JP7370883B2 - Heat transfer member and cooling device having heat transfer member - Google Patents

Description

The present invention relates to a heat transfer member that transfers heat from a heating element to change the phase of a first refrigerant from a liquid phase to a gas phase, and a cooling device that includes this heat transfer member.

With the increasing functionality of electronic devices in recent years, heating elements such as electrical and electronic components (hereinafter simply referred to as "heating elements") are mounted in a high density inside electronic devices. The amount of heat generated tends to increase. If the temperature of the heating element rises above a predetermined permissible temperature, it may cause the heating element to malfunction, so it is necessary to maintain the temperature of the heating element at or below the permissible temperature at all times. Therefore, a cooling device for cooling the heating element is usually installed inside the electronic device. As such a cooling device, for example, a boiling cooling device that utilizes latent heat (heat of vaporization) by changing the phase of a refrigerant from a liquid phase to a gas phase is known.

As described above, heating elements such as electric/electronic components that constitute electronic devices tend to generate more heat, so there is a demand for further improvement in the cooling performance of boiling cooling devices. In order to further improve the cooling performance of the evaporative cooling device, it is useful to smooth the phase change of the refrigerant from the liquid phase to the gas phase, and in particular to smooth the heating and boiling of the refrigerant.

As a means for smoothing the heating and boiling of the refrigerant, for example, Patent Document 1 discloses that a plurality of first fins are provided on the outer circumferential surface of a tube body through which a heating fluid flows; and a plurality of second fins provided at predetermined intervals, and by combining these first fins and second fins, a cavity having an inlet into which the refrigerant flows is formed, and the refrigerant flows into the cavity. Disclosed is a boiling heat exchanger tube in which a plurality of discharge ports are formed for discharging bubbles to the outside when the refrigerant is boiled by the heating medium, and the heat transfer performance is improved by smoothing the inflow of the refrigerant and the discharge of the bubbles. has been done.

In this way, by forming the boiling surface that comes into contact with the refrigerant (the outer peripheral surface of the tube body in Patent Document 1) with a cavity structure having a large number of cavities with a wide interior and a narrow entrance, heat transfer performance including cooling performance is improved. It is known to do.

Japanese Patent Application Publication No. 2005-121238

However, in Patent Document 1, since a large number of cavities are formed on the outer circumferential surface of the tube body so as to be continuous in the circumferential direction, there is no opening end of the cavities in the circumferential direction. It is not possible to enter the cavity through the open end. Therefore, in the heat exchanger tube described in Patent Document 1, the refrigerant enters the cavity through the inlet ports formed at the upper part of the cavity and spaced narrowly at intervals of 0.02 to 0.2 mm. However, since the outlet has a larger opening size than the inlet, it is thought that the refrigerant tends to enter the cavity not only from the inlet but also from the outlet at the same time. As a result, it cannot be said that the flow of refrigerant into the cavity and the discharge of bubbles to the outside of the cavity can be performed smoothly, and there is a need for further improvement.

In addition, as another means for smoothing the heating and boiling of the refrigerant, for example, a structure in which a wick structure made of a sintered body of particulate metal powder is provided on the surface that contacts the refrigerant (boiling surface) is available. Can be mentioned. Although such a wick structure has an excellent ability to retain liquid phase refrigerant, the flow of the refrigerant that enters the wick structure and the flow of bubbles generated by boiling when they are released to the outside of the wick structure As a result of the refrigerant colliding with each other, it is difficult to say that the transfer of latent heat (heat transfer coefficient) when the refrigerant changes phase from the liquid phase to the gas phase is carried out sufficiently. It is desired to develop a new structure (shape) of (boiling surface).

An object of the present invention is to provide a first refrigerant-contacting surface ( By optimizing the shape of the boiling surface (boiling surface), it is possible to improve the efficiency of latent heat transfer and increase the heat transfer coefficient when the first refrigerant changes from the liquid phase to the gas phase. An object of the present invention is to provide a cooling device having improved cooling efficiency by having this heat transfer member.

