Effect of Al2O3 nanoparticle dispersion on the thermal properties of a eutectic salt for solar power applications: Experimental and molecular simulation studies.

Thermophysical properties of molten salts aid in determining the storage efficiency of thermal energy storage (TES) systems in concentrating solar power plants. In this research, a novel ternary molten salt (4NaCl–37KCl–59LiNO 3 , mol%) was utilized as the phase change material (PCM), while Al 2 O 3 nanoparticles (NPs) were employed as a thermal conductivity enhancer. Experimental measurements and molecular dynamics simulations were conducted to confirm that the introduction of Al 2 O 3 NPs as dopants enhanced the specific heat, thermal conductivity, and energy storage density of the eutectic salt. Specifically, at an Al 2 O 3 NP content of 0.5 wt%, the composite PCM exhibited a 44.23 % increase in liquid-state specific heat and a 40.82 % increase in liquid-state thermal conductivity, along with a 15.73 % increase in storage density. This study demonstrates that the enhanced thermal properties of eutectic salts by adding Al 2 O 3 NPs are primarily attributed to the emergence of nanostructures and alterations in atomic potential energy, as evidenced by both experimental and simulated microstructural analyses. These findings offer valuable insight into the selection of thermal storage materials and additives, as well as their implementation in medium-temperature TES systems, with the objective of optimizing the efficient utilization of solar energy. • Eutectic ratios of ternary molten salts predicted by thermodynamic calculations. • Thermophysical properties can be improved by doping with Al 2 O 3 nanoparticles. • The effect of nanoparticle content on thermophysical properties were studied. • Doping with 0.5 wt% Al 2 O 3 nanoparticles achieves a maximum energy storage density. [ABSTRACT FROM AUTHOR]