JP2015032657A - Thermoelectric power generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoelectric power generation device capable of enhancing heat transfer efficiency in an endotherm part of a plurality of thermoelectric power generation units and improving heat recovery efficiency as a whole.SOLUTION: A thermoelectric power generation device 10 includes a plurality of thermoelectric power generation units 13. The plurality of thermoelectric power generation units 13 are provided in a first heat medium passage 12 so as to extend in the direction intersecting with the axial direction of the first heat medium passage 12, respectively. Out of the plurality of thermoelectric power generation units 13, a first thermoelectric power generation unit 13A or 13B located on the upstream side in the flow direction of a heat medium G in the first heat medium passage 12, and a second thermoelectric power generation unit 13B or 13C located on the downstream side thereof are arranged so as to be intersected with each other in the axial direction of the first heat medium passage 12.

Description

  The present invention relates to a thermoelectric generator that performs thermoelectric generation using a temperature difference between both heat media while passing a high temperature side heat medium and a low temperature side heat medium.

  Conventionally, as a thermoelectric power generator that thermoelectrically generates by arranging a plurality of thermoelectric conversion elements between a high-temperature heat source and a low-temperature heat source, for example, an exhaust heat recovery type that recovers while converting exhaust heat from exhaust gas of an internal combustion engine into electric energy A thermoelectric generator is known.

  As such a thermoelectric generator, for example, an inner pipe through which exhaust gas passes and an outer shell with a radiating fin surrounding the inner pipe are formed flat, and a thermoelectric conversion element is flattened between the inner pipe and the outer shell. There is one in which a module is sandwiched between them (see, for example, Patent Document 1).

  In addition, there is a type in which a cylindrical thermoelectric power generation unit containing a plurality of modularized thermoelectric conversion elements is arranged perpendicular to the flow direction of exhaust gas, and cooling water is passed through each thermoelectric power generation unit. (For example, refer to Patent Document 2).

Japanese Patent Laid-Open No. 11-036981 Special table 2012-533972 gazette

  However, in the conventional thermoelectric power generation apparatus as described in Patent Document 1 described above, when a plurality of thermoelectric power generation units are arranged in parallel with the flow direction of the exhaust gas, the exhaust gas is the thermoelectric power generation unit. Since it flows along the outer surface, the flow of exhaust gas tends to be laminar. If the flow of exhaust gas becomes laminar, it may be difficult for some of the exhaust gas to hit the endothermic part of the thermoelectric power generation unit, that is, the end surface on the high temperature side of the thermoelectric power generation unit, or not touch the end surface on the high temperature side There is.

  Therefore, the heat transfer efficiency in the heat absorption part of the thermoelectric power generation unit is reduced, and the heat recovery efficiency in the exhaust heat recovery type thermoelectric power generator, that is, the efficiency of the thermoelectric power generator (power generation efficiency, energy recovery efficiency) may be reduced. There was sex.

  On the other hand, if it is set as the form which arrange | positions a some thermoelectric power generation unit perpendicular | vertical with respect to the flow direction of exhaust gas as described in the above-mentioned patent document 2, it will be easy for exhaust gas to hit the heat absorption part of a thermoelectric power generation unit. Therefore, it is possible to increase the heat transfer efficiency in the thermoelectric power generation unit as compared with the configuration in which the exhaust gas is arranged in parallel to the flow direction.

  However, in a form in which a plurality of thermoelectric power generation units are arranged perpendicular to the flow direction of the exhaust gas, when the exhaust gas flow rate becomes relatively large, the exhaust gas that has passed through the upstream outer peripheral wall surface of each thermoelectric power generation unit The exhaust gas is less likely to flow along the downstream outer peripheral wall surface of each thermoelectric power generation unit.

  In particular, when the thermoelectric power generation units are arranged in parallel so as to overlap on the same plane when viewed from the upstream side in the flow direction of the exhaust gas, when the flow rate of the exhaust gas becomes relatively large, the exhaust gas flows into each thermoelectric power generation unit. It becomes difficult to flow along not only the downstream outer peripheral wall surface but also the upstream outer peripheral wall surface of the downstream thermoelectric power generation unit.

  For this reason, the exhaust gas is not sufficiently in contact with the heat absorption part of the thermoelectric power generation unit, so that the heat transfer efficiency in the thermoelectric power generation unit is relatively lowered, and the heat recovery efficiency in the thermoelectric power generation device may be reduced.

  The present invention has been made in order to solve the above-described conventional problems, and can improve the heat transfer efficiency in the heat absorption part of a plurality of thermoelectric power generation units and improve the heat recovery efficiency as a whole. The purpose is to provide.

  In order to achieve the above object, the thermoelectric generator according to the present invention is (1) a case in which a first heat medium passage through which one of the low temperature side heat medium and the high temperature side heat medium passes is formed. And forming a second heat medium passage through which the other heat medium out of the low temperature side heat medium and the high temperature side heat medium is formed on the inner peripheral side and contacting the one heat medium on the outer peripheral side. A thermoelectric power generation unit, and the plurality of thermoelectric power generation units are provided in the first heat medium passage so as to extend in a direction intersecting the axial direction of the first heat medium passage, A first thermoelectric power generation unit located upstream in the flow direction of the one heat medium in the first heat medium passage among the plurality of thermoelectric power generation units; and a downstream side of the first thermoelectric power generation unit. Second heat located The power generation unit, and a what is arranged to intersect with the axial direction of the first heat medium passage.

