JP2015133421A - Stack type cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for making small a difference in flow rate of a refrigerant flowing along cooling plates of a stack type cooling system with a simple structure.SOLUTION: A stack type cooling system includes: a plurality of cooling plates which are stacked alternately with bodies to be cooled and in which a refrigerant flows; a refrigerant supply path which penetrates the cooling plate group in the stacking direction of the cooling plates and supplies the refrigerant to the respective cooling plates; and a valve body which is elastically supported in a flow passage of each cooling plate and makes the flow passage area of the cooling plate smaller as the flow rate of the passing refrigerant is larger. More specifically, the valve body which closes a part of the flow passage of each cooling plate is pressed with the energy of the refrigerant more as the flow rate of the refrigerant is higher to deform to increase the area of the flow passage. When the flow rate of the refrigerant becomes small, the valve body returns to an original position (attitude) with elastic force to make the area of the flow passage small.

Description

  The present invention relates to a stacked cooling system. In particular, the present invention relates to a stacked cooling system that cools electric devices for electric vehicles. In this specification, the electric vehicle includes an electric vehicle having only a motor and no engine, a fuel cell vehicle, and a hybrid vehicle having both a motor and an engine.

  A cooling system for cooling an electric device (for example, an inverter) for driving a motor of an electric vehicle or a hybrid vehicle with a refrigerant has been developed. As an example of such a cooling system, a stack in which a plurality of objects to be cooled (for example, a semiconductor card sealing a semiconductor element) constituting an electrical device and cooling plates in which a coolant flows are alternately stacked. There is a mold cooling system. This cooling system generally includes a refrigerant supply path that supplies refrigerant to each cooling plate when passing through a plurality of cooling plates in the stacking direction, and a refrigerant that passes through the stacking direction and is discharged from each cooling plate. And a refrigerant discharge path for collecting the refrigerant. The refrigerant supply path and the refrigerant discharge path are arranged on both sides of the object to be cooled when viewed in the stacking direction of the cooling plates. And the inside of the cooling plate is hollow, and itself becomes a refrigerant flow path. The refrigerant pumped by the pump is supplied to each cooling plate via the refrigerant supply path, absorbs heat from the adjacent object to be cooled while flowing inside the cooling plate, and returns to the pump again through the refrigerant discharge path. . Examples of such a cooling system are disclosed in Patent Documents 1 and 2.

  Depending on the situation, it may be desired to change the flow rate flowing through each cooling plate. Therefore, in the cooling system of Patent Document 1, a flow rate adjusting valve is provided at the refrigerant flow path inlet of each cooling plate. The valve is made of a shape memory alloy and changes the flow channel area at the flow channel inlet in response to a temperature change. Moreover, in the cooling system of patent document 2, an electromagnetic valve is provided in the flow path of each cooling plate to adjust the amount of refrigerant flowing into each cooling plate.

JP 2006-147924 A JP 2013-26434 A

  The present specification provides a technique for adjusting the flow rate of each cooling plate by a mechanism different from that of the above-mentioned Patent Documents 1 and 2. In particular, a technique for reducing the difference in the flow rate of refrigerant flowing through a plurality of cooling plates with a simple structure is provided.

  In the laminated cooling system described above, the refrigerant is distributed to each cooling plate through a refrigerant supply path that penetrates the plurality of cooling plates in the laminating direction. When the structure of the branch point from the refrigerant supply path to each cooling plate is the same for a plurality of cooling plates, the ratio of the amount of refrigerant flowing downstream of the refrigerant supply path at the branch point to the amount of refrigerant diverted to the cooling plate is The same at the branch point. Then, the flow rate of the cooling plate downstream of the refrigerant supply path decreases. Therefore, one policy for adjusting the refrigerant flow rate in the plurality of cooling plates is to reduce the difference between the refrigerant flow rate flowing through the cooling plate on the upstream side of the refrigerant supply path and the refrigerant flow rate flowing through the cooling plate on the downstream side.