In order to achieve the above object, the gist of the present invention is as follows.
(1) It is formed on the inner surface of the bottom of the container at a position corresponding to the mounting position of at least one heating element thermally connected to the outer surface of the bottom, and the heat from the heating element is transferred to the bottom of the container. In the heat transfer member, the heat transfer member heats and boils the first refrigerant by transmitting the heat to the first refrigerant in a liquid phase sealed in a lower part of the internal space, and changes the phase of the first refrigerant from the liquid phase to the gas phase. The member includes a plate-shaped part having a lower surface fixed to the inner surface of the bottom of the container, and an upper surface of the plate-shaped part, and at least one continuous piece that extends continuously along the upper surface of the plate-shaped part. a cavity, and a plurality of columnar fin parts forming a pair located on both sides of the continuous cavity at intervals along the extending direction of the continuous cavity and disposed on the upper surface of the plate-like part, A heat transfer member characterized in that the continuous cavity has an opening formed in a ceiling portion at a position sandwiched between the pair of columnar fin portions.
(2) The heat transfer member according to (1) above, wherein the height of the columnar fin portion is at least twice the height of the continuous cavity.
(3) The plurality of columnar fin portions constitute a group of columnar fin portions arranged on both sides of the continuous cavity at intervals along the extending direction of the continuous cavity, or (1) above; The heat transfer member according to (2).
(4) The method for manufacturing a heat transfer member according to any one of (1) to (3) above, wherein a plurality of plate-shaped fin portions each having an uneven upper end portion are provided on the upper surface of the plate-shaped portion. By machining the recess position of the upper end portion of the plate-like fin portion that constitutes the integrated workpiece material with the fins facing each other at intervals, the plurality of columnar fin portions and the continuous cavity are . A method of manufacturing a heat transfer member, comprising forming a ceiling portion in which the opening is not formed.
(5) The method for manufacturing a heat transfer member according to any one of (1) to (3) above, wherein a plurality of plate-shaped fin portions each having a flat upper end portion are provided on the upper surface of the plate-shaped portion. By machining predetermined positions of the upper end portions of the plate-like fin portions constituting the integrated workpiece material while facing each other at intervals, the plurality of columnar fin portions and the continuous cavity are . A method of manufacturing a heat transfer member, comprising forming a ceiling portion in which the opening is not formed.
(6) a container in which at least one heating element is thermally connected to the outer surface of the bottom and a liquid-phase first refrigerant is sealed in the lower part of the inner space; , a cooling device including a condensing pipe extending through the container and through which a second refrigerant flows, the cooling device being connected to an inner surface of the bottom of the container and an outer surface of the bottom is formed at a position corresponding to the mounting position of at least one heating element thermally connected to the heating element, and transmits heat from the heating element to a liquid phase first refrigerant sealed in a lower part of the internal space of the container. a heat transfer member that heats and boils the first refrigerant and changes the phase of the first refrigerant from a liquid phase to a gas phase; the heat transfer member is fixed to the inner surface of the bottom of the container; at least one continuous cavity that includes the upper surface of the plate-shaped part and extends continuously along the upper surface of the plate-shaped part, and an interval along the extending direction of the continuous cavity. and a plurality of paired columnar fin portions located on both sides of the continuous cavity and arranged on the upper surface of the plate-like portion, the continuous cavity being sandwiched between the pair of columnar fin portions. A cooling device characterized in that an opening is formed in a ceiling portion at a position where the cooling device is opened.

According to the present invention, by having a heat transfer member that improves the transfer efficiency of latent heat when changing the phase of the first refrigerant from the liquid phase to the gas phase and increases the heat transfer coefficient, and this heat transfer member, It becomes possible to provide a cooling device with improved cooling efficiency.

FIG. 1 is a perspective view showing the main parts of a cooling device having a heat transfer member according to a first embodiment of the present invention. FIG. 2 is an enlarged perspective view of a part of the heat transfer member constituting the cooling device of FIG. 1. FIGS. 3(a) and 3(b) are explanatory diagrams when a continuous cavity is formed on the upper surface of the plate-shaped part of the heat transfer member by pressing the concave part of the plate-shaped fin part having an uneven upper end part. It is. 4(a) and (b) show that a continuous cavity is formed on the upper surface of the plate-shaped part of the heat transfer member by pressing a predetermined position of the upper end part of the plate-shaped fin part having a flat upper end part. FIG. FIG. 5 is an enlarged perspective view of a part of the heat transfer member of the second embodiment. FIG. 6 is an explanatory diagram when (part of) the heat transfer member of the third embodiment is formed using three plate materials, and FIG. Figure 6(b) shows the state before joining two punched plates, and the state immediately before joining the two punched plates to the top surface of one rectangular plate and then bending them in the direction of the arrow. FIG. 6(c) shows the state when the heat transfer member is formed by bending. FIG. 7 is a perspective view of a heat transfer member of a comparative example. Figure 8 shows the heat flux and heat transfer coefficient measured and calculated using a cooling device having the heat transfer member of the present invention example and the heat transfer member of the comparative example, and the horizontal axis is the calculated heat flux, and the calculated heat FIG. 3 is a diagram plotting transmissibility on the vertical axis.

