Thermodynamic and carbon emission analysis with low GWP refrigerants in automobile air conditioning system

Automotive air conditioning systems negatively impact the environment through emissions. These emissions are impacted by ambient temperature and engine speed. Hence, this paper compares thermodynamic performance and carbon emissions of the low GWP refrigerants such as R1234yf, R1243zf, R450A, R143m, and R161 against R134a at different evaporator, condenser, and ambient temperatures and engine speeds. It is found that higher ambient temperatures lead to higher work consumption. Also, indirect emissions have a positive correlation with engine speed. After R161, refrigerant R134a has the highest input power, total exergy destruction, and cooling capacity. R1243zf, R143m, and R450A show approximately similar cooling capacities. Furthermore, at idle speed, R134a indicates the highest Total Equivalent Warming Impact (TEWI) of 7.65 tons CO2 per year. Whereas, at normal and high speeds, R161 shows the highest value of 12.38 and 17.33 tons CO2 per year, respectively. R1243zf, 1234yf, and R450A are the best alternative refrigerants to R134a.