Abstract: In order to operate the town polyethylene gas pipeline safely and reduce the operational risk, the possible accidents were analyzed that the town gas polyethylene pipe could occur and its reasons. Using fault tree analysis method, both the fault tree model and its sub fault tree model of the town polyethylene gas pipeline were established. Through the calculation of the minimum cut sets, the minimum path sets and the structure importance of it, the possible malfunctions of the town polyethylene gas pipeline and the reasons were analyzed. The research results show that the failure of town polyethylene gas pipeline had a larger threat, and the threat of pipeline auxiliary facilities failure was less. Among the reasons of pipeline failure, the influence of the outside interference was the largest|the scratches and defects of the pipeline had a minor influence|and the aging pipes and stress effect on the pipeline had the least influence on the pipeline accidents.

Key words: Town gas pipeline, Polyethylene, Fault tree analysis, Minimum cut sets, Minimum path sets

摘要： 为了城镇聚乙烯燃气管道的安全运营并降低运营风险, 对城镇聚乙烯燃气管道可能发生的事故及其原因进行了分析。采用故障树分析法, 建立了城镇聚乙烯燃气管道故障树及其子故障树模型, 分别计算了故障树的最小割集、 最小径集和结构重要度, 指出了城镇聚乙烯燃气管道可能发生的故障并分析了成因。研究结果表明, 城
镇聚乙烯燃气管道失效对管道运行威胁较大, 管道附属设施失效威胁较小; 在管道失效的成因中, 管道受到的外界干扰对管道发生故障的影响最大, 管道划痕与缺陷的影响次之, 管道老化与应力破坏对管道事故的影响最小。

关键词: 城镇燃气管道, 聚乙烯, 故障树分析, 最小割级, 最小径集