JP2001028416A - 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 realize the enhancement of the burn-out resistance 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 small thickness with respect to its width and a refrigerant 8 is provided in the interior of the tank 3. A plurality of ribs 13 are provided in the chamber 8 for aiming at increase in the heat dissipation area of the tank 3. These ribs 3 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, are provided extendedly along the direction of the flow of a refrigerant vapor to flow out from the chamber 8 and moreover, are provided in a trapezoid-shaped section having a width W in the left and right directions, which gradually becomes narrow from the side of the inner wall surface 8a on one side toward the side of the other inner wall surface 8b. Provided that, there is a gap 8c between the protruded point surfaces 13a of the ribs 13 and the other inner wall surface 8b and fellow passage-shaped space parts 8A, which are formed to the left and right on both sides of the ribs 13, are communicated to each other through the above gap 8c in the chamber 8.

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. As shown in FIG. 13, this boiling cooling device has a refrigerant tank 100 configured by using an extruded material, and an IGBT module as a heating element 110 is attached to the surface of the refrigerant tank 100. Further, the inside of the refrigerant tank 100 is divided into a plurality of passage-like space portions 130 by ribs 120 provided on the extruded material. By providing the ribs 120, the rigidity of the refrigerant tank 100 can be increased, and the heat radiation area can be increased. Can be increased.

[0003]

However, when the heating element 110 is mounted on only one surface (one surface) of the refrigerant tank 100, as shown in the graph of FIG. 14, the ribs 120 move away from the mounting surface of the heating element. Temperature drops,
In the non-boiling region, the degree of boiling superheat is reduced, so that it is not an effective boiling region. As a result, in the non-boiling region of the rib 120, the effect of increasing the heat radiation area by the rib 120 is not obtained, and the presence of the rib 120 hinders the boiling flow (flow of bubbles) rising in the refrigerant tank 100. Could cause burnout. 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]

Means for Solving the Problems The refrigerant tank is arranged so that at least one of the two inner wall surfaces facing the thickness direction of the refrigerant chamber, which has a large amount of heat radiation, is directed to the other inner wall surface. And has a column extending along the flow direction of the refrigerant vapor flowing out of the refrigerant chamber, and the column has a width in the left-right direction that gradually decreases from one inner wall to the other inner wall. It is provided so that it becomes. According to this configuration, the heat radiation area can be increased by providing the pillar portion on one inner wall surface side having a large heat radiation amount, and the width of the pillar portion can be reduced on the other inner wall surface side having a small heat radiation amount so that the refrigerant vapor ( Bubbles)
The passage cross-sectional area in which the height increases can be secured large. As a result,
In the non-boiling region of the column, the flow of the refrigerant vapor rising in the refrigerant chamber is less likely to be hindered by the column, and the circulation of the refrigerant can be improved.

[0005] (Means of Claim 2) The pillar portion is provided with a gap between the front end surface in the protruding direction and the other inner wall surface. Under some conditions, the temperature at the tip of the pillar cannot be raised to a sufficient temperature for boiling. In such a case, by providing a gap between the tip surface of the pillar portion and the other inner wall surface,
In addition to ensuring a large passage cross-sectional area where the refrigerant vapor (bubbles) rise, the passage-shaped space formed on the left and right sides of the column can communicate with each other through the gap, so that the refrigerant vapor is diffused in the left-right direction, and the refrigerant chamber is diffused. This has the effect of making the air volume distribution uniform in the process.

According to a third aspect of the present invention, the pillar has a tip in a protruding direction connected to the other inner wall surface. In this case, the column portion connecting one inner wall surface and the other inner wall surface functions as a reinforcing material, so that the pressure resistance of the refrigerant tank can be improved.

The refrigerant tank has a partition portion connecting one inner wall surface and the other inner wall surface with a constant width, and the partition portion forms a plurality of passage-like space portions in the refrigerant chamber. And a pillar portion is provided in the passage-like space portion.
According to this configuration, by providing the partition portion, the pressure resistance of the refrigerant tank can be increased, and the heat radiation area of the refrigerant tank can be further increased.

[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 (b), two hollow members 6 are arranged in parallel at the center. The refrigerant chamber 8 is provided with a plurality of ribs 13 for the purpose of increasing the heat radiation area and increasing the rigidity of the surface of the refrigerant tank to which the heating element 2 is attached. As shown in FIG. 4, the rib 13 projects from one inner wall surface 8a facing the thickness direction of the refrigerant chamber 8 (vertical direction in FIG. 4) toward the other inner wall surface 8b, and flows out of the refrigerant chamber 8. It is provided in a trapezoidal cross-section in which the width w in the left-right direction gradually decreases from one inner wall surface 8a side to the other inner wall surface 8b side. However, there is a gap 8c between the protruding front end surface 13a of the rib 13 and the other inner wall surface 8b, and the passage-like space portions 8A formed on the left and right sides of the rib 13 in the refrigerant chamber 8 are connected to the gap 8c. Through. The heating element 2 is attached to the surface of the coolant tank on the side of the one inner wall surface 8a 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. A part of the refrigerant vapor flowing up the vapor passage 21 and flowing into the upper tank 17 is mainly condensed and liquefied on the inner wall surface of the upper tank 17, and the remaining refrigerant vapor is also condensed in the condensate liquid passage 22 by the inner fin 20. It condenses on the surface and the inner wall surface of the tube 16 and liquefies.

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.

