JP2000156444A - Boiling cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boiling cooling device where cooling medium is circulated well by a method wherein liquid cooling medium that flies away together with cooling medium vapor is prevented from entering a heat dissipating tube. SOLUTION: A heat dissipating tube 21 provided to a core is provided with one end that is inserted into a slit bored in the head plate 19a of a vapor side header 19 and protruded into the vapor-side header 19 through the inner wall of the header plate 19a, and an opening 21a is provided to the one end of the heat dissipating tube 21. By this setup, even if liquid cooling medium which flies away together with cooling medium vapor from a boiling space in the cooling medium tank 3 enters the vapor-side header 19, liquid cooling medium and cooling medium vapor are isolated from each other by a vapor liquid isolating structure (end of a heat dissipating tube 21 protrudes into the inside of the vapor-side header 19 from the inner wall surface of the header plate 19a), so that liquid cooling medium can be stopped from entering the heat dissipating tube 21, and nearly only cooling medium vapor is capable of entering the heat dissipating tube 21.

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 a boiling and condensing action of a refrigerant.

[0002]

2. Description of the Related Art A boiling cooling device is used to transfer heat between a heat receiving portion and a heat radiating portion in order to transfer heat from a refrigerant tank to a radiator by repeating boiling (evaporation) and condensation of the refrigerant. If the refrigerant does not circulate well, it cannot be operated stably. Therefore, when the refrigerant vapor boiled in the refrigerant tank moves to the radiator, the liquid refrigerant scattered along with the refrigerant vapor directly enters the radiator tube of the radiator. , The refrigerant cannot circulate satisfactorily. 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 capable of preventing a liquid refrigerant scattered with a refrigerant vapor from entering a heat radiating tube and allowing a good circulation of the refrigerant. Is to do.

[0003]

(Means for Solving the Problems) A gas-liquid separation structure is provided in the header so that substantially only the refrigerant vapor flows from the header into which the refrigerant vapor boiling in the boiling space flows into the radiating tube. . Thereby, even if the liquid refrigerant scattered together with the refrigerant vapor enters the header, the liquid refrigerant and the refrigerant vapor are separated by the gas-liquid separation structure in the header, and substantially only the refrigerant vapor can enter the radiation tube. .

The above-mentioned gas-liquid separation structure has a structure in which the end of the heat radiation tube is inserted into the inside of the header and protrudes from the inner wall surface of the header. In this case, the liquid refrigerant that has entered the header together with the refrigerant vapor cannot directly enter the radiation tube along the inner wall surface of the header, and the refrigerant vapor predominantly (substantially only the refrigerant vapor) enters the radiation tube. Can be.

[0005] (Claim 2) The gas-liquid separation structure has a structure in which the opening of the heat radiating tube is opened on the downstream side in the traveling direction of the refrigerant vapor traveling in the header.

(Claim 3) The gas-liquid separation structure has a structure in which a projection is provided on the inner wall surface of the header.

[0007] (Claim 4) The gas-liquid separation structure has a structure in which the protrusions are arranged in a staggered manner.

[0008] (Claim 5) The gas-liquid separation structure has a structure in which projections are arranged obliquely with respect to the traveling direction of the refrigerant vapor traveling in the header.

(Claim 6) The gas-liquid separation structure has a structure in which the projection contacts the heat radiating tube on the upstream side of the heat radiating tube with respect to the traveling direction of the refrigerant vapor traveling in the header.

[0010]

Next, an embodiment of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a perspective view showing a gas-liquid separation structure in a steam side header. The boiling cooling device 1 of the present embodiment is similar to that of FIG.
As shown in FIG. 2, a cooling medium for cooling a heating element 2 (see FIG. 3) such as a computer chip mounted on a printed circuit board and storing therein a liquid refrigerant (for example, water, alcohol, fluorocarbon, chlorofluorocarbon, etc.) A tank 3 and a radiator 4 for liquefying refrigerant vapor, which has received heat from the heating element 2 in the refrigerant tank 3 and boiled, by heat exchange with an external fluid (for example, air) are provided. The coolant tank 3 and the radiator 4 are integrally formed by brazing.

