Server system

Abstract

This server system comprises: a plurality of servers each including a heat-generating element and a cold plate; a rack that accommodates the plurality of servers; a plurality of introduction lines that are respectively connected to the plurality of servers and allow introduction of a refrigerant into the cold plate; a plurality of discharge lines that are respectively connected to the plurality of servers and through which the refrigerant discharged from the cold plate circulates; a heat exchanger that cools the refrigerant fed from the plurality of discharge lines; and a pressure-feeding line that pressure-feeds the refrigerant that has passed through the heat exchanger. The heat exchanger comprises: a manifold case to which the plurality of discharge lines are connected and that includes therein a refrigerant space into which the refrigerant flowing out from the plurality of discharge lines is introduced; and a heat exchange line that passes through the refrigerant space in the manifold case and that circulates a heat exchange medium for cooling the refrigerant from the outside of the manifold case.

Description

Server system

[0001] This disclosure relates to a server system. This application claims priority from Japanese Patent Application No. 2025-024813 filed in Japan on February 19, 2025, the content of which is incorporated herein by reference.

[0002] Patent Document 1 discloses an electronic device having a plurality of computer units and a rack housing these units. Inside the computer unit, a cold plate (cooling plate) that contacts an element as a heat generating body and a heat pipe that contacts the cold plate and through which a refrigerant flows are provided. The rack is provided with a thermal contact portion that receives heat from the heat pipe.

[0003] Japanese Unexamined Patent Application Publication No. 2009-271643

[0004] By the way, in recent years, with the performance improvement of elements such as CPUs (Central Processing Units) and GPUs (Graphics Processing Units), the amount of heat generated by these elements has been increasing. In data centers and the like equipped with servers in which these elements are intensively arranged, it is required to cool the elements more efficiently. As a cooling method for the elements, a liquid cooling method using a liquid state refrigerant for the refrigerant that cools the cold plate is known.

[0005] When using a refrigerant in a liquid state as described above, when cooling an element with a large amount of heat generation using a cold plate, the liquid state refrigerant may evaporate and become a gaseous state refrigerant. When the refrigerant changes from a liquid to a gas, the volume of the refrigerant expands. Therefore, in the piping system through which the gaseous state refrigerant passing through the cold plate flows, it is necessary to increase its cross-sectional area. When the cross-sectional area of the piping system is increased, if the piping systems from a plurality of computer units are aggregated on the inlet side of the heat exchanger that cools the gaseous state refrigerant, the pipe diameter will become particularly large. Therefore, it becomes difficult to arrange the heat exchanger and the piping system in the limited space inside the rack, and the layout of members other than the piping system is restricted.

[0006] This disclosure was made to solve the above-mentioned problems and aims to provide a server system that can effectively utilize the limited space within a rack.

[0007] To solve the above problems, the server system according to this disclosure comprises a plurality of servers, a rack, a plurality of inlet lines, a plurality of outlet lines, a heat exchanger, and a pressurized line. The plurality of servers each have a heating element and a cold plate for cooling the heating element. The rack houses the plurality of servers. The plurality of inlet lines are connected to each of the plurality of servers within the rack. The plurality of inlet lines can introduce refrigerant to the cold plate. The plurality of outlet lines are connected to each of the plurality of servers within the rack. The plurality of outlet lines through which the refrigerant discharged from the cold plate flows. The heat exchanger is located within the rack. The plurality of outlet lines cool the refrigerant supplied from the plurality of outlet lines. The pressurized line pressurizes the refrigerant that has passed through the heat exchanger toward the plurality of inlet lines. The heat exchanger comprises a manifold case and heat exchange lines. The manifold case is connected to the plurality of outlet lines. The manifold case has a refrigerant space into which the refrigerant flowing out from multiple discharge lines is introduced. The heat exchange line passes through the refrigerant space within the manifold case. The heat exchange line circulates a heat exchange medium that cools the refrigerant from outside the manifold case.

[0008] According to the server system disclosed herein, the limited space within the rack can be used effectively.

