摘要
为研究甲烷吸附孔隙压力对煤膨胀变形的影响,实验应用μCT225k VFCB型高精度显微CT实验系统,对直径为5 mm的细观煤样进行了不同孔隙压力下的吸附瓦斯扫描实验,并通过对其孔隙率与膨胀变形量的观测与分析得到了煤吸附瓦斯细观特性。研究发现:在细观实验中煤样吸附瓦斯会导致煤体孔隙率下降,并发生体积膨胀变形;体积膨胀变形规律符合朗格缪尔方程,且煤样不同位置的孔隙率与体积变化均具有非均匀性。研究结果表明:在吸附瓦斯过程中,煤体骨架体积膨胀会导致煤体孔隙体积减小与外观体积膨胀,且煤体骨架膨胀变形时更倾向于通过挤压煤体原始孔隙来获得膨胀空间。
To investigate the effects of pore pressure of methane adsorption on porosity and swelling deformation of coal,a micro-CT system named μCT225k VFCB was adopted and the coal sample was molded to cylinder shape with a diameter of 5 mm. The samples were scanned for 360 degree during methane adsorption to observe the mesoscopic characteristics. It concludes that the coal porosity decreases and the volume swelling deformation are caused by methane adsorption,and the volumetric swelling deformation obeys the Langmuir Equation. The changes of the volume swelling deformation and porosity are non-homogeneity in meso-scale coal sample,and the porosity in adsorption state is effectively estimated by the determination of coal bulk volume swelling deformation. In the process of gas adsorption,the decrease of pore volume and the expansion of bulk volume are resulted from coal skeleton volume swelling.Both of them have effects on the porosity of coal,and it inclines to squeeze the original porosity of coal to obtain spatial expansion.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2015年第1期98-102,共5页
Journal of China Coal Society
基金
国家自然科学基金资助项目(21373146
51304142)
山西省基础研究计划资助项目(2013021029-3)
关键词
吸附
瓦斯孔隙率
膨胀变形
孔隙压力
adsorption
gas
porosity
swelling deformation
pore pressure
