Liquid immersion cooling device and control method therefor

Abstract

Provided is a liquid immersion cooling device capable of dealing with equipment troubles in a cooling system of cooling liquid. A liquid immersion cooling device (1) includes: radiators (11) that cool cooling water by exchanging heat with outside air; CDUs (7) where the cooling water cooled by the radiators (11) is introduced and exchanges heat with cooling liquid; a cooling water circulation system in which the cooling water is circuited between the radiators (11) and the CDUs (7); liquid immersion containers (5) into which the cooling liquid cooled by the CDUs (7) are introduced and which retain therein cooling liquid for immersing and cooling electronic equipment; and a cooling liquid circulation system (9) in which cooling liquid is circulated between the CDUs (7) and the liquid immersion containers (5). The radiators (11), the CDUs (7), the cooling water circulation system, the liquid immersion containers (5), and the cooling liquid circulation system (9) are provided in a plurality of parallel arrangements.

Description

Immersion cooling device and control method thereof

[0001] The present disclosure relates to an immersion cooling apparatus suitable for use in cooling servers in data centers, for example, and a control method thereof.

[0002] Patent Document 1 discloses that electronic devices such as servers and storage devices are cooled in a data center by immersing them in a cooling liquid.

[0003] Patent No. 6658312

[0004] However, the immersion cooling system described in Patent Document 1 has a single cooling system for the coolant, and if a malfunction occurs in the cooling system, the coolant may generate heat and cause the server to shut down.

[0005] Data centers are also being asked to reduce PUE (Power Usage Effectiveness: total power consumption of a facility divided by the power consumption of IT equipment), an index that indicates power usage efficiency. To reduce PUE, it is necessary to optimize the operation of the cooling system, but there is little operational experience with immersion cooling data centers, and no means of optimizing the operation method have been established. For example, with feedback control using a single target temperature for the immersion cooling equipment, there are a wide variety of adjustment parameters (such as refrigerant flow rate and fan rotation speed), which complicates the device configuration of the control system and may increase the probability of control problems occurring.

[0006] The present disclosure has been made in view of the above circumstances, and aims to provide an immersion cooling apparatus and a control method thereof that can deal with equipment trouble in the cooling system of the coolant. Another aim of the present disclosure is to provide an immersion cooling apparatus and a control method thereof that can easily control the target temperature of the immersion cooling apparatus.

[0007] An immersion cooling apparatus according to one aspect of the present disclosure includes a radiator that cools cooling water by heat exchange with outside air, an immersion heat exchanger to which the cooling water cooled by the radiator is guided and which exchanges heat with a cooling liquid, a cooling water circulation system through which the cooling water is circulated between the radiator and the immersion heat exchanger, an immersion vessel to which the cooling liquid cooled by the immersion heat exchanger is guided and which stores the cooling liquid for immersing and cooling an electronic device, and a cooling liquid circulation system through which the cooling liquid is circulated between the immersion heat exchanger and the immersion vessel, and a plurality of the radiators, and / or the immersion heat exchangers, and / or the cooling water circulation system, and / or the immersion vessels, and / or the cooling liquid circulation system are provided in parallel.

[0008] an immersion cooling apparatus according to one aspect of the present disclosure, the apparatus comprising: a radiator that cools cooling water by heat exchange with outside air; an immersion heat exchanger to which the cooling water cooled by the radiator is guided and which exchanges heat with a cooling liquid; a cooling water circulation system through which the cooling water is circulated between the radiator and the immersion heat exchanger; an immersion vessel to which the cooling liquid cooled by the immersion heat exchanger is guided and which stores the cooling liquid for immersing and cooling an electronic device; and a cooling liquid circulation system through which the cooling liquid is circulated between the immersion heat exchanger and the immersion vessel, the apparatus comprising: a plurality of the radiators and the immersion heat exchangers arranged in parallel; a control map that represents the number of radiators in use and the number of immersion heat exchangers in use, with the outside air temperature as a first axis and the heat generation amount of the electronic device to be cooled as a second axis; and a control unit that determines the number of radiators in use and the number of immersion heat exchangers in use from the control map, based on the outside air temperature and the heat generation amount of the electronic device during operation.

