Numerical energy and exergy analysis of cooling systems: low GWP alternative refrigerants (R450A and R1234ze) to R134a

Abstract

The use of new generation refrigerants in heating and cooling systems operating according to vapor compression cycles and the preference of renewable energy sources is very important to reduce the negative effects on the environment. Here, the energy and exergy performance of refrigerant R450A and R1234ze, which are alternatives to R134a, were theoretically examined. Energy and exergy analysis of cooling system were performed under the same working conditions (source temperature is between -15 and 15 oC, and heat sink temperature is constant 30 oC). The COP values of R134a, R1234ze, and R450A were 2.00, 1.98 and 1.97, respectively, while the heat source temperature was -15 oC. The heat source temperature was 15 oC, the COP values of R134a, R1234ze, and R450A were 4.82, 4.83 and 4.79, respectively. Under the given operating conditions, the highest total exergy destruction occurred at R134a, while the lowest total Exergy destruction occurred at R1234ze. The refrigerant with the highest and lowest cooling capacity was R134a and R1234ze. According to the results obtained from the analysis, it was concluded that R450A and R1234ze can be used instead of R134a.