Incident tree model and incident tree analysis method for quantified risk assessment: An in-depth accident study in traffic operation

Fault tree analysis (FTA) is a logically structured process that can help identify potential causes of system failure before the failures actually occur. However, FTA often suffers from a lack of enough probabilistic basic events to check the consistency of the logic relationship among all events through linkage with gates. Sometimes, even logic relationship among all events is difficult to determine, and failures in system operation may have been experienced rarely or not at all. In order to address the limitations, this paper proposes a novel incident tree methodology that characterizes the information flow in a system instead of logical relationship, and the amount of information of a fuzzy incident instead of probability of an event. From probability statistics to fuzzy information quantities of basic incidents and accident, we propose an incident tree model and incident tree analysis (ITA) method for identification of uncertain, random, complex, possible and variable characteristic of accident occurrence in quantified risk assessment. In our research, a much detailed example for demonstrating how to create an incident tree model has been conducted by an in-depth analysis of traffic accident causation. The case study of vehicle-leaving-roadway accident with ITA illustrates that the proposed methodology may not only capture the essential information transformations of accident that occur in system operation, but also determine the various combinations of hardware faults, software failures and human errors that could result in the occurrence of specified undesired incident at the system level even accident.     

基于自适应神经网络的通风系统故障过程及其规律研究

首先对影响通风系统故障过程特征量进行了定义;然后通过对矿井通风系统故障过程及其改善和劣化状态的分析,建立了基于两参数的Weibull过程故障率函数,给出了系统故障过程改善和劣化的判别式;最后,基于自适应神经网络技术对通风系统的故障规律进行了仿真研究,并应用C 语言和Matlab语言强大的解算及绘图功能,求出了故障过程特征参数值,绘制了故障曲线.     

安全生产检测检验机构管理信息系统的设计与实现

安全生产检测检验机构管理信息系统主要用于安全生产检测检验机构的资质管理工作,该系统主要服务对象为资质管理机关(各级监管监察部门)、安全生产检测检验机构、技术服务机构、评审专家和社会公众。本文重点介绍安全生产检测检验机构管理信息系统的功能划分、技术特点、网络构成等,并以网上申报管理子系统和数据交换子系统为例阐述如何设计和实现其功能。该系统的应用可以显著提高工作效率,节约办公成本,进一步提升资质管理水平和效率。     

管座焊缝内侧的相控阵超声自动检测

本文介绍应用相控阵技术结合配有编码动作的机械装置,对插入式管座焊缝从接管内侧用线阵探头进行超声检测的方法。建立实验模型,可为声柬全覆盖所必须考虑的物理参数,提供验证数据。建模和实测结果表明：利用声线跟踪法,扫查布置图（Scanplan）能提供所需覆盖范围的适当显示。当从接管内表面进行扫查时,用于引导探头扫查动作的机械装置往往可设计得减少复杂性。本文所述方法可望为承压设备结构较复杂的管座焊缝,实施超声相控阵检测（PAUT）符合ASME最新版要求提供有用借鉴。     

Ageing management and monitoring of critical equipment at Seveso sites: An ontological approach

A safe “ageing” of Seveso establishments is a challenge for both operators and regulators. To this scope, Seveso III Directive required to integrate the equipment integrity issue into the safety management system for the major accident prevention; at the same time, the Italian Authority adopted a short-cut method for a quick ageing evaluation, which awards the application of the best techniques to control integrity and prevent deterioration-related failures. In this paper, the use of the ontology has been proposed to support decision-making about the implementation of technical solutions to control equipment ageing and comply the requirements of the Seveso legislation. To contrast deterioration mechanisms, the rapid development of data intensive smart sensors should be exploited and, in this frame, the automated on-line direct monitoring of equipment conditions, based on innovative low-cost sensors, is a novelty and promising solution. The developed ontology-based system points towards the adoption, when possible, of on-line monitoring. This solution provides much more data than traditional measurements and it is essential for the operators to understand how to merge concurrent information and data and to adequately control equipment deterioration. The ontology-based approach appears a viable solution even for this purpose. To demonstrate its potentiality, a real use-case has been used, where the model has been tested in finding the best technical solutions to improve the ageing management of an atmospheric distillation unit of a refinery in order to comply with safety requirements. A further use-case is given to show how the model can be used to react, after real-time damage signals, to restore safety conditions by means of an adequate decision-making.     

遂昌金矿通风系统测定及评价

介绍了遂昌金矿通风系统的现状及测定结果，找出了该系统存在的问题，并提出相应的改进措施。     

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.     