  In the thermoelectric power generation device according to the present invention, the flow of one heat medium (for example, exhaust gas) in the first heat medium path (for example, exhaust gas path) is the first thermoelectric power generation unit and the second thermoelectric power generation unit. Since it is arranged so as to intersect with the direction and intersect with the axial direction of the first heat medium passage, the flow of the exhaust gas is hindered, and the downstream outer periphery of each of the first and second thermoelectric power generation units The exhaust gas flows in a vortex in the vicinity of the wall surface, and the flow of the exhaust gas in that portion is disturbed (generation of turbulence).

  That is, the first and second thermoelectric power generation units are not arranged in parallel so as to overlap in the same plane when viewed from the upstream side in the exhaust gas flow direction, so even if the exhaust gas flow rate increases, Due to the turbulent flow generated in the vicinity of the downstream outer peripheral wall surface of the first thermoelectric power generation unit, the exhaust gas can be more reliably applied to the upstream outer peripheral wall surface of the second thermoelectric power generation unit located on the downstream side. Thereby, the heat transfer efficiency in the heat absorption part of a 2nd thermoelectric power generation unit can be improved, and the electric power generation performance of a thermoelectric power generator can be improved.

  Therefore, the thermoelectric power generation device according to the present invention can increase the heat transfer efficiency in the heat absorption part of the plurality of thermoelectric power generation units, and can improve the heat recovery efficiency as a whole.

  In the thermoelectric power generation device according to (1) above, (2) at least one of the first thermoelectric power generation unit and the second thermoelectric power generation unit is the one in the first heat medium passage. It may be arranged so as to incline from the upstream side toward the downstream side in the flow direction of the heat medium.

  The thermoelectric power generation device according to the present invention is such that at least one of the first thermoelectric power generation unit and the second thermoelectric power generation unit has a first heat medium passage (for example, an exhaust gas passage) from the upstream side to the downstream side. The structure in which one heat medium (for example, exhaust gas) easily flows from the outer peripheral side of the exhaust gas passage toward the inner peripheral side along the wall surface in the extending direction of the thermoelectric power generation unit. It has become. As a result, the exhaust gas flowing in the vicinity of the outer periphery of the exhaust gas passage can be guided to the inner peripheral direction of the exhaust gas passage, and the exhaust heat recovery efficiency of the exhaust gas flowing in the outer peripheral direction can be improved. .

  In the thermoelectric power generation device according to (1) or (2) above, (3) each of the plurality of thermoelectric power generation units extends along the axial direction of the second heat medium passage on the outer peripheral side of the thermoelectric power generation unit. It may have a plurality of fins spaced apart from each other, and the plurality of fins may be provided in a direction along the flow direction of the one heat medium in the first heat medium passage.

  In the thermoelectric power generation device according to the present invention, since a plurality of fins are provided in each of the plurality of thermoelectric power generation units, each thermoelectric power generation unit and one heat medium (for example, exhaust gas) are interposed via the plurality of fins. It is possible to increase the area (heat transfer area) for heat exchange between the two. Thereby, the heat transfer efficiency in the outer peripheral wall surface of a some thermoelectric power generation unit becomes higher, and since heat generation efficiency becomes high, heat recovery efficiency can further be improved as the whole thermoelectric power generation apparatus.

  (1) In the thermoelectric generator according to (1) to (3), (4) an inner cylindrical heat transfer in which each of the plurality of thermoelectric generator units has an inner peripheral wall surface that forms the second heat medium passage. A member, an outer cylindrical heat transfer member that surrounds the inner cylindrical heat transfer member and has an outer peripheral wall surface that contacts the one heat medium in the first heat medium passage, and the inner cylindrical heat transfer member And a thermoelectric conversion module including a plurality of thermoelectric conversion elements interposed between the heat member and the outer cylindrical heat transfer member.

  The thermoelectric power generation device according to the present invention comprises a thermoelectric power generation unit in which a plurality of thermoelectric conversion elements are modularized together with an inner cylindrical heat transfer member and an outer cylindrical heat transfer member as a cartridge that can be easily mounted on a case. be able to.

  According to the present invention, it is possible to provide a thermoelectric generator that can increase the heat transfer efficiency in the heat absorption part of a plurality of thermoelectric power generation units and improve the heat recovery efficiency as a whole.

It is a figure which shows 1st Embodiment of the thermoelectric power generation apparatus which concerns on this invention, and is a figure which shows schematic structure containing the cross section of the several thermoelectric power generation unit arrange | positioned in the case of a thermoelectric power generation apparatus. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the thermoelectric power generation apparatus which concerns on this invention, (a) is a perspective view which shows schematic structure of the principal part of a thermoelectric power generation apparatus, (b) is several in a thermoelectric power generation apparatus. It is the front view which looked at the thermoelectric power generation unit of from the upstream in the flow direction of exhaust gas. It is a figure which shows 1st Embodiment of the thermoelectric power generation apparatus which concerns on this invention, and is a longitudinal cross-sectional view which shows the structure of the cylindrical thermoelectric power generation unit made into the cartridge. It is a figure which shows 1st Embodiment of the thermoelectric power generation apparatus which concerns on this invention, and is a cross-sectional view of the thermoelectric power generation unit when it sees along the AA line of FIG. It is a figure which shows 2nd Embodiment of the thermoelectric power generation apparatus which concerns on this invention, and is a cross-sectional view of the thermoelectric power generation unit in a thermoelectric power generation apparatus. It is a figure which shows 3rd Embodiment of the thermoelectric power generation apparatus which concerns on this invention, (a) is a figure which shows typically the example of arrangement | positioning of the several thermoelectric power generation unit in a thermoelectric power generation apparatus, (b) is It is a figure which shows typically the other example of arrangement | positioning of the several thermoelectric power generation unit in a thermoelectric power generation apparatus.

