深井低孔隙率煤层混合式注水模拟及应用

Simulation and Application of Hybrid Water Injection Process for Low Porosity Coal Seams in Deep Mines

为实现滕东生建煤矿大采深、低孔隙率条件下的煤层有效注水,进而降低采煤工作面粉尘浓度,首先,基于统一的非饱和-饱和流动的连续方程和应力平衡微分方程,从定性角度分析了煤层注水渗流过程的内在规律;其次,结合矿井实际地质情况和上述的煤层注水渗流方程,利用COMSOL Multiphysics软件模拟了长度为50 m与80 m钻孔的注水渗流压力场分布;然后,结合数值模拟结论,选择80 m长度的钻孔与相应的动静压混合式注水技术参数,并在3下105工作面进行实际施工应用。在实施注水工艺后,现场监测的工作面全尘平均降尘率为65.9%,呼尘平均降尘率为60.6%,有效地降低了粉尘浓度。所得研究结论可为相似煤矿煤层注水工艺的实施提供借鉴。

In order to realize the efficient water injection to coal seam with large mining depth, low porosity in Tengdong Shengjian Coal mine, and reduce the dust concentration in coal mining face, the internal law of the coal seam water injection and seepage process was qualitatively analyzed based on a unified unsaturated-saturated flow continuity equation and stress e- quilibrium differential equations ; Secondly, with the mine actual geological conditions and the mine coal seam seepage equation above, the seepage pressure distribution of borehole at 50 m and 80 m was simulated by using COMSOL Muhiphysics software. Then, combined with the conclusion from numerical simulation,80 m of borehole and the related mixed hydrostatic water injec- tion technical parameters were chosen, and applied into 3 lower 105 working face. Finally, after the implementation of water in- jection,and through the field monitoring,average dustfall rate of total dust at working face was 65.96% ,and average dusffall i . rate of respirable dust was 60.6%. It effectively reduced dust concentration at working face. The research provides references for implementing the coal seam water injection in similar coal mines.