危险化学品泄漏事故演化机理研究

为了分析危险化学品泄漏事故演化机理,简化其定量风险分析过程,先假设容器失效导致的初始事件为危险化学品泄漏事件,再根据危险化学品物质特性分类和中间演化事件场景,构建了常见的各类危险化学品发生泄漏初始事件后的通用事件树,并根据已有的研究成果,对事件树中各种中间演化事件概率进行取值研究。研究结果表明,通用事件树能很好地揭示基于物质特性和中间事件场景的泄漏事故演化规律,应用含中间演化事件概率的通用事件树能计算出各种事故后果发生的频率,对危险化学品事故的快速定量风险分析有十分重要的参考意义。     

基于 MIMAH 的工业事故场景辨识

介绍了事故场景概念,并根据欧盟ARAMIS项目框架下提出的MIMAH（辨识重要事故危险方法）,即从危险设备的角度来辨识与设备相关的关键事件,并利用事故树（ FTA ）、事件树（ ETA）,建立一个以关键事件为中心的蝴蝶结结构图来描述事故场景。通过运用这种方法,能够对事故场景的辨识更加具有系统性、针对性。最后,以液氨储罐装置作为示例进行说明。     

上海市企业环境污染事故应急预案完备性研究

在分析企业环境污染事故应急预案编写完备性的基础上,从企业基本情况、潜在事故风险、预防与预警、应急响应和应急保障5方面构建企业环境污染事故应急预案编制完备性评估指标体系,评估了2006—2008年间上海市120家企业编制的环境污染事故应急预案。其结果表明:企业编制的环境污染事故应急预案总体完备性较差;不同企业预案编制的完备性差异明显;编制完备性较好的企业数量少;在所构建的评估指标体系中,不同指标项所占百分比相差悬殊等;最后提出了改进建议。     

十字路口乘用车与二轮车典型危险场景聚类及推演

为了给智能汽车研发提供有效的场景推演构建方案,统计分析国家车辆事故深度调查体系(NAIS)数据库中乘用车与二轮车发生在十字路口的事故场景数据,得到2类高占比的基础场景;选取7个场景关联变量,并就2类基础场景对应的静态特性数据进行聚类分析;建立运动学推演模型,结合5类典型危险场景的动态参数实际阈值,构建5类典型危险场景的速度-距离危险模型。结果表明:通过统计分类、聚类分析和运动学模型叠加推演方法,可得到5类符合中国道路交通情况的十字路口乘用车与二轮车典型危险场景,进而得出5个危险场景集。     

城市轨道交通系统灾害链网络模型构建与评价

为定量描述城市轨道交通灾害事件间的传播关系,帮助决策者在发生灾害事件时作出更加科学的判断,采用危险与可操作性分析(HAZOP)法,提出城轨系统灾害事件集的提取方法;基于城轨事故历史数据,通过共现矩阵的构造和Jaccard指数的计算,构建灾害链有向网络模型;然后,针对给出的灾害链网络,结合复杂网络统计指标,定量评价其节点和边的重要程度。利用历史事故数据,验证模型和评价方法。结果表明:所建灾害链网络模型能客观反映灾害事件间的传播关系;网络的边和节点的重要度评价结果与实际情况相符。     

危险化学品事故多米诺效应历史数据研究评述

系统整理分析近十五年来国内外利用历史数据进行危险化学品事故多米诺效应研究的相关文献,介绍该领域研究的主要数据来源、主要研究方法,对主要研究内容进行交叉比对,整理挖掘包括危险化学品多米诺事故场景下的易发物质、高发区域/过程、主要事故致因、高频事故序列、致死概率5项事故内在规律并对规律的运用进行初步探讨。提出在后续研究中可以从改进采样时间区间设计和进行细分事故场景研究作为该领域的完善方向。     

空中危险接近的系统动力学机理及仿真研究

为了探索空中危险接近的形成过程与反馈机制,运用系统动力学的方法深入分析了空中危险接近影响因素间的复杂相互作用和回馈效应,建立了空中危险接近发生机理的动态模型,包括管制服务、人力资源和安全三大子系统,利用Vensim软件对其进行模拟仿真,可预测不同场景下空中危险接近的变化趋势。结果表明:乐观场景时,2005—2015年空中危险接近数量呈缓慢增长趋势,2015年之后保持不变,这表明在国内航班量稳步增长时,空中危险接近事件的数量不变,事故率越来越低;悲观场景时,空中危险接近数量一直处于上升趋势,2021年之前缓慢增长,这表明虽然设备故障率和管制员的防撞培训频率不高,但缩短TCAS(Traffic Alert and Collision Avoidance System,空中交通预警和防撞系统)反应时间能在短期内明显提高管制员的专注程度,从而延缓空中不安全事件的数量增长,但随着2021年后指挥架次的增加,反应时间越短,空中危险接近事件会越多。     

