水雾对典型壁面装饰材料火灾发展的影响研究
发布时间：2018-08-03 21:28
【摘要】： 壁面装饰材料是火灾中火势蔓延的重要途径,水雾是有效地火蔓延抑制手段。与自动喷水灭火系统相比,水喷雾系统水滴更小、比表面积大,单位时间内吸收更多的热量,具有灭火时间短及节约水的特点。而以往很少有水雾对壁面材料的灭火特性研究。本文将主要研究水雾水平方向抑制壁面装饰材料火蔓延的情况,并选择了两种典型的壁面装饰材料胶合板和壁面软包材料聚氨脂软质海绵进行研究。 分析了在壁面向上火蔓延的材料预热区施加水雾的情况下,水雾的控火作用和灭火作用,理论分析了水雾对火焰从控火作用到灭火作用的转变,得到了临界水雾施加量的理论模型,以及影响控火作用的临界水雾施加量的因素。在标准燃烧室内进行了模拟真实条件下,受限空间内水雾对壁面材料的燃烧抑制作用实验,得到了水雾施加在火焰预热区时由控火作用转变为灭火作用的临界水施加率。从理论上介绍了计算临界水施加率的方法,并根据实验情况进行了推导计算,得到临界水施加率。 在标准燃烧室内进行了在不同位置施加水雾对壁面材料火灾发展的影响的实验研究,得到了不同喷射条件下分别在胶合板的预热区和热解区施加水雾时,壁面装饰材料的热释放速率,CO浓度及温度等参数。分析了水雾施加在胶合板预热区和热解区时流量对竖直火蔓延的影响规律。 由于火区阻力作用,粒径在到达火焰面时需有足够的初速度才有可能到达壁面,因此本文理论分析了雾滴水平运动时的粒径与初速度对雾滴在空气中的运动的影响,得到了不同尺寸与初速度的雾滴的极限距离,并分析了雾滴在水平穿越火焰区时粒径的变化与时间及运行距离之间的关系。 根据水雾粒径与速度的关系,可以把水雾的灭火作用分为气相灭火作用与表面相灭火作用。理论分析了水雾水平方向作用于火焰与垂直作用于火焰区的区别,指出了当水雾水平方向作用于壁面火时,其灭火作用以表面相灭火为主。并在标准燃烧室内开展了对比实验,对理论分析结果进行了验证。 开展了水雾对壁面软包材料聚氨脂软质海绵的火蔓延抑制作用研究,分析了水雾作用于软包装修材料时水雾最小施加率的影响因素,实验得到了软包装修中经常采用的2cm厚的聚氨酯软质海绵灭火所需的最小水施加率。
[Abstract]:Wall decoration material is an important way of fire spreading, and water mist is an effective means to restrain fire spread. Compared with the automatic sprinkler system, the water spray system has the advantages of smaller water droplets, larger specific surface area, more heat absorbed per unit time, shorter fire-extinguishing time and water saving. However, in the past, few researches have been made on the fire extinguishing characteristics of water mist to wall materials. In this paper, the horizontal direction of water mist is mainly studied to restrain the fire spread of wall decoration materials, and two typical plywood and polyurethane soft sponge are selected. In this paper, the fire control and fire extinguishing action of water mist is analyzed when the water mist is applied in the preheating zone of materials facing to the fire spread. The transformation of water mist on the flame from fire control to fire extinguishing is theoretically analyzed. The theoretical model of critical water mist application and the factors influencing the critical water mist application are obtained. Under the simulated real conditions in the standard combustion chamber, the combustion inhibition effect of water mist on the wall material in confined space is tested. The critical water exertion rate of water mist applied in the flame preheating zone from fire control to fire extinguishing is obtained. In this paper, the method of calculating the application rate of critical water is introduced theoretically, and the calculation is carried out according to the experimental conditions, and the application rate of critical water is obtained. The influence of water mist applied in different positions on the fire development of wall materials was studied in the standard combustion chamber. The water mist was applied in the preheating zone and pyrolytic zone of plywood under different injection conditions. Heat release rate and CO concentration and temperature of wall decoration materials. The effect of water mist on vertical fire propagation in the preheating zone and pyrolysis zone of plywood was analyzed. Due to the effect of fire resistance, it is necessary to have enough initial velocity to reach the wall when the particle size reaches the flame surface. Therefore, the influence of particle size and initial velocity on the droplet movement in the air is theoretically analyzed in this paper. The limit distances of droplets with different sizes and initial velocities are obtained, and the relationship between the particle size change and the time and running distance of droplets passing horizontally through the flame zone is analyzed. According to the relationship between the particle size and the velocity of water mist, the fire extinguishing action of water mist can be divided into gaseous fire extinguishing and surface fire extinguishing. The difference between the horizontal direction of water mist acting on the flame and the vertical direction of the water mist acting on the flame zone is analyzed theoretically, and it is pointed out that when the horizontal direction of the water mist acts on the wall fire, the fire extinguishing action is mainly surface phase. A comparative experiment was carried out in the standard combustion chamber, and the theoretical analysis results were verified. The fire propagation inhibition effect of water mist on polyurethane soft sponge was studied, and the factors influencing the minimum application rate of water mist were analyzed. The minimum water application rate of 2cm thick polyurethane soft sponge for fire extinguishing was obtained.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2008
