Patent ID: 7194873

Claim:
A refrigerating machine equipped with an outdoor unit containing a compressor and an outdoor heat exchanger serving as a heat-source side heat exchanger, a plurality of indoor units each of which contains an indoor heat exchanger as a using side heat exchanger and is connected to the outdoor unit through an inter-unit pipe, one end of the outdoor heat exchanger being selectively connected to any one of a refrigerant discharge pipe and a refrigerant suction pipe of the compressor, the inter-unit pipe comprising a high-pressure pipe connected to the refrigerant discharge pipe, a low-pressure pipe connected to the refrigerant suction pipe and an intermediate-pressure pipe connected to the other end of the outdoor heat exchanger, and one end of the indoor heat exchanger of each of the indoor units being selectively connected to any one of the high-pressure pipe and the low-pressure pipe while the other end of the indoor heat exchanger concerned is connected to the intermediate-pressure pipe, whereby the plural indoor units carry out any one of cooling operation and heating operation at the same time or carry out both cooling operation and heating operation in mixture at the same time, characterized in that the compressor has an intermediate-pressure portion in which refrigerant having intermediate pressure higher than the pressure of the refrigerant at the suction side of the compressor and lower than the pressure of the refrigerant at the discharge side of the compressor is allowed to be introduced, and an intermediate-pressure receiver that is inserted in a refrigerant flow path between the heat-source side heat exchanger and the using side heat exchanger to carry out gas-liquid separation on gas-liquid mixed refrigerant after heat exchange in the heat-source side heat exchanger or the using side heat exchanger and then feed gas-phase refrigerant to the intermediate-pressure portion.