To remove water entering a refrigerating cycle, improve the reliability of a device and simultaneously improve an operating efficiency upon operation under a condition of intermediate load and an operating efficiency upon operation under a condition of high load in an air conditioner using a refrigerant which does not destroy the ozone layer.
An air conditioner including a compressor 1, a condenser 2, a main pressure reducing device 3 and an evaporator 4 which are connected together through a piping comprises a bypass circuit 20 branched at a branch point 28 and connected to a main circuit at a connecting point 29, an auxiliary pressure reducing device 5, an auxiliary heat exchanger 6 and a drier 7. A single refrigerat including no chlorine in molecules or a mixed refrigerant is employed as a refrigerant and a heat exchanging is performed between the refrigerant from the branch point 28 to the main pressure reducing device 3 and the refrigerant from the auxiliary pressure reducing device 5 to the connecting point 29 by the auxiliary heat exchanger 6. The auxiliary pressure reducing device 5 is controlled based on the operating load of the compressor 1 by a bypass flow controller 8. At least one of the evaporator 4 and the condenser 2 narrows the passage of the refrigerant to increase the flow velocity of the refrigerant.
YOSHIDA YUJI
OKAZA NORIHO
