JP4816974B2 - Electronic equipment cooling system - Google Patents

Description

  The present invention relates to an electronic device cooling system and cooling method, and more particularly, to an electronic device cooling system for efficiently cooling an electronic device that requires precise operation such as a computer and a server and generates a large amount of heat from itself. About.

  In recent years, with the improvement of information processing technology and the development of the Internet environment, the amount of information processing required has increased, and a data processing center for processing a large amount of various types of information has attracted attention as a business. A large number of electronic devices such as computers and servers are gathered in a server room of this data processing center, for example, and are continuously operated day and night. In general, the rack mount method is the mainstream for installing electronic devices in a server room. The rack mount system is a system in which racks (casings) that divide and store electronic devices into functional units are stacked in a cabinet, and a large number of such cabinets are arranged and arranged on the floor of a server room. Electronic devices that process such information are rapidly increasing in processing speed and processing capacity, and the amount of heat generated from the electronic devices is steadily increasing.

  On the other hand, these electronic devices require a certain temperature environment for operation, and the temperature environment for normal operation is set to be relatively low. Cause trouble.

  Against this background, techniques for efficiently cooling electronic devices have been proposed. For example, Patent Document 1 discloses that an air conditioner for cooling a space in which an electronic device or the like is housed includes a mechanism that prevents the cooling space from being exposed. Specifically, the evaporation temperature of the refrigerant is set so that the surface temperature of the refrigerant pipe in the evaporator constituting the air conditioner is equal to or higher than the dew point temperature of the gas sucked into the evaporator.

Moreover, although not about the cooling system of an electronic device, in Patent Document 2, in the refrigerant natural circulation type cooling system, based on the outside air temperature measured by the outside air temperature sensor, the set energy amount (the low temperature liquid supplied to the condenser is A method of changing the estimated temperature and circulating flow rate) is disclosed. Thereby, the fluctuation | variation of the condensing pressure in a condenser based on the fluctuation | variation of outside temperature is suppressed.
JP 2005-147623 A JP 2007-127315 A

  However, in the above-mentioned Patent Document 1, a certain effect can be expected from the viewpoint of preventing condensation of the evaporator, but there is a problem that the power cost is increased, for example, the amount of air blown from the indoor fan is increased in order to raise the refrigerant temperature.

  Further, neither of the above-mentioned Patent Documents 1 and 2 takes measures to prevent dew condensation of the evaporator caused by outside air temperature fluctuation or electronic equipment load fluctuation.

  That is, the outside air temperature fluctuates in the morning or evening or in the summer and winter, but when natural circulation operation is performed, if the outside air temperature becomes extremely low, the condensation temperature of the refrigerant is significantly reduced and condensation occurs near the inlet of the evaporator. is there. The amount of heat generated from the electronic device varies depending on the amount of information processing (processing load). For this reason, even when the processing load is low, the condensation temperature of the refrigerant decreases as described above, and condensation may occur near the inlet of the evaporator. Such condensation is a problem particularly in data centers that handle electronic devices that perform precise processing.

  The present invention has been made in view of such circumstances, and cooling of an electronic device that prevents condensation in a cooling device that cools heat generated by an electronic device such as a computer or a server and realizes a safe driving environment at a low power cost. The purpose is to provide a system.

In order to achieve the above-mentioned object, the invention according to claim 1 is provided near the electronic device and a chamber in which the electronic device is disposed, and vaporizes the refrigerant with heat generated from the electronic device. An evaporator that cools the electronic device, a water spraying means that sprays water on a refrigerant distribution pipe through which the coolant flows, and water that is sprayed by the water spraying means is forced to contact outside air to cool the water by latent heat of evaporation. A cooling tower that cools the refrigerant supplied to the evaporator, and an outside air temperature measuring unit that measures the outside air temperature, and an outside air temperature measuring unit. Based on the measurement result, a refrigerant condensing condition for maintaining the refrigerant temperature at the inlet of the evaporator at a predetermined temperature higher than the dew point temperature in the room is calculated. And a first control means for controlling the refrigerant condensing temperature in the cooling tower to be constant by adjusting the air flow rate of the outside air and the circulation flow rate of the water by the water sprinkling means. An electronic equipment cooling system is provided.

