民航机内非定常燃烧过程的计算机模拟

本文采用数值方法,对民航机内火灾非定常燃烧过程包括其内固体可燃物的受热热解及其挥发份的湍流气相燃烧进行了较为细致的计算,揭示了其火灾非定常燃烧的规律,得到了较好的结果。     

建筑火灾模拟模型设计

数值模拟是火灾科学研究中的一种重要方法。本文描述了建筑火灾模拟模型的建模思想和方法，该思想可用于研究建筑火灾过程规律、新的火灾安全方案或策略的工作效果和经济性分析，模拟模型可以给系统性能和火灾防治经济性以定量说明。并对在建模中存在的问题进行了探讨．     

火灾烟气伤害机理和伤害模型

建筑物发生火灾时，燃烧产生的烟气对人构成主要威胁。本文分析火灾烟气的伤害机理，提出烟气伤害指数概念及其计算方法，探讨它在材料防火性能评价和建筑物火灾安全评价方面的应用可能性。     

火灾下圆钢管约束钢筋混凝土短柱轴压性能分析

利用ABAQUS软件建立了火灾下圆钢管约束钢筋混凝土轴压短柱非线性有限元模型,在确定混凝土和钢材的本构基础上,对其火灾下轴压性能进行了数值计算,并与已有相关试验数据进行了对比验证。分析了环境温度、混凝土强度、钢管屈服强度、截面尺寸、含钢率等参数对火灾下轴压性能的影响规律。结果表明:火灾下各试件核心混凝土纵向应力发展规律较为相似,且应力分布趋向均匀;环境温度对试件轴压刚度的影响大于极限承载力,材料强度对极限承载力的影响较大,增大钢管含钢率可一定程度提高试件轴压刚度;提出了火灾下此类试件极限承载力和轴压刚度的简化计算公式,可为工程实际应用提供参考。     

金属热颗粒引燃可燃堆积材料的实验研究

电焊操作、烟花燃放、工业磨削和高压电线碰撞等过程容易产生高温热颗粒。这些热颗粒一旦接触可燃材料就有可能引燃材料,导致火灾。该文对热颗粒引燃可燃堆积材料的行为进行实验研究,从而为工业堆积材料的火灾防控方法提供参考。实验加热一系列不同直径(6mm,8mm,10mm,12mm,15mm,20mm)的黄铜金属颗粒作为热源,并采用三种常见的工业堆积材料(木粉,炭粉,羟丙基甲基纤维素HPMC)作为可燃材料的代表物,研究不同功率金属热颗粒对材料的引燃行为,分析金属热颗粒引燃材料的临界功率。结果表明,材料本身的性质会影响热颗粒的引燃行为,HPMC的引燃时间最长,木粉的引燃时间最短。随着热颗粒直径的增加,热颗粒引燃三种材料所需的功率值整体呈增大的趋势。由于燃烧空腔的形成,HPMC的引燃临界功率相对较高。     

Revised fire consequence models for offshore quantitative risk assessment

Offshore oil and gas platforms are well known for their compact geometry, high degree of congestion, limited ventilation and difficult escape routes. A small mishap under such conditions can quickly escalate into a catastrophe. Among all the accidental process-related events occurring offshore, fire is the most frequently reported. It is, therefore, necessary to study the behavior of fires and quantity the hazards posed by them in order to complete a detailed quantitative risk assessment. While there are many consequence models available to predict fire hazards-varying from point source models to highly complex computational fluid dynamic models—only a few have been validated for the unique conditions found offshore.

In this paper, we have considered fire consequence modeling as a suite of sub-models such as individual fire models, radiation model, overpressure model, smoke and toxicity models and human impact models. This comprehensive suite of models was then revised by making the following modifications: (i) fire models: existing fire models have been reviewed and the ones most suitable for offshore conditions were selected; (ii) overpressure impact model: a model has been developed to quantify the overpressure effects from fires to investigate the possible damage from the hot combustion gases released in highly confined compartments; (iii) radiation model: instead of a point/area model, a multipoint grid-based model has been adopted for better modeling and analysis of radiation heat flux consequences. A comparison of the performance of the revised models with the ones used in a commercial software package for offshore risk assessment was also carried out and is discussed in the paper.     

木质类人造板材炭化痕迹实验及数值重构研究

利用锥形量热仪测定不同辐射热通量和不同燃烧时间下木质类人造板材的炭化深度,建立木质类人造板材炭化痕迹的数学模型,并嵌入到FDS(Fire Dynamics Simulator)源程序中,与自身功能相结合,实现重构木质类人造板材炭化痕迹的功能。同时实验研究了不同油盘尺寸、不同燃烧时间、不同火源位置和不同材料种类对炭化痕迹的影响,并利用新编译的FDS程序对实验进行重构,对比重构结果和实验结果,证明该程序可以用于重现木质类人造板材的炭化痕迹。     

籽棉和皮棉阴燃特性的对比实验研究

分别对具有相同尺寸、相同质量的籽棉和皮棉进行阴燃实验并对实验结果进行对比分析,得到在无外部辐射热源的自然条件下,发生阴燃时皮棉的温升速率较大、阴燃最高温度较高、阴燃前期600s内的CO生成速率和质量流量较大,但籽棉的阴燃时间较长,约为皮棉阴燃时间的4倍;同时将阴燃分为三个阶段,在阴燃的缓慢发展阶段和衰减阶段,籽棉阴燃的火灾危险性较大,在快速发展阶段,皮棉阴燃的火灾危险性较大。     

Human behaviour and evacuation time for large underground comprehensive buildings during fire risk process

Human factors play an indispensable role in process safety during fire risk process. Fire evacuation of underground comprehensive buildings is a critical consideration for practical importance. Here, evacuation experiments were conducted in the Guangzhou East Railway Station Plaza, a large underground comprehensive building in Guangdong, China, with the plaza occupants as the participants. The evacuation factors, namely evacuation time and evacuee-selected evacuation routes, were evaluated using empirical equations (the Togawa model and the Melinek and Booth model) and evacuation modelling software (EVACNET 4 and composite occupant evacuation model). The experimental data were used to verify the empirical equations and evacuation models and to modify specific empirical parameters. The effect on escape route judgement and selection under emergency situations was analysed. The results demonstrated that direct access to outdoor exits could considerably reduce evacuation time. The experimental N and t_s were 1 person/m·s and 28 s, respectively. The total evacuation time was 281 s, and the EVACNET 4 and composite models’ simulations of safe evacuation were 285–290 s, which was consistent with the experimental data—validating the high accuracy and applicability of the models.     

基于火灾动力学模拟的古建筑火灾探测系统设计研究

古建筑的消防安全工作作为古建筑保护工作内容的重要组成部分,需要深入开展的消防科学的研究工作.目前在我国,缺少关于古建筑防火安全方面的规范,通常使用的处方式规范一般不适用于古建筑.性能化方法能够提供更加灵活和符合实际的解决方案.并且这可能是唯一可行的使古建筑达到可接受风险水平的方法.以布达拉宫东大殿为研究对象,探讨了性能化防火分析方法在古建筑防火保护中的应用.以对古建筑进行早期探测报警为目标进行了消防设施设置.应用FDS软件进行了模拟研究,根据模拟结果进行分析,得到了一些有益的结论并应用于消防设施设置.通过对探测器响应时间分析,探测器的设置合理,能够在第一时间报警,并且实现了消防安全设计的科学化、合理化和成本效益的最优化.