Data centers and their cooling systems

Abstract

To provide a cooling system that can improve the processing capacity of a data center, and a data center equipped with such system. [Solution] The cooling system of the data center 10 comprises a floor forming section 302 that forms a floor on which multiple computer devices are installed, an outside air flow path forming section 304 that forms an outside air flow path in which outside air flows while isolated from the floor space, a refrigerant flow path forming section 306 that forms a refrigerant flow path through which a refrigerant for cooling each computer device flows, and a heat exchanger 308 that is located inside the outside air flow path forming section 304 for heat exchange between the outside air and the refrigerant.

Description

Technical Field

[0001] This disclosure relates to a data center and its cooling system.

Background Art

[0002] Patent Document 1 describes a heat exchange structure for extracting the heat of a coolant in a cooling device having a radiator that radiates the heat of the coolant while containing a coolant that absorbs the heat of an object to be cooled in a container. This heat exchange structure is characterized by providing a base portion made of a good heat-conductive material that is radiated by the radiator, and a plurality of plate-shaped fins made of a good heat-conductive material that project inward from the base portion into the container and at least a part of which is immersed in the coolant.

[0003] Patent Document 2 describes an air conditioning system configured to include an indirect outdoor air cooling device. This air conditioning system includes an outdoor unit that cools a refrigerant by heat exchange with the outdoor air, an indirect outdoor air cooling device that performs cooling with the refrigerant, an outdoor unit room where the outdoor unit is provided and an intake for taking in the outdoor air is provided, and an outdoor air utilization system that enables the use of the outdoor air after heat exchange in the outdoor unit room.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of this disclosure is to provide a cooling system that can improve the processing capacity of a data center and a data center equipped with the same.

Means for Solving the Problems

[0006] A data center cooling system according to one aspect of this disclosure comprises: a floor forming section that forms a floor on which a plurality of computer devices are installed; an outside air flow path forming section that forms an outside air flow path through which outside air flows in isolation from the space of the floor; a refrigerant flow path forming section that forms a refrigerant flow path through which a refrigerant for cooling each of the computer devices flows; and a heat exchanger disposed inside the outside air flow path forming section for heat exchange between the outside air and the refrigerant.

[0007] A cooling system for a data center relating to other aspects of this disclosure is characterized in that the outside airflow channel forming section is positioned higher than the computer equipment.

[0008] A cooling system for a data center relating to other aspects of this disclosure has an external airflow channel forming section which includes an external airflow channel forming member that constitutes the ceiling, and the external airflow channel forming member separates the external airflow channel from the floor space.

[0009] A cooling system for a data center relating to another aspect of this disclosure is one in which the external airflow channel forming section is a duct.

[0010] A cooling system for a data center relating to another aspect of the present disclosure further comprises a plurality of storage racks for housing the computer equipment, wherein the refrigerant flow path forming section extends upward from each of the plurality of storage racks.

[0011] A cooling system for a data center relating to another aspect of this disclosure has a plurality of compartments formed inside the outside air flow channel forming section in a direction intersecting the direction of outside air flow, and the heat exchanger is arranged in each of the plurality of compartments.

[0012] A cooling system for a data center relating to other aspects of this disclosure has a primary side flow path and a secondary side flow path formed inside the outside air flow path forming section, and outside air flowing through the primary side flow path flows through the heat exchanger to the secondary side flow path.

[0013] In other aspects of this disclosure, the cooling system for a data center is such that the refrigerant behaves as a boiling two-phase flow.

[0014] A data center cooling system relating to other aspects of this disclosure further comprises a cooling jacket for cooling the computer equipment with the refrigerant, and a gas-liquid separator for separating bubbles generated in the refrigerant as it passes through the cooling jacket.

[0015] A cooling system for a data center relating to other aspects of the present disclosure further comprises a tubular section extending from the cooling jacket and forming a channel through which the gas-liquid mixture of the refrigerant flows, the upper end of which is above the liquid level inside the gas-liquid separator.

[0016] A cooling system for a data center relating to other aspects of this disclosure further comprises a tank positioned higher than the gas-liquid separator, wherein the refrigerant vapor, which was originally a bubble, separated by the gas-liquid separator passes through the tank and is returned to the outlet of the gas-liquid separator.

