JP2001028415A - Boiling and cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a boiling and cooling device into a constitution, where the device has ribs for increasing the heat dissipation area of a refrigerant tank, and to contrive the improvement of the burn-out resitance of the device. SOLUTION: A hollow member, which is used for a refrigerant tank 3, is an extrusion molded item, the tank 3 is provided into a thin form having a thin thickness with respect to its width, and a refrigerant chamber 8, a liquid return passage and a heat-insulating passage are provided in the interior of the tank 3. The chamber 8 is a constitution, where a liquid refrigerant which is stagnated in the interior of the chamber 8 receives the heat of a heating element 2 to form a boiling region, and is sectioned into a plurality of passage-shaped space parts 8A by ribs 13. Provided that the ribs 13 protrude from the inner wall surface 8a on one side of the inner wall surfaces 8a and 8b opposing to the thickness direction of the chamber 8 toward the other inner wall surface 8b and provided extended along the direction of the flow of a refrigerant vapor to flow out from the chamber 8 and there is some gap 8c between the protruded point surfaces of the ribs 13 and the other inner wall surface 8b. Accordingly, the fellow space parts 8A, which are formed to the left and right of both sides of the ribs 13, are communicated with each other through the gap 8c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiling cooling apparatus for transporting heat by repeatedly boiling and condensing a refrigerant.

[0002]

2. Description of the Related Art As a prior art, for example, Japanese Unexamined Patent Publication No.
A boiling cooling device disclosed in Japanese Patent No. 7818 is known. This boiling cooling device has a refrigerant tank constituted by using an extruded material, and an IGB as a heating element is provided on the surface of the refrigerant tank.
A T module is installed. Further, as shown in FIG. 15A, the inside of the refrigerant tank is divided into a plurality of passages by ribs 110 provided on the extruded material 100, and the provision of the ribs 110 increases the rigidity of the refrigerant tank. And the heat radiation area can be increased.

[0003]

However, in the IGBT module attached to the refrigerant tank, the entire heat radiation surface in contact with the surface of the refrigerant tank does not have a uniform heat radiation temperature. (Left-right direction). Therefore, as described above, the inside of the refrigerant tank is
When divided into a plurality of passages by 10, the amount of foaming in each passage differs, and as shown in FIG. 15B, a passage 120 with many bubbles and a passage 130 with few bubbles are generated. As a result, there is a problem that burnout occurs in the passage 120 with many bubbles, and the heat radiation performance is greatly reduced. This problem often occurs when the amount of heat released from the heating element increases, particularly when the thickness of the coolant tank is reduced to reduce the amount of expensive coolant (see FIG. 15A). . The present invention has been made based on the above circumstances, and an object of the present invention is to provide a boiling cooling device capable of improving burnout resistance with a configuration having a rib for increasing a heat radiation area of a refrigerant tank. is there.

[0004]

According to a first aspect of the present invention, a refrigerant tank is provided in a flat shape in which a thickness of a refrigerant chamber is small, and at least one of both inner wall surfaces opposed to each other in a thickness direction of the refrigerant chamber. A column protruding from the inner wall surface toward the other inner wall surface and extending along the flow direction of the refrigerant vapor flowing out of the refrigerant chamber, and a gap formed between the inner wall surface and the column portion is formed. And the passage-shaped space portions formed on both left and right sides of the pillar portion communicate with each other through a gap. According to this configuration, even when the amount of foaming in the two space portions formed on the left and right sides of the pillar portion is different due to the temperature distribution on the heat radiation surface of the heating element that is in contact with the surface of the coolant tank, the two space portions are not separated from each other. Are communicated through the gap, so that the air bubbles generated in both space portions can be diffused in the left-right direction of the refrigerant chamber. As a result, the distribution of air bubbles in the refrigerant chamber is made uniform, so that the burnout resistance can be improved.