[0009] This figure shows the schematic configuration of a server system according to the first embodiment of this disclosure. This is a plan view showing the configuration of a server system according to the embodiment of this disclosure. This figure shows the schematic configuration of a server system according to the second embodiment of this disclosure.

[0010] <First Embodiment> Hereinafter, a server system according to the embodiment of this disclosure will be described with reference to Figures 1 to 3. (Overall Configuration of the Server System) As shown in Figure 1, the server system 1A of this embodiment comprises a rack 2, a plurality of servers 3, and a cooling mechanism 100. The server system 1A is housed in a server room (not shown) provided in, for example, a data center. Multiple sets of the server system 1A are installed in the server room.

[0011] (Rack Configuration) Rack 2 is installed on the floor of the server room (not shown). Rack 2 is, for example, a box-shaped, cylindrical, or frame-shaped structure extending in the vertical direction Dv, and houses multiple servers 3 inside. Rack 2 houses multiple servers 3, for example, spaced apart in the vertical direction Dv. In this embodiment, rack 2 houses, for example, four servers 3. The number of servers 3 housed in rack 2 is not limited to four and can be changed as appropriate.

[0012] (Server Configuration) Figure 2 is a plan view showing the configuration of a server system according to the present disclosure. Each server 3 is supported in a rack 2 via support brackets, etc. (not shown). As shown in Figures 1 and 2, each server 3 comprises a housing 31, a circuit board 32, a heating element 33, and a cold plate 35.

[0013] The housing 31 is formed in the shape of a rectangular parallelepiped, for example, with a rectangular shape when viewed from the vertical direction Dv and having a predetermined thickness in the vertical direction Dv. The substrate 32, heating element 33, and cold plate 35 are housed inside the housing 31.

[0014] The substrate 32 extends in a direction intersecting the vertical direction Dv. In this embodiment, the substrate 32 is formed in a plate shape extending horizontally. In this embodiment, for example, one substrate 32 is provided in one server 3. The number of substrates 32 provided in one server 3 is not limited to one, but may be two or more. Furthermore, when two or more substrates 32 are provided, the multiple substrates 32 may be arranged side by side in a direction intersecting the vertical direction Dv, or at least a portion of them may be stacked in the vertical direction Dv.

[0015] The heating element 33 is mounted on the surface of the substrate 32. In this embodiment, the heating element 33 is mounted on the surface of the substrate 32 facing upward in the vertical direction Dv. The heating element 33 may also be mounted on the surface of the substrate 32 facing downward in the vertical direction Dv. Multiple heating elements 33 are provided in one server 3 in this embodiment. There are no limitations on the number or arrangement of heating elements 33 provided in one server 3. The heating element 33 is an electronic element that generates heat when operating. The heating element 33 is, for example, a CPU, GPU, etc. When multiple heating elements 33 are provided in one server 3, the types and uses of the multiple heating elements 33 may be different.

[0016] The cold plate 35 cools the heating element 33. The cold plate 35 is provided so as to be in contact with at least a portion of the outer surface of the heating element 33. The cold plate 35 is provided so as to cover the heating element 33 from the vertical direction Dv, for example. The cold plate 35 is made of a metallic material such as an aluminum alloy. The cold plate 35 has a flow path (not shown) for a coolant supplied by the cooling mechanism 100. The cold plate 35 cools the heating element 33 by exchanging heat between the coolant flowing through the flow path and the heating element 33 in contact with the cold plate 35. Here, the shape, material, size, and structure of the cold plate 35 are not limited in any way.

[0017] (Configuration of the cooling mechanism) As shown in Figure 1, the cooling mechanism 100 includes a storage tank 101, a pressure supply line 102, a plurality of introduction lines 110, a plurality of discharge lines 120, a heat exchanger 5, and a pressure reducing unit 130.

