Air-conditioning apparatus

Abstract

An air-conditioning apparatus includes: a refrigerant circuit; a branch circuit branching off from the refrigerant circuit at a first connection point that is located between the outdoor heat exchanger and the expansion unit in the refrigerant circuit and is closer to the outdoor heat exchanger than the expansion unit, and joining the refrigerant circuit at a second connection point that is located between the outdoor heat exchanger and the expansion unit and is closer to the expansion unit than the outdoor heat exchanger; and a refrigerant heat exchanger configured to cause heat exchange to be performed between refrigerant that flows in a first flow passage in the refrigerant circuit and refrigerant that flows in a second flow passage in the branch circuit, the first flow passage being located between the compressor and the indoor heat exchanger.

1 . An air-conditioning apparatus comprising:
 a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion unit, and an indoor heat exchanger are successively connected by refrigerant pipes, and refrigerant is circulated;   a branch circuit branching off from the refrigerant circuit at a first connection point that is located between the outdoor heat exchanger and the expansion unit in the refrigerant circuit and is closer to the outdoor heat exchanger than the expansion unit, and joining the refrigerant circuit at a second connection point that is located between the outdoor heat exchanger and the expansion unit and is closer to the expansion unit than the outdoor heat exchanger;   a refrigerant heat exchanger configured to cause heat exchange to be performed between refrigerant that flows in a first flow passage in the refrigerant circuit and refrigerant that flows in a second flow passage in the branch circuit, the first flow passage being located between the compressor and the indoor heat exchange;   a refrigerant flow control valve connected to the branch circuit and configured to adjust a flow rate of refrigerant that flows in the branch circuit;   a temperature detector configured to detect a temperature of refrigerant that flows on a suction side of the compressor; and   a controller configured to increase an opening degree of the refrigerant flow control valve when the temperature detected by the temperature detector is higher than or equal to a threshold temperature determined in advance.   
     
     
         2 . The air-conditioning apparatus of  claim 1 , further comprising a check valve provided at the branch circuit, and configured to allow the refrigerant to flow from a first connection point side where the first connection point is located to a second connection point side where the second connection point is located, and shut off a flow of the refrigerant from the second connection point side to the first connection point side. 
     
     
         3 . (canceled) 
     
     
         4 . An air-conditioning apparatus comprising:
 a refrigerant circuit in which a compressor, an outdoor heat exchanger, an expansion unit, and an indoor heat exchanger are successively connected by refrigerant pipes and refrigerant is circulated, the outdoor heat exchanger and the expansion unit being directly connected to each other:   a branch circuit branching off from the refrigerant circuit at a first connection point that is located between the outdoor heat exchanger and the expansion unit and is closer to the outdoor heat exchanger than the expansion unit, and joining the refrigerant circuit at a second connection point that is located between the outdoor heat exchanger and the expansion unit and is closer to the expansion unit than the outdoor heat exchanger;   a refrigerant flow control valve connected to the branch circuit and configured to adjust a flow rate of refrigerant that flows in the branch circuit;   a temperature detector configured to detect a temperature of refrigerant that flows on a suction side of the compressor, and   a controller configured to increase an opening degree of the refrigerant flow control valve when the temperature detected by the temperature detector is higher than or equal to a threshold temperature determined in advance.