考虑优先性的罐区火灾事故应急行动研究

为提高工业罐区火灾事故的应急救援效率,本文采用时间混合Petri网对罐区火灾事故应急响应过程进行建模仿真,分析应急过程中的行动优先性及时间性能;对某工业罐区进行考虑应急行动优先性和不考虑应急行动优先性2种救援模式进行建模仿真和对比分析。研究表明:考虑应急行动优先性的救援模式可对随机到达的资源进行调配,可提高罐区火灾应急救援效率。     

烤漆房防火

烤漆房应用在汽车、机械、五金、家具、化工等行业用于工件表面喷漆、烤漆作业。近年来，各地汽修厂火灾事故不绝于耳，究其原因，多发生在烤漆房。汽车涂料生产及涂装作业的过程中所使用的各种化学品大都易于着火，烤漆房高温作业环境配上油漆这种易燃易爆物品，让烤漆房已成为高危作业点。然而汽修厂维修技工的不规范作业，也增加了烤漆房发生火灾事故的次数。2008年8月，     

用油淬火的火灾防治

现在不时仍有因淬火油使用不当而发生的火灾事故和惨剧，这不仅造成了巨大的经济损失，而助对环境和安全生产构成了巨大威胁，对使用淬火油可能产生火灾事故的原因进行了分析，提出了应对措施和建议。     

火灾事故中的调查询问

在进行火灾事故调查的过程中,调查询问主要是确定火灾发生的原因,这也是调查人员最常采用的手段,但调查询问的结果会直接影响到后期的调查记录以及办案质量。本文主要是针对火灾事故调查中调查询问方式的有效应用进行了相关分析,希望能够通过有效的调查询问来确定火灾事故的原因,进而找到消灭火灾事故的突破口。     

北京市城中村火灾事故风险分析

把城中村作为一个系统,从软件、硬件、环境和人四个方面详细分析了火灾风险要素。依据火灾风险要素,用事故树分析的方法对城中村火灾事故进行分析,明确各风险要素在城中村火灾发生、发展过程中的因果关系,并得到城中村火灾事故因果分析图。利用因果分析图,可了解影响城中村消防安全的重要风险因素。     

复杂网络下密室逃脱类场所火灾风险评估研究

为了预防密室逃脱类场所火灾事故，利用梯形模糊数方法与复杂网络理论，研究密室逃脱类场所火灾事故风险演化过程。通过确定密室逃脱类场所火灾事故风险因素，分析典型火灾事故场景，从宏观角度分析场所内风险因素从被激发、互相影响，最终传递形成人员未能顺利疏散的火灾事故全过程，构建基于复杂网络理论的密室逃脱类场所火灾事故模型。运用梯形模糊数计算各连接边演化过程中的不确定性，采用Dijkstra算法得到最短路径即风险概率最大路径。结果表明：密室逃脱类场内使用明火的初始风险因素作用下，因人员精神状态高度紧张、内部结构复杂或房屋闭锁所导致的火灾演化风险概率最大，并极易造成人员无法疏散。最后从政府等监管部门、场所经营者及参与游戏人员3个方面提出了火灾预防策略。     

最小割集在系统安全分析方法中的应用

利用事故树分析法对矿井火灾进行分析 ,结合平煤六矿建立了矿井火灾事故树。阐述了最小割集理论及其在事故分析中的作用 ,着重提出了对事故树底部事件进行排序分级的加权结构重要度分析法。该方法新颖、简洁而实用 ,为系统安全分析提供了新的方法和途径。     

消防灭火救援中的环境污染问题与应对策略研究

随着社会经济的快速发展和工业化进程的不断深入,环境污染问题日益凸显,需引起社会各界的高度重视。近年来,火灾事故频繁发生,但在消防灭火救援工作中不可避免出现了很多环境污染问题,给生态环境造成了较大破坏。因此,如何有效减少消防灭火救援中的环境污染,已成为我国亟需解决的热点问题。本文对火灾事故发生原因和消防灭火救援中的环境污染问题及产生原因进行了简要分析,并提出了应对策略,以期为有关单位提供借鉴。     

基于FTA-Petri网的地铁火灾事故安全性研究

鉴于城市轨道交通安全的复杂性及重要性,应用FTA-Petri综合分析方法对城市轨道交通系统安全性进行分析并构建轨道交通系统火灾事故安全性模型。该模型具有FTA与Petri网方法的优点。在利用传统的FTA方法深入分析火灾事故原因的基础上,选择典型的火灾事故成因,利用Petri网方法动态模拟火灾事故发生的过程;借鉴已有的概率计算方法对所建立的火灾Petri网模型进行定量求解分析;最后,针对分析结果提出可行性方案。提出将FTA-Petri综合分析方法应用到城市轨道交通安全领域,在地铁火灾安全性定量分析方面作出了探索性的研究。     

