工艺过程危险有害因素辨识的研究

鉴于化工企业工艺过程的特殊性,笔者建议其危险、有害因素的辨识可以在直观经验分析法和系统安全分析法的基础上,结合危险和可操作性研究(HAZOP)的思想来进行辨识。笔者尝试性地给出了相关术语的说明、介绍辨识方法和操作程序,并分别从生产过程(包括化学反应、化工操作单元和物料输送)和工艺设备、装置角度,对其中的所包含的具体内容进行剖析,最后以电解过程举例说明,该方法可用于化工企业进行危险性因素辨识。     

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.     

HAZOP研究与故障树分析在合成氨装置危险辨识中的应用

合成氨装置的原料、产品危险性高,并且生产过程复杂,因此在运行过程中可能导致火灾、爆炸、中毒等事故,有些事故甚至给社会和环境造成严重破坏.对HAZOP研究与故障树分析进行组合,应用在合成氨装置的危险辨识中.通过HAZOP研究,合成氨主体装置共发现风险因素23项,其中合成氨装置的合成气压缩单元安全隐患较多,因此对其进行故障树分析,合成气压缩机单元火灾、爆炸故障树的最小割集为72个,最小径集为6个.从基本事件结构重要度结果来看,压缩机三级出口压力探测器( PIA3-2)故障,对压缩机发生火灾、爆炸的影响程度最大,应重点防范.     

Instruction of hazard analysis of methods for chemical process safety at the university level

Young practicing chemical engineers must be able to operate safely in an industrial setting. Therefore, chemical process safety education is essential for undergraduate chemical engineers and ABET (the University Accreditation Board) supports this initiative by requiring that university graduates understand the hazards associated with chemical processes. One way to understand the hazards associated with processes is to conduct a process hazard analysis. This analysis can be conducted in an experiential learning environment by collaborating with an industrial partner or by utilizing facilities on the university campus. In this environment students are able to see and interact with the processes under normal operating conditions. Utilizing industrial or research mentors allows students to receive formative feedback as they analyze the process. In addition, these process hazard analyses require students to practice “soft skills” such as teamwork, problem solving, and oral and written communication which are essential work place skills. This paper reviews teaching hazard analysis methods to chemical engineering students at the undergraduate and graduate levels. Covered are examples of how students are introduced to the checklist and bowtie analysis methods, and the conduction of a HAZOP. Examples of the different resources that can be utilized are described. Ultimately, from these experiences, students are more prepared to enter the chemical process industries with first-hand knowledge of how to conduct various hazard analyses before reaching their place of employment.     

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.     

层次分析法在HAZOP分析中的应用

利用HAZOP分析方法分析系统的工艺流程,找出系统中潜在的风险,提出合理的建议措施。在HAZOP分析的基础上引入层次分析法,基于HAZOP分析的参数建立评价指标体系,实现设备安全评价的半定量化。     

Ontology-based computer aid for the automation of HAZOP studies

Hazard and Operability (HAZOP) studies are conducted to identify and assess potential hazards which originate from processes, equipment, and process plants. These studies are human-centered processes that are time and labor-intensive. Also, extensive expertise and experience in the field of process safety engineering are required. There have been several attempts by different research groups to (semi-)automate HAZOP studies in the past. Within this research, a knowledge-based framework for the automatic generation of HAZOP worksheets was developed. Compared to other approaches, the focus is on representing semantic relationships between HAZOP relevant concepts under consideration of the degree of abstraction. In the course of this, expert knowledge from the process and plant safety (PPS) domain is embedded within the ontological model. Based on that, a reasoning algorithm based on semantic reasoners is developed to identify hazards and operability issues in a HAZOP similar manner. An advantage of the proposed method is that by modeling causal relationships between HAZOP concepts, automatically generated but meaningless scenarios can be avoided. The results of the enhanced causation model are high quality extended HAZOP worksheets. The developed methodology is applied within a case study that involves a hexane storage tank. The quality and quantity of the automatically generated results agree with the original worksheets. Thus the ontology-based reasoning algorithm is well-suited to identify hazardous scenarios and operability issues. Node-based analyses involving multiple process units can also be carried out by a slight adjustment of the method. The presented method can help to support HAZOP study participants and non-experts in conducting HAZOP studies.     

