基于危险的事故场景及其形式化描述

事故场景的鉴别是复杂装备系统安全风险分析的基础,其完备性直接影响风险评估的有效性,因为任何事故场景的遗漏即意味着设计上可能存在潜在的事故隐患。提出从鉴别系统危险出发。建立危险与其原因(关联引发事件)、事件与系统要素以及系统各要素之间的映射关系,通过对这些关系的运算来获取事故场景的新方法并给出其形式化表述,以期在理论上确保事故场景鉴别的完备性。     

多米诺效应定量风险分析

根据多米诺效应的特点,提出了针对多米诺场景和效应后果的定量风险分析方法.首先辨识多米诺效应的事故场景,针对场景的复杂性和事故后果的严重性,运用数学模型和概率分析手段对主要事故场景进行分析; 其次根据初始事故的影响,运用设备损坏概率模型计算二次目标设备的损坏概率和场景的后果; 最后,运用人体脆弱性模型对效应后果进行分析,量化多米诺效应的风险,结合风险分析方法和理论得到直观的个人风险和F-N社会风险曲线.多米诺分析流程及计算的结果表明,多米诺效应对个人风险和社会风险都造成了显著的变化,加强多米诺效应分析有利于工厂规划布局和安全管理.     

核事故应急后果评价系统研究综述

通过简要分析核武器事故的特点,回顾国内外民用核设施事故后果评价系统功能及特征,总结美国武器事故后果评价系统的研究进展,对比分析民用核设施同核武器事故后果评价系统的异同,探讨核武器事故后果评价系统的发展趋势。分析表明,核武器事故与民用核设施事故在功能和结构上具有相似之处,开发适合多种事故源项、环境条件的后果评价系统是未来核事故后果评价系统的发展方向。     

氯气储罐泄漏扩散范围的主要影响因素

本文使用PHAST软件,模拟了氯气泄漏的事故后果,分析了液氯储罐泄漏孔径、泄漏时间、气象条件等不同状况下对事故后果的影响。通过泄漏事故后果模拟结果可以看出,设定的典型泄漏场景下,泄漏孔径和气象条件对半致死浓度最大扩散范围影响较大。研究结果可为安全生产应急救援提供数据和参考。     

基于风险矢量图的多场景保护层分析方法研究*

为解决多场景保护层分析（LOPA）存在的问题,建立风险矢量导图,将事故场景、独立保护层、修正因子、事故后果发生频率等因素进行系统分析,分别采用最大值法求和法计算后果发生频率,探讨多重初始事件导致事故发生频率的最优计算方法;阐述点火源、暴露因子以及致死概率等修正因子的使用方法并提出改进建议,避免常规LOPA下致死概率过高的问题。以柴油加氢装置原料油缓冲罐液位过高风险点为例,进行多场景LOPA,应用综合计算法得出多重初始事件导致的液位高后果失效频率为3.2E-02。结果表明:风险矢量导图和正确使用修正因子可有效提高LOPA的质量;不同初始事件导致的场景失效频率值相差较大或存在共用保护层的情况适用最大值法,其他情况则可采用求和法;如果多场景同时适用最大值法和求和法,则采用综合计算法;求和法过于保守,最大值法过于乐观,综合计算法更为准确。     

基于虚拟现实技术的喷射火事故三维动态仿真及应用

基于Shell模型的原理和计算方法,把喷射火焰视为近似倒立圆台形,构建了不同风向影响下的喷射火三维模型,运用虚拟现实技术和三维可视化技术对喷射火事故进行模拟与仿真。以Delphi和OpenGL/GLScene为开发工具,实现了喷射火三维模型的程序化与三维场景绘制,同时引入粒子特效系统,实现了喷射火焰燃烧的实时动态仿真,完成了喷射火三维动态可视化软件系统的开发。最后,利用该系统进行实例分析。应用表明:虚拟现实技术与事故后果模拟相结合,使整个系统实现实时性和形象性的统一,虚拟现实技术在化工行业具有广泛应用前景,也为事故后果预测评估提供科学依据。     

