Server unit and server rack

Abstract

This server unit comprises: a casing in which a heat-generating element is accommodated and a first refrigerant is stored such that the heat-generating element is immersed; a cold plate disposed in the casing so as to be in contact with the heat-generating element; a supply line for supplying a second refrigerant into the cold plate from the outside of the casing; and a discharge line for discharging the second refrigerant in the cold plate to the outside of the casing.

Description

Server unit and server rack

[0001] The present disclosure relates to a server unit and a server rack. This application claims priority to Japanese Patent Application No. 2024-220176, filed in Japan on December 16, 2024, the content of which is incorporated herein by reference.

[0002] Patent Document 1 discloses a server rack having a rack and a plurality of servers housed in the rack so as to be arranged vertically, each having a heating element. A cold plate that contacts the heating element is provided inside the server. A supply line for supplying a refrigerant and a discharge line for discharging the refrigerant are connected to the cold plate. A plurality of fans for air-cooling each server are provided on the side of this server rack so as to correspond to each server.

[0003] Japanese Patent Application Laid-Open No. 2024-39232

[0004] By the way, in recent years, with the improvement in the performance of elements such as CPUs and GPUs, the amount of heat generated by these elements has been increasing. Therefore, in data centers and the like where these elements are intensively arranged, it is required to cool the elements more efficiently. Also, it is required to effectively cool the structures around these elements.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a server unit and a server rack capable of improving cooling efficiency.

[0006] In order to solve the above problems, a server unit according to the present disclosure includes a casing in which a heating element is housed and a first refrigerant is stored so as to immerse the heating element, a cold plate arranged to contact the heating element inside the casing, a supply line for supplying a second refrigerant from the outside of the casing into the cold plate, and a discharge line for discharging the second refrigerant in the cold plate to the outside of the casing.

[0007] A server rack according to the present disclosure includes the above plurality of server units and a rack body for housing the plurality of server units in a vertically arranged state.

[0008] According to the server rack and server unit of this disclosure, cooling efficiency can be improved.

[0009] This is a schematic side view showing the general configuration of a server rack according to the first embodiment of this disclosure. This is a longitudinal cross-sectional view showing the general configuration of a server unit second embodiment of this disclosure. This is a longitudinal cross-sectional view showing the general configuration of a server unit of a server rack according to the third embodiment of this disclosure. This is a longitudinal cross-sectional view showing the general configuration of a server unit of a server rack according to the fourth embodiment of this disclosure. This is a longitudinal cross-sectional view showing the general configuration of a server unit of a server rack according to the fifth embodiment of this disclosure.

[0010] <First Embodiment> A server rack 1 according to the first embodiment of this disclosure will be described with reference to Figures 1 and 2.

[0011] <Server Rack> The server rack 1 shown in Figure 1 is installed in a data center. The server rack 1 comprises a rack body 2, a supply-side manifold 11, a discharge-side manifold 12, a first line 16, a second line 17, a circulation pump 18, a cooling device 19, and a server unit 20.

[0012] <Rack Body> The rack body 2 is a rectangular box shape that extends vertically. The inside of the rack body 2 is a storage space. Part of the rack body 2 is configured to be openable and closable. This allows workers to access the storage space of the rack body 2 from the outside.

[0013] <Supply-side manifold, discharge-side manifold> The supply-side manifold 11 and the discharge-side manifold 12 are tubular members that are arranged to extend vertically within the storage space of the rack body 2.

[0014] <First Line> The first line 16 is connected to the lower end of the supply-side manifold 11 and extends to the outside of the rack body 2.

[0015] <Second Line> The second line 17 is connected to the lower end of the discharge manifold 12 and extends to the outside of the rack body 2.

[0016] <Circulation Pump> The circulation pump 18 is located outside the rack body 2 on the first line 16. The circulation pump 18 pumps the refrigerant circulating inside the first line 16 toward the supply side manifold 11.

[0017] <Cooling device> The cooling device 19 is located outside the rack body 2. Alternatively, the cooling device 19 may be located inside the rack body 2. The cooling device 19 is connected to a first line 16 and a second line 17. A flow path is formed inside the cooling device 19 to introduce refrigerant from the second line 17 to the first line 16. The cooling device 19 cools the refrigerant flowing through this flow path.

