Zeotropic refrigerants, compared with conventional refrigerants, have different characteristics during evaporation and condensation. This article summarizes the special characteristics of zeotropic refrigerants in five aspects: fractionation behaviour; non-leakage-related concentration change; leakage-associated concentration change; gliding temperature and the limitation on media flow rate; and degradation in heat transfer. The relevant thermo-dynamic performance has been analysed. Newly developed technology for improving system efficiency and reliability has been incorporated in the discussion.
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