  Hereinafter, embodiments of a thermoelectric generator according to the present invention will be described with reference to the drawings.

(First embodiment)
1 to 4 show the configuration of a thermoelectric power generator according to a first embodiment of the present invention.

  The thermoelectric generator according to the present embodiment uses exhaust gas of an internal combustion engine (hereinafter simply referred to as “engine”) mounted on a vehicle such as an automobile as a high-temperature heat source, and uses engine cooling water or the like as a low-temperature heat source. A cooling medium (not necessarily limited to water but a coolant suitable as a low-temperature heat source) is used.

  In this thermoelectric generator, a plurality of thermoelectric conversion elements are interposed between a high-temperature heat source and a low-temperature heat source, and the plurality of thermoelectric conversion elements are connected in parallel and electrically in series to generate thermoelectric power. Thus, the exhaust heat recovery function of recovering the exhaust heat generated by the exhaust gas of the engine while converting it into electric energy is provided.

  The high temperature heat source constitutes a high temperature side heat medium as one of the low temperature side heat medium and the high temperature side heat medium according to the present invention, and the low temperature heat source represents the low temperature side heat medium according to the present invention. A low temperature side heat medium as the other heat medium of the medium and the high temperature side heat medium is configured. The high temperature side heat medium refers to a second heat medium having a higher temperature than the first heat medium when the low temperature side heat medium is the first heat medium.

  First, the configuration of the thermoelectric generator according to this embodiment will be described.

  As shown in FIG. 1, the thermoelectric generator 10 according to the present embodiment includes a case 11 into which exhaust gas G exhausted from a vehicle driving drive engine (not shown) is introduced. 1 has an exhaust gas passage 12 as a heat medium passage.

  The case 11 constitutes a part of a bypass pipe 3 that bypasses an exhaust gas control valve 2 attached to an exhaust pipe 1 of an engine (not shown), and a part of the exhaust passage 1a is throttled by the exhaust gas control valve 2. At this time, a part of the exhaust gas G which is a heat medium on the high temperature side flows into the exhaust gas passage 12.

  The exhaust gas control valve 2 is a thermostat type that introduces engine cooling water W, which is a low-temperature heat medium, and rotates the exhaust control valve body 2a in accordance with the temperature of the cooling water W.

  Note that the case 11 may be a part of the exhaust pipe 1 instead of a part of the bypass pipe 3, and the exhaust gas control valve 2 may be of another type using an actuator, a shape memory alloy, or the like. Of course.

  The case 11 includes a cylindrical main body part P1 having both ends opened, an exhaust gas introduction part P2 joined to one open end of the main body part P1, and an exhaust gas exhaust joined to the other open end of the main body part P1. Part P3. As shown in FIG. 2, the main body P1 of the case 11 is formed so that its cross-sectional shape is a regular hexagon.

  Further, the exhaust gas introduction portion P2 of the case 11 has a tapered shape in which the cross-sectional area gradually decreases from one opening end of the main body portion P1 toward the upstream side in the exhaust gas G flow direction in the exhaust gas passage 12. It has a formed part, and the cross-sectional shape on the upstream side is formed, for example, in a circular shape through this tapered part.

  Similarly, the exhaust gas discharge part P3 of the case 11 has a tapered shape in which the cross-sectional area gradually decreases from the other opening end of the main body part P1 toward the downstream side in the flow direction of the exhaust gas G in the exhaust gas passage 12. The downstream cross-sectional shape is formed, for example, in a circular shape through the tapered portion.

  In the thermoelectric generator 10 according to the present embodiment, the cross-sectional shape of the main body portion P1 of the case 11 forming the exhaust gas passage 12 is a regular hexagon, but the cross-sectional shape is not limited to this, and other polygons (rectangular shapes) , Octagons, etc.), circles, ellipses, etc.

  As shown in FIGS. 1 and 2, a plurality of cylindrical thermoelectric power generation units 13 are formed inside the main body P <b> 1 of the case 11 in a direction intersecting the axial direction (X direction in the drawing) of the exhaust gas passage 12. Is arranged to extend. Specifically, each of the plurality of thermoelectric power generation units 13 includes the exhaust gas passage 12 in a plane orthogonal to the flow direction of the exhaust gas G in the exhaust gas passage 12 (a plane including the Y direction and the Z direction in the drawing). It is provided so as to extend in a direction toward the peripheral wall surface 11s of the case 11 to be formed. Further, the thermoelectric power generation unit 13 is provided such that both ends 13 a and 13 b thereof are located on the opposing surfaces of the peripheral wall surface 11 s of the case 11.

  As shown in FIG. 2, the plurality of thermoelectric power generation units 13 includes three groups in this embodiment, that is, a first group thermoelectric power generation unit 13 </ b> A, a second group thermoelectric power generation unit 13 </ b> B, and a third group thermoelectric power generation. The units 13C are arranged separately. Each thermoelectric power generation unit 13A, 13B, 13C includes two thermoelectric power generation units 13 as a group, and these two thermoelectric power generation units 13 are on the same plane orthogonal to the flow direction of the exhaust gas G in the exhaust gas passage 12. They are arranged in parallel at regular intervals.

