Optimization Analysis on the Structure Parameters of a 20×104 m3 Ultra-Large Tank for Crude Oil Storage

With the advantages of low investment, small footprint, ease of operation management etc., large-scale vertical tanks for crude oil storage have become an obvious trend. However, stress intensity of the tank wall increases with constant enlargement of oil tank’s parameters, and the yield strength of the steel used as tank wall material can not be more than 490 MPa. Besides, the maximum thickness of shell plate generally should be not over 45 mm subjected to the restriction of manufacturing process. So, it is important to design the structure of tank reasonably and reduce the stress as much as possible. This paper combines theoretical analysis and numerical simulation together, analyzing and calculating the stress of shell plate and bottom plate of an ultra-large tank for crude oil storage which is 200000 cubic meters, and comparing the stress level of three design schemes about shell plate and bottom annular plate, then giving a scheme whose stress distribution is more reasonable. The study shows that combined cylindrical shell method is applicable to the theoretical stress calculation of shell plates of ultra-large crude oil storage tanks, finite element method using contact element could simulate the stress distribution of bottom plate well, and give the optimal structure parameter scheme by controlling the hoop stress of tank wall and radial stress of bottom plate. The result of this paper has a certain practical guiding significance to the optimization design of ultra-large tanks for crude oil storage.