Cooling system and cooling method

Abstract

This invention provides a cooling system and cooling method that can flexibly combine air cooling and liquid cooling methods. [Solution] The cooling system comprises a plurality of heat source units, one or more liquid-cooled heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and a liquid that cools the device to be cooled, one or more air conditioning heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and air that cools the device to be cooled, and a selection unit that includes a plurality of valves and selects the circulation path of the cooling water from a plurality of selectable circulation paths by opening and closing a plurality of valves.

Description

Technical Field

[0001] The present disclosure relates to a cooling system and a cooling method.

Background Art

[0002] Patent Document 1 describes the following cooling system. The cooling system described in Patent Document 1 is housed in a predetermined space such as a floor of a data center, sucks air in the predetermined space, releases heat to the air, and exhausts the air that has absorbed heat to the predetermined space to cool a cooling target device such as a computing device. Further, this cooling system includes an outdoor unit, a liquid cooling unit, an intermediate heat exchanger, and an ambient air conditioner. The outdoor unit is disposed outside the predetermined space and supplies a cooled refrigerant. The liquid cooling unit is disposed in thermal contact with the cooling target device, and cools the heat generated from the cooling target device by absorbing it into a liquid cooling refrigerant different from the refrigerant supplied from the outdoor unit. The intermediate heat exchanger performs heat exchange between the refrigerant and the liquid cooling refrigerant. The ambient air conditioner cools the air in the predetermined space using the refrigerant before heat exchange is performed in the intermediate heat exchanger. According to the cooling system described in Patent Document 1, the refrigerant supplied from the outdoor unit is used for cooling in the order of the ambient air conditioner and the liquid cooling unit, and then returns to the outdoor unit again for cascade use. Therefore, it is said that the operating efficiency of the cooling system is easily increased as compared with a case where each of the ambient air conditioner and the liquid cooling unit has a parallel configuration in which the refrigerant is circulated separately.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described in Patent Document 1, data centers and the like use an air cooling system in which cool air is blown to the vicinity of the racks in which the ICT devices (information and communication devices) are housed, allowing the ICT devices to dissipate heat into the cool air, and a liquid cooling system in which the CPUs (central processing units) and other components housed in the ICT devices are directly cooled with circulating water or a coolant.

[0005] Incidentally, in cooling systems, there is a need to be able to flexibly combine air cooling and liquid cooling methods depending on the specifications, combination, and operation of the equipment being cooled.

[0006] This disclosure has been made in view of the above circumstances and aims to provide a cooling system and cooling method that can flexibly combine an air cooling system and a liquid cooling system. [Means for solving the problem]

[0007] To achieve the above objective, the cooling system according to this disclosure comprises a plurality of heat source units, one or more liquid-cooled heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and a liquid that cools the device to be cooled, one or more air conditioning heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and air that cools the device to be cooled, and a selection unit that includes a plurality of valves and selects the circulation path of the cooling water from a plurality of selectable circulation paths by opening and closing the plurality of valves.

[0008] The cooling method according to this disclosure uses a plurality of heat source units, one or more liquid-cooled heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and a liquid that cools the device to be cooled, and one or more air conditioning heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and air that cools the device to be cooled, and selects the circulation path of the cooling water from a plurality of selectable circulation paths by opening and closing a plurality of valves. [Effects of the Invention]

[0009] The cooling system and cooling method of this disclosure allow for a flexible combination of air cooling and liquid cooling. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the general configuration of the cooling system according to the first embodiment of this disclosure. [Figure 2] This is a schematic diagram showing an example of the configuration of a cooling system according to the first embodiment of this disclosure. [Figure 3] This is a schematic diagram showing the general configuration of the cooling system according to the first embodiment of this disclosure. [Figure 4] This is a schematic diagram showing the general configuration of the cooling system according to the first embodiment of this disclosure. [Figure 5] This figure shows an example of the relationship between cooling load and compressor efficiency according to the first embodiment of this disclosure. [Figure 6] This is a schematic diagram showing the general configuration of the cooling system according to the first embodiment of this disclosure. [Figure 7] This is a schematic diagram showing the general configuration of the cooling system according to the first embodiment of this disclosure. [Figure 8] This is a schematic diagram showing the general configuration of a cooling system according to the second embodiment of this disclosure. [Figure 9] This is a schematic diagram showing the general configuration of a cooling system according to the second embodiment of this disclosure. [Figure 10] This is a schematic diagram showing the general configuration of a cooling system according to the third embodiment of this disclosure. [Figure 11] This is a schematic diagram showing the general configuration of a cooling system according to the fourth embodiment of this disclosure. [Figure 12] This is a schematic diagram showing the general configuration of a cooling system according to the fifth embodiment of this disclosure. [Figure 13] This is a schematic block diagram showing the configuration of a computer according to at least one embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, a cooling system and a cooling method according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 13. In each figure, the same or corresponding components are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

[0012] (First Embodiment) FIG. 1 is a schematic diagram showing a schematic configuration of a cooling system according to the first embodiment of the present disclosure. FIG. 2 is a schematic diagram showing an installation example of the cooling system according to the first embodiment of the present disclosure. FIG. 2 shows an example in which the cooling system 1 according to the first embodiment of the present disclosure is configured as a cooling system in a building 30 such as a data center. In the example shown in FIG. 2, a server room 31 and an air conditioner room 32 are provided in the building 30. Further, a plurality of liquid-cooled server racks 33, a plurality of air-cooled server racks 35, and a control device 21-1 are provided in the server room 31. The plurality of liquid-cooled server racks 33 and the plurality of air-cooled server racks 35 (and the devices housed therein) shown in FIG. 2 are examples of the cooling target devices 36 to be cooled by the cooling system 1.

