom plate 32) and the low temperature side surface 16B in contact with the low temperature side heat exchanger 14. .

  As shown in FIGS. 1 and 4, the low-temperature side heat exchanger 14 is formed in a rectangular shape having a length and width substantially equal to the high-temperature side heat exchanger case 18 in a plan view and flattened in the vertical direction. Is formed. As shown in FIG. 1, the low-temperature side heat exchanger 14 closes the opening end of the low-temperature side heat exchanger case 34 that opens to the thermoelectric generator module 16 side with a lid plate 36, so Is formed. Further, in this embodiment, a partition wall 34A that divides the cooling water flow path 38 into two cooling water flow paths 38A and 38B that are arranged in parallel in the width direction is provided upright at the center in the width direction of the low temperature side heat exchanger case 34. .

  In this low temperature side heat exchanger 14, the low temperature side heat exchanger case 34 and the cover plate 36 are not joined, and the thermoelectric generation module 16 is sandwiched between the low temperature side heat exchanger 14 and the high temperature side heat exchanger 12. The low-temperature side heat exchanger case 34 and the lid plate 36 sandwiching a waterproof packing (not shown) maintain the state in which the cooling water flow path 38 is formed by a holding load to be described later for holding. Although not shown, the low temperature side heat exchanger 14 has a cooling water introduction part for introducing engine cooling water into the cooling water passages 38A and 38B, and an exhaust for discharging engine cooling water from the cooling water passages 38A and 38B. A cooling water discharge part is provided. In addition, a plurality of radiating fins 36A formed in a plate shape along the vertical direction and the cooling water flow direction (exhaust gas flow direction) are erected from the lid plate 36 at regular intervals.

  The exhaust thermoelectric generator 10 includes a bracket 40 and a disc spring 42 as an elastic body that is disposed between the bracket 40 and the low-temperature side heat exchanger 14 in a compressed state and constitutes a holding load applying unit. ing. In the exhaust thermoelectric generator 10, the thermoelectric generator module 16 is placed between the low temperature side heat exchanger 14 and the high temperature side heat exchanger 12 by a holding load along the vertical direction based on the biasing force (restoring force) of the disc spring 42. It comes to hold.

  In the exhaust thermoelectric generator 10 in which the thermoelectric generator module 16 and the low temperature side heat exchanger 14 are arranged on both upper and lower sides of the high temperature side heat exchanger 12, the bracket 40 is formed in an annular shape that is not in contact with the high temperature side heat exchanger 12. ing. Specifically, as shown in FIGS. 1 and 4, the bracket 40 includes a flange 40 </ b> C formed by overlapping half bodies 40 </ b> A and 40 </ b> B formed in a hat shape in front view, and bolts and nuts as main components. By being fixed by the fastening means 40D, the whole is formed in an annular shape as described above. The bracket 40 that is formed in an annular shape and is not in contact with the high temperature side heat exchanger 12 is configured to be hardly affected by the heat from the high temperature side heat exchanger 12.

  In this embodiment, one disc spring 42 is provided for one thermoelectric generation module 16. Thereby, in the exhaust thermoelectric generator 10, the holding load of the disc spring 42 corresponding to each thermoelectric generator module 16 acts. More specifically, as shown in FIG. 1, a disc spring 42 is provided corresponding to each of the two upper and lower thermoelectric generator modules 16 disposed along the circumferential direction of the high temperature side heat exchanger 12. A common bracket 40 supports the four disc springs 42. Therefore, in this embodiment, the exhaust thermoelectric generator 10 has the four brackets 40 arranged along the flow direction of the exhaust gas.

  Furthermore, in this embodiment, as shown in FIG. 1, the exhaust thermoelectric generator 10 includes a load adjustment mechanism 44 that can adjust the holding load based on the compression amount of the disc spring 42, that is, the restoring force of the disc spring 42. . As shown in FIGS. 1 and 3, the load adjusting mechanism 44 is provided for each thermoelectric generation module 16 (four for each bracket 40) corresponding to the plurality of disc springs 42, that is, the thermoelectric generation modules 16. The holding load of the thermoelectric generator module 16 can be adjusted independently.

