MIXED REFRIGERANT FOR TURBO CHILLERS, TURBO CHILLERS USING SAME, MANUFACTURING METHOD FOR MIXED REFRIGERANT FOR TURBO CHILLERS, AND METHOD FOR DETERMINING MIXING RATIO OF MIXED REFRIGERANT FOR TURBO CHILLERS

摘要

Provided is a mixed refrigerant capable of being used in conventional impellers for which a plurality of refrigerants is mixed, and the sound speed of the mixed refrigerant is adjusted to correspond to the sound speed of a conventional impeller in a turbo chiller. A mixed refrigerant for a turbo chiller comprises a first refrigerant with a GWP of no more than 700 and a density of no less than 15 kg/m³ and no more than 25 kg/m³ and a second refrigerant with a GWP of no less than 1 and no more than 10 and a density of no less than 10 kg/m³ and no more than 15 kg/m³, and the density of the gas taken into the compressor after mixing is no less than 10 kg/m³ and no more than 25 kg/m³. As a result, a sound speed approximately equal to the case of using R410A, that has been conventionally used, as the refrigerant, can be ensured for a centrifugal compressor (3) of a turbo chiller (1). Furthermore, a mixed refrigerant can be provided that has a GWP smaller than the case of using a single refrigerant having a high density but also having a large GWP, which is currently in wide use.