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基于CESE方法的煤矿风井泄爆全过程模拟与消波增效研究

Numerical simulation on explosion venting processes and venting enhancement methods of the coal mine air shaft based on CESE method

  • 摘要: 为揭示煤矿风井泄爆过程、探寻增强泄爆效果方法,针对现行泄爆方法和多种改进泄爆方法,建立了系列全尺寸三维仿真模型,利用LS−DYNA软件的CESE求解器,进行了全过程流固耦合模拟分析。结果表明:现行防爆门在泄爆过程中会引发较强烈的反射冲击波且不能快速有效地予以消弱,致使风硐中先后出现可对风机造成二次冲击的2道冲击波;去除防爆门立壁结构对提升泄爆效果作用不明显,但可使防爆门受到的冲击明显减弱;在一定范围内,减轻防爆门质量对提高泄爆效果的作用较为有限,且会使防爆门吸收的爆炸能量明显增加;在增量不大的情况下,增大防爆门到风井和风硐交岔点的距离即能有效改善泄爆效果;侧向和正向先行泄爆方法均能明显增强泄爆效果,并对防爆门有显著的减冲和保护作用,在算例条件下,最优可使反射波超压峰值下降49.4%和28.3%;防爆门开启时间、泄爆面积和防爆门到风井/风硐交岔点的距离是影响泄爆效果的重要因素;风井达到良好泄爆效果所需要的开启时间比现行防爆门要短得多;仅在井口设置防爆门存在不能消减风硐中第1道冲击波超压峰值的局限性。基于对风井泄爆过程、机理和方法的新认识,提出了以“两区域多通道”泄爆为特征的主辅防爆门协同泄爆方法,以系统提升风井泄爆效果和防爆水平。

     

    Abstract: In order to disclose the explosion venting processes of the air shaft and explore the venting enhancement methods in coal mines, a series of full-size 3D simulation models had been established for the current and several improved explosion venting methods, and the whole process of fluid- solid coupling simulations analysis was carried out using the CESE solver of LS−DYNA software. The results shown that, the current explosion-proof door will cause strong reflected shock wave and cannot be quickly and effectively attenuated during the explosion venting process, resulting in the emergence of two shock waves in the air tunnel that can cause secondary impacts on the air turbine. Removing the explosion-proof door wall structure to enhance the effect of explosion venting was not obvious, but can make the explosion-proof door to the impact of a significant decrease. Within a feasible range, reducing the mass of the explosion-proof door to improve the effect of explosion venting was more limited, and will make the explosion-proof door absorbed by the explosion energy increased significantly. In small increments, increasing the distance from the explosion-proof door to the intersection of the air shaft and air tunnel can improve the effectiveness of explosion venting. Both lateral and forward advance explosion venting methods can significantly enhance the venting effect, and there was a significant shock absorption and protection for explosion-proof door. Optimized to reduce reflected wave overpressure peak by 49.4% and 28.3% under arithmetic conditions. The opening time of the explosion-proof door, the area of explosion venting and the distance from the explosion-proof door to the intersection of the air shaft and air tunnel were key factors in the effectiveness of explosion venting. The opening time required to achieve a favorable explosion venting effect in the air shaft was much shorter than that of the current explosion-proof door. The limitations of setting explosion-proof door only at the shaft entrance cannot reduce the overpressure peak of the first shockwave in the air tunnel. Based on the new understanding of the explosion venting process, mechanism and method of air shaft, a coordinated explosion venting method of main and auxiliary explosion-proof doors characterized by “two-area multi-channel” was proposed to systematically improve the venting effect and the explosion-proof level of air shaft.

     

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