(High temperature side heat exchanger fin structure)
As shown in FIGS. 2, 3, and 5, the fin heat collecting section 20 constituting the high temperature side heat exchanger 12 has a plurality of units (four in this embodiment) arranged along the arrow F direction. A unit fin heat collecting part 46 as a heat collecting part is provided. Each unit fin heat collecting portion 46 is configured as an aggregate of a large number of heat collecting fins 48. In this embodiment, each heat collection fin 48 is provided (extended) along the direction of arrow F, and comes into contact with the exhaust gas flowing in the direction of arrow F to receive heat from the exhaust gas. ing.

  As shown in FIG. 6, which is a cross-sectional view taken along line 6-6 in FIG. 5, each heat collection fin 48 has an upper end 48A and an outer surface of the high temperature side heat exchanger case 18 as an upper heat transfer surface 12A. While being fixedly connected to the top plate 30, the lower end 48B is fixedly connected to the bottom plate 32 whose outer surface is the lower heat transfer surface 12B. In this embodiment, the high temperature side heat exchanger case 18 and the heat collecting fins 48 constituting the high temperature side heat exchanger 12 through which high temperature exhaust gas flows are excellent in heat resistance (creep resistance) such as stainless steel, for example. The heat collecting fin 48 and the top plate 30 and the bottom plate 32 of the high temperature side heat exchanger case 18 are joined by brazing. The space between each heat collection fin 48 and the inner wall 28A located at the outer end in the width direction is sealed with a sealing agent (not shown).

  As described above, in each unit fin heat collecting section 46, the heat received by the heat collecting fin 48 from the exhaust gas is transmitted to the upper heat transfer surface 12A, the lower heat transfer surface 12B, that is, the high temperature side of each thermoelectric generator module 16. Has been. In this embodiment, each heat collection fin 48 is formed to be curved with respect to the vertical direction. Specifically, as shown in FIG. 6, each heat collection fin 48 is formed in a substantially wave shape in which the amplitude direction substantially coincides with the width direction (the direction perpendicular to the arrow F direction and the vertical direction), Each is formed in the same shape. Thereby, in each unit fin heat collecting part 46, the space | interval G between the adjacent heat collecting fins 48 is made substantially constant for each heat collecting fin 48, and the vertical direction between the same heat collecting fins 48 is set. Each part is also substantially constant. The curved shape of each of the heat collecting fins 48 corresponds to the “fin deformation direction restricting means” in the present invention.

  Further, as shown in FIG. 6, the unit fin heat collecting portions 46 adjacent to each other in the arrow F direction in the high temperature side heat exchanger case 18 are spaced apart at a predetermined interval in the arrow F direction. Thereby, the diffusion gas layer 50 which is a space | gap is set between the unit fin heat collection parts 46 adjacent to the arrow F direction, respectively. The diffusion gas layer 50 is a space for allowing the exhaust gas that has passed through the upstream unit fin heat collecting section 46 to diffuse before being introduced into the unit fin heat collecting section 46 on the downstream side.

  As shown in FIGS. 2 and 3, the four unit fin heat collecting portions 46 arranged at predetermined intervals along the arrow F direction are respectively connected to the upper heat transfer surface 12 </ b> A and the lower heat transfer surface of the high temperature side heat exchanger 12. It arrange | positions corresponding to each thermoelectric generation module 16 arrange | positioned along the arrow F direction at the hot surface 12B side. In other words, the gap between the thermoelectric generator modules 16 adjacent in the arrow F direction corresponds to the diffusion gas layer 50. Therefore, in the high temperature side heat exchanger 12, one unit fin heat collecting section 46 collects (collects) the heat of the exhaust gas for each of the four thermoelectric modules 16 in total, two in the vertical direction. It is configured.

