JP2009250559A - Ebullient cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure necessary cooling performance with respect to a heating element arranged on an upper side without increasing the amount of a refrigerant filled within an ebullient cooling device, in the ebullient cooling device having a plurality of heating elements juxtaposed vertically. <P>SOLUTION: A separation means 5 for separating air bubbles generated by boiling of the refrigerant by receiving heat of a lower side heating element arranged on the lower side out of two heating elements 2 juxtaposed vertically from an inner wall face 3b of a refrigerant tank 3 is provided inside the refrigerant tank 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a boiling cooling device that absorbs heat from a heating element by boiling a refrigerant with heat generated in the heating element.

An example of the boiling cooling device is disclosed in Patent Document 1. The boiling cooling device shown in FIG. 42 of Patent Document 1 includes a refrigerant tank having a heating element attached to a side surface, and a heat radiating portion provided on the upper part of the refrigerant tank. The refrigerant tank is formed by extruding an aluminum block material.
Japanese Patent No. 3608272

  By the way, in the boiling cooling apparatus described in Patent Document 1, a plurality of heating elements are arranged in the vertical direction in the refrigerant tank. And if a refrigerant | coolant boils with the heat | fever of a lower side heat generating body (henceforth a lower side heat generating body), a refrigerant | coolant vapor | steam will become a bubble and will move to an upper side by buoyancy, and the upper side heat generating body ( Hereinafter, the liquid refrigerant in the vicinity of the portion corresponding to the arrangement portion of the upper heating element) is excluded. For this reason, there is a problem that good heat transfer cannot be performed between the upper heating element and the liquid refrigerant, and the cooling performance for the upper heating element is lowered.

  On the other hand, if the thickness of the part corresponding to the arrangement part of the upper heating element in the refrigerant tank, that is, the length in the direction orthogonal to the vertical direction is increased, the part corresponding to the arrangement part of the upper heating element. Since the amount of liquid phase refrigerant in the vicinity can be secured, it is possible to suppress a decrease in cooling performance with respect to the upper heating element.

  However, in the boiling cooling device described in Patent Document 1, since the refrigerant tank is formed by extrusion, it is not possible to increase the thickness of only the part corresponding to the arrangement part of the upper heating element in the refrigerant tank. That is, it is necessary to increase the thickness in the entire vertical direction of the refrigerant tank. Therefore, the amount of the refrigerant sealed in the boiling cooling device increases, leading to an increase in cost.

  In view of the above points, the present invention is a boiling cooling device in which a plurality of heating elements are arranged in the vertical direction, and the necessity for a heating element arranged on the upper side without increasing the amount of refrigerant sealed in the device. The purpose is to ensure proper cooling performance.

  In order to achieve the above object, in the invention described in claim 1, the refrigerant tank (3) has a lower side disposed on the lower side of the two heating elements (2) arranged side by side in the vertical direction. A peeling means (5) for peeling bubbles generated by boiling of the refrigerant by receiving heat from the heating element from the inner wall surface (3b) of the refrigerant tank (3) is provided.

  According to this, the bubbles generated by receiving the heat of the lower heating element move upward by buoyancy, but the peeling means (5) causes the upper heat generation in the inner wall surface (3b) of the refrigerant tank (3). Bubbles can be separated from the vicinity of the part corresponding to the arrangement part of the body. For this reason, a liquid phase refrigerant | coolant remains in the site | part corresponding to the arrangement | positioning site | part of an upper side heat generating body, and favorable heat transfer can be performed between an upper side heat generating body and a liquid phase refrigerant | coolant. At this time, since it is not necessary to change the thickness of the refrigerant tank (3), it is possible to ensure the necessary cooling performance for the upper heating element without increasing the amount of refrigerant enclosed in the boiling cooling device (1). It becomes possible.

  In addition, the “vertical direction” in the claims means a direction in which bubbles generated by boiling of the refrigerant by receiving heat from the heating element (2) move by buoyancy.

  The invention described in claim 2 is characterized in that a volume reducing means (6) for reducing the volume in the refrigerant tank (3) is provided on the lower side in the refrigerant tank (3). .

  Usually, since it becomes difficult for the boiling cooling device (1) to secure the cooling performance toward the upper side of the refrigerant tank (3), the cooling performance for the upper heating element arranged on the upper side of the refrigerant tank (3). It is designed to ensure. Therefore, the refrigerant amount is excessive on the lower side of the refrigerant tank (3).

