JP2011247506A - Cooling system for data center - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling system for a data center in which a load and a running cost of a chiller unit for cooling a cooling medium are reduced, and the temperature of the cooling medium is raised by drawing heat from electronic equipment.SOLUTION: The cooling system for a data center includes: a heat exchanger 6 which transfer heat generated from electronic equipment 4 to the cooling medium to draw the heat therefrom; an ice thermal storage device 10 which freezes the cooling medium by radiating the heat of the cooling medium to the atmosphere by means of a heat pipe 15 to store cold energy; and a mixing tank 9 for mixing the cooling medium the temperature of which is made high by drawing the heat of the electronic equipment 4 by the heat exchanger 6 and the cooling medium which is cooled by the ice thermal storage device 10 or a cooler 11 where at least a part of the cooling medium mixed by the mixing tank 9 is supplied to the ice thermal storage device 10 and at least the other part is supplied to the heat exchanger 6 or the cooler 11.

Description

  The present invention relates to a data center cooling system including a plurality of electric devices that generate heat during data processing.

  As a data center cooling system, it has been studied to cool a plurality of electronic devices that generate heat during data processing with a cooling medium such as water cooled by a chiller unit. In this type of cooling system, data processing by electronic equipment is performed without interruption, so it is necessary to always operate a chiller unit that cools the cooling medium. Therefore, as the heat generation amount of the electronic equipment increases, The cooling load increases and the running cost increases. Therefore, it is desired to reduce the size of the device for cooling the data center and reduce the running cost.

  In Patent Document 1, cold energy is stored in an ice heat storage tank in the form of ice by operating a refrigerator using nighttime power, which is cheaper than in the daytime, and ice is stored in the ice heat storage tank. An invention is described in which cold energy stored in the form is taken out in the form of cold water and the cold water is circulated inside the cold water showcase. In addition, a coil portion is provided outside the cold water showcase so that the refrigerant of the refrigerator can circulate, and an invention is described in which the cold water showcase functions as an evaporation portion of the refrigerator.

  Patent Document 2 discloses a heat exchanger that performs heat exchange between a cooling device and a chiller unit, and an ice heat storage device that stores cold in the form of ice by a chiller unit, takes out the cold storage heat using cold water, and supplies the cooling device to the cooling device. Are connected in parallel, and when the cooling device is cooled by operating the chiller unit, when the cooling device is cooled using cold storage heat, the cooling device is cooled using both the chiller unit and the cold storage heat. An invention configured to perform a multipurpose cooling operation such as a case is described. Further, it is described in the ice heat storage tank that the chiller unit is operated by using nighttime electric power and thereby ice heat is stored.

JP 2002-372354 A JP-A-11-223449

  As described in Patent Document 1 and Patent Document 2, if the chiller unit is operated at night when the electricity rate is cheap compared to the daytime to store ice heat and the ice is used as a cold source during the daytime, Minutes and daytime chiller unit loads and running costs can be reduced. However, the devices described in Patent Document 1 and Patent Document 2 select the electric power to be used, operate the chiller unit to store ice, and use the cold energy in the daytime to reduce the load on the chiller unit in the daytime. However, there is still room for improvement.

  The present invention has been made paying attention to the above technical problem, and can reduce the load and running cost of a chiller unit that cools a cooling medium whose temperature has been increased by taking heat from an electronic device. The object is to provide a cooling system for the center.

  In order to achieve the above object, the invention of claim 1 uses a cooling medium whose temperature is lowered by a cooler to take out heat generated from a plurality of electronic devices that perform data processing and release it to the outside. In the cooling system of the data center for cooling the electronic device, the heat exchanger for transferring the heat generated from the electronic device to the cooling medium and taking it away, and the heat transport direction in one direction of the heat of the cooling medium An ice heat storage device that cools and cools the cooling medium by radiating heat to the atmosphere with a heat pipe, and the cooling medium whose temperature is increased by removing heat from the electronic device with the heat exchanger And a mixing tank that mixes the cooling medium whose temperature has been lowered by the ice heat storage device or the cooler, and at least the cooling medium mixed in the mixing tank Some fed toward the ice thermal storage device, and is characterized in that it is configured to at least another part to supply toward the heat exchanger or the cooler.

  According to a second aspect of the present invention, in the first aspect of the invention, the mixing tank includes a plurality of mixing tanks for mixing the cooling medium having the increased temperature and the cooling medium having the decreased temperature in series. A communication hole that is disposed and communicates with the mixing tanks adjacent to each other, and the cooling medium is circulated between the mixing tanks, and the temperature of the electronic device is increased by removing heat from the electronic device in any one of the mixing tanks. The cooling medium is introduced, and the cooling medium whose temperature is lowered by the ice heat storage device or the cooler is introduced into one of the other storage tanks. This is a data center cooling system.