A) The refrigerant tank 3 is composed of a thin container 5 and a lid plate 6 formed of a metal material (eg, aluminum) having excellent heat conductivity, and is used in an upright state. a) The thin container 5 has a vertically long rectangular shape as shown in FIG. 4, and has a flat surface on one side in the thickness direction (the back side in FIG. 4) and is used as a mounting surface for the heating element 2, and the other side. Is provided with a boiling space 7, a set of header connection portions 8, 9, a liquid return passage 10, and a refrigerant injection portion 11 described below. A plurality of holes 12 penetrating the thin container 5 in the thickness direction are provided on the outer peripheral portion of the thin container 5.

The boiling space 7 forms a space in which the liquid refrigerant boils by receiving heat from the heating element 2, and is provided over the entire central portion of the thin container 5. In the boiling space 7, a large number of prisms 13 are arranged in a grid pattern at regular intervals, and the entire boiling space 7 forms a refrigerant passage partitioned like a grid. The large number of prisms 13 provided in the boiling space 7 also function as reinforcing ribs for securing the strength of the refrigerant tank 3. The header connection portions 8 and 9 are portions where the headers 19 and 20 (described below) of the radiator 4 are connected, and spaces corresponding to the cross-sectional shapes of the headers 19 and 20 are provided. One header connection portion 8 is provided adjacent to the upper right side of the boiling space 7 and communicates with the boiling space 7 through the steam outlet 14. The other header connection portion 9 is provided on the upper left side of the boiling space 7 and communicates with the boiling space 7 through the liquid return passage 10.

The liquid return passage 10 is a passage for returning the condensed liquid liquefied by the radiator 4 to the boiling space 7. The liquid return passage 10 extends downward from the lower portion of the other header connection portion 9, and is provided.
To the bottom. The refrigerant injection part 11 is an injection passage for injecting the refrigerant into the inside of the refrigerant tank 3 (boiling space 7), and is provided, for example, below one header connection part 8,
It leads to the boiling space 7. In addition, the boiling space 7, the header connection portions 8, 9, the liquid return passage 10, the coolant injection portion 11, and the like can be formed by cutting, electric discharge machining, forging, casting, or the like. The hole 12 is provided for fixing the heating element 2 to the surface (flat surface) of the thin container 5 by a fixing member (not shown).

B) The lid plate 6 is made of, for example, a clad material in which a brazing material is integrally molded on the surface, and covers the other side of the thin container 5 entirely, and the boiling space 7 and the liquid provided in the thin container 5 are provided. The opening surface of the return passage 10 is closed. However,
Openings 15 and 16 (see FIG. 3) for inserting headers 19 and 20 are opened on both upper sides of the lid plate 6, and the openings 15 and 16 communicate with the header connection portions 8 and 9, respectively. In the lid plate 6, a round hole 17 communicating with the refrigerant injection section 11 provided in the thin container 5 is opened at a lower portion of one insertion port 15, and an injection pipe 18 is connected to the round hole 17. The injection pipe 18 is an injection port for injecting the refrigerant into the refrigerant tank 3, and the injection pipe 1
After injecting a predetermined amount of refrigerant into the refrigerant tank 3 through 8, the opening at the end of the injection pipe 18 is sealed.

B) The radiator 4 includes a set of headers (steam-side header 19 and liquid-side header 20) and a core portion (radiation tube 2).
1 and a radiation fin 22), and a duct 23
An external fluid is supplied via (see FIG. 2). a) One set of headers is a vapor-side header 19 into which refrigerant vapor boiled by receiving heat from the heating element 2 in the refrigerant tank 3 flows, and a liquid-side header 20 into which condensed liquid liquefied in the core part flows.
Each is composed of header plates 19a and 19b and header plates 20a and 20b (see FIG. 3).

One end of the vapor side header 19 in the longitudinal direction is inserted into the inside of the refrigerant tank 3 (one header connection portion 8) from one insertion port 15 of the cover plate 6, and the cover plate 6
Are arranged so as to extend in a substantially vertical direction with respect to. As shown in FIG. 3, the vapor side header 19 has a communication port 24 (which is connected to the vapor outlet 14) communicating with the vapor outlet 14 in the refrigerant tank 3 at an end of a header plate 19 a inserted into the refrigerant tank 3. (Substantially the same size). Further, in the header plate 19a, a plurality of long holes for inserting one end of the heat radiation tube 21 are formed at equal intervals in upper and lower two stages.