[0005] (Means of Claim 2) The pillar portion protrudes from one inner wall surface toward the other inner wall surface, and forms a gap with the other inner wall surface. In this case, since the rigidity of the refrigerant tank wall surface on one inner wall surface side having the column portion can be increased, by attaching a heating element to the refrigerant tank surface on the one inner wall surface side, the refrigerant tank surface and the heating element Can be reduced, and the heat radiation area on one inner wall side can be increased, so that the heat radiation performance can be improved.

According to a third aspect of the present invention, the pillar has one pillar projecting from one inner wall surface toward the other inner wall surface and the other pillar projecting from the other inner wall surface toward the one inner wall surface. And a gap is formed between one pillar and the other pillar. In this case, since the column portions are provided on both the one inner wall surface and the other inner wall surface, the rigidity of both side wall surfaces of the refrigerant tank can be increased. Thereby, even when the heating elements are attached to both surfaces of the refrigerant tank, the contact thermal resistance between the surface of the refrigerant tank and the heating element can be reduced.

[0007] (Means of Claim 4) The refrigerant tank has a partition part which connects one inner wall surface and the other inner wall surface and divides the refrigerant chamber into a plurality of passages. According to this configuration, even when sufficient rigidity cannot be obtained only by the pillar portion, the provision of the partition portion can increase the pressure resistance of the refrigerant tank and increase the heat radiation area of the refrigerant tank.

[0008] (Claim 5) The refrigerant tank is formed by using an extruded material in which a pillar is integrally formed in the refrigerant chamber by extrusion molding. In this case, by using extruded material,
A column or a partition can be easily formed.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a side view of a boiling cooling device 1.
The boiling cooling device 1 of the present embodiment cools the heating element 2 by repeatedly boiling and condensing the refrigerant, and includes a refrigerant tank 3 for storing a liquid refrigerant therein, and a radiator mounted on the upper part of the refrigerant tank 3. , And manufactured by integral brazing. The heating element 2 is, for example, an IGBT module that forms an inverter circuit of an electric vehicle, and is fixed to the surface of the refrigerant tank 3 with bolts 5 or the like as shown in FIG.

The coolant tank 3 is constituted by combining a hollow member 6 and an end plate 7. The hollow member 6 is an extruded product made of a metal material having excellent thermal conductivity such as aluminum, and is provided in a thin shape having a small thickness with respect to the width as shown in FIG. 8, a liquid return passage 9 and a heat insulating passage 10. As shown in FIG. 3B, the upper end of the hollow member 6 has a height difference between left and right ends including the liquid return passage 9 and the heat insulating passage 10 and a center portion including the refrigerant chamber 8. The central portion is provided so as to protrude upward, and the upper end surface of the central portion is inclined as shown in FIG. In the following description, the upper end opening of the refrigerant chamber 8 opening at the upper end surface of the hollow member 6 is called a vapor outlet 11, and the upper end opening of the liquid return passage 9 opening at the upper end surface of the hollow member 6 is referred to as a liquid outlet. Called inlet 12.

The refrigerant chamber 8 forms an area in which the liquid refrigerant stored therein receives heat from the heating element 2 and boils.
As shown in FIG. 2B, a plurality of passage-like space portions 8 are provided at two places in the center of the hollow member 6 and each is provided by a rib 13.
A. However, the rib 13 projects from one inner wall surface 8a facing the thickness direction of the refrigerant chamber 8 (the vertical direction in FIG. 3A) toward the other inner wall surface 8b, and the refrigerant vapor flowing out of the refrigerant chamber 8 And has a slight gap 8c (see FIG. 4) between the protruding tip surface of the rib 13 and the other inner wall surface 8b. Therefore, the passage-like space portions 8A formed on the left and right sides of the rib 13
The units communicate with each other through the gap 8c. In addition,
The heating element 2 is attached to the surface of the coolant tank on one inner wall surface 8a side having the rib 13.

