当前位置: X-MOL 学术Int. J. Therm. Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Numerical and experimental study on the effects of a ceiling beam on the critical velocity of a tunnel fire based on virtual fire source
International Journal of Thermal Sciences ( IF 4.5 ) Pub Date : 2021-01-01 , DOI: 10.1016/j.ijthermalsci.2020.106635
Xiangliang Tian , Chang Liu , Maohua Zhong

Abstract Ceiling beams, such as smoke screens, supporting beams, and ceiling pipelines, exist in several types of tunnels. The ceiling structure of a tunnel has a significant influence on smoke propagation. This study determines the critical velocity required to control fire smoke in a tunnel with a ceiling beam. We conducted model experiments and numerical simulations to analyze the effects of a ceiling beam on air flow structure and smoke propagation. An air re-circulation length model was fitted to determine whether a fire source lies within the vortex swirling zone. Using a virtual fire source, we obtained the critical velocity prediction model for a tunnel with a ceiling beam. The results indicate that the re-circulation length of the vortex swirling zone is determined by the beam height and tunnel height, but is independent of the longitudinal airflow speed. The form of the critical velocity model for a tunnel with a ceiling beam is consistent with that of conventional models, wherein the dimensionless critical velocity is proportional to the dimensionless heat release rate raised to the power of one-third. This implies that a virtual fire source can be used to determine the critical velocity. The proposed prediction model of the critical velocity for a tunnel with a ceiling beam is an improvement on previous models and can be used in the design of smoke control systems in tunnels with beams.

中文翻译:

基于虚拟火源的吊顶梁对隧道火灾临界速度影响的数值与试验研究

摘要 顶梁,如烟幕、支撑梁和天花板管道,存在于几种类型的隧道中。隧道顶棚结构对烟气传播有显着影响。本研究确定了在带有天花板横梁的隧道中控制火灾烟雾所需的临界速度。我们进行了模型实验和数值模拟,以分析天花板横梁对气流结构和烟雾传播的影响。拟合空气再循环长度模型以确定火源是否位于涡旋涡流区内。使用虚拟火源,我们获得了天花板梁隧道的临界速度预测模型。结果表明,涡旋涡旋区的再循环长度由梁高和隧道高度决定,但与纵向气流速度无关。吊顶梁隧道临界速度模型的形式与常规模型一致,其中无量纲临界速度与无量纲热释放率的三分之一次方成正比。这意味着可以使用虚拟火源来确定临界速度。所提出的吊顶梁隧道临界速度预测模型是对先前模型的改进,可用于吊梁隧道烟气控制系统的设计。其中无量纲临界速度与无量纲热释放率的三分之一次方成正比。这意味着可以使用虚拟火源来确定临界速度。所提出的吊顶梁隧道临界速度预测模型是对先前模型的改进,可用于吊梁隧道烟气控制系统的设计。其中无量纲临界速度与无量纲热释放率的三分之一次方成正比。这意味着可以使用虚拟火源来确定临界速度。所提出的吊顶梁隧道临界速度预测模型是对先前模型的改进,可用于吊梁隧道烟气控制系统的设计。
更新日期:2021-01-01
down
wechat
bug