JP7792871B2 - liquid immersion cooling device - Google Patents

Description

This disclosure relates to an immersion cooling device.

Patent Document 1 discloses a cooling system for cooling electronic devices that have heat-generating elements. The cooling system has a cooling tank filled with a refrigerant. The electronic devices are immersed in the refrigerant in the cooling tank. Multiple electronic devices are arranged upright in the cooling tank. The refrigerant in the cooling tank cools the heat-generating elements, and then circulates to be cooled outside the cooling tank and supplied back to the cooling tank.

International Publication No. 2016/075838

However, in the cooling system described in Patent Document 1, multiple electronic devices are arranged vertically within a single cooling tank, resulting in a large cooling system. Therefore, improving layout efficiency is an issue from the perspective of miniaturizing the cooling system. Additionally, improving cooling efficiency is also an issue from the perspective of saving energy and refrigerant.

The present disclosure has been made to solve the above-mentioned problems, and aims to provide an immersion cooling device that can improve placement efficiency and cooling efficiency.

In order to solve the above problems, the immersion cooling apparatus according to the present disclosure is an immersion cooling apparatus that cools a heat generating element provided on a substrate, and includes: a casing group having a box-like inclined casing that extends downward toward one horizontal side and that houses the substrate and the heat generating element, the inclined casings being arranged in a vertical direction; a supply-side header that extends in a vertical direction on the other horizontal side of the casing group and is capable of introducing a first refrigerant into each of the inclined casings; a discharge-side header that extends in a vertical direction on one horizontal side of the casing group and into which the first refrigerant is introduced from each of the inclined casings; a refrigerant pumping unit that pumps the first refrigerant from the discharge-side header to the supply-side header; and a heat exchange unit that cools the first refrigerant by exchanging heat between the first refrigerant and a second refrigerant supplied from outside.

The immersion cooling device disclosed herein can improve placement efficiency and cooling efficiency.

1 is a schematic diagram showing a schematic configuration of an entire immersion cooling apparatus according to an embodiment of the present disclosure. FIG. FIG. 2 is a schematic diagram showing a schematic configuration inside a tilted casing according to an embodiment of the present disclosure. FIG. 10 is an enlarged view showing the configuration of the end portion of the inclined casing near the supply-side header according to the embodiment of the present disclosure. FIG. 1 is a schematic diagram illustrating a schematic configuration inside a server housing according to an embodiment of the present disclosure. FIG. 1 is a schematic diagram illustrating a rail provided within a tilted casing according to an embodiment of the present disclosure. FIG. 1 is a schematic diagram illustrating a schematic configuration inside a server housing according to an embodiment of the present disclosure.

An immersion cooling apparatus 10 according to an embodiment of the present disclosure will now be described with reference to FIGS. 1 to 6. FIG.
1, an immersion cooling apparatus 10 is used to cool electronic devices that perform high-speed calculations. In this embodiment, the immersion cooling apparatus 10 is used in a server 1 installed in a data center. A plurality of servers 1 are provided.

As shown in Figure 2, server 1 has a printed circuit board and elements such as CPU and GPU chips mounted on the printed circuit board. Because the CPU and GPU are components responsible for high-speed calculations, they are subjected to high loads and generate heat at higher temperatures than other parts of server 1.

A data center is equipped with a heat exchanger 4 that uses water as a refrigerant. Examples of the heat exchanger 4 include a dry cooler and a chiller. The immersion cooling apparatus 10 of this embodiment is installed separately from the heat exchanger 4 and is used to cool elements that generate high temperatures, such as CPUs and GPUs.

In the following, the printed circuit board of server 1 will be referred to simply as "board 2," and elements within board 2 that generate particularly high temperatures, such as the CPU and GPU, will be referred to as "heat generating elements 3."

The substrate 2 is formed in the shape of a rectangular plate. A heating element 3 is provided on the surface of the substrate 2.

(Configuration of the liquid immersion cooling device)
Next, the configuration of the immersion cooling apparatus 10 will be described.
As shown in FIGS. 1 and 2 , the immersion cooling apparatus 10 includes a rack 20, a casing group 30, a seal unit 11, a server housing 40, a nozzle 12, a backflow prevention door 50, a supply-side header 60, a supply-side connection line 13, a valve 14, a discharge-side header 70, a backflow prevention cover 80, a refrigerant pressure-feeding unit 15, a first connecting pipe 16, a second connecting pipe 17, and a heat exchange unit 90.

(rack)
The rack 20 is a cubic storage shelf that houses the casing group 30 therein. The rack 20 has a rack body 21, an entrance door 22, an exit door 23, support columns 24, and beams 25.
The rack body 21 has a rectangular plate-like upper wall 21a extending horizontally, a lower wall 21b formed in the same shape as the upper wall and positioned directly below the upper wall, and a pair of side walls 21c connecting the side edges of the upper wall 21a and the lower wall 21b and provided opposite each other in the horizontal direction. The rack body 21 is formed in a cylindrical shape that opens on both sides in the horizontal direction perpendicular to the opposing direction of the pair of side walls 21c.

