结合流程图与ISM的区域管制运行风险分析

为保障区域管制系统运行的安全,采用流程图法从管制员、设备、环境、管理四方面识别各运行环节潜在的风险,并建立风险因素集合。运用解释结构模型(ISM),对风险因素间的关系进行推理和计算,最终形成一个五级递阶结构解释模型,将风险因素之间原本模糊不清的关系转化为直观的具有层次分明的结构。通过对解释结构模型的分析找出了影响区域管制运行安全的直接因素、间接因素以及深层次的因素,并提出了相应的风险控制措施。     

Determination of the critical length of the crack-like flaws and its effect on safety

Methodologies of API 579 have been widely accepted as the de-facto standard guideline for fitness for service assessment on crack-like flaws in pressure equipment. For different purposes and needs, the evaluation is divided into three levels, from critical length estimation in level 1, use of the failure analysis diagram (FAD) in level 2, to performing finite element stress analysis in level 3, that is from simplified to accurate. It is generally considered safe as long as the crack is smaller than the critical crack, but not all of them are actually the case. Therefore, it is very important to study the physical meaning behind the critical crack and understand the conservativeness of it.In this study, numerous examples of critical cracks determined according to API 579 Level 1 were put into Level 2 analysis for comparison. Each case is mapped onto the FAD of level 2 analysis to see its position and distance from the borderline between safe and danger zones. A huge amount of examples covering the majority of possible scenarios, including the geometry, thickness, inner diameter, pressure and half-length of the flaw, depth of the crack, crack tip and crack bottom, as a whole, there are 960 cases to be analyzed.Results show that cracks on the circumferential direction of the cylindrical and spherical vessels are distributed tightly in a small area far from the borderline on the FAD diagram. In these cases, the vessel is actually not as dangerous as the critical crack implies, since most of the points lie quite far from the danger zone. As for the longitudinal cracks of a cylindrical vessel, the results are scattered around, and three data points are located outside the allowable zone. The peculiar results are partly due to a discrepancy of interpolating procedure as the influence coefficient is being computed. Through this study, it is also found that the cumbersome process of estimating the critical crack length can be greatly simplified for longitudinal cracks in a cylindrical vessel.     

The influence of iron flow on iron resource efficiency in the steel manufacturing process

An iron resource efficiency is proposed to define a measure of the natural iron resources saved in the steel manufacturing process. A simplified iron flow diagram is presented for the steel manufacturing process. The influences of various deviations in iron flow from the simplified iron flow diagram on iron resource efficiency are analyzed. The relationships between iron resource efficiency of unit processes and the final product are also discussed. As an example, data from a steel plant are used to analyze the influence of iron flow on its iron resource efficiency of finial product in the steel manufacturing process, the influence of iron resource efficiency of unit process on iron resource efficiency of the final product, and give some measures to improve the iron resource efficiency of the steel manufacturing process.     

城市生命线系统的地震网络可靠性研究

震后生命线系统的网络可靠性对于灾后的应急救援和恢复至关重要,因此,评价城市生命线系统网络在一定地震强度下,网络系统保持连通的能力已成为研究生命线地震网络可靠性的重要内容。以经典的系统单元可靠性模型为基础,在众多的网络可靠性计算方法中根据方法实现的难易程度和计算效率,选择采用了不交化穷举集合法和有序二分决策图方法,比较研究了网络系统的可靠性问题,并与Monte Carlo方法进行了对照。此外,针对淮南市配水管网的实际案例,采用上述方法计算了相应的可靠度,计算结果表明,所提方法能够高效地应用于一般的工程实践,具有显著的实用意义。     

TND-PHA法在项目安全管理中的应用

在项目安全管理中,结合项目时间管理中常用的网络图,运用预先危险性分析法对网络图中的每项活动进行分析,根据分析结果制定安全防范措施,并开展有针对性的教育和培训,可以有效避免事故的发生.     

基于方向图的天线分类模型的分析与研究

文章重点考察不同天线在远区场同一接收阵列处的场强大小之间的不同关系特征,并利用神经网络对不同天线的这种非线性特征进行模拟,从而实现基于天线方向图对不同天线的分类,并对不同分类模型进行对比。     

动态主逻辑图--一种改进的安全风险建模方法

用主逻辑图,可以比较直观地建立起复杂系统的安全风险模型,但是这种模型运用的是布尔代数理论,所以无法模拟具有动态行为的系统.动态主逻辑图就是在主逻辑图的基础上,运用模糊数学（逻辑）的理论,分析复杂系统中的动态行为.介绍了动态主逻辑图的8种基本形态,并以利用动态主逻辑图对系统进行全面诊断和描述系统的部分失效的行为为例,简要说明了动态主逻辑图的新特点.     

工程系统一体化安全风险模型研究

借鉴功能模拟原理,利用目标树-成功树-主逻辑图(GTST-MLD)框架,提出了一个一体化安全风险模型。该模型对关联于工程系统安全特性的目标、功能、结构、行为等因素予以综合,提供了从多层次研究解决安全问题的模型基础,克服了基于事件树/故障树模型的概率风险评估等传统方法而分别对系统结构、行为、事件进行研究的问题,支持实现在更高的系统功能层面上对系统安全性的分析研究。通过研究该模型在安全风险评估、事故因果关联分析、潜在交互作用鉴别中的应用,表明研究成果为解决复杂工程系统安全问题提供了新的分析手段。     

老空水水害事故原因分析及防治措施研究

矿井老空水水害一直是困扰煤矿安全生产的不利因素,必须加强其防治措施方面的研究。通过对老空水水害事故的分析,建立了一个系统全面的老空水水害事故的致因鱼刺图模型;并针对鱼刺图模型的各个致因事件提出了老空水防治的具体措施;然后根据安全技术措施等级顺序要求的具体原则,对措施进行等级排序。笔者提出了以下观点老空水的防治是多方位的;防治措施是有等级的;合理设计,严禁剃头开采是消除老空水水害事故的本质安全型措施。