中文摘要：

利用自主研发的MCQ-Ⅱ型煤层瓦斯驱替试验装置,对原煤大尺寸（100 mm×100 mm×200 mm）试件,进行了恒定温压（25℃,31 MPa）条件下CO2在贫煤、贫瘦煤和弱黏煤3种煤阶煤中的注入储存试验,对CO2注入储存过程中煤体膨胀变形特性进行了测量分析;并对小尺寸（6 mm×6 mm×6 mm）原煤试件通过CT扫描,研究了3种煤样的微观结构特征。主要结果为：对最小观测尺度为4.5μm的CT重建图像,通过统计分析,发现贫煤孔隙率（4.67%）小于贫瘦煤孔隙率（5.39%）小于弱黏煤孔隙率（12.10%）;在31 MPa体积应力约束条件下,持续12 h的CO2注入过程中,煤体膨胀变形受孔隙压力与CO2吸附变形的共同作用,且体积膨胀百分比与CO2注入储存量呈线性关系;在注入储存相同量气态CO2条件下,贫煤体积膨胀应变大于弱黏煤大于贫瘦煤;由于煤体层理性结构特征,弹性模量在垂直与平行层理2个方向上的差异性,煤体在垂直层理方向膨胀应变大于平行层理方向应变,且2个方向膨胀应变均与CO2储存量呈线性关系。

英文摘要：

In order to investigate the coal volumetric swelling during CO2 storage,the self-developed MCQ-ⅡCO2-ECBM experimental equipment was used to perform coal deformation through injecting CO2 to meager coal,meagerlean coal and weakly caking coal samples（100 mm × 100 mm × 200 mm） with constant injection pressure under31 MPa bulk stress at 25 ℃. At the same time, the micro-pores were investigated with nine small coal samples（6 mm×6 mm×6 mm） through a micro-CT system. The results show that：At minimum 4. 5 μm observation of CT sec-tion structure,the meager coal porosity（4. 67%） is less than that of meager lean coal（5. 39%） and weakly cakingcoal（12. 10%）;During 12 hours of CO2 injection,coal volumetric strain is influenced by pore pressure and CO2ad-sorption swelling,which is linearly proportional to the amount of gaseousness CO2 storage under 31 MPa confinementpressure;With the same CO2 storage,the volumetric swelling strain of the meager coal is more than that of the weaklycaking coal and meager lean coal;Due to the anisotropy of modulus of elasticity,the radial strain increases faster thanthe axial strain and both of them are linearly proportional to the amount of gaseousness CO2 storage.