Thermal Stress Analysis Of LNG Tank When Inner Tank Leaks

Through theoretical calculation and finite element simulation,the temperature field and stress distribution of a bimetallic full containment LNG storage tank with a volume of 1×10~4m~3are studied.Based on the heat transfer analysis of the LNG storage tank,the heat leakage of the tank top and the tank bottom and the tank bottom were calculated,and the daily evaporation rate of the storage tank was obtained as 0.07234%.A two-dimensional axisymmetric model of the LNG storage tank is established,and the overall temperature field and thermal field of the storage tank under the ambient temperature in summer and winter under normal conditions,small hole leakage,light leakage,moderate leakage and full leakage are analyzed through numerical simulation.Temperature distribution law of corner protection system.After applying a variety of load combinations,the deformation and stress results of the inner and outer tanks under normal conditions,hydraulic tests and several leakage conditions are obtained.analysis.Use the obtained temperature field as the temperature load to conduct a temperature-stress coupling analysis on the inner and outer tanks of LNG tank,and check the primary stress and secondary stress on the key paths of the tank wall according to the specifications.The stress results of the inner and outer tanks do not exceed the allowable limit value set by the standard.According to the design of the storage tank,four TCP structures are proposed.The stress and deformation of the four structures are compared at different heights of leaking LNG,and the stress of the TCP system under the condition of welding with the outer tank is checked,and the TCP structure is concluded.It is concluded that the structure of TCP B is better.