JPH02303076A - Thermoelectric device and method of controlling same - Google Patents

Abstract

PURPOSE:To keep high efficiency at all times by controlling a current in each thermoelectric element group in response to a load. CONSTITUTION:A plurality of thermoelectric element groups 8 constituted of at least one thermoelectric element are electrically connected in parallel, and direct current rectified through a rectifier circuit 9 flows. A constant current maximizing the efficiency of each element group 8 is applied to each element group 8. On an electrode wiring connected with each element group 8, a switching circuit 10 is installed and controls the current flowing into each element group 8 by a controlling signal from a controlling circuit 11. Thereby each thermoelectric element group 8 or the number of the thermoelectric elements can be increased or decreased in accordance with a load.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention improves thermoelectric devices used in air conditioners that electrically cool or heat air using the Beltier effect, or power generation devices that generate electricity using temperature differences due to the Seebeck effect. Thermoelectric device (component) for converting heat into electricity or electricity into heat (component).
P type lower conductor 4 or N by metal plate 1 and metal plate 2
The metal plate 1 on both sides is constructed by electrically connecting elements in series or parallel with a type semiconductor 3 sandwiched therein.
Electricity is generated by the temperature difference between the two, or cold paper is heated by applying voltage and passing current. Problems to be Solved by the Invention Regarding the Terminals of Metal Plates 1 and 2 In general, in a thermoelectric element, its efficiency has a maximum value for a certain current value. When attempting to obtain cooling output or heating output by electrically connecting multiple such thermoelectric elements,
If the load is constant, this power is not a problem (if the load fluctuates, it is necessary to change the output by changing the amount of current).
Although it is difficult to always maintain the current value that maximizes efficiency, in other words, if you try to operate a thermoelectric device composed of multiple thermoelectric elements while maintaining the element efficiency at the maximum value, it will be difficult to maintain the current value that maximizes the efficiency. It is necessary to change the number of elements, but this is not possible with a thermoelectric device like the one shown in Figure 4. In other words, with a conventional thermoelectric device, the number of elements must be changed. There is also the problem that the efficiency of this conventional thermoelectric device is very low. The semiconductors 3, 4 and the metal plates 1, 2 are bonded and held on a substrate 7 made of ceramic or the like, and solder is generally used to connect them. In this case, it is necessary to make the metal plates 1 and 2 longer, which increases the weight and causes problems such as the solder and the semiconductors 3 and 4 becoming easier to separate from each other due to the warping of the board 7, resulting in lower reliability. Moreover, the high temperature atmosphere and low temperature atmosphere are metal plates 1 and 2,
Since the relatively thin air and substrate 7 are in contact with each other on both sides, there is a problem that a large amount of heat leaks and the efficiency deteriorates. t or to the opposite side It is necessary to bond the heat dissipation fins, but since the bonding surface is limited, there is a problem that not only the fin efficiency deteriorates, but also the efficiency decreases due to contact resistance.Invention 1 In view of the problems of conventional technology such as Yogore et al., the number of elements can be increased in response to load fluctuations while keeping the current value flowing through each thermoelectric element at a constant value that maintains the efficiency close to the maximum value. The purpose of this project is to provide a thermoelectric device and its control method that can increase or decrease the amount of heat and maintain high efficiency at all times, and also provide a thermoelectric device and a method for controlling the same, which have a small amount of heat leaking from a high-temperature atmosphere to a low-temperature atmosphere, and which are easy to configure into a large-area thermoelectric device. The purpose of the present invention is to provide a method for controlling the thermoelectric device, and a means for solving the problem.
The thermoelectric element group consisting of a plurality of thermoelectric elements is electrically connected in parallel, and the current flowing to each thermoelectric element group can be controlled according to the load. In addition to changing the number of thermoelectric element groups, the current value is always maintained in the thermoelectric element group through which current flows so that the efficiency of each thermoelectric element constituting the group is at its maximum value. An electric circuit or a semiconductor is placed on electrode wiring patterned in advance on a substrate, and a group of thermoelectric elements is configured in a corrugated shape and inserted into a through hole on the electrode pattern of the substrate. The effects obtained by the thermoelectric device having the above configuration and its control method are as follows.

1. By controlling the current flowing to each thermoelectric element group according to the load, the performance is significantly better than before.In particular, the current is passed so that the efficiency of each thermoelectric element is maximized, and the number of thermoelectric elements is varied. By adjusting the load to accommodate the load, performance near maximum efficiency can always be obtained.

