|
| 含水煤电阻率与孔隙结构的关联性实验研究 |
| Experimental Study on the Effects of Varied Pore Structures on Electrical Resistivity in Dry and Water-Saturated Coal Samples |
| 投稿时间：2025-09-12 修订日期：2025-10-18 |
| DOI： |
| 中文关键词: 煤电阻率 LCR电桥法 煤变质程度 煤孔隙度 含水煤样 |
| 英文关键词: coal Electrical resistivity LCR bridge method Metamorphic grades of coal coal porosity Water-saturated coal samples |
| 基金项目:煤矿井下瓦斯抽采场-区-网耦合模型及抽采参数自适应调控机制,国家自然科学基金项目（面上项目，重点项目，重大项目） |
|
| 摘要点击次数: 140 |
| 全文下载次数: 0 |
| 中文摘要: |
| 为探究煤体电阻率与孔隙结构之间的内在关联，研究选取西北地区四种不同变质程度的烟煤样品，通过LCR电桥法测定其在干燥与饱和水状态下的电阻率变化，并引入无量纲参数ρP以定量表征孔隙系统对导电行为的贡献程度。同时，借助低场核磁共振技术获取总孔隙率、有效孔隙率及孔径分布等关键微观结构参数。实验结果表明：煤电阻率随变质程度提高呈先升后降趋势，总孔隙率与ρP呈显著线性正相关（R2>0.9），有效孔隙率每提高10%，ρP平均上升约5.2%；残余孔隙率每增加10%，ρP下降约4.8%。孔径分布分析进一步表明，微孔与小孔占比每增加10%，ρP下降约7.3%；中孔与大孔占比每提升10%，ρP上升约6.5%，大中孔是促进导电性能提升的主要因素。枣庄煤样因微孔占比超过70%，出现饱和电阻率高于干燥值的异常现象。研究表明，孔隙结构是决定煤电阻率的核心因素，孔喉连通性与有效孔隙比例直接影响水分赋存状态与导电路径的形成，该结果从微观机制层面揭示了不同孔隙结构对煤电阻特性的差异影响，为基于电阻率测试反演煤体内部渗流特征提供了理论与实验依据。 |
| 英文摘要: |
| To investigate the correlation between coal resistivity and pore structure, four bituminous coal samples with different metamorphic grades from Northwest China were selected. Resistivity under both dry and water-saturated conditions was measured using the LCR bridge method. A dimensionless parameter ρP was introduced to quantitatively characterize the contribution of the pore system to the overall electrical conductivity. Key microstructural parameters, including total porosity, effective porosity, and pore size distribution, were obtained using low-field nuclear magnetic resonance (NMR) technology.Experimental results indicate that the electrical resistivity of coal exhibits an initial increase followed by a decrease with increasing metamorphic grade. A significant linear positive correlation (R2> 0.9) is observed between total porosity and ρP. For every 10% increase in effective porosity,ρP rises by approximately 5.2% on average; conversely, a 10% increase in residual porosity leads to a decrease in ρP of about 4.8%. Pore size distribution analysis further reveals that a 10% increase in the proportion of micropores and small pores results in an approximate 7.3% reduction in ρP, while a 10% increase in the proportion of mesopores and macropores leads to an approximate 6.5% increase in ρP, indicating that mesopores and macropores are the primary factors enhancing electrical conductivity. An anomalous phenomenon is observed in the Zaozhuang coal sample, where the saturated resistivity exceeds the dry resistivity, which is attributed to a micropore proportion exceeding 70%. The study demonstrates that pore structure is a fundamental factor governing coal resistivity, with pore throat connectivity and the proportion of effective pores directly influencing moisture occurrence and the formation of conductive pathways. These findings elucidate the differential impacts of various pore structures on the electrical properties of coal at a microscopic level and provide a theoretical and experimental basis for interpreting internal seepage characteristics in coal via resistivity measurements. |
|
View Fulltext
查看/发表评论 下载PDF阅读器 |
| 关闭 |
