JPH09181360A - Thermoelectric converter - Google Patents

Abstract

(57) [PROBLEMS] To provide a thermoelectric conversion device in which breakage of a thermoelectric element due to thermal expansion and contraction is suppressed to prolong the service life. SOLUTION: The plate-shaped heat exchangers 1 and 2 facing each other,
A thermoelectric element 4 having at least a pair of P-type semiconductors 5a and N-type semiconductors 5b arranged in parallel between the heat exchangers, and P-type semiconductors and N-type semiconductors of the thermoelectric elements are alternately arranged in series. In the thermoelectric conversion device including the electrode 10 connected to the heat exchanger and attached to the heat exchanger as described above, the thermoelectric element is formed in a substantially cylindrical shape and is substantially perpendicular to the heat exchanger. In addition, the deformation suppressing body 6 formed of a ceramic material is arranged inside the cylindrical shape, and the cross-sectional area of the deformation suppressing body in a direction substantially parallel to the heat exchanger is equal to that of the heat exchanger. It was formed so as to become larger as it goes away from the approximate center.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric converter for converting electricity into heat or heat into electricity.

[0002]

2. Description of the Related Art Conventionally, there is a thermoelectric converter that converts electricity into heat using the Peltier effect and heat into electricity using the Seebeck effect. As shown in FIG. 7 and FIG. 8, this thermoelectric conversion device includes a high temperature side heat exchanger 1 and a low temperature side heat exchanger 2 which are arranged in a substantially flat plate shape and face each other. 2, a thermoelectric element 4 having a plurality of P-type semiconductors 5a and N-type semiconductors 5b arranged side by side in a grid pattern, and P-type semiconductors 5a and N-type semiconductors 5b of thermoelectric element 4 are alternately arranged in series. Electrodes 10 connected so as to be arranged and attached to the heat exchangers 1 and 2.

The P-type semiconductor 5a and the N-type semiconductor 5b of this thermoelectric element 4 are substantially rectangular parallelepiped made of heavy metal formed by sintering or the like, and the P-type semiconductor 5a and the N-type semiconductor 5b and the electrode 10 are solder
It is joined at 7 mag. The electrode 10 is fixed to the high temperature side heat exchanger 1 or the low temperature side heat exchanger 2 made of aluminum with an adhesive or the like. Further, although not shown, the high temperature side heat exchanger 1 and the low temperature side heat exchanger 2 position each heat exchanger 1, 2 at a predetermined position by tightening with a screw or the like, and each heat exchanger 1 , 2 sandwich the thermoelectric element 4 and the electrode 10 between them. Then, by passing an electric current through the thermoelectric conversion device, heat is dissipated in the high temperature side heat exchanger 1 and heat is absorbed in the low temperature side heat exchanger 2.

[0004]

In the thermoelectric converter described above, the high-temperature side and low-temperature side heat exchangers are held at predetermined positions so that the thermoelectric element and the electrodes are sandwiched, and the high-temperature side and low-temperature side heat exchanges are performed. The thermal conductivity between the container, the thermoelectric element, and the electrode is improved. However, since each heat exchanger has a large thermal expansion because it is formed of aluminum or the like having good thermal conductivity, the clamping force between the thermoelectric element and the electrode becomes too large when each heat exchanger is positioned, Large thermal stress may be applied to the thermoelectric elements and electrodes. As a result, cracks may occur in the thermoelectric element or the like, leading to disconnection and shortened life.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thermoelectric conversion device in which breakage of a thermoelectric element due to thermal expansion and thermal contraction is suppressed to prolong the service life. It is to be.

[0006]

In order to solve the above-mentioned problems, the thermoelectric conversion device according to claim 1 is arranged in parallel between heat exchangers of substantially flat plate shape facing each other and between the heat exchangers. A thermoelectric element having at least one pair of P-type semiconductor and N-type semiconductor, and a heat exchanger, wherein the P-type semiconductor and the N-type semiconductor of the thermoelectric element are alternately connected in series so as to be arranged in series. In the thermoelectric conversion device, the thermoelectric element is provided with a deformation suppressing body made of a ceramic material.

Further, the thermoelectric converter according to claim 2 is
The thermoelectric element according to claim 1 is formed in a substantially cylindrical shape so as to be arranged substantially perpendicular to the heat exchanger, and the deformation suppressing body is arranged inside the cylindrical shape.

The thermoelectric converter according to claim 3 is
The thermoelectric element according to claim 1 is formed so as to have a layered crystal structure and is arranged so that its layered surface is substantially perpendicular to the heat exchanger, and the deformation suppressing body is arranged between the layers. It is configured.

