This paper attempts to disclose the advances of zeotropic refrigerant mixture R236fa/R32 over the traditional refrigerants and the energy-saving mechanism of the DCS-THIC AC system. For this purpose, the physical and thermodynamic properties of R236fa/R32, R22, R410A, R407C and R134a refrigerants were compared, and the performance of R236fa/R32 refrigeration system was investigated on a 4.0kW double evaporating temperature (DET) chiller, which applies to the temperature and humidity independent control (THIC) AC system. The results show that the R236fa/R32 refrigerant mixture can save more energy than the traditional refrigerates. When the mass fraction of R32 reaches 60%, the coefficient of performance (COP) of R236fa/R32 refrigerant mixture peaks at 4.55, and the compressor power is minimized at 1.2kW. In addition, the humidity control effect and fresh air volume of the THIC AC system with dual cooling sources (DCS-THIC AC) in four operating modes were compared to the traditional AC system in three operating modes. The comparison reveals that the DCS-THIC AC system using R236fa/R32 (0.4/0.6) refrigerator mixture saves more energy than the AC system using pure R22. Particularly, the energy efficiency can be improved by 27.22% by the DCS-THIC AC system in Mode 4. The research findings shed new light on the energy conservation of AC system in hot summer and cold winter region.
coefficient of performance (COP), temperature and humidity independent control (THIC), double evaporating temperature (DET) chiller
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