基于跑道侵入场景仿真的危险分析方法

为刻画跑道侵入场景的动态过程,规范不安全事件危险分析流程,提出基于多agent仿真和形式化推理的危险分析方法。通过总结时态逻辑方法特征,建立一种典型跑道侵入场景的多agent形式化模型,并给出场景形式化规则属性。选取真实跑道侵入案例,建立不安全事件仿真模型,实现事件的时态逻辑仿真,生成动态轨迹,并结合场景规则属性进行形式化推理分析。试验结果表明,跑道侵入场景仿真能使分析者从具体操作层面理清不安全事件发生的逻辑过程,规范化形式推理分析能识别出诱发不安全事件发生的危险要素。     

基于蝴蝶型突变理论的安全生产保障系统分析和探讨

利用突变理论探讨事故致因模型,揭示事故致因的基本要素及其内在联系,对构成的要素进行抽象化,将对众多复杂企业的不安全因素进一步归纳为"人-机-环境-管理"安全生产保障系统,分析建立该系统的必要性,在突变理论的蝴蝶型与该系统结合性的基础上,探讨和建立安全决策和安全对策模型,将企业的安全生产危险程度分为理想的安全区域、危险区域、相对的安全区域。提出了危险程度和安全状况改进的数学模型,蝴蝶型突变理论能够揭示企业的安全状况。     

基于系统安全的风险管控模型

以往的事故致因理论多侧重于单一风险分析研究,但现实系统是一个由多危险源、多事故风险及多危害因素构成的一个复杂系统.单一事故风险的控制一般由危害因素的辨识与控制、事故隐患的检查与纠正及事故事件的应急与处理3个环节构成.由于系统要素的变化会从危险源、风险种类、危害因素及控制措施等方面对风险管控系统产生具体影响,因此,系统管控的核心,就是动态监测系统要素的变化对系统危险源、事故风险、危害因素及其控制措施(事故隐患)等风险要素产生的各种影响,从而采取针对性的防控措施.系统的风险管控过程至少应包括系统风险辨识、系统风险控制、系统资源保障、系统审核与评审等4个方面.     

A conceptual offshore oil and gas process accident model

The purpose of this paper is to present and discuss an accident prevention model for offshore oil and gas processing environments. The accidents that are considered in this work relate specifically to hydrocarbon release scenarios and any escalating events that follow. Using reported industry data, the elements to prevent an accident scenario are identified and placed within a conceptual model to depict the accident progression. The proposed accident model elements are represented as safety barriers designed to prevent the accident scenario from developing. The accident model is intended to be a tool for highlighting vulnerabilities of oil and gas processing operations and to provide guidance on how to minimize their hazards. These vulnerabilities are discussed by applying the 1988 Piper Alpha and the 2005 BP Texas City disaster scenarios to the model.     

ExSys-LOPA for the chemical process industry

The chemical process industries are characterized by the use, processing, and storage of large amounts of dangerous chemical substances and/or energy. Among different missions of chemical plants there are two very important ones, which: 1. provide a safe work environment, 2. fully protect the environment. These important missions can be achieved only by design of adequate safeguards for identified process hazards. Layer of Protection Analysis (LOPA) can successfully answer this question. This technique is a simplified process of quantitative risk assessment, using the order of magnitude categories for initiating cause frequency, consequence severity, and the likelihood of failure of independent protection layers to analyze and assess the risk of particular accident scenarios. LOPA requires application of qualitative hazard evaluation methods to identify accident scenarios, including initiating causes and appropriate safeguards. This can be well fulfilled, e.g., by HAZOP Studies or What-If Analysis. However, those techniques require extensive experience, efforts by teams of experts as well as significant time commitments, especially for complex chemical process units. In order to simplify that process, this paper presents another strategy that is a combination of an expert system for accident scenario identification with subsequent application of LOPA. The concept is called ExSys-LOPA, which employs, prepared in advance, values from engineering databases for identification of loss events specific to the selected target process and subsequently a accident scenario barrier model developed as an input for LOPA. Such consistent rules for the identification of accident scenarios to be analyzed can facilitate and expedite the analysis and thereby incorporate many more scenarios and analyze those for adequacy of the safeguards. An associated computer program is under development. The proposed technique supports and extends the Layer of Protection Analysis application, especially for safety assurance assessment of risk-based determination for the process industries. A case study concerning HF alkylation plant illustrates the proposed method.     

Mechanism analysis and risk assessment of escalation scenario in chemical industry zones

Many major hazard installations (MHIs) are located in chemical industry zones and escalation effect may be triggered when the fire or explosion occurs on a MHI. To investigate the mechanism of the accident escalation, a systematic quantitative assessment methodology is proposed by the considering the feature and uncertainty of the escalation scenario. The main accident energy carriers of the escalation are heat radiation, overpressure of blast and fragments. The escalation probability, joint influence of the three energy carriers and risk characterization of the accident scenarios are carried out. By the new methodology, the escalation scenario in chemical industry zones can be analyzed and the risk escalation morphology is demonstrated by the simulation software. The visualized risk cloud figure gives a supplementary way to prevent the escalation scenario in chemical industry zones planning.     