[0017] A cooling system for a data center relating to other aspects of this disclosure further comprises a tank positioned higher than the gas-liquid separator into which steam, which is the bubbles separated by the gas-liquid separator, is introduced, and a heat exchanger positioned downstream of the gas-liquid separator and higher than the gas-liquid separator and the tank, and functions as a condenser, in which the steam that has passed through the tank exchanges heat with the outside air.

[0018] A data center relating to one aspect of this disclosure comprises: computer devices housed in a plurality of server racks; a floor forming section that forms a floor on which the plurality of server racks are installed; an outside air flow path forming section that forms an outside air flow path through which outside air flows in isolation from the space of the floor; a refrigerant flow path forming section that forms a refrigerant flow path through which a refrigerant for cooling each of the computer devices flows; and a heat exchanger disposed inside the outside air flow path forming section for heat exchange between the outside air and the refrigerant. [Effects of the Invention]

[0019] According to the present disclosure, a cooling system capable of improving the processing capacity of a data center and a data center equipped with the same can be provided.

Brief Description of the Drawings

[0020] [Figure 1] It is a diagram showing an outline of a data center according to a first embodiment of the present disclosure. (A) is an explanatory diagram of a data center equipped with a cooling system by forced circulation of a refrigerant (liquid) using a pump, and (B) is an explanatory diagram of a data center equipped with a cooling system by natural circulation of a refrigerant (liquid). [Figure 2] It is a diagram showing the flow of heat in a server rack in the cooling system included in the data center. (A) is an explanatory diagram when there is one pump, and (B) is an explanatory diagram when there are a plurality of pumps provided in parallel. [Figure 3] It is a diagram showing a modified example of the cooling system included in the data center. (A) is an explanatory diagram showing a cooling system by natural circulation of a refrigerant without a pump, and (B) is an explanatory diagram showing a cooling system by air cooling. [Figure 4] It is an explanatory diagram showing the configuration of a cooling system included in a data center according to a second embodiment of the present disclosure. [Figure 5] (A) to (C) are modified examples of FIG. 4, and are explanatory diagrams showing the first to third modified examples of the cooling system included in the data center, respectively. [Figure 6] (A) and (B) are explanatory diagrams showing the cooling systems of the heat-generating circuit boards in the server rack installed in the data center, respectively. [Figure 7] (A) and (B) are explanatory diagrams showing the structure of the cooling system included in the data center and an arrangement example of a gas-liquid separation device. [Figure 8] It is an explanatory diagram showing the structure of a cooling jacket provided on a heat-generating circuit board in a server rack installed in the data center. [Figure 9](A) and (B) are explanatory diagrams showing examples of the arrangement of heat-generating circuit boards and cooling jackets within a server rack, respectively. [Figure 10] (A) is a plan view diagram illustrating the internal structure of an outside air intake duct, and (B) is a modified version thereof. [Figure 11] (A) is a side view diagram illustrating the internal structure of an outside air intake duct, different from that shown in Figure 10, and (B) is a plan view diagram illustrating a modified example thereof. [Modes for carrying out the invention]

[0021] Next, embodiments of this disclosure will be described with reference to the attached drawings. Note that parts not relevant to the description may be omitted from the illustrations.

[0022] [First Embodiment] As shown in Figure 1(A), the data center 10 according to the first embodiment of this disclosure is a facility where various computer devices are installed, and is equipped with computer devices and a cooling system for cooling the computer devices.

[0023] A computer device is any device equipped with an arithmetic unit, control unit, memory device, input / output device, etc. Specific examples include servers, storage devices, and communication devices. The computer equipment is housed in a server rack 20 (an example of a storage rack), and is used as a single unit within the server rack 20, stacked so that the vertical direction is the thickness direction. Hereafter, such computer devices may simply be referred to as "units." Inside the unit, heat-generating circuit boards, which are printed circuit boards on which heat-generating semiconductors S such as CPUs are mounted, are arranged in parallel in the vertical or horizontal direction.

[0024] The cooling system can discharge the heat generated by the computer equipment to the outside of the data center 10. The cooling system includes a floor forming section 302, an outside air intake duct 304, a refrigerant flow path forming section 306, and a heat exchanger 308.

[0025] The floor forming section 302 is a component that forms the walls and floors, and forms the floor of each level. A space is formed on each floor, and multiple computer devices housed in server racks 20 are installed there. Furthermore, data center 10 does not necessarily have to be multi-story.

