基于SDG模型的HAZOP分析方法在钻井作业中的应用

HAZOP分析方法是目前危险性分析领域最盛行的分析方法之一,广泛地应用于石油化工行业。但是其分析过程仅依靠专家积累的知识与经验,不仅评价的内容不严格,而且分析的可信程度有限,对实际工作的指导意义不高,不能适应工业现场的要求。鉴于HAZOP分析方法中的不足,提出了基于SDG模型的HAZOP分析方法,并利用该方法对钻井作业过程进行了危险性分析。基于SDG模型的HAZOP分析方法从复杂系统的内部逻辑入手,进行深层次的推理,不仅提高了分析效率,而且分析所得结果的完备性较好。     

The integration of HAZOP expert system and piping and instrumentation diagrams

The main purpose of hazard and operability (HAZOP) analysis is to identify the potential hazards in the process design which nowadays is generally developed through a computer aided design (CAD) package. Due to the time and effort consuming nature of HAZOP, it is not done in every engineering firm for every design project. To make HAZOP an integral part of process design, an integration framework is proposed in this paper to seamlessly integrate the commercial process design package Smart Plant P&ID (SPPID, Intergraph) with one of the HAZOP expert systems (named as LDGHAZOP) developed by authors. This integration makes it possible to perform HAZOP analysis easily at anytime of the whole lifecycle of a chemical plant as long as the process design is available, which might help the improvement of design quality. One industrial case study is used to illustrate the ability of the integrated system.     

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.     

基于三角模糊数的HAZOP分析在石油化工装置中的应用

工艺危害分析强调运用系统的方法对危害进行辨识、分析,并采取必要的措施消除和减少危害。HAZOP分析能对工艺过程非常系统、全面的进行分析,但传统的HAZOP分析在量化风险时,对于偏差原因发生的可能性评价存在较大的主观性。本文对于没有统计资料的HAZOP分析偏差原因发生可能性,采用专家打分法,利用三角模糊数来表示其模糊发生概率。对于有统计资料的偏差原因,直接表示成三角模糊数。这种方法能够很好的表示HAZOP分析偏差发生概率。介绍了基于三角模糊数的HAZOP分析步骤,并在石油化工装置中进行了应用。这对HAZOP分析技术在石油化工装置中的推广具有重要意义。     

Alarm management optimization in chemical installations based on adapted HAZOP reports

Most current alarm systems used in chemical installations show poor performance due to alarm flooding. This study focuses on alarm management systems optimization using the deviation propagation relationship hidden in the hazard and operability study (HAZOP) report, which can be transformed into a critical information source for alarm optimization management. More concretely, this means matching the alarm tag number with the process deviations in the deviation column, possible cause column, and consequence column. Furthermore, a backtracking method and a reasoning method were established to identify the initial alarm and associated alarms. Besides, a root fault diagnosis was carried out. A method of detecting hardware faults and unreasonable alarm thresholds is established using alarm causality corresponding to the deviation causality and associated alarm generation-skipping tracing method. According to the severity of the consequence corresponding to the deviation, a determined alarm priority method is constructed. The results show that the deviation propagation relationship in the HAZOP report is clear, and the topological relationship is easy to build based on the deviation propagation relationship. With comprehensive and in-depth HAZOP analysis reports in China, the alarm management optimization technology based on adapted HAZOP reports shows good prospects for application and promotion.     

在役柴油加氢装置HAZOP分析技术

柴油加氢装置属甲类火灾危险生产装置,为了保障其安全生产,实现事故早期预防,对其进行风险分析和安全评价势在必行.HAZOP分析方法是流程工业广泛使用的一种危险辨识和分析方法,具有较好的系统性和完备性.首先介绍了HAZOP分析方法的由来及应用情况,其次分析了在役装置HAZOP分析的难点,并提出了相应的建议,然后详述了在役装置HAZOP方法的分析流程.最后以中石油某石化公司在役柴油加氢装置为例进行了HAZOP分析,辨识出可能存在的安全隐患和潜在危险,对较高风险提出了必要的安全保护措施和合理的改进建议.结果表明,HAZOP分析是提高在役装置安全性的一种有效手段,其结果为装置安全管理提供了可靠的依据.     

