JP2012202570A - Evaporator and cooling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporator and a cooling apparatus capable of stably cooling a heat source body.SOLUTION: The evaporator includes a hollow container having a first opening for a liquid refrigerant to flow in and a second opening for a gaseous refrigerant to flow out, and having a first surface for transferring heat from a heat source; a porous body arranged abutting on the first surface in the container and permeating the liquid refrigerant; a passage plate arranged abutting on the porous body and having, in the abutment surface, first grooves opened to the first region side connected to the first opening, and second grooves opened to the second region side connected to the second opening; a first passage formed by the porous body and the first grooves and communicating with the first region while being isolated from the second region; and a second passage formed by the porous body and the second grooves and communicating with the second region while being isolated from the second region.

Description

  Embodiments described herein relate generally to an evaporator and a cooling device.

  A circulation type heat pipe used as a cooling device for a heat source body has an evaporator, and drives a liquid refrigerant by a capillary force of a porous body provided in the evaporator. The refrigerant that permeates into the porous body is evaporated by the heat of the heat source body, and the vaporized refrigerant transports the latent heat to cool the heat source body.

Japanese Examined Patent Publication No. 6-33972

  However, for example, when the heat generation amount of the heat source body is large and the amount of evaporation of the refrigerant is large, the porous body dries and the refrigerant cannot be driven by capillary force. As a result, the cooling efficiency of the heat source body decreases and is stable. There was a problem that it could not be cooled.

  Therefore, in order to solve these problems, an object of the present embodiment is to provide an evaporator and a cooling device that can stably cool a heat source body.

  An evaporator according to an embodiment has a first opening through which liquid refrigerant flows and a second opening through which gaseous refrigerant flows out, and a hollow container having a first surface for transferring heat from a heat source A porous body that is disposed in contact with the first surface in the container and allows the liquid refrigerant to permeate, and is disposed in contact with the porous body, and the first opening is disposed on the contact surface. A flow path plate having a first groove that opens to the side of the first region that is connected, and a second groove that opens to the side of the second region that is connected to the second opening, the porous body, and the Formed by a first groove, communicated with the first region, isolated from the second region, formed by the porous body and the second groove, and A second flow path that communicates with the second region and is isolated from the second region.

  The cooling device according to the embodiment includes the above-described evaporator, has a third opening and a fourth opening, and condenses the gaseous refrigerant into the liquid refrigerant by radiating heat, and the evaporation A first pipe for communicating the liquid refrigerant, a second opening for the evaporator, and a fourth opening for the condenser. And a second pipe through which the gaseous refrigerant flows.

The block diagram of the cooling device which concerns on 1st embodiment. FIG. 2 is an exploded view of the evaporator shown in FIG. 1. The perspective view of the flow-path board shown by FIG. The block diagram inside the evaporator shown by FIG. FIG. 5 is a cross-sectional view of the evaporator shown in FIG. BB sectional drawing of the evaporator shown by FIG. CC sectional drawing of the evaporator shown by FIG. FIG. 5 is a cross-sectional view taken along line AA according to a first modification of the evaporator shown in FIG. 4. The top view of the flow-path board which concerns on the 2nd modification of the evaporator shown by FIG. The block diagram of the cooling device which concerns on 2nd embodiment. FIG. 11 is an exploded view of the evaporator shown in FIG. 10. FIG. 11 is an internal configuration diagram of the evaporator shown in FIG. 10. The perspective view of the flow-path board shown by FIG. FIG. 13 is a DD cross-sectional view of the evaporator shown in FIG. 12. EE sectional drawing of the evaporator shown by FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a configuration diagram of a cooling device 100 according to the first embodiment. In FIG. 1, a cooling device 100 includes an evaporator 10 that cools a heat source with a refrigerant, a condenser 30 that releases heat of the refrigerant, a liquid pipe 40 through which the refrigerant moves through the evaporator 10 and the condenser 30, and A steam pipe 50 is provided, and these are connected in a ring shape. The cooling device 100 is filled with a refrigerant (for example, water, antifreeze, alcohol, alternative chlorofluorocarbon, ammonia, etc.), and the refrigerant circulates in the cooling device 100 in one direction while changing the state between liquid and gas.

  The cooling device 100 can be used to cool a heat source body (not shown) such as a CPU in an electronic device, for example. That is, by arranging the evaporator 10 in contact with the heat source body, the heat from the heat source body is absorbed, and the refrigerant is transported to the condenser 30 to cool the heat source body.