(Exhaust gas guide structure for high temperature side heat exchanger)
As shown in FIGS. 2 and 3, the upstream side connection duct 25 constituting the high temperature side heat exchanger 12 includes a catalytic converter 22 having a substantially circular cross section and a high temperature side heat exchanger case 18 having a flat rectangular shape in cross section. Are communicated by continuously changing (gradually changing) the cross-sectional shape. For this reason, the upstream side connection duct 25 has a reduced flow shape that restricts the exhaust gas passage in the vertical direction as the first predetermined direction in a side view, and the exhaust gas passage in the second predetermined direction in a plan view. It has a widening shape that widens in the width direction.

  A gas diffusion guide 52 as guide means for guiding the exhaust gas is disposed in the upstream connection duct 25 so as to disperse the flow of the exhaust gas in the width direction of the high temperature side heat exchanger case 18. As shown in FIG. 3, the gas diffusion guide 52 has a plurality of inclined portions with respect to the direction of the arrow F in plan view so that the downstream end is positioned on the outer side in the width direction than the upstream end in the exhaust gas flow direction. A flat guide piece 54 is included. As shown in FIG. 2, each guide piece 54 has an upper end fixedly connected to the upper wall portion 25A of the upstream connection duct 25 and a lower end fixedly connected to the lower wall portion 25B.

  Thereby, a part of the exhaust gas passing through the upstream connection duct 25 is guided outward in the width direction by the gas diffusion guide 52, that is, each guide piece 54, and the exhaust gas as a whole extends in the width direction of the high temperature side heat exchanger case 18. To be distributed. Further, the gas diffusion guide 52 disperses the exhaust gas flow toward the central portion of the high temperature side heat exchanger case 18 in the width direction according to the contracted shape in the side view, thereby reducing the vertical contracted flow (center The flow velocity of the flow concentrated on the part) is suppressed. As a result, the total heat amount of the exhaust gas passing through the upstream connection duct 25 is introduced into the high temperature side heat exchanger case 18, that is, the respective portions of the high temperature side heat exchanger 12 in a substantially uniform manner.

  Next, the operation of the embodiment will be described.

  In the exhaust heat power generation apparatus 10 having the above-described configuration, when the internal combustion engine of the automobile is started, the exhaust gas of the engine is introduced into the high temperature side heat exchanger 12 (high temperature side heat exchanger case 18) via the catalytic converter 22. The The exhaust gas contacts the fin heat collecting section 20 and the top plate 30 and the bottom plate 32 of the high temperature side heat exchanger case 18 to exchange heat with them, and gives heat to the top plate 30 and the bottom plate 32. Thereby, the high temperature side of each thermoelectric generation module 16 that is in contact with the upper heat transfer surface 12A and the lower heat transfer surface 12B that are the outer surfaces of the top plate 30 and the bottom plate 32 is heated. The exhaust gas passing through the high temperature side heat exchanger 12 while being cooled by the heat exchange is discharged out of the apparatus through the exhaust pipe connecting portion 24.

  On the other hand, the engine cooling water circulates in the order of, for example, the cooling water passages 38 (respective cooling water passages 38A and 38B) of the upper and lower low-temperature heat exchangers 14, the internal combustion engine, and the radiator by the operation of a water pump (not shown) of the engine. . Engine cooling water that passes through the cooling water flow path 38 of the low-temperature side heat exchanger 14 contacts the heat radiating fins 36 </ b> A and the lid plate 36, exchanges heat therewith, and takes heat from the lid plate 36. Thereby, the low temperature side of each thermoelectric generation module 16 in contact with the cover plate 36 is cooled.

  As described above, the high temperature side of each thermoelectric generation module 16 is heated by effectively using the heat of the exhaust gas, and the low temperature side of each thermoelectric generation module 16 is cooled by the engine cooling water. The temperature difference between the 16 high and low temperature sides is ensured, and each thermoelectric generation module 16 generates an electromotive force based on this temperature difference. That is, in the exhaust thermoelectric generator 10, each thermoelectric generator module 16 generates electric power. The generated electric power is stored in, for example, a battery that is a storage battery mounted on an automobile (charges the battery).