基于Unity3D的L-CNG加气站事故仿真研究

为了提高员工对站内储罐事故后果的认识,采用灾害机理和灾害效果仿真相结合的方法,在选取泄漏、火球热辐射及爆炸冲击波机理模型并建立L-CNG加气站三维场景的基础上,分别计算火球热辐射和爆炸冲击波的伤害半径,并用Unity3D中的粒子系统模拟了泄漏、火焰、爆炸事故后果及伤害范围,最终开发了一套基于Unity3D平台的事故仿真系统,直观呈现灾害影响范围,对L-CNG加气站的选址及应急方案的制定具有重要意义。     

危险化学品道路运输事故对环境敏感区影响研究

为预测危险化学品道路运输事故对环境承载力造成的破坏,本文考虑天气及地理环境等多因素进行危险化学品道路运输风险评价模型优化,基于熵权法对环境敏感区进行事故后果量化评估.以北京六环为场景实例研究,结果表明:医院、学校、住宅区、公共绿地和风景名胜区在事故后果影响中所占比重更高,西六环的环境敏感区后果值最大;该模型与现实风险分级指数评价法计算结果进行对比分析,可知该风险量化模型进行环境敏感区影响评价具有一定合理性和科学性.     

基于ArcGIS Engine设计天然气管道泄漏事故后果评估系统

城市天然气管道是城市不可缺少的基础设施之一,为有效遏制天然气管道事故造成的重大灾害,需加强对应急救援系统的研究。选取高斯模型分析泄漏的天然气的扩散过程,并划分事故后果评估区域。利用ArcGIS Engine平台,设计并建立一个城市天然气管道泄漏事故的应急救援系统。利用该系统可模拟天然气管道泄漏后可能发生的气体扩散、火灾、爆炸等事故后果,通过天然气理化参数、天然气泄漏的初始状态和周围环境的气象条件,以可视化方式直观显示不同等级的事故后果评估缓冲区。     

基于后果的土地利用安全规划方法在化工园区的应用

土地利用安全规划是预防和控制重大工业事故的重要手段,本文讨论国外常见重大危险源土地利用规划的三种方法,给出一个基于后果的土地利用安全规划的方法。提出火灾、爆炸和毒物泄漏等事故场景下的伤害阈值标准并以此进行事故后果伤害分区,给出脆弱性目标的分级原则,最终给出土地利用安全规划的判断准则。以南方某化工园区为实例应用此方法进行分析研究。本方法可应用于重大危险源或化工园区的安全规划、安全评价以及应急规划等工作。     

Mapping safety culture attributes with integrity management program to achieve assessment goals: A framework for oil and gas pipelines industry

Introduction: The safety of oil and gas pipelines is an increasing concern for the public, government regulators, and the industry. A safety management system cannot be efficient without having an effective integrity management program (IMP) and a strong safety culture. IMP is a formal document (policies, planning, scheduling, and technical processes) while safety culture is a measure of views, beliefs, and traditions about safety. For regulatory authorities and O&G companies, assessing the effectiveness of both the IMP and safety culture through regulatory audits is a daunting task with indistinct findings. Method: An integrated framework based on regulatory audits is developed to assess the maturity of safety culture based on IMP efficacy through risk-based approach by using failure mode and effect analysis (FMEA). The framework focuses on three distinct aspects, the probability of failure occurrence in case of the non-compliance of regulatory and program requirements, severity of non-compliance, and effectiveness of the corrective actions. Results: Program requirements and performance indicators are translated into assessment questions which are grouped into 18 IMP components. Subsequently, these components are linked with four safety culture attributes. Sensitivity analysis revealed that four IMP components, i.e., organizational roles and responsibilities, policy and commitment, risk assessment, and training and competency, significantly affect the safety culture maturity level. Conclusions: Individual assessment of IMP and safety culture in O&G sector consumes extensive time and efforts in the auditing process. The framework facilitates the process by pursuing common criteria between IMP and safety culture. The O&G companies and regulator can prioritize the improvement plans and guidelines using the framework's findings. Practicalapplications:The integrated framework developed in this research will improve the existing assessment mechanism in O&G companies. The framework has been effectively implemented on a case of 17 upstream O&G pipeline-operating companies in the province of British Columbia, Canada.     

