Analyses of Cold Thermal Energy Storage Systems Using Eutectic Mixtures of Inorganic Hydrated Salts as Phase Change Materials

Cold thermal energy storage using phase changing materials is being researched to find freezing and thawing points. The use of inorganic hydrated salts, a type of phase changing material (PCM) used in cold energy storage systems without the use of existing renewable energy systems, allows for a longer cooling effect and saves energy. A high volumetric storage density and relatively high thermal conductivity make hydrated salts suitable materials for thermal energy storage. They can be used only as inorganic mixtures or else they can also be used as eutectic mixtures, which involve mixtures of inorganic–inorganic salts or simply a combination of two or more inorganic salts. This research deals with eutectic mixtures, which are 4% KNO₃ + 96% H₂O, 4% NaHCO₃ + 96% H₂O, and 2% KNO₃ + 2% NaHCO₃ + 96% H₂O. Three different novel eutectic mixtures were examined and found a suitable mixture for a cold thermal energy system. An efficient phase change approach involving 2% KNO₃ + 2% NaHCO₃ + 96% H₂O may result in stable phase change behavior and moderate temperature change, increasing versatility.