KR20080077448A - A heat exchanger using thermoelectric element - Google Patents

Abstract

A heat exchanger using a thermoelectric element is provided to enhance heat exchange efficiency by allowing cooling water to be introduced and discharged to unit heat exchangers in parallel. A heat exchanger comprises a plurality of unit heat exchangers that are layered to each other. The unit heat exchanger includes a water cooling plate(110) incorporated with a water passage(111), a thermoelectric element(120), a support plate(130), and a cooling fin(140). The water passage includes an inlet(112a~112c) and an outlet(113a~113c) that are formed at downstream side of intake air and at a surface having the inlet at upstream side of intake air, respectively. The thermoelectric element is provided at upper/lower surfaces of the water cooling plate in parallel to the water passage. The support plate is adhered closely to the outside of a layer including the thermoelectric element. The cooling fin is supported against the outside of the support plate to circulate air in the width direction of the water cooling plate. The inlets of the unit heat exchangers are connected in parallel to each other through an intake pipe(114), and the outlets of the unit heat exchangers are connected in parallel to each other through an exhaust pipe(115).

Description

Thermoelectric Heat Exchanger {A Heat Exchanger using Thermoelectric Element}

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

Figure 2 is a thermoelectric element heat exchanger according to the prior art.

Figure 3 is a side view and a front view of the thermoelectric element heat exchanger according to the present invention.

4 is a perspective view of a water cooling plate.

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

6 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: inlet 113: outlet

114: inlet pipe 114a: inlet pipe inlet

115: discharge pipe 115b: discharge pipe outlet

116: bubble emitter

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 thermoelectric element is a thermo-electric heat pump that is designed to perform a cooling function similar to a freon compressor or an endothermic refrigerator even with a small solid-state 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.

It is well known that the thermoelectric element is changed in efficiency and capacity according to the operating environment, and the efficiency tends to decrease as the temperature difference between both sides of cold and hot increases. Therefore, it can be seen that the efficiency of the thermoelectric element increases as the temperature difference between both sides of the cold temperature of the thermoelectric element is reduced.

As such, thermoelectric devices are devices that allow electrical energy and thermal energy to be exchanged with each other, and there have been studies to improve performance of general heat exchangers using thermoelectric devices. In US Patent 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. 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. FIG. 2B shows a part of the thermoelectric element heat exchanger according to the prior art 2. As shown in FIG. The air flow shown in FIG. 2 (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.

However, the prior art 1 and the prior art 2 has a number of problems, such as the thermoelectric device. As described above, 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, so that the efficiency of the thermoelectric element also decreases. There is a problem. 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 large and the heat transfer efficiency is reduced, and the heat exchanger having a configuration in which the air-cooled heat exchanger further includes a thermoelectric element is less efficient and performance than the water-cooled type. have.

In addition, in the conventional thermoelectric element heat exchanger, the cooling water distribution to the water cooling plate is uneven, and the heat exchange performance is reduced. In particular, the pressure resistance of the cooling water flow path is large, so that the capacity of the cooling water circulation pump must be very large. have. In addition, there is a problem that a loss occurs in the heat exchange performance by bubbles generated inside the cooling water flow path to reduce the heat transfer area.

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 that improves the heat transfer efficiency by reducing the thermal resistance of the thermoelectric element and the temperature difference between both cross-sections, and also reduce the capacity of the cooling water circulation pump.

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 Positions parallel to the water cooling plate 110 and the waterway 111 in which the waterway 111 formed in the longitudinal direction of the water outlet 111 in which the cooling water is discharged on the surface on which the inlet 112 is formed upstream is formed therein; the thermoelectric elements 120, the thermoelectric element support plate 130, the support plate which is provided in close contact with the outer sides of the layer composed of the 120 provided in the top and bottom surfaces of the water-cooling plate 110 in accordance with the number of (130) a unit heat exchanger (100) which is supported and fixed on both sides of the outer side, and comprises heat dissipation fins (140) for distributing air in the width direction of the water cooling plate (110); Including, a plurality of the unit heat exchanger 100 is configured to be stacked in the height direction, the inlet pipe 114 for connecting the water inlet (111) inlet 112 of the unit heat exchangers 100 in parallel with each other; And a discharge pipe 115 connecting the water passages 111 and the outlets 113 of the unit heat exchangers 100 to each other in parallel.

