Liquid immersion cooling device and control method thereof

Abstract

To provide a liquid immersion cooling device capable of coping with equipment troubles in the cooling system of a cooling liquid.SOLUTION: An immersion cooling device 1 includes a radiator 11 that cools cooling water by heat exchange with outside air, a CDU 7 to which the cooling water cooled by the radiator 11 is guided and which exchanges heat with the cooling liquid, a cooling water circulation system through which the cooling water is circulated between the radiator 11 and the CDU 7, an immersion vessel 5 to which the cooling liquid cooled by the CDU 7 is guided and which stores the cooling liquid for immersing and cooling electronic devices, and a cooling liquid circulation system 9 through which the cooling liquid is circulated between the CDU 7 and the immersion vessel 5, in which there are provided a plurality combinations each of which is the radiator 11, the CDU 7, the cooling water circulation system, the immersion vessel 5, and the cooling liquid circulation system 9 are in parallel.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6658312 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the liquid immersion cooling system described in Patent Document 1 has a single cooling system for the coolant, and if an equipment problem occurs in the cooling system for the coolant, the coolant may generate heat and cause the server to stop.

[0005] Datacenters are also being asked to lower PUE (Power Usage Effectiveness: total power consumption of a facility divided by power consumption of IT equipment), an index that indicates power usage efficiency. In order to lower PUE, it is necessary to optimize the operation of the cooling system, but there is little operational experience with immersion type datacenters, and no means of optimizing the operation method have been established. For example, in the feedback control method, where the target temperature of the immersion cooling device is set as a single target, 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 consideration of the above circumstances, and has an object to provide an immersion cooling apparatus and a control method thereof that can deal with equipment troubles in the cooling system of the coolant. Another object of the present disclosure is to provide an immersion cooling apparatus that can easily control the target temperature of the immersion cooling apparatus and a control method thereof. [Means for solving the problem]

[0007] An immersion cooling apparatus according to one embodiment 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, the immersion heat exchangers, the cooling water circulation system, 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 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 guided and which exchanges heat with the cooling liquid, and a cooling water circulation system in which the cooling water is circulated between the radiator and the immersion heat exchanger; the cooling liquid cooled in the immersion heat exchanger is guided to a liquid immersion container in which the cooling liquid for immersing and cooling an electronic device is stored, and a cooling liquid circulation system in 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 control map shows the number of radiators in use and the number of immersion heat exchangers in use in a map in which the outside air temperature is set as a first axis and the amount of heat generated by the electronic device to be cooled is set as a second axis, and a control unit is provided 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.

[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 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 container into which the cooling liquid cooled by the immersion heat exchanger is guided and which stores therein the cooling liquid for immersing and cooling an electronic device, and a control method for controlling the immersion heat exchanger and the immersion container. and a cooling liquid circulation system in which a cooling liquid is circulated between the radiators, the immersion heat exchangers, the cooling water circulation systems, the immersion vessels, and / or the cooling liquid circulation systems, wherein a plurality of the radiators, the immersion heat exchangers, the cooling water circulation systems, the immersion vessels, and / or the cooling liquid circulation systems are provided in parallel, the control method for an immersion cooling apparatus comprising the steps of: switching the radiators, the immersion heat exchangers, the cooling water circulation systems, the immersion vessels, and / or the cooling liquid circulation systems.

[0010] A control method for an immersion cooling apparatus according to one embodiment 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 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, and in which the cooling liquid is circulated between the immersion heat exchanger and the immersion container, the control method comprising the steps of: 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 and the amount of heat generated by the electronic device during operation. Effect of the Invention

[0011] It is possible to cope with equipment troubles in the cooling system of the cooling liquid, and also to simply control the target temperature of the liquid immersion cooling device. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of an immersion cooling device. [Diagram 2] FIG. 2 is a perspective view showing the free cooling device mounted on a common installation panel. [Diagram 3] FIG. 4 is a diagram showing an outline of map control. [Figure 4A] This is a control map for the number of radiators and the number of CDUs. [Figure 4B] 1 is a control map for the fan rotation speed. [Figure 4C] 4 is a control map for the flow rate of a cooling water pump. [Figure 4D] 4 is a control map for the flow rate of a radiator pump. [Figure 4E] 4 is a control map for the flow rate of a coolant pump. [Figure 4F] 4 is a control map for switching times of a radiator, a coolant outlet pipe, and a coolant inlet pipe. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. 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 container 5, a free cooling unit 3, and a CDU (immersion heat exchanger) 7.

