Cooling device

Abstract

A cooling device disclosed herein comprises: a housing in which a space is formed and which has a recess recessed inward from the outer surface; a server which is provided inside the housing and has a terminal protruding into the recess; an optical module which is provided in the recess and is connected to the terminal; a refrigerant supply part which supplies a refrigerant into the housing; and a refrigerant discharge part which discharges the refrigerant from the housing. The optical module is in contact with the inner surface of the recess.

Description

Cooling Device

[0001] This application claims priority to Japanese Patent Application No. 2023-171320, filed on October 2, 2023, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 discloses a cooling jacket. The cooling jacket includes first and second cylindrical portions through which a refrigerant flows, and a main body portion connected to the respective side surfaces of the first and second cylindrical portions. The main body portion defines a flow path through which the refrigerant flows by a single member, and cools an object to be cooled.

[0003] Patent No. 5533215

[0004] Incidentally, in the network racks of data centers, for example, small heat-generating elements are densely packed together. These heat-generating elements are cooled by the supply of air. For example, if these heat-generating elements are optical modules, small optical modules measuring only a few centimeters are packed together. For this reason, air-cooling methods that supply air to the optical modules to cool them require a lot of electricity. Given the recent need for decarbonization, reducing power consumption has become an important issue.

[0005] Another cooling method that reduces power consumption is the immersion method, in which a heat-generating element is immersed in a coolant. However, when the heat-generating element is an optical module, light is used as the medium for information transmission. For this reason, the immersion method, in which an optical module is immersed in a coolant that changes the refractive index of light, cannot be used as a cooling method for optical modules, and the air-cooling method described above has had to be adopted.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a cooling device that can improve cooling efficiency and reduce power consumption.

[0007] In order to solve the above problems, the cooling device of the present disclosure comprises a housing having a space formed inside and a recess recessed inward from the outer surface, a server provided within the housing and having a terminal protruding into the recess, an optical module provided within the recess and connected to the terminal, a refrigerant supply unit that supplies refrigerant into the housing, and a refrigerant discharge unit that discharges refrigerant from the housing.

[0008] According to the cooling device of the present disclosure, it is possible to improve cooling efficiency and reduce power consumption.

[0009] FIG. 1 is a perspective view of a cooling device according to a first embodiment of the present disclosure. FIG. 2 is a cross-sectional view taken along the depth direction of a cooling device according to the first embodiment of the present disclosure. FIG. 3 is a cross-sectional view taken along the width direction of a cooling device according to the first embodiment of the present disclosure. FIG. 4 is a perspective view of a cooling device according to a second embodiment of the present disclosure. FIG. 5 is a cross-sectional view taken along the depth direction of a cooling device according to the second embodiment of the present disclosure. FIG. 6 is a cross-sectional view taken along the width direction of a cooling device according to the second embodiment of the present disclosure. FIG. 7 is a cross-sectional view of a cooling device according to a third embodiment of the present disclosure. FIG. 8 is a cross-sectional view of a cooling device according to a fourth embodiment of the present disclosure. FIG. 9 is a cross-sectional view of a cooling device according to a fifth embodiment of the present disclosure. FIG. 10 is a cross-sectional view of a cooling device according to a sixth embodiment of the present disclosure. FIG. 11 is a cross-sectional view of a cooling device according to a seventh embodiment of the present disclosure. FIG. 12 is a perspective view of a cooling device according to an eighth embodiment of the present disclosure. FIG. 13 is a cross-sectional view of a cooling device according to the eighth embodiment of the present disclosure. FIG. 14 is a cross-sectional view of a cooling device according to a ninth embodiment of the present disclosure. FIG. 15 is a cross-sectional view of a cooling device according to another embodiment of the present disclosure.

[0010] First Embodiment (Configuration of Cooling Device) A cooling device 1 according to an embodiment of the present disclosure will now be described with reference to Figures 1 to 3. As shown in Figures 1 to 3, the cooling device 1 includes a housing 10, a server 2, an optical module 20, a refrigerant supply unit 3, a refrigerant discharge unit 4, a refrigerant line 5, and a heat exchanger 6.

[0011] (Housing) The housing 10 houses electronic devices such as the server 2 (described later). The housing 10 is formed by, for example, additive manufacturing (AM). The housing 10 includes a housing body 11 and a jacket 12.

[0012] (Housing Body) The housing body 11 is formed, for example, in a cubic shape. The housing body 11 has a bottom wall 13 extending horizontally, an top wall 14 spaced above the bottom wall 13, and a plurality of side walls 15 connecting the outer edges of the bottom wall 13 and the upper wall 14 in the up-down direction Dv. The bottom wall 13 is formed in a rectangular plate shape. The top wall 14 is formed in a rectangular plate shape having the same shape as the bottom wall 13. Each side wall 15 is formed in a rectangular plate shape extending in the up-down direction Dv. The bottom wall 13, the upper wall 14, and the side walls 15 form an enclosed space S inside the housing body 11. The housing body 11 is arranged to extend in the up-down direction Dv and also in the horizontal direction. The housing body 11 is formed, for example, from a metal material.

[0013] In the following description, one of the horizontal directions perpendicular to the up-down direction Dv will be referred to as the width direction Dw. Furthermore, one of the horizontal directions perpendicular to the up-down direction Dv, perpendicular to the width direction Dw, will be referred to as the depth direction Ds. In this embodiment, four side walls 15 are provided. Two of the four side walls 15 are arranged to face each other in the width direction Dw. Furthermore, the other two of the four side walls 15 are arranged to face each other in the depth direction Ds.

