Evaluation of discharging performance of molten salt/ceramic foam composite phase change material in a shell-and-tube latent heat thermal energy storage unit

Molten salts are widely used energy storage media in integrated solar power systems, however, due to their high corrosivity and the extreme high-temperature environment, many current methods of heat transfer enhancement do not apply. Herein, we proposed to use ceramic foam to enhance the discharging performance of molten salt to efficiently supply heat for power generation. The ceramic foam was prepared and its corrosion resistance was confirmed experimentally. The discharging performance in a shell-and-tube latent heat thermal energy storage unit was numerically studied. It is found that compared to the configuration without enhancement, the solidification time of the ceramic foam-enhanced unit is shortened by up to 52.0%. The unit with the upper foam insert shows better discharging performance than the one with the lower foam insert. Different foam filling height is also considered and results indicate that the thermal energy release rate always increases with the foam filling height and that of the fully foam-inserted unit is 118.1% higher than that of the none foam-inserted unit. For the first time, the discharging performance of ceramic foam-enhanced molten salt is quantitatively evaluated. This study provides guidance on designing thermal energy storage sub-system with excellent heat supply performance for solar power generation.