JP5075707B2 - Thermoelectric device and thermoelectric module - Google Patents

Description

  The present invention relates to a thermoelectric device that directly converts thermal energy into electrical energy and electrical energy into thermal energy, and a thermoelectric module composed of these devices.

  In general, a thermoelectric device is composed of two electrodes facing each other and a pair of a p-type thermoelectric conversion semiconductor and an n-type thermoelectric conversion semiconductor inserted between them. Then, by using a thermoelectric effect such as a Thomson effect, a Peltier effect, or a Seebeck effect that the thermoelectric conversion semiconductor has, heat energy is directly converted into electric energy and electric energy is directly converted into heat energy. Moreover, practically, a thermoelectric module configured by arranging thermoelectric element devices in parallel is used.

  An example of such a thermoelectric conversion device or thermoelectric module is described in Patent Document 1. Patent Document 1 discloses a thermoelectric conversion device including an opposing electrode, and a columnar p-type heat-electric direct conversion element and an n-type heat-electric direct conversion element that stand between them.

  The thermoelectric element and the heat dissipation electrode are joined by soldering, and the heat absorption electrode has a deformable net structure member in a part of the thermoelectric element. It touches movably.

In the above-described thermoelectric conversion device, the deformation and sliding of the net structure member alleviates the thermal stress due to the difference in thermal expansion between the endothermic electrode and the thermoelectric element, thereby preventing the thermoelectric conversion device from being damaged or damaged. it can.
JP-A-2005-64457

  However, in the thermoelectric conversion device disclosed in Patent Document 1, under the practical situation of the high temperature side heat source, the thermoelectric conversion device is locally deformed due to the presence of a thermal expansion difference due to the temperature distribution of the heat source. give. Therefore, while the net structure member is provided between the endothermic electrode and the thermoelectric semiconductor, the thermal stress is alleviated, while the net structure member is always in a state where it can easily transmit heat over the entire surface of the thermoelectric element. I can't say that.

  That is, since the area where heat can be transmitted from the heat source to the high temperature side of the thermoelectric conversion device becomes small, there is a disadvantage that the thermoelectric conversion performance inherent to the thermoelectric conversion device cannot be fully exhibited.

  Such a phenomenon is a problem that can naturally occur not only in the thermoelectric conversion device disclosed in Patent Document 1, but also in a thermoelectric conversion device in which a heat absorption electrode and a thermoelectric element are directly joined.

  Further, in the thermoelectric conversion device, the generated electric power increases as the temperature difference between the upper and lower sides of the thermoelectric element increases. Therefore, it is necessary to increase the heat receiving area and transfer heat through a plurality of paths to the high temperature side of the thermoelectric element.

  The present invention eliminates the above inconveniences and allows the thermoelectric element to transfer heat through a plurality of paths and efficiently transfer heat even when local deformation occurs due to the temperature distribution of the high temperature side heat source. An object is to provide an element device and a thermoelectric module using the element device.

  In order to achieve the above object, a thermoelectric device according to an embodiment of the present invention is configured as follows.

  (1) The thermoelectric element device according to the present embodiment is composed of an n-type conductive part and a p-type conductive part that are separated from each other, and a thermoelectric element pair made of a material having a thermoelectric effect, and one end side of the thermoelectric element pair A high-temperature side substrate placed on the substrate, a first electrode placed between the thermoelectric element pair and the high-temperature side substrate, and a transmission disposed between the thermoelectric element pair so as to be in contact with the thermoelectric element pair. A thermal member, a low temperature side substrate disposed on the other end side of the thermoelectric element pair, and a second electrode disposed between the thermoelectric element pair and the low temperature side substrate.

  (2) The thermoelectric element device according to the present embodiment is the above (1), and the heat transfer member has an Ω-shaped cross section in the lateral direction.

  (3) The thermoelectric device according to the present embodiment is the above (2), and the heat transfer member is sandwiched between and contacts the upper surface of each thermoelectric element pair and the first electrode. .

  (4) The thermoelectric element device according to the present embodiment is the above (3), wherein the heat transfer member is in contact with each side surface of the thermoelectric element pair at least one place.

