Reliability Study Of The Tank And Pipeline In LNG Terminal

LNG tank and LNG pipeline are the key equipment of LNG terminal,which is related to LNG terminal safe and stable operation.According to the characteristics of LNG tank and pipeline,build reliability model of LNG tank and LNG pipeline,adopt statistical methods to complete reliability calculation,then determine the reliability of LNG tank and LNG pipeline under different conditions.The LNG pipeline is split into two parts: stainless steel pipeline and cold insulation layer,reliability of stainless steel pipeline adopt stress-strength interference theory,reliability of cold insulation layer adopt the data of experimental which accelerate the aging of hard polyurethane foam,the life equation of rigid polyurethane foam can be obtained after processing the data and the probability of failure is calculated.According to the series logic relationship between the two components,the overall reliability of the LNG process pipeline is obtained.The LNG tank is split into three parts: concrete external tank,Ni9% internal tank and valve.Calculation of chlorine ion erosion in external tank use DuraCrete model,calculation of stress loss of concrete shrinkage creep use GB50010 model,adopt Monte Carlo method to calculate reliability,and the reliability of the external tank can be obtained through the parallel logic relation.Calculation of Ni9%internal tank use elastic-rigid foundation beam coupling method,check the bending stress of the tank wall and the bottom of the tank,and adopt Monte Carlo method to calculate internal tank reliability.For the tank valve,it is believed that its life is subject to two parameters weibull distribution.Refer to the data of timed truncation life test,get the valve life reliability lower limit according to the reliability analysis of non-failure data.The overall reliability of LNG tank is obtained according to the series logic relation between three parts.