JP2005093532A - Thermoelectric element module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoelectric element module which can generate power at high efficiency. <P>SOLUTION: The thermoelectric element module is provided with an endotherm board 1 and a heat slinger 2 by which counter arrangement is carried out, a first thermoelectric element 3a constituted of a plurality of prisms which generate electromotive force from a low temperature side to a high temperature side by applying temperature difference to a part between both end portions, a second thermoelectric element 3b constituted of a plurality of prisms which generate electromotive force from a high temperature side to the low temperature side, and connection members which are installed on the endotherm board 1 and the heat slinger 2 respectively, and connect electrically a plurality of the first thermoelectric elements 3a and the second thermoelectric elements 3b in series by connecting alternately end portions of the endotherm board 1 side and end portions of the heat slinger 2 side along the juxtaposition direction of the first thermoelectric element 3a and the second thermoelectric element 3b. Out of the first thermoelectric element 3a and the second thermoelectric element 3b, cross section with larger Seebeck coefficient is enlarged relatively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a thermoelectric element module that generates power using a temperature difference.

  The configuration of a conventional thermoelectric element module is shown in FIG.

  As shown in FIG. 6, this thermoelectric element module has a heat absorbing plate 100 a that is arranged on the high temperature side and acts as a heat absorbing surface, and a heat radiating plate 100 b that is arranged on the low temperature side and acts as a heat radiating surface.

  A plurality of first thermoelectric elements 102a that generate an electromotive force from the low temperature side to the high temperature side by providing a temperature difference between both ends between the heat absorption plate 100a and the heat dissipation plate 100b. A plurality of second thermoelectric elements 102b that generate an electromotive force from the high temperature side toward the low temperature side are alternately arranged in parallel at predetermined intervals.

  The first thermoelectric element 102a and the second thermoelectric element 102b are formed of columnar bodies having substantially the same length, and are formed so that the cross-sectional areas orthogonal to the axial center line are substantially equal.

  Adjacent first thermoelectric elements 102a and second thermoelectric elements 102b are alternately connected while shifting the combination by the connection member 103 on the heat absorbing plate 100a or the heat radiating plate 100b, and thereby the plurality of first thermoelectric elements 102a and The second thermoelectric elements 102b are electrically connected in series.

  In the thermoelectric element module configured as described above, when a temperature difference is given between the heat absorbing plate 100a and the heat radiating plate 100b, between both ends of the first thermoelectric element 102a and between both ends of the second thermoelectric element 102b. A predetermined potential difference is generated. The potential difference generated between the first thermoelectric element 102a and the second thermoelectric element 102b is added through the connection member 103, and becomes an output voltage of the thermoelectric element module.

  As described above, since the plurality of first thermoelectric elements and the second thermoelectric elements are electrically connected in series, the same current flows through the first thermoelectric element and the second thermoelectric element. Become.

  However, since the first thermoelectric element and the second thermoelectric element have different characteristics such as Seebeck coefficient and resistivity, there is a difference in the current value for obtaining the maximum output [W] as shown in FIG. Therefore, conventionally, the maximum output [W] of the first thermoelectric element and the second thermoelectric element cannot be obtained simultaneously, and the power generation efficiency cannot be maximized.

  This invention is made | formed in view of the said situation, The place made into the objective is providing the thermoelectric element module which can generate electric power with high efficiency.

  In order to solve the above problems and achieve the object, the thermoelectric module of the present invention is configured as follows.

(1) The first insulating substrate and the second insulating substrate that are arranged to face each other, and the first insulating substrate and the second insulating substrate that are arranged in parallel to each other at a predetermined interval so as to connect the first insulating substrate and the second insulating substrate. A plurality of first thermoelectric elements that generate an electromotive force in a first direction, a plurality of second thermoelectric elements that generate an electromotive force in a second direction opposite to the first direction, and the first The ends on the first insulating substrate side and the ends on the second insulating substrate side of the thermoelectric element and the second thermoelectric element are alternately connected along the parallel arrangement direction of the first thermoelectric element and the second thermoelectric element. Thus, a connecting member that electrically connects the plurality of first thermoelectric elements and the second thermoelectric elements in series is provided. Of the first thermoelectric elements and the second thermoelectric elements, the one with the larger Seebeck coefficient The cross-sectional area is relatively large.