Hereinafter, the horizontal direction in which the rack body 21 opens will be referred to as the "front-rear direction Da," and the horizontal direction perpendicular to the front-rear direction Da will be referred to as the "width direction Dw." Furthermore, one side of the front-rear direction Da will be referred to as "one horizontal side D1," and the other side of the front-rear direction Da will be referred to as "the other horizontal side D2."

In the following description, the opening of the rack body 21 on the other horizontal side D2 will be referred to as the "entrance side opening 21d," and the opening on the one horizontal side D1 will be referred to as the "exit side opening 21e."
An entrance door 22 is provided at the entrance side opening 21d, and an exit door 23 is provided at the exit side opening 21e.

The entrance door 22 is provided on the other horizontal side D2 of the rack 20. The entrance door 22 is a rectangular plate-shaped member extending in the vertical direction that opens and closes the space within the rack 20. The entrance door 22 closes all of the entrance-side opening 21d except for the lower end. The entrance door 22 is rotatable, for example, from 80 to 110 degrees around one edge 21f extending in the vertical direction on the entrance-side opening 21d side of the outer surface of the side wall 21c when the entrance-side opening 21d is closed. In this embodiment, the entrance door 22 is rotatable 90 degrees around the edge 21f on the entrance-side opening 21d side.

The exit door 23 is provided on one horizontal side D1 of the rack 20. The exit door 23 is a rectangular plate-shaped member extending in the vertical direction that opens and closes the space within the rack 20. The exit door 23 closes all of the exit-side opening 21e except for the lower end. The exit door 23 is configured to be rotatable, for example, from 80 to 110 degrees around one edge 21g extending in the vertical direction on the entrance-side opening 21d side of the outer surface of the side wall 21c when the exit-side opening 21e is closed. In this embodiment, the exit door 23 is rotatable 90 degrees around the edge 21g on the exit-side opening 21e side.

In the space partitioned by the rack body 21, entrance door 22, and exit door 23, a support pillar 24 is provided, extending upward from the bottom wall 21b of the rack body 21.

The four support columns 24 are arranged in a rectangular lattice pattern when viewed from above and below. All four support columns 24 are fixed to the inner surface of the side wall 21c of the rack body 21. Two of the four support columns 24 are located near the entrance opening 21d, and the remaining two support columns 24 are located near the exit opening 21e.
Hereinafter, the two pillars 24 near the entrance opening 21d will be referred to as "first pillars 24a," and the two pillars 24 near the exit opening 21e will be referred to as "second pillars 24b."

The two first support columns 24a face each other in the width direction Dw. Similarly, the two second support columns 24b face each other in the width direction Dw.
The two first support columns 24a and the two second support columns 24b are connected to each other by beams 25 extending in the width direction Dw.

The beams 25 are rod-shaped members formed with a rectangular cross section when viewed from the width direction Dw. Hereinafter, the beam 25 connecting the two first columns 24a will be referred to as the "first beam 25a," and the beam 25 connecting the two second columns 24b will be referred to as the "second beam 25b."

The first beams 25a and second beams 25b are provided in plurality, spaced at equal intervals in the vertical direction. The same number of first beams 25a and second beams 25b are provided, and they are located at the same positions in the vertical direction. However, the first beams 25a are formed thicker in the vertical direction than the second beams 25b. Furthermore, when the first beams 25a and second beams 25b are located at the same positions in the vertical direction, the upper surface 25c of the first beam 25a is located higher than the upper surface 25d of the second beam 25b.

(Casing group)
The casing group 30 is housed in the rack 20. The casing group 30 has box-shaped inclined casings 31 extending horizontally, and is an assembly of these inclined casings 31 arranged in the vertical direction.

(inclined casing)
The inclined casing 31 accommodates the circuit board 2 of the server 1. That is, the inclined casing 31 can accommodate the heating element 3 provided on the circuit board 2. The inclined casing 31 is disposed on top of the first beam 25a and the second beam 25b, which are located at the same vertical position, so as to bridge the first beam 25a and the second beam 25b. As described above, when the first beam 25a and the second beam 25b are located at the same vertical position, the upper surface 25c of the first beam 25a is located higher than the upper surface 25d of the second beam 25b. Therefore, the inclined casing 31 is inclined so as to extend downward as it approaches one horizontal side D1.

A first refrigerant R1 can be stored within the inclined casing 31. The first refrigerant R1 is an insulating refrigerant. The first refrigerant R1 cools the heating element 3 in its liquid phase. Examples of the first refrigerant R1 include fluorocarbon-based liquids.

Next, the shape of the inclined casing 31 will be described in more detail.
The inclined casing 31 includes a casing body 32 , a flange 33 , a supply-side manifold 34 , and a rail 35 .

