Performance Investigation of Natural Refrigerant R290 as a Substitute to R22 in Refrigeration Systems

Use of natural refrigerant R290 can play a vital role in fulfilling the objectives of the international protocols like Montreal and Kyoto. Because of environmental problems such as ozone depletion and global warming, R22 needs to be phased out on urgent basis. This paper analyzes the possibilities of R290 as a potential substitute to R22. Thermodynamic performance analysis of refrigerants R290 and R22 was carried out using standard vapour compression cycle, with evaporating temperature range of -25°C to 10°C for the condensing temperature of 45°C, based on analytical calculations. Refrigerant properties were obtained from REFPROP 9.0. Performance parameters like, discharge temperature, volumetric refrigerating capacity and required mass flow of refrigerant were found to be lower with R290 when compared to R22. Coefficient of performance with R290 is slightly lower than that of with R22. However, higher COP can be expected by especially designed system pertaining to the properties of R290. Overall, R290 can be a better substitute to R22 in real applications because of its excellent environmental and thermo-physical properties.