Comparative experimental study of an open piston compressor working with R-1234yf, R-134a and R-290

Among the different alternatives proposed in the automotive field to replace R-134a and R-1234yf is a new generation fluid which has recently gained great importance for MAC (Mobile Air Conditioning) systems. This fluid has the advantage of having a low GWP (Global Warming potential) and thermodynamic properties similar to R-134a. But there is some criticism regarding the non-natural origin of the fluid and its possible long-term effects on the environment have not been studied. In that sense, hydrocarbons and particularly R-290 can be considered as alternatives. This paper presents a comparative study between R-1234yf, R-134a and R-290 for an open piston compressor at different operating conditions. The text matrix comprised two compressor speeds, evaporation temperatures from −15 °C to 15 °C and condensation temperatures from 40 °C to 65 °C. From these tests, the compressor behavior with these refrigerants has systematically been analyzed in terms of compressor efficiency, volumetric efficiency, losses to the ambient and oil-refrigerant properties.

► R290 improves efficiencies and has less thermal losses.
► The new refrigerant R-1234yf has better efficiencies compared to R-134a for high pressure ratios.
► The capacity of the system with this new refrigerant is also reduced 10%–15%.
► R-1234yf discharge temperature is approximately 10 K lower than the other refrigerants.
► Oil sump temperature in R-1234yf could indicate lubrication problems with the used oil.