Next, heat transfer members according to some embodiments of the present invention will be described below.

<Heat transfer member>
(First embodiment)
FIG. 1 is a perspective view showing the main parts of a cooling device having a heat transfer member according to a first embodiment of the present invention, and is shown in a transparent state so that the internal structure of a container constituting the cooling device can be seen. FIG. 2 is an enlarged perspective view of a part of the heat transfer member constituting the cooling device of FIG. 1.

The heat transfer member 10 of the present invention has a configuration that can contact the first refrigerant R1 sealed in the internal space S of the container 30 and transfer heat through the first refrigerant R1, such as a cooling device or a heat exchanger. It can be used in various heat transfer devices such as containers. Note that the heat transfer member 10 of the first embodiment shown in FIG. 1 is used by being attached to a cooling device 1.

The heat transfer member 10 is located on the inner surface 31a of the bottom 31 of the container 30 constituting the cooling device 1, and is located at a mounting position P of at least one heating element (not shown) that is thermally connected to the outer surface 31b of the bottom 31. The first refrigerant R1 is heated and boiled by transmitting heat from the heating element to the liquid phase first refrigerant R1 sealed in the lower part of the internal space S of the container 30. The phase of the refrigerant R1 is changed from a liquid phase to a gas phase. Note that the first refrigerant R1 exists in the internal space S of the container 30 in a phase-changed state between a liquid phase state and a gas phase state. ), the first refrigerant in the gas phase may be given a different symbol from R1(g).

The internal space S of the container 30 is a space sealed from the external environment, and is depressurized by degassing.

The heat transfer member 10 mainly includes a plate-shaped portion 11, a continuous cavity 12, and a columnar fin portion 13.

The material constituting the heat transfer member 10 is not particularly limited, and examples thereof include thermally conductive materials. Specific examples of the material constituting the heat transfer member 10 include metal materials such as copper, copper alloy, aluminum, aluminum alloy, iron alloy (for example, stainless steel), and carbon materials such as graphite. The heat transfer member 10 also includes particles such as a sintered body of a thermally conductive material such as a metal sintered body, an aggregate of carbon particles and/or metal powder, etc. An aggregate of thermally conductive materials may be formed in a layered manner. As a result, the surface of the heat transfer member 10 formed of a layered sintered body or the like becomes a porous layer, and the primary refrigerant R1 (L) is retained in the porous layer for a longer time, improving heat transfer characteristics. Therefore, the phase change of the primary refrigerant R1 from the liquid phase to the gas phase is further promoted, and the cooling performance of the cooling device 1 can be further improved.

The plate-shaped portion 11 has a lower surface that is attached (fixed) to the inner surface 31a of the bottom portion 31 of the container 30. The shape of the plate part does not need to be particularly limited, and various shapes such as a rectangular shape as shown in FIG. 1, a circle, a triangle, and a polygon can be mentioned. , it is preferable that the shape corresponds to the shape of the contact surface of the heating element attached to the mounting position P of the heating element.

The continuous cavity 12 includes the upper surface 11a of the plate-shaped part 11 and extends continuously along the upper surface 11a of the plate-shaped part 11, and at least one continuous cavity 12 is formed in the heat transfer member 10. .

The continuous cavity 12 has an opening O formed in the ceiling portion at a position sandwiched between the pair of columnar fin portions 13. The continuous cavity 12 has an extended shape in which the space is continuous when viewed from the extension direction opening end 17 toward the extension direction L of the continuous cavity 12. This extended shape only needs to be continuous, and may be not only linear but also curved.

The columnar fin portions 13 are located on both sides of the continuous cavity 12 at intervals along the extending direction L of the continuous cavity 12, and a plurality of paired columnar fin portions 13 are arranged on the upper surface of the plate-like portion 11. has been done.

