Boiling cooling device

Abstract

To provide a boiling cooling device capable of suppressing reduction of a cooling performance.SOLUTION: A boiling cooling device comprises a heat reception section, a heat dissipation section, a first tube section including a first flow passage for transporting a gas phase coolant, which is generated by evaporating a coolant in the heat reception section, to the heat dissipation section and a second tube part including a second flow passage for transporting a liquid phase coolant, which is generated by condensing the gas phase coolant in the heat dissipation section, to the heat reception section. A portion of the first tube part is positioned inside of a heat dissipation container. The first tube part includes a first opening which is opened toward the heat reception section, a second opening which is positioned within the heat dissipation container, and a fifth opening which is positioned within the heat dissipation container. The second tube part includes a third opening which is opened toward the heat dissipation section and a fourth opening which is opened toward the heat dissipation section. Each of the second opening and the fifth opening is opened beside the first tube part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a boiling cooling device and a method for cooling a heat generating body. [Background technology]

[0002] 2. Description of the Related Art A boiling cooling device is known that cools a heat-generating body by utilizing heat transport due to latent heat caused by boiling of a refrigerant.

[0003] The cooling device described in Patent Document 1 has a heat receiving part, a heat radiating part, and two connecting parts that connect them. The heat receiving part receives heat from an object to be cooled and vaporizes a refrigerant using that heat. The heat radiating part condenses and liquefies the refrigerant. One of the two connecting parts is a vapor pipe that transports the refrigerant vaporized in the heat receiving part to the heat radiating part. The other is a liquid pipe that transports the refrigerant condensed and liquefied in the heat radiating part to the heat receiving part. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2015 / 146110 Summary of the Invention [Problem to be solved by the invention]

[0005] A liquid film is formed in the heat dissipation section as the refrigerant condenses. When the heat dissipation section of a conventional cooling device is used at an angle relative to the vertical, the thickness of the liquid film becomes non-uniform compared to when the heat dissipation section is positioned along the vertical. As a result, there are areas in the heat dissipation section where the liquid film is thicker than when the heat dissipation section is not tilted. In these areas, the thermal resistance of the liquid film increases as the thickness increases. As a result, the efficiency of condensation heat transfer decreases. This makes it difficult for the liquid to circulate, resulting in a problem of reduced cooling performance. [Means for solving the problem]

[0006] To solve the above problems, A boil cooling device according to one embodiment of the present invention comprises a heat receiving section that accommodates a refrigerant and receives heat from a heat generating element, a heat dissipation section having a heat dissipation container and dissipating heat from the heat receiving section, a first pipe section having a first flow path that transports gaseous refrigerant produced by evaporation of the refrigerant in the heat receiving section to the heat dissipation section, and a second pipe section having a second flow path that transports liquid refrigerant produced by condensation of the gaseous refrigerant in the heat dissipation section to the heat receiving section, wherein a portion of the first pipe section is located within the heat dissipation container, and the first pipe section has a first opening that opens toward the heat receiving section, a second opening that is located within the heat dissipation container, and a fifth opening that is located within the heat dissipation container, and the second pipe section has a third opening that opens toward the heat receiving section and a fourth opening that opens toward the heat dissipation section, and each of the second opening and the fifth opening opens to a side of the first pipe section. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional perspective view showing a schematic configuration of a boil cooling device according to a first reference example. [Figure 2] FIG. 2 is a plan view of the boil cooling device shown in FIG. [Figure 3] FIG. 2 is a vertical cross-sectional view showing the boil cooling device shown in FIG. [Figure 4] 1 is a vertical cross-sectional view showing a boiling cooling device according to an embodiment of the present invention; [Figure 5] 1 is a cross-sectional view of an embodiment of a boiling cooling device. [Figure 6] 6 is a diagram showing another example of the first pipe portion shown in FIG. 5. FIG. [Figure 7] FIG. 10 is a vertical cross-sectional view showing a boil cooling device according to a second embodiment of the present invention. [Figure 8] FIG. 10 is a cross-sectional view showing a first pipe portion and a second pipe portion in a first modified example. [Figure 9] 9 is a diagram showing another example of the first pipe portion shown in FIG. 8. FIG. [Figure 10] FIG. 10 is a cross-sectional perspective view showing a schematic configuration of a boil cooling device according to a second modified example. [Figure 11]FIG. 11 is a plan view of the boil cooling device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the dimensions and scale of each part in the drawings may differ from the actual dimensions and some parts are shown schematically to facilitate understanding. Furthermore, the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited thereto.

[0009] 1.First reference example 1-1. Overview of boiling cooling device 1 FIG. 1 is a cross-sectional perspective view showing a schematic configuration of a boil cooling device 1 according to a first reference example. FIG. 2 is a plan view of the boil cooling device 1 shown in FIG. 1. Note that FIG. 1 shows a cross section taken along line BB in FIG. 2. In the following, for convenience of explanation, the mutually perpendicular X-axis, Y-axis, and Z-axis will be appropriately used. Furthermore, one direction along the X-axis will be referred to as the X1 direction, and the direction opposite to the X1 direction will be referred to as the X2 direction. One direction along the Y-axis will be referred to as the Y1 direction, and the direction opposite to the Y1 direction will be referred to as the Y2 direction. One direction along the Z-axis will be referred to as the Z1 direction, and the direction opposite to the Z1 direction will be referred to as the Z2 direction. Furthermore, a view in the Z1 direction or the Z2 direction will be referred to as a planar view.

[0010] The boiling cooling device 1 shown in Figures 1 and 2 is used for cooling power electronics products such as inverters or rectifiers mounted on railroad cars, automobiles, or household electrical appliances. The power electronics products have power semiconductor elements such as diodes or IGBTs (Insulated Gate Bipolar Transistors). The power semiconductor elements are an example of a heat generating element that is the object to be cooled by the boiling cooling device 1.

