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 dissipating 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 the heat. The heat dissipating 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 dissipating part. The other is a liquid pipe that transports the refrigerant condensed and liquefied in the heat dissipating 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] In the heat dissipation section, a liquid film is formed by condensing the refrigerant. When the heat dissipation section of a conventional cooling device is used at an incline with respect to a vertical line, the thickness of the liquid film becomes non-uniform compared to when the heat dissipation section is used arranged along a vertical line. Therefore, the heat dissipation section has a portion where the liquid film is thicker than when the heat dissipation section is used without being inclined. In the portion, the thermal resistance of the liquid film increases with the increase in thickness. As a result, the efficiency of condensation heat transfer decreases. Therefore, there is a problem that the liquid becomes difficult to circulate, and thus the cooling performance decreases. [Means for solving the problem]

[0006] In order to solve the above problems, A boil cooling device according to one embodiment of the present invention includes a heat receiving section that accommodates a refrigerant and receives heat from a heat generating element, a heat dissipation section that has a heat dissipation container and dissipates heat from the heat receiving section, a first pipe section that has a first flow path that transports a gas phase refrigerant generated by evaporation of the refrigerant in the heat receiving section to the heat dissipation section, and a second pipe section that has a second flow path that transports a liquid phase refrigerant generated by condensation of the gas phase 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 description of the drawings]

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

[0008] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Note that the dimensions or scale of each part in the drawings may differ from the actual dimensions, and some parts are shown diagrammatically 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 boiling cooling device 1 according to a first reference example. FIG. 2 is a plan view of the boiling cooling device 1 shown in FIG. 1. Note that FIG. 1 shows a cross section along line BB in FIG. 2. In addition, for convenience of explanation, the following will be explained using the X-axis, Y-axis, and Z-axis that are orthogonal to each other as appropriate. Also, one direction along the X-axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. One direction along the Y-axis is the Y1 direction, and the direction opposite to the Y1 direction is the Y2 direction. One direction along the Z-axis is the Z1 direction, and the direction opposite to the Z1 direction is the Z2 direction. Also, a view in the Z1 direction or the Z2 direction is a plan view.

[0010] The boiling cooling device 1 shown in Fig. 1 and Fig. 2 is used for cooling power electronics products such as inverters or rectifiers mounted on railroad cars, automobiles, household electric machines, etc. 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 heating element that is an object to be cooled in the boiling cooling device 1.

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

[0012] The boil cooling device 1 shown in Fig. 1 has a heat receiving section 10, a heat dissipating 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 dissipating section 20 is located in the Z1 direction from the heat receiving section 10, and the heat receiving section 10 and the heat dissipating 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 section 10 shown in Fig. 1 is a structure having a storage chamber S10 and receiving heat from a heating element (not shown). The storage chamber S10 is a space for storing a liquid refrigerant RE. In the heat receiving section 10, the refrigerant RE is vaporized by the heat of the heating element (not shown) to generate a gas-phase refrigerant.

[0014] In the example shown in FIG. 1, the heat receiving section 10 is box-shaped to form a storage chamber S10. The heat receiving section 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 to each other over the entire circumference. Note that the bottom plate 11 and the side wall 13 are integral in the illustrated example. Also, the side wall 13 extends along the Z axis. In the illustrated example, 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 having excellent thermal conductivity. Specific examples of the materials of the bottom plate 11, the top plate 12, and the side walls 13 include metal materials such as copper, aluminum, or an alloy of any of these. The materials of the bottom plate 11, the top plate 12, and the side walls 13 may be the same or different. The bottom plate 11, the top plate 12, and the side walls 13 may each be made of a separate member, or the bottom plate 11, the top plate 12, and the side walls 13 may be made of an integral member.

[0016] The heat receiving portion 10 is thermally connected to a heat generating body (not shown). "Thermally connected" means that any one of the following conditions a, b, or c is satisfied. 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 have a heat dissipation 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, etc. may be present between the two components under each condition. In this case, it is preferable that the adhesive contains a heat conductive filler, etc., from the viewpoint of increasing the thermal conductivity.

