JPH11177153A - Power generator - Google Patents

Abstract

(57) [Problem] To provide a power generation device having a small shear stress at a joint between a semiconductor element and a metal segment. SOLUTION: Many P-type and N-type semiconductor layers 7,
, A high-temperature side electrode 4 and a low-temperature side electrode 11 for electrically connecting the respective semiconductor layers 7 and 8, and the high-temperature side electrode 4
In the power generating apparatus having the high-temperature side heat conductor 1 arranged on the high-temperature side of the above and the low-temperature side heat conductor 13 arranged on the low-temperature side of the low-temperature side electrode 11, a bellows 23 is provided on the low-temperature side of the low-temperature side heat conductor 13. A nozzle 26 that is arranged and injects the liquid heat transfer medium 16 toward the low-temperature side heat conductor 13 in the hollow portion of the bellows 23 is provided so as not to hinder the displacement of the bellows 23. It is characterized by.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generator using the Seebeck effect of P-type and N-type semiconductors, and more particularly to a power generator using a liquid heat transfer medium.

[0002]

2. Description of the Related Art FIG. 10 is a cross-sectional view of a conventional power generation device, and FIG. 11 is an exploded view of a power generation module used in the power generation device. In these figures, reference numeral 100 denotes a high-temperature gas passage through which a high-temperature gas G such as a combustion gas flows.
1 is a power generation module, 102 is a fixing plate, 103 is a heat sink having fins, 104 is a mounting screw, 105 is a mounting nut, 106 is a mounting washer, 107 is between the mounting washer 106 and the flange of the heat radiating plate 103. The interposed coil spring 108 is a heat dissipation fan.

As shown in FIG. 11, the power generation module 101 includes a heat absorbing side heat conductor 109, a thermoelectric element group 110,
A heat radiation side heat conductor 111, a thermoelectric element group fixing screw 112 for fixing the thermoelectric element group 110 to the heat radiation side heat conductor 111,
The thermoelectric element group 110 includes a holding screw 113 that holds the thermoelectric element group 110 between the heat absorbing side heat conductor 109 and the heat radiating side heat conductor 111, and a coil spring 114 interposed at the head of the holding screw 113.

Further, the thermoelectric element group 110 supports P-type and N-type semiconductor layers 115, and a heat-absorbing electrode 116, a heat-radiating electrode 117, and a heat-radiating electrode 117 disposed on both surfaces of the semiconductor layer 115, respectively. Module substrate 118 and fastening screws 11 for fastening these laminates
9. As shown in FIG. 10, the power generation module 101 is elastically held between the fixed plate 102 and the heat radiating plate 103.

[0005]

By the way, the conventional power generator uses a coil spring, but since the whole is fastened by screws to improve heat transfer, a joint between the semiconductor layer and the metal segment is provided. In addition, a large degree of deformation is less likely to occur, and a large shear stress is likely to be generated. If the heat history (expansion and shrinkage) is repeated, the semiconductor layer and the junction between the semiconductor layer and the metal segment may be damaged or broken.

The present invention solves the above-mentioned disadvantages of the prior art,
An object of the present invention is to provide a power generation device having good thermal conductance and excellent thermoelectric conversion characteristics and life characteristics in which stress relaxation is effectively performed.

[0007]

According to the present invention, there is provided a semiconductor device comprising a plurality of P-type and N-type semiconductor layers;
A high-temperature side electrode and a low-temperature side electrode for electrically connecting each semiconductor layer, a high-temperature side heat conductor disposed on the high-temperature side of the high-temperature side electrode, and a low-temperature side disposed on the low-temperature side of the low-temperature side electrode It is intended for a power generator having a heat conductor.

