JPH1183359A - Ebullient cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ebullient cooler for circulating condensate to a refrigerant tank even at the time of inclining without bringing about a large scale in size of a constitution. SOLUTION: A radiator 4 has a lower tank coupled to an upper part of a refrigerant tank 3, and a plurality of radiating tubes 7 laminated on the upper part of the lower tank. The lower tank is partitioned therein by a refrigerant flow control plate 11 into an inlet chamber 12 and an outlet chamber 13. The laminated tubes 7 communicate with communicating parts 7a, 7b provided at both ends in a longitudinal direction in a laminating direction to form an inlet side communicating part and an outlet side communicating part. And, communicating ports 7a for communicating with refrigerant passages communicate in the laminating direction to form communicating passages between channels at the respective tubes 7. The passages between the channels communicate with the chamber 13 in the lower tank, The plate 11 guides refrigerant vapor obtained by ebullition in the tank 3 to the inlet side communicating part even at the time of inclining, and guides condensate dripping from the passages between the channels to a liquid return passage 5a in the tank 3.

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 transport by repeated boiling and condensation of a refrigerant.

[0002]

2. Description of the Related Art Conventionally, as a refrigerant circulation type boiling cooling device, for example, Japanese Utility Model Laid-Open No. 62-151755 and Japanese Patent Application Laid-Open No. 6-53376 have been known. These conventional devices have a vapor passage and a condensed liquid passage connecting the refrigerant tank and the radiator, and the refrigerant vapor boiling due to the heat of the heating element in the refrigerant tank flows into the radiator through the vapor path. The condensed liquid cooled and liquefied by the radiator can return to the refrigerant tank through the condensed liquid passage. Thereby, interference between the refrigerant vapor flowing from the refrigerant tank toward the radiator and the condensed liquid flowing from the condenser toward the refrigerant tank can be prevented, and a favorable refrigerant circulation flow can be formed.

[0003]

SUMMARY OF THE INVENTION However, Japanese Patent Laid-Open No.
In the apparatus described in Japanese Patent No. 53376, if the entire apparatus is tilted in the direction in which the condensed liquid flows backward, the condensed liquid cannot be returned to the refrigerant tank, so that the refrigerant circulating flow cannot be formed. Further, Japanese Utility Model Application Laid-Open Publication No. 62-151755 discloses an example in which the refrigerant passage of the radiator is inclined in advance so that the condensate flows easily. In this case, the condensed liquid can be returned to the refrigerant tank until the refrigerant passage becomes substantially horizontal, even if the entire device is inclined to the side opposite to the inclination direction of the refrigerant passage. However, there has been a problem that the overall height of the device is increased or the width thereof is increased, resulting in an increase in physical size.
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 return a condensed liquid to a refrigerant tank even when inclined, without increasing the physical size. It is in.

[0004]

[Means for Solving the Problems]

(Claim 1) The refrigerant tank has a boiling region in which the liquid refrigerant boils by receiving the heat of the heating element, and a liquid return passage into which the condensed liquid condensed by the radiator flows. A plurality of refrigerant passages extending substantially in the lateral direction, an inflow-side communication portion communicating with one end of each refrigerant passage, an outflow-side communication portion communicating with the other end of each refrigerant passage, a boiling region of the refrigerant tank, and an inflow side. An inflow chamber that communicates with the communication portion, an outflow chamber that communicates the liquid return passage of the refrigerant tank with the outflow communication portion, and a plurality of refrigerant passages that communicate with each other between the inflow communication portion and the outflow communication portion. And a communication passage between flow passages that opens to the outflow chamber. In the present invention, when the entire device is inclined in a direction in which the condensed liquid flows backward in the refrigerant passage, a part of the condensed liquid is pushed by the flow of the refrigerant vapor flowing from the inflow side communication portion to the outflow side communication portion in the refrigerant passage. Although it can flow from the refrigerant passage to the outflow-side communicating portion, the remaining condensate flows back through the refrigerant passage due to gravity. The condensed liquid flowing backward in the refrigerant passage can flow to the outflow chamber as it is through the inter-flow passage communicating the refrigerant passages between the inflow-side communication portion and the outflow-side communication portion. As a result, part of the condensed liquid that has been pushed by the flow of the refrigerant vapor and has flowed to the outflow-side communicating portion, and the remaining condensate that has flowed to the outflow chamber through the inter-flow path communication passage, respectively, has a refrigerant tank from the outflow chamber To the liquid return passage.

