KR20080039115A - A heat exchanger using thermoelectric element - Google Patents

Abstract

A heat exchanger using a thermoelectric element is provided to improve space utility of an engine room by reducing a size of the heat exchanger in a compact size. A heat exchanger using a thermoelectric element comprises individual heat exchangers having a water cooling plate(110), a thermoelectric element(120), a support plate(130), and radiator fins(140), respectively. The water cooling plate is provided therein with a water path(111). The water path includes inlet ports extending lengthwise along the water path and outlet ports extending lengthwise along the water path on a surface where the inlet ports are positioned to discharge the cooling water. The thermoelectric element is formed on top and bottom surfaces of the water cooling plate and extends in parallel to the water path. The support plate closely adheres to both sides of a layer including the thermoelectric element.

Description

Thermoelectric Heat Exchanger {A Heat Exchanger using Thermoelectric Element}

1 is a principle of operation of the thermoelectric element shown in brief.

2 is a characteristic graph of a thermoelectric element.

3 is a thermoelectric element heat exchanger according to the prior art.

Figure 4 is a side view and front view of the thermoelectric element heat exchanger according to the present invention.

5 is a perspective view of a water cooling plate.

6 is a detailed side view of the thermoelectric element and the depression.

7 is a flow direction of cooling water and a flow direction of air.

8 is a method of forming a cooling water distribution path in a thermoelectric element heat exchanger consisting of a plurality of unit heat exchangers.

** Description of the symbols for the main parts of the drawings **

1000: thermoelectric heat exchanger

100, 100a, 100b, 100c: unit heat exchanger

110: water cooling plate 111: waterway

112: entrance 113: exit

114: depression 115: connection pipe

120: thermoelectric element 130: support plate

140: heat dissipation fin 200: separation plate

The present invention relates to a thermoelectric element heat exchanger, and more particularly, to a thermoelectric element heat exchanger to increase the cooling efficiency by using a thermoelectric element in an air-cooled heat exchanger.

Thermoelectric Element is a generic term for elements that use various effects caused by the interaction of heat and electricity.Thermistor, temperature, which is a device with the characteristics of negative resistance temperature coefficient that decreases as the temperature increases, the electrical resistance decreases. There is a device using the Seebeck effect, a phenomenon in which electromotive force is generated by a difference, and a device using the Peltier effect, a phenomenon in which heat absorption (or generation) is caused by current. Here, by using the Peltier effect, a device made to perform a cooling function similar to a freon compressor or an endothermic refrigerator even as a small solid-state device as a thermo-electric heat pump will be referred to as a thermoelectric device. The Peltier effect is a phenomenon in which one side is heated and the other side is cooled according to the direction of current when DC power is applied to two different electrical conductors. This phenomenon is caused by electrons moving from one semiconductor to the other. It is caused by absorbing thermal energy to increase Figure 1 shows a simple circuit that can explain the operating principle of such a thermoelectric element. Connecting an N-type semiconductor (semiconductor whose current carrier is mainly electrons) and a P-type semiconductor (semiconductor whose current carriers are mainly holes) as shown in FIG. 1 and applying a DC power source (3), electrons obtain the energy necessary to pass through the system. In the process of moving electrons from the N-type semiconductor to the P-type semiconductor, the electrons passing through the upper surface 5 absorb the thermal energy, so that the upper surface 5 is cooled, and the lower surface 4 emits the thermal energy. Therefore, the lower surface 4 is heated. At this time, if proper heat transfer is performed between the upper surface 5 where cooling takes place and the lower surface 4 where heating occurs, the thermoelectric element operates as a heat pump that transfers heat from the upper surface 5 to the lower surface 4. Done.

The thermoelectric device has a change in efficiency and capacity according to an operating environment. FIG. 2 is a graph showing the change in efficiency and capacity of the thermoelectric device. In Fig. 2, ΔT is the temperature difference between both sides of the thermoelectric element cold and cold, V is the voltage, I is the current, Q is the amount of heat dissipation, and the max subscript is the maximum value under various operating conditions. As shown in the graph of FIG. 2, as the temperature difference ΔT on both sides of the cold and hot approaches the maximum value, the Q / Q _max value approaches 0, that is, as the temperature difference increases, the heat dissipation amount tends to decrease. Therefore, it can be seen that as the temperature difference ΔT on both sides of the cold temperature of the thermoelectric element is decreased, the capacity of the thermoelectric element is increased and the efficiency is increased.

