Assessing the hazards from a BLEVE and minimizing its impacts using the inherent safety concept

Many worlds' major process industry accidents are due to BLEVE such as at Feyzin, France, 1966 and San Juan Ixhuatepec, Mexico City, 1984. One of the approaches to eliminate or minimize such accidents is by the implementation of inherently safer design concept. This concept is best implemented where the consequence of BLEVE can be evaluated at the preliminary design stage, and necessary design improvements can be done as early as possible. Thus, the accident could be avoided or minimized to as low as reasonably practicable (ALARP) without resorting to a costly protective system. However, the inherent safety concept is not easy to implement at the preliminary design stage due to lack of systematic technique for practical application. To overcome these hurdles, this paper presents a new approach to assess process plant for the potential BLEVE at the preliminary design stage and to allow modifications using inherent safety principles in order to avoid or minimize major accidents. A model known as Inherent Fire Consequence Estimation Tool (IFCET) is developed in MS Excel spreadsheet to evaluate BLEVE impacts based on overpressure, radiation heat flux and missile effects. In this study, BLEVE impacts are the criteria used as the decision-making for the acceptability of the design. IFCET is integrated with iCON process design simulator for ease of data transfer and quick assessment of potential BLEVE during the design simulation stage. A case study was conducted to assess of potential BLEVE from a propane storage vessel at the design simulation stage using this new approach. The finding shows promising results that this approach has a potential to be developed as a practical tool.     

Application of inherent safety principles to dust explosion prevention and mitigation

The aim of the current work is to explicitly link the inherent safety principles of minimization, substitution, moderation and simplification with strategies for dust explosion prevention and mitigation. A brief review of inherent safety and its basic principles is first given. This is followed by a discussion of various ways in which the dust explosion hazard can be minimized, substituted, moderated and simplified. Particular attention is paid to the relationship between each inherent safety principle and (i) various dust explosibility parameters, (ii) alternate methods of processing, (iii) selection of process equipment, and (iv) development and implementation of safe-work procedures. Original research results are presented, along with industrial case studies and previously published results that have been reinterpreted in terms of inherent safety and its basic principles. It is anticipated that this research will be of value to industry as a complement to the relatively well-established suite of engineered and procedural dust explosion risk reduction measures.     

运用本质安全原理预防煤粉爆炸

旨在将本质安全原理与粉尘爆炸(以煤粉爆炸为例)的风险控制联系起来。利用20 L球形爆炸装置的标准测试方法测试煤粉及煤粉-CaCO3混合物的爆炸下限、最大爆炸压力、压力上升速度等爆炸特性。基于本质安全基本原理和试验结果,讨论预防煤粉爆炸的各种基本方法,并重点阐述本质安全原理与粉尘爆炸影响因素、不同的预防方法、过程设备的选择等之间的关系,对已制定的爆炸风险控制措施进行完善和补充。     

浅谈日常安全工作的两个“五”

从安全管理的思维方式入手,具体地落实到如何使安全教育、督导等工作在实际生产过程中发挥其应有的效果,以保证安全生产和生产安全。     

Inherent risk assessment—A new concept to evaluate risk in preliminary design stage

Quantitative Risk Assessment (QRA) has been a very popular and useful methodology which is widely accepted by the industry over the past few decades. QRA is typically carried out at a stage where complete plant has been designed and sited. At that time, the opportunity to include inherent safety design features is limited and may incur higher cost. This paper proposes a new concept to evaluate risk inherent to a process owing to the chemical it uses and the process conditions. The risk assessment tool is integrated with process design simulator (HYSYS) to provide necessary process data as early as the initial design stages, where modifications based on inherent safety principles can still be incorporated to enhance the process safety of the plant. The risk assessment tool consists of two components which calculate the probability and the consequences relating to possible risk due to major accidents. A case study on the potential explosion due to the release of flammable material demonstrates that the tool is capable to identify potential high risk of process streams. Further improvement of the process design is possible by applying inherent safety principles to make the process under consideration inherently safer. Since this tool is fully integrated with HYSYS, re-evaluation of the inherent risk takes very little time and effort. The new tool addresses the lack of systematic methodology and technology, which is one of the barriers to designing inherently safer plants.     

