PREDICTION OF PERFORMANCE OF A JET COOLING SYSTEM OPERATING WITH PURE REFERIGERATING OR NONAZEOTROPIC MIXTURES

This paper investigates a simple model of an ejector-compression refrigeration cycle and its applications to air conditioning. The efficiency of the machine using either classical refrigerants (R11, R22, R114), other pure refrigerants (R123, R133a, R134a, R141b, R142b, R152a, RC318) or non-azeotropic mixtures is presented. The results suggest that, for different temperatures of the heat source and the heat sink, the entrainment ratio and the system efficiency depend mainly on the fluid type and the mixture composition. An exergetic analysis shows that the major part of the exergy destruction takes place in the ejector, but the boiler and condenser exergetic losses are significant too. Also studied was the use of mixtures having a molecular weight in the power loop different from that of the refrigerant loop, owing to a distillation at the ejector output.