At this time, the inlet pipe inlet 114a through which the coolant flows into the inlet pipe 114 is located at the lowermost side of the inlet pipe 114 and the outlet pipe outlet 115a through which the coolant is discharged from the outlet pipe 115. ) Is located at the uppermost side of the discharge pipe (115).

In addition, the discharge pipe outlet 115a is characterized in that the bubble emitter 116 is further provided.

In addition, the separation 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; Characterized in that further comprises.

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.

3 is a side view and a front view of a thermoelectric element heat exchanger according to the present invention. As shown in the side view of Figure 3 (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. 4, 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. It is W-shaped to have. Of course, the internal flow path of the water-cooled plate 110 may be in various forms such as U-shaped as well as W-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 fins 140 are attached to the outside thereof, and the heat dissipation fins 140 are formed on the water cooling plate 110. It arrange | positions so that air may pass in the direction orthogonal to the width direction. In addition, the inlet 112 through which the coolant flows is disposed downstream of the inlet air. By doing in this way, the flow direction of a cooling water is made to become a counterflow with respect to the flow direction of air, and performance improves. According to the front view of FIG. 3 (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. 3B. 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. In the present invention, as described above, the flow direction of the cooling water and the flow direction of the air are 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, and 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. Figure 5 shows the flow direction of the cooling water and the flow direction of the air, it is shown that the side where the air is hot and the coolant is high temperature, and the side where the air is low temperature and the side where the coolant is low temperature 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 above, the thermoelectric device has a lower efficiency as the temperature difference between both sides increases, and the thermoelectric device exhibits 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. Of course, the heat exchange capacity may be increased by arranging the unit heat exchangers 100 in series, but when the heat exchange capacity is increased in series, the unit heat exchanger is likely to decrease in heat exchange performance. When connecting a plurality of (100), it is preferable to stack vertically (parallel).

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. 6 illustrates a method of forming a cooling water distribution path in a thermoelectric element heat exchanger including a plurality of unit heat exchangers. The thermoelectric element heat exchanger of the present invention, the inlet pipe 114 for connecting the inlet 112 of each unit heat exchanger 100 in parallel with each other, the discharge for connecting the outlet 113 of each unit heat exchanger in parallel with each other It comprises a pipe 115. In this case, as shown in FIG. 6, the inlet pipe inlet 114a through which the coolant flows into the inlet pipe 114 is located at the lowermost side of the inlet pipe 114 and the coolant from the outlet pipe 115. The discharge pipe outlet 115a to be discharged is preferably located at the uppermost side of the discharge pipe 115.

As the inflow and outflow of the cooling water is performed in this manner, the amount of the cooling water circulated in each unit heat exchanger 100 is not only distributed evenly, but also the temperature of the cooling water circulated is constant in the vertical direction. Accordingly, the heat exchange performance in each unit heat exchanger 100 may be much increased. In addition, when the circulation of the cooling water is made in parallel in this way, the pressure resistance in the water channel 111 becomes smaller, so that the cooling water is much easier, in particular, the capacity of the cooling water circulation pump does not need to be increased and the cooling water of the small capacity is reduced. Since only the circulation pump can sufficiently distribute the coolant to the thermoelectric element heat exchanger channel 111 of the present invention, it is very effective in the overall system.