The casing body 32 is a component that constitutes the main part of the inclined casing 31 and is used to house the substrate 2. The casing body 32 is formed in a box shape with a rectangular plate-like outer shape extending horizontally. The casing body 32 is open in the front-rear direction Da (see FIGS. 3 and 4).
Hereinafter, the opening on the other horizontal side D2 of the casing body 32 will be referred to as the "first opening 32a," and the opening on the one horizontal side D1 will be referred to as the "second opening 32b."

As shown in Figures 2 and 3, the flange 33 is provided around the entire periphery of the end of the casing body 32 on the first opening 32a side. The flange 33 is provided so as to protrude vertically from the outer surface of the casing body 32.

The supply-side manifold 34 is provided at the end of the casing body 32 on the first opening 32a side. The supply-side manifold 34 extends in the width direction Dw. The supply-side manifold 34 distributes the first refrigerant R1 introduced from the supply-side header 60 (described below) evenly within the casing body 32 in the width direction Dw.

The supply side manifold 34 has a manifold body 36 , a lid portion 37 , and an introduction portion 38 .
The manifold body 36 is a box-shaped container extending in the width direction Dw. The manifold body 36 is fitted into the first opening 32a. The manifold body 36 has a rectangular cross section when viewed from the width direction Dw, and is open toward the other horizontal side D2.

The lid portion 37 closes the opening of the manifold body 36 from the other horizontal side D2. The lid portion 37 is formed in the shape of a rectangular plate extending in the width direction Dw. The outer peripheral edge of the lid portion 37 overlaps the flange 33. The lid portion 37 is fixed to the flange 33, for example, by bolting.

The introduction section 38 is provided at the end opposite the manifold body 36 across the lid section 37 in the front-to-rear direction Da. The introduction section 38 is a cylindrical member that introduces the first refrigerant R1 from the supply-side header 60 to the supply-side manifold 34. The introduction section 38 is in communication with the manifold body 36. Multiple introduction sections 38 (three in this embodiment) are provided, spaced at equal intervals in the width direction Dw.

As shown in Figures 2 and 5, the rails 35 are provided on each of a pair of side walls 32c that face each other in the width direction Dw of the casing main body 32. The rails 35 protrude inward in the width direction Dw from plate members 39 that are overlapping and fixed to the inner surfaces of the side walls 32c, and extend in the front-to-rear direction Da. The rails 35 are square bar-shaped members that have a rectangular cross section when viewed in the front-to-rear direction Da.

(Sealing part)
As shown in Figures 3 and 4, the seal portions 11 are provided at the ends of each inclined casing 31 on one horizontal side D1 and the other horizontal side D2. The seal portions 11 suppress leakage of the first refrigerant R1. More specifically, at the end of the inclined casing 31 on the supply-side manifold 34 side, seal portions 11 are provided between the manifold body 36 and the first opening 32a of the inclined casing 31 and between the lid portion 37 and the flange 33 of the inclined casing 31. Furthermore, at the end of the inclined casing 31 opposite the supply-side manifold 34, seal portions 11 are provided between the outer surface of the inclined casing 31 and an inlet 73 of a discharge-side header 70 (described later).

(server chassis)
A server housing 40 is provided inside each casing. The server housing 40 is box-shaped and houses the board 2 of the server 1. As shown in Fig. 6, the server housing 40 is formed in the shape of a rectangular plate extending horizontally.

Inlet holes 41a are formed in the front wall 41 on the other horizontal side D2 of the server housing 40 to introduce the first refrigerant R1 into the server housing 40. Multiple inlet holes 41a are formed throughout the front wall 41. Additionally, exhaust holes 42a are formed in the rear wall 42 on the one horizontal side D1 of the server housing 40 to discharge the first refrigerant R1 from within the server housing 40 to the outside. Multiple exhaust holes 42a are formed throughout the rear wall 42.

Guides 44 are provided on a pair of side walls 43 of the server housing 40 that face each other in the width direction Dw. The guides 44 are components that position the server housing 40 and guide its movement in the front-to-rear direction Da when the server housing 40 is inserted or removed from the inclined casing 31. The guides 44 protrude outward in the width direction Dw from the outer surfaces of the side walls 43 and extend in the front-to-rear direction Da. The guides 44 are square rod-shaped components with a rectangular cross section when viewed in the front-to-rear direction Da. Two guides 44 are provided on each side wall, spaced apart in the vertical direction, and sandwich the rails 35 of the inclined casing 31 from above and below. Therefore, when the server housing 40 is inserted or removed from the inclined casing 31, the server housing 40 moves linearly in the front-to-rear direction Da along the rails 35.

(nozzle)
1 and 2, the nozzles 12 are provided in each inclined casing 31 and attached to the outer bottom surface of the supply-side manifold 34 on the side opposite the lid 37. The nozzles 12 communicate with the supply-side manifold 34 and spray the first refrigerant R1 supplied from the supply-side header 60 radially toward the server housings 40. The nozzles 12 are formed in a tapered shape that widens in diameter toward one horizontal side D1.

