Seismic Response Analysis of Large Molten Salt Storage Tanks

Abstract Molten salt storage tanks are critical energy storage components in solar thermal power generation systems. During actual operation, these tanks are subjected to structural damage caused by seismic loads. Therefore, seismic loads are essential factors to consider in the analysis and design of molten salt storage tanks. Housner’s model and the Jacobsen–Veletsos’s model are commonly used for the seismic analysis and design of storage tanks, forming the basis of design standards employed by the American Petroleum Institute API 650 and Eurocode 8, respectively. To investigate the response of molten salt storage tanks under seismic loads and perform analytical verification, this study determines the acceleration response spectrum based on the seismic load conditions and site class of the tank’s location. Both Housner’s model and the Jacobsen–Veletsos’s model are employed to calculate the dynamic pressure on the tank under seismic loads. Additionally, a finite element model of the tank is used for further analysis. The results show that the finite element models employing two different dynamic pressure distributions yield similar outcomes. The discrepancies in the maximum membrane stress and maximum Mises stress calculated by both models are 1.5% and 2.6%, respectively, and both models successfully pass the strength verification. Furthermore, an evaluation based on the combined analysis of hoop stress and longitudinal stress confirms that the storage tank will not experience elephant-foot buckling or diamond buckling under seismic loading. Additionally, the maximum positive displacement along the Z-axis obtained from the two models is 4.35 mm and 3.91 mm, respectively, demonstrating that the storage tank will not undergo overturning failure under seismic excitation. The findings of this study provide a valuable reference for the seismic analysis of molten salt storage tanks.