JPH1074873A - Ebullient cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ebullient cooling device which is simple in structure and can circulate refrigerant at a low cost. SOLUTION: In the device 1, a radiator 4, which has a plurality of refrigerant condensing pipes 9 and radiating fins 10, is located on 1 both sides of a refrigerant bath 3. The refrigerant condensing pipes 9 are bent into U-shapes, both open ends 9a and 9b of which are inserted into round holes made in a wall of a bath body 5 to be opened to a communication chamber 8 and are integrally connected thereto, together with the refrigerant bath 3 by brazing. With respect to the refrigerant condensing pipes 9, however, a positional relationship between one open end 9a and the other open end 9b is the vertical one relative to the refrigerant bath 3, and one open end 9a positioned at an upper position has an open cross section area (pipe diameter) than the other open end 9b positioned at a lower position.

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 heat transfer by repeated boiling and condensation of a refrigerant.

[0002]

2. Description of the Related Art As a prior art, Japanese Patent Application Laid-Open No. 3-28345 is disclosed.
Patent Document 4 discloses a boiling cooling device. In this boiling cooling device, the inside of a tank of a radiator is partitioned into a first compartment into which vapor refrigerant vaporized and vaporized in a refrigerant tank flows, and a second compartment into which condensate cooled and liquefied by the radiator flows. At the same time, a return pipe for guiding the condensate from the second compartment to the bottom of the refrigerant tank is provided. As a result, the condensed liquid liquefied by the radiator can be supplied to the refrigerant tank by the return pipe without being affected by the vapor refrigerant flowing from the refrigerant tank to the radiator. Can be improved.

[0003]

However, in the above structure, the radiator is provided with a tank, the inside of the tank is divided into a first compartment and a second compartment, and a refrigerant tank is provided from the second compartment. Since the return pipe is provided up to the bottom, the structure is complicated and the product price increases. In addition, since it is necessary to pass a return pipe through a connecting pipe that connects the refrigerant tank and the radiator, it is extremely difficult to manufacture a boiling cooling device in which airtightness is important. 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 having a simple structure and a structure capable of circulating a refrigerant at low cost.

[0004]

According to the first aspect of the present invention, a refrigerant having one opening end opening to the communication chamber of the refrigerant tank and the other opening end opening to the communication chamber below one opening end. It has a condenser tube, and the refrigerant condenser tube is characterized in that the opening cross-sectional area of the other opening end is smaller than the opening cross-sectional area of the other opening end. As a result, the vapor refrigerant vaporized by the heat of the heating element in the refrigerant tank flows into the refrigerant condensing tube from one opening end having a larger opening cross-sectional area than the other opening end (that is, having a small inflow resistance), and And flows into the communication chamber from the other open end, and falls downward to be supplied to the liquid refrigerant. According to the present invention, a circulating flow of the refrigerant can be formed by a simple configuration in which the opening cross-sectional area of one opening end of the refrigerant condensing pipe is smaller than that of the other opening end, so that a high-performance boiling cooling device can be manufactured at low cost. Can be provided.

According to the second aspect of the present invention, the communication chamber is divided by the partition plate provided in the communication chamber of the refrigerant tank into an upper region in which one opening end of the refrigerant condensing tube is opened and the other opening end of the refrigerant condensing tube being opened. And a refrigerant supply port through which the condensate flowing out from the refrigerant condensing pipe to the upper region can be supplied below the partition plate. Thereby, the vapor refrigerant, which has been boiled and vaporized by receiving the heat of the heating element in the refrigerant tank, flows into the refrigerant condensing tube from the other opening end that opens to the lower region of the communication chamber,
After flowing into the pipe, it is condensed and liquefied and flows out from one opening end to the upper region, and then falls below the partition plate through the refrigerant supply port to be supplied to the liquid refrigerant. ADVANTAGE OF THE INVENTION According to this invention, since the circulation flow of a refrigerant | coolant can be formed by the simple structure of only providing a partition plate and a refrigerant supply port in the communication chamber of a refrigerant tank, a high-performance boiling cooling apparatus can be provided at low cost.