[0018] <Server Unit> Next, the server unit 20 will be described. Multiple server units 20 are housed vertically within the rack body 2 with spacing between them. As shown in detail in Figure 2, the server unit 20 includes a casing 30, a semiconductor substrate 40, a cold plate 50, a supply line 60, a discharge line 70, a first refrigerant supply and discharge line 80, and an on / off valve 81.

[0019] <Casing> The casing 30 is thin in the vertical direction and has a rectangular box shape with the entire top surface open. The casing 30 has a bottom plate 31 and side walls 32. The casing 30 may also have a box shape with the top surface closed. The bottom plate 31 is a plate that extends horizontally and has a rectangular shape when viewed from above. The side walls 32 are plate-shaped and are formed to rise upward from the entire outer edge of the bottom plate 31. The bottom plate 31 and side walls 32 constitute a box shape that opens upward.

[0020] <Semiconductor Substrate> The semiconductor substrate 40 is housed in the casing 30. The semiconductor substrate 40 has a substrate body 41 and a heating element 42. The substrate body 41 is a so-called printed circuit board and is in the shape of a plate extending in the horizontal direction. The heating element 42 is an element such as a CPU or GPU provided on the upper surface of the substrate body 41.

[0021] <Cold Plate> The cold plate 50 is installed inside the casing 30 in contact with the heating element 42 of the semiconductor substrate 40, covering the heating element 42 from above. The cold plate 50 is, for example, a plate-like shape with its thickness in the vertical direction and extending horizontally. The cold plate 50 is hollow, meaning that a space is formed inside the cold plate 50.

[0022] <Supply Line> The supply line 60 extends from the outside of the casing 30 to the inside of the casing 30. The supply line 60 is designed to allow refrigerant to flow through its interior. The upstream end of the supply line 60 is connected to the supply-side manifold 11, as shown in Figure 1. The flow path of the supply line 60 and the interior of the supply-side manifold 11 are in communication with each other. The downstream end of the supply line 60 is connected to the cold plate 50 from a horizontal direction, as shown in Figure 2. The flow path of the supply line 60 and the internal space S of the cold plate 50 are in communication with each other.

[0023] <Discharge Line> The discharge line 70 extends from inside the casing 30 to the outside of the casing 30. The discharge line 70 is designed to allow refrigerant to flow through its interior. The upstream end of the discharge line 70 is connected horizontally to the cold plate 50, as shown in Figure 2. The flow path of the discharge line 70 and the internal space S of the cold plate 50 are in communication with each other. The downstream end of the discharge line 70 is connected to the discharge side manifold 12, as shown in Figure 1. The flow path of the discharge line 70 and the interior of the discharge side manifold 12 are in communication with each other.

[0024] <First Refrigerant> Here, the first refrigerant R1 is stored inside the casing 30. As a result, the semiconductor substrate 40 and the cold plate 50 are completely immersed in the first refrigerant R1 inside the casing 30. The downstream portion of the supply line 60 and the upstream portion of the discharge line 70 are also immersed in the first refrigerant R1.

[0025] <Second Refrigerant> Furthermore, a refrigerant system through which the second refrigerant R2 flows is configured by the supply line 60, cold plate 50, discharge line 70, discharge side manifold 12, second line 17, cooling device 19, first line 16, and supply manifold 11. When the circulation pump 18 is driven, the second refrigerant R2 circulates sequentially through the supply line 60, cold plate 50, discharge line 70, discharge side manifold 12, second line 17, cooling device 19, first line 16, supply manifold 11, supply line 60, and so on. The second refrigerant R2 circulates through the refrigerant system while being cooled by the cooling device 19.

[0026] The first refrigerant R1 and the second refrigerant R2 may be the same type of refrigerant or different types of refrigerants. For the first refrigerant R1 and the second refrigerant R2, for example, water or various organic solvents can be used. The first refrigerant R1 and the second refrigerant R2 do not mix within the server rack 1 and exist independently of each other.

[0027] <First refrigerant supply and discharge line> The first refrigerant supply and discharge line 80 has one end that opens inside the casing 30 and the other end that opens outside the casing 30.