  (5) The thermoelectric element device according to the present embodiment is the above (4), and the heat transfer member is made of a metal material having elasticity.

  (6) The thermoelectric element device according to the present embodiment is the above (5), wherein the heat transfer member includes two layers of the elastic metal material and a copper film, and the first electrode And contact through the copper film.

  (7) The thermoelectric element device according to the present embodiment is the above (1), and includes a frame in which the first electrode, the second electrode, and the thermoelectric element pair are shielded from outside air.

  (8) The thermoelectric device according to the present embodiment is the above (1), wherein the first electrode includes an electrode member, an elastic member having conductivity and provided on the electrode member, and conductivity. And a soaking member provided on the elastic member and in contact with the thermoelectric element pair.

  (9) The thermoelectric device according to the present embodiment is the above (1), wherein the second electrode is an electrode member, an elastic member having conductivity and provided on the electrode member, and conductivity. And a soaking member provided on the elastic member and in contact with the thermoelectric element.

(10) The thermoelectric device according to the present embodiment is any one of the above (1) to (9), and the material having a thermoelectric effect in the thermoelectric device pair includes a compound of bismuth and tellurium as a main phase. The main phase is a substance having a filled skutterudite structure in which elements are filled in voids in a CoSb _3- based compound crystal having a skutterudite-type crystal structure. A substance, a substance mainly composed of a half-Heusler compound having an MgAgAs type crystal structure, a clathrate compound containing barium and gallium, a mixture thereof, or a conjugate thereof.

  (11) The thermoelectric device according to the present embodiment is any one of the above (1) to (10), and the thermoelectric device pair includes an n-type conductive portion and a p-type conductive portion that are separated from each other. A first portion in which one of the first electrode and the second electrode is disposed on the n-type conductive portion, and a second portion disposed on the p-type conductive portion, Separate.

  (12) The thermoelectric module according to this embodiment includes a plurality of thermoelectric element devices described in any one of (1) to (11) above, and the plurality of thermoelectric element devices are all It is configured to be electrically connected to the adjacent thermoelectric module.

  The thermoelectric element device according to the present invention and the thermoelectric module using the thermoelectric element device can provide heat from a side surface of the thermoelectric element by providing an elastic heat transfer member, so that the temperature difference between the thermoelectric elements can be increased. For this reason, the generated electric power also increases.

  In addition, even when a gap is generated between the electrode and the contact surface of the thermoelectric element due to the thermal stress generated in the thermoelectric element device, heat can be applied from the side surface of the thermoelectric element by providing an elastic heat transfer member. Therefore, the thermoelectric power generation performance is not deteriorated.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. Further, the attached drawings only schematically show the thermoelectric device 200 and the thermoelectric module 100 according to the embodiment. For this reason, it should be noted that the relationship between the thickness and the planar dimensions, the ratio of the thicknesses of the respective members, and the like are not necessarily shown as in actual design.

  FIG. 1 is a schematic diagram showing a configuration of a thermoelectric module 100 according to an embodiment of the present invention. As illustrated, the thermoelectric module 100 is configured by two-dimensionally arranging a plurality of thermoelectric element devices 200. Here, the thermoelectric device 200 is composed of the high temperature side electrode 10 and the low temperature side electrode 5 and the thermoelectric element 4 electrically and thermally connected therebetween. In the thermoelectric module 100, a plurality of thermoelectric element devices 200 are surrounded by a case 6, as shown in FIG. Then, by sandwiching the thermoelectric module 100 between the low temperature side system 1 and the high temperature side system 2, it is possible to generate electric power due to the temperature difference generated in the thermoelectric module 100.

  In addition, transfer of electrical energy between the thermoelectric module 100 and the external circuit is performed by two conductive wires 20 provided in connection with the low temperature side electrode 2.

  As is clear from FIG. 1, each thermoelectric device 200 is electrically arranged in series between the two conductors 20. For this reason, when a direct current voltage is applied between the two conductive wires 20 to pass a current, the current flows through each thermoelectric device 200, and either the high temperature side electrode 10 or the low temperature side electrode 3 is a heat dissipation surface, The other functions as an endothermic surface.

