Dynamic Risk Analysis Of Emergency Repair Process For Natural Gas Pipeline Leakage

Natural gas pipeline prone to pipeline leakage accident due to various factors after long time of gas transmission operation,secondary injury accident was likely to occur because of violation of personnel,equipment failure,inadequate management,inflammable and explosive gas and the operating conditions in the process of construction of the emergency repair,caused serious casualties and huge economic losses.However,there are few studies on the dynamic risk analysis and dynamic feedback mechanism of the emergency repair process of natural gas pipeline leakage accident,and then the further study is an urgent to do.This paper intends to quantify dynamic risk of repair process aimed at real-time risk and emergency repair time in emergency repair process.This paper intends to build dynamic feedback mechanism through real-time risk and emergency repair time in emergency repair process and then form a natural gas pipeline leakage accident emergency repair process risk dynamic"Monitoring"in order to ensure emergency repair to implement in safe and orderly manner.First,aimed at the repair process about gas pipeline leakage accident,we carry out static risk analysis by using Fuzzy-AHP comprehensive analysis method,the result shows that the risk level which is 5.4469 in the repair process,the risk of the emergency repair process of the natural gas pipeline leakage accident is in the"general"and in favor of higher risk.Second,the BN model of the process has been established according to the basic principle and method of Bayesian in emergency repair process,at the same time,the Bayesian network was used to analyze the sensitivity and sensitivity of the early preparation stage and the repair stage,and put forward the risk control measures.Then,the emergency repair event tree was established according to the emergency repair process and the dynamic risk analysis of the 32 consequences of emergency repair is carried out by using the BN network,and the trend of different accident consequences changed with time is obtained.The results show that for the same repair consequences,with the progress of the emergency repair,the risk gradually reduced;The highest risk of in different periods is C32,especially when T=34,the risk of C32 is 0.9512,and at same time the risk of C1 reduced to 1.209×10^-15,close to zero.The risk analysis results are realistic.Finally,the equivalent repair time of different repair consequences was calculated using the Stochastic Petri Net?SPN?and the whole emergency repair system performance of pipeline leakage accident was analyzed.Then the dynamic feedback was carried on through of repair time and risk in the fourth chapter of different repair consequences.The results show that for the same consequences,the longer the average repair time,the greater the risk.