TWO-STAGE COMPRESSIBLE REFRIGERANT COMPRESSOR

摘要

PROBLEM TO BE SOLVED: To improve the startability of a two-stage compressible refrigerant compressor. SOLUTION: This refrigerant compressor is formed so that an electric motor 5 operated at variable speeds and a two-stage compression mechanism 4 connected to the electric motor 5 are disposed in an enclosed container 3. Only when the electric motor 5 runs at a speed exceeding a set speed, a stop valve communicates the downstream side of an expansion device 15b in a two-stage compression refrigeration cycle with the suction side of the high-stage compression element of a two-stage compression mechanism 4. Thus, the refrigerant gas in compression stage flows reversely to the downstream side of the expansion device 15b, the specified, torque of the electric motor can be assured and the stoppage of the compressor due to abrupt variation in compression can be avoided.