JP2000266482A - Boiling and cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the performance for circulating refrigerant of a boiling and cooling device by preventing the interference between a condensed liquid and refrigerant vapor in the refrigerant chamber of the device. SOLUTION: A refrigerant flow control plate 18 covers the topside of a vapor outlet port 21 in the transverse direction in a lower tank 17. In addition, the plate 18 is the highest at the central part in the transverse direction and is gradually downwardly inclined toward both sides. In the longitudinal direction, however, the central part is the lowest and the plate 18 is gradually upwardly inclined toward both sides. Consequently, a condensed liquid flowing passage 23 which is downwardly inclined toward both sides in the transverse direction is formed in the central part in the longitudinal direction on the upper surface of the plate 18. The condensed liquid dropping onto the upper surface of the plate 18 from heat radiating tubes 19 flow to both sides in the transverse direction along the passage 23 of the plate 18 and can flow in a liquid returning passage 9 through a liquid inlet port 22 made through the lower tank 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiling cooling device for cooling a heating element by repeating evaporation and condensation of a refrigerant.

[0002]

2. Description of the Related Art As a prior art, Japanese Patent Laid-Open Publication No.
The cooler described in Japanese Patent Publication No. 5 is known. This cooler uses the principle of a thermosiphon, and has, as shown in FIG. 11, an evaporator 100 for storing a liquid refrigerant and a condenser 110 provided above the evaporator 100. Refrigerant vapor boiled by receiving heat from the heating element in the section 100 flows into the condensing section 110, is cooled by heat exchange with an external fluid in the condensing section 110, liquefies, and returns to the evaporating section 100 again. Due to the repetition of the evaporation and condensation of the refrigerant, the heat of the heating element is transmitted to the refrigerant in the evaporator 100, transported to the condenser 110, and released to the external fluid in the condenser 110.

[0003]

However, the above-described cooler has a configuration in which the condensed liquid liquefied in the condensing section 110 returns to the evaporating section 100 from the passage 101 or the recirculation passage 102 of the evaporating section 100. Passage 101 in mounting area
In this case, since the refrigerant vapor boiling due to the heat of the heating element rises, the condensed liquid and the refrigerant vapor flow in opposite directions and interfere with each other. As a result, the refrigerant vapor hardly escapes from the evaporating section 100, and the condensed liquid flowing from the condensing section 110 to the evaporating section 100 is blown up by the refrigerant vapor rising from the evaporating section 100, so that it is difficult to return to the evaporating section 100. , Evaporator 10
At the boiling surface of 0, burnout (rapid rise in temperature) is likely to occur and there is a problem that heat radiation performance is reduced. This problem is caused by a demand for cost reduction, as the thickness of the evaporating section 100 is reduced in order to reduce the amount of expensive refrigerant to be charged, and the heat dissipation performance is more likely to deteriorate due to 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 in which interference between a condensed liquid and a refrigerant vapor in a refrigerant chamber is prevented to improve the circulation of the refrigerant. It is in.

[0004]

(Means for Solving the Problems) A refrigerant flow control means for controlling the flow of condensed liquid dropped from the heat radiating portion into the connection tank, wherein the refrigerant flow control means is provided in the connection tank. To form a condensed liquid passage for guiding the condensed liquid dropped from the radiator to the upper surface of the refrigerant flow control means to the liquid inlet. According to this configuration, the refrigerant flow control plate covering the upper part of the vapor outlet can prevent the condensed liquid dripping into the connection tank from the heat radiating part from entering the vapor outlet, and the condensate of the refrigerant flow control plate can be prevented. The condensed liquid dropped on the upper surface of the refrigerant flow control means can be guided to the liquid inlet by the passage. As a result, interference between the refrigerant vapor and the condensate in the refrigerant chamber can be reduced, and the refrigerant can be circulated satisfactorily to improve the heat radiation performance.

[0005] (Means of the second aspect) The refrigerant chamber is provided in a flat shape whose thickness in the front-rear direction is thinner than the width in the left-right direction,
Heating elements are attached to both front and rear or one side of the refrigerant chamber,
The liquid inlet and the reflux passage are provided on both left and right sides of the refrigerant chamber. According to this configuration, the condensed liquid can be more stably supplied to the refrigerant chamber as compared with the case where the return passage is formed only on one side of the refrigerant chamber. Further, even if the boiling cooling device is tilted to the left or right, the condensed liquid can flow from the liquid inlet to the reflux passage, so that the condensed liquid can be stably returned to the refrigerant chamber.

(Claim 3) The refrigerant flow control means has a lower central portion in the front-rear direction and is provided with a concave cross section to form a condensate passage. In this case, the condensed liquid passage can be formed by a simple configuration in which the refrigerant flow control means is provided in a concave cross section. In other words, there is no need to provide a member that forms a condensate passage separately from a member that covers above the vapor outlet, and the same member can cover above the vapor outlet and form the condensate passage, so that the configuration is simple. At low cost.