As such, a thermoelectric device is a device that enables electrical energy and thermal energy to be exchanged with each other, and there have been studies to improve performance of a general heat exchanger using a thermoelectric device. In US Pat. No. 5,561,981 (“Heat Exchanger for Thermoelectric Cooling Device”, hereinafter referred to as Prior Art 1), a water cooling block having a cooling water inlet and an outlet is disposed at the center of the thermoelectric element heat exchanger as shown in FIG. 3 (A). In addition, a thermoelectric element array and a heat dissipation fin block in which a plurality of thermoelectric elements are arranged outside of the water cooling block are arranged to allow cooling and heating at the same time in one heat exchanger. The heat dissipation fin block has a structure in which a plurality of rows of fins are stacked in parallel, and the central water cooling block and the heat dissipation fin block are arranged in parallel with each other.

In Japanese Patent Laid-Open No. 1999-002421 (hereinafter referred to as Prior Art 2), fins are provided at both ends of a thermoelectric module so that cooling and heating occur simultaneously. Figure 3 (B) shows a part of the thermoelectric element heat exchanger according to the prior art 2. The air flow shown in FIG. 3 (B) shows the direction when the winter season, and the high temperature bet is cooled by the endothermic side heat exchanger and discharged to the outside of the vehicle, and the low temperature outside air is warmed by the heat dissipation side heat exchanger to the inside of the vehicle. The thermoelectric element introduced between the heat absorbing side heat exchanger and the heat radiating side heat exchanger assists the cooling and heating actions occurring in the upper and lower heat exchangers.

By the way, the prior art 1 and the prior art 2 has a number of problems as follows. As described in the description of FIG. 2, the smaller the temperature difference between both cross-sections of the thermoelectric element, the higher the efficiency. In the prior art 1 and the prior art 2, the temperature difference between both cross-sections of the thermoelectric element becomes larger in the construction of the thermoelectric element. There is also a problem that efficiency is lowered. In addition, there is a problem in that the inlet and outlet of the water cooling block or the water cooling plate through which the cooling water enters and occupies both ends of the heat exchanger to occupy a lot of space. In addition, due to the large wall thickness between the thermoelectric element and the cooling water, the heat resistance is not only large, resulting in a low heat transfer efficiency, but a heat exchanger having a configuration in which the air-cooled / air-cooled heat exchanger further includes a thermoelectric element has a lower efficiency and performance than a water-cooled type. There is this.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to compact the size of the heat exchanger itself to increase the space utilization of the engine room, as well as between the thermoelectric element and the cooling water It is to provide a thermoelectric element heat exchanger to improve the heat transfer efficiency by reducing the thermal resistance of the thermoelectric element and the temperature difference between both cross-sections.

The thermoelectric element heat exchanger of the present invention for achieving the object as described above, the cooling water flows therein and extends in the longitudinal direction, the inlet 112 is formed in the longitudinal direction in which the cooling water is introduced downstream of the inlet air is formed in the inlet air A water cooling plate (110) having a waterway (111) formed therein with a discharge port (113) formed in a longitudinal direction in which a cooling port is discharged on a surface on which an inlet (112) is formed upstream; A thermoelectric element 120 disposed on upper and lower surfaces of the water cooling plate 110 along the channel at a position parallel to the channel 111; A support plate 130 provided in close contact with both outer sides of the layer formed of the thermoelectric element 120; A heat dissipation fin 140 that is supported and fixed to both sides of the support plate 130, and distributes air in a width direction of the water cooling plate 110; It characterized in that it comprises a unit heat exchanger (100) consisting of. At this time, the water-cooled plate 110 is characterized in that the depression 114 having a predetermined depth so that the thermoelectric element 120 is inserted in the position where the thermoelectric element 120 is provided.

