Air-conditioning apparatus

Abstract

An air-conditioning apparatus includes a first branch unit, a fourth flow control device arranged in each of a plurality of pipes split from a first connection pipe side and connected to each indoor-side heat exchanger, and a solenoid valve arranged in each of pipes split from a pipe connecting each fourth flow control device and each indoor-side heat exchanger. An opening degree of the fourth flow control device is controlled based on a state of refrigerant to be caused to flow into the fourth flow control device.

1 . An air-conditioning apparatus, which is configured by connecting a heat source unit and a plurality of indoor units through a first connection pipe and a second connection pipe to supply refrigerant from the heat source unit to each of the plurality of indoor units to perform a cooling operation and/or a heating operation,
 the heat source unit including a compressor, a switching valve, and a heat-source-unit-side heat exchanger,   each of the plurality of indoor units including an indoor-side heat exchanger and a first flow control device,   the air-conditioning apparatus including:   a first branch unit for switchably connecting one of a refrigerant inlet and a refrigerant outlet of the indoor-side heat exchanger of each of the plurality of indoor units to the first connection pipe or the second connection pipe; and   a second branch unit connected on one side thereof to the second connection pipe and split on an other side thereof into a plurality of branches each connected to an other one of the refrigerant inlet and the refrigerant outlet of the indoor-side heat exchanger of each of the plurality of indoor units through the first flow control device,   the first branch unit including:   a branch-side flow control device provided to each of a plurality of pipes split from the first connection pipe and connected to the indoor-side heat exchanger of corresponding one of the plurality of indoor units; and   a solenoid valve provided to each of pipes split from a pipe connecting the branch-side flow control device and the indoor-side heat exchanger of corresponding one of the plurality of indoor units, wherein   an opening degree of the branch-side flow control device is controlled based on a state of the refrigerant to be caused to flow into the branch-side flow control device, wherein   the state of the refrigerant to be caused to flow into the branch-side flow control device is determined based on an outlet subcooling value of the indoor-side heat exchanger that performs the heating operation before switching to the cooling operation.   
     
     
         2 - 8 . (canceled) 
     
     
         9 . An air-conditioning apparatus, which is configured by connecting a heat source unit and a plurality of indoor units through a first connection pipe and a second connection pipe to supply refrigerant from the heat source unit to each of the plurality of indoor units to perform a cooling operation and/or a heating operation,
 the heat source unit including a compressor, a switching valve, and a heat-source-unit-side heat exchanger,   each of the plurality of indoor units including an indoor-side heat exchanger and a first flow control device,   the air-conditioning apparatus including:   a first branch unit for switchably connecting one of a refrigerant inlet and a refrigerant outlet of the indoor-side heat exchanger of each of the plurality of indoor units to the first connection pipe or the second connection pipe; and   a second branch unit connected on one side thereof to the second connection pipe and split on an other side thereof into a plurality of branches each connected to an other one of the refrigerant inlet and the refrigerant outlet of the indoor-side heat exchanger of each of the plurality of indoor units through the first flow control device,   the first branch unit including:   a branch-side flow control device provided to each of a plurality of pipes split from the first connection pipe and connected to the indoor-side heat exchanger of corresponding one of the plurality of indoor units; and   a solenoid valve provided to each of pipes split from a pipe connecting the branch-side flow control device and the indoor-side heat exchanger of corresponding one of the plurality of indoor units, wherein   an opening degree of the branch-side flow control device is controlled based on a state of the refrigerant to be caused to flow into the branch-side flow control device, wherein   the state of the refrigerant to be caused to flow into the branch-side flow control device is determined by estimating an inlet-outlet pressure difference of the branch-side flow control device.