安全仪表系统的可用性分析  

Availability Analysis of Safety Instrumented Systems

作　　者：王子洋[1] Wang Ziyang(Sinopec Maoming Company,Maoming,525000)

机构地区：[1]中国石油化工股份有限公司茂名分公司,广东茂名525000

出　　处：《石油化工自动化》2023年第5期55-59,共5页Automation in Petro-chemical Industry

摘　　要：基于安全和风险管理的角度,安全仪表系统(SIS)的设计需要具备高安全性和高可用性的特点,安全性可通过安全完整性等级(SIL)衡量,可用性可通过平均无误停车的工作时间(MTTF_(spurious))和平均修复时间(MTTR)衡量。介绍了可用性分析过程及分析方法,以某国产化SIS为例,阐述了通过可靠性框图计算安全仪表功能回路的误停车率(STR)的方法,确定SIS的可用性指标,为设计阶段的硬件选型、系统配置以及后续的维护条件对于可用性的提升提供指导建议。From the perspective of safety and risk management,the design of a safety instrumented system(SIS)needs to have high levels of safety and availability.Safety is measured through Safety Integrity Levels(SIL),while availability is measured by mean time to dangerous failure(MTTF_(spurious))and mean time to repair(MTTR).The usability analysis process and analysis methods are introduced.Taking a domestic SIS as an example,the method is explained to calculate the STR of safety instrumented function loops using reliability block diagrams,determining the availability indicators of SIS.It provides guidance and recommendations for hardware selection,system configuration during the design phase,and improving availability through maintenance conditions.

关 键 词：安全仪表系统 安全完整性等级 安全仪表功能 平均无误停车的工作时间 平均修复时间 误停车率 

分 类 号：TQ086[化学工程]