油气长输管道外腐蚀维护风险缓解程度模型

Degree Model of the Corrosion Maintenance and Risk Deduction outside the Long Oil and Gas

对危害油气长输管道安全性的因数进行分析,通过故障树分析法,找出了导致管道外腐蚀穿孔破坏的31种影响因素,确定了各影响因素的逻辑关系,建立了故障树最小割集。通过专家主观评判对各基本事件的失效情况进行分析,将专家自然语言通过模糊数学的方法转换为模糊数,然后采用左右模糊排序法将[0,1]区间的模糊数转换位模糊失效概率值。针对危害管道的失效因素,采取现行比较常用的外腐蚀管道维护方法和对基本事件进行安全整改,然后聘请专家对管道维护前后的情况进行评判,采用所建立的计算基本事件失效概率值方法和所建立的最小割集,计算出外腐蚀管道维护前后失效概率,表明采取有针对性的维修和维护措施,管道的失效概率将会明显减低,降低了该管段的风险值。

This paper firstly focuses on the analysis of factors endangering the safety of the long oil and gas pipeline. By means of faulty tree methods, 31 relevant factors that lead to pitting corrosion damage have been found out, followed by the confirmation of the logh＇al relation among different factors and the establishment of the minimum eut set of faulty tree. Aceording to the expert subjective assessments, the analysis is made on the failure condition of elementary events, and then expert natural language is turned into fuzzy numbers through the fuzzy mathematical method. Next, the fuzzy numbers [o, 1 ]interval are transformed into fuzzy failure probability by left-rlght fuzzy sequence. In view of failure factors harmful to the pipeline, the following measures are taken in applying the maintaining method to the outside corrosion of pipeline, carrying out safety reform on the elementary events, and evaluating the condition around the pipeline maintenance by invited experts. Besides,the failure probability around the maintenance of the outer corrosion pipeline can be figured out by the use of the established failure probability on the elementary events and minimum cut set. As a resuit, it is concluded that the failure probability of pipeline will be reduced clearly and the risk value will also be lowered on this pipeline if the right maintenance and the maintaining method are used.