Experimental investigation on high energy-density and power-density hydrated salt-based thermal energy storage

Thermal energy storage based on phase change materials (PCMs) plays a key role in bridging the gap between energy supply and demand for renewable energy applications. Hydrated salt is one kind of the most promising PCMs due to high phase-change enthalpy, non-flammability and low cost. Herein, we design and fabricate a lab-scale high energy-density and power-density thermal energy storage (TES) device using hydrated salt-based phase change composite (PCC). The thermophysical properties of the hydrated salt-based PCC are characterized and the thermal performances of the PCC-based TES device are analyzed at different operating conditions during charging and discharging processes. The Differential Scanning Calorimeter (DSC) analysis shows that the PCC has high phase-change enthalpy of 184.5 kJ.kg(-1) and suitable phase-change temperature of 50 degrees C for hot water heating. The experimental results show that the PCC-based TES device exhibits high specific energy storage density up to 88.4 kWh.m(-3), approximately 2.6 times higher than the conventional water tank storage device. In discharging process, the PCC-based TES device exhibits high energy density (-81.6 kWh.m(-3)), high efficiency (-92.3 %), high power density (-669.9 W.kg(-1)), and stable output hot water temperature (45 -47 degrees C) at different water flow rates (0.42 -2.42 L.min(-1)) and inlet cold water temperatures (8 -25 degrees C).

Automated summary

Thermal energy storage using hydrated salt-based phase change composite shows high energy density and power density, making it a promising material for thermal energy storage. The experimental results demonstrate good thermal performance and stable hot water output temperature of the hydrated salt-based phase change composite-based thermal energy storage device under different operating conditions.