Exergy analyses of two and three stage cryogenic cycles

Abstract Cryogenics has an important influence on industry and science. In this study, optimum working conditions are obtained by applying exergy analysis local optimization methods to two- three-stage vapor compression cascade cryogenic cycle. The first second laws of thermodynamics, analysis, applied the By considering needs demands, it is possible create new cycles adding devices and/or stages these cycles. results operating for It seen that achieve high COP values efficiency; necessary reduce ratio compressor as much fluid allows. For two-stage cycle, minimum total work required cooling around P 7 = 2,400 kPa. value 0.30 between 2,800 kPa, maximum efficiency 0.235. first-stage at pressures increases losses entire cycle from 7,500 18,550 kW. increase in 247%, 160%. When second-stage operated low pressure, 2%, 20%, decrease 40%.