In the heat transfer member 10 of the present embodiment, when the heating element generates heat and the temperature rises, the heat of the heating element is transferred to the plate-shaped part 11 of the heat transfer member 10 via the bottom 31 of the container 30. , is also transmitted from the plate portion 11 to the columnar fin portion 13. Therefore, in the heat transfer member 10, the first refrigerant R1 (L) located around the outside of the continuous cavity 12 is immediately heated by the plate portion 11 and the columnar fin portion 13 of the heat transfer member 10, and its temperature rises. Since the first refrigerant R1 (L) in the liquid phase whose temperature has increased flows into the continuous cavity 12 mainly from the opening end 17 in the extending direction of the continuous cavity 12, the first refrigerant R1 (L) in the liquid phase that has flowed into the continuous cavity 12 ) reaches boiling temperature with a small amount of heat and bubbles are generated. The generation of air bubbles can significantly improve the heat transfer coefficient due to its disturbing effect. In addition, the continuous cavity 12 can hold the liquid-phase first refrigerant R1 (L) that has flown in for a certain period of time until bubbles grow, which also contributes to suppressing the occurrence of dryout. The bubbles generated by heating and boiling within the continuous cavity 12 grow into larger bubbles using this as a nucleus, and the grown bubbles pass through the opening O formed in the upper part (ceiling part) of the continuous cavity 12 to the continuous cavity. This promotes so-called nucleate boiling, which occurs outside of 12. As a result, the efficiency of transferring latent heat when the first refrigerant R1 (L) is changed from the liquid phase to the gas phase is increased, and the heat transfer coefficient is improved.

It is preferable that the height h1 of the columnar fin portion 13 is at least twice the height h2 of the continuous cavity 12. If the height h1 of the columnar fin portion 13 is less than twice the height h2 of the continuous cavity 12, the first refrigerant R1 (L) cannot be caused to flow into the continuous cavity in a sufficiently heated state. This is because there is a tendency that nucleate boiling cannot be efficiently generated in a short period of time.

A plurality of columnar fin portions 13 are arranged, and the plurality of columnar fin portions 13 are arranged on both sides of the continuous cavity 12, and are arranged at intervals along the extending direction L of the continuous cavity 12. It is preferable to form groups 14-1 and 14-2 of the parts. In FIG. 1, a plurality of columnar fin portions 13 are disposed between seven continuous cavities 12, 12, . Groups 14-1, 14-2, . . . of eight rows of columnar fin portions in which eight columnar fin portions 13, 13, . . . are arranged at intervals along the extending direction L of the cavity 12. 14-8 (the total number of columnar fin portions 13 is 64) is shown as an example. However, the number of columnar fin portions 13 and continuous cavities 12 can be increased or decreased as necessary.

The method of forming the columnar fin portion 13 and the ceiling portion 16 of the continuous cavity 12 (which does not form the opening O) is not particularly limited, but for example, first, a plurality of plate-like fin portions are formed on the upper surface of the plate-like portion. A workpiece material 10' is produced in which the workpiece materials 10' are integrated in a state where they are arranged facing each other with a gap between them. There are no particular limitations on the method for producing the material to be processed, but examples thereof include cutting, casting such as precision casting, metal powder injection molding (MIM), 3D printer, and the like. Next, the columnar fin portion 13 and the ceiling portion 16 of the continuous cavity 12 can be formed by subjecting the produced workpiece material to pressing, bending, laser processing, or the like.

In the embodiment shown in FIGS. 3(a) and 3(b), the workpiece material 10' includes a plurality of plate-like fin parts having an uneven shape (preferably a pulse wave shape) on the upper surface of the plate-like part. The columnar fin parts 13, and shows an example of forming the ceiling portion 16 of the continuous cavity 12.

Further, in the embodiment shown in FIGS. 4A and 4B, a plurality of plate-shaped fin parts each having a flat upper end portion are arranged facing each other at intervals on the upper surface of the plate-shaped part as the workpiece material 10A'. By processing (for example, press processing) a predetermined position 15A' of the upper end portion of each of these plate-like fin parts, the columnar fin part 13 and the ceiling of the continuous cavity 12 are formed. This is an example of forming the portion 16.