  Further, the first group thermoelectric power generation unit 13A, the second group thermoelectric power generation unit 13B, and the third group thermoelectric power generation unit 13C are directed from the upstream side to the downstream side in the flow direction of the exhaust gas G in the exhaust gas passage 12. In this order, the exhaust gas passages 12 are provided in the exhaust gas passage 12 so as to be separated from each other along the axial direction of the exhaust gas passage 12.

  Among the thermoelectric power generation units 13A, 13B, and 13C of each group, the first group thermoelectric power generation unit 13A located on the most upstream side in the flow direction of the exhaust gas G constitutes the first thermoelectric power generation unit according to the present invention. . In this case, the second group thermoelectric power generation unit 13B or the third group thermoelectric power generation unit 13C constitutes a second thermoelectric power generation unit according to the present invention. Further, when the second group of thermoelectric power generation units 13B located on the upstream side constitutes the first thermoelectric power generation unit according to the present invention, the third group of thermoelectric power generation units 13C located on the downstream side of the present invention The 2nd thermoelectric power generation unit which concerns is comprised.

  Further, the thermoelectric power generation units 13A, 13B, and 13C of each group that are spaced apart in the axial direction of the exhaust gas passage 12 are viewed from the upstream side in the flow direction of the exhaust gas G as shown in FIG. Sometimes, both ends 13a, 13b of the thermoelectric generator units 13A, 13B, 13C are arranged so as to be shifted from each other by a predetermined angle θ in the circumferential direction of the case 11 forming the exhaust gas passage 12. That is, the thermoelectric power generation units 13 </ b> A, 13 </ b> B, 13 </ b> C of each group are arranged so as to intersect in the axial direction of the exhaust gas passage 12.

  Specifically, each group of thermoelectric power generation units 13A, 13B, and 13C includes a first group of thermoelectric power generation units 13A located on the most upstream side in the flow direction of the exhaust gas G and a second group of thermoelectric power generation units 13A located downstream thereof. The thermoelectric power generation unit 13B is shifted by 60 ° in the circumferential direction of the case 11, the second group thermoelectric power generation unit 13B and the third group of thermoelectric power generation units 13C located downstream thereof are shifted by 60 ° in the same circumferential direction, The three groups of thermoelectric power generation units 13C and the first group of thermoelectric power generation units 13A located downstream thereof are arranged so as to be shifted by 60 ° in the same circumferential direction.

  In the example of FIG. 1, only the first group of thermoelectric power generation units 13 </ b> A is representative of the thermoelectric power generation units 13 </ b> A, 13 </ b> B, 13 </ b> C of each group in order to make it easier to see the arrangement of the plurality of thermoelectric power generation units 13 in the case 11. It shows.

  The thermoelectric power generation apparatus 10 according to the present embodiment has a plurality of thermoelectric power generation units 13 divided into three groups, but may be configured to be divided into four or more groups. In this case as well, four or more groups of thermoelectric power generation units are provided in the exhaust gas passage 12 so as to be separated from each other along the axial direction of the exhaust gas passage 12 and upstream in the flow direction of the exhaust gas G. The exhaust gas passages 12 are arranged so as to be shifted from each other by a predetermined angle in the circumferential direction of the case 11 forming the exhaust gas passage 12 (for example, by 30 ° if divided into six groups).

  In the thermoelectric generator 10 according to the present embodiment, each group of thermoelectric power generation units 13A, 13B, and 13C includes two thermoelectric power generation units 13, but includes three or more thermoelectric power generation units 13 as a group. You may comprise as follows. Or you may comprise so that the thermoelectric power generation unit 13A, 13B, 13C of each group may contain the one thermoelectric power generation unit 13, respectively.

  The plurality of thermoelectric power generation units 13 constituting each of the thermoelectric generation units 13A, 13B, and 13C of the first group, the second group, and the third group are element lead wires 38 that electrically connect thermoelectric conversion modules 35 to be described later. Are connected to each other via the electrical wiring and connected to a battery charging circuit (not shown). Thereby, the some thermoelectric power generation unit 13 can store now the electrical energy collect | recovered from the exhaust heat by exhaust gas in a battery.

  As shown in FIGS. 3 and 4, the thermoelectric power generation unit 13 includes an inner cylindrical heat transfer member 32, an outer cylindrical heat transfer member 33, an inner cylindrical heat transfer member 32, and an outer cylindrical heat transfer member. A thermoelectric conversion module 35 including a plurality of thermoelectric conversion elements 34 a and 34 b interposed between the heat members 33.

  The inner cylindrical heat transfer member 32 has a cooling medium passage 31 as a second heat medium passage therein. Specifically, the inner cylindrical heat transfer member 32 has an inner peripheral wall surface 32a that forms a cooling medium passage 31 through which the cooling water W passes, and the cooling medium passage 31 extends in the axial direction. It is a pipe.

  The outer cylindrical heat transfer member 33 has an inner peripheral wall surface 33 a having a diameter larger than the outer diameter of the inner cylindrical heat transfer member 32 and an outer peripheral wall surface 33 b that contacts the exhaust gas G in the exhaust gas passage 12. doing. The outer cylindrical heat transfer member 33 surrounds the inner cylindrical heat transfer member 32 from the outer peripheral side, and is separated from the outer peripheral wall surface 32b of the inner cylindrical heat transfer member 32 by a predetermined radial distance. The cylindrical heat transfer member 32 is disposed on the same central axis.

  In the present embodiment, the inner cylindrical heat transfer member 32 and the outer cylindrical heat transfer member 33 have a circular cross-sectional shape, but the cross-sectional shape is not limited to this, and an elliptical shape, an oval shape, a rectangular shape, or the like. It may be a polygon.

