U型和Y型通风方式下工作面流场特征及瓦斯浓度分布规律探究

Study on flow field characteristics and gas concentration distribution law of working face under U and Y ventilation modes

保证采煤工作面的安全通风是矿井安全生产的重要保障。不同通风类型下工作面流场形态和瓦斯浓度分布特性不同,为探究采煤工作面不同通风类型下瓦斯浓度分布及流场分布特征,以U型和Y型通风方式为例,运用COMSOL数值分析软件,建立了工作面和采空区瓦斯流动的物理模型,并对两种通风类型下的工作面和采空区流场分布和瓦斯浓度分布规律进行了模拟研究。结果表明:在U型通风条件下,工作面有三个瓦斯易产生积聚的地点,瓦斯浓度达到了1.25%,而Y型通风条件下只存在一个,瓦斯浓度1.20%~1.25%之间;在采空区瓦斯浓度分布方面,U型通风条件下不管是瓦斯积聚区域面积还是瓦斯浓度均大于Y型通风条件;两种通风类型下,流场在工作面都经历的复杂到简单再到复杂的转换过程,Y型通风较于U型通风,采空区瓦斯浓度整体降低,并且在Y型通风条件下,采空区上隅角的流场情况发生改变,可有效解决U型通风条件下,上隅角瓦斯积聚的问题。

Ensuring the safe ventilation of coal working face is an important guarantee for the safe production of mine.The flow field shape and gas concentration distribution characteristics of working face are different under different ventilation types.In order to explore the gas concentration distribution and flow field distribution characteristics under different ventilation types of coal working face,the physical model of gas flow in working face and goaf is established by using COMSOL numerical analysis software,taking U-type and Y-type ventilation modes as examples.The flow field distribution and gas concentration distribution in working face and goaf under two ventilation types are simulated.The results show that under U-type ventilation,there are three places where gas is easy to accumulate,and the gas concentration reaches 1.25%,while under Y-type ventilation,there is only one place,and the gas concentration is between 1.20 and 1.25%.In terms of the distribution of gas concentration in goaf,both the area and concentration of gas accumulation under U-type ventilation are larger than that under Y-type ventilation.Under the two ventilation types,the flow field in the working face goes through a transition process from complex to simple to complex.Compared with U-type ventilation,Y-type ventilation reduces the gas concentration in the goaf overall.Moreover,under Y-type ventilation,the flow field in the upper corner of the goaf changes,which can effectively solve the problem of gas accumulation in the upper corner under U-type ventilation.