[0014] (Jacket) The jacket 12 is provided on one side wall 15 that is disposed perpendicular to the depth direction Ds. The jacket 12 is provided so as to protrude inward from the outer surface 10a of the housing 10. The jacket 12 has a recess 16.

[0015] (Recess) The recess 16 is formed in the jacket 12 so as to be recessed inward from the outer surface 10 a of the housing 10 .

[0016] In this embodiment, the jacket 12 is integrally formed of the same material as the housing body 11. The jacket 12 is formed of, for example, a metal material and has a predetermined rigidity. The shape and arrangement of the jacket 12 (the shape and arrangement of the recess 16) will be described in detail later.

[0017] (Server) The server 2 is provided in the space S within the housing 10. In the illustrated example, the server 2 is shown schematically, and electronic devices other than the server 2 are omitted. The server 2 has terminals 2a that protrude into the recesses 16. In this embodiment, the server 2 has a plurality of terminals 2a. At least one terminal 2a is provided for each recess 16.

[0018] (Optical Module) One optical module 20 is provided in each recess 16. In the illustrated example, the optical module 20 is illustrated schematically. The optical module 20 is inserted into the recess 16 from the outside of the housing 10. The optical module 20 is connected to a terminal 2a of the server 2. An optical fiber 22 is connected to the end of the optical module 20 opposite to the terminal 2a. The optical module 20 transmits and receives information to and from other devices via the optical fiber 22.

[0019] (Refrigerant Supply Unit) The refrigerant supply unit 3 supplies the refrigerant R into the housing 10. The refrigerant supply unit 3 is provided in the center of the bottom wall 13 of the housing main body 11. The refrigerant supply unit 3 is a supply pipe that communicates with the space S inside the housing 10 and extends downward from the bottom wall 13. The refrigerant R supplied from the refrigerant supply unit 3 fills the housing 10 in a liquid state. All of the jackets 12 are immersed in the refrigerant R inside the housing 10.

[0020] (Refrigerant Discharge Section) The refrigerant discharge section 4 discharges the refrigerant R from the housing 10. The refrigerant discharge section 4 is provided in the center of the top wall 14 of the housing main body 11. The refrigerant discharge section 4 is a discharge pipe that communicates with the space S inside the housing 10 and extends upward from the top wall 14.

[0021] (Refrigerant Line) The refrigerant line 5 is a pipe that connects the upstream end of the refrigerant supply unit 3 and the downstream end of the refrigerant discharge unit 4. The refrigerant line 5 guides the refrigerant R discharged from the refrigerant discharge unit 4 back to the refrigerant supply unit 3.

[0022] (Heat Exchanger) The heat exchanger 6 is provided in the refrigerant line 5. The heat exchanger 6 cools the refrigerant R that has exchanged heat with the optical module 20. The heat exchanger 6 may be an air-cooled type or a liquid-cooled type.

[0023] (Detailed Structure of the Jacket Surrounding Area) The following describes the detailed structure of the jacket 12 and its surroundings. Here, the shape of the optical module 20 is simplified to be a cube extending in one direction, as an example.

[0024] As shown in Figures 2 and 3, the outer shape of the jacket 12 is formed into a cube extending in one direction to match the shape of the optical module 20. A plurality of jackets 12 are provided on one of the side walls 15. When viewed from the depth direction Ds, the plurality of jackets 12 are arranged in a rectangular lattice pattern, aligned in the vertical direction Dv and the width direction Dw. The plurality of jackets 12 are arranged at intervals in the vertical direction Dv and the width direction Dw. In the illustrated example, three rows of four jackets 12 are arranged in the width direction Dw, each row being provided in the vertical direction Dv. Within each row, the jackets 12 are arranged at equal intervals in the width direction Dw. The rows of jackets 12 are also arranged at equal intervals in the vertical direction Dv.

[0025] Each jacket 12 is formed with a recess 16 extending in one direction to match the shape of the optical module 20. In this embodiment, each jacket 12 is provided with the recess 16 recessed in the depth direction Ds. In this embodiment, the optical module 20 contacts the inner surface 16a of the recess 16. More specifically, the inner surface 16a of the recess 16 and the optical module 20 are in contact with each other without any gaps in the width direction Dw and the up-down direction Dv. Furthermore, a heat-generating surface 21, which is another area of ​​the surface of the optical module 20 and generates a relatively large amount of heat, contacts the inner surface 16a of the recess 16. In the illustrated example, the heat-generating surface 21 of the optical module 20 is disposed to face upward and contacts the upper surface of the inner surface 16a of the recess 16. The heat-generating surface 21 is a horizontal surface extending in the width direction Dw and the depth direction Ds.

[0026] The jacket 12 has a heat transfer promotion portion 17. The heat transfer promotion portion 17 is a portion of the wall portion that constitutes the jacket 12 with which the optical module 20 comes into contact. In this embodiment, the heat transfer promotion portion 17 constitutes the upper wall of the jacket 12. The heat transfer promotion portion 17 has a heating surface 18. The heating surface 18 constitutes a part of the outer surface of the jacket 12. The heating surface 18 faces the opposite side to the inner surface 16a of the recess 16 that contacts the heat generating surface 21 of the optical module 20. The heating surface 18 transfers heat from the heat generating surface 21 to the refrigerant R inside the housing 10 to heat the refrigerant R. In this embodiment, the heating surface 18 is a horizontal surface that faces upward and extends in the width direction Dw and the depth direction Ds.

