Comparative Research Analysis Of The Effect Of Earthquake On LNG Storage Tank

As a safe, clean and high calorific energy, Liquefied Natural Gas (LNG) is changing the composition of the energy application in our country. Despite the rapid development of LNG industry, the construction of Large-scale LNG storage tank remains very expensive because of the lack of independent design and construction technology. What’s more, as an ultra-low temperature, flammable and explosive gas, in the event of leakage, LNG will cause serious secondary disasters. So it is very important to study the seismic behavior of LNG storage tank. In this paper, a160thousand cubic meters LNG tank will be studied as a sample and theory of seismic response analysis of liquid storage tanks is used to calculate the dynamic liquid pressure, bottom shear and overturning moment of the inner tank. And comparison with results of finite element software abaqus will be made to evaluate the seismic behavior of LNG storage tanks.First, this paper respectively summarizes the characteristics of single containment tank, double containment tank, full containment tank and membrane tank which are categorized according to their different structural forms and then introduces the widely used double containment tank in detail which will provide reference for choosing the type of tank to construct.Second, according to the earthquake response theory of liquid storage tank, the thesis evaluates the response of the inner tank of LNG tank under earthquake effect on the condition of the impulsive pressure and no convective pressure; Then evaluates the response of LNG storage tank considering the liquid pressure associated with ground motion, wall deformation relative to the ground, and liquid sloshing. The former regard the liquid storage tank wall as rigid, and the latter regard storage the wall as flexible.At last, the thesis does the seismic time-history analysis of LNG storage tank with the finite element software abaqus. Considering the inefficiency in the traditional numerical simulation of fluid-solid coupling calculation, my thesis makes dynamic water pressure under the earthquake effect equivalent to the additional mass which causes the inertia force and it promotes computing efficiency greatly. It can be found that prestressed concrete wall and insulating layer prevent the radial deformation of inner tank to a large extent, and the response of LNG storage tank is very small under the frequently-occurred earthquake effect.