  By the way, in the exhaust thermoelectric generator 10, each heat collection fin 48 which comprises the fin heat collecting part 20 expands thermally by contact with high temperature exhaust gas, and upper and lower ends are fixed to the high temperature side heat exchanger case 18. Therefore, thermal deformation (bending or bending) is caused to escape the thermal expansion.

  Here, in the exhaust thermoelectric generator 10, the heat collecting fins 48 are formed in a substantially wave shape, so that the vertical portions of the heat collecting fins 48 adjacent in the width direction are deformed in the same direction. (Bend). For this reason, even if the heat collection fins 48 are thermally deformed by the heat from the exhaust gas, the gap G between the heat collection fins 48 adjacent in the width direction is kept substantially constant. For example, in a configuration in which the upper and lower ends of the flat plate-like heat collecting fins extending in the vertical direction in a non-circulating state of the exhaust gas are constrained by the high-temperature side heat exchanger case 18, Therefore, a portion where the interval between the heat collecting fins adjacent to each other in the width direction is wide and a portion where the heat collecting fin is narrow are generated. Since the exhaust gas hardly flows in the portion where the interval between the heat collecting fins adjacent in the width direction is narrow, it causes the heat recovery efficiency to deteriorate. On the other hand, in the exhaust thermoelectric generator 10, as described above, the interval G between the heat collecting fins 48 adjacent in the width direction is kept substantially constant, so that the heat recovery efficiency is improved.

  Here, in the exhaust thermoelectric generator 10, since the diffusion gas layer 50 is set between the unit fin heat collecting portions 46 constituting the fin heat collecting portion 20, the exhaust gas that has passed through the upstream unit fin heat collecting portion 46 is Since the exhaust gas diffused in the diffusion gas layer 50 and having a uniform temperature flows into the next unit fin heat collecting section 46, the heat recovery efficiency is further improved. That is, in general, in a fin type heat exchanger, the exhaust gas becomes cold at the base side (upper and lower ends) near the heat transfer surface of the fin, and the exhaust gas becomes hot at the center in the vertical direction of the fin. Since the downstream side of the flow is more conspicuous, for example, in the configuration without the diffusion gas layer 50, the exhaust gas temperature difference between the fin base portion and the central portion increases toward the downstream side of the exhaust gas flow. Since the gas temperature is non-uniform in the cross section perpendicular to the flow direction, the heat recovery rate is low.

  On the other hand, in the exhaust thermoelectric generator 10, as described above, the gas diffused in the diffusion gas layer 50 and having a uniform temperature flows into the downstream unit fin heat collector 46, and therefore, downstream of the exhaust gas flow. Also on the side, the temperature difference between the root portion and the center portion of each heat collection fin 48 is small. As a result, in the exhaust thermoelectric generator 10, the unit fin heat collecting section 46 performs heat exchange with the exhaust gas having a substantially uniform temperature distribution (particularly, a uniform temperature distribution in the vertical direction) at each part in the exhaust gas flow direction. In this case, each heat collection fin 48 of each unit fin heat collection section 46 is effectively used as a heat collection member, so that heat recovery efficiency is high.

  Moreover, since the diffusion gas layer 50 is set between the unit fin heat collecting portions 46, in other words, the heat collecting fins 48 constituting each unit fin heat collecting portion 46 are discontinuous in the exhaust gas flow direction. Therefore, the temperature of the exhaust gas flowing downstream while the heat is being deprived becomes lower as the downstream side becomes lower, so that the heat collecting fins 48 of the upstream unit fin heat collecting section 46 and the downstream unit fins Even if the amount of thermal deformation differs between the heat collecting fins 48 of the heat collecting section 46, the difference in the amount of deformation upstream and downstream of the fins causes distortion of the fins as in the configuration having fins continuous in the exhaust gas flow direction. (Propagation) is prevented by the presence of the diffusion gas layer 50, and the gap G between the heat collecting fins 48 adjacent in the width direction is kept substantially constant. For this reason, the heat recovery efficiency is further improved.