[0027] (Refrigerant Circulation) Next, the circulation of the refrigerant R within the cooling device 1 will be described. The housing 10 is filled with liquid-phase refrigerant R. In the following description, the liquid-phase refrigerant R will be referred to as liquid refrigerant RL, and the gas-phase refrigerant R will be referred to as gas refrigerant RG. When the optical module 20 generates heat, the heat from the optical module 20 is transferred to the jacket 12 housing the optical module 20. This heat transfer occurs primarily at the heat transfer promotion section 17 of the jacket 12, which is in contact with the heat-generating surface 21 of the optical module 20. The heat from the optical module 20 is transferred via the jacket 12 to the liquid refrigerant RL present around the jacket 12. In particular, the refrigerant R in contact with the heating surface 18 of the jacket 12 is heated by the heat transferred from the heating surface 18 and boils. As a result, gas refrigerant RG (vapor of refrigerant R) is generated at the heating surface 18 and moves upward. The gas refrigerant RG that reaches the top wall 14 is discharged to the outside of the housing 10 through the refrigerant discharge section 4. The gas refrigerant RG is then cooled in the heat exchanger 6. The cooled gas refrigerant RG is condensed to become a liquid refrigerant RL. This liquid refrigerant RL is guided to the refrigerant supply unit 3 and supplied again into the housing 10. In this way, the refrigerant R circulates within the cooling device 1 due to thermal convection caused by heat generation from the optical module 20.

[0028] (Operation and Effect) In this embodiment, the cooling device 1 includes a housing 10, a server 2, an optical module 20, a refrigerant supply unit 3, and a refrigerant discharge unit 4. The housing 10 has a space S formed therein and a recess 16 recessed inward from the outer surface 10a. The server 2 is provided within the housing 10 and has a terminal 2a protruding into the recess 16. The optical module 20 is provided within the recess 16 and connected to the terminal 2a. The refrigerant supply unit 3 supplies a refrigerant R into the housing 10. The refrigerant discharge unit 4 discharges the refrigerant R from the housing 10.

[0029] This allows the coolant R to circulate around the recess 16 in which the optical module 20 is housed. Therefore, the heat of the optical module 20 can be efficiently transferred to the coolant R without the optical module 20 coming into direct contact with the coolant R. This provides cooling efficiency equivalent to that of immersion cooling. This reduces power consumption compared to air-cooling methods that require a large amount of power for blowing air. Therefore, the above configuration improves cooling efficiency and reduces power consumption.

[0030] In this embodiment, the optical module 20 is in contact with the inner surface 16 a of the recess 16 .

[0031] This can promote heat transfer between the optical module 20 and the coolant R. Therefore, the cooling efficiency can be further improved.

[0032] In this embodiment, the housing 10 has a jacket 12 that protrudes inward from the outer surface 10a and has a recess 16 formed therein. A heat-generating surface 21, which generates a relatively large amount of heat among the surfaces of the optical module 20, is in contact with the inner surface 16a of the recess 16. The jacket 12 has a heating surface 18 that faces the opposite side to the inner surface 16a of the recess 16 that is in contact with the heat-generating surface 21 and transfers heat from the heat-generating surface 21 to the refrigerant R inside the housing 10 to heat the refrigerant R.

[0033] This allows the heat of the optical module 20 to be efficiently transferred to the refrigerant R via the heating surface 18. This makes it easier to boil the refrigerant R on the heating surface 18, and allows a large amount of heat from the optical module 20 to be dissipated as the heat of vaporization of the refrigerant R. This further improves the cooling efficiency.

[0034] Second Embodiment A cooling device 201 according to a second embodiment of the present disclosure will be described below with reference to Figures 4 to 6. Configurations similar to those in the above-described embodiments will be designated by similar names and reference numerals, and descriptions thereof will be omitted as appropriate. This embodiment differs from the first embodiment in that the heat-generating surface 21 and the heating surface 18 are vertical surfaces extending in the up-down direction Dv.

[0035] 4, in this embodiment, the refrigerant supply unit 3 is provided near a corner of the bottom wall 13 of the housing body 11, and the refrigerant discharge unit 4 is provided near a corner of the top wall 14 of the housing body 11. When viewed from above, the refrigerant supply unit 3 and the refrigerant discharge unit 4 are disposed on a diagonal line of the top wall 14.

[0036] 5 and 6 , in this embodiment, the multiple jackets 12 are arranged in a rectangular lattice pattern in the vertical direction Dv and the width direction Dw when viewed from the depth direction Ds. The multiple jackets 12 are arranged at intervals in the vertical direction Dv and the width direction Dw. In the illustrated example, two rows of six jackets 12 are arranged in the vertical direction Dv, each row being equal intervals in the width direction Dw. In each row, the jackets 12 are arranged at equal intervals in the width direction Dw.

[0037] The two jackets 12 arranged in the vertical direction Dv are integrally formed, with the upper jacket 12 sharing the lower wall and the lower jacket 12 sharing the upper wall.

[0038] The heat-generating surface 21 of the optical module 20 is disposed so as to face one side in the width direction Dw, and is in contact with the side surface facing the width direction Dw of the inner surface 16a of the recess 16. The heat-generating surface 21 is a vertical surface extending in the up-down direction Dv and the depth direction Ds.

[0039] In this embodiment, the heat transfer acceleration portion 17 constitutes a side wall of the jacket 12. The heating surface 18 of the heat transfer acceleration portion 17 is a vertical surface that faces one side in the width direction Dw and extends in the up-down direction Dv and the depth direction Ds, similar to the corresponding heat generating surface 21. The two jackets 12 arranged in the up-down direction Dv are provided so that their heating surfaces 18 are flush with each other. These two heating surfaces 18 are continuous.