[0013] The cooling system 1 shown in FIGS. 1 and 2 includes i (i is a natural number) CDUs (Coolant Distribution Units) 10-1,..., 10-i (in the example shown in FIG. 2, i = 3), j (j is a natural number) DCs (Dry Coolers) 11-1,..., 11-j (in the example shown in FIG. 2, j = 3), and a pump 12. Further, the cooling system 1 includes m (m is a natural number) AHUs (Air Handling Units) 13-1,..., 13-m (in the example shown in FIG. 2, m = 3), n (n is a natural number) DCs 14-1,..., 14-n (in the example shown in FIG. 2, n = 3), and a pump 15. Further, the cooling system 1 includes a plurality (seven in FIGS. 1 and 2) of chillers 16-1 to 16-7 and a plurality of valves 17-1 to 17-16. Further, the cooling system 1 includes a selection unit 21. Note that a plurality of sensors such as temperature sensors and flow rate sensors are provided in the cooling system 1, but are not shown in the figures.

[0014] In the following, when collectively referring to CDU10-1, …, 10-i, it is called CDU10. When collectively referring to DC11-1, …, 11-j, it is called DC11. When collectively referring to AHU13-1, …, 13-m, it is called AHU13. When collectively referring to DC14-1, …, 14-n, it is called DC14. When collectively referring to chillers 16-1 to 16-7, it is called chiller 16. When collectively referring to valves 17-1 to 17-16, it is called valve 17.

[0015] CDU10 is an example of the "liquid-cooled heat exchanger" according to the present disclosure, and performs heat exchange between the cooling water supplied from chiller 16 and the liquid for cooling the device 36 to be cooled. For example, as shown in FIG. 2, CDU10 is installed in server room 31 and performs heat exchange between the refrigerant loop 34 for chip cooling provided in liquid-cooled server rack 33 and the cooling water supplied from chiller 16, and cools the refrigerant flowing through the refrigerant loop 34 for chip cooling, thereby cooling, for example, liquid-cooled servers, CPUs mounted on the liquid-cooled servers, processing devices such as GPUs (Graphics Processing Unit), etc., installed in liquid-cooled server rack 33 which is the device 36 to be cooled. In the example shown in FIG. 2, CDU10-1 to 10-3 are operated in parallel by connecting the respective inlets 10i of the cooling water to each other and connecting the respective outlets 10o of the cooling water to each other. In CDU10, the cooling water discharged from pump 12 enters through inlet 10i, and the cooling water discharged from outlet 10o enters DC11. Note that the cooling of the device 36 by CDU10 is not limited to this example, and it can also be used, for example, for cooling using an immersion device.

[0016] DC11 is an example of the "air-cooled heat exchanger" according to the present disclosure, has no compressor, and cools the cooling water by heat exchange with air. In the example shown in FIG. 2, DC11 is installed outside building 30. In the example shown in FIG. 2, DC11-1 to 11-3 are operated in parallel by connecting the respective inlets 11i of the cooling water to each other and connecting the respective outlets 11o of the cooling water to each other. In DC11, the cooling water discharged from CDU10 enters through inlet 11i, and the cooling water discharged from outlet 11o enters selection unit 21. The selection unit 21 will be described later.

[0017] Pump 12 takes in the cooling water discharged from the selection unit 21 and, through the action of pressure, sends it to the CDU 10, thereby circulating the cooling water.

[0018] AHU13 is an example of an "air conditioning heat exchanger" according to this disclosure, and performs heat exchange between cooling water supplied from chiller 16 and air that cools the cooling target device 36. As shown in Figure 2, for example, AHU13 is installed in the air conditioning room 32 and performs heat exchange between the air flowing in server room 31 and air conditioning room 32 and the cooling water supplied from chiller 16, thereby cooling the air and cooling the cooling target device 36, which is the air-cooled server rack 35 and ICT equipment such as air-cooled servers inside the air-cooled server rack 35. In the example shown in Figure 2, AHU13-1 to 13-3 are operated in parallel by connecting their respective cooling water inlets 13i to each other and connecting their respective cooling water outlets 13o to each other. In AHU13, the cooling water from pump 15 enters through inlet 13i, and the cooling water from outlet 13o enters DC14.

[0019] DC14 is an example of an "air-cooled heat exchanger" according to this disclosure, and like DC11, it does not have a compressor and cools the cooling water by heat exchange with air. In the example shown in Figure 2, DC14 is installed outside the building 30. In the example shown in Figure 2, DC14-1 to 14-3 are operated in parallel by connecting their respective cooling water inlets 14i to each other and connecting their respective cooling water outlets 14o to each other. In DC14, the cooling water from AHU13 enters through the inlet 14i, and the cooling water from the outlet 11o enters the selection unit 21.

[0020] Pump 15 takes in the cooling water discharged from the selection unit 21 and, through the action of pressure, sends it to AHU 13, circulating the cooling water.

[0021] Chiller 16 is an example of a "heat source unit" according to this disclosure. In this disclosure, a heat source unit is a device that supplies heat or a device that heats or cools objects. A heat source unit can also be called a heat source device, heat source equipment, etc. Chiller 16 cools by introducing cooling water from the cooling water inlet 16i and discharging the cooled cooling water from the cooling water outlet 16o. The chiller is a heat source unit that constitutes a refrigeration cycle with a compressor, evaporator, condenser, etc., and cools or heats water (cooling of cooling water in this embodiment). The chiller is a heat source unit having a compressor that operates on electricity. In this embodiment, chiller 16 may be replaced with another heat source unit having a compressor, such as a turbo chiller. In this disclosure, a heat source unit includes heat source units having a compressor and heat source units without a compressor. In this disclosure, the DC (air-cooled heat exchanger) described above is a heat source unit without a compressor.