HAZOP技术在氨合成塔危险辨识中的应用

介绍了HAZOP技术的特点及分析步骤。运用HAZOP方法,对氨合成塔进行危险性辨识。分析了氨合成塔中有意义的偏差、偏差发生的原因、可能导致的后果,并提出相应的对策措施。氨合成塔的HAZOP分析表明,反应温度偏高、反应压力偏高、合成气泄漏是重要的偏差,对氨合成塔的安全运行具有很大的威胁,易引起爆炸事故,应予以特别重视,尤其是控制温度条件是确保氨合成塔安全生产的最重要因素。研究结论是对氨合成塔常见的和可能发生的安全事故的一个系统总结,详细的偏差原因分析、安全对策措施建议,为工程技术人员实现对氨合成塔的安全控制、预防和减少、避免类似事故,提供了具体参考和重要依据。     

HAZOP方法的定量改进措施研究

HAZOP方法通过结构化和系统化的方式识别潜在的危险与可操作性问题,在化工安全评价中得到了广泛应用.但其做为一种定性评价方法,定量化是其发展的趋势.探讨了定量化风险矩阵技术在HAZOP分析中应用的问题,研究提出了将火灾、爆炸危险指数方法应用于风险矩阵事故后果严重度的计算和将事故树评价方法应用于风险矩阵事故发生概率的计算,实现了风险矩阵的定量化并应用于不饱和聚酯树脂工艺HAZOP分析,为HAZOP分析的定量化提供了一种新的技术方法.     

An extended HAZOP analysis approach with dynamic fault tree

An extended hazard and operability (HAZOP) analysis approach with dynamic fault tree is proposed to identify potential hazards in chemical plants. First, the conventional HAZOP analysis is used to identify the possible fault causes and consequences of abnormal conditions, which are called deviations. Based on HAZOP analysis results, hazard scenario models are built to explicitly represent the propagation pathway of faults. With the quantitative analysis requirements of HAZOP analysis and the time-dependent behavior of real failure events considered, the dynamic fault tree (DFT) analysis approach is then introduced to extend HAZOP analysis. To simplify the quantitative calculation, the DFT model is solved with modularization approach in which a binary decision diagram (BDD) and Markov chain approach are applied to solve static and dynamic subtrees, respectively. Subsequently, the occurrence probability of the top event and the probability importance of each basic event with respect to the top event are determined. Finally, a case study is performed to verify the effectiveness of the approach. Results indicate that compared with the conventional HAZOP approach, the proposed approach does not only identify effectively possible fault root causes but also quantitatively determines occurrence probability of the top event and the most likely fault causes. The approach can provide a reliable basis to improve process safety.     

国外化工企业工艺安全技术管理概述

国外化工企业工艺安全技术管理范畴主要包括PHA、MOC、RA/RM、事故调查、其他工艺安全管理工具等。本文主要介绍了国外化工企业常规工艺安全技术管理MOC———变更管理的概念、流程,临时MOC、MSR、PSSR等概念及流程。PHA———工艺危险性分析是国外化工企业工艺安全技术管理核心,主要应用于大型或复杂项目,重点详述了工艺危险性分析的流程、步骤以及四种常用的危险识别方法———HAZOP、SCA、What-If、FEMA的概念、主要步骤、分析过程及主要优点。一旦工艺危险被分析识别后,阐述了如何运用风险评估和风险管理（RA/RM）步骤、后果等级、频率评价、风险等级矩阵和风险降低的主要方法,如何采用故障树FTA和事件树ETA两种不同的方法测算各种事件或故障发生的概率以及事故的后果等级,最后介绍了故障树FTA和事件树ETA的主要步骤和方法。     

乙炔干燥变温吸附装置安全性分析与燃爆事故预防对策

针对乙炔变温吸附装置的燃爆事故问题,采用HAZOP方法对该装置进行安全性分析,找出存在的安全隐患,提出整改措施,指出装置发生燃爆事故的可能性;又将该装置可能发生的燃爆事故作为顶上事件,利用FTA方法进行分析,得到了装置发生燃爆事故的可能原因,制定了预防发生燃爆事故的对策。通过将HAZOP和FTA分析方法结合使用,有效地识别出乙炔装置存在的隐患,降低了装置操作的危险性,预防了燃爆事故的发生,值得推广应用。     