According to the means of claim 3, the refrigerant condensing tube is
There is a liquid passage portion through which the liquefied condensate flows toward the communication chamber of the refrigerant tank, and the liquid passage portion is inclined downward toward the communication chamber. Thus, the boiling cooling device can be installed at an angle within a range in which the condensed liquid can flow out of the refrigerant condensing pipe (liquid passage portion) into the communication chamber.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a cooling apparatus according to the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a side view of a boiling cooling device, and FIG. 2 is a front view of the boiling cooling device. Boiling cooling device 1 of the present embodiment
Is for cooling the heating element 2 by heat transfer by repeated boiling and condensation of the refrigerant, and is composed of a refrigerant tank 3, a radiator 4, and a cooling fan (not shown). Heating element 2
Is an IGBT module constituting an inverter circuit of, for example, an electric vehicle or a general electric power control device. The refrigerant tank 3 is tightened with bolts (not shown) in a state where the heat radiation surface of the heating element 2 is in close contact with the outer wall surface of the refrigerant tank 3. It is fixed to.

The refrigerant tank 3 comprises a hollow tank main body 5 having both ends opened, and a pair of end caps 6 for closing both end open surfaces of the tank main body 5. A refrigerant (for example, fluorocarbon) is sealed inside. I have. The tank body 5 is made of, for example, an extruded material made of aluminum, and is provided in a flat shape having a small width relative to the width. End cap 6
Is made of aluminum similarly to the tank body 5, and is hermetically joined to the opening end face of the tank body 5 by brazing or the like. The upper end cap 6 is provided with a sealing pipe 7 which is sealed after injecting the refrigerant into the refrigerant tank 3. The amount of the refrigerant sealed in the refrigerant tank 3 is about 2/3 of that of the refrigerant tank 3 as shown in FIG. 1, and the vapor (boiling vaporized by the heat of the heating element 2) is provided above the refrigerant (liquid refrigerant). A space (hereinafter referred to as a communication chamber 8) filled with the refrigerant is secured.

The radiator 4 comprises a plurality of refrigerant condenser tubes 9 and radiating fins 10 and is arranged on both sides of the refrigerant tank 3 (see FIG. 1). The refrigerant condensing tube 9 is an aluminum clad tube whose outer surface is clad with a brazing material, and has both open ends 9a,
9b is bent in a U-shape so as to face in the same direction, and after the radiating fin 10 is attached, both open ends 9a and 9b are opened in the wall surface of the tank body 5 forming the communication chamber 8 ( (Not shown), is opened to the communication chamber 8, and is brazed together with the refrigerant tank 3. However, this refrigerant condenser tube 9
The one open end 9a and the other open end 9b are in the vertical direction of the coolant tank 3, and the upper open end 9a is more open than the lower open end 9b. The cross-sectional area (tube diameter) is large (see FIG. 2).
The change in the pipe diameter is set in the U-shaped bent portion 9A. In other words, the refrigerant condensing tube 9 has a U-shaped bent portion 9A having a variable tube diameter, and a vapor passage formed of a thick linear portion extending from one open end 9a to the U-shaped bent portion 9A. It comprises a portion 9B and a liquid passage portion 9C formed of a straight portion with a small diameter from the other open end 9b to the U-shaped bent portion 9A.

The heat dissipating fin 10 is made of a thin plate made of aluminum and having a rectangular planar shape (see FIG. 2), and has two large and small round holes through which the vapor passage 9B and the liquid passage 9C of the refrigerant condensing tube 9 pass. (Not shown) are provided for the number of the refrigerant condensing tubes 9. The plurality of radiating fins 10 attached to the refrigerant condensing tube 9 are arranged at a certain interval from each other as shown in FIG. The cooling fan blows air to the radiator 4, and is arranged above the radiator 4 so that the blowing direction is substantially perpendicular to the radiator 4 (from above to below).

