基于马尔可夫模型“1oo1”结构的误跳车计算方法研究和分析

Study and Analysis on Spurious Trip Calculation Method of One Out of One Structure Based on Markov Model

针对安全联锁系统误跳车的问题,根据ISA 84.0介绍了有关PFD和STR的简单计算方法,通过计算对常规的冗余结构做了分析和比较。结合现阶段石油化工厂中还存在许多“1oo1”结构的实际情况,提出了一种基于AMO诊断的“1oo1”结构的马尔可夫模型,在一定程度上降低了系统的误跳车概率,并对安全仪表功能回路设计提出了建议,从而达到石化装置减少联锁误动作的目的。

Aiming at the problem of spurious trip of safety interlock system,according to ISA84.0,the simple calculation method for PFD and STR is introduced.Analysis and comparison for conventional redundant structure are conducted with calculation.According to the actual situation that there are many“one out of one”structures in refinery and chemical factory at the present stage,a Markov model with“one out of one”structure based on AMO diagnose is proposed.The spurious trip rate of the system is reduced in some extent.Suggestion on safety instrumented function loop design is approached.The purpose of reducing the interlock malfunction for the chemical installation is realized.