  FIG. 2 is a schematic side sectional view showing the configuration of the thermoelectric module 100 and the thermoelectric element 200 according to the embodiment of the present invention.

  2 is a cross-sectional side view taken along the line AA of the thermoelectric module 100 shown in FIG. 1 including the case 6 and the like omitted in FIG. 1. The side cross-sectional view showing the configuration of the thermoelectric module 100 and the thermoelectric element 200 shown in FIG.

  As illustrated, the thermoelectric module 100 includes a low temperature side electrode 3, a thermoelectric element 4, a low temperature side substrate 5, a case 6, a high temperature side substrate 7, a high temperature side electrode 10, and a heat transfer member 30. It is sandwiched between side systems 2.

  The heat transfer member 30 will be described in detail later. The thermoelectric element 4 is composed of a pair of a p-type thermoelectric element and an n-type thermoelectric element. The low temperature side electrodes 3 provided on the low temperature side arranged corresponding to the positions where the thermoelectric elements 4 are arranged are arranged in an array on the low temperature side substrate 5. And the low temperature side system | strain 1 for cooling the thermoelectric module 100 is provided so that the low temperature side board | substrate 5 may be contact | connected.

  The low temperature side substrate 5 is made of an electrically insulating material in order to electrically insulate the low temperature side electrode 3 connected to the thermoelectric element 4. The low temperature side substrate 5 side of the thermoelectric element 4 is thermally connected to the low temperature side system 1.

  The thermoelectric element 4 is composed of a pair of thermoelectric elements 4 spaced apart from each other, as shown in FIG. The thermoelectric elements 4 are each composed of a thermoelectric material having a thermoelectric effect such as a Peltier effect, Seebeck effect, or Thomson effect. Typical examples of such materials include the following thermoelectric semiconductors: substances having a main phase of a bismuth and tellurium compound, substances having a main phase of a bismuth and antimony compound, and a skutterudite type crystal structure. A substance containing a compound having a filled skutterudite structure in which voids in the CoSb3-based compound crystal are filled as a main phase, a substance containing a half-Heusler compound having a MgAgAs type crystal structure as a main phase, and a clathrate containing barium and gallium There are compounds.

  Moreover, the thermoelectric element 4 can also be comprised from these mixtures. Furthermore, you may comprise the thermoelectric element 4 with the conjugate | zygote of these substances, a compound, or a mixture. These have the property that heat conductivity is comparatively small. For this reason, when the thermoelectric element 4 is comprised from these substances etc., since the temperature gradient in the thermoelectric element 4 is easy to be maintained, the performance of the thermoelectric module 100 is improved.

  In addition, these thermoelectric semiconductors have two conductivity types, p-type conductivity and n-type conductivity. When the thermoelectric elements 4 are configured as a pair as in this embodiment, typically, one of the pair is n-type conductivity and the other is p-type conductivity.

  Moreover, the thermoelectric module 100 has a case 6 that is a casing so as to block the plurality of thermoelectric elements 4 from the outside air. The case 6 is composed of a metal frame surrounding the periphery of the plurality of thermoelectric elements 4, and is connected to the low temperature side substrate 5 to seal the plurality of thermoelectric elements 4. The case 6 shields the internal components composed of the plurality of thermoelectric elements 4 and the like from the outside air, and holds the inside of the case 6 in a vacuum or an inert gas atmosphere.

  The inert gas is preferably composed of a gas selected from nitrogen, helium, neon, argon, krypton and xenon. Or these mixed gas may be sufficient. By enclosing these non-oxidizing gases in the case 6 and making the internal atmosphere inactive, it is possible to effectively prevent components such as semiconductor chips from being deteriorated due to oxidation or the like, and to achieve high conversion efficiency over a long period of time. A thermoelectric module 100 that can be maintained is obtained.

  Moreover, in the thermoelectric module 100, it is preferable that the pressure of inert gas atmosphere is set lower than external pressure at normal temperature. By setting the pressure of the inert gas atmosphere in the case 6 to be lower than the external pressure, it is possible to prevent damage due to the increase of the internal pressure at a high temperature and to retain moisture in the inert gas atmosphere in the case 6. It is possible to effectively prevent deterioration damage of the semiconductor chip due to moisture. Furthermore, since the thermal conductivity in the gas atmosphere in the case 6 is reduced, heat can be prevented from being dissipated from the thermoelectric element 4 in the direction of the metal frame, and the heat-electric conversion efficiency can be increased.