  Hereinafter, the configuration of the cooling device 100 will be described in detail.

  The evaporator 10 is a device that absorbs the heat of the heat source body by the latent heat of evaporation of a liquid refrigerant (hereinafter, liquid refrigerant) that is disposed inside the heat source body in contact with the heat source body so that heat can be transferred. The evaporator 10 is composed of a thin rectangular container.

  The condenser 30 is a device that cools a gaseous refrigerant (hereinafter, gaseous refrigerant) generated in the evaporator 10 and condenses it into a liquid refrigerant. As the condenser 30, a heat sink or the like to which heat radiating fins are attached is used. Here, if necessary, forced air cooling by a fan, liquid cooling, or the like may be used in combination to improve the heat dissipation performance of the heat sink. The heat dissipating fins take the heat of the gaseous refrigerant by heat transfer and cool the gaseous refrigerant to condense again into the liquid refrigerant. The heat at this time is released to the outside of the apparatus by the heat radiation fins dissipating heat.

  The liquid pipe 40 is connected to the evaporator 10 and the condenser 30, and communicates the evaporator 10 and the condenser 30. The refrigerant liquefied by the condenser 30 flows in one direction in the liquid pipe 40 and moves to the evaporator 10.

  The steam pipe 50 communicates with the evaporator 10 and the condenser 30 by connecting to the evaporator 10 and the condenser 30. The gaseous refrigerant evaporated in the evaporator 10 flows in one direction through the vapor pipe 50 and moves to the condenser 30.

  Next, the configuration of the evaporator 10 will be described in detail with reference to FIGS. 2 to 7.

  FIG. 2 is an exploded view of the evaporator 10. The evaporator 10 includes a heat transfer plate 11 that transfers heat from a heat source body, a porous plate 14 that permeates the liquid solvent by capillary force, a flow path plate 15 in which a plurality of grooves are formed, an upper lid 16, Is provided. As shown in FIG. 2, a container is formed by the upper lid 16 and the heat transfer plate 11, and a porous plate 14 and a flow path plate 15 are laminated inside. The container is preferably made of a metal material such as aluminum or copper, or a material having excellent thermal conductivity such as an alloy thereof. In the following description, the upper lid side 16 is defined as the upper side, and the heat transfer plate 11 side is defined as the lower side.

  The heat transfer plate 11 is in contact with the heat source body directly or through a heat connection member such as grease, and has a rectangular heat transfer surface on the bottom surface that transfers heat from the heat source body to the inside. Wall surfaces (wall surfaces A, B, C, D) are provided at the edges of the heat transfer surface. Further, the wall surface A of the heat transfer plate 11 is connected to the liquid pipe 40, the inlet 12 through which the liquid refrigerant flows, and the wall surface C opposite to the wall surface A are connected to the steam pipe 50, An outflow port 13 through which the refrigerant flows out to the vapor pipe 50 is formed.

  The porous plate 14 is a rectangular porous member (side surfaces a, b, c, d) that allows the liquid solvent to penetrate by capillary force. The porous plate 14 has a flat surface in contact with the heat transfer surface of the heat transfer plate 11 and side surfaces on two wall surfaces B and D perpendicular to the wall surfaces A and C having the inlet 12 and the outlet 13. b and d are brought into contact with each other and arranged above the heat transfer plate 11.

  The flow path plate 15 is a rectangular member (side surfaces e, f, g, h) having a plane of the same size as the porous plate 14. 3 is a perspective view showing a lower surface of the flow path plate 15 in FIG. As shown in FIG. 3, the flow path plate 15 has a plurality of grooves 17 ′ extending from one side surface in the direction from the side surface e to the side surface g and having an opening only on the side surface e side. And a plurality of grooves 18 ′ extending in the direction and having openings only on the side surface g side. The grooves 17 ′ and 18 ′ are formed in parallel and alternately at equal intervals over the entire surface of the flow path plate 15.

  Then, the flow path plate 15 is disposed such that the surface on which the grooves 17 ′ and 18 ′ are formed is in contact with the upper surface of the porous plate 14 and the side surfaces are aligned. At this time, the upper surface of the flow path plate 15 and the upper surface of the wall surface of the heat transfer plate 11 have the same height.

