JP3810119B2 - Boiling cooler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a boiling cooling device for cooling a heating element such as a semiconductor element.
[0002]
[Prior art]
As a prior art, there is a cooling device disclosed in Japanese Patent Laid-Open No. 51-118038.
This cooling device is inserted into the refrigerant tank that stores the refrigerant, the hollow cooling fin that sandwiches the heating element, the joint pipe that communicates the refrigerant tank and the cooling fin, and the cooling fin and the joint pipe, and is formed to be widened toward the end. An inner tube whose upper end opens into the refrigerant tank is provided. According to this cooling device, the vapor refrigerant boiled by the heat of the heating element flows into the refrigerant tank through the outside of the inner tube, and the liquid refrigerant stored in the refrigerant tank cools through the inside of the inner tube. Can flow into the fins. As a result, the vapor refrigerant and the liquid refrigerant are separated by the inner tube so that the vapor refrigerant and the liquid refrigerant are circulated well, so that the so-called flooding in which the vapor refrigerant and the liquid refrigerant collide with each other to reduce the cooling performance is performed. Can be prevented.
[0003]
[Problems to be solved by the invention]
However, in the above cooling device, since the low-temperature liquid refrigerant flows inside the inner tube and the high-temperature vapor refrigerant flows outside, the heat exchange is performed between the vapor refrigerant and the liquid refrigerant through the wall surface of the inner tube. Done. For this reason, the temperature of the liquid refrigerant flowing into the cooling fins rises and the cooling effect decreases.
Further, when a part of the liquid refrigerant is vaporized due to the rise in the temperature of the liquid refrigerant, the vapor refrigerant and the liquid refrigerant flow reverse to each other, so the amount of the liquid refrigerant flowing into the cooling fins is reduced and the cooling capacity is lowered. It cannot completely prevent flooding.
Furthermore, since it is necessary to insert the inner tube into the cooling fin and the joint pipe, there is a problem that the structure becomes complicated and the cost increases.
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 that can circulate the vapor refrigerant and the liquid refrigerant satisfactorily with a simple structure (inexpensive). .
[0004]
[Means for Solving the Problems]
In the first aspect of the invention, the refrigerant tank is provided by bending an extruded material having a thin cross-sectional flat shape with respect to the lateral width into a substantially U shape, and the outer wall on one end side from the bent portion of the extruded material. A heating element is attached to the flat portion. Therefore, the vapor refrigerant boiled and vaporized by the heat of the heating element rises in the through hole formed in the extruded material, flows into the radiator from one end side opening of the refrigerant tank, and is cooled by the radiator. After flowing into the through-hole from the opening at the other end of the refrigerant tank, it is supplied to the boiling region where the heating element is attached through the bent portion. Thus, the cooling performance is improved by the good circulation of the vapor refrigerant and the liquid refrigerant.
In particular, in the present invention, since the lower communication member that communicates the lower ends of the plurality of heat radiating pipes is provided, the vapor refrigerant heated in the refrigerant tank can be distributed to the heat radiating pipes. Further, in the present invention, the one end side opening of the refrigerant tank opens at a position higher than the other end side opening of the refrigerant tank, so that the vapor refrigerant is radiated without shortcut to the other end side opening. Can flow into the vessel. In addition, since the liquid refrigerant in the radiator flows into the through hole from the other end side opening that opens at a position lower than the one end side opening, the circulation of the vapor refrigerant and the liquid refrigerant is performed better, Effective in reducing flooding. Furthermore, according to the present invention, since the cooling tank can be bent into a substantially U shape and the flooding can be reduced with a simple structure in which both ends are joined to the radiator, the cost is lower than that of a conventional cooling device. It is.
[0006]
In the invention of claim 2 , the through-hole formed in the extruded material is partitioned into a plurality of passages by the partition wall. Thereby, while the pressure resistance of a refrigerant tank improves, heat dissipation performance improves by expanding a heat-transfer area.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, the boiling cooling device of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is an overall perspective view of the boiling cooling device.
The boiling cooling device 1 of the present embodiment cools the heating element 2 by the boiling / condensation heat transfer of the refrigerant, and includes a refrigerant tank 3, a radiator 4, and a cooling fan (not shown).
