铁路客运站候车厅病毒飞沫液滴传播研究
Study on virus droplet transmission in waiting halls of railway stations
摘要：
通过研究铁路客运站候车厅内全新风工况下的气流流动,选取存在气流旋涡而不利于旅客咳嗽飞沫液滴传播扩散的6个座位位置,分别对6个位置处患病旅客咳嗽喷出的飞沫液滴在候车厅气流流场中的扩散运动进行了数值模拟计算,并对飞沫液滴的沉积率、沉积液滴粒径分布、沉积速率、回风口逃逸率、沉积耗时、候车厅空气完全净化时间进行了分析。结果表明:患病旅客飞沫液滴中平均73.4%沉积在墙体表面和地面,11.8%从回风口逃逸,14.1%沉积在旅客表面,旅客座位距离、座位长度等直接影响旅客感染病毒的风险;液滴粒径越大,沉积速率越快,沉积率越大,粒径小于30 μm的液滴在高大空间流场中的运动具有一定的一致性,而粒径大于40 μm的液滴在流场中的运动则受重力的影响更多;飞沫液滴的2.5%～23.8%将在60 s内沉积到旅客表面,且60 s内的沉积速率最快,600 s后飞沫液滴悬浮率在1.4%以内的波动并不会大幅改变空气洁净所需时间。
Abstract：
By studying the airflow in the waiting hall of a railway station under full outdoor air condition, six-seat positions with airflow vortex are selected, which are not conducive to the transmission of droplets from the passengers’ cough, and the transmission of droplets from the cough of sick passengers at the six positions in the airflow field of the waiting hall is numerically simulated. The deposition rate of droplets, particle size distribution of deposition droplets, deposition speed, escape rate at air outlets, deposition time and complete air purification time of the waiting hall are analysed. The results show that 73.4% of the droplets from sick passengers are deposited on the surfaces of the wall and ground, 11.8% escaped from the air outlets, and 14.1% deposited on the surface of the passengers. The distance and length of the passenger seats directly affect the risk of passengers infecting virus. The larger the droplet size is, the faster the deposition speed is, and the greater the deposition rate is. The motion of droplets with particle size less than 30 μm in the high-space airflow field has a certain consistency, while the motion of droplets with particle size greater than 40 μm is more affected by gravity. 2.5% to 23.8% of droplets will be deposited on the passenger surface within 60 s, and the deposition speed is the fastest within 60 s. The fluctuation of the droplet suspension rate within 1.4% after 600 s will not greatly change the time required for air cleaning.
Keywords:railway station; waiting hall; droplet; virus; transmission; deposition; particle size