(Claim 4) The refrigerant flow control means has an inclined surface which is highest at the center in the left-right direction and gradually decreases toward the left and right sides. According to this configuration, the condensed liquid dropped from the heat radiating portion onto the upper surface of the refrigerant flow control means flows to the left and right sides of the condensed liquid passage along the inclined surface of the refrigerant flow control means, and stably flows into the liquid inlet. be able to. In addition, when the return passages are provided on both the left and right sides of the refrigerant chamber, the condensed liquid can be returned to the refrigerant chamber substantially evenly from the return passages on both sides, so that the refrigerant circulation is better performed and the heat dissipation performance is improved. Can be improved.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of the 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 constituting an inverter circuit of an electric vehicle, and is fixed to both surfaces of the refrigerant tank 3 by bolts 5 or the like as shown in FIG.

The refrigerant tank 3 comprises a hollow member 6 and an end cap 7, and is provided with a refrigerant chamber 8, a liquid return passage 9, a heat insulating passage 10, and a communication passage 11 therein. Hollow member 6
Is an extruded product made of a metal material having excellent thermal conductivity, such as aluminum, provided in a flat shape having a small thickness with respect to the width, and a plurality of partition walls having different thicknesses (the first partition wall 12, the first partition wall 12). It has two partition walls 13, a third partition wall 14, and a fourth partition wall 15). The end cap 7 is made of, for example, the same aluminum as the hollow member 6, is covered on the lower end of the hollow member 6, and has a space between the end cap 7 and the lower end surface of the hollow member 6.

The refrigerant chamber 8 is provided on both left and right sides of a first partition wall 12 provided at the center of the hollow member 6, and the inside thereof is a second partition wall.
A plurality of passages are defined by the partition wall 13. The refrigerant chamber 8 forms a space in which the liquid refrigerant stored therein receives heat from the heating element 2 and boils. The liquid return passage 9 is
A passage into which the condensed liquid cooled and liquefied by the radiator 4 flows,
It is provided on both left and right sides of the hollow member 6. Insulated passage 10
Is a passage for insulating the space between the refrigerant chamber 8 and the liquid return passage 9. The passage is partitioned from the refrigerant chamber 8 by the third partition wall 14 and is separated from the liquid return passage 9 by the fourth partition wall 15.
The communication passage 11 is a passage for supplying the condensed liquid flowing into the liquid return passage 9 to the refrigerant chamber 8, and is formed by the space inside the end cap 7, and connects the liquid return passage 9 with the refrigerant chamber 8 and the heat insulating passage 10. Communicate with each other.

The radiator 4 comprises a core portion (described below), an upper tank 16 and a lower tank 17 (the connection tank of the present invention), and a refrigerant flow control plate 18 is provided inside the lower tank 17. . The core portion is a heat radiating portion of the present invention that cools the refrigerant vapor that has boiled by receiving heat from the heat generating element 2 by heat exchange with an external fluid (for example, air), and includes a plurality of heat radiating tubes 19 and each of the heat radiating tubes 19. And radiation fins 20 interposed therebetween. The heat radiating tube 19 forms a refrigerant passage through which the refrigerant flows, and is formed by cutting a flat tube made of, for example, aluminum into a predetermined length to form the lower tank 1.
7 and the upper tank 16 are arranged in parallel, and communicate the lower tank 17 and the upper tank 16. The radiating fins 20 are formed by alternately bending thin metal plates (for example, aluminum plates) having excellent thermal conductivity and forming them into a wavy shape, and are joined to the surface of the radiating tube 19.

The upper tank 16 is formed by combining a shallow dish-shaped core plate 16A and a deep dish-shaped tank plate 16B, and a plurality of heat radiating tubes are provided in a plurality of long holes (not shown) formed in the core plate 16A. The upper end of 19 is inserted. The lower tank 17 is the upper tank 16
Similarly, a shallow dish-shaped core plate 17A and a deep dish-shaped tank plate 17B are combined, and a plurality of long holes (not shown) opened in the core plate 17A.
The lower end of the heat radiating tube 19 is inserted into each of the holes, and the upper end of the hollow member 6 is inserted into an opening formed in the bottom surface of the tank plate 17B (see FIG. 1). Thereby, the upper end opening of the refrigerant chamber 8, the upper end opening of the liquid return passage 9, and the upper end opening of the heat insulating passage 10 are each opened in the lower tank 17. Here, the upper end opening of the refrigerant chamber 8 is a vapor outlet 21 from which the refrigerant vapor boiling in the refrigerant chamber 8 flows out, and the upper end opening of the liquid return passage 9 is provided with a condensed liquid cooled and liquefied by the heat radiating part. The liquid inlet 22 into which the liquid flows.

