考虑煤基质压缩效应的煤全孔径分布特征研究

刘纪坤; 任棒; 王翠霞

doi:10.13272/j.issn.1671-251x.2021060077

考虑煤基质压缩效应的煤全孔径分布特征研究

doi: 10.13272/j.issn.1671-251x.2021060077

西安科技大学安全科学与工程学院, 陕西西安 710054

基金项目:

国家自然科学基金资助项目（51404188）；陕西省教育厅一般专项科学研究计划项目（20JK0773）。

详细信息

作者简介:
刘纪坤(1982-),男,河南濮阳人,副教授,博士,主要研究方向为矿山煤岩动力灾害预防及控制,E-mail:271143890@qq.com。

中图分类号: TD712
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出版历程
- 收稿日期: 2021-06-29
- 修回日期: 2022-01-28
- 网络出版日期: 2022-03-01

Study on coal full pore aperture distribution characteristics considering coal matrix compression effect

College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an 710054, China

摘要

摘要: 采用单一煤孔隙结构表征方法只能对某一孔径范围内的孔隙结构进行表征，联合压汞法和低温液氮吸附法可表征煤全孔径分布特征，然而煤基质压缩效应会给孔径分布测量结果带来误差，且目前的研究均未考虑煤基质压缩效应对孔径分布测量结果的影响。为研究不同变质程度煤全孔径分布特征，选取4种煤样进行压汞和低温液氮吸附实验。当汞压为0.124~20 MPa时，煤基质被压缩，孔隙结构发生变形，且随着汞压增加，煤基质压缩效应逐渐明显，孔隙结构变形程度逐渐增加；当汞压为20~206 MPa时，煤基质压缩效应显著，孔隙结构遭到破坏。考虑煤基质压缩效应的影响，提出了一种联孔分析原则：将联孔分界点设定为62.35 nm（汞压为20 MPa时对应的孔径为62.35 nm），当孔径小于62.35 nm时，采用低温液氮吸附法分析孔体积和比表面积；当孔径大于62.35 nm时，结合煤基质压缩性系数对压汞法所测累计进汞体积进行校正来分析孔体积和比表面积。结果表明：微孔和过渡孔对比表面积的贡献最大，中孔及大孔对孔体积的贡献最大；煤样变质程度越大，微孔和过渡孔对比表面积的贡献越大，中孔及大孔对孔体积的贡献越大。
- 煤基质压缩 /
- 全孔径分布 /
- 压汞法 /
- 低温液氮吸附法 /
- 联孔分界点
Abstract: The single pore structure characterization method can only characterize the pore structure within a certain pore aperture range, the combined Mercury intrusion porosimetry and low-temperature liquid nitrogen adsorption method can characterize the full pore aperture distribution characteristics of coal. However, the coal matrix compression effect will bring errors to the pore aperture distribution measurement results, and the current research has not considered the impact of coal matrix compression effect on the pore aperture distribution measurement results. In order to study the full pore aperture distribution characteristics of coal with different metamorphic degrees, Mercury intrusion porosimetry and low-temperature liquid nitrogen adsorption experiments are carried out on four kinds of coal samples. When the mercury pressure is 0.124-20 MPa, the coal matrix is compressed and the pore structure is deformed. With the increase of mercury pressure, the compression effect of coal matrix becomes obvious and the deformation degree of pore structure increases gradually. When the mercury pressure is 20-206 MPa, the compression effect of coal matrix is significant, and the pore structure is destroyed. Considering the impact of coal matrix compression effect, a joint pores analysis principle is proposed. The boundary point of the joint pores is set at 62.35 nm (the corresponding pore aperture is 62.35 nm when the mercury pressure is 20 MPa). When the pore diameter is less than 62.35 nm, the pore volume and specific surface area are analyzed by low-temperature liquid nitrogen adsorption. When the pore aperture is greater than 62.35 nm, the cumulative mercury intrusion volume measured by mercury intrusion method is corrected in combination with the compressibility coefficient of coal matrix so as to analyze the pore volume and specific surface area. The results show that micropore and transition pore contribute the most to the surface area, mesopore and macropore contribute the most to the pore volume. The greater the degree of coal metamorphism, the greater the contribution of micropores and transition pores to the specific surface area, and the greater the contribution of mesopores and macropores to the pore volume.
- coal matrix compression /
- full pore aperture distribution /
- Mercury intrusion porosimetry /
- low-temperature liquid nitrogen adsorption /
- joint pores boundary point

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参考文献(16)