[0017] The refrigerant RE is not particularly limited, but examples thereof include water-based refrigerants such as water, alcohol-based refrigerants such as methanol, ketone-based refrigerants such as acetone, glycol-based refrigerants such as ethylene glycol, fluorocarbon-based refrigerants such as Fluorinert, fluorocarbon-based refrigerants such as HFC134a, and hydrocarbon-based refrigerants such as butane. If necessary, a surfactant such as a fluorine-based surfactant, a silicone-based surfactant, or a hydrocarbon-based surfactant may be added to the refrigerant RE. 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 dissipation section 20 shown in FIG. 1 is a structure that dissipates heat from the heat receiving section 10. The heat dissipation section 20 has a condensation chamber S20, which is a space in which the refrigerant RE is condensed from a vaporized state to a liquid state. In the heat dissipation section 20, the gas-phase refrigerant generated in the heat receiving section 10 is condensed to generate a liquid-phase refrigerant. Specifically, the heat dissipation 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 dissipating heat from the heat receiving section 10 to the outside. The external fluid is not particularly limited and may be a liquid or a gas, but is typically, for example, air.

[0019] 1, the heat dissipation section 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. The 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 the horizontal plane.

[0020] The heat dissipation container 21 has a bottom plate 211, a top plate 212, and a tube portion 213. The space surrounded by the bottom plate 211, the top plate 212, and the tube portion 213 is the condensation chamber S20. The bottom plate 211 and the top plate 212 are arranged parallel to each other. Each of the bottom plate 211 and the top plate 212 is a flat plate extending in a direction perpendicular to the Z axis. The tube 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 over the entire circumference. The tube portion 213 extends along the Z axis. In the illustrated example, the tube portion 213 is perpendicular to the bottom plate 211, but may not be perpendicular. In addition, the bottom plate 211 has a hole into which a first tube portion 31 of the heat transporting part 30 described later is inserted, and a hole into which a second tube portion 32 of the heat transporting part 30 is inserted.

[0021] The shape of the condensation chamber S20 of the heat dissipation container 21 is cylindrical, but may be, for example, prismatic. As shown in FIG. 2, the planar shape of the condensation chamber S20 is circular, but may be, for example, polygonal. The heat dissipation container 21 is made of a material with excellent thermal conductivity. Specific examples of the material of the heat dissipation container 21 include metal materials such as copper, aluminum, or an alloy of either 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 a separate member.

[0022] Each of the heat dissipating fins 22 shown in FIG. 1 is thermally connected to the heat dissipating container 21. Each of the heat dissipating fins 22 is a flat plate-shaped member. In the illustrated example, each of the heat dissipating fins 22 extends in a direction perpendicular to the Z axis. The multiple heat dissipating fins 22 are arranged at intervals from each other in the thickness direction. In this embodiment, the heat dissipating fins 22 are arranged so as to overlap over almost the entire range of the heat receiving part 10 in a plan view. Each of the heat dissipating fins 22 has holes for inserting the multiple heat dissipating containers 21. Each of the heat dissipating fins 22 is made of a material having excellent thermal conductivity. Specific examples of the material of the heat dissipating fins 22 include metal materials such as copper, aluminum, or an alloy of any of these. For example, the heat dissipating fins 22 are fixed to the heat dissipating container 21 by pipe expansion, 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 necessary, and may be omitted. However, by having a plurality of heat dissipation fins 22 in the heat dissipation unit 20, the gas of the refrigerant RE can be efficiently condensed and liquefied.

[0024] 1-1c. Heat transport section 30 The heat transporting part 30 shown in Fig. 1 is a structure that transports heat from the heat receiving part 10 to the heat dissipating part 20 by using the movement of the 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. Note that 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 with a tube 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 generated 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 with 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 tube section 31 and the second tube section 32 are made of a material having excellent thermal conductivity. Specific examples of the material for the first tube section 31 and the second tube section 32 include metal materials such as copper, aluminum, or an alloy of either of these. The first tube section 31 and the second tube section 32 are fixed to the top plate 12 by brazing or the like. The first tube section 31 and the second tube section 32 may be made of the same material or different materials.