[0011] The boiling cooling device 1 is a loop-type thermosiphon cooler that utilizes the density difference between vaporized refrigerant RE and liquefied refrigerant RE. The boiling cooling device 1 is used to cool a heat-generating body while being inclined relative to a horizontal plane. That is, the boiling cooling device 1 is used while being inclined relative to a vertical line.

[0012] The boil cooling device 1 shown in Fig. 1 has a heat receiving section 10, a heat radiating section 20, and a heat transporting section 30. The heat transporting section 30 has a first pipe section 31 and a second pipe section 32. The heat radiating section 20 is located in the Z1 direction from the heat receiving section 10, and the heat receiving section 10 and the heat radiating section 20 are connected via the heat transporting section 30. Each section will be described below.

[0013] 1-1a. Heat receiving part 10 The heat receiving part 10 shown in Fig. 1 has a storage chamber S10 and is a structure that receives heat from a heat generating element (not shown). The storage chamber S10 is a space that stores a liquid refrigerant RE. In the heat receiving part 10, the refrigerant RE is vaporized by the heat of the heat generating element (not shown), thereby generating a gas-phase refrigerant.

[0014] In the example shown in FIG. 1 , the heat receiving unit 10 is box-shaped and forms a storage chamber S10. The heat receiving unit 10 has a bottom plate 11, a top plate 12, and a side wall 13. The space surrounded by the bottom plate 11, the top plate 12, and the side wall 13 is the storage chamber S10. The bottom plate 11 and the top plate 12 are each a flat plate extending in a direction perpendicular to the Z axis. The side wall 13 is located between the bottom plate 11 and the top plate 12 and connects the outer peripheries of the bottom plate 11 and the top plate 12 along the entire periphery. In the example shown, the bottom plate 11 and the side wall 13 are integral. Furthermore, the side wall 13 extends along the Z axis. In the example shown, the side wall 13 is perpendicular to the bottom plate 11, but it does not have to be perpendicular to the bottom plate 11. The top plate 12 also has a hole into which a first pipe part 31 of the heat transporting part 30, which will be described later, is inserted, and a hole into which a second pipe part 32 of the heat transporting part 30 is inserted.

[0015] The heat receiving portion 10 is made of a material with excellent thermal conductivity. Specific examples of the material for the bottom plate 11, top plate 12, and side walls 13 include metal materials such as copper, aluminum, or alloys of any of these. The materials for the bottom plate 11, top plate 12, and side walls 13 may be the same or different. The bottom plate 11, top plate 12, and side walls 13 may each be made of separate members, or the bottom plate 11, top plate 12, and side walls 13 may be made integrally.

[0016] The heat receiving portion 10 is thermally connected to a heat generating body (not shown). "Thermal connection" means that one of the following conditions a, b, or c is met. Condition a: The two members are in direct physical contact. Condition b: The two members are arranged with a gap of 50 μm or less between them. Condition c: The two members are arranged with a gap of 10 W·m -1 ·K -1 The two components are physically connected via another member having the above thermal conductivity. Note that a heat-transfer grease, adhesive, or the like may be present between the two components under each condition. In this case, the adhesive preferably contains a heat-conductive filler or the like to enhance thermal conductivity.

[0017] The refrigerant RE is not particularly limited, but examples thereof include aqueous refrigerants such as water, alcohol refrigerants such as methanol, ketone refrigerants such as acetone, glycol refrigerants such as ethylene glycol, fluorocarbon refrigerants such as Fluorinert, chlorofluorocarbon refrigerants such as HFC134a, and hydrocarbon refrigerants such as butane. If necessary, the refrigerant RE may contain a surfactant such as a fluorine-based surfactant, a silicone-based surfactant, or a hydrocarbon-based surfactant. The refrigerant RE may also be a combination of two or more of the above-mentioned refrigerants.

[0018] 1-1b. Heat radiation part 20 The heat radiating section 20 shown in FIG. 1 is a structure that radiates heat from the heat receiving section 10. The heat radiating section 20 has a condensation chamber S20, which is a space where the refrigerant RE is condensed from a vaporized state to a liquid state. In the heat radiating section 20, the gas-phase refrigerant generated in the heat receiving section 10 is condensed to generate a liquid-phase refrigerant. Specifically, the heat radiating section 20 condenses and liquefies the gas-phase refrigerant by exchanging heat between the refrigerant RE and an external fluid in the condensation chamber S20, thereby radiating heat from the heat receiving section 10 to the outside. The external fluid is not particularly limited and may be either a liquid or a gas, but is typically air, for example.

[0019] 1, the heat dissipation unit 20 has a heat dissipation container 21 and a plurality of heat dissipation fins 22. The heat dissipation container 21 is a box-shaped member that forms the condensation chamber S20. In the illustrated example, the heat dissipation container 21 is a vertically elongated container with the Z1 direction as the longitudinal direction. Cooling of the heat-generating body by the boiling cooling device 1 is performed, for example, with the heat dissipation container 21 inclined with respect to a horizontal plane.

[0020] The heat dissipation container 21 has a bottom plate 211, a top plate 212, and a tubular portion 213. The space surrounded by the bottom plate 211, the top plate 212, and the tubular portion 213 is the condensation chamber S20. The bottom plate 211 and the top plate 212 are arranged parallel to each other. The bottom plate 211 and the top plate 212 are each a flat plate extending in a direction perpendicular to the Z-axis. The tubular portion 213 is located between the bottom plate 211 and the top plate 212 and connects the outer peripheries of the bottom plate 211 and the top plate 212 to each other along the entire periphery. The tubular portion 213 extends along the Z-axis. In the illustrated example, the tubular portion 213 is perpendicular to the bottom plate 211, but it does not have to be perpendicular. The bottom plate 211 also has a hole into which a first pipe portion 31 (described later) of the heat transporting part 30 is inserted, and a hole into which a second pipe portion 32 of the heat transporting part 30 is inserted.

