放顶煤综采采空区“三带”的理论计算与观测分析

The Theoretical Calculation and Observation Analysis of the "three Zones "in the Goaf of Fully Mechanized Face with Top Coal Drawing

本文应用非线性渗流理论建立采空区流场二维平面非线性渗流流函数微分方程,利用有限元技术求得各结点上的流函数值和各单元上的流速v_x、v_y、v_o在此基础上,得到采空区风流流线和等速线。依据煤自燃所对应的风速上下限,得到放顶煤综采采空区不自燃带、可能自燃带和窒息带的形态和范围。对采空区矿压显现、采空区温度变化及氧浓度变化进行的观测表明,理论计算与实际观测所得结果基本一致。

Applying the theory of nonlinear infiltration this paper has established the flow function equation of the nonlinear infiltration for two dimension plane goaf. The flow function value at each joint and the flow velocity vx, vy, v in each element have been evaluated by finite element, and the air flow line and isolach in the goaf can thus be obtained. According to the upper and lower limits of the air velocity corresponding to coal spontaneous combustion, the state and extent of the nonspontaneous combustion zone, the possible spontaneous combustion zone and the suffocative zone in the goaf of the fully mecha-nized face with top coal drawing have been determinated. The observation analysis of pressure manifestation, temperature variation and concentration variation of oxygen in the goaf show that the results of theoretical calculation is consistent with that of practice.