[0040] (Operation and Effect) In this embodiment, a plurality of jackets 12 are provided and arranged in the up-down direction Dv. The heating surface 18 is a vertical surface extending in the up-down direction Dv.

[0041] This prevents the flow of vapor of the refrigerant R generated on the heating surface 18 of the lower jacket 12 from being obstructed by the upper jacket 12. This further improves the cooling efficiency.

[0042] Third Embodiment A cooling device 301 according to a third embodiment of the present disclosure will be described below with reference to Fig. 7. Configurations similar to those in the above-described embodiments will be designated by similar names and reference numerals, and descriptions thereof will be omitted as appropriate. This embodiment differs from the second embodiment in that the optical module 20 and the jacket 12 in which the optical module 20 is housed are offset in the up-down direction Dv.

[0043] In this embodiment, as shown in Fig. 7, two jackets 12 are arranged in the vertical direction Dv with a gap therebetween. The two jackets 12 arranged in the vertical direction Dv are arranged so that their heating surfaces 18 are positioned on the same vertical plane.

[0044] (Operation and Effect) In this embodiment, the jackets 12 arranged in the up-down direction Dv are provided with intervals between them.

[0045] This allows the refrigerant R to flow between the jackets 12 arranged in the vertical direction Dv. Therefore, the heat transfer area of ​​the jackets 12 that comes into contact with the refrigerant R increases, thereby further improving the cooling efficiency.

[0046] Fourth Embodiment A cooling device 401 according to a fourth embodiment of the present disclosure will be described below with reference to Fig. 8. Configurations similar to those in the above-described embodiments will be designated by similar names and reference numerals, and descriptions thereof will be omitted as appropriate. This embodiment differs from the third embodiment in that the jacket 12 further includes a surface area increasing member 19 on the heating surface 18.

[0047] (Surface Area Increasing Member) In this embodiment, as shown in Fig. 8, a surface area increasing member 19 is provided on the heating surface 18 of each jacket 12. The surface area increasing member 19 is a member that is thermally connected to the heating surface 18 and increases the surface area of ​​the heating surface 18. In this embodiment, the surface area increasing member 19 is a plurality of fins that protrude from the heating surface 18 in the width direction Dw. Note that the surface area increasing member 19 is not limited to fins and may be, for example, a lattice or a porous material.

[0048] (Operation and Effect) In this embodiment, the jacket 12 further includes, on the heating surface 18 , a surface area increasing member 19 that increases the surface area of ​​the heating surface 18 .

[0049] This increases the contact area between the refrigerant R and the heating surface 18, thereby promoting heat exchange between the optical module 20 and the jacket 12. Furthermore, the increased contact area between the refrigerant R and the heating surface 18 increases the critical heat flux, thereby suppressing a sudden transition on the heating surface 18 from nucleate boiling, which has good heat transfer efficiency, to film boiling.

[0050] Fifth Embodiment A cooling device 501 according to a fifth embodiment of the present disclosure will be described below with reference to Fig. 9. Configurations similar to those in the above-described embodiments will be designated by similar names and reference numerals, and descriptions thereof will be omitted as appropriate. This embodiment differs from the second to fourth embodiments in that the heat-generating surface 21 of the optical module 20 and the heating surface 18 of the jacket 12 are inclined relative to the horizontal plane.

[0051] In this embodiment, as shown in Fig. 9, the multiple jackets 12 are arranged in a rectangular lattice pattern in the up-down direction Dv and the width direction Dw when viewed from the depth direction Ds. As in the second embodiment, the multiple jackets 12 are arranged at intervals in the up-down direction Dv and the width direction Dw. In the illustrated example, two rows of six jackets 12 arranged in the width direction Dw are provided in the up-down direction Dv. In each row, the jackets 12 are arranged at equal intervals in the width direction Dw.

[0052] The two jackets 12 arranged in the vertical direction Dv are arranged so that the lower end of the upper jacket 12 and the upper end of the lower jacket 12 are in contact with each other when viewed from the depth direction Ds.

[0053] In this embodiment, the heating surfaces 18 are inclined with respect to the horizontal plane. More specifically, the multiple heating surfaces 18 all face the same direction, and each heating surface 18 faces upward and toward one side in the width direction Dw. Each heating surface 18 is inclined at approximately 45 degrees with respect to the horizontal plane. The inclination angle of each heating surface 18 with respect to the horizontal plane can be changed as appropriate.

[0054] (Operation and Effect) In this embodiment, a plurality of jackets 12 are provided lined up in the up-down direction Dv, and the heating surface 18 is an inclined surface that is inclined with respect to the horizontal plane.

[0055] This allows bubbles of refrigerant R generated on the heating surface 18 to easily escape from the heating surface 18. This allows the vapor of refrigerant R to easily escape upward without stagnation. This prevents a decrease in the heat removal performance of each jacket 12 and further improves the cooling efficiency.

[0056] Sixth Embodiment A cooling device 601 according to a sixth embodiment of the present disclosure will be described below with reference to Fig. 10. Configurations similar to those in the above-described embodiments will be designated by similar names and reference numerals, and descriptions thereof will be omitted as appropriate. This embodiment differs from the fifth embodiment in that the optical module 20 and the jacket 12 in which the optical module 20 is housed are offset in the up-down direction Dv.

[0057] In this embodiment, as shown in FIG. 10, two jackets 12 are arranged side by side in the vertical direction Dv with a gap therebetween.

[0058] (Operation and Effect) In this embodiment, the jackets 12 arranged in the up-down direction Dv are provided with intervals between them.