[0021] The shape of the condensation chamber S20 in the heat dissipation container 21 is cylindrical, but may be, for example, a prismatic shape. Furthermore, as shown in FIG. 2, the planar shape of the condensation chamber S20 is circular, but may be, for example, a polygonal shape. Furthermore, the heat dissipation container 21 is made of a material with excellent thermal conductivity. Specific examples of the material for the heat dissipation container 21 include metal materials such as copper, aluminum, or an alloy of any of these. In the illustrated example, the bottom plate 11, the top plate 12, and the side wall 13 are integrally formed, but the bottom plate 11, the top plate 12, and the side wall 13 may each be formed of separate members.

[0022] Each heat dissipation fin 22 shown in FIG. 1 is thermally connected to the heat dissipation container 21. Each heat dissipation fin 22 is a flat plate-shaped member. In the illustrated example, each heat dissipation fin 22 extends in a direction perpendicular to the Z axis. The multiple heat dissipation fins 22 are arranged at intervals in the thickness direction. In this embodiment, the heat dissipation fins 22 are arranged so as to overlap over almost the entire area of ​​the heat receiving unit 10 in a plan view. Each heat dissipation fin 22 has holes for inserting multiple heat dissipation containers 21. Each heat dissipation fin 22 is made of a material with excellent thermal conductivity. Specific examples of materials for the heat dissipation fins 22 include metal materials such as copper, aluminum, or an alloy of these. The heat dissipation fins 22 are fixed to the heat dissipation container 21 by, for example, expanding the pipe, press-fitting, adhesive, screwing, brazing, welding, or the like.

[0023] The shape of the heat dissipation fins 22 is not limited to the example shown in Fig. 1 and may be any shape. The heat dissipation fins 22 may be provided as needed, or may be omitted. However, by providing the heat dissipation unit 20 with a plurality of heat dissipation fins 22, the gaseous refrigerant RE can be efficiently condensed and liquefied.

[0024] 1-1c. Heat transport section 30 1 is a structure that transports heat from the heat receiving part 10 to the heat dissipating part 20 by using the movement of a refrigerant RE. In the example shown in FIG. 1, the heat transporting part 30 has a first pipe part 31 and a second pipe part 32. The top plate 12 of the heat receiving part 10 may also serve as a part of the heat transporting part 30.

[0025] The first pipe section 31 transports the gas phase refrigerant generated by vaporizing the refrigerant RE in the heat receiving section 10 to the heat dissipating section 20. In this embodiment, the first pipe section 31 is configured as a pipe extending linearly along the Z axis. The first pipe section 31 is connected to both the heat receiving section 10 and the heat dissipating section 20. Specifically, the first pipe section 31 is connected to both the top plate 12 of the heat receiving section 10 and the bottom plate 211 of the heat dissipating section 20.

[0026] The second pipe section 32 transports the liquid-phase refrigerant, which is produced by condensing the gas-phase refrigerant in the heat dissipation section 20, to the heat receiving section 10. In this embodiment, the second pipe section 32 is configured as a pipe extending linearly along the Z-axis. The second pipe section 32 is connected to both the heat receiving section 10 and the heat dissipation section 20. Specifically, the second pipe section 32 is connected to both the top plate 12 of the heat receiving section 10 and the bottom plate 211 of the heat dissipation section 20. In the example shown in FIG. 2 , the first pipe section 31 and the second pipe section 32 are aligned in the direction along the X-axis.

[0027] The first pipe portion 31 and the second pipe portion 32 are made of a material with excellent thermal conductivity. Specific examples of materials for the first pipe portion 31 and the second pipe portion 32 include metal materials such as copper, aluminum, or an alloy of either of these. The first pipe portion 31 and the second pipe portion 32 are fixed to the top plate 12 by brazing or the like. The first pipe portion 31 and the second pipe portion 32 may be made of the same material or different materials.

[0028] The boil-off cooling device 1 having the above-described schematic configuration is a thermosiphon cooler, as described above. In the boil-off cooling device 1, the refrigerant RE is vaporized in the heat receiving section 10 to generate a gas-phase refrigerant, which is introduced into the heat radiating section 20 from the first pipe section 31 due to the density difference between the gas and liquid. The gas-phase refrigerant is condensed and liquefied in the heat radiating section 20 to generate a liquid-phase refrigerant. The liquid-phase refrigerant is then introduced into the heat receiving section 10 from the second pipe section 32 due to gravity. The liquid-phase refrigerant is then vaporized again to become a gas-phase refrigerant. In this way, a circulating flow accompanied by a phase change of the refrigerant RE is formed, and heat is transported from the heat receiving section 10 to the heat radiating section 20 by latent heat. In this way, the thermosiphon cooler allows the refrigerant RE to circulate without using a pump.

[0029] 1-1d. Detailed configuration of the heat transfer section 30 3 is a vertical cross-sectional view of the heat transporting part 30 shown in FIG. 1, i.e., a cross-sectional view taken along line BB in FIG. 2. For example, as shown in FIG. 3, when the boiling cooling device 1 is used to cool a heat-generating body, the boiling cooling device 1 is placed in a predetermined location so that the center line A0 of the heat dissipation container 21 is inclined with respect to the vertical line A. In this specification, the vertically upward direction and the vertically obliquely upward direction are both referred to as "upward." The vertically downward direction and the vertically obliquely downward direction are both referred to as "downward."

