JPH10275943A - Thermoelectric generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the temperature difference in elements for enhancing the generating efficiency by a method wherein the path walls made of respective p- and n-type thermoelectric materials are composed to be electrically and alternately further flowed with the fluid having temperature difference from that on the opposite surface to the path walls. SOLUTION: The heat conduction tubes 1, 2 of p-type and n-type elements composed of respective thermoelectric materials become a heat exchanger. Then, every wall surface of p-type and n-type element-made heat conduction tubes 1, 2 forms the path walls 4. These heat conduction tubes 1, 2 are alternately series-connected with one another in a high temperature fluid header 6 using electrodes 3. In such a constitution, the high temperature fluid runs leftward and the low temperature fluid runs rightward inside respective heat conduction tubes 1, 2 to heat exchange both fluids holding the tubes 1, 2 so that the temperature difference corresponding to the temperature change may be made in the flowing direction of the high temperature fluid for acquiring the electromotive force. Accordingly, this electromotive force can be efficiently recovered as an electric power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a power generator using thermoelectric conversion.

[0002]

2. Description of the Related Art The prior art is shown in FIGS. FIG. 3 is a diagram showing a conventional thermoelectric generator. FIG. 4 is a diagram showing a temperature distribution of a working fluid of a conventional thermoelectric generator.

[0003] A thermoelectric generator is a device in which a large number of thermocouples combining p-type and n-type thermoelectric materials are connected in series, and a thermoelectromotive force generated in proportion to a temperature difference between a high-temperature end and a low-temperature end is taken out as electric power. It is.

As shown in FIG. 3, a conventional technique is to connect a p-type element 101 and an n-type element 102 by using an electrode 103, and further connect a large number of electrodes in series to form a thermoelectric module. To form a heat transfer surface.

The module typically has a support panel 104 for sealing the hot and cold fluids 105 and 106 and for providing strong support for the module. The high temperature fluid 105 and the low temperature fluid 106 are respectively supplied to both sides of the thermoelectric module,
Since heat is exchanged through the module, a temperature difference occurs in the module in the thickness direction.

[0006] Since the module is constituted by a thermocouple composed of thermoelectric elements, electromotive force is generated and power can be generated. The electrodes serve to connect the thermoelectric elements to form a thermocouple, and also to take out a current when taking out power.

[0007]

However, the prior art has the following problems. (1) FIG. 4 shows the temperature distribution of the conventional thermoelectric generator and working fluid.
As shown in the figure, the fluid has a temperature distribution along the heat transfer surface,
The temperature difference between the two sides of the thermoelectric generator is smaller than the inlet temperature difference between the high temperature fluid and the low temperature fluid (shaded area), and the efficiency of the generator is low. (2) In order to increase power generation efficiency, it is necessary to increase the temperature difference between both surfaces of the module.

At this time, the outlet temperature of the low-temperature fluid decreases, and the exergy of the low-temperature fluid decreases. (3) If the temperature difference is increased by increasing the thickness of the module,
The heat flux passing through the module is reduced, the heat transfer surface is widened, and the generator becomes large. An object of the present invention is to provide a device that can solve these problems.

[0009]

[Means for Solving the Problems]

(First Means) A thermoelectric generator according to the present invention is characterized in that (A) p
A flow path wall made of a thermoelectric material, (B) a flow path wall made of an n-type thermoelectric material, (C) an electrode, and (D) a desired surface of the flow path wall on an opposite surface (a desired surface). And (E) a channel wall made of the p-type thermoelectric material and a channel wall made of the n-type thermoelectric material,
It is characterized by being electrically connected alternately by electrodes. (Second Means) In the thermoelectric generator according to the first means, (A) a flow channel wall made of a p-type thermoelectric material;
(B) a flow path wall made of the n-type thermoelectric material is alternately laminated, and (B) a flow path wall made of the p-type thermoelectric material and n
It is characterized in that the flow path walls made of a thermoelectric material are electrically connected alternately by electrodes. (Third Means) The thermoelectric generator according to the present invention comprises: (A) a heat transfer tube 1 made of a p-type element formed into a tubular shape, through which a fluid having a temperature difference from the outside is passed; A heat transfer tube 2 made of an n-type element formed therein and through which a fluid having a temperature difference from the outside passes, and (C) an electrode 3; (D) a heat transfer tube 1 made of the p-type element and made of an n-type element. The heat transfer tubes 2 are characterized by being electrically connected alternately by electrodes 3.

That is, in the thermoelectric generator of the present invention, the heat transfer surface is made of a thermoelectric material, and a thermoelectromotive force is generated by utilizing a temperature difference due to a temperature gradient of the heat transfer surface generated in the flow direction of the fluid to generate power. And a heat exchanger that performs the following.

Therefore, the operation is as follows. (1) Since each of the p-type and n-type elements forms the heat transfer surface, the temperature difference in the flow direction of the heat transfer surface becomes the temperature difference of the device as it is, and the temperature difference of the element is in the thickness direction of the heat transfer surface. Larger than in the case of arrangement, and high power generation efficiency. (2) Since it is not necessary to maintain a temperature difference in the thickness direction of the heat transfer surface, the thickness of the heat transfer surface can be reduced, and the power generator can be made compact.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
Shown in FIG. 1 shows an example in which a thermoelectric generator is configured in the shape of a shell tube type heat exchanger.

In FIG. 1, reference numeral 1 denotes a heat transfer tube made of a p-type element;
Is a heat transfer tube made of an n-type element, 3 is an electrode, 5 is a baffle plate, 6 is a high temperature fluid header, 7 is a body, 8 is a high temperature fluid inlet, 9 is a high temperature fluid outlet, 10 is a low temperature fluid inlet, and 11 is a low temperature fluid outlet. It is.