The heating element 2 is an IGBT module that constitutes an inverter circuit such as an electric vehicle or a general power control device. The heating element 2 has a heat radiating plate 2 a that releases heat generated inside, and is fixed to the refrigerant tank 3 by tightening bolts 5 in a state where the heat radiating plate 2 a is in close contact with the outer wall plane portion 3 a of the refrigerant tank 3. (See FIG . 1 and FIG. 2).
[0010]
The refrigerant tank 3 is formed by bending an extruded material formed by extrusion from an aluminum block material into a substantially U shape, and two refrigerant tanks 3 are provided for the radiator 4 in this embodiment.
The extruded material has a vertically long shape and is provided in a cross-sectional flat shape having a thin thickness with respect to the lateral width, and a through hole 6 (see FIG. 2) is opened inside. Further, screw holes 3b for screwing the bolts 5 are formed in both sides of the through hole 6 in the width direction (left and right sides in FIG. 2) in the outer wall flat surface portion 3a of the extruded material.
[0011]
The heat radiator 4 communicates a plurality of heat radiating pipes 7, heat radiating fins 8 interposed between the heat radiating pipes 7, a lower communication member 9 that communicates the lower ends of the heat radiating pipes 7, and the upper ends of the heat radiating pipes 7. The upper communication member 10 is used.
The heat radiating tube 7 is a flat aluminum tube, and its lower end portion is inserted into a burring portion (not shown) formed on a lower plate 9a (see FIG. 3) constituting the lower communication member 9, and is airtightly joined to the lower plate 9a. The upper end portion is inserted into a burring portion formed in an upper plate (not shown) constituting the upper communication member 10 and is airtightly joined to the upper plate.
The radiating fins 8 are formed by forming a thin aluminum plate into a wave shape (corrugated type), and are joined in a state where each bent portion is in contact with the outer wall surface of the radiating tube 7.
[0012]
The lower communication member 9 includes an aluminum lower plate 9a and a lower tank 9b (see FIG. 3). The lower tank 9b is provided with a burring portion 9c into which both end openings of the refrigerant tank 3 are inserted.
Similar to the lower communication member 9, the upper communication member 10 includes an aluminum upper plate and an upper tank.
Each component constituting the radiator 4 and the refrigerant tank 3 are temporarily assembled so as to form the entire shape shown in FIG. 1 and joined by integral brazing, and then the refrigerant tank 3 (through hole 6) and the radiator. Fluorocarbon-based refrigerant is sealed in a sealed space formed by 4 (each radiating pipe 7, the lower communication member 9, and the upper communication member 10).
In addition, the heat generating body 2 is attached to the one end side from the bending part (lower end part of the refrigerant | coolant tank 3) of an extruded material, as shown in FIG.
[0013]
Next, the operation of this embodiment will be described.
The vapor refrigerant boiled and vaporized by receiving heat from the heating element 2 rises in the through hole 6 of the refrigerant tank 3 and flows into the lower communication member 9 of the radiator 4 from the one end side opening 6a, and then the lower communication member. 9 to the heat radiating pipes 7. The vapor refrigerant rising in each radiating pipe 7 is condensed and liquefied on the inner wall surface of the radiating pipe 7 which is cooled by receiving air from the cooling fan, and flows into the radiating pipe 7 as droplets. It returns to the inside of the lower communication member 9 again. The liquid refrigerant accumulated in the lower communication member 9 flows into the through hole 6 from the other end side opening 6b of the refrigerant tank 3 as shown by a solid arrow in FIG. Through the bent portion), the heating element 2 is supplied again to the boiling region where the heating element 2 is fixed.
On the other hand, the condensation latent heat released when the vapor refrigerant is condensed is transmitted from the wall surface of the heat radiating pipe 7 to the heat radiating fins 8 and is released to the blown air passing between the heat radiating pipes 7.
[0014]
(Effect of this embodiment)
In the present embodiment, the refrigerant tank 3 is formed in a substantially U shape, and the heating element 2 is fixed to one end from the bent portion, so that the vapor refrigerant boiled and vaporized by the heat of the heating element 2 is the refrigerant tank. 3 flows into the lower communication member 9 of the radiator 4 from the one end side opening 6a, and the liquid refrigerant accumulated in the lower communication member 9 flows into the through hole 6 from the other end side opening 6b of the refrigerant tank 3. To do. In this way, the refrigerant tank 3 made of the extruded material is formed in a substantially U shape, and the vapor refrigerant rising path and the liquid refrigerant descending path are made independent, so that the circulation of the vapor refrigerant and the liquid refrigerant is excellent. This improves the cooling performance. In addition, since a space is secured between the ascending path and the descending path, heat exchange is not performed between the vapor refrigerant that rises in the ascending path and the liquid refrigerant that flows down the descending path, and the liquid refrigerant A decrease in cooling effect due to temperature rise can be prevented.