The radiator guides the refrigerant vapor boiling in the boiling region of the refrigerant tank to the inflow-side communication portion, and guides the condensed liquid dropped from the inter-channel communication passage to the liquid return passage. A flow control plate is provided, and the refrigerant flow control plate partitions between the inflow chamber and the outflow chamber. In this case, it is not necessary to form the inflow chamber and the outflow chamber independently. For example, a refrigerant flow control plate is arranged in a tank portion (a portion connected to the refrigerant tank) of the radiator, and the inflow chamber and the outflow chamber flow through the tank portion. All you have to do is partition the room. Thus, the condenser flowing backward through the refrigerant passage and dripping from the inter-channel communication passage can flow along the refrigerant flow control plate as it is, and can be returned to the liquid return passage of the refrigerant tank.

(Means of Claim 3) The refrigerant flow control plate is arranged in a posture inclined downward from the inflow side communication portion side to the outflow side communication portion side. This makes it easier for the refrigerant vapor boiling in the boiling region of the refrigerant tank to flow to the inflow-side communication portion along the refrigerant flow control plate, and that the condensed liquid that has dropped onto the refrigerant flow control plate from the inter-channel communication passage is cooled. Since it is easy to flow along the control plate to the liquid return passage, a favorable refrigerant circulation flow can be formed. In addition, even if the entire device is inclined in a direction in which the condensed liquid flows backward in the refrigerant passage, the condensed liquid dropped from the inter-channel communication passage is directed to the liquid return passage along the surface of the refrigerant flow control plate arranged in an inclined posture. Can be refluxed.

(Claim 4) The cross-sectional area of the inter-channel communication passage opening to the outflow chamber is set smaller than the cross-sectional area of the refrigerant passage. In this case, the refrigerant vapor that has flowed into the refrigerant passage from the inflow-side communication portion tends to flow through the refrigerant passage having a larger cross-sectional area than the inter-flow passage communication passage. Can be prevented from flowing out.

[0008] (Means of claim 5) The at least one communication passage between the flow passages is provided between the inflow side communication portion and the outflow side communication portion near the inflow side communication portion. It is desirable that the inter-channel communication path is provided near the inflow-side communication path that is the most downstream when the refrigerant path is inclined. Accordingly, a large amount of condensed liquid flowing backward in the refrigerant passage can return from the outflow chamber to the liquid return passage through the inter-channel communication passage. Further, the communication passage between the flow paths does not need to be provided at one place, and may be provided at two or more places.

[0009]

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 front view of a boiling cooling device 1, and FIG. 2 is a side view of the boiling cooling device 1. The boiling cooling device 1 of the present embodiment cools the heating element 2 by utilizing the boiling and condensing action of the refrigerant, and includes a refrigerant tank 3 for storing a liquid refrigerant therein, and a heat radiation provided above the refrigerant tank 3. And a vessel 4.

The coolant tank 3 comprises a hollow container 5 and an end cap 6 made of a metal material having excellent heat conductivity such as aluminum. The hollow container 5 is, for example, an extruded product, and has a thickness (FIG.
Are provided in a thin flat shape, and inside the container, a plurality of passages 5d defined by ribs 5a, 5b, 5c extending in the pushing direction (the vertical direction in FIG. 1),
5e are formed. Each of the ribs 5a, 5b, 5c is provided with a thick rib 5a provided at a substantially central portion in the left-right direction, a middle rib 5b provided on both sides in the left-right direction, and provided between both middle ribs 5b and the thick rib 5a. And a plurality of thin ribs 5c. However, except for the middle rib 5b located on the left side of FIG.
The upper end is slightly shorter and removed. Also, the thick rib 5a
A plurality of round holes 5f for passing bolts (not shown) for fixing the heating element 2 are formed in the middle ribs 5b through both in the width direction of the hollow container 5. Each passage 5d, 5
e is composed of a passage 5d defined by each thin rib 5c between the thick rib 5a and both middle ribs 5b, and a passage 5e formed outside the both middle ribs 5b.

The end cap 6 is, for example, a press-formed product, and is covered on the lower end of the hollow container 5. However, a predetermined space is secured inside the end cap 6 between the lower end surface of the hollow container 5 and the passages 5d and 5e formed in the hollow container 5 through this space. The heating element 2 is, for example, an IGBT module that forms an inverter circuit of an electric vehicle or a general power control device, and is fixed to the surface of the coolant tank 3 by tightening bolts and nuts. As the refrigerant, for example, water, alcohol, ammonia, fluorocarbon, chlorofluorocarbon or the like is used, and is injected into the refrigerant tank 3 through an injection pipe (not shown).

