基于序列偏差的化工过程危险辨识

研究了化工事故中偏差连锁关系以及控制化工事故的作用连锁关系.将变化论的思想应用到HAZOP分析中,提出了一种基手序列偏差的HAZOP分析程序,用于化工过程危险辨识.在常规HAZOP分析的基础上构建序列偏差图,以此确定各个偏差的重要度,选择偏差控制策略.以某聚氯乙烯聚合工艺过程中的偏差"引发剂贮槽搅拌无"为例介绍了该方法.应用该方法认清了偏差如何发展为事故,如何选择控制策略,以预防事故发生,达到系统安全的目的.     

氯乙烯生产过程中的危险源辨识

氯乙烯生产是现代化工企业中常见的工艺,生产过程复杂,涉及参数较多,具有一定的危险性.一旦发生意外事故,将会导致人员伤亡和经济损失.用系统安全的理论和方法对乙炔法制备氯乙烯生产过程中的主要危险物质、生产工艺和危险操作单元进行了危险源辨识,并提出在化工生产危险源辨识的过程中,应进行重大危险源的辨识,能够有针对性采用不同评价方法得到较精确的评价结果.对化工企业的风险评价工作有很大的借鉴意义.     

基于HYSYS和HAZOP的工艺参数偏差模拟与后果量化

为解决危险与可操作性分析(HAZOP)不能有效回答工艺偏差临界范围及各种可能的偏差后果量化问题,拟将HAZOP分析与化工过程模拟软件(HYSYS)相结合,实现量化分析。以某汽提塔抽提工艺为例,对工艺参数偏差进行传统HAZOP分析及风险筛分。采用HYSYS对筛分出的高风险偏差进行动态模拟,定量描述偏差后果。结果表明:HAZOP与HYSYS相结合的量化模拟分析方法可用于指导化工装置在实际运行阶段的偏差量化分析与事故预防,为过程风险控制措施及相关建议提供可操作的量化指标。     

基于真三维GIS的危险化学气体泄漏扩散动态模拟仿真系统

针对传统危险化学气体泄漏扩散软件在模拟表现力方面的不足,提出将改进的随机游走大气泄漏扩散模型集成到真三维地理环境信息系统中,完成了基于真三维GIS环境下的危险化学品泄漏扩散模拟仿真系统的设计与开发.该系统能够在真三维场景中直观地展示危险化学气体的三维扩散过程,实时显示危险化学品泄漏扩散浓度分布图及事故不同程度的危害范围.同时通过与PHAST软件模拟结果对比,验证了该系统的可靠性.系统可以直观地、有效地帮助应急指挥人员组织应急救援和疏散,为企业、政府在危险化学品泄漏事故预防、预测和评估以及应急预案的制定提供参考.     

化工生产过程HAZOP安全评价技术

化工生产过程涉及大量易燃、易爆、有毒、有害物质,一旦物质或能量的正常运行状态遭到破坏,便会发生火灾、爆炸或泄漏导致灾难性后果。为防止化工生产过程危险事故的发生和蔓延,实现事故早期预防,需要对化工生产过程进行安全评价。危险与可操作性分析(Hazard and Operability,HAZOP)是l套应用较广的评价方法,但是人工评价存在费时、费力、成本高等缺点。本文介绍了计算机辅助安全评价技术的发展和人工HAZOP安全评价技术,重点讨论了一种基于SDG(Signed Directed Graph)的计算机辅助危险与可操作性分析安全评价技术。这种安全评价技术基于SDG定性模型过程模型,通用性强,且又能分析各种具体工艺的特定信息,与人工专家评价相比,该评价技术具宵完备性好、省时、省力、成本低、评价结果系统性和条理性强等众多优点。     

基于人的认知可靠性(HCR)模型的人因操作失误研究

以人的认知可靠性(HCR)模型为指导,选择包含技能型、规则型和知识型3种认知类型,结合大连化工集团公司影响运行安全的17个异常事件,对54名操纵员的时间响应状况和允许操作时间进行录像、记录与分析;依据IAEA提供的指标[1],找出操纵员在生产过程中可能出现的操作失误类别及其可能造成的危害;基于3参数威布尔模型推导出操纵员操作响应失误概率模型,并从人机工程学角度提出了具体预防事故的安全对策措施。结果表明,基于HCR模型的大化集团公司操纵员的人因操作失误模型实用、有效,为实现操作者与机器系统相协调的目标、正确评估操作着实时操作的响应时间提供了重要参考依据。     

