Numerical investigations of thermal performance enhancement in phase change energy storage system effective for solar adsorption cooling systems

Abstract

Solar cooling systems requires an uninterrupted heat input for their continued operation. Thermal energy storage systems using phase change material (PCM) has the ability to deliver heat near isothermally and are effective for solar cooling applications. But these high energy dense storage systems exhibits poor thermal performance due to the low thermal conductivity of PCMs and are bulky. The main objective of this study is to design a phase change energy storage system (PCES) unit with different fin configurations, and to select a proper PCM for solar adsorption cooling systems (SAC). It projects the Preference Selection Index (PSI) method as the effective way to select the PCMs, and the result suggests the commercial PCM SavE-HS89 as a potential candidate among the different materials considered. This study also numerically investigates the thermal performance of different fins shapes, namely, positively tapered, negatively tapered and straight fins; among these the negatively tapered fins are found to be capable of compensating the slow melting process at the bottom region of the storage unit. It has been found that the negatively tapered fin improves the thermal performance of the PCES unit by reducing the melting time by up to 13% and 36% in comparison with the conventional straight fin and positively tapered fin, respectively. A case study of actual plant data of a SAC with different fin shapes shows that the storage system with the desirable configuration can save up to 46% of heat storage cost as compared to PCES without fin.