| 摘要 |
PROBLEM TO BE SOLVED: To defrost an outdoor heat exchanger 7 efficiently while sustaining a sufficient feeling of heating. SOLUTION: The heat pump type air conditioner comprises a hot gas bypass circuit 20 branched from the delivery side of a compressor 1 and passing hot gas to the outdoor heat exchanger 7, and a refrigerant return circuit 30 branched from the downstream side of a receiver 5 and joining refrigerant on the upstream side of an accumulator 8. A control means 40 closes an expansion valve for outdoor unit during defrost operation to supply the outdoor heat exchanger 7 with high temperature refrigerant through the hot gas bypass circuit 20 while sustaining heating operation through the refrigerant return circuit 30. Since the refrigerant on the indoor heat exchanger 3 side flows through the refrigerant return circuit 30, heating performance is sustained even during defrost operation. Furthermore, frost on the surface of the outdoor heat exchanger 7 can be melted efficiently because a part of the high temperature refrigerant flows through the hot gas bypass circuit 20.
|