  The metal constituting the case 6 is formed of a heat resistant alloy such as a nickel base alloy or a heat resistant metal, for example. As a heat-resistant alloy or heat-resistant metal, nickel, carbon steel, stainless steel, iron-based alloys including chromium, iron-based alloys including silicon, and cobalt are included in addition to nickel-based alloys from the viewpoint of durability in high-temperature use environments. It is preferably selected from either an alloy to be made or an alloy containing nickel or copper.

  In the thermoelectric element 4, the high temperature side electrode 10 is in contact with the side opposite to the side in contact with the low temperature side electrode 3. And the high temperature side board | substrate 7 is provided so that the high temperature side electrode 10 may be contacted. The high temperature side substrate 7 is provided in contact with the case 6, and the high temperature side system 2 for heating the thermoelectric module 100 is provided so as to face the high temperature side substrate 7.

  The p-type thermoelectric element and the n-type thermoelectric element constituting the thermoelectric element 4 are connected in series by a high temperature side electrode 10 and a low temperature side electrode 4 as shown in FIG.

  Next, the heat transfer member 30 according to the embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is an exploded perspective view showing the thermoelectric device 200 shown in FIG. FIG. 4 is an enlarged view of the heat transfer member 30 with respect to a side cross-sectional view illustrating the configuration of the thermoelectric module 100 and the thermoelectric element 200 illustrated in FIG. 2.

  The heat transfer member 30 is provided on the high temperature side electrode 10 side and between the thermoelectric elements 4 connected by the high temperature side electrode 10, and transfers heat to the side surface of the thermoelectric element 4.

  The heat transfer member 30 is formed by deforming one metal plate. For convenience of explanation, the heat transfer member 30 will be described as being composed of a first flat surface portion 301, a curved surface portion 302, and a second flat surface portion 303. Specifically, as shown in FIG. 3 or FIG. 4, the heat transfer member 30 has an Ω-shaped cross section with an opening facing upward, and the curved surface portion 302 of the heat transfer member 30 constitutes the thermoelectric element 4. Sandwiched between a p-type thermoelectric element and an n-type thermoelectric element. The flat plate portions 301 and 303 of the heat transfer member 30 are arranged so as to be in contact with each other between the high temperature side electrode 10 and the thermoelectric element 4. 3 and 4, the flat plate portions 301 and 303 are provided so as to be completely in contact with the upper surface of the thermoelectric element 4. However, the heat transfer member 30 is formed of the p-type thermoelectric element and the n-type thermoelectric element 4. You may make it contact | connect with a part of upper surface of the thermoelectric element 4 so that it may suspend in between.

  That is, the flat plate portions 301 and 303 have both a function of holding the position of the heat transfer member 30 between the thermoelectric elements 4 and a function of securing a heat receiving surface. Further, the curved surface portion 302 of the heat transfer member 30 is formed of a curved surface so as to be in contact with at least one of the p-type thermoelectric element and the n-type thermoelectric element constituting the thermoelectric element 4.

  Further, since the thermoelectric element device 200 generates electric power due to a temperature difference generated between the upper surface and the lower surface of the thermoelectric element device 200, the position where the curved surface portion 302 is in contact with the side surface of the thermoelectric element 4 is the upper portion of the side surface of the thermoelectric element 4. Some are preferred. Therefore, by providing the heat transfer member 30, it is possible to increase the heat receiving area for the thermoelectric element 4 and expand the heat transfer path.

  Moreover, since the heat transfer member 30 has an Ω-shaped cross-sectional shape, it has a spring property with respect to the lateral direction of the thermoelectric device 200. Therefore, as shown in FIG. 3, when the heat transfer member 30 is inserted between the thermoelectric elements 4, the thermoelectric element 4 is disposed so as to press-contact the heat transfer member 30. Therefore, even when the thermoelectric element device 200 is laterally displaced due to thermal stress or external influence, the heat transfer member 30 follows it, so that the thermoelectric element 4 is always in contact with the thermoelectric element 4. It is.