(Backflow prevention door)
The backflow prevention door 50 is provided in each inclined casing 31 and prevents the first refrigerant R1 in the inclined casing 31 from flowing back toward the other horizontal side D2. The backflow prevention door 50 has a hinge 51 and a backflow prevention door body 52.
As shown in Figure 4, the hinge 51 is disposed within the inclined casing 31 and attached to the upper wall 32d. The hinge 51 is a spring-loaded hinge. The backflow prevention door body 52 extends downward from the hinge 51 and also extends in the width direction Dw. The elastic force of the spring of the hinge 51 attempts to maintain the backflow prevention door body 52 in a position perpendicular to the horizontal plane.

The backflow prevention door 50 closes the flow path of the first refrigerant R1 and opens the flow path of the first refrigerant R1 when it receives an external force of a predetermined magnitude or greater in the horizontal direction toward one side D1. In this embodiment, when a server housing 40 is not placed inside the inclined casing 31, the backflow prevention door main body 52 inside the inclined casing 31 is maintained in a position perpendicular to the horizontal plane by the elastic force of the hinge 51. Therefore, the flow path of the first refrigerant R1 inside the inclined casing 31 is closed by the backflow prevention door main body 52. In contrast, when a server housing 40 is placed inside the inclined casing 31, the backflow prevention door main body 52 is pushed by the server housing 40 and receives an external force in the horizontal direction toward one side D1. This external force causes the backflow prevention door main body 52 to rotate around the hinge 51, opening the flow path of the first refrigerant R1.

(Supply side header)
1 and 2 , the supply-side header 60 is provided on the inner surface of the entrance door 22. The supply-side header 60 extends vertically on the other horizontal side D2 of the casing group 30 and is capable of introducing the first refrigerant R1 into each of the inclined casings 31. The supply-side header 60 is formed in a cylindrical shape extending vertically. The supply-side connection line 13 is provided with a plurality of supply-side connection lines 13.

(Supply side connection line)
The supply-side connection line 13 connects the supply-side header 60 to each of the inclined casings 31 in a fluid communication state. A plurality of supply-side connection lines 13 (three in this embodiment) are provided for each inclined casing 31, and each is connected to the introduction section 38 of the corresponding inclined casing 31. The supply-side connection line 13 is provided with a valve 14 that can open and close the supply-side connection line 13.

(valve)
A valve 14 is provided for each inclined casing 31. In this embodiment, one valve 14 is provided at the base of the three supply-side connection lines 13 connected to the corresponding inclined casing 31, and can simultaneously open and close these three supply-side connection lines 13. The supply-side connection lines 13 are flexible tubes that can be deformed in accordance with the rotation of the entrance door 22.

(Discharge side header)
The discharge-side header 70 is housed in the rack body 21 and extends in the vertical direction on one horizontal side D1 of the casing group 30. The first refrigerant R1 is introduced into the discharge-side header 70 from each of the inclined casings 31. The discharge-side header 70 has a discharge-side header main body 71 and a storage section 72.

The discharge-side header body 71 is adjacent to one horizontal side D1 of the casing group 30. The discharge-side header body 71 is a box-shaped container with a rectangular plate-like outer shape extending vertically. In this embodiment, both ends of the discharge-side header body 71 in the width direction Dw are fixed to the inner surface of the side wall 21c of the rack body 21. The discharge-side header body 71 is provided with inlets 73 at positions corresponding to each inclined casing 31. The first refrigerant R1 introduced from the inclined casing 31 flows into the inlet 73. In this embodiment, the second opening 32b of the corresponding inclined casing 31 is inserted into each inlet 73. In addition, the above-mentioned seal portion 11 is provided between the inlet 73 and the inclined casing 31.

The storage section 72 is provided at the lower end of the inclined casing 31. The storage section 72 stores the refrigerant introduced into the discharge header main body 71. The dimension of the storage section 72 in the front-to-rear direction Da is larger than the dimension of the inclined casing 31 in the front-to-rear direction Da. The storage section 72 is placed on the bottom wall 21b of the rack main body 21.

(Backflow prevention cover)
The backflow prevention covers 80 are provided at positions corresponding to the inlets 73 in the discharge header 70. The backflow prevention covers 80 prevent the first refrigerant R1 from flowing back from the discharge header 70 into the inclined casing 31. The backflow prevention covers 80 extend in the width direction Dw and cover the inlets 73 from above and one horizontal side D1 at a distance. As shown in FIG. 4 , the backflow prevention cover 80 has an upper wall 81 and a rear wall 82.