  According to the first aspect, by installing the evaporator close to the electronic device, the refrigerant in the evaporator can be heat exchanged with the high-temperature exhaust heat, so that the condensation temperature of the refrigerant can be set high. Further, in the condenser using the outside air temperature, based on the measurement result of the outside air temperature, the refrigerant condensing temperature is controlled by the first control means so that the refrigerant temperature at the inlet of the evaporator is higher than the indoor dew point temperature. To do. As a result, the condensation temperature of the refrigerant can be kept constant regardless of fluctuations in the outside air temperature, so that condensation near the inlet of the evaporator can be prevented. The refrigerant condensation temperature is synonymous with the refrigerant cooling temperature in the condenser.

According to claim 1 , when a watering type cooling tower is used as a condenser, based on the measurement result of the outside air temperature, the cooling tower is set so that the refrigerant temperature in the vicinity of the inlet of the evaporator becomes higher than the dew point temperature. Controls the flow rate of outside air and the circulation flow rate of sprinkling water. Thereby, the condensation temperature of the refrigerant in the watering type cooling tower can be kept constant regardless of the fluctuation of the outside air temperature, and condensation near the inlet of the evaporator can be prevented.

According to a second aspect of the present invention, in the first aspect , the electronic device is a server.

According to the second aspect , it is possible to suppress the formation of dew condensation in the vicinity of a server that requires precise processing, and it is possible to safely cool an electronic device such as a server.

  The electronic device cooling system according to the present invention prevents condensation in a cooling device that cools heat generated by an electronic device such as a computer or a server, thereby realizing a safe driving environment at a low power cost.

  Hereinafter, preferred embodiments of a cooling system for an electronic device according to the present invention will be described in detail with reference to the accompanying drawings. Although an example of a server disposed in a server room will be described as an example of an electronic device, the present invention is not limited to this.

  FIG. 1 is a conceptual diagram showing an example of a cooling system 10 for an electronic device according to the present invention.

  As shown in FIG. 1, server rooms 14 </ b> A and 14 </ b> B are formed on the first floor and the second floor in the two-story building 12. Underfloor chambers 22A and 22B are formed on the back sides of the floor surfaces 20A and 20B on the first floor and the second floor, respectively. Note that reference numeral 18 indicates two or more floors.

  As shown in FIG. 2, a server rack 26 is disposed in the server rooms 14A and 14B, and a plurality of servers 28 are stored in a stacked state in the server rack 26. The server rack 26 is preferably provided with a moving caster 24 so as to be movable. The server 28 includes a fan 30, and heat generated in the server 28 is exhausted from the server 28 by sucking and exhausting the air in the server rooms 14 </ b> A and 14 </ b> B as indicated by an arrow 32. Note that the number of the two-story building 12, the server rooms 14A and 14B, the number of server racks 26 arranged in the server rooms 14A and 14B, and the number of servers 28 stacked in the server rack 26 shown in FIG. Etc. are examples, and are not limited to FIGS. 1 and 2. Further, as shown in FIG. 1, each server 28 housed in the server rack 26 is provided with an evaporator 34. In FIG. 1, the server 28 is illustrated instead of the server rack 26 so that the relationship between the server 28 and the evaporator 34 can be easily understood.

  As shown in FIG. 1, a cooling coil 36 is provided inside the evaporator 34, and the refrigerant liquid flowing in the cooling coil 36 evaporates with hot air generated from the server 28, thereby removing the heat of vaporization from the surroundings and gasifying it. . Thereby, the hot air discharged | emitted from the server 28 itself or the server 28 is cooled.

  On the other hand, a cooling tower 38 is provided on the roof of the building 12, and a circulation line 40 through which the refrigerant naturally circulates is formed between the cooling tower 38 and each of the evaporators 34 described above. That is, in the cooling tower 38, a spiral pipe 41 through which a refrigerant flows is accommodated, and a sprinkling pipe 42 that sprinkles water into the spiral pipe 41 is provided above the spiral pipe 41. In addition, a fan 44 is provided above the sprinkling pipe 42, and by taking outside air from the side opening of the cooling tower 38 and discharging it from the top opening, a counter current is formed between the water to be sprinkled and the taken outside air. Thereby, outside air is taken in and cooled to be lower than the temperature.