[0030] 3, the first pipe portion 31 and the second pipe portion 32 are arranged parallel to each other. Specifically, the center line A1 of the first flow path S1 of the first pipe portion 31 and the center line A2 of the second flow path S2 of the second pipe portion 32 are parallel to each other.

[0031] The first pipe section 31 is connected to the heat receiving section 10 and the heat dissipating section 20, respectively, and opens to the accommodation chamber S10 and the condensing chamber S20. The first pipe section 31 has a first inner wall surface 310 that forms a first flow path S1. The first flow path S1 is a space that transports the gas-phase refrigerant generated by vaporizing the refrigerant RE in the heat receiving section 10 to the heat dissipating section 20. Each condensing chamber S20 communicates with the accommodation chamber S10 of the heat receiving section 10 via the first flow path S1.

[0032] In the illustrated example, the thickness of the first pipe portion 31 is constant. The first inner wall surface 310 of the first pipe portion 31 is a cylindrical surface parallel to the center line A1 of the first flow path S1. The inner diameter of the first inner wall surface 310 is constant. Therefore, the cross-sectional area of ​​the first flow path S1 is constant.

[0033] The first pipe section 31 has a first opening 301 that opens toward the heat receiving section 10 and a second opening 302 that opens toward the heat dissipation section 20. The first opening 301 is a space surrounded by the edge of the first inner wall surface 310 in the Z2 direction. The second opening 302 is a space surrounded by the edge of the first inner wall surface 310 in the Z1 direction. The first opening 301 and the second opening 302 each have a circular shape in a plan view.

[0034] The position of the first opening 301 in the Z1 direction is the same as the position of the lower surface of the top plate 12 in the Z1 direction. However, the first opening 301 may be located, for example, in the Z2 direction relative to the lower surface of the top plate 12. The first opening 301 is located above the liquid level RE0 of the refrigerant RE present in the accommodation chamber S10. In other words, the first opening 301 is located between the liquid level RE0 and the heat dissipation unit 20. Therefore, the first opening 301 is not in contact with the liquid level RE0.

[0035] The position of the second opening 302 in the Z1 direction is the same as the position of the upper surface of the bottom plate 211 in the Z1 direction. However, the second opening 302 may be located in the Z1 direction relative to the bottom plate 211 of the heat dissipation container 21.

[0036] 3, the second pipe section 32 is connected to the heat receiving section 10 and the heat dissipating section 20, respectively, and opens to the accommodation chamber S10 and the condensation chamber S20. Each second pipe section 32 has a second inner wall surface 320 that forms a second flow path S2. The second flow path S2 is a space that transports the liquid-phase refrigerant generated by condensing the gas-phase refrigerant in the heat dissipating section 20 to the heat receiving section 10. The condensation chamber S20 of each heat dissipating container 21 communicates with the accommodation chamber S10 of the heat receiving section 10 via the second flow path S2.

[0037] In the illustrated example, the thickness of the second pipe portion 32 is constant. The second inner wall surface 320 of the second pipe portion 32 is a cylindrical surface parallel to the center line A2 of the second flow path S2. The inner diameter of the second inner wall surface 320 is constant. Therefore, the cross-sectional area of ​​the second flow path S2 is constant.

[0038] The second pipe section 32 has a third opening 303 that opens toward the heat receiving section 10 and a fourth opening 304 that opens toward the heat dissipation section 20. The third opening 303 is a space surrounded by the end of the second inner wall surface 320 in the Z2 direction. The fourth opening 304 is a space surrounded by the end of the second inner wall surface 320 in the Z1 direction. The third opening 303 and the fourth opening 304 each have a circular shape in a plan view.

[0039] The position of the third opening 303 in the Z1 direction is the same as the position of the lower surface of the top plate 12 in the Z1 direction. However, the third opening 303 may be located, for example, in the Z2 direction relative to the lower surface of the top plate 12. In this embodiment, the third opening 303 is located above the liquid level RE0 of the refrigerant RE present in the accommodation chamber S10. In other words, the third opening 303 is located between the liquid level RE0 and the heat dissipation unit 20. Therefore, the third opening 303 is not in contact with the liquid level RE0.

[0040] The position of the fourth opening 304 in the Z1 direction is, for example, the same as the position of the upper surface of the bottom plate 211 in the Z1 direction. However, the fourth opening 304 may be located in the Z1 direction relative to the bottom plate 211 of the heat dissipation container 21.

[0041] In the illustrated example, the average cross-sectional area of ​​the first flow path S1 of the first pipe portion 31 is larger than the average cross-sectional area of ​​the second flow path S2 of the second pipe portion 32. Therefore, compared to when the cross-sectional areas of the first flow path S1 and the second flow path S2 are the same, the gas-phase refrigerant flows more easily through the first flow path S1 and the liquid-phase refrigerant flows more easily through the second flow path S2. This allows the boiling cooling device 1 to function favorably as a loop-type thermosiphon.

[0042] As described above, the first pipe section 31 and the second pipe section 32 are straight pipes. Therefore, the center line A1 of the first flow path S1 and the center line A2 of the second flow path S2 each extend straight. This reduces the flow path resistance in the first flow path S1 and the second flow path S2 compared to when the first pipe section 31 and the second pipe section 32 are bent. This makes it less likely that the circulation of the refrigerant RE will be impeded. This allows the refrigerant RE to circulate smoothly. Furthermore, no processing such as bending is required during the manufacture of the first pipe section 31 and the second pipe section 32. This allows the first pipe section 31 and the second pipe section 32 to be manufactured inexpensively.