[0018] The pumping line 102 pumps liquid refrigerant to each of the multiple servers 3. In this embodiment, the pumping line 102 pumps, for example, water, as the liquid refrigerant. The server system 1A is equipped with a storage tank 101 in the rack 2. The storage tank 101 stores liquid refrigerant. One end of the pumping line 102 is connected to the storage tank 101. The other end of the pumping line 102 is connected to the introduction-side manifold 104. A supply pump 103 is provided in the middle of the pumping line 102. The supply pump 103 pumps the liquid refrigerant (water) stored in the storage tank 101 through the pumping line 102 to the introduction-side manifold 104.

[0019] The introduction-side manifold 104 distributes the liquid refrigerant supplied from the pressure line 102 to a plurality of introduction lines 110. As shown in Figures 1 and 2, the introduction-side manifold 104 is installed inside the rack 2 and extends, for example, in the vertical direction Dv. The introduction-side manifold 104 is not limited to being installed inside the rack 2, but may also be installed outside the rack 2. The introduction-side manifold 104 is positioned on the first side D1a of the first direction D1 that intersects the vertical direction Dv with respect to the plurality of servers 3. For example, if each of the plurality of servers 3 is configured to be able to be pulled out from the rack 2 on the first side D1a of the first direction D1, it is preferable to position the introduction-side manifold 104 so as not to interfere when the plurality of servers 3 are pulled out.

[0020] One end of each of the multiple supply lines 110 is connected to the supply-side manifold 104. The other end of each of the multiple supply lines 110 is connected to each of the multiple servers 3 within the rack 2. The multiple supply lines 110 supply liquid refrigerant, which is supplied via the supply-side manifold 104, to each of the multiple servers 3.

[0021] As shown in Figure 2, each of the multiple introduction lines 110 has multiple branch introduction lines 115. Each introduction line 110 branches into multiple branch introduction lines 115 within the server 3. The multiple branch introduction lines 115 are connected to each of the multiple cold plates 35. In each server 3, the introduction line 110 introduces liquid refrigerant supplied via the introduction-side manifold 104 to each cold plate 35 through the multiple branch introduction lines 115. In this embodiment, the case in which the introduction line 110 is connected to the server 3 on a one-to-one basis is illustrated, but for example, multiple introduction lines 110 may be connected to a single server 3.

[0022] As shown in Figures 1 and 2, multiple discharge lines 120 are connected to each of the multiple servers 3 within the rack 2. Coolant discharged from the cold plate 35 of each server 3 flows through each discharge line 120.

[0023] As shown in Figure 2, each discharge line 120 has a plurality of branch discharge lines 125. One end of each of the plurality of branch discharge lines 125 is connected to each of the plurality of cold plates 35 of each server 3. Coolant discharged from each of the plurality of cold plates 35 flows through each of the plurality of branch discharge lines 125. The other end of each of the plurality of branch discharge lines 125 merges into the discharge line 120 within the server 3.

[0024] Here, if the heat output of the heating element 33 is large, at least a portion of the refrigerant (water) that has undergone heat exchange with the heating element 33 in the cold plate 35 may evaporate and become vapor. Therefore, the refrigerant flowing through each discharge line 120 (branch discharge line 125) may contain at least a portion of vapor and expand in volume. For this reason, the pipe diameter of the piping forming each discharge line 120 (branch discharge line 125) is larger than the pipe diameter of the piping forming each inlet line 110 (branch inlet line 115).

[0025] (Heat exchanger configuration) The heat exchanger 5 cools the refrigerant supplied from multiple discharge lines 120. The heat exchanger 5 is located inside the rack 2. Within the rack 2, the heat exchanger 5 is located on the second side D1b (one side) of the first direction D1 for multiple servers 3. The heat exchanger 5 comprises a manifold case 51 and a heat exchange line 52.

[0026] The manifold case 51 extends, for example, in the vertical direction Dv, and a plurality of discharge lines 120 are connected to it. When viewed from the vertical direction Dv, the manifold case 51 is formed, for example, in the shape of a rectangular hollow box. The manifold case 51 may also constitute a panel that forms at least a part of the side or back of the rack 2.