[0026] The outside air intake duct (an example of an outside air flow path forming section) 304 is located above each floor and forms an outside air flow path in which outside air flows while being isolated from the floor space. More specifically, the outside air intake duct 304 has an outside air passage forming member that constitutes the ceiling 310, and is formed as an area above the ceiling that is separated from the floor space by this outside air passage forming member. However, the outside air intake duct 304 does not have to be formed as the ceiling space itself; it may be a duct located in the ceiling space, or it may be a duct located so as to pass through the upper part of the interior of the floor space (below the ceiling 310).

[0027] In other words, the external airflow channel forming unit can be positioned higher than the computer equipment and, as mentioned above, can form an external airflow channel that allows outside air to flow while being isolated from the floor space. Furthermore, the external airflow channel forming unit only needs to be able to form an external airflow channel that prevents moisture contained in the outside air from entering the floor space and causing malfunctions in the computer equipment. Outside air is introduced by a fan 312 installed inside the outside air intake duct 304.

[0028] The refrigerant flow path forming section 306 is a pipe that forms a refrigerant flow path through which refrigerant (liquid) flows to cool each computer device. The refrigerant flow path forming section 306 extends vertically in part, and the refrigerant flow path is configured such that the refrigerant flowing inside circulates between the server rack 20 and the heat exchanger 308. The refrigerant is forcibly circulated by the pump P. Thus, since the server rack 20 and the heat exchanger 308 are connected by a refrigerant flow path forming section 306 that extends in the vertical direction, replacement of the server rack 20 is easier compared to the case where a refrigerant flow path forming section that extends in the horizontal direction is provided.

[0029] Depending on the required specifications, pump P may not always be necessary, and the refrigerant may circulate through the refrigerant flow path in a way that allows for natural convection, as shown in data center 10a in Figure 1(B). The following describes a cooling system in which the refrigerant is forcibly circulated by pump P, and may omit explanations of cooling systems that rely on natural convection.

[0030] The heat exchanger 308 consists of multiple air-cooled heat exchangers located inside the outside air intake duct 304. Each heat exchanger 308 is positioned above the corresponding server rack 20. However, the heat exchanger 308 does not have to be placed directly above the server rack 20; it may be placed at a predetermined distance from the position directly above the server rack 20 when viewed from above. The heat exchanger 308 is preferably of the fin and tube type, for example.

[0031] In the cooling system of the data center 10 configured as described above, as shown in Figure 2(A), the refrigerant flow path formed by the refrigerant flow path forming unit 306 branches out to each unit downstream of the pump P that delivers the refrigerant, then merges again and flows upward to the heat exchanger 308. Downstream of the heat exchanger 308, the refrigerant flow path flows downward from the heat exchanger 308 and returns to the pump P.

[0032] However, the pump P for supplying the refrigerant does not necessarily have to be provided for each server rack 20; as shown in Figure 2(B), it may be provided for each branched refrigerant flow path. Furthermore, as mentioned above, as shown in Figure 3(A), the computer device may be cooled by natural circulation of the refrigerant without the need for a pump P. Furthermore, as shown in Figure 3(B), the computer equipment may be cooled by using air as the refrigerant, with the air supplied by fan F being introduced into the sealed server rack 20a and circulating between the server rack 20a and the heat exchanger.

[0033] In the cooling system described above, heat generated from the semiconductors of the computer device is absorbed by a refrigerant and then dissipated by a heat exchanger 308 located in an outside air intake duct 304, which is isolated from the floor space.

[0034] Thus, according to the cooling system of the data center 10 in this embodiment, an outside air intake duct 304 is formed through which outside air flows in isolation from the floor space. This prevents outside cooling air containing moisture that can cause condensation from entering the floor, thereby reducing the possibility of computer equipment failure.

[0035] [Second Embodiment] Next, a data center according to a second embodiment of this disclosure will be described. Components identical to those in the data center 10 according to the first embodiment are denoted by the same reference numerals and their detailed descriptions are omitted. The cooling system of the data center according to the second embodiment further includes a gas-liquid separator 602, as shown in Figure 4, and the refrigerant behaves as a boiling two-phase flow. In other words, the cooling system of the data center can handle the case where boiling occurs in the refrigerant in the cooling system of data center 10 shown in Figure 2(A).

[0036] The gas-liquid separator 602 is located downstream of each unit and upstream of the heat exchanger 308, and can separate bubbles generated in the refrigerant. The gas-liquid separator 602 receives a refrigerant into which bubbles have been generated by heat absorption from the heat-generating semiconductor S. After the bubbles are separated inside the separator, the refrigerant vapor, now in gaseous form, is released from the gas-liquid separator 602.