Risk analysis for oil & gas pipelines: A sustainability assessment approach using fuzzy based bow-tie analysis

Vast amounts of oil & gas (O&G) are consumed around the world everyday that are mainly transported and distributed through pipelines. Only in Canada, the total length of O&G pipelines is approximately 100,000 km, which is the third largest in the world. Integrity of these pipelines is of primary interest to O&G companies, consultants, governmental agencies, consumers and other stakeholder due to adverse consequences and heavy financial losses in case of system failure. Fault tree analysis (FTA) and event tree analysis (ETA) are two graphical techniques used to perform risk analysis, where FTA represents causes (likelihood) and ETA represents consequences of a failure event. ‘Bow-tie’ is an approach that integrates a fault tree (on the left side) and an event tree (on the right side) to represent causes, threat (hazards) and consequences in a common platform. Traditional ‘bow-tie’ approach is not able to characterize model uncertainty that arises due to assumption of independence among different risk events. In this paper, in order to deal with vagueness of the data, the fuzzy logic is employed to derive fuzzy probabilities (likelihood) of basic events in fault tree and to estimate fuzzy probabilities (likelihood) of output event consequences. The study also explores how interdependencies among various factors might influence analysis results and introduces fuzzy utility value (FUV) to perform risk assessment for natural gas pipelines using triple bottom line (TBL) sustainability criteria, namely, social, environmental and economical consequences. The present study aims to help owners of transmission and distribution pipeline companies in risk management and decision-making to consider multi-dimensional consequences that may arise from pipeline failures. The research results can help professionals to decide whether and where to take preventive or corrective actions and help informed decision-making in the risk management process. A simple example is used to demonstrate the proposed approach.     

An integrated methodology to manage risk factors of aging urban oil and gas pipelines

Aging urban oil and gas pipelines have a high failure probability due to their structural degradation and external interference. The operational safety of the aging urban oil and gas pipeline is challenged by different hazards. This paper proposes a novel methodology by integrating an index-based risk evaluation system and fuzzy TOPSIS model for risk management of aging urban oil and gas pipelines, and it is carried out by evaluating the priority of hazards affecting pipeline safety. Firstly, the hazard factors of aging urban oil and gas pipelines are identified to establish an index-based risk evaluation system. Subsequently, the fuzzy TOPSIS model is employed to evaluate the importance of these hazard factors and to decide which factors should be managed with priority. This work measures the importance of a hazard factor from three aspects, i.e. occurrence (O), severity (S) and detectability (D), and the weights of these three parameters are determined by a combination weight method. Eventually, the proposed methodology is tested by an industrial case to illustrate its effectiveness, and some safety strategies to reduce the operational risk of the pipeline are presented. The proposed methodology is a useful tool to implement more efficient risk management of aging urban oil and gas pipelines.     

城镇燃气管道动火作业安全评价

针对城镇燃气管道动火作业的高危险性,为保障生命财产安全,提出一种基于未确知测度的安全评价方法。首先,从动火施工作业的前、中、后3个阶段对整个作业过程进行安全分析,并基于作业的前阶段建立安全评价体系。然后,引入未确知测度模型,将因素的量化值与测度函数结合得出测度评价矩阵,采用变异系数法处理评价矩阵,确定各危害因素的客观权重。最后,根据测度评价矩阵与因素权重得出动火作业的安全等级,并对危害因素进行排序。实例结果表明:应用该方法能有效地确定出城镇燃气管道动火作业的安全等级,对于不安全的施工作业,可根据排序确定高危险因素,并采取措施降低其危险性,提高整个动火作业过程的安全性。     

城镇燃气管道第三方施工损伤风险评价方法研究

针对第三方施工对城镇燃气管道的不利影响,提出一种半定量风险评价方法。首先,基于“人—机—环境—管理”系统确定失效因素,利用G2赋权法对因素赋权,并引入物元模型分析失效可能性;然后,建立喷射火焰、闪火和蒸气云爆炸的数学模型计算管道泄漏的伤害面积,确定失效后果等级;最后,根据API 581中的风险矩阵得出燃气管道第三方施工破坏风险等级。实例分析表明,该方法兼具定性评价与定量评价的优点,能更加准确有效地进行风险分析,确定风险等级。     

Taking Credit for Loss Control Measures in the Plant with the Likely Loss Fire and Explosion Index (LL-F&EI)

This communication proposes a new relationship for estimation of the damage factor (DF) used in the Dow Fire and Explosion Index (F&EI). The proposed new relation more clearly shows how the damage factor depends on other factors in the F&EI, such as material factor (MF) and Process Unit Hazards Factor, and leads to the definition of a new index which accounts for loss control measures implemented in the plant, and thus gives a measure of risk. Analysis shows that three types of relations exist between DF and Process Unit Hazards Factor depending on the size of the MF—low, medium or high. Further analysis shows, that the procedure in the current F&EI Guide may overestimate the DF for a very low MF and moderate to high Process Unit Hazards Factor.The analysis leads to the definition of the Likely Loss Fire & Explosion Index, which provides an estimate of risk of losses from fires and explosions as well as degrees of risk similar to the estimate of hazards and degrees of hazard associated with the Fire & Explosion Index.     