  FIG. 4 is a configuration diagram of the inside of the evaporator 30 with the top cover 16 removed. In the heat transfer plate 11, a liquid space 19 that stores liquid refrigerant on the inlet 12 side and a gas space 20 that stores gaseous refrigerant on the outlet 13 side are formed by the porous plate 14 and the flow path plate 15. The

  Here, AA, BB, and CC sectional views in FIG. 4 are shown in FIGS. As shown in FIGS. 5 to 7, in the central portion (AA), the liquid flow path 17 is defined as a space surrounded by the grooves 17 ′ and 18 ′ of the flow path plate 15 and the plane of the porous plate 14. And the gas flow path 18 are formed (FIG. 5), the liquid space 19 (BB) has an opening of the liquid flow path 17 and is isolated from the gas space 20 (FIG. 6). CC) has an opening for the gas flow path 18 and is isolated from the liquid space 19 (FIG. 7).

  The upper cover 16 substantially seals the evaporator 10 by being disposed in contact with the upper surface of the flow path plate 15 and the upper surface of the wall surface of the heat transfer plate 11. As a result, the liquid space 19 and the gas space 20 are isolated without communication.

  The porous plate 14 has a pore diameter capable of generating a capillary force necessary for the heat transport amount assumed from the calorific value of the heat source body, a sintered metal or a solidified carbon, a resin such as urethane, etc. The material can be used. The flow path plate 15 may be made of any material that can form a groove. However, when a metal is used, the heat conductivity is compared in order to suppress the temperature rise of the liquid refrigerant in the liquid flow path 17. Are preferred.

  Further, the heat transfer plate 11, the porous plate 14, the flow path plate 15, and the upper lid 16 may be joined by bonding, brazing, or the like in accordance with each material.

  Furthermore, the contact surface between the porous plate 14 and the flow channel plate 15 needs to be flattened so that the liquid refrigerant does not flow directly from the liquid flow channel 17 to the adjacent gas flow channel 18. Therefore, if a rubber-based or silicon-based material that is also used as a sealing material is used as the material of the flow path plate 15, the liquid flow path 17 to the gas flow path 18 is sandwiched between the upper lid 16 and the heat transfer plate 11. It is possible to suppress the flow of

  The operation of the cooling device 100 configured as described above will be described in detail below. In addition, since the function of the condenser 30 is as above-mentioned, the function of the evaporator 10 is demonstrated here.

  In the evaporator 10 described above, the side surface a of the porous plate 14 and the side surface e of the flow channel plate 15 are in contact with the liquid space 19. For this reason, the liquid refrigerant in the liquid space 19 gradually permeates from the side surface a into the porous plate 14 by capillary force. At this time, a liquid refrigerant is held inside the porous plate 14.

  Further, since the liquid channel 17 formed between the porous plate 14 and the channel plate 15 has an opening on the liquid space 19 side, the liquid channel 17 is filled with a liquid refrigerant. . Since the liquid flow path 17 is not open to the gas space 20 side, the liquid refrigerant does not flow into the gas space 20. This prevents the liquid refrigerant from flowing into the vapor pipe 50 communicating with the gas space 20 and hindering the flow of the gaseous refrigerant in the vapor pipe 50.

  Here, when the heat source body generates heat, heat is transferred to the porous plate 14 through the heat transfer plate 11 of the evaporator 10 disposed in contact with the heat source body.

  With this heat, the liquid refrigerant in the porous plate 14 is heated and evaporated into the space of the gas flow path 18. The gaseous refrigerant generated by evaporation moves to the gas space 20 through the gas flow path 18.

  Since the gas flow path 18 is not open to the liquid space 19 side, the gaseous refrigerant does not flow back into the gas flow path 18 and flow into the liquid space 19. This prevents the gaseous refrigerant from flowing into the liquid pipe 40 communicating with the liquid space 19 and hindering the flow of the liquid refrigerant in the liquid pipe 40.

  Therefore, since the evaporator 10 changes the state from the liquid refrigerant to the gaseous refrigerant, the latent heat of vaporization at this time can be taken from the heat source body and the heat source body can be cooled.

  Further, although the pressure in the gas space 20 increases due to the evaporation of the liquid refrigerant, the gaseous refrigerant in the gas space 20 does not flow directly into the liquid space 19 that is isolated from the gas space 20. The pressure in 19 does not increase.