One end of the liquid side header 20 in the longitudinal direction is inserted into the inside of the refrigerant tank 3 (the other header connection portion 9) from the other insertion port 16 of the lid plate 6.
Are arranged in a state of extending substantially perpendicular to (in parallel with the steam-side header 19). The liquid-side header 20 has a liquid return passage 1 formed in a lower wall surface of an end portion inserted into the inside of the refrigerant tank 3.
The communication opening to 0 is opened. Further, in the header plate 20a, a plurality of long holes for inserting the other end of the heat radiation tube 21 are formed at equal intervals in upper and lower two stages.

B) The core portion is a heat radiating portion that receives the heat of the heating element 2 and releases the heat of the refrigerant vapor that has boiled to an external fluid.
It is composed of a plurality of heat radiating tubes 21 and heat radiating fins 22 interposed between the heat radiating tubes 21. The heat radiating tubes 21 are provided in a flat shape having a small thickness with respect to the width of the outer wall surface with which the heat radiating fins 22 come in contact, and are arranged in two stages, upper and lower, between the vapor header 19 and the liquid header 20. And a plurality of heat radiating tubes 2 through the heat radiating fins 22, respectively.
1 are juxtaposed.

The heat radiating tube 21 has one end inserted into a long hole formed in the header plate 19a of the vapor side header 19 and the other end formed in the header plate 20a of the liquid side header 20. The vapor-side header 19 and the liquid-side header 20 communicate with each other by being inserted into the holes. In particular, as shown in FIG. 1, one end of the heat radiating tube 21 is located between the inner wall surface of the header plate 19a and the steam side header 1.
9, and is provided with an opening 21a at the tip thereof.
have. In the liquid header 20, similarly to the vapor header 19, the other end of the heat radiating tube 21 may be provided so as to protrude from the inner wall surface of the header plate 20 a into the liquid header 20. The radiating fins 22 are formed by alternately bending thin metal plates (for example, aluminum plates) having excellent thermal conductivity into a wavy shape.
1 is thermally bonded to the outer wall surface.

As shown in FIG. 2, the duct 23 is provided so as to pass through the outside of the headers 19 and 20 and surround the radiator 4. In addition, the duct 23 is provided with each header 19, 20.
Of each header 1 to such an extent that a large gap does not occur between the outer wall surfaces (outer surfaces of the header plates 19b and 20b), or substantially in contact with the outer wall surfaces of the headers 19 and 20.
9 and 20 are arranged along the outer wall surface. Duct 23
The external fluid introduced into the core portion through flows through from below to above in FIG.

Next, the operation of this embodiment will be described. The liquid refrigerant in the refrigerant tank 3 is boiled by receiving the heat of the heating element 2 and then passes through the vapor outlet 14 from the boiling space 7 to the vapor side header 19.
And flows from the steam side header 19 to each of the heat radiating tubes 21. The refrigerant vapor flowing through the heat radiating tube 21 is cooled by the external fluid introduced into the core portion through the duct 23, and condenses in the heat radiating tube 21. The condensed refrigerant becomes droplets and is pushed down to the liquid-side header 20, and further drops from the liquid-side header 20 through the liquid return passage 10 to return to the boiling space 7 in the refrigerant tank 3. The flow of the refrigerant in this operation is shown by an arrow in FIG.

(Effects of the present embodiment) In the boiling cooling device 1 of the present embodiment, one end of the heat radiation tube 21 is inserted into a long hole formed in the header plate 19a of the steam side header 19, and the header is provided. The gas-liquid separation structure of the present invention is formed by projecting from the inner wall surface of the plate 19a to the inside of the steam-side header 19. Thereby, even if the liquid refrigerant scattered with the refrigerant vapor from the boiling space 7 of the refrigerant tank 3 enters the vapor side header 19, the liquid refrigerant and the refrigerant vapor are separated by the gas-liquid separation structure in the vapor side header 19. In addition, the liquid refrigerant can be prevented from entering the heat radiating tube 21. As a result, substantially only the refrigerant vapor can enter the heat radiating tube 21, and the refrigerant can satisfactorily circulate between the refrigerant tank 3 and the radiator 4, so that stable operation can be achieved.

(Second Embodiment) FIG. 6 is a perspective view showing a gas-liquid separation structure in the steam side header 19. As shown in FIG. 6, in the gas-liquid separation structure of the present embodiment, the opening 21a of the heat radiating tube 21 inserted in the steam The structure is also open to the downstream side. In this case, as in the first embodiment, even if the liquid refrigerant scattered with the refrigerant vapor enters the vapor header 19, the liquid refrigerant and the refrigerant vapor are separated by the gas-liquid separation structure in the vapor header 19. In addition, the liquid refrigerant can be prevented from entering the heat radiating tube 21, and substantially only the refrigerant vapor can enter the heat radiating tube 21.
In the case of the present embodiment, the distal end opening of the heat radiation tube 21 is closed, and the opening 2
By providing 1a, the gas-liquid separation effect can be further enhanced.

