数据不确定条件下安全仪表系统SIL等级验证方法研究

为减小数据缺失或数据不确定对安全完整性等级(SIL)验证结果的影响,引入基于有限差分法的参数重要度评估方法,分别对低要求操作模式及高要求操作模式下的多个典型冗余结构进行参数重要度计算,对SIL验证所需参数进行重要度排序,并通过Monte-Carlo方法对重要参数进行仿真,建立数据不确定条件下的SIL验证评估方法,并以某分液系统为例进行SIL验证。结果表明:该数据不确定性条件下的SIL验证方法能够结合工程实际完成安全仪表系统的SIL等级评估,并能有效减小数据缺乏等不确定性因素对SIL验证结果的影响。
In order to reduce the impact of data missing or data uncertainties related to safety instrumented level, a method of finite difference approach for data uncertainty assessment of reliability estimates is introduced to analyze parameter sensitivity of different redundancy structures of low demand mode and high demand mode scenarios. The importance of parameters is ranked. Monte-Carlo simulation method is introduced to calculate important parameters and SIL confidence interval. A SIL verification method for scenarios of data uncertainty is established. This approach was done based on a case of flare knock-out drum. The results show that the approach of SIL verification considering data uncertainty is an effective method of SIL evaluation based on the actual engineering situation. The proposed method is superior to decrease the influence of data uncertainties on results of SIL verification