基于Bow-Tie的复杂场景保护层分析方法研究

Research on Analyzing Methods of Protective Layers in Bow-Tie-Based Complex Scenarios

为解决复杂场景保护层分析中采用最大值法或加和法存在的问题,将Bow-Tie融入LOPA分析中,建立复杂场景的Bow-Tie计算模型。通过采用事故树分析方法,计算Bow-Tie模型中顶上事件发生的概率,确定预防类保护层及减缓类保护层的失效概率,给出了复杂场景事故发生概率合理的计算方法;通过计算Bow-Tie模型中事故树底事件的概率重要度和临界重要度,提出了判断复杂场景保护层重要度的方法。运用上述方法对某LNG储罐超压损坏的复杂场景进行了计算。研究表明,本方法能实现包含多重初始事件的复杂事故场景后果风险更合理的计算及保护层重要度的判定,从而为提高系统安全性及风险决策提供依据。

In order to solve the problems of using the maximum value method or summation method in the analysis of protective layers in complex scenarios,Bow-Tie is integrated into the LOPA analysis to establish a Bow-Tie calculation model for complex scenarios.The probability of events on the top of the Bow-Tie model is calculated via Fault Tree Analysis,to determine the failure probability of preventive and mitigating protective layers.A reasonable calculation method for the probability of accidents in complex scenarios is thus given.A method to judge the importance of protective layers in complex scenarios is also offered by calculating the probability importance and critical importance of events at the bottom of the Fault Tree in the Bow-Tie model.These methods are applied in calculating a complex over-pressure damage scenario of an LNG storage tank.The study shows that this method can realize a more reasonable calculation of the consequential risks of complex accidents containing multiple initial events and help to determine the importance of the protective layer.Thus,it provides a basis to improve the system safety and supports risk decision-making.