The embodiment shown in FIGS. 3A and 3B has the advantage that the height of the columnar fin portion 13 can be increased even if the press pressure during press working is lowered. Furthermore, in the embodiment shown in FIGS. 4(a) and 4(b), when increasing the height dimension of the columnar fin portion 13, it is necessary to set the press pressure high, but the press working position 15A' is Unlike the embodiments shown in FIGS. 3(a) and 3(b), there is no need to perform press processing to match the concave position 15' in the upper end portion of the plate-shaped fin portion, so there are advantages such as easy press processing. be. Therefore, the method of forming the columnar fin portion 13 and the ceiling portion 16 of the continuous cavity 12 can be appropriately selected depending on the shape and dimensions of the heat transfer member 10.

In addition, in FIG. 1, the arrangement pitch between adjacent columnar fin portions 13, 13 constituting the same columnar fin group 14-1 (or 14-2, . . . ) is as shown in FIG. 3(a). Dimensions along the extending direction of the continuous cavity 12 of the processed area at the concave position 15' of the upper end portion of the plate-shaped fin portion shown in FIG. It can be adjusted as appropriate by changing .

The method of attaching the heat transfer member 10 to the inner surface 31a of the bottom portion 31 of the container 30 includes, for example, a method of integrally forming the heat transfer member 10 on the inner surface 31a of the container 30 using a mold, or a method of forming a separate member from the container 30 into the inner surface 31a of the container 30. Examples include a method of attaching it to the inner surface of 30. The method of forming the columnar fin portion 13 includes, for example, attaching (fixing) a separately manufactured plate-like fin to the inner surface 31a of the container 30 by soldering, brazing, welding, sintering, etc., or cutting the inner surface of the container 30. Examples include methods such as a method of molding, an extrusion molding method, an etching method, and the like.

(Second embodiment)
Further, FIG. 5 is an enlarged perspective view of a part of the heat transfer member of the second embodiment. The heat transfer member 10B of the second embodiment has the same configuration as the heat transfer member 10 of the first embodiment in that it is mainly composed of a plate portion 11B, a continuous cavity 12B, and a columnar fin portion 13B. However, instead of the plate-like part 11 having a constant thickness, a plate-like part 11B having a stepped thickness is used by connecting a thin plate part 11a and a thick plate part 11b. The above differs greatly. Furthermore, the upper surface height positions of the processed portions 15B located on both sides of the continuous cavity 12B, which constitute the ceiling portion 16B in which the opening O is not formed, of the continuous cavity 12B are formed to be shifted from each other. This is caused by a difference in level due to the difference in thickness between the plate portion 11B, which includes the thin plate portion 11a and the thick plate portion 11b. Furthermore, the heat transfer member 10B is provided with a plurality of columnar fin portions 13B having different heights. As a result, even if the upper surface 11a of the plate-shaped portion 11B is not flat but has a three-dimensional shape with steps or the like, the continuous cavity 12B and columnar fins 13B can be formed in accordance with the three-dimensional shape.

(Third embodiment)
FIGS. 6(a) to 6(c) are partially enlarged perspective views of the heat transfer member of the third embodiment. FIG. 6(a) shows the state before joining one rectangular plate 21 and two punched plates 22 and 23. In FIG. 6(b), two punched plates 22 and 23 are joined to the upper surface of one rectangular plate 21 to form a joint W, and then a force is applied in the direction of the arrow F to bend the plate. Shows the state immediately before application. FIG. 6(c) shows the state when the heat transfer member is formed by bending. The heat transfer member 10C of the third embodiment has the same basic structure as the heat transfer member 10 of the first embodiment, but the difference in structure is that the ceiling portion 16C of the continuous cavity 12C is as shown in FIG. 6(b). As shown in FIG. 1, a portion 15C' located between adjacent columnar fin portions 13C and 13C forming one group of columnar fin portions of the group of columnar fin portions located across the continuous cavity 12C. The ceiling portion 16C of the continuous cavity 12c is formed by bending.

<Cooling device>
Next, a cooling device according to an embodiment of the present invention will be described below.
The cooling device 1 of this embodiment includes a container 30 and a condensing pipe 50.

In the container 30, at least one heating element is thermally connected to the outer surface 31b of the bottom portion 31, and a liquid phase first refrigerant R1 (L) is sealed in the lower part of the internal space S.

