Experimental study on the blocking effect of metal mesh on seepage of molten salt in tank foundation materials.

• The seepage blocking characteristics analyses of molten salt in tank foundations under different operating conditions were studied. • A method for blocking molten salt seepage based on the presetting metal mesh was proposed. • Parametric analysis and optimization were conducted to the proposed seepage blocking method. Leakage of molten salt storage tanks in concentrated solar power plants poses a major threat to operating safety. This paper focuses on arranging metal mesh in the storage tank foundation to control the seepage and migration range of molten salt in the thermal-steady foundation materials after leakage occurs. The influences of different conditions, including the metal mesh aperture, metal mesh position, operating temperature, and the mass of leaked molten salt, on the blocking effect were investigated through a custom-built experimental system that modeled the actual leaking process. The results showed that the metal mesh can effectively block seepage of molten salt. When the metal mesh aperture is made smaller or the mesh is placed further toward the bottom of the tank, the metal mesh has a significant blocking effect on molten salt seepage. Especially when the metal mesh aperture is 0.15 mm and the depth of placement is 325 mm, seepage of molten salt can be completely blocked. Nevertheless, it has been found that the depth of molten salt seepage distinctly increases with higher operating temperature or larger leaked molten salt mass. These experimental results will provide references for pollution control and disposition of molten salt leakage accidents and help power plant engineers re-examine tank foundation designs. [ABSTRACT FROM AUTHOR]