[0009] A control method for an immersion cooling apparatus according to one aspect of the present disclosure includes a radiator that cools cooling water by heat exchange with outside air, an immersion heat exchanger into which the cooling water cooled by the radiator is introduced and which exchanges heat with a cooling liquid, a cooling water circulation system through which the cooling water is circulated between the radiator and the immersion heat exchanger, an immersion vessel into which the cooling liquid cooled by the immersion heat exchanger is introduced and which stores the cooling liquid for immersing and cooling an electronic device, and a control system for controlling the immersion heat exchanger and the immersion vessel. and a coolant circulation system through which a coolant is circulated between the radiators, the immersion heat exchangers, the coolant circulation systems, the immersion vessels, and / or the coolant circulation systems, wherein a plurality of the radiators, the immersion heat exchangers, the coolant circulation systems, the immersion vessels, and / or the coolant circulation systems are provided in parallel, and the control method for an immersion cooling apparatus includes switching between the radiators, the immersion heat exchangers, the coolant circulation systems, the immersion vessels, and / or the coolant circulation systems.

[0010] a cooling liquid circulation system through which the cooling liquid is circulated between the radiator and the immersion heat exchanger; an immersion vessel into which the cooling liquid cooled by the immersion heat exchanger is guided and which stores the cooling liquid for immersing and cooling an electronic device; and a cooling liquid circulation system through which the cooling liquid is circulated between the immersion heat exchanger and the immersion vessel, wherein the cooling liquid is circulated between the immersion heat exchanger and the immersion vessel, and wherein the cooling liquid is arranged in parallel; the control map represents the number of radiators in use and the number of immersion heat exchangers in use, with the outside air temperature as the first axis and the heat generation amount of the electronic device to be cooled as the second axis; and the control map determines the number of radiators in use and the number of immersion heat exchangers in use based on the outside air temperature and the heat generation amount of the electronic device during operation.

[0011] This allows for the response to equipment troubles in the cooling system of the coolant, and also allows for the target temperature of the liquid immersion cooling device to be easily controlled.

[0012] Fig. 1 is a schematic diagram showing the general configuration of an immersion cooling device. Fig. 2 is a perspective view showing a state in which free cooling devices are mounted on a common installation panel. Fig. 3 is a diagram showing an outline of map control. Fig. 4 is a control map for the number of radiators and the number of CDUs. Fig. 5 is a control map for the fan rotation speed. Fig. 6 is a control map for the flow rate of a cooling water pump. Fig. 7 is a control map for the flow rate of a radiator pump. Fig. 8 is a control map for the flow rate of a coolant pump. Fig. 9 is a control map for the switching times of a radiator, a cooling water outlet pipe, and a cooling water inlet pipe.

[0013]

[0016] An embodiment of the present disclosure will be described below with reference to the drawings. Fig. 1 shows a schematic configuration of an immersion cooling apparatus 1 used in an immersion data center. The immersion cooling apparatus 1 includes an immersion vessel 5, a free cooling unit 3, and a CDU (immersion heat exchanger) 7.

[0014] The immersion vessel 5 is a bottomed vessel in which a cooling liquid is stored. The cooling liquid is an electrically insulating liquid, such as silicone oil. The cooling liquid is filled to a height sufficient to completely immerse a plurality of substrates (electronic devices) arranged inside the immersion vessel 5. Each substrate constitutes, for example, a server, and is arranged at predetermined intervals. The substrates are mounted with a plurality of electronic components that constitute the server, such as a CPU, a power supply unit, memory, storage such as a hard disk or SSD (Solid State Drive), and a communication unit. These electronic components generate heat during server operation and are cooled by the cooling liquid.

[0015] In this embodiment, two immersion vessels 5 are provided in parallel, but the number of immersion vessels 5 is not limited to this, and three or more immersion vessels 5 may be provided in parallel.

[0016] CDU 7 is an abbreviation for Coolant Distribution Unit (coolant circulation device), and is a heat exchanger that exchanges heat between the cooling water supplied from the free cooling device 3 and the cooling liquid supplied to the immersion vessel 5 .

[0017] In this embodiment, a total of four CDUs 7 are provided, two for each immersion vessel 5. However, the number of CDUs 7 is not limited to this, and three or more CDUs 7 may be provided for each immersion vessel 5.

[0018] A coolant circulation system 9 for circulating a coolant is provided between the CDU 7 and the immersion vessel 5. One coolant circulation system 9 is provided for each CDU 7, and in this embodiment, a total of four coolant circulation systems 9 are provided in parallel.

[0019] Each coolant circulation system 9 includes a supply pipe 9a that supplies the coolant from the CDU 7 to the immersion vessel 5, a return pipe 9b that returns the coolant from the immersion vessel 5 to the CDU 7, an automatic on-off valve 9c provided on the supply pipe 9a, an automatic on-off valve 9d provided on the return pipe 9b, and a coolant pump 9e that transports the coolant. The operation of the automatic on-off valves 9c and 9d is controlled by a control unit (not shown). The rotation speed of the coolant pump 9e is controlled by the control unit (not shown), making the flow rate variable.