  The thermoelectric conversion module 35 generates an electromotive force corresponding to a temperature difference between the heat receiving substrate and the heat dissipation substrate by the Seebeck effect, and a heat receiving substrate (not illustrated) that configures the end surface on the high temperature side, a heat dissipation substrate (not illustrated) that configures the end surface on the low temperature side. And an N-type thermoelectric conversion element 34a and a P-type thermoelectric conversion element 34b. The heat receiving substrate and the reinforcing substrate are made of, for example, insulating ceramics, and the N-type thermoelectric conversion element 34a and the P-type thermoelectric conversion element 34b are made of semiconductor elements.

  The thermoelectric conversion module 35 includes a plurality of pairs of N-type thermoelectric conversion elements 34a and P-type thermoelectric conversion elements 34b, and the N-type thermoelectric conversion element 34a and the P-type thermoelectric conversion element 34b are disposed on the inner electrodes 36a and 36a, respectively. It is configured by being electrically connected in series in the circumferential direction via the outer electrode 36b. That is, in the thermoelectric conversion module 35, each pair of thermoelectric conversion elements 34a and 34b has a so-called π-type structure together with one of the inner electrode 36a and the outer electrode 36b.

  In the thermoelectric generator 10 according to the present embodiment, a π-type structure is adopted as a form in which the thermoelectric conversion elements 34a and 34b are mounted on the thermoelectric power generation unit 13, but the present invention is not necessarily limited thereto. It is also possible to adopt an N-type structure or the like.

  The N-type and P-type thermoelectric conversion elements 34a and 34b are rod-shaped elements arranged in parallel at equal angular intervals in the circumferential direction of the inner cylindrical heat transfer member 32 and the outer cylindrical heat transfer member 33. Each length has a length close to the outer diameter of the case 11 forming the exhaust gas passage 12 (the length between the opposed peripheral wall surfaces 11s).

  In the thermoelectric power generation apparatus 10 according to this embodiment, the thermoelectric power generation unit 13 constitutes a thermoelectric conversion module 35 in which a plurality of rod-shaped thermoelectric conversion elements 34a and 34b are arranged in parallel at equal angular intervals. Of course, it is not limited to.

  For example, the thermoelectric power generation unit 13 may be configured such that a plurality of pairs of N-type thermoelectric conversion elements formed in an annular shape and P-type thermoelectric conversion elements formed in a cylindrical shape are alternately arranged in the axial direction. Further, it goes without saying that the plurality of rod-like or plate-like thermoelectric conversion elements 34a, 34b can be divided into a plurality of portions in the axial direction and the arrangement of these divided bodies can be shifted in the circumferential direction.

  More specifically, the inner cylindrical heat transfer member 32 constituting the low temperature part of each thermoelectric conversion unit 13 electrically connects the plurality of inner electrodes 36a to each other at least in the outer peripheral portion in contact with the plurality of inner electrodes 36a. It has electrical insulation to insulate. Similarly, the outer cylindrical heat transfer member 33 constituting the high temperature portion of each thermoelectric conversion unit 13 electrically insulates the plurality of outer electrodes 36b from each other at least in the inner peripheral portion in contact with the plurality of outer electrodes 36b. It has electrical insulation.

  Further, as shown in FIGS. 3 and 4, a cylindrical space S between the inner cylindrical heat transfer member 32 and the outer cylindrical heat transfer member 33, which is an arrangement space of the thermoelectric conversion module 35, is a pair. Are closed by an annular closing member 37a, 37b, and an inert gas, for example, is enclosed as an oxidative degradation preventing agent for the thermoelectric conversion module 35 therein.

  The pair of annular closing members 37 a and 37 b protrude from both ends in the axial direction of the outer cylindrical heat transfer member 33, and are airtightly fixed and supported in mounting holes 11 b formed in the side plate portion 11 a of the case 11. .

  That is, the thermoelectric power generation unit 13 according to this embodiment includes a portion near both ends on the outer peripheral side of the inner cylindrical heat transfer member 32 and an inner side of the outer cylindrical heat transfer member 33 via the pair of annular closing members 37a and 37b. It has a structure in which peripheral portions near both ends are joined. In this structure, both ends of the inner cylindrical heat transfer member 32 and both ends of the outer cylindrical heat transfer member 33 constitute both ends of the thermoelectric power generation unit according to the present invention.

  Further, as shown in FIG. 3, the thermoelectric power generation unit 13 has a plurality of fins 41 that are separated from each other along the axial direction (Z direction in the drawing) of the cooling medium passage 31 on the outer peripheral side thereof. The plurality of fins 41 are provided in a direction along the flow direction (X direction in FIG. 2) of the exhaust gas G in the exhaust gas passage 12 (see FIG. 2).

  More specifically, each of the plurality of fins 41 has an annular plate shape that protrudes radially outward from the outer cylindrical heat transfer member 33 at a constant height, and is provided on the outer peripheral side of the thermoelectric generation unit 13 as a cooling medium. They are arranged in parallel so as to be separated from each other in the axial direction of the passage 31. The plurality of fins 41 absorb heat of the exhaust gas by heat transfer from the exhaust gas G flowing in the exhaust gas passage 12, and efficiently heat the outer cylindrical heat transfer member 33, which is a heat receiving material on the high temperature side. It has a function as an endothermic fin to conduct.

  For example, the cooling water W that has passed through the exhaust gas control valve 2 (see FIG. 1) or the cooling water W from the engine is introduced into the cooling medium passages 31 of the plurality of thermoelectric power generation units 13 through a coolant pipe (not shown). It is like that.

