地铁隧道通风竖井突发污染物扩散研究

Study on Dispersion of Sudden Pollutants in Ventilation Shaft of Metro Tunnel

本文以带竖井地铁隧道为研究对象,研究列车运行过程中,以面源的形式在风井口持续性释放污染物后,污染物在向隧道内迁移的扩散规律,以及污染物扩散的影响因素问题。本文运用数值模拟的方法,通过用动态网格技术和离散相模型相结合的方式,选取列车运行速度、通风竖井数量及颗粒物的粒径为变量,探究这三个因素对于通风竖井突发污染物的扩散影响。研究发现:隧道内污染物浓度沿列车行驶方向逐渐降低,污染物浓度出现垂直分层状况;风井数量越多颗粒物进入区间隧道的时间越早;亚细微颗粒物(粒径小于10μm)具有良好的跟随性;粒径越大颗粒物受重力作用越明显,颗粒的沉积量就越大。

In this paper,the subway tunnel with vertical ventilation shaft is taken as the research object.The diffusion law of pollutants migrating into the tunnel after the continuous release of pollutants at the ventilation shaft mouth,in the form of surface source during train operation is studied.The factors affecting the diffusion of pollutants are also studied.In this paper,the method of numerical simulation is used,which combines dynamic mesh technology with discrete phase model.The running speed of train,the number of ventilation shafts and the particle size are selected as variables,to explore the influence of these three factors on the diffusion of sudden pollutants in ventilation shafts.The study found that the concentration of pollutants in the tunnel decreases gradually along the direction of train running,and the concentration of pollutants appears vertical stratification.The more the number of ventilation shafts,the earlier the particulate matter enters the interval tunnel.Submicron particles(particle size less than 10μm)have good followability.The larger the particle size,the more obvious the particle is affected by gravity,and the larger the amount of particle deposition.