[0059] This allows the refrigerant R to flow between the jackets 12 arranged in the vertical direction Dv. Therefore, the heat transfer area of ​​the jackets 12 that comes into contact with the refrigerant R increases, thereby further improving the cooling efficiency.

[0060] Seventh Embodiment A cooling device 701 according to a seventh embodiment of the present disclosure will be described below with reference to Fig. 11. Configurations similar to those in the above-described embodiments will be designated by similar names and reference numerals, and descriptions thereof will be omitted as appropriate. This embodiment differs from the sixth embodiment in that the optical modules 20 and the rows extending in the width direction Dw of the jacket 12 in which the optical modules 20 are housed are offset in the horizontal direction.

[0061] 11 , a plurality of jackets 12 are arranged in the vertical direction Dv and the width direction Dw when viewed from the depth direction Ds. The jackets 12 arranged in the vertical direction Dv are offset in the width direction Dw so that the heating surfaces 18 of the jackets 12 are offset in the width direction Dw. As a result, of the two rows of jackets 12 extending in the width direction Dw, the upper row of jackets 12 is arranged close to the side wall 15 on one side in the width direction Dw, and the lower row of jackets 12 is arranged close to the side wall 15 on the other side in the width direction Dw.

[0062] (Operation and Effect) In the present embodiment, a plurality of jackets 12 are provided and lined up in the width direction Dw. The jackets 12 lined up in the up-down direction Dv are arranged with a staggered arrangement in the width direction Dw such that the heating surfaces 18 of the jackets 12 are shifted from each other in the width direction Dw.

[0063] This prevents the flow of refrigerant R vapor generated on the heating surface 18 of the lower jacket 12 from being obstructed by the upper jacket 12. This allows the refrigerant R vapor to escape upward more smoothly. This prevents a decrease in the heat removal performance of each jacket 12 and further improves cooling efficiency.

[0064] Eighth Embodiment A cooling device 801 according to an eighth embodiment of the present disclosure will be described below with reference to Figures 12 to 14. Configurations similar to those in the above-described embodiments will be designated by similar names and reference numerals, and descriptions thereof will be omitted as appropriate. This embodiment differs from the first embodiment in that multiple optical modules 20 are installed in one recess 16.

[0065] In this embodiment, as shown in Figures 12 to 14, two jackets 12 are arranged side by side in the up-down direction Dv. Each jacket 12 is formed to extend in the depth direction Ds and also extend long in the width direction Dw. Each jacket 12 also has one recess 16. This recess 16 is formed to extend long in the depth direction Ds and also extend long in the width direction Dw to match the outer shape of the jacket 12.

[0066] A plurality of optical modules 20 are housed in one recess 16. The heat-generating surfaces 21 of the plurality of optical modules 20 are arranged to face upward and are in contact with the upper surface of the inner surface 16a of the recess 16. The heat-generating surfaces 21 are horizontal surfaces extending in the width direction Dw and the depth direction Ds. In this embodiment, the plurality of optical modules 20 are installed in the recess 16 with no gaps in the width direction Dw.

[0067] In this embodiment, the heat transfer promotion portion 17 forms the upper wall of the jacket 12. The heating surface 18 of the heat transfer promotion portion 17 is a horizontal surface that faces upward like the corresponding heat generation surface 21 and extends in the width direction Dw and the depth direction Ds.

[0068] (Operation and Effect) In this embodiment, a plurality of optical modules 20 are housed in one recess 16 .

[0069] This makes it possible to eliminate partitions separating adjacent optical modules 20 within one recess 16. This makes it possible to reduce the size of the cooling device 1 while maintaining the same number of mounted optical modules 20. In this embodiment, the recess 16 is formed long in the width direction Dw, and multiple optical modules 20 are arranged side by side in the width direction Dw without any gaps within one recess 16. This makes it possible to reduce the size of the cooling device 1 in the width direction Dw compared to when optical modules 20 are installed one by one in the recess 16 and the same number of optical modules 20 are arranged in the width direction Dw as in this embodiment.

[0070] In the present embodiment, the recess 16 is provided so as to extend elongately in the width direction Dw, but this is not limited thereto. The recess 16 may be provided so as to extend elongately in the up-down direction Dv, for example.

[0071] In the present embodiment, the optical modules 20 are arranged in the recess 16 without any gaps in the width direction Dw, but this is not limiting. The optical modules 20 accommodated in the same recess 16 may be arranged with intervals in the width direction Dw.

[0072] Ninth Embodiment A cooling device 901 according to a ninth embodiment of the present disclosure will be described below with reference to Figs. 15 and 16. Configurations similar to those in the above-described embodiments will be designated by similar names and reference numerals, and descriptions thereof will be omitted as appropriate. This embodiment differs from the eighth embodiment in that the cooling device 901 further includes a cooling plate 30 that directly cools a heat-generating element.

[0073] 15 and 16 , in the same way as in the eighth embodiment, the recesses 16 are formed to extend elongatedly in the width direction Dw, and a plurality of optical modules 20 are housed in one recess 16. The plurality of optical modules 20 are arranged without any gaps in the width direction Dw in the recess 16. Furthermore, the cooling device 1 of this embodiment further includes a cooling plate 30, a second refrigerant supply unit 31, a second refrigerant discharge unit 32, a second refrigerant line 33, and a second heat exchanger 34 in addition to the configuration of the eighth embodiment.