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

[0015] In this embodiment, two immersion containers 5 are provided in parallel. However, the number of immersion containers 5 is not limited to this, and three or more immersion containers 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, through which a coolant is circulated, 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 cooling liquid circulation system 9 includes a supply pipe 9a for supplying the cooling liquid from the CDU 7 to the immersion vessel 5, a return pipe 9b for returning the cooling liquid from the immersion vessel 5 to the CDU 7, an automatic on-off valve 9c provided in the supply pipe 9a, an automatic on-off valve 9d provided in the return pipe 9b, and a cooling liquid pump 9e for transporting the cooling liquid. The operation of the automatic on-off valves 9c and 9d is controlled by a control unit (not shown). The rotation speed of the cooling liquid pump 9e is controlled by a control unit (not shown) to vary the flow rate.

[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 radiator 11 is, for example, a fin-tube type heat exchanger, and cools the coolant by exchanging heat with outside air. Outside air is supplied to the radiator 11 by a fan 13. The rotation speed of the fan 13 is variable and is controlled by a control unit. The cooling water flowing out from each radiator 11 is sent to a cooling water tank 15 through each radiator outlet pipe 11a. Between the cooling water return tank 17 and each radiator 11, a radiator inlet pipe 11b is provided to return the cooling water 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 section. The cooling water pump 16b has a variable flow rate and is controlled by the control section. In this embodiment, two cooling water outlet pipes 16 are provided in parallel. It is also possible to provide three or more cooling water outlet pipes 16 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 portion 10. In this embodiment, two cooling water inlet pipes 18 are provided in parallel. Note that 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 section 10 is concentrated and arranged 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 a position 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 characters A-1, A-2, and A-3 shown on the branch supply pipe 10c correspond to the reference characters A-1, A-2, and A-3 shown 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 a 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 from the corresponding CDU 7 to each branch return pipe 10h. An automatic on-off valve 10i controlled by the control unit is provided in each branch return pipe 10h. In FIG. 1, the reference characters B-1, B-2, and B-3 shown on the branch return pipe 10h correspond to the reference characters B-1, B-2, and B-3 on the outlet side shown on 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 transmitted 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 adapted to obtain the amount of heat generated by electronic devices such as a server housed in the immersion container 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), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions is stored in a storage medium or the like in the form of a program, for example, and the CPU reads this program into the RAM or the like and executes information processing and arithmetic processing to realize various functions. The program may be installed in a ROM or other storage medium in advance, may be provided in a state stored in a computer-readable storage medium, or may be distributed via a wired or wireless communication means. The computer-readable storage medium may be a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like.

[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, the fan 13, the cooling water tank 15, the cooling water return tank 17, the cooling water outlet pipe 16, the cooling water inlet pipe 18, etc. are mounted on a 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, a control method by the control unit will be described. The control unit sets the cooling liquid temperature in the immersion vessel 5 to a desired value using map control.

[0033] 3 shows an outline of map control. In map control, input values ​​are the outside air temperature around the immersion cooling apparatus 1 and the amount of heat generated by electronic devices such as servers. Control items include the number of operating radiators 11, the number of operating CDUs 7, the cooling water flow rate controlled by the cooling water pump 16b, the cooling liquid flow rate controlled by the cooling liquid pump 9e, and the rotation speed of the fan 13. The control target value is the cooling liquid temperature of the immersion vessel 5 that cools the electronic devices. However, the desired value of the cooling liquid 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 the current values, and the amount of heat generated by the electronic devices, and controls the operating state of each device using the control map described below.

[0034] FIG. 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 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 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 air temperature is low and the server load is small, the fan 13 is stopped and no air is blown. As the outside air 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] FIG. 4C shows a control map for the flow rate of the cooling water pump 16b. The vertical and horizontal axes are the same as in FIG. 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 air temperature. Note that "(low flow rate)" in the figure 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 increases according to the outside air temperature.

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

[0040] FIG. 4E shows a control map for the flow rate of the coolant pump 9e. The vertical and horizontal axes are the same as in FIG. 4A. Since 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. When the outside temperature and server load increase, the control map transitions so that the number of coolant pumps 9e and the flow rate increase. Note that in this figure, the interpretations of "low flow rate," "medium flow rate," and "high flow rate" are the same as in FIG. 4D. However, "very low flow rate" means a flow rate smaller than "low flow rate."