  For example, the case 11 is provided with a cooling water tank partitioned from the exhaust gas passage 12 by at least the side plate portion 11a, and the cooling water W is distributed to the cooling medium passages 31 of the plurality of thermoelectric power generation units 13 by the cooling water tank. It may be.

  In addition, the cooling water W is first passed through the cooling medium passage 31 positioned on the most downstream side in the flow direction of the exhaust gas G. From the cooling medium passage 31 positioned on the most upstream side in the flow direction of the exhaust gas G, the engine side or the radiator is provided. The cooling water may return to the side.

  Next, the operation will be described.

  In the thermoelectric power generation apparatus 10 of the present embodiment configured as described above, a plurality of tubular thermoelectric power generation units 13 are arranged so as to extend in a direction intersecting the axial direction of the exhaust gas passage 12, respectively. Moreover, since both ends 13a and 13b of each thermoelectric power generation unit 13 are arranged so as to be shifted from each other by a predetermined angle θ in the circumferential direction of the case 11 forming the exhaust gas passage 12, the exhaust gas G in the exhaust gas passage 12 is disposed. The flow of the exhaust gas G is swirled near the downstream outer peripheral wall surface of each thermoelectric power generation unit 13, and the flow of the exhaust gas G in that portion is disturbed (occurrence of turbulence).

  That is, each thermoelectric power generation unit 13 is not arranged so as to overlap on the same plane when viewed from the upstream side in the flow direction of the exhaust gas G as shown in FIG. Even in this case, the turbulent flow generated in the vicinity of the downstream outer peripheral wall surface of the thermoelectric power generation unit 13 located on the relatively upstream side causes the exhaust gas G to flow on the upstream outer peripheral wall surface of the thermoelectric power generation unit 13 positioned on the downstream side. Can be more reliably applied.

  As a result, the amount of exhaust gas G hitting the upstream outer peripheral wall surface of the thermoelectric power generation unit 13 located relatively downstream in the flow direction of the exhaust gas G in the exhaust gas passage 12 is increased by the turbulent flow generated upstream. Can be made. As a result, the heat transfer efficiency in the heat absorption part of the thermoelectric power generation unit 13 positioned relatively downstream (that is, the outer cylindrical heat transfer member 33 constituting the high temperature part of the thermoelectric conversion unit 13) can be increased. The power generation performance of the thermoelectric generator 10 can be improved.

  Thus, the thermoelectric power generation apparatus 10 according to the present embodiment can increase the heat transfer efficiency in the heat absorption part of the plurality of thermoelectric power generation units 13 and can improve the heat recovery efficiency as a whole.

  Further, in the thermoelectric generator 10 according to the present embodiment, since a plurality of fins 41 are provided in each of the plurality of thermoelectric power generation units 13, a cylindrical shape outside each thermoelectric generation unit 13 via the plurality of fins 41. The area (heat transfer area) for heat exchange between the heat transfer member 33 and the exhaust gas G can be increased. Thereby, the heat transfer efficiency in the outer peripheral wall surface of the some thermoelectric power generation unit 13 becomes higher, and since the power generation efficiency becomes higher, the heat recovery efficiency can be further improved as the thermoelectric power generation apparatus 10 as a whole.

  Further, the thermoelectric power generation apparatus 10 according to the present embodiment includes a thermoelectric power generation unit 13 in which a plurality of thermoelectric conversion elements 34a and 34b are modularized together with an inner cylindrical heat transfer member 32 and an outer cylindrical heat transfer member 33. 11 can be configured as a cartridge that can be easily attached to the cartridge 11. Thereby, the loading efficiency of the thermoelectric power generation unit 13 can be sufficiently increased, and the assembling work at the time of manufacturing the thermoelectric power generation apparatus 10 can be facilitated.

(Second Embodiment)
FIG. 5 shows a configuration of a thermoelectric power generation unit in the thermoelectric power generation apparatus according to the second embodiment of the present invention.

  In the first embodiment described above, the cross-sectional shape of each thermoelectric power generation unit 13 is cylindrical (see FIG. 4). However, in this second embodiment, the inner cylinder that sandwiches the thermoelectric conversion module from both sides thereof. The difference is that the cross-sectional shapes of the cylindrical heat transfer member and the outer cylindrical heat transfer member are rectangular or oval.

  As shown in FIG. 5, the thermoelectric power generation unit 50 according to this embodiment is different in the cross-sectional shape from the first embodiment described above, but the overall configuration including other parts is the same as that of the first embodiment. Substantially the same. Therefore, with respect to the same configuration as the first embodiment, the same reference numerals as the corresponding components in FIGS. 1 to 4 are used, and the difference between the present embodiment and the first embodiment is mainly described. Explained.

  As shown in FIG. 5, the thermoelectric power generation unit 50 includes an inner cylindrical heat transfer member 52, an outer cylindrical heat transfer member 53, an inner cylindrical heat transfer member 52, and an outer cylindrical heat transfer member 53. And a thermoelectric conversion module 55 including a plurality of thermoelectric conversion elements 54a and 54b interposed therebetween.

  The inner cylindrical heat transfer member 52 has a cooling medium passage 51 as a second heat medium passage therein. Specifically, the inner cylindrical heat transfer member 52 has an inner peripheral wall surface 52a that forms a cooling medium passage 51 through which cooling water passes, and the cooling medium passage 31 is in the axial direction (Z in the figure). The pipe has an oval cross section extending in the direction).