  Between the cooling coil 36 provided in the evaporator 34 and the spiral pipe 41 provided in the cooling tower 38, a return pipe 46 for returning the refrigerant gas gasified by the evaporator 34 to the cooling tower 38, and a refrigerant The refrigerant is liquefied by cooling and condensing the gas in the cooling tower 38 and is connected to a supply pipe 48 that supplies the evaporator 34 with the refrigerant liquid. The return pipe 46 and the supply pipe 48 are branched on the way, so that the evaporator 34 of the server 28 disposed in the server room 14A on the first floor through the lower floor chambers 22A and 22B on the first floor or the second floor, and the second floor. To the evaporator 34 of the server 28 disposed in the server room 14B.

  In addition to the cooling tower 38, a heat exchanger 54 having a larger cooling capacity than the cooling tower 38 is installed on the roof of the building 12, and the refrigerant flowing through the circulation line 40 is exchanged with the cooling tower 38 by the switching means 56. It is preferable to be configured to be able to flow to at least one of the heat exchanger 54. That is, as shown in FIG. 1, the branch return pipe 58 and the branch supply pipe 60 branched from the return pipe 46 and the supply pipe 48 are connected to the secondary coil 62 of the heat exchanger 54. Thereby, the branch circulation line 64 branched from the circulation line 40 is formed. Switching means 56 (for example, a three-way valve) is provided at the branch position where the branch return pipe 58 branches and the branch position where the branch supply pipe 60 branches. By switching the switching means 56, the refrigerant flowing through the circulation line 40 can flow to at least one of the cooling tower 38 or the heat exchanger 54. The switching means 56 is configured to be able to adjust the distribution amount of the refrigerant.

  The primary coil 66 of the heat exchanger 54 is connected to a chilled water supply pipe 70 and a chilled water return pipe 72 from the refrigerator 68, and a liquid feed pump 74 is provided in the chilled water supply pipe 70. Thereby, the cold water (primary refrigerant) manufactured by the refrigerator 68 exchanges heat with the refrigerant (secondary refrigerant) in the heat exchanger 54 to cool the refrigerant.

  In such a configuration, the high-temperature heat generated (discharged) from the server 28 is directly heat-exchanged with the refrigerant flowing through the evaporator 34 in a high-temperature state to promote the evaporation of the refrigerant. Transportation power for transporting the evaporated refrigerant gas to the cooling tower 38 installed at a high place can be obtained. Thereby, a circulation line 40 for natural circulation of the refrigerant is formed between the evaporator 34 and the cooling tower 38. That is, the evaporator 34, the cooling tower 38, and the circulation line 40 constitute a non-powered heat pipe in which a refrigerant is sealed. Further, since the amount of heat generated from the server 28 is increased and a high-temperature refrigerant gas can be formed, the cooling temperature for condensing the refrigerant gas can be set higher, and the refrigerant gas can be condensed even with the cooling capacity of the cooling tower 38. The condensed refrigerant liquid flows down to the evaporator 34 located below the cooling tower 38.

  Furthermore, in the present embodiment, a control mechanism is provided that suppresses the refrigerant condensation temperature in the cooling tower 38 or the heat exchanger 54 from being extremely lowered due to a decrease in the outside air temperature or the processing load.

  That is, the cooling tower 38 is provided with a temperature sensor 80 (wet bulb thermometer) for measuring the outside wet bulb temperature and a temperature sensor 82 for measuring the temperature of water sprayed from the water spray pipe 42, both of which are the first. It connects so that it may output to the controller 86 (1st control means). Similarly, a temperature sensor 88 for measuring the refrigerant temperature is installed near the inlet of the evaporator 34 and connected so as to be output to the first controller 86. In addition, as an installation place of the temperature sensor 88, piping of the upstream refrigerant | coolant liquid side branched to the top floor is preferable. This is because on the lower floor, the evaporation temperature does not fall below the top floor.