The liquid return passage 9 is a passage through which the condensed liquid cooled and liquefied by the radiator 4 flows, and is provided at both ends of the hollow member 6. The heat insulation passage 10 is a passage for insulating the space between the refrigerant chamber 8 and the liquid return passage 9, and is provided adjacent to the inside of the liquid return passage 9 (center side).

The end plate 7 is made of, for example, the same aluminum as the hollow member 6, is elongated in the left-right direction, and is provided with an inner portion 7b slightly projecting from the outer peripheral edge 7a, as shown in FIG. As shown in FIG. 6, the end plate 7 has an inner portion 7b protruding fitted into the lower end opening of the hollow member 6, and an outer peripheral edge 7a is attached to the hollow member 6 as shown in FIG.
The lower end opening of the hollow member 6 is closed by contacting the outer peripheral lower end surface of the hollow member 6. At the lower end of the hollow member 6 closed by the end plate 7, a communication passage 14 for supplying the condensate flowing into the liquid return passage 9 to the refrigerant chamber 8 is formed (see FIG. 6). Passage 9 and refrigerant chamber 8 and heat insulation passage 1
0 communicates with each other.

The radiator 4 includes a plurality of tubes 16 arranged side by side through radiating fins 15, an upper tank 17 provided above each tube 16, and a lower tank 18 provided below each tube 16. And a refrigerant flow control plate 19 is installed inside the lower tank 18. The radiation fins 15 are formed by alternately bending thin metal plates having excellent thermal conductivity (for example, a thin aluminum plate) to form a wave shape, and are joined to the surface of the tube 16. The tubes 16 form a refrigerant passage through which the refrigerant flows. For example, a flat tube made of aluminum is cut into a predetermined length, and a plurality of tubes 16 are arranged in parallel between the upper tank 17 and the lower tank 18. ing.

The inner fin 20 is inserted into the tube 16 as shown in FIG. The inner fin 20 is formed by alternately bending a thin metal plate (for example, an aluminum plate) having excellent heat conductivity at a predetermined pitch P (see FIG. 7A) to form a wavy shape. It is used for the purpose of increasing and increasing the refrigerant circulation path (described later) in the tube 16. The inner fin 20 is inserted into the tube 16 with the extending direction of the bent portion (peaks and valleys) oriented in the direction of passage of the tube 16 (vertical direction in FIG. 7B), and in the width direction of the tube 16 ( In the left-right direction in FIG. 7), each bent portion abuts against the inner wall surface of the tube 16,
Be brazed.

Accordingly, in the tube 16, a plurality of first passages (hereinafter referred to as steam passages 21) secured on the left side of the inner fins 20 in FIG. 2 (hereinafter, referred to as a condensate passage 22), and the vapor passage 21 and the condensate passage 22 constitute the above-described refrigerant circulation passage. In addition,
The tubes 16 are arranged along the flow direction of the cooling air blown to the radiator 4 on both side surfaces which are the joining surfaces with the radiating fins 15.
The direction of the tube 16 is specified such that 1 is located on the downstream side in the flow direction of the cooling air (see FIG. 1).

The upper tank 17 is constructed by combining a shallow dish-shaped core plate 17A and a deep dish-shaped tank plate 17B. Tubes 16 are respectively provided in a plurality of long holes (not shown) opened in the core plate 17A. Is inserted into the upper end of each tube to communicate with each tube 16. The lower tank 18 is configured by combining a shallow dish-shaped core plate 18A and a deep dish-shaped tank plate 18B (see FIG. 8), and is provided in a plurality of long holes (not shown) opened in the core plate 18A. The lower end of the tube 16 is inserted and communicates with each tube 16. In the lower tank 18, the upper end of the refrigerant tank 3 (hollow member 6) is inserted into an opening 23 formed in the tank plate 18B (see FIG. 1), and the refrigerant tank 3 communicates with each tube 16. are doing.

