Multistage Compressor

Abstract

A multistage compressor employing a gas injection system for CO2 cycle that attains enhancements of compression efficiency and compression performance. The multistage compressor is multistage compressor (2) for CO2 cycle (1) adapted to carry out two-stage compression involving emitting the CO2 refrigerant gas compressed by inferior-stage side rotary compression means (4) into sealed housing (3) and having the intermediate-pressure refrigerant gas within the sealed housing (3) suctioned by superior-stage side scroll compression means (5), wherein to the sealed housing (3), there is connected gas injection circuit (15) capable of injection of intermediate-pressure CO2 refrigerant gas extracted from a refrigerant circuit into the sealed housing (3), and wherein the inferior-stage side rotary compression means (4) and the superior-stage side scroll compression means (5) are approximately identical with each other in pressure ratio and approximately equivalent with each other in displacement ratio.

Dependencies are inferred from the claim text.