Fuzzy risk modeling of process operations in the oil and gas refineries

Operating several assets has resulted in more complexity and so occurrence of some major accidents in the refining industries. The process operations risk factors including failure frequency and the consequence components like employees' safety and environment impacts, operation downtime, direct and indirect cost of operations and maintenance, and mean time to repair should be considered in the analysis of these major accidents in any refinery. Considering all of these factors, the risk based maintenance (RBM) as a proper risk assessment methodology minimizes the risk resulting from asset failures. But, one of the main engineering problems in risk modeling of the complex industries like refineries is uncertainty due to the lack of information. This paper proposes a model for the risk of the process operations in the oil and gas refineries. The fuzzy logic system (FLS) was proposed for risk modeling. The merit of using fuzzy model is to overcome the uncertainty of the RBM components. This approach also can be accounted as a benchmark for future failures. A unified risk number would be obtained to show how the criticality of units is. The case study of a gas plant in an oil refinery is performed to illustrate the application of the proposed model and a comparison between the results of both traditional RBM and fuzzy method is made.For the case study, 26 asset failures were identified. The fuzzy risk results show that 3 failures have semi-critical level and other 23 failures are non-critical. In both traditional and fuzzy RBM methods, some condenser failures had the highest risk number and some pumps were prioritized to have the lowest risk level. The unit with unified risk number less than 40 is in the non-critical conditions. Proposed methodology is also applicable to other industries dealing with process operations risks.     

法布里-珀罗光纤传感器在桥梁健康监测中的应用

对桥梁实施监测 ,是诊断桥梁健康状况的主要手段 ,现代传感技术和计算机技术的发展 ,使桥梁健康状态的实时监测变为可能。笔者分析了法布里 -珀罗光纤传感器的基本原理和特性 ,设计了一种法布里 -珀罗应变测试系统 ,并在预应力混凝土连续桥梁上与电阻式应变传感器进行了应变对比测试试验。试验结果表明 ,法布里 -珀罗光纤传感器对环境温度不敏感 ,易与钢筋、混凝土复合 ,适用于桥梁结构的应变测试 ,可用于桥梁健康状态的在线监测     

城市群公共安全联动的检验检测能力共享体系

为优化城市群公共安全联动的检验检测能力,针对国内外现状,开展对城市群公共安全联动的检验检测能力共享体系研究。首先,对城市群公共安全联动等基本概念进行界定;然后,对公共安全所需的检验检测能力进行分类,进而初步建立起城市群公共安全联动的检验检测能力共享体系,并在此基础上对体系进行可行性分析。结果表明:共享体系具有必要性和可行性,对增强城市群公共安全联动有积极作用。     

Common cause failures in safety instrumented systems on oil and gas installations: Implementing defense measures through function testing

This paper presents a common cause failure (CCF) defense approach for safety instrumented systems (SIS) in the oil and gas industry. The SIS normally operates in the low demand mode, which means that regular testing and inspection are required to reveal SIS failures. The CCF defense approach comprises checklists and analytical tools which may be integrated with current approaches for function testing, inspection and follow-up. The paper focuses on how defense measures may be implemented to increase awareness of CCFs, to improve the ability to detect CCFs, and to avoid introducing new CCFs. The CCF defense approach may also be applicable for other industry sectors.     

Developing an expert prognosis system of the reciprocating compressor based on associations among monitoring parameters and maintenance records

The reciprocating compressor is, in general, a critical equipment in a process plant. For certain ultra-high-pressure process, if the reciprocating compressor fails, often it will cause serious impact to not just the compressor itself, but also the process surrounds it. To prevent compressors from failures, an expert diagnosis system is needed. However, the traditional rule-based expert system is quite inefficient and difficult to create.For an expert prognosis system that is customized to meet needs of a specific process, one needs to refer to plant maintenance history, which is hard to come by due to the fact that most maintenance was poorly documented. This research attempt to demonstrate the feasibility of developing an expert prognosis system through implementation of association rules. Rather than mining from maintenance history, records of failure cases were collected from technical journal articles by extracting information containing failure symptoms and causes on failed components, that mimicking repair history. In total, 115 failure information out from 41 journal articles were gathered. Applications of this approach to practical use in a process plant is easy by replacing the failure information table with that from datamining the repair history. The failure information was first tabulated and then put through association analysis for support, confidence, and lift between two parameters. The demonstration program has been successful with 1-to-1, many-to-1, and many-to-many analysis among failed components, failure modes, and operation parameters.     

