隧道L型斜井施工期通风系统配置优化

Optimization of Ventilation System Configuration during the Construction of L-Shaped Inclined Shafts of Tunnels

针对隧道L型斜井的施工期通风问题,以某隧道为依托工程,采用数值模拟软件对L型斜井隧道进行模拟,分析不同风机组合下的通风效果,并对L型斜井进行通风优化。研究结果表明,施工期通风系统初选需风量为3491m^(3)/min,风压为5230Pa,考虑到斜井线型为L型,对三种满足初选要求的方案进行比选,模拟发现2×160kw风机的通风效果较好,但出口断面处CO的平均浓度为4.072×10^(-5)m^(3)/min,仍不符合规范。在此基础上进行优化,在转角处设置1台75kw的局扇,优化后出口断面CO的平均浓度为3.25×10^(-12)kg/m^(3),满足规范要求,建议该工程选用2×160kw(风机)+1×75kw(局扇)通风方案进行斜井通风。研究成果可为类似工程施工期通风方案的确定提供参考。

Aiming at the ventilation problem of tunnel L-shaped inclined shaft during the construction period,a tunnel is taken as the support project,and numerical simulation software is adopted to simulate the tunnel with L-shaped inclined shaft,to analyse the ventilation effect under different combinations of fans and to optimize the ventilation of L-shaped inclined shaft.The results of the study show that the initial selection of the ventilation system during the construction period requires an air volume of 3491m^(3)/min and an air pressure of 5230Pa.Considering that the line shape of the inclined shaft is L-type,three schemes that satisfy the initial selection requirements are compared,and the simulation reveals that the ventilation effect of the 2×160kw fan is better,but the average concentration of CO at the exit section is 4.072×10^(-5) m^(3)/min,which is still out of compliance with the specification.On this basis,optimization is carried out,and 1 set of 75kw local fan is set at the corner,and the average concentration of CO at the exit section after optimization is 3.25×10^(-12) kg/m^(3),which meets the specification requirements,and it is recommended that 2×160kw(fan)+1×75kw(local fan)ventilation scheme should be selected for inclined shaft ventilation in this project.The research results can provide reference for the determination of ventilation programme during the construction period of similar projects.