Tian Xiangliang, Ding Xiaoqiang, Xiang Linchuan, Liu Chang, Fu Shigen, Zhong Maohua
Institute of Mine Safety Technology, China Academy of Safety Science and Technology, Beijing, 100012, China.
College of Ocean Science and Engineering, Shanghai Maritime University, Shanghai, 201306, China.
Sci Rep. 2024 Dec 5;14(1):30373. doi: 10.1038/s41598-024-82368-w.
Ceiling beams at the top of tunnels are more common in actual projects. Under the influence of thermal buoyancy, the ceiling structure significantly affects the diffusion characteristics of fire smoke within the tunnel. This study performed several sets of model experiments and numerical simulations to investigate the impact of the height and spacing of ceiling beams on the diffusion of smoke in tunnel fires, which results show that the maximum temperature rise and temperature decay patterns of fire smoke follow exponential changes. The increased height of the ceiling beams and the reduced spacing correspond to higher maximum temperatures on the ceiling. Furthermore, as the height of the ceiling beams increases and the spacing decreases, the longitudinal attenuation of ceiling temperature accelerates within the tunnel. A predictive model for ceiling temperature rise and a dimensionless temperature attenuation model were developed to characterize this phenomenon. The relative error between the predicted results and experimental findings falls within ± 15%. This study broadens the application scope of fire smoke diffusion models, which can provide technical support for smoke prevention and exhaust design of tunnels with similar structures.
隧道顶部的吊顶梁在实际工程中较为常见。在热浮力的影响下，吊顶结构对隧道内火灾烟气的扩散特性有显著影响。本研究进行了多组模型试验和数值模拟，以研究吊顶梁的高度和间距对隧道火灾中烟气扩散的影响，结果表明火灾烟气的最大温升和温度衰减模式呈指数变化。吊顶梁高度增加和间距减小对应于吊顶上更高的最高温度。此外，随着吊顶梁高度增加和间距减小，隧道内吊顶温度的纵向衰减加快。建立了吊顶温度升高预测模型和无量纲温度衰减模型来表征这一现象。预测结果与实验结果之间的相对误差在±15%以内。本研究拓宽了火灾烟气扩散模型的应用范围，可为类似结构隧道的防排烟设计提供技术支持。
