JPH08222773A - Planar thermoelectric module - Google Patents

Abstract

PURPOSE: To provide a thin module excellent in packaging which can obtain large temperature difference between a high temperature end and a low temperature end, without arranging a thermoelectric element itself in the stretching direction toward a heat source. CONSTITUTION: High thermal conductivity plates 5A, 5B are formed on the upper and the lower main plate surfaces of a thermoelectric element 1, via heat insulating material 4A, 4B. Between the high thermal conductivity plate 5A and the high temperature end 1A of the thermoelectric element 1, heat is conducted through a heat conducting part member 6A. Between the high thermal conductivity plate 5B and the low temperature end 1B of the thermoelectric element 1, heat is conducted through a heat conducting part member 6B. The heat generated from a heat source reaches the high temperature end 1A of the thermoelectric element 1, through the high thermal conductivity plate 5A and the heat conducting part member 6A. The heat is radiated from the low temperature end 1B of the thermoelectric element 1 through the heat conducting part member 6B and the high thermal conductivity plate 5B. Temperature difference is generated between the high temperature end 1A and the low temperature end 1B of the thermoelectric element 1, and a voltage can be lead out from the thermoelectric element 1. Basically the module consists of lamination structure of a high thermal conductivity plate, thermal insulating material, a thermoelectric element, thermal insulating material and a high thermal conductivity plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar thermoelectric module, and more particularly, to an improvement of a thermoelectric module which is utilized as a generator with no moving parts or as a temperature sensor by utilizing the characteristic of converting thermal energy into electric energy. .

[0002]

2. Description of the Related Art A general thermoelectric element is one in which a block body of a p-type semiconductor and a block body of an n-type semiconductor are joined via a metal (π-type junction). When heated, a Seebeck effect generates an electromotive force proportional to the temperature difference between the high temperature end and the semiconductor end on the opposite side (hereinafter referred to as the “low temperature end”) calculated by the following formula. To do. The Seebeck coefficient is a numerical value peculiar to the material.

Electromotive force (V) = Seebeck coefficient (V / K)
× Temperature difference (K) As described above, in the case of the thermoelectric element in which the p-type semiconductor and the n-type semiconductor are joined at the high temperature end, the total voltage of the electromotive force generated in each semiconductor can be taken out from the low temperature end. Has become. To give specific numerical values, when FeSi ₂ system is used as the semiconductor composition, 0.3 V at a temperature difference of 600 ° C.
The element that generates the voltage is made.

Conventionally, thermoelectric elements have been used as generators or temperature sensors by taking advantage of such characteristics.

FIG. 3 is a block diagram of a conventional thermoelectric module using a thermoelectric element used for such an application.
The lead wire 2 is connected to the low temperature end side of the thermoelectric element 1 and fixed by the alumina insulator 3, and the voltage generated by the temperature difference between the high temperature end 1A generated by the heat received at the high temperature end 1A and the low temperature end in the alumina insulator 3 Is taken out by the lead wire 2.

By the way, in the thermoelectric element, in order to increase the temperature difference between the high temperature end and the low temperature end and obtain a large voltage, the low temperature end is separated from the heat source as much as possible, that is, the distance between the high temperature end and the low temperature end is large. It is common to design the total length to be long so that the size becomes large. For example, in the case of a thermoelectric element used in a safety device for extinguishing a gas lamp, the width is 5 mm and the thickness is 2 mm.
In contrast, the length is 30 mm. With such a thermoelectric element, even if the low temperature end is not forcedly cooled, if the high temperature end is heated to 800 ° C., the low temperature end becomes about 50 ° C.,
A temperature difference of 750 ° C can be taken. On the other hand, the length is 20
In mm, the low temperature end rises to about 250 ° C., and the temperature difference is only 550 ° C. Therefore, the output voltage is reduced by about 30%.

[0007]

As described above, in order to obtain a large voltage from the thermoelectric element, it is necessary to increase the total length of the thermoelectric element. In this case, naturally, the heat source and the lead wire connection at the low temperature end are connected. The distance to the section becomes large. However,
Due to the design restrictions of the device in which the thermoelectric element is to be incorporated, it may not be possible to keep a sufficient distance from the heat source. For example, in an electronic device that is strictly required to be downsized, it is not allowed to save a large space for installing a thermoelectric element. Further, from the viewpoint of mounting problems, it is generally desired that the shape is planar and easy to assemble.

On the other hand, in a water heater, a small boiler, etc., there is room in space, but if many rod-shaped elements are placed in the combustion chamber, the original heat exchange efficiency may be affected. Therefore, there is a demand for a thermoelectric element having a flat shape (having a low overall height) that can be installed on the side wall without a gap.

The present invention solves the above-mentioned problems of the prior art, and enables a large temperature difference between the high temperature end and the low temperature end to be obtained without installing the thermoelectric element itself in a direction extending toward the heat source. It is an object of the present invention to provide a planar thermoelectric module having excellent mountability.