[0027] Multiple discharge lines 120 are connected to the manifold case 51 through which refrigerant discharged from multiple servers 3 flows. As shown in Figure 1, the multiple discharge lines 120 are connected, for example, to the upper end of the manifold case 51. The manifold case 51 has a refrigerant space 51s inside which refrigerant flowing out from the multiple discharge lines 120 is introduced.

[0028] The heat exchange line 52 is provided to pass through the refrigerant space 51s within the manifold case 51. Multiple heat exchange lines 52 are provided within the refrigerant space 51s of the manifold case 51. Each heat exchange line 52 extends, for example, in the vertical direction Dv within the refrigerant space 51s of the manifold case 51.

[0029] The heat exchanger 5 is connected to an external medium supply source 55 via a medium supply line 56 and a medium discharge line 57. The medium supply source 55 supplies a heat exchange medium to cool the refrigerant (vapor) in the refrigerant space 51s. In this embodiment, water is used as the heat exchange medium. An example of the medium supply source 55 is an air-cooled chiller that cools the heat exchange medium by heat exchange with the outside air. However, a medium supply source other than an air-cooled chiller may be used as the medium supply source 55.

[0030] The heat exchange medium from the medium supply source 55 is supplied through the medium supply line 56 to a header 59 formed at the upper end of the manifold case 51. The heat exchange medium supplied to the header 59 flows from top to bottom through a plurality of heat exchange lines 52, cooling the refrigerant in the refrigerant space 51s. After passing through the plurality of heat exchange lines 52, the heat exchange medium is returned to the medium supply source 55 from the lower end of the manifold case 51 through the medium discharge line 57.

[0031] In this way, the refrigerant vapor is cooled in the refrigerant space 51s of the heat exchanger 5, liquefying and returning to water (liquid refrigerant). The refrigerant that has passed through the heat exchanger 5 is returned to the storage tank 101 via the return line 140, as shown in Figure 1. The refrigerant that has passed through the heat exchanger 5 is then pumped again through the pump line 102 to the multiple introduction lines 110.

[0032] (Configuration of the pressure reduction section) The pressure reduction section 130 reduces the pressure of the refrigerant in the multiple inlet lines 110 and the multiple discharge lines 120. The pressure reduction section 130 in this embodiment has a vacuum pump 131 and a pressure reduction line 132. One end of the pressure reduction line 132 is connected to the vacuum pump 131. The other end of the pressure reduction line 132 is in communication with, for example, the manifold case 51 of the heat exchanger 5. The pressure reduction section 130 reduces the pressure of the refrigerant in the multiple inlet lines 110 and the multiple discharge lines 120 via the pressure reduction line 132 and the manifold case 51 using the negative pressure generated by the vacuum pump 131. By reducing the pressure of the refrigerant in the multiple inlet lines 110 and the multiple discharge lines 120 in this way, the boiling point of the liquid refrigerant (water) is lowered, and the heat-generating element 33 can be efficiently cooled by the latent heat of vaporization of the refrigerant (water) on the cold plate 35.

[0033] (Effects) In the server system 1A of the above embodiment, the heat exchanger 5 comprises a manifold case 51 to which a plurality of discharge lines 120 are connected, and a heat exchange line 52 that passes through the refrigerant space 51s within the manifold case 51. The refrigerant is supplied to a plurality of servers 3 in the rack 2 through each of the plurality of introduction lines 110. In each of the plurality of servers 3, the refrigerant introduced from the introduction line 110 to the cold plate 35 cools the heat-generating element 33, causing its temperature to rise. The refrigerant, whose temperature has risen, is introduced from the plurality of servers 3 through the plurality of discharge lines 120 into the refrigerant space 51s within the manifold case 51 of the heat exchanger 5. The refrigerant, whose temperature has risen, is cooled in the refrigerant space 51s by heat exchange with the heat exchange medium flowing through the heat exchange line 52. The cooled refrigerant is circulated to the plurality of introduction lines 110 through the pressure line 102. In this configuration, the plurality of discharge lines 120 that discharge refrigerant from the plurality of servers 3 are connected to the manifold case 51 of the heat exchanger 5. Therefore, compared to the case where multiple discharge lines 120 discharging refrigerant from multiple servers 3 are merged before connecting the piping to the heat exchanger 5, the need to increase the diameter of the piping connected to the refrigerant inlet side of the heat exchanger 5 can be suppressed. This reduces the difficulty in connecting the heat exchanger 5 and the piping system within the limited space of the rack 2, and also prevents restrictions on the layout of components other than the piping system. As a result, the limited space within the rack 2 can be used effectively.

