Performance Analysis of Ejector Assisted Vapor Compression Cascade Refrigeration System

In the present study, the thermodynamic balances and computational code of a cascade vapor compression cycle with an ejector are developed to reach a refrigeration temperature of \(-{{50\,}^{\circ }}\) C. The working fluids proposed for analysis are R744 (carbon dioxide, \( CO_{2}\) ), R707 (ammonia, \( NH_{3}\) ), R600a (Isobutane, \((H_{3}C)-CHCH_{3}-CH_{3}\) ), and R290 (propane, \(CH_{3}-CH_{2}-CH_{3}\) ) given the low values of ozone depletion potential (ODP) and global warming potential (GWP). The first and second laws of thermodynamics are used to evaluate the efficiency and exergy destruction of the system keeping \(CO_2\) in the low-temperature cycle and proposing the use of an ejector. The pair of working fluids R600a/R744 is outlined with the highest efficiency potential (COP = 7.63), lowest exergy destruction (3.3307 kW), and a good prospect for future development.