(2) The thermoelectric element module described in (1), wherein the first thermoelectric element and the second thermoelectric element have a rectangular cross section perpendicular to the axial center line, and each side surface faces each other. Further, the shapes and dimensions of the side surfaces opposed to each other are substantially equal.

  According to the present invention, it is possible to generate power with high efficiency with respect to a given temperature difference.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a front view illustrating a configuration of a thermoelectric element module according to an embodiment of the present invention, omitting a heat absorbing plate, and FIG. 2 is a side view illustrating the configuration of the thermoelectric element module according to the embodiment from the direction of arrow A. FIG. 3 is a side view showing the configuration of the thermoelectric element module according to the embodiment from the arrow B side.

  As shown in FIGS. 1 to 3, the thermoelectric element module includes a heat absorbing plate 1 that is disposed on the high temperature side and functions as a heat absorbing surface, and a heat radiating plate 2 that is disposed on the low temperature side and functions as a heat radiating surface.

  The heat absorbing plate 1 and the heat radiating plate 2 are made of a substantially rectangular insulating material, and are opposed to each other with a predetermined interval. As the material of the heat absorbing plate 1, an insulating material having heat resistance such as ceramic, and as the material of the heat radiating plate 2, a general insulating material such as aluminum oxide is used.

  A power generation layer 3 is provided between the heat absorbing plate 1 and the heat radiating plate 2. The power generation layer 3 includes a plurality of first thermoelectric elements 3a that generate an electromotive force in a direction from the low temperature side to the high temperature side (first direction) by giving a temperature difference between both ends, and low temperature from the high temperature side. It consists of a plurality of second thermoelectric elements 3b that generate an electromotive force in a direction toward the side (second direction). As the first thermoelectric element 3a, a metal material having a larger Seebeck coefficient [μV / K] and a smaller resistivity [Ω / m] than the second thermoelectric element 3b is used.

  The first thermoelectric elements 3a and the second thermoelectric elements 3b are alternately arranged at predetermined intervals with respect to the X direction and the Y direction orthogonal to each other.

  The first thermoelectric element 3a and the second thermoelectric element 3b that are adjacent to each other in the X direction have a first connection electrode 4a (connection member) made of aluminum arranged in parallel on the heat absorption plate 1 at a predetermined interval, and a predetermined value on the heat dissipation plate 2. The second connection electrodes 4b (connection members) made of aluminum arranged in parallel at intervals are alternately connected while shifting the combination of the first and second thermoelectric elements 3a and 3b. Thus, the first thermoelectric element 3a and the second thermoelectric element 3b arranged in parallel in the X direction are connected in a meandering manner in a side view.

  The first and second thermoelectric elements 3a and 3b and the first and second connection electrodes 4a and 4b are electrically connected by a bonding material 5 having heat resistance. For example, Al-12 wt% Si or the like is used as the material of the bonding material 5.

  On the other hand, the first thermoelectric element 3a and the second thermoelectric element 3b, which are arranged at both ends in the X direction and are adjacent to the Y direction, are copper third connection electrodes provided in a staggered manner on both sides in the X direction of the heat absorbing plate 1. 4c (connection member) and the fourth connection electrode 4d (connection member) are alternately connected.

  The first and second thermoelectric elements 3a and 3b and the third and fourth connection electrodes 4c and 4d are electrically connected by a bonding material 8 that is generally used. Note that solder or the like is used as the material of the bonding material 8.

  Thus, all the first thermoelectric elements 3a and the second thermoelectric elements 3b are electrically connected in series via the first to fourth connection electrodes 4a to 4d.