[0022] The outlet 16o of chiller 16-1 is connected to one connection end of valve 17-1 and to one connection end of valve 17-2 via pipe 40 (hereinafter referred to simply as "pipe" without using symbols). Similarly, the outlets 16o of chillers 16-2 to 16-7 are connected to one connection end of valves 17-2 to 17-7 and to one connection end of valves 17-3 to 17-8 via pipe. In addition, the inlet 16i of chiller 16-1 is connected to one connection end of valve 17-9 and to one connection end of valve 17-10 via pipe. Similarly, the inlets 16i of chillers 16-2 to 16-7 are connected to one connection end of valves 17-10 to 17-15 and to one connection end of valves 17-11 to 17-16 via pipe. Valves 17-1 to 17-8 are connected in series via pipe. Valves 17-9 to 17-16 are also connected in series via pipe. Furthermore, the connection ends of valves 17-1 and 17-9 that are not connected to the chiller 16 are connected via pipe 41. Also, the connection ends of valves 17-8 and 17-16 that are not connected to the chiller 16 are connected via pipe 42. Pipe 41 is connected to the inlet of pump 12, and pipe 42 is connected to the inlet of pump 15.

[0023] In this embodiment, CDU10 and DC11 within the dashed block A are referred to as the liquid-cooled heat exchanger (or simply the liquid-cooled side). Also, AHU13 and DC14 within the dashed block B are referred to as the air-cooled heat exchanger (or simply the air-cooled side).

[0024] The selection unit 21 comprises a plurality of valves 17, piping 18 connecting each valve 17 to each chiller 16, and a control device 21-1. The control device 21-1 is electrically connected to the plurality of valves 17 and the plurality of chillers 16 via control lines (not shown). In this embodiment, the selection unit 21 includes a plurality of valves 17 and selects a cooling water circulation path 50 from a plurality of selectable cooling water circulation paths (for example, circulation paths 50-1 (Figure 1), 50-2 (Figure 3), 50-3 (Figure 4), 50-4 (Figure 6), and 50-5 (Figure 7)) by opening and closing the plurality of valves 17 (i.e., one of the selectable circulation paths 50-1 to 50-5 is selected to be the circulation path 50). In this embodiment, the cooling water circulation path 50 is the path from the cooling water discharged from the heat source unit, through at least one of the CDU 10 and AHU 13, to the heat source unit (return), and may include multiple independent (separated) paths or a single path. Hereinafter, when referring to multiple selectable circulation paths 50-1 to 50-5, etc., the term "circulation path 50" will be used collectively. In each figure, the white-painted valve 17 is in the open state, and the black-painted valve 17 is in the closed state. The valve 17 can be, for example, an automatically controllable gate valve. However, there are no limitations on the structure of the valve.

[0025] Furthermore, the control device 21-1 controls each valve 17 to open or close according to the selected circulation path 50 (to constitute the selected circulation path 50), and sets the outlet temperature (target temperature) of the cooling water for each chiller 16. The control device 21-1 also instructs each chiller 16 to operate or stop. Note that the temperature setting of each chiller 16, the instruction to operate or stop, and the opening and closing of the multiple valves 17 may be performed manually, in which case the control device 21-1 may be omitted.

[0026] In the circulation path 50-1 shown in Figure 1, by closing valves 17-5 and 17-13 and opening the remaining valve 17, chillers 16-1 to 16-4 are operated as chillers 16 supplying cooling water to the liquid-cooled side, and chillers 16-5 to 16-7 are operated as chillers 16 supplying cooling water to the air-cooled side. In this case, the cooling water flow 51 on the liquid-cooled side, indicated by the white-filled arrows, and the cooling water flow 52 on the air-cooled side, also indicated by the white-filled arrows, are independent, and the cooling water flow rate and cooling water temperature can be controlled independently for the liquid-cooled side and the air-cooled side. The number of chillers 16 to be assigned to the liquid-cooled side and the air-cooled side can be determined, for example, according to the cooling load ratio of the liquid-cooled side and the air-cooled side. In this embodiment, by changing the valve closing position according to the cooling load ratio of the liquid-cooled side and the air-cooled side, cooling according to the cooling load ratio can be achieved without changing the total number of chillers (without increasing the equipment). In the example shown in Figure 1, the set temperature of the coolant outlets for chillers 16-1 to 16-4 is 30°C, and the set temperature of the coolant outlets for chillers 16-5 to 16-7 is 10°C. However, these set temperatures are just examples and are not limited to this example.

[0027] An example of a situation where the load ratio between the air-cooled and liquid-cooled sides changes is when an air-cooled server is replaced with a liquid-cooled server. In such cases, this embodiment can be addressed simply by changing the valve closing position, and the liquid-cooled chiller does not need to be reinforced.

[0028] In the circulation path 50-2 shown in Figure 3, by closing valves 17-3 and 17-11 and opening the remaining valve 17, chillers 16-1 and 16-2 are operated as chillers 16 that supply cooling water to the liquid-cooled side, and chillers 16-3 to 16-7 are operated as chillers 16 that supply cooling water to the air-cooled side. In the example shown in Figure 3, the cooling water outlet set temperature for chillers 16-1 and 16-2 is 30°C, and the cooling water outlet set temperature for chillers 16-3 to 16-7 is 10°C.

[0029] In the circulation path 50-3 shown in Figure 4, by closing valves 17-6 and 17-14 and opening the remaining valve 17, chillers 16-1 to 16-5 are operated as chillers 16 that supply cooling water to the liquid-cooled side, and chillers 16-6 and 16-7 are operated as chillers 16 that supply cooling water to the air-cooled side. In the example shown in Figure 4, the cooling water outlet set temperature for chillers 16-1 to 16-5 is 30°C, and the cooling water outlet set temperature for chillers 16-6 and 16-7 is 10°C.

[0030] Furthermore, if the cooling load of the chiller 16 decreases or increases, the compressor may be operated in a region where the compressor efficiency deteriorates (Figure 5). Figure 5 shows an example of the relationship between cooling load and compressor efficiency, with the horizontal axis representing the cooling load and the vertical axis representing the efficiency of the compressor of the chiller 16. In the example shown in Figure 5, the compressor efficiency may decrease when the cooling load is relatively low or relatively high. In such cases, in this embodiment, energy saving can be achieved by increasing or decreasing the number of operating chillers 16 using the control device 21-1 to maintain a load per unit that allows the compressor to operate at a high efficiency level.