A bellows is arranged on the low-temperature side of the low-temperature side heat conductor, and a nozzle for injecting a liquid heat transfer medium such as water toward the low-temperature side heat conductor into a hollow portion of the bellows, The bellows is provided so as not to hinder the displacement of the bellows.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention is configured as described above,
Since the bellows can be displaced in any of up, down, left, right, and diagonal directions, even if the heat history (expansion and contraction) is repeated, the displacement is effectively absorbed by the bellows. It is possible to provide a power generation device which is excellent in thermoelectric conversion characteristics and life characteristics in which the junction between the metal segment and the metal segment is not damaged or broken, has good thermal conductance, and effectively alleviates stress.

Next, an embodiment of the present invention will be described with reference to the drawings. 1 is an exploded view of a part of a power generator according to an embodiment of the present invention, FIG. 2 is a plan view of the power generator with an upper part thereof removed, and FIG. 3 is an enlarged sectional view of an element block used in the power generator. FIG. 4 is a plan view of a barrier metal layer used in the element block, FIG. 5 is a plan view of an electrode used in the element block, FIG. 6 is a partial cross-sectional view of a water-cooled bellows of the power generator, FIG.
FIG. 3 is a system diagram of the water cooling jacket portion.

In FIG. 1, reference numeral 1 denotes a high-temperature side heat conductor made of a metal having good thermal conductivity, for example, copper. Are formed. 3 is a skeleton type skeleton type element block as shown in FIG. 3, and a high temperature side electrode 4 made of a nickel-plated copper plate.
A solder layer 5a, a barrier metal layer 6a on which a surface treatment film such as nickel or iron is formed, a P-type semiconductor layer 7 and an N-type semiconductor layer 8 made of Pb-Te, and a surface treatment film such as nickel or iron And the formed barrier metal layer 6b. Each member constituting the element block 3 is integrally sintered.

As shown in FIGS. 3 and 4, the barrier metal layer 6 is provided with a peripheral wall projection 9 and a central projection 10 on the side in contact with the semiconductor layers 7 and 8, and has a bonding strength with the semiconductor layer 7 (8). Is increasing. The central projection 10 is not always necessary.

The barrier metal layer 6b and the low-temperature side electrode 11
Are joined by the solder layer 5b. 12 is a thin film made of silicone gel, 13 is a low-temperature side heat conductor made of aluminum, and an electrical insulating layer 14 made of alumite is formed on the upper surface. Reference numeral 15 denotes a water-cooled bellows joined to the low-temperature-side heat conductor via the thin film 12, and has a system in which cooling water 16 is forcibly circulated. The configuration of the water-cooled bellows 15 will be described later in detail.

When the electrode 4 and the barrier metal layer 6a and the barrier metal layer 6b and the low-temperature side electrode 11 are bonded to each other, the solder layers 6a and 6b are not necessarily required.

As shown in FIG. 5, on both sides of the electrode 4 (11), semiconductor junction regions 17, 17 for joining the P-type semiconductor layer 7 and the N-type semiconductor layer 8 are provided.
7, one side edge 4a (11) of the electrode 4 (11).
1 extending from a) to the other side edge 4b (11b)
The first notch 19a in the form of a notch groove and the electrode 4 (1
1) from the other side edge 4b (11b) to the one side edge 4
a (11a) and the first notch 19a
One notch-shaped second notch 19b formed at a more displaced position is provided in parallel. And this first
A narrow conducting portion 20 is formed between the notch portion 19a and the second notch portion 19b, and the planar shape of the electrode 4 (11) is substantially S-shaped.

As shown in FIG. 5, these semiconductor junction regions 17, 17, notches 19a, 19b,
Are provided symmetrically with respect to the center O of the electrode 4 (11). In the present embodiment, a completely symmetric electrode 4
Although (11) is used, it is not always necessary to be completely symmetric.

FIG. 8 is a plan view showing a modification of the electrode 4 (11). In this example, notches 19b, 19b are formed on both sides of the notch 19a. Also in the case of this example, the semiconductor junction regions 17, 17 and the notches 19a, 1
9b and the conducting section 20 are provided at symmetrical positions with respect to the center O of the electrode 4 (11).