Next, the operation of this embodiment will be described. The refrigerant boiled by the heat generated from the heat generating element 2 is transferred as bubbles into the refrigerant tank 3 and flows from the communication chamber 8 of the refrigerant tank 3 into the refrigerant condensing pipe 9. At this time, the refrigerant condensing pipe 9 has one opening end 9a having a larger opening cross-sectional area than the other opening end 9b and a smaller inflow resistance, so that the vapor refrigerant in the communication chamber 8 mainly has one opening end 9a. Flows into the refrigerant condensing pipe 9 from the outlet. The vapor refrigerant that has flowed into the refrigerant condenser tube 9 emits latent heat of condensation when flowing through the tube and is condensed and liquefied, and the condensed liquid that has become droplets flows out from the other open end 9b into the communication chamber 8, and goes downward as it is. It falls and is supplied to the liquid refrigerant.
With arrows). On the other hand, the latent heat of condensation released when the vapor refrigerant is condensed in the refrigerant condenser tube 9 is transmitted from the tube wall of the refrigerant condenser tube 9 to the radiating fins 10, and is released into the air blown by the cooling fan.

(Effect of First Embodiment) According to the present embodiment,
The vapor refrigerant flows into the refrigerant condensing pipe 9 from one opening end 9a, and the condensate can flow out to the communication chamber 8 from the other opening end 9b. That is, the flow direction of the refrigerant flowing through the refrigerant condenser tube 9 is one direction. Further, since the refrigerant tank 3 has a sufficiently large width (width in the left-right direction in FIG. 2) with respect to the thickness, the condensed liquid condensed in the refrigerant condensing pipe 9 is sufficiently supplied to the bottom of the refrigerant tank 3. This allows the refrigerant to circulate through the refrigerant tank 3 and the radiator 4 (refrigerant condensing tube 9) satisfactorily, thereby providing the boiling cooling device 1 having excellent heat radiation performance. In addition, in comparison with the conventional device which requires a return pipe or the like, in the present embodiment, a simple configuration in which the opening cross-sectional area of one opening end 9a of the refrigerant condensing pipe 9 is smaller than that of the other opening end 9b is achieved. Since the circulation flow of the refrigerant can be formed, the high-performance boiling cooling device 1 can be provided at low cost.

(Second Embodiment) FIG. 3 is a side view of the boiling cooling device 1. This embodiment shows an example in which the refrigerant condensing tube 9 is attached to the refrigerant tank 3 (communication chamber 8) in two upper and lower stages. Also in this case, both the upper refrigerant condensing pipe 9 and the lower refrigerant condensing pipe 9 have one opening end 9 having a large opening cross-sectional area.
a, a condensed liquid flows out from the other opening end 9b having a small opening cross-sectional area, and a circulation flow of the refrigerant can be formed.

(Third Embodiment) FIG. 4 is a side view of the boiling cooling device 1, and FIG. 5 is a plan view showing the shape of the heat radiation fin 10. This embodiment shows an example in which the heat radiation fins 10 formed in a needle shape (strip shape) are used.

(Fourth Embodiment) FIG. 6 is a side view of a boiling cooling device 1 according to a fourth embodiment of the present invention, in which the direction of air flow of a cooling fan to a radiator 4 is substantially horizontal. In this case, the space between the one open end 9a and the other open end 9b of the refrigerant condensing tube 9 is made large in the vertical direction, and the plurality of radiating fins 10 are vertically spaced from the refrigerant condensing tube 9 by a predetermined distance. Is kept in place. The refrigerant condensing tube 9
A portion extending vertically (a portion to which the radiating fins 10 are attached) is set to have the same pipe diameter as the one open end 9a.