[0031] In the circulation path 50-4 shown in Figure 6, by closing valves 17-3, 17-11, 17-6, and 17-14 and opening the remaining valve 17, chillers 16-1 and 16-2 are operated as chillers 16 supplying cooling water to the liquid-cooled side, chillers 16-6 and 16-7 are operated as chillers 16 supplying cooling water to the air-cooled side, and the operation of chillers 16-3 to 16-5 is stopped. In the example shown in Figure 6, the cooling water outlet set temperature for chillers 16-1 and 16-2 is 30°C, and the cooling water outlet set temperature for chillers 16-6 and 16-7 is 10°C.

[0032] The control device 21-1 can increase or decrease the number of operating units by, for example, determining the overall cooling load of the cooling system 1 based on the measured values ​​of the cooling water inlet and outlet temperatures and flow rates, the power consumption of the cooling target device 36, and then adopting the optimal number of operating units that has been calculated in advance based on the characteristics of the cooling load and compressor efficiency, according to the determined cooling load.

[0033] Furthermore, in the circulation path 50-5 shown in Figure 7, by closing valves 17-1 and 17-9 and opening the remaining valve 17, cooling water is not supplied from chiller 16 to the liquid-cooled side, and chillers 16-1 to 16-7 operate as chillers 16 that supply cooling water to the air-cooled side. In the example shown in Figure 4, the cooling water outlet temperature set for chillers 16-1 to 16-7 is 10°C. In the circulation path 50-5, the cooling water on the liquid-cooled side is cooled by DC11. In addition to the circulation path 50-5, for example, by further closing valves 17-8 and 17-16 and stopping all chillers 16, the cooling water on the air-cooled side may also be cooled by DC14.

[0034] (Effects and Benefits) As described above, the cooling system 1 of the first embodiment comprises a plurality of heat source units (chillers 16, etc.), one or more liquid-cooled heat exchangers (CDU 10), one or more air conditioning heat exchangers (AHU 13), and a selection unit 21. The plurality of heat source units supply cooled cooling water. One or more liquid-cooled heat exchangers (CDU 10) perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and the liquid that cools the device to be cooled 36. One or more air conditioning heat exchangers (AHU 13) perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and the air that cools the device to be cooled 36. The selection unit 21 includes a plurality of valves 17 and selects the cooling water circulation path 50 from a plurality of selectable circulation paths 50-1 to 50-5, etc., by opening and closing the plurality of valves 17. With this configuration, the selection unit 21 allows the cooling water circulation path 50 to be selected by opening and closing the valve 17, thus enabling a flexible combination of air cooling and liquid cooling methods.

[0035] Furthermore, the cooling method of the first embodiment uses a plurality of heat source units (chillers 16, etc.), one or more liquid-cooled heat exchangers (CDU 10) that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and the liquid that cools the device to be cooled 36, and one or more air conditioning heat exchangers (AHU 13) that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and the air that cools the device to be cooled 36, and by opening and closing a plurality of valves 17, the cooling water circulation path 50 is selected from a plurality of selectable circulation paths 50-1 to 50-5. With this configuration, since the cooling water circulation path 50 can be selected by opening and closing the valves 17 by providing a selection unit 21, the air cooling method and the liquid cooling method can be flexibly combined.

[0036] Furthermore, in the cooling system 1 of the first embodiment, the selectable circulation paths 50 include multiple circulation paths 50-1 to 50-3 in which the number of heat source units (chillers 16) supplying cooling water to the liquid-cooled heat exchanger (CDU 10) and the number of heat source units (chillers 16) supplying cooling water to the air conditioning heat exchanger (AHU 13) differs among the circulation paths 50. With this configuration, the number of heat source units allocated to the liquid-cooled side and the air-cooled side can be changed by opening and closing the valve 17.

[0037] Furthermore, in the cooling system 1 of the first embodiment, the heat source includes a heat source with a compressor (chiller 16) and heat source without a compressor (DC11 and DC14), and the selectable multiple circulation paths 50 include a circulation path 50-5 that passes through the heat source without a compressor without passing through the heat source with a compressor. With this configuration, a circulation path that does not pass through the heat source with a compressor can be used.

[0038] Furthermore, in the cooling system 1 of the first embodiment, the heat source unit includes one having a compressor (chiller 16), and the selection unit 21 selects the circulation path 50-4 such that the number of heat source units (chillers 16) with compressors through which cooling water circulates changes according to the efficiency of the compressors. With this configuration, even when the cooling load changes, the compressor can maintain a highly efficient state.

[0039] Furthermore, the cooling system 1 of the first embodiment includes a plurality of heat sources (chillers 16, etc.), such as a first heat source (e.g., chiller 16-1 shown in Figure 1), a second heat source (e.g., chiller 16-2), and a third heat source (e.g., chiller 16-3). The multiple valves 17 include at least a first valve (valve 17-10) that opens and closes the cooling water inlet 16i of the first heat source unit (chiller 16-1) and the cooling water inlet 16i of the second heat source unit (chiller 16-2); a second valve (valve 17-11) that opens and closes the cooling water inlet 16i of the second heat source unit (chiller 16-2) and the cooling water inlet 16i of the third heat source unit (chiller 16-3); a third valve (valve 17-2) that opens and closes the cooling water outlet 16o of the first heat source unit (chiller 16-1) and the cooling water outlet 16o of the second heat source unit (chiller 16-2); and a fourth valve (valve 17-3) that opens and closes the cooling water outlet 16o of the second heat source unit (chiller 16-2) and the cooling water outlet 16o of the third heat source unit (chiller 16-3). In this configuration, for example, by opening the first valve (valve 17-10) and the third valve (valve 17-2), and closing the second valve (valve 17-11) and the fourth valve (valve 17-3), the first heat source unit (chiller 16-1) and the second heat source unit (chiller 16-2) can be connected in parallel, while the third heat source unit (chiller 16-3) can be separated from the first heat source unit (chiller 16-1) and the second heat source unit (chiller 16-2). Furthermore, for example, by closing the first valve (valve 17-10) and the third valve (valve 17-2), and opening the second valve (valve 17-11) and the fourth valve (valve 17-3), the second heat source unit (chiller 16-2) and the third heat source unit (chiller 16-3) can be connected in parallel, while the first heat source unit (chiller 16-1) can be separated from the second heat source unit (chiller 16-2) and the third heat source unit (chiller 16-3). The selection unit 21 includes such valves 17 and piping 18, allowing for the selection of multiple circulation paths 50 with different chiller 16 connection configurations.