  According to a third aspect of the present invention, in the first aspect of the present invention, a first circulation pipe for circulating the cooling medium between the heat exchanger and the mixing tank is formed. On the way, a first switching means that is switched to supply the cooling medium from any of the plurality of mixing tanks to the heat exchanger according to the temperature of the cooling medium in the plurality of mixing tanks. And a first pump for flowing the cooling medium closer to the electronic device than the first switching means is interposed, and the cooling medium is circulated between the cooler and the mixing tank. A second circulation line is formed, and in the middle of the second circulation line, from one of the plurality of mixing tanks to the cooler according to the temperature of the cooling medium in the plurality of mixing tanks Switching operation is performed to supply the cooling medium. Second switching means is provided, and a second pump for causing the cooling medium to flow closer to the cooler than the second switching means is interposed, and the temperature of the electronic device is deprived of heat. A third circulation line for circulating the cooling medium is formed between the mixing tank of the mixing tank into which the raised cooling medium flows and the ice heat storage device, and the third circulation line in the third circulation line A cooling system for a data center, wherein a third pump for flowing the cooling medium is interposed on the inlet side of the ice heat storage device.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the ice heat storage device includes a storage tank that temporarily stores the cooling medium, and the heat pipe has an evaporating portion that is cooled in the storage tank. A cooling system for a data center, wherein the cooling system is arranged so as to be immersed in a working medium and the condensing part is exposed to the atmosphere.

  According to a fifth aspect of the present invention, in the first or fourth aspect of the present invention, the heat pipe encloses a working fluid that circulates and flows with evaporation and condensation inside an airtight container, and the liquid phase is operated by gravity. The data center cooling system includes a thermosyphon that recirculates a fluid to a lower end portion that is the evaporation portion of the sealed container.

  According to the invention of claim 1, the ice heat storage device is configured to cool the heat of the cooling medium by radiating the heat in the air by the heat pipe whose heat transport direction is controlled in one direction, and to freeze the ice by freezing. Has been. The cold heat stored in the form of ice in the ice heat storage device is taken out by a liquid-phase cooling medium that circulates and flows between the ice heat storage device and the heat exchanger. The circulating cooling liquid medium is cooled by ice. The cooling medium cooled by the ice heat storage device or the cooler and the cooling medium whose temperature has risen due to the removal of heat from the electronic device are mixed in the mixing tank. At least a part of the cooling medium mixed in the mixing tank is supplied to the ice heat storage device to be cooled, and new cold energy is taken out from the ice heat storage device. A part of the cooling medium mixed in the mixing tank is supplied to the heat exchanger to cool the electronic device. At least another part of the cooling medium mixed in the mixing tank is supplied to the cooler and cooled by the cooler. The cooling medium supplied to the electronic device is lower in temperature than the cooling medium whose temperature is higher than the temperature of the cooling medium cooled by the ice heat storage device or the cooler and whose temperature is increased by taking heat from the electronic device. Is done. Since the cooling medium whose temperature is adjusted in the mixing tank is supplied to the electronic device, it is possible to prevent or suppress overcooling or insufficient cooling of the electronic device. The cooling medium whose temperature has risen due to the removal of heat from the electronic equipment is supplied to the ice storage device after the temperature is lowered in the mixing tank as described above, preventing excessive cooling from being taken out from the ice storage device. Or it can be suppressed. Since the cooling medium whose temperature is lowered compared to the cooling medium that has taken heat from the electronic device is supplied to the cooler, the load on the cooler can be reduced. When the temperature of the cooling medium mixed in the mixing tank is equal to or lower than the predetermined temperature, it is not necessary to cool the mixed cooling medium by supplying it to the cooler. Electronic equipment can be cooled without operating a cooler. The ice heat storage device described above is configured to dissipate the heat of the cooling medium into the atmosphere by a heat pipe having a heat diode characteristic in which the heat transport direction is controlled in one direction to cool and freeze. Thus, no mechanical device or power for cooling the cooling medium is required. The ice heat storage device can have a simpler configuration than a cooler or the like, and can be a device that does not require or reduces maintenance and running costs.

