Effects of alternative refrigerants on the ejector dimensions for single and dual ejectors enhanced bus air conditioning system

Abstract

One of the most critical criteria influencing the performance of an ejector enhanced vapor compression refrigeration system is the ejector size. R134a was chosen as the refrigerant in the majority of the research studies since it is widely used in practical applications. The use of R134a refrigerant, on the other hand, is restricted under the Kyoto Protocol due to its high global warming potential (GWP). In this study, an investigation was conducted to evaluate the differences in ejector dimensions that may occur when alternate refrigerants such as R1234yf, R1234ze(E), or R600a were used in the ejector enhanced bus air conditioning system. The cycle is analyzed thermodynamically to determine the state points. The diameters and lengths of the ejectors were determined using continuity, energy, and momentum equations. It can be observed that the kind of refrigerant has a significant impact on the size of the ejector. It is also determined that the R1234yf has the closest size to the R134a, and it can be deduced that utilizing a dual ejector decrease the overall size of the ejector, hence eliminating technical concerns in the ejector production process.