  The stacked cooling system disclosed in this specification has the following configuration. The stacked cooling system is alternately stacked with objects to be cooled, and includes a plurality of cooling plates in which refrigerant flows, and a cooling plate group in the stacking direction of the plurality of cooling plates and each cooling of the refrigerant. A refrigerant supply path for supplying to the plate, and a valve body that is elastically supported in the flow path of each cooling plate and reduces the flow path area in the cooling plate as the flow rate of the refrigerant passing therethrough increases. Yes. More specifically, the valve element that closes a part of the flow path of each cooling plate is deformed by being pushed by the momentum of the refrigerant as the flow rate of the refrigerant increases, and the area that closes the flow path increases. That is, the channel area is reduced. When the flow rate of the refrigerant decreases, the position (posture) of the valve body is restored to the original by the elastic force, and the flow path area increases.

  In the structure in which the refrigerant is distributed to each cooling plate through the refrigerant supply path that penetrates the plurality of cooling plates in the stacking direction, the flow rate of the refrigerant decreases in the downstream of the refrigerant supply path. According to the cooling system described above, the flow path area becomes larger as the cooling plate is downstream of the refrigerant supply path, and the refrigerant flows easily. As a result, the amount of refrigerant flowing through the refrigerant supply path decreases toward the downstream of the refrigerant supply path, but the ratio of the refrigerant flow rate to the cooling plate increases with respect to the flow rate downstream of the refrigerant supply path. As a result, the flow rate difference between the cooling plate on the upstream side and the cooling plate on the downstream side of the refrigerant supply path is reduced.

  A preferred embodiment of the cooling plate including the valve body is as follows. An intermediate plate that bisects the flow path in the cooling plate in the stacking direction is provided. And the valve body is elastically supported by the edge part of the refrigerant | coolant flow upstream of an intermediate | middle plate. The valve body extends from the end of the intermediate plate so as to incline with respect to the direction of the refrigerant flow toward the upstream side of the refrigerant flow. And the length from the edge part of an intermediate plate to the front-end | tip of a valve body is shorter than the length from the intermediate plate and the flow path inner surface facing this.

It is a perspective view of the cooling system 90 of an Example. It is a disassembled perspective view of the cooling plate 2 which comprises the cooling system 90 of an Example. It is sectional drawing of the cooling system 90 of an Example. It is an expanded sectional view near regulating valve 5 in cooling system 90 of an example. It is an expanded sectional view of the regulating valve 105 in the cooling system 90 of another form.

  The electric vehicle includes an electric device (an inverter or a boost converter) for supplying electric power to the traveling motor. Since these electric devices output a large amount of power, they generate a large amount of heat. The cooling system 90 of the present embodiment is a system that cools such an electric device with a refrigerant.

  As shown in FIG. 1, in the cooling system 90 of the embodiment, a plurality of semiconductor cards 60 constituting an electric device and cooling plates 2 through which a refrigerant flows are alternately stacked. The cooling system 90 is a so-called stacked cooling system. The refrigerant is supplied from the supply pipe 3 to the cooling system 90, passes through the inside of each cooling plate 2, and is discharged from the discharge pipe 4. The cooling plate is simply represented as a cooling plate 2 when a specific cooling plate is not designated. Moreover, when distinguishing each cooling plate 2, the code | symbol of 2a-2g is attached | subjected (refer FIG. 1, FIG. 3). The upper plate in FIG. 1 (the side on which the supply pipe 3 and the discharge pipe 4 are provided) is the cooling plate 2a, and the lower side in FIG. 1 is the cooling plate 2g. The refrigerant is a liquid, for example, LLC (Long Life Coolant).

