In order to solve the problems of large amounts of pollutants, low efficiency of air replacement and serious local concentration of harmful gases in the working space of extra-long railway tunnel, this paper proposed a relay ventilation system for long air cabin of extra-long railway tunnel. Through the analysis of on-site monitoring data and full-size numerical simulation, this paper deeply studies the dynamic transport characteristics of pollutants under the conditions of the relay ventilation system with long air-cabin, reveals the transport characteristics of pollutants such as CO and dust and the blocking effect of lining trolly on dust diffusion. The results indicate that the stability of the airflow field is affected by the longitudinal return air velocity of the tunnel, and the fluctuation range of the airflow field is relatively large within the range of 0.5 m/s ∼ 0.7 m/s, which is not conducive to the discharge of pollutants. In the case of single tunnel and double tunnel tunneling, continuous ventilation for 900 s can meet the requirement of CO allowable concentration in the 200-meter range of the tunnel face; trolley has significant blocking effect on the diffusion of blasting dust. The overall dust reduction rate of the second lining trolley area is about 42 % lower than that of the trolley-free construction area, and the peak dust concentration is increased by 37 %. Compared with the trolley operation section, the dust reduction efficiency of the trolley-free operation section is improved by about 2.5 times.

中文翻译：

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用于超长铁路隧道的长气室接力通风系统：爆破后污染物输送特性的案例研究


为解决超长铁路隧道工作空间污染物量大、换气效率低、有害气体局部集中严重等问题，本文提出了一种超长铁路隧道长风舱接力通风系统。本文通过对现场监测数据的分析和全尺寸数值模拟，深入研究了长气室接力通风系统条件下污染物的动态传输特性，揭示了CO、粉尘等污染物的传输特性以及衬车对粉尘扩散的阻挡作用。结果表明：气流场的稳定性受隧道纵向回风速度的影响，在0.5 m/s∼ 0.7 m/s范围内气流场的波动范围相对较大，不利于污染物的排放。在单隧道和双隧道掘进的情况下，连续通风 900 s 即可满足掌子面 200 m 范围内 CO 容许浓度的要求;手推车对喷砂粉尘的扩散有明显的堵塞作用。第二衬砌小车区整体降尘率比无小车施工区低42%左右，峰值粉尘浓度提高37%。与小车操作段相比，无小车操作段的除尘效率提高了约 2.5 倍。