JPH10178292A - Boiling cooler and housing cooler employing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a boiling cooler in which the body size can be reduced through a novel structure while preventing the level of coolant from lowering. SOLUTION: The boiling cooler comprises a fluid separator 2 for separating a high temperature fluid from a low temperature fluid, a coolant tank 3a disposed on the high temperature fluid side while encapsulating a coolant, connecting tubes 34a, 34b one of which is connected with the coolant tank 3a, and a radiator 3b disposed on the low temperature fluid side while being connected with the other connecting tubes 34a, 34b. The coolant tank 3a comprises a plurality of tubular members, i.e., heat absorbing tubes 31a, arranged substantially in parallel with each other, wherein the tubular member is a flat tube having oval cross-section sectioned into a plurality of small passages vertically. Diameter (maximum) of each small passage is set at 0.5-1mm. Since the heat absorbing tubes 31a is flat, bubbles are combined easily in the way of ascent through boiling and since a large combined bubble ascends through the flat heat absorbing tube while spreading, the liquid coolant is entrained together. Consequently, a lowered liquid level can be raised and the coolant liquid level can be prevented from lowering.

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 that causes a refrigerant to boil with the heat of a high-temperature medium and then condenses to release the heat of the high-temperature medium.

[0002]

2. Description of the Related Art Heretofore, there has been a case where a heating element such as an electronic component is housed in a sealed housing and used. In this case, as a method of cooling the heating element, a method of exchanging heat between the air inside the housing and the air outside the housing has been performed because it is not possible to directly take in outside air into the inside of the housing for ventilation. Assuming that the number of components is small and the amount of heat transfer is large,
There is known a method using a heat pipe (a refrigerant is sealed inside) disposed through a housing as shown in Japanese Patent Application Publication No. 20-200.

In a heat pipe 200 as disclosed in Japanese Patent Publication No. 2-3320, the refrigerant inside the housing is boiled by the high-temperature air inside the housing, and the heat is radiated by condensing the refrigerant in a heat radiating portion arranged outside the housing. Then, the condensed refrigerant is dropped again on the heat absorbing portion located inside the housing. However, as described in Japanese Patent Publication No. 2-3320, the heat pipe has a structure in which the vapor refrigerant that rises by boiling and the condensed refrigerant that condenses and moves in the same pipe. Is not performed efficiently.

[0004] Therefore, as disclosed in Japanese Utility Model Application Laid-Open No. 62-162847, a boiling cooling device capable of efficiently radiating heat by circulating a refrigerant is known. Shokai 62
In the boiling cooling device disclosed in Japanese Patent No. 162847, a heating element is fixed to a refrigerant tank, heat generated by the heating element is absorbed by the refrigerant sealed in the refrigerant tank, and the refrigerant vaporized by the heat absorption is cooled by the refrigerant tank. Is condensed and liquefied by a radiator disposed above, and the condensed and liquefied refrigerant is returned to the refrigerant tank via a refrigerant return pipe inserted into the refrigerant tank.

[0005]

However, in the boiling cooling device disclosed in Japanese Utility Model Application Laid-Open No. 62-162847, even if the refrigerant is sealed so as to cover the heat receiving surface of the refrigerant tank at the time of manufacture, the boiling will occur when the heat is actually received. The temperature inside the cooling device rises,
The internal pressure also increases. This increases the gas phase ratio of the refrigerant.
Further, the amount of refrigerant in the path from boiling in the refrigerant tank to condensing in the radiator and returning to the refrigerant tank increases. For these reasons, as the amount of heat received increases, the liquid level of the refrigerant in the refrigerant tank decreases, the area where heat can be transferred by boiling decreases, and performance deteriorates.

To avoid this, if a large amount of refrigerant is added at the time of production, when the amount of heat received is not large, the liquid level of the refrigerant becomes too high, and the area that should be used for condensation in the radiator is reduced. If the amount of the refrigerant liquid is unnecessarily large, the circulation path of the boiling steam is restricted and the circulation of the refrigerant is hindered. As a result, there is a problem that heat radiation performance is reduced. Also,
The deterioration of the heat radiation characteristics leads to an increase in physique.

The present invention has been made based on the above circumstances, and a first object of the present invention is to reduce the size of a physique with a novel configuration. A second object is to obtain a boiling cooling device that can prevent a decrease in the liquid level of the refrigerant.

[0008]

According to the first aspect of the present invention, the refrigerant sealed in the refrigerant tank receives heat of a high-temperature portion in the tubular member constituting the refrigerant tank and evaporates. .
The boiling vaporized refrigerant is bubbled, rises up the tubular member constituting the refrigerant tank, crosses the liquid surface of the refrigerant, and is then sent out as a gas-phase refrigerant to a radiator arranged above the refrigerant tank. In the radiator, the heat of the refrigerant is released to a low-temperature portion, and the refrigerant is condensed and liquefied. The condensed and liquefied refrigerant returns to the refrigerant tank by gravity and receives heat again.

In the present invention, at least the refrigerant tank is formed of a tubular member, and the tubular member is a porous tube having a plurality of small passages therein. Rises and pushes up the apparent coolant level. Thus, it is possible to prevent the refrigerant liquid level from lowering and exposing the heat receiving surface of the refrigerant tank to lower the heat radiation performance. Further, the refrigerant is sealed more than necessary in order to prevent the liquid level of the refrigerant from lowering, thereby preventing the circulation of the vapor refrigerant and preventing the liquid level from rising to the radiator and lowering the heat radiation performance of the radiator.
As a result, since heat can be efficiently received and radiated, the size can be reduced.

According to the second aspect of the present invention, the refrigerant tank is
Since a plurality of heat absorbing tubes arranged substantially in parallel and each heat absorbing tube is a perforated tube, the entire refrigerant can be distributed in the small passages of each heat absorbing tube, further reducing the liquid level per small passage. Can be reduced. Thus, due to the generation of bubbles and the rise of bubbles, the liquid refrigerant rises in each small passage, and can further push up the apparent refrigerant liquid level.