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。     

A new approach of integrating industry prior knowledge for HAZOP interaction

Accidents often occur in the petrochemical industry, which have a negative impact on society and the environment. Learning Process Safety Knowledge (PSK) from accident cases is essential to prevent accidents and improve safety level. Hazard and Operability Analysis (HAZOP) is a popular hazard risk analysis method. Its report contains large-scale PSK, which can provide safety analysis and decision support for the industry. Subject to the characteristics of PSK, existing researches mine them in the form of sequence labeling. However, there are two intractable problems that cause the PSK mined by the model to be inaccurate. (1) PSK in HAZOP is domain specific, which is rare or even absent in general-domain texts. (2) The entity boundaries are ambiguous. Most domain-specific entities for HAZOP lack boundary characters. Inaccurate security knowledge is not acceptable from the perspective of process safety engineering. To solve the problems, we present a PSK mining architecture with External Lexicon Prior knowledge called EDPMA, EDPMA is prior knowledge-based multi-task HAZOP knowledge mining model. Specifically, EDPMA consists of prior knowledge constructor and sequence labeling model. The prior knowledge constructor expresses prior knowledge in the form of word embedding by three steps. For the sequence annotation model, we improve its embedding and decoding layers. The former incorporated the word vectors generated by the prior knowledge constructor, and the latter added the task of entity boundary prediction. We conduct multiple evaluation experiments on HAZOP datasets. The experimental results show that the accuracy, recall and F1-score of the EDPMA model are 92.92%, 91.85% and 92.38% respectively, which is better than the existing research. Our study represents a meaningful attempt to introduce prior knowledge in HAZOP knowledge mining and makes an important contribution to intelligence the field of process safety.     

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。     

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.     

Integration of process control protection layer into a simulation-based HAZOP tool

This paper discusses the framework methodology behind the proposed simulation-based HAZOP tool. Simulation-based approach is one of the many ways to support conventional HAZOP by its automation. Compared to knowledge-based and other approaches, a HAZOP software tool based on deviations simulation is able to examine the investigated process more into detail and so find root causes of hazardous consequences. Another advantage is the ability to identify also potential hazards which did not occur in the past and might be overlooked. The presented framework methodology uses a layer of protection analysis (LOPA) concept of independent protection layers (IPLs) testing. Control system integrated into the raw process design represents the first of various protection layers of the LOPA concept. As a case study, a CSTR chemical production with nonlinear behavior under Proportional-Integral-Derivative (PID) actions as the predominant type of classical feedback control strategy is used. The presented tool identifies hazardous regimes under conditions when control loop introduces hazardous consequences or even acts synergically with existing hazardous events. Risk derived from different consequences is ranked by the risk assessment matrix (RAM) as a part of the conventional quantitative HAZOP study.     

烷基苯联合装置风险及控制研究

烷基苯联合装置含有国家安全监管总局首批重点监管的15种危险化工工艺中的加氢工艺、烷基化工艺两种,装置工艺介质为易燃、易爆、有毒及强腐蚀性物质,生产中潜在危险性较大;开展工艺风险研究,落实控制措施,对于提高装置本质安全性具有极为重要意义.首先探讨了工艺危险和要害部位,确认装置主要风险为火灾、爆炸和毒性危害;然后应用HAZOP方法,以加氢反应进料加热炉、烷基化反应器为分析对象,研究了工艺状态参数温度、压力、物料流量等方面出现偏差的原因、后果及安全措施;还对氢气泄漏发生火灾、爆炸和苯泄漏发生火灾、爆炸、人员中毒进行了事故后果定量分析,提出了相应的安全措施,以消除或降低工艺危险,保障装置安全.     

Safety study of an LNG regasification plant using an FMECA and HAZOP integrated methodology

A safety analysis was performed to determine possible accidental events in the storage system used in the liquefied natural gas regasification plant using the integrated application of failure modes, effects and criticality analysis (FMECA) and hazard and operability analysis (HAZOP) methodologies. The goal of the FMECA technique is the estimation of component failure modes and their major effects, whereas HAZOP is a structured and systematic technique that provides an identification of the hazards and the operability problems using logical sequences of cause-deviation-consequence of process parameters. The proposed FMECA and HAZOP integrated analysis (FHIA) has been designed as a tool for the development of specific criteria for reliability and risk data organisation and to gain more recommendations than those typically provided by the application of a single methodology. This approach has been applied to the risk analysis of the LNG storage systems under construction in Porto Empedocle, Italy. The results showed that FHIA is a useful technique to better and more consistently identify the potential sources of human errors, causal factors in faults, multiple or common cause failures and correlation of cause-consequence of hazards during the various steps of the process.     

Development of inherent safety and health index for formulated product design

The numerous formulated products which are introduced to the market consist of chemical ingredients that may cause various safety and health hazards to the consumers. Therefore, it is extremely important to practice a systematic methodology to formulate products with acceptable safety and health performances. This work presents an index-based methodology to assess the safety and health hazards of the ingredients during the early formulation stage of product design. Hence, new inherent safety and health sub-indexes are introduced to improve the current safety and health hazards that are needed in formulated product design. The inherent safety and health sub-indexes are assigned with scores based on the degree of potential hazards. A higher score indicates a higher safety risk or severe health effect, and vice versa. The proposed methodology will greatly assist the users to identify the adverse safety and health effects caused by the ingredients. Hence, it is pivotal to eliminate or reduce the safety and health impacts from product usage. A case study on common ingredients used in the formulation of paint is presented on this study to describe the proposed method.