  The internal structure of the cooling plate 2 will be described with reference to FIG. The arrows in FIG. 2 indicate the direction in which the refrigerant flows. The cooling plate 2 includes an upper plate 21 and a lower plate 23 corresponding to a casing, and an intermediate plate 22 sandwiched between them. It should be noted that the terms “upper plate” and “lower plate” are for convenience derived from the positional relationships in the drawings shown in FIGS. 1 to 4 and are relative to the direction of gravity when the cooling system 90 is implemented. It does not mean a positional relationship. Further, the upper plate 21 and the lower plate 23 are members having the same shape, although their orientations when arranged in the cooling system 90 are different. The container-like upper plate 21, lower plate 23 and middle plate 22 are formed by pressing an aluminum plate. Fins 24 made of corrugated plates are arranged inside the upper plate 21, and the intermediate plate 22 holds the fins 24. Further, fins 24 are also arranged inside the lower plate 23, and this is also suppressed by the intermediate plate 22. The fins 24 are in contact with both the middle plate 22, the upper plate 21, and the lower plate 23, so that heat transmitted from the semiconductor card 60 is easily diffused throughout the cooling plate 2. Moreover, the fin 24 increases the contact area with the refrigerant flowing inside the cooling plate 2 and improves the heat transfer efficiency to the refrigerant.

  The upper plate 21 has through holes at both ends in the longitudinal direction. Connection pipes 25 and 26 are provided at the positions of the through holes in the upper plate 21. Each of the connecting pipes 25 and 26 extends from the outer surface (upper surface in FIG. 2) of the upper plate 21 toward the outer surface (upper side in FIG. 2) of the upper plate 21. Similarly, the lower plate 23 has through holes at both ends in the longitudinal direction, and the connecting pipes 27 and 28 extend from the outer surface of the lower plate 23 (the lower surface in FIG. 2) to the outer side of the lower plate 23 (the lower side in FIG. 2). ). The intermediate plate 22 also has through holes 29 and 30 at both ends in the longitudinal direction. The connection pipe 25 of the upper plate 21, the through hole 29 of the middle plate 22, and the connection pipe 27 of the lower plate 23 are provided at positions overlapping when viewed from above (when viewed in the Y-axis direction in the figure). It has been. Similarly, the connecting pipe 26 of the upper plate 21, the through hole 29 (see FIGS. 2 and 4) of the middle plate 22, and the connecting pipe 28 of the lower plate 23 are provided at positions overlapping when viewed from above in FIG. 2. ing. The cooling system 90 shown in FIG. 1 is configured by laminating a plurality (seven in FIG. 1) of the cooling plates 2 shown in the exploded perspective view of FIG. Specifically, the lower plate 23g (see FIG. 3) of the cooling plate 2 (ie, the cooling plate 2g) located on the lowermost side in FIGS. 1 and 3 does not require a through hole and a connecting pipe. For this reason, FIGS. 1 and 3 show an example in which the lower plate 23g is not provided with a through hole and a connecting pipe. However, the lower plate 23g may be provided with a through hole and a connecting pipe (that is, the same member as the lower plate 23 of the other cooling plate 2 is used), and the connecting pipe may be closed with a cap or the like.

  As shown in FIGS. 2 to 4, the intermediate plate 22 has a regulating valve 5. The regulating valve 5 has a substantially rectangular flat plate shape. The regulating valve 5 is connected to the intermediate plate 22 via the connecting portion 6. In the following description, the portion of the intermediate plate 22 excluding the adjusting valve 5 and the connecting portion 6 may be referred to as a main body portion of the intermediate plate 22. The regulating valve 5 is provided so as to protrude inside the through hole 29. The regulating valve 5 is provided at a position on the center side of the middle plate 22 at the edge of the through hole 29. The main body portion, the connection portion 6 and the adjustment valve 5 of the intermediate plate 22 are each formed by pressing a single plate. For this reason, the intermediate plate 22 can be manufactured relatively easily. The connecting portion 6 is formed in a semicircular arc shape. For this reason, the spring constant of the connection part 6 is low. As a result, the regulating valve 5 can change its posture by rotating around the connecting portion 6 as a fulcrum. The function of the regulating valve 5 will be described in detail later.

