论文部分内容阅读
煤层的瓦斯扩散系数、浓度流动系数、初始运移强度系数和衰减系数,是煤体孔隙结构和煤质特性的力学表征。为研究煤层瓦斯运移机制,量化煤层瓦斯运移能力,依据Fick扩散理论和质量守恒方程,建立了描述煤体瓦斯浓度与扩散速率的计算模型,采用变量分离法进行数学求解,并通过数据迭代方法获取煤体内瓦斯的扩散系数和表面浓度流动系数;通过室内4种煤样瓦斯运移实验数据比较发现,煤体瓦斯质量增量与运移时间成负指数关系,且随煤阶升高而增大;瓦斯运移速度和衰减系数取决于煤的吸附能力和煤质组分,且煤种之间差异明显;渗透率与扩散系数成线性关系,与流动系数成二次函数关系,且随煤阶升高整体呈增加趋势。
The gas diffusion coefficient, concentration flow coefficient, initial migration intensity coefficient and attenuation coefficient of coal seam are the mechanical characters of pore structure and coal quality of coal seam. In order to study the mechanism of gas migration in coal seam and quantify the gas migration ability of coal seam, a calculation model describing the gas concentration and diffusion rate of coal was established based on Fick diffusion theory and mass conservation equation. The variable separation method was used to solve the problem mathematically. Methods The gas diffusion coefficient and surface concentration flow coefficient in coal were obtained. According to the experimental data of gas migration in four coal samples, it was found that there was a negative exponential relationship between the gas mass increment and the migration time. With the increase of coal rank Increase; gas transport velocity and attenuation coefficient depends on the adsorption capacity of coal and coal quality components, and significant differences between the coal; permeability and diffusion coefficient linear relationship with the flow coefficient is a quadratic function, and with The coal rank increased overall showed an increasing trend.