放顶煤采空区瓦斯源强度与自燃的关联性

研究了采空区瓦斯涌出与遗留煤自燃之间的内在耦合关联问题。通过运用G3软件对采空区非线性渗流-多组分气体-温度场和非均匀耗氧的数值模型的求解，量化给出采空区不同瓦斯涌出强度下各变量分布状态。计算结果表明：采空区瓦斯源涌出与工作面风压形成压力平衡，决定着工作面与采空区之间的风流交换和瓦斯涌出，影响变化近似呈一一对应的线性关系。瓦斯涌出强度越大，采空区氧浓度分布空间大大缩小，采空区自燃氧化带宽度与瓦斯涌出近似呈衰减变化。从自燃升温过程模拟得到，高强度瓦斯涌出能够抑制采空区自燃升温，延长了采空区自然发火期。模拟结果符合现场实际情况。研究指出高瓦斯易自燃矿井采空区瓦斯治理应与自燃防治相结合综合考虑。

Study on relevance between gas source strength and spontaneous combustion in goaf of top coal caving

The internal coupling correlation problem between the spontaneous combustion of residual coal and gas emission of goaf was studied.The numerical model of nonlinear seepage-muticomponent gas-temperature field of goaf and non-uniform oxygen consumption was solved by using software G3,and the distribution state of all variables was quantitatively provided for different strength of gas emission in goaf.The computed results show that the pressure balance is formed between gas emission in goaf and air pressure in working face,and it determines the airflow exchange and gas emission between the working face and goaf.The influence variety approximately presents linear relations corresponding to one another.The distribution space of oxygen concentration in goaf is greatly reduced with increasing the strength of gas emission.The attenuation change is approximately presented between the oxidation zone width of spontaneous combustion and gas emission in goaf.Through simulating the process of the temperature increase of spontaneous combustion,the gas emission with high strength can inhibit the temperature increase due to the spontaneous combustion of goaf,and prolong the spontaneous combustion period of goaf.The simulated results accord with the actual situation on site.The research indicates that the gas control should combine with the spontaneous combustion prevention of goaf for the high gas mine with easily spontaneous combustion coal seam.