Off-Design Analysis of Hydrocarbon-based Ejector-Expansion Refrigeration Cycle

In this paper, the off-design performance of an ejector-expansion refrigeration cycle (EERC) using several hydrocarbon refrigerants including propane, butane, isobutane and propylene as working fluids is analyzed based on energy and exergy concepts. A constant-pressure ejector flow model is employed in the simulation. The results indicate that, the hydrocarbon-based EERCs have higher COP, volumetric cooling capacity and exergy efficiency, as well as lower exergy destruction compared with the standard refrigeration cycle. In addition, as the difference between the condensing and evaporation temperatures increases, the advantages of the hydrocarbon-based EERCs become more prominent under off-design conditions. Propane and propylene used in the EERC in general have better performance than those of isobutene and butane.