  According to the invention of claim 2, in addition to the same effect as that of the invention of claim 1, the mixing tank has a plurality of mixing tanks arranged in series, and the cooling medium is circulated between the mixing tanks adjacent to each other. A communication hole is formed. Cooling medium that has been heated to a high temperature by taking the heat of the electronic equipment into any one of the mixing tanks, and cooled by an ice heat storage device or a cooler into any one of the other mixing tanks Is supposed to flow in. Since the plurality of mixing tanks in the mixing tank are communicated by the communication holes, the high-temperature cooling medium and the low-temperature cooling medium can flow between the plurality of mixing tanks. As a result, the high-temperature cooling medium and the low-temperature cooling medium can be mixed stepwise. The cooling medium whose temperature is relaxed or adjusted in the mixing tank can be supplied from any mixing tank to the heat exchanger or the cooler according to the temperature of the cooling medium.

  According to invention of Claim 3, in addition to the effect similar to the effect by invention of Claim 1, a 1st circulation line is formed between a heat exchanger and a mixing tank, and a cooler, a mixing tank, A second circulation line is formed between the two. The first switching means provided in the first circulation pipeline is switched according to the temperature of the cooling medium in each mixing tank, and the second switching means provided in the second circulation pipeline is each mixed. Switching operation is performed according to the temperature of the cooling medium in the tank, and the cooling medium is supplied to the cooler from any of the plurality of mixing tanks in the mixing tank. Compared to the temperature of the cooling medium cooled by the ice heat storage device or the cooler, the temperature of the cooling medium is higher than the temperature of the cooling medium that has been deprived of heat from the electronic equipment and increased in temperature. Since it can be supplied to an electronic device, it is possible to prevent or suppress overcooling and insufficient cooling of the electronic device. Compared with the cooling medium supplied from the heat exchanger to the mixing tank, a cooling medium having a lower temperature can be supplied to the cooler, so that the cooling load of the cooler can be reduced. A pump for causing the cooling medium to flow is provided closer to the electronic device than the first switching means in the first circulation line. A pump for causing the cooling medium to flow is provided closer to the cooler than the second switching means in the second circulation line. The first switching means or the second switching means is switched, and the cooling medium is caused to flow through the circulation line even if any one of the plurality of mixing tanks of the mixing tank is used as a cooling medium supply source, and a heat exchanger or Can be supplied to the cooler. A third circulation line is formed between the ice heat storage device and the mixing tank, and a pump for flowing the cooling medium is provided on the ice heat storage device side in the third circulation line. The cooled cooling medium can be supplied to the ice heat storage device.

  According to the invention of claim 4, in addition to the same effect as that of the invention of claim 1, the ice heat storage device includes a storage tank for temporarily storing the cooling medium, and the heat pipe is stored in the storage tank. The evaporating part is immersed in the cooling medium, and the condensing part is disposed outside the storage tank and exposed to the upper atmosphere. The heat of the cooling medium is transported by a heat pipe, and the temperature is lowered by being radiated into the atmosphere. As a result, the ice heat storage device does not require mechanical devices such as a condenser for cooling the cooling medium such as a cooler or a power source for operating the cooler, and electric power. Therefore, a simple configuration can be achieved, and maintenance can be unnecessary or reduced.

  According to the invention of claim 5, in addition to the effect similar to the effect of the invention of claim 1 or 4, the heat pipe includes a thermosiphon that recirculates the condensed working fluid to the evaporation part by gravity. The thermosyphon transports the heat of the cooling medium from the evaporating part to the condensing part due to the thermal diode characteristic in which the heat transport direction is limited to one direction, so the part that heats the working fluid enclosed in the sealed container When the vaporized working fluid is condensed, the heat flow is not generated, and the operation is not performed in the top heat mode. As a result, in the thermosyphon, the evaporation part at the lower end is immersed in the cooling medium and the condensation part is exposed to the atmosphere outside the storage tank, so that the heat transport direction can be limited or restricted to one direction. . The thermosyphon does not take in the heat of the outside air or raise the temperature of the cooling medium inside the storage tank. The temperature rise of the cooling medium due to the backflow of heat can be prevented or suppressed. When the temperature of the outside air falls below a predetermined temperature, the thermosyphon can dissipate the heat of the cooling medium into the atmosphere to cool the cooling medium and freeze it. By installing an ice heat storage device equipped with a thermosyphon and using cold storage heat for cooling electronic devices, the load on the cooler can be reduced compared to before installing such a device, and the running cost of the cooler is reduced. it can.

It is a figure which shows typically an example of the cooling system of the data center which concerns on this invention.