“百草枯”生产的环境风险评价

结合河北省桃园农药厂开发的百草枯新工艺(低温钠法)，对百草枯生产过程中的环境风险进行评价。首先介绍了百草枯生产的工艺流程，然后系统分析了金属钠、吡啶、氯甲烷以及百草枯等危险物的性质及其危害性，并在上述分析的基础上，采用相应的评价模型对钠化釜及合成釜中吡啶可能造成的爆炸与扩散进行了评价。最后，就百草枯生产的环境风险提出了相应的对策和防范措施。     

Multiple pool fires: Occurrence,simulation, modeling and management

When two or more pool fires burn in such close proximity of one another that they can influence each other, they are termed ‘multiple pool fires’ (MPF). The characteristics and the structure of MPFs are significantly different from that of stand-alone pool fires. Even though MPFs have known to occur fairly often in chemical process industries, much lesser work has been done towards simulation, modeling and control of MPFs as compared to stand-alone pool fires.This paper is perhaps the first-ever attempt at surveying the MPF state-of-the-art. It recounts MPF accidents and catalogs the controlled experiments that have been done to understand the mechanism and impact of MPFs. Attempts to model MPFs have been assessed and possible ways to manage MPFs have been touched upon.     

雷击火形成及预防扑救对策

雷击火作为天然火源是一种难以控制的自然现象,其形成机理极为复杂。雷击火与雷暴的活动密切相关。     

Theoretical analysis and experimental study on critical conditions of backdraft

Backdraft is one of the most special behaviors of enclosure fires which has strong characteristics of concealment and suddenness. Once backdraft occurs in an enclosure, the fire will quickly engulf the entire enclosure and create a huge extrusive fireball out of the openings. In such circumstance, it is very difficult for people inside to evacuate and firefighters to enter to perform rescue. That’s why backdraft usually leads to serious consequences in both industrial and civil building fires. Experimental investigations on backdraft in enclosure fires caused by solid fuels have been carried out in the study, and the backdraft phenomenon has been reproduced in the small-scale enclosure fire tests. Based on the theories of heat transfer and fire dynamics, the theoretical model of conditions that backdraft occurs in enclosure fires has been established and the critical condition expressions have been deduced. Combining the results of theoretical analyses with those of experimental studies, a new backdraft criterion expressed by β, which is the ration between the combustible gas volume fraction and the lower explosive limit of the mixture, has been put forward.     

利用直升飞机进行森林防火的研究——水用于防止落叶被点燃的方法

每年世界上都会发生大量森林火灾.虽然森林火灾对自然环境造成严重破坏,但现有的火灾防治措施仍不足以防止火灾发生.山区大的绿化区常常在强干燥空气条件下由于火蔓延的作用而被毁灭.很多案例中,尽管消防部门直升飞机和一般飞机被投入使用,仍需要花费很长时间来抑制大规模森林火灾.燃烧的木块可以很容易从下风方向的山脊越过山谷,并在强风作用下广为散播.因此,如何阻止由于燃烧木块而引发的快速火蔓延,是非常重要的研究课题.通常,当燃烧木块在新的地点点燃当地可燃物的初期,火势还是相对微弱的,尺寸也很小,因此,有可能可以在火灾早期借助直升飞机或一般飞机来以水攻火.本文的目标,就是研究在燃烧木块到达的下风区利用直升飞机和一般飞机中的水的方法.本文通过实验室实验和计算机模拟研究了阻止火从一个山脊蔓延到另一个下风方向的山脊的有效方法.     

小尺度森林火灾的渐近幂律分布

森林火灾系统是一个自组织临界性系统，它的表现之一就是火灾的尺度分布满足幂律规律。然而实际数据分析表明，在尺度最大和最小的两个区域，火灾分布与幂律规律存在较大的差异。对小尺度火灾的偏离现象，研究者通常猜测是由于小面积火灾记录数据遗漏较多造成的，目前尚没有一个理论上的依据，而小尺度火灾的分布规律对大尺度火灾的预测起看关键作用。为了解释这种偏离现象，该文将火灾看作一个生灭过程，并对火灾蔓延和熄灭的机理进行了分析，最终得到了森林火灾分布与火灾尺度的定量依赖关系及其机理。将该文的结果与日本近年来全国范围内的森林火灾统计数据进行了对比，表明该文得到的结果与真实数据得到较好符合，并且成功解释了小尺度森林火灾分布与幂律关系的偏离现象。该研究可望对深入认识火灾系统的自组织临界性和防治火灾具有一定的实际意义。     

Assessment of four turbulence models in simulation of large-scale pool fires in the presence of wind using computational fluid dynamics (CFD)

Pool fires are the most common of all process industry accidents. Pool fires often trigger explosions which may result in more fires, causing huge losses of life and property. Since both the risk and the frequency of occurrence of pool fires are high, it is necessary to model the risks associated with pool fires so as to correctly predict the behavior of such fires.Among the parameters which determine the overall structure of a pool fire, the most important is turbulence. It determines the extent of interaction of various parameters, including combustion, wind velocity, and entrainment of the ambient air. Of the various approaches capable of modeling the turbulence associated with pool fires, computational fluid dynamics (CFD) has emerged as the most preferred due to its ability to enable closer approximation of the underlying physical phenomena.A review of the state of the art reveals that although various turbulence models exist for the simulation of pool fire no single study has compared the performance of various turbulence models in modeling pool fires. To cover this knowledge-gap an attempt has been made to employ CFD in the assessment of pool fires and find the turbulence model which is able to simulate pool fires most faithfully. The performance of the standard k–? model, renormalization group (RNG) k–? model, realizable k–? model and standard k–ω model were studied for simulating the experiments conducted earlier by Chatris et al. (2001) and Casal (2013). The results reveal that the standard k–? model enabled the closest CFD simulation of the experimental results.     