  The arrows in FIG. 3 indicate the flow of the refrigerant. In FIG. 3, for example, the configuration corresponding to the cooling plate 2 a is denoted by the symbol “a” after each symbol, and denoted as the upper plate 21 a, the connecting pipes 25 a, 26 a, 27 a, 28 a, and the middle plate 22 a. (The same applies to the cooling plates 2b and 2g). 3, illustration of the cooling plates 2c, 2d, 2e, and 2f shown in FIG. 1 is omitted. The refrigerant supplied from the supply pipe 3 flows into the cooling plate 2a through the connection pipe 25a of the upper plate 21a of the cooling plate 2a. A part of the refrigerant flowing in from the connection pipe 25a flows from the position of the connection pipe 25a to the right in FIG. 3 through the inside of the cooling plate 2a. Here, the intermediate plate 22 bisects the flow path in the cooling plate 2a in the vertical direction in FIG. 3 (the stacking direction of the cooling plates 2). For this reason, the refrigerant flowing in the cooling plate 2a flows separately into the flow path 7a located on the upper side of the middle plate 22 in FIG. 3 and the flow path 8a located on the lower side of the middle plate 22 in FIG.

  Of the refrigerant flowing in from the connection pipe 25a, the refrigerant other than the refrigerant flowing through the flow paths inside the cooling plate 2a (that is, the flow paths 7a and 8a) flows out of the cooling plate 2a through the connection pipe 27a of the lower plate 23a. . The refrigerant that has flowed out of the cooling plate 2a flows into the cooling plate 2b through the connection pipe 25b of the upper plate 21b of the cooling plate 2b. The refrigerant flow in the cooling plate 2b is the same as that of the cooling plate 2a. That is, a part of the refrigerant flows into the flow paths 7b and 8b positioned above and below the middle plate 22b, and the remaining refrigerant flows out from the connecting pipe 27b of the lower plate 23b and is adjacent to the lower side of the cooling plate 2b in FIG. It flows into the cooling plate 2c (see FIG. 1 since the cooling plate 2c is not shown in FIG. 3). However, in the cooling plate 2g located on the lowermost side in FIGS. 1 and 3, all of the refrigerant flowing from the connection pipe 25g of the upper plate 21g flows into the flow paths 7g and 8g located above and below the middle plate 22g (see FIG. 3).

  In the following description, a flow path from the supply pipe 3 through each cooling plate 2 to the cooling plate 2g is referred to as a refrigerant supply path 40. In other words, the coolant supply path 40 penetrates the plurality of cooling plates 2 in the stacking direction and supplies the coolant to each cooling plate 2.

  Similarly, the cooling system 90 of the present embodiment includes a refrigerant discharge path 50 that passes through the plurality of cooling plates 2 in the stacking direction and collects refrigerant discharged from each cooling plate. For example, the refrigerant that has flowed through the flow paths 7b and 8b of the cooling plate 2b flows out of the cooling plate 2b through the connection pipe 26b of the cooling plate 2b. The refrigerant that has flowed out of the cooling plate 2b flows into the cooling plate 2a from the connection pipe 28a of the cooling plate 2a, and merges with the refrigerant that has passed through the flow paths 7a and 8a of the cooling plate 2a. That is, the refrigerant that has passed through the cooling plates 2 a to 2 g is finally discharged from the discharge pipe 4 through the refrigerant discharge path 50.

  Here, the function of the regulating valve 5 will be described with reference to FIG. As described above, the adjustment valve 5 is provided so as to protrude inside the through hole 29 of the intermediate plate 22. This means that the regulating valve 5 is disposed so as to protrude into the refrigerant supply path 40 described above. The refrigerant flow flows from the left to the right in the drawing in the vicinity of the regulating valve 5. Therefore, in other words, the regulating valve 5 extends toward the upstream of the refrigerant flow so as to incline with respect to the refrigerant flow direction. The regulating valve 5 is connected to the intermediate plate 22 (the main body portion of the intermediate plate 22) on the center side (right side in FIG. 4) of the intermediate plate 22 at the edge of the through hole 29 of the intermediate plate 22, and the through hole 29. It protrudes toward the inner side direction (left direction in FIG. 4). The regulating valve 5 is located at the end of the intermediate plate 22 on the upstream side of the refrigerant flow path (left side in FIG. 3).

