基于FLAC^(3D)的综放工作面巷道布置及风量分配研究

Study on roadway layout and air volume distribution in fully-mechanized caving face based on FLAC^(3D)

为掌握保德煤矿综放工作面瓦斯涌出规律,得到综放工作面通风方式与配风量这2个通风关键因素对采空区遗煤瓦斯涌出的影响规律,针对性地采取瓦斯防治对策,实现矿井安全生产,首先采用FLAC^(3D)数值模拟软件对综放工作面采空区上覆岩层塑性演化规律进行了模拟研究,得出8号煤层顶板的垮落带高度约为20 m,断裂带高度约为80 m。提出了U型通风方式、三进一回偏Y型通风方式和三进一回Y型通风方式,通过建立综放工作面采空区遗煤瓦斯运移CFD稳态计算模型,对三种通风方式下工作面配风量对上隅角瓦斯体积分数、采空区低体积分数瓦斯区域、工作面两端压差、煤层自燃条件和地质条件等因素的差异性进行对比分析,确定了最合理的通风方式及最优配风比,使工作面瓦斯治理工作达到最优化。结果表明:偏Y型通风方式是在治理上隅角瓦斯、工作面供风、除尘、同时防止采空区遗煤自燃的综合条件最佳的通风方式,在采用偏Y型通风时,当进风巷和胶带巷配风比为2.5∶1时,采空区低体积分数瓦斯区域最大,上隅角瓦斯体积分数最低,工作面两端能够维持较大压差,风流稳定,胶带巷进风能顺利带走冲刷过工作面的污风,且工作面通风和除尘效果也最好。

In order to grasp the gas gushing law of the fully mechanized caving face of Baode Coal Mine,especially the influence law of the two key factors of ventilation on the fully mechanized caving face,namely the ventilation mode and the air distribution volume,on the gas gushing of the coal left in the goaf,the gas prevention and control measures are carried out in a targeted manner.Countermeasures to achieve safe production in mines,firstly,the FLAC^(3D)numerical simulation software was used to simulate the plastic evolution law of the overlying rock in the goaf of the fully mechanized caving face,and it was concluded that the height of the caving zone of the No.The height is about 80 m.The U-shaped ventilation mode,the three-in-one-return Y-type ventilation mode,and the three-in-one-return Y-type ventilation mode are proposed.The air distribution of the working face under the mode of comparison and analysis of the differences in factors such as the gas volume fraction in the upper corner,the low volume fraction gas area in the goaf,the pressure difference between the two ends of the working face,the spontaneous combustion conditions of the coal seam and the geological conditions,the most reasonable one is determined.The ventilation mode and the optimal air distribution ratio can optimize the gas control work of the working face.The results show that the partial Y-shaped ventilation method is the best ventilation method for the comprehensive conditions of controlling the gas in the upper corner,supplying air at the working face,removing dust,and preventing the spontaneous combustion of coal left in the goaf.When the air distribution ratio between the wind channel and the belt channel is 2.5:1,the low volume fraction gas area in the goaf is the largest,and the gas volume fraction in the upper corner is the lowest.The two ends of the working face can maintain a large pressure difference,the wind flow is stable,and the tape The trough inlet air can smoothly take away the dirty air that has washed over the working face,and the ventilation and dust removal effects of the working face are also the best.