[0037] In the cooling system, the refrigerant flow path branches into separate units downstream of the pump P, forming an inclined section A that extends diagonally upward, with the position increasing as it moves downstream. A cooling jacket 70 for cooling the heat-generating semiconductor S is provided in this inclined section A. The branched refrigerant flow paths pass through the cooling jacket 70, each entering and opening into a gas-liquid separator 602, and then proceeding to a heat exchanger 308 located at a higher position than the gas-liquid separator 602. Downstream of the heat exchanger 308, the refrigerant flow path is formed to flow downward from the heat exchanger 308 and return to the pump P.

[0038] From another perspective, a portion of the refrigerant flow path forming section forms parallel flow paths, with each heat-generating circuit board equipped with a cooling jacket 70 having its flow path inclined and running parallel to the others. These parallel flow paths are opened up inside the gas-liquid separator 602, which is located upstream of the heat exchanger 308 and at a lower height than the heat exchanger 308. The parallel flow channels through which the gas-liquid mixture of refrigerant flows are opened to the vapor space VS, which is a relatively large space inside the gas-liquid separator 602 and above the liquid surface. This suppresses mutual interference of the flow between each flow channel and mitigates the inevitable backflow of refrigerant in a part of the parallel flow channels, thereby promoting smooth heat removal.

[0039] Here, if it is not possible to secure a large steam space VS due to constraints such as placement, but it is desired to more effectively suppress the backflow of refrigerant occurring in a part of the parallel flow path, this can be addressed by placing a tank (not shown) at a higher position than the gas-liquid separator 602 to substantially widen the steam space VS. This tank has an inlet and an outlet, with a pipe extending from the steam space VS connected to the inlet and the outlet connected to the outlet of the gas-liquid separator 602. Therefore, the refrigerant vapor, which was originally a bubble, enters the tank from the inlet, fills the inside of the tank, and exits from the outlet. However, the outlet of the tank may be connected to the heat exchanger 308 instead of the outlet of the gas-liquid separator 602. In this case, the heat exchanger 308 (condenser), which functions as a condenser by exchanging heat with the outside air for the refrigerant vapor, is located downstream of the gas-liquid separator 602 and at a higher position than the gas-liquid separator and the tank, and the refrigerant condensed in the heat exchanger 308 (condenser) is guided to the refrigerant flow path forming section 306.

[0040] In other words, the cooling system has a gas-liquid separator 602 and pipe sections 72 that form parallel flow paths, and the upper end (downstream end) of the pipe section 72 is exposed to the vapor space VS above the liquid level, so that the refrigerant containing bubbles flows stably in the parallel flow path, enabling more stable cooling.

[0041] Thus, in the cooling system, the heat generated from the semiconductor S of the computer device is absorbed by the refrigerant, and the absorbed refrigerant flows downstream as a boiling two-phase flow, where it is discharged (the refrigerant condenses) in the heat exchanger 308 located in the outside air intake duct 304. At this time, in the upward refrigerant flow path from the server rack 20 to the heat exchanger 308, the refrigerant contains bubbles that have been generated, and in the downward refrigerant flow path from the heat exchanger 308 to the server rack 20, the vapor condenses and the refrigerant becomes liquid. As a result, the density difference of the refrigerant between the upward and downward sides of the refrigerant flow path becomes large, and a circulating force is generated by the refrigerant itself.

[0042] Furthermore, the following first to third variations can be cited as cooling systems using boiling two-phase flow. A first modified version of the cooling system, as shown in Figure 5(A), does not have a gas-liquid separator, and the refrigerant in a boiling two-phase flow state is heat-exchanged in a heat exchanger. A second modification of the cooling system, as shown in Figure 5(B), involves mounting the semiconductor S horizontally, and the cross-sectional area of ​​the flow path for the refrigerant flowing inside the cooling jacket 70a provided on the semiconductor S gradually increases as it moves downstream. A third modification of the cooling system, as shown in Figure 5(C), involves cooling multiple heat-generating circuit boards 802 on which semiconductors S are mounted, while they are immersed inside a cooling tank 804. The refrigerant vapor, now in gaseous form, exits from the top of the cooling tank 804, passes through piping that penetrates the ceiling 310, undergoes heat exchange by a heat exchanger 308, and the condensed refrigerant returns to the cooling tank 804.

