Simulation and performance evaluation of trans-critical CO2 refrigeration system with modified evaporative cooled finned tube gas cooler in Indian context

Abstract

The gas cooler is the most sensitive component which affects the performance of the CO2 system in the trans-critical cycle, and its performance highly depends on the climatic conditions. The CO2 system operating in high ambient conditions has lower performance; therefore, it is necessary to improve the system. The present work investigates the performance of trans-critical CO2 refrigeration system with proposed modified evaporative cooled finned tube gas cooler and with finned tube gas cooler for typical Indian climatic conditions. A mathematical model of CO2 refrigeration system finned tube gas cooler has been developed and validated with experimental data (literature), for different operating conditions. Further, it is integrated with a separate subroutine developed for the modified evaporative cooler (experimentally validated). The simulation has been performed in MATLAB to evaluate and compare the annual performance of systems for five selected cities in India of different climatic conditions, with different operating conditions. The result shows a maximum increase in seasonal energy efficiency ratio is 28% at 8 MPa for Ahmedabad city using the system with modified evaporative cooled finned tube gas cooler compared to a system with finned tube gas cooler. The overall improvements in SEER for all the selected cities are in the range of 10–28%.