According to the third aspect of the present invention, since the small passage of the refrigerant tank extends from the heat-absorbing lower communication portion to the heat-absorbing upper communication portion, the liquid refrigerant rises in each small passage. And
In addition to the effect of the first aspect of the present invention, the apparent coolant level can be further increased. Further, heat can be absorbed evenly from the upper part to the lower part of the refrigerant tank. According to the fourth aspect of the present invention, the radiator includes a plurality of radiating tubes arranged substantially in parallel, and each of the radiating tubes is a perforated tube. In addition to the effects of the first aspect, there is an effect that the heat radiation characteristics can be further improved.

According to the fifth aspect of the present invention, since the small passage extends from the lower radiating side communication portion to the upper radiating side communication portion side, in addition to the effect of the fourth aspect, Further, there is an effect that the condensed refrigerant can be efficiently returned to the refrigerant tank, and the refrigerant can be efficiently circulated. According to the sixth aspect of the present invention, the refrigerant boils and evaporates in each small passage. When the amount of heat absorption increases and boiling approaches the limit, bubbles become large and the heat absorption performance in the small passage becomes saturated,
Since the tubular member is arranged in the refrigerant tank such that a plurality of small passages are stacked in the direction in which the high-temperature fluid flows, the refrigerant in the small passage located in front (upstream of the high-temperature fluid) is vaporized in order. As the heat that cannot be absorbed is absorbed by the small passage at the subsequent stage (downstream of the high-temperature fluid), it is possible to prevent the heat radiation characteristics from being reduced.

According to the seventh aspect of the present invention, since the outer shape of the tubular member has a flat cross section, it has a large contact area with high-temperature air, promotes boiling in the tubular member, and further prevents the liquid level from lowering. The effect is obtained. Thereby, in addition to the effect of the invention described in claim 1, there is an effect that the heat radiation characteristic can be further improved. According to the invention described in claim 8, a small passage is constituted by a plurality of passages surrounded by a plurality of plate-like members and two wall surfaces. There is an effect that heat conductivity with the refrigerant in the passage can be improved.

According to the ninth aspect of the present invention, since the tubular member has a substantially O-shaped cross section, in addition to the effect of the first aspect, the heat transfer between the outside and the refrigerant in the small passage is further improved. The effect that can be made to play is produced. According to the invention of claim 10 wherein, the diameter of the small passages in the tubular member, to be set to 1 to 10 ² times the cell diameter at the boiling surface withdrawal of the refrigerant does not interfere with the boiling refrigerant. Since the amount of the refrigerant that contacts the wall surface can be reduced, the heat capacity of the refrigerant is reduced, and the refrigerant is more likely to boil. As a result, the bubbles are united and the liquid refrigerant can be immediately lifted in the small passage by the bubbles.

According to the eleventh aspect of the present invention, the first aspect is provided.
In addition to the effects of the invention according to any one of claims 10 to 10,
Further, there is an effect that heat of the high-temperature fluid side can be efficiently radiated to the low-temperature fluid side. According to the invention of claim 12,
Since the refrigerant is injected into the refrigerant tank to a position where the liquid level when it is not vaporized substantially coincides with the position of the fluid separator, the liquid level of the refrigerant can be further prevented from lowering.

According to the thirteenth aspect of the present invention, the refrigerant vaporized in the refrigerant tank is sent to the radiator by the high-temperature side communication pipe, and the refrigerant condensed and liquefied by the radiator is returned to the refrigerant tank by the low-temperature side communication pipe. Therefore, the refrigerant can be efficiently circulated. According to the fourteenth aspect of the present invention, in the internal communication chamber, the refrigerant tank is arranged so that a plurality of small passages are stacked in the direction in which the high-temperature fluid flows, and the radiator is further arranged in the direction in which the low-temperature fluid flows. Since a plurality of small passages are arranged so as to be stacked on each other, an effect equivalent to the effect of the invention described in claim 6 can be obtained.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 case where a cooler according to a first embodiment is applied to a casing cooling device.
FIG. 2 is a plan view of FIG. 1 as viewed from the outside, that is, from the left side of the drawing. 3 is a perspective view of the boiling cooling device 1, FIG. 4 is a front view in FIG. 3, FIG. 5 is a partial sectional view in FIG. 4, FIG. 6 is a II-II sectional view in FIG. It is explanatory drawing of the boiling cooling device 1 shown in FIG.

The cooler according to the present embodiment is mounted in a housing 80 forming a closed space 9 as shown in FIG. The sealed space 9 accommodates, for example, a transceiver such as a communication device and a heating element 7 including a power amplifier for driving the transceiver. Figure 1,
As shown in FIG. 2, a closed space 9 is provided above and below the cooler, respectively.
The openings 13 and 14 are provided to communicate with the opening. The cooler is provided with a vent 13 which is an opening communicating with the upper part of the closed space 9 in order to take in the gas in the closed space 9 into the heat transfer space 11 on the high temperature side. Specifically, an air passage 23 extending vertically in the cooler between the side wall surface 9a and the partition wall 22.
The upper end of the air passage 23 is opened as an air vent 13 in the upper part of the closed space 9 (above the fluid separator 2). At the outlet of the ventilation hole 13, the introduction of the cool air from the lower part of the closed space 9 is suppressed, and the introduction opening at the upper part of the closed space 9 is made so as to positively introduce the hot air from the upper part of the closed space 9. A mouth 221 is formed.

As a result, the gas heated to a high temperature by the heat of the heating element 7 is introduced from the ventilation port 13 into the air passage 23 and smoothly guided to the refrigerant tank 3a, so that the temperature in the closed space 9 is kept uniform. be able to. That is, since the gas heated to high temperature by the heat generated from the heating element 7 rises in the closed space 9 by convection, the cooling efficiency in the closed space 9 is better when the vent 13 is provided in the upper part in the closed space 9. Good. In other words, when the vent 13 is located at a position lower than the fluid separator 2, relatively low-temperature gas in the closed space 9 is introduced from the vent 13 into the air passage 23 and guided to the refrigerant tank 3a.
There is a possibility that the cooling efficiency in the closed space 9 is reduced.

