Performance analysis of sub-cooled transcritical CO2 refrigeration system using vapour absorption refrigeration system and dew point evaporative cooling

Abstract

Shifting towards natural refrigerants is expected to reduce the environmental damage in terms of refrigerants leaks, as they have zero ozone depletion potential as well as minimal global warming potential. A CO2 transcritical cycle is analysed thermodynamically in this study. Further, to improve the performance of the CO2 system, a vapour absorption refrigeration system (driven by the heat available at the exit of the compressor) has been integrated with it. Also, to counter the effects of hot climatic conditions, in Indian context, a dew point evaporative cooling system is further utilized to take up the heat from the gas-cooler. A thermodynamic and economic study of the proposed integrated system is performed. The effect of various performance parameters; such as ambient dry bulb temperature, relative humidity, evaporator temperature has been studied on the overall performance of the system. Compared to the base case, the coefficient of performance is improved in the range of 40%–270 %, for the hybrid systems, under the different climatic conditions. Moreover, the proposed system provided a low-cost performance of about 0.024 $/kWh, as compared to the base case consumption of about 0.05 $/kWh.