长隧洞施工有毒有害气体迁移规律研究

Study on migration law of poisonous and harmful gas during long tunnel construction

目前在建抽蓄电站长隧洞的施工大多以爆破为主要开挖手段,爆破后产生的有毒有害气体给施工环境带来了较大的影响。基于大涡模拟(LES)数值方法,建立了施工长隧洞空气流动及不同气体组分输运的数值仿真模型,针对在建的安徽金寨抽蓄电站施工隧洞爆破后有毒有害气体迁移规律进行仿真计算。通过现场实测数据对数值计算模型可靠性进行了验证,得到了与实际较为吻合的气体浓度迁移变化规律。在此基础上,进一步模拟了不同通风速度和不同掘进深度下的有毒有害气体运移规律,预测了气体停留时间。研究成果对抽蓄电站地下施工隧洞通风设计和安全施工具有指导意义。

At present,blasting is the main excavation method in the construction of underground tunnels of building pumped storage stations.The toxic and harmful gases produced by blasting has great impact on the construction environment.Based on the large eddy simulation(LES),taking the Jinzhai pumped storage power station in Anhui Province as a case,a numerical model for air flow and transport of different gas components in underground powerhouse was established in this paper.The reliability of the numerical model was verified by the measured data,and the law of gas concentration migration was obtained.On this basis,the migration laws of toxic and harmful gases under different ventilation conditions and mining depths were further simulated,and the gas residence time was predicted.This study is of guiding significance for ventilation design and safety construction of underground tunnels in pumped storage power station.