2. Since an electrode pattern is created on the substrate and a group of thermoelectric elements are bonded onto the electrode pattern, it is easy to manufacture even in the case of a large area and a low load, or a small area and a high load. By inserting and supporting a group of corrugated thermoelectric elements into holes penetrating the substrate, the degree of freedom with respect to loads is high.
Thermoelectric elements are easy to increase in area, can be constructed lightweight, and can reduce heat leakage from the high-temperature side to the low-temperature side by separating the low-temperature side atmosphere from the high-temperature side atmosphere by using an insulating wall on the substrate. It is possible to make it very compact by providing a semiconductor or circuit for rectifying current control on the board on which the thermoelectric element group is installed. By doing so, the decrease in heating efficiency and cooling efficiency due to Joule heat generated by these electric circuits can be reduced. This figure shows a schematic configuration of the control circuit of the device.

In FIG. 1, a current that is electrically connected in parallel and converted into direct current by the rectifier circuit 9 flows through a plurality of thermoelectric element groups 8ζ consisting of at least one thermoelectric element. A switching circuit 1O1 is provided on each electrode wiring that passes a constant current such that 8 has the maximum efficiency and passes through each thermoelectric element group 8.
The current flowing through each thermoelectric element group 8 is controlled by the control signal from 1.

This control circuit 11 performs control so that the thermoelectric output from the operating thermoelectric element group 8 and the load to be heated or cooled are balanced. In other words, when the load is larger than the thermoelectric output, the number of thermoelectric element groups 8 that operate is increased, and when the load is smaller than the thermoelectric output, the number of thermoelectric element groups 8 that are operated is decreased. A transistor formed of a thin film may also be used (°C) With this configuration and control method, unlike conventional methods, it is possible to increase or decrease the number of individual thermoelectric elements or the number of thermoelectric elements according to the load.8 Current flowing through each thermoelectric element The output can be controlled without changing the value, keeping it set to a constant value that maximizes the efficiency of each thermoelectric element.As a result, the efficiency can always be maintained at the maximum value for the load, which reduces running costs. Figure 2 is a front view of a thermoelectric device in another embodiment of the present invention.In this embodiment, a substrate made of a heat insulating material is used. Although the electrode wiring 13 is formed by a copper film on the electrode wiring 12, the electrode wiring 13 between the two electrode terminals 17 and 17 that connect an external power source is
Above, a group of three thermoelectric elements 14 are arranged at 211. Even if the two switching circuits 15 and one rectifier circuit 16 are electrically connected, that is, even if the alternating current applied from the electrode terminal 17 is rectified by the rectifier circuit 16 and converted to direct current, which one of the direct currents will be? One of the switching circuits 15 is controlled to be turned on or off by an external signal. When the switching circuit 15 is on, current flows into the thermoelectric element group 14 and applies heat and cooling to the front and back sides of the substrate 12. In this embodiment, the switching circuit 15 uses a TPT and is not connected to external signals. In addition, in this embodiment, one switching circuit 15 is provided for one set of three thermoelectric element groups 14 connected in series (this is shown in FIG. 1). As in the example above, each thermoelectric device group 14 and the switching circuit may be provided as a pair (that is, in this embodiment, two parallel thermoelectric circuits are configured between the two electrode terminals 17, 17, Although one switching circuit 15 is connected to the circuit, the number of thermoelectric element groups 14 can be set freely (~Also, for the rectifier circuit 16, the number of the thermoelectric element groups 14 can be set freely)
2 may or may not be provided. FIG. 3 shows the thermoelectric element group 14 in more detail. In other words, the thermoelectric element group 14 is arranged between an N-type semiconductor 19 and a P-type semiconductor 19 between the copper plate 18. Although it is made by sandwiching a semiconductor 20 and has a corrugated shape, this thermoelectric element group 14 is soldered to the copper electrode wiring 13 plated on the substrate 12. 19 or 20 and the copper plate 18, heat is generated on one side, and heat is absorbed on the other side.Also, in this embodiment, heat is generated on the electrode wiring 13 side. The Joule heat radiated from the thermoelectric element group 14 is radiated to the high temperature side, improving heating efficiency or cooling efficiency.A heat shield plate 21 is also installed on this thermoelectric element group 14 to maintain the thermoelectric element group 14 from the high temperature side to the low temperature side. In this embodiment, the substrate 12 is constructed as a heat insulating wall, and the thin thermoelectric element group 14 made of a copper plate is used, so it is extremely light and has excellent heat insulation properties. It is possible to make a thermoelectric device by plating the thin electrode wiring 13 on the substrate 12 in advance, and then fabricating the thermoelectric element group 14 separately and joining them by soldering. Therefore, it can be easily manufactured, and has a large area and high output. In addition, by changing the length of the copper plate 18 according to the amount of heat dissipated on the cooling side and the heat generation side, the optimum heat dissipation state can be realized from an economical efficiency point of view. Thermoelectric elements with this configuration can also be used to convert heat from a heat source into electricity by the Seebeck effect, and it goes without saying that the same effect will be produced in that case as well. Same area for rectification Same area for switching Electrode wiring, etc. 1 side As described in the detailed explanation of the invention, the thermoelectric device according to the present invention (electrode wiring, etc., connected to one or more thermoelectric element groups) A control circuit is provided to change the number of thermoelectric elements that operate according to the load, allowing current to flow through the operating thermoelectric elements so as to produce a maximum efficiency of 4, and the thermoelectric elements are corrugated. By installing the thermoelectric elements on a board with electrical wiring in advance and providing a switching circuit etc. on the wiring, the following effects can be achieved. 1. The number of thermoelectric elements can be controlled while maintaining the maximum efficiency of each thermoelectric element. , because it corresponds to the load, it is possible to obtain efficiency close to the maximum efficiency regardless of the load, 2, it is possible to mass-produce thermoelectric devices with a very large area at low cost with a simple process, 3, and the heat transfer area is Because it can be made wider, the temperature difference with the external load is reduced and heat dissipation efficiency is improved.4 However, the high temperature side and the low temperature side are separated by an insulating wall, and the electric circuit that generates Joule heat is installed on the high temperature side. Therefore, it is possible to implement the present invention in order to improve the overall cooling or heating performance.
It is highly economical, and also enables the realization of large-area thermoelectric devices with high cooling or heating performance.

