A THERMODYNAMIC ANALYSIS OF VARIOUS EJECTOR EXPANSIONS IN R-744 TRANS-CRITICAL CYCLES AT WARM WEATHER CONDITION

摘要

Refrigeration and air conditioning addresses fundamental human requirement in the fields like foodrnconservation, health care and thermal comfort worldwide. Major research is currently focused towardsrnimproving the cycle efficiency of natural refrigerants as they have much lower GWP and ODP.rnTranscritical R-744 cycle is a promising refrigeration cycle using natural refrigerant. In this study, fiverndifferent configurations of ejector expansion R-744 trans-critical cycle are identified from literature.rnThermodynamic analysis of each are carried out using constant pressure mixing model assumingrnequivalent cooling load and warm weather operating condition. Performance parameters such as COP,rnentrainment ratio, pressure recovery and exergy destruction rate are compared for the various cycles byrnvarying motive nozzle inlet condition and evaporator condition. Study clearly brings out relative meritsrnof ejector expansion cycles in improving COP at warm weather operating condition.