综掘工作面不同截割路径粉尘运移及分布规律

Dust migration and distribution characteristics under different cutting paths in a fully mechanized excavation face

  • 摘要: 为了探究综掘工作面不同截割路径对粉尘运移及分布规律的影响,以淮北矿业股份有限公司朱仙庄煤矿Ⅱ853综掘工作面为研究对象,利用Fluent软件对综掘工作面4种截割路径的粉尘运移及分布规律进行数值模拟研究。结果表明:① 在长压短抽通风条件下,综掘工作面风流场沿巷道走向分为3个特征区域:0~10 m为紊乱区,10~40 m为过渡区,40~60 m为稳定区;在距工作面10 m范围内的中部区域形成范围小、风速高的局部涡流,在抽风口后方20 m范围内形成范围大、风速低的涡流。② 不同截割路径下粉尘空间分布与时间演化特征差异显著:“先中心、后四周”式截割路径下,粉尘浓度呈“底板高、顶板低”的分布规律,呼吸带高度的粉尘浓度随时间波动小、稳定性好;“自下而上”式截割路径下,粉尘浓度呈“呼吸带最低、底板与顶板基本持平”的分布特征,呼吸带高度的粉尘浓度随时间波动剧烈、稳定性差。③ 截割路径与风流场的匹配程度对距工作面20 m范围内的粉尘浓度及分布影响显著,但随着粉尘颗粒沿巷道向后方运移,风流场逐渐稳定,各截割路径粉尘分布趋于一致。

     

    Abstract: To investigate the effects of different cutting paths on dust migration and distribution in a fully mechanized excavation face, the fully mechanized excavation face II853 of Zhuxianzhuang Coal Mine, Huaibei Mining Co., Ltd., was selected as the study object. Numerical simulations of dust migration and distribution under four cutting paths were conducted using Fluent software. The results showed that: ① under the long-forcing short-exhaust ventilation mode, the airflow field in the fully mechanized excavation face could be divided into three characteristic regions along the roadway: a turbulent region (0–10 m), a transition region (10–40 m), and a stable region (40–60 m). A small-scale, high-velocity local vortex formed in the central area within 10 m of the working face, whereas a large-scale, low-velocity vortex formed within 20 m behind the exhaust outlet. ② Significant differences were observed in the spatial distribution and temporal evolution of dust under different cutting paths. Under the "center-first, periphery-later" cutting path, the dust concentration exhibited a distribution pattern of "higher near the floor and lower near the roof", and the dust concentration at the breathing zone fluctuated slightly over time with good stability. Under the "bottom-up" cutting path, the dust concentration showed a distribution pattern in which the breathing zone had the lowest concentration, while the concentrations near the floor and roof were nearly the same. In addition, the dust concentration at the breathing zone fluctuated markedly over time and exhibited poor stability. ③ The degree of matching between the cutting path and the airflow field significantly affected the dust concentration and distribution within 20 m of the working face. However, as dust particles migrated downstream along the roadway, the airflow field gradually became stable, and the dust distribution under different cutting paths tended to converge.

     

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