Simulation Study On Temperature Field Of LNG Outer Tank Under Leakage Conditions

Liquefied natural gas(LNG) in China’s energy structure in the proportion increased year by year. LNG storage tank as an important part of the LNG receiving station, the safety of the LNG storage tank is very important.This paper mainly adopts the method of numerical simulation, simulation of the LNG dynamic leakage process which leak from a hole. Analysis the temperature field of the insulation layer and the outer tank wall during the inner tank dynamic leakage and after leakage completion, study the temperature field under different conditions and research the relation of temperature field change in single condition is different.First, two dimensional model of the insulation layer and the outer tank wall of the tank are established by using the finite element software FLUENT under ANSYS.Comprehensive analyze the leak height and area’s influence on temperature field after leakage and find its rule, analysis the role of the TCP(thermal corner protection)at the same time; Then separately analysis the effect of environment temperature on temperature field.At last, three dimensional model of the LNG tank are established by using FLUENT, select the leakage condition that is consistent with the previous condition for the analysis and comparison of the data.After simulation and analysis of the leakage condition, we find that when the other conditions were the same, if the leak hole area is bigger than others, the temperature of external surface of outer tank reached the minimum value spend less time; The position is closer to the leak hole, the temperature of external surface of outer tank reached the minimum value spend less time; The TCP can obviously protect the bottom of the tank after leakage; The temperature change of the concrete tank external wall after leakage is greatly influenced by the environment temperature. By comparing with the simulation results of the two dimensional working conditions and the three-dimensional conditions, it can be found that there are differences in the temperature changes, but the change trend is consistent.The research of this paper is helpful to analyze the change trend of the temperaturefield of the tank after leakage. We can establish a complete database, if we know the general leakage conditions we can analyze how the temperature field of the tank change. We can research the change of stress field based on the change of the temperature field.