[0028] The boiling cooling device 1 having the above-mentioned schematic configuration is a thermosiphon cooler as described above. In the boiling cooling device 1, the gas-phase refrigerant generated by vaporizing the refrigerant RE in the heat receiving section 10 is introduced from the first pipe section 31 to the heat dissipating section 20 due to the density difference between the gas and the liquid. The gas-phase refrigerant is condensed and liquefied in the heat dissipating section 20 to generate a liquid-phase refrigerant. The liquid-phase refrigerant is introduced from the second pipe section 32 to the heat receiving section 10 by gravity. Then, the liquid-phase refrigerant is 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 dissipating 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 showing the heat transporting part 30 shown in FIG. 1, that is, 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 at 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 section 31 and the second pipe section 32 are arranged parallel to each other. Specifically, the center line A1 of the first flow path S1 of the first pipe section 31 and the center line A2 of the second flow path S2 of the second pipe section 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, and opens to the accommodation chamber S10 and the condensation 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 a gas-phase refrigerant generated by vaporizing the refrigerant RE in the heat receiving section 10 to the heat dissipating section 20. Each condensation 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 an end of the first inner wall surface 310 in the Z2 direction. The second opening 302 is a space surrounded by an end 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. Also, 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, 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 tube 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 an end of the second inner wall surface 320 in the Z2 direction. The fourth opening 304 is a space surrounded by an 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 section 31 is larger than the average cross-sectional area of ​​the second flow path S2 of the second pipe section 32. Therefore, compared to a case where 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 pipes that extend linearly. Therefore, the center line A1 of the first flow path S1 and the center line A2 of the second flow path S2 each extend linearly. Therefore, the flow path resistance in the first flow path S1 and the second flow path S2 can be reduced compared to when the first pipe section 31 and the second pipe section 32 are bent. Therefore, the circulation of the refrigerant RE is less likely to be hindered. Therefore, the refrigerant RE can circulate smoothly. Furthermore, no processing such as bending is required when manufacturing each of the first pipe section 31 and the second pipe section 32. Therefore, each of the first pipe section 31 and the second pipe section 32 can be manufactured at low cost.

[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 at a predetermined location so that the heat dissipation container 21 is disposed at an incline with respect to the vertical line A. Specifically, the boiling cooling device 1 is placed at a predetermined location so that the bottom plate 211, the top plate 212, and the tube portion 213 of the heat dissipation container 21 are each inclined with respect to the vertical line A or the horizontal plane G0. Furthermore, with the inclination of the heat dissipation container 21, the first pipe portion 31, the second pipe portion 32, and the bottom plate 11, the top plate 12, and the 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 cooled by the 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 tube 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 higher the thermal resistance. For this reason, in the portion where the liquid film F0 is thick, the cooling performance decreases due to a decrease in the efficiency of condensation heat transfer compared to the portion where the liquid film F0 is thin.

[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 located 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 located above the center O4 of the fourth opening 304.

[0046] Since 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. Therefore, the decrease in momentum of the vapor flow caused by the gas-phase refrigerant ejected from the second opening 302 is suppressed. Therefore, the liquid film F0 in the heat dissipation container 21 can be efficiently disturbed by the vapor flow. As a result, the liquid film F0 can be suppressed from becoming thicker, and therefore, the increase in the thermal resistance of the liquid film F0 can be suppressed. Therefore, the decrease in efficiency of condensation heat transfer can be suppressed, and therefore the decrease in cooling performance can be suppressed. In particular, since the entire second opening 302 is located above the entire fourth opening 304, the decrease in cooling performance can be effectively suppressed.

[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, compared to when the center O4 is located above the center O2. Therefore, the refrigerant RE can be circulated smoothly.

[0048] Furthermore, when the heat dissipation container 21 is inclined 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 easily flows 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 particularly easily flows into the first opening 301.