SDG-based HAZOP analysis of operating mistakes for PVC process

As modern chemical plants are becoming more complex and bigger in scale, the associated chance of things going wrong is also increasing rapidly. Due to the flammable, explosive, toxic and corrosive nature of chemical process, any single accident may trigger a major catastrophe that brings tremendous environmental, social and economical loss. In order to prevent any accident from happening, hazard and operability (HAZOP) analysis has been brought in to monitor chemical process and provide early warning for signs of accident. However, most existing HAZOP is carried out manually, and there are always obstacles in terms of cost overrun and incompleteness of the analysis. To address the difficulties in current HAZOP method, this paper proposes a signed digraph (SDG)-based HAZOP analysis method. It is used to identify the most likely operating mistakes that may cause certain process variable deviating from its normal value, which is the main source of safety concern. A case study on polyvinyl chloride (PVC) plant is presented to demonstrate the effectiveness of SDG-based HAZOP analysis method in providing complete analysis result.     

基于模糊数学的石油化工装置HAZOP风险分析技术研究

对传统的HAZOP分析中偏差原因发生可能性进行量化。对于有统计数据的,根据行业数据、公司经验及企业事故建立HAZOP风险分析统计数据库;对于没有统计数据的HAZOP分析偏差原因发生概率,通过专家主观评判,用模糊数理论将专家自然语言转换为模糊数,采用左右模糊排序法将模糊数转换为模糊失效概率值。研究了偏差后果严重程度的划分标准,并根据偏差原因概率和偏差后果严重程度确定风险等级,利用风险矩阵得出偏差风险的大小。从而把HAZOP分析方法从定性改进为半定量的分析方法。据此对石油化工装置进行了HAZOP风险分析。     

State of research on the automation of HAZOP studies

For more than 30 years, multiple research groups have worked on the automation of hazard and operability (HAZOP) studies, or more specifically on the hazard identification process. So far, very few of these approaches have been used in the chemical process industry. Automatic hazard identification is a knowledge-intensive process that demands high standards with regard to the way in which knowledge is stored and made available. There are various suitable approaches to the qualitative modeling of processes and plants, which are the foundation for reasoning systems that are used for the identification of hazards. Additionally, there are quantitative methods that are based on process simulations and can be used to identify potential hazards. The investigation of the state of research demonstrates that there are sophisticated technologies for automated systems that include powerful reasoning techniques. The benefits and shortcomings of existing technologies are discussed with regard to their industrial applicability. Often, the quality of the necessary specific and generic knowledge is not sufficient to detect potential hazardous events and operational malfunctions. Computer-aided HAZOP systems should be integrated with computer-aided design- or process simulation software using common data models based on the digital representation of the process plant. In order to be used by HAZOP practitioners automated systems need to be comprehensive, serve as specialized decision support systems, and be tested and evaluated using round robin tests.     

基于动态SDG模型的间歇过程HAZOP方法研究

危险与可操作性分析（HAZOP）是目前应用最为广泛的安全评价方法之一。然而,通过对国内外已实施的生产过程安全评价方法及相关计算机辅助安全评价软件调查发现,目前对间歇过程HAZOP分析的研究还较少。因此,将Petfi网与符号定向图（SDG）相结合,以SDG模型为主,Petri网模型为辅,建立专门针对间歇过程HAZOP分析的动态SDG模型。由于Petfi网可以准确描述间歇过程的离散事件特性,而SDG能够恰当描述间歇过程的连续特性,二者结合使该模型成为间歇过程HAZOP分析的有力工具。     

Using a system theory based method (STAMP) for hazard analysis in process industry

