摘要
在相关事故概率统计数据缺少的情况下,为提高LNG储备库的整体安全性,解决传统安全性分析方法无法考虑复杂系统内部关联性、事故分析思路较为分散、忽视组件交互及宏观控制的问题,保证液化天然气储备库分层翻滚事故和火灾事故正演结果的准确性,建立基于系统论事故分析模型(Systems-Theoretic Accident Modeling and Process,STAMP)及系统理论过程分析(System-Theoretic Process Analysis,STPA)的LNG储备库典型事故正演模型,使得后续系统隐患分析、事故原因分析的更加全面完善。首先,根据LNG储罐分层翻滚事故和火灾事故过程中涉及的设备设施、工艺流程及相互间的关联关系,对事故进行初步危险分析、辨识导致事故发生的各个因素、找出危险的关键节点,并在此基础上分析事故所在系统的安全需求及对应的安全性约束,包括可能导致事故发生的控制与反馈操作,建立STAMP模型,模型需包含相关设施、组件之间的控制、反馈关系,和控制反馈回路;然后,采用STPA方法识别LNG保障过程中的四种不安全的控制行为(未提供的控制行为、提供错误或不安全供控制行为、未及时提供控制行为、控制行为结束过早),并从控制行为执行不充分、反馈信息错误或不足两方面分析事故整体过程中涉及到的初始值(如储罐LTD参数)、当前状态(如进液操作)以及状态转换(如储罐与冷却完成准备进液),找出导致不安全控制行为的关键原因,建立完整的LNG储备库典型事故正演模型;最后,结合具体事故案例验证分析LNG储备库典型事故正演模型的有效性与可实施性,并将分析结果可视化,以知识图谱的方式直观展现。研究表明:该模型可从控制和约束角度对复杂系统LNG储备库典型事故进行过程分析,使得事故演化过程更加直观、准确,原因梳理更加清晰;从系统的角度考虑了各风险因素在分层翻滚事故和火灾事故正演中的因果关系,为后续LNG储备库的安全管理工作提供了可行、有针对性的价值信息。
In the absence of relevant accident probability statistics,in order to improve the overall safety of the Liquefied Natural Gas(LNG)system,we need to solve the problems that traditional safety analysis methods cannot consider.These are the internal correlation of complex systems,component interaction and macro control.The analysis ideas are scattered and we need to ensure the accuracy of the forward results of stratification,rollover and fire accident of LNG repositories,A STAMP-STPA(Systems-Theoretic Accident Model and Processes)-(Systems-Theoretic Process Analysis)based a forward model of typical LNG repository accidents was established,making the follow-up system of unexpected trouble analysis and accident cause analysis better and more comprehensive.First,according to the equipment and facilities,process and their correlation with each other involved in stratification and rollover accidents and fire accidents of LNG storage tanks,a preliminary risk analysis of the accidents was carried out,and then the factors leading to the accidents were identified,and the key nodes of the risk were ascertained.On this basis,the safety requirements and safety constraints of the accident system were analyzed,including control and feedback operations that may lead to accidents.A STAMP model was established which included the control and feedback relationships among the relevant facilities,components,and control feedback loops.Second,the STPA method was adopted to identify four unsafe control behaviors in the LNG safeguard process(including failure to provide control behavior,error or unsafe supply control behavior,failure to provide control behavior in a timely manner,and premature end of control behavior),and analyze the initial value(such as tank LTD parameter),current state(such as infusion operation)and state transition(such as tank and cooling completion preparation)involved in the overall process of the accident from two aspects of insufficient execution of control behavior,feedback error or insufficiency,and then understand the key causes of unsafe control behaviors,and established the complete forward model of typical accidents in LNG storage tanks.Finally,combined with specific accident cases to verify and analyze the effectiveness and practicality of the typical accident forward model of the LNG storage tank,and visualize the analysis results in the form of knowledge graphs.The study shows that the model can systematically analyze typical LNG accident processes of LNG tanks in complex systems from the perspective of control and constraints,which makes the accident evolution process more intuitive and the reasons for unsafe control behaviors clearer;and fully considers the causal relationship of various risk factors in the stratification,rollover and fire accidents forward from the system perspective,thus providing feasible and effective value information for the subsequent safety management of LNG storage tanks.
作者
胡瑾秋
董绍华
王融涵
张曦月
HU Jinqiu;DONG Shaohua;WANG Ronghan;ZHANG Xiyue(Department of Safety and Marine Engineering,China University of Petroleum-Beijing,Beijing 102249,China)
出处
《石油科学通报》
2021年第3期481-493,共13页
Petroleum Science Bulletin
基金
国家重点研发计划(2017YFC0805801)
北京市科技新星计划(Z181100006218048)联合资助。
作者简介
通信作者:胡瑾秋,hujq@cup.edu.cn.