[0034] Furthermore, in the above embodiment, the heat exchanger 5 is positioned on the second side D1b in the first direction D1 for multiple servers 3 housed in the rack 2 at intervals in the vertical direction Dv. In this way, the heat exchanger 5 can be positioned along, for example, the back or side of the rack 2, making effective use of the limited space within the rack 2.

[0035] Furthermore, in the above embodiment, in a configuration where the server 3 has multiple cold plates 35, multiple branch inlet lines 115 branching from the inlet line 110 and multiple branch discharge lines 125 merging with multiple discharge lines 120 are connected to the multiple cold plates 35. As a result, multiple discharge lines 120 connected to each of the multiple servers 3 are connected to the manifold case 51 of the heat exchanger 5. Therefore, while suppressing an increase in the number of pipes connected to the manifold case 51 of the heat exchanger 5, each of the multiple servers 3 can supply and discharge refrigerant to the multiple cold plates 35 through the multiple branch inlet lines 115 and branch discharge lines 125.

[0036] Furthermore, in the above embodiment, the pressure reduction unit 130 reduces the pressure of the refrigerant in the multiple introduction lines 110, thereby lowering the boiling point of the refrigerant and enabling efficient cooling by the latent heat of vaporization of the refrigerant at the cold plate 35. On the other hand, when the refrigerant evaporates, its volume expands, but since the multiple discharge lines 120 that discharge the refrigerant from the multiple servers 3 are connected to the manifold case 51 of the heat exchanger 5, it is possible to suppress the increase in diameter of the piping connected to the refrigerant inlet side of the heat exchanger 5. This makes it possible to effectively utilize the limited space in the rack 2 while ensuring the cooling efficiency of the cold plate 35.

[0037] Furthermore, in the above embodiment, since the refrigerant is water, the expansion rate when the refrigerant is evaporated is larger compared to other fluorine-based refrigerants. Therefore, when using water, which has a large expansion rate, as the refrigerant, the configuration of the above embodiment makes it possible to effectively utilize the limited space in the rack 2 while ensuring the cooling efficiency of the cold plate 35.

[0038] <Second Embodiment> Next, a second embodiment of the server system according to the present disclosure will be described. In the second embodiment described below, only the configuration of the heat exchanger differs from that of the first embodiment, so the same reference numerals are used for the same parts as in the first embodiment and redundant explanations are omitted.

[0039] FIG. 3 is a diagram showing a schematic configuration of a server system according to a second embodiment of the present disclosure. As shown in FIG. 3, the server system 1B of this embodiment includes, as a heat exchanger 5, two first heat exchangers 5A and a second heat exchanger 5B.

[0040] The first heat exchanger 5A is fed with refrigerant from first discharge lines 120A and 120B, which are discharge lines 120 connected to some of the servers 3A and 3B located above among the plurality of servers 3A to 3D.

[0041] The second heat exchanger 5B is fed with refrigerant from second discharge lines 120C and 120D, which are discharge lines 120 connected to the remaining servers 3C and 3D located below among the plurality of servers 3A to 3D.

