Study On Evaluation Method Of Failure Risk And Safety Barriers Of Industrial Pipelines In Natural Gas Purification Plant

With the adjustment of China's economic structure and the emphasis on environmental protection,the exploitation,import and use of natural gas,as one of the most popular clean energy,have increased dramatically year after year.Because of the solid particles,hydrogen sulfide,carbon dioxide and other gas impurities,the natural gas can only be delivered to the user after being purified by the purification plant and reaching the combustion standard.Therefore,the safety of natural gas purification plants,especially a large number of industrial pipelines,has attracted much attention,and pipeline risk and safety barrier assessment is an important link to ensure their safety.The main research contents and achievements are as follows:Investigate the basic situation of a purification plant pipeline through on-site testing and other means,and the safety condition of the sample pipeline was graded according to the investigation results.The results show that the main reason of pipeline failure is the corrosion of hydrogen sulfide and carbon dioxide.Pipeline risk is also influenced by and correlated with the working conditions such as temperature and pressure of the media in the pipeline.Based on the comparison and selection of the mainstream risk assessment methods,combined with the actual situation in China,a pipeline risk assessment model of natural gas purification plant is constructed,which combines fault tree analysis,analytic hierarchy process(AHP)and Kent scoring method.The model is used to evaluate the safety of the industrial pipeline of a natural gas purification plant in Western China.The recognition rate of the dangerous pipeline is 84.2%,and the recognition rate of the dangerous pipeline in the engineering verification is85.7%.On this basis,the inspection strategy is revised.Aiming at how to compare and comprehensively evaluate the safety barriers of industrial pipelines in natural gas purification plants,a comprehensive evaluation model based on Fuzzy Bayesian and TOPSIS is proposed.Similar aggregation method(SAM)is used to deal with experts' fuzzy opinions and Bayesian network is introduced to calculate the effectiveness of security barriers.Combined with the effectiveness,cost,reliability and other factors concerned by enterprises and society,TOPSIS is used to comprehensively evaluate the safety barrier.This model can provide guidance for the selection and deployment of security barriers.