[0043] Furthermore, as described above, when the boiling cooling device 1 is used to cool a heat-generating body, the boiling cooling device 1 is placed in a predetermined location so that the heat dissipation container 21 is disposed at an angle with respect to the vertical line A. Specifically, the boiling cooling device 1 is placed in a predetermined location so that the bottom plate 211, top plate 212, and tubular portion 213 of the heat dissipation container 21 are each inclined with respect to the vertical line A or the horizontal plane G0. Furthermore, as the heat dissipation container 21 is inclined, the first pipe portion 31, the second pipe portion 32, and the bottom plate 11, top plate 12, and side wall 13 of the heat receiving portion 10 are inclined with respect to the vertical line A in the same direction as the heat dissipation container 21.

[0044] Here, the gas-phase refrigerant in the heat-dissipating container 21 is cooled on the inner wall surface of the heat-dissipating container 21 by contact with the heat-dissipating container 21, which has been cooled by outside air, and becomes a liquid-phase refrigerant while releasing latent heat. The liquid-phase refrigerant becomes a liquid film F0 in the heat-dissipating container 21. The liquid film F0 flows downward along the upper surface of the bottom plate 211 and the inner wall surface of the cylindrical portion 213. As a result, the thickness of the liquid film F0 increases toward the bottom of the heat-dissipating container 21. The thicker the liquid film F0, the greater the thermal resistance. Therefore, in areas where the liquid film F0 is thick, the efficiency of condensation heat transfer decreases compared to areas where the liquid film F0 is thin, resulting in reduced cooling performance.

[0045] In this embodiment, in order to suppress a decrease in cooling performance due to the influence of the liquid film F0, the second opening 302 is positioned above the fourth opening 304 when the heat dissipation container 21 is inclined with respect to the vertical line A. Specifically, the center O2 of the second opening 302 is positioned above the center O4 of the fourth opening 304.

[0046] Because the center O2 is located above the center O4, the second opening 302 is less likely to be blocked by the liquid film F0 than when the center O2 is located below the center O4. This reduces the decrease in momentum of the vapor flow caused by the gas-phase refrigerant ejected from the second opening 302. This allows the vapor flow to efficiently disturb the liquid film F0 in the heat dissipation container 21. As a result, the liquid film F0 is prevented from becoming thicker, thereby reducing the thermal resistance of the liquid film F0. This reduces the decrease in condensation heat transfer efficiency, thereby reducing the decrease in cooling performance. In particular, because the entire second opening 302 is located above the entire fourth opening 304, the decrease in cooling performance can be effectively reduced.

[0047] Furthermore, since the center O4 is located below the center O2, the liquid-phase refrigerant in the heat dissipation container 21 can more easily flow into the fourth opening 304 than when the center O4 is located above the center O2. Therefore, the refrigerant RE can circulate smoothly.

[0048] Furthermore, when the heat radiation container 21 is tilted with respect to the vertical line A, the center O1 of the first opening 301 is located above the center O3 of the third opening 303. Therefore, compared to when the center O1 is located below the center O3, the first opening 301 is less likely to be blocked by the liquid refrigerant RE, and the gas-phase refrigerant flows more easily into the first opening 301. This allows the refrigerant RE to circulate smoothly. Furthermore, since the entire first opening 301 is located above the entire third opening 303, the gas-phase refrigerant flows particularly easily into the first opening 301.

[0049] The inclination angle θ of the heat dissipation container 21 is not particularly limited, but is, for example, greater than 0° and less than 45°. The inclination angle θ is the angle formed between the center line A0 of the heat dissipation container 21 and the vertical line A.

[0050] Furthermore, the center line A1 of the first flow path S1 is located above the center line A2 of the second flow path S2, which makes it easier to position the second opening 302 above the fourth opening 304 than when the center line A1 is located below the center line A2.

[0051] As described above, the heat dissipation unit 20 has heat dissipation fins 22 thermally connected to the heat dissipation container 21. The heat dissipation fins 22 are inclined with respect to the vertical line A. This allows the heat dissipation container 21 to be cooled more efficiently than when the heat dissipation fins 22 are arranged along a horizontal plane G0 perpendicular to the vertical line A. If the heat dissipation fins 22 were parallel to the horizontal plane G0, the heat dissipation fins 22 would prevent the air heated between the fins 22 from rising. This makes it easier for heat to accumulate between the fins 22, making it less likely for natural accumulation to occur. In contrast, since the heat dissipation fins 22 are inclined with respect to the horizontal plane G0, the air heated between the fins 22 can be more easily moved upward along the fins 22 than when the fins are not inclined, thereby suppressing heat accumulation between the fins 22. This improves the cooling performance within the heat dissipation container 21.

[0052] The heat dissipation fins 22 may be inclined with respect to a plane perpendicular to the center line A0. However, from the viewpoint of ease of assembly of the heat dissipation unit 20, it is preferable that the heat dissipation fins 22 be inclined with respect to the vertical line A in accordance with the inclination of the heat dissipation container 21. Specifically, it is preferable that the heat dissipation fins 22 be parallel to the plane perpendicular to the center line A0, that is, parallel to the bottom plate 211. This makes it easy to assemble the heat dissipation container 21 and the heat dissipation fins 22, and also makes it possible to easily incline the heat dissipation fins 22 in accordance with the inclination of the heat dissipation container 21.

[0053] 2. Embodiment Hereinafter, an embodiment of the present invention will be described. In the following exemplary embodiments, for elements whose actions and functions are similar to those of the first reference example, the reference numerals used in the description of the first reference example will be used, and detailed descriptions of each element will be omitted as appropriate.

