Thermodynamic investigation of R744 and R134a based refrigeration cycle

Abstract

The present work is an investigation of refrigerating cycles and the compressors work for R134a and CO2/R744 refrigerants. Relative demonstration conferred has been peculiarly created design for small cooling capacities and an evaporation temperature. An accurate numerical feigning miniature for compressors work performance has been used to numerically collate both R134a and R744 based compressor prototypes. To validate the detailed numerical simulation of the thermal and fluid dynamic behavior of single stage vapor compression refrigerating unit has been developed and utilized. The numerical outcomes obtained from the thermodynamic investigation reveals a satisfactory agreement, while the relative global values indicate resembling efficiencies under the identical working conditions. Compare is made between R744 and R134a as a refrigerant to pick up heat at −17.7°C and reject at 60°C. R744 requires significantly higher pressures and results in higher temperature from compressor and have lower coefficient of performance. Thermodynamic calculations are done with REFPROP software.