  The present invention will be specifically described with reference to the drawings. FIG. 1 schematically shows an example of a data center cooling system according to the present invention. The data center 1 includes a predetermined building 2 and at least a plurality of server racks 3 are provided in the room. Each server rack 3 accommodates a plurality of servers. The building 2 is for housing the server rack 3, and may be an appropriate one such as a construction building or a shipping container. Each server has a plurality of electronic devices 4 that generate heat during data processing on its board. Examples of the electronic device 4 that generates heat include a CPU (Central Processing Unit), a storage device such as a memory and a storage, and a power supply unit. In the example shown in FIG. 1, each electronic device 4 is in contact with a cold plate 5 that directly cools them by heat exchange so that heat can be transferred.

  The cold plate 5 is formed in a hollow plate shape, and a cooling medium flows through the hollow interior. Since the cold plate 5 needs to transfer heat between the inside and the outside, the cold plate 5 is preferably made of a material having high thermal conductivity, and is preferably made of copper or a copper alloy. The cooling medium is a fluid that transports heat, and is mainly composed of water or an aqueous solution in which an arbitrary rust inhibitor is dissolved in water, ethylene glycol or calcium chloride, and the freezing point is 0 ° C. or lower. Brine adjusted to 1 (sometimes referred to as antifreeze) or alternative CFCs such as R-134a can be used. The cold plate 5 cools the electronic device 4 by depriving the heat generated by the electronic device 4 that is in contact with the heat transfer by transferring it to a cooling medium that flows through the hollow interior.

  Between the cold plate 5 and the heat exchanger 6, a circulation pipe for circulating the cooling medium described above is formed. The heat exchanger 6 exchanges heat between a high-temperature fluid and a low-temperature fluid, and an appropriate heat exchanger such as a plate heat exchanger can be used. The cooling medium whose temperature has risen due to heat removal from the electronic device 4 by exchanging heat in the cold plate 5 is caused to flow through the above-described circulation line from the cold plate 5 toward the heat exchanger 6, and the heat exchanger 6 is cooled by exchanging heat with a low-temperature cooling medium. The cooling medium cooled in the heat exchanger 6 is caused to flow through the above-described circulation conduit from the heat exchanger 6 toward the cold plate 5 to cool the electronic device 4.

  An expansion tank 7 is provided in the middle of the above-described circulation line from the cold plate 5 to the heat exchanger 6. The expansion tank 7 is for temporarily storing a cooling medium whose volume is expanded by taking heat generated in the electronic device 4 and absorbing or buffering a volume change accompanying a temperature change of the cooling medium. . Although details are not shown, it is preferable that the expansion tank 7 is connected to the above-described circulation line via an optional relief valve. A pump 8 is interposed closer to the heat exchanger 6 than the expansion tank 7 in the circulation line. The pump 8 is for circulating and flowing the cooling medium in the above-described circulation pipeline, and a commonly used pump can be used.

  The cooling medium whose temperature has been increased by heat exchange in the heat exchanger 6 is supplied to the mixing tank 9 according to the present invention. The mixing tank 9 is supplied with a cooling medium cooled by the ice heat storage device 10 and the chiller unit (cooler) 11 according to the present invention. The mixing tank 9 is configured to mix the cooling medium whose temperature has increased in the heat exchanger 6 and the cooling medium cooled by the ice heat storage device 10 or the chiller unit 11. The high temperature cooling medium and the low temperature cooling medium are mixed to buffer the temperature of the cooling medium.

  A part of the cooling medium mixed in the mixing tank 9 is supplied to the ice heat storage device 10, and a circulation pipe for circulating the cooling medium between the mixing tank 9 and the ice heat storage device 10. A road is formed. The other part of the cooling medium mixed in the mixing tank 9 is supplied to the heat exchanger 6 and the chiller unit 11, and a circulation pipe for circulating the cooling medium is formed.

  The mixing tank 9 will be specifically described. In the example shown in FIG. 1, the mixing tank 9 includes six mixing tanks 9a, 9b, 9c, 9d, 9e, and 9f that store the cooling medium in a flowable state. ing. A communication hole 12 is formed between adjacent mixing tanks. In each communication hole 12, adjacent communication holes 12 are opposed to each other in the vertical direction. The mixing tanks 9 a, 9 b, 9 c, 9 d, 9 e, 9 f are connected in series via the communication holes 12. A high temperature cooling medium from the heat exchanger 6 is supplied to the mixing tank 9a, and a cooling medium cooled by the ice heat storage device 10 or the chiller unit 11 is supplied to the mixing tank 9f.