【分类号】：TU892
本文编号：2163045
[Abstract]:Wall decoration material is an important way of fire spreading, and water mist is an effective means to restrain fire spread. Compared with the automatic sprinkler system, the water spray system has the advantages of smaller water droplets, larger specific surface area, more heat absorbed per unit time, shorter fire-extinguishing time and water saving. However, in the past, few researches have been made on the fire extinguishing characteristics of water mist to wall materials. In this paper, the horizontal direction of water mist is mainly studied to restrain the fire spread of wall decoration materials, and two typical plywood and polyurethane soft sponge are selected. In this paper, the fire control and fire extinguishing action of water mist is analyzed when the water mist is applied in the preheating zone of materials facing to the fire spread. The transformation of water mist on the flame from fire control to fire extinguishing is theoretically analyzed. The theoretical model of critical water mist application and the factors influencing the critical water mist application are obtained. Under the simulated real conditions in the standard combustion chamber, the combustion inhibition effect of water mist on the wall material in confined space is tested. The critical water exertion rate of water mist applied in the flame preheating zone from fire control to fire extinguishing is obtained. In this paper, the method of calculating the application rate of critical water is introduced theoretically, and the calculation is carried out according to the experimental conditions, and the application rate of critical water is obtained. The influence of water mist applied in different positions on the fire development of wall materials was studied in the standard combustion chamber. The water mist was applied in the preheating zone and pyrolytic zone of plywood under different injection conditions. Heat release rate and CO concentration and temperature of wall decoration materials. The effect of water mist on vertical fire propagation in the preheating zone and pyrolysis zone of plywood was analyzed. Due to the effect of fire resistance, it is necessary to have enough initial velocity to reach the wall when the particle size reaches the flame surface. Therefore, the influence of particle size and initial velocity on the droplet movement in the air is theoretically analyzed in this paper. The limit distances of droplets with different sizes and initial velocities are obtained, and the relationship between the particle size change and the time and running distance of droplets passing horizontally through the flame zone is analyzed. According to the relationship between the particle size and the velocity of water mist, the fire extinguishing action of water mist can be divided into gaseous fire extinguishing and surface fire extinguishing. The difference between the horizontal direction of water mist acting on the flame and the vertical direction of the water mist acting on the flame zone is analyzed theoretically, and it is pointed out that when the horizontal direction of the water mist acts on the wall fire, the fire extinguishing action is mainly surface phase. A comparative experiment was carried out in the standard combustion chamber, and the theoretical analysis results were verified. The fire propagation inhibition effect of water mist on polyurethane soft sponge was studied, and the factors influencing the minimum application rate of water mist were analyzed. The minimum water application rate of 2cm thick polyurethane soft sponge for fire extinguishing was obtained.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2008
【分类号】：TU892
【引证文献】
相关期刊论文 前1条
1 周勇;张和平;杨健鹏;万玉田;李立明;梅鹏;黄冬梅;;作用于杉木板预热区的侧向水喷雾临界水施加率试验研究[J];安全与环境学报;2011年01期
，本文编号：2163045
本文链接：https://www.wllwen.com/wenyilunwen/shinazhuanghuangshejilunwen/2163045.html