  As the material of the heat transfer member 30, for example, the following materials are used.

  For example, (1) Fe, Ni, Co, Cr, Nb, Mo, Ta, W, Hf, Ag, Zn, Cu, Sb, Mn, Ti, Zr, Sn are formed of a material composed of at least one. . (2) Any one of stainless steel, Ni-based superalloy, Ni-Co-based superalloy, and Co-based superalloy may be used. (3) An Fe-based alloy containing at least one of Ni, Cr, Mn, Si, Al, Ti, Cu, C, V, Co, W, Mo, Nb, and N may be used. (4) A Ni-based alloy containing at least one of Fe, Cr, Mn, Si, Al, Ti, C, V, Co, W, Mo, Nb, and N may be used. (5) A Co-based alloy containing at least one of Fe, Ni, Cr, Mn, Si, C, V, W, Mo, Nb, and N may be used. (6) A Ni—Cu alloy containing at least one of Fe, Mn, Si, C, V, W, Mo, Nb, N, Al, and Ti may be used. (7) The material shown in (1) may be clad or plated with the material shown in (1) above. (8) The material shown in the above (1) may be clad or plated with the material shown in the above (2) to (6).

  As shown above, a material that does not melt or chemically react even at high temperatures and has a spring property is suitable.

  The heat transfer member 30 has a two-layer structure as shown in (7) or (8) above. FIG. 4 is a diagram in which the heat transfer member 30 has a two-layer structure, for example, a copper layer is provided. When the heat transfer member 30 has a two-layer structure, as shown in FIG. 4, the heat transfer member 30 is provided with a copper layer as a clad or plated material on the surface that does not contact the thermoelectric element 4. That is, the copper layer of the heat transfer member 30 is in contact with the high temperature side electrode 10. By providing the heat transfer member 30 with a copper layer for reducing thermal resistance, heat can be efficiently transferred to the side surface of the thermoelectric element 4 via the heat transfer member 30.

  Therefore, the thermoelectric element 4 can transfer heat not only to the upper surface of the thermoelectric element 4 in contact with the high temperature side electrode 10 but also to the side surface of the thermoelectric element 4 via the heat transfer member 30. Heat can be transferred through a plurality of paths. For this reason, the electric power generated in the thermoelectric module 100 also increases.

  Moreover, the high temperature side board | substrate 7 which comprises the thermoelectric module 100 shown in FIG. 2 has a thermal expansion difference by generation | occurrence | production of the temperature distribution of a heat source. Therefore, the high temperature side substrate 7 gives local deformation to the thermoelectric module 100. Due to the influence, the high temperature side electrode 10 is not always in contact with the entire upper surface of the thermoelectric element 4. Therefore, the area where heat can be transferred from the high temperature side system 2 to the thermoelectric element 4 is reduced.

  Even in this case, by providing the heat transfer member 30, heat can be transmitted to the thermoelectric element 4 via the heat transfer member 30, so that power generation efficiency does not decrease.

  Furthermore, since the interval at which the p-type thermoelectric element and the n-type thermoelectric element constituting the thermoelectric element 4 are arranged is extremely narrow, there may be a case where the thermoelectric element 4 is directly contacted by thermal stress or external impact. When the thermoelectric element 4 is in direct contact, the thermoelectric element 4 cannot maintain its original performance, so the heat transfer member 30 also plays a role of maintaining the position of the thermoelectric element 4.

  In addition, the heat transfer member 30 has a structure having elasticity in the lateral direction with respect to the thermoelectric module 100 and may be any structure that can transfer heat in contact with the high temperature side electrode 10, and therefore, as shown in FIG. 5. You can also.

  That is, a part of the heat transfer member 30 is disposed at a position sandwiched between the upper surface of the thermoelectric element 4 and the high temperature side electrode 10. Between the thermoelectric elements 4, the heat transfer member 30 has an annular cross-section, and may be configured to be in contact with at least one p-type thermoelectric element and n-type thermoelectric element that constitute the thermoelectric element 4. . Since the heat transfer member 30 has an annular cross section, it has an elastic effect similar to the heat transfer member 30 shown in FIG.