In addition, the thermoelectric element heat exchanger 1000 of the present invention is characterized in that the plurality of unit heat exchangers 100 are stacked in the height direction. At this time, the thermoelectric element heat exchanger 1000 connects the channel 111 of one unit heat exchanger 100 and the channel 111 of the other unit heat exchanger 100 to each other to connect a circulation pipe for circulating cooling water. 115; And a separation plate 200 provided on the laminated surfaces of the stacked unit heat exchangers 100 to protect the heat dissipation fins 140 of the unit heat exchangers 100 adjacent to each other when stacked. Characterized in that further comprises.

In addition, the connection pipe 115 is the inlet 112 of the channel 111 of one unit heat exchanger 100 and the other unit heat exchanger 100 at a position closest to the one unit heat exchanger 100. The outlet 111 of the channel 111 is characterized in that connected to each other.

Hereinafter, the thermoelectric element heat exchanger according to the present invention having the configuration as described above will be described in detail with reference to the accompanying drawings.

4 is a side view and a front view of the thermoelectric element heat exchanger according to the present invention. As shown in the side view of Figure 4 (A), the thermoelectric element heat exchanger 1000 of the present invention is a unit heat exchanger consisting of a water cooling plate 110, a thermoelectric element 120, a support plate 130, a heat radiation fin 140 It is comprised by 100. As shown in FIG. 5, the water cooling plate 110 has a channel 111 through which cooling water flows. The water channel 111 extends in the direction parallel to the longitudinal direction of the water cooling plate 110, the inlet 112 through which the coolant flows into the same surface on one side of the water cooling plate 110 and the outlet 113 through which the coolant is discharged. U-shaped to have. Of course, the internal flow path of the water-cooled plate 110 may be in various forms such as W-shaped as well as U-shaped. In this way, since the inlet 112 and the outlet 113 are formed on the same surface, the heat exchanger itself may be connected to only one side of the heat exchanger in comparison with the conventional heat exchanger, which had to connect a pipe or a hose to both sides of the heat exchanger. The size of the can be made compact.

The thermoelectric element 120 and the support plate 130 are positioned outside the upper and lower sides of the water cooling plate 111, and the heat dissipation fin 140 is attached to the outside thereof, and the heat dissipation fin 140 has a width of the water cooling plate 110. The air is arranged to pass in the direction orthogonal to the direction. In addition, the inlet 112 through which the coolant flows is disposed downstream of the inlet air. In this way, the flow direction of the cooling water is formed to face the flow direction of the air. According to the front view of FIG. 4 (B), the right side outlet is the inlet 112 and the left side outlet is the outlet 113, but this is when the air flow direction is based on FIG. 4B. Since it flows from left to right, the inlet 112 and the outlet 113 are determined as described above, and the positions of the inlet 112 and the outlet 113 may be changed according to the direction of the air.

The thermoelectric element 120 is provided to increase the heat exchange efficiency between the cooling water flowing through the water cooling plate 110 and the air flowing through the heat dissipation fins 140. Therefore, the thermoelectric element 120 is provided between the water cooling plate 110 and the heat dissipation fin 140, and for the same reason, the thermoelectric element 120 is disposed side by side at the channel 111 of the water cooling plate 110. To be located. The thermoelectric element 120 is attached to the upper and lower sides of the water-cooled plate 110 while forming a line like the channel 111, and if the heat radiation fin 140 is directly attached thereto, not only is not firmly fixed, but also the radiation fin 140 Or the thermoelectric element 120 may be damaged, so that the support plate 130 is attached on the layer made by the thermoelectric element 120 and the heat dissipation fin 140 is attached to the outer side of the thermoelectric element 120. .

The unit heat exchanger 100, the heat is transferred from the cooling water flowing through the waterway 111 through the wall of the water cooling plate 110, the heat passes through the support plate 130 between the heat radiation fins 140 The cooling water is cooled by being diverted to the air flowing in circulation, and the thermoelectric element 120 is mounted to further increase the heat exchange efficiency therebetween. At this time, the water cooling plate 110 to be distributed in the cooling water has a limit that is manufactured to have a predetermined thickness because it must be solid. However, even if the thermoelectric element 120 is attached to a position parallel to the position of the channel 111 in the water cooling plate 110, the heat resistance is large because the wall thickness from the channel 111 to the thermoelectric element 120 is thick. As a result, the adverse effect of reducing the heat transfer efficiency occurs.