  Further, in the exhaust thermoelectric generator 10, since the gas diffusion guide 52 is provided in the upstream connection duct 25, the flow of the exhaust gas that has passed through the catalytic converter 22 is changed to the central portion (vertical and width) of the high temperature side heat exchanger case 18. Without being concentrated toward the direction center line), and is distributed substantially uniformly in each part in the width direction of the high temperature side heat exchanger case 18. For example, in the comparative example 100 that does not include the gas diffusion guide 52, as shown in FIG. 7B, the flow of the exhaust gas is concentrated at the center of the high temperature side heat exchanger case 18 (the thickness of the white arrow indicates the flow rate). However, in the exhaust thermoelectric generator 10, as shown in FIG. 7A, the exhaust gas is uniformly dispersed in each part in the width direction by the guide pieces 54 of the gas diffusion guide 52. As a result, in the exhaust thermoelectric generator 10, each unit fin heat collecting section 46 performs heat exchange with the exhaust gas having a substantially uniform flow rate distribution in each part in the exhaust gas flow direction, particularly in the uppermost stream. Since each heat collection fin 48 of the heat collection unit 46 is effectively used as a heat collection member, the heat recovery efficiency is high.

  Thus, in the high temperature side heat exchanger 12 constituting the exhaust thermoelectric generator 10 according to the present embodiment, changes in the fin interval G due to thermal deformation of the fins 48 can be suppressed. Further, in the exhaust thermoelectric generator 10, since the heat recovery efficiency by the high temperature side heat exchanger 12 is high, the temperature difference between the high temperature side and the low temperature side of each thermoelectric module 16 can be kept large, and the power generation efficiency is improved as a whole. improves.

  In the above-described embodiment, an example in which each heat collecting fin 48 is an independent plate has been described. However, the present invention is not limited to this, and for example, as shown in FIG. A so-called corrugated fin structure may be employed in which the connecting portions 56 for alternately connecting the upper end 48A and the lower end 48B of the heat fin 48 are provided. In this configuration, handling of each heat collection fin 48 and brazing operation with the high temperature side heat exchanger case 18 are easy.

  Moreover, in the said embodiment, although the example in which this invention was applied to the high temperature side heat exchanger 12 which comprises the exhaust heat power generator 10 was shown, this invention is not limited to this, The heat exchanger of this invention is It is applicable to various uses.

It is a figure which shows the exhaust heat power generator which concerns on embodiment of this invention, Comprising: It is sectional drawing along the 1-1 line | wire of FIG. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. FIG. 5 is a cross-sectional view taken along line 3-3 in FIG. 4. It is a side view of the exhaust heat power generator concerning the embodiment of the present invention. It is a plane sectional view of the high temperature side heat exchanger which constitutes the exhaust heat power generator concerning the embodiment of the present invention. It is a figure which shows the fin shape of the high temperature side heat exchanger which comprises the exhaust heat power generator which concerns on embodiment of this invention, Comprising: It is sectional drawing along line 6-6 in FIG. (A) is a plane sectional view showing a guidance state of inflow exhaust gas of a high temperature side heat exchanger which constitutes an exhaust heat power generator concerning an embodiment of the present invention, and (B) is a plane showing an exhaust gas inflow state in a comparative example It is sectional drawing. It is sectional drawing corresponding to FIG. 6 which shows the modification of the fin shape of the high temperature side heat exchanger which comprises the exhaust heat power generator which concerns on embodiment of this invention.