The upper wall 81 is provided on the inner surface of the discharge header 70 on the side where the inlet 73 is formed. The upper wall 81 is attached to the corresponding inlet 73 by, for example, welding, and extends in the front-to-rear direction Da. The upper wall 81 is linearly inclined so as to be positioned gradually lower as it extends rearward.
The rear wall 82 is provided at the rear end of the upper wall 81 and extends vertically downward from the rear end of the upper wall 81. The rear wall 82 is formed at a position spaced rearward from the second opening 32b of the inclined casing 31 so as to cover the entire second opening 32b. The rear wall 82 is also formed integrally with the upper wall 81.

(Refrigerant pressure delivery section)
As shown in FIG. 1 , the refrigerant pumping unit 15 is housed in the rack 20 and disposed below the casing group 30. The refrigerant pumping unit 15 is connected to the lower part of the discharge side header 70 by a first connecting pipe 16 and to the lower part of the supply side header 60 by a second connecting pipe 17. The first connecting pipe 16 connects the discharge side header 70 to the refrigerant pumping unit 15, and the second connecting pipe 17 connects the supply side header 60 to the refrigerant pumping unit 15. The refrigerant pumping unit 15 pumps the first refrigerant R1 from the lower part of the discharge side header 70 to the lower part of the supply side header 60. In this embodiment, the refrigerant pumping unit 15 is a pump.

(Heat exchange part)
The heat exchange unit 90 is provided below the casing group 30. In this embodiment, the heat exchange unit 90 is provided in the storage unit 72 of the discharge header 70. The heat exchange unit 90 cools the first refrigerant R1 by exchanging heat between the second refrigerant R2 supplied from the outside and the first refrigerant R1.

In this embodiment, the heat exchange section 90 is a plurality of heat transfer tubes 91 that penetrate the storage section 72 in the width direction Dw. The heat transfer tubes 91 are connected to an external heat exchanger 4. The second refrigerant R2 of the heat exchanger 4 flows through the heat transfer tubes 91. The heat transfer tubes 91 extend parallel to one another and are arranged at equal intervals. In this embodiment, the second refrigerant R2 in the heat transfer tubes 91 flows in a countercurrent direction opposite to the flow direction of the first refrigerant R1 in at least a portion of the storage section 72.

(Circulation of the first refrigerant)
Next, the circulation of the first refrigerant R1 within the immersion cooling apparatus 10 will be described.
First, when the refrigerant pumping unit 15 is operated, the first refrigerant R1 is supplied from the supply-side header 60 into each inclined casing 31. At this time, the first refrigerant R1 is sprayed into the inclined casing 31 by the multiple nozzles 12. The first refrigerant R1 flows as a jet in the front-to-rear direction Da within each casing. The first refrigerant R1 within the casing flows into the server casing 40, passes through the heating elements 3, and exchanges heat with the heating elements 3. This cools the heating elements 3. Meanwhile, the first refrigerant R1 is heated by the heat from the heating elements 3. The first refrigerant R1 is then discharged from the server casing 40 and introduced into the discharge-side header 70 from each inclined casing 31. The first refrigerant R1 flows downward within the discharge-side header 70 due to the pressure of the refrigerant pumping unit 15 and its own weight. The first refrigerant R1 is then temporarily stored in the storage section 72 of the discharge-side header 70.

Meanwhile, within the heat transfer tubes 91, the second refrigerant R2 flows in the width direction Dw. As the first refrigerant R1 flows through the discharge header 70, it exchanges heat with the second refrigerant R2. As a result, the first refrigerant R1 is cooled and the second refrigerant R2 is heated. After exchanging heat with the first refrigerant R1, the second refrigerant R2 is sent to the external heat exchanger 4. The second refrigerant R2 is cooled by the heat exchanger 4 and supplied again to each heat transfer tube 91.

Once the first refrigerant R1 is cooled by heat exchange with the second refrigerant R2, it is pressure-fed again to the supply header 60 by the refrigerant pressure-fed section 15. As described above, the first refrigerant R1 is then supplied again into the inclined casing 31. In this way, the first refrigerant R1 circulates within the immersion cooling apparatus 10.

(Action and effect)
The immersion cooling apparatus 10 of this embodiment provides the following advantageous effects.
In this embodiment, the immersion cooling apparatus 10 includes a casing group 30 including inclined casings 31 arranged in a vertical direction, each capable of accommodating a heating element 3, a supply header 60 extending in a vertical direction on the other horizontal side D2 of the casing group 30 and capable of introducing the first refrigerant R1 into each of the inclined casings 31, and a discharge header 70 extending in a vertical direction on one horizontal side D1 of the casing group 30 and into which the first refrigerant R1 is introduced from each of the inclined casings 31. The inclined casings 31 extend downward as they approach the one horizontal side D1.

The casing group 30 is configured by arranging a plurality of inclined casings 31 in the vertical direction, which prevents the plurality of inclined casings 31 from being randomly arranged and spreading out in the horizontal direction, thereby improving arrangement efficiency.
Furthermore, because each inclined casing 31 extends downward as it moves horizontally, the first refrigerant R1 can flow smoothly horizontally inside the inclined casing 31. This allows the immersion cooling apparatus 10 to quickly guide the first refrigerant R1 that has absorbed heat from the heat-generating element 3 to the discharge header 70, thereby improving cooling efficiency.

