This paper establishes thermal and stress models for molten salt storage tanks
and investigates the effects of the support stiffness of tank walls and bottom plates on the mechanical properties of storage tanks under the action of thermal-mechanical coupling and variable liquid levels. The results show that the temperature distribution of storage tanks with different liquid levels is roughly consistent
and the maximum temperature difference of approximately 4 ℃ exists at the position of the outward-extending weld of the bottom plate and the connection position of the dome roof. Hydrostatic pressure mainly affects the settlement of the tank body
with the maximum settlement amount being about 0.2 m under the full-load condition. Thermal stress mainly affects the radial displacement of the tank body
and the maximum radial displacement is approximately 0.28 m. Increasing the stiffness of the tank bottom is conducive to reducing the settlement and stress of the tank body
and the optimal design stiffness of the bottom is 5 MPa/m. The deformation of the tank body is insensitive to the change of tank wall stiffness
and the increase of tank wall stiffness leads to a sharp increase in stress. Therefore
it is not advisable to restrict the radial displacement of the tank body caused by thermal stress. The research results of this paper can provide theoretical guidance for the design of practical large-scale high-temperature molten salt storage tanks.
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