JP2000205721A - Evaporative cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporative cooling device which is improved in refrigerant circulating property by reducing the interference between condensate and refrigerant vapor in a refrigerant chamber. SOLUTION: A refrigerant tank 3 is constituted in such a way that the upper- end opening (vapor flowing-out port 17) of a refrigerant chamber is protruded from the upper-end opening (liquid flowing-in port 18) of a liquid returning passage and the vapor flowing-out port 17 is provided in an inclined state. The tank 3 is assembled with the lower tank 21 of a radiator 4 in a steeply inclined state and is inserted into the opening 26 of the lower tank 21 with its heating element 2 attaching surface downside so that the vapor flowing-out port 17 which is opened in the tank 21 is directed obliquely upward. In the lower tank 21, in addition, the lowest part of the port 17 is positioned above the lowest part of the liquid flowing-in port 18 and the port 17 is opened at a position higher than that of the port 18 as a whole.

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 repeatedly boiling and condensing 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 as shown in FIG. 14, has 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 reduced to improve the circulation of the refrigerant. It is in.

[0004]

(Means for Solving the Problems) A vapor outlet from which refrigerant vapor boiled in the refrigerant chamber flows out, and a liquid inlet for flowing condensed liquid cooled and liquefied by the heat radiating portion, Both the vapor outlet and the liquid inlet are open in the connecting tank, and the liquid inlet is open at a position lower than the vapor outlet. According to this configuration, the condensed liquid dropped into the connection tank from the heat radiating section can preferentially flow into the liquid inlet that opens at a position lower than the vapor outlet. As a result, the amount of condensed liquid flowing from the vapor outlet to the refrigerant chamber can be reduced, so that interference between the condensed liquid and refrigerant vapor in the refrigerant chamber can be reduced.

[0005] (Means of claim 2) The refrigerant chamber is provided in a thin shape having a small thickness in the front-rear direction with respect to 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) A refrigerant having a refrigerant chamber and a recirculation passage inside thereof, the upper end opening of the refrigerant chamber being a vapor outlet, and the upper end opening of the recirculation passage being a liquid inlet. A tank is provided, wherein the refrigerant tank is mounted obliquely with respect to the connection tank, and the lowermost part of the vapor outlet is located above the lowermost part of the liquid inlet. In this case, it is difficult to make the entire opening of the vapor outlet higher than the entire opening of the liquid inlet because the refrigerant tank is attached to the connecting tank at an angle. Therefore, if the lowermost part of the vapor outlet is located above the lowermost part of the liquid inlet, the condensate in the connection tank can flow preferentially into the liquid inlet that opens at a lower position.

According to a fourth aspect of the present invention, in the boiling cooling apparatus according to the third aspect, the refrigerant tank is provided so that the vapor outflow port projects forward from the liquid inflow port. This allows
Even when the refrigerant tank is mounted obliquely with respect to the connection tank, the lowermost part of the vapor outlet is located above the lowermost part of the liquid inlet.

According to a fifth aspect of the present invention, in the boiling cooling apparatus according to the fourth aspect, the refrigerant tank has a vapor outlet opening diagonally upward. In this case, the opening area of the steam outlet can be increased, and the steam outlet can be further increased as compared with the case where the steam outlet is open in the inclination direction of the refrigerant tank (when the steam outlet is not inclined with respect to the refrigerant tank). The lowermost part of the outlet can be provided above the lowermost part of the liquid inlet.

(Means of Claim 6) In the boiling cooling device according to any one of claims 3 to 5, the lower side of the steam outlet is closed. In this case, the height difference between the opening (unblocked portion) of the vapor outlet and the liquid inlet can be increased, so that the condensed liquid in the connection tank can flow into the liquid inlet more stably. .

(Claim 7) The refrigerant tank is formed using an extruded material. By using extruded material,
Cost reduction by mass production is possible.

(Claim 8) A refrigerant tank having a refrigerant chamber and a return passage therein, a refrigerant chamber and a connection tank are communicated with each other, and an opening opening in the connection tank is provided as a vapor outlet. And a liquid return pipe communicating with the reflux passage and the connection tank and having an opening opening in the connection tank as a liquid inlet. In this configuration, the number of the steam pipes and the liquid return pipes can be increased or decreased according to the heat radiation amount of the heating element, so that it is possible to efficiently cope with the heating elements having different heat radiation amounts. In other words, regardless of the amount of heat dissipation,
Stable heat radiation performance can be secured.