[Brief explanation of the drawing]

FIG. 1 shows a control circuit of a thermoelectric device in one embodiment of the present invention. FIG. 2 shows a front view of a thermoelectric device in another embodiment of the present invention. FIG. 3 shows a detailed perspective view of the thermoelectric device group in FIG. 2. 4
The figure is a perspective view of a conventional thermoelectric device. ,,Thermoelectric element method Q, 16. , , Rectifier circuit 1 generation 15, , , Switching circuit 1 generation 11. ,,
Control times! 120. , substrate, 13. ,, Heavy metal wiring 1
8. ,, Copper plate 1 generation 20. , , Name of Handojo agent Patent attorney Shigetaka Awano Haka 1 person Figure 2 Figure 2 178 Ikari Chorou

Claims (8)

[Claims] (1) A plurality of thermoelectric elements having a configuration in which a semiconductor is sandwiched between metals is divided into a plurality of thermoelectric element groups that are electrically connected to each other, and each of the thermoelectric element groups is electrically connected in parallel, and the A thermoelectric device comprising means for controlling the current flowing through each thermoelectric element group. (2) The thermoelectric device according to claim 1, wherein each thermoelectric element group has the same number of thermoelectric elements electrically connected in series. (3) Arranging a plurality of thermoelectric element groups and a semiconductor element that controls the electric liquid flowing through each thermoelectric element group on a substrate, and bonding the thermoelectric element group and the semiconductor element with a metal electrode patterned in advance on the substrate. The thermoelectric device according to claim 1. (4) The thermoelectric element group has a corrugated structure consisting of a curved metal plate and P-type and N-type semiconductors, and the thermoelectric element group is inserted into a hole penetrating the substrate. thermoelectric device. (5) The current flowing through a plurality of thermoelectric element groups constituted by a plurality of thermoelectric elements is controlled on and off, and the number of the thermoelectric element groups through which current flows is changed depending on the size of the load. A method for controlling a thermoelectric device. (6) The current value flowing through the thermoelectric elements that make up the thermoelectric element group is
6. The method of controlling a thermoelectric device according to claim 5, wherein the value is a constant value that substantially maximizes the efficiency of the thermoelectric element. (7) An electric circuit that converts alternating current into direct current, and a semiconductor or electric circuit that controls current flowing through a plurality of thermoelectric element groups constituted by a plurality of thermoelectric elements, on the substrate surface on which the thermoelectric element groups are installed. A thermoelectric device characterized in that it is disposed on top. (8) Claim 7, wherein an electric circuit for converting alternating current into direct current and a semiconductor or an electric circuit for controlling current flowing to the thermoelectric element group are arranged on the substrate surface on the side heated by the thermoelectric element group. thermoelectric device.