The tank plate 18B is shown in FIG.
As shown in (c), the side surface viewed from the longitudinal direction has an inclined surface 18a having a large inclination angle with respect to the lowest bottom surface (the surface facing the upper end opening on which the core plate 18A is covered). The opening 23 is open on the inclined surface 18a. Therefore, as shown in FIG. 1, the refrigerant tank 3 is attached to the lower tank 18 with a large inclination. However, the coolant tank 3 is inserted into the opening 23 with the mounting surface of the heating element 2 facing downward so that the vapor outlet 11 faces obliquely upward in the lower tank 18 (that is, the heating element 2 is Attached to the lower surface of the tank 3). As a result, in the lower tank 18, the lowermost part of the vapor outlet 11 is located above the lowermost part of the liquid inlet 12, and the vapor outlet 11 is generally higher than the liquid inlet 12. (See FIG. 2).

The refrigerant flow control plate 19 guides the refrigerant vapor flowing out of the vapor outlet 11 so as to flow preferentially into the vapor passage 21 in the tube 16, and the condensed liquid liquefied in the tube 16 flows through the vapor outlet 11. It is installed to prevent falling. This refrigerant flow control plate 19 is provided in FIG.
As shown in FIG. 7, the hollow member 6 inserted into the lower tank 18 is attached to the upper end surface of the hollow member 6 with screws 24 or the like, and is disposed below the condensate passage 22 formed in the tube 16. However, it is desirable that the refrigerant flow control plate 19 is attached in a state of being gently inclined such that the front end side is slightly higher than the attachment portion side in the front-rear direction shown in FIG. 1 when attached to the hollow member 6. This refrigerant flow control plate 19
FIG. 9 shows the shape of.

Next, the operation of this embodiment will be described. The liquid refrigerant stored in the refrigerant chamber 8 boils due to the heat of the heating element 2, turns into refrigerant vapor, and flows from the vapor outlet 11 to the lower tank 1.
8 flows out. As shown in FIG. 10, the refrigerant vapor flowing out of the vapor outlet 11 flows in the arrow direction along the refrigerant flow control plate 19, and mainly flows into the vapor passage 21 in the tube 16. The refrigerant vapor flowing up the vapor passage 21 and flowing into the upper tank 17 mainly flows into the condensed liquid passage 22 and condenses and liquefies on the surface of the inner fin 20 and the inner wall surface of the tube 16.

Most of the condensed liquid liquefied in the condensed liquid passage 22 falls into the lower tank 18, but a part of the condensed liquid is held below the inner fin 20 by surface tension to form a liquid pool 25. (See FIG. 10). When the amount of heat dissipation increases, the liquid reservoir 25 is such that the liquid refrigerant that is blown up together with the refrigerant vapor from the vapor outlet 11 and rises hits the lower surface of the inner fin 20 and is caught in the lower portion of the inner fin 20 by surface tension. But it is formed. The condensed liquid accumulated in the liquid pool 25 of the inner fin 20 also falls sequentially from the liquid pool 25 into the lower tank 18 due to the pressure of the refrigerant vapor rising in the vapor passage 21. The condensed liquid accumulated at the bottom of the lower tank 18 flows into the liquid inlet 12 when the liquid level exceeds the height of the lowermost part of the liquid inlet 12, passes through the communication passage 14 from the liquid return passage 9, and passes through the refrigerant chamber. 8 can be refluxed.

(Effects of the First Embodiment) In the boiling cooling device 1 of the present embodiment, the refrigerant chamber 8 is divided into a plurality of passage-like spaces 8A by the ribs 13, so that it contacts the surface of the refrigerant tank 3. The amount of foaming in each passage-like space 8A differs depending on the temperature distribution on the heat radiation surface of the heating element 2. On the other hand, since the gap 8c is provided at the end of the rib 13, the passage-shaped space portions 8A formed on both right and left sides of the rib 13 communicate with each other through the gap 8c. As a result, as shown in FIG. 11 ((a) horizontal cross-sectional view and (b) vertical cross-sectional view of the refrigerant tank 3), bubbles generated in each passage-shaped space portion 8A diffuse in the left-right direction of the refrigerant chamber 8. Since the distribution of the amount of bubbles in the refrigerant chamber 8 is made uniform, burnout in the passage-like space 8A having a large amount of foaming can be prevented. As a result, the burnout resistance of the boiling cooling device 1 can be improved.