Further, each of the heat transfer spaces 1 on the high temperature side and the low temperature side
In the first and the second, the gas passing through the refrigerant tank 3a and the radiator 3b smoothly flows from the suction ports 13 and 16 to the discharge ports 14 and 17 respectively.
The entire boiling cooling device 1 is arranged in a state inclined in the front-back direction (the left-right direction in FIG. 1). Thereby, the refrigerant tank 3a
In addition, since the change in the flow direction of the gas passing through the radiator 3b can be moderated, the airflow path loss in a narrow space can be reduced. As a result, the size of the internal fan 15 in the closed space 9 can be reduced, and the amount of heat generated by the internal fan 15 can be reduced. Therefore, the amount of heat generated by the heating element 7 can be increased accordingly (that is, the cooling capacity can be reduced). If the size of the internal fan 15 is increased in order to raise the heat, the calorific value of the internal fan 15 increases, and as a result, the calorific value of the heating element 7 cannot be increased.

The internal fan 15 as an internal circulation fan is composed of an axial fan, and sucks the high-temperature air (high-temperature air as a high-temperature fluid) introduced into the ventilation port 13 through the inlet port 221 to suck the refrigerant in the refrigerant tank 3a. Between the endothermic tubes 31a. The internal fan 15 is connected to the heat absorbing tube 3 of the refrigerant tank 3a.
It is inclined so as to be parallel to 1a. Note that the internal fan 15 may be inclined with respect to the heat absorbing tube 31a of the refrigerant tank 3a.

The external fan 18 as an external circulating fan is composed of an axial fan, and sucks the low-temperature air (low-temperature air as a low-temperature fluid) introduced through the ventilation port 16 to each radiator pipe of the radiator 3b. It is introduced between 31b. The external fan 18 is arranged to be inclined with respect to the radiator tube 31b of the radiator 3b. On the discharge side of the external fan 18, there is provided a deflecting plate 181 for deflecting the wind exiting the external fan 18 upward. The wind that has exited the external fan 18 passes through the vent 17 opened on the upper surface of the cooler by the deflecting plate 181, and is discharged to the outside.

On the side of the radiator 3b of the cooler in FIG. 1, a maintenance lid 9b for maintaining the radiator 3b is provided.
Is provided. Since the radiator 3b introduces external air, dust and dirt contained in the external air are removed from the radiator tube 31b.
Although there is a possibility of clogging between them, the provision of the maintenance lid 9b makes it possible to easily remove them. The maintenance lid 9b is fixed to the cooler during operation and is opened during cleaning.

FIG. 3 is a perspective view showing a boiling cooling device.
A plurality of ebullient cooling devices are stacked in the direction in which the high-temperature fluid and the low-temperature fluid flow, respectively. As shown in FIGS. 3 and 4, the boiling cooling device 1 is a fluid separator 2 that separates a high-temperature fluid (for example, high-temperature air) from a low-temperature fluid (for example, low-temperature air). A refrigerant tank 3a composed of a plurality of heat absorbing tubes 31a disposed therein, a refrigerant 8 (not shown) sealed in the heat absorbing tube 31a and receiving heat from a high-temperature fluid and boiling and evaporating, one of which is airtight to the refrigerant tank 3a. And a pair of low-temperature side communication pipes 34a, high-temperature side communication pipes 34b, low-temperature side communication pipes 34a, and high-temperature side communication pipes 34b which are connected to each other and extend to the low-temperature fluid side through the fluid separator 2. And a radiator 3b, which is disposed closer to the low-temperature fluid than the fluid separator 2 and is composed of a plurality of radiator tubes 31b, and is fused between the heat absorbing tubes 31a of the refrigerant tank 3a (for example, brazed). Heat receiving fins 6a joined in the Radiating fins 6b joined in a fused state (for example, brazed state) between the respective radiating tubes 31b of the heat sink 3b, between the refrigerant tank 3a and the low-temperature side communication tube 34a, and between the radiator 3b and the low temperature. A heat insulating material buried between the side communication pipe 34b and a heat conduction suppressing means for suppressing heat transfer from the refrigerant tank 3a to the low temperature communication pipe 34a and heat transfer from the radiator 3b to the high temperature communication pipe 34b. 50 (for example, urethane foam which is a foamable resin).

The fluid separating plate 2 forms, for example, one wall surface of a closed space in which the inside has a high temperature, is made of a metal material such as aluminum, and is integrally joined with the low-temperature communication pipe 34a and the high-temperature communication pipe 34b. (Eg brazing).
The fluid separator 2 is provided with an insertion hole through which the low-temperature communication pipe 34a and the high-temperature communication pipe 34b pass. Note that a resin such as rubber for suppressing heat transfer may be interposed between the fluid separator 2 and each communication pipe. The fluid separator 2 may be insulated from the surroundings (at least one of a low-temperature fluid and a high-temperature fluid) with a heat insulating material made of a foamable resin such as urethane foam.

The refrigerant tank 3a is provided with a plurality of heat absorbing tubes 31a as a plurality of tubular members arranged substantially in parallel with each other, and a heat absorbing side lower communicating portion disposed below the heat absorbing tubes 31a and communicating these heat absorbing tubes 31a downward. And a heat-absorbing-side upper communication portion 42 disposed above the heat-absorbing tube 31a and communicating the heat-absorbing tube 31a upward. The heat absorbing tube 31a is a flat tube having a cross section of an elliptical shape (or an elongated rectangular shape) made of a metal material having excellent heat conductivity (for example, aluminum or copper).

