High-performance cold thermal energy storage for clean and efficient cooling

This study aims to optimise the thermal performance and space efficiency of Cold Thermal Energy Storage (CTES) systems using a beneficial and unbeneficial probability utility index analysis. The optimisation framework simultaneously minimises complete solidification time (St) and complete melting time (Mt), while maximising the compactness factor (C). The effects of fin height, fin spacing, and fin thickness on heat transfer performance and system compactness are systematically evaluated. The optimisation results identify an optimal configuration with a fin height of 10 mm, a fin spacing of 2.4 mm, and a fin thickness of 0.75 mm, resulting in an enhancement in heat transfer efficiency and a reduction in both solidification and melting times compared to the baseline design reported in the literature. Sensitivity analysis indicates that fin height is the dominant parameter, contributing 95.8% to overall thermal performance, followed by fin spacing (2.75%) and fin thickness (0.94%). The proposed methodology provides a robust and systematic framework for balancing thermal efficiency, compactness, and response time in CTES systems. These findings offer practical design guidelines for high-performance CTES applications in refrigeration, air conditioning, and peak-load shifting, and support future advancements in cold thermal energy storage technologies.