  This heat transfer member 30 can block the heat transmitted by radiation from the high temperature side surface inside the thermoelectric module 100 to the low temperature side surface inside the thermoelectric module 100 and transmit it to the cooling side surface via the thermoelectric element 4. Since the amount of heat applied does not contribute to power generation and is discarded from the low temperature side, higher output can be obtained.

  The heat transfer member 30 described above is not limited to the thermoelectric module 100 described with reference to FIG. 2, and can be used for a structure to which the following configuration is added.

  For example, as shown in FIG. 6, a metal having a higher elasticity between the high temperature side electrode 10 and the thermoelectric element 4 than the elasticity of the thermoelectric element 4 and equal to or higher than the elasticity of the high temperature side electrode 10. A metal film 12 can also be provided between the elastic member 11 composed of braided wires such as a fine wire net, the elastic member 11, and the thermoelectric element 4. The elastic member 11 can relieve the thermal stress generated in the thermoelectric module 100. That is, even if the thermoelectric element 4 or the high temperature side electrode 10 is deformed by thermal stress, the contact area between the thermoelectric element 4 and the high temperature side electrode 10 via the elastic member 11 does not become small. The thermoelectric conversion efficiency can be fully demonstrated.

  By providing the heat transfer member 30 on this, as described above, the number of paths through which heat is transferred increases, and therefore the thermoelectric power generation performance of the thermoelectric module 100 is further improved.

  Moreover, the high temperature side board | substrate 7 may be divided | segmented into plurality. Since each of the divided high temperature side substrates 7 is structurally independent, the members constituting the high temperature side system 2 are divided at positions facing the deformed portions of the members constituting the high temperature side system 2. Further, it is possible to move following the deformation of each part of the high temperature side substrate 7. The same effect as when the elastic member 11 is used is produced.

  A combination of the case where the high temperature side substrate 7 described above is divided into the case where the elastic member 11 is used produces the same effect.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

The perspective view of the thermoelectric conversion module which concerns on embodiment of this invention. 1 is a lateral cross-sectional view of a thermoelectric conversion module according to an embodiment of the present invention. The perspective view which shows the structure of the heat-transfer member which concerns on embodiment of this invention. The transverse direction sectional view showing the structure of the heat transfer member concerning the embodiment of the present invention. The transverse direction sectional view showing the structure of the heat transfer member concerning other embodiments of the present invention. The transverse direction sectional view of the thermoelectric conversion module concerning other embodiments to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Low temperature side system, 2 ... High temperature side system, 3 ... Low temperature side substrate electrode material, 4 ... Thermoelectric element, 5 ... Low temperature side substrate, 6 ... Case, 7 ... High temperature side substrate, 8 ... High temperature side substrate base material, 9 DESCRIPTION OF SYMBOLS ... High temperature side board | substrate reinforcement material, 10 ... High temperature side board | substrate electrode material, 11 ... Elastic member, 12 ... Metal film, 20 ... Conductor, 30 ... Heat-transfer member, 100 ... Thermoelectric module, 200 ... Thermoelectric element device, 301 ... Plane part 302: curved surface portion, 303: flat surface portion.

Claims (4)

A thermoelectric element pair composed of a material having a thermoelectric effect, which is composed of an n-type conductive portion and a p-type conductive portion that are separated from each other;
A high temperature side substrate installed on one end side of the thermoelectric element pair;
A first electrode disposed between the thermoelectric element pair and the high temperature side substrate;
A heat transfer member that is disposed between the thermoelectric element pair so as to be in contact with each side surface of the thermoelectric element pair at least one place , and is made of a metal material ;
A low temperature side substrate installed on the other end side of the thermoelectric element pair;
A second electrode disposed between the thermoelectric element pair and the low temperature side substrate;
A thermoelectric device characterized by comprising:   The thermoelectric device according to claim 1, wherein the heat transfer member has a Ω-shaped cross section in the lateral direction. The thermoelectric element device according to claim 2 , wherein the heat transfer member is sandwiched and contacted between an upper surface of each thermoelectric element pair and the first electrode. The heat transfer member, thermoelectric element device according to claim 3, wherein the benzalkonium which have a resilient.

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