Thermodynamic and experimental analysis of using of the new refrigerants at vehicle air conditioning units

In this thesis, it was aimed to design an Minibus air conditioning unit. In this context, utilization of two different refrigerants, R-1234yf and R-134a were assessed, theoretically.The need for low GWP refrigerants and the transition to these refrigerants were explained in a chronological order, while the legislations and restrictions were also considered. The new refrigerant R-1234yf was explained in more detail and its utilization in refrigeration applications was presented. Ideal cycle analyses of R-134a, R-1234yf, R-1234ze and R-407C, were performed at eight different evaporating and four condensing temperatures. Their performances were assessed and compared with each other. Cooling load calculations were made for a volume of a minibus cabinnet and subsequently, the cooling cycle analyses of these four refrigerants at a cooling load of 9 kW were made for these two refrigerants. The main components of the system using R-1234yf and R134a were selected according to the results of the cycle analysis. Finally, the findings were assessed and the performance of R-1234yf was compared to R134a multifaceted.