Screw compressor and freezer

摘要

A screw compressor has a screw rotor and a cylinder having an economizer port. The economizer port communicates with a compression chamber formed between the screw rotor and the cylinder. The economizer port is configured and arranged to jet a refrigerant into the compression chamber before closing the compression chamber. Accordingly, the economizer is in communication with the compression chamber while the inner pressure of the compression chamber is low.