Thermodynamic Cycle Analysis of Mobile Air Conditioning System Using Hfo-1234yf as an Alternative Replacement of Hfc-134a

Abstract

This paper presents thermodynamic cycle analysis of mobile air conditioning system using HFO1234yf as alternative replacement for HFC-134a. Under a wide range of working conditions (Varying Condensing temperature, Evaporating temperature, Sub cooling and sub heating with Internal heat exchanger (IHX) and without internal heat exchanger) on simple vapor compression system, we compare the energy performance of both refrigerants - R134a and HFO1234yf. Result shows that without using an Internal heat exchanger, At lower condensing temperature (35oC), Mass flow rate increases about 27-32%, refrigerating effect decreases 22-25%, co mpressor work increases 4-6% and COP decreases about 3-5%. While at higher condensing temperature (55oC), mass flow rate increases about 35-42%, refrigerating capacity decreases 27-30%, and compressor work increases 8-13% and COP decreases 7-10%. Using an internal heat exchanger (IHX), these differences in the energy performance are significantly reduced. At lower condensing temperature (35oC), mass flow rate decreases about 18-22%, refrigerating capacity decreases 15-18%, compressor work increases 1-3% and COP decreases about 2-3% and At higher condensing temperature (55oC), mass flow rate decreases 23-28%, refrigerating capacity decreases 18-22%, compressor work increases 5-8% and COP decreases about 4-7%. The energy performance parameters of HFO1234yf are close to those obtained with HFC-134a at Low condensing temperature and making use of an IHX. Even though the values of performance parameters for HFO1234yf are smaller than that of HFC-134a, but difference is small so it can be a good alternative to HFC-134a because of its environmental friendly properties with introducing IHX.