通风及细水雾耦合系统与柴油池火相互作用的研究

发布时间：2019-04-24 12:03

【摘要】：火灾是人类所面临的的最严重的灾害之一,对人类社会和自然环境的危害巨大,其中隧道火灾尤为引人关注。日益严峻的消防形势推动了防火灭火技术的研究与应用。随着维也纳公约及蒙特利尔议定书的签订,已广泛应用的卤代烷灭火剂停止使用,因而寻找其理想替代物,成为亟待解决的问题。细水雾以其环境友好、灭火迅速、应用广泛等特点,被认为是卤代烷灭火剂的理想替代品,受到了各国研究人员的重视。然而由于其在通风等复杂环境中的灭火机理尚不明确,导致其无法广泛应用。因此,探寻细水雾抑制熄灭火灾的灭火机理,是推动细水雾灭火系统走向实用阶段的重要环节。本文围绕通风及细水雾耦合系统与柴油池火的相互作用这一研究课题,首先搭建了6m×1.5m×2m的小尺度隧道工程实验平台,通过对实验过程中质量损失速率、火场温度、火源热辐射及02、CO浓度等的测定和分析,将通风与细水雾耦合作用下抑制熄灭柴油池火的过程分为三个阶段,即强化阶段、控制阶段和熄灭阶段,分析了三个不同阶段通风与细水雾耦合作用的灭火机理,同时探寻了影响通风与细水雾耦合作用灭火效果的主要影响因素。结果表明：从灭火机理来看,强化阶段主要表现为火焰冷却和衰减热辐射；控制阶段为表面冷却和衰减热辐射；熄灭阶段为动力学作用和表面冷却。从耦合系统的控火效果来看,顶部排烟模式与细水雾的耦合作用效果优于纵向排烟模式；当细水雾的工作压力提高到10MPa,工作压力的增加对于细水雾灭火效果的提升非常有限；细水雾喷头的安装间距应小于等于环境风速导致的细水雾偏移量。基于隧道实验平台的实验结果及对耦合作用系统灭火过程的尺度分析,建立了隧道工程大尺度空间数值模拟模型,应用火灾动力学模拟软件FDS进行了数值模拟,通过对实验与模拟结果的对比,探讨了尺度关系的可靠性以及小尺度实验结果应用到大尺度空间的适用性。结果表明,大尺度数值模拟与模型实验中的灭火过程及火灾温度场的发展规律基本一致,说明相应的尺度关系和实验结果可以适用于预测通风环境中细水雾熄灭抑制隧道柴油池火的过程。
[Abstract]:Fire is one of the most serious disasters faced by human beings, and it has great harm to human society and natural environment, especially tunnel fire. The increasingly severe fire fighting situation has promoted the research and application of fire prevention and fire extinguishing technology. With the signing of the Vienna Convention and the Montreal Protocol, the widely used halogenated alkane fire extinguishing agent has ceased to be used, so finding its ideal substitute has become an urgent problem to be solved. Water mist is regarded as an ideal substitute for halogenated alkane fire extinguishing agent because of its friendly environment, rapid fire extinguishing and wide application. It has been paid more and more attention by researchers all over the world. However, its fire extinguishing mechanism in ventilation and other complex environment is not clear, so it can not be widely used. Therefore, exploring the fire extinguishing mechanism of water mist suppression is an important link to push the water mist fire extinguishing system to practical stage. Based on the study of the interaction between ventilation and water mist coupling system and diesel pool fire, a small scale tunnel engineering experiment platform of 6m 脳 1.5m 脳 2m has been set up at first, and the mass loss rate and the temperature of the fire field during the experiment have been studied. According to the measurement and analysis of the thermal radiation of the fire source and the concentration of 02 and CO, the process of suppressing and extinguishing the diesel fuel pool fire under the coupling action of ventilation and water mist is divided into three stages: strengthening stage, controlling stage and quenching stage. The fire extinguishing mechanism of the coupling action of ventilation and water mist in three different stages is analyzed. At the same time, the main factors affecting the fire extinguishing effect of the coupling action of ventilation and water mist are explored. The results show that flame cooling and attenuation of heat radiation are the main features in the strengthening stage, surface cooling and attenuation heat radiation in the control stage and kinetic action and surface cooling in the quenching stage from the point of view of the fire extinguishing mechanism. According to the fire control effect of the coupling system, the coupling effect of the top exhaust mode and the water mist is better than that of the longitudinal one, and when the working pressure of the water mist is increased to 10 MPA, the increase of the working pressure is very limited to the improvement of the fire extinguishing effect of the water mist. The installation spacing of water mist nozzles should be less than or equal to the water mist offset caused by ambient wind speed. Based on the experimental results of the tunnel experiment platform and the scale analysis of the fire extinguishing process of the coupled action system, a large-scale spatial numerical simulation model of tunnel engineering is established, and the numerical simulation is carried out by using the fire dynamics simulation software FDS. The reliability of the scale relation and the applicability of the small-scale experiment results to the large-scale space are discussed by comparing the experimental results with the simulation results. The results show that the large-scale numerical simulation is consistent with the fire extinguishing process and the fire temperature field in the model experiment. The results show that the corresponding scale relation and experimental results can be used to predict the process of water mist extinguishment and suppression of diesel fuel pool fire in ventilation environment.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU998.13

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