  For this reason, the amount of refrigerant on the lower side of the refrigerant tank (3) can be reduced by providing the volume reducing means (6) on the lower side in the refrigerant tank (3). At this time, since the amount of refrigerant on the upper side of the refrigerant tank (3) is not reduced, good heat transfer can be performed between the upper heating element and the liquid refrigerant. Therefore, it is possible to ensure the necessary cooling performance for the upper heating element without increasing the amount of refrigerant sealed in the boiling cooling device (1).

  Moreover, in invention of Claim 3, in the invention of Claim 1, the volume reduction means (6) which reduces the volume in a refrigerant tank (3) is provided in the downward side in a refrigerant tank (3). It is characterized by being provided. According to this, it becomes possible to reduce the refrigerant | coolant amount enclosed in a boiling cooling device (1).

  In the invention according to claim 4, the peeling means (5) is disposed above the lower heating element of the two heating elements (2) in the inner wall surface (3b) of the refrigerant tank (3). It arrange | positions between the site | part corresponding to the arrangement | positioning site | part of the upper side heat generating body and the site | part corresponding to the arrangement | positioning site | part of a lower side heat generating body.

  According to this, since air bubbles can be separated over the entire area corresponding to the arrangement part of the upper heating element in the inner wall surface (3b) of the refrigerant tank (3), the upper heating element and the liquid phase refrigerant can be separated. Better heat transfer between the two. Therefore, it is possible to improve the inevitable performance for the upper heating element.

  Moreover, in invention of Claim 5, volume reduction means (6) is comprised by making the plate | board thickness of the lower end surface of a refrigerant tank (3) thick so that it leaves | separates from an inner wall surface (3b). It is a feature.

  According to this, since a sufficient amount of liquid-phase refrigerant can be present in the vicinity of the portion corresponding to the arrangement portion of the lower heating element in the inner wall surface (3b) of the refrigerant tank (3), the lower heat generation. It becomes possible to improve the cooling performance for the body.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view showing a boiling cooling device 1 according to this embodiment.

  As shown in FIG. 1, a boiling cooling device 1 of the present embodiment cools a heating element 2 by repeating boiling and condensation of a refrigerant, a refrigerant tank 3 that stores a liquid-phase refrigerant therein, and the refrigerant The heat radiating core part 4 assembled | attached to the outer wall surface 3a of the tank 3 is provided, and it manufactures by integral brazing. The heating element 2 is, for example, an IGBT module that constitutes an inverter circuit of an electric vehicle, and is closely fixed to the outer wall surface 3a of the refrigerant tank 3 with a bolt (not shown) or the like.

  In the present embodiment, one heat radiating core portion 4 is arranged on each of the two outer wall surfaces 3 a of the refrigerant tank 3. That is, the boiling cooling device 1 of the present embodiment has two heat radiating core portions 4. And in each of the two outer wall surfaces 3a, the six heat generating bodies 2 are arrange | positioned under the thermal radiation core part 4. FIG.

  The six heating elements 2 arranged on one outer wall surface 3a are arranged side by side in the vertical direction. That is, the two heat generating elements 2 are disposed at the lower end portion of the outer wall surface 3a, the two heat generating elements 2 are disposed immediately below the upper end portion of the outer wall surface 3a, that is, the heat radiating core portion 4, and the upper end portion of the outer wall surface 3a. Two heating elements 2 are disposed between the lower end portion and the lower end portion. Hereinafter, the two heating elements 2 arranged at the lower end portion of the outer wall surface 3 a are referred to as a lower heating element 21, and the two heating elements 2 arranged at the upper end portion of the outer wall surface 3 a, that is, immediately below the heat radiating core portion 4. Is referred to as the upper heating element 22, and the two heating elements 2 disposed between the lower heating element 21 and the upper heating element 22 are referred to as the middle heating element 23. The two lower heating elements 21, the two upper heating elements 22, and the two middle heating elements 23 are arranged in the horizontal direction.

  The heat radiating core portion 4 includes a plurality of tubes 41 that are assembled substantially upright on the outer wall surface 3 a of the refrigerant tank 3, and wavy heat radiating fins 42 that are joined to the outer surface of each tube 41. The tube 41 forms a refrigerant passage through which the refrigerant flows. Further, the tube 41 has both side surfaces, which are joint surfaces with the radiation fins 42, arranged along the flow direction of the cooling air blown to the radiation core portion 4. The cooling air corresponds to the external fluid of the present invention.

