Abstract: In a refrigerating cycle device using carbon dioxide as a refrigerant, there exists a problem that the provision of a receiver at a low-pressure side increases cost and volume due to a pressure resistance design necessary for ensuring safety. By adjusting a refrigerant holding quantity of a first heat exchanger in such a manner that a refrigerant pressure of the first heat exchanger 13 is changed by operating a first decompressor 12 and a second decompressor 15, an imbalance of a refrigerant quantity between time for space cooling and time for heating or dehumidifying can be alleviated and hence, it is possible to perform an operation of the refrigerating cycle device with high efficiency with a miniaturized receiver or without providing the receiver.

Abstract: A refrigeration cycle apparatus having a linear compressor is provided with a volume circulation rate instruction unit for obtaining a volume circulation rate Vco of a refrigerant in accordance with refrigerating capacity required of the refrigeration cycle apparatus, on the basis of an ambient temperature of an indoor heat exchanger (evaporator), a target temperature set on the evaporator by the user, and an ambient temperature of an outdoor heat exchanger (condenser). A volume circulation rate detector is provided for detecting a volume circulation rate Vcd of the refrigerant that actually circulates in a refrigerant circulation path of the refrigeration cycle apparatus; and an inverter is provided for generating an AC current for driving the linear compressor. The inverter is controlled so as to decrease a difference between the volume circulation rate Vco and the volume circulation rate Vcd.

Abstract: Refrigeration-cycle equipment using carbon dioxide (CO2) as the refrigerant can prevent problems such as the sharp elevation of high pressure on startup or the like, and the unsuccessful startup of the compressor due to the operation of the high-pressure protecting mechanism, by constituting the refrigeration-cycle equipment wherein an oil separator is installed as a refrigerant vessel in a part of the high-pressure-side circuit; a linear compressor of an oil-less type or an oil-poor type is used; or the quantity of the CO2 refrigerant filled in the circuit is 0.25 kg or less per liter on the basis of the total internal volume of the circuit.

Abstract: A refrigeration cycle apparatus having a linear compressor is provided with a volume circulation rate instruction unit for obtaining a volume circulation rate Vco of a refrigerant in accordance with refrigerating capacity required of the refrigeration cycle apparatus, on the basis of an ambient temperature of an indoor heat exchanger (evaporator), a target temperature set on the evaporator by the user, and an ambient temperature of an outdoor heat exchanger (condenser); a volume circulation rate detector for detecting a volume circulation rate Vcd of the refrigerant that actually circulates in a refrigerant circulation path of the refrigeration cycle apparatus; and an inverter for generating an AC current for driving the linear compressor; wherein the inverter is controlled so as to decrease a difference between the volume circulation rate Vco and the volume circulation rate Vcd.