Fractionation, Low GWP blends, Miscibility, Solubility, Material Compatibility
The development of lower global warming potential (GWP) blends offers an alternative for the widely used high GWP fluids such as R404A. Commercial refrigeration systems for supermarkets are a common example for such systems. These kinds of systems show relatively large refrigerant leakage rates of 15% to 20% per year. The newly developed R404A lower GWP alternatives are zeotropic blends, meaning they show a temperature glide during phase change processes in the evaporator and condenser of the system. Because of the glide, there is a concern within end users that the blend components could separate, or fractionate, during a leak event. Â This paper will describe the results from tests carried out to determine the effect of refrigerant fractionation and its effect on the performance of an actual refrigeration system subject to multiple leak events. The second part of this paper provides characteristics for the solubility and miscibility of R448A with POE oil and results from a material compatibility study of R448A with common materials used in refrigeration equipment.