FIG. 5 is a partial sectional view showing the heat absorbing tube 31a. In this figure, the heat receiving fins 6a are omitted.
As shown in the figure, the heat absorption tube 31a is a flat tube having an elliptical cross section, and has a plurality of internal partition plates 33 formed therein in the vertical direction (substantially square cross section). . With this internal partition plate 33, the heat absorbing tube 31a is configured as a perforated tube whose inside is divided into a plurality of small passages 330. That is, the tubular member constituting the heat absorption tube 31a is provided with two opposing wall surfaces and a plurality of plate members in contact with the two wall surfaces inside, and is surrounded by the plurality of plate members and the two wall surfaces. Small passage 3 with multiple passages
30 can be said to be configured. As a result, there are effects such as improvement of pressure resistance performance and improvement of heat absorption efficiency due to an increase in contact surface area with the refrigerant. The heat absorbing tube 31a can be easily formed by extrusion. The diameter of each small passage 330 (the maximum diameter of each side when the small passage is rectangular, and the maximum diameter when the small passage is circular or elliptical) is the bubble when the refrigerant boils and leaves the inner wall of the heat absorbing tube. preferably from 1 to 10 ² times the diameter, in the present embodiment is set to 0.5 to 1 mm. The heat absorbing tube is arranged such that the small passages 330 open in the vertical direction (from the heat absorbing side lower communicating portion 41 to the heat absorbing side upper communicating portion 42), and the small passages 330 are stacked in the direction in which the high-temperature fluid flows. Are arranged as follows.

The radiator 3b includes a plurality of radiator tubes 31b arranged substantially in parallel and a lower portion of the radiator tubes 31b.
The heat radiation pipe 31b includes a heat radiation side lower communication part 43 that communicates downward, and a heat radiation side upper communication part 44 that is disposed above the heat radiation pipe 31b and communicates the heat radiation pipe 31b upward. The heat radiating tube 31b is also formed by forming a metal material having excellent heat conductivity (for example, aluminum or copper) into a flat tube having a cross-sectional shape of an ellipse (or an elongated rectangle). Similarly to the heat absorbing tube 31a shown in FIG. 5, the heat radiating tube 31b is also formed by a flat tube having an elliptical cross-sectional shape, and has a plurality of internal partitioning plates 33 formed therein in the vertical direction (see FIG. 5). Omitted). As a result, there are effects such as improvement of pressure resistance performance and improvement of heat radiation efficiency due to an increase in contact surface area with the refrigerant. This radiator tube 31b can also be easily formed by extrusion. The heat radiating pipe 31b has a small passage 3 similarly to the heat absorbing pipe 31a.
30 are arranged so as to open in the up-down direction (radiation side lower communication part 43 to heat radiation side upper communication part 44), and small passages 330 are arranged so as to be stacked in the direction in which the low-temperature fluid flows.

The high-temperature communication pipe 34b is connected to the heat-absorbing upper communication section 42 of the refrigerant tank 3a and the heat-radiation-side upper communication section 44 of the radiator 3b.
And the refrigerant 8 boiled and vaporized in the refrigerant tank 3a is sent to the radiator 3b. The high-temperature side communication pipe 34b is substantially parallel to the heat absorption pipe 31b and at a predetermined interval (preferably each heat absorption pipe 3b).
1b are arranged with an interval larger than the distance between them, more preferably an interval of twice or more the interval between them.

The low-temperature side communication pipe 34a is connected to the heat-radiation-side lower communication part 43 of the radiator 3b and the heat-absorption-side lower communication part 41 of the refrigerant tank 3a.
The refrigerant 8 cooled and liquefied by the radiator 3b is returned to the refrigerant tank 3a. The low-temperature side communication pipe 34a is substantially parallel to the heat radiating pipe 31a and at a predetermined interval (preferably each heat radiating pipe 31a
They are arranged with an interval larger than the distance between them, and more preferably, at least twice the interval between them.

The refrigerant 8 is HFC-134a (chemical formula: C
H ₂ FCF ₃ ), water, etc., in a range where the pressure inside the container is not so high (in the case of HFC-134a, for example, a pressure of several tens of atmospheres or less), it is possible to boil with a high temperature fluid and condense with a low temperature fluid. Is set to Specifically, the refrigerant 8 is selected to be boiled at a maximum of 100 ° C. or less. Here, as the refrigerant, a refrigerant having a plurality of compositions may be mixed, or a refrigerant mainly having a single composition may be used. Further, the refrigerant 8 is sealed in the refrigerant tank 3a to such an extent that the liquid level coincides with the position of the fluid separator 2 during non-operation, or to a certain extent in the heat absorbing upper communication part 42. It is preferable that the liquid level of the refrigerant does not reach the radiator tube 31b during operation. However, the refrigerant 8 is sealed in the heat absorbing tube 31a.
And after the heat absorbing fin 6a and the heat radiating fin 6b are brazed to the heat radiating tube 31b, respectively.

The heat receiving fins 6a are arranged between the heat absorbing tubes 31a, and the heat radiating fins 6b are arranged between the heat radiating tubes 31b. Heat receiving fin 6a and heat radiating fin 6b
Is a corrugated fin formed by alternately pushing back a thin plate (having a thickness of about 0.02 to 0.5 mm) of a metal (for example, aluminum) having excellent heat conductivity to form a corrugated fin.
a, It is brazed to the flat outer wall surface of the heat radiating tube 31b (that is, joined in a fused state). The heat receiving fins 6a facilitate the transfer of heat on the high-temperature fluid side to the refrigerant 8, and at the same time improve the strength of the heat absorbing tube 31a. The radiating fins 6b facilitate the transfer of the heat of the refrigerant 8 to the low-temperature fluid side, and at the same time improve the strength of the radiating tube 31b.

A high-temperature passage 35a through which high-temperature fluid as a high-temperature fluid flows is formed in the high-temperature portion, and a low-temperature passage 35b through which low-temperature air as the low-temperature fluid flows is formed in the low-temperature portion. And as a heat conduction suppressing means, at least between the refrigerant tank 3a and the low temperature side communication pipe 34a, the radiator 3b
A plate-like member disposed between the first and second communication pipes 34b is used.

