雷东记, 郑媛媛, 马涛,等.高强电场激励下煤体吸附模型及机理探讨[J].河南理工大学学报（自然科学版）,2023,42(1):35-45.

LEI D J, ZHENG Y Y, MA T,et al.Adsorption model and mechanism of coal under high-strength electrical excitation[J].Journal of Henan Polytechnic University(Natural Science) ,2023,42(1):35-45.

高强电场激励下煤体吸附模型及机理探讨

雷东记1,2, 郑媛媛1, 马涛1,3, 王亚娟1

1.河南理工大学 河南省瓦斯地质与瓦斯治理重点实验室-省部共建国家重点实验室培育基地，河南 焦作  454000；2.河南理工大学 中原经济区煤层（页岩）气河南省协同创新中心，河南 焦作  454000；3.神华神东煤炭集团有限责任公司，陕西 神木  719300

摘要:基于电场强化下煤体响应表现出的电动效应、热效应和激发极化效应，设计高强电场下煤体吸附试验系统，研究电场实时加载下煤体对不同吸附质的吸附特征，并在经典Langmuir、D-R吸附模型基础上构建适用于高强电场下的煤体吸附模型。结果表明：实时加载高强电场下，随着施加电场强度增大，煤体吸附能力呈线性减小趋势，受电场影响CO₂吸附能力变化率更大，与未加电场相比，电场强度为30，60，90 kV/m时煤体吸附瓦斯的能力分别下降了10.9%，15.7%，18.9%，吸附CO₂的能力分别下降了8.5%，12.1%，22.9%；基于Langmuir吸附模型和D-R吸附方程，以煤体吸附试验数据为依据，在吸附模型基础上引入含有电场强度的修正项系数(1-C·E)，分析构建含有电性参数的吸附模型，新模型试验拟合度均在0.99以上，能够预测并表征高强电场下煤体吸附特征，其影响机理主要归结为：煤体孔隙结构改变，经高强电场强化后煤样微孔向小孔及中大孔过渡，增强了煤体的扩散性能；影响了煤体吸附瓦斯表面自由能，且吉布斯自由能随着场强增大而减小，揭示了电场抑制煤体对瓦斯的吸附；煤体发生激发极化，电场通过改变煤体电性参数介电常数与电阻率进而影响瓦斯的吸附解吸能力。

关键词:高强电场;吸附模型;实时加电;机理分析

doi:10.16186/j.cnki.1673-9787.2021070089

基金项目:国家自然科学基金资助项目（51704101）；河南省科技攻关项目（182102310780，192102310）；中国博士后基金资助项目（2019M6525352536）；河南省高校基本科研业务费专项项目（NSFRF200307）

收稿日期:2021/07/23

修回日期:2021/10/08

出版日期:2023/01/25

Adsorption model and mechanism of coal under high-strength electrical excitation

LEI Dongji1,2, ZHENG Yuanyuan1, MA Tao1,3, WANG Yajuan1

1.State Key Laboratory Cultivation Base for Gas Geology and Gas Control，Henan Polytechnic University，Jiaozuo  454000，Henan，China；2.Coal Seam （Shale） Gas Collaborative Innovation Center of Henan Province，Jiaozuo  454000，Henan，China；3.Shenhua Shendong Coal Group Co.，Ltd.，Shenmu  719300，Shaanxi，China

Abstract:Based on the electric effect，thermal effect and induced polarization effect of coal response under electric field strengthening，a coal adsorption test system under high strength electric field was designed and constructed.The adsorption characteristics of coal to different adsorbates under real-time electric field loading were studied experimentally，and the coal adsorption model suitable for electric field was constructed based on the classical Langmuir and D-R adsorption models.The results showed that，under real-time loading of high-strength electric field，with the increase of electric field intensity，the adsorption capacity of coal decreases linearly，and the change rate of carbon dioxide adsorption capacity affected by electric field was larger.When the electric field intensity was 30，60 and 90 kV/m，the adsorption capacity of coal to methane decreased by 10.9%，15.7% and 18.9%，while the adsorption capacity of carbon dioxide decreased by 8.5%，12.1% and 22.9%.Based on the Langmuir adsorption model and D-R adsorption equation and the experimental data of coal adsorption，a modified coefficient (1-C·E) with electric field intensity was introduced into the coal adsorption model，the coal adsorption model with electrical parameters was constructed.The experimental fitting degree of the new model was above 0.99，which could predict and characterize the adsorption characteristics of coal under electric field.The mechanism of coal modification by high strength electric strengthening was mainly summarized as follows：The pore structure of coal was changed.After electric field strengthening，the micropores of coal samples transited to small pores and medium and large pores，which increased the diffusion performance of coal.It affected the surface free energy of coal adsorbing gas，and Gibbs free energy decreased with the increase of electric field strength，which revealed that the electric field inhibitted the adsorption of coal to gas molecules.Excited polarization occurred in coal，and the electric field could change the physical properties such as dielectric constant and resistivity of coal electrical parameters，and then act on the adsorption and diffusion ability of gas.

Key words:high strength electric field;adsorption model;power up in real-time;mechanism analysis

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