  By the way, in this embodiment, the flow direction of the refrigerant vapor in the refrigerant tank 3 (hereinafter referred to as the vapor flow direction X1) coincides with the longitudinal direction of the refrigerant tank 3. Further, the inflow direction of the refrigerant vapor into the tube 41, that is, the heat dissipation core portion 4 (hereinafter referred to as the vapor inflow direction X <b> 2) coincides with the arrangement direction of the refrigerant tank 3 and the heat dissipation core portion 4. The steam inflow direction X2 is orthogonal to the steam flow direction X1. Note that the stacking direction of the tubes 41 (hereinafter referred to as the tube stacking direction X3) is orthogonal to the steam flow direction X1 and the steam inflow direction X2.

  And the lower end part of the tube 41, ie, the lower end part of the thermal radiation core part 4, inclines at a predetermined angle in the steam inflow direction X2 with respect to the steam flow direction X1. For this reason, the tube 41 has a trapezoidal cross section.

  Moreover, the 1st fin press board part 43 which hold | suppresses the radiation fin 42 from the outer side in the tube lamination direction X1 is each arrange | positioned at the both ends in the tube lamination direction X3 of the thermal radiation core part 4. FIG. In addition, a second fin pressing plate portion 44 that presses the radiation fin 42 from the outside in the steam inflow direction X2 is disposed at the end of the heat radiation core portion 4 in the steam inflow direction X2.

  FIG. 2 is a cross-sectional view taken along the line AA of FIG. As shown in FIG. 2, the refrigerant tank 3 of the present embodiment is a flat box-like container in which a plurality of plates 30 are joined in a stacked state and a space in which liquid-phase refrigerant is stored is formed. It has become.

  Inside the refrigerant tank 3, peeling means 5 is provided for peeling bubbles generated by boiling of the refrigerant by receiving heat from the lower heating element 21 from the inner wall surface 3 b of the refrigerant tank 3. The peeling means 5 is disposed between the portion corresponding to the arrangement portion of the lower heating element 21 and the portion corresponding to the arrangement portion of the middle heating element 23 in the inner wall surface 3b of the refrigerant tank 3, and the arrangement of the middle heating element 23. It arrange | positions between the site | part corresponding to the site | part, and the site | part corresponding to the arrangement | positioning site | part of the upper stage heating element 22, respectively. The lower heating element 21 corresponds to the lower heating element of the present invention, and the upper heating element 22 and the middle heating element 23 correspond to the upper heating element.

  In the inner wall surface 3 b of the refrigerant tank 3, the peeling means 5 provided at the portion corresponding to the arrangement portion of the middle heating element 23 and the portion corresponding to the arrangement portion of the upper heating element 22 is the heat of the lower heating element 21. As a result, not only bubbles generated by boiling of the refrigerant but also bubbles generated by boiling of the refrigerant by receiving heat from the middle heating element 23 can be separated from the inner wall surface 3b of the refrigerant tank 3. .

  In the present embodiment, the peeling means 5 has a substantially L-shaped cross section viewed from the tube stacking direction X3. More specifically, the peeling means 5 extends from the inner wall surface 3b of the refrigerant tank 3 toward the inward side of the refrigerant tank 3 in a direction substantially parallel to the vapor inflow direction X2 and then bends and flows upward in the vapor flow direction. It extends substantially parallel to X1.

  Further, inside the refrigerant tank 3, volume reducing means 6 for reducing the volume in the refrigerant tank 3 is provided. The volume reducing means 6 is formed so as to protrude from the lower end surface of the refrigerant tank 3 toward the inner side of the refrigerant tank 3. In the present embodiment, the volume reducing means 6 gradually increases the thickness of the lower end surface of the refrigerant tank 3 as the distance from the inner wall surface 3b increases, that is, toward the central portion of the lower end surface in the steam inflow direction X2. It is constituted by.

  As described above, by providing the peeling means 5 inside the refrigerant tank 3, when the bubbles generated by receiving the heat of the lower heating element 21 move upward due to buoyancy, the peeling means 5 causes the refrigerant tank to The bubbles can be separated from the vicinity of the part corresponding to the arrangement part of the upper heating element 22 and the middle heating element 23 in the inner wall surface 3b of the three. That is, the peeling means 5 can inhibit the growth and aggregation of bubbles generated by receiving heat from the lower heating element 21. For this reason, since the liquid refrigerant remains in the part corresponding to the arrangement part of the upper stage heating element 22 and the middle stage heating element 23, between the upper stage heating element 2 and the liquid phase refrigerant and between the middle stage heating element 23 and the liquid. Good heat transfer can be performed with the phase refrigerant. At this time, since it is not necessary to change the thickness of the refrigerant tank 3, that is, the length of the steam inflow direction X2, the upper heating element 22 and the middle heating element 23 are not increased without increasing the amount of the refrigerant sealed in the boiling cooling device 1. It is possible to ensure the necessary cooling performance for the above.