化工过程安全管理

<正>化工过程伴随易燃易爆、有毒有害等物料和产品,涉及工艺、设备、仪表、电气等多个专业和复杂的公用工程系统。加强化工过程安全管理,是国际先进的重大工业事故预防和控制方法,是及时消除安全隐患、预防事故、构建企业安全生产长效机制的重要基础性工作。当前,我国危险化学品安全生产虽总体稳定向好,但基础仍薄弱,形势依然严峻,尤其近年来发生在危化行业的一系列重特大事故,教训十分深刻。为加强化工企业安全生产基础工作,全面     

化工装置火灾、爆炸、毒物扩散危险快速辨识方法

化工装置火灾、爆炸、毒物扩散的危险辨识是进一步进行定量化风险评估等安全分析的基础,笔者提出考虑该3种破坏效应显著的11种事故模式,以化工装置的介质性质、操作条件等参数作为基本事件对各种事故模式进行事故树分析;从而得到各基本参数对不同事故模式发生的影响并以其为依据建立了一种基于危险分析调查表和事故模式-字符串映射表的问卷式快速危险辨识体系;最后采用VB6.0作为开发平台,对该辨识系统进行了软件化实施。     

HAZOP分析中优选偏差方法及应用

<正>随着现代化工的蓬勃发展,越来越多的易燃、易爆、剧毒类危险化学品被使用,在创造巨大经济利益的同时,也带来了火灾、爆炸、毒物泄漏等重大危险。近些年,这种涉及危险化学品的重特大事故时有发生,造成了严重的人员、财产损失以及环境污染。为了最大限度的预防事故发生、降低事故危险,就必须要对生产工作场所进行危险辨识,以了解可能存在的风险以及控制事故发生的安全保护措施。危险与可操作性分析(Hazard and     

事故发生原理及安全对策

生产活动过程实际上是系统能量传递、转换与做功的过程,生产过程的能量或危险物质是造成事故的最根本的致因,而事故隐患则是发生事故的激发条件.针对事故发生的各种因素,提出了预防事故的安全对策,为企业安全管理提供借鉴.     

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.     

A new intelligent assistant system for HAZOP analysis of complex process plant

There are several problems that should be solved in the practical application of HAZOP analysis, such as the inheritance instrument of experience knowledge, the classification of accident reasons, the recurrence of analysis process and the verification of analysis results. This paper presents a new HAZOP assistant program named HELPHAZOP, which can be used to cope with these problems. With the aid of this program, a number of influence relationship models, which can be utilized to present the relationship structure of the whole system, can be established, and a variety of spread paths, which can be employed to describe the occurrence of the accidents, can be identified. These models and paths can help analyzers to understand the analysis process of different chemical processes and to verify the analysis results. Experience knowledge or information of process parameters stored in this program, including deviations, abnormal reasons, consequences and disaster-causing ways, can contribute to the analysis of some new plants. The program has been applied in the HAZOP analysis process of residuum hydrotreating process. The probability of the human errors which would be happened because of the misunderstanding or the deficiency of plant experience in the HAZOP analysis has been reduced and the accuracy, practicability and analysis efficiency of the accident forecast have been greatly improved.     

A novel knowledge database construction method for operation guidance expert system based on HAZOP analysis and accident analysis