[0028] <On / Off Valve> The on / off valve 81 is provided in the first refrigerant supply and discharge line 80. The on / off valve 81 is designed to be openable and closable. By opening the on / off valve 81 from the closed state, the first refrigerant R1 inside the casing 30 can be discharged to the outside. In addition, by connecting the other end of the first refrigerant supply and discharge line 80 to a tank containing the first refrigerant R1, the first refrigerant R1 can be supplied into the casing 30 via the first refrigerant supply and discharge line 80.

[0029] <Effects> When each server unit 20 of the server rack 1 is operated, the heat-generating element 42 of the semiconductor substrate 40 generates heat. Then, the heat from the heat-generating element 42 is removed via the cold plate 50 by the circulation of the second refrigerant R2. That is, the second refrigerant R2, which is circulated while being cooled by the cooling device 19, is sequentially introduced into the cold plate 50, thereby removing heat from a localized high heat flux by the second refrigerant R2. As a result, the heat-generating element 42, which generates a large amount of heat, can be removed effectively and efficiently.

[0030] Meanwhile, heat is generated in the semiconductor substrate 40 simultaneously with the heat-generating element 42. This heat is absorbed by the first refrigerant R1 because the semiconductor substrate 40 is immersed in the first refrigerant R1. Therefore, heat removal can be performed simultaneously for the entire substrate 41. The heat absorbed by the first refrigerant R1 is then transported to the outside via the cold plate 50, supply line 60, and discharge line 70, which are immersed in the first refrigerant R1.

[0031] In other words, the second refrigerant R2 also plays a role in removing heat from the first refrigerant R1. Furthermore, since the casing 30 is open upwards, heat can be actively released from the liquid surface of the first refrigerant R1. As a result, the temperature of the first refrigerant R1 does not rise excessively, and the entire system can be cooled appropriately according to the amount of heat generated.

[0032] Furthermore, the cooling targets of the first refrigerant R1 include not only the substrate body 41 but also relatively low-heat generating elements mounted on the substrate body 41. In addition, if the heat-generating element 42 is a GPU, it is preferable to maintain the GPU at a temperature of 80°C or lower. For example, this can be achieved by circulating and cooling the second refrigerant R2 at a temperature of 20°C to 60°C.

[0033] Furthermore, according to this embodiment, even if the temperature of the second refrigerant R2 is further reduced when the heat generation of the heating element 42 is large, condensation will not occur on the surface of the semiconductor substrate 40 because the semiconductor substrate 40 itself is immersed in the first refrigerant R1. Therefore, it is possible to avoid unexpected short circuits and failures.

[0034] <Second Embodiment> Next, a second embodiment of the present disclosure will be described with reference to Figure 3. In Figure 3, the same reference numerals are used for components identical to those in the first embodiment, and detailed descriptions are omitted.

[0035] The supply line 60 in the second embodiment is composed of a supply pipe 61 and a supply-side flexible pipe 62.

[0036] The supply pipe 61 is made of a relatively rigid material, such as plastic or metal. The supply pipe 61 is located in the upstream portion of the supply line 60 and is positioned so as not to be immersed in the first refrigerant R1. The upstream end of the supply pipe 61 is connected to the supply side manifold 11 as the upstream end of the supply line 60.

[0037] <Supply-side flexible pipe> The supply-side flexible pipe 62 has its upper end connected to the downstream end of the supply pipe 61 and is immersed in the first refrigerant R1. The supply-side flexible pipe 62 is made of a flexible and elastic material such as rubber. The downstream end of the supply-side flexible pipe 62 is connected to the cold plate 50.

[0038] The discharge line 70 in the second embodiment is composed of a discharge pipe 71 and a discharge-side flexible pipe 72.

[0039] The discharge pipe 71 is made of a relatively rigid material such as plastic or metal. The discharge pipe 71 is located in the downstream portion of the discharge line 70 and is positioned so as not to be immersed in the first refrigerant R1. The downstream end of the discharge pipe 71 is connected to the discharge manifold 12 as the downstream end of the discharge line 70.

[0040] <Discharge side flexible pipe> The discharge side flexible pipe 72 is connected in communication with the upstream end of the discharge pipe 71 and is immersed in the first refrigerant R1. The discharge side flexible pipe 72 is made of a flexible and elastic material such as rubber.