[0010]

A planar thermoelectric module of the present invention is a plate-shaped thermoelectric element having first and second main plate surfaces facing each other, one end of which is a high temperature end and the other end of which is a high temperature end. A thermoelectric element having a low temperature end, a first high thermal conductive plate facing the first main plate surface of the thermoelectric element via a first heat insulating material, and a second main plate surface of the thermoelectric element A second high thermal conductive plate disposed face-to-face via a second heat insulating material, a first heat transfer member configured to transfer heat between the first high thermal conductive plate and the high temperature end of the thermoelectric element, and A second heat transfer member for transferring heat between the second high thermal conductive plate and the low temperature end of the thermoelectric element.

The present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a flat type thermoelectric module 10 of the present invention.
2 is a cross-sectional view taken along line-in FIG. 1. However, FIG. 2 shows a state in which the second heat transfer plate 6B of FIG. 1 is mounted.

Reference numeral 1 denotes a first main plate surface 1a and a second main plate surface 1a which face each other.
Is a plate-shaped thermoelectric element having a main plate surface 1b of 1., and one end of this thermoelectric element is a high temperature end 1A and the other end is a low temperature end 1B.

On the first main plate surface 1a of the thermoelectric element 1, a first high thermal conductive plate 5A is arranged face-to-face with a first heat insulating material 4A, while on the other hand, on the second main plate surface 1b of the thermoelectric element 1. The second high thermal conductive plate 5B is arranged face-to-face with the second heat insulating material 4B interposed therebetween.

A first heat transfer member 6A is in contact with the end surface of the high temperature end 1A of the thermoelectric element 1. One end of the first heat transfer member 6A is brought into direct contact with the first high heat conductive plate 5A, so that heat is transferred between the high temperature end 1A of the thermoelectric element 1 and the first high heat conductive plate 5A. It is configured. The other end surface of the first heat transfer member 6A is in contact with the second heat insulating material 4B and is insulated from the second high thermal conductive plate 5B.

On the other hand, a second heat transfer member 6B is in contact with the end surface of the low temperature end 1B of the thermoelectric element 1. One end of the second heat transfer member 6B is brought into direct contact with the second high thermal conductive plate 5B, so that heat is transferred between the low temperature end 1B of the thermoelectric element 1 and the second high thermal conductive plate 5B. It is configured. The other end surface of the second heat transfer member 6B is in contact with the first heat insulating material 4A and is thermally insulated from the first high thermal conductive plate 5A.

In such a flat type thermoelectric module, the first high thermal conductive plate 5A which is heat-transferred to the high temperature end 1A of the thermoelectric element 1 via the first heat transfer member 6A serves as a heat collecting surface, On the other hand, the second heat transfer member 6 is attached to the low temperature end 1B of the thermoelectric element 1.
The second high thermal conductive plate 5B that is transferred via B serves as a heat dissipation surface, and the heat generated from the heat source is applied to the first high thermal conductive plate 5B.
It is transmitted to the high temperature end 1A of the thermoelectric element 1 via A and the second heat transfer member 6A. On the other hand, from the low temperature end 1B of the thermoelectric element 1,
Heat is radiated through the second heat transfer member 6B and the second high thermal conductive plate 5B, whereby a temperature difference occurs between the high temperature end 1A and the low temperature end 1B of the thermoelectric element 1, and a voltage can be taken out. Becomes

At this time, the first and second high thermal conductive plates 5A,
5B is laminated on the thermoelectric element 1 via the first and second heat insulating materials 4A and 4B, respectively, and the first high thermal conductive plate 5A is arranged at a high temperature of the thermoelectric element 1 only via the first heat transfer member 6A. Edge 1
The second high heat conductive plate 5B transfers heat to A and the second heat transfer member 6
Since the heat is transferred to the low temperature end 1B of the thermoelectric element 1 only through B, the heat can be collected or radiated without being affected by the thermal influence of other parts.

In the present invention, the first and second high thermal conductive plates may have any good thermal conductivity, and in general, metal plates such as aluminum and copper are used. A good ceramics or the like can be used. However, it is preferable to use a metal plate in terms of workability and cost. Further, as the first and second heat transfer members, members made of a high heat conductive material similar to the high heat conductive plate can be used.

On the other hand, as the first and second heat insulating materials, those having excellent heat insulating properties such as porous ceramics are used, but in addition, resin materials having low heat conductivity may be used. However, it is preferable to use ceramics from the viewpoint of high temperature stability.

To join and integrate the first and second high thermal conductive plates, the first and second heat insulating materials, the first and second heat transfer members and the thermoelectric element, for example, the thermoelectric element and the first , The second heat insulating material is joined with alumina cement, the first and second heat insulating materials and the first and second high thermal conductive plates are joined with zirconia cement, and the first and second heat transfer members are joined. The thermoelectric element may be joined with alumina cement. Further, the first and second high heat conductive plates and the first and second heat transfer members can be joined by screwing or by welding or the like when each is made of a metal material.

