火气系统功能有效性的绩效评估方法

摘要

As one of the safety instrument systems of the disaster mitigation and protection layer,with the goal of eliminating the risks of fire and gas leakage,the fire and gas system (FGS) plays an important protective role in petrochemical fields.Risk suppression capability depends on the functional effectiveness of FGS;it is affected by many factors,such as the layout of the detectors in the field,the configuration of the system,and the capability of emergency response and extinguishing,etc.To achieve the performance evaluation of functional effectiveness of FGS,it is necessary to comprehensively analyze multiple factors.The event tree risk analysis model recommended by ISA-TR84.00.07 can be used;the analysis includes three aspects,i.e.,the coverage of detection,the safety integrity,and the disaster mitigation measures,then the functional effectiveness of system and risk suppression capability are calculated,thus the quantitative evaluation is implemented.Through analyzing the practical cases,the basic theories and methods of the coverage analysis technology and safety integrity assessment technology are introduced and sorted,the operability of the assessment theory based on event tree model is verified.It is proved that event tree model combing with the basic theories of detector coverage and functional safety is effective for function effectiveness evaluation of FGS.%火气系统作为减灾保护层安全仪表系统,以抑制火灾和气体泄漏带来的风险为目的,在石化现场发挥着重要的保护作用.风险抑制能力取决于火气系统的功能有效性,受多方因素影响,如现场探测器的布置、系统自身配置、应急响应和灭火能力等.要实现对火气系统功能有效性的绩效评估,需要综合多方因素进行分析.采用ISA-TR84.00.07推荐的事件树风险分析模型,从探测覆盖率、系统安全完整性及灾难抑制措施有效性三个层面综合分析、计算系统的功能有效性和风险抑制能力,从而实现定量评价.通过典型案例分析,对探测覆盖率分析技术和安全完整性评估技术的基本理论和方法进行了梳理和介绍,并验证了基于事件树模型的火气系统有效性评估理论的可操作性,证明了采用事件树模型、结合探测覆盖率和功能安全基础理论,可以较好地实现火气系统功能有效性的绩效评估.