  The adjustment valve 5 adjusts the flow path area of the cooling plate 2. Specifically, the adjustment valve 5 adjusts the flow path area of the cooling plate 2 at the position of the branch point from the refrigerant supply path 40 to the cooling plate 2. The adjustment valve 5 directly adjusts the flow area of the flow path 8 located on the lower side of the intermediate plate 22 in the cooling plate 2 in FIG. Here, the flow path 7 located on the upper side in FIG. 4 of the intermediate plate 22 in the cooling plate 2 is not affected by the regulating valve 5. For this reason, adjusting the flow path area of the flow path 8 means adjusting the flow path area of the cooling plate 2.

  The regulating valve 5 is displaced by receiving a force from the refrigerant flowing through the refrigerant supply path 40. As the flow rate of the refrigerant flowing through the refrigerant supply path 40 increases, the force that the regulating valve 5 receives from the refrigerant also increases. When the adjusting valve 5 does not receive a force from the refrigerant, the adjusting valve 5 takes a posture illustrated by a solid line in FIG. On the other hand, the regulating valve 5 extends toward the upstream side of the refrigerant flow so as to incline with respect to the flow direction of the refrigerant. Therefore, when the force is received from the refrigerant, the regulating valve 5 takes a posture illustrated by a two-dot chain line in FIG. When the regulating valve 5 is in the position of the solid line in FIG. 4, the width at the entrance of the flow path 8 of the cooling plate 2 (the vertical direction in FIG. 4, ie, the width in the stacking direction of the cooling plate 2) is Lf. On the other hand, when the regulating valve 5 is at the position of the two-dot chain line in FIG. 4, the width at the entrance of the flow path 8 is Lg. Here, the width Lg is narrower than the width Lf. In other words, the regulating valve 5 opens the flow path 8 of the cooling plate 2 at the position indicated by the solid line in FIG. 4 (the flow path area of the flow path 8 is increased). On the other hand, at the position of the two-dot chain line in FIG. 4, the flow path 8 of the cooling plate 2 is closed (the flow path area of the flow path 8 is reduced). For this reason, in the following description, the position indicated by the solid line in FIG. 4 of the regulating valve 5 may be referred to as the “open side” position. Further, the position indicated by a two-dot chain line in FIG. 4 may be referred to as a “closed side” position. That is, the greater the force received from the refrigerant, the more the regulating valve 5 is displaced from the open side position to the closed side position.

  The length Lh from the base end portion of the connecting portion 6 to the tip end portion of the regulating valve 5 is smaller than the distance Li between the middle plate 22 and the bottom of the lower plate 23. For this reason, even if the adjustment valve plate 5 is greatly displaced, for example, when the flow rate of the refrigerant is very large, the flow path area of the flow path 8 does not become zero.

  As described above, the cooling system 90 according to the present embodiment includes a plurality of cooling plates 2, and includes a refrigerant supply path 40 that passes through the plurality of cooling plates 2 and supplies a refrigerant to each cooling plate 2. Have. In such a cooling system, if the structure of the branch point from the coolant supply path 40 to each cooling plate 2 is the same in the plurality of cooling plates 2, the following is obtained. That is, since the structure of the branch point of each cooling plate 2 is the same, the ratio of the amount of refrigerant flowing from the branch point to the downstream of the refrigerant supply path 40 and the amount of refrigerant diverted to the cooling plate 2 is 2 equals the value. For example, a certain ratio of the refrigerant flowing into the cooling plate 2a flows into the cooling plate 2b adjacent to the downstream side of the cooling plate 2a. Similarly thereafter, a certain ratio of the refrigerants flowing into the cooling plate 2b flows into the cooling plate 2c adjacent to the downstream side of the cooling plate 2b. That is, the amount of refrigerant flowing through each cooling plate 2 gradually decreases from the upstream side to the downstream side of the refrigerant supply path 40.