  The outer cylindrical heat transfer member 53 has an inner peripheral wall surface 53 a having a diameter larger than the outer diameter of the inner cylindrical heat transfer member 52 and an outer peripheral wall surface 53 b that contacts the exhaust gas G in the exhaust gas passage 12. doing. The outer cylindrical heat transfer member 53 surrounds the inner cylindrical heat transfer member 52 from the outer peripheral side and is spaced from the outer peripheral wall surface 52b of the inner cylindrical heat transfer member 52 by a predetermined radial distance. The cylindrical heat transfer member 52 is disposed on the same central axis.

  The thermoelectric conversion module 55 generates an electromotive force according to a temperature difference between the heat receiving substrate and the heat dissipation substrate by the Seebeck effect, and a heat receiving substrate (not illustrated) that configures the end surface on the high temperature side, a heat dissipation substrate (not illustrated) that configures the end surface on the low temperature side. And an N-type thermoelectric conversion element 54a and a P-type thermoelectric conversion element 54b. Similarly to the first embodiment described above, the heat receiving substrate and the reinforcing substrate are made of insulating ceramics, and the N-type thermoelectric conversion element 54a and the P-type thermoelectric conversion element 54b are made of semiconductor elements.

  The thermoelectric conversion module 55 includes a plurality of pairs of N-type thermoelectric conversion elements 54a and P-type thermoelectric conversion elements 54b, and each of the N-type thermoelectric conversion element 54a and the P-type thermoelectric conversion element 54b is an inner electrode. It is configured by being electrically connected in series in the circumferential direction via 56a and the outer electrode 56b.

  Further, as shown in FIG. 5, the thermoelectric power generation unit 50 has a plurality of fins 61 that are separated from each other in the axial direction (Z direction in the drawing) of the cooling medium passage 31 on the outer peripheral side thereof. The plurality of fins 61 are provided in a direction along the flow direction (X direction in the drawing) of the exhaust gas G in the exhaust gas passage 12 (see FIG. 2). Specifically, the plurality of fins 61 are rectangular plates that protrude outward at a certain height from the surface facing the vertical direction (Y direction in the figure) of the outer cylindrical heat transfer member 53 having a substantially rectangular cross section. As in the first embodiment described above, it has a function as an endothermic fin.

  The thermoelectric generator according to the second embodiment configured as described above is different from the first embodiment described above in the cross-sectional shape of the thermoelectric generator unit 50, but the exhaust gas passages 12 of the plurality of thermoelectric generator units 13. Since the arrangement mode is the same as that of the first embodiment, the same effects as those of the first embodiment can be achieved.

(Third embodiment)
FIG. 6 shows a configuration of a thermoelectric power generation unit in a thermoelectric power generation apparatus according to the third embodiment of the present invention.

  In the first embodiment described above, the plurality of thermoelectric power generation units 13 are arranged in a direction orthogonal to the flow direction of the exhaust gas G in the exhaust gas passage 12 (see FIGS. 1 and 2). The embodiment is different in that a plurality of thermoelectric power generation units 13 are arranged so as to be inclined from the upstream side toward the downstream side in the flow direction of the exhaust gas G in the exhaust gas passage 12.

  The thermoelectric generators 10A and 10B shown in FIGS. 6A and 6B are different from the first embodiment described above in the arrangement of the plurality of thermoelectric generator units 13 in the exhaust gas passage 12, respectively. The overall configuration including the part is substantially the same as that of the first embodiment. Therefore, with respect to the same configuration as the first embodiment, the same reference numerals as the corresponding components in FIGS. 1 to 4 are used, and the difference between the present embodiment and the first embodiment is mainly described. Explained.

  In the thermoelectric power generation apparatus 10A shown in FIG. 6A, a plurality of thermoelectric power generation units 13 are arranged in the same direction from the upstream side toward the downstream side in the exhaust gas G flow direction in the exhaust gas passage 12 by a predetermined angle θ1. It is arranged to incline. On the other hand, in the thermoelectric power generation apparatus 10B shown in FIG. 6B, a plurality of thermoelectric power generation units 13 are alternately arranged for each predetermined number from the upstream side to the downstream side in the flow direction of the exhaust gas G in the exhaust gas passage 12. It is arranged so as to be inclined by a predetermined angle θ2 in the opposite direction.

  In the example shown in FIG. 6, the thermoelectric power generation of the first group among the thermoelectric power generation units 13 </ b> A, 13 </ b> B, 13 </ b> C (see FIG. 2) of each group in order to make the arrangement of the plurality of thermoelectric power generation units 13 in the case 11 easier to see. Only the unit 13A is representatively shown.

  Further, in the example shown in FIG. 6, all of the plurality of thermoelectric power generation units 13 are arranged so as to be inclined from the upstream side to the downstream side in the flow direction of the exhaust gas G. You may arrange | position so that only at least one thermoelectric generation unit among the thermoelectric generation units 13 may incline. Specifically, among the thermoelectric power generation units 13A, 13B, and 13C of each group, only the first group of thermoelectric power generation units 13A is inclined, and the second group and the third group of thermoelectric power generation units 13B and 13C are described above. Similarly to the first embodiment, the exhaust gas passage 12 may be arranged in a direction orthogonal to the flow direction of the exhaust gas G.

  The thermoelectric generators 10A and 10B according to the third embodiment configured as described above are arranged such that each thermoelectric generator unit 13 is inclined from the upstream side to the downstream side in the exhaust gas passage 12, The exhaust gas G is easy to flow from the outer peripheral side of the exhaust gas passage 12 toward the inner peripheral side along the wall surface in the extending direction of the thermoelectric power generation unit 13.

