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煤屑瓦斯解吸扩散规律的研究对应用解吸法测定煤层瓦斯含量以及预测煤层突出危险性有着重要的现实意义。受煤层地质条件、煤的物理力学性质、钻取工艺等多种因素影响,所取的煤屑会呈现不同的形状,其解吸扩散参数也不尽相同。通过对宏观上可根据肉眼分辨其形状的煤屑的几何形状对煤屑的瓦斯扩散规律的影响进行数学模拟,得出了不同煤屑形状下的瓦斯解吸扩散数学模型及其解析解。考虑到解吸放散时间不同,得到了不同解吸扩散模型的近似式。并通过对比分析发现,同一粒度分布范围内,煤屑瓦斯初期解吸时受到煤屑形状的较大影响;随着解吸时间的延长,煤屑形状的不同对解吸扩散规律影响趋于变小,不同形状的煤屑颗粒内部瓦斯有效扩散形状逐渐近似于球形。
The research on desorption and diffusion rules of coal gas desulfurization plays an important role in determining gas content in coal seam and predicting the prominent danger of coal seam by using desorption method. Affected by the geological conditions of the coal seam, the physical and mechanical properties of the coal, the drilling process and other factors, the coal chips taken will have different shapes and the desorption and diffusion parameters will also vary. By mathematically simulating the influence of coal dust on the macroscopically the shape of coal dust, the mathematical model of gas desorption and diffusion under different coal dust shapes and its analytical solutions are obtained. Considering the different desorption and diffusion time, the approximate formulas of different desorption and diffusion models are obtained. Through the comparative analysis, it is found that coal gas is greatly influenced by the shape of coal chips during the initial desorption of coal gas within the same particle size distribution. With the desorption time prolonging, the influence of different coal chip shapes on desorption and diffusion tends to be smaller, The shape of the gas inside the coal particles effectively diffusion shape gradually similar to the spherical shape.