Research On Risk Assessment Method Of SL Airport Apron Pipelines

Apron pipelines,as an important part of airport fuel systems,include lots of facilities which are highly concentrated and always operate continuously.If there is leakage caused by corrosion,operational errors,equipment failure and other factors,serious accidents like fires or explosions would easily occur.With the fast development of the air freight,it becomes a hard task for pipeline companies to secure the normal operation of pipeline stations.Risk assessment is an important foundation work for the risk management of airport fuel systems.Since various uncertainties exist during the risk assessment(RA),it would negatively affect the RA results and even lead to erroneous risk decisions if those uncertainties are not dealt with properly.This dissertation,taking SL airport apron pipelines as object,explores the theories and approaches of QRA for apron pipelines accidents,and introduces some specific mathematical theories for quantification and dealing with uncertainties such as Bayes and Monte Carlo.All these efforts contribute to acquiring reasonable and accurate assessment results.This dissertation focuses on the following studies:(1)On the basis of studying the current situation and development trend of domestic and foreign oil and gas pipeline risks,this dissertation makes clear its approaches and perspectives and try to combine uncertainty theory effectively with the QRA for apron pipelines with the characteristics of the apron pipelinnes.(2)Through analysis of the process and features of apron pipelines,this dissertation analyzes and summarizes hazard factors for apron pipelines and constructs a failure tree of the apron pipeline.Through the qualitative analysis of this fault tree,a fault tree was obtained.The minimum cut sets and the order of importance of basic event structures pave the way for quantitative analysis of fault trees.(3)The uncertainty factors in the process of quantifying the risk of apron pipelines are analyzed and studied.A calculation model for the failure probability of 17 unique basic events of the apron pipeline based on Bayesian correction is established.At the same time,72 basic event fuzzy failure probability calculation models based on classical expert judgments are established,and statistical statistics data are used to statistically infer the failure rate of basic fault events.Combining the calculation model of the failure probability of the basic event and the calculation result of the basic failure fuzzy failure probability calculation model,the failure probability distribution model of the failure treetop event based on Monte Carlo simulation was established.The failure probability distribution of the top event is calculated using MATLAB software.(4)After Analyzing the consequences of leakage accidents at the apron pipeline of SL airport,the impact area of aeronautical pipeline leakage accidents such as pool fire,steam cloud explosion and flash fire at four different leakage sizes is calculated.On this basis,the number of casualties and economic losses is calculate and the quantitative consequences of the indicators is analyzed.(5)The probabilistic grades and loss grades described in natural language in the traditional risk assessment matrix are quantitatively divided,and Meta-risk theory and fuzzy logic system are introduced.The risk assessment model for apron pipeline risk based on Meta Risk and Fuzzy Logic System is established.The risk index is obtained by defuzzifying the fuzzy risk index,and then the membership degree of the risk at different levels of membership is obtained by using the fuzzy risk index membership function.This has better reference value for the risk management decision.