The thermoelectric converter according to claim 4 is
The layered surface of the thermoelectric element according to claim 3 is arranged so as to be substantially parallel to the radiation extending from substantially the center of the heat exchanger.

The thermoelectric converter according to claim 5 is
The deformation suppressing body according to any one of claims 1 to 4 is formed so that a cross-sectional area in a direction substantially parallel to the heat exchanger increases as the distance from the center of the heat exchanger increases.

Further, in the thermoelectric conversion device according to a sixth aspect of the present invention, substantially flat plate-shaped heat exchangers facing each other and at least one pair of P-type semiconductor and N-type semiconductor arranged in parallel between the heat exchangers are provided. A thermoelectric element having: and a P-type semiconductor and an N-type semiconductor of the thermoelectric element are connected to each other via solder so as to be alternately arranged in series and are attached to the heat exchanger. In the electric conversion device, the thermoelectric element is formed so as to have a layered crystal structure, and the layered surface is arranged so as to be substantially perpendicular to the heat exchanger, and the layered surface is located substantially from the center of the heat exchanger. It is arranged so as to be substantially parallel to the extending radiation.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 is a front view of the thermoelectric conversion device, and FIG. 2 is a cross-sectional view of the thermoelectric conversion device. The thermoelectric conversion device includes a high temperature side heat exchanger 1 and a low temperature side heat exchanger.
2, the thermoelectric element 4, and the electrode 10 are main constituent members. Members having the same basic functions as those described in the related art are designated by the same reference numerals.

The high temperature side heat exchanger 1 includes a thermoelectric element 4 which will be described later.
It radiates the heat generated at one end to the outside, and is formed of a material having good heat conduction such as aluminum in a substantially flat plate shape having an outer surface 1a and an inner surface 1b. This outer surface 1a is
Contact with gases or solids that want to transfer heat.

The low temperature side heat exchanger 2 includes a thermoelectric element 4 which will be described later.
It absorbs heat from the outside as the other end of it cools, and like the high temperature side heat exchanger 1, it has an outer surface 2a and an inner surface 2b.
Is formed of a material having good heat conduction such as aluminum in a substantially flat plate shape. The outer surface 2a also comes into contact with a gas, a solid, or the like that wants to absorb heat. The low temperature side heat exchanger 2 and the high temperature side heat exchanger 1 have inner surfaces 2b, 1b facing each other substantially parallel to each other, and have a predetermined space for accommodating and sandwiching a thermoelectric element 4 and an electrode 10 described later. It is fixed with screws or the like (not shown) so as to have it.

The thermoelectric element 4 is for converting electricity into heat, and as shown in FIG. 3, is formed of an element body 5 and a deformation suppressing body 6 into a substantially columnar shape. The element body 5 is one through which an electric current flows, and is formed of a heavy metal such as a P-type semiconductor 5a or an N-type semiconductor 5b into a substantially cylindrical shape by a method such as sintering. The deformation suppressing body 6 suppresses the deformation of the thermoelectric element 4, and is formed into a columnar shape by a method such as sintering using a ceramic material such as alumina ceramic having high rigidity and low electrical conductivity and low thermal conductivity. It is formed and disposed inside the element body 5.

In the thermoelectric element 4 having this structure, the P-type semiconductors 5a and the N-type semiconductors 5b are alternately arranged as shown in FIGS. 1 and 2, and the central axis of the thermoelectric element 4 is in each heat exchanger 1. ,
The heat exchangers 1 and 2 are arranged side by side in a grid pattern so as to be substantially perpendicular to 2. In addition, each heat exchanger of the deformation suppressing body 6
The cross-sectional area in the direction substantially parallel to 1, 2 increases as it goes away from the approximate center of the heat exchangers 1, 2, that is, as the cylindrical diameter of the deformation suppressing body 6 increases away from the approximate center. The thermoelectric element 4 is thus formed. Reference numeral 7 is solder, which joins the end face of the thermoelectric element 4 and the electrode 10 described later.

The electrode 10 is one in which P-type semiconductors 5a and N-type semiconductors 5b, which are the element body 5 of the thermoelectric element 4, are alternately arranged and are connected in series, and the first electrode 11 and the first electrode 11 are connected. Two
It is composed of electrodes 12 and attached to heat exchangers 1 and 2. The first electrode 11 and the second electrode 12 are formed of a conductive material such as copper into a substantially flat plate shape. The first electrode 11 is on the inner surface 1b of the high temperature side heat exchanger 1, and the second electrode 12 is on the low temperature side. Inner surface 2b of heat exchanger 2
It is attached via an adhesive or grease. The thermoelectric elements 4 do not have to be all connected in series, and a structure in which a plurality of thermoelectric elements 4 are connected in series may be used. And this element body
The P-type semiconductor 5a and the N-type semiconductor 5b, which are 5, are P-type semiconductors.
Where current flows from 5a to N-type semiconductor 5b, one end thereof generates heat, and where current flows from N-type semiconductor 5b to P-type semiconductor 5a, the other end thereof is cooled. .