In the present invention, in order to solve such a problem, as shown in FIG. 6, the recess 114 is formed in a portion where the thermoelectric element 120 is disposed on both top and bottom sides of the water cooling plate 110. As the recess 114 is formed, the thickness of the wall of the water cooling plate 110 between the thermoelectric element 120 and the channel 111, that is, the cooling water becomes thin, thereby hardly affecting the firmness of the water cooling plate 110 itself. It is possible to greatly reduce the thermal resistance between the thermoelectric element 120 and the cooling water, thereby increasing the heat transfer efficiency. In addition, the recess 114 also serves to guide the thermoelectric element 120 to be firmly fixed in place, thereby increasing the durability and lifespan of the entire thermoelectric element heat exchanger 1000. It works.

In addition, as described above, the present invention allows the flow direction of the cooling water and the flow direction of the air to be in opposite directions. The low temperature cooling water introduced into the heat exchanger takes away heat from the high temperature side of the thermoelectric element and is discharged at high temperature. The high temperature air introduced into the heat exchanger is discharged at low temperature by transferring heat to the low temperature side of the thermoelectric element. FIG. 7 shows the flow direction of the cooling water and the flow direction of the air, and it is shown that the side where the air is hot, the side where the coolant is hot, and the side where the air is low and the side where the coolant is low are generally the same. You can see that it is in the direction. As such, the temperature difference between the upper and lower surfaces of each of the thermoelectric elements 120 may not be very large by allowing the high temperature air-high temperature coolant / low temperature air-low temperature coolant to be substantially at the same position. As described in the thermoelectric device characteristic graph of FIG. 2, the thermoelectric device exhibits low efficiency as the temperature difference between both surfaces increases, and shows high performance as the temperature difference decreases. Therefore, when the thermoelectric element heat exchanger 1000 of the present invention is used, since the flow path is designed to minimize the temperature difference between the cooling water and the air, that is, both sides of the thermoelectric element 120 in each region where the heat exchange occurs, the thermoelectric The performance of the device 120 can be maximized.

In addition, the thermoelectric element heat exchanger 1000 according to the present invention includes a single water cooling plate 110, a pair of upper and lower layers of thermoelectric elements 120, a pair of upper and lower support plates 130, and a pair of upper and lower radiating fins 140. Only the unit heat exchanger 100 may be operated as an independent heat exchanger. However, the present invention, as well as by stacking the unit heat exchanger 100 vertically can implement a higher capacity heat exchanger very easily and simply. At this time, when the heat dissipation fins 140 are vertically stacked, if the heat dissipation fins 140 are in contact with each other, the heat dissipation fins 140 are made of a very thin material, and thus the heat dissipation fins 140 are damaged or destroyed. May occur. Therefore, the present invention eliminates the possibility of such a problem by inserting the separator plate 200 in the laminated surface as shown in FIG. The separator plate 200 is preferably made of a metal material having high thermal conductivity such as aluminum.

After stacking the plurality of unit heat exchangers 100 as described above, it is possible to form a high capacity thermoelectric element heat exchanger 1000 by simply configuring a flow path so that the coolant can be connected and distributed. 8 illustrates a method of forming a cooling water distribution path in a thermoelectric element heat exchanger including a plurality of unit heat exchangers. FIG. 8 (A) shows a front view of stacking three unit heat exchangers 100 of the present invention and connecting the cooling water distribution paths of the unit heat exchangers 100 using a connection pipe 115. As shown in FIG. 8 (A), since air flows from left to right, the connection pipe 115 is configured to allow the coolant to flow from the far side in the air inflow direction to be discharged from the unit heat exchanger 100. To be provided in a diagonal direction as shown. In FIG. 8A, the coolant flowing into the inlet 112a of the first unit heat exchanger 100a is discharged to the outlet 113a and the inlet of the second unit heat exchanger 100b through the connection pipe 115. 112b). The cooling water is also discharged to the outlet 113b of the second unit heat exchanger 100b, and is introduced into the inlet 112c of the third unit heat exchanger 100c by the connecting pipe 115 and then discharged to the outlet 113c. do. 8 (B) shows a flow direction of the coolant simply in FIG. 8 (B). By connecting the connection pipes 115 as described above, air and coolant in each unit heat exchanger 100 as shown in FIG. 7 is connected. It is possible to obtain a cooling water distribution path that can minimize the temperature difference between the two. That is, in the thermoelectric element heat exchanger 1000 formed by stacking the plurality of unit heat exchangers 100 as described above, the performance of the thermoelectric element 120 may be maximized as in the single unit heat exchanger 100. In addition, the cooling water is introduced into the unit heat exchanger 100 of the lowermost layer and discharged to the unit heat exchanger 100 of the uppermost layer, thereby maximizing the cooling performance of the thermoelectric element in cooling the cooling water.