  On the other hand, when attention is paid to the flow rate of the refrigerant flowing through the refrigerant supply path 40, the flow rate of the refrigerant is larger in the upstream of the refrigerant supply path 40, and the flow rate of the refrigerant is smaller as it is downstream of the refrigerant supply path 40. In other words, the flow rate of the refrigerant is large upstream of the refrigerant supply path 40, and the flow rate of the refrigerant decreases as it goes downstream of the refrigerant supply path 40. The cooling system 90 of the present embodiment adjusts the ratio of the flow rate that is divided from the coolant supply path 40 to each cooling plate 2 using the difference in flow rate in the coolant supply path 40.

  As described above, in the refrigerant supply path 40, the flow rate decreases in order from the upstream side (cooling plate 2a side) to the downstream side (cooling plate 2g side). The regulating valve 5 on the upstream side (cooling plate 2a side) of the refrigerant supply path 40 is located on the “closed side” (two-dot chain line in FIG. 4). On the other hand, the closer the adjustment valve 5 is to the downstream side (cooling plate 2g side) of the refrigerant supply path 40, the closer the position is to the “open side” (solid line in FIG. 4). In other words, the flow path area of the cooling plate 2 decreases toward the upstream side of the refrigerant supply path 40, and the flow path area of the cooling plate 2 increases toward the downstream side of the refrigerant supply path 40. Thereby, the difference between the flow rate of the refrigerant on the upstream side cooling plate 2 and the flow rate of the refrigerant on the downstream side cooling plate 2 is reduced. In other words, the amount of refrigerant flowing through the cooling plates 2a to 2g is made uniform.

  In the cooling system 90 of the present embodiment, each of the cooling plates 2a to 2g has the same regulating valve 5 (that is, has the same middle plate 22). For this reason, the kind of component of the cooling system 90 can be reduced.

  Next, another form of the cooling system 90 will be described with reference to FIG. Another form of the cooling system 90 includes a middle plate 122 instead of the middle plate 22. In the middle plate 22 of the above-described embodiment, the main body portion, the regulating valve 5 and the connection portion 6 of the middle plate 22 are formed by pressing a single plate. On the other hand, in another form of the intermediate plate 122, the main body of the intermediate plate 122 and the adjustment valve 105 are configured separately. Further, the main body of the intermediate plate 122 and the adjustment valve 105 are connected by a spring member 106 (note that the spring member 106 is schematically shown in FIG. 5). Specifically, the spring member 106 is formed of a spring steel material. The shape of the spring member 106 can be selected as appropriate, but may be, for example, a plate shape, a wire shape, or a coil shape. In this embodiment, each of the main body 122 and the adjustment valve 105 and the spring member 106 are separated from each other, so that each can be formed of a suitable material (for example, the adjustment valve 105 is formed of aluminum, For example, the spring member 106 is made of spring steel. Thereby, the flow volume of each cooling plate 2 can be adjusted suitably.

  In the above embodiment and other embodiments, the intermediate plates 22 and 122 are examples of “intermediate plates” in the claims, and the control valves 5 and 105 are examples of “valve bodies” in the claims.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. In addition, the technical elements described in the present specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in the present specification or the drawings can achieve a plurality of objects at the same time, and has technical utility by achieving one of the objects.

2, 2a, 2b, 2c, 2d, 2e, 2f, 2g; cooling plates 5, 5a, 5b, 5c, 5d, 5e, 5f, 5g; regulating valve 3; supply pipe 4; discharge pipe 5; regulating valve 6; Connection portion 7, 7a, 7b, 7g, 8, 8a, 8b, 8g; flow path 21, 21a, 21b, 21g; upper plate 22, 22a, 22b, 22g; middle plate 23, 23a, 23b, 23g; lower plate 24; Fin 40; Refrigerant supply path 50; Refrigerant discharge path 60; Semiconductor card 90; Cooling system

Claims (1)

A plurality of cooling plates that are alternately stacked with objects to be cooled and in which a coolant flows,
A refrigerant supply path that penetrates the plurality of cooling plates in the stacking direction and supplies a refrigerant to each cooling plate;
A valve body that is elastically supported in the flow path of each cooling plate and reduces the flow path area of the cooling plate as the flow rate of the refrigerant passing therethrough increases.
A stacked cooling system comprising:

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