超临界CO_(2)吸附引起煤体变形及吸附应力的研究  

Study on Coal Deformation and Adsorption Stress Caused by Supercritical CO_(2) Adsorption

作　　者：王磊[1] 杨栋[1] 邢俊旺 WANG Lei;YANG Dong;XING Jun-wang(Key Laboratory of In-situ Property Improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,山西太原030024

出　　处：《东北大学学报（自然科学版）》2023年第5期726-734,共9页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(52104144,51974191);国家重点研发计划项目(2019YFA0705501);山西省基础研究项目(20210302124136)。

摘　　要：对煤体恒温吸附氦气/超临界CO_(2)及变形进行测试试验,对煤体产生的轴向变形和径向变形实时监测,揭示有效应力作用和吸附应力作用分别引起的煤体膨胀变形量以及煤体对超临界CO_(2)的吸附应力.研究结果表明:煤体吸附不同气体表现出的轴向应变值要高于径向应变,氦气和超临界CO_(2)引起的煤体应变随注气压力的变化规律具有相似性.在温度升高过程中,煤体吸附氦气体积应变表现为先增后减的特征,而煤体吸附超临界CO_(2)体积应变逐步减小.随着温度的升高,煤体吸附超临界CO_(2)过程中煤体变形从吸附应力引起的变形占主导逐渐转变为有效应力引起的变形占主导,吸附应力体积应变与有效应力体积应变之比在逐步减小.煤体对超临界CO_(2)的吸附应力随着温度的升高而减小,温度从60℃增加到80℃,吸附应力仅降低了29%,同时超临界CO_(2)与瓦斯吸附应力的比值在60℃达到最大,该温度下超临界CO_(2)驱替瓦斯效果最优.The constant temperature adsorption of helium/supercritical CO_(2)(SC-CO_(2))and deformation of coal are tested,the axial deformation and radial deformation of coal are real-time monitored,and the coal expansion deformation caused by effective stress and adsorption stress and the adsorption stress of coal to SC-CO_(2) are revealed.The results show that the axial strain by coal adsorption of different gases is higher than the radial strain,and the variation law of coal strain caused by helium and SC-CO_(2) with gas injection pressure is similar.In the process of increasing the temperature,the volume strain of coal adsorbed helium increased first and then decreased,while the volume strain of coal adsorbed SC-CO_(2) gradually decreased.With the increase of temperature,the deformation of coal during the adsorption of SC-CO_(2) gradually changed from the deformation caused by adsorption stress to the deformation caused by effective stress.The ratio of the volume strain of adsorption stress to the volume strain of effective stress is gradually decreased.The adsorption stress of coal to SC-CO_(2) decreases with the increase of temperature.When the temperature increases from 60℃to 80℃,the adsorption stress only decreases by 29%.At the same time,the ratio of SC-CO_(2) adsorption stress to gas adsorption stress reaches the maximum at 60℃,and the SC-CO_(2) has the best gas displacement effect at this temperature.

关 键 词：吸附变形 吸附应力 有效应力 超临界CO_(2) 热力耦合 

分 类 号：TD801[矿业工程—矿山开采]