[0020] The free cooling device 3 includes a plurality of radiators 11, fans 13 provided in each radiator, a cooling water tank 15 for storing the cooling water flowing out from each radiator 11, and a cooling water return tank 17 for returning the cooling water to each radiator 11.

[0021] The radiators 11 are, for example, fin-and-tube heat exchangers, and cool the coolant by exchanging heat with outside air. Outside air is supplied to the radiators 11 by fans 13. The fan 13 has a variable rotation speed and is controlled by the control unit. The coolant flowing out of each radiator 11 is sent to the coolant tank 15 through each radiator outlet pipe 11a. A radiator inlet pipe 11b is provided between the coolant return tank 17 and each radiator 11 to return the coolant to the radiator 11. A radiator pump 11c and an automatic on-off valve 11d are provided in the radiator inlet pipe 11b. The radiator pump 11c has a variable flow rate and is controlled by the control unit. The automatic on-off valve 11d is controlled by the control unit.

[0022] The cooling water tank 15 is provided with a cooling water outlet pipe 16 that guides the cooling water to the branch header section 10. The cooling water outlet pipe 16 is provided with an automatic on-off valve 16a and a cooling water pump 16b. The automatic on-off valve 16a is controlled by the control unit. The cooling water pump 16b has a variable flow rate and is controlled by the control unit. In this embodiment, two cooling water outlet pipes 16 are provided in parallel. However, three or more cooling water outlet pipes 16 may be provided in parallel.

[0023] The cooling water return tank 17 is provided with a cooling water inlet pipe 18 that returns the cooling water from the branch header section 10. In this embodiment, two cooling water inlet pipes 18 are provided in parallel. However, three or more cooling water inlet pipes 18 may be provided in parallel.

[0024] As described above, two cooling water outlet pipes 16 are provided in parallel, and two cooling water inlet pipes 18 are provided in parallel, so that two cooling water circulation systems are provided.

[0025] The branch header section 10 is provided between the free cooling device 3 and the CDU 7, and is composed of piping for distributing cooling water and an on-off valve. The branch header sections 10 are arranged in a concentrated manner in a predetermined area.

[0026] The branch header section 10 includes an inlet header 10a to which each cooling water outlet pipe 16 is connected. An automatic on-off valve 10b controlled by the control unit is provided at the location where each cooling water outlet pipe 16 is connected. A plurality of branch supply pipes 10c are connected to the inlet header 10a. Each branch supply pipe 10c supplies cooling water to a corresponding CDU 7. Each branch supply pipe 10c is provided with an automatic on-off valve 10d controlled by the control unit. In FIG. 1, the reference numerals A-1, A-2, and A-3 indicated on the branch supply pipes 10c correspond to the reference numerals A-1, A-2, and A-3 indicated on the inlet side of each CDU 7.

[0027] The branch header section 10 includes an outlet header 10f to which each cooling water inlet pipe 18 is connected. An automatic on-off valve 10g controlled by the control unit is provided at the position where each cooling water inlet pipe 18 is connected. A plurality of branch return pipes 10h are connected to the outlet header 10f. Cooling water is guided to each branch return pipe 10h from a corresponding CDU 7. Each branch return pipe 10h is provided with an automatic on-off valve 10i controlled by the control unit. In FIG. 1, the reference numerals B-1, B-2, and B-3 indicated on the branch return pipes 10h correspond to the reference numerals B-1, B-2, and B-3 indicated on the outlet side of each CDU 7.

[0028] The immersion cooling apparatus 1 is equipped with an outside air temperature sensor 20 that measures the outside air temperature around the immersion cooling apparatus 1. The output of the outside air temperature sensor 20 is sent to the control unit. Note that the outside air temperature sensor 20 may not be provided, and the control unit may acquire the temperature of the room in which the immersion cooling apparatus 1 is placed.

[0029] The control unit is configured to obtain the amount of heat generated by electronic devices such as servers housed in the immersion vessel 5. The amount of heat generated by the electronic devices can be obtained from, for example, a higher-level control system.

[0030] The control unit is composed of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium, for example, in the form of a program. The CPU reads this program into RAM and executes information processing and arithmetic operations to realize various functions. The program may be pre-installed in a ROM or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Examples of computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memories.

[0031] 2 shows the free cooling device 3 mounted on a common installation panel 22. As shown in the figure, the free cooling device 3, i.e., the radiator 11, fan 13, cooling water tank 15, cooling water return tank 17, cooling water outlet piping 16, cooling water inlet piping 18, etc. are mounted on the plate-shaped installation panel 22. Although not shown, a pure water production device may also be mounted on the common installation panel 22.