  By the way, normally, since it becomes difficult for the boiling cooling device 1 to ensure the cooling performance toward the upper side of the refrigerant tank 3, the necessary cooling performance for the upper heating element 22 disposed on the upper side of the refrigerant tank 3 is ensured. Designed to be able to. Therefore, the refrigerant amount is excessive on the lower side of the refrigerant tank 3.

  On the other hand, the amount of refrigerant on the lower side of the refrigerant tank 3 is reduced by providing the volume reducing means 6 for reducing the volume in the refrigerant tank 3 on the lower side in the refrigerant tank 3 as in this embodiment. Can do. At this time, since the amount of the refrigerant on the upper side of the refrigerant tank 3 is not reduced, good heat transfer can be performed between the upper heating element 22 and the liquid phase refrigerant. Therefore, it is possible to ensure the necessary cooling performance for the upper heating element 22 while reducing the amount of refrigerant sealed in the boiling cooling device 1.

  In addition, by disposing the peeling means 5 between the part corresponding to the arrangement part of the lower heating element 21 and the part corresponding to the arrangement part of the middle heating element 23 in the inner wall surface 3 b of the refrigerant tank 3, the refrigerant Bubbles can be released over the entire region of the inner wall surface 3b of the tank 3 corresponding to the portion where the middle heating element 23 is disposed. For this reason, since better heat transfer can be performed between the middle-stage heating element 23 and the liquid-phase refrigerant, the cooling performance for the middle-stage heating element 23 can be improved.

  Similarly, by disposing the peeling means 5 between the part corresponding to the arrangement part of the middle heating element 23 and the part corresponding to the arrangement part of the upper heating element 22 in the inner wall surface 3b of the refrigerant tank 3, Bubbles can be separated over the entire region of the inner wall surface 3b of the refrigerant tank 3 corresponding to the portion where the upper heating element 22 is disposed. For this reason, since better heat transfer can be performed between the upper heating element 22 and the liquid refrigerant, it is possible to improve the cooling performance for the upper heating element 22.

  In addition, the volume reducing means 6 is configured by increasing the thickness of the lower end surface of the refrigerant tank 3 as the distance from the inner wall surface 3b increases, so that the lower heating element 21 is disposed on the inner wall surface 3b of the refrigerant tank 3. A sufficient amount of the liquid-phase refrigerant can be present in the vicinity of the portion corresponding to. Thereby, the cooling performance for the lower heating element 21 can be improved.

  Further, by inclining the lower end portion of the tube 41, that is, the lower end portion of the heat radiating core portion 4, in the steam inflow direction X2 with respect to the steam flow direction X1, the entire boiling cooling device 1 is in the steam inflow direction X2 with respect to the gravity direction. When it inclines, the refrigerant | coolant condensed in the heat radiating core part 4 can be suppressed, and a refrigerant | coolant can be recirculated from the heat radiating core part 4 to the refrigerant tank 3. FIG. For this reason, it is possible to ensure the heat dissipation performance even when tilting.

(Other embodiments)
In the above-described embodiment, the peeling means 5 is arranged on the lower heating element arrangement portion arranged on the lower side of the two heating elements 2 arranged in the vertical direction on the inner wall surface 3 b of the refrigerant tank 3. Although the example arrange | positioned between the corresponding site | part and the site | part corresponding to the arrangement | positioning site | part of the upper side heating element arrange | positioned above a lower side heating element was demonstrated, the arrangement | positioning location of the peeling means 5 is not limited to this. .

  For example, you may arrange | position the peeling means 5 in the site | part corresponding to the arrangement | positioning site | part of a lower side heat generating body among the inner wall surfaces 3b of the refrigerant | coolant tank 3. FIG. In this case, since the refrigerant bubbles boiled by receiving heat from the lower part of the lower heating element from the peeling means 5 can be peeled from the inner wall 3b of the refrigerant tank 3, the cooling performance for the upper heating element Can be improved.

  Further, the peeling means 5 may be disposed in a portion of the inner wall surface 3b of the refrigerant tank 3 corresponding to the portion where the upper heating element is disposed. In this case, the refrigerant bubbles boiled by the heat of the lower heating element, and the refrigerant bubbles boiled by receiving the heat of the lower part of the upper heating element from the peeling means 5 are converted into the inner wall of the refrigerant tank 3. It can be made to peel from 3b. For this reason, the cooling performance with respect to the site | part above the peeling means 5 among upper side heat generating bodies can be improved.

