风口非对称布置排烟隧道耦合烟控参数CFD寻优分析

CFD Optimization on Coupling Smoke Control Parameters in Tunnel with Non-symmetry-laid Damper

以上海某长大越江公路隧道为背景,针对三个大尺度风口非对称布置在火源两侧的特殊情况,借助经模型实验验证的CFD模拟,详细分析多种纵向风速、排烟量组合下,风口风量分配、排烟温度、烟气水平扩散距离等物理量的变化。进一步提出热烟气水平扩散不超过火源附近3个风口范围以及排烟量最小的排烟优化设计思路。借助CFD模拟通过反复计算比较,得到不同火灾热释放速率、隧道坡度、坡向变化下优化耦合烟控参数,并将优化结果整理得到适用于工程应用的无量纲准则关联式。

With respect to three vents located on both sides of the fire source in an asymmetrical arrangement, series of CFD simulations and reduced-scale experimental tests are carried out. And further analysis is undertaken for several parameters, such as airflow distribution, flue gas temperature and smoke horizontal diffusion distance etc, with different combinations of the longitudinal velocity and exhaust rate. It is found that horizontal diffusion distance of smoke is confined in three vents bordering the fire source and optimization design with minimal exhaust rate is further proposed. With multiple CFD simulations, series of dimensionless correlations are recommended for further tunnel fire safety design with some parameters, such as heat release rate, tunnel inclination and optimized parameters with slope variation.