[0054] Fig. 4 is a longitudinal sectional view showing the boil cooling device 1A of the embodiment. Fig. 5 is a transverse sectional view of the boil cooling device 1A of the embodiment, corresponding to the cross section taken along line CC in Fig. 4. The boil cooling device 1A shown in Figs. 4 and 5 is the same as the heat transporting part 30 of the first reference example, except that it has a heat transporting part 30A instead of the heat transporting part 30 of the first reference example. Below, differences between the heat transporting part 30A and the heat transporting part 30 will be described, and descriptions of the same points as the heat transporting part 30 will be omitted.

[0055] As shown in FIG. 4, the heat transporting part 30A has a first pipe part 31A and a second pipe part 32. A part of the first pipe part 31A is located inside the heat dissipation container 21 so that the end of the first pipe part 31A in the Z1 direction is located further in the Z1 direction than the bottom plate 211 of the heat dissipation container 21. The first pipe part 31A also has a plurality of openings. Specifically, the first pipe part 31A has a second opening part 302A and a fifth opening part 305. The second opening part 302A and the fifth opening part 305 are holes that penetrate the pipe wall of the first pipe part 31A. Note that no opening is provided at the end of the first pipe part 31A in the Z1 direction, and the end is closed.

[0056] As shown in FIG. 5, the second opening 302A and the fifth opening 305 each open to a side of the first pipe portion 31A. Specifically, the second opening 302A opens in the X2 direction. The fifth opening 305 opens in the X1 direction. Therefore, the second opening 302A and the fifth opening 305 open in opposite directions. When the heat dissipation container 21 is tilted, the center O5 of the fifth opening 305 is located below the center O2 of the second opening 302A. Furthermore, the center O2 of the second opening 302A and the center O5 of the fifth opening 305 are each located above the center O4 of the fourth opening 304.

[0057] In this embodiment, as in the first reference example, the center O2 of the second opening 302A is located above the center O4 of the fourth opening 304. Therefore, the second opening 302A is less likely to be blocked by the liquid film F0 than when the center O2 is located below the center O4. This allows the liquid film F0 in the heat dissipation container 21 to be efficiently disturbed by the vapor flow. This prevents a decrease in the efficiency of condensation heat transfer, thereby preventing a decrease in cooling performance.

[0058] As described above, a portion of the first pipe portion 31A is located inside the heat dissipation container 21. In other words, a portion of the first pipe portion 31A protrudes in the Z1 direction from the bottom plate 211. Therefore, the second opening 302A is less likely to be blocked by the liquid film F0 than when a portion of the first pipe portion 31A does not protrude from the bottom plate 211. Therefore, the liquid film F0 inside the heat dissipation container 21 can be efficiently disturbed by the vapor flow.

[0059] Furthermore, as described above, the first pipe section 31A has the fifth opening 305 in addition to the second opening 302A. By having multiple openings in the first pipe section 31A, the liquid film F0 in the heat dissipation container 21 can be more efficiently disturbed by the vapor flow of the gas-phase refrigerant sprayed from the first pipe section 31A than when the first pipe section 31A has only one opening.

[0060] Additionally, the second opening 302A and the fifth opening 305 open to the side of the first pipe section 31A. Therefore, the liquid film F0 in the heat dissipation container 21 can be more efficiently disturbed by the vapor flow than when the upper end of the first pipe section 31A is open.

[0061] Furthermore, when the second opening 302A and the fifth opening 305 open to the side of the first pipe section 31A, it is preferable that no opening is provided at the upper end of the first pipe section 31A. By not providing an opening at the upper end, the liquid film F0 in the heat dissipation container 21 can be efficiently disturbed by the vapor flow of the gas-phase refrigerant ejected from the second opening 302A and the fifth opening 305.

[0062] Since the second opening 302A and the fifth opening 305 are open to the side of the first pipe section 31A, the liquid film F0 can be efficiently disturbed by the vapor flow not only when the heat dissipation container 21 is inclined with respect to the vertical line A but also when it is not inclined. Therefore, even when the heat dissipation container 21 is not inclined with respect to the vertical line A, the cooling performance can be improved.

[0063] Furthermore, with the heat dissipation container 21 tilted relative to the vertical line A, the second opening 302A faces downward. Specifically, the second opening 302A faces diagonally downward. By facing the second opening 302A downward, the gas-phase refrigerant can be sprayed from the second opening 302A toward the lower portion of the heat dissipation container 21 where the liquid film F0 is thickest. Therefore, the liquid film F0 in the heat dissipation container 21 can be more efficiently disturbed by the vapor flow of the gas-phase refrigerant.

[0064] On the other hand, when the heat dissipation container 21 is tilted with respect to the vertical line A, the fifth opening 305 faces upward. Specifically, the fifth opening 305 faces diagonally vertically upward. Therefore, when the second opening 302A faces downward and the fifth opening 305 faces upward, the liquid film F0 in the heat dissipation container 21 can be more efficiently disturbed by the steam flow than when the fifth opening 305 faces downward. In other words, when the fifth opening 305 and the second opening 302A face in opposite directions, the liquid film F0 in the heat dissipation container 21 can be more efficiently disturbed by the steam flow than when they face in the same direction.

[0065] Fifth opening 305 is located below second opening 302A. The opening area, i.e., cross-sectional area, of fifth opening 305 is larger than the opening area, i.e., cross-sectional area, of second opening 302A. Therefore, since the cross-sectional area of ​​fifth opening 305 is larger than the cross-sectional area of ​​second opening 302A, the amount of vapor flow of gas-phase refrigerant sprayed from fifth opening 305 can be increased compared to when the cross-sectional area of ​​fifth opening 305 is smaller. Furthermore, since fifth opening 305 is located below second opening 302A, the gas-phase refrigerant can be sprayed from fifth opening 305 toward a lower portion of heat dissipation container 21 where the thickness of liquid film F0 is the thickest.

