旋转环形射流对上隅角积聚瓦斯的作用机理

Action mechanism of rotary-jet pulse ventilation on the upper corner's gas accumulation in U-shaped working face

在简要分析环形射流基本特性的基础上 ,推导出环形射流完全发展区的速度分布计算公式和卷吸含瓦斯流的沿程平均瓦斯浓度分布计算公式 ,分析了环形环绕射流横穿巷道主风流时的弯曲变形及驱散上隅角积聚瓦斯的过程 ,论述了旋转频率及环形射流与圆形射流有效出射面积比对射流的射程及弯曲变形的影响 .现场试验验证了环绕射流的卷吸和风速脉动特性具有柔性排放效应 ,可有效、安全地驱散上隅角积聚瓦斯 .

Based on the basic characteristics of annular jet analyzed briefly, the velocity and the average methane concentration distribution formula of annular jet which draws flow contained in gas have been deduced in the fully developed field. When annular rotary jet injects across the main flow, its curved shape and the process of dispersing the upper corners gas accumulation of U shaped working face are analyzed. The influence of rotary frequency and the outlet area ratio of annular jet and circular jet on shooting range and curving degree is expounded. Through field experiment, it has been proved that the drawing airflow and the pulsing velocity characteristics of rotary jet can produce the gentle discharging effect which disperses the upper corners gas accumulation effectively and safely.