An expert system for operation guidance will contribute to identifying the operatoration problems and indicating the resolutions thereof, because the information stored in the expert system can be utilized to resolve the corresponding technical problems. However, there are several problems that should be solved in the practical application of the expert system, such as lack of corresponding knowledge or resolutions utilized to cope with the problems, inapplicable resolutions, too many resolutions for the operators to choose from to obtain the best one in the first time, etc. Obtaining and storing as much as information in the database of the expert system are important issues in the construction process of the expert system. The accident analysis results contain a limited number of accident cases and the HAZOP analysis only refers to a single deviation analysis. This paper has presented a novel knowledge database construction method for an operation guidance expert system based on the HAZOP analysis and the accident analysis, which can be used to resolve the above problems. The HAZOP analysis results are combined with the accident analysis results and the combination information can be stored in the database of the expert system, and can be employed to forecast accidents or identify accident causes. The structures of the operation guidance table and the accident investigation table have been illustrated. The residuum hydrotreating process expert system is taken as an example to illustrate the knowledge database construction method. With the aid of this expert system, the operators will well understand the operations and adopt the best resolutions to deal with the abnormal situations. Also the operators can identify potential risks existing in the plant which will result in accidents according to the accident analysis results associated with the HAZOP analysis results.     

Dynamic failure assessment of an ammonia storage unit: A case study

Chemical Process Industries usually contain a diverse inventory of hazardous chemicals and complex systems required to perform process operations such as storage, separation, reaction, compression etc. The complex interactions between the equipment make them vulnerable to catastrophic accidents. Risk and failure assessment provide engineers with an intuitive tool for decision making in the operation of such plants. Abnormal events and near-miss situations occur regularly during the operation of a system. Accident Sequence Precursors (ASP) can be used to demonstrate the real-time operating condition of a plant. Dynamic Failure Assessment (DFA) methodology is based on Bayesian statistical methods incorporates ASP data to revise the generic failure probabilities of the systems during its operational lifetime.In this paper, DFA methodology is applied on an ammonia storage unit in a specialized chemical industry. Ammonia is stored in cold storage tanks as liquefied gas at atmospheric pressure. These tanks are susceptible to failures due to various abnormal conditions arising due process failures.Tank failures due to three such abnormal conditions are considered. Variation of the failure probability of the safety systems is demonstrated. The authors use ASP data collected from plant specific sources and safety expert judgement. The failure probabilities of some safety systems concerned show considerable deviation from the generic values. The method helps to locate the components which have undergone more degradation over the period and hence must be paid attention to. In addition, a Bayesian predictive model has been used to predict the number of abnormal events in the next time interval. The user-friendly and intuitive nature of the tool makes it appropriate for application in safety assessment reports in process industries.     

化学事故危害后果评估与应急救援的辅助决策系统设计

根据重大城市的化学事故后果评估与应急救援的实际需要出发,提出了研制辅助决策系统任务需求和设计构想,阐述了该系统的系统结构、系统实现的流程和系统功能,并做了可行性分析。系统的模块包括：化学品基础信息模块、化学事故类型划分模块、地理信息系统模块、化学源周围道路交通模块、实时的天气预报模块、数学模型模块、危害后果评估模块、救援方案生成模块、人员疏散撤离方案生成模块、人机交互模块。系统与地理信息系统（G IS）、卫星导航系统（GPS）、遥感成像技术结合后能够实现精确定位、快速评估。将物联网技术与系统结合,还可实现对大型固定化学源远程时时监控,确保在事故发生后第一时间掌握信息,为后果评估和应急救援赢得时间,将化学突发事故的危害降到最低。该系统在信息化条件下,较好地为决策者进行化学事故后果评估,为应急救援决策提供了依据,可大幅度提高应急救援效能。     

Research on 3D dynamic visualization simulation system of toxic gas diffusion based on virtual reality technology

A three-dimensional (3D) model of toxic gas diffusion was advanced based on Monte Carlo method with the presupposition that toxic gas diffusion process can be considered as random walk process of a large number of toxic gas particles. Compared to other existing models, this model includes analysis of both movement and non-movement attributes of toxic gas particles, and can well meet the need of dynamic simulation. Then, a 3D gas diffusion visualization scene management subsystem, including leak hazard source (tank), leak background (ground and sky) and surroundings near the leak area, was developed based on virtual reality (VR) technology. In this system, diffusion scene can be designed in accordance with the reality, which embodies the reunification between VR technology and engineering application. Finally, according to OpenGL particle system theory, by using Delphi and OpenGL as main programming tools, the diffusion simulation subsystem of toxic gas diffusion process and real-time concentration prediction and consequence simulation subsystem was completed. Application shows that by using VR technology in the accident consequence simulation, the whole system is of real-time, lifelike and visual characteristics, which not only embodies the great engineering value of virtual reality technology in the field of safety engineering, but also provides references for accident impact prediction, assessment and emergency plan.     