[0032] Next, the control method by the control unit will be described. The control unit sets the temperature of the cooling liquid in the immersion vessel 5 to a desired value using map control.

[0033] An outline of map control is shown in Figure 3. Map control uses the outside air temperature around the immersion cooling apparatus 1 and the heat generation amount of electronic devices such as servers as input values. Control items include the number of operating radiators 11, the number of operating CDUs 7, the coolant flow rate controlled by the coolant pump 16b, the coolant flow rate controlled by the coolant pump 9e, and the rotation speed of the fan 13. The control target value is the coolant temperature in the immersion vessel 5 that cools the electronic devices. However, the desired value of the coolant temperature is managed within a certain temperature range (for example, a temperature range of ±several degrees Celsius). The control unit obtains the outside air temperature from the outside air temperature sensor 20, which are current values, and the heat generation amount of the electronic devices, and controls the operating state of each device using the control map described below.

[0034] 4A shows a control map for the number of radiators 11 and the number of CDUs 7. A control map is created with the outside air temperature (°C) on the horizontal axis and the server load (kW), which is the amount of heat generated by the electronic devices, on the vertical axis. This control map is stored in the memory of the control unit. As shown in the figure, when the outside air temperature is low and the server load is small, only one of the two radiators 11 is operated and the fan 13 is stopped. Also, only two of the four CDUs 7 are operated.

[0035] The control map transitions so that the number of radiators 11 and the number of CDUs 7 increase as the outside air temperature increases and the server load increases.

[0036] 4B shows a control map for the rotation speed of the fan 13. The rotation speed of the fan 13 is proportional to the airflow rate. The vertical and horizontal axes are the same as those in FIG. 4A. As shown in the figure, when the outside temperature is low and the server load is small, the fan 13 is stopped and no air is blown. As the outside temperature increases and the server load increases, the control map transitions to increase the rotation speed of the fan 13 and increase the airflow rate.

[0037] Figure 4C shows a control map for the flow rate of the cooling water pump 16b. The vertical and horizontal axes are the same as those in Figure 4A. As shown in the figure, when the server load is low, only one cooling water pump 16b is used and the flow rate (rotation speed) is reduced regardless of the outside temperature. Note that in the figure, "(low flow rate)" means that the flow rate per cooling water pump 16b is "low" when divided into three levels: high, medium, and low. The same applies to the interpretation of "medium flow rate" and "high flow rate."

[0038] The control map transitions so that when the server load increases, the number and flow rate of the cooling water pumps 16b increase according to the outside air temperature.

[0039] Figure 4D shows a control map for the flow rate of the radiator pump 11c. The vertical and horizontal axes are the same as those in Figure 4A. As the outside temperature and server load increase, the control map transitions so that the total flow rate increases, i.e., the number of radiator pumps 11c in use and the flow rate increase. Note that the interpretations of "low flow rate," "medium flow rate," and "high flow rate" in this figure are the same as those in Figure 4D.

[0040] Figure 4E shows a control map for the flow rate of the coolant pump 9e. The vertical and horizontal axes are the same as those in Figure 4A. Because a coolant pump 9e is provided for each CDU 7, the number of coolant pumps 9e in use corresponds to the number of CDUs 7 in use. This control map transitions so that the number of coolant pumps 9e and the flow rate increase as the outside temperature and server load increase. Note that the interpretations of "low flow rate," "medium flow rate," and "high flow rate" in this figure are the same as those in Figure 4D. However, "very low flow rate" means a flow rate lower than "low flow rate."

[0041] FIG. 4F shows a control map for the switching time of the radiator 11 and the cooling water outlet pipe 16 and the cooling water inlet pipe 18. The vertical and horizontal axes are the same as those in FIG. 4A. As shown in the figure, the switching time is set to one hour because there is a risk of freezing when the outside air temperature is below 5°C. Specifically, the radiator 11 is limited to one hour of use. After one hour of continuous use, the control unit stops the supply of cooling water to the radiator 11, and coolant is supplied to the radiator 11 that had not been used until then. The control unit also instructs the cooling water outlet pipe 16 and the cooling water inlet pipe 18 to switch over in a similar manner. The control unit appropriately operates automatic on-off valves to switch over. When the outside air temperature is above 5°C, where there is no risk of freezing, the switching occurs every 24 hours. This is to extend the service life by evenly distributing the usage frequency. However, when the outside air temperature is high (above 25°C) and the server load is heavy, switching is not performed because server cooling is prioritized.