In addition, in the thermoelectric element heat exchanger of the present invention, the inlet pipe inlet 114a through which the coolant flows into the inlet pipe 114 is located at the lowermost side of the inlet pipe 114 as described above. The discharge pipe outlet 115a through which the coolant is discharged from 115 is located at the uppermost side of the discharge pipe 115. Such a configuration is a configuration for maximizing heat exchange with the cooling water. Due to such a configuration, the cooling performance of the cooling water is maximized.

However, there is a possibility that bubbles are generated in the channel 111 due to problems in the flow path design or the occurrence of an unexpected situation. When bubbles exist in the channel 111 in this manner, the heat transfer area in the water cooling plate 110 is reduced, resulting in a loss of heat transfer efficiency. Therefore, removing bubbles in the channel 111 is a very important problem for increasing the heat transfer efficiency.

In the thermoelectric element heat exchanger of the present invention, the inlet pipe inlet 114a is located at the lowermost end and the outlet pipe outlet 115a is located at the uppermost end so that bubbles in the water channel 111 can be naturally removed in accordance with the flow of the cooling water. Since air is much less dense than coolant and tends to move upward in the coolant, when the coolant flows from the bottom up, bubbles naturally rise upwards as the coolant flows.

In addition, since the bubbles inside the waterway 111 are removed to rise upward, the discharge pipe outlet 115a may further include a bubble emitter 116 so as to discharge the collected air.

As described above, in the thermoelectric element heat exchanger according to the present invention, the flow path is designed to maximize the heat exchange with the cooling water, thereby increasing the cooling performance of the cooling water, as well as the structure and bubble of the inlet pipe 114 and the discharge pipe 115. Bubbles in the channel 111 are effectively removed by the emitter 116, thereby minimizing the loss of heat transfer efficiency, thereby further maximizing the cooling performance of 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 temperature difference between both ends of the thermoelectric element is reduced by forming a counter flow of cooling water and air, thereby improving the operating efficiency of the thermoelectric element. Therefore, these 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.

Particularly, according to the present invention, since the coolant is introduced and discharged in parallel to the stacked unit heat exchangers, the amount of the coolant circulated is distributed evenly and the coolant temperature in the longitudinal direction is also constant, so that the heat exchange efficiency is greatly improved. There is. In addition, since the cooling water flows in parallel, the pressure resistance of the cooling water flow passage does not become too large, and thus, a smaller capacity of the cooling water circulation pump can be used, which is very efficient.

In addition, according to the present invention, by collecting the bubbles through the inlet / outlet position design of the bubble discharger and the inlet pipe / discharge pipe so that the bubbles generated in the cooling water flow path is not stagnant can minimize the effect of reducing the heat transfer efficiency due to bubbles Excellent effect

Claims (4)

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 is formed upstream of the inlet air. A water cooling plate (110) having a discharge port (113) formed in the longitudinal direction is formed in the upper and lower surfaces of the water cooling plate (110) along the water channel at a position parallel to the water passage (111). The thermoelectric element 120, the support plate 130 is provided in close contact with the outer both sides of the layer consisting of the thermoelectric element 120, is supported and fixed on both sides of the outer side of the support plate 130, the water-cooled plate 110 A unit heat exchanger (100) consisting of heat dissipation fins (140) for distributing air in the width direction of the upper and lower sides ; Including, a plurality of the unit heat exchanger 100 is configured to be stacked in the height direction, An inlet pipe (114) connecting the channel (111) inlets (112) of the unit heat exchangers (100) to each other in parallel; And And a discharge pipe (115) connecting the channel (111) outlets (113) of the unit heat exchangers (100) to each other in parallel. The method of claim 1, The inlet pipe inlet 114a through which the coolant flows into the inlet pipe 114 is located at the lowermost side of the inlet pipe 114. And a discharge pipe outlet (115a) through which the coolant is discharged from the discharge pipe (115) is located at the uppermost side of the discharge pipe (115). The method of claim 2, The discharge pipe outlet (115a) is a thermoelectric element heat exchanger, characterized in that the bubble emitter 116 is further provided. The method of claim 3, wherein 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.

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