As shown in FIG. 3 (a), the refrigerant flow control plate 18 is long in the left-right direction and gently curved so that both sides are lower than the center. Also,
In the front-rear direction, as shown in FIG. 3 (b), the center portion has the lowest slope and the slope gradually increases toward both front and rear sides. Further, on both sides in the front-rear direction of the refrigerant flow control plate 18,
A stay 18a for attaching to the lower tank 17 is provided integrally. The refrigerant flow control plate 18 is fixedly attached to the front and rear side surfaces of the lower tank 17 with the stay 18a, and both ends in the left-right direction inside the lower tank 17 are formed by the fourth partition wall 15, as shown in FIG. It reaches the upper part and covers the upper part of the steam outlet 21 and the heat insulating passage 10. Also, as shown in FIG.
7 and a predetermined gap is secured between the lower tank 17 and the side surface. The refrigerant flow control plate 18 shown in FIG. 1 has a slope that is highest at the center in the left-right direction and gradually decreases toward both the left and right sides, but is functionally shown in FIG. This is equivalent to the refrigerant flow control plate 18.

Next, the operation of this embodiment will be described. The refrigerant vapor boiled by receiving the heat of the heating element 2 in the refrigerant chamber 8 enters the lower tank 17 through the vapor outlet 21, and the lower tank 1
Through the gap secured around the refrigerant flow control plate 18 in the inside 7, the liquid enters the heat radiation tubes 19 from the lower tank 17. The refrigerant vapor flowing through the heat radiating tube 19 is cooled by heat exchange with an external fluid passing through the core portion, releases latent heat, and condenses on the inner surface of the heat radiating tube 19. The released latent heat is transmitted from the wall surface of the radiation tube 19 to the radiation fin 20, and is released to the external fluid via the radiation fin 20. On the other hand, the condensed liquid that has been condensed into droplets descends along the inner surface of the heat radiation tube 19 due to gravity and drops from the heat radiation tube 19 into the lower tank 17.

Since the refrigerant flow control plate 18 covers the upper part of the vapor outlet 21 and the heat insulating passage 10 in the lower tank 17, the condensed liquid dropped from the heat radiation tube 19 falls to the vapor outlet 21. Can be prevented. Also,
Since the refrigerant flow control plate 18 is provided lower on both sides than the center in the left-right direction and lower on the center than both sides in the front-rear direction, the upper surface of the refrigerant flow control plate 18 A condensed liquid passage 23 is formed at the center portion, which is inclined to both sides in the left-right direction. As a result, the condensed liquid that has fallen from the heat radiating tube 19 onto the upper surface of the refrigerant flow control plate 18 is
8, flows into the left and right sides along the condensed liquid passage 23, flows into the liquid return passage 9 through the liquid inflow port 22 opened in the lower tank 17, and then returns to the refrigerant chamber 8 through the communication passage 11.

(Effects of Embodiment) In this embodiment, the refrigerant flow control plate 18 disposed in the lower tank 17 can prevent the condensed liquid dropped from the heat radiation tube 19 from dropping to the vapor outlet 21. The condensed liquid dropped from the heat radiation tube 19 can flow into the liquid inlet 22 along the condensed liquid passage 23 formed on the upper surface of the refrigerant flow control plate 18. Thereby, the interference between the refrigerant vapor and the condensed liquid in the refrigerant chamber 8 can be prevented, and the condensed liquid is not efficiently blown up by the refrigerant vapor flowing out from the vapor outlet 21 in the lower tank 17, so that the condensed liquid can be efficiently produced. Since the refrigerant can be returned to the refrigerant chamber 8, the circulation of the refrigerant is improved, and burnout on the boiling surface can be suppressed.

In particular, when the thickness of the refrigerant tank 3 is reduced, the boiling surface of the refrigerant chamber 8 becomes difficult to be filled with the liquid refrigerant necessary and sufficient for the boiling, and the heat radiation performance is easily deteriorated due to the burnout of the boiling surface. Therefore, in the thinned refrigerant tank 3 of the present embodiment, the refrigerant flow control plate 18 improves the circulation of the refrigerant,
It can be said that the effect of easily returning the condensed liquid to the refrigerant chamber 8 is great. Further, the condensed liquid can be prevented from flowing into the refrigerant chamber 8 from the vapor outlet 21 by the single refrigerant flow control plate 18 and the condensed liquid passage 23 for guiding the condensed liquid to the liquid inlet 22 can be formed. The effects of the embodiment (the interference between the condensed liquid and the refrigerant vapor in the refrigerant chamber 8 can be prevented and the circulation of the refrigerant can be improved) can be realized with a simple configuration and at low cost.