[0043] Next, the arrangement of the heat-generating circuit board 202 (see Figures 6(A) and 6(B)) inside the unit installed in the server rack 20 in the data center according to this embodiment will be described. The heat-generating circuit boards 202, which are placed inside the unit, are arranged so that the horizontal direction is the thickness direction, as shown in Figure 6(A). By arranging the heating circuit boards 202 in this manner, the refrigerant path that branches downstream of the pump P can be positioned to extend upward within the unit. This generates buoyancy in the air bubbles contained in the refrigerant, creating a circulating force within the refrigerant itself, and as a result, the capacity required of the pump P is reduced.

[0044] The heating circuit boards 202 may also be arranged horizontally in a tilted position from the vertical, as shown in Figure 6(B). Furthermore, the gas-liquid separator may be one gas-liquid separator 602a for multiple units, as shown in Figure 7(A), or it may be a gas-liquid separator 602b provided for each unit, as shown in Figure 7(B).

[0045] The cooling jacket 70 attached to the heat-generating semiconductor S is designed so that, taking into account that the refrigerant enters a boiling two-phase flow state inside, the cross-sectional area of ​​the flow path on the outlet side, indicated by width dimension L2, is larger than the cross-sectional area of ​​the flow path on the inlet side, indicated by width dimension L1, as shown in Figure 8. Preferably, the cooling jacket 70 is provided with a guide plate 702 inside the inlet side to suppress uneven flow of the refrigerant.

[0046] Inside each unit, a coolant path is formed through such a cooling jacket 70, and as shown in Figure 9(A), a cooling jacket 70 is provided for each semiconductor S mounted on the heat-generating circuit board 202. However, as shown in Figure 9(B), multiple semiconductors S arranged in the direction of the refrigerant flow may be cooled together in a single cooling jacket 70b.

[0047] Next, the arrangement of the heat exchanger 308 and the internal structure of the outside air intake duct 304 will be described in detail. As shown in Figure 10(A), the outside air intake duct 304 is divided internally by multiple partition plates 305a, forming multiple parallel compartments through which outside air flows in directions intersecting the flow direction. A heat exchanger 308 is installed in each compartment. Thus, because a compartment is formed inside the outside air intake duct 304, unlike the case where the heat exchanger 308 is arranged along the flow without a compartment being formed, the temperature of the introduced outside air does not rise significantly as it moves downstream. Therefore, the decrease in the cooling capacity of the heat exchanger 308 is suppressed. If the desired cooling performance is maintained, multiple heat exchangers 308 may be arranged along the flow of outside air in each compartment partitioned by the partition plate 305b, as shown in Figure 10(B).

[0048] Alternatively, the following outside air intake duct 404a or outside air intake duct 404b may be used instead of the outside air intake duct 304. As shown in Figure 11(A), the outside air intake duct 404a is divided vertically by a partition plate 405a, forming a lower primary flow path FP1a and an upper secondary flow path FP2a. The arrow Z shown in the figure indicates the vertical direction.

[0049] The primary flow path FP1a is a flow path through which low-temperature outside air is introduced, and a heat exchanger 308 is positioned along the direction of flow. The introduced outside air flows through the heat exchanger 308 to the secondary flow path FP2a, driven by a fan 313 provided for each heat exchanger 308. The secondary flow path FP2a is through which the outside air, which has become hot after passing through the heat exchanger 308, flows. The hot outside air is then discharged to the outside.

[0050] Compared to the outside air intake duct 404a, the outside air intake duct 404b is partitioned in a different direction, and as shown in Figure 11(B), the interior is partitioned to the left and right by a partition plate 405b, thereby forming a primary side flow path FP1b and a secondary side flow path FP2b. The materials of the aforementioned partition plates 305a, 305b and partition plates 405a, 405b are preferably materials that have heat insulating properties.

[0051] Thus, compared to a system without this configuration, the cooling system according to this embodiment allows for even higher density mounting of semiconductors and a higher density arrangement of heat-generating circuit boards 202 inside the unit, thereby increasing the data processing capacity per computer device and reducing the floor area required for installation of the computer devices.