The condensing pipe 50 is disposed at an upper position of the internal space S of the container 30 so as to penetrate the container 30 and extend both inside and outside the container 30, and the second refrigerant R2 flows through the inside of the condensing pipe 50. . The inside of the condensing pipe 50 and the internal space S of the container 30 are not communicated with each other. That is, the second refrigerant R2 passing through the condensing pipe 50 includes the first liquid refrigerant R1 (L) sealed in the lower part of the internal space S of the container 30 and the first refrigerant R1 (L) in the liquid phase. does not come into contact with any of the first refrigerant (g) that has boiled into a gas phase. The condensing pipe 50 flows through the second refrigerant R2 that absorbs heat from the first refrigerant (g) in the gas phase, condenses the first refrigerant R1 (g) in the gas phase, and converts the first refrigerant R1 in the liquid phase to the first refrigerant R1 in the liquid phase. This is a member provided to change the phase to (L). In order to improve the cooling efficiency, the condensing tube 50 may have a portion increasing the surface area, such as unevenness, on the outer surface of the condensing tube 50, but it may also have a smooth surface. Further, the inner surface of the condensing tube 50 may also have a portion that increases the surface area, such as an uneven surface, but may also be a smooth surface.

The cooling device 1 is provided with a plurality of condensing pipes, and in FIG. 1, two condensing pipes 50, 50 are provided. The condensing pipes 50 are arranged in parallel in two stages, upper and lower, in the interior space S of the container 30 so as to be substantially coplanar with each other. The cross-sectional shape of the condensing tube 50 is not particularly limited, and includes various shapes such as a circular shape as shown in FIG. 1, an elliptical shape, a flattened shape, a square shape, and a rounded rectangular shape.

A method for attaching the condensing pipe 50 to the container 30 is to provide two through holes 51, 51 for each condensing pipe 50 in the container 30. By tightly fitting into these through-holes 51, 51, the condensing pipe 50 can be attached to the container 30 while maintaining the sealed state of the internal space S of the container 30.

A liquid-phase secondary refrigerant R2 flows through the condensing tube 50 in one direction (from right to left in FIG. 1) along the extending direction of the condensing tube 50. Therefore, the secondary refrigerant R2 flows through the wall surface of the condensing pipe 50 and through the upper part of the internal space S of the container 30. The secondary refrigerant R2 is cooled, for example, to a liquid temperature lower than the maximum allowable temperature of the heating element.

The material of the container 30 is not particularly limited, and a wide variety of materials can be used, such as copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, stainless steel, titanium, titanium alloy, and the like.

The material of the condensing tube 50 is not particularly limited, and examples thereof include copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy, iron alloy (for example, stainless steel), titanium, titanium alloy, and the like.

The primary refrigerant R1 (L) is not particularly limited, and a wide variety of materials can be used, such as electrically insulating refrigerants. Specific examples include water, fluorocarbons, cyclopentane, ethylene glycol, and mixtures thereof. Among these primary refrigerants R1 (L), fluorocarbons, cyclopentane, and ethylene glycol are preferred from the viewpoint of electrical insulation, and fluorocarbons are particularly preferred.

The secondary refrigerant R2 is not particularly limited, and examples thereof include water, antifreeze (containing ethylene glycol as a main component, for example), and the like.

The cooling device 1 includes the heat transfer member 10 as described above.

