Cooling method and cooling system for electronic device

Abstract

A cooling method for an electronic device, comprising: naturally circulating a refrigerant between: an evaporator which vaporizes the refrigerant by heat exchange with exhaust hot air from the electronic device, and cools the exhaust hot air; and one of a cooling tower and a condenser which is placed at a position higher than the evaporator, and liquefies the vaporized refrigerant; and valve-controlling a flow rate of a refrigerant liquid to be supplied to the evaporator so that an air temperature after heat has been exchanged for cooling by the evaporator becomes a temperature suited to an operating environment of the electronic device, wherein one of a condensation temperature and a condensation pressure of a refrigerant gas in one of the cooling tower and the condenser do not fluctuate even when the flow rate of the refrigerant liquid to be supplied to the evaporator is valve-controlled.

1 . A cooling method for an electronic device, comprising:
 naturally circulating a refrigerant between: an evaporator which vaporizes the refrigerant by heat exchange with exhaust hot air from the electronic device, and cools the exhaust hot air; and one of a cooling tower and a condenser which is placed at a position higher than the evaporator, and liquefies the vaporized refrigerant; and   valve-controlling a flow rate of a refrigerant liquid to be supplied to the evaporator so that an air temperature after heat has been exchanged for cooling by the evaporator becomes a temperature suited to an operating environment of the electronic device, wherein   one of a condensation temperature and a condensation pressure of a refrigerant gas in one of the cooling tower and the condenser do not fluctuate even when the flow rate of the refrigerant liquid to be supplied to the evaporator is valve-controlled.   
     
     
         2 . A cooling system for an electronic device, comprising:
 an evaporator which vaporizes the refrigerant by heat exchange with exhaust hot air from the electronic device, and cools the exhaust hot air; and   a cooling tower which is placed at a position higher than the evaporator, and liquefies the vaporized refrigerant;   wherein a refrigerant is naturally circulated between the evaporator and the cooling tower, and a flow rate of a refrigerant liquid to be supplied to the evaporator is valve-controlled so that an air temperature after heat has been exchanged for cooling by the evaporator becomes a temperature suited to an operating environment of the electronic device, and   wherein   the cooling tower comprises:
 a cooling tower main body in which a take-in port and an exhaust port for outside air are formed; 
 a heat exchange coil which is provided inside of the cooling tower main body, and includes: an entrance connected to gas piping through which a refrigerant gas returning from the evaporator flows; and an exit connected to liquid piping through which a refrigerant liquid to be supplied to the evaporator flows; 
 a sprinkler which sprinkles water to the heat exchange coil; 
 a blower which takes in the outside air from the take-in port to blow the taken-in outside air to the heat exchange coil, and exhausts the air from the exhaust port; 
 a blowing amount adjustment device which adjusts a blowing amount of the blower; 
 a refrigerant liquid temperature sensor which measures a temperature of the refrigerant liquid at the exit of the heat exchange coil; and 
 a controller which controls the blowing amount adjustment device on a basis of the temperature measured by the refrigerant liquid temperature sensor; and 
 the controller controls the blowing amount of the blower by means of the blowing amount adjustment device so that the temperature measured by the refrigerant liquid temperature sensor is maintained at a predetermined temperature without fluctuating so as to follow fluctuations in evaporation temperature of the evaporator due to valve control in the evaporator. 
   
     
     
         3 . The cooling system for the electronic device according to  claim 2 , wherein:
 the refrigerant liquid temperature sensor is replaced with a refrigerant liquid pressure sensor; and   the controller controls the blowing amount of the blower by means of the blowing amount adjustment device so that a pressure measured by the refrigerant liquid pressure sensor is maintained at a predetermined pressure without fluctuating so as to follow the fluctuations in evaporation temperature of the evaporator due to the valve control in the evaporator.   
     
