安全功能仪表回路故障失效概率的简化计算方法

Simplified calculation on PFD of SIL

安全功能仪表回路大量应用于石化项目重要设备的安全保护,不同回路分析后会得到不同安全完整性等级,在初设中设计人员需要粗算整条回路的故障失效概率(PFD),从而评估当前回路设计合理性。针对现行相关标准内容过于宽泛,缺乏行业针对性,本文通过提炼国际知名石油公司通用设计导则,结合基础规范。总结得到PFD计算的一种简化方法,为设计人员提供了便利。

SIF loop is widely used for the important equipment's safety protection in petrochemical projects,different SIL will be got during different loop analysis.In basic design,designer need simply calculates the whole loop's PFD for assessing the current loop's reasonability.In terms of current loose standards and lack of the industry pertinence,the article summarizes a simplified method of PFD calculation based on the world famous petroleum company's practices and basic standards,which will provide the convenience for peer designers.