(Means of Claim 9) A refrigerant control plate is provided to cover above the vapor outlet in the connection tank. The refrigerant control plate can prevent the condensed liquid cooled and liquefied in the heat radiating portion from directly dropping to the vapor outlet, so that interference between the refrigerant vapor rising from the refrigerant chamber at the vapor outlet and the condensed liquid can be reduced.

[0013]

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 refrigerant tank 3 comprises a hollow member 6 and an end plate 7, and has therein a refrigerant chamber 8, a liquid return passage 9, a heat insulating passage 10, and a communication passage 11 (see FIG. 2). 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. (A first partition wall 12, a second partition wall 13, a third partition wall 14, and a fourth partition wall 15). However, as shown in FIG. 3B, the lower end of each of the partition walls 12 to 15 is deleted by a predetermined length, and the hollow member 6 is removed.
The lower end surfaces of the partition walls 12 to 15 are located higher than the lower end surfaces of the partition walls 12 to 15. In addition, the first partition wall 12 and the third partition wall 14
Are provided with a plurality of screw holes 16 for screwing the bolts 5. The upper end of the hollow member 6 has a difference in height between a portion outside and a portion inside the left and right third partition walls 14,
The inner portion is provided to protrude upward from the outer portion, and the upper end surface of the inner portion is inclined as shown in FIG.

The end plate 7 is made of, for example, the same aluminum as the hollow member 6, and is elongated in the left-right direction, as shown in FIG. 4, and provided with an inner portion 7b slightly protruding from an outer peripheral edge 7a. As shown in FIG. 5, the end plate 7 has an inner portion 7b projecting into the opening at the lower end 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. However, a predetermined space is provided between the surface of the inner portion 7b of the end plate 7 fitted into the lower end opening of the hollow member 6 and the lower end surfaces of the partition walls 12 to 15 of the hollow member 6.

In FIG. 3 (b), the refrigerant chamber 8 is provided between the first partition wall 12 and the left and right third partition walls 14 located on the right side of the center of the hollow member 6, and each has a second partition wall. 13 define a plurality of passages. The refrigerant chamber 8 forms a space in which the liquid refrigerant stored therein receives heat from the heating element 2 and boils. In the following description, the upper opening of the refrigerant chamber 8 that opens at the upper end surface of the hollow member 6 is referred to as a vapor outlet 17. As described above, the vapor outlet 17 protrudes upward from the upper end opening surface of the liquid return passage 9, and the opening surface is inclined.

The liquid return passage 9 is a passage through which the condensed liquid cooled and liquefied by the radiator 4 flows, and is provided on the left and right sides of the hollow member 6. In the following description, the upper opening of the liquid return passage 9 that opens at the upper end surface of the hollow member 6 is referred to as a liquid inlet 18. The heat-insulating passage 10 is a passage for insulating the space between the refrigerant chamber 8 and the liquid return passage 9.
4 and a liquid return passage 9 by a 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 at the lower end of the hollow member 6 closed by the end plate 7 (see FIG. 5). The return passage 9 communicates with the refrigerant chamber 8 and the heat insulating passage 10.

The radiator 4 comprises a core 19, an upper tank 2
0, a lower tank 21 (the connection tank of the present invention), and a refrigerant control plate 22 is installed inside the lower tank 21. The core portion 19 is a heat radiating portion of the present invention that cools the refrigerant vapor that has boiled by receiving the heat of the heating element 2 by heat exchange with an external fluid (for example, air). And a radiation fin 24 interposed therebetween.

The heat radiating tube 23 forms a refrigerant passage through which the refrigerant flows. For example, a flat tube made of aluminum is cut into a predetermined length to form a plurality of tubes between the lower tank 21 and the upper tank 20. The lower tank 21 and the upper tank 20 communicate with each other. In addition, heat radiation tube 2
An inner fin 25 bent in a wavy shape may be inserted into the inside of 3 (see FIG. 6). However, in this case, the inner fins 25 are arranged such that the extending direction of the ridges and valleys is along the passage direction of the heat radiation tube 23 (the vertical direction in FIG. 6), and
It is desirable that the inner fins 25 are arranged such that a gap is formed on both sides of the inner fins 25 to serve as the refrigerant passages 23a. Radiation fins 24
Is formed by alternately bending a thin metal plate (for example, an aluminum plate) having excellent thermal conductivity to form a wavy shape, and is joined to the surface of the heat radiation tube 23.