[0066] Since the cross-sectional area of ​​the fifth opening 305 is larger than the cross-sectional area of ​​the second opening 302A, the liquid film F0 in the heat-dissipating container 21 can be efficiently disturbed by the vapor flow not only when the heat-dissipating container 21 is inclined with respect to the vertical line A but also when it is not inclined. Therefore, even when the heat-dissipating container 21 is not inclined with respect to the vertical line A, the cooling performance can be improved.

[0067] FIG. 6 is a diagram illustrating another example of the first pipe section 31A shown in FIG. 6. The first pipe section 31A shown in FIG. 6 has three or more openings. Specifically, the first pipe section 31A has a sixth opening 306 and a seventh opening 307 in addition to a second opening 302A and a fifth opening 305. The sixth opening 306 opens in the Y1 direction. The seventh opening 307 opens in the Y2 direction. By having multiple openings, the liquid film F0 in the heat dissipation container 21 can be more efficiently disturbed by the vapor flow. In addition, in the example shown in FIG. 6, the openings open in different directions in a plan view. Therefore, the liquid film F0 can be more efficiently disturbed than when the openings open in the same direction. Furthermore, the openings are located at different positions on the vertical line A and in the Z1 direction. Therefore, the liquid film F0 can be more efficiently disturbed than when the openings are located at the same positions on the vertical line A and in the Z1 direction.

[0068] 3.Second reference example A second embodiment of the present invention will be described below. In the following exemplary embodiment, the elements having the same actions and functions as those in the first embodiment will be designated by the same reference numerals as those in the first embodiment, and detailed descriptions thereof will be omitted as appropriate.

[0069] Fig. 7 is a longitudinal cross-sectional view showing a boiling cooling device 1B of the second reference example. The boiling cooling device 1B shown in Fig. 7 is the same as the heat transporting part 30 of the first reference example, except that it has a heat transporting part 30B instead of the heat transporting part 30 of the first reference example. Below, differences between the heat transporting part 30B and the heat transporting part 30 will be described, and explanations of the same points as the heat transporting part 30 will be omitted.

[0070] 7, the heat transporting part 30B has a first pipe part 31B and a second pipe part 32B. A part of the first pipe part 31B is located inside the heat dissipation container 21. In other words, a part of the first pipe part 31B protrudes upward from the bottom plate 211.

[0071] A portion of the second pipe portion 32B is located within the heat receiving portion 10. In other words, a portion of the second pipe portion 32B protrudes downward from the top plate 12. In addition, the third opening portion 303B is located below the liquid level RE0 of the refrigerant RE present in the accommodation chamber S10. In other words, the third opening portion 303B is in contact with the liquid refrigerant RE.

[0072] In this embodiment, as in the first reference example, the center O2 of the second opening 302B is located above the center O4 of the fourth opening 304B of the second pipe portion 32B. Therefore, the second opening 302B is less likely to be blocked by the liquid film F0 than when the center O2 is located below the center O4. This allows the liquid film F0 in the heat dissipation container 21 to be efficiently disturbed by the vapor flow caused by the injection of the gas-phase refrigerant from the second opening 302B. This prevents a decrease in cooling performance.

[0073] Furthermore, as described above, a portion of the first pipe portion 31B is located inside the heat dissipation container 21. Because a portion of the first pipe portion 31B protrudes from the bottom plate 211 in the Z1 direction, the second opening 302B is less likely to be blocked by the liquid film F0 than when a portion of the first pipe portion 31B does not protrude from the bottom plate 211. Therefore, the liquid film F0 can be more efficiently disturbed by the vapor flow.

[0074] Furthermore, in this embodiment, the cross-sectional area of ​​the first flow path S1 of the first pipe section 31B is substantially equal to the cross-sectional area of ​​the second flow path S2 of the second pipe section 32B. In this case, since a portion of the first pipe section 31B is located within the heat dissipation container 21, it is easier to position the second opening 302B higher on the vertical line A than when a portion of the first pipe section 31B is not located within the heat dissipation container 21. This further suppresses the liquid-phase refrigerant from flowing into the first pipe section 31B. Therefore, it is more difficult for the liquid-phase refrigerant to flow into the second opening 302B than into the fourth opening 304.

[0075] As described above, the third opening 303B of the second pipe section 32B is located lower than the first opening 301 of the first pipe section 31. Therefore, the third opening 303B is more likely to come into contact with the refrigerant RE than the first opening 301. On the other hand, the first opening 301 of the first pipe section 31B is less likely to come into contact with the refrigerant RE. Therefore, compared to the first pipe section 31B, the liquid-phase refrigerant from the heat radiating section 20 flows down more easily into the second pipe section 32B, and the gas-phase refrigerant from the heat receiving section 10 flows more easily into the first pipe section 31B. This allows the refrigerant RE to circulate more smoothly.

[0076] 4. Variations The above-described exemplary embodiments may be modified in various ways. Specific modified aspects that can be applied to the above-described embodiments are exemplified below. Two or more aspects arbitrarily selected from the following examples may be appropriately combined to the extent that they are not mutually inconsistent. Furthermore, the following modified examples of the first reference example may be appropriately combined with the second or third reference example to the extent that they are not mutually inconsistent.

[0077] 4-1. First modified example In the first reference example, the first pipe portion 31 and the second pipe portion 32 are aligned in the X1 direction, but they may be aligned in a direction other than the X1 direction as long as they are aligned in a direction intersecting the Z axis.