[0074] (Cooling Plate) The cooling plate 30 is provided in the recess 16. The cooling plate 30 is in contact with the optical modules 20. In this embodiment, the cooling plate 30 is disposed between the optical modules 20 and the heat transfer promotion section 17 of the jacket 12. The cooling plate 30 is formed to extend in the width direction Dw and is in direct contact with the heat generating surfaces 21 of the multiple optical modules 20. A space capable of storing the second refrigerant R2 is formed within the cooling plate 30. The optical modules 20 are cooled by heat exchange between the optical modules 20 and the second refrigerant R2 via the cooling plate 30. The second refrigerant R2 may be the same medium as the refrigerant R.

[0075] (Second Coolant Supply Unit) The second coolant supply unit 31 supplies the second coolant R2 into the cooling plate 30. The second coolant supply unit 31 is a supply pipe that communicates with the space inside the cooling plate 30.

[0076] (Second Coolant Discharge Portion) The second coolant discharge portion 32 discharges the coolant R from the cooling plate 30. The second coolant discharge portion 32 is a discharge pipe that communicates with the space inside the cooling plate 30.

[0077] (Second refrigerant line) The second refrigerant line 33 is a pipe that connects the upstream end of the second refrigerant supply unit 31 and the downstream end of the second refrigerant discharge unit 32. The second refrigerant line 33 guides the refrigerant R discharged from the second refrigerant discharge unit 32 back to the second refrigerant supply unit 31.

[0078] (Second Heat Exchanger) The second heat exchanger 34 is provided in the second refrigerant line 33. The second heat exchanger 34 cools the second refrigerant R2 that has exchanged heat with the optical module 20. The second heat exchanger 34 may be air-cooled or liquid-cooled.

[0079] (Effects) In this embodiment, the cooling device 1 further includes a cooling plate 30, a second refrigerant supply unit 31, and a second refrigerant discharge unit 32. The cooling plate 30 is provided in the recess 16 and is in contact with the optical module 20. The second refrigerant supply unit 31 supplies the second refrigerant R2 into the cooling plate 30. The second refrigerant discharge unit 32 discharges the second refrigerant R2 from the cooling plate 30.

[0080] This allows heat exchange between the optical module 20 and the second refrigerant R2, and the optical module 20 can be further cooled by the cooling plate 30. Therefore, compared to the case where the optical module 20 is cooled by the refrigerant R alone, the optical module 20 can be cooled in a shorter time.

[0081] In this embodiment, a plurality of optical modules 20 are housed in one recess 16. The cooling plate 30 is in contact with the plurality of optical modules 20.

[0082] This allows a plurality of optical modules 20 to be cooled collectively by one cooling plate 30. This further improves the cooling efficiency.

[0083] In this embodiment, the cooling plate 30 is provided in the recess 16 extending in the width direction Dw of the eighth embodiment and cools a plurality of optical modules 20, but the present invention is not limited to this. The cooling plate 30 may be provided in the recess 16 of the first to seventh embodiments, and one cooling plate 30 may cool one optical module 20. In this case, the cooling plate 30 is arranged to extend in the depth direction Ds.

[0084] In this embodiment, the cooling plate 30 is disposed between the optical module 20 and the heat transfer promoting portion 17 of the jacket 12, but this is not limiting. The position of the cooling plate 30 within the recess 16 can be changed as appropriate. For example, the cooling plate 30 may be disposed at a position where it contacts the surface of the optical module 20 opposite to the heat generating surface 21.

[0085] (Other Embodiments) While the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the gist of the present disclosure. In the above embodiment, the housing body 11 is formed in a cubic shape, but this is not limiting. For example, the housing body 11 may be formed in a polygonal tubular shape or a cylindrical shape, and the shape of the housing body 11 can be appropriately changed depending on the installation conditions of the cooling device 1, 201, 301, 401, 501, 601, 701, 801, 901.

[0086] In the above embodiment, the jacket 12 is formed integrally with the housing body 11, but this is not limiting. For example, the jacket 12 may be formed separately from the housing body 11 and attached to the housing body 11.

[0087] In the above embodiment, the jacket 12 is formed of, for example, a metal material and has a predetermined rigidity, but this is not limited thereto. For example, the jacket 12 may be formed of a flexible material. In this case, the shape of the jacket 12 can be changed to match the surrounding structures, such as the shape of the housing main body 11, the arrangement of the electronic devices inside, and the shape of the optical module 20.

[0088] In the above embodiment, each jacket 12 is arranged so that the recess 16 is recessed in the horizontal direction, but this is not limited to this. The jacket 12 can be installed in a location other than the side wall 15 of the housing body 11, such as the bottom wall 13 or the top wall 14. In other words, the recess 16 may be provided so as to be recessed inward from the outer surface 10a of the housing 10 in a direction other than the horizontal direction, such as the up-down direction Dv.

[0089] In the above embodiment, a case where a plurality of jackets 12 are provided on one housing 10 has been described, but this is not limiting. Only one jacket 12 may be provided on one housing 10. In other words, only one recess 16 may be provided on one housing 10.

[0090] In the above embodiment, the shape of the optical module 20 is simplified and the optical module 20 is formed into a cube extending in one direction, but this is not limiting. The shape of the optical module 20 can be changed as appropriate, and the shape of the jacket 12 can be changed as appropriate to match the shape of the optical module 20.

[0091] In the above embodiment, the inner surface 16 a of the recess 16 and the optical module 20 are in contact with each other without any gaps in the width direction Dw and the up-down direction Dv, but the present invention is not limited to this. The inner surface 16 a of the recess 16 and the optical module 20 may be spaced apart from each other in the width direction Dw or the up-down direction Dv.