Risk on the ramble: The international transfer of risk and vulnerability

In this paper the purpose is to discuss a concept of technology that can explain how the transfer of technology implies the risk of new failures, misuse, accidents and unhealthy workplaces. Production technologies are often transformed through a steady stream of incremental changes appropriate to their social context, and the technology will therefore gradually acquire some contextually dependent preconditions for use. These preconditions will most probably be revealed when a technology is transferred from one context to another. Thus, a technology transfer project may trigger a long process of re-innovations just to make the technology fully operational in its new context. In a transfer process, technological risks may arise due to incomplete transfer of mastering capacity; mismatch between transferred technology and the environment; transfer of latent conditions for failure; and the transformation of latent conditions or known risks when the technology is installed in a new environment. Longitudinal data from the Norwegian petroleum industry indicates that the first phases in a transfer process will create high technological risks. It will take many years before the transferred technologies are adapted to the new context and the risk level has been normalised.     

既有建筑结构安全性检测过程质量脆弱性评价

为了提高我国建筑结构安全性检测过程质量的可靠性和合理性,确保建筑结构安全服役,针对我国建筑结构检测工程的特点,构建了基于DEA对抗交叉模型的建筑结构检测过程质量脆弱性评价模型,并将模型应用于8个检测工程实例中,确定了其脆弱性等级,分析了既有建筑结构安全性检测过程质量脆弱性的影响因素,对其进行了优劣排序,为检测过程质量管理人员提供理论支持。     

SIL determination: Recognising and handling high demand mode scenarios

The International Standards for Functional Safety (IEC 61508 and IEC 61511) are well recognised and have been adopted globally in many of the industrialised countries during the past 10 years or so. Conformance with these standards involves determination of the requirements for instrumented risk reduction measures, described in terms of a safety integrity level (SIL). During this period within the process sector, layer of protection analysis (LOPA) has become the most widely used approach for SIL determination. Experience has identified that there is a type of hazardous event scenario that occurs within the process sector that is not well recognised by practitioners, and is therefore not adequately handled by the standard LOPA approach. This is when the particular scenario places a high demand rate on the required safety instrumented function. This paper will describe how to recognise a high demand rate scenario. It will discuss what the standards have to say about high demand rates. It will then demonstrate how to assess this type of situation and provide a case study example to illustrate how to determine the necessary integrity level. It will conclude by explaining why it is important to treat high demand rate situations in this way and the resulting benefit of a lower but sufficient required integrity level.     

压力阀试验系统的设计与应用研究

介绍了压力阀试验液压系统 ,阐述了如何操作这个系统对溢流阀进行测试 ,以及对溢流阀的测试项目和方法     

Dynamic Bayesian network modeling of reliability of subsea blowout preventer stack in presence of common cause failures

A subsea blowout preventer (BOP) stack is used to seal, control and monitor oil and gas wells. It can be regarded as a series–parallel system consisting of several subsystems. This paper develops the dynamic Bayesian network (DBN) of a parallel system with n components, taking account of common cause failures and imperfect coverage. Multiple error shock model is used to model common cause failures. Based on the proposed generic model, DBNs of the two commonly used stack types, namely the conventional BOP and modern BOP are developed. In order to evaluate the effects of the failure rates and coverage factor on the reliability and availability of the stacks, sensitivity analysis is performed.     

便携式布氏硬度计在电厂金属硬度检测中的应用

针对电厂金属部件及焊缝现场硬度检测中里氏硬度计误差较大的问题,介绍了有关标准的进展情况,以及便携式布氏硬度计和压痕自动测量装置的最新技术.结果表明:在现场硬度检测中,对有争议的硬度值宜采用便携式布氏硬度计进行测量校核,国内已形成关于便携式布氏硬度计的标准体系,自动压痕测量装置配合便携式布氏硬度计非常适于电厂的现场硬度检测,通过换算得到的数据,不能作为投诉和满足验收要求的依据.     

基于RBI技术的海上平台延期服役静设备定量化安全评估技术

针对海上延期服役平台静设备的安全风险评估与控制问题,应用RBI风险评估技术的评估理论和方法对海上延期服役平台静设备的定量化安全管理方法进行了实践和探索,并选择某延期服役平台进行风险分析相关结论的工程验证。其具体过程是运用定量RBI技术,首先根据工艺流程和介质特点对海上平台静设备分别进行了物流回路和损伤回路的划分,并以此为基础对延期服役平台静设备的安全风险进行定量评估,进而得出各静设备单元的失效可能性、失效后果及风险等级,最后通过得出的损伤模式、损伤机理及对应的腐蚀速率,从而制定针对性的检测策略。将利用这些检验策略所检测出的真实情况与分析结论进行对比,最终验证了RBI技术在延期服役平台静设备风险评估方面具有很强的适用性。