In this embodiment, the immersion cooling apparatus 10 further includes a plurality of supply-side connection lines 13 that connect the supply-side header 60 to each of the inclined casings 31 in a fluid communication state, and a valve 14 that is provided for each inclined casing 31 and can open and close the supply-side connection line 13.

As a result, by operating the valve 14 to close the supply side connection line 13, the supply of the first refrigerant R1 to the inclined casing 31 connected to that supply side connection line 13 can be easily stopped. This makes it easy to remove any inclined casing 31. This makes it easy to remove each inclined casing 31 individually for maintenance.

In this embodiment, the immersion cooling apparatus 10 further includes a backflow prevention door 50 that is provided within each inclined casing 31 and that closes the flow path of the first refrigerant R1 and opens the flow path of the first refrigerant R1 when an external force of a predetermined magnitude or greater is applied in the direction toward one horizontal side D1.

This prevents the first refrigerant R1 from flowing back to the other horizontal side D2 within the inclined casing 31 without impeding the first refrigerant R1 from flowing to the one horizontal side D1.

In this embodiment, the discharge header 70 is provided with inlets 73 at positions corresponding to each inclined casing 31, through which the first refrigerant R1 introduced from the inclined casing 31 flows. The immersion cooling apparatus 10 further includes backflow prevention covers 80 that are provided at positions corresponding to each inlet 73 in the discharge header 70 and cover the inlet 73 from above and one horizontal side D1 at a distance.

This prevents the first refrigerant R1 from flowing back into the inclined casing 31 as the first refrigerant R1 flows downward within the discharge side header 70, without preventing the first refrigerant R1 from being discharged from the inclined casing 31 toward the discharge side header 70.
In this way, providing the backflow prevention door 50 or the backflow prevention cover 80 in the immersion cooling apparatus 10 prevents the first refrigerant R1 from flowing backward, allowing the first refrigerant R1 to flow more smoothly inside the inclined casing 31. Therefore, the immersion cooling apparatus 10 can more quickly guide the first refrigerant R1 that has absorbed heat from the heating element 3 to the discharge header 70, thereby further improving cooling efficiency.

Furthermore, by providing the immersion cooling apparatus 10 with the above-described valve 14, backflow prevention door 50, and backflow prevention cover 80 as in this embodiment, it is possible to stop the flow of the first refrigerant R1 into each inclined casing 31 without stopping the overall flow of the first refrigerant R1 within the immersion cooling apparatus 10. This allows the servers 1 housed in the inclined casings 31 to be removed individually and maintenance of each server 1 performed individually.

In this embodiment, the immersion cooling apparatus 10 further includes a rack 20 in which the casing group 30 is housed. The rack 20 has an entrance door 22 on the other horizontal side D2 that can open and close the space within the rack 20. The supply side header 60 is provided on the entrance door 22.

When the entrance door 22 is opened, the supply header 60 moves with the entrance door 22. This makes it easier to remove the inclined casing 31. This makes it even easier to remove the server 1 along with the inclined casing 31 for maintenance.

In this embodiment, the heat exchange unit 90 is located below the casing group 30.

This allows the first refrigerant R1 to be cooled by the heat exchanger 4 without filling the supply side header 60 and the discharge side header 70 with the first refrigerant R1, thereby reducing the amount of first refrigerant R1 used.

In this embodiment, the immersion cooling apparatus 10 further includes a nozzle 12 provided within each inclined casing 31 and spraying the first refrigerant R1 supplied from the supply header 60.

As a result, the immersion cooling apparatus 10 can smooth the flow of the first refrigerant R1 within the inclined casing 31 by tilting the inclined casing 31, while generating convection within the first refrigerant R1 within the inclined casing 31 by spraying from the nozzle 12. This improves the heat exchange efficiency between the heating element 3 and the first refrigerant R1, further improving cooling efficiency.

In this embodiment, the immersion cooling apparatus 10 further includes seal portions 11 provided at the ends of the horizontal side D1 and the horizontal side D2 of each inclined casing 31 to prevent leakage of the first refrigerant R1.

This prevents leakage of the first refrigerant R1 when the first refrigerant R1 is introduced into the inclined casing 31 and when the first refrigerant R1 is discharged from the inclined casing 31, thereby reducing the amount of first refrigerant R1 used.

(Other embodiments)
The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

In the above embodiment, the heat exchange unit 90 is provided in the storage section 72 of the discharge header 70, but this is not limited to this. The heat exchange unit 90 may be provided directly below the casing group 30, and may perform heat exchange between the first refrigerant R1 and the second refrigerant R2 in the first connecting pipe 16 and the second connecting pipe 17 connecting the supply header 60 and the discharge header 70.