[0041] 4F shows a control map of the switching time of the radiator 11, and the switching time of the coolant outlet pipe 16 and the coolant inlet pipe 18. The vertical and horizontal axes are the same as those in FIG. 4A. As shown in the figure, when the outside air temperature is below 5°C, there is a risk of freezing, so the switching time is set to one hour. Specifically, the use time of the radiator 11 is limited to one hour, and when the radiator 11 has been used continuously for one hour, the supply of cooling water is stopped by the control unit, and cooling water is supplied to the radiator 11 that has not been used until then. The cooling water outlet pipe 16 and the cooling water inlet pipe 18 are also switched in the same manner by instructions from the control unit. The control unit appropriately operates the automatic opening and closing valve to perform the switching. When the outside air temperature is above 5°C and there is no risk of freezing, the switching is performed every 24 hours. This is to extend the lifespan by evenly distributing the frequency of use. However, when the outside air temperature is high (above 25°C) and the server load is large, the switching is not performed. This is to prioritize cooling of the server.

[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 having 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 provides redundancy to the cooling system, and allows for a configuration in which cooling can be continued and electronic devices such as servers do not stop even when equipment trouble occurs.

[0043] By consolidating the branch header section 10 equipped with multiple automatic on-off valves 10b, 10d, 10g, and 10i in a specified 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, it becomes possible to transport the branch header section 10 as a whole, which shortens the time required for on-site piping installation.

[0044] By changing the number of CDU7 units used, it is possible to adjust the heat transfer area of ​​the heat exchanger. 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 breakdown.

[0045] By switching the number of radiators 11 used, it is possible to adjust the heat transfer area of ​​the heat exchanger. 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 due to a breakdown or other reasons.

[0046] The flow rate of the cooling water and the cooling water supplied to the CDU 7 is controlled by using the cooling water pump 16b and the cooling liquid pump 9e, which are variable in flow rate. This makes it possible to reduce the number of flow rate adjustment valves and to reduce the probability of equipment trouble. In addition, the control method can be simplified, and the probability of control trouble can be reduced.

[0047] We decided to use map control to select the optimal cooling system operation according to the amount of heat generated by the electronic devices (server load) and the outside air temperature. In other words, the number of radiators 11 to be used and the number of CDUs 7 to be used are determined by two factors: the amount of heat generated by the electronic devices and the outside air temperature. This makes it possible to significantly reduce adjustment parameters, simplify the device configuration of the control system, and reduce the probability of control trouble occurring.

[0048] The free cooling devices 3 are all installed on a common installation panel 22. This allows the equipment to be transported as an integrated unit installed on the common installation panel 22, reducing the number of on-site construction steps. The installation location can be easily changed depending on the local conditions. A water purifier may also be provided on the common installation panel 22. For heat exchangers that use copper pipes, it is recommended to use water purifiers from the viewpoint of corrosion. Normally, water purifiers are used, but as the water purifier is provided on the common installation panel, it is possible to supply the required amount of 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, and water-cooled racks for water-cooling electronic devices.

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

[0051] The immersion cooling apparatus (1) according to the first 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 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 in which the cooling liquid for immersing and cooling an electronic device is stored, 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, which allows for a configuration that continues cooling and does not shut down electronic devices such as servers even when equipment trouble occurs.

[0053] The immersion cooling apparatus according to a second aspect of the present disclosure is the above-mentioned first aspect, in which a plurality of the immersion heat exchangers are provided in parallel, and 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 off to each of the plurality of immersion heat exchangers, and the branch header sections are concentrated in a predetermined area.

[0054] By consolidating the branch headers equipped with the switching valves in a specified 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 headers can be transported as a single unit, which shortens the time required for on-site piping installation.

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

[0056] By changing the number of immersion heat exchangers 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 due to a breakdown.

[0057] The 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, further comprising a controller that controls the number of the radiators to be used simultaneously, and a plurality of the radiators are provided in parallel.

[0058] By switching the number of radiators used, it is possible to adjust the heat transfer area of ​​the heat exchanger. 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 breakdown.

[0059] The immersion cooling apparatus according to a fifth aspect of the present disclosure is configured in such a way that in any one of the first to fourth aspects, 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 have variable flow rates.

[0060] The flow rate of the cooling water and the cooling water immersion heat exchanger is supplied by a variable flow rate pump. This makes it possible to reduce the number of flow rate adjustment valves and to reduce the probability of equipment trouble. In addition, the control method can be simplified, and the probability of control trouble can be reduced.