Different hazard analysis techniques are used in the chemical process industry. Most of these techniques were developed long time ago. There is an argument that significant changes have occurred in the process industry but these techniques have not been modified accordingly. Therefore, there may be limitations in identifying hazards related to the modern process industry in complex sociotechnical environment using these techniques. Recently new hazard analysis techniques based on systems theory have been introduced. STPA (System-Theoretic Process Analysis) is one of these systemic techniques. It has been used in some fields with promising results but with limited application in the process industry. This paper applies STPA to a process plant as an industrial case study. Recommendations generated by STPA are compared with the HAZOP study of the process plant which is a traditional technique. Conclusions are presented on the application of systemic techniques to the process industry as a complementary study to analyze the safety of the system as a whole and also to capture interactions between component of the system. Further studies are required to study STPA in more details and evaluate if it can be used as an alternative to HAZOP.     

基于贝叶斯网络气化炉供料系统风险分析

为解决当前气化炉供料系统风险分析不完善的状况，提出1种基于贝叶斯网络和HAZOP的风险分析模型。以某单日投煤量3 000 t级气化炉煤化工企业实际运行情况为研究对象，应用HAZOP法对其进行风险分析，并将HAZOP分析结果中各偏差产生原因转化为贝叶斯网络节点；考虑到先验知识的缺乏问题，引入Leaky Noisy OR模型，通过文献资料和相关领域专家经验知识获得先验概率，并利用贝叶斯网络进行风险分析，找出系统运行的薄弱环节。结果表明:未知因素影响会使各节点的后验概率值差异性降低，更加贴合实际；在引入未知因素影响后，系统运行薄弱环节并未发生改变。     

基于HAZOP分析的加氢装置工程设计方法

加氢装置属甲类火灾、爆炸危险生产装置。为了在设计阶段尽可能消除或控制潜在风险,本文总结了多套加氢装置HAZOP分析报告中的设备类别及其分析内容,提出了基于危险与可操作性(HAZOP)分析的加氢装置工程设计方法。在传统工程设计方法的基础上增加了参数敏感性工程设计方法,依据分析报告中的设计建议,利用ASPEN软件计算过程参数变化对目标参数的影响程度,确定参数稳定操作区域;建立了数据库管理界面实现了加氢装置工程安全设计经验知识的有序管理。应用基于HAZOP分析的加氢装置工程设计方法,有助于将安全隐患问题在设计阶段消除或加以控制,可为降低石化装置改造成本和提高装置的安全水平提供方法依据。     

合成氨装置系统安全仪表系统安全完整性等级分析

论文在介绍安全仪表系统、安全完整性等级的基本原理基础上,综合分析了危险与可操作性分析(HAZOP)、保护层分析(LOPA)等系统风险分析理论的应用方法。并结合上述理论,确定了安全仪表系统的安全完整性等级(SIL)定级。以合成氨装置为例,应用HAZOP及保护层分析方法,得出了合成塔压力过高及废热锅炉液位过低2个场景下的安全完整性SIL等级。结果表明:合成塔装置仪表的SIL等级为1,废热锅炉仪表的SIL等级为2。     

Qualitative Assessment for Inherently Safer Design (QAISD) at preliminary design stage

Conventional hazard evaluation techniques such as what-if checklist and hazard and operability (HAZOP) studies are often used to recognise potential hazards and recommend possible solutions. They are used to reduce any potential incidents in the process plant to as low as reasonably practicable (ALARP) level. Nevertheless, the suggested risk reduction alternatives merely focus on added passive and active safety systems rather than preventing or minimising the inherent hazards at source through application of inherently safer design (ISD) concept. One of the attributed reasons could be the shortage of techniques or tools to support implementation of the concept. Thus, this paper proposes a qualitative methodology that integrates ISD concept with hazard review technique to identify inherent hazards and generate ISD options at early stage of design as proactive measures to produce inherently safer plant. A modified theory of inventive problem solving (TRIZ) hazard review method is used in this work to identify inherent hazards, whereby an extended inherent safety heuristics tool is developed based on established ISD principles to create potential ISD options. The developed method namely Qualitative Assessment for Inherently Safer Design (QAISD) could be applied during preliminary design stage and the information required to apply the method would be based on common process and safety database of the studied process. However, user experiences and understanding of inherent safety concept are crucial for effective utilisation of the QAISD. This qualitative methodology is applied to a typical batch reactor of toluene nitration as a case study. The results show several ISD strategies that could be considered at early stage of design in order to prevent and minimise the potential of thermal runaway in the nitration process.     

