Refrigeration cycle apparatus

Abstract

A refrigeration cycle apparatus includes: a first heat exchanger including heat transfer tubes and a first header configured to distribute refrigerant to the heat transfer tubes; a gas-liquid separator configured to separate the refrigerant that flows into the first heat exchanger into gas refrigerant and liquid refrigerant; a gas bypass circuit configured to cause the gas refrigerant to flow from the gas-liquid separator into the first header; a liquid bypass circuit configured to cause the liquid refrigerant to flow from the gas-liquid separator into the first header; and a bypass valve provided at at least one of the gas bypass circuit and the liquid bypass circuit. The gas bypass circuit is connected to the first header at a position which is located downward of a position where the liquid bypass circuit is connected to the first header, in a flow direction of the liquid refrigerant in the first header.

1 . A refrigeration cycle apparatus comprising:
 a first heat exchanger including a plurality of heat transfer tubes and a first header configured to distribute refrigerant that flows into the first heat exchanger via a refrigerant pipe to the plurality of heat transfer tubes;   a gas-liquid separator configured to separate the refrigerant that flows into the first heat exchanger, into gas refrigerant and liquid refrigerant;   a gas bypass circuit connecting the gas-liquid separator and the first header, and configured to cause the gas refrigerant to flow from the gas-liquid separator into the first header;   a liquid bypass circuit connecting the gas-liquid separator and the first header, and configured to cause the liquid refrigerant to flow from the gas-liquid separator into the first header; and   a bypass valve provided at at least one of the gas bypass circuit and the liquid bypass circuit,   wherein   the gas bypass circuit is connected to the first header at a position which is located downward of a position where the liquid bypass circuit is connected to the first header, in a flow direction of the liquid refrigerant in the first header, and   the bypass valve is a valve configured to keep constant, a pressure difference between the refrigerant at an inlet port of the bypass valve and the refrigerant at an outlet port of the bypass valve.   
     
     
         2 . (canceled) 
     
     
         3 . The refrigeration cycle apparatus of  claim 1 , wherein a plurality of bypass valves including the bypass valve are provided, and as the plurality of bypass valves, a gas bypass valve provided in the gas bypass circuit and a liquid bypass valve provided in the liquid bypass circuit are provided. 
     
     
         4 . The refrigeration cycle apparatus of  claim 3 , wherein the liquid bypass valve is a valve configured to increase a pressure difference between the gas-liquid separator and the first header such that the pressure difference exceeds a predetermined pressure. 
     
     
         5 . The refrigeration cycle apparatus of  claim 1 , wherein
 the plurality of heat transfer tubes are connected to the first header at different positions in a direction of gravity, and   the gas bypass circuit is connected to the first header at a lower position than a position where the liquid bypass circuit is connected to the first header.   
     
     
         6 . The refrigeration cycle apparatus of  claim 5 , comprising:
 a compressor configured to compress and discharge the refrigerant;   a second heat exchanger configured to cause heat exchange to be performed between air and refrigerant discharged from the compressor;   an expansion valve configured to expand refrigerant discharged from the second heat exchanger and causes the expanded refrigerant to flow out to the gas-liquid separator; and   a four-way valve configured to set a flow direction of the refrigerant discharged from the compressor to a first flow direction or a second flow direction, the first flow direction being a flow direction of the refrigerant from the compressor to the first heat exchanger, the second flow direction being a flow direction of the refrigerant from the compressor to the second heat exchanger,   wherein   the first heat exchanger includes a second header configured to distribute, to the plurality of heat transfer tubes, refrigerant that flows from the four-way valve into the first heat exchanger, in a case where the flow direction of the refrigerant is set to the first flow direction by the four-way valve, and   the bypass valve is configured to be made in a fully open state in a case where the bypass valve is provided at the gas bypass circuit and the flow direction of the refrigerant is set to the second flow direction by the four-way valve.   
     
     
         7 . The refrigeration cycle apparatus of  claim 1 , further comprising:
 a temperature sensor configured to detect a temperature of the refrigerant; and   a controller configured to adjust an opening degree of the bypass valve such that a detection value obtained by the temperature sensor falls within a predetermined range,   wherein   the plurality of heat transfer tubes are connected to the first header at different positions in a direction of gravity, and   the temperature sensor is provided at at least one of a first heat transfer tube and a second heat transfer tube of the plurality of heat transfer tubes, the first heat transfer tube being a highest one of the plurality of heat transfer tubes, the second heat transfer tube being a lowest one of the plurality of heat transfer tubes.   
     
     
         8 . The refrigeration cycle apparatus of  claim 7 , wherein
 a plurality of temperature sensors including the temperature sensor are provided, and as the plurality of temperature sensors, a first temperature sensor provided at the first heat transfer tube and a second temperature sensor provided at the second heat transfer tube are provided, and   the controller is configured to adjust the opening degree of the bypass valve such that a temperature difference between a detection value obtained by the first temperature sensor and a detection value obtained by the second temperature sensor is less than or equal to a predetermined threshold.