Patent ID: 6615597
Filing Date: 2003-09-09
Classification: F25B

Abstract:
A refrigeration system, comprising:an outdoor unit (1) including a compressor (4), a flow path switching mechanism (5) for switching a circulation direction of a refrigerant discharged from the compressor (4), an outdoor heat exchanger (6), and an expansion valve (7) capable of being fully closed; an indoor unit (2) including an indoor heat exchanger (8); and a communication pipe (3) for connecting the outdoor unit (1) and the indoor unit (2) to each other, wherein: the outdoor unit (1) includes: a receiver (10) provided upstream of the expansion valve (7); a gas vent passageway (12) for connecting the receiver (10) and a downstream side pipe (24) of the expansion valve (7) to each other; gas vent opening/closing means (13) provided along the gas vent passageway (12); and a bridge circuit (11), wherein during a cooling operation, the bridge circuit (11) only allows a refrigerant flow in such a direction as to lead the refrigerant, which has been condensed through the outdoor heat exchanger (6), to the receiver (10) and a refrigerant flow in such a direction as to lead the refrigerant, which has been depressurized through the expansion valve (7), to the indoor heat exchanger (8), and during a heating operation, the bridge circuit (11) only allows a refrigerant flow in such a direction as to lead the refrigerant, which has been condensed through the indoor heat exchanger (8), to the receiver (10) and a refrigerant flow in such a direction as to lead the refrigerant, which has been depressurized through the expansion valve (7), to the outdoor heat exchanger (6); and the refrigeration system further comprises control means (35) for, before shutting down the compressor (4), opening the gas vent opening/closing means (13) and closing the expansion valve (7) while the compressor (4) is left operating, and for closing the gas vent opening/closing means (13) upon subsequent shut down of the compressor (4).