1. College of Safety Science and Engineering,Liaoning Technical University,Huludao　 125105,China; 2. Key Laboratory of Mine Thermo-motive Disaster & Prevention,Ministry of Education,Huludao　 125105,China; 3. State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University, Chongqing　 400044,China; 4. School of Architectural Engineering & Art Design,Chongqing Industry Polytechnic College,Chongqing　 401120,China

为深入研究煤层吸附气体过程中的变形特性,开展了He,CH4,CO2三种气体作用下的煤层吸附变形实验,同步测试煤样在CH4,CO2气氛下的气体吸附量,探讨了煤样等温吸附变形机理,建立了综合考虑吸附态气体和游离态气体作用的煤等温吸附变形模型。结果表明,He作用下煤样产生压缩变形,应变曲线可分为孔隙压密和线弹性变形两个阶段; CH4和CO2气氛下煤样吸附变形与吸附量均呈非线性关系,相同吸附量条件下煤样吸附CH4产生的膨胀变形量大于吸附CO2产生的膨胀变形量;煤基质在CO2气氛下比在CH4气氛下更容易产生压缩变形;游离态气体不仅通过孔隙压力对煤基质有压缩作用,还能通过改变煤结构促进煤的膨胀变形。可用二次函数表达游离态气体作用下的煤样变形量与孔隙压力关系。与相关模型的对比分析表明,建立的等温吸附变形模型能够对试验数据进行精确拟合,并能够很好地描述煤样在不同吸附性气体作用下的吸附变形特征。

In order to investigate the characteristics of adsorption-induced deformation of coal,the coal defor-mation ex- periments with He,CH4 and CO2 gases were carried out. At the same time,the amount of gas adsorption under the at- mosphere of CH4 and CO2 was tested. The mechanism of isothermal adsorption-induced deformation of coal samples was discussed,and a coal isothermal adsorption-induced deformation model was established with the consideration of the effect of adsorbed gas and free gas. The results show that the compression deformation of coal samples is produced under the action of He,and the strain curve can be divided into pore compaction and elastic deformation of two stages. In the gas of CH4 and CO2 ,there is a nonlinear relationship between the adsorp-tion-induced strain and the adsorption capacity of coal samples. Under the same adsorption capacity,the swelling deformation of coal samples adsorbed CH4 is greater than that of CO2 adsorption. In CO2 ,the coal matrix is more likely to produce compression deformation than that in CH4 . The free gas not only compresses the coal matrix through pore pressure,but also promotes the swelling deformation of coal by changing the coal structure. The relationship between the deformation of coal sample and pore pressure caused by free gas can be simplified to quadratic function. Comparative analysis with related models shows that the model can accurately fit the experi-mental data,and can well describe the characteristics of adsorption-induced de- formation of coal in different ad-sorptive gases.

国家自然科学基金资助项目(51704147)；辽宁省教育厅辽宁省高等学校基本科研基金资助项目(LJYL005)；重庆市基础与前沿研究计划资助项目(cstc2016jcyjA0085)；

ZHANG Zunguo,QI Qingjie,CAO Shugang,et al. Characteristics of coal deformation during its adsorption of He,CH4 and CO2 [J]. Journal of China Coal Society,2018,43(9):2484-2490.