PERFORMANCE OPTIMIZATION OF INORGANIC SALT HYDRATE PCMs FOR THERMAL ENERGY STORAGE IN TROPICAL APPLICATIONS

The phase change materials (PCMs) for thermal energy storage (TES) are becoming more and more popular as a result of the growing demand for effective energy storage solutions. The use of inorganic salt hydrates, which are recognized for their high thermal energy storage and desirable thermophysical properties, has the potential to enhance TES performance. This study explores the thermophysical properties and phase transition behavior of selected inorganic salt hydrates, investigating their suitability for energy storage. Innovative synthesis methods, including the direct mixing of molten salts and the combination of multiple salt hydrates, were employed to address issues such as supercooling and phase segregation. A novel eutectic salt hydrate-based mixture was formulated by integrating thickening agents, resulting in improved performance. The study utilized aqueous solutions of calcium chloride hexahydrate (CaCl₂·6H₂O), strontium chloride hexahydrate (SrCl₂·6H₂O), potassium chloride (KCl), as well sodium chloride (NaCl), with thermophysical properties analyzed via Differential Scanning Calorimetry (DSC). The best mixture, containing 96.0 wt.% CaCl₂·6H₂O, 1.5 wt.% SrCl₂·6H₂O, 2.0 wt.% KCl, and 0.5 wt.% NaCl, demonstrated a 4.65% increase in latent heat capacity. Additionally, the mixture displayed stable melting onset temperatures, making it ideal for TES applications in tropical climates like Malaysia. The effectiveness of the optimized salt hydrate composition is highlighted in this study, marking a significant sustainable advancement in storing energy.