Explanation of symbols

10 Exhaust thermoelectric generator (Thermoelectric generator)
12 High temperature side heat exchanger (heat exchanger, heating part)
12A Upper heat transfer surface (heat transfer surface)
12B Lower heat transfer surface (heat transfer surface)
14 Low temperature side heat exchanger (cooling section)
16 Thermoelectric module (thermoelectric generator)
18 High-temperature side heat exchanger case (shell)
20 Fin heat collector (heat collector)
22 Catalytic converter (heat exchange medium supply pipe)
25 Upstream connection duct (connection flow path forming part)
30 Top plate (Surround wall, facing surface)
32 Bottom plate (shell peripheral wall, facing surface)
46 Unit fin heat collector (unit heat collector)
48 Heat collection fin (Fin, Fin deformation direction regulating means)
52 Gas diffusion guide (guide means)
54 Guide piece (guide means)

Claims (8)

A shell that forms a flow path of the heat exchange medium, and at least a part of the outer surface of the peripheral wall is a heat transfer surface in contact with the heat transfer target;
A plurality of fins that are erected from the back surface side of the heat transfer surface in the peripheral wall of the shell, and are arranged in parallel along the flow direction of the heat exchange medium;
Fin deformation direction restricting means for matching the heat deformation direction of the plurality of fins;
With heat exchanger. The plurality of fins are connected to each of a back surface of the heat transfer surface and a surface facing the back surface of the peripheral wall of the shell,
2. The heat according to claim 1, wherein the fin deformation direction restricting means has a bent shape formed by bending an intermediate portion of the fin erection direction to the same side so that the plurality of fins connect opposite surfaces of the shell with a curve. Exchanger. The shell forms the flow path having a rectangular cross section, and the outer surfaces of the opposed portions of the peripheral wall are the heat transfer surfaces, respectively.
The plurality of fins are respectively connected to back surfaces of the heat transfer surfaces of the peripheral wall of the shell facing each other.
2. The heat according to claim 1, wherein the fin deformation direction restricting means has a bent shape formed by bending an intermediate portion of the fin erection direction to the same side so that the plurality of fins connect opposite surfaces of the shell with a curve. Exchanger.   4. The heat exchanger according to claim 1, wherein the unit heat collecting portions in which the plurality of fins are configured in parallel along the flow direction of the heat exchange medium are arranged at predetermined intervals in the flow direction of the heat exchange medium. . A shell that forms a flow path of the heat exchange medium, and at least a part of the outer surface of the peripheral wall is a heat transfer surface in contact with the heat transfer target;
A plurality of unit heat collecting units configured by a plurality of fins arranged in parallel along the flow direction of the heat exchange medium and respectively connected to the back surface of the heat transfer surface and the surface opposite to the back surface of the peripheral wall of the shell A heat collecting part configured by arranging the parts at predetermined intervals in the flow direction of the heat exchange medium;
With heat exchanger. The inlet side of the heat exchange medium in the shell is provided with a connected flow path forming part connected to the heat exchange medium supply pipe while gradually changing the cross-sectional shape of the flow path,
6. The guide means for guiding a part of the heat exchange medium in the direction away from the center part of the shell in the shell is provided in the connection flow path forming part. The described heat exchanger. The connection flow path forming section narrows the flow path of the heat exchange medium in a first predetermined direction perpendicular to the flow direction of the heat exchange medium, and each of the flow direction of the heat exchange medium and the first predetermined direction. Expanding the flow path of the heat exchange medium in a second predetermined direction forming a right angle;
The heat exchanger according to claim 6, wherein the guide means is configured to disperse a flow of the heat exchange medium in a second predetermined direction.   A thermoelectric generator that generates an electromotive force due to a temperature difference between the high temperature side and the low temperature side, a cooling unit for cooling the low temperature side of the thermoelectric generator, and a heating unit for heating the high temperature side of the thermoelectric generator, The heating unit uses an exhaust gas as the heat exchange medium, and the heat transfer target is the high temperature side of the thermoelectric generator. The thermoelectric generator which is a heat exchanger of description.

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