压入式掘进巷道风流粉尘运移规律及最佳压风量研究

Dust Transportation Law and Optimal Pressure Air Volume of Driving Roadway under Press-in Ventilation

掌握巷道内风流场局部特征和粉尘运移规律是解决巷道粉尘严重污染问题的理论前提。本文运用数值模拟与现场实测相结合的方法,利用FLUENT数值模拟软件对掘进巷道单压入式通风条件下的风流流场分布及粉尘运移规律进行了研究,并通过改变压风量得到了通风控尘效果最佳压风量;最后,通过现场实测验证了模拟结果的准确性。结果表明:掘进巷道在单压入式通风条件下,风流场可分为射流区、涡流区、回流区3个区域,其中风流速度变化在流场中主要呈现为射流区风速衰减较快,涡流区风速较小,回流区风速衰减较慢;粉尘运移过程中受风流影响较大,回流侧的粉尘质量浓度高于风筒侧,质量浓度超过350 mg/m^(3)的粉尘主要集中在掘进机前方、涡流区域及回流侧;提高风筒压风量在一定程度上可以提高通风控尘的效果,但压风量过大会造成巷道内二次扬尘,当压风量为1400 m^(3)/min时,控尘效果最佳。

The local characteristics of the air flow field and dust transportation law could be the theoretical premise to solve the serious dust pollution in the roadway.In this paper,by numerical simulation by FLUENT and on-site measurements,we studied the distribution of the air flow field and dust transportation law under the single press-in ventilation in the roadway and obtained the best pressure air volume for the ventilation and dust control by changing the air volume.Finally,the simulation accuracy was verified by on-site measurement.The results show that,under the single press-in ventilation,the air flow field could be divided into three parts:jet zone,vortex zone,and backflow zone.The wind velocity attenuation is quick in the jet zone,the wind velocity is smaller in the vortex zone,and the wind velocity attenuation is slow in the backflow zone.Dust is mainly affected by the air flow during transportation,and the dust mass concentration on the backflow side is higher than that on the ventiduct side.The dust with mass concentration of more than 350 mg/m^(3) is mainly concentrated in the front of the tunnel boring machine,the vortex zone,and the backflow side.Increasing the pressure air volume of the ventiduct can improve the ventilation and dust control to a certain extent but large pressure air volume could cause secondary dust in the tunnel.The dust control effect is best when the air volume is 1400 m^(3)/min.