Further, by providing the ribs 13 in the refrigerant chamber 8, the heat radiation area of the refrigerant tank 3 can be increased, and the rigidity of the wall of the refrigerant tank on the side of the one inner wall surface 8a having the ribs 13 can be increased. As a result, compared with the case where the ribs 13 are not provided in the refrigerant chamber 8, the heat radiation performance can be improved with an increase in the heat radiation area, and the heating element 2 is placed on the surface of the refrigerant tank on one inner wall surface 8 a side of the refrigerant chamber 8. By attaching, the contact thermal resistance between the surface of the coolant tank and the heat radiating surface of the heating element 2 can be reduced, so that the heat radiating performance can be improved.

(Second Embodiment) FIG. 12 is a sectional view of a refrigerant tank 3. As shown in FIG. 12A, the refrigerant tank 3 of the present embodiment is configured such that one inner wall surface 8a of the refrigerant chamber 8 is connected to the other inner wall surface 8a.
b, and one rib 13B protruding from the other inner wall surface 8b toward the one inner wall surface 8a.
3B are provided facing each other, and as shown in FIG. 12B, a gap 8c is formed between one rib 13A and the other rib 13B.

According to this configuration, each of the passage-like space portions 8A defined by the one rib 13A and the other rib 13B.
Communicate with each other through the gap 8c, as in the first embodiment, even when the amount of foaming in each of the passage-shaped spaces 8A is different, the air bubbles generated in each of the passage-shaped spaces 8A are generated in the left-right direction of the refrigerant chamber 8. And the distribution of air bubbles in the refrigerant chamber 8 is made uniform, so that burnout in the passage-like space 8A having a large amount of foaming can be prevented. As a result, the burnout resistance of the boiling cooling device 1 can be improved. In the configuration of the present embodiment, the ribs 13 are provided on both inner wall surfaces 8a and 8b of the refrigerant chamber 8, respectively.
Since A and 13B are provided, the rigidity of both wall surfaces of the refrigerant tank 3 can be increased. In this case, even if the heating elements 2 are attached to both surfaces of the coolant tank 3, the contact thermal resistance between the coolant tank surface and the heat radiation surface of the heating element 2 can be reduced.

(Third Embodiment) FIG. 13 is a sectional view of the refrigerant tank 3. As shown in FIG. 13A, the refrigerant tank 3 of the present embodiment is configured such that one inner wall surface 8a of the refrigerant chamber 8 is connected to the other inner wall surface 8a.
b, and a second rib 26 connecting one inner wall surface 8a and the other inner wall surface 8b. The first rib 13 is provided with a gap 8c between the first rib 13 and the other inner wall surface 8b as in the first embodiment. Therefore, the passage-like space portions 8A formed on the left and right sides of the first rib 13 communicate with each other through the gap 8c.
The second ribs 26 are alternately arranged, for example, with the first ribs 13 to completely separate the left and right passage-like spaces 8A from each other on the left and right sides of the second rib 26.

According to this configuration, since the passage-like spaces 8A formed on the left and right sides of the first rib 13 communicate with each other through the gap 8c, bubbles can be diffused between the passage-like spaces 8A. Accordingly, burnout resistance can be improved. Further, compared with the case where only the first rib 13 is provided, the provision of the second rib 26 has an effect that the pressure resistance of the refrigerant tank 3 can be improved and the heat radiation area can be increased. In FIG. 13A, the first ribs 13 and the second ribs 26 are alternately arranged. However, as shown in FIG. 13B, the number of the second ribs 26 is reduced. Is also good. Further, the second rib 26 can be applied to the configuration of the refrigerant tank 3 having one rib 13A and the other rib 13B shown in the second embodiment.