The radiator 4 includes a lower tank (described below) connected to the upper end of the refrigerant tank 3 (hollow container 5), a plurality of radiator tubes 7 (see FIG. 5) stacked on the lower tank,
And radiation fins 8 interposed between the radiation tubes 7. The lower tank is formed by a tank plate 9 and a core plate 10. Tank plate 9
Is, for example, a press-formed product, which is provided in an elongated cup shape as shown in FIG. 3, and has an elongated hole 9a in the center portion into which the upper end of the hollow container 5 is fitted. The core plate 10 is press-molded in the same shape as the core plate 10 (see FIG. 6) forming the heat radiation tube 7, and covers the opening of the tank plate 9. Further, a refrigerant flow control plate 11 (described later) as shown in FIG. 4 is arranged inside the lower tank, and the inside of the lower tank is divided into an inflow chamber 12 and an outflow chamber 13 by the refrigerant flow control plate 11. I have.

As shown in FIG. 5, the heat radiating tube 7 is formed by joining two core plates 10 formed by press forming, and the other heat radiating tubes 7 are provided at both ends in the longitudinal direction (left and right direction in FIG. 5). The communication parts 7a and 7b which are communicated with are provided. In the radiator tube 7, a portion between the communicating portions 7a and 7b is formed as a refrigerant passage 7c. ing. As shown in FIG. 6 (a), the core plate 10 has round holes 10 forming communication portions 7a and 7b at both ends in the longitudinal direction.
a and 10b are open, and communication holes 7d which are open in a long hole shape are provided at substantially equal intervals between the round holes 10a and 10b.
As shown in FIG. 6B, the periphery of the round holes 10a and 10b and the periphery of the communication port 7d protrude toward the surface of the core plate 10 (below the FIG. 6B) by a predetermined height. I have.
The communication port 7d formed in the core plate 10 is the same as that shown in FIG.
As shown in FIG. 7, the core plate 10 may be divided in the width direction (vertical direction in FIG. 7).

The heat radiating pipe 7 formed by the two core plates 10 is laminated with other plural heat radiating pipes 7 in the thickness direction, and is stacked on the lower tank. In the stacked upper and lower heat radiation tubes 7, the communication portions 7a and 7b and the communication ports 7d abut each other and communicate with each other. The lowermost radiating pipe 7 and the lower tank are composed of the core plate 10 of the radiating pipe 7 and the core plate 1 of the lower tank.
0 and round holes 10a and 10b and a communication port 7d
They are abutted and communicate with each other. It goes without saying that the uppermost heat radiation tube 7 has the upper core plate 10 closed (the round holes 10a and 10b and the communication port 7d are not formed). In the following description, a portion where one of the communication portions 7a (the right side in FIG. 1) of each heat radiation tube 7 communicates in the stacking direction is defined as an inflow side communication portion.
A portion where the other communication portions 7b of the heat radiation tubes 7 are formed to communicate with each other in the stacking direction is referred to as an outflow side communication portion. As shown in FIG. 8, one communication passage formed by connecting the communication ports 7d of the heat radiation tubes 7 to each other in the stacking direction is referred to as an inter-channel communication passage.
Therefore, in this embodiment, a plurality of inter-channel communication paths are formed between the inflow side communication section and the outflow side communication section.

The radiating fins 8 are corrugated fins formed by alternately bending thin metal plates made of a material such as aluminum and having excellent thermal conductivity into a corrugated shape, and are interposed between the refrigerant passages 7c of the radiating tubes 7 (see FIG. 1). (See FIG. 9). As shown in FIG. 1, the refrigerant flow control plate 11 is disposed inclined in the lower tank, the lower end is connected to the upper end surface of the middle rib 5b located on the left side of the hollow container 5, and the upper end is the core of the lower tank. One round hole 10a provided in the plate 10 and the communication port 7d
(The communication port 7d closest to the round hole 10a). In the boiling cooling device 1, the refrigerant tank 3 and the radiator 4 are combined to assemble the entire shape as shown in FIG. 1, and then each joint is hermetically joined by integral brazing.

Next, the operation of this embodiment will be described. When the heat of the heating element 2 attached to the surface of the refrigerant tank 3 is transmitted to the liquid refrigerant in the refrigerant tank 3, the liquid refrigerant boils in a boiling region in the refrigerant tank 3 and becomes a bubble in each passage 5d. Rise. The boiling region is a region in which the refrigerant boils by receiving heat from the heating element 2. The boiling refrigerant vapor flows from the refrigerant tank 3 through the inflow chamber 12 of the lower tank to one communication portion 7a (inflow-side communication portion) of each of the heat radiation tubes 7. At this time, the refrigerant vapor passing through the lower tank is guided to the inflow side communication part while the flow is regulated by the refrigerant flow control plate 11 arranged in the lower tank. The refrigerant vapor flowing from the inflow side communication portion to the refrigerant passage 7c of each heat radiation pipe 7 is cooled by the cooling air sent to the radiator 4 and condensed on the wall surface of the refrigerant passage 7c to form droplets.