Further, as the heat conduction suppressing means, there is provided a heat insulating material 50 made of, for example, a foamable resin, more specifically, urethane foam. As shown in FIGS. 4 and 6, the heat insulating material 50 is disposed between the refrigerant tank 3a and the low-temperature side communication pipe 34a and between the radiator 3b and the high-temperature side communication pipe 34b.
The heat insulating material 50 transfers heat from the refrigerant tank 3a to the low-temperature side communication pipe 34a, and the heat transfer from the high-temperature side communication pipe 34b to the radiator 3 respectively.
The heat transfer to b is suppressed. In FIG. 6, each refrigerant tank is configured by alternately stacking heat absorbing tubes 31a and heat receiving fins 6a, and each of the heat absorbing tubes 31a has a small passage.

Here, the heat insulating material 50 is provided between the refrigerant tank 3a and the low-temperature communication pipe 34a, and between the radiator 3b and the high-temperature communication pipe 34b.
And covers the outer circumferences of the low-temperature communication pipe 34a and the high-temperature communication pipe 34b. This coating may cover the entire outer circumference of the low-temperature communication pipe 34a and the high-temperature communication pipe 34b, or may cover a part (a part in the vertical direction). The heat insulating material 50 is connected to each of the communication pipes 34a, 3a.
4b does not cover the entire outer periphery, and the refrigerant tank 3a and the low-temperature side communication pipe 3
4a, and between the radiator 3b and the high-temperature side communication pipe 34b.

The high-temperature passage 35a is composed of the fluid separating plate 2 and a high-temperature side partition member 50d which is a plate-like member surrounding the outer periphery of the refrigerant tank 3a. The coolant tank 3a is disposed in the high-temperature passage 35a, and the low-temperature side communication pipe 34a is separated into a region at a lower temperature than the high-temperature passage 35a. This can be achieved by disposing the low-temperature side communication pipe 34a outside the high-temperature side partition member 50d as shown in FIG. And the low-temperature side communication pipe 3 on the upstream side through which the high-temperature air flows
A bracket is arranged on the entire surface of 4a to prevent high-temperature air from flowing into the space where the low-temperature side communication pipe 34a is arranged.

Similarly, the low-temperature passage 35b is composed of the fluid separating plate 2 and a low-temperature side partition member 50c formed of a plate-like member surrounding the outer periphery of the radiator 3b. And radiator 3b
Is disposed in the low temperature passage 35a, and the high temperature side communication pipe 34b
Is separated into a region having a higher temperature than the low-temperature passage 35b. This is because the high temperature side communication pipe 34b is connected to the low temperature side partition member 50.
This can be achieved by arranging outside c.

The flange serves to fix the ebullient cooling device, and serves to maintain a predetermined distance between the refrigerant tank 31a and the low-temperature side communication pipe 34a. At predetermined intervals. Further, the boiling cooling device 1 is arranged in parallel such that the refrigerant tanks are arranged in parallel and the radiators are arranged in parallel.

Next, the operation of this embodiment will be described. The heating element 7 generates heat by operating, and the inside of the closed space 9 becomes high temperature. The internal fan 15 circulates the high-temperature air and introduces the high-temperature air into the refrigerant tank 3a. Refrigerant tank 3
The refrigerant 8 sealed in each of the heat absorbing tubes 31a receives heat transmitted from the high-temperature air through the heat receiving fins 6a and evaporates. The vaporized refrigerant vapor is condensed and liquefied on the inner wall surface in each radiator pipe 31b of the radiator 3b which is exposed to the low-temperature fluid and has a low temperature, and the latent heat of condensation is transmitted to the low-temperature air through the radiation fins 6b. Refrigerant 8 condensed and liquefied by radiator 3b
Drops along the inner wall surface due to its own weight to the lower heat-communication side communication portion 41 of the refrigerant tank 3a. The external fan 18 continuously sucks low-temperature air from the outside and introduces it into the radiator 3b. By repeatedly boiling and condensing and liquefying the refrigerant 8, the heat of the heating element 7 can be efficiently radiated to the outside without mixing the high-temperature air and the low-temperature air.

Hereinafter, effects of the present embodiment will be described. Such a boiling cooling device, even if the refrigerant is sealed up to the B level in FIG. 7 so as to cover the heat receiving surface of the refrigerant tank during manufacturing,
When the heat is actually received, the temperature inside the boiling cooling device rises and the internal pressure also rises.The refrigerant exists in a closed vessel in a liquid phase and a gas phase that are balanced by the temperature inside the vessel. The rise in temperature increases the proportion of refrigerant in the gas phase and decreases the proportion of liquid phase, and the amount of refrigerant in the path from boiling in the refrigerant tank to condensation in the radiator and returning to the refrigerant tank increases. Accordingly, as the amount of heat received increases, the coolant level in the coolant tank decreases (C level), and the area in which heat can be transferred by boiling decreases, and the performance decreases.

In order to avoid this, if a large amount of refrigerant (A level or more) is added at the time of production, when the amount of heat received is not large,
The refrigerant liquid level becomes too high, and the area that should be used for condensation in the radiator 3b is reduced, or the diameter of the circulation path of the refrigerant vapor in the heat-absorbing-side upper communication part 42 of the refrigerant tank 3a is reduced, and the refrigerant is vaporized by the heat-absorbing tube 31a. The cooled refrigerant vapor cannot smoothly rise to the high-temperature side communication pipe 34b. As a result, there is a problem that heat radiation performance is reduced.

Particularly, this phenomenon is caused by a heat pipe type in which the liquefied refrigerant returns from the upper part of the heat absorbing tube wall as shown in FIG.
The refrigerant 8 is connected to a low-temperature communication pipe 34 different from the high-temperature communication pipe 34b.
This has a greater effect on the type that returns to the heat-absorbing lower communication portion 41 than a. FIG. 8 is a diagram illustrating an effect obtained by using a perforated tube for the refrigerant tank 3a. Here, FIGS. 7A and 7B are reference diagrams, and FIGS. 7C and 7D are explanatory diagrams of the present application.

