Thermal and mechanical degradation assessment in refractory concrete as thermal energy storage container material in concentrated solar plants

This study evaluates the proposal of a concrete storage tank as molten salt container, for concentrating solar power applications. A characterization of the thermal and mechanical properties including compression resistance, density, thermal conductivity and chemical degradation were evaluated in a pilot plant storage tank in contact with solar salt (60%NaNO3 + 40%KNO3) during 120 hours at 565 degrees C. XRD and SEM analysis were carried out after the molten salt test, observing a penetration of salts in the concrete about 14.5 cm. The chemical and mechanical results in the concrete showed a good behaviour and resistance after the exposure test. Nevertheless, the presence of molten salt in the concrete changed its thermal properties, increasing the density and the thermal conductivity in the concrete zones closer to the molten salt reservoir.

Automated summary

This study evaluated the proposal of using a concrete storage tank as a molten salt container for concentrating solar power applications. The results showed good chemical and mechanical performance of the concrete during the molten salt test, but it was found that the presence of molten salt changed the thermal properties of the concrete, increasing density and thermal conductivity in the areas closer to the molten salt reservoir.