The integration of Dow's fire and explosion index (F&EI) into process design and optimization to achieve inherently safer design

For the processing industries, it is critically to have an economically optimum and inherently safer design and operation. The basic concept is to achieve the best design based on technical and business performance criteria while performing within acceptable safety levels. Commonly, safety is examined and incorporated typically as an after-thought to design. Therefore, systematic and structured procedure for integrating safety into process design and optimization that is compatible with currently available optimization and safety analysis methodology must be available.The objective of this paper is to develop a systematic procedure for the incorporation of safety into the conceptual design and optimization stage. We propose the inclusion of the Dow fire and explosion index (F&EI) as the safety metric in the design and optimization framework by incorporating F&EI within the design and optimization framework. We first develop the F&EI computer program to calculate the F&EI value and to generate the mathematical expression of F&EI as a function of material inventory and operating pressure. The proposed procedure is applied to a case study involving reaction and separation. Then, the design and optimization of the system are compared for the cases with and without safety as the optimization constraint. The final result is the optimum economic and inherently safer design for the reactor and distillation column system.     

基于G1法的高危作业疲劳风险模糊综合评判

疲劳严重威胁作业安全,许多事故都直接或间接由疲劳引发。针对高危作业疲劳风险评价问题,考虑作业疲劳致因,综合运用G1法,提出高危作业疲劳风险的模糊综合评判方法。首先,根据疲劳的表现,系统分析影响高危作业疲劳的因素,以管理因素、岗位因素、作业环境、生理、心理等5个因素为准则,构建作业疲劳风险的评价指标体系。然后,应用G1法,确定指标权重,建立高危作业疲劳风险多级模糊综合评价模型,评判疲劳状况。最后,通过一个案例验证了模型方法的可行性与有效性,为综合评判高危作业疲劳发生可能性提供了一个新视角与方法。     

Developing safety indicators for preventing offshore oil and gas deepwater drilling blowouts

An important question with respect to the Macondo blowout is whether the accident is a symptom of systemic safety problems in the deepwater drilling industry. An answer to such a question is hard to obtain unless the risk level of the oil and gas (O&G) industry is monitored and evaluated over time. This article presents information and indicators from the Risk Level Project (RNNP) in the Norwegian O&G industry related to safety climate, barriers and undesired incidents, and discusses the relevance for deepwater drilling. The main focus of the major hazard indicators in RNNP is on production installations, whereas only a limited number of incident indicators and barrier indicators are related to mobile drilling units. The number of kicks is an important indicator for the whole drilling industry, because it is an incident with the potential to cause a blowout. Currently, the development and monitoring of safety indicators in the O&G industry seems to be limited to a short list of “accepted” indicators, but there is a need for more extensive monitoring and understanding. This article suggests areas of extensions of the indicators in RNNP for drilling based on experience from the Macondo blowout. The areas are related to schedule and cost, well planning, operational aspects, well incidents, operators’ well response, operational aspects and status of safety critical equipment. Indicators are suggested for some of the areas. For other areas, more research is needed to identify the indicators and their relevance and validity.     

节段预制悬臂拼装梁施工安全风险评价

为了准确地对节段预制悬臂拼装梁的施工过程进行安全风险评价,对该类桥梁的施工提供有效借鉴,提出基于组合赋权的灰色聚类综合评价模型。首先根据该施工技术的工艺特点及相关规范,建立风险评价指标体系,利用G1法和C-OWA算子分别确定评价指标体系的主观权重和客观权重,并运用最小信息熵原理优化组合赋权,进一步利用三角白化权函数建立灰色聚类评价模型,确定风险综合评价值,最后依据风险测度界定范围判断施工安全风险等级。最后,运用此评价模型进行实例分析,并根据评价结果提出改进策略,同时验证了该模型的适用性和有效性,进而为该类桥梁施工安全风险管控策略的制定提供理论依据。