A theoretical and experimental study on the variable evaporating temperature refrigeration performance of non-azeotropic refrigerant mixtures.

A variable evaporating temperature refrigeration system of new non-azeotropic refrigerant mixtures with wide gliding temperature is proposed which can efficiently provide 7°C/12°C and 18°C/23°C cold water for THIC. The system based on the Lorenz cycle, in this work, R236fa/R32 (0.7/0.3) was selected as the working fluid. The cycle performance was analyzed based on the simulation of the ideal cycle and the working cycle. The air conditioning load was fixed at 4.66 kW, Comparing with the conventional refrigeration system are analyzed, and the effects on the properties of heat and moisture load matching unit are analyzed. The influence of variable evaporation temperature on the performance of the unit were studied through experiment. The research show that, when 0.2< α <0.5, this system has the effect of saving energy relatively Carnot cycle, the largest COP increased 22%. The COP decreases with increasing α. This system is not recommended for high wet load ratio (α >0.5) and low wet load ratio (α <0.2) air conditioning system. The evaporation temperature rises, the refrigerating system capacity and the COP increase with the evaporation temperature rises.