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

[0050] In addition, the center line A1 of the first flow passage S1 is located above the center line A2 of the second flow passage S2. Therefore, it is 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 the 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. Therefore, the heat dissipation container 21 can 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 are parallel to the horizontal plane G0, the movement of the air heated between the heat dissipation fins 22 is prevented by the heat dissipation fins 22 even if the air tries to rise between the heat dissipation fins 22. Therefore, heat is likely to be retained between the heat dissipation fins 22, and natural retention is unlikely to occur. On the other hand, since the heat dissipation fins 22 are inclined with respect to the horizontal plane G0, the air heated between the heat dissipation fins 22 is likely to be moved upward along the heat dissipation fins 22 compared to when the heat dissipation fins 22 are not inclined, so that retention of heat between the heat dissipation fins 22 can be suppressed. Therefore, the cooling performance in the heat dissipation container 21 can be improved.

[0052] The heat dissipating 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 dissipating section 20, it is preferable that the heat dissipating fins 22 are inclined with respect to the vertical line A in accordance with the inclination of the heat dissipating container 21. Specifically, it is preferable that the heat dissipating fins 22 are 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 dissipating container 21 and the heat dissipating fins 22, and allows the heat dissipating fins 22 to be easily inclined with the inclination of the heat dissipating container 21.

[0053] 2. Embodiment Hereinafter, an embodiment of the present invention will be described. In the following exemplary embodiments, for elements having the same actions and functions as those in the first embodiment, the reference symbols used in the description of the first embodiment will be used and detailed descriptions of each 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, which corresponds to the cross section of 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. In the following, the differences between the heat transporting part 30A and the heat transporting part 30 will be described, and the description 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 tube part 31A and a second tube part 32. A part of the first tube part 31A is located inside the heat dissipation container 21 so that the end of the first tube part 31A in the Z1 direction is located in the Z1 direction from the bottom plate 211 of the heat dissipation container 21. The first tube part 31A has a plurality of openings. Specifically, the first tube 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 penetrating the tube wall of the first tube part 31A. Note that no opening part is provided at the end of the first tube part 31A in the Z1 direction, and the end is blocked.

[0056] As shown in FIG. 5, the second opening 302A and the fifth opening 305 each open to the side of the first tube portion 31A. Specifically, the second opening 302A opens toward the X2 direction. The fifth opening 305 opens toward the X1 direction. Therefore, the second opening 302A and the fifth opening 305 open in opposite directions. When the heat dissipation container 21 is inclined, the center O5 of the fifth opening 305 is located below the center O2 of the second opening 302A. Also, the center O2 of the second opening 302A and the center O5 of the fifth opening 305 each are 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 steam flow. This allows the efficiency of condensation heat transfer to be prevented from decreasing, and therefore the cooling performance to be prevented from decreasing.

[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 from the bottom plate 211 in the Z1 direction. Therefore, the second opening 302A is less likely to be blocked by the liquid film F0 compared to a case in which 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 steam 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 a plurality of 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] In addition, 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 steam flow than in the case where 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] In addition, 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 steam 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] Moreover, 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 vertically downward. By facing the second opening 302A downward, the gas phase refrigerant can be sprayed from the second opening 302A toward the lower part of the heat dissipation container 21 where the liquid film F0 is the 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 inclined with respect to the vertical line A, the fifth opening 305 faces upward. Specifically, the fifth opening 305 faces vertically and obliquely upward. Therefore, while the second opening 302A faces downward, the fifth opening 305 faces upward, so that 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. That is, 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] The fifth opening 305 is located below the second opening 302A. The opening area, i.e., the cross-sectional area, of the fifth opening 305 is larger than the opening area, i.e., the cross-sectional area, of the second opening 302A. Therefore, since the cross-sectional area of ​​the fifth opening 305 is larger than the cross-sectional area of ​​the second opening 302A, the amount of vapor flow of the gas-phase refrigerant injected from the fifth opening 305 can be increased compared to when the cross-sectional area of ​​the fifth opening 305 is smaller. In addition, since the fifth opening 305 is located below the second opening 302A, the gas-phase refrigerant can be injected from the fifth opening 305 toward the lower part of the heat dissipation container 21 where the thickness of the liquid film F0 is the thickest.

[0066] In addition, 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 dissipation container 21 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.

