Air-conditioning apparatus

An air-conditioning apparatus including a main pipe that connects at least one indoor unit and an outdoor unit such that a refrigerant circulates therethrough, the air-conditioning apparatus further comprising:

• an indoor heat exchanger provided in the at least one indoor unit;
• a first flow control valve configured to control a flow rate of the refrigerant entering the indoor heat exchanger;
• an injection compressor including an injection port allowing part of the refrigerant circulating to be injected therethrough into the refrigerant undergoing compression;
• a refrigerant flow switching device configured to switch between a cooling operation and a heating operation;
• a plurality of outdoor heat exchangers provided in the outdoor unit and connected in parallel;
• a first bypass pipe having a first end connected between the injection compressor and the refrigerant flow switching device and a second end connected to first ones of inlet and outlet sides of the plurality of outdoor heat exchangers;
• a first bypass flow control valve provided to the first bypass pipe and configured to control a flow rate of the refrigerant;
• a second bypass pipe having a first end connected to the injection port or a pipe connected to the injection port and a second end connected to second ones of the inlet and outlet sides of the plurality of outdoor heat exchangers;
• a first flow switching device configured to switch a flow of the refrigerant to the main pipe or the first bypass pipe;
• and
• a second flow switching device configured to switch the flow of the refrigerant to the main pipe or the second bypass pipe,
• wherein in a defrosting operation of removing frost in any of the plurality of outdoor heat exchangers,
• the first flow switching device causes part of the refrigerant discharged from the injection compressor to flow through the first bypass pipe and decompress thereof by the first bypass flow control valve, and the refrigerant is supplied to an outdoor heat exchanger comprising the plurality of outdoor heat exchangers and targeting for defrosting, and
• the second flow switching device causes part of the refrigerant supplied to the outdoor heat exchanger targeting for defrosting to enter the second bypass pipe.