Refrigerating cycle apparatus with a compressor having simultaneously driven two compressor means

A refrigerating cycle apparatus with a compressor having two compressor means driven simultaneously, comprising `a compressor having first compressor means and second compressor means in a sealed container, said first and second compressor means being driven simultaneously by a motor unit and sucking refrigerant gas, said first compressor means discharging the compressed refrigerant gas into the sealed casing, and said second compressor means discharging the compressed refrigerant gas to an intermediate discharge pipe;

• a suction refrigerant pipe connected to the sealed casing of the compressor, and a suction refrigerant pipe connected to the suction side of the first and second compressor means;
• a refrigerating cycle circuit including a condenser for condensing and liquefying the refrigerant gas compressed and pressurized by the compressor, a pressure-reducing device for pressure-reducing the refrigerant liquefied by the condenser, an evaporator for evaporating for the pressure-reduced refrigerant to effect refrigeration, and said compressor, which condenser, pressure-reducing device, evaporator and compressor are successively connected between the discharge refrigerant pipe and each suction refrigerant pipe;
• a check valve, provided on the suction refrigerant pipe of the first compressor means, for checking the counterflow of the refrigerant from the first compressor means to the evaporator;
• and
• an electromagnetic three-way valve, provided on the discharge refrigerant pipe of the second compressor means, for selecting one of two discharge directions of the refrigerant gas from the second compressor means, wherein the electromagnetic three-way valve is operated such that the refrigerant gas compressed by the second compressor means is let to flow into the sealed casing when a refrigeration cycle load is equal to or higher than a predetermined value, thereby performing a parallel compression operation with use of the first and second compressor means, and the refrigerant gas compressed by the second compressor means is let to flow to the downstream side of the check valve when the refrigeration cycle load is lower than the predetermined value, thereby performing a two-stage compression operation in which compression is performed first by the first compressor means and then by the second compressor means.