[0042] The first heat exchanger 5A and the second heat exchanger 5B are arranged side by side in the rack 2 with a gap therebetween, for example, in the vertical direction Dv. Note that the heat exchange performance of each of the heat exchangers 5A and 5B illustrated in this second embodiment is half of the heat exchange performance of the heat exchanger 5 of the first embodiment. And the length of the heat exchangers 5A and 5B in the vertical direction Dv is about half of the length of the heat exchanger 5 in the vertical direction Dv of the first embodiment. Also, the shape of the heat exchanger 5A illustrated in this second embodiment is the same as the shape of the heat exchanger 5B.

[0043] (Operation and Effect) According to the server system 1B of the second embodiment described above, similar to the first embodiment, the limited space in the rack 2 can be effectively utilized.

[0044] Also, in the second embodiment, by having the first heat exchanger 5A and the second heat exchanger 5B as the heat exchanger 5, the first heat exchanger 5A and the second heat exchanger 5B can be miniaturized. As a result, compared with the case where only one large heat exchanger 5 is arranged, the degree of freedom in the layout of the first heat exchanger 5A and the second heat exchanger 5B in the rack 2 is increased.

[0045] (Other Embodiments) As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings. However, 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. In each of the above embodiments, in the heat exchanger 5, a liquid refrigerant is used as the heat exchange medium for cooling the refrigerant, but it is not limited to this. The heat exchanger 5 may cool the refrigerant by the air (air) sent by the fan.

[0046] Also, in each of the above embodiments, the introduction-side manifold 104 is arranged on the first side D1a in the first direction D1 with respect to the plurality of servers 3, and the heat exchanger 5 is arranged on the second side D1b in the first direction D1 with respect to the plurality of servers 3. However, it is not limited to this. For example, the introduction-side manifold 104 and the heat exchanger 5 may be arranged on the same side in the first direction D1 with respect to the plurality of servers 3.

[0047] Further, in each of the above embodiments, the manifold case 51 is formed in a rectangular hollow box shape, for example, when viewed from the vertical direction Dv, but it is not limited to this. For example, the manifold case 51 may be formed in a rectangular or circular cylindrical shape when viewed from the vertical direction Dv.

[0048] Also, in the second embodiment, the first heat exchanger 5A and the second heat exchanger 5B are arranged side by side in the vertical direction Dv, but it is not limited to this. The arrangement of the first heat exchanger 5A and the second heat exchanger 5B may be other than those exemplified in the second embodiment. Also, the heat exchanger 5 is not limited to two units of the first heat exchanger 5A and the second heat exchanger 5B, and may include three or more units.

[0049] <Supplementary Note> The server systems 1A and 1B described in each embodiment are understood as follows, for example.

[0050] (1) The server systems 1A and 1B according to the first embodiment include a plurality of servers 3 having a heating element 33 and a cold plate 35 for cooling the heating element 33, a rack 2 housing the plurality of servers 3, a plurality of introduction lines 110 connected to each of the plurality of servers 3 within the rack 2 and capable of introducing refrigerant to the cold plate 35, a plurality of discharge lines 120 connected to each of the plurality of servers 3 within the rack 2 and through which the refrigerant discharged from the cold plate 35 flows, and a supply located within the rack 2 that supplies from the plurality of discharge lines 120 The system comprises a heat exchanger 5 for cooling the refrigerant being introduced, and a pressure line 102 for pressurizing the refrigerant that has passed through the heat exchanger 5 toward a plurality of introduction lines 110. The heat exchanger 5 comprises a manifold case 51 to which a plurality of discharge lines 120 are connected and which has a refrigerant space 51s into which the refrigerant flowing out from the plurality of discharge lines 120 is introduced, and a heat exchange line 52 that passes through the refrigerant space 51s within the manifold case 51 and also circulates a heat exchange medium for cooling the refrigerant from outside the manifold case 51.

