SCREW COMPRESSOR AND REFRIGERATOR

摘要

The invention provides a screw compressor with increased efficiency at part load and a refrigerator capable of increasing the performance of an economizer circuit in a part load region. An inverter (22) controls the rotational speed of a motor (27) to control the capacity of a screw compressor (21). Since no slide valve is provided in the screw compressor (21), compression chambers (C1, C2) are sealed at part load, and the refrigerant is spouted through an economizer passage to the compression chambers (C1, C2). Consequently, refrigerant supply will not become short if it is spouted into the compression chambers (C1, C2). The efficiency at part load thus increases by the fact that the motor (27) and the screw rotor (33) rotate at low speed and that the refrigerant spouted through the economizer passage has a sufficient cooling effect without affecting the refrigerant supply to the compression chambers (C1, C2) at part load.