突出煤体的瓦斯解吸特征及其影响因素分析

Analysis on Gas Desorption Characteristics and Influence Factors of Outburst Coal

在适宜的外界条件下,煤体中的吸附瓦斯迅速解吸为游离瓦斯后可释放出巨大的能量,从而产生强烈的气体动力效应。通过理论分析得出影响瓦斯解吸速度的重要因素——瓦斯的浓度梯度和孔壁产生的能垒。在一定的煤层条件下,吸附瓦斯浓度梯度取决于外部裂隙中高压瓦斯的释放速度,而孔壁的能垒与煤体的粒度关系密切。研究分析了不同吸附压力和煤样颗粒对瓦斯解吸特征的影响,得出瓦斯解吸速度和解吸量随孔隙压力和煤体破坏程度变化的规律。

Under proper outside conditions, the absorped gas in the coal will quickly desorb into free gas, release enormous energy and thus produce a strong gas dynamic effect. Through the theoretical analysis, the key factors affecting the gas desorption velocity - the gas concentration gradient and the pore wall energy barrier were obtained. Under certain conditions of coal seams, the concentration gradient of the absorbed gas depended on the release velocity of the high-pressure gas in the external fracture, and there was a close relation between the energy barrier of pore wall and the particle sizes of coal. In this paper, analysis was carried out on the influence of different adsorption pressures and particle sizes of coal smaples upon the gas desorption features, and the the change rule of the gas desorption velocity and quantity with the pore pressure and the damage degree of coal was obtained.