基于不同阶段安全功能失效的安全仪表系统性能评估方法

从系统安全角度出发,安全仪表系统的性能评估应尽可能的覆盖各种安全功能失效。本文基于不同使用阶段的安全功能失效,建立了安全仪表系统的性能评估方法。根据安全仪表系统使用过程中的特点,该方法综合考虑了安全仪表系统在被动休眠期、过程要求时和维修测试期内可能发生的系统安全功能失效,并分别进行定量,最后给出了安全仪表系统的整体安全功能失效模型。应用实例表明该方法更加详尽合理。

Performance Assessment Method for Safety Instrumented System Based on Different Period Probability of Failure for a Safety Function

From the point of view on system safety,the performance assessment of safety instrumented system（SIS） should include all kinds of probability of failure for a safety function,and the more perfect performance assessment model of safety instrumented system based on different period probability of failure for a safety function was set up.According to the characteristic of the safety instrumented system on-line,the probability of failure for a safety function during the period of passive dormancy,process demand,maintenance and testing were considered and quantified.At last,the total probability of failure of a safety function for SIS was quantified.An application example indicates that this method is more reasonable.