FIG. 8 (a) shows a heat absorbing tube 31a for preventing the performance of the refrigerant 8 from being lowered due to a decrease in the liquid level of the refrigerant 8 during heat absorption.
Is a cross-sectional view of the heat absorbing tube 31a when is flattened, and FIG. 2B is a cross-sectional view taken along line BB of FIG. FIG. 8A,
As shown in (b), since the heat absorbing tube 31a is flat, the air bubbles tend to coalesce while boiling and rising, and when the air bubbles that have become large as a result rise in the flat heat absorbing tube, they spread into the heat absorbing tube and rise. To raise the liquid refrigerant together. As a result, the lowered liquid level can be lifted.

FIG. 8 (c) is a cross-sectional view of the heat absorbing tube 31a when the heat absorbing tube 31a is a porous tubular member in FIG. 8 (a), and FIG. FIG.
As shown in FIGS. 8 (c) and 8 (d), by making the endothermic tube 31a a porous tubular member, the bubbles become almost the same in diameter, and the liquid refrigerant rises between the bubbles. , Greatly raises the liquid level. This can prevent the coolant level from lowering. In addition, since this effect is due to bubbles generated by heat absorption, when the heat absorption is small (the decrease in the liquid level is small), the lifting effect by the bubbles is reduced, and the liquid level does not become too high. Porous tubular member, if it is the equivalent diameter of 1 to 10 ^double order of cell diameter at the boiling surface withdrawal of the tube diameter of the one refrigerant, not interfere with the boiling of the refrigerant, immediately by bubble coalescence The effect of lifting the liquid refrigerant by bubbles in the pipe can be obtained.

Further, as shown in FIGS. 8 (a) and 8 (c), by flattening the heat absorbing tube 31a (reducing the distance between the two planes), the united bubbles are sandwiched between the tube walls, and as shown in FIG. Crush and rise. At this time, a region where the liquid film of the liquid refrigerant becomes thinner (δ> liquid film) is formed between the heat absorbing tube 31a and the bubble, and in this region, the heat received from the tube wall is transmitted to the thin liquid refrigerant. Since the heat capacity of the thin liquid refrigerant is small and the amount of heat escaping to the other liquid refrigerant by heat conduction is reduced, the adjacent bubbles evaporate immediately. This is an evaporation phenomenon having a smaller thermal resistance than "boiling" which generates bubbles in the liquid refrigerant, and the performance is further improved.

However, as shown in FIG.
When the area where the liquid refrigerant becomes thin between the air bubbles becomes excessively wide,
Due to the evaporation phenomenon with a small thermal resistance, the thin liquid refrigerant is immediately vaporized, and the supply of the refrigerant from the surrounding thick liquid refrigerant side may not be enough. In that case, the region where evaporation occurs is reduced. However, by using a porous tubular member as shown in FIG. 8C, the size of the coalesced bubbles is restricted by the wall of the small passage 330, and there is an effect that the above-mentioned phenomenon is unlikely to occur. Further, there is a merit that the wall surface area is further increased and the effect of reducing thermal resistance is further obtained.

In the case of a boiling cooling device which receives heat from a high-temperature fluid and boils and condenses the refrigerant enclosed therein as in the present invention, the direction in which the high-temperature fluid flows and the boiling and rise of the enclosed refrigerant rise. The direction of the flowing stream is closer to right angle than parallel. FIG. 10A shows the endothermic tube 31 shown in FIG.
FIG. 10 is a schematic diagram showing a state of generation of bubbles in FIG.
FIG. 11B is a diagram showing a temperature distribution of the high-temperature air passing near the heat absorbing tube 31a shown in FIG. FIG.
FIG. 10C is a schematic diagram showing a state of generation of bubbles in the heat absorbing tube 31a shown in FIG. 8C, and FIG.
It is the figure which showed the temperature distribution of the hot air which passes near the heat absorption tube 31a shown to (c). In the case of a tubular member having a single hole as shown in FIGS. 10A and 10B, boiling starts from the inlet side of the high-temperature fluid in the tube, and the bubbles coalesce and rise. Thereby, especially when the length of the heat absorbing tube is long, the upper part of the heat absorbing tube is covered with the coalesced bubbles, and when the bubbles are large and the calorie of the high-temperature fluid is large, the efficiency of the upper part of the heat absorbing tube may be reduced. That is, as shown in FIG.
Among the high-temperature air introduced in 1, the high-temperature air introduced into the lower part III and the middle part II decreases to the temperature T2 as it passes near the intake pipe 31, but the high-temperature air introduced into the upper part I Cannot be transmitted to the endothermic tube 31a, and only decreases to T3 higher than T2. In contrast, FIG.
In the case of the endothermic tube 31a shown in FIG. 0 (c), since a porous tubular member is used in the flow direction of the high-temperature flow, the refrigerant in the tube on the downstream side also boils at the upper part I of the endothermic tube 31a. Can be reduced. This can prevent performance degradation.

The radiator tube 31b exchanges heat with a low-temperature fluid outside the closed casing. Therefore, the air flow path of the low-temperature fluid on the side of the radiator tube 31b is directly connected to the environment outside the enclosure. FIG.
As shown in the figure, if it is a general heat pipe type circular pipe, the wake (flow of air passing near the pipe) will be turbulent,
Noise is generated. On the other hand, by using a flat heat radiation tube, the turbulence of the wake of the heat radiation tube is reduced, and the ventilation resistance is also reduced, so that noise can be reduced even with the same ventilation volume. This is a great advantage especially on the side of the radiator connected to the outside of the housing.

When taking in an external low-temperature fluid,
We take in garbage together. At this time, the radiator 3b is periodically cleaned, but the cleaning is often performed from the front of the radiator 3b using a cleaning device or the like. At this time, the flat radiator has few shaded portions and can be efficiently cleaned. In addition, due to the structure of sandwiching the fin between flat tubes,
It is thin and easily deformed, which protects the heat receiving and radiating fins. The perforated heat-absorbing tube and heat-radiating tube, and the cross-shaped structure are useful for improving brazing properties by increasing the rigidity of the tube when laminating the tube and fins and brazing integrally. Also, by using an extruded material, it can be manufactured at low cost. Since the equivalent diameter of each tube becomes smaller, the pressure resistance increases. In addition, due to the flat structure, the possibility that foreign matter from the outside of the housing (implantation of foreign matter due to tucks) damages the radiator tube in which the refrigerant is sealed is reduced.