[0040] The selectable circulation routes 50 are not limited to those described above, and may include, for example, circulation routes 50 with a different number of chillers 16 than those described above, or circulation routes 50 with a different number of chillers 16 that are stopped than those described above.

[0041] (Second Embodiment) Next, with reference to Figures 8 and 9, a cooling system 1a according to the second embodiment of this disclosure will be described. The cooling system 1a of the second embodiment includes a selection unit 21a (a modified version of the selection unit 21 in Figure 1) that allows the cooling water circulation path 50 to be switched to a cascade circuit from the CDU 10 to the AHU 13, for example, when the required cooling water temperature on the liquid cooling side is low. Note that the cooling system 1a of the second embodiment and the cooling system 1 of the first embodiment are identical in terms of the CDU 10, DC 11, pump 12, AHU 13, DC 14, pump 15, and chiller 16. Note that Figures 8 and 9 show different open / closed states of the valve 17. The circulation path 50-6 shown in Figure 8 constitutes a cascade circuit. In the circulation path 50-6, the flow 53 of cooling water supplied from the chiller 16 is a series flow from the liquid cooling side to the air cooling side. The flow of cooling water in the circulation path 50-7 shown in Figure 9 is the same as in the circulation path 50-1 shown in Figure 1, consisting of two independent cooling water flows 51 and 52.

[0042] As shown in Figures 8 and 9, the selection unit 21a is newly equipped with valves 17-21 to 17-31, and also has a piping 18a which is an additional pipe connected to valves 17-21 to 17-31, compared to the piping 18 shown in Figure 1. Furthermore, the control device 21a-1 equipped in the selection unit 21a is newly equipped with the function of opening and closing the valves 17-21 to 17-31, compared to the control device 21-1 shown in Figure 1.

[0043] In the selection section 21a, pipe 41 and DC11 are connected via valve 17-21, pipe 41 and pipe 42 are connected via valves 17-21 to 17-24 and pipe 43, and pipe 42 and DC14 are connected via valves 17-23 and 17-28. In addition, valves 17-24 to 17-31 and a portion of the piping 18a connected to valves 17-24 to 17-31 are configured by opening and closing valves 17-24 to 17-31 to create a circulation path 50-6 shown in Figure 8 and a circulation path 50-7 shown in Figure 9, where the inlet and outlet of the cooling water for AHU13, DC14, and pump 15 are the same.

[0044] In the circulation path 50-6 that constitutes the cascade circuit shown in Figure 8, by closing valves 17-8, 17-21, 17-23, 17-25, 17-27, 17-28, and 17-31, and opening the remaining valve 17, the cooling water from chillers 16-1 and 16-7 is supplied to the liquid cooling side, and the cooling water from the liquid cooling side is supplied to the air cooling side in the same order. The flow of cooling water 53 in the circulation path 50-6 flows to the pump 15 in the order of cooling water flow 53a from chiller 16 → flow 53b from CDU 10 → flow 53c from DC 11 → flow 53d from AHU 13 → flow 53e from DC 14. In the example shown in Figure 8, the set temperature of the cooling water outlets of chillers 16-1 to 16-7 is 10°C.

[0045] In the circulation path 50-7 shown in Figure 9, by closing valves 17-5, 17-13, 17-22, 17-24, 17-26, 17-29, and 17-30, and opening the remaining valve 17, chillers 16-1 to 16-4 are operated as chillers 16 supplying cooling water to the liquid-cooled side, and chillers 16-5 to 16-7 are operated as chillers 16 supplying cooling water to the air-cooled side. In this case, the cooling water flow 51 on the liquid-cooled side and the cooling water flow 52 on the air-cooled side are independent, and the cooling water flow rate and cooling water temperature can be controlled independently for the liquid-cooled side and the air-cooled side. In the example shown in Figure 9, the cooling water outlet set temperature for chillers 16-1 to 16-4 is 30°C, and the cooling water outlet set temperature for chillers 16-5 to 16-7 is 10°C.

[0046] (Effects and Benefits) As described above, in the cooling system 1a of the second embodiment, the selectable circulation paths 50 include a circulation path 50-6 that supplies cooling water (flow 53b) supplied from the heat source unit (chiller 16) to the liquid-cooled heat exchanger (CDU 10) and then supplied to the air conditioning heat exchanger (AHU 13). With this configuration, in addition to the functions and effects of the first embodiment, it is also possible to operate with a cascade circuit from the CDU 10 to the AHU 13.

[0047] (Third embodiment) Figure 10 shows the part of the cooling system 1b according to the third embodiment that corresponds to the configuration within block A shown in Figure 1. In the cooling system 1b shown in Figure 10, there are seven CDU10 units, CDU10-1 to 10-7. Each cooling water inlet 10i of CDU10-1 to 10-7 is connected to the cooling water outlet of pump 12 via valves 17-41 to 17-47. Each cooling water outlet 10o of CDU10-1 to 10-7 is connected to the cooling water inlet 11i of DC11. In addition, each cooling water outlet 10o of CDU10-1 to 10-7 is provided with temperature sensors 19-1 to 19-7 for measuring the temperature of the cooling water. Valves 17-41 to 17-47 are control valves or adjustment valves that control the flow rate of the cooling water so that the temperature of the cooling water outlet 10o becomes a constant value (44°C in the example of Figure 10) based on the measurements of temperature sensors 19-1 to 19-7.