Hereinafter, a modified example of the refrigerant flow control plate 18 will be described. a) The refrigerant flow control plate 18 shown in FIG. 4 is provided with end plates 18b extending downward at both left and right ends, and a refrigerant vapor is provided between a lower end of the end plate 18b and an upper end surface of the fourth partition wall 15. A gap through which water can flow out is secured. In this case, the condensed liquid flowing through the condensed liquid passage 23 of the refrigerant flow control plate 18 can be more reliably guided to the liquid inlet 22 along the end plate 18b.

B) The refrigerant flow control plate 18 shown in FIG.
3 is formed. c) The refrigerant flow control plate 18 shown in FIG. 6 forms the condensed liquid passage 23 by depressing a central portion in the front-rear direction with a constant width. d) The refrigerant flow control plate 18 shown in FIG. 7 has a condensed liquid passage 23 formed by curving the whole in an arc shape.

E) The refrigerant flow control plate 18 shown in FIG. 8 forms the condensate passage 23 wide and narrows the condensate passage 23 on both sides in the left-right direction so that the condensate passage 23 gradually narrows. The condensate flowing through the liquid inlet 22
It is easy to flow into. f) The refrigerant flow control plate 18 shown in FIG. 9 has openings 18d for passing steam on both sides in the front-rear direction. g) The refrigerant flow control plate 18 shown in FIG. 10 has a condensed liquid passage 23 formed on both sides lower than the center in the front-rear direction.

[Brief description of the drawings]

FIG. 1 is a front view of a boiling cooling device.

FIG. 2 is a side view of the boiling cooling device.

FIG. 3 is a perspective view (a) and a sectional view (b) of a refrigerant flow control plate.
It is.

FIG. 4 is a perspective view (a) and a sectional view (b) of a refrigerant flow control plate.
It is.

FIG. 5 is a perspective view (a) and a cross-sectional view (b) of a refrigerant flow control plate.
It is.

FIG. 6 is a perspective view (a) and a sectional view (b) of a refrigerant flow control plate.
It is.

FIG. 7 is a perspective view (a) and a cross-sectional view (b) of a refrigerant flow control plate.
It is.

FIG. 8 is a perspective view (a) and a sectional view (b) of a refrigerant flow control plate.
It is.

FIG. 9 is a perspective view (a) and a sectional view (b) of a refrigerant flow control plate.
It is.

FIG. 10 is a sectional view showing the inside of a lower tank.

FIG. 11 is a front sectional view of a boiling cooling device (prior art).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 boiling cooling device 2 heating element 8 refrigerant chamber 9 liquid return passage (return passage) 11 communication passage (return passage) 17 lower tank (connection tank) 18 refrigerant flow control plate (refrigerant flow control means) 19 heat radiation tube (refrigerant passage) 21 Vapor outlet 22 Liquid inlet 23 Condensate passage

Claims (4)

[Claims] 1. A refrigerant chamber for storing a liquid refrigerant that boils by receiving heat from a heating element, a vapor outlet from which refrigerant vapor boiling in the refrigerant chamber flows out, and a refrigerant vapor flowing out from the vapor outlet flows into the refrigerant chamber. A radiator that has a refrigerant passage and cools the refrigerant vapor flowing through the refrigerant passage by heat exchange with an external fluid; a liquid inlet into which condensed liquid cooled and liquefied by the heat radiator flows; A recirculation passage for recirculating the condensed liquid to the refrigerant chamber; and a connection tank provided between the heat dissipating part, the refrigerant chamber, and the recirculation passage, and communicating the refrigerant passage with the refrigerant chamber and the recirculation passage. And a refrigerant flow control means provided in the connection tank and controlling the flow of condensed liquid dropped from the heat radiating portion, wherein the vapor outlet and the liquid inlet both open into the connection tank. And the cold The flow control means covers the upper part of the vapor outlet in the connection tank, and forms a condensate passage for guiding the condensate dropped from the radiator to the upper surface of the refrigerant flow control means to the liquid inlet. A boiling cooling device. 2. The refrigerant chamber is provided in a flat shape having a small thickness in the front-rear direction with respect to a width in the left-right direction, and the heating element is attached to both front and rear surfaces or one surface of the refrigerant chamber; 2. The boiling cooling device according to claim 1, wherein the return passage is provided on both left and right sides of the refrigerant chamber. 3. 3. The refrigerant flow control means according to claim 1, wherein the condensate passage is formed by being provided with a concave portion in a cross section at a center portion in the front-rear direction. Boiling cooling device. 4. The boiling method according to claim 1, wherein said refrigerant flow control means has an inclined surface which is highest at a central portion in the left-right direction and gradually becomes lower toward both left and right sides. Cooling system.