  Therefore, due to the pressure difference between the gas space 20 and the liquid space 19, the gaseous refrigerant in the gas space 20 passes through the outlet 13 of the evaporator 10 and flows to the vapor pipe 50 and reaches the condenser 30 in one direction. The gaseous refrigerant that reaches the condenser 30 is condensed into a liquid refrigerant and flows in the liquid pipe 40 in one direction, thereby reaching the liquid space 19 again.

  Here, in the porous plate 14 of the evaporator 10, in order to prevent a decrease in capillary force due to drying, it is necessary to supply the liquid refrigerant to the inside at any time simultaneously with the evaporation of the liquid refrigerant. The liquid refrigerant supplied from the side surface a of the porous plate 14 gradually penetrates into the porous plate 14. However, for example, when the amount of heat generated from the heat source is large, the evaporation amount of the liquid refrigerant also increases. In some cases, the permeation of the liquid refrigerant does not catch up with evaporation and a part of the porous plate 14 is dried.

  According to the evaporator 30 of the present embodiment, since the liquid flow path 17 is formed above the porous plate 14, the liquid refrigerant in the liquid flow path 17 in addition to the permeation from the side surface a of the porous plate 14. Can penetrate into the porous plate 14, and the liquid refrigerant can be rapidly supplied into the porous plate 14. Thereby, even if it is a case where the evaporation amount of a liquid refrigerant is large, drying of the porous board 14 can be prevented and the fall of the cooling performance by the fall of capillary force can be prevented.

  Furthermore, since the liquid flow path 17 is provided on the opposite side to the heat transfer surface of the heat transfer plate 11 that contacts the heat source body with respect to the porous body 14, the heat from the heat transfer surface is directly transferred to the liquid flow path. 17 is not transmitted. Therefore, it is possible to prevent generation of bubbles due to evaporation of the liquid refrigerant in the liquid flow path 17. Thereby, bubbles do not hinder the flow of the liquid refrigerant in the liquid flow path 17.

  That is, according to the cooling device 100 of the present embodiment, the heat source body can be stably cooled without degrading the cooling performance.

(First modification)
Next, a first modification of the evaporator 10 in the first embodiment will be shown and described. Here, FIG. 8 is a cross-sectional view taken along the line AA shown in FIG.

  In the evaporator 10, the liquid refrigerant held on the porous plate 14 evaporates due to the heat transmitted from the heat transfer surface and exits to the gas flow path 18. At this time, a part of the gaseous refrigerant may escape to the liquid flow path 17, and this gaseous refrigerant may be recondensed into the liquid refrigerant by cooling with the liquid refrigerant in the liquid flow path 17, or the liquid flow Backflow in the passage 17 may impede the penetration of the liquid refrigerant. Therefore, it is desirable to let the gaseous refrigerant escape to the gas flow path 18 side as much as possible.

  Therefore, as shown in FIG. 8, in the first modification, the width of the opening in the cross section perpendicular to the extending direction of the gas flow path 18 is set to the width of the opening in the cross section perpendicular to the extending direction of the liquid flow path 17. Form wider than. Alternatively, the area of the opening of the gas channel 18 is formed larger than the area of the opening of the liquid channel 17.

  Further, a convex portion 21 is provided in a region located immediately below the gas flow path 18 on the heat transfer surface of the heat transfer plate 11. At the same time, a concave portion is provided in the porous body 14 in accordance with the convex portion 21. Thereby, the distance between the contact surface of the porous body 14 with the gas flow path 18 and the heat transfer surface is shorter than the distance between the contact surface of the porous body 14 with the liquid flow path 17 and the heat transfer surface.

  With the above configuration, the width of the opening in the cross section of the gas flow path 18 is wider and the contact area with the porous plate 14 is wider than the amount of the gaseous refrigerant that escapes from the liquid flow path 17. The amount of gaseous refrigerant that escapes increases.

  Furthermore, the distance between the contact surface with the porous plate 14 and the heat transfer surface is short, so that the heat conduction speed is high and the heat density is high, and the gaseous refrigerant evaporates from the porous body 14 immediately below the gas flow path 18. As a result, the amount of gaseous refrigerant that escapes from the gas flow path 18 increases.

  According to the cooling device 100 of the present modified example, when the liquid refrigerant evaporates in the evaporator 10, the amount of the gaseous refrigerant that escapes from the gas flow path 18 is smaller than the amount of the gaseous refrigerant that escapes from the liquid flow path 17. Since it can be increased, it becomes possible to efficiently carry out heat transport. Further, the back flow of the gaseous refrigerant in the liquid channel 17 can be suppressed.