As shown in FIG. 1, the flat type thermoelectric module of the present invention includes a first high thermal conductive plate 5A, a first heat insulating material 4A,
Thermoelectric element 1, second heat insulating material 4B and second high thermal conductive plate 5
Because of the laminated structure of B, the first and second high thermal conductive plates having a thickness of about 0.1 to 0.2 mm and the thickness of 1 to 1 are used for the thermoelectric element having a thickness of about 1.6 to 2.0 mm. The first and second heat insulating materials having a thickness of about 0 to 1.5 mm can be laminated to have a total thickness of about 4.0 to 6.0 mm, which is thin and has excellent mountability.

The planar thermoelectric module 1 shown in FIG.
Reference numeral 0 is one embodiment of the flat type thermoelectric module of the present invention, and the present invention is not limited to the illustrated one as long as it does not exceed the gist thereof. For example, the first high heat conductive plate and the first heat transfer member, and the second high heat conductive plate and the second heat transfer member do not necessarily have to be separate bodies, and they are integrated respectively. A member having an L-shaped cross section may be used.

[0024]

In the flat type thermoelectric module of the present invention, the heat generated from the heat source is transmitted to the high temperature end of the thermoelectric element via the first high thermal conductive plate and the second heat transfer member, and the low temperature end of the thermoelectric element is transferred. Since heat is released through the second heat transfer member and the second high thermal conductive plate, a temperature difference occurs between the high temperature end and the low temperature end of the thermoelectric element, and a voltage can be taken out from the thermoelectric element. it can.

The flat type thermoelectric module of the present invention basically has a laminated structure of a high heat conductive plate, a heat insulating material, a thermoelectric element, a heat insulating material and a high heat conductive plate, and is thin and excellent in mountability.

[0026]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

Example 1 An FeSi ₂ type thermoelectric element (width 5 mm, thickness 1.6 mm, length 30 mm) was used as the thermoelectric element, and porous ceramics (thickness 1.0 mm) was used as the first and second heat insulating materials. , First,
Aluminum plate (thickness 0.2m as the second high thermal conductive plate
m) and an aluminum plate having a thickness of 1.0 mm as the first and second heat transfer members, the flat thermoelectric module of the present invention shown in FIG. 1 was produced. The thermoelectric element and the first and second heat insulating materials were joined by alumina cement, and the first and second heat insulating materials and the first and second high thermal conductive plates were joined by zirconia cement. Also, the first and second
The high heat conductive plate and the first and second heat transfer members were joined by screwing, and the first and second heat transfer members and the thermoelectric element were joined by alumina cement.

The size of this flat type thermoelectric module is 2 in total length.
It was thin with 0 mm, overall width 5 mm, and overall height (thickness) 5 mm.

This module was placed on a hot plate with the heat collecting surface (first high thermal conductive plate 5A) facing down and heated to 300.degree. On the other hand, the heat radiating surface (the second high thermal conductive plate 5B) was brought into contact with a copper tube in which cooling water was flown and kept at 25 ° C.

When the temperature was measured by bringing a thermocouple into contact with the high temperature end of this thermoelectric element, it was 230 ° C., and the temperature at the low temperature end was also measured, which was 65 ° C. In this state, the thermoelectric element had a voltage of 80 mV. Was able to occur.

When a conventional thermoelectric module as shown in FIG. 3 was assembled using thermoelectric elements of the same size, an installation space of at least 30 mm was required toward the heat source. It only needed to incorporate a 5 mm flat type thermoelectric module, the space required was about ⅙ of that of the conventional product, and the flat shape had an advantage that it was easy to mount.

[0032]

As described in detail above, according to the flat type thermoelectric module of the present invention, a thin thermoelectric module having excellent mountability is provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a planar thermoelectric module of the present invention.

FIG. 2 is a sectional view taken along the line − in FIG.

FIG. 3 is a configuration diagram showing a conventional thermoelectric module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermoelectric element 1A High temperature end 1B Low temperature end 4A First heat insulating material 4B Second heat insulating material 5A First high heat conductive plate 5B Second high heat conductive plate 6A First heat transfer member 6B Second heat transfer member 10 Flat thermoelectric module

Claims (1)

[Claims] 1. A thermoelectric element having plate-like thermoelectric elements having first and second main plate surfaces facing each other, one end of which is a high temperature end and the other end of which is a low temperature end, and a thermoelectric element of the thermoelectric element. A first high thermal conductive plate which is arranged to face the first main plate surface via a first heat insulating material, and a second high heat conductive plate which is arranged to face the second main plate surface of the thermoelectric element via a second heat insulating material. A second high heat conductive plate; a first heat transfer member for transferring heat between the first high heat conductive plate and the high temperature end of the thermoelectric element; and a second high heat conductive plate and the low temperature end of the thermoelectric element And a second heat transfer member for heat transfer with the flat thermoelectric module.