集中排烟模式下隧道烟气层吸穿现象研究

发布时间：2018-07-01 16:48

本文选题：隧道 + 集中排烟　；参考：《中南大学》2014年硕士论文

【摘要】：摘要：集中排烟模式是公路隧道火灾排烟的发展趋势,而排烟系统的有效利用是工程设计的关键。吸穿会降低发生该现象的排烟口的排烟效率,使得排烟系统不能得到充分利用,并可能导致排烟口烟气拥堵,易对疏散救援造成消极影响。针对目前发展迅速的集中排烟模式的公路隧道,现有相关研究并未对集中排烟模式下不同因素对烟气层吸穿的影响如何进行深入研究,不能为其在防止吸穿的发生的工程设计中提供完善的指导,故亟需开展公路隧道集中排烟模式下吸穿现象的研究。本文首先通过数值模拟和实验定量研究了隧道集中排烟模式下不同排烟速率、排烟口个数及间距与烟气层厚度、温度以及蔓延范围的规律,揭示了集中排烟隧道中排烟口发生烟气层吸穿现象时的烟气层特性。通过引入弗洛德数,从模拟及实验所测得的烟气温度及烟气层厚度入手,提出了适用于集中排烟隧道的防止吸穿发生的临界排烟速率公式及临界弗洛德数。本文还通过观察不同排烟速率下烟气层温度变化规律,引入烟气平均温度,将烟气温度及烟气层厚度无量纲化,建立了烟气层竖向温度分布公式,结合烟气平均温度在隧道纵向的分布规律,完善了集中排烟隧道下纵截面的烟气温度计算公式。本文研究了公路隧道集中排烟模式下的吸穿现象,为我国集中排烟隧道防止吸穿发生的排烟量设计的规范制订、排烟口间距及个数的选取等提供参考。
[Abstract]:Abstract: the mode of centralized exhaust smoke is the development trend of highway tunnel fire smoke exhaust, and the effective use of smoke exhaust system is the key of engineering design. Inhaling will reduce the efficiency of smoke exhaust, make the exhaust system can not be fully utilized, and may lead to smoke congestion at the exhaust, which will easily have a negative impact on the evacuation and rescue. In view of the highway tunnel with the rapid development of centralized smoke exhaust mode, the existing relevant studies have not deeply studied the influence of different factors on smoke layer penetration under the centralized smoke exhaust mode. It can not provide perfect guidance in the engineering design of prevention of sucking through, so it is urgent to carry out the research on the phenomenon of sucking in highway tunnel under the mode of centralized exhaust smoke. In this paper, the numerical simulation and experimental results are used to study the different exhaust rates, the number and spacing of exhaust outlets, the thickness of flue gas layer, the temperature and the spread range. The characteristics of flue gas layer when smoke layer penetrates in the flue gas outlet in the centralized exhaust tunnel are revealed. Starting with the smoke temperature and the thickness of flue gas layer measured by simulation and experiment, a formula of critical smoke exhaust rate and critical Froude number, which is suitable for the tunnel with concentrated exhaust smoke, is put forward by introducing Frod number. The vertical temperature distribution formula of flue gas layer is established by observing the variation law of flue gas layer temperature under different exhaust rates, introducing the average flue gas temperature, and dimensionless the flue gas temperature and thickness of flue gas layer. Based on the distribution of the average flue gas temperature in the longitudinal section of the tunnel, the formula for calculating the flue gas temperature in the longitudinal section of the centralized exhaust tunnel is improved. In this paper, the phenomenon of entrainment under the mode of centralized exhaust smoke in highway tunnel is studied, which provides a reference for the design of exhaust quantity in the centralized exhaust tunnel of our country, and the selection of the distance and the number of exhaust outlets.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U458;U453.5

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