[0042] The effects of the present embodiment described above are as follows: Four radiators 11 are provided in parallel, four CDUs 7 are provided in parallel, two cooling water circulation systems each including a cooling water inlet pipe 18 and a cooling water inlet pipe 18 are provided in parallel, two immersion vessels 5 are provided in parallel, and four cooling liquid circulation systems 9 are provided in parallel. This allows for redundancy in the cooling system, and a configuration can be achieved in which cooling can be continued even in the event of equipment trouble, preventing the shutdown of electronic devices such as servers.

[0043] By consolidating the branch header section 10 equipped with multiple automatic on-off valves 10b, 10d, 10g, and 10i in a predetermined area, it becomes easier to check and monitor the status of the automatic on-off valves 10b, 10d, 10g, and 10i compared to when the switching valves are distributed. In addition, the branch header section 10 can be transported as a single unit, which shortens the time required for on-site piping installation.

[0044] By switching the number of CDUs used, the heat transfer area of ​​the heat exchanger can be adjusted. The temperature of the coolant can be lowered even with the same PUE. For example, it is possible to improve the cooling speed when emergency cooling is required in the event of a malfunction.

[0045] By switching the number of radiators 11 in use, the heat transfer area of ​​the heat exchanger can be adjusted. This allows the coolant temperature to be lowered even with the same PUE. For example, this makes it possible to improve the cooling speed when emergency cooling is required in the event of a breakdown.

[0046] The cooling water pump 16b and the cooling liquid pump 9e, which have variable flow rates, are used to supply the cooling water and the cooling water to the CDU 7. This allows for the elimination of valves for adjusting the flow rate, lowering the probability of equipment trouble. The control method is also simplified, lowering the probability of control trouble.

[0047] Map control is used to select the optimal cooling system operation according to the heat generation (server load) of the electronic devices and the outside air temperature. In other words, the number of radiators 11 and the number of CDUs 7 to be used are determined by two factors: the heat generation of the electronic devices and the outside air temperature. This allows for a significant reduction in adjustment parameters, simplifies the device configuration of the control system, and reduces the probability of control problems occurring.

[0048] The free cooling devices 3 are all installed on a common installation panel 22. This allows the integrated unit to be installed on the common installation panel 22 and transported, reducing the man-hours required for on-site construction. The installation location can be easily changed depending on the local conditions. A pure water production system may also be installed on the common installation panel 22. For heat exchangers that use copper pipes, it is recommended to use pure water from the perspective of corrosion. Normally, pure water is produced separately, but since the pure water production system is installed on the common installation panel, it is possible to supply the required amount of pure water when needed, and it is not dependent on the local water quality.

[0049] The above-described immersion cooling apparatus 1 can also be applied to a container-type data center housed in a container, and also to a data center equipped with air-cooled racks for air-cooling electronic devices such as servers, or water-cooled racks for water-cooling electronic devices.

[0050] The immersion cooling apparatus and the control method thereof described in each of the above-described embodiments can be understood, for example, as follows.

[0051] The immersion cooling apparatus (1) according to the first aspect of the present disclosure comprises a radiator (11) that cools cooling water by heat exchange with outside air, an immersion heat exchanger (7) to which the cooling water cooled by the radiator is guided and which exchanges heat with a cooling liquid, a cooling water circulation system in which the cooling water is circulated between the radiator and the immersion heat exchanger, an immersion vessel (5) to which the cooling liquid cooled by the immersion heat exchanger is guided and which stores the cooling liquid for immersing and cooling an electronic device, and a cooling liquid circulation system (9) in which the cooling liquid is circulated between the immersion heat exchanger and the immersion vessel, and a plurality of the radiators, the immersion heat exchangers, the cooling water circulation system, the immersion vessels, and / or the cooling liquid circulation system are provided in parallel.

[0052] By providing multiple radiators, immersion heat exchangers, and / or cooling water circulation systems, and / or immersion vessels, and / or cooling liquid circulation systems in parallel, it is possible to provide redundancy to the cooling system, thereby enabling a configuration in which cooling can be continued and electronic devices such as servers do not stop operating even when equipment trouble occurs.

[0053] The immersion cooling apparatus according to a second aspect of the present disclosure is the immersion cooling apparatus of the first aspect, wherein a plurality of the immersion heat exchangers are provided in parallel, the cooling water circulation system includes a branch header section (10) having switching valves (10d, 10i) that switch the flow to the cooling water pipes branched to each of the plurality of immersion heat exchangers, and the branch header sections are concentrated in a predetermined area.

