Paper presented at the 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Turkey, 19-21 July, 2010.
Refrigeration systems using natural hydrocarbon (HC) refrigerants have a favourable direct impact on the environment. However, their total contribution can match that of the corresponding systems using synthetic refrigerants if they are less efficient. Considering the added costs due to safety considerations, the energy efficiency of HC systems is crucial for their acceptability. This paper describes a theoretical computer model developed for evaluating propane-butane mixtures as natural alternative refrigerants. The model, which compares the performance of these refrigerants with that of conventional synthetic refrigerants, is validated against experimental data that compared LPG to Rl2 for domestic refrigeration. Results of the present model show that it correctly predicts the differences observed in the experiment. The model shows that an 8% increase in the refrigeration capacity can be achieved with LPG as compared to R12.