  The 1st thermoelectric element 3a and the 2nd thermoelectric element 3b consist of a columnar body of substantially the same length, and the cross section orthogonal to the axial center line | wire has comprised rectangular shape. Moreover, the 1st thermoelectric element 3a and the 2nd thermoelectric element 3b are arrange | positioned so that two mutually parallel side surfaces may each follow an X direction and a Y direction.

  The length dimension with respect to the Y direction of the 1st thermoelectric element 3a and the 2nd thermoelectric element 3b is formed substantially equal. On the other hand, the length dimension with respect to the X direction of the 1st thermoelectric element 3a is formed longer than the 2nd thermoelectric element 3b. Thereby, the area of the cross section orthogonal to the axial center line of the first thermoelectric element 3a is set larger than that of the second thermoelectric element 3b.

  According to the thermoelectric element module configured as described above, when a temperature difference is given to the heat absorbing plate 1 and the heat radiating plate 2, the first thermoelectric element 3a and the second thermoelectric element 3b disposed between them have a predetermined potential difference due to the Seebeck effect. Occurs.

  The potential difference generated in the first and second thermoelectric elements 3a and 3b is added through the first to fourth connection electrodes 4a to 4d connecting the thermoelectric elements 3a and 3b, and the output voltage [V ].

  By the way, in the Seebeck effect, a material having a larger Seebeck coefficient generates a larger electromotive force with respect to a temperature difference given to the heat absorbing plate 1 and the heat radiating plate 2. Therefore, in the present invention, a large output voltage [V] is obtained by making the cross-sectional area of the first thermoelectric element 3a having a large Seebeck coefficient larger than the cross-sectional area of the second thermoelectric element 3b having a small Seebeck coefficient. .

  However, increasing the cross-sectional area of the first thermoelectric element 3a increases the size of the thermoelectric element module. Therefore, when the cross-sectional area of the first thermoelectric element 3a is increased, it is desired to reduce the cross-sectional area of the second thermoelectric element 3b accordingly.

  However, since the second thermoelectric element has a high resistivity, if the cross-sectional area is reduced, a large voltage drop occurs when a current flows through the second thermoelectric element, resulting in a decrease in output power [W].

  Therefore, the inventor not only makes the cross-sectional area of the first thermoelectric element 3a larger than that of the second thermoelectric element 3b, but also measures the actual output power [W], thereby obtaining the maximum output. The area ratio of the cross section of the second thermoelectric element 3b was measured.

  As a result, as shown in FIG. 5, it was confirmed that there is an optimum area ratio for obtaining the maximum output power [W] between the first thermoelectric element 3a and the second thermoelectric element 3b. The optimum area ratio is determined by the materials of the first thermoelectric element 3a and the second thermoelectric element 3b, but the first thermoelectric element 3a and the second thermoelectric element 3b according to the present embodiment. In the combination, it can be seen that the optimal area ratio is obtained when the cross-sectional area of the first thermoelectric element 3a / the cross-sectional area of the second thermoelectric element 3b is 2.

  Therefore, in the present embodiment, the cross-sectional area of the first thermoelectric element 3a is approximately twice that of the second thermoelectric element 3b, that is, the length dimension of the first thermoelectric element 3a in the X direction is approximately 2 times that of the second thermoelectric element 3b. Doubled.

  As a result, a large output power [W] can be obtained for a given temperature difference. In other words, it is possible to generate power with high efficiency for a given temperature difference.

  Next, a process for manufacturing the thermoelectric element module having the above configuration will be described.

  4A to 4C are process diagrams showing the manufacturing process of the thermoelectric element module according to the embodiment.

  As shown in FIG. 4A, the first connection electrode 4a, the third connection electrode 4c, and the fourth connection electrode 4d are formed at predetermined positions on the heat absorbing plate 1.