(Fifth Embodiment) FIG. 7 is a side view of the boiling cooling device 1. This embodiment shows an example in which the heating element 2 is disposed inside the refrigerant tank 3. In this case, the heating element 2
Is transferred directly to the refrigerant without passing through the wall of the refrigerant tank 3,
It is possible to provide the boiling cooling device 1 having good heat transfer and excellent cooling performance.

(Sixth Embodiment) FIG. 8 is a side view of the boiling cooling device 1. This embodiment shows an example in which a refrigerant condensing tube 9 is attached to a refrigerant tank 3 at an angle. As shown in FIG. 8, the refrigerant condensing pipe 9 has a vapor passage 9B and a liquid passage 9C each having one open end 9a and the other open end 9b.
It extends more diagonally upward. This makes it easier for the condensed liquid to flow through the liquid passage section 9C toward the communication chamber 8, so that the condensed liquid does not accumulate in the refrigerant condensing pipe 9, and the circulation of the refrigerant is performed more favorably. Further, in this case, even if the boiling cooling device 1 is installed inclined forward or backward, the condensed liquid remains in the refrigerant tank 3 until the liquid passage portion 9C is substantially horizontal.
, It is possible to prevent a situation in which the refrigerant condensing tube 9 arranged on one side of the refrigerant tank 3 cannot be used. The same effect can be obtained even if the steam passage section 9B is not inclined.

(Seventh Embodiment) FIG. 9 is a side view of the boiling cooling device 1, and FIG. 10 is a front view of the boiling cooling device 1. In this embodiment, a partition plate 11 is provided in the communication chamber 8 and the partition plate 11 is provided.
FIG. 1 shows an example of forming a circulating flow by controlling the flow of a refrigerant by means of a flow chart. As shown in FIG. 10, the partition plate 11 is provided between a portion to which one open end 9a is connected and a portion to which the other open end 9b is connected, and connects the communication chamber 8 to one open end 9a. The opening region 9a is divided into an upper region 8a in which an opening is formed and a lower region 8b in which the other opening end 9b is opened. However, the partition plate 11 is attached at an angle as shown in FIG. 10, and its lower end communicates with the upper region 8a and the lower region 8b to allow the condensate in the upper region 8a to flow downward. A coolant supply port 12 that can be supplied is provided.

According to the present embodiment, the vapor refrigerant vaporized by the heat of the heating element 2 boiled and evaporated from the lower region 8b below the partition plate 11 necessarily passes through the other open end 9b. And flows into the pipe to be condensed and liquefied when flowing through the pipe, and flows out as condensed liquid from one opening end 9a to the upper region 8a. The condensed liquid flowing out flows along the partition plate 11 attached at an angle, falls down through the refrigerant supply port 12, and is supplied to the liquid refrigerant in the refrigerant tank 3. In the case of this embodiment, since the flow of the refrigerant can be controlled by the partition plate 11 to form a circulating flow, the refrigerant condensing pipe 9 may have the same diameter from one open end 9a to the other open end 9b (FIG. 9). reference).

(Eighth Embodiment) FIG. 11 is a front view of the boiling cooling device 1. This embodiment shows an example in which a condensed liquid passage 3a is provided in the refrigerant tank 3 in addition to the configuration shown in the sixth embodiment. The refrigerant tank 3 is provided with a condensed liquid passage 3 a through which the condensed liquid flows below the refrigerant supply port 12.
Are separated by a boiling region 3b and a passage wall 3c corresponding to the mounting portion. In addition, the passage wall 3c can be provided at the same time when the tank body 5 is extruded. However, a gap 3d is provided between the lower end surface of the passage wall 3c and the end cap 6 for communicating the condensate passage 3a with the boiling region 3b. With the above configuration, the condensed liquid that has dropped through the refrigerant supply port 12 flows into the condensed liquid passage 3a as it is, flows down the condensed liquid passage 3a, and boils through the gap 3d between the passage wall 3c and the end cap 6. It is supplied to the area 3b.
In this way, a good circulation flow can be obtained without collision between the vapor refrigerant and the condensed liquid even in the refrigerant tank 3, so that the heat radiation performance can be further improved.