Further, the present embodiment has the following effects. (1) A high-temperature side partition member 50d that partitions the high-temperature passage 35a together with the fluid separator 2 is provided between the low-temperature side communication tube 34a and the radiator tube 31a. It is separated into a lower temperature region than the high temperature passage 35a. As a result, the high-temperature passage to the low-temperature side communication pipe 3
4a can be suppressed. Also, the high-temperature side communication pipe 34
b and the heat absorbing tube 31b, there is a low-temperature side partition member 50c for partitioning the low-temperature passage 35b together with the fluid separator 2, and the low-temperature side partition member 50c causes the high-temperature side communication pipe 34b to have a higher temperature than the low-temperature passage 35a. Separate into regions. Thereby, heat conduction from the low-temperature side communication pipe 34a to the low-temperature passage 35b can be suppressed. As a result, it is possible to prevent the circulation of the refrigerant from being hindered.

(2) The boiling cooling device can be divided into a blowable portion (fin portion) and a blowable portion (low-temperature communication pipe 34a, high-temperature communication pipe 34b). When a fan (not shown) simply blows air to a multistage boiling cooling device such as this embodiment, the blown air contracts when flowing into the fin portion, becomes an expanded flow after passing through the fin portion, and reduces pressure loss. Can occur. On the other hand, in the present embodiment, the high temperature passage 35a is defined by the fluid separator 2 and the high temperature side partition member 50d, and the low temperature passage 35b is defined by the fluid separator 2 and the low temperature side partition member 50c. The air flowing through each of the passages 35a and 35b flows linearly, thereby reducing pressure loss. This is useful for reducing the power consumption of the fan and reducing the blowing noise. In addition, since the cross-sectional area of the air blow is limited as compared with the case where no partition is made, the flow rate of the fin portion can be increased.

(3) The high-temperature side communication pipe 34 b is
b, and is disposed at a predetermined interval (preferably, an interval larger than the distance between the heat absorbing tubes 31b, more preferably, twice or more the interval between the heat absorbing tubes 31b).
The vapor refrigerant, which evaporates and rises in the refrigerant tank 3a, radiates heat to the low-temperature radiator 3b via the high-temperature communication pipe 34b, and can be prevented from falling in the high-temperature communication pipe 34b. Further, the low-temperature side communication pipe 34a is communicated with the heat-radiation-side lower communication part 43 of the radiator 3b and the heat-absorption-side lower communication part 41 of the refrigerant tank 3a, and the refrigerant 8 cooled and liquefied by the radiator 3b is supplied to the refrigerant tank 3a. return. The low-temperature side communication pipe 34a is
1a, it is arranged with a predetermined interval (preferably, an interval larger than the distance between the heat radiating tubes 31a, more preferably, twice or more the interval between the heat radiating tubes 31a). The condensed refrigerant, which is condensed and liquefied in 3b and descends, absorbs heat from the high-temperature refrigerant tank 3a through the low-temperature communication pipe 34a, and can be prevented from receiving a rising force in the low-temperature communication pipe 34a. (4) Since the refrigerant tank 3a can receive heat in the plurality of heat absorbing tubes 31a, the heat absorbing efficiency is improved. The refrigerant that boils and evaporates due to the heat absorption is transferred to the upper heat-absorbing-side upper communication section 42.
And the refrigerant is sent to the radiator 3b by the high-temperature side communication pipe 31b, so that the number of pipes for communicating the radiator 3b and the refrigerant tank 3a can be reduced, Processing can be facilitated. Similarly, the radiator 3b emits heat through the plurality of heat absorbing tubes 31b, so that the heat radiation efficiency is improved. The condensed and liquefied refrigerant is collected at the lower heat-radiation-side lower communication portion 43, and the refrigerant is sent to the refrigerant tank 3a by the low-temperature communication pipe 34a, so that the radiator 3b communicates with the refrigerant tank 3a. The number of tubes for the fluid separator 2 can be reduced, and the processing of the fluid separator 2 can be facilitated.

(5) A heat insulating material 50a is provided on the outer circumference of the low-temperature communication pipe 34a, and a heat insulating material 50b is provided on the outer circumference of the high-temperature communication pipe 34b. This can prevent the circulation of the refrigerant from being hindered. (6) Further, since the heat receiving fin 6a and the heat radiating fin 6b are joined in a state of being fused with the refrigerant tank 3a and the radiator 3b, respectively, the heat receiving fin 6a and the heat radiating fin 6b are connected to the refrigerant tank 3a and the heat radiator 3b. The heat resistance between each fin and the boiling cooling pipe can be reduced as compared with the case where the fins are mechanically attached. This makes it possible to further reduce the size of the entire boiling cooling device as compared with the case where the heat receiving fins 6a and the heat radiating fins 6b are mechanically attached to the refrigerant tank 3a and the radiator 3b.

Even in the heat pipe type boiling cooler as shown in FIG. 12, the refrigerant condensed in the upper radiating pipe 31b does not wet the entire wall of the heat absorbing pipe and descends. Of the refrigerant tank, the heat absorbing tube of the refrigerant tank is made of a porous tubular member, which has an effect of preventing the refrigerant liquid level from lowering.

[Brief description of the drawings]

FIG. 1 is a side view of a casing cooling device using a boiling cooling device according to a first embodiment.

FIG. 2 is a plan view of the case cooling device shown in FIG. 1 as viewed from the outside.

FIG. 3 is a perspective view showing a boiling cooling device according to the first embodiment.

FIG. 4 is a front view of the boiling cooling device in FIG. 3;

FIG. 5 is a partial sectional view of the boiling cooling device shown in FIG. 4;

FIG. 6 is a sectional view taken along the line II-II in FIG.

FIG. 7 is a schematic diagram for explaining the boiling cooling device of FIG. 4;

FIGS. 8A to 8D are explanatory diagrams of a boiling cooling device according to the first embodiment.

FIG. 9 is an explanatory diagram of a boiling cooling device according to the first embodiment.