In addition, in the above embodiment, the heat exchange unit 90 is a plurality of heat transfer tubes 91 that penetrate the storage unit 72 in the width direction Dw, but this is not limited to this. The heat exchange unit 90 may be, for example, heat transfer tubes 91 that extend vertically within the discharge header 70. In this case, the backflow prevention door 50 and backflow prevention cover 80 do not need to be provided. If the backflow prevention door 50 and backflow prevention cover 80 are not provided, the first refrigerant R1 is sprayed directly from the inclined casing 31 onto the heat transfer tubes 91, which may improve the heat exchange efficiency between the first refrigerant R1 and the second refrigerant R2.

In addition, in the above embodiment, the second refrigerant R2 in the heat transfer tube 91 flows in a countercurrent flow direction opposite to the flow direction of the first refrigerant R1 in at least a portion of the storage section 72, but this is not limited to this. The second refrigerant R2 in the heat transfer tube 91 may flow in the same direction as the first refrigerant R1 in the storage section 72, or the flow of the second refrigerant R2 in the heat transfer tube 91 may be set without taking into account the flow of the first refrigerant R1.

<Additional Notes>
The immersion cooling apparatus 10 described in each embodiment can be understood, for example, as follows.

(1) The immersion cooling apparatus 10 relating to the first aspect is an immersion cooling apparatus 10 that cools a heating element 3 provided on a substrate 2, and includes a casing group 30 that is box-shaped extending downward toward one horizontal side D1 and has inclined casings 31 that can accommodate the heating element 3, and is formed by arranging these inclined casings 31 in a vertical direction; a supply side header 60 that extends vertically on the other horizontal side D2 of the casing group 30 and can introduce a first refrigerant R1 into each of the inclined casings 31; a discharge side header 70 that extends vertically on one horizontal side D1 of the casing group 30 and into which the first refrigerant R1 is introduced from each of the inclined casings 31; a refrigerant pressure-transfer section 15 that pressure-transfers the first refrigerant R1 from the discharge side header 70 to the supply side header 60; and a heat exchange section 90 that cools the first refrigerant R1 by exchanging heat between a second refrigerant R2 supplied from outside and the first refrigerant R1.

The casing group 30 is composed of multiple inclined casings 31 arranged in the vertical direction. Furthermore, because each inclined casing 31 extends downward as it approaches the horizontal direction, the first refrigerant R1 can flow smoothly horizontally within the inclined casing 31.

(2) The second aspect of the immersion cooling apparatus 10 may be the immersion cooling apparatus 10 of (1), further comprising a plurality of supply-side connection lines 13 that connect the supply-side header 60 to each of the inclined casings 31 in a fluid communication state, and a valve 14 that is provided for each inclined casing 31 and can open and close the supply-side connection line 13.

As a result, by operating the valve 14 to close the supply side connection line 13, the supply of the first refrigerant R1 to the inclined casing 31 connected to that supply side connection line 13 can be easily stopped. This makes it easy to remove any inclined casing 31.

(3) The immersion cooling apparatus 10 of the third aspect is the immersion cooling apparatus 10 of (1) or (2), and may further include a backflow prevention door 50 that is provided within each inclined casing 31 and closes the flow path of the first refrigerant R1 and opens the flow path of the first refrigerant R1 when an external force of a predetermined magnitude or greater is applied in the direction toward one horizontal side D1.

This prevents the first refrigerant R1 from flowing back to the other horizontal side D2 within the inclined casing 31 without impeding the first refrigerant R1 from flowing to the one horizontal side D1.

(4) A fourth aspect of the immersion cooling apparatus 10 is the immersion cooling apparatus 10 of any one of (1) to (3), wherein the discharge header 70 is provided with inlets 73 at positions corresponding to each of the inclined casings 31, through which the first refrigerant R1 introduced from the inclined casings 31 flows, and may further include backflow prevention covers 80 provided at positions corresponding to each of the inlets 73 in the discharge header 70, covering the inlets 73 from above and one horizontal side D1 at a distance.

This prevents the first refrigerant R1 from flowing back into the inclined casing 31 as it flows downward within the discharge header 70, without preventing the first refrigerant R1 from being discharged from the inclined casing 31 toward the discharge header 70.

(5) A fifth aspect of the immersion cooling apparatus 10 is the immersion cooling apparatus 10 of any one of (1) to (4), further comprising a rack 20 in which the casing group 30 is housed, the rack 20 having an entrance door 22 on the other horizontal side D2 that can open and close the space within the rack 20, and the supply side header 60 may be provided on the entrance door 22.

When the entrance door 22 is opened, the supply header 60 moves with the entrance door 22. This makes it easy to remove the inclined casing 31.

(6) A sixth aspect of the immersion cooling apparatus 10 is the immersion cooling apparatus 10 of any one of (1) to (5), in which the heat exchange unit 90 may be provided below the casing group 30.

This allows the first refrigerant R1 to be cooled by the heat exchanger 4 without filling the supply side header 60 and the discharge side header 70 with the first refrigerant R1.