[0051] In these server systems 1A and 1B, the heat exchanger 5 comprises a manifold case 51 to which multiple discharge lines 120 are connected, and a heat exchange line 52 that passes through the refrigerant space 51s within the manifold case 51. The refrigerant is supplied to multiple servers 3 in the rack 2 through each of the multiple inlet lines 110. In each of the multiple servers 3, the refrigerant introduced from the inlet line 110 to the cold plate 35 cools the heat-generating element 33, causing its temperature to rise. The heated refrigerant is introduced from the multiple servers 3 through the multiple discharge lines 120 into the refrigerant space 51s within the manifold case 51 of the heat exchanger 5. The heated refrigerant is cooled within the refrigerant space 51s by heat exchange with the heat exchange medium flowing through the heat exchange line 52. The cooled refrigerant is circulated back to the multiple inlet lines 110 through the pressure line 102. In this configuration, the multiple discharge lines 120 that discharge refrigerant from the multiple servers 3 are connected to the manifold case 51 of the heat exchanger 5. Therefore, the need to merge multiple discharge lines 120 that discharge refrigerant from multiple servers 3 before connecting them to the heat exchanger 5 is reduced. Consequently, the diameter of the piping connected to the refrigerant inlet side of the heat exchanger 5 can be kept to a minimum. This reduces the difficulty in connecting the heat exchanger 5 and the piping system within the limited space of the rack 2, and prevents restrictions on the layout of components other than the piping system. As a result, the limited space within the rack 2 can be used effectively.

[0052] (2) Server systems 1A and 1B according to the second embodiment are the server systems 1A and 1B of (1), wherein the rack 2 accommodates a plurality of servers 3 at intervals in the vertical direction Dv, and the heat exchanger 5 is positioned within the rack 2 on one side D1b of the first direction D1 that intersects the vertical direction Dv with respect to the plurality of servers 3.

[0053] With this configuration, the heat exchanger 5 can be positioned along, for example, the back or side of the rack 2, making effective use of the limited space within the rack 2.

[0054] (3) The server system 1B according to the third embodiment is the server system 1B of (1) or (2), wherein the heat exchanger 5 comprises a first heat exchanger 5A, which is a heat exchanger 5 into which the refrigerant is supplied from first discharge lines 120A, 120B, which are the discharge lines 120 connected to some of the servers 3A, 3B of the plurality of servers 3A to 3D, and a second heat exchanger 5B, which is a heat exchanger 5 into which the refrigerant is supplied from second discharge lines 120C, 120D, which are the discharge lines 120 connected to the remaining servers 3C, 3D of the plurality of servers 3A to 3D.

[0055] This configuration allows for miniaturization of the first heat exchanger 5A and the second heat exchanger 5B. This increases the flexibility of the layout of the first heat exchanger 5A and the second heat exchanger 5B within the rack 2 compared to when a single large heat exchanger 5 is installed.

[0056] (4) The server systems 1A and 1B according to the fourth embodiment are any one of the server systems 1A and 1B of (1) to (3), wherein each of the plurality of servers 3 has a plurality of cold plates 35, each of the plurality of introduction lines 110 has a plurality of branch introduction lines 115 that branch within the server 3 and can introduce refrigerant to each of the plurality of cold plates 35, and each of the plurality of discharge lines 120 has a plurality of branch discharge lines 125 through which the refrigerant discharged from each of the plurality of cold plates 35 flows and merges within the server 3.

[0057] With this configuration, multiple discharge lines 120 connected to each of the multiple servers 3 are connected to the manifold case 51 of the heat exchanger 5. This keeps the number of pipes connected to the manifold case 51 of the heat exchanger 5 from increasing, while allowing each of the multiple servers 3 to supply and discharge refrigerant to multiple cold plates 35 through multiple branch inlet lines 115 and branch discharge lines 125.

[0058] (5) The server systems 1A and 1B according to the fifth embodiment are any one of the server systems 1A and 1B of (1) to (4), further comprising a pressure reducing unit 130 for reducing the pressure of refrigerant in a plurality of introduction lines 110 and a plurality of discharge lines 120.