In FIGS. 5 and 8, L1 / 2 <L2
And the first notch 77a and the second notch 77
b overlaps near the center O.

For example, as shown in FIGS. 1 and 2, a water-cooled bellows 15 is provided for each of the element blocks 3 including the semiconductor layers 7 and 8. This water-cooled bellows 15
As shown in FIG. 6, an extensible bellows 23 is disposed between the movable substrate 21 and the fixed substrate 22 and has upper and lower ends liquid-tightly welded 24 to the movable substrate 21 and the fixed substrate 22, respectively.
have. The moving substrate 21, the fixed substrate 22, and the bellows 23 are made of a metal such as stainless steel, aluminum, or copper.

A coil spring 25 is disposed inside the bellows 23 so as to resiliently contact the movable substrate 21 and the fixed substrate 22, and a nozzle 26 is provided inside the bellows 23 so as to approach the lower surface of the movable substrate 21. As shown in FIG. 2 and FIG. 7, bellows 23 are arranged on a wide fixed substrate 22 at predetermined intervals, and as shown in FIG.
A drain port 27 is formed in the inside corresponding to 3, and a circulation path 28 communicating with the nozzle 26 and the drain port 27 is provided inside the fixed substrate 22.

The circulation path 28 is connected to a single pipe 29 as shown in FIG. 7, and a radiator 30 and a circulation pump 31
Is arranged near the fan 31. Although not shown, the space between each element block 3 and the space between each water-cooled bellows 15 and each water-cooled bellows 15 are filled with heat insulating powder.

When this power generation device is assembled, the movable substrate 21 is moved by the elastic force of the coil spring 25 so that the thin film 12
The low-temperature-side heat conductor 13 is elastically contacted with the low-temperature-side electrode 11 via the thin film 12.

The high temperature gas such as the combustion gas is used as the high temperature side heat conductor 1
Directly or indirectly, the heat conduction generates an electromotive force between the electrodes 4 and 11, and the electromotive force is boosted to a rated voltage by a DC / DC converter (not shown), and the heat is reduced to the low-temperature side heat. It is absorbed by the water-cooled bellows 15 via the conductor 13.

That is, the cooling water 16 pressurized by the circulation pump 31 passes through the pipe 29 and the circulation path 28,
Injection is performed substantially vertically from each nozzle 26 toward the lower surface of the moving substrate 21. The cooling water 16 collides with the moving substrate 21 to instantaneously remove the heat of the moving substrate 21, and the bellows 23
, Passes through the drain port 27, passes through the circulation path 27, and is led to the radiator 30 via the pipe 29 to lower the temperature of the cooling water 16 and is used again for cooling the moving substrate 21. In this embodiment, the lower surface of the movable substrate 21 facing the bellows 23 is flat. However, if necessary, the contact surface with the cooling water 16 can be increased by forming an uneven surface.

In the above embodiment, water is used as the liquid heat transfer medium. However, the present invention is not limited to this, and another liquid heat transfer medium can be used.

In the above embodiment, the low-temperature-side heat conductor and the movable substrate are separately provided. However, the present invention is not limited to this, and even if the end of the bellows is directly joined to the low-temperature-side heat conductor. Good.

In the above embodiment, the coil spring is arranged inside the bellows, but the coil spring can be arranged outside the bellows.

[0028]

FIG. 9 shows the lengths (heights) of the semiconductor elements of the power generation device according to the embodiment of the present invention and the conventional power generation device when a temperature difference between 550 ° C. and 50 ° C. is given, and In the characteristic diagram showing the relationship of the shear stress between the semiconductor element and the metal segment, the triangle in the figure is a power generator according to an embodiment of the present invention,
The symbol ▲ indicates a conventional power generator.

As is clear from this figure, the conventional power generating device uses a spring, but since it is entirely tightened with a fastening screw, the shear stress at the joint between the semiconductor element and the metal segment is large, In particular, when the length of the semiconductor element is shortened, an increase in shear stress is conspicuous, and the shear stress generated at the joint damages or destroys the semiconductor element and the joint between the semiconductor element and the metal segment.

