旁侧分支风阻对瓦斯风压引起风流逆转的影响

Effect of Parallel Branch Wind Resistance on Methane Draft Pressure Caused Airflow Reversion

高浓度瓦斯积聚在煤矿倾斜巷道会形成瓦斯风压,瓦斯风压可能导致上行通风巷道并联旁侧分支风流逆转.通过构建实验系统、进行物理实验,研究旁侧分支风阻的变化对逆转过程的影响.实验中,通过蝶阀控制旁侧分支的风阻,得到了旁侧分支不同风阻的5组实验数据.从实验结果中可以看出,旁侧分支风阻的增大会减小旁侧分支风速的变化范围及瓦斯排出的速率,但不影响瓦斯流入旁侧分支的速率.推导了旁侧分支风量变化范围和巷道风阻之间的关系式,该关系式考虑了旁侧分支风阻对风压分配及风流阻力变化的影响,并且与实验数据较为符合.对该关系式分析可以得出结论：随着旁侧分支风阻的增大,其风量范围的变化幅度减小.

High concentrations of methane accumulation in coalmine tilted roadway can form methane draft pressure. The methane draft pressure may cause airflow reversion in the parallel branch.This paper studied the effect of the parallel branch wind resistance on airflow reversion process through a self-built experimental system. The wind resistance of the parallel branch was controlled by a butterfly valve for 5 groups of experiments. The experimental results show that the variation in wind resistance will narrow the scope of wind speed in parallel branch and decrease the rate of the oxygen concentration recovery,but not affect the rate of oxygen concentration decline. The relationship between wind speed scope and wind resistance of each roadway is derived. The derivation considered the effect of parallel branch wind resistance on ventilation pressure distribution and the resistance of the airflow variety. The derived relationship is much in agrees well with the experimental data. The relationship between wind speed scope and wind resistance of each roadway indicates that an increase in wind resistance of the parallel branch will reduce the variation rate of volume flow scope in parallel branch.