  The first controller 86 is connected to an inverter 90 that adjusts the operating frequency of the fan 44 and a sprinkling flow rate adjusting means 92 that adjusts the flow rate of water to be sprinkled. Then, the inverter 90 and the sprinkling flow rate adjusting means 92 are set so that the refrigerant temperature measured by the temperature sensor 88 by the first controller 86 is higher than the indoor dew point temperature based on the measurement result of the temperature sensor 80. To be controlled.

  In the present embodiment, the indoor dew point temperature refers to a temperature at which dew condensation occurs in the supply pipe 48 near the inlet of the evaporator 34 in the room temperature and humidity of the server rooms 14A and 14B. This indoor dew point temperature can be obtained using dew point temperature detection means (a device having a relative humidity sensor and a room temperature sensor and calculating the dew point temperature from the detected relative humidity and room temperature).

  The heat exchanger 54 is also provided with a control mechanism similar to the above. That is, the temperature sensor 96 that measures the temperature of the primary chilled water in the heat exchanger 54 and the result detected by the temperature sensor 88 are connected so as to be output to the second controller 98 (second control means). . In this case, the temperature sensor 88 can function as a means for detecting fluctuations in the amount of heat generated due to fluctuations in the processing load of the server 28.

  Further, the branch supply pipe 60 is provided with a valve 102 for adjusting the flow rate of the cold water flowing in the primary side coil 66 and a three-way valve 104 for adjusting the temperature of the cold water. The three-way valve 104 is configured to be switched between a path that circulates in the primary coil 66 while cooling the chilled water through the refrigerator 68 and a path that circulates in the primary coil 66 without passing the refrigerator 68. Has been.

Based on the measurement results of the temperature sensor 88 and the temperature sensor 96, the second controller 98 adjusts the degree of opening of the valve 102 so that the refrigerant temperature measured by the temperature sensor 88 becomes a set temperature higher than the indoor dew point temperature. (Or) The three-way valve 104 is switched. Thereby, the circulating flow rate of the cold water in the primary coil 66 or the cold water cooling temperature by the refrigerator 68 can be adjusted.

  Although it does not specifically limit as a temperature sensor, Well-known and public things, such as various thermometers and thermistors which detect the surface temperature of piping, can be used.

  Further, the calculation result of the indoor dew point temperature may be input to the first and second controllers, respectively, or the detected relative humidity and room temperature are directly input to the first and second controllers. The controller may be configured to calculate the set temperature of the refrigerant temperature.

  Next, the operation of the control mechanism in the cooling system 10 of the present embodiment will be described.

  First, the case where only the cooling tower 38 is used without using the heat exchanger 54 will be described.

  The refrigerant temperature near the inlet of the evaporator 34 is monitored by a temperature sensor 88, and the monitored result is output to the first controller 86.

  When the first controller 86 detects a decrease in the outside air temperature using the temperature sensor 80, the refrigerant temperature near the inlet of the evaporator 34 (the temperature measured by the temperature sensor 88) becomes a set temperature that is higher than the indoor dew point temperature. Thus, the refrigerant condensing condition is calculated. It can be set to be higher than the room dew point temperature and lower than the air temperature at the outlet of the evaporator 34 (room temperature, for example, 25 ° C.).

  And based on the said calculation result, the 1st controller 86 controls the inverter 90 and the sprinkling flow volume adjustment means 92, and adjusts the flow volume of the external air and the flow volume of the water sprinkled. Thereby, the condensation temperature of the refrigerant in the cooling tower 38 can be set to a calculated value, and the condensation temperature of the refrigerant can be kept constant. Specifically, when the temperature sensor 80 detects a decrease in the outside air temperature, the amount of outside air flow or the flow rate of water is reduced, and the condensation temperature of the refrigerant is kept constant. Thus, the refrigerant condensing temperature can be made constant regardless of the decrease in the outside air temperature, and the refrigerant temperature in the vicinity of the inlet of the evaporator 34 can be maintained at a set temperature higher than the indoor dew point temperature. The first controller 86 controls the water temperature to be lower than the set condensation temperature by an approach amount while monitoring the water temperature to be sprinkled with the temperature sensor 82.