(Effect of First Embodiment) In the boiling cooling device 1 of the present embodiment, the rib 13 provided in the refrigerant chamber 8 has a trapezoidal cross section, and the heat radiation amount from one of the inner wall surfaces 8a having a large heat radiation amount. The width w of the rib 13 is formed so as to gradually decrease toward the other inner wall surface 8b. Thereby, the rib 13 on the other inner wall surface 8b side where the heat radiation amount is small.
Has a small width w, and has a gap 8 between itself and the other inner wall surface 8b.
c, refrigerant vapor (bubbles) in the refrigerant chamber 8
The passage cross-sectional area in which the height increases can be secured large. As a result,
On the other inner wall surface 8b side where the heat release amount is small, the flow of the refrigerant vapor rising in the refrigerant chamber 8 is hardly obstructed by the ribs 13 and the circulation of the refrigerant can be improved.
Burnout can be prevented.

Further, since there is a gap 8c between the protruding front end surface 13a of the rib 13 and the other inner wall surface 8b, air bubbles generated in each passage-like space 8A formed on the left and right sides of the rib 13 are formed. Can be diffused in the left-right direction of the refrigerant chamber 8 through the gap 8c. As a result, the distribution of air bubbles in the refrigerant chamber 8 is made uniform, so that the burnout resistance of the refrigerant tank 3 can be improved. Further, on one inner wall surface 8a having a large heat radiation amount, the heat radiation area can be increased by providing the ribs 13,
The rigidity of the wall surface of the coolant tank to which the heating element 2 is attached 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 gap between the surface of the refrigerant tank to which the heating element 2 is attached and the heat radiation surface of the heating element 2 can be improved. Can also reduce the contact thermal resistance, so that the heat radiation performance can be improved.

(Second Embodiment) FIG. 11 is a sectional view of the refrigerant tank 3. This embodiment shows an example in which the protruding tip of the rib 13 provided in the refrigerant chamber 8 is connected to the other inner wall surface 8b.
As shown in FIG. 11, the rib 13 is provided in a trapezoidal cross section in which the width w decreases from one inner wall surface 8a of the refrigerant chamber 8 to the other inner wall surface 8b, and the protruding tip has the other inner wall surface 8b. It is connected to. Also in this configuration, since the cross-sectional area of the passage where the refrigerant vapor (bubbles) rises on the other inner wall surface 8b side where the heat release amount is small can be increased, the flow of the refrigerant vapor rising in the refrigerant chamber 8 is the same as in the first embodiment. There is little hindrance by the ribs 13 and the circulation of the refrigerant can be improved. Further, since the rib 13 connecting the one inner wall surface 8a and the other inner wall surface 8b also functions as a reinforcing material, there is an effect that the pressure resistance of the refrigerant tank 3 can be improved.

(Third Embodiment) FIG. 12 is a sectional view of the refrigerant tank 3. As shown in FIG. 12, the refrigerant tank 3 of the present embodiment
It has a first rib 13 protruding from one inner wall surface 8a of the refrigerant chamber 8 toward the other inner wall surface 8b, and a second rib 26 connecting the one inner wall surface 8a and the other inner wall surface 8b. are doing. As in the first embodiment, the first rib 13 is formed such that the width w in the left-right direction is gradually reduced from one inner wall surface 8a side to the other inner wall surface 8b side, and is formed with the other inner wall surface 8b. It is provided with a gap 8c between them.

The second rib 26 has a constant width in the left-right direction and is provided together with the first rib 13 by extrusion. According to this configuration, the cross-sectional area of the passage on the side of the other inner wall surface 8b having a small heat radiation amount can be increased by the first rib 13, and the pressure resistance of the refrigerant tank 3 can be improved by providing 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 sectional view of a refrigerant tank (second embodiment).

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

FIG. 13 is a cross-sectional view of a refrigerant tank (a description of a conventional technique).

FIG. 14 is a graph showing a temperature gradient of a rib (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 chamber 8A Passive space 8a One inner wall surface 8b The other inner wall surface 8c Gap 13 Rib / first rib (column portion) 13a) Projecting tip surface of rib (tip surface in the projecting direction of pillar portion) 26 Second rib (partition portion)

Claims (5)

[Claims] 1. A refrigerant chamber having a heating element mounted on a surface thereof, a refrigerant chamber for storing a liquid refrigerant therein, and a refrigerant tank provided in a flat shape having a thinner width of the refrigerant chamber; A radiator that receives the heat of the heat-generating body and flows in the refrigerant vapor that has boiled, and that releases the heat of the refrigerant vapor to an external fluid. Of the two opposing inner wall surfaces, at least a column projecting from one of the inner wall surfaces having a large amount of heat radiation toward the other inner wall surface, and extending along the flow direction of the refrigerant vapor flowing out of the refrigerant chamber, The boiling cooling device is characterized in that the column portion is provided so that the width in the left-right direction gradually decreases from the one inner wall surface side to the other inner wall surface side. 2. The boiling cooling device according to claim 1, wherein the pillar portion is provided with a gap between a tip end surface in a protruding direction and the other inner wall surface. 3. The boiling cooling device according to claim 1, wherein the pillar has a tip in a protruding direction connected to the other inner wall surface. 4. The refrigerant tank has a partition portion connecting the one inner wall surface and the other inner wall surface at a fixed width, and the partition divides the refrigerant chamber into a plurality of passage-like space portions. The boiling cooling device according to claim 2, wherein the pillar portion is provided in the passage-shaped space portion. 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.