<Cooling mechanism of cooling device>
Next, the cooling mechanism of the cooling device 1 of the present invention will be explained below.
First, when the heating element generates heat, the heat is transferred to the heat transfer member 10 through the bottom of the container 30 constituting the cooling device 1, the temperature of the heat transfer member 10 rises, and the heat transfer member 10 is sealed in the lower part of the internal space S of the container 30. The liquid-phase primary refrigerant R1 (L) is heated, and the liquid-phase primary refrigerant R1 (L) undergoes a phase change to the gas-phase primary refrigerant R1 (g), which releases heat from the heating element. is absorbed as latent heat. Next, the primary refrigerant R1 (g) that has changed to the gas phase moves upward through the internal space S of the container 30 and comes into contact with the condensing pipe 50. A low-temperature secondary refrigerant R2 flows inside the condensing pipe 50. Therefore, when the primary refrigerant R1 (g) that has changed to the gas phase comes into contact with or approaches the outer surface of the condensing tube 50, it releases latent heat due to the heat exchange action of the condensing tube 50, and changes from the gas phase to the liquid phase. The phase changes to During the phase change from the gas phase to the liquid phase, the latent heat released from the gas phase primary refrigerant R1 (g) is transferred to the secondary refrigerant R2 flowing through the condensing pipe 50. Further, the primary refrigerant R1 (L) that has undergone a phase change to the liquid phase flows back through the internal space S of the container 30 from the upper part to the lower part under the action of gravity. The primary refrigerant R1 (L) repeats a phase change from a liquid phase to a gas phase and from a gas phase to a liquid phase in the sealed internal space S of the container 10. In addition, in the cooling device 1, when the primary refrigerant R1 repeats a phase change from a liquid phase to a gas phase and a phase change from a gas phase to a liquid phase in the internal space of the container 30, a There is no need to form a circulation path for the next refrigerant R1. Therefore, the container 30 can be formed with a simple structure. The secondary refrigerant R2, which has received heat from the gas phase primary refrigerant R1 (g), flows from the inside of the cooling device 1 to the outside along the extending direction of the condensing pipe 50, thereby generating heat from the heating element. is transported to the outside of the cooling device 1.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and includes all aspects included in the concept of the present invention and the scope of the claims. It can be modified to .

The present invention will be explained in more detail below based on Examples, but the present invention is not limited thereto.

(Example of the present invention)
A cooling device 1 according to an example of the present invention has an internal structure shown in FIG. The container 30 is a rectangular parallelepiped-shaped copper container. The heat transfer member 10 was formed using a copper material. A plurality of continuous cavities 12 are arranged in parallel to extend continuously in a straight line. The columnar fin portions 13 have a prismatic shape, are located on both sides of the continuous cavity at intervals along the extending direction of the continuous cavity 12, and have a plurality of rows of a group of columnar fin portions each consisting of a plurality of columnar fin portions. , are arranged on the upper surface 11a of the plate-shaped portion 11. The continuous cavity 12 has an opening O formed in the ceiling portion at a position sandwiched between the pair of columnar fin parts 13, 13. Further, the processed portions 15, which are the portions between the columnar fin portions, were formed by press working, and the arrangement pitch between the processed portions 15, 15 located in the same group of columnar fin portions was 1.0 mm. Water was used as the first refrigerant R1 (L), and the interior space S of the container 30 was filled with the first refrigerant R1 (L), which was then sealed under reduced pressure.

(Comparative example)
As shown in FIG. 7, the cooling device of the comparative example includes a plate-like body 101 made of copper material and having a flat plate shape, and a sintered layer 102 made of copper powder that covers the upper surface of this plate-like body 101. The configuration was the same as the example of the present invention except that the configured heat transfer member 100 was used.

(Performance evaluation)
Performance evaluation of the cooling device was performed under the following conditions.
For each cooling device shown in Fig. 1 or a cooling device produced by replacing the heat transfer member with the heat transfer member shown in Fig. 6, a 50-400W heater (heating element) is attached to the outer surface of the bottom of the container with thermal conductive grease. The temperature difference between the temperature of the second refrigerant passing through the condensing pipe and the temperature of the heater at that time was measured. Then, the thermal resistance is calculated by dividing the measured temperature difference by the amount of heat input, and the heat transfer coefficient (kW/m ² K) is calculated from this calculated thermal resistance (K/W) to evaluate the performance of the cooling device. did. Note that water was used as both the first refrigerant and the second refrigerant sealed in the internal space of the container.

FIG. 8 is a diagram plotting the heat fluxes measured and calculated using the cooling devices of the inventive example and the comparative example on the horizontal axis and the calculated heat transfer coefficient on the vertical axis. From the results in FIG. 8, the cooling device of the present invention has a higher heat transfer coefficient at all heat fluxes than the cooling device of the comparative example, and the heat transfer coefficient improves as the heat flux value increases. It can be seen that the percentage is high.