[0048] When the load on the liquid-cooled server, which is the device to be cooled, fluctuates, the load on the CDU10 (liquid-cooled heat exchanger) also fluctuates. For example, if the cooling water flow rate is not changed when the load decreases, the water temperature at the outlet of the liquid-cooled heat exchanger (temperature of outlet 10o) will decrease, reducing the temperature difference with the atmosphere at DC11 and worsening the heat exchange performance. Therefore, in the third embodiment, the cooling water flow rate of the CDU10 (liquid-cooled heat exchanger) is increased or decreased using valves 17-41 to 17-47, etc., in response to load fluctuations, thereby maintaining the outlet cooling water temperature at a target value and also maintaining the temperature difference with the atmosphere at DC11. By monitoring the outlet temperature of the CDU10 (liquid-cooled heat exchanger) and controlling the cooling water flow rate in this way, deterioration of energy-saving operation during load fluctuations is prevented.

[0049] In the example shown in Figure 10, CDU10-1, 10-5, and 10-7 are under high load, and the openings of the corresponding valves 17-41, 17-45, and 17-47 are controlled to be larger, while CDU10-2 to 10-4 and 10-6 are under low load, and the openings of the corresponding valves 17-42 to 17-44 and 17-46 are controlled to be smaller.

[0050] (Effects and Benefits) As described above, in the third embodiment, the cooling system 1b has multiple CDU10 (liquid-cooled heat exchangers), and cooling water is supplied to each CDU10 in parallel. The flow rate of the cooling water supplied to each CDU10 is controlled so that the temperature of the cooling water outlet 10o of each CDU10 is equal. With this configuration, fluctuations in the temperature of the cooling water outlet 10o of the CDU10 can be suppressed.

[0051] (Fourth embodiment) Figure 11 shows the part of the cooling system 1c according to the fourth embodiment that corresponds to the configuration within block B shown in Figure 1. In the cooling system 1c shown in Figure 11, there are seven AHUs 13-1 to 13-7. Each cooling water inlet 13i of AHUs 13-1 to 13-7 is connected to the cooling water outlet of the pump 15 via valves 17-51 to 17-57. Each cooling water outlet 13o of AHUs 13-1 to 13-7 is connected to the cooling water inlet 14i of the DC 14. In addition, each cooling water outlet 13o of AHUs 13-1 to 13-7 is provided with temperature sensors 19-11 to 19-17 for measuring the temperature of the cooling water. Valves 17-51 to 17-57 are control valves or adjustment valves that control the flow rate of the cooling water so that the temperature of the cooling water outlet 13o becomes a constant value (24°C in the example of Figure 11) based on the measured values ​​of the temperature sensors 19-11 to 19-17.

[0052] When the load on the air-cooled server, which is the device to be cooled, fluctuates, the load on the AHU13 (air conditioning heat exchanger) also fluctuates. For example, if the cooling water flow rate is not changed when the load decreases, the outlet water temperature of the air conditioning heat exchanger (temperature of outlet 13o) will decrease, reducing the temperature difference with the atmosphere at DC14 and worsening the heat exchange performance. Therefore, in the fourth embodiment, the cooling water flow rate of the AHU13 (air conditioning heat exchanger) is increased or decreased using valves 17-51 to 17-57, etc., in response to load fluctuations, thereby maintaining the outlet cooling water temperature at a target value and also maintaining the temperature difference with the atmosphere at DC14. By monitoring the outlet temperature of the AHU13 (air conditioning heat exchanger) and controlling the cooling water flow rate in this way, deterioration of energy-saving operation during load fluctuations is prevented.

[0053] In the example shown in Figure 11, AHU13-1, 13-5, and 13-7 are under high load, and the openings of the corresponding valves 17-51, 17-55, and 17-57 are controlled to be larger, while AHU13-2 to 13-4 and 13-6 are under low load, and the openings of the corresponding valves 17-52 to 17-54 and 17-56 are controlled to be smaller.

[0054] (Effects and Benefits) As described above, in the fourth embodiment, the cooling system 1c has multiple AHUs 13 (air conditioning exchangers), and cooling water is supplied to each AHU 13 in parallel. The flow rate of the cooling water supplied to each AHU 13 is controlled so that the temperature of the cooling water outlet 13o of each AHU 13 is equal. With this configuration, fluctuations in the temperature of the cooling water outlet 13o of the AHUs 13 can be suppressed.

[0055] Furthermore, the fourth and third embodiments may be used in combination.

[0056] (Fifth embodiment) This embodiment addresses a case where there are multiple CDU10 (liquid-cooled heat exchangers), and the heat resistance temperatures of the chips in the liquid-cooled server that exchange heat with them are multiple different values.

[0057] Figure 12 shows the portion of the cooling system 1d according to the fifth embodiment that corresponds to the configuration within block A shown in Figure 1. In the cooling system 1d shown in Figure 12, there are seven CDUs 10-1 to 10-7. Each cooling water inlet 10i of CDUs 10-1 to 10-7 is connected to the cooling water outlet of the pump 12 via valves 17-61 to 17-67.

[0058] Furthermore, in CDU10-1 to 10-7, CDU10-1 to 10-3 have a low heat resistance temperature for the chips included in the cooling device 36. CDU10-4 and 10-5 have a medium heat resistance temperature, which is higher than the low heat resistance temperature for the chips included in the cooling device 36. CDU10-6 and 10-7 have a high heat resistance temperature, which is higher than the medium heat resistance temperature for the chips included in the cooling device 36.