[0041] Here, the supply-side flexible pipe 62 and the discharge-side flexible pipe 72 each extend along the upper surface of the substrate body 41 on the semiconductor substrate 40. In this embodiment, they extend in a way that bypasses or meanders along the upper surface of the substrate body 41. That is, the supply-side flexible pipe 62 and the discharge-side flexible pipe 72 are not connected to the cold plate 50 via the shortest path, but are deliberately arranged to increase their extension within the first refrigerant R1.

[0042] <Function and Effect> According to this embodiment, in addition to the function and effect of the first embodiment, the following function and effect are achieved. That is, since the extension dimensions of the supply-side flexible tube 62 and the discharge-side flexible tube 72 immersed in the first refrigerant R1 are set to be long, the heat of the first refrigerant R1 can be more effectively removed than in the first embodiment.

[0043] Also, for example, when there are elements with a certain amount of heat generation other than the GPU and CPU on the substrate body 41, by routing one of the supply-side flexible tube 62 and the discharge-side flexible tube 72 through the vicinity of the element, the heat of the element can be actively removed.

[0044] <Third Embodiment> Next, the third embodiment of the present disclosure will be described with reference to FIG. 4. In FIG. 4, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0045] <Heat Exchange Promotion Part> In this embodiment, in addition to the configuration of the first embodiment, a heat exchange promotion part 90 is provided. The heat exchange promotion part 90 is a fin or a protruding member provided so as to protrude from the outer surfaces of the cold plate 50, the supply line 60, and the discharge line 70. The heat exchange promotion part 90 is formed of a material with high thermal conductivity such as aluminum, for example.

[0046] <Fourth Embodiment> Next, the fourth embodiment of the present disclosure will be described with reference to FIG. 5. In FIG. 5, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0047] <Stirring Pump> In this embodiment, a stirring pump 100 is provided so as to be immersed in the first refrigerant R1 in the casing 30.

[0048] The stirring pump 100 can stir the entire first refrigerant R1 by circulating the first refrigerant R1 in the casing 30. The stirring pump 100 is fixed, for example, to the inner surface of the side wall 32. When a local hot spot occurs in the first refrigerant R1, the hot spot can be eliminated by the stirring pump 100. Further, by making the temperature distribution of the first refrigerant R1 uniform, the heat removal efficiency from the liquid surface of the first refrigerant R1 can be particularly enhanced.

[0049] <Fifth Embodiment> Next, the fourth embodiment of the present disclosure will be described with reference to FIG. 6. In FIG. 6, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0050] <Bubble Supply Unit> In the present embodiment, a bubble supply unit 110 is provided near the bottom surface in the casing 30. The bubble supply unit 110 is a diffuser pipe that extends along the bottom surface of the casing 30 and has a large number of through holes, and is configured to be able to supply air from the outside. In addition, various configurations such as a sparger and an air nozzle can be adopted as the bubble supply unit 110.

[0051] By supplying bubbles into the first refrigerant R1 by the bubble supply unit 110, effects such as temperature uniformity due to stirring of the first refrigerant R1 and elimination of hot spots can be obtained.

[0052] <Other Embodiments> Although the embodiments of the present disclosure have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included.

[0053] For example, a server unit 20 combining the configurations of various embodiments may be configured. Thereby, a server unit 20 having various effects can be realized.

[0054] Further, a fan may be installed inside or outside the rack body 2, and a configuration for cooling the casing 30 with air from the outside may be used in combination. Thereby, more effective cooling can be performed.

[0055] <Note> The server unit 20 and server rack 1 described in each embodiment can be understood, for example, as follows.

[0056] (1) The server unit 20 according to the first embodiment comprises a casing 30 in which a heating element 42 is housed and a first refrigerant R1 is stored so as to immerse the heating element 42; a cold plate 50 arranged in the casing 30 so as to be in contact with the heating element 42; a supply line 60 for supplying a second refrigerant R2 into the cold plate 50 from outside the casing 30; and a discharge line 70 for discharging the second refrigerant R2 from the cold plate 50 to the outside of the casing 30.

[0057] Elements that generate a large amount of heat can have their heat removed locally via the second refrigerant R2 circulating within the cold plate 50. On the other hand, other structures that generate less heat than the heat-generating element 42 have their heat absorbed by the first refrigerant R1 stored within the casing 30. The first refrigerant R1 itself is cooled via the cold plate 50.