安全心理学基础原理及其体系研究

心理学与安全生产有重要的关联性。基于安全科学原理体系现有研究成果及安全心理学研究背景,定义了安全心理学原理,并阐述了安全心理学原理的特征及其研究内容;归纳了安全心理学原理下属的6条基础原理——事故频发倾向原理、安全心理激励原理、心理阈值有限原理、安全认知原理、安全个性心理原理和安全生理心理原理,并论述了这6条原理的内涵及机理,对于部分原理进一步给出了其下属原理的研究思路;在构建安全心理学原理枝叶形体系的基础上,整理了安全心理学原理体系的应用机理,以及这6条原理在体系中各自的功能和地位;最后论述了这6条原理在安全工程实践中的意义。研究表明,该安全心理学原理体系对人员部署、制度规划、安全管理等安全生产层面有积极的影响。     

Bayesian networks based laboratory retrofitting towards inherent safety: A risk-based implementation framework

Over the years, a number of high-profile laboratory accidents involving severe injuries, fatalities, and economic losses have been reported, prompting a significant increase in efforts towards laboratory safety. However, the dominant safety measures rely excessively on add-on safeguards such as sprinklers and respirators and pay little attention to reducing the hazardous factors at their sources. This study introduced the inherent safety concept to minimize laboratory hazards and developed a dedicated implementation tool called Generic Laboratory Safety Metric (GLSM). The Traditional Laboratory Safety Checklist (TLSC) was first used to represent the safety indicators, and then the Precedence Chart (PC) and Bayesian Networks (BN) methods were used to reconcile the safety indicators to develop the GLSM. The developed GLSM was subsequently demonstrated through a case study of a university laboratory. The results revealed that the safety level increased from 2.44 to 3.52 after the risk-based inherently safer retrofitting, thus creating laboratory conditions with a relatively satisfactory safety level. This work presented a set of generic solutions to laboratory retrofitting towards inherent safety with a novel GLSM as the implementation tool. The proposed GLSM would contribute to risk quantification and identification of key risk factors for assigning targeted and fundamental safety measures to achieve inherently safer laboratories.     

基于本质安全理论的安全管理体系研究

传统安全方法是通过附加的安全和防护装置或系统来保护人和设备的安全,本质安全方法强调从源头上消除或减小生产系统中的危险。本质安全理论及方法已从技术层面向系统管理方向发展。笔者简要介绍本质安全的内涵及其设计应用的基本原则。从系统综合防范风险的角度,分析了本质安全方法与传统安全方法在应用上的区别,强调在实际安全管理过程中,应当将本质安全方法与传统安全方法相结合,形成以本质安全理论为基础的综合风险管理理念。笔者将本质安全思想与PDCA管理模式融合,提出了具有可操作性的基于本质安全化的PDCA管理模式。     

Quantification of inherent safety aspects of the Dow indices

The Dow fire and explosion index (F&EI) and chemical exposure index (CEI) have been successfully implemented in a Visual Basic environment as a tool for the inherent safety assessment of chemical processes. Subprograms were developed to quantify the inherent safety aspects of the Dow indices. These aspects are presented graphically with the indices on the vertical axis and an inherent safety indicator on the horizontal axis. Dow indices of the MIC storage unit involved in the Bhopal disaster were evaluated to quantify the effects of process temperature, pressure and inventory of hazardous materials on the index values.