  In the above-described embodiment, the peeling means 5 is bent from the inner wall surface 3b of the refrigerant tank 3 toward the inner side of the refrigerant tank 3 in a direction substantially parallel to the vapor inflow direction X2, and then bent upward. Although the example formed in the cross-sectional substantially L shape extended substantially parallel to the flow direction X1 was demonstrated, the shape of the peeling means 5 is not limited to this. For example, the peeling means 5 may be formed so as to extend from the inner wall surface 3 b of the refrigerant tank 3 toward the inner side and the upper side of the refrigerant tank 3, and a part of the inner wall surface 3 b is formed inside the refrigerant tank 3. You may form by cutting up toward the side.

  Moreover, although the said embodiment demonstrated the example which provided both the peeling means 5 and the volume reduction means 6 in the refrigerant tank 3, it is not restricted to this, You may provide only the peeling means 5, or the volume reduction means 6 You may provide only.

  Moreover, in the said embodiment, although the volume reduction means 6 was comprised by thickening stepwise so that the plate | board thickness of the lower end surface of the refrigerant tank 3 may leave | separate from the inner wall surface 3b, the shape of the volume reduction means 6 is limited to this. Not. For example, the volume reducing means 6 may be configured by continuously increasing the thickness of the lower end surface of the refrigerant tank 3 as the distance from the inner wall surface 3 b increases. You may comprise by making it curve in a dome shape so that it may become convex toward an inward side.

  Moreover, although the said embodiment demonstrated the example which has arrange | positioned the thermal radiation core part 4 to the two outer wall surfaces 3a of the refrigerant tank 3 one each, it is not restricted to this, The thermal radiation core is set to one outer wall surface 3a of the refrigerant tank 3. One unit 4 may be arranged.

  In the above-described embodiment, the example in which the plurality of heating elements 2 are arranged in three stages in the vertical direction has been described. However, the present invention is not limited to this, and may be arranged in two stages in the vertical direction. These may be arranged side by side. Further, if at least two of the plurality of heating elements 2 are arranged side by side in the vertical direction, the remaining heating elements 2 may be arranged at arbitrary locations.

  In the above-described embodiment, the example in which the lower end portion of the tube 41 is inclined in the steam inflow direction X2 with respect to the steam flow direction X1 has been described. .

1 is a perspective view showing a boiling cooling device 1 according to an embodiment of the present invention. It is AA sectional drawing of FIG.

Explanation of symbols

2 Heating element 3 Refrigerant tank 3a Outer wall surface 3b Inner wall surface 4 Radiation core 5 Separation means 6 Volume reduction means

Claims (5)

A heat generating body (2) is attached to the outer wall surface (3a), and a refrigerant tank (3) for storing a refrigerant that boiled by receiving heat from the heat generating body (2);
A boiling cooling device comprising: a heat radiating core (4) configured to condense the refrigerant vapor by flowing heat between the refrigerant vapor and an external fluid by flowing the refrigerant vapor boiled in the refrigerant tank (3). ,
In the inside of the refrigerant tank (3), the refrigerant is boiled by receiving the heat of the lower heating element arranged on the lower side of the two heating elements (2) arranged in the vertical direction. A boiling cooling device characterized in that a peeling means (5) for peeling off the generated bubbles from the inner wall surface (3b) of the refrigerant tank (3) is provided. A heat generating body (2) is attached to the outer wall surface (3a), and a refrigerant tank (3) for storing a refrigerant that boiled by receiving heat from the heat generating body (2);
A boiling cooling device comprising: a heat radiating core (4) configured to condense the refrigerant vapor by flowing heat between the refrigerant vapor and an external fluid by flowing the refrigerant vapor boiled in the refrigerant tank (3). ,
On the lower side in the refrigerant tank (3), a volume cooling means (6) for reducing the volume in the refrigerant tank (3) is provided.   2. The boiling cooling device according to claim 1, wherein a volume reducing means (6) for reducing the volume in the refrigerant tank (3) is provided on the lower side in the refrigerant tank (3). .   The peeling means (5) is an upper heating element disposed above the lower heating element in the two heating elements (2) in the inner wall surface (3b) of the refrigerant tank (3). The boiling cooling device according to claim 1 or 3, wherein the boiling cooling device is disposed between a portion corresponding to the arrangement portion and a portion corresponding to the arrangement portion of the lower heating element.   The said volume reduction means (6) is comprised by making the plate | board thickness of the lower end surface of the said refrigerant | coolant tank (3) thick, so that it leaves | separates from the said inner wall surface (3b), It is characterized by the above-mentioned. The boiling cooling apparatus according to 1.

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