In addition, since the refrigerant tank 3 is made of an extruded material, the strength design of the refrigerant tank 3 is easy.
Furthermore, it is possible to reduce the occurrence of flooding with a simple structure in which the extruded material is bent into a substantially U shape and both ends thereof are joined to the radiator 4, so that the cost is lower than that of a conventional cooling device. It is.
[0015]
(Second embodiment)
FIG. 4 is a horizontal sectional view of the refrigerant tank 3.
In the refrigerant tank 3 of the present embodiment, the extruded material through-hole 6 is partitioned into a plurality of passages 6d by partition walls 6c. Thereby, since each partition wall 6c functions as a reinforcing material for the refrigerant tank 3, the pressure resistance of the refrigerant tank 3 is improved, and the heat transfer area is expanded, so that the heat radiation performance is improved.
[0016]
(Third embodiment)
FIG. 5 is a longitudinal sectional view of the lower communication member 9 and the refrigerant tank 3.
The refrigerant tank 3 of the present embodiment is joined to the lower communication member 9 at a position where the one end side opening 6a to which the heating element 2 is fixed is higher than the other end side opening 6b. Thereby, the liquid refrigerant accumulated in the lower communication member 9 can flow into the through hole 6 from the other end side opening 6b that opens at a position lower than the one end opening 6a. For this reason, the circulation of the vapor refrigerant and the liquid refrigerant is performed better, and the flooding is reduced.
[0017]
(Fourth embodiment)
FIG. 6 is a longitudinal sectional view of the lower communication member 9 and the refrigerant tank 3.
This embodiment shows a case where the number of heating elements 2 fixed to the refrigerant tank 3 is large.
In this case, the length of the extruded material can be easily dealt with simply by cutting it long according to the number of the heating elements 2. Even if the number of the heating elements 2 increases as in this embodiment, the refrigerant tank 3 is located at two locations (one end side opening 6a and the other end side opening 6b) with respect to the lower communication member 9 of the radiator 4. Since it is joined, it can be said that the rigidity is high and the durability is good with respect to the increase in mass.
[Brief description of the drawings]
FIG. 1 is an overall perspective view of a boiling cooling device.
FIG. 2 is a horizontal sectional view of a refrigerant tank.
FIG. 3 is a longitudinal sectional view of a lower communication member and a refrigerant tank.
FIG. 4 is a horizontal sectional view of a refrigerant tank (second embodiment).
FIG. 5 is a longitudinal sectional view of a lower communication member and a refrigerant tank (third embodiment).
FIG. 6 is a longitudinal sectional view of a lower communication member and a refrigerant tank (fourth embodiment).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Boiling cooler 2 Heat generating body 3 Refrigerant tank 4 Radiator 6 Through-hole 6c Partition wall 6d Passage

Claims (2)

A boiling cooling device comprising a refrigerant tank having a heating element attached therein and containing therein a refrigerant that is vaporized by receiving heat from the heating element; and a radiator that releases heat of vapor refrigerant vaporized in the refrigerant tank. There,
The radiator has a plurality of heat radiating tubes and heat radiating fins arranged between the heat radiating tubes,
The lower part of the radiator is provided with a lower communication member for communicating the lower end of the radiator pipe,
The refrigerant tank is formed of an extruded material having a cross-sectional flat shape with a thin width relative to the lateral width, and a through-hole penetrating the inside in the longitudinal direction is formed by extrusion processing. The extruded material is substantially U-shaped. The both ends are joined to the lower communication member , the through hole communicates with the inside of the radiator, and the heating element is attached to the outer wall plane portion on one end side from the bent portion ,
The boiling cooling device , wherein the one end side opening of the refrigerant tank is opened at a position higher than the other end side opening of the refrigerant tank . The boiling cooling device according to claim 1 , wherein the refrigerant tank is partitioned into a plurality of passages by a partition wall in which the through hole extends in a longitudinal direction of the extruded material .

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