The present invention is not limited to the above-described embodiments, and the scope of application of the present invention is not limited to those of ordinary skill in the art to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Of course, various modifications can be made.

As described above, according to the present invention, the depression is formed in the portion where the thermoelectric element is located, thereby reducing the thermal resistance between the water-cooled plate and the thermoelectric element, thereby improving heat transfer efficiency, and the recessed portion has a different position at the thermoelectric element. By acting as a guide that is firmly fixed in place without leaving the furnace, there is a dual effect of increasing durability and lifespan of the entire thermoelectric element heat exchanger.

In addition, the temperature difference between both ends of the thermoelectric element is reduced by forming a counter current between the cooling water and the air, thereby improving the operating efficiency of the thermoelectric element. Therefore, such effects have the effect that the heat exchange performance of the heat exchanger is greatly increased as a result. In particular, when compared with an air-cooled / air-cooled heat exchanger that is conventionally employed by using a thermoelectric element, the present invention is able to obtain a much higher cooling and heating performance and efficiency improvement effect because it is a water-cooled / air-cooled heat exchanger.

In addition, by forming the inlet and outlet of the water-cooled plate on one side has the effect of compacting the heat exchanger itself, thereby increasing the space utilization in the engine room significantly. In addition, according to the present invention, since the structure of the unit heat exchanger is stacked, the designer simply needs to determine the number of unit heat exchangers to be stacked according to the desired capacity, thereby making the adjustment of the capacity much simpler. The ease of the effect is greatly increased.

Claims (5)

Cooling water is circulated therein and extends in the longitudinal direction, and the inlet 112 through which the coolant is introduced downstream of the inlet air is formed in the longitudinal direction, and the coolant is discharged to the surface on which the inlet 112 on the upstream side of the inlet air is formed. A water cooling plate 110 having a water outlet 111 having a discharge port 113 formed in a length direction thereof; A thermoelectric element 120 disposed on upper and lower surfaces of the water cooling plate 110 along the channel at a position parallel to the channel 111; A support plate 130 provided in close contact with both outer sides of the layer formed of the thermoelectric element 120; A heat dissipation fin 140 that is supported and fixed to both sides of the support plate 130, and distributes air in a width direction of the water cooling plate 110; Thermoelectric element heat exchanger comprising a unit heat exchanger (100) consisting of. The method of claim 1, wherein the water cooling plate 110 Thermoelectric element heat exchanger, characterized in that the depression portion 114 having a predetermined depth is formed so that the thermoelectric element 120 is inserted in the position where the thermoelectric element 120 is provided. The method according to claim 1 or 2, Thermoelectric element heat exchanger, characterized in that a plurality of the unit heat exchanger (100) is stacked in the height direction. The method of claim 3, wherein A connection pipe 115 connecting the water channel 111 of one unit heat exchanger 100 and the water channel 111 of the other unit heat exchanger 100 to distribute cooling water; And Separating plate 200 provided on the laminated surface of the stacked unit heat exchangers 100 to protect the heat radiation fins 140 of each unit heat exchanger 100 adjacent to each other when stacked; Thermoelectric element heat exchanger characterized in that it further comprises. The method of claim 4, wherein the connecting pipe 115 Channel 111 inlet 112 of one unit heat exchanger 100 and channel 111 outlet 113 of another unit heat exchanger 100 at a position closest to the one unit heat exchanger 100. Thermoelectric element heat exchanger characterized in that connected to each other.

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