(Ninth Embodiment) FIG. 12 is a side view of the boiling cooling device 1, and FIG. 13 is an enlarged view of a portion A in FIG. The present embodiment shows an example in which a flat tube having a flat cross section is used as the refrigerant condensing tube 9 and corrugated fins are used as the radiating fins 10. Refrigerant condenser tube 9 (flat tube)
Is provided so as to meander in a meandering manner between one open end 9a and the other open end 9b so that the other open end 9b located below one open end 9a has a smaller opening cross-sectional area. It is deformed and connected to the refrigerant tank 3 (communication chamber 8) (see FIG. 13). The heat radiation fins 10 are interposed between the flat tubes bent in a meandering shape, and joined to the tube wall surface by brazing.

[Brief description of the drawings]

FIG. 1 is a side view (including a partial cross section) of a boiling cooling device (first embodiment).

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

FIG. 3 is a side view of a boiling cooling device (second embodiment).

FIG. 4 is a side view of a boiling cooling device (third embodiment).

FIG. 5 is a plan view showing the shape of a heat radiation fin (third embodiment).
Example).

FIG. 6 is a side view (including a partial cross section) of a boiling cooling device (fourth embodiment).

FIG. 7 is a side view (including a partial cross section) of a boiling cooling device (fifth embodiment).

FIG. 8 is a side view (including a partial cross section) of a boiling cooling device (sixth embodiment).

FIG. 9 is a side view (including a partial cross section) of a boiling cooling device (seventh embodiment).

FIG. 10 is a front view (including a partial cross section) of a boiling cooling device (seventh embodiment).

FIG. 11 is a front view (including a partial cross section) of a boiling cooling device (eighth embodiment).

FIG. 12 is a side view (including a partial cross section) of a boiling cooling device (ninth embodiment).

FIG. 13 is an enlarged sectional view of a portion A in FIG. 12 (ninth embodiment).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiling cooling device 2 Heating element 3 Refrigerant tank 4 Radiator 8 Communication chamber 8a Upper area 8b Lower area 9 Refrigerant condensing pipe 9C Liquid passage part 11 Partition plate 12 Refrigerant supply port

Claims (3)

[Claims] 1. A boiling cooling device for cooling a heating element by heat transfer by repetition of boiling and condensation of a refrigerant, the refrigerant tank containing a liquid refrigerant and having a communication chamber above the liquid refrigerant. An open end is connected to the refrigerant tank and opens to the communication chamber, and the other open end is connected to the refrigerant tank below the one open end and opens to the communication chamber. A radiator for releasing heat of the vapor refrigerant flowing into the refrigerant condenser tube, wherein the refrigerant condenser tube has an opening cross-sectional area at the other opening end smaller than an opening cross-sectional area at the one opening end. A boiling cooling device, characterized in that: 2. A boiling cooling device for cooling a heating element by heat transfer by repetition of boiling and condensation of a refrigerant, the refrigerant tank containing a liquid refrigerant and having a communication chamber above the liquid refrigerant. An open end is connected to the refrigerant tank and opens to the communication chamber, and the other open end is connected to the refrigerant tank below the one open end and opens to the communication chamber. A radiator for releasing the heat of the vapor refrigerant flowing into the refrigerant condenser tube, wherein the refrigerant tank has an upper region where the one open end is open to the communication chamber and a lower region where the other open end is opened. A boiling cooling device, comprising: a partition plate for partitioning the refrigerant into a region, and a refrigerant supply port for supplying condensate flowing from the refrigerant condenser tube to the upper region below the partition plate. 3. The refrigerant condensing pipe has a liquid passage portion through which the liquefied condensate flows toward the communication chamber, and the liquid passage portion is inclined downward toward the communication chamber. The boiling cooling device according to claim 1 or 2, wherein