Experimental exergy analysis of R513A to replace R134a in a small capacity refrigeration system

Abstract

The replacement of HFCs using lower GWP refrigerants in the coming years is a priority to reduce the predicted climate change. The exergy analysis of vapor compression systems can help to identify the feasibility of alternative fluids in existing installations and the potential to improve them. In this sense, this paper presents an exergy analysis of an experimental setup which operates with R134a and the alternative HFO/HFC mixture R513A. The evaporating temperature is ranges between −15 °C and 5 °C, while the condensing temperature is set at 30 °C and 35 °C. In this analysis, the highest amount of exergy destruction rate is obtained at the compressor, followed by the evaporator. The maximum exergy efficiencies are observed at the condenser and the thermostatic expansion device. Finally, the average global exergy efficiency of R513A when replaced R134a in this refrigeration experimental setup is 0.4% higher (absolute difference), and with respect to the components, there is only slight reduction in efficiency in the condenser using R513A. Therefore, the R513A replacement is acceptable according to the second law of thermodynamics.