混煤质量比对吸附常数及放散初速度的影响

Effect of mass ratio of mixed coal on adsorption constants and initial velocity of methane emission

为了揭示煤吸附常数及其放散初速度与混合煤样质量比变化的关系,采用流体力学的理论知识,分析了动力粘性系数与气体压力之间的关系,并按照不同的质量比制作出混合煤样.运用Langmuir单分子层吸附理论,对硬煤和软煤处于不同质量比条件下混合煤样吸附甲烷特性的影响进行了实验研究.研究结果表明:孔隙气体压力随孔隙气体粘性系数而变大,而且在软煤质量和其上部硬煤质量近似相等时,吸附常数a及放散初速度ΔP达到最大值,吸附常数b达到最小值.这一发现充分说明了在这种情况下,煤体对甲烷的吸附量及其压力均达到最大值,一旦扰动此类煤体,便会形成很大的压力梯度,发生大量的瓦斯涌出.

In order to reveal the relationship between the adsorption constants and methane emission initial velocity and the mass ratio of mixed coal,using fluid mechanics theory,this study analyzes the relationship between kinetic viscosity and gas pressure,and prepares the samples of mixed coal with different mass ratios.Consequently,using the Langmuir monolayer theory for coal methane adsorption,the study investigates the effect of mass ratio variation of hard-coal and soft-coal on methane adsorption.The experimental results show that the pore gas pressure increases with the increase of kinetic viscosity.The adsorption constants a and the initial velocity of methane diffusion ΔP reach their maximum values and the adsorption constant b reaches its minimum value when the mass of hard-coal and soft-coal are equal.The study findings indicate that under these conditions,the adsorption capacity and the gas pressure reach their maximum values,and it may form a great pressure gradient and great gas emission if the coal is disturbed.