Cooling system

Abstract

A cooling system comprises a first heat exchanger installed inside a room; a second heat exchanger installed outside the room; and a piping system that enables a refrigerant to naturally circulate between the first heat exchanger and the second heat exchanger. The piping system includes the first supply pipe and the second supply pipe. The first supply pipe supplies liquid refrigerant from the second heat exchanger to the first heat exchanger and the liquid refrigerant is heated by heat exchanging in a third heat exchanger with vaporized refrigerant supplied from the first heat exchanger to the second heat exchanger. The second supply pipe supplies liquid refrigerant from the second heat exchanger to the first heat exchanger bypassing the third heat exchanger.

1 . A cooling system comprising:
 a first heat exchanger installed inside a room;   a second heat exchanger installed outside the room; and   a piping system that enables a refrigerant to naturally circulate between the first heat exchanger and the second heat exchanger,   wherein the piping system includes:   a first supply pipe that supplies liquid refrigerant from the second heat exchanger to the first heat exchanger, the liquid refrigerant being heated by heat exchanging in a third heat exchanger with vaporized refrigerant supplied from the first heat exchanger to the second heat exchanger; and   a second supply pipe that supplies liquid refrigerant from the second heat exchanger to the first heat exchanger bypassing the third heat exchanger.   
     
     
         2 . The cooling system according to  claim 1 ,
 wherein the piping system further includes a changeover valve system that switches between using the first supply pipe and the second supply pipe,   the cooling system further comprises a control unit that controls the changeover valve system, and   the control unit includes a functional unit that switches from the second supply pipe to the first supply pipe using the changeover valve system when a temperature of liquid refrigerant outputted from the second heat exchanger becomes equal to or below a first set temperature.   
     
     
         3 . The cooling system according to  claim 2 ,
 wherein the second heat exchanger includes a second tube and a second fan that supplies outside air to the second tube,   wherein the control unit further includes a functional unit that stops the second fan before switching from the second supply pipe to the first supply pipe using the changeover valve system when the temperature of the liquid refrigerant outputted from the second heat exchanger becomes equal to or below the first set temperature.   
     
     
         4 . The cooling system according to  claim 2 ,
 wherein the control unit includes a functional unit that closes the first supply pipe and the second supply pipe using the changeover valve system when a temperature of outside air becomes equal to or below a second set temperature that is lower than the first set temperature.   
     
     
         5 . A hybrid air conditioning system comprising:
 a cooling system according to  claim 1 , and   a main air conditioning system that further cools air that has been cooled by the first heat exchanger of the cooling system and supplies cooled air.   
     
     
         6 . A control method of a cooling system, the cooling system including a first heat exchanger installed inside a room, a second heat exchanger installed outside the room, and a piping system that enables a refrigerant to naturally circulate between the first heat exchanger and the second heat exchanger, the piping system including: a first supply pipe that supplies liquid refrigerant, which has been heated by heat exchanging in a third heat exchanger with vaporized refrigerant supplied from the first heat exchanger to the second heat exchanger, from the second heat exchanger to the first heat exchanger; a second supply pipe that supplies liquid refrigerant from the second heat exchanger to the first heat exchanger bypassing the third heat exchanger; and a changeover valve system that switches between using the first supply pipe and the second supply pipe,
 the control method comprising of switching by a control unit that controls the changeover valve system, from the second supply pipe to the first supply pipe using the changeover valve system when temperature of liquid refrigerant outputted from the second heat exchanger becomes equal to or below a first set temperature.   
     
     
         7 . The control method according to  claim 6 ,
 wherein the second heat exchanger includes a second tube and a second fan that supplies outside air to the second tube,   and the control method further comprises of stopping the second fan before the step of switching when the temperature of the liquid refrigerant outputted from the second heat exchanger becomes equal to or below a first set temperature.   
     
     
         8 . The control method according to  claim 6 ,
 further comprising closing the first supply pipe and the second supply pipe using the changeover valve system when temperature of outside air becomes equal to or below a second set temperature that is lower than the first set temperature.