A design method for inner tank height of LNG storage tank

Abstract

The invention relates to a method for designing the height of an inner tank of an LNG storage tank. The method includes the steps that a liquid unit is constructed according to the motion type of LNG liquid in a cylindrical container; a numerical model is established; modal analysis is carried out on the numerical model through a reduction method to obtain the inherent frequency, the damping ratio and the modal shape of each mode; seismic acceleration spectrums corresponding to different damping ratios are input and combined with modal analysis results for response spectrum analysis, and seismic response results are calculated; response spectrum analysis results are extracted and the sloshing wave height is determined; influencing parameters are determined and sensitivity analysis is carried out on the parameters, so that the sloshing wave height calculation formula is determined through a multi-parameter fitting method according to the influence rule of the parameters; the height of the inner tank of the LNG storage tank is determined according to the calculated sloshing wave height. The height of the inner tank of the LNG storage tank is determined by accurately calculating the sloshing wave height of the liquid in the LNG storage tank under seismic excitation, and the method can be widely applied to LNG storage tank design.

Description

technical field [0001] The invention relates to a design method of an LNG (liquefied natural gas) storage tank, in particular to a design method of an inner tank height of an LNG storage tank. Background technique [0002] As an emerging industry, the LNG industry is developing rapidly. At present, a large number of LNG receiving stations have been invested and built around the world. As LNG storage equipment, LNG storage tanks account for a very large proportion of the investment costs of receiving stations. In the design of LNG storage tanks, the determination of the height of the inner tank is the key to the design of the inner tank of the LNG storage tank. If the height of the inner tank is not enough, the LNG will easily overflow from the inner tank under earthquake excitation, causing damage to the LNG storage tank and affecting the storage tank. The safety of service; if the height of the inner tank is too large, the manufacturing cost of the LNG storage tank will be ...

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Problems solved by technology

[0003] In the initial stage of LNG technology development, the method for calculating the height of liquid sloshing waves in LNG storage tanks under earthquake excitation mainly relied on the empirical formula derived by R.S. However, the calculation process of these formulas is complicated, a large number of intermediate parameters need to be calculated, and the adaptability is poor. Once the structure of the inner tank changes, it is difficult to use the formula to calculate

Later, with the development of numerical technology, relevant scholars studied the numerical calculation method of LNG sloshing wave height under earthquake excitation. The simulation of the tank structure has good adaptability, but the boundary element can only accurately simulate the interaction between LNG and the inner tank, and it is difficult to accurately simulate the sloshing form of LNG under earthquake excitation, so it is difficult to accurately calculate sloshing wave height

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