[0059] DC11 includes DC11-1a to 11-3a arranged in series. When chips with different heat resistance temperatures are mixed in the server room 31, the temperature of the cooling water flowing out of the CDU10 (liquid-cooled heat exchanger) may also be different, and in order to obtain high heat dissipation performance in DC11, it is better to flow cooling water out of the CDU10 at a higher cooling water temperature according to the heat resistance temperature. If cooling water flowing out of the CDU10 (liquid-cooled heat exchanger) at different temperatures is mixed and introduced into DC11, the heat dissipation performance will decrease. Therefore, in the fifth embodiment, DC11-1a to 11-3a are arranged in series, and high-temperature cooling water (44°C in the example in Figure 12) flowing out from the CDU10-6 and 10-7 (liquid-cooled heat exchangers) for high heat resistance chips is introduced into the cooling water inlet 11i of the upstream DC11-1a. The cooling water inlet 11i of the intermediate DC11-2a receives medium-temperature cooling water (35°C in the example in Figure 12) that has flowed out from the upstream DC11-1a, and medium-temperature cooling water (35°C in the example in Figure 12) that has flowed out from the CDU10-4 and 10-5 (liquid-cooled heat exchangers) for medium-temperature chips. The cooling water inlet 11i of the downstream DC11-3a receives low-temperature cooling water (30°C in the example in Figure 12) that has flowed out from the intermediate DC11-2a, and low-temperature cooling water (30°C in the example in Figure 12) that has flowed out from the CDU10-1~10-3 (liquid-cooled heat exchangers) for low-temperature chips.

[0060] (Effects and Benefits) As described above, in the fifth embodiment, the cooling system 1d is equipped with a plurality of DC11-1a to 11-3a (air-cooled heat exchangers) arranged in series to cool the cooling water through heat exchange with air, and there are a plurality of CDU10 (liquid-cooled heat exchangers), with cooling water supplied in parallel to each CDU10-1 to 10-7 (liquid-cooled heat exchanger), and the cooling water outlet 10o of each CDU10 (liquid-cooled heat exchanger) is connected to one of the cooling water inlets 11i of each DC11-1a to 11-3a (air-cooled heat exchanger) according to the heat resistance temperature of the device to be cooled 36. With this configuration, by performing heat exchange in DC11 while maximizing the difference between the cooling water temperature and the ambient temperature, high heat dissipation performance of DC11 can be obtained, resulting in energy savings.

[0061] (Computer configuration) Figure 13 is a schematic block diagram showing the configuration of a computer according to at least one embodiment. The computer 90 includes a processor 91, main memory 92, storage 93, and an interface 94. The control devices 21-1 and 21a-1 described above are implemented in the computer 90. The operation of each of the processing units described above is stored in storage 93 in the form of a program. The processor 91 reads the program from storage 93, loads it into main memory 92, and executes the above processing according to the program. The processor 91 also allocates storage areas in main memory 92 corresponding to each of the storage units described above, according to the program.

[0062] The program may be for implementing some of the functions that the computer 90 is to perform. For example, the program may perform functions in combination with other programs already stored in storage, or in combination with other programs implemented in other devices. In other embodiments, the computer may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to, or instead of, the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), FPGA (Field Programmable Gate Array), etc. In this case, some or all of the functions implemented by the processor may be implemented by the integrated circuit.

[0063] Examples of storage 93 include HDDs (Hard Disk Drives), SSDs (Solid State Drives), magnetic disks, magneto-optical disks, CD-ROMs (Compact Disc Read Only Memory), DVD-ROMs (Digital Versatile Disc Read Only Memory), and semiconductor memory. Storage 93 may be an internal medium directly connected to the bus of the computer 90, or an external medium connected to the computer 90 via an interface 94 or a communication line. Furthermore, if this program is distributed to the computer 90 via a communication line, the computer 90 that receives the program may expand it into main memory 92 and execute the above processing. In at least one embodiment, storage 93 is a tangible storage medium that is not temporary.

[0064] <Note> The cooling system described in each embodiment can be understood, for example, as follows:

[0065] (1) The cooling system 1 or 1a of the first embodiment includes a plurality of heat source units, one or more liquid-cooled heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and a liquid that cools the device to be cooled, one or more air conditioning heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and air that cools the device to be cooled, and a selection unit that includes a plurality of valves and selects the circulation path of the cooling water from a plurality of selectable circulation paths by opening and closing the plurality of valves. According to this embodiment and the following embodiments, an air-cooling method and a liquid-cooling method can be flexibly combined.

[0066] (2) A cooling system 1a in a second embodiment is the cooling system 1 or 1a of (1), wherein the selectable plurality of circulation paths include a plurality of circulation paths in which the number of heat source units supplying the cooling water to the liquid-cooled heat exchanger and the number of heat source units supplying the cooling water to the air conditioning heat exchanger differ among the circulation paths.

[0067] (3) A third embodiment of the cooling system 1 or 1a is the cooling system 1a of (1) or (2), wherein the selectable plurality of circulation paths include the circulation path that supplies the cooling water supplied from the heat source to the liquid-cooled heat exchanger and which has absorbed heat in the liquid-cooled heat exchanger to the air conditioning heat exchanger.

[0068] (4) A cooling system 1 or 1a of a fourth embodiment is a cooling system 1 or 1a of (1) to (3), wherein the heat source includes a heat source having a compressor and a heat source without a compressor, and the selectable plurality of circulation paths include the circulation path that passes through the heat source without a compressor but not through the heat source having a compressor.

[0069] (5) The cooling system 1 or 1a of the fifth embodiment is the cooling system 1 or 1a of (1) to (4), wherein the heat source unit has a compressor, and the selection unit selects the circulation path such that the number of heat source units having compressors through which the cooling water circulates changes according to the efficiency of the compressor.