[0052] As a result, even when processing power is required on an order of magnitude greater due to the widespread use of 3D images and videos, for example, it is possible to cope by increasing the processing capacity of existing data centers without drastically increasing the number of data centers to be installed. Furthermore, it avoids the energy-inefficient situation in existing data centers where heat from server racks is first discharged into the floor space and then re-dissipated into the outside air by cooling systems. This promotes energy conservation and, ultimately, contributes to global conservation by reducing electricity consumption. [Explanation of Symbols]

[0053] 10, 10a Data Center 20, 20a Server Rack 70, 70a, 70b Cooling Jackets 72 Pipe section 202 Heat-generating circuit board 302 Floor forming section 304 Outdoor air intake duct 305a, 305b Partition Plate 306 Refrigerant flow path forming section 308 Heat exchanger 310 Ceiling 312, 313 Fans 404a, 404b Outdoor air intake duct 405a, 405b Partition Plate 602, 602a, 602b gas-liquid separator 702 Information board 802 Heat-generating circuit board 804 Cooling tank F Fan P Pump S Semiconductor VS Steam Space FP1a, FP1b Primary flow path FP2a, FP2b Secondary flow path

Claims

1. A floor forming section that forms a floor on which multiple computer devices are installed, An external air channel forming section that forms an external air channel through which external air flows in isolation from the space of the aforementioned floor, A refrigerant channel forming section that forms a refrigerant channel through which a refrigerant for cooling each of the aforementioned computer devices flows, A cooling system for a data center, comprising a heat exchanger disposed inside the external airflow channel forming section for exchanging heat between the external air and the refrigerant.

2. In the cooling system for a data center according to claim 1, A data center cooling system in which the external airflow channel forming section is located at a higher position than the computer device.

3. In the data center cooling system according to claim 2, The aforementioned external airflow channel forming section has an external airflow channel forming member that constitutes the ceiling, A cooling system for a data center in which the space between the outside air passage and the floor is partitioned by the outside air passage forming member.

4. In the data center cooling system according to claim 2, The aforementioned external airflow channel forming section is a duct in a data center cooling system.

5. In the data center cooling system according to claim 3 or 4, The system further comprises multiple storage racks for housing the aforementioned computer equipment, A cooling system for a data center in which the refrigerant flow path forming section extends upward from each of the multiple storage racks.

6. In the cooling system for a data center according to claim 5, Multiple compartments are formed inside the aforementioned airflow channel forming section in a direction intersecting the direction of airflow. A cooling system for a data center, wherein the heat exchangers are located in each of the aforementioned compartments.

7. In the cooling system for a data center according to claim 5, A primary side channel and a secondary side channel are formed inside the external air channel forming section. A data center cooling system in which outside air flows through the primary side channel and then flows through the heat exchanger to the secondary side channel.

8. In the cooling system for a data center according to claim 5, A data center cooling system in which the aforementioned refrigerant behaves as a boiling two-phase flow.

9. In the data center cooling system according to claim 8, A cooling jacket for cooling the computer device with the refrigerant, A cooling system for a data center further comprising: a gas-liquid separator for separating bubbles generated in the refrigerant that has passed through the cooling jacket.

10. In the data center cooling system according to claim 9, The device further comprises a tubular section extending from the cooling jacket, which forms a passage through which the gaseous liquid refrigerant flows, A cooling system for a data center in which the upper end of the aforementioned pipe section is above the liquid level inside the gas-liquid separator.

11. In the data center cooling system according to claim 10, The system further includes a tank positioned higher than the aforementioned gas-liquid separator, A data center cooling system in which the refrigerant vapor, which was originally a bubble, separated by the gas-liquid separator, passes through the tank and is returned to the outlet of the gas-liquid separator.

12. In the data center cooling system according to claim 10, The system further comprises a tank positioned higher than the aforementioned gas-liquid separator, into which steam, which is the gas bubbles separated by the gas-liquid separator, is introduced. The heat exchanger is positioned downstream of the gas-liquid separator and at a higher position than the gas-liquid separator and the tank, and functions as a condenser. A data center cooling system in which steam that has passed through the tank exchanges heat with the outside air in the heat exchanger.

13. Computer equipment housed in multiple server racks, A floor forming section that forms a floor on which the aforementioned multiple server racks are installed, An external air channel forming section that forms an external air channel through which external air flows in isolation from the space of the aforementioned floor, A refrigerant channel forming section that forms a refrigerant channel through which a refrigerant for cooling each of the aforementioned computer devices flows, A data center comprising a heat exchanger disposed inside the external airflow channel forming section for heat exchange between the external air and the refrigerant.

Images