[0054] By concentrating the branch header sections equipped with switching valves in a predetermined area, it becomes easier to check and monitor the status of the switching valves compared to when the switching valves are distributed. In addition, the branch header sections can be transported as a whole, which shortens the time required for on-site piping installation.

[0055] An immersion cooling apparatus according to a third aspect of the present disclosure is the immersion cooling apparatus of the first aspect or the second aspect, in which a plurality of the immersion heat exchangers are provided in parallel and a control unit is provided that controls the number of the immersion heat exchangers that are used simultaneously.

[0056] By changing the number of immersion heat exchangers in use, the heat transfer area of ​​the heat exchanger can be adjusted. This allows the temperature of the coolant to be lowered even with the same PUE. For example, this makes it possible to improve the cooling speed when emergency cooling is required in the event of a malfunction.

[0057] An immersion cooling apparatus according to a fourth aspect of the present disclosure is the immersion cooling apparatus of any one of the first to third aspects, wherein a plurality of the radiators are provided in parallel and further includes a control unit that controls the number of the radiators to be used simultaneously.

[0058] By switching the number of radiators used, it is possible to adjust the heat transfer area of ​​the heat exchanger. This allows the coolant temperature to be lowered even with the same PUE. For example, this makes it possible to improve the cooling speed when emergency cooling is required in the event of a malfunction.

[0059] The immersion cooling apparatus according to a fifth aspect of the present disclosure is the immersion cooling apparatus of any one of the first to fourth aspects, wherein the cooling water pump 16b provided in the cooling water circulation system and / or the cooling liquid pump 9e provided in the cooling liquid circulation system are variable in flow rate.

[0060] A variable flow pump is used to supply the cooling water and the cooling water immersion heat exchanger. This allows for the elimination of flow rate adjustment valves, lowering the probability of equipment trouble. The control method is also simplified, lowering the probability of control trouble.

[0061] An immersion cooling apparatus (1) according to a sixth aspect of the present disclosure includes a radiator (11) that cools cooling water by heat exchange with outside air, an immersion heat exchanger (7) to which the cooling water cooled by the radiator is introduced and which exchanges heat with a cooling liquid, a cooling water circulation system in which the cooling water is circulated between the radiator and the immersion heat exchanger, an immersion vessel (5) to which the cooling liquid cooled by the immersion heat exchanger is introduced and which stores the cooling liquid for immersing and cooling an electronic device, and a heat exchanger between the immersion heat exchanger and the immersion vessel. a cooling liquid circulation system (9) in which a cooling liquid is circulated, wherein a plurality of the radiators and the immersion heat exchangers are provided in parallel, a control map is provided in which the number of the radiators to be used and the number of the immersion heat exchangers to be used are represented by a map in which the outside air temperature is represented as a first axis and the heat generation amount of the electronic device to be cooled is represented as a second axis, and a control unit is provided that determines the number of the radiators to be used and the number of the immersion heat exchangers to be used from the control map based on the outside air temperature and the heat generation amount of the electronic device during operation.

[0062] Map control is performed to select the optimal cooling system operation according to the heat generation amount of the electronic devices and the outside air temperature. In other words, the number of radiators and the number of immersion heat exchangers to be used are determined based on two factors: the heat generation amount of the electronic devices and the outside air temperature. This allows for a significant reduction in adjustment parameters, simplifies the device configuration of the control system, and reduces the probability of control problems occurring. It is preferable to manage the target coolant temperature of the immersion cooling device within a certain range.

[0063] An immersion cooling apparatus according to a seventh aspect of the present disclosure is the immersion cooling apparatus of the sixth aspect, further comprising: fans (13) provided corresponding to each of the radiators; a plurality of radiator pumps (11c) provided corresponding to each of the radiators and supplying cooling water to the radiators; a plurality of cooling water pumps (16b) provided in the plurality of cooling water circulation systems; and a plurality of cooling liquid pumps (9e) provided in the plurality of cooling liquid circulation systems, wherein the control unit has a control map that represents the airflow rates of the fans and / or the number of the radiator pumps in use and / or the number of the cooling water pumps in use and / or the number of the cooling liquid pumps in use, and determines the airflow rates of the fans and / or the number of the radiator pumps in use and / or the number of the cooling water pumps in use and / or the number of the cooling liquid pumps in use from the control map based on an outside air temperature and a heat generation amount of an electronic device during operation.

[0064] Furthermore, controllability can be further improved by performing map control of the radiator fan, radiator pump, cooling water pump, and coolant pump.

[0065] An immersion cooling apparatus according to an eighth aspect of the present disclosure is any one of the first to seventh aspects, wherein the radiator, a cooling water tank that stores cooling water cooled by the radiator, and a cooling water return tank that stores cooling water returned from the immersion heat exchanger and cooling water before being returned to the radiator are all provided on a common installation panel (22).