(Fourth Embodiment) FIG. 14 is a sectional view of the refrigerant tank 3. This embodiment is an example in which the first rib 13 shown in the third embodiment has a mountain shape as shown in FIG. In this case, there is an effect that bubbles generated in the passage-like space portions 8A formed on the left and right sides of the first rib 13 are easily diffused to another adjacent passage-like space portion 8A via the first rib 13. . Note that the rib shape of the present embodiment can be applied to the configuration of the first embodiment (the configuration without the second rib 26).

[Brief description of the drawings]

FIG. 1 is a side view of a boiling cooling device (first embodiment).

FIG. 2 is a front view of a boiling cooling device (first embodiment).

FIG. 3 is a top view (a), a front view (b), and a side view (c) of a hollow member.

FIG. 4 is a sectional view of a main part of the hollow member.

FIG. 5 is a side view (a), a plan view (b), and a cross-sectional view (c) of an end plate.

FIG. 6 is a sectional view showing a mounted state of an end plate.

FIGS. 7A and 7B are a top view and a front view of a tube into which an inner fin is inserted. FIGS.

FIG. 8 is a front view (a), a side view (b), and a bottom view (c) of the lower tank.

FIG. 9 is a front view (a) and a side view (b) of the refrigerant flow control plate.

FIG. 10 is a cross-sectional view of a radiator showing a flow of a refrigerant vapor.

FIG. 11 is a cross-sectional view of a refrigerant tank showing a diffusion state of bubbles.

FIG. 12 is a sectional view of a refrigerant tank (second embodiment).

FIG. 13 is a sectional view of a refrigerant tank (third embodiment).

FIG. 14 is a sectional view of a refrigerant tank (fourth embodiment).

FIG. 15 is a cross-sectional view of a refrigerant tank showing a foaming state of bubbles (explanation of a conventional technique).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiling cooling device 2 Heating element 3 Refrigerant tank 4 Radiator 6 Hollow member (extruded material) 8 Refrigerant room 8A Passage-like space (passage-like space) 8a One inner wall surface 8b The other inner wall surface 8c Gap 13 rib / First rib (column) 13A One rib (one column) 13B The other rib (the other column) 26 Second rib (partition)

Claims (5)

[Claims] 1. A refrigerant tank having a heating element mounted on a surface thereof and forming a refrigerant chamber for storing a liquid refrigerant therein, and a refrigerant vapor boiled by receiving heat of the heating element in the refrigerant chamber flows into the refrigerant chamber. A radiator that releases heat of vapor to an external fluid, wherein the refrigerant tank is provided in a flat shape with a thinner width of the refrigerant chamber, and is opposed to a thickness direction of the refrigerant chamber. A column protruding from at least one of the inner wall surfaces toward the other inner wall surface, and extending along the flow direction of the refrigerant vapor flowing out of the refrigerant chamber, between the inner wall surfaces. A boiling cooling device having a gap formed between the column and the column, wherein passage-shaped spaces formed on both left and right sides of the column communicate with each other through the gap. 2. The apparatus according to claim 1, wherein said pillar portion protrudes from said one inner wall surface toward the other inner wall surface, and forms said gap with said other inner wall surface. Boiling cooling device as described. 3. The pillar portion protrudes from the one inner wall surface to the other inner wall surface, and the other pillar portion protrudes from the other inner wall surface to the one inner wall surface. The boiling cooling device according to claim 1, wherein the gap is formed between the one pillar portion and the other pillar portion. 4. The refrigerant tank according to claim 1, further comprising a partition connecting the one inner wall surface and the other inner wall surface to divide the refrigerant chamber into a plurality of passages. The boiling cooling device described in any one of 1 to 3. 5. The cooling apparatus according to claim 1, wherein said refrigerant tank is formed by using an extruded material in which said pillar portion is integrally formed in said refrigerant chamber by extrusion molding. apparatus.