The upper tank 20 is formed by combining a shallow dish-shaped core plate 20A and a deep dish-shaped tank plate 20B, and a plurality of heat radiation tubes are provided in a plurality of long holes (not shown) formed in the core plate 20A. The upper end of 23 is inserted. The lower tank 21 is
Similarly to the above, a shallow dish-shaped core plate 21A and a deep dish-shaped tank plate 21B (see FIG. 7) are combined, and heat is radiated to a plurality of long holes (not shown) opened in the core plate 21A. The lower end of the tube 23 is inserted, and the upper end of the hollow member 6 is inserted into the opening 26 opened in the tank plate 21B (see FIG. 1). As shown in FIG. 7C, the tank plate 21B has a larger inclination angle with respect to the lowest bottom surface (the surface facing the upper opening on which the core plate 21A is covered) in the shape viewed from the longitudinal direction. It has an inclined surface 21a, and the opening 26 is opened in the inclined surface 21a (see FIG. 7).

Therefore, as shown in FIG.
It is attached to the lower tank 21 with a large inclination. This is effective when the refrigerant tank 3 is assembled in an upright posture with respect to the lower tank 21 because the height of the entire apparatus becomes large, and the installation space in the upward direction is limited. However, the coolant tank 3 is inserted into the opening 26 with the mounting surface of the heating element 2 facing downward so that the vapor outlet 17 faces obliquely upward in the lower tank 21 (that is, the heating element 2 is Attached to the lower surface of the tank 3). As a result, in the lower tank 21, the lowermost part of the vapor outlet 17 is located above the lowermost part of the liquid inlet 18, as shown in FIG. It opens at a position higher than the liquid inlet 18.

The refrigerant control plate 22 is for preventing the condensed liquid cooled and liquefied in the core portion 19 from dropping directly to the vapor outlet 17, as shown in FIG. Both ends of the refrigerant control plate 22 reach the upper part of the heat insulating passage 10, and also cover the vapor outlet 17 and the upper part of the heat insulating passage 10 in the front-rear direction (see FIG. 1). This refrigerant control plate 22 is long in the left-right direction as shown in FIG.
A round hole 22a for inserting a screw 27 or the like is formed at one end in the front-rear direction, and the hollow member 6 inserted into the lower tank 21 can be attached to the upper end surface of the hollow member 6 with the screw 27 or the like (FIG. 1). reference). At this time, it is desirable that the refrigerant control plate 22 is mounted in a state of being gently inclined such that the front end side is slightly higher than the mounting portion side in the front-rear direction shown in FIG.

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 21 through the vapor outlet 17, and flows into the lower tank 2.
1 enters each heat radiation tube 23. The refrigerant vapor flowing through the heat radiating tube 23 is cooled by heat exchange with an external fluid passing through the core 19, releases latent heat, and condenses in the heat radiating tube 23. The released latent heat is transmitted from the wall surface of the heat radiating tube 23 to the heat radiating fins 24 and is released to the external fluid via the heat radiating fins 24. A part of the refrigerant condensed in the heat radiating tube 23 is held below the inner fin 25 by surface tension, and forms a liquid pool as shown in FIG. The liquid pool portion is also formed when the refrigerant vapor rising from below hits the lower surface of the inner fin 25 and the bubble liquid film is caught in the lower portion of the inner fin 25 by surface tension.

The condensed liquid accumulated in the liquid pool of the inner fin 25 is pushed into the lower tank 21 from the liquid pool by being pushed by the pressure of the refrigerant vapor that has risen in the gap (refrigerant passage 23a) formed on both sides of the inner fin 25. Fall. Also,
The condensed liquid condensed on the inner surface of the heat radiating tube 23 and formed as droplets descends along the inner surface of the heat radiating tube 23 by weight, and drops from the heat radiating tube 23 into the lower tank 21. The condensed liquid that has dropped from the heat radiating tube 23 onto the upper surface of the refrigerant control plate 22 flows along the inclination of the refrigerant control plate 22 and then passes through the passage formed by the side surface of the lower tank 21 and the refrigerant control plate 22 in the left-right direction. It flows into the liquid inlet 18.
Further, the condensed liquid accumulated at the bottom of the lower tank 21 flows into the liquid inlet 18 when the liquid level exceeds the height of the lowermost part of the liquid inlet 18, and passes through the communication passage 11 from the liquid return passage 9. The refrigerant can be returned to the refrigerant chamber 8.

