综掘工作面双径向旋流屏蔽通风控尘机理

Dust control mechanism of double radial swirl shielding ventilation in fully mechanized heading face

  • 摘要: 双径向旋流屏蔽通风是综掘工作面一种新型的通风控尘方式。为了获得该新型通风方式的控尘机理,以广西百色百矿集团某煤矿综掘工作面为原型,建立了综掘工作面双径向旋流屏蔽通风数值仿真模型。基于Fluent软件,采用 Realizable k-ε湍流模型和DPM离散相模型相结合,对该种通风方式下的综掘工作面风流流场和粉尘质量浓度分布进行了数值仿真。结果表明:双径向旋流屏蔽通风可在工作面形成2道旋转风幕,即掘进机司机前方的1号风幕与转载点前方的2号风幕;1号风幕在吸风筒吸风作用下形成具有独特的伞形结构,可将掘进产尘屏蔽在掘进端头有限区域;2号风幕可将转载点处扬尘与掘进机司机区域分隔,保证司机区域不被转载点粉尘污染;综掘工作面双径向旋流屏蔽通风所产生的环形径向旋转射流能在巷道横断面形成稳定旋风,而且整个断面速度分布均匀,相较于传统的附壁风筒通风形成的径向风幕具有更高的强度和粉尘阻隔效率;双径向旋转风幕将综掘工作面的两大主要尘源(掘进机产尘和转载点扬尘)与掘进机司机区域有效隔离,阻止粉尘扩散至司机区域,为掘进司机提供一个良好的作业环境;吹吸流量比是影响该通风方式控尘效果的重要参数,司机处粉尘质量浓度随着吹吸流量比的增大呈现先降低后增大的变化趋势,并在吹吸流量比为1.5时达到最低值。

     

    Abstract: The double radial swirl shield ventilation is a new type of ventilation and dust control method in fully mechanized heading face. In order to obtain the dust control mechanism of this new ventilation method, a numerical simulation model of double radial swirl shielding ventilation for a fully mechanized heading face was established based on a fully mechanized heading face at a coal mine of Guangxi Baise Coal Group. Based on the Fluent software, the Realizable k-ε turbulence model and the DPM (discrete phase model) are combined to simulate the wind flow field and dust concentration distribution of the fully mechanized heading face under this ventilation method. The results show that the double radial swirl shield ventilation can form two rotating air curtains in the fully mechanized heading face, namely the No.1 air curtain in front of the roadheader driver and No.2 air curtain in front of the transfer point. No.1 air curtain has a unique umbrella structure under the suction of the air duct which can shield the heading dust in the limited area of the heading end. No.2 air curtain can separate the dust at the transfer point from the driver's area of the roadheader to ensure that the driver's area is not polluted by the dust of the transfer point. The annular radial rotating jet generated by the double radial swirl shielding ventilation of the fully mechanized heading face can form a stable swirl in the cross section of the heading, and the velocity distribution in the whole section is uniform. Compared with the radial air curtain generated by the traditional wall-mounted ventilation duct, it has higher strength and dust prevention efficiency. The double radial swirl shielding air curtain can effectively isolate the two main dust sources (dust produced by the roadheader and the dust from the transfer point) of the fully mechanized heading face from the driver's area of the roadheader, preventing the dust from spreading to the driver's area, providing a good working environment. The blowing and suction volume ratio is an important parameter that effects the dust control effect of the ventilation mode. Dust concentration at the driver's position decreases first and then increase with the increase of the blowing and suction volume ratio, and reaches the lowest value when the blowing and suction volume ratio is 1.5.

     

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