A part of the condensed liquid that has become droplets is
c, flows out from a plurality of communication ports 7d provided in the liquid supply passage 7d, drops through the communication passages between the flow paths into the lower tank, and the liquid return passage 5e of the refrigerant tank 3 along the inclined refrigerant flow control plate 11.
Flows into The remaining condensate flows into the other communication portion 7b (outflow-side communication portion) while being pushed by the flow of the refrigerant vapor flowing through the refrigerant passage 7c, and flows through the outflow chamber 13 in the lower tank from the outflow-side communication portion. The solution is dropped into the liquid return passage 5e in the tank 3. The liquid return passage 5e is a passage into which the condensed liquid liquefied by the radiator 4 flows, and in this embodiment, a passage 5e formed outside the middle rib 5b located on the left side in the hollow container 5. Say The condensed liquid flowing into the liquid return passage 5e is supplied to a boiling region (passage 5d) in the refrigerant tank 3 through a communication passage formed inside the end cap 6. The heat transmitted from the heating element 2 to the refrigerant is released as condensation latent heat when the refrigerant vapor condenses in the radiator 4, and is released to the atmosphere through the radiation fins 8.

Next, the operation when the entire apparatus is inclined in the direction in which the condensed liquid flows backward in the refrigerant passage 7c will be described with reference to FIG.
This will be described with reference to the schematic diagram shown in FIG. In this case, a part of the condensed liquid liquefied in each refrigerant passage 7c flows into the outflow side communication portion while being pushed by the flow of the refrigerant vapor flowing through the refrigerant passage 7c as shown by an arrow a in FIG. The liquid can be dropped into the liquid return passage 5e in the refrigerant tank 3 through the outflow chamber 13 in the lower tank. However, the remaining condensate flows back through the refrigerant passage 7c due to gravity as shown by an arrow b in FIG. 10 because the entire apparatus is inclined (in FIG. 10, the condensate flows through the refrigerant passage 7c from the left side). Flows to the right).
The condensed liquid that has flowed back flows out from the communication port 7d provided in the refrigerant passage 7c, drops through the communication passage between the flow passages onto the refrigerant flow control plate 11 in the lower tank, and then flows on the surface of the refrigerant flow control plate 11. To flow into the liquid return passage 5e of the refrigerant tank 3.

(Effects of the First Embodiment) In this embodiment, even if the entire apparatus is installed in an inclined manner in the direction in which the condensed liquid flows backward in the refrigerant passage 7c, the condensed liquid flowing backward is supplied to the inflow side communication part. Without flowing to the refrigerant flow control plate 11 that is inclined in the lower tank through the inter-channel communication path, and then flows on the surface of the refrigerant flow control plate 11 to It is possible to return to the return passage 5e. Therefore, the condensed liquid flowing backward in the refrigerant passage 7c can be returned to the liquid return passage 5e in the refrigerant tank 3 without interfering with the refrigerant vapor flowing into the inflow-side communicating portion. Thus, when the entire apparatus is installed at an angle, the condensed liquid flows into the refrigerant tank 3.
Burnout caused by the inability to return to the
Required heat radiation performance can be secured. Further, in this embodiment, as in the example described in Japanese Utility Model Application Laid-Open No. 62-151755, the overall height of the apparatus is not increased and the width is not increased, so that the apparatus can be prevented from being enlarged.

(Second Embodiment) FIG. 11 is a front view of the boiling cooling device 1. The present embodiment shows an example in which only one communication path between the flow paths is provided near the inflow-side communication part. Therefore, the core plate 10 forming the heat radiating pipe 7 is
As shown in FIG. 12, a long hole-shaped communication port 7d is provided only at one location near one round hole 10a. In the case of the present embodiment, since the communication passage between the flow paths is provided in one place, the area of the heat radiation fin 8 can be increased by that much, so that there is a merit that the heat radiation performance can be further improved.