  Next, as shown in FIG. 4B, a bonding material 5 such as Al—Si is supplied onto the first, third, and fourth connection electrodes 4 a, 4 c, and 4 d, and the bonding material 5 is cured on the bonding material 5. The 1st thermoelectric element 3a and the 2nd thermoelectric element 3b are arrange | positioned using a tool (not shown). Then, the endothermic plate 1 and the first and second thermoelectric elements 3a and 3b are put together with a jig in a non-oxidizing atmosphere furnace such as a hydrogen furnace and heated to about 600 degrees. As a result, the bonding material 5 is melted, and the first and second thermoelectric elements 3 a and 3 b are fixed on the heat absorbing plate 1.

  On the other hand, apart from the above-described steps, the second connection electrode 4b is formed at a predetermined position of the heat sink 2 as shown in FIG. Next, the bonding material 8 such as a solder paste is supplied onto the second connection electrode 4b, and the first and second thermoelectric elements 3a and 3b fixed on the heat absorbing plate 1 are disposed on the bonding material 8. Then, the bonding material 8 is heated to fix the heat absorbing plate 1 to the first and second thermoelectric elements 3a and 3b.

  This completes the manufacturing process of the thermoelectric element module.

  As described above, by using the jig when fixing the first and second thermoelectric elements 3a and 3b on the heat absorbing plate 1, the plurality of first and second thermoelectric elements 3a and 3b can be accurately arranged. it can. Moreover, since the relative positions of the first and second thermoelectric elements 3a and 3b are maintained by the jig even during heating, the first and second thermoelectric elements 3a, The position of 3b does not shift with respect to the heat absorbing plate 1.

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

  The thermoelectric element module according to the present embodiment is used for generating electricity using a temperature difference, but includes a Peltier module that promotes heat transfer by energization.

The front view explaining the structure of the thermoelectric element module which concerns on one embodiment of this invention abbreviate | omitting a heat sink. The side view which shows the structure of the thermoelectric element module which concerns on the same embodiment from the arrow A direction. The side view which shows the structure of the thermoelectric element module which concerns on the same embodiment from the arrow B side. Process drawing which shows the manufacturing process of the thermoelectric element module which concerns on the same embodiment. The graph which shows the output at the time of changing the area ratio of the cross section of the 1st thermoelectric element and 2nd thermoelectric element which concern on the same embodiment variously. Schematic which shows the structure of the conventional thermoelectric element module. The graph which shows the current-output characteristic of a 1st thermoelectric element and a 2nd thermoelectric element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heat-absorbing plate (1st insulated substrate), 2 ... Heat sink (2nd insulated substrate), 3a ... 1st thermoelectric element, 3b ... 2nd thermoelectric element, 4a-4d ... 1st-4th connection electrode (connection member) ).

Claims (2)

A first insulating substrate and a second insulating substrate disposed opposite to each other;
A plurality of first thermoelectric elements that are arranged in parallel at a predetermined interval so as to connect the first insulating substrate and the second insulating substrate, and generate an electromotive force in a first direction by giving a temperature difference between both ends; A plurality of second thermoelectric elements that generate an electromotive force in a second direction that is opposite to the first direction;
The ends of the first thermoelectric element and the second thermoelectric element on the first insulating substrate side and the ends of the second insulating substrate side are aligned along the direction in which the first thermoelectric element and the second thermoelectric element are juxtaposed. By connecting alternately, a connection member that electrically connects the plurality of first thermoelectric elements and second thermoelectric elements in series;
Comprising
The thermoelectric element module characterized by relatively increasing the cross-sectional area of the first thermoelectric element and the second thermoelectric element having a larger Seebeck coefficient.   The first thermoelectric element and the second thermoelectric element have a rectangular cross section orthogonal to the axial center line, are arranged so that the side surfaces thereof are opposed to each other, and the shapes and dimensions of the opposed side surfaces are substantially equal. The thermoelectric element module according to claim 1.

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