Refrigeration cycle apparatus

Abstract

In a refrigeration cycle apparatus according to the present disclosure, the circulation direction of refrigerant is switched between a first circulation direction and a second circulation direction opposite to the first circulation direction. The first circulation direction is a circulation direction in order of a compressor, a first heat exchanger, a first expansion valve, a third heat exchanger, a fourth heat exchanger, a second expansion valve, and a second heat exchanger. When a circulation direction of the refrigerant is the first circulation direction, the refrigerant from the third heat exchanger exchanges heat with the refrigerant from the second heat exchanger in the fourth heat exchanger. When a circulation direction of the refrigerant is the second circulation direction, the refrigerant from the fourth heat exchanger exchanges heat with the refrigerant from the first heat exchanger in the third heat exchanger.

1 . A refrigeration cycle apparatus in which a circulation direction of refrigerant is switched between a first circulation direction and a second circulation direction opposite to the first circulation direction, the refrigeration cycle apparatus comprising:
 a compressor;   a first heat exchanger;   a second heat exchanger;   a third heat exchanger;   a fourth heat exchanger;   a first expansion valve; and   a second expansion valve,   the first circulation direction being a circulation direction in order of the compressor, the first heat exchanger, the first expansion valve, the third heat exchanger, the fourth heat exchanger, the second expansion valve and the second heat exchanger,   when a circulation direction of the refrigerant is the first circulation direction, the refrigerant from the third heat exchanger exchanging heat with the refrigerant from the second heat exchanger in the fourth heat exchanger, and   when a circulation direction of the refrigerant is the second circulation direction, the refrigerant from the fourth heat exchanger exchanging heat with the refrigerant from the first heat exchanger in the third heat exchanger.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , further comprising a first switch and a second switch, wherein
 when a circulation direction of the refrigerant is the first circulation direction,
 the first switch directs the refrigerant from the compressor to flow to the first heat exchanger without flowing through the third heat exchanger, and 
 the second switch directs the refrigerant from the second heat exchanger to flow through the fourth heat exchanger to the compressor, and 
   when a circulation direction of the refrigerant is the second circulation direction,
 the second switch directs the refrigerant from the compressor to flow to the second heat exchanger without flowing through the fourth heat exchanger, and 
 the first switch directs the refrigerant from the first heat exchanger to flow through the third heat exchanger to the compressor. 
   
     
     
         3 . The refrigeration cycle apparatus according to  claim 2  wherein
 the first switch comprises a first check valve and a second check valve, 
 the third heat exchanger is connected between an output port of the first check valve and an input port of the second check valve, 
 the output port of the first check valve is connected to the first heat exchanger, 
 the second switch comprises a third check valve and a fourth check valve, 
 the fourth heat exchanger is connected between an input port of the third check valve and an output port of the fourth check valve, 
 an output port of the third check valve is connected to the second heat exchanger and an input port of the fourth check valve, and 
 an input port of the first check valve communicates with a discharge port of the compressor when a circulation direction of the refrigerant is the first circulation direction, and communicates with a suction port of the compressor when a circulation direction of the refrigerant, is the second circulation direction. 
 
     
     
         4 . The refrigeration cycle apparatus according to  claim 2 , further comprising a controller configured to control the first switch and the second switch, wherein
 the first switch comprises a first port, a second port, and a third port, and is configured to selectively switch a port that communicates with the first port, between the second port and the third port,   the third heat exchanger is connected between the second port and the third port,   the first port is connected to the first heat exchanger,   the second switch comprises a fourth port, a fifth port, and a sixth port, and is configured to selectively switch a port that communicates with the fourth port, between the fifth port and the sixth port,   the fourth heat exchanger is connected between the fifth port and the sixth port,   the fourth port is connected to the second heat exchanger,   when a circulation direction of the refrigerant is the first circulation direction,
 the second port communicates with a discharge port of the compressor, and 
 the controller is configured to cause the first port to communicate with the second port and cause the fourth port to communicate with the fifth port, and 
   when a circulation direction of the refrigerant is the second circulation direction,
 the second port communicates with a suction port of the compressor, and 
 the controller is configured to cause the first port to communicate with e third port and cause the fourth port to communicate with the sixth port. 
   
     
     
         5 . The refrigeration cycle apparatus according to  claim 1 , wherein
 a state of the refrigerant flowing between the third heat exchanger and the fourth heat exchanger is a gas-liquid two-phase state,   when a circulation direction of the refrigerant is the first circulation direction, the refrigerant flowing out of the fourth heat exchanger is in a liquid state, and   when a circulation direction of the refrigerant is the second circulation direction, the refrigerant flowing out of the third heat exchanger is in a liquid state.   
     
     
         6 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the third heat exchanger comprises a first receiver configured to store the refrigerant, and   the fourth heat exchanger comprises a second receiver configured to store the refrigerant.   
     
     
         7 . The refrigeration cycle apparatus according to  claim 1 , wherein
 a minimum value and a maximum value of a flow coefficient of the first expansion valve are equal to a minimum value and a maximum value of a flow coefficient of the second expansion valve, respectively, and   the maximum value of the flow coefficient of the first expansion value is lower than a maximum value of a flow coefficient required when refrigerant in a gas-liquid two-phase state is assumed to flow into the first expansion valve.