[0092] In the above embodiment, the case where the refrigerant R boils and evaporates on the heating surface 18 has been described, but the present invention is not limited to this. The refrigerant R may circulate within the cooling device 1 in a liquid phase without evaporating on the heating surface 18.

[0093] In the above embodiment, the refrigerant supply unit 3 is provided on the lower wall 13, and the refrigerant discharge unit 4 is provided on the upper wall 14. However, this is not limiting. The locations of the refrigerant supply unit 3 and the refrigerant discharge unit 4 can be changed as appropriate. For example, the refrigerant supply unit 3 and the refrigerant discharge unit 4 may each be provided on the side wall 15.

[0094] In the above embodiment, the refrigerant R is circulated by natural circulation utilizing a phase change of the refrigerant R, but the present invention is not limited to this. For example, as shown in Fig. 17, a pump 8 may be provided in the refrigerant line 5, and the refrigerant R may be forced to circulate by the pump 8. In this case, even if the refrigerant R does not evaporate on the heating surface 18, the refrigerant R can be smoothly circulated in its liquid phase.

[0095] In the above embodiment, the heat exchanger 6 may be air-cooled or liquid-cooled. When the heat exchanger 6 is air-cooled, a cylindrical member 9 may be provided above the heat exchanger 6, as shown in Fig. 17, so that air is naturally introduced into the heat exchanger 6 by draft force generated by the upward flow of air heated by the heat exchanger 6. Furthermore, using the cooling device 1 of the first embodiment as an example, the configuration in which the refrigerant R is circulated in liquid phase by the pump 8 and the configuration in which the cylindrical member 9 is provided have been described, but these configurations can also be applied to the cooling devices 201, 301, 401, 501, 601, 701, 801, and 901 of the second to ninth embodiments.

[0096] <Additional Notes> The cooling devices 1, 201, 301, 401, 501, 601, 701, 801, and 901 described in the respective embodiments can be understood, for example, as follows.

[0097] (1) The cooling device 1, 201, 301, 401, 501, 601, 701, 801, 901 of the first aspect comprises a housing 10 having a space S formed inside and a recess 16 recessed inward from an outer surface 10a, a server 2 provided within the housing 10 and having a terminal 2a protruding into the recess 16, an optical module 20 provided within the recess 16 and connected to the terminal 2a, a refrigerant supply unit 3 that supplies a refrigerant R into the housing 10, and a refrigerant discharge unit 4 that discharges the refrigerant R from the housing 10.

[0098] This allows the coolant R to circulate around the recess 16 in which the optical module 20 is housed. Therefore, the heat of the optical module 20 can be efficiently transferred to the coolant R without the optical module 20 coming into direct contact with the coolant R. This allows for cooling efficiency equivalent to that of immersion cooling. Therefore, power consumption can be reduced compared to air cooling methods that require a large amount of power for blowing air.

[0099] (2) The cooling device 1, 201, 301, 401, 501, 601, 701, 801, 901 of the second aspect may be the cooling device 1, 201, 301, 401, 501, 601, 701, 801, 901 of the first aspect, in which the optical module 20 is in contact with the inner surface 16a of the recess 16.

[0100] This allows the heat transfer between the optical module 20 and the coolant R to be promoted.

[0101] (3) The cooling device 1, 201, 301, 401, 501, 601, 701, 801 of the third aspect is the cooling device 1, 201, 301, 401, 501, 601, 701, 801 of the second aspect, in which the housing 10 is arranged to protrude inward from the outer surface 10a and has a jacket 12 in which the recess 16 is formed, a heat-generating surface 21 of the surface of the optical module 20 that generates a relatively large amount of heat is in contact with the inner surface 16a of the recess 16, the jacket 12 faces the opposite side to the inner surface 16a of the recess 16 that is in contact with the heat-generating surface 21, and may have a heating surface 18 that transfers heat from the heat-generating surface 21 to the refrigerant R in the housing 10 to heat the refrigerant R.

[0102] This allows the heat of the optical module 20 to be efficiently transferred to the refrigerant R via the heating surface 18. This makes it easier to boil the refrigerant R on the heating surface 18, and allows a large amount of heat from the optical module 20 to be dissipated as the heat of vaporization of the refrigerant R.

[0103] (4) The cooling device 201, 301, 401 of the fourth aspect is the cooling device 201, 301, 401 of the third aspect, and the jacket 12 may be arranged in multiple rows in the vertical direction Dv, and the heating surface 18 may be a vertical surface extending in the vertical direction Dv.

[0104] This makes it possible to prevent the flow of vapor of the refrigerant R generated on the heating surface 18 of the lower jacket 12 from being obstructed by the upper jacket 12.

[0105] (5) A cooling device 301 according to a fifth aspect is the cooling device 301 according to the fourth aspect, and the jackets 12 arranged in the vertical direction Dv may be spaced apart.

[0106] This allows the refrigerant R to flow between the jackets 12 arranged in the vertical direction Dv.

[0107] (6) The cooling device 401 of the sixth aspect is the cooling device 401 of any one of the third to fifth aspects, and the jacket 12 may further have a surface area increasing member 19 on the heating surface 18 that increases the surface area of ​​the heating surface 18.

[0108] This increases the contact area between the refrigerant R and the heating surface 18. This promotes heat exchange between the optical module 20 and the jacket 12.

[0109] (7) The cooling devices 501, 601, and 701 of the seventh aspect are the cooling devices 501, 601, and 701 of the third aspect, and the jackets 12 may be arranged in multiple rows in the vertical direction Dv, and the heating surface 18 may be an inclined surface inclined with respect to a horizontal plane.

