不同变质程度煤的瓦斯放散特性实验研究

Experimental Study on Gas Diffusion Characteristic of Different Metamorphic Grade of Coal

为了研究煤的变质程度对瓦斯放散特性的影响,采用现场取样、实验室测试的方法,对9种不同煤样的瓦斯放散初速度和孔径分布进行了测试,测试结果表明:煤的变质程度越高,瓦斯放散初速度越大,瓦斯放散初速度随着变质程度的降低呈现出负指数减小的趋势;煤的微孔比表面积越大,瓦斯放散初速度越大,瓦斯放散初速度随着微孔比表面积的增加呈现出线性增加的趋势,根本原因是微孔比表面积的增加为瓦斯吸附提供了更多的吸附位,增大了瓦斯吸附量。

In order to study the influence of metamorphic grade of coal on gas diffusion characteristic, this study adopted the on - site coal sampling coupled with lab testing and initial velocity of gas diffusion and pore diameter distribution were tested. The results show that the metamorphic grade of coal is higher, the initial ve- locity of gas diffusion is bigger. The initial velocity of gas diffusion would be decreased with the reduction of coal metamorphic grade in index. The metamorphic grade of coal is higher, the specific surface area of micro- pore is bigger. The initial velocity of gas diffusion has linear increasing trend along with the increase of coal metamorphic grade. The fundamental cause is that the increase of micropore＇ s specific surface area is provide more adsorption sites for gas adsorption and it increase the adsorbed quantity of gas.