  In addition, even if it does not provide a recessed part in the porous board 14 by using the porous member with elasticity, such as urethane and rubber | gum, as a material of the porous board 14, it presses against the heat-transfer board 11, a heat-transfer board The shape can be adapted to the 11 convex portions 21.

  Further, the cross-sectional shape in the extending direction of the liquid flow path 17 and the gas flow path 18 is not limited to the rectangular shape or the circular shape shown in FIG. 8, but is a shape capable of flowing a liquid refrigerant or a gaseous refrigerant. I just need it.

(Second modification)
Next, a second modification of the evaporator 10 in the first embodiment will be shown and described. Here, FIG. 9 shows the flow path plate 15 in this modification.

  In the first embodiment, it has been described that the grooves 17 ′ and 18 ′ are formed at equal intervals over the entire surface of the flow path plate 15. The second modification is different in that the grooves 17 'and 18 of the flow path plate 15 are formed in consideration of the positional relationship with the heat source body.

  Specifically, when the evaporator 10 is disposed in contact with the heat source body, the grooves 17 ′ and 18 ′ are formed more densely at a position directly above the heat source body than at a place other than directly above the heat source body. Here, as shown in FIG. 9, the lengths of the grooves 17 ′ and 18 ′ in the extending direction are changed so that the grooves 17 ′ and 18 ′ are adjacent to each other at a position immediately below the heat source body.

  In addition to the above, it is possible to narrow the interval between the grooves at a position directly above the position other than directly above the heat source body, or to increase the width perpendicular to the extending direction of the grooves.

  Thereby, compared with the case where the grooves 17 ′ and 18 ′ are formed over the entire surface of the flow path plate 15, the heat source body can be efficiently cooled with fewer grooves.

(Second embodiment)
Hereinafter, the cooling device 200 of the present embodiment will be described in detail with reference to FIGS. 10 to 14.

  FIG. 10 is a configuration diagram of a cooling device 200 according to the second embodiment. The cooling device 200 of FIG. 10 includes an evaporator 60, a condenser 30, and a liquid pipe 40 and a vapor pipe 50 that communicate these. Here, the condenser 30, the liquid pipe 40, and the steam pipe 50 have the same configuration as the cooling device 100 of the first embodiment, and a description thereof is omitted.

  FIG. 11 is an exploded view of the evaporator 60. FIG. 12 is an internal configuration diagram of the evaporator 60 with the upper lid 66 removed.

  The heat transfer plate 61 of the evaporator 60 has a rectangular heat transfer surface on the bottom surface, and wall surfaces (wall surfaces a, b, c, d) are provided at the edges of the heat transfer surface. Further, the heat transfer plate 61 is connected to the wall surface A with the liquid pipe 40, the inlet 62 through which the liquid refrigerant flows, and the wall surface C facing the wall surface A are connected to the steam pipe 50, Each has an outlet 63 through which the refrigerant flows out to the vapor pipe 50.

  The porous plate 64 is a rectangular porous member (side surfaces a, b, c, d). The porous plate 64 is disposed above the heat transfer plate 11 so that the flat portion is in contact with the heat transfer surface. At this time, unlike the first embodiment, the wall surface b and the side surface b and the wall surface d and the side surface d are separated from each other.

  13 is a perspective view showing a lower surface of the flow path plate 65 in FIG.

  The flow path plate 65 is a rectangular member (side surfaces e, f, g, h) having a plane of the same size as the porous plate 64. The flow path plate 65 has a plurality of grooves 67 ′ extending on one surface in the direction from the side surface e to the side surface g and having an opening only on the side surface e side, and extending in the direction from the side surface g to the side surface e. and a plurality of grooves 68 ′ having openings only on the g side. Further, as shown in FIG. 12, a plurality of holes 22 are formed in the groove 67 'along the extending direction.

  Then, the flow path plate 65 is disposed such that the surface on which the grooves 67 ′ and 68 ′ are formed is in contact with the upper surface of the porous plate 64 and the side surfaces are aligned. At this time, unlike the first embodiment, the upper surface of the flow path plate 65 is configured to be lower than the height of the wall surface of the heat transfer plate. The upper lid 66 is disposed in contact with the upper surface of the wall surface of the heat transfer plate 61.