  The flow of the cooling medium in the mixing tank 9 will be specifically described. The cooling medium heated to a high temperature in the heat exchanger 6 is supplied to the mixing tank 9a of the mixing tank 9, and mixed with the low-temperature cooling medium flowing in the mixing tanks 9b, 9c, 9d, 9e, and 9f in the mixing tank 9a. And the temperature is lowered. When a high-temperature cooling medium and a low-temperature cooling medium are mixed, convection occurs in the mixing tank 9a due to a temperature difference between the mixed cooling media. The high temperature cooling medium flows downward in the mixing tank 9a when the temperature is lowered, and the low temperature cooling medium increases in temperature and flows upward in the mixing tank 9a. . The high-temperature cooling medium flows into the mixing tank 9b that stores the relatively low-temperature cooling medium through the communication hole 12 formed on the lower side in the mixing tank 9a. Through this communication hole 12, the low-temperature cooling medium in the mixing tank 9b flows into the mixing tank 9a. The high-temperature cooling medium supplied to the mixing tank 9a flows from the mixing tank 9a toward the mixing tank 9f through the communication hole 12, and the temperature is gradually lowered.

  On the contrary, the low-temperature cooling medium supplied to the mixing tank 9f is mixed with the high-temperature cooling medium flowing from the mixing tanks 9a, 9b, 9c, 9d, 9e in the mixing tank 9f. The temperature is raised. The low-temperature cooling medium flows downward in the mixing tank 9f, and the high-temperature cooling medium flows upward in the mixing tank 9f. The cooling medium in the mixing tank 9f convects the mixing tank 9f, and the low-temperature cooling medium flows through the communication hole 12 to the mixing tank 9e that stores the high-temperature cooling medium. The low-temperature cooling medium supplied to the mixing tank 9f flows from the mixing tank 9f toward the mixing tank 9a through the communication hole 12, and the temperature is gradually raised. The temperature of the cooling medium stored in the mixing tank 9 is different for each mixing tank 9a, 9b, 9c, 9d, 9e, 9f, and for cooling in each mixing tank 9a, 9b, 9c, 9d, 9e, 9f. The medium flows between the mixing tanks depending on the temperature.

  A part of the cooling medium supplied to the mixing tank 9a of the mixing tank 9 and having its temperature lowered is caused to flow through the circulation line formed between the mixing tank 9 and the ice heat storage device 10 described above, The ice heat storage device 10 is supplied. A pump 13 for feeding a cooling medium is interposed in the middle of the circulation line from the mixing tank 9 to the ice heat storage device 10. The ice heat storage device 10 is configured to store the cold energy by cooling or freezing the cooling medium with the cold air of the outside air by radiating the heat of the cooling medium supplied from the mixing tank 9 in the air. The ice heat storage device 10 takes out the cold heat stored in the form of ice by the cooling medium supplied from the mixing tank 9 and cools the cooling medium supplied from the mixing tank 9 by the ice. It is configured. The ice heat storage device 10 freezes the cooling medium to store the cold air of the outside air in the form of ice and needs to cool the cooling medium supplied from the mixing tank 9 by the cold heat. Therefore, the data center 1 and the ice heat storage device No. 10 is preferably provided in a cold region where the accumulated coldness is 400 ° C. · day or more.

  The ice heat storage device 10 will be described more specifically. The ice heat storage device 10 includes a storage tank 14 that temporarily stores the cooling medium supplied from the mixing tank 9a described above, and a cooling that is stored in the storage tank 14. And a heat pipe 15 for cooling and freezing by radiating the heat of the working medium to the atmosphere. Since the storage tank 14 is a hollow container and temporarily stores therein the cooling medium whose temperature has been lowered in the mixing tank 9, it prevents water from entering or penetrating into the tank from the outside. In addition, it is preferable that a waterproof measure is taken to prevent leakage of the cooling medium. The storage tank 14 freezes a cooling medium inside to store cold heat, functions as a cold heat source, and supplies a low-temperature cooling medium to the mixing tank 9. Therefore, it is preferable to be made of a material with low heat insulation or low thermal conductivity. Examples of the material mentioned above include concrete. The storage tank 14 may be provided in the ground from the viewpoint of heat insulation. When the storage tank 14 is provided in the ground, the heat insulation effect can be improved compared with the case where it is provided on the ground surface.