(7) The seventh aspect of the immersion cooling apparatus 10 is the immersion cooling apparatus 10 of any one of (1) to (6), and may further include a nozzle 12 provided within each of the inclined casings 31 and spraying the first refrigerant R1 supplied from the supply-side header 60.

As a result, the immersion cooling apparatus 10 can smooth the flow of the first refrigerant R1 within the inclined casing 31 by tilting the inclined casing 31, while generating convection within the first refrigerant R1 within the inclined casing 31 by spraying from the nozzle 12.

(8) The immersion cooling apparatus 10 of the eighth aspect is the immersion cooling apparatus 10 of any one of (1) to (7), and may further include a seal portion 11 provided at the end of each of the inclined casings 31 on one horizontal side D1 and the other horizontal side D2, to suppress leakage of the first refrigerant R1.

This prevents leakage of the first refrigerant R1 when the first refrigerant R1 is introduced into the inclined casing 31 and when the first refrigerant R1 is discharged from the inclined casing 31.

1...Server 2...Substrate 3...Heat generating element 4...Heat exchanger 10...Immersion cooling device 11...Sealing section 12...Nozzle 13...Supply side connection line 14...Valve 15...Refrigerant pressure delivery section 16...First connecting pipe 17...Second connecting pipe 20...Rack 21...Rack body 21a...Upper wall 21b...Lower wall 21c...Side wall 21d...Inlet side opening 21e...Outlet side opening 21f...Edge 21g...Edge Da...Front-to-rear direction Dw...Width direction D1...One horizontal side D2...Other horizontal side 22...Entrance door 23...Exit door 24...Support 24a...First support 24b...Second support 25...Beam 25a...First beam 25b...Second beam 25c...Top surface 25d...Top surface 30 Casing group 31...Inclined casing 32...Casing body 32a...First opening 32b...Second opening 32c...Side wall 32d...Upper wall 33...Flange 34...Supply side manifold 35...Rail 36...Manifold body 37...Cover portion 38...Inlet portion 39...Plate 40...Server housing 41...Front wall 41a...Inlet hole 42...Rear wall 42a...Discharge hole 43...Side wall 44...Guide 50...Backflow prevention door 51...Hinge 52...Backflow prevention door body 60...Supply side header 70...Discharge side header 71...Discharge side header body 72...Storage portion 73...Inlet port 80...Backflow prevention cover 81...Upper wall 82...Rear wall 90...Heat exchange portion 91...Heat transfer tube R1...First refrigerant R2...Second refrigerant A...Tilt angle Da...Front-rear direction D1...One side in horizontal direction D2...Other side in the horizontal direction Dw...Width direction

Claims (8)

An immersion cooling device that cools a heat generating element provided on a substrate,
a casing group including inclined casings each having a box shape extending downward toward one horizontal side and accommodating the substrate and the heating element , the inclined casings being arranged in a vertical direction;
a supply-side header extending in the vertical direction on the other horizontal side of the casing group and capable of introducing the first refrigerant into each of the inclined casings;
a discharge-side header extending in the vertical direction on one horizontal side of the casing group, into which the first refrigerant is introduced from each of the inclined casings;
a refrigerant pumping unit that pumps the first refrigerant from the discharge-side header to the supply-side header;
a heat exchange unit that cools the first refrigerant by exchanging heat between the first refrigerant and a second refrigerant supplied from an external source;
An immersion cooling device comprising: a plurality of supply-side connection lines that connect the supply-side header and each of the inclined casings in a state of communication with each other;
a valve provided for each of the inclined casings and capable of opening and closing the supply side connection line;
The immersion cooling apparatus of claim 1 further comprising: The immersion cooling apparatus of claim 1 or 2 further comprises a backflow prevention door provided within each of the inclined casings, which closes the flow path of the first refrigerant and opens the flow path of the first refrigerant when an external force of a predetermined magnitude or greater is applied in one horizontal direction. the discharge-side header is provided with inlet ports at positions corresponding to the inclined casings, through which the first refrigerant introduced from the inclined casings flows,
3. The immersion cooling apparatus according to claim 1, further comprising backflow prevention covers provided in the discharge header at positions corresponding to the inlets, the backflow prevention covers covering the inlets from above and one horizontal side at intervals. Further, a rack is provided in which the casing group is accommodated,
the rack has an entrance door on the other side in the horizontal direction that can open and close the space inside the rack,
The immersion cooling apparatus according to claim 1 , wherein the supply-side header is provided on the entrance door. The immersion cooling apparatus of claim 1 or 2, wherein the heat exchange unit is located below the casing group. The immersion cooling apparatus of claim 1 or 2, further comprising a nozzle provided within each of the inclined casings for spraying the first refrigerant supplied from the supply header. The immersion cooling apparatus of claim 1 or 2 further comprises seal portions provided at the ends of one horizontal side and the other horizontal side of each of the inclined casings to prevent leakage of the first refrigerant.