  Here, DD and EE sectional views in FIG. 11 are shown in FIGS. 14 and 15, respectively. At this time, as shown in FIG. 14, a liquid channel 67 and a gas channel 68 are formed by the grooves 67 ′ and 68 ′ and the porous plate 64, respectively.

  Further, as shown in FIG. 15, a wall 63 is formed between the upper lid 66, the heat transfer plate 61, the porous plate 64, and the flow path plate 65 in the vicinity of the outlet 63, Is separated into a liquid space 69 on the inlet 62 side and a gas space 70 on the outlet 63 side.

  That is, the liquid space 69 is not only between the side surfaces a and e and the wall surface A, but also between the side surfaces b and f and the wall surface B, between the side surfaces d and h and the wall surface D, and between the upper surface of the flow path plate 65 and the upper lid 66. Will have space.

  With the above configuration, the contact area between the liquid space 69 and the porous plate 64 can be increased, and the liquid refrigerant can be quickly supplied to the porous plate 64. Further, since the liquid refrigerant can be supplied to the liquid channel 67 at any time through the hole 22, it is possible to prevent the liquid refrigerant in the liquid channel 67 from being depleted.

  The liquid space 69 includes a space between the side surfaces a and e and the wall surface A, a space between the upper surface of the flow path plate 65 and the upper lid 66, and the side surfaces b and f, the wall surface B, and the side surfaces d and h. A configuration in which the wall surface D is brought into contact with each other is also possible.

  According to the cooling device 200 of the present embodiment, it is possible to stably cool the heat source body without reducing the cooling performance.

  These embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention and are also included in the invention described in the claims and the equivalents thereof.

10, 60 ... evaporator 11, 61 ... heat transfer plate 12, 62 ... inlet 13, 63 ... outlet 14, 64 ... porous plate 15, 65 ... flow path Plates 16, 66 ... upper lids 17 ', 18', 67 ', 68' ... grooves 17, 67 ... liquid channels 18, 68 ... gas channels 19, 69 ... liquid space 20 70 ... Gas space 21 ... Convex part 22 ... Hole 30 ... Condenser 40 ... Liquid pipe 50 ... Steam pipe 63 ... Wall part 100, 200 ... Cooling apparatus

Claims (7)

A hollow container having a first opening through which liquid refrigerant flows and a second opening through which gaseous refrigerant flows out and having a first surface for transferring heat from a heat source;
A porous body disposed in contact with the first surface in the container and infiltrated with the liquid refrigerant;
A first groove that is disposed in contact with the porous body and opens on the first surface side that is connected to the first opening, and a second region side that is connected to the second opening. A flow path plate having a second groove opened to
A first flow path formed by the porous body and the first groove, in communication with the first region, and isolated from the second region;
A second flow path formed by the porous body and the second groove, communicating with the second region, and isolated from the second region;
With an evaporator.   The first opening and the second opening are respectively provided at both ends in the first direction of the container, and the first flow path and the second flow path are substantially in the first direction. The evaporator according to claim 1, which extends in parallel and is adjacent at least at one point.   The evaporator according to claim 2, wherein the width of the opening perpendicular to the extending direction of the second flow path is wider than the width of the opening perpendicular to the extending direction of the first flow path.   The evaporator according to claim 2 or 3, wherein a cross-sectional area of the opening perpendicular to the extending direction of the second flow path is larger than a cross-sectional area of the opening perpendicular to the extending direction of the first flow path. The first surface has a convex portion directly below the second flow path,
The spacing between the contact surface of the porous body with the first flow path and the contact surface with the first surface is such that the contact surface of the porous body with the second flow path The evaporator according to any one of claims 1 to 4, wherein the evaporator is wider than a distance between contact surfaces with one surface.   The evaporator according to any one of claims 2 to 5, wherein at least one of an interval between the flow paths, a length in a stretching direction, and a width perpendicular to the stretching direction varies depending on a positional relationship with the heat source. The evaporator according to any one of claims 1 to 6, comprising:
A condenser having a third opening and a fourth opening for condensing the gaseous refrigerant into the liquid refrigerant by heat radiation;
A first pipe that communicates the first opening of the evaporator and the third opening of the condenser and causes the liquid refrigerant to flow;
A second pipe that communicates the second opening of the evaporator and the fourth opening of the condenser and causes the gaseous refrigerant to flow;
A cooling device comprising:

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