On the other hand, the power generating apparatus (marked by 〇) according to the embodiment of the present invention uses a bellows filled with a liquid heat transfer medium. In addition, the bellows can effectively absorb the displacement even after repeated severe thermal histories (expansion and contraction), resulting in shear stress regardless of the length of the semiconductor element. Therefore, a highly reliable power generation device can be provided without breaking the semiconductor element and the junction between the semiconductor element and the metal segment.

[Brief description of the drawings]

FIG. 1 is an exploded view of a part of a power generator according to an embodiment of the present invention.

FIG. 2 is a plan view in which an upper part of the power generator is removed.

FIG. 3 is an enlarged sectional view of an element block used in the power generation device.

FIG. 4 is a plan view of a barrier metal layer used for the element block.

FIG. 5 is a plan view of an electrode used for the element block.

FIG. 6 is a partial sectional view of a water-cooled bellows of the power generation device.

FIG. 7 is a system diagram of the water cooling jacket portion.

FIG. 8 is a plan view showing a modification of the electrode.

FIG. 9 is a characteristic diagram showing a relationship between the length of the semiconductor element and the shear stress.

FIG. 10 is a partial sectional view of a conventional power generator.

FIG. 11 is an exploded view of a power generation module used in the power generation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High-temperature-side heat conductor 3 Element block 4 High-temperature-side electrode 7 P-type semiconductor layer 8 N-type semiconductor layer 11 Low-temperature-side electrode 13 Low-temperature-side heat conductor 15 Water-cooled bellows 16 Cooling water 17, 18 Semiconductor joining area 19a First cutout 19b 2nd notch part 20 electricity supply part 21 moving substrate 22 solid substrate 23 bellows 24 welding 25 coil spring 26 nozzle 27 drainage port 28 circulation path 29 piping 30 radiator 31 circulation pump 32 fan O electrode center

Claims (6)

[Claims] A plurality of P-type and N-type semiconductor layers;
A high-temperature side electrode and a low-temperature side electrode for electrically connecting each semiconductor layer, a high-temperature side heat conductor disposed on the high-temperature side of the high-temperature side electrode, and a low-temperature side disposed on the low-temperature side of the low-temperature side electrode In a power generator having a heat conductor, a bellows is arranged on a low temperature side of the low temperature side heat conductor, and a nozzle for injecting a liquid heat transfer medium toward a direction of the low temperature side heat conductor into a hollow portion of the bellows, A power generating device provided so as not to hinder the displacement of the bellows. 2. The power generator according to claim 1, wherein the nozzle is arranged so that the liquid heat transfer medium is injected substantially vertically toward a plane of the low-temperature side heat conductor. . 3. The semiconductor layer according to claim 1, wherein a low-temperature side heat conductor and a bellows are individually provided for the paired P-type and N-type semiconductor layers, and each of the bellows is arranged on one fixed substrate. A power generator, wherein an elastic member is provided in parallel with the bellows, and the low-temperature-side heat conductor elastically contacts the low-temperature-side electrode by the elastic member. 4. The electrode according to claim 1, wherein at least a part of the electrode has a semiconductor junction region near both ends, and between one side edge of the electrode and the other between the semiconductor junction regions. A first notch extending toward the side edge, and a second notch extending from the other side edge of the electrode toward one side edge and formed at a position offset from the first notch. A power generator, comprising: a notch; and a narrow current-carrying portion formed between the first notch and the second notch. 5. The power generation device according to claim 4, wherein the semiconductor junction region, the notch portion, and the current-carrying portion are respectively provided at symmetrical positions from the center of the electrode. 6. The power generator according to claim 4, wherein a plane shape of the electrode is substantially S-shaped by the semiconductor junction region, the cutout portion, and the conducting portion.