[0061] An immersion cooling apparatus (1) according to a sixth aspect of the present disclosure includes a radiator (11) that cools cooling water by exchanging heat 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) in which the cooling liquid cooled by the immersion heat exchanger is guided and in which the cooling liquid for immersing and cooling an electronic device is stored, and a heat exchanger (8) between the immersion heat exchanger and the immersion vessel. a cooling liquid circulation system (9) in which a cooling liquid is circulated, the radiators and the immersion heat exchangers are provided in parallel in plurality, the control system has a control map in which the number of radiators to be used and the number of immersion heat exchangers to be used are represented on a map in which the outside air temperature is set as a first axis and the heat generation amount of the electronic device to be cooled is set as a second axis, and the control system is configured to determine 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 and the heat generation amount of the electronic device during operation.

[0062] Map control is performed to select the optimal operation of the cooling system according to the heat generation amount of the electronic devices and the outside air temperature. In other words, the number of radiators to be used and the number of immersion heat exchangers to be used are determined from two items: the heat generation amount of the electronic devices and the outside air temperature. This makes it possible to significantly reduce adjustment parameters, simplify the device configuration of the control system, and reduce the probability of control trouble occurring. It is preferable to manage the target cooling liquid temperature of the immersion cooling device within a certain range.

[0063] The immersion cooling apparatus according to a seventh aspect of the present disclosure is the same as that of the sixth aspect, except that the immersion cooling apparatus includes 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, and the control unit has the control map in which 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 are represented in a map, and the control unit 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 an outside air temperature and a heat generation amount of electronic devices 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, in any one of the first to seventh aspects, characterized in that 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 provided on a common installation panel (22).

[0066] Since the equipment can be transported as an integrated unit mounted on a common installation panel, the man-hours required for on-site construction can be reduced. The installation location can be easily changed according to the local conditions. Furthermore, a radiator fan and a cooling water pump for supplying cooling water may be provided on a common installation panel. A water purifier may also be installed on the common installation panel. For heat exchangers that use copper pipes, it is recommended to use water purifiers to prevent corrosion. Normally, water purifiers are used that are made separately, but since the water purifier is installed on the common installation panel, it is possible to supply the required amount of 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 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 container in which the cooling liquid cooled by the immersion heat exchanger is guided and which stores therein the cooling liquid for immersing and cooling an electronic device, and a control system for controlling the immersion heat exchanger and the immersion container. 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 includes switching 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 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 in which the cooling liquid cooled by the immersion heat exchanger is guided and in which the cooling liquid for immersing and cooling an electronic device is stored, and a control method for controlling the cooling liquid between the immersion heat exchanger and the immersion vessel a cooling liquid circulation system in which a cooling liquid is circulated, and a plurality of the radiators and the immersion heat exchangers are provided in parallel, the control method comprising: determining the number of the radiators to be used and the number of the immersion heat exchangers to be used from the control map, the control map representing the number of the radiators to be used and the number of the immersion heat exchangers to be used in a map with an outside air temperature as a first axis and a heat generation amount of the electronic device to be cooled as a second axis, based on the outside air temperature and the heat generation amount of the electronic device during operation, based on the outside air temperature and the heat generation amount of the electronic device during operation, based on the control map, the control method comprising: [Explanation of symbols]

[0069] 1 Immersion cooling device 3 Free cooling equipment 5. Immersion container 7 CDU (immersion heat exchanger) 9 Coolant circulation system 9a Supply piping 9b Return piping 9c Automatic shut-off valve 9d Automatic shut-off valve 9e Coolant pump 10 Branch header section 10a Inlet Header 10b Automatic shut-off valve 10c Branch supply pipe 10d Automatic shut-off valve 10f Exit Header 10g Automatic shut-off valve 10h Branch return pipe 10i Automatic shut-off valve 11 Radiator 11a Radiator outlet pipe 11b Radiator inlet pipe 11c Radiator pump 11d Automatic shut-off valve 13 Fan 15 Cooling water tank 16 Cooling water outlet piping 16a Automatic shut-off valve 16b Cooling water pump 17 Cooling water return tank 18 Cooling water inlet piping 20 Outside Air Temperature Sensor

Claims

1. A radiator that cools the cooling water by exchanging heat with outside air; a liquid immersion heat exchanger into which the cooling water cooled by the radiator is guided and into which the cooling water exchanges heat with a cooling liquid; a cooling water circulation system in which cooling water is circulated between the radiator and the immersion heat exchanger; an immersion container into which the cooling liquid cooled by the immersion heat exchanger is guided and into which the cooling liquid for immersing and cooling an electronic device is stored; a coolant circulation system in which a coolant is circulated between the immersion heat exchanger and the immersion vessel; Equipped with An immersion cooling apparatus in which a plurality of the radiators, and / or the immersion heat exchangers, and / or the cooling water circulation systems, and / or the immersion vessels, and / or the cooling liquid circulation systems are provided in parallel.