In this thermoelectric conversion device, by passing a current, one end of the P-type semiconductor 5a and the N-type semiconductor 5b of the thermoelectric element 4 generates heat and the other end thereof is cooled. Therefore, the heat generated at one end is transmitted to the high temperature side heat exchanger 1 through the first electrode 11 and is radiated from the outer surface 1a, while the heat is absorbed from the outer surface 2a of the low temperature side heat exchanger 2. Has been
Heat is transferred to the other ends of the P-type semiconductor 5a and the N-type semiconductor 5b through the second electrode 12.

Each of the heat exchangers 1 and 2 expands and contracts due to a change in temperature, but its thermal deformation is suppressed by a deformation suppressing body 6 formed of a ceramic material having rigidity, and the thermoelectric element 4 In order to reduce the thermal stress due to the above, cracks are less likely to occur in the thermoelectric element 4 and disconnection is less likely to occur, so that the service life can be extended. In addition, since the cross-sectional area of the deformation suppressing body 6 increases as it moves away from the approximate center of the heat exchangers 1 and 2, the magnitude of thermal deformation and the cross-sectional area, that is, the rigidity, are in a substantially proportional relationship, so that further heat stress It becomes easy to control.

Next, a second embodiment of the present invention will be described with reference to FIGS. This is different from the first embodiment in the structure of the thermoelectric element 4. Note that, in FIG. 4 and FIG. 6 described later, the thermoelectric element 4 and the like are omitted.

The thermoelectric element 4, as shown in FIG.
5 and the deformation suppressing body 6 are formed into a substantially rectangular parallelepiped shape. The element body 5 is formed of a heavy metal such as a P-type semiconductor 5a or an N-type semiconductor 5b by a melt drawing method or the like so as to have a layered crystal structure. The deformation suppressing body 6 is arranged between the layers.

Further, the thermoelectric element 4 has its layered surface substantially perpendicular to the heat exchangers 1, 2, and the heat exchangers 1, 2.
2 is arranged so as to be substantially parallel to the radiation extending from the substantially center of the heat exchanger 1, and the cross-sectional area of the deformation suppressing body 6 in the direction substantially parallel to the heat exchangers 1, 2 is equal to that of the heat exchangers 1, 2. The deformation suppressing body 6 is formed so that it becomes larger as it goes away from the substantially center, that is, the thickness of the deformation suppressing body 6 becomes thicker as it goes away from the substantially center.

In this device, since the thermoelectric element 4 has a layered crystal structure and the deformation suppressing body 6 is disposed between them, the rigidity of the thermoelectric element 4 is increased, so that the thermoelectric element 4 is further improved.
It is difficult for cracks to occur and breaks. Further, since the layered surface is arranged substantially parallel to the radiation extending from the approximate center of the heat exchangers 1 and 2, the thermoelectric element 4 against expansion and contraction with the approximate center of the heat exchangers 1 and 2 as a reference. Since such deformations are suppressed, cracks are less likely to occur in the thermoelectric element 4 and disconnection is more difficult.

Next, a third embodiment of the present invention will be described with reference to FIG. This is obtained by removing the deformation suppressing body 6 from the thermoelectric element 4 of the second embodiment. If the heat stress is not great, such a structure can be used.

Although the thermoelectric converter of the present invention has been described as one that converts electricity into heat by utilizing the Peltier effect, it can also be used by converting heat into electricity by utilizing the Seebeck effect. . Further, although the cross-sectional area of the deformation suppressing portion is increased as the distance from the center of the heat exchanger is increased, the shape is not limited to this, and the deformation suppressing portion may be formed with a uniform cross-sectional area, or may be formed according to heat stress. The cross-sectional area may be changed depending on the location. Furthermore, although the deformation suppressing portion is formed of a ceramic material, it is of course possible to use another material as long as it has rigidity higher than that of the element body.

[0026]

According to the thermoelectric conversion device of the present invention, the thermal deformation caused by the thermal expansion and the thermal contraction is suppressed by the deformation suppressing body formed of the rigid ceramic material, and the thermal stress of the thermoelectric element or the like is suppressed. In order to make the thermoelectric element smaller, cracks are less likely to occur in the thermoelectric element and disconnection is less likely to occur, so that the life can be extended.