Evaluation on consequences prediction of fire accident in emergency processes for oil-gas storage and transportation by scenario deduction

This paper takes the safety in emergency processes as the starting point, from the perspective of scenario deduction, to study the consequences of fire accidents for oil-gas storage and transportation. Through the statistical analysis of actual accident cases, 19 frequently occurring basic scenarios in emergency processes are summarized. The scenario evolution paths of fire accidents for oil-gas storage and transportation are given by analyzing the evolution law of the accident development. Fuzzy numbers are introduced to express experts' qualitative judgment on accident scenarios. The empirical probabilities of scenario nodes are obtained by defuzzification calculation, and the state probability of each scenario node is calculated by using the dynamic Bayesian network joint probability formula. Under the comprehensive consideration about the probability statistics of actual accident cases, the critical scenario nodes on the evolution path and their final scenario probabilities are jointly determined to realize the optimization of the scenario evolution path. By constructing the correlation between the optimized scenario evolution path and the accident consequences, an accident consequence prediction model is established. The occurrence probability of accident consequences is calculated by the defuzzification method and dynamic Bayesian network. The accuracy of the consequence prediction model is verified by the July 16 Dalian's Xingang Harbor oil pipeline explosion accident. The research results provide scientific basis for helping decision makers to make the effective emergency measures that are most conducive to the rapid elimination of accidents and reducing the severity of accident consequences.     

Risk assessment of an oxygen-enhanced combustor using a structural model based on the FMEA and fuzzy fault tree

The oxygen-enhanced combustor has the advantages of high burning efficiency and low emissions. However, it should not be promoted for industrial use until its reliability and safety have been fully recognized. A new methodology is proposed to assess the risk of an oxygen-enhanced combustor using a structural model based on the FMEA and fuzzy fault tree. In addition, it is applied to a selected pilot semi-industrial combustor. To identify the hazard source comprehensively, the pilot is divided into four subsystems: the combustor subsystem, feed subsystem, ignition subsystem and exhaust subsystem. According to the operational parameters of flow (flow rate, temperature and pressure) and the component functions in different subsystems, the cause and effect matrix can be built using the structural model, and the relationship between the operational parameters and the effects of the change for the operational parameters on the system can be presented. Based on the results of cause and effect matrix, the FMEA can be built to describe the failed models and accident scenarios of the pilot. The main accident forms include leakage, injury, fire and explosion. Accordingly, with the severity and probability analysis of different accident forms, the fire and explosion accidents should be further accessed quantitatively using the fuzzy fault tree analysis. The fault trees can be obtained in accordance with the FMEA, and the qualitative assessments of the basic events can be collected by using expert scoring. A hybrid approach for the fuzzy set theory and weight analysis is investigated to quantify the occurrence probability of basic events. Then, the importance analysis of the fault trees, including the hazard importance of basic events and the cut set importance, is performed to help determine the weak links of the fire and explosion trees. Finally, some of the most effective measures are presented to improve the reliability and safety of the combustion system.     

Dynamic safety analysis of process systems by mapping bow-tie into Bayesian network

Among the various techniques used for safety analysis of process systems, bow-tie (BT) analysis is becoming a popular technique as it represents an accident scenario from causes to effects. However, the BT application in the dynamic safety analysis is limited due to the static nature of its components, i.e. fault tree and event tree. It is therefore difficult in BT to take accident precursors into account to update the probability of events and the consequent risk. Also, BT is unable to represent conditional dependency. Event dependency is common among primary events and safety barriers. The current paper illustrates how Bayesian network (BN) helps to overcome these limitations. It has also been shown that BN can be used in dynamic safety analysis of a wide range of accident scenarios due to its flexible structure. This paper also introduces the application of probability adapting in dynamic safety analysis rather than probability updating. A case study from the U.S. Chemical Safety Board has been used to illustrate the application of both BT and BN techniques, with a comparison of the results from each technique.     

Resilience assessment of chemical industrial areas during Natech-related cascading multi-hazards

In chemical industrial areas, technological accidents triggered by natural events (Natech events) may escalate. Complex cascading multi-hazard scenarios with high uncertainties may be caused. Resilience is an essential property of a system to withstand and recover from disruptive events. The present study focuses on the change of the resilience level due to (possible) interactions between cascading hazards, chemical installations and safety barriers during the dynamic evolution of fire escalations triggered by a natural hazard (certain cascading multi-hazard scenarios). A quantitative resilience assessment method is developed to this end. The state transition of a system facing accidents in the context of resilience is explored. Moreover, the uncertainties accompanying an accident evolution are quantified using a Dynamic Bayesian Network, allowing a detailed analysis of the system performance in different time steps. System resilience is measured as a time-dependent function with respect to the change of system performance. The applicability of the proposed methodology is demonstrated by a case study, and the effects of different configurations of safety barriers on improving resilience are discussed. The results are valuable to support disaster prevention within chemical industrial areas.     

重大危险源辨识与监控是企业建立事故应急体系的基础

本文简要介绍了重大工业事故预防控制体系要素和国家法律、法规与政策对企业重大危险源监控与应急体系建设的要求,论述了重大危险源辨识、监控是企业建立事故应急体系和重大事故预防控制体系的基础和前提,对企业重大危险源监控和应急预案编制要求提出了建议.