引水隧洞独头掘进工作面风流和粉尘扩散的模拟

Simulation on ventilation and dust diffusion on heading face of the diversion tunnel

本文结合改进的高雷诺k-ε紊流模型及响应函数,建立独头引水隧洞风流和粉尘扩散的三维非稳态欧拉两相流模型,在动量方程中考虑了曳力、虚拟质量力、升力的作用;模拟云南南汀河新塘房水电站引水隧洞独头掘进工作面爆破通风过程,分析隧洞内的风流结构分布,研究涡流、壁面粗糙度对粉尘扩散的影响,揭示壁面粉尘浓度随通风时间的变化关系。结果表明,在压入式通风情况下,独头掘进工作面附近存在涡流分布;粉尘浓度从涡流中心向周围空间逐渐降低;与光滑壁面相比,粗糙壁面对粉尘滞留作用大。与Nakayama通风模型试验进行了对比,模拟结果与实验测定结果基本吻合。

A three-dimensional transient Eulerian model of two-phase flow is set up to simulate the velocity fields and dust diffusion on heading face of diversion tunnel. The momentum equation includes the drag, virtual mass and lift forces. The ventilation is modeled based on the modified high Reynolds number k-ε equations and response function. Heading face of the diversion tunnel of Xin Tangfang power station on Nanting River is used as a case. The flow framework of forced ventilation on heading face is analyzed. The effect of eddies and wall roughness on dust diffusion is studied. The concentration distribution of dust on the wall varying with time is revealed. According to the result of numerical simulation, several vortexes are distributed nearby the Jheading face of the diversion tunnel under condition of forced ventilation. The concentration of dust gradually decreases from vortex center to surrounding space. Compared with smooth wall, rough wall has great influence on dust detention. The result o（ numerical simulation agrees with that of experiment by Shinsuke Nakayama ventilation model.