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根据计算流体动力学(CFD)理论,运用Fluent软件对掘进工作面的风流流场及瓦斯分布进行数值模拟,研究了在断面形状为梯形的掘进巷道中,瓦斯从掘进迎头和巷道两帮均匀涌出时,风筒出口离掘进迎头的距离对掘进巷道中风流流场和瓦斯分布的影响。结果表明:压入式局部通风掘进巷道工作面风流从风筒出口流出后,沿风流方向瓦斯浓度逐渐增大,在靠近迎头处巷道两帮底部和顶部瓦斯浓度较高;随着瓦斯涌出量的增加,由于高浓度瓦斯密度降低而产生的上浮力的作用,在靠近迎头的上部区域发生瓦斯沿顶板逆风流方向流动的现象;上浮力的作用会改变流场的分布状况,在靠近迎头处产生涡流;风筒出口离掘进迎头越近,风流到达迎头时携带的瓦斯量越少,且迎头处的风速越大,靠近迎头区域中的瓦斯浓度越低。
According to computational fluid dynamics (CFD) theory, Fluent software was used to simulate the flow field and gas distribution in the heading face. In the tunnel with trapezoidal cross section, The effect of the distance of the exit of the hair dryer from the heading of heading on the flow field and the distribution of the wind flow in the tunneling roadway was analyzed. The results show that the gas concentration along the airflow direction increases gradually when the airflow in the working face of the partial pressure ventilation roadway flows out from the outlet of the wind tunnel, and the methane concentration at the bottom and top of the two gangways is higher near the heading heading. As the gas emission The phenomenon of gas flowing along the top plate in the direction of reverse wind flow occurs due to the buoyancy force caused by the decrease of the density of high-concentration gas. The effect of the buoyancy force will change the distribution of the flow field, And the eddy current is generated. The closer the exit of the air duct to the heading of heading, the less the amount of gas carried by the wind flow on arrival, and the greater the wind speed at the heading, the lower the gas concentration near the heading area.