(Effects of the First Embodiment) In the present embodiment, since the liquid inlet 18 is lower than the vapor outlet 17 in the lower tank 21, the heat radiation tube 23 is connected to the lower tank 21. The condensed liquid dropped in the liquid can flow into the liquid inlet 18 preferentially. Further, in the lower tank 21, since the refrigerant control plate 22 covers the upper part of the vapor outlet 17, it is possible to prevent the condensed liquid dropped from the heat radiation tube 23 from flowing directly into the vapor outlet 17. As a result, the condensed liquid is not blown up by the refrigerant vapor flowing out from the vapor outlet 17 in the lower tank 21, and the condensed liquid can be efficiently returned to the refrigerant chamber 8, so that the circulation of the refrigerant is improved and the boiling surface is improved. Burnout can be suppressed. In particular, if the condensed liquid is difficult to return to the refrigerant chamber 8 as the thickness of the refrigerant tank 3 is reduced, the heat radiation performance is likely to be reduced due to the burnout of the boiling surface. Therefore, in the thinned refrigerant tank 3 of the present embodiment, the effect that the condensed liquid can be easily returned to the refrigerant chamber 8 by making a difference in height between the vapor outlet 17 and the liquid inlet 18 is great.

(Second Embodiment) FIG. 9 is a side view of the boiling cooling device 1. This embodiment is applied to the boiling cooling device 1 described in the first embodiment. As shown in FIG. 9, the lower side of the steam outlet 17 opening in the lower tank 21 is closed by a plate 28. This is an example. The plate 28
As shown in FIG. 10, the steam outlet 17 is provided over the entire region in the longitudinal direction. In this case, the opening of the vapor outlet 17 not closed by the plate 28 and the liquid inlet 1
8, the condensate stored in the lower tank 21 can flow into the liquid inlet 18 more stably, and the condensate flowing from the vapor outlet 17 into the refrigerant chamber 8 can be further reduced. Can be reduced.

(Third Embodiment) FIG. 11 is a side view of the boiling cooling device 1. This embodiment is applied to the boiling cooling device 1 described in the first embodiment and the second embodiment.
This is an example in which the radiator 4 is installed at an angle as shown in FIG.
This boiling cooling device 1 is suitable, for example, when the refrigerant tank 3 is mounted facing the vehicle front side (the right side in FIG. 11).
In this case, when the vehicle travels on an uphill, the radiator 4 can be maintained substantially upright, so that the radiator 4 can maintain the position where the performance can be maximized.

(Fourth Embodiment) FIG. 12 is a front view of the boiling cooling device 1. In the present embodiment, the refrigerant tank 3 and the lower tank 21
This is an example in which both are separated by a steam pipe 29 and a liquid return pipe 30. As shown in FIG.
It has a refrigerant chamber 8, a liquid return passage 9, a heat insulating passage 10, and a communication passage 11 therein. An end plate 31 is mounted on an upper end opening of the hollow member 6, and a steam pipe 29 and a liquid return pipe are provided in the end plate 31. A round hole 31a into which the hole 30 is inserted is formed. The round hole 31 a is opened in the upper part of the refrigerant chamber 8 and the upper part of the liquid return passage 9. Further, as shown in FIG. 13, the refrigerant tank 3 is disposed substantially upright below the lower tank 21. The lower tank 21 is a tank plate 21B
A connection port 21b into which the steam pipe 29 and the liquid return pipe 30 are inserted is opened in the bottom surface of the.

The lower end of the steam pipe 29 has the end plate 3.
1 is inserted into the round hole 31a formed in the first tank 1. The upper end is inserted from the connection port 21b formed in the tank plate 21B to the middle of the lower tank 21 (above the bottom surface of the lower tank 21). It communicates with the lower tank 21. The liquid return pipe 30 has a lower end inserted into a round hole 31a formed in the end plate 31 and an upper end formed through a connection port 21b formed in the tank plate 21B.
The liquid return passage 9 and the lower tank 21 are communicated with each other. However, the upper end opening of the liquid return pipe 30, that is, the liquid inlet 18 is opened at substantially the same height as the bottom surface of the lower tank 21.

