综放面风量调节范围与安全评价的数值模拟分析

Analysis on Numerical Simulation of Ventilation Control Range and Safety Assessment of Fully Mechanized Long-wall Top Coal Caving Face

结合实际算例 ,用迎风有限元方法 ,从理论上得出了采空区瓦斯绝对涌出量与工作面风量呈指数关系 ,采空区氧化带宽度与工作面风量呈负指数关系。按排放瓦斯要求和工作面生产的供风要求 ,确定风量下限 ,从防止采空区自然发火的角度 ,确定风量的上限 ,由此 ,得出合理的风量范围。引入了范围极差的概念 ,当风量极差越大 ,安全情况越好 ,反之 ,采空区的自然发火与瓦斯涌出二者是不可调和的 ,必须采取防治措施来提高风量极差值。

From the practical calculation examples and by using upwind finite element method, it could be concluded from the theory that the relation between absolute gas emission rate in goaf and the air quantity in working face is exponential; and the relation with the width of oxidizing zone shows negative exponential. The lower limit of air quantity is determined according to the necessity of gas dilution through ventilation and the demand of air supply at working face. The upper limit of air quantity is determined from the point of view of preventing the spontaneous combustion in goaf. Then the rational range of air quantity could be obtained. The concept of range extremity difference is introduced. The bigger the range extremity difference is, the better the safety situation will be. Since the spontaneous combustion is contradictory to gas emission, control measures must be taken to optimize the extremity difference of the air quantity.