煤的分形维数及其对瓦斯吸附的影响

为了从分形的角度研究煤体性质对瓦斯吸附的影响，采用高压容量法测试了8种煤样的瓦斯吸附能力，并根据Langmuir方程拟合得到了表征煤样吸附能力的参数Langmuir体积和Langmuir压力。同时，根据液氮吸附实验，利用分形理论计算得到了煤样的分形维数，并研究了分形维数对瓦斯吸附的影响。研究结果表明：煤样在不同压力段时具有不同的吸附特性，因此具有不同的分形维数D1和D2。D1和D2对瓦斯吸附的影响作用不同，随着D1的增大，煤体吸附瓦斯的能力增强，而随着D2的增大，煤体吸附瓦斯的能力减弱，而且，D1对吸附能力的影响作用比D2强。随着D1的增大，Langmuir压力逐渐减小，煤样在低压段的吸附能力增强，煤体更容易吸附瓦斯，而D2对Langmuir压力无显著影响。

Fractal dimensions of coal and their influence on methane adsorption

In order to study the influence of coal properties on methane adsorption from the point of fractal,methane adsorption capacities of 8 coal samples were tested by using high-pressure volumetric method and two parameters,Langmuir volume and Langmuir pressure,were obtained to characterize the adsorption capacity according to the Langmuir equation.Meanwhile,on the basis of N2 adsorption test,fractal dimensions of coal samples were obtained by using fractal theory and the relationships between fractal dimensions and methane adsorption were investigated.The results show that coal has different adsorption characteristics in different pressure intervals and therefore has different fractal dimensions,D1 and D2.D1 and D2 have different influence on methane.With the increase of D1,the methane adsorption capacity enhanced,while it weakened with the increase of D2.Moreover,D1 has greater influence on adsorption capacity than D2.The Langmuir pressure decreases with the increase of D1 which means that the adsorption capacity at low pressure strengthened.However,D2 has no significant influence on Langmuir pressure.