JJMIE Volume 14, Number 2, June. 2020 ISSN 1995-6665 Pages 183 - 193 Jordan Journal of Mechanical and Industrial Engineering Simulation and Performance Evaluation of CO 2 Booster System Integrated with Modified Evaporative Cooling for Supermarket Application in India Manju Lata, Rishabh Yadav, Dileep Kumar Gupta * Institute of Infrastructure Technology Research And Management (IITRAM) Ahmedabad, Gujarat, India Received December 7 2019 Accepted April 25 2020 Abstract CO2 is one of the rediscovered, ecologically safe refrigerants with very low global warming potential which has favorable thermo-physical properties. The CO2 booster refrigeration system has already been identified as a suitable choice for the supermarket application to replace the conventional R404A (high GWP) system. However, the performance of the CO2 booster system is still comparatively lower than the conventional R404A system, especially when operated at high ambient temperature, which compels to improve the performance of the CO2 system with suitable modification. In the present work, an attempt has been made to examine the year-round performance of the basic booster system and basic booster system with the integrated modified evaporative cooling system for Ahmedabad city weather conditions (Hot and Dry climate region). The experimentally investigated and validated data are used for the modified evaporative cooling system with real-time weather data taken from the weather station installed in the institute. Subsequently, the performance of the BBS, BBS-MEC, and R404A systems have been compared in terms of COP, power consumption, and seasonal energy efficiency ratio. The results show that for BBS- MEC, SEER enhances by 28.66% and annual power consumption decreases by 22.89% as compared with BBS. In addition to that, the total environment warming impact is also found significantly lower in the case of the BBS-MEC system. © 2020 Jordan Journal of Mechanical and Industrial Engineering. All rights reserved Keywords: CO2 refrigeration, booster system, evaporative cooling, R744, natural refrigerator, supermarket; 1. Introduction Supermarket installations are continuously increasing worldwide, which lead to an increase in the use of R404A as a refrigerant for the supermarket. The refrigerant leakage rate predicted using this refrigerant ranges from 3% to 35% [1], which contributes to direct global warming due to high GWP. Subsequently, the power consumption of the system contributes to increasing global warming indirectly. Several alternative low GWP refrigerants, viz. CO2, R600a, R32, NH4, R290, and R1234yf, etc. have been proposed to reduce the direct contribution of global warming. However, except CO2, afore said refrigerants are either toxic and/or flammable. As a natural refrigerant with excellent thermo- physical and heat transfer characteristics, CO2 has been recognized as an encouraging substitute [2]. Further, safety features i.e. non-flammability and non-toxicity in nature make CO2 an attractive replacement of the conventional refrigerants. CO2 has already been effectively commercialized in low-temperature climate regions, however, using in high-temperature climate regions, is still a challenge due to poor system performance at high ambient temperature [3].The lower critical temperature of CO2i.e. 31.1oC makes the CO2 cycle trans-critical, consequently, the CO2 system performs vulnerably at high-temperature climates. Several studies have been carried out on the use of CO2 as a refrigerant for supermarket applications in different ambient conditions, some of the recent developments are summarized below, The water spray technique was used for reducing gas cooler outlet temperature when operated at high ambient temperatures [4]. The yearly energy savings were limited to 3-5% and stated that saving is significant due to the high cost of electricity in peak summer periods. A theoretical investigation was done on two main trans-critical CO2 systems centralized with an accumulation tank at the medium temperature and parallel with two separate circuits for low and medium temperature [5]. The performance of the centralized system with two-stage compression was found better in ambient temperature range 10- 40ºC.Theoretical analysis is done of the trans-critical booster system for supermarket applications [6].The possible parameters were identified which affect the performance of the system at high ambient temperature. It was concluded that high side pressure, is highly dependent on compressor efficiency, ambient temperature, and suction line heat exchanger. Comparison is done for different configurations of the CO2 system with the baseline R404A direct expansion system using bin analyses in the eight climate zones of the * Corresponding author e-mail: dileep.vnit@gmail.com.