摘要
旋转射流屏蔽通风是应用于机掘工作面中的一种新型通风方式。在理论分析的基础上,利用计算流体力学软件Fluent对这种通风方式下机掘工作面风流流场和有害物控制情况进行了数值模拟。结果表明:旋转射流屏蔽通风能在机掘工作面前方形成一旋转风幕,将掘进产生的粉尘阻隔在旋转风幕和掘进端头之间的有限空间内,并在吸口吸气流的作用下将其排出;在旋风流场和抽风筒吸气流的共同作用下,集尘-除尘装置风口前方巷道中心吸风口部位压力较周围压力低,从而使气流向抽风筒汇集,大大提高了吸风口的抽吸效果;旋转射流作用下的吸气流动轴线速度衰减较普通抽吸缓慢,提高了控制粉尘的能力,有利于远距离粉尘的捕集;旋转射流在巷道横断面上形成稳定旋风,使得工作面的粉尘和瓦斯被卷吸到巷道中心,并在巷道中心横向风共同作用下将粉尘和瓦斯带到吸风口附近,有利于吸气风筒对粉尘和瓦斯的捕集。
The paper aims to present the results of our numerical study of the efflux features of the rotational efflux shield ventilation at the tunneling workface. As is known, the rotational efflux shield ven- tilation is a brand-new ventilation device applied in tunneling work face. Based on the theoretical analysis, we have adopted the CFD software-fluent to simulate the airflow situation and the distribution of deleterious substances at the tunneling workface in the condition of el- flux shield ventilation, which helps to reveal the working mechanism of the given-type ventilation while trying to provide more reliable the- oretical basis for popularization of the new technique. The results of our simulation prove that： It can form a rotary air curtain in the front of tunneling work face under the new-type ventilation. The dust brought about by the tunnel-boring machiny can be acreened in a lim- ited space between the air curtain and head-face, which is expected to get drained by the exhaust airflow of suction head. In accordance with the combined action of the rotational ettlux and the exhaust emis- slon, it can be found that the central pressure of the roadway in the front of the dust-collecting and cleaning device should be lower than any other regions, and, therefore, it is necessary to enhance the air- flow converges at the suction mouth and the suction power. The suc- tion-airflow under the rotation jet attenuates tardily, which greatly im- proves the control of dust and can realize long-distance trapping dust. Under the action of rotational efflux, it would be possible to form a stable rotational efflux at the vertical section of the roadway. At the same time, the gas and dust can be entrained to the central area of the roadway by means of the rotational airflow and taken to the suction mouth by the crossflow, which is favorable for trapping the dust and gas away. Besides, the rotational effux shield ventilation is highly promising for its brilliant application prospect in dust prevention and security ensurence at the tunneling workface. Thus, it can be concluded that the results of our numerical study are of a great value for theoretical selection and optimization of the tunneling ventilation parameters.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第6期198-203,共6页
Journal of Safety and Environment
基金
国家自然科学基金项目(50974060)
关键词
安全工程
机掘工作面
旋转射流
流场
safety engineering
tunneling working face
rotation jet
airflow field
