Performance analysis of a jet cooling system using refrigerant mixtures

The optimisation of a jet cooling system using refrigerant mixtures as substitutes of pure refrigerants has been investigated. A steady-state simulation program, for given temperatures of the sources, integrating simple models of each component has been developed. A Peng-Robinson equation of state assuming equality of the fugacities of the two phases was used to model the thermodynamic properties of the vapour and liquid-vapour equilibrium. The refrigerants investigated in this study are: the pure refrigerants R142b, R152a, RC318, R124, R134a, R22 and the binary refrigerants R22/RC318, R22/R142b, R22/R124, R22/R152a, R22/R134a, R134a/R142b, R152a/R142b and R134a/R152a. Results show that the use of a binary mixture does not always increase the performance of system. Generally, when the mixture is strongly zeotropic (e.g.: R22/RC318), the cooling efficiency of the system decreases. However, when the mixture is mildly zeotropic (e.g. R134a/R142b) or almost azeotropic (e.g. R134a/R152a), efficiency and energetic efficiency increase. (C) 1999 Elsevier Science Ltd and IIR. All rights reserved.