Thermodynamic Analysis of Various Refrigerants for Automotive Air Conditioning System

摘要

This study investigates numerically the thermodynamic analysis of various refrigerants on the basis of vapor compression refrigeration cycle. The refrigerants studied are R134a, R152a, R1234yf, R404A, R407C, R410A and R507A. The aim of this research is to find the alternative refrigerant of R134a numerically. EES Professional V9.944-3D is used in the modeling of thermodynamic cycle of VCRC and calculating the performance parameters of VCRC. The comparison of thermodynamic VCRC for all the refrigerants is made. The performance parameters include: cooling capacity, input power of compressor, COP, compression ratio and discharge temperature. These parameters are calculated at engine speeds of 1000rpm, 2000rpm and 3000rpm, condenser temperature of 50 degrees C and evaporator temperature of 5C. The compressor volumetric efficiencies are taken as 0.75, 0.65 and 0.55 corresponding to engine speeds of 1000 rpm, 2000rpm and 3000rpm. The results of performance parameters for all refrigerants studied are exported to MATLAB R2017a software where the comparative analysis is performed. Results show that R152a is the only refrigerant which can be used as alternative in current AACS with minimum modification. The cooling capacity of R152a is slightly less than that of R134a, while its COP is found to be higher than that of R134a. R152a shows the highest COP improvement of 5.33% at engine speed of 1000rpm. It has very low GWP and almost same saturation pressure corresponding to condenser and evaporator temperature as that of R134a, so it can serve as alternative refrigerant in current AACS.