  Since the heat pipe 15 is for radiating and cooling the heat of the cooling medium temporarily stored in the storage tank 14 to the atmosphere as described above, and freezing, in the example shown in FIG. One end 15 a of the heat pipe 15 is immersed in a cooling medium temporarily stored in the storage tank 14. The other end 15b of the heat pipe 15 is arranged outside the storage tank 14 and exposed to the atmosphere. One end portion 15a of the heat pipe 15 is an evaporation portion 15a that heats and vaporizes the working fluid enclosed therein, and the other end portion 15b dissipates the latent heat of the vaporized working fluid. The condensing part 15b is condensed by this. A plurality of fins 15 c for heat dissipation are provided in the condensing part 15 b of the heat pipe 15. In the example shown in FIG. 1, the longitudinal direction of the heat pipe 15 is provided so as to be parallel to the direction of gravity, and the heat pipe 15 is perpendicular to the horizontal plane of the cooling medium stored in the storage tank 14. Or it is provided substantially vertically.

  It is preferable to use a heat pipe 15 having a heat diode characteristic in which the heat transport direction is limited or restricted to one direction. As an example, it is preferable to use a thermosyphon (sometimes called a thermosiphon heat pipe) 15. The thermosyphon 15 is configured, for example, by enclosing a working fluid in a state where a non-condensable gas such as air is deaerated in a predetermined hollow container (sometimes referred to as a container) that is airtight. . The container is, for example, a hollow tube, and it is necessary to transfer heat between the inside and the outside. Therefore, the hollow tube is preferably made of a material having high thermal conductivity, and a copper tube is used. It is preferable to do. A working fluid is a fluid that transports heat in the form of latent heat by being heated and evaporated, and radiating and condensing. The thermosiphon 15 is configured such that the working fluid condensed in the condensing unit 15b is refluxed to the evaporation unit 15a by gravity and is not operated in the top heat mode.

  In the case of using a wick for returning the working fluid condensed by the capillary action to the evaporating unit 15a for the thermosyphon 15, a wick having a length corresponding to the length or depth at which the thermosyphon 15 is immersed in the cooling medium. Is disposed at the lower end of the thermosiphon 15 in the example shown in FIG. By limiting the arrangement of the wicks, the evaporation portion 15a can be formed over the entire portion where the wicks are arranged, and thermal diode characteristics can be imparted even to the thermosyphon 15 provided with the wicks.

  In the present invention, the thermosiphon 15 is preferably operated when the outside air temperature is equal to or lower than a predetermined temperature. For example, the thermosiphon 15 is preferably configured to operate when the outside air temperature is 10 ° C. or lower. Specifically, it is preferable to use ammonia having a boiling point of 10 ° C. or less or alternative chlorofluorocarbon such as R-134a for the working fluid enclosed in the thermosiphon 15. The amount of the working fluid enclosed in the thermosyphon 15 is preferably about 20 to 30 vol% of the internal volume. When the thermosiphon 15 is configured as described above, when the outside air temperature becomes 10 ° C. or less, the working fluid vaporized by the heat of the cooling medium in the evaporation unit 15a is condensed at a relatively low temperature and low pressure. It moves to the part 15b, dissipates the heat in the air, condenses by releasing the heat, and the liquid-phase working fluid is returned to the evaporation part 15a by gravity. As a result, when the outside air temperature becomes lower than the predetermined temperature (10 ° C.), the ice heat storage device 10 can cool the cooling medium with the cold air and can freeze. When the outside air temperature becomes higher than the predetermined temperature, the thermosyphon 15 does not operate in the top heat mode as described above, so that the thermosiphon 15 takes in the heat of the outside air and the temperature of the cooling medium inside the storage tank 14 Will not raise. The cooling medium supplied to the ice heat storage device 10 and taking out the cold heat of the ice stored therein and cooled by the ice flows through the circulation pipe described above and is supplied to the mixing tank 9f. .

  In the example shown in FIG. 1, it is configured so that a low-temperature cooling medium can be supplied from the mixing tank 9 a or the mixing tank 9 f of the mixing tank 9 toward the heat exchanger 6. Is intervening. By switching the switching valve 16, the cooling medium can be supplied to the heat exchanger 6 from either the mixing tank 9 a or the mixing tank 9 f of the mixing tank 9. A pump 17 for feeding the cooling medium to the heat exchanger 6 side of the switching valve 16 in the pipe line is interposed. The switching valve 16 switches the mixing tank that supplies the low-temperature cooling medium to the heat exchanger 6, and detects the temperature of the cooling medium stored in each of the mixing tanks 9a and 9f. It is designed to operate depending on the temperature. For example, when the temperature of the cooling medium stored in the mixing tank 9a is higher than a predetermined temperature, the switching valve 16 is operated so that the cooling medium can be supplied from the mixing tank 9f to the heat exchanger 6. For example, when the temperature of the cooling medium stored in the mixing tank 9a is lower than a predetermined temperature, the switching valve 16 is operated so that the cooling medium can be supplied from the mixing tank 9a to the heat exchanger 6.