[0066] Since the equipment can be installed on a common installation panel and transported as an integrated unit, on-site construction man-hours can be reduced. The installation location can be easily changed depending on the local conditions. Furthermore, the radiator fan and the cooling water pump that supplies the cooling water can be installed on the common installation panel. The pure water production system can also be installed on the common installation panel. For heat exchangers that use copper pipes, it is recommended to use pure water from the perspective of corrosion. Normally, pure water is produced separately, but since the pure water production system is installed on the common installation panel, it is possible to supply the required amount of pure water when needed, and it is not dependent on the local water quality.

[0067] A control method for an immersion cooling apparatus according to a first aspect of the present disclosure includes a radiator that cools cooling water by heat exchange with outside air, an immersion heat exchanger to which the cooling water cooled by the radiator is introduced and which exchanges heat with a cooling liquid, a cooling water circulation system in which the cooling water is circulated between the radiator and the immersion heat exchanger, an immersion vessel to which the cooling liquid cooled by the immersion heat exchanger is introduced and which stores the cooling liquid for immersing and cooling an electronic device, and a control system for controlling the immersion heat exchanger and the immersion vessel. and a coolant circulation system in which a coolant is circulated between the radiators, the immersion heat exchangers, the coolant circulation systems, the immersion vessels, and / or the coolant circulation systems, wherein a plurality of the radiators, the immersion heat exchangers, the coolant circulation systems, the immersion vessels, and / or the coolant circulation systems are provided in parallel, and the control method for an immersion cooling apparatus is to switch between the radiators, the immersion heat exchangers, the coolant circulation systems, the immersion vessels, and / or the coolant circulation systems.

[0068] A control method for an immersion cooling apparatus according to a second aspect of the present disclosure includes a radiator that cools cooling water by heat exchange with outside air, an immersion heat exchanger to which the cooling water cooled by the radiator is introduced and which exchanges heat with a cooling liquid, a cooling water circulation system in which the cooling water is circulated between the radiator and the immersion heat exchanger, an immersion vessel to which the cooling liquid cooled by the immersion heat exchanger is introduced and which stores the cooling liquid for immersing and cooling an electronic device, and a control method for circulating the cooling liquid between the immersion heat exchanger and the immersion vessel. a cooling liquid circulation system through which a cooling liquid is circulated, and a plurality of the radiators and the immersion heat exchangers are provided in parallel, wherein a control map is used in which the number of radiators to be used and the number of immersion heat exchangers to be used are represented by a map in which the outside air temperature is used as a first axis and the heat generation amount of an electronic device to be cooled is used as a second axis, and the number of radiators to be used and the number of immersion heat exchangers to be used are determined from the control map based on the outside air temperature and the heat generation amount of the electronic device during operation.

[0069] 1 Immersion cooling device 3 Free cooling device 5 Immersion vessel 7 CDU (immersion heat exchanger) 9 Coolant circulation system 9a Supply piping 9b Return piping 9c Automatic on-off valve 9d Automatic on-off valve 9e Coolant pump 10 Branch header 10a Inlet header 10b Automatic on-off valve 10c Branch supply pipe 10d Automatic on-off valve 10f Outlet header 10g Automatic on-off valve 10h Branch return pipe 10i Automatic on-off valve 11 Radiator 11a Radiator outlet piping 11b Radiator inlet piping 11c Radiator pump 11d Automatic on-off valve 13 Fan 15 Coolant tank 16 Coolant outlet piping 16a Automatic on-off valve 16b Coolant pump 17 Coolant return tank 18 Coolant inlet piping 20 Outside air temperature sensor

Claims

1. An immersion cooling device comprising: a radiator that cools cooling water by exchanging heat with outside air; an immersion heat exchanger to which the cooling water cooled by the radiator is guided and which exchanges heat with a cooling liquid; a cooling water circulation system through which the cooling water is circulated between the radiator and the immersion heat exchanger; an immersion vessel to which the cooling liquid cooled by the immersion heat exchanger is guided and which stores the cooling liquid for immersing and cooling an electronic device; and a cooling liquid circulation system through which the cooling liquid is circulated between the immersion heat exchanger and the immersion vessel, wherein a plurality of the radiators, and / or the immersion heat exchangers, and / or the cooling water circulation system, and / or the immersion vessels, and / or the cooling liquid circulation system are provided in parallel.