  The same control can be performed not only when the outside air temperature decreases but also when the temperature sensor 88 detects a decrease in the refrigerant temperature due to a decrease in the processing load of the server 28 or the like.

  In the present embodiment, an example is shown in which the refrigerant temperature detected by the temperature sensor 88 is controlled to be a set temperature higher than the indoor dew point temperature. However, the refrigerant temperature is less than or equal to the chilled water temperature in the cooling tower 38. Therefore, the chilled water temperature in the cooling tower 38 may be controlled to be equal to or higher than the indoor dew point temperature.

  Next, the case where only the heat exchanger 54 is used without using the cooling tower 38 will be described.

  The refrigerant temperature near the inlet of the evaporator 34 is monitored by a temperature sensor 88, and the monitored result is output to the second controller 98.

  When the second controller 98 detects a decrease in the refrigerant temperature in the temperature sensor 88 due to, for example, a reduction in the processing load on the server 28, the refrigerant temperature near the inlet of the evaporator 34 is higher than the room temperature dew point temperature. The refrigerant condensing conditions (the set values such as the flow rate of the cold water on the primary side to be circulated through the heat exchanger 54 and the cold water temperature) are calculated.

  Then, the second controller 98 controls the valve 102 and the three-way valve 104 so that the chilled water temperature in the temperature sensor 96 becomes the calculated value, and adjusts the chilled water flow rate and the chilled water temperature flowing through the primary coil 66. Specifically, when the temperature sensor 88 detects a decrease in the refrigerant temperature, the opening of the valve 102 is reduced, and the three-way valve 104 switches to a circulation path that does not pass through the refrigerator 68. Thereby, the temperature of the cold water flowing in the primary coil 66 is set high, and the condensation temperature of the refrigerant in the heat exchanger 54 is set to a set value.

  In the present embodiment, an example is shown in which the refrigerant temperature detected by the temperature sensor 88 is controlled to be a set temperature higher than the indoor dew point temperature, but the refrigerant temperature is equal to or lower than the chilled water temperature in the heat exchanger 54. Therefore, the cold water temperature in the primary coil of the heat exchanger 54 may be controlled so as to be equal to or higher than the indoor dew point temperature.

  Further, when the cooling tower 38 and the heat exchanger 54 are used in combination, the refrigerant temperature control near the inlet of the evaporator 34 may be performed by either the cooling tower 38 or the heat exchanger 54. You may carry out with both the tower 38 and the heat exchanger 54. FIG. When the refrigerant temperature is controlled by both the cooling tower 38 and the heat exchanger 54, the first controller controls the refrigerant detected by the temperature sensor 88 in order to keep the refrigerant condensing temperature with respect to the decrease in the outside air temperature constant. It is preferable to control the temperature drop by the second controller.

  In the present embodiment, the refrigerant temperature is the lowest in the vicinity of the entrance of the evaporator 34 installed on the top floor among the floors. Therefore, the temperature sensor 88 is installed on the upper floor to sense the refrigerant temperature, and based on the sensing result. However, the present invention is not limited to this. For example, a temperature sensor 88 is installed on each floor, and the value of one temperature sensor is adopted. Also good.

  In the present embodiment, the temperature sensor 88 is used as a means for detecting a decrease in processing load. However, the present invention is not limited to this, and a refrigerant gas pressure measuring means is provided near the inlet of the cooling tower 38 to provide a cooling tower. 38 or the refrigerant condensing pressure of the heat exchanger 54 may be controlled. Further, instead of the temperature sensor 88, a pressure sensor may be provided to control the refrigerant condensing pressure. Any other method may be used as long as it measures the processing load of the server 28, for example, a load control unit that monitors or controls the information processing amount of the server 28, or a power meter that measures the power consumption of the server 28. .

  Further, in the present embodiment, the cooling system in which the cooling tower 38 and the heat exchanger 54 can be used in a switchable manner has been described. However, the present invention is not limited to this. For example, the cooling tower 38 or the heat exchanger 54 has no switching means. A cooling system including only one of them may be used.