The thermoelectric converter according to claim 2 is
In addition to the effect of the first aspect, since the thermoelectric element is formed in a substantially cylindrical shape, the rigidity of the thermoelectric element is increased, so that the thermoelectric element is less likely to crack and break.

The thermoelectric converter according to claim 3 is
In addition to the effect of claim 1, since the thermoelectric element has a layered crystal structure and the deformation suppressing body is provided between them, the rigidity of the thermoelectric element is increased, and thus cracks are less likely to occur in the thermoelectric element. It is hard to break.

The thermoelectric conversion device according to claim 4 is
In addition to the effect of claim 3, since the layered surface is arranged substantially parallel to the radiation extending from the approximate center of the heat exchanger, the thermoelectric element against expansion and contraction with the approximate center of the heat exchanger as a reference. Since such deformations are suppressed, cracks are less likely to occur in the thermoelectric element and disconnection is more difficult.

Further, the thermoelectric conversion device according to claim 5 is
In addition to the effect of any one of claims 1 to 4, since the cross-sectional area of the deformation suppressing body increases as the distance from the approximate center of the heat exchanger increases, the rigidity of the thermoelectric element further increases, and the breakage of the thermoelectric element is less likely to occur.

Further, in the thermoelectric conversion device according to the sixth aspect, the thermoelectric element has a layered crystal structure, and the layered surface is arranged substantially parallel to the radiation extending from the substantially center of the heat exchanger. Since deformation of the thermoelectric element and the like due to expansion and contraction with the approximate center of the exchanger as a reference is suppressed, cracks are less likely to occur in the thermoelectric element and disconnection is more difficult.

[Brief description of the drawings]

FIG. 1 is a front view in which a thermoelectric conversion device according to a first embodiment of the present invention is partially broken so that a thermoelectric element can be seen.

FIG. 2 is a sectional view of a thermoelectric element of the thermoelectric conversion device.

FIG. 3 is a perspective view of the thermoelectric element.

FIG. 4 is a front view of a thermoelectric conversion device showing a second embodiment of the present invention.

FIG. 5 is a perspective view of the thermoelectric element.

FIG. 6 is a front view of a thermoelectric conversion device showing a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of a thermoelectric conversion device showing a conventional embodiment of the present invention.

FIG. 8 is a cross-sectional view of a thermoelectric conversion device showing another conventional embodiment of the present invention.

[Explanation of symbols]

 1 High temperature side heat exchanger 2 Low temperature side heat exchanger 4 Thermoelectric element 5 Element body 5a P type semiconductor 5b N type semiconductor 6 Deformation suppressor 7 Solder 10 Electrode 11 First electrode 12 Second electrode

Claims (6)

[Claims] 1. A substantially flat plate-shaped heat exchanger facing each other, a thermoelectric element having at least one pair of P-type semiconductor and N-type semiconductor arranged in parallel between the heat exchangers, and P of the thermoelectric element. A thermoelectric conversion device, comprising: an electrode connected to a heat exchanger, the electrodes being connected to each other via solder so that type semiconductors and N-type semiconductors are alternately arranged in series, wherein the thermoelectric element is ceramic. A thermoelectric conversion device comprising a deformation suppressing body formed of a material. 2. The thermoelectric element is formed in a substantially cylindrical shape and arranged so as to be substantially perpendicular to the heat exchanger,
The thermoelectric conversion device according to claim 1, wherein the deformation suppressing body is arranged inside the cylindrical shape. 3. The thermoelectric element is formed so as to have a layered crystal structure and is arranged so that its layered surface is substantially perpendicular to the heat exchanger, and a deformation suppressing body is arranged between the layers. The thermoelectric conversion device according to claim 1, wherein: 4. The thermoelectric conversion device according to claim 3, wherein the layered surface of the thermoelectric element is arranged so as to be substantially parallel to the radiation extending from substantially the center of the heat exchanger. 5. The deformation suppressing body is formed so that a cross-sectional area in a direction substantially parallel to the heat exchanger increases as the distance from the substantially center of the heat exchanger increases.
The thermoelectric conversion device according to any one of claims 1 to 4. 6. A substantially flat plate-shaped heat exchanger facing each other, a thermoelectric element having at least one pair of P-type semiconductor and N-type semiconductor arranged in parallel between the heat exchangers, and P of the thermoelectric element. A thermoelectric conversion device, comprising: an electrode connected to a heat exchanger, the electrodes being connected via solder so that the N-type semiconductors and the N-type semiconductors are alternately arranged in series; It was formed to have a crystal structure and its layered surface was arranged so as to be substantially perpendicular to the heat exchanger, and its layered surface was arranged so as to be substantially parallel to the radiation extending from the substantially center of the heat exchanger. A thermoelectric conversion device characterized by the above.