水电站地下厂房钻爆施工工作面粉尘运移模拟

水电站地下厂房钻爆开挖过程中的通风问题严重影响着施工效率和施工安全。针对地下厂房结构复杂以及各洞室相互贯通而导致的通风排尘困难问题,本文采用三维非稳态欧拉两相流紊流模型,在动量方程和紊流模型中考虑了气固间相互作用力的影响。针对某水电站地下主厂房二层双头掘进钻爆施工通风过程,分析厂房内风流结构和粉尘运移规律,并揭示了不同时刻下的粉尘分布变化。结果表明:两工作面附近风流分布趋势相似,均形成阻碍粉尘扩散的涡流区;通风排尘效果明显,施工通风1300 s左右,主厂房二层内粉尘浓度达到安全标准,粉尘浓度曲线峰值不断向出口迁移,且随时间增加呈递减趋势。

Simulation of dust migration at working faces during drill-blasting construction of underground hydropower houses

Ventilation during construction of underground hydropower houses has serious effects on construction efficiency and safety. This paper describes a 3D unsteady Euler two-phase turbulence model considering the effect of gas-solid interaction force, aiming at difficulties in dust discharge caused by complex structure with inter-connected tunnels. We have applied this model in a case study of the ventilation in drill-blasting construction for an underground hydropower house in China and analyzed the airflow structure and dust migration. The analysis reveals a relationship of dust distribution versus ventilation time and an eddy zone that forms near the working face and hinders dust discharge. A comparison of two different working faces shows similar airflow structures near them. For the ventilation scheme studied, dust concentration in the main powerhouse is significantly reduced with a longer ventilating operation, and it can meet the safety standard if ventilating operation takes roughly 1300s. The peak of dust concentration migrates continuously toward the tunnel outlet and its amplitude decreases with time.