2. A plurality of the immersion heat exchangers are provided in parallel, the cooling water circulation system includes a branch header portion having a switching valve for switching a flow to a cooling water pipe branched to each of the plurality of immersion heat exchangers; The immersion cooling apparatus according to claim 1 , wherein the branch header portions are concentrated in a predetermined area.

3. A plurality of the immersion heat exchangers are provided in parallel, The immersion cooling apparatus according to claim 1 , further comprising a control unit for controlling the number of the immersion heat exchangers to be used simultaneously.

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

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. A radiator that cools the cooling water by exchanging heat with outside air; a liquid immersion heat exchanger into which the cooling water cooled by the radiator is guided and into which the cooling water exchanges heat with a cooling liquid; a cooling water circulation system in which cooling water is circulated between the radiator and the immersion heat exchanger; an immersion container into which the cooling liquid cooled by the immersion heat exchanger is guided and into which the cooling liquid for immersing and cooling an electronic device is stored; a coolant circulation system in which a coolant is circulated between the immersion heat exchanger and the immersion vessel; Equipped with A plurality of the radiators and the immersion heat exchangers are provided in parallel, The immersion cooling apparatus includes a control map in which the number of radiators to be used and the number of immersion heat exchangers to be used are represented on a map in which an outside air temperature is set as a first axis and a heat generation amount of an electronic device to be cooled is set as a second axis, and the immersion cooling apparatus is equipped with a control unit that determines 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 and the heat generation amount of the electronic device during operation.

7. a fan provided corresponding to each of the radiators; a plurality of radiator pumps provided corresponding to the radiators, each pump supplying cooling water to the radiators; A plurality of cooling water pumps provided in the plurality of cooling water circulation systems; A plurality of coolant pumps provided in the plurality of coolant circulation systems; Equipped with 7. The liquid immersion cooling apparatus according to claim 6, wherein the control unit has a control map in which the airflow of the fan, 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 are represented in a map, and the control unit determines the airflow of the fan, 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 during operation and a heat generation amount of electronic devices.

8. The radiator; a cooling water tank for storing the cooling water cooled by the radiator; a cooling water return tank that stores the cooling water returned from the immersion heat exchanger and that stores the cooling water before being returned to the radiator; The immersion cooling apparatus according to claim 1 , wherein the first and second cooling members are provided on a common installation plate.

9. A radiator that cools the cooling water by exchanging heat with outside air; a liquid immersion heat exchanger into which the cooling water cooled by the radiator is guided and into which the cooling water exchanges heat with a cooling liquid; a cooling water circulation system in which cooling water is circulated between the radiator and the immersion heat exchanger; an immersion container into which the cooling liquid cooled by the immersion heat exchanger is guided and into which the cooling liquid for immersing and cooling an electronic device is stored; a coolant circulation system in which a coolant is circulated between the immersion heat exchanger and the immersion vessel; Equipped with A method for controlling an immersion cooling apparatus in which a plurality of the radiators, the immersion heat exchangers, the cooling water circulation systems, the immersion vessels, and / or the cooling liquid circulation systems are provided in parallel, A control method for an immersion cooling apparatus, which switches the radiator, and / or the immersion heat exchanger, and / or the cooling water circulation system, and / or the immersion vessel, and / or the cooling liquid circulation system.

10. A radiator that cools the cooling water by exchanging heat with outside air; a liquid immersion heat exchanger into which the cooling water cooled by the radiator is guided and into which the cooling water exchanges heat with a cooling liquid; a cooling water circulation system in which cooling water is circulated between the radiator and the immersion heat exchanger; an immersion container into which the cooling liquid cooled by the immersion heat exchanger is guided and into which the cooling liquid for immersing and cooling an electronic device is stored; a coolant circulation system in which a coolant is circulated between the immersion heat exchanger and the immersion vessel; Equipped with A control method for an immersion cooling apparatus in which a plurality of the radiators and the immersion heat exchangers are provided in parallel, comprising the steps of: a control map showing the number of radiators in use and the number of immersion heat exchangers in use in a map in which an outside air temperature is set as a first axis and a heat generation amount of the electronic device to be cooled is set as a second axis; 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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