[0059] This allows the depressurization unit 130 to reduce the pressure of the refrigerant in the multiple introduction lines 110, thereby lowering the boiling point of the refrigerant and making it easier to evaporate, enabling efficient cooling by the latent heat of vaporization of the refrigerant at the cold plate 35. When the refrigerant evaporates, its volume expands, but in this case, since the multiple discharge lines 120 that discharge the refrigerant from the multiple servers 3 are connected to the manifold case 51 of the heat exchanger 5, it is possible to suppress the need to increase the diameter of the piping connected to the refrigerant inlet side of the heat exchanger 5. This ensures the cooling efficiency of the cold plate 35 while effectively utilizing the limited space within the rack 2.

[0060] (6) The server systems 1A and 1B according to the sixth embodiment are any one of the server systems 1A and 1B described in (1) to (5), wherein the refrigerant is water.

[0061] In this configuration, since the refrigerant is water, its expansion rate upon evaporation is larger compared to other fluorine-based refrigerants. Thus, when using water, which has a high expansion rate, as the refrigerant, it is possible to ensure cooling efficiency with the cold plate 35 while effectively utilizing the limited space within the rack 2.

[0062] According to the server system disclosed herein, the limited space within the rack can be used effectively.

[0063] 1A, 1B Server System 2 Rack 3, 3A-3D Server 5 Heat Exchanger 5A First Heat Exchanger 5B Second Heat Exchanger 31 Enclosure 32 Circuit Board 33 Heating Element 35 Cold Plate 51 Manifold Case 51s Refrigerant Space 52 Heat Exchange Line 55 Medium Supply Source 56 Medium Supply Line 57 Medium Discharge Line 59 Header 100 Cooling Mechanism 101 Storage Tank 102 Pressure Line 103 Supply Pump 104 Inlet Manifold 110 Inlet Line 115 Branch Inlet Line 120 Discharge Line 120A, 120B First Discharge Line 120C, 120D Second Discharge Line 125 Branch Discharge Line 130 Pressure Reducing Section 131 Vacuum Pump 132 Pressure Reducing Line 140 Return Line

Claims

1. A server system comprising: a plurality of servers each having a heating element and a cold plate for cooling the heating element; a rack housing the plurality of servers; a plurality of introduction lines connected to each of the plurality of servers within the rack and capable of introducing refrigerant to the cold plate; a plurality of discharge lines connected to each of the plurality of servers within the rack and through which the refrigerant discharged from the cold plate flows; a heat exchanger disposed within the rack and cooling the refrigerant supplied from the plurality of discharge lines; and a pressure line for pressurizing the refrigerant that has passed through the heat exchanger toward the plurality of introduction lines, wherein the heat exchanger comprises: a manifold case to which the plurality of discharge lines are connected and which has a refrigerant space into which the refrigerant flowing out from the plurality of discharge lines is introduced; and a heat exchange line that passes through the refrigerant space within the manifold case and also circulates a heat exchange medium for cooling the refrigerant from outside the manifold case.

2. The server system according to claim 1, wherein the rack accommodates a plurality of servers with vertical spacing between them, and the heat exchanger is located within the rack on one side in a first direction that intersects the plurality of servers in the vertical direction.

3. The server system according to claim 1 or 2, wherein the heat exchanger comprises a first heat exchanger, which is a heat exchanger to which the refrigerant is supplied from a first discharge line, which is a discharge line connected to some of the servers among the plurality of servers, and a second heat exchanger, which is a heat exchanger to which the refrigerant is supplied from a second discharge line, which is a discharge line connected to the remaining servers among the plurality of servers.

4. The server system according to claim 1 or 2, wherein each of the plurality of servers has a plurality of cold plates, each of the plurality of introduction lines has a plurality of branch introduction lines that branch within the server and can introduce refrigerant to each of the plurality of cold plates, and each of the plurality of discharge lines has a plurality of branch discharge lines through which the refrigerant discharged from each of the plurality of cold plates flows and merges within the server.

5. The server system according to claim 1 or 2, further comprising a plurality of introduction lines and a plurality of discharge lines, a pressure reducing unit for reducing the pressure of refrigerants.

6. The server system according to claim 1 or 2, wherein the refrigerant is water.

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