HAZOP – Local approach in the Mexican oil & gas industry

HAZOP (Hazard and Operability) studies began about 40 years ago, when the Process Industry and complexity of its operations start to massively grow in different parts of the world. HAZOP has been successfully applied in Process Systems hazard identification by operators, design engineers and consulting firms. Nevertheless, after a few decades since its first applications, HAZOP studies are not truly standard in worldwide industrial practice. It is common to find differences in its execution and results format. The aim of this paper is to show that in the Mexican case at National level in the oil and gas industry, there exist an explicit acceptance risk criteria, thus impacting the risk scenarios prioritizing process. Although HAZOP studies in the Mexican oil & gas industry, based on PEMEX corporate standard has precise acceptance criteria, it is not a significant difference in HAZOP applied elsewhere, but has the advantage of being fully transparent in terms of what a local industry is willing to accept as the level of risk acceptance criteria, also helps to gain an understanding of the degree of HAZOP applications in the Mexican oil & gas sector. Contrary to this in HAZOP ISO standard, risk acceptance criteria is not specified and it only mentions that HAZOP can consider scenarios ranking. The paper concludes indicating major implications of risk ranking in HAZOP, whether before or after safeguards identification.     

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 structural approach to the HAZOP – Hazard and operability technique in the biopharmaceutical industry

Recently, the use of analytical techniques to identify, assess and address risks within the pharmaceutical industry is increasing from the initial and operating phases until the final use of products aiming to eliminate or reduce the severity of deviations. The hazard and operability studies – HAZOP establish that accidents are the result of failure modes in process variables out of operational parameters. In this paper, the HAZOP methodology was used to assess risks in the system for recombinant protein production where a multidisciplinary group used the brainstorming strategy to identify the risk level and deviations in nodes defined by functionality in the system. Nineteen critical nodes were identified, deviations were established in based on knowledge, and experience by the group, thus precluded the need of deviation's records to estimate frequency and impacts of events. It was also shown that in the pharmaceutical industry the most-critical risks are those that have adverse impacts on production like partial and total losses and when noncompliance of regulations are involved. The HAZOP risk assessment tool can be easily followed by people who are interested in starting to use this technique to improve the security environment within the institution and when required by regulatory agencies.     

改进的HAZOP风险评价方法

HAZOP方法是一种使用简单却高度专业化、系统化,能够覆盖过程工业安全评价各个环节的危险辨识与评估方法。但是,HAZOP方法作为一种定性风险分析方法,仅仅是从定性方面分析装置中是否存在的潜在风险,对于存在的潜在风险,不能量化其严重度和可能性,HAZOP定量/半定量化分析成为本研究领域的发展趋势。本文从三个方面提出了改进HAZOP分析方法。首先,由于工艺参数和引导词构成偏差,根据工艺参数的分类,将偏差划分为数值型和逻辑型,进行了一步半定量化;其次,引入了毒性参数,对后果严重等级重新划分为五级;最后根据风险矩阵理论,运用风险矩阵C=X＋Y规则,计算出风险矩阵,按照风险评价的需要并且根据生产的实际安全管理状况,划分风险等级为四级,得到了新的风险矩阵,从而把HAZOP分析法从一种定性的方法改进为一种半定量的方法。