受限空间内细水雾与火相互作用的实验研究

细水雾灭火系统作为卤代烷系列灭火剂的替代产品之一，以其高效无毒、经济实用的优点，近年来在国际上研究得非常活跃。本文在受限空间内利用先进的材料热释放速率测量仪研究了细水雾与火的相互作用过程，并得到了以下结论：细水雾通过汽化吸热冷却燃料及氧化剂、体积膨胀隔氧以及吸收热辐射降低对燃料的热回馈等效应与火相互作用，达到控制和扑灭火灾的目的，在受限空间内汽化隔氧效应起着重要作用。     

CFD simulation of pool fires situated at differing elevation

When two or more pool fires happen to burn so close to each other that they interact, they are termed ‘multiple pool fires’ (MPF). Past accident analysis reveals that MPFs occur quite frequently in chemical process industries. Controlled experiments done so far to study MPFs have indicated that MPFs lead to increase in the fuel burning rate, flame height and heat release rate (HRR) but the nature and the extent of the impacts of different factors on these manifestations is as yet poorly understood. In this context computational fluid dynamics (CFD) appears to be a tool which can enable more detailed and realistic simulation of MPFs than other possible approaches, especially due to its ability to closely approximate the underlying physical phenomena. In tank farms there are situations where different storage tanks are placed at different elevations yet close to each other. If such tanks happen to catch fire, the resulting fires may influence each other in a manner that may be a function of the difference in the tanks’ elevation. However no CFD study has been carried out which addresses this type of situation. Hence an attempt has been made to employ CFD to study MPFs involving two pools with fuel surfaces are at different elevations. Results reveal that good correlation is possible between the experimental findings and the CFD simulations.     

An experimental study on the burning rate of a continuously released n-heptane spill fire on an open water surface

Spill fires are common during oil product storage and transportation after a loss of containment. Since the burning fuel is moving and the fuel depth is quite shallow, the burning rate in a spill fire is different from that of a pool fire with a static burning zone. Unlike pool fires, which have been studied for decades and have well-established correlations for burning rate, research on spill fires is inadequate. In this paper, continuously released n-heptane spill fire experiments were conducted on open water surfaces with varying fuel discharge rates. The pool diameters were measured, and the spill fire burning rates were estimated based on a dynamic balance between fuel supply and combustion. The burning rates in n-heptane pool fires from the literature were reviewed and compared with the estimated burning rates in spill fires of the same dimension. The spill fire burning rate was found to be close to that in a pool fire during the initial burning phase but lower than that in a bulk burning pool fire and that in a “fuel-level-controlled” pool fire. The distinction between the burning rates of spill fires and pool fires is explained by the heat balance analysis of the fuel layer. A model for the spill fire burning rate was proposed accordingly. The results calculated with the presented model are closer to the measured data than those calculated with pool fire models.     

Computational fluid dynamics (CFD) study of heat radiation from large liquefied petroleum gas (LPG) pool fires

Liquefied petroleum gas (LPG) is flammable and has risks of pool fires during its transportation, storage, and applications. The heat radiation by LPG pool fires poses hazards to individuals nearby and can lead to potential failures of ambient facilities. Due to the high costs and invasive nature of experiments for investigating large-scale pool fires, computational fluid dynamics (CFD) is employed in this study as the cost-effective and noninvasive method to simulate the process and analyze the characteristics of large hydrocarbon pool fires. Specifically, an experimentally validated 3-D CFD model has been built to simulate surface emissive power (SEP) and incident radiation of large-scale LPG pool fires with three different diameters and wind speeds. Steady-state simulations with P1 radiation and probability density function (PDF) combustion models were employed to obtain reliable data after the optimizations based on the comparisons with experimental data and empirical models. The comparison with benchmark experimental data demonstrates that the CFD model employed in this study can accurately predict the incident radiation of large LPG pool fires. A new SEP correlation is also proposed, which is specifically for LPG pool fires with a diameter between 10 m and 20 m. Additionally, the safe separation distances between LPG facilities and surrounded objects have been estimated based on the CFD simulation results. The high-resolution CFD model for large LPG pool fires in this work provides noninvasive and direct quantitative evidence to enhance the fundamental understanding on the safety of large LPG pool fires and can assist regulatory agencies in refining the safety limits in the cost-effective and time-saving manners.