煤粒瓦斯扩散及扩散系数测定方法的研究

Study on the measurement of coal particale gas diffusion and diffusion coefficient

基于理论分析建立了第三类边界条件下的煤粒瓦斯扩散方程，并给出了解析解。对解析解的分析表明，第一类边界条件下及煤粒内部浓度均匀一致条件下的扩散是第三类边界条件下的特例或近似过程。煤粒瓦斯扩散过程能否近似简化成第一类边界条件下和内部浓度均匀一致条件下的扩散过程，取决于煤粒内部扩散系数和表面扩散传质采数的相对大小，文中介绍了这两个系数的测试方法，并给出了测试实例。

The differential equations of coal particle gas diffusion under the third kind boundary condition and its analytical solution have obtained on the basis of theoretical analysis.It shows that coal particle gas diffusion under the first kind boundary condition and uniform gas concentration within coal particles is a special instance or approximate process under the third kind boundary condition.Whether coal particle gas diffusion can be approximated to diffusion under the first kind boundary condition and uniform is dependant upon the diffusion coefficient and surface mass transfer coefficient.The paper introduces the method of measurement of these two coefficients and gives examples of measurement.