旋转径向射流驱散积聚瓦斯的理论分析

Theory Analysis of Rotary Radial Jet Eliminating Local Gas Accumulation

应用混合长度理论,阐述了风流的横向和纵向脉动速度是影响风流横向瓦斯传质速度的主要因素,分析了旋转径向射流可大大地提高了巷道整个断面风流中各处横向和纵向脉动速度,强化风流横向的瓦斯传质,有效驱散局部积聚瓦斯.通过理论分析和实际观测发现,旋转径向射流排放工作面上隅角积聚瓦斯具有3种效应:周期性的不断稀释、驱散并排向巷道主风流、逐转排放工作面上隅角积聚瓦斯的柔性排放效应和瓦斯浓度分布迅速均匀化.试验表明,旋转径向射流可安全、可靠、经济、有效的排放上隅角积聚瓦斯.

By applying the mixed-length theories, it was discussed that the main factors influencing on cross-gas migration mass-transferring velocity are the cross-and longitudinal pulsing velocity of airflow in tunnel. It was also analyzed that rotary radial jet can greatly enhance the cross-and longitudinal pulsing velocity of airflow in every place of whole cross section of tunnel, intensify cross-gas migration mass-transferring, effectively eliminate the local gas accumulation. On the basis of theoretical analysis and practical observation, it is indicated that by means of rotary radial jet to discharge gas accumulating in upper corner of coalface there are three kinds of effects, that is, gas periodically diluted; gas dispelled and discharged into main airflow in tunnel; the gentle discharging effect of rotary radial jet discharging gas accumulating in upper corner of coalface and the effect of methane concentration even distributing rapidly in airflow. It has been proved by the field experiment that the method of rotary radial jet discharging gas accumulating in upper corner of coalface is really safety, dependable, economical and validly.