The heat transfer tube 1 made of a p-type element and the heat transfer tube 2 made of an n-type element constitute a heat transfer tube with respective thermoelectric materials and constitute a heat exchanger. The wall surface of the p-type element heat transfer tube 1 is
(Not shown) is formed.

The wall of the heat transfer tube 2 made of the n-type element is also
(Not shown) is formed. n-type element heat transfer tube 2 and p
The heat transfer tubes 1 made of a die element are alternately connected in series in the high-temperature fluid header 6 using the electrodes 3.

The high-temperature fluid header 6 has a function of supplying the high-temperature fluid 106 to the heat transfer tube and a role of collecting the high-temperature fluid 106 discharged from the heat transfer tube.
It is supplied from the high-temperature fluid inlet 8 on the right side in FIG.

A low-temperature fluid is supplied from a low-temperature fluid inlet 10 and flows inside the heat transfer tubes 1 and 2 in FIG.
It is discharged from the low temperature fluid outlet 11. In such a manner, the high-temperature fluid and the low-temperature fluid come into contact with each other with the heat transfer tube interposed therebetween to perform heat exchange.

The baffle plate 5 increases the flow rate of the low-temperature fluid in the body to improve the heat transfer coefficient. The wall 12 blocks mixing of the high-temperature fluid and the low-temperature fluid, and supports the p-type element heat transfer tube 1 and the n-type element heat transfer tube 2.

The present embodiment simulates the shape of a general heat exchanger having a plurality of passes on the barrel side, and a baffle plate is not necessarily required. (Second Embodiment) FIG. 2 shows a second embodiment of the present invention.
Shown in

FIG. 2 shows an example in which the thermoelectric generator is configured in the form of a compact heat exchanger. As shown in FIG. 2, the heat transfer tube 1 made of a p-type element and the heat transfer tube 2 made of an n-type element form a heat transfer surface with respective thermoelectric materials, thereby forming a compact heat exchanger.

On the heat transfer surface, n-type element heat transfer tubes 2 and p-type element heat transfer tubes 1 are alternately connected in series using electrodes 3 in the header. The hot fluid 106 is supplied from the right side of FIG. 2 and flows to the left. Cryogenic fluid 105 is supplied from the left side of FIG. 2 and flows to the right. In this manner, the two fluids come into contact with each other with the heat transfer surface interposed therebetween to perform heat exchange.

[0022]

Since the present invention is configured as described above, it has the following effects. (1) Due to the heat exchange of the fluid, a temperature difference corresponding to the temperature change of the fluid occurs in the flow direction of the high-temperature fluid in the heat transfer tube 1 made of the p-type element and the heat transfer tube 2 made of the n-type element, thereby generating an electromotive force.

By taking this as electric power, electric power can be recovered from the loss due to heat conduction in the heat transfer tube in the axial direction. (2) Since the heat exchanger is configured using a large number of heat transfer tubes, by connecting them in series, it is possible to configure the same thermoelectric module as connecting a large number of thermocouples. (3) Since the heat transfer tube is constituted by one element, the dissimilar material joint can be minimized. (4) It is not necessary to increase the thickness of the heat transfer surface in order to provide a temperature difference between the front and the back of the heat transfer surface, and the generator can be made compact. (5) Since the temperature difference of the element is maintained by the temperature distribution in the flow direction of the fluid, the effect of the thermal conductivity is reduced among the thermoelectric properties of the element, and even a thermoelectric material having a high thermal conductivity and a low figure of merit is used. Power can be generated efficiently.

[Brief description of the drawings]

FIG. 1 is a diagram showing a thermoelectric generator according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a thermoelectric generator according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a conventional thermoelectric generator.

FIG. 4 is a diagram showing a temperature distribution of a working fluid of a conventional thermoelectric generator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heat transfer tube made of a p-type element 2 ... Heat transfer tube made of an n-type element 3 ... Electrode 4 ... Flow path wall 5 ... Baffle plate 6 ... High temperature fluid header 7 ... Body 8 ... High temperature fluid inlet 9 ... High temperature fluid outlet 10 ... Low temperature fluid Inlet 11 ... Low temperature fluid outlet 12 ... Wall 101 ... P-type element 102 ... N-type element 103 ... Electrode 104 ... Support panel 105 ... Low temperature fluid 106 ... High temperature fluid

Claims (3)

[Claims] (A) a channel wall made of a p-type thermoelectric material;
(B) A fluid having a temperature difference from an opposite surface (a desired back surface) on a desired surface of the flow channel wall, (C) an electrode, and (D) a desired surface of the flow channel wall. Means to pass through,
(E) A thermoelectric generator, wherein the channel wall made of the p-type thermoelectric material and the channel wall made of the n-type thermoelectric material are electrically connected alternately by electrodes. (A) a flow channel wall made of a p-type thermoelectric material;
(B) a flow path wall made of the n-type thermoelectric material is alternately laminated, and (B) a flow path wall made of the p-type thermoelectric material and n
2. The thermoelectric generator according to claim 1, wherein the flow path walls made of a thermoelectric material are electrically connected alternately by electrodes. 3. A heat transfer tube (1) made of a p-type element, which is formed in a tubular shape and through which a fluid having a temperature difference from the outside is passed.
(B) a heat transfer tube (2) made of an n-type element formed into a tubular shape and through which a fluid having a temperature difference from the outside is passed, and (C) an electrode (3); (D) the p-type element Heat transfer tube (1)
And a heat transfer tube (2) made of an n-type element and electrically connected alternately by electrodes (3).