As operating pressure was reduced, the F&EI decreased in accordance with the principles of inherent safety. The change in F&EI due to reduction of inventory was more significant than that resulting from pressure reduction. The results show that the F&EI change, given the same range of the independent variables (quantity of hazardous materials, operating temperature and pressure), is larger when a unit in the process area is evaluated compared to a unit in a storage area (tank farm). Reduction of the inventory of hazardous materials had no direct effect on the CEI for vapor releases, whereas the size of the hole diameter impacted the CEI to a great extent. However, there is a significant change in the CEI as the inventory of materials decreases for liquid releases involving temperatures above their flash and boiling points. Pressure reduction decreases the CEI, whereas temperature reduction leads to an increase in the CEI when these parameters are treated independently.     

本质安全化管理思想及实证研究框架

分析国内本质安全化管理研究现状及存在问题,指出两类系统本质安全化实现路径的差异性:①技术系统本质安全性等于构成要素的本质安全性乘积,只要保证要素本质安全化,系统也趋于本质安全化;②社会技术系统关键要素是智能体,从根本上无法达到本质安全化,但智能体自身具有一定容错性和自组织性,在相对可靠条件下,需要通过和谐交互机制使系统而获得本质安全化。分析和研讨的基础上,提出交互式安全管理理论的本质安全化管理研究基本思路:基于3层次和谐交互机制的本质安全化动态演化机制;并对系统本质安全化进行了量化;给出判定系统能否实现本质安全化条件以及本质安全化管理的基本函数关系;得出了系统本质安全化是系统安全性极限的结论。     

电磁污染事故树分析

从安全系统工程学的有关原理出发,采用事故树分析法(FTA)探究引发电磁污染事故各因素之间内在的、因果的逻辑关系,且就电磁污染可采取的防护措施作些尝试性的探讨.     

Promoting inherent safety

By inherent safety is meant that a hazard is eliminated rather than being managed by various add-on equipment and procedures. Practices of inherent safety have been developed in the chemical industry, and include for instance the substitution of hazardous substances by less hazardous ones. Inherently safer design strives to eliminate the possibility of major adverse events even when the probabilities of these events are small or cannot be meaningfully estimated. Considerations of security can be more easily incorporated into this approach than into most other branches of risk and safety analysis. Therefore, inherent safety has a great potential as a meeting-ground for the much-needed coordination of safety and security work. Its philosophical underpinnings are outlined, and proposals are made for more efficient promotion of its principles.     

Using process stream index (PSI) to assess inherent safety level during preliminary design stage

In the current practice, safety assessment is conducted once the process design has been completed. At this stage of design, the freedom to change the conceptual design is very limited and whatever strategies to be implemented will only control the hazard. This paper reports on the development of inherent safety index known as a process stream index (PSI) for inherent safety level assessment at preliminary design stage from the perspective of an explosion. The aim for PSI is to calculate, compare and prioritize the level of inherent safety of process streams during simulation work that influences the explosion. By prioritizing the streams based on the potential for the explosion, the design engineers can easily identify the critical streams to be considered for improvement in order to avoid or minimize explosion hazards. An enhancement technique to reflect the contribution of the individual components in the mixture is introduced, which provide significant contribution to the ranking of inherent safety level of process streams. The assessment of inherent safety level using PSI is demonstrated by case studies of HYSYS simulation for Acrylic Acid Plant and Natural Gas Liquid (NGL) plant.     

安全氛围对企业安全行为的影响研究

国外大量研究表明,安全氛围调查在改进企业的安全行为方面有积极的作用,为组织制订未来的安全政策提供依据。本研究通过查阅文献、国外类似的诊断调查工具及软件,根据所提出的理论假设,采用线性结构方程建模的方法,构建了本研究的LISREL理论模型,并设计了相应的调查问卷和量表。从所建立的安全氛围的三个构面(安全管理、安全认知、安全态度)入手探讨企业的安全氛围对企业的安全行为(两个构面:安全执行、安全处理)的影响。本研究采用问卷调查的方式采集数据,将所得资料用SPSS11.0和LISREL8.3软件来分析处理和检验研究假设,研究结果为实证单位改进企业的安全行为提供了帮助。     