[0110] This allows bubbles of the refrigerant R generated on the heating surface 18 to easily separate from the heating surface 18. This allows the vapor of the refrigerant R to easily escape upward.

[0111] (8) The cooling devices 601 and 701 of the eighth aspect are the cooling devices 601 and 701 of the seventh aspect, and the jackets 12 arranged in the vertical direction Dv may be provided with an interval therebetween.

[0112] This allows the refrigerant R to flow between the jackets 12 arranged in the vertical direction Dv.

[0113] (9) The cooling device 701 of the ninth aspect is the cooling device 701 of the seventh or eighth aspect, wherein the jackets 12 are arranged in a horizontal line, and the jackets 12 arranged in the vertical direction Dv may be arranged with a horizontal offset so that the heating surfaces 18 of each jacket 12 are horizontally offset.

[0114] This makes it possible to prevent the flow of vapor of the refrigerant R generated on the heating surface 18 of the lower jacket 12 from being obstructed by the upper jacket 12.

[0115] (10) The cooling device 801, 901 of the tenth aspect may be the cooling device 801, 901 of any one of the first to ninth aspects, and may house a plurality of optical modules 20 in one recess 16.

[0116] This makes it possible to eliminate the need for partitions separating adjacent optical modules 20 within one recess 16 .

[0117] (11) The cooling device 901 of the eleventh aspect may be any one of the cooling devices 901 of the first to ninth aspects, and may further include a cooling plate 30 that is provided in the recess 16 and contacts the optical module 20, a second refrigerant supply unit 31 that supplies a second refrigerant R2 into the cooling plate 30, and a second refrigerant discharge unit 32 that discharges the second refrigerant R2 from the cooling plate 30.

[0118] This allows heat exchange between the optical module 20 and the second refrigerant R2, and the optical module 20 can be further cooled by the cooling plate 30.

[0119] (12) The cooling device 901 of the 12th aspect is the cooling device 901 of the 11th aspect, wherein a plurality of optical modules 20 are accommodated in one recess 16, and the cooling plate 30 may be in contact with the plurality of optical modules 20.

[0120] This allows a single cooling plate 30 to cool a plurality of optical modules 20 .

[0121] According to the cooling device of the present disclosure, it is possible to improve cooling efficiency and reduce power consumption.

[0122] DESCRIPTION OF SYMBOLS 1...cooling device 2...server 2a...terminal 3...refrigerant supply section 4...refrigerant discharge section 5...refrigerant line 6...heat exchanger 8...pump 9...cylindrical member 10...casing 10a...outer surface 11...casing body 12...jacket 13...bottom wall 14...top wall 15...side wall 16...recess 16a...inner surface 17...heat transfer promotion section 18...heating surface 19...surface area increasing member 20...optical module 21...heat generating surface 22...optical fiber 30...cooling plate 31...second refrigerant supply section 32...second refrigerant discharge section 33...second refrigerant line 34...second heat exchanger 201...cooling device 301...cooling device 401...cooling device 501...cooling device 601...cooling device 701...cooling device 801...cooling device 901...cooling device Dv...vertical direction Dw: Width direction Ds: Depth direction R: Refrigerant R2: Second refrigerant RL: Liquid refrigerant RG: Gas refrigerant S: Space

Claims

1. A cooling device comprising: a housing having a space formed inside and a recess recessed inward from the outer surface; a server provided within said housing and having a terminal protruding into said recess; an optical module provided within said recess and connected to said terminal; a refrigerant supply unit that supplies a refrigerant into said housing; and a refrigerant discharge unit that discharges the refrigerant from said housing.

2. The cooling device according to claim 1, wherein the optical module is in contact with an inner surface of the recess.

3. The cooling device according to claim 2, wherein the housing has a jacket that protrudes inward from its outer surface and has the recess formed therein, a heat-generating surface of the optical module that generates a relatively large amount of heat is in contact with the inner surface of the recess, and the jacket faces the opposite side to the inner surface of the recess that is in contact with the heat-generating surface and has a heating surface that transfers heat from the heat-generating surface to a refrigerant inside the housing to heat the refrigerant.

4. The cooling device according to claim 3, wherein a plurality of the jackets are arranged in a vertical direction, and the heating surface is a vertical surface extending in the vertical direction.

5. The cooling device according to claim 4, wherein the jackets arranged vertically are spaced apart.

6. A cooling device according to any one of claims 3 to 5, wherein the jacket further comprises a surface area increasing member on the heating surface for increasing the surface area of ​​the heating surface.

7. The cooling device according to claim 3, wherein the jacket is provided in a plurality of rows in the vertical direction, and the heating surface is an inclined surface inclined with respect to a horizontal plane.

8. The cooling device according to claim 7, wherein the jackets arranged vertically are spaced apart.

9. The cooling device according to claim 7 or 8, wherein the jackets are arranged in a horizontal line, and the jackets arranged vertically are horizontally offset so that the heating surfaces of the jackets are horizontally offset from each other.

10. A cooling device according to any one of claims 1 to 5, wherein a plurality of optical modules are housed within one of said recesses.

11. A cooling device as described in any one of claims 1 to 5, further comprising: a cooling plate provided within the recess and in contact with the optical module; a second refrigerant supply section that supplies a second refrigerant into the cooling plate; and a second refrigerant discharge section that discharges the second refrigerant from the cooling plate.

12. The cooling device according to claim 11, wherein a plurality of optical modules are housed in one of said recesses, and said cooling plate is in contact with a plurality of said optical modules.

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