  Therefore, the thermoelectric generators 10A and 10B according to the third embodiment can guide the exhaust gas G flowing in the vicinity of the outer periphery of the exhaust gas passage 12 in the inner peripheral direction of the exhaust gas passage 12. Compared with the case of the first embodiment, the exhaust heat recovery efficiency of the exhaust gas G flowing in the outer circumferential direction can be further improved.

  In each of the above-described embodiments, the exhaust gas passage 12 that is a high-temperature side heat medium passage is formed in the case 11 and the exhaust gas passage 12 extends in a direction that intersects the axial direction of the exhaust gas passage 12. The case where the cooling medium passage 31 that is the low-temperature side heat medium passage is formed inside the plurality of thermoelectric power generation units 13 arranged in the gas passage 12 has been described.

  However, the positional relationship between the exhaust gas passage 12 and the cooling medium passage 31 may be reversed from that in the above-described embodiments. That is, a cooling medium passage which is a low-temperature side heat medium passage is formed in the case 11, and the high-temperature side heat medium passage is provided in a plurality of thermoelectric power generation units 13 arranged so as to intersect the cooling medium passage. An exhaust gas passage may be formed. Needless to say, the high-temperature heat medium is not limited to engine exhaust gas, and the low-temperature heat medium is not limited to cooling water.

  Moreover, in each embodiment mentioned above, although the case where one internal channel | path (inner cylindrical heat-transfer member) was provided inside the outer cylindrical heat-transfer member which comprises each thermoelectric power generation unit 13 was demonstrated, Not only this form but a plurality of internal passages may be formed in each thermoelectric power generation unit 13.

  Moreover, each thermoelectric power generation unit 13 does not necessarily need to be straight, and may have a curved shape. In short, it is sufficient that each thermoelectric power generation unit 13 is provided in the exhaust gas passage 12 so as to extend in a direction intersecting the axial direction of the exhaust gas passage 12.

  As described above, the thermoelectric power generation device according to the present invention has the effect that the heat transfer efficiency in the heat absorption part of the plurality of thermoelectric power generation units can be improved and the heat recovery efficiency can be improved as a whole. The present invention is useful for all thermoelectric power generation apparatuses that perform thermoelectric power generation using a temperature difference between both heat mediums while passing through the heat medium and the low temperature side heat medium.

  DESCRIPTION OF SYMBOLS 1 ... Exhaust pipe, 3 ... Bypass pipe, 10, 10A, 10B ... Thermoelectric power generator, 11 ... Case, 11a ... Side plate part, 11b ... Mounting hole part, 11s ... Circumferential wall surface, 12 ... Exhaust gas passage (first heat Medium passage), 13 ... thermoelectric generation unit, 13A ... first group thermoelectric generation unit (first thermoelectric generation unit), 13B ... second group thermoelectric generation unit (second thermoelectric generation unit or first thermoelectric generation) Unit), 13C ... Third group thermoelectric power generation unit (second thermoelectric power generation unit), 13a, 13b ... both ends, 31 ... cooling medium passage (second heat medium passage), 32 ... inner cylindrical heat transfer member 32a ... inner peripheral wall surface, 33 ... outer cylindrical heat transfer member, 33b ... outer peripheral wall surface, 34a, 34b ... thermoelectric conversion element, 35 ... thermoelectric conversion module, 36a ... inner electrode, 36b ... outer electrode, 3, a, 37b ... ring closure member, 38 ... device leads, 41 ... fin, 50 ... thermoelectric power generation unit, 61 ... fin

Claims (4)

A case forming a first heat medium passage through which one of the low temperature side heat medium and the high temperature side heat medium passes, and the low temperature side heat medium and the high temperature side heat medium on the inner peripheral side, respectively A plurality of thermoelectric power generation units that form a second heat medium passage through which the other heat medium passes and contact the one heat medium on the outer peripheral side,
The plurality of thermoelectric power generation units are provided in the first heat medium passage so as to extend in directions intersecting with the axial direction of the first heat medium passage,
A first thermoelectric power generation unit located upstream in the flow direction of the one heat medium in the first heat medium passage among the plurality of thermoelectric power generation units; and a downstream side of the first thermoelectric power generation unit. The second thermoelectric power generation unit positioned is arranged so as to intersect in the axial direction of the first heat medium passage.   At least one thermoelectric power generation unit of the first thermoelectric power generation unit and the second thermoelectric power generation unit is directed from the upstream side to the downstream side in the flow direction of the one heat medium in the first heat medium passage. The thermoelectric generator according to claim 1, wherein the thermoelectric generator is arranged to be inclined.   Each of the plurality of thermoelectric power generation units has a plurality of fins spaced apart from each other along the axial direction of the second heat medium passage on the outer peripheral side of the thermoelectric power generation unit, and the plurality of fins are the first The thermoelectric generator according to claim 1, wherein the thermoelectric generator is provided in a direction along a flow direction of the one heat medium in the heat medium passage.   Each of the plurality of thermoelectric power generation units surrounds the inner tubular heat transfer member having an inner peripheral wall surface forming the second heat medium passage, the inner tubular heat transfer member, and the first heat. An outer cylindrical heat transfer member having an outer peripheral wall surface in contact with the one heat medium in the medium passage, and a plurality interposed between the inner cylindrical heat transfer member and the outer cylindrical heat transfer member The thermoelectric power generating device according to any one of claims 1 to 3, further comprising a thermoelectric conversion module including the thermoelectric conversion element.

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