  Although not shown in detail, the switching valve 16 is electrically controlled to switch the supply source of the cooling medium, and is an electromagnetically controlled type configured to switch the flow path by applying a voltage. A three-way valve or the like can be used. The switching valve 16 only needs to be configured to switch the flow path through which the cooling medium flows. Instead of the electromagnetic valve, the switching valve 16 is configured to switch the flow path by a power source such as a motor. Also good. The switching valve 16 corresponds to the first switching means. The pump 17 sends the cooling medium stored in the mixing tank 9 a or the mixing tank 9 f of the mixing tank 9 to the heat exchanger 6, and mixes the cooling medium whose temperature is increased by heat exchange in the heat exchanger 6. 9 is used for feeding liquid to the mixing tank 9a, and a commonly used pump can be used.

  Between the mixing tank 9a and the mixing tank 9f of the mixing tank 9 and the chiller unit 11, a circulation pipe is formed as described above, and one of the cooling media stored in the mixing tank 9a or the mixing tank 9f is formed. The cooling medium cooled by the chiller unit 11 can be supplied to the mixing tank 9 f of the mixing tank 9. A switching valve 18 is interposed in the middle of the circulation line for supplying the cooling medium from the mixing tank 9 to the chiller unit 11. By switching the switching valve 18, the mixing tank for supplying the cooling medium to the chiller unit 11 can be switched to either the mixing tank 9a or the mixing tank 9f. The switching valve 18 switches the mixing tank that supplies the cooling medium to the chiller unit 11, detects the temperature of the cooling medium stored in each of the mixing tanks 9a and 9f, and depends on the detected temperature. Thus, the mixing tanks 9a and 9f can be switched appropriately. As the switching valve 18, an electromagnetically controlled three-way valve configured to switch the flow path by applying a voltage can be used. The switching valve 18 corresponds to second switching means. When the temperature of the cooling medium stored in the mixing tank 9f is higher than a predetermined temperature, the switching valve 18 is operated so that the cooling medium can be supplied from the mixing tank 9f to the chiller unit 11 and cooled. When the temperature of the cooling medium stored in the mixing tank 9f is lower than a predetermined temperature, the switching valve 18 is operated so that the cooling medium can be supplied from the mixing tank 9a to the chiller unit 11 and cooled.

  A pump 19 for feeding the cooling medium to the chiller unit 11 side of the switching valve 18 in the above-described pipeline is interposed. The pump 19 sends the cooling medium stored in the mixing tank 9 a or the mixing tank 9 f of the mixing tank 9 to the chiller unit 11, and the cooling medium cooled by the chiller unit 11 is sent to the mixing tank 9 f of the mixing tank 9. A pump that is used for liquid feeding and that is generally used can be used.

  The chiller unit 11 is a cooler that cools a cooling medium that transports heat, and a commonly used chiller unit 11 can be used. For example, a turbo chiller or a screw chiller using an alternative chlorofluorocarbon as a refrigerant, an absorption chiller using water as a refrigerant, or the like can be used. In the example shown in FIG. 1, the chiller unit 11 is supplied with a high-temperature cooling medium from the heat exchanger 6 and is supplied from the mixing tank 9 whose temperature has been increased by mixing with the high-temperature cooling medium. The medium is configured to be cooled.

  In the example shown in FIG. 1, the waste heat generated by cooling the above-described cooling medium in the chiller unit 11 is configured to be radiated from the cooling tower 20 to the atmosphere. Between the chiller unit 11 and the cooling tower 20, a circulation pipe for circulating cooling water is formed. A pump 21 for circulating and flowing the cooling water is interposed in the middle of the pipeline. The waste heat of the chiller unit 11 is radiated to the cooling water, and the cooling water is supplied to the cooling tower 20 by flowing through the above-described pipeline. The heat transported by the cooling water is radiated to the atmosphere by the fan 22 or the like in the cooling tower 20.

  In the configuration described above, the cooling medium whose temperature has risen due to the heat from the electronic device 4 and the cooling medium stored in the form of ice in the ice heat storage device 10 are taken out and cooled by the cooling medium or the chiller unit 11 which has been cooled to a low temperature. The mixed cooling medium is mixed in the mixing tank 9. The cooling medium deprived of heat of the electronic device 4 and brought to a high temperature is supplied to the ice heat storage device 10 after being cooled to a low temperature in the mixing tank 9 and also supplied to the chiller unit 11. As a result, it is possible to prevent or suppress excessive extraction of the cold heat stored in the ice heat storage device 10 in the form of ice. Since the low-temperature cooling medium is supplied to the chiller unit 11, the load on the chiller unit 11 can be reduced. Since the temperature of the cooling medium cooled by the ice heat storage device 10 and the chiller unit 11 is raised in the mixing tank and then supplied to the heat exchanger 6 to cool the electronic device 4, the electronic device 4 is prevented from being overcooled or Can be suppressed.

