Performance Enhancement of Transcritical CO₂ Refrigeration Systems Using Modified Evaporative Cooling under Indian Climatic Conditions

Abstract

The performance of transcritical CO₂ refrigeration systems deteriorates in high ambient conditions, posing a challenge for their deployment in Indian climates. This study investigates the integration of Modified Evaporative Gas Cooling (MEGC) as an enhancement strategy and evaluates its effectiveness in two distinct climatic zones: hot–dry (Ahmedabad) and moderate (Bangalore). Experimental validation in Ahmedabad and MATLAB simulations extended to Bangalore demonstrate substantial improvements in both cooling capacity and coefficient of performance (COP). Quantitatively, the Annual Average Gas Cooling Capacity (AAGC) increased by 7.5–33.9% in Ahmedabad and by 5.1–10.0% in Bangalore compared to the finned gas cooler (FGC). COP enhancements were most pronounced at lower operating pressures, with Ahmedabad recording a 20.4% improvement at 7.5 MPa and Bangalore showing a 9.7% gain under similar conditions. Seasonal Energy Efficiency Ratio (SEER) values further confirmed annualized benefits, reaching up to 27.8% in Ahmedabad and ~15% in Bangalore. Qualitatively, the results reveal that hot–dry climates maximize the advantages of evaporative cooling, whereas moderate climates provide steady but consistent performance gains across all operating pressures. The novelty of this work lies in its combined experimental validation and location-specific simulation, offering both technical insights and practical guidelines for designing sustainable CO₂ refrigeration systems tailored to diverse Indian climatic conditions.