| The transcritical CO2 (R-744) automotive air conditioning system is a promising green solution to the currently used HFC-134a (R-134a) system and its considerable global warming impact. The advantages as well as the remaining challenges of the CO2 system have been deduced based on a comprehensive literature review. To optimize the CO2 air conditioning system and to increase its performance to the level of the conventional HFC-134a system, a comparison between CO2 and HFC-134a system performances was conducted in this simulation study.; The simulation was performed on CO2 and HFC-134a automotive air conditioning systems as a comprehensive parametric study under practical system operating conditions. During the system operation, the characteristics of the transcritical CO2 refrigeration cycle were investigated in detail, and the beneficial thermophysical properties of CO2 refrigerant were identified.; In addition, a detailed analysis based on the first and second laws of thermodynamic was applied to identify the thermodymanic losses of transcritical CO2 and conventional HFC-134a refrigeration systems. (Abstract shortened by UMI.)... |