     
         4 . A cooling system for an electronic device, comprising:
 an evaporator which vaporizes the refrigerant by heat exchange with exhaust hot air from the electronic device, and cools the exhaust hot air; and   a cooling tower which is placed at a position higher than the evaporator, and liquefies the vaporized refrigerant;   wherein a refrigerant is naturally circulated between the evaporator and the cooling tower, and a flow rate of a refrigerant liquid to be supplied to the evaporator is valve-controlled so that an air temperature after heat has been exchanged for cooling by the evaporator becomes a temperature suited to an operating environment of the electronic device, and   
       wherein
 the cooling tower comprises:
 a cooling tower main body in which a take-in port and an exhaust port for outside air are formed; 
 a heat exchange coil which is provided inside of the cooling tower main body, and includes: an entrance connected to gas piping through which a refrigerant gas returning from the evaporator flows; and an exit connected to liquid piping through which a refrigerant liquid to be supplied to the evaporator flows; 
 a sprinkler which sprinkles water to the heat exchange coil; 
 a blower which takes in the outside air from the take-in port to blow the taken-in outside air to the heat exchange coil, and exhausts the air from the exhaust port; 
 a refrigerant liquid temperature sensor which measures a temperature of the refrigerant liquid at the exit of the heat exchange coil; 
 a circulation duct which returns part of the exhaust outside air exhausted from the exhaust port to a vicinity of the take-in port, and mixes the part of the exhaust outside air with the taken-in outside air from the take-in port; 
 a circulation air amount adjustment device which adjusts an air amount of the exhaust outside air flowing through the circulation duct; and 
 a controller which controls the circulation air amount adjustment device on a basis of the temperature measured by the refrigerant liquid temperature sensor; and 
 the controller controls the circulation air amount of the exhaust outside air flowing through the circulation duct by means of the circulation air amount adjustment device so that the temperature measured by the refrigerant liquid temperature sensor is maintained at a predetermined temperature without fluctuating so as to follow fluctuations in evaporation temperature of the evaporator due to valve control in the evaporator. 
 
 
     
     
         5 . The cooling system for the electronic device according to  claim 4 , wherein:
 the refrigerant liquid temperature sensor is replaced with a refrigerant liquid pressure sensor; and   the controller controls the circulation air amount of the exhaust outside air flowing through the circulation duct by means of the circulation air amount adjustment device so that a pressure measured by the refrigerant liquid pressure sensor is maintained at a predetermined pressure without fluctuating so as to follow the fluctuations in evaporation temperature of the evaporator due to the valve control in the evaporator.   
     
     
         6 . A cooling system for an electronic device, comprising:
 an evaporator which vaporizes the refrigerant by heat exchange with exhaust hot air from the electronic device, and cools the exhaust hot air; and   a cold water type condenser which is placed at a position higher than the evaporator, and liquefies the vaporized refrigerant;   wherein a refrigerant is naturally circulated between the evaporator and the cold water type condenser, and a flow rate of a refrigerant liquid to be supplied to the evaporator is valve-controlled so that an air temperature after heat has been exchanged for cooling by the evaporator becomes a temperature suited to an operating environment of the electronic device, and   
       wherein
 the cold water type condenser includes: an entrance connected to gas piping through which a refrigerant gas returning from the evaporator flows; and an exit connected to liquid piping through which a refrigerant liquid to be supplied to the evaporator flows, and is a condenser which obtains cold energy for condensing the refrigerant gas into the refrigerant liquid by using cold water which is supplied to the cold water type condenser via cold water supply piping; 
 the cold water type condenser comprises:
 a cold water amount adjustment device which is provided to the cold water supply piping, and adjusts a flow rate of the cold water to be supplied to the cold water type condenser; 
 a refrigerant liquid temperature sensor which measures a temperature of the refrigerant liquid at the exit of the cold water type condenser; and 
 a controller which controls the cold water amount adjustment device on a basis of the temperature measured by the refrigerant liquid temperature sensor; and 
 the controller controls the flow rate of the cold water to be supplied to the cold water type condenser by means of the cold water amount adjustment device so that the temperature measured by the refrigerant liquid temperature sensor is maintained at a predetermined temperature without fluctuating so as to follow fluctuations in evaporation temperature of the evaporator due to valve control in the evaporator. 
 
 
     
     
         7 . The cooling system for the electronic device according to  claim 6 , wherein:
 the refrigerant liquid temperature sensor is replaced with a refrigerant liquid pressure sensor; and   the controller controls the flow rate of the cold water flowing through the cold water supply piping by means of the cold water amount adjustment device so that a pressure measured by the refrigerant liquid pressure sensor is maintained at a predetermined pressure without fluctuating so as to follow the fluctuations in evaporation temperature of the evaporator due to the valve control in the evaporator.   
     
     
         8 . The cooling system for the electronic device according to  claim 6 , wherein the water supplied to the cold water type condenser is cooled by using outside air when a temperature of the outside air is equal to or lower than 10° C.