AFRA – Heuristic expert system to assess the atmospheric risk of sulphide waste dumps

In 2006, an unprecedented atmospheric confined space accident took place in a sampling shed at the Sullivan Mine in Kimberley, British Columbia. This accident suggests that a risk assessment should be carried out on a regular basis at mine reclamation sites for many years after closure. In this paper, an Atmospheric Fuzzy Risk Assessment (AFRA) tool is described that can assess atmospheric risk given heuristic and measured data at such sites. It can also serve to transfer knowledge about atmospheric hazards in an enclosed structure. The system uses fuzzy logic to input and output information and to perform weighted inferencing. The paper describes the developmental process as well as system verification and validation based on a number of known test and reference waste dumps. AFRA is a heuristic expert system based on fuzzy logic and the first tool that was developed to assess the atmospheric risk of mine waste dumps. The atmospheric risk is estimated by fuzzy Mamdani system given the values of four major elements of risk comprising of: gas generation, gas emission, gas confinement, and human exposure. The ability of AFRA to adapt its risk assessment to different climate conditions is explained. There are many physical, chemical, and environmental factors which fluctuate over time affecting oxygen-depletion in waste dumps. AFRA can help mining engineers and mine managers recognize this type of danger when conducting a confined space inventory at a reclamation site.     

Risk assessment of chemical process considering dynamic probability of near misses based on Bayesian theory and event tree analysis

With the development of modern automatic control systems, chemical accidents are of low frequency in most chemical plants, but once an accident happens, it often causes serious consequences. Near-misses are the precursor of accidents. As the process progresses, near misses caused by abnormal fluctuation of process variables may eventually lead to accidents. However, variables that may lead to serious consequences in the production process cannot update the risk in the life cycle of the process by traditional risk assessment methods, which do not pay enough attention to the near misses. Therefore, this paper proposed a new method based on Bayesian theory to dynamically update the probability of key variables associated with process failure risk and obtain the risk change of the near-misses. This article outlines the proposed approach and uses a chemical process of styrene production to demonstrate the application. In this chemical process, the key variables include flow rate, liquid level, pressure and temperature. In order to study the dynamic risk of the chemical process with consideration of near misses, according to the accumulated data of process variables, firstly the abnormal probability of the variables and the failure rate of safety systems associated with the variables were updated with time based on Bayesian theory. On the basis of the dynamic probability of key process variables, an event tree of possible consequences caused by variable anomalies was established. From the logical relationship of the event tree, the probability of different consequences can be obtained. The results show that the proposed risk assessment method based on Bayesian theory can overcome the shortcomings of traditional analysis methods. It shows the dynamic characteristics of the probability of different near misses, and achieves the dynamic risk analysis of chemical process accidents.     

省域安全生产应急救援指挥平台框架体系研究

分析省级安全生产应急救援指挥的业务特点,认为它是一个平时模拟演练和事故现场应急指挥并重、平战结合的一体化过程,是一个广域多部门实时动态的联动过程;笔者提出安全生产应急救援的框架体系,并以网络为基础,以信息技术为手段,以智能设备为前端而构建一个实时直观的应急指挥有机体,包括基础支持系统、综合应用系统、数据库系统、移动指挥平台、前端展示系统,以及法律法规等体系、安全保障体系等,同时重点分析其中的网络结构、综合应用系统,以及与其他单位系统的接口。该框架体系通过广东省安全生产监督管理部门的验证,在实践中是可行的。     

GIS在化工园区事故应急救援辅助决策中的应用

采用GIS平台与应急决策支持技术相结合,以园区高危工艺和重大危险源作为分析对象,开发化工园区安全管理系统中的应急救援辅助决策模块,针对园区内高危工艺或重大危险源事故后果预测与事故应急救援管理的科学性和有效性,扩展为对整个化工园区的事故风险管理与事故应急救援辅助决策支持。运用该模块可实现园区内突发事故后果预测、最优救援和疏散路径规划、应急辅助决策方案生成,有效提高化工园区事故救援的科学性和效率,减少人员伤亡和财产损失,提高化工园区安全管理水平。