[0067] FIG. 6 is a diagram showing 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 the second opening 302A and the fifth opening 305. The sixth opening 306 opens in the Y1 direction. The seventh opening 307 opens in the Y2 direction. By having a plurality of 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 directions in which the plurality of openings open in a plan view are different from each other. Therefore, the liquid film F0 can be more efficiently disturbed than when the plurality of openings open in the same direction. In addition, the positions of the plurality of openings on the vertical line A and in the Z1 direction are different from each other. Therefore, the liquid film F0 can be more efficiently disturbed than when the positions of the plurality of openings on the vertical line A and in the Z1 direction are the same.

[0068] 3.Second reference example The second embodiment of the present invention will be described below. In the following 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 vertical 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. In the following, the differences between the heat transporting part 30B and the heat transporting part 30 will be described, and the description 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 with respect to 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. Also, the third opening 303B is located below the liquid level RE0 of the refrigerant RE present in the accommodation chamber S10. In other words, the third opening 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. Therefore, the liquid film F0 in the heat dissipation container 21 can be efficiently disturbed by the vapor flow caused by the injection of the gas-phase refrigerant from the second opening 302B. Therefore, the deterioration of the cooling performance can be suppressed.

[0073] As described above, a portion of the first pipe portion 31B is located inside the heat dissipation container 21. By having a portion of the first pipe portion 31B protrude from the bottom plate 211 in the Z1 direction, the second opening 302B is less likely to be blocked by the liquid film F0 compared to a case in which 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] 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, by positioning a part of the first pipe section 31B inside the heat dissipation container 21, it is easier to position the position of the second opening 302B on the vertical line A upward than when the part is not located inside the heat dissipation container 21. Therefore, the liquid-phase refrigerant is more unlikely to flow into the first pipe section 31B. Therefore, the liquid-phase refrigerant is more unlikely 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 below 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 is more likely to flow down into the second pipe section 32B, and the gas phase refrigerant of the heat receiving section 10 is more likely to flow into the first pipe section 31B. Therefore, the refrigerant RE can be circulated more smoothly.

[0076] 4. Variations The above-described exemplary embodiments may be modified in various ways. Specific modified aspects that may be applied to the above-described embodiments are illustrated below. Two or more aspects arbitrarily selected from the following examples may be appropriately combined to the extent that they are not mutually inconsistent. In addition, the following modified examples of the first reference example may be appropriately combined with the second or second 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 section 31 and the second pipe section 32 in the first modified example. The first pipe section 31 and the second pipe section 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 section 31 and the second pipe section 32 shown in FIG. 8 do not overlap each other in the X1 direction and the Y1 direction. In the example shown in FIG. 8, 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 in a state in which the heat dissipation container 21 is inclined with respect to the vertical line A, thereby suppressing a decrease in cooling performance.

[0079] Fig. 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 a portion overlapping each other in the Y1 direction. The second opening 302 and the fourth opening 304 have a portion overlapping each other in the Y1 direction. In the example shown in Fig. 9, similarly to 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 in a state in which 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 above-mentioned first reference example, one heat dissipation container 21, one first pipe section 31, and one second pipe section 32 are provided for one heat receiving section 10. However, a plurality of heat dissipation containers 21, a plurality of first pipe sections 31, and a plurality of second pipe sections 32 may be provided for one heat receiving section 10.

[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 dissipating part 20C, and a heat transporting part 30C. The heat dissipating part 20C has a plurality of heat dissipation 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 dissipation 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 heat dissipation containers 21 are arranged in a staggered pattern in a plan view. The arrangement of the heat dissipation containers 21 is not limited to the staggered arrangement, and may be another regular arrangement such as a matrix arrangement, or may be an irregular arrangement. The number of heat dissipation containers 21 is not limited to the number shown in the example shown in Fig. 11, and is arbitrary. The volumes of the condensation chambers S20 are equal to each other, but may be different from each other.

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

[0084] Although the present invention has been described above based on each preferred embodiment, the present invention is not limited to the above-mentioned embodiment. Any configuration of each of the above-mentioned 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-mentioned embodiment, and 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 dissipation portion, 21... heat dissipation container, 22... heat dissipation fin, 30... heat transport portion, 31... first tube portion, 32... second tube portion, 211... bottom plate, 212... top plate, 213... cylinder 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 for transporting 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 dissipation 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 dissipating portion, Each of the second opening and the fifth opening opens 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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