基于模糊Bow-tie模型的城镇燃气管道泄漏定量风险评价

Quantitative risk assessment of urban gas pipelines based on the fuzzy Bow-tie model

燃气管道事故一旦发生后果大多比较严重。为全面分析燃气管道风险的前因后果,确定重点维护和监控的管段区域,引入了Bow-tie模型,将管道泄漏的故障树与事件树统一到一起对燃气管道进行定量风险评价。采用模糊集相关理论与专家评价相结合的方法得出管道泄漏的模糊可能值;然后基于模糊层次分析法确定管道泄漏后果因素的权重系数;再通过矩阵乘法求得泄漏后果值。以某段燃气管线为案例,全面识别出各风险因素,量化得到管道各泄漏后果事件的风险值。实际应用结果表明:①该方法可快速合理地评判出管道系统的相对风险大小;②三角模糊数与层次分析法的应用减少了传统评价中主观及模糊因素产生的评价偏差,使得评价结果更接近客观实际;③依据评价结果制订有针对性的预防维护措施,能够实现有限维护资源的合理配置,保障燃气管道的安全可靠运行。

Serious consequences will be inevitable once any accident occurs in urban gas pipelines. The Bow-tie model was applied to have an overall analysis of causes and consequences of urban gas pipelines risks and to determine the highlighted pipe section areas of maintenance and monitoring. The fault tree and the event tree were unified by using the Bow-tie model to perform a quantitative risk analysis of gas pipelines. The leakage possibility of gas pipelines was obtained by combining the fuzzy set theory with expert evalua- tion. The weight coefficients of the leakage consequences of gas pipelines were defined by the Fuzzy Analytic Hierarchy Process. The consequences of pipeline leakage were calculated by the matrix multiplication method. Taking the risk assessment of a certain gas pipe section as an example, the risk factors were identified and the risk values of the pipeline leakage events were quantified. The fol- lowing findings were concluded. （1） The relative risk values of gas system can be evaluated quickly in practice by use of this method. （2） The employment of the triangular fuzzy number and the analytic hierarchy process helps reduce the evaluation deviation due to the subjective and fuzzy factors in the traditional evaluation methods so the assessment results are much closer to reality. （3） The corresponding preventive and maintenance plans will be made based on the assessment results, making it easier to achieve the rational allocation of the limited maintenance resources and ensure the safe and reliable operation of urban gas pipelines.