(Third Embodiment) FIG. 7 is a plan view showing a gas-liquid separation structure in the steam side header 19. The gas-liquid separation structure of this embodiment is a structure in which a plurality of protrusions 25 are provided in the vapor-side header 19. The projections 25 can be provided on the header plate 19a or the header plate 19b of the steam side header 19, and are arranged in, for example, two rows shown in FIG.
It can be arranged in a staggered manner as shown in (b) or inclined with respect to the heat radiation tube 21 as shown in (c). In these cases, when the refrigerant vapor advances in the vapor-side header 19, the liquid refrigerant that has entered the vapor-side header 19 together with the refrigerant vapor collides with the projection 25 and is retained, whereby gas-liquid separation can be performed. it can.

(Fourth Embodiment) FIG. 8A is a plan view showing a gas-liquid separation structure in the vapor side header 19, and FIG. 8B is a sectional view. In the gas-liquid separation structure of the present embodiment, a part of the projection 25 provided inside the vapor
The contact structure is In this embodiment, the same effects as in the third embodiment can be obtained. In the third embodiment and the fourth embodiment, as shown in FIGS. 7 and 8, a gas-liquid separation structure (projection 25) may be provided on the entire inside of the vapor-side header 19. It may be provided only in a portion near one header connection portion 8 of the refrigerant tank 3 where ejection is intense.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a gas-liquid separation structure in a steam-side header.

FIG. 2 is a perspective view of a boiling cooling device.

FIG. 3 is an exploded perspective view of the boiling cooling device.

FIG. 4 is a plan view of a thin container.

FIG. 5 is a perspective view of a boiling cooling device showing a flow of a refrigerant.

FIG. 6 is a perspective view showing a gas-liquid separation structure in a steam side header.

FIG. 7 is a plan view showing a gas-liquid separation structure in a vapor side header.

FIGS. 8A and 8B are a plan view and a cross-sectional view illustrating a gas-liquid separation structure in a steam side header.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiling cooling device 2 Heating element 3 Refrigerant tank 4 Radiator 7 Boiling space 19 Steam side header 20 Liquid side header 21 Heat radiating tube 21a Opening of heat radiating tube 25 Projection

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiyoshi Kawaguchi 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside Denso Corporation (72) Inventor Takahide Ohara 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Denso Corporation (72) Inventor Akihiro Maeda 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 5F036 AA01 BA08 BB45 BB53

Claims (6)

[Claims] An evaporative cooling device for transferring heat by a phase change of a refrigerant, the refrigerant tank storing a liquid refrigerant therein, and forming a boiling space in which the liquid refrigerant boils by receiving heat from a heating element. A header into which the refrigerant vapor boiling in the boiling space flows, and a core part having a heat radiation tube opened in the header, and liquefying the refrigerant vapor flowing from the header through the heat radiation tube by heat exchange with an external fluid. A gas-liquid separation structure is provided in the header so that refrigerant vapor flows dominantly from the header to the heat dissipation tube, and the gas-liquid separation structure is such that an end of the heat dissipation tube is inside the header. Characterized by having a structure that is inserted into the header and protrudes from the inner wall surface of the header. 2. The gas-liquid separation structure according to claim 1, wherein the opening of the heat radiating tube is opened on the downstream side in the traveling direction of the refrigerant vapor traveling in the header. The boiling cooling device described in 1. 3. The boiling cooling device according to claim 1, wherein the gas-liquid separation structure further includes a projection provided on an inner wall surface of the header. 4. The gas-liquid separation structure according to claim 3, wherein the projections are arranged in a staggered manner.
The boiling cooling device described in 1. 5. The gas-liquid separation structure according to claim 3, wherein the projection is arranged to be inclined with respect to a traveling direction of the refrigerant vapor traveling in the header. Boiling cooling device. 6. The gas-liquid separation structure has a structure in which the protrusion contacts the heat radiating tube on the upstream side of the heat radiating tube with respect to the traveling direction of the refrigerant vapor traveling in the header. The boiling cooling device according to claim 3.