Performance analysis of a jet cooling system using refrigerant mixtures

The optimisation of a jet cooling system using refrigerant mixtures as subs titutes of pure refrigerants has been investigated. A steady-state simulati on program, for given temperatures of the sources, integrating simple model s of each component has been developed. A Peng-Robinson equation of state a ssuming equality of the fugacities of the two phases was used to model the thermodynamic properties of the vapour and liquid-vapour equilibrium. The r efrigerants investigated in this study are: the pure refrigerants R142b, R1 52a, RC318, R124, R134a, R22 and the binary refrigerants R22/RC318, R22/R14 2b, R22/R124, R22/R152a, R22/R134a, R134a/R142b, R152a/R142b and R134a/R152 a. Results show that the use of a binary mixture does not always increase t he 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 azeotro pic (e.g. R134a/R152a), efficiency and energetic efficiency increase. (C) 1 999 Elsevier Science Ltd and IIR. All rights reserved.