Refrigeration system incorporating scroll type compressor

A refrigeration system comprising:

• a scroll type compressor including a fixed scroll member having an end plate and a spiral warp protruding upright therefrom, an orbiting scroll member having an end plate and a spiral wrap protruding upright therefrom, a discharge port formed in a central portion of said end plate of said fixed scroll member, a suction port formed in a peripheral portion of said end plate of said fixed scroll member, at least one gas injection port formed through the thickness of said end plate of said fixed scroll member in a portion of said end plate near said spiral wrap, at a position spaced from the wall of said spiral wrap by a radial distance smaller than a thickness of said spiral wrap, a discharge pipe connected to said discharge port, a suction pipe connected to said suction port, and means for causing an orbiting movement of said orbiting scroll member with respect to said fixed scroll member without permitting the same to rotate around its own axis;
• a refrigerant circuit means connected between said suction pipe and said discharge pipe of said scroll type compressor and including a four-way valve, indoor heat exchanger, first pressure reducer, gas-liquid separator, second pressure reducer, and an outdoor heat exchanger;
• and
• a gas injection passage means connected between a gas outlet formed in an upper part of said gas-liquid separator and said gas injection port, so as to permit the refrigerant gas in the upper part of said gas-liquid separator to be additionally supplied into the compression chambers under compression in said scroll type compressor.