CIESC Journal ›› 2021, Vol. 72 ›› Issue (5): 2754-2762.DOI: 10.11949/0438-1157.20201224

• Process system engineering • Previous Articles     Next Articles

SIL grading method of associated overpressure interlock protection circuit considering flare load risk

LIU Yin1(),WANG Haiqing1(),XU Xiaolin2,LIU Meichen1   

  1. 1.Mechanical and Electrical Engineering, China University of Petroleum, Qingdao 266580, Shandong, China
    2.PetroChina Guangdong Petrochemical Company Equipment Management Center, Jieyang 522000, Guangdong, China
  • Received:2020-08-30 Revised:2020-10-17 Online:2021-05-05 Published:2021-05-05
  • Contact: WANG Haiqing

考虑火炬负荷风险的关联联锁回路SIL定级方法

刘荫1(),王海清1(),许小林2,刘美晨1   

  1. 1.中国石油大学(华东)机电工程学院,山东 青岛 266580
    2.中石油广东石化分公司设备管理中心,广东 揭阳 522000
  • 通讯作者: 王海清
  • 作者简介:刘荫(1996—),女,硕士研究生,liuyin_upc@163.com
  • 基金资助:
    国家重点研发计划项目(2019YFB2006305);山东省自然科学基金项目(ZR201702160283)

Abstract:

The current international standards for the SIL rating of safety interlocking circuits are only for a single scenario and cannot consider the impact of risk coupling between multiple associated scenarios. When designing the risk distribution and reduction plan of multiple overpressure protection SIF circuits for large-scale combined equipment, it is necessary to consider the risk of flare system overload when the initial event causes multiple devices to discharge at the same time. Based on the situation, the traditional LOPA grading method of the protective layer is improved by the simultaneous discharge superposition method of multiple discharge sources, and a quantitative load calculation method is proposed to determine the safety integrity level of multiple overpressure interlocking protection circuits that affect each other: Reversely realize the check of the safety integrity level of the upstream overpressure interlock by the quantitative data and allowable risk level of the associated release risk of flare system. The case shows that by calculating the frequency of an overpressure accident of the flare system during a power outage, the safety integrity level of multiple overpressure interlocking protection SIF circuits coupled with risk can be recalculated, thereby completing the correction of the traditional LOPA rating results.

Key words: risk coupling, safety integrity level, safety interlock system, safety, instrumentation, optimization

摘要:

现行国际标准对安全联锁回路的SIL定级只针对单一场景而无法考虑多个关联场景之间的风险耦合影响。而设计大型联合装置多个超压保护SIF回路的风险分配与降低方案时,需要考虑同一初始事件导致多个装置同时泄放情形下的火炬负荷超载风险。基于上述现状,使用多泄放源同时泄放叠加方法对传统保护层LOPA定级方法进行改进,提出一种定量负荷计算方法来确定多个相互影响的超压联锁保护回路的安全完整性等级(SIL):依据关联泄放时火炬风险量化数据及允许风险等级,逆向实现上游超压联锁的SIL等级校核。案例表明,通过计算停电时火炬系统超压事故的频率,实现对风险耦合的多个超压联锁保护SIF回路SIL等级的重新核算,从而完成对传统LOPA定级结果的修正。

关键词: 风险耦合, 安全完整性等级, 安全联锁系统, 安全, 仪表, 优化

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