长输管线失效状况模糊故障树分析方法

采用故障树法分析了长输管线的失效状况,根据管线失效的两种主要模式:泄漏和断裂,建立了管线失效的故障树。通过对故障树的定性分析,可得到引起管线失效的52个最小割集;通过定量分析则可以计算顶事件的发生概率以及进行底事件的重要度分析。采用专家判断法和模糊集理论相结合的方法评估了故障树的底事件发生概率的模糊性,并以长输管线故障树系统中的“安装质量差”这一底事件为例,计算出其模糊失效率为2.3545×10^-4。该方法可为处理模糊事件失效概率提供一种研究思路。

Fuzzy fault tree analysis method for assessing oil and gas pipeline's fault

Fault tree analysis (FTA) is a very powerful technique and widely used for evaluating the safety and reliability of complex system.The failure of oil and gas pipeline was analyzed by fault tree analysis in this paper.According to the two major failure modes of leak and rupture,the fault tree of pipeline was established.And 52 minimal cut sets have been achieved with qualitative analysis,while the failure probability of top event and the criticality analysis of basic events could be calculated with quantitative analysis.In conventional fault tree analysis,the probability of ambiguous and imprecise events among basic events is treated as precise values.But this method can’t reflect the real situation of system well,because there are many variable factors for affecting the basic events.To overcome this disadvantage,a novel technique is proposed by combining expert judgement and fuzzy set theories to evaluate the probability of events.As an example,the failure rate of bad installation quality of oil and gas pipeline was assessed by using the proposed method.The result shows that the fuzzy failure rate of the pipeline is 2.3545× 10^-4.The method given in this article is effective to treat failure probability of fuzzy events.