1 Cooling device 10, 10A, 10B, 10C Heat transfer member 10', 10A', 10B', 10C' Work material 30 Container 31 Bottom of container 31a Inner surface of bottom of container 31b Outer surface of bottom of container 11, 11A, 11B , 11C Plate-shaped part 11a Thin plate part of the plate-shaped part 11b Thick plate part of the plate-shaped part 12, 12A, 12B, 12C Continuous cavity 13, 13A, 13B, 13C Column-shaped fin part 17 Opening end in the extending direction of continuous cavity 14- 1 to 14-8 Group of columnar fin parts 16, 16A, 16B, 16C Ceiling part of continuous cavity 15, 15A, 15B, 15C Part between columnar fin parts (or processed part)
21 Rectangular plate 22, 23 Punched plate 50 Condensing tube 51 Through hole 100 Heat transfer member 101 Plate portion 102 Sintered layer h1 Height of columnar fin portion h2 Height of continuous cavity L Extending direction of continuous cavity O Opening P Mounting position of heating element R1 First refrigerant R1 (L) First refrigerant in liquid phase R1 (g) First refrigerant in gas phase R2 Second refrigerant S Internal space W Joint part

Claims (6)

It is formed on the inner surface of the bottom of the container at a position corresponding to the mounting position of at least one heating element thermally connected to the outer surface of the bottom, and is configured to transfer heat from the heating element to the inner space of the container. A heat transfer member that heats and boils the first refrigerant by transmitting it to a liquid-phase first refrigerant sealed in a lower part, and changes the phase of the first refrigerant from a liquid phase to a gas phase,
a plate-shaped portion having a lower surface on which the heat transfer member is fixed to the inner surface of the bottom of the container;
at least one continuous cavity that includes the upper surface of the plate-like part and extends continuously along one direction of the upper surface of the plate-like part;
a plurality of columnar fin portions forming a pair located on both sides of the continuous cavity at intervals along the extending direction of the continuous cavity and disposed on the upper surface of the plate-like portion;
The heat transfer member is characterized in that the continuous cavity has an opening formed in a ceiling portion at a position sandwiched between the pair of columnar fin portions. The heat transfer member according to claim 1, wherein the height of the columnar fin portion is at least twice the height of the continuous cavity. The plurality of columnar fin portions constitute a group of columnar fin portions that are arranged on both sides of the continuous cavity at intervals along the extending direction of the continuous cavity, respectively. Heat transfer member. A method for manufacturing a heat transfer member according to any one of claims 1 to 3, comprising:
The upper end portion of the plate-like fin portion that constitutes an integrated workpiece material in which a plurality of plate-like fin portions each having an uneven upper end portion are arranged facing each other at intervals on the upper surface of the plate-like portion. A method for manufacturing a heat transfer member, characterized in that the plurality of columnar fin portions and the ceiling portion of the continuous cavity in which the opening is not formed are formed by processing the recessed portion positions of the heat transfer member. A method for manufacturing a heat transfer member according to any one of claims 1 to 3, comprising:
The upper end portion of the plate-like fin portion constitutes a workpiece material in which a plurality of plate-like fin portions each having a flat upper end portion are arranged facing each other at intervals on the upper surface of the plate-like portion. A method for manufacturing a heat transfer member, characterized in that the plurality of columnar fin portions and a ceiling portion of the continuous cavity in which the opening is not formed are formed by processing a predetermined position. At least one heating element is thermally connected to the outer surface of the bottom, and a liquid-phase first refrigerant is sealed in the lower part of the inner space;
A cooling device comprising: a condensing pipe extending through the container at an upper position of the internal space of the container, and through which a second refrigerant flows;
The cooling device is formed on the inner surface of the bottom of the container at a position corresponding to the mounting position of at least one heating element thermally connected to the outer surface of the bottom, and the cooling device is configured to absorb heat from the heating element. The heat transfer member includes a heat transfer member that heats and boils the first refrigerant by transmitting the heat to the liquid phase first refrigerant sealed in the lower part of the internal space of the container, and changes the phase of the first refrigerant from the liquid phase to the gas phase. death,
a plate-shaped portion having a lower surface on which the heat transfer member is fixed to the inner surface of the bottom of the container;
at least one continuous cavity that includes the upper surface of the plate-like part and extends continuously along one direction of the upper surface of the plate-like part;
a plurality of columnar fin portions forming a pair located on both sides of the continuous cavity at intervals along the extending direction of the continuous cavity and disposed on the upper surface of the plate-like portion;
The cooling device is characterized in that the continuous cavity has an opening formed in a ceiling portion at a position sandwiched between the pair of columnar fin portions.

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