大断面模拟掘进巷道通风除尘系统数值分析

    Numerical Analysis of Ventilation System in Large Section Simulation Tunneling Roadway

    • 摘要: 为研究大断面掘进巷道的通风除尘特点,在某大断面模拟巷道对压入式、抽出式及长压短抽式通风系统进行了实验,测量测点的沿程速度,进而分析大断面掘进巷道在不同通风方式下的风流场特征。用Fluent对各实验模型进行了仿真分析,结果表明实验和仿真结果的趋势一致;且由于掘进面太大,抽出式通风在一般抽风量下难以保证掘进面附近风速高于安全风速范围;而长压短抽式通风系统相对压入式通风系统巷道内涡流区小,除尘效率高;因此针对大断面掘进巷道,长压短抽通风系统被优先推荐使用。在此基础上对原长压短抽通风系统进行了数值优化,发现针对该大断面掘进巷道当压抽比为1.2左右、抽风筒高度为2 m左右、压风筒高度为4 m左右时除尘效果最佳。

       

      Abstract: In order to study the characteristics of dust removal by ventilation in large section tunneling roadway, experiments are carried out in a certain large section tunneling roadway under three different ventilation systems namely forcing, exhausting and mixed ventilation system. The velocity of observation point is obtained in the experiment. Then the wind flow field characteristics of the tunneling roadway with large cross-section under three different ventilation systems are analyzed. The software Fluent is used to simulate the experimental models. The results show that trend of simulated result is consistent with the trend of experimental result; and for tunneling roadway with large cross-section, exhausting system can hardly assure wind velocity near the working face in the required safe range; and compared with forcing system, there are few vortexes in tunnel under mixed ventilation system, and there is obvious air curtain, which means high dust removal efficiency; so mixed ventilation system is highly recommended to be used in tunneling roadway with large cross-section. Then numerical optimization is applied to the suggested mixed ventilation system. When the ratio of pressing air volume to absorption volume is about 1.2 and the height of forcing and exhausting pipe is about 2 m and 4 m respectively, the dust removal effect is better.

       

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