[0058] (2) The server unit 20 according to the second embodiment is the server unit 20 of (1) further comprising a first refrigerant supply and discharge line 80 capable of discharging the first refrigerant R1 from the casing 30 and supplying the first refrigerant R1.

[0059] This makes it possible to supply the first refrigerant R1 into the casing 30 and to discharge the first refrigerant R1 from inside the casing 30.

[0060] (3) The server unit 20 of the third embodiment is the server unit 20 according to (1) or (2), comprising a substrate body 41 that extends along a horizontal plane within the casing 30 and has the heating element 42 provided on its upper surface, and at least one of the supply line 60 and the discharge line 70 has a flexible tube that extends along the upper surface within the casing 30.

[0061] This improves the cooling performance across the entire surface of the circuit board 41.

[0062] (4) The server unit 20 of the fourth embodiment is the server unit 20 according to (1) or (2), further comprising a heat exchange promoting section 90 that protrudes from at least one outer surface of the cold plate 50, the supply line 60 and the discharge line 70 within the casing 30.

[0063] This allows the heat of the first refrigerant R1 to be absorbed more effectively through the coal plate, supply line 60, and discharge line 70.

[0064] (5) The server unit 20 of the fifth embodiment is the server unit 20 according to (1) or (2), further comprising a pump for agitating the first refrigerant R1 within the casing 30.

[0065] By circulating the first refrigerant R1, cooling can be achieved more effectively.

[0066] (6) The server unit 20 of the sixth embodiment is the server unit 20 according to (1) or (2), further comprising a bubble supply unit 110 disposed within the casing 30 and supplying bubbles from below the heating element 42.

[0067] This allows for more effective cooling.

[0068] (7) The server rack 1 of the seventh embodiment comprises any of the above-mentioned plurality of server units 20 and a rack body 2 that houses the plurality of server units 20 arranged vertically.

[0069] This allows the heat-generating elements 42 of multiple server units 20 to be cooled.

[0070] (8) The server rack 1 of the eighth embodiment further comprises a cooling device 19 that cools the second refrigerant R2 from the discharge line 70 and supplies it to the supply line 60.

[0071] This allows the heating element 42 to be cooled locally and effectively.

[0072] According to the server rack and server unit of this disclosure, cooling efficiency can be improved.

[0073] 1 Server rack 2 Rack body 11 Supply manifold 12 Discharge manifold 16 First line 17 Second line 18 Circulation pump 19 Cooling device 20 Server unit 30 Casing 31 Bottom plate 32 Side wall 40 Semiconductor substrate 41 Substrate body 42 Heating element 50 Cold plate 60 Supply line 61 Supply pipe 62 Supply side flexible pipe 70 Discharge line 71 Discharge pipe 72 Discharge side flexible pipe 80 First refrigerant supply and discharge line 81 On / off valve 90 Heat exchange promotion unit 100 Agitation pump 110 Bubble supply unit S Internal space R1 First refrigerant R2 Second refrigerant

Claims

1. A server unit comprising: a casing that houses a heating element and stores a first refrigerant so as to immerse the heating element; a cold plate positioned within the casing in contact with the heating element; a supply line that supplies a second refrigerant into the cold plate from outside the casing; and a discharge line that discharges the second refrigerant from the cold plate to the outside of the casing.

2. The server unit according to claim 1, further comprising a first refrigerant supply and discharge line capable of discharging the first refrigerant from the casing and supplying the first refrigerant.

3. The server unit according to claim 1 or 2, comprising a substrate body extending along a horizontal plane within the casing and having the heating element provided on its upper surface, wherein at least one of the supply line and the discharge line has a flexible tube extending along the upper surface within the casing.

4. The server unit according to claim 1 or 2, further comprising a heat exchange promoting portion protruding from at least one outer surface of the cold plate, the supply line, and the discharge line within the casing.

5. The server unit according to claim 1 or 2, further comprising a pump for agitating the first refrigerant within the casing.

6. The server unit according to claim 1 or 2, further comprising a bubble supply unit disposed within the casing and supplying bubbles from below the heating element.

7. A server rack comprising: a plurality of server units according to claim 1 or 2; and a rack body for housing the plurality of server units arranged vertically.

8. The server rack according to claim 7, further comprising a cooling device for cooling the second refrigerant from the discharge line and supplying it to the supply line.

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