  As described above, by configuring the embodiment of the cooling system 10 for an electronic device, it is possible to prevent dew condensation in the cooling device that cools the heat generated by the electronic device such as a computer or a server, and to secure the electronic device at a low power cost and safely. Can be cooled.

  In the above embodiment, a water-cooled condenser is used as the heat exchanger 54. However, the present invention is not limited to this. For example, a condenser using other refrigerant (ammonia or the like), an air-cooled condenser, or the like. Etc. can also be used.

  In the above embodiment, the server 28 is described as an example of the electronic device. However, the present invention is not particularly limited, and the present invention can be applied to exhaust heat treatment of various electronic devices and apparatuses.

  In the above embodiment, from the viewpoint of preventing condensation near the entrance of the evaporator, the control method in the case where the outside air temperature or the processing load on the electronic device is reduced has been described. However, the following usage method is also available. . That is, when the outside air temperature rises or the processing load on the electronic device increases, the electronic device can be efficiently and stably cooled by performing an operation opposite to the control method described above. Specifically, when the outside air temperature rises, the refrigerant temperature also rises. Therefore, the air flow rate of the fan 44 of the cooling tower 38 and the circulation flow rate of water to be sprinkled so as to keep the refrigerant condensing temperature necessary for cooling the electronic equipment. It is possible to perform control such as increasing the temperature or decreasing the cooling water temperature in the heat exchanger 54. In this case, the switching means 56 may be provided with a controller for controlling the refrigerant distribution amount to the cooling tower 38 and the heat exchanger 54.

It is a conceptual diagram explaining 1st Embodiment which is an example of the cooling system of the electronic device of this invention. It is explanatory drawing explaining schematic structure of the server rack in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Cooling system, 12 ... Building, 14A ... Server room on the first floor, 14B ... Server room on the second floor, 16A ... Ceiling surface on the first floor, 16B ... Ceiling surface on the second floor, 20A ... Floor surface on the first floor, 20B ... 2nd floor, 22A ... 1st floor chamber, 22B ... 2nd floor chamber, 24 ... Casters, 26 ... Server rack, 28 ... Server, 30 ... Fan (for server), 32 ... Hot air, 34 ... Evaporator, 36 ... Cooling coil, 38 ... Cooling tower, 40 ... Circulation line, 41 ... Spiral pipe, 42 ... Sprinkling pipe, 44 ... Fan (for cold water tower), 46 ... Return pipe, 48 ... Supply pipe, 54 ... Heat exchanger 56 ... switching means 58 ... branch return pipe 60 ... branch supply pipe 62 ... secondary coil 64 ... branch circulation line 66 ... primary coil 68 ... refrigerator 70 ... cold water supply Piping, 72 ... Cold water return piping, 74 ... Liquid pump, 80 ... wet bulb thermometer, 82, 88, 96 ... temperature sensor, 86 ... first controller, 92 ... sprinkling flow rate adjusting means, 98 ... second controller, 90 ... inverter, 102 ... valve, 104 ... Three-way valve

Claims (2)

A room where electronic devices are placed;
An evaporator that is provided in the vicinity of the electronic device and cools the electronic device by evaporating a refrigerant with heat generated from the electronic device;
Sprinkling means for spraying water to the coolant circulation pipe through which the coolant flows, and a blower for cooling the water by latent heat of evaporation by forcibly bringing outside air into contact with water sprayed by the sprinkling means. A cooling tower for cooling the refrigerant supplied to the vessel, and an electronic device cooling system comprising:
An outside air temperature measuring means for measuring the outside air temperature;
Based on the measurement result of the outside air temperature measuring means, a refrigerant condensing condition for maintaining the refrigerant temperature at the inlet of the evaporator at a predetermined temperature higher than the dew point temperature in the room is calculated, and the blower is calculated based on the calculation result. And a first control means for controlling the refrigerant condensing temperature in the cooling tower to be constant by adjusting an air flow rate of the outside air and a circulation flow rate of the water by the water sprinkling means. A cooling system for electronic devices. The electronic device cooling system according to claim 1 , wherein the electronic device is a server.

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