不同中庭高宽比对排烟效果影响的模拟研究

发布时间：2018-01-18 05:35

本文关键词：不同中庭高宽比对排烟效果影响的模拟研究　出处：《安徽理工大学》2014年硕士论文　论文类型：学位论文

【摘要】：经济的快速发展带动了复杂高大建筑的发展,中庭建筑由于其创造了宽敞、舒适、明亮的室内环境,保证了许多活动免受外界的影响而受到人们的普遍欢迎。随着我国城市现代化的发展,中庭建筑必将迅猛发展。然而,中庭建筑的蓬勃发展也带来了严峻的火灾形势,据火灾统计显示,近年来许多重大、特大火灾与中庭建筑相关。所以,研究中庭建筑的火灾特点及提出防治措施,已经成为火灾研究的重要课题。本文采用理论分析与模拟分析相结合的方法研究了不同高宽比中庭火灾烟气的流动过程以及在机械排烟与自然排烟下烟气控制效果分析。首先,在大空间建筑火灾发展及烟气蔓延与控制的理论基础上,结合中庭建筑特点,分析了中庭建筑火灾特性、烟气特性、及烟气流动蔓延规律。然后,根据现实生活中常见的中庭样式及相关的行业规范,确定了火灾模拟中的中庭模型,火源特性,火灾荷载及排烟量等火灾场景参数,本文设计了14种不同的火灾模拟场景,并使用FDS仿真模拟工具,建立了不同中庭建筑火灾烟气控制模型。最后,对14种火灾场景的模拟结果进行对比分析。通过分析各中庭模型的能见度、温度、烟气层高度变化情况,得出了下列结论：随着中庭高宽比增加,在相应的机械排烟与自然排烟条件下,中庭的能见度下降速率增大,烟气层高度下降速率也增大,烟气层温度降低,综合分析,烟气控制效果下降；中庭高宽比增加,烟气生成量增加,烟气蔓延范围扩大；自然排烟与机械排烟对各中庭的烟气控制效果差别不大,自然排烟烟气控制效果略好；当中庭高度增加时,自然排烟的烟囱效应会更加明显,自然排烟量增大；在夏季高温时,高大中庭出现热障效应,在排烟初期,会影响自然排烟的排烟效果,随着烟气积累,自然排烟仍能发挥较好的排烟效果。本文的研究结论可为中庭建筑及大空间建筑的防火性能优化设计及建筑火灾烟气控制提供一定的参考和指导。
[Abstract]:The rapid development of economy has led to the development of complex tall buildings, the atrium building has created spacious, comfortable, bright indoor environment. With the development of the city modernization in our country, the atrium building will develop rapidly. The vigorous development of atrium has also brought severe fire situation, according to fire statistics, in recent years, a lot of major fires and atrium buildings related. It has become an important subject in fire research to study the fire characteristics of atrium building and put forward prevention and control measures. In this paper, the flow process of smoke in atrium with different aspect ratio and the effect of smoke control under mechanical and natural smoke exhaust are studied by combining theoretical analysis with simulation analysis. Firstly, on the basis of the theory of fire development and smoke spread and control in large space buildings, combined with the characteristics of atrium building, the fire characteristics, smoke characteristics and smoke flow spreading law of atrium building are analyzed. Then, according to the common atrium style and related industry standards in real life, the fire scene parameters such as atrium model, fire source characteristics, fire load and smoke emission in fire simulation are determined. In this paper, 14 different fire simulation scenarios are designed, and the smoke control models of different atrium buildings are established by using FDS simulation tools. Finally, the simulation results of 14 kinds of fire scenes are compared and analyzed. By analyzing the visibility, temperature and smoke height of each atrium model, the following conclusions are drawn: with the increase of atrium aspect ratio. Under the corresponding conditions of mechanical and natural smoke exhaust, the visibility of atrium increases, the height of smoke layer increases, the temperature of flue gas layer decreases, and the effect of smoke control is decreased by comprehensive analysis. The ratio of height to width of atrium is increased, the amount of flue gas is increased, and the range of smoke spread is enlarged. The effect of natural smoke exhaust and mechanical smoke exhaust on the smoke control of each atrium is not significant, and the natural exhaust smoke control effect is slightly better. When the height of atrium increases, the chimney effect of natural smoke exhaust will be more obvious, and the amount of natural smoke exhaust will increase. In the summer high temperature, the large atrium appeared the thermal barrier effect, in the early stage of smoke exhaust, it will affect the natural smoke exhaust effect. With the accumulation of smoke, the natural smoke exhaust can still play a better effect. The conclusions of this paper can provide some reference and guidance for the optimization design of fire resistance performance of atrium building and large space building and the smoke control of building fire.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU834

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