According to the structure of this embodiment, the lower tank 21
The condensed liquid accumulated in the liquid flows into the liquid inlet 18 opening at a position lower than the vapor outlet 17 preferentially, and the liquid return pipe 3
0, flows into the liquid return passage 9 of the refrigerant tank 3, and is further supplied to the refrigerant chamber 8 through the communication passage 11. As a result, the condensed liquid flowing from the vapor outlet 17 into the refrigerant chamber 8 can be reduced, so that interference between the condensed liquid in the refrigerant chamber 8 and the refrigerant vapor can be reduced, and the heat radiation performance can be improved. In addition, since the number of the steam pipes 29 and the number of the liquid return pipes 30 can be increased or decreased according to the heat radiation amount of the heating element 2 attached to the refrigerant tank 3, it is possible to efficiently cope with the heating elements 2 having different heat radiation amounts. In other words, stable heat radiation performance can be ensured regardless of the amount of heat radiation. In the boiling cooling device 1 as well, a refrigerant control plate may be disposed above the steam outlet 17 in the lower tank 21 as in the first embodiment.

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

FIG. 5 is a sectional view showing a mounted state of an end plate.

FIG. 6 is a cross-sectional view of a heat radiation tube in which inner fins are arranged.

FIG. 7 is a front view (a), a side view (b), and a bottom view (c) of a lower tank.

FIG. 8 is a front view (a) and a side view (b) of the refrigerant control plate.

FIG. 9 is a side view of a boiling cooling device (second embodiment).

FIG. 10 is a front view of a boiling cooling device (second embodiment).

FIG. 11 is a side view of a boiling cooling device (third embodiment).

FIG. 12 is a front view of a boiling cooling device (fourth embodiment).

FIG. 13 is a side view of a boiling cooling device (fourth embodiment).

FIG. 14 is a front view of a boiling cooling device (prior art).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiling cooling device 2 Heating element 3 Refrigerant tank 8 Refrigerant room 9 Liquid return passage (Reflux passage) 11 Communication passage (Reflux passage) 17 Vapor outlet 18 Liquid inlet 19 Core part (radiator) 21 Lower tank (Connection tank) 22 Refrigerant control plate 23 Heat dissipation tube (refrigerant passage) 29 Vapor tube 30 Liquid return tube

Claims (9)

[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 radiator and the refrigerant chamber and the recirculation passage, and communicating the refrigerant passage with the refrigerant chamber and the recirculation passage. Wherein the steam outlet and the liquid inlet are both opened in the connection tank, and the liquid inlet is opened at a position lower than the vapor outlet. apparatus. 2. The refrigerant chamber is provided in a thin shape having a small thickness in the front-rear direction with respect to the 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 chamber and the return passage are provided therein, and an upper end opening of the refrigerant chamber is provided as the vapor outlet, and an upper end opening of the return passage is provided as the liquid inlet. A refrigerant tank, wherein the refrigerant tank is attached to the connection tank at an angle, and a lowermost part of the vapor outlet is located above a lowermost part of the liquid inlet. Item 3. The boiling cooling device according to Item 1 or 2. 4. The evaporative cooling device according to claim 3, wherein the refrigerant tank is provided with the vapor outlet protruding forward from the liquid inlet. 5. The boiling cooling device according to claim 4, wherein the vapor outlet of the refrigerant tank is open obliquely upward. 6. The boiling cooling device according to claim 3, wherein a lower portion of the steam outlet is closed. 7. The boiling cooling device according to claim 3, wherein the refrigerant tank is formed using an extruded material. 8. A refrigerant tank having the refrigerant chamber and the return passage therein, and an opening communicating with the refrigerant chamber and the connection tank and opening into the connection tank is provided as the vapor outlet. And a liquid return pipe communicating with the reflux passage and the connection tank, and having an opening opening in the connection tank provided as the liquid inlet. The boiling cooling device described in 1. 9. A refrigerant control plate for covering a portion above the vapor outlet in the connection tank.
9. The cooling apparatus according to any one of items 1 to 8.