矿山通风巷道风门后的风速分布特性研究

Characteristics of Wind Speed Distribution Behind Air Door in Underground Ventilation Drift

为了提高矿山通风巷道障碍物后风速测量精准性,依据障碍物对风流分布的理论分析,以某矿山含卷帘式风门巷道段为例,采用计算流体力学方法研究了进口风速、风门开合程度和粗糙度对风速分布特性的影响。结果表明,风门后流场存在空腔区及尾流区,与理论分析一致;井巷通风安全规程内风速(1~6 m/s)改变对风速分布无明显影响;风门开合程度减小,空腔区风速波及范围增大;增加粗糙度使巷道内风速减小,风速分布沿巷道方向出现分层;传感器距风门距离大于9H(H为障碍物高度)时,可摆脱空腔区影响,距离大于35H时,测量风速可达到进口风速的90%;传感器距粗糙顶壁的距离大于2R(R为粗糙度)时,测量风速可达标准值约90%。

In order to improve the measurement precision for the wind speed behind the obstacle in the underground ventilation drift,an underground ventilation drift with air curtain was taken for study.Based on the theoretical analysis of obstacles on wind flow distribution,effects of the inlet wind speed,the door opening angle and the roughness on the wind speed distribution characteristics in the drift were explored by using computational fluid dynamics methods.The results show that there is a detachment area and wake area in the air-flow field behind the air door,which is consistent with the theoretical analysis;the range of wind speed variation(1~6 m/s)stipulated in the safety regulations for underground ventilation drift has no obvious effect on the wind speed distribution;as the opening angle of the air door decreases,the wind speed ratio and the detachment area influenced by the wind speed increase;an increase in roughness can reduce the wind speed in the drift,and also can result in the distribution of stratified wind along the direction of the drift;when the distance from the horizontal position of the sensor to the air door is greater than 9H(H is the height of the obstacle),the detachment area won′t bring impact to the sensor,while this distance is greater than 35H,the measured wind speed can reach about 90%of the inlet wind speed;when the distance from the vertical position of the sensor to the rough roof is greater than 2R(R is the roughness),the measured wind speed can reach 90%of the standard value.