  By providing the mixing tank 9 for mixing the high temperature cooling medium and the low temperature cooling medium, the temperature of the cooling medium supplied to the heat exchanger 6 for cooling the electronic device 4 and the ice storage device 10 are supplied. The temperature of the cooling medium to be supplied and the temperature of the cooling medium supplied to the chiller unit 11 can be controlled or optimized. By providing the mixing tank 9, a cooling system for the data center 1 with high thermal efficiency can be configured. By increasing or decreasing the number of mixing tanks of the mixing tank 9, the temperature of the cooling medium supplied from the mixing tank 9 to the heat exchanger 6, the ice heat storage device 10 and the chiller unit 11 can be adjusted. In the configuration described above, the load on the chiller unit 11 can be reduced, so that the running cost of the chiller unit 11 and the amount of carbon dioxide emission can be reduced.

  DESCRIPTION OF SYMBOLS 1 ... Data center, 4 ... Electronic equipment, 6 ... Heat exchanger, 9 ... Mixing tank, 10 ... Ice thermal storage device, 11 ... Chiller unit.

Claims (5)

In the cooling system of the data center that cools the electronic device by taking the heat generated from the plurality of electronic devices that perform data processing and releasing it to the outside using the cooling medium whose temperature is lowered by the cooler,
A heat exchanger that transfers heat generated from the electronic device to the cooling medium and takes it away;
An ice heat storage device that cools the cooling medium and freezes and stores it by radiating heat of the cooling medium into the atmosphere by a heat pipe having a unidirectional heat transport direction; and
A mixing tank that mixes the cooling medium whose temperature has been increased by taking heat of the electronic device with the heat exchanger and the cooling medium whose temperature has been decreased with the ice heat storage device or the cooler;
At least a part of the cooling medium mixed in the mixing tank is supplied to the ice heat storage device, and at least another part is supplied to the heat exchanger or the cooler. This is a data center cooling system.   The mixing tank includes a plurality of mixing tanks that mix the cooling medium whose temperature has been increased and the cooling medium whose temperature has been decreased, and the mixing tanks arranged in series and adjacent to each other to communicate the mixing tank. A communication hole for circulating the cooling medium between the tanks, and the cooling medium whose temperature has been increased by taking heat of the electronic device into any one of the mixing tanks, 2. The data center cooling system according to claim 1, wherein the cooling medium whose temperature has been lowered by the ice heat storage device or the cooler is introduced into the cooling system. 3. A first circulation pipe for circulating the cooling medium between the heat exchanger and the mixing tank is formed, and the cooling medium in the plurality of mixing tanks is formed in the middle of the first circulation pipe. First switching means that is switched to supply the cooling medium to the heat exchanger from any one of the plurality of mixing tanks according to temperature is provided, and the electronic device is more than the first switching means. A first pump for flowing the cooling medium on the device side is interposed,
A second circulation line for circulating the cooling medium between the cooler and the mixing tank is formed, and the cooling medium in the plurality of mixing tanks is disposed in the middle of the second circulation line. A second switching means that is switched to supply the cooling medium from any of the plurality of mixing tanks to the cooler according to temperature is provided, and the cooling is performed more than the second switching means. A second pump for flowing the cooling medium on the side of the vessel is interposed,
A third circulation line is formed to circulate the cooling medium between the mixing tank of the mixing tank into which the cooling medium whose temperature has been increased due to the heat of the electronic device being introduced and the ice storage device. The data center according to claim 1, wherein a third pump for flowing the cooling medium is interposed on an inlet side of the ice heat storage device in the third circulation pipe. Cooling system. The ice heat storage device includes a storage tank that temporarily stores the cooling medium,
2. The data center according to claim 1, wherein the heat pipe is disposed in a state in which an evaporation section is immersed in the cooling medium in the storage tank and a condensation section is exposed to the atmosphere. Cooling system. The heat pipe encloses a working fluid that circulates and flows with evaporation and condensation inside the sealed container, and returns the working fluid in a liquid phase to the lower end portion, which is the evaporation section, in the sealed container by gravity 5. The data center cooling system according to claim 1, further comprising a thermosiphon.

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