Thermodynamic analysis of two evaporator vapor compression refrigeration system with low GWP refrigerants in automobiles

Abstract

Due to the growing demand for refrigerators and air conditioners in automobiles, there is a need for an innovative and efficient design to achieve both refrigeration and air conditioning. To address this, the present work has evaluated a two-evaporator vapor compression system to eliminate the requirement for separate refrigeration and air conditioning units. Theoretical energy and exergy performance assessment of the same is carried out along with the variation in the condenser and evaporators temperature. Various low GWP refrigerants such as R1234yf, HFO1336mzz(Z), R513A, and R450A are compared against high GWP R134a and R452A. The results reveal that maximum exergy efficiency and COP and lowest compressor power of 31.50%, 2.47, and 6.304 kW, respectively, are obtained with HFO1336mzz(Z). After HFO1336mzz(Z), R134a shows the highest exergy efficiency and COP of 30.56% and 2.41, respectively, and the lowest compressor power of 5.61kW. HFO1336mzz(Z) exhibits the optimum performance, whereas R452A shows the worst thermodynamic performance in the system. It is also found that the performance of R450, R513A, R450A, and R1234yf is approximately equivalent to each other. Moreover, component-wise exergy destruction analyses indicate that the efficiency of the compressor needs to be improved as the maximum destruction of 61.84–56.00% occurs in the compressor while the minimum exergy destruction of 0.42–0.54% occurs in the expansion valve. This study proposes the two-evaporator system for both refrigeration and air conditioning in automobiles. It is also found that R450A, R1234yf, R513A, and HFO1336mzz(Z) can be the potential alternative to R134a.