Fault Tree+软件在长输天然气管道定量风险分析中的应用

Application of Fault Tree+software for quantitative risk analysis of long distance natual gas pipeline

为了确定影响长输天然气管道系统发生事故的各种因素,减少事故发生所造成的损失,保证管道安全运行,借助Fault Tree+软件对天然气管道系统进行了定量风险分析。根据相关资料,建立了长输天然气管道系统的故障树,明确了44个基本事件的概率,并运用Fault Tree+软件分析、计算功能,确定了管道穿孔、断裂等中间事件以及管道失效顶事件的概率。再以"断裂泄漏"事故开展事件树分析,建立"立即点燃"、"延迟点燃"等事件,并推导了可能导致的所有后果及概率,计算出"延迟点燃"事件没有发生以及发生"爆炸"事故的概率。最后以经济损失来度量"断裂泄漏"各后果事件的失效风险,累加每个后果事件的经济损失,得到某段天然气管道"断裂泄漏"事故的风险值。

Fault Tree ＋ software was applied on quantitative risk analysis in pipeline system to safeguard long dis- tance pipeline syst em operation by the identification various factors influencing long distance natural gas pipeline system and to minimize the loss caused by occurrence of accidents. A fault tree of natural gas pipeline system was established according to related researches. Occurrence probabilities were determined for intermediate events of the pipeline perforation and/or fracture and of top event of failure, and 44 basic events were definituded using powerful analytic and computational functionality of Fault Tree ＋. A event tree analysis was demonstrated by taking ＂fracture leakage＂ accident of some pipeline system as an example, in which the following events such as ignition instantly, delayed ignition and explosion were established and all the consequent situations and correspond probabilities were deduced. Probabilities of events including no delayed ignition and explosion accident were calculated by Fault Tree ＋ software. The ultimate risk values of ＂fracture leakage＂ risk for a certain segment of natural gas pipeline system were determined according to the economic loss of the ＂fracture leakage＂ event by the summation of the mathematic expectation of the economic loss of each consequence events using the calculation formula of the total risk value.