[0070] (6) The cooling system 1 or 1a of the sixth embodiment is the cooling system 1 or 1a of (1) to (5), wherein the liquid-cooled heat exchangers are a plurality, the cooling water is supplied in parallel to each of the liquid-cooled heat exchangers, and the flow rate of the cooling water supplied to each of the liquid-cooled heat exchangers is controlled so that the temperature of the outlet of the cooling water of each of the liquid-cooled heat exchangers is equal.

[0071] (7) The cooling system 1 or 1a of the seventh embodiment is the cooling system 1 or 1a of (1) to (6), wherein the air conditioning heat exchangers are a plurality, the cooling water is supplied in parallel to each of the air conditioning heat exchangers, and the flow rate of the cooling water supplied to each of the air conditioning heat exchangers is controlled so that the temperature of the outlet of the cooling water at each of the air conditioning heat exchangers is equal.

[0072] (8) The cooling system 1 or 1a of the eighth embodiment is the cooling system 1 or 1a of (1) to (7), comprising a plurality of air-cooled heat exchangers that cool the cooling water by heat exchange with air arranged in series, wherein there are a plurality of liquid-cooled heat exchangers, the cooling water is supplied in parallel to each of the liquid-cooled heat exchangers, and the outlet of the cooling water of each of the liquid-cooled heat exchangers is connected to one of the inlets of the cooling water of each of the air-cooled heat exchangers, according to the heat resistance temperature of the device to be cooled.

[0073] (9) A cooling system 1 or 1a of the ninth embodiment is a cooling system 1 or 1a of (1) to (8), wherein the plurality of heat sources include a first heat source, a second heat source and a third heat source, and the plurality of valves include at least a first valve for opening and closing the cooling water inlet of the first heat source and the cooling water inlet of the second heat source, a second valve for opening and closing the cooling water inlet of the second heat source and the cooling water inlet of the third heat source, a third valve for opening and closing the cooling water outlet of the first heat source and the cooling water outlet of the second heat source, and a fourth valve for opening and closing the cooling water outlet of the second heat source and the cooling water outlet of the third heat source. [Explanation of Symbols]

[0074] 1, 1a... Cooling system 10, 10-1~10-7…CDU 11, 11-1~11-3, 14, 14-1~14-3...DC 12, 15... pump 13, 13-1~13-7…AHU 16, 16-1~16-7… Chiller 17, 17-1~17-16, 17-21~17-31… valve 18, 18a... Piping 21, 21a...Selection section 21-1, 21a-1…Control devices 50, 50-1~50-7…Circulatory pathways

Claims

1. Multiple heat source units, One or more liquid-cooled heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and a liquid that cools the device to be cooled, One or more air conditioning heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and air that cools the device to be cooled, A selection unit that includes multiple valves and selects the circulation path of the cooling water from among a plurality of selectable circulation paths by opening and closing the multiple valves, A cooling system equipped with [the following features].

2. The aforementioned selectable multiple circulation paths include multiple circulation paths in which the number of heat source units supplying the cooling water to the liquid-cooled heat exchanger and the number of heat source units supplying the cooling water to the air conditioning heat exchanger differ among the circulation paths. The cooling system according to claim 1.

3. The selectable multiple circulation paths include a circulation path that supplies the cooling water, which is supplied from the heat source to the liquid-cooled heat exchanger and has absorbed heat in the liquid-cooled heat exchanger, to the air conditioning heat exchanger. The cooling system according to claim 1.

4. The heat source includes a heat source having a compressor and a heat source without a compressor. The selectable multiple circulation paths include the circulation path that passes through a heat source without a compressor and the circulation path that passes through a heat source without a compressor. The cooling system according to claim 1.

5. The heat source includes one having a compressor. The selection unit selects the circulation path such that the number of heat source units having the compressors through which the cooling water circulates changes according to the efficiency of the compressors. The cooling system according to claim 2.

6. The liquid-cooled heat exchangers are a plurality of units, and the cooling water is supplied in parallel to each of the liquid-cooled heat exchangers, and the flow rate of the cooling water supplied to each of the liquid-cooled heat exchangers is controlled so that the temperature of the cooling water outlet of each liquid-cooled heat exchanger is equal. The cooling system according to claim 1.

7. The aforementioned air conditioning heat exchangers are a plurality of units, and the cooling water is supplied to each of the air conditioning heat exchangers in parallel, and the flow rate of the cooling water supplied to each of the air conditioning heat exchangers is controlled so that the temperature of the cooling water outlets of each air conditioning heat exchanger is equal. The cooling system according to claim 1.

8. It comprises a plurality of air-cooled heat exchangers arranged in series to cool the cooling water through heat exchange with air, The liquid-cooled heat exchangers are a plurality of units, and the cooling water is supplied in parallel to each of the liquid-cooled heat exchangers. The outlet of the cooling water of each liquid-cooled heat exchanger is connected to either the inlet of the cooling water of each air-cooled heat exchanger, depending on the heat resistance temperature of the device being cooled. The cooling system according to claim 1.

9. The aforementioned plurality of heat source units include a first heat source unit, a second heat source unit, and a third heat source unit. The aforementioned plurality of valves A first valve that opens and closes the connection between the cooling water inlet of the first heat source and the cooling water inlet of the second heat source, A second valve that opens and closes the connection between the cooling water inlet of the second heat source and the cooling water inlet of the third heat source, A third valve that opens and closes the outlet of the cooling water from the first heat source and the outlet of the cooling water from the second heat source, A fourth valve that opens and closes the outlet of the cooling water from the second heat source and the outlet of the cooling water from the third heat source, Includes at least A cooling system according to any one of claims 1 to 8.

10. Multiple heat source units, One or more liquid-cooled heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and a liquid that cools the device to be cooled, One or more air conditioning heat exchangers that perform heat exchange between cooling water supplied from at least one of the plurality of heat source units and air that cools the device to be cooled, Using By opening and closing multiple valves, the circulation path of the cooling water is selected from among a selection of multiple circulation paths. Cooling method.

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