(Third Embodiment) FIG. 13 is a front view of the boiling cooling device 1. This embodiment shows an example in which the inter-channel communication passage is provided closer to the inflow-side communication portion than in the second embodiment. Therefore, as shown in FIG. 14, the core plate 10 forming the heat radiating tube 7 has only one long-hole-shaped communication port 7d in the immediate vicinity of one of the round holes 10a. When the entire apparatus is inclined in the direction in which the condensed liquid flows backward, the inter-channel communication path is preferably located near the inflow-side communication path that is the most downstream in the direction in which the condensed liquid flows. Accordingly, a large amount of condensed liquid flowing backward in the refrigerant passage 7c can be returned to the refrigerant tank 3 through the inter-flow passage.

In each of the above embodiments, it is desirable that the cross-sectional area of the inter-flow path communicating with the outlet chamber 13 is set smaller than the cross-sectional area of the refrigerant passage 7c. In this case, the refrigerant vapor that has flowed into the refrigerant passage 7c from the inflow-side communication portion tends to flow through the refrigerant passage 7c having a larger cross-sectional area than the inter-flow passage communication passage. It is possible to suppress the outflow into the outflow chamber 13. However, it is not necessary to set the cross-sectional area of all the communication ports 7d constituting the inter-channel communication path to be smaller than the cross-sectional area of the refrigerant path 7c.
It is sufficient that the passage cross-sectional area of only the (lowest communication port 7d) is smaller than that of the refrigerant passage 7c.

[Brief description of the drawings]

FIG. 1 is a front view of a boiling cooling device (first embodiment).

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

FIG. 3 is a plan view (a) and a side view (b) of a tank plate.
(First embodiment).

FIG. 4 is a front view (a) and a side view (b) of a refrigerant flow control plate (first embodiment).

FIG. 5 is a side view of the radiator tube (first embodiment).

FIG. 6 is a plan view (a) and a side view (b) of a core plate (first embodiment).

FIG. 7 is a plan view of a core plate (first embodiment).

FIG. 8 is a sectional view taken along line AA of FIG. 1 (first embodiment).

FIG. 9 is a sectional view taken along line BB of FIG. 1 (first embodiment).

FIG. 10 is a schematic diagram showing the flow of condensate when the device is inclined.

FIG. 11 is a front view of a boiling cooling device (second embodiment).

FIG. 12 is a plan view (a) and a side view (b) of a core plate.
(Second embodiment).

FIG. 13 is a front view of a boiling cooling device (third embodiment).

FIG. 14 is a plan view (a) and a side view (b) of a core plate.
(Third Example)

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiling cooling device 2 Heating element 3 Refrigerant tank 4 Radiator 5d Passage (boiling region) 5e Liquid return passage 7a One communication part (inflow side communication part) 7b The other communication part (outflow side communication part) 7c Refrigerant path 7d communication Port (communication passage between flow paths) 11 Refrigerant flow control plate 12 Inflow chamber 13 Outflow chamber

Claims (5)

[Claims] 1. A boiling cooling device for cooling a heating element by heat transport by repeated boiling and condensation of a refrigerant, comprising: a refrigerant tank for storing a liquid refrigerant therein; A radiator that receives the heat of the heating element and causes the refrigerant vapor that has boiled to flow in, and that condenses and liquefies the refrigerant vapor by heat exchange with an external fluid. And a liquid return passage into which the condensed liquid condensed by the radiator flows.The radiator has a plurality of refrigerant passages extending substantially in the lateral direction, and one end of each refrigerant passage. An inflow-side communication portion that communicates the sides;
An outflow-side communication portion that communicates the other end of each refrigerant passage, an inflow chamber that communicates the boiling region of the refrigerant tank with the inflow-side communication portion, a liquid return passage of the refrigerant tank, and the outflow-side communication portion. And an outflow chamber communicating the plurality of refrigerant passages between the inflow side communication portion and the outflow side communication portion, and an interflow passage communication passage opening to the outflow chamber. Characterized boiling cooling device. 2. The refrigerant radiator guides a refrigerant vapor boiling in a boiling region of the refrigerant tank to the inflow-side communication part, and guides a condensed liquid dropped from the inter-channel communication path to the liquid return path. The boiling cooling device according to claim 1, further comprising a flow control plate, wherein the refrigerant flow control plate partitions between the inflow chamber and the outflow chamber. 3. The boiling according to claim 2, wherein the refrigerant flow control plate is disposed in a posture inclined downward from the inflow side communication portion side toward the outflow side communication portion side. Cooling system. 4. The cross-sectional area of the inter-channel communication passage opening to the outlet chamber is set smaller than the cross-sectional area of the refrigerant passage. Boiling cooling device. 5. The communication path between flow paths is provided at at least one position between the inflow side communication section and the outflow side communication section near the inflow side communication section.
5. The boiling cooling device according to any one of items 1 to 4.