2. The immersion cooling apparatus according to claim 1, wherein a plurality of the immersion heat exchangers are provided in parallel, the cooling water circulation system comprises a branch header section having a switching valve for switching the flow to the cooling water pipes branched off to each of the plurality of immersion heat exchangers, and the branch header sections are concentrated in a predetermined area.

3. The immersion cooling apparatus according to claim 1, further comprising a control unit that controls the number of the immersion heat exchangers to be used simultaneously, the immersion heat exchangers being provided in parallel in a plurality of stages.

4. The liquid immersion cooling apparatus according to claim 1, further comprising a control unit that controls the number of the radiators to be used simultaneously, the radiators being provided in parallel in a plurality of stages.

5. The immersion cooling apparatus according to claim 1, wherein the cooling water pump provided in the cooling water circulation system and / or the cooling liquid pump provided in the cooling liquid circulation system are variable in flow rate.

6. An immersion cooling device comprising: a radiator that cools cooling water by exchanging heat with outside air; an immersion heat exchanger to which the cooling water cooled by the radiator is guided and which exchanges heat with a cooling liquid; a cooling water circulation system through which the cooling water is circulated between the radiator and the immersion heat exchanger; an immersion container to which the cooling liquid cooled by the immersion heat exchanger is guided and which stores the cooling liquid for immersing and cooling an electronic device; and a cooling liquid circulation system through which the cooling liquid is circulated between the immersion heat exchanger and the immersion container, wherein a plurality of the radiators and the immersion heat exchangers are provided in parallel, the device has a control map that represents the number of radiators in use and the number of immersion heat exchangers in use, with the outside air temperature as the first axis and the amount of heat generated by the electronic device to be cooled as the second axis, and a control unit that determines the number of radiators in use and the number of immersion heat exchangers in use from the control map, based on the outside air temperature and the amount of heat generated by the electronic device during operation.

7. The liquid immersion cooling apparatus of claim 6, comprising: fans provided corresponding to each of the radiators; a plurality of radiator pumps provided corresponding to each of the radiators and supplying cooling water to the radiators; a plurality of cooling water pumps provided in a plurality of the cooling water circulation systems; and a plurality of cooling liquid pumps provided in a plurality of the cooling liquid circulation systems, wherein the control unit has a control map that represents the airflow of the fans, and / or the number of the radiator pumps in use, and / or the number of the cooling water pumps in use, and / or the number of the cooling liquid pumps in use, and determines the airflow of the fans, and / or the number of the radiator pumps in use, and / or the number of the cooling water pumps in use, and / or the number of the cooling liquid pumps in use from the control map based on the outside air temperature during operation and the amount of heat generated by electronic devices.

8. The immersion cooling apparatus according to claim 1, wherein the radiator, a cooling water tank for storing the cooling water cooled by the radiator, and a cooling water return tank for storing the cooling water returned from the immersion heat exchanger and for storing the cooling water before being returned to the radiator are mounted on a common installation panel.

9. A control method for an immersion cooling apparatus comprising: a radiator that cools cooling water by exchanging heat with outside air; an immersion heat exchanger to which the cooling water cooled by the radiator is guided and which exchanges heat with a cooling liquid; a cooling water circulation system through which the cooling water is circulated between the radiator and the immersion heat exchanger; an immersion vessel to which the cooling liquid cooled by the immersion heat exchanger is guided and which stores the cooling liquid for immersing and cooling an electronic device; and a cooling liquid circulation system through which the cooling liquid is circulated between the immersion heat exchanger and the immersion vessel, wherein a plurality of the radiators, and / or the immersion heat exchangers, and / or the cooling water circulation system, and / or the immersion vessels, and / or the cooling liquid circulation system are provided in parallel, the control method for an immersion cooling apparatus comprising: switching between the radiators, and / or the immersion heat exchangers, and / or the cooling water circulation system, and / or the immersion vessels, and / or the cooling liquid circulation system.

10. A control method for an immersion cooling device comprising: a radiator which cools cooling water by heat exchange with outside air; an immersion heat exchanger to which the cooling water cooled by the radiator is guided and which exchanges heat with a cooling liquid; a cooling water circulation system in which the cooling water is circulated between the radiator and the immersion heat exchanger; an immersion vessel to which the cooling liquid cooled by the immersion heat exchanger is guided and which stores the cooling liquid for immersing and cooling an electronic device; and a cooling liquid circulation system in which the cooling liquid is circulated between the immersion heat exchanger and the immersion vessel, wherein the control method comprises the steps of: The control method for an immersion cooling apparatus includes determining the number of radiators to be used and the number of immersion heat exchangers to be used from the control map based on the outside air temperature during operation and the amount of heat generated by electronic devices.

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