FIGS. 10A to 10D are explanatory diagrams of a boiling cooling device according to the first embodiment.

FIGS. 11A and 11B are explanatory diagrams of a boiling cooling device according to the first embodiment.

FIG. 12 is a sectional view showing another configuration of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 boiling cooling device 11 high-temperature side heat transfer space 12 low-temperature side heat transfer space 13, 16 suction-side vent 14, 17 discharge-side vent 15 internal fan 2 fluid separator 22 partition wall 23 air passage 3 a refrigerant tank 3b Heat radiator 31a Heat absorption tube 31b Heat radiation tube 330 Small passage 33 Internal partition plate 34a Low temperature side communication tube (communication tube) 34b High temperature side communication tube (communication tube) 35a High temperature passage (high temperature portion) 35b Low temperature passage (low temperature portion) 41 Heat absorption Lower side communication part 42 Heat absorption side upper communication part 43 Heat radiation side lower communication part 44 Heat radiation side upper communication part 50a, b Heat insulating material (heat conduction suppressing means) 50c Low temperature side partition member 50d High temperature side partition member 6a Heat receiving fin 6b Radiation fin 7 Heating element 8 Refrigerant 9 Enclosed space 9a Wall surface

Claims (14)

[Claims] 1. A refrigerant tank in which a refrigerant that receives heat from a high-temperature part and evaporates and evaporates is enclosed therein, one of which is air-tightly connected to the refrigerant tank, and the other extends to a low-temperature part lower in temperature than the high-temperature part. And the communication pipe is airtightly communicated with the other of the communication pipes, is disposed above the refrigerant tank, and discharges heat of the refrigerant vaporized in the refrigerant tank to the low-temperature portion to condense the refrigerant. A radiator for liquefaction, wherein at least the refrigerant tank is formed of a tubular member, and the tubular member is a porous tube having a plurality of small passages therein. 2. The boiling cooling device according to claim 1, wherein the refrigerant tank comprises a plurality of heat absorbing tubes arranged substantially in parallel, and each of the heat absorbing tubes is a perforated tube. 3. The heat-absorbing side lower communication part, which is disposed below the plurality of heat-absorbing tubes and communicates the plurality of heat-absorbing tubes, and is disposed above the plurality of heat-absorbing tubes. A heat-absorbing-side upper communication portion for communicating the plurality of heat-absorbing tubes with each other, wherein the small passage extends from the heat-absorbing-side lower communication portion to the heat-absorbing-side upper communication portion. The boiling cooling device according to claim 2. 4. The boiling cooling device according to claim 1, wherein the radiator includes a plurality of radiating tubes arranged substantially in parallel, and each of the radiating tubes is a perforated tube. 5. A heat-dissipation-side lower communication portion disposed below the plurality of heat-dissipation tubes and communicating the plurality of heat-dissipation tubes, respectively.
A heat-dissipation-side upper communication portion disposed above the plurality of heat-dissipation tubes and communicating the plurality of heat-dissipation tubes, respectively, wherein the small passage extends from the heat-dissipation-side lower communication portion side to the heat-dissipation-side upper communication portion side The evaporative cooling device according to claim 4, wherein the elongate cooling device is extended toward the evaporator. 6. The high-temperature portion is a passage through which a high-temperature fluid flows, and the refrigerant member is provided with the tubular member such that the plurality of small passages are stacked in a direction in which the high-temperature fluid flows. The boiling cooling device according to any one of claims 1 to 5, characterized in that: 7. The boiling cooling device according to claim 1, wherein the outer shape of the tubular member has a flat cross section. 8. The tubular member has a flat shape having two opposing wall surfaces, and a plurality of plate members in contact with the two wall surfaces are arranged inside the tubular member. The boiling cooling device according to any one of claims 1 to 7, wherein the small passage is constituted by a plurality of passages surrounded by two wall surfaces. 9. The cooling apparatus according to claim 8, wherein the tubular member has a substantially O-shaped cross section. 10. The method of claim 1 in which the diameter of the small passages in the tubular member constituting the refrigerant tank, characterized in that it is set to 1 to 10 ² times the cell diameter at the boiling surface separation of the refrigerant The boiling cooling device according to claim 9. 11. A high-temperature fluid flows through the high-temperature portion,
The low-temperature fluid flows through the low-temperature portion, the high-temperature fluid and the low-temperature fluid are isolated by a fluid separator, and the refrigerant tank is disposed closer to the higher-temperature fluid than the fluid separator and receives heat from the high-temperature fluid, One of the communication pipes is air-tightly connected to the refrigerant tank, and the other is extended to the low-temperature fluid side through the fluid separator, and the radiator is disposed closer to the lower-temperature fluid side than the fluid separator. The boiling cooling device according to any one of claims 1 to 10, wherein the cooling device is provided to release heat of the boiling vaporized refrigerant to the low-temperature fluid. 12. The boiling according to claim 11, wherein the refrigerant is injected into the refrigerant tank until the liquid level when the liquid is not vaporized substantially coincides with the position of the fluid separator. Cooling system. 13. The communication pipe according to claim 1, wherein the communication pipe is a high-temperature communication pipe that sends the refrigerant vaporized in the refrigerant tank to the radiator, and a low-temperature communication pipe that returns the refrigerant condensed and liquefied by the radiator to the refrigerant tank. The boiling cooling device according to any one of claims 1 to 12, comprising: 14. A boiler / cooler according to claim 1, wherein a housing accommodating an electric device which generates heat when activated, and an internal communication communicating with the inside of the housing. And an internal circulation fan that generates the high-temperature fluid in the internal communication chamber by circulating air in a region including the electric device, and an external communication chamber that is communicated with the outside of the housing. An external circulation fan that generates the low-temperature fluid in the external communication chamber by performing air circulation with the outside, and the refrigerant tank is provided in the internal communication chamber in a direction in which the high-temperature fluid flows. The evaporator is arranged such that the small passages are stacked, and the radiator is further arranged so that the plurality of small passages are stacked in the direction in which the low-temperature fluid flows. Case cooling device.