英国和丹麦安全生产立法及监察的启示和思考

国家安全生产监管总局赴英国、丹麦组织安全生产法律法规标准化考察团针对英国、丹麦和国际劳工组织的职业安全健康立法、执法和监察等方面进行了座谈和交流。作为发达国家,英国和丹麦的职业安全健康绩效在全球处于领先地位,主要介绍了英国职业健康安全组织机构和职责、健康安全法律法规制修订程序、健康安全法律法规体系和立法执法及监察经验,以及丹麦职业安全健康组织机构、安全健康法律法规体系和安全健康监察经验。以此为基础,在关于法律原则和定位方面、法律法规落实、落实企业的安全生产主体责任和监察人员履行监察职责、基于风险的分级监察和建立企业安全生产诚信评级系统等五方面提出对我国安全生产立法及监察工作的启示和思考。     

论企业安全文化建设与安全管理体系运行

安全文化的概念被提出以来,国内外出现了多种安全文化的定义,对企业优秀安全文化特征的论述也多种多样。总体看来,优秀的企业安全文化应具有鼓励报告性、公平公正性、持续改进性和灵活可塑性四种基本属性。此外,在拥有优秀的安全文化的企业中,组织的全体成员应具有积极的安全态度、较高的风险认知能力和安全行为能力。优秀的安全文化不是自然形成的,需要正确的安全文化建设方法。基于对如何建设优秀安全文化的分析,建立了安全文化建设和安全管理体系运行之间的关系,分析了优秀安全文化的特征内容和安全管理体系要素之间的对应关系,提出了通过企业安全管理体系的有效运行来建设安全文化的思路,避免了企业安全文化建设和安全管理工作的重复和交叉。     

安全评价工作若干问题探讨

指出目前安全评价中范围确定、评价单元划分、评价方法选用、对策建议制定、重大危险源辨识工作容易出现的问题及误区,对相关问题产生的原因及带来的影响进行分析与探讨,阐明范围确定、评价单元划分、评价方法选用、对策建议制定、重大危险源辨识工作相关原则与方法,可以避免安全评价工作中出现重大失误,影响安全评价工作的客观性与质量,以期共同提高安全评价工作的质量。     

城市物流系统安全规划的战略思考

从系统安全角度来理解城市物流系统安全规划的深刻含义,分析了城市物流系统安全规划与区域规划、城市总体规划、土地利用规划间的关系,提出了安全规划制定和实施的原则,研究了城市物流系统安全规划编制内容及程序,为有关机构对城市物流系统进行安全规划、安全决策及安全管理提供科学依据.     

Implementing inherent safety throughout process lifecycle

Inherent safety should be implemented as early as possible in the design life cycle, since the changes in process design are easier and cheaper the earlier they are done. The problem is, how to evaluate process alternatives in the terms of inherent safety in the early design phases, when much of the information is missing. In this paper the process life cycle phases and the possibilities of implementing and evaluating inherent safety are discussed. The applicability and accuracy of an inherent safety index method is presented by a case study.     

政府层面安全生产规划编制方法和要点探讨

为科学贯彻落实新《安全生产法》“县级以上人民政府应编制安全生产规划”的要求,进一步提高政府安全生产规划编制的质量与水平,针对目前地方政府对安全生产规划编制方法与要点把握不到位、造成规划操作性不强的问题,结合以往政府安全生产规划编制的实践经历,研究提出将政府安全生产规划编制程序归纳为背景分析、框架确定、对策设计、文本起草四大部分,重点探讨了政府层面安全生产规划编制过程中的背景调查、现状评价、趋势分析、规划范围设定、规划原则确定、规划目标与指标体系构建、规划依据查找、措施设计、方案优化论证等环节的实施要求、实施方法和注意事项。研究结果将为各级政府编制好安全生产规划提供有益参考与指导。