[0078] FIG. 8 is a cross-sectional view showing the first pipe portion 31 and the second pipe portion 32 in the first modified example. The first pipe portion 31 and the second pipe portion 32 shown in FIG. 8 are aligned in a direction intersecting both the X1 direction and the Y1 direction in a plan view. The second opening 302 and the fourth opening 304 are aligned in a direction intersecting both the X1 direction and the Y1 direction in a plan view. The first pipe portion 31 and the second pipe portion 32 shown in FIG. 8 do not overlap each other in the X1 direction or the Y1 direction. In the example shown in FIG. 8 , as in the first reference example, the heat dissipation container 21 is tilted with respect to the vertical line A, and the center line A1 of the first pipe portion 31 is positioned higher on the vertical line A than the center line A2 of the second pipe portion 32, thereby suppressing a decrease in cooling performance.

[0079] 9 is a diagram showing another example of the first pipe section 31 of FIG. 8. The first pipe section 31 and the second pipe section 32 shown in FIG. 9 have portions that overlap with each other in the Y1 direction. The second opening section 302 and the fourth opening section 304 have portions that overlap with each other in the Y1 direction. In the example shown in FIG. 9, as in the first reference example, the center line A1 of the first pipe section 31 is positioned higher on the vertical line A than the center line A2 of the second pipe section 32 when the heat dissipation container 21 is inclined with respect to the vertical line A, thereby suppressing a decrease in cooling performance.

[0080] 4-2. Second modified example In the first reference example described above, one heat-receiving portion 10 is provided with one heat-dissipating container 21, one first pipe portion 31, and one second pipe portion 32. However, one heat-receiving portion 10 may be provided with a plurality of heat-dissipating containers 21, a plurality of first pipe portions 31, and a plurality of second pipe portions 32.

[0081] Fig. 10 is a cross-sectional perspective view showing a schematic configuration of a boil cooling device 1C in a second modified example. As shown in Fig. 10, the boil cooling device 1C has a heat receiving part 10, a heat radiating part 20C, and a heat transporting part 30C. The heat radiating part 20C has a plurality of heat radiating containers 21. The heat transporting part 30C has a plurality of first pipe parts 31C and a plurality of second pipe parts 32C. Each of the first pipe parts 31C and the second pipe parts 32C is provided for each heat radiating container 21. The plurality of first pipe parts 31C and the plurality of second pipe parts 32C are connected to a common heat receiving part 10.

[0082] FIG. 11 is a plan view of the boil cooling device 1C shown in FIG. 10. In the example shown in FIG. 11, the multiple heat radiation containers 21 are arranged in a staggered pattern in a plan view. The arrangement of the heat radiation containers 21 is not limited to a staggered arrangement, and may be other regular arrangements such as a matrix arrangement, or an irregular arrangement. The number of heat radiation containers 21 is not limited to the number shown in the example shown in FIG. 11, and is arbitrary. The volumes of the multiple condensation chambers S20 are equal to each other, but may also be different from each other.

[0083] In the second modification, the heat receiving part 10 has one container that forms the accommodation chamber S10, but may have a plurality of containers that form the accommodation chamber S10. The container may be provided for each heat dissipation container 21.

[0084] Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the above-described embodiments. Any configurations of the above-described embodiments may be combined. Furthermore, the configuration of each part of the present invention may be replaced with any configuration that exhibits the same function as the above-described embodiments, or any configuration may be added. [Explanation of symbols]

[0085] 1... boiling cooling device, 10... heat receiving portion, 11... bottom plate, 12... top plate, 13... side wall, 20... heat radiating portion, 21... heat radiating container, 22... heat radiating fin, 30... heat transport portion, 31... first pipe portion, 32... second pipe portion, 211... bottom plate, 212... top plate, 213... cylindrical portion, 301... first opening, 302... second opening, 303... third opening, 304... fourth opening, 305... fifth opening, 306... 6th opening, 307...7th opening, 310...first inner wall surface, 320...second inner wall surface, A...vertical line, A0...center line, A1...center line, A2...center line, F0...liquid film, G0...horizontal plane, O1...center, O2...center, O3...center, O4...center, O5...center, RE...refrigerant, RE0...liquid level, S1...first flow path, S10...storage chamber, S2...second flow path, S20...condensation chamber, θ...tilt angle.

Claims

1. a heat receiving portion that accommodates a refrigerant and receives heat from a heating element; a heat dissipation section having a heat dissipation container and dissipating heat from the heat receiving section; and a first pipe section having a first flow path that transports a gas phase refrigerant generated by vaporizing the refrigerant in the heat receiving section to the heat dissipation section. a second pipe portion having a second flow path that transports a liquid-phase refrigerant generated by condensing the gas-phase refrigerant in the heat radiating portion to the heat receiving portion, a portion of the first pipe portion is located within the heat dissipation container; the first pipe portion has a first opening portion that opens toward the heat receiving portion, a second opening portion that is located within the heat dissipation container, and a fifth opening portion that is located within the heat dissipation container, the second pipe portion has a third opening portion that opens toward the heat receiving portion and a fourth opening portion that opens toward the heat radiating portion, The second opening and the fifth opening each open to a side of the first pipe portion. Boiling cooler.

2. A center line of the first flow path is located above a center line of the second flow path. The boiling cooling device according to claim 1.

3. The cross-sectional area of ​​the first flow path is larger than the cross-sectional area of ​​the second flow path. The boiling cooling device according to claim 1 or 2.

4. The second opening faces downward. The boiling cooling device according to claim 1.

5. The fifth opening faces upward. The boiling cooling device according to claim 1.

6. the fifth opening is located below the second opening, The opening area of ​​the fifth opening is larger than the opening area of ​​the second opening. The boil cooling device according to any one of claims 1 to 5.

7. the heat dissipation unit further includes a heat dissipation fin thermally connected to the heat dissipation container, The heat dissipation fins are inclined with respect to a vertical line. The boil cooling device according to any one of claims 1 to 6.

8. The opening area of ​​the fifth opening is larger than the opening area of ​​the second opening. The boil cooling device according to any one of claims 1 to 7.

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