[1]	杨明,柳磊,张学博,等.不同阶煤孔隙结构与流体特性的核磁共振试验研究[J].中国安全科学学报,2021,31(1):81-88. YANG Ming,LIU Lei,ZHANG Xuebo,et al.Nuclear magnetic resonance experimental study on pore structure and fluid characteristics of coal at different ranks[J].China Safety Science Journal,2021,31(1):81-88.
[2]	刘彦伟,张帅,左伟芹,等.典型软硬煤全孔径孔隙结构差异性研究[J].煤炭科学技术,2021,49(10):98-106. LIU Yanwei,ZHANG Shuai,ZUO Weiqin,et al.Study on differences of pore structure of typical soft and hard coal[J].Coal Science and Technology,2021,49(10):98-106.
[3]	LI Xiangchen,KANG Yili,HAGHIGHI M.Investigation of pore size distributions of coals with different structures by nuclear magnetic resonance(NMR) and mercury intrusion porosimetry(MIP)[J].Measurement,2017,116:122-128.
[4]	张玉贵,焦银秋,雷东记,等.煤体纳米级孔隙低温氮吸附特征及分形性研究[J].河南理工大学学报(自然科学版),2016,35(2):141-148. ZHANG Yugui,JIAO Yinqiu,LEI Dongji,et al.Study on adsorption characteristics and fractal properties of nano-scale pores at low temperature coal[J].Journal of Henan Polytechnic University(Natural Science),2016,35(2):141-148.
[5]	杨昌永,常会珍,邵显华,等.扫描电镜下不同煤体结构煤微孔隙特征研究[J].煤炭科学技术,2019,47(12):194-200. YANG Changyong,CHANG Huizhen,SHAO Xianhua,et al.Study on micro-pore characteristics of structural coal in different coal bodies under scanning electron microscopy[J].Coal Science and Technology,2019,47(12):194-200.
[6]	张磊.基于高精度显微CT技术的煤微观孔隙结构特征研究[D].青岛:山东科技大学,2016. ZHANG Lei.Coal microscopic pore features study based on high-resolution micro-CT technology[D].Qingdao:Shandong University of Science and Technology,2016.
[7]	聂百胜,王科迪,樊堉,等.基于小角X射线散射技术计算不同孔形的煤孔隙特征比较研究[J].矿业科学学报,2020,5(3):284-290. NIE Baisheng,WANG Kedi,FAN Yu,et al.The comparative study on calculation of coal pore characteristics of different pore shapes based SAXS[J].Journal of Mining Science and Technology,2020,5(3):284-290.
[8]	FAN Chaojun,ELSWORTH D,LI Sheng,et al.Thermo-hydro-mechanical-chemical couplings controlling CH₄ production and CO₂ sequestration in enhanced coalbed methane recovery[J].Energy,2019,173:1054-1077.
[9]	江泽标,彭鑫,韦善阳,等.基于氮吸附、压汞联合试验的CO₂致裂对煤岩孔隙的影响[J].安全与环境学报,2021,21(1):101-108. JIANG Zebiao,PENG Xin,WEI Shanyang,et al.Influence of CO₂ cracking on the coal and rock pore based on the nitrogen adsorption and mercury press combined experiment[J].Journal of Safety and Environment,2021,21(1):101-108.
[10]	郝晋伟,李阳.构造煤孔隙结构多尺度分形表征及影响因素研究[J].煤炭科学技术,2020,48(8):164-174. HAO Jinwei,LI Yang.Research on multi-scale fractal characteristics of pore structure in tectonic coal and analysis of its influence factors[J].Coal Science and Technology,2020,48(8):164-174.
[11]	林海飞,卜婧婷,严敏,等.中低阶煤孔隙结构特征的低温液氮吸附法和压汞法联合分析[J].西安科技大学学报,2019,39(1):1-8. LIN Haifei,BU Jingting,YAN Min,et al.Joint analysis of pore structure characteristics of middle and low rank coal with nitrogen adsorption and mercury intrusion method[J].Journal of Xi'an University of Science and Technology,2019,39(1):1-8.
[12]	何珊.煤岩甲烷高压吸附特性及其影响因素研究[D].北京:中国地质大学(北京),2020. HE Shan.The characteristic and influencing factors of high-pressure methane adsorption on dry coals[D].Beijing:China University of Geosciences(Beijing),2020.
[13]	肖鹏,杜媛媛.构造煤微观结构对其吸附特性的影响实验[J].西安科技大学学报,2021,41(2):237-245. XIAO Peng,DU Yuanyuan.Experiment on the influence of microstructure of tectonic coal on its adsorption characteristics[J].Journal of Xi'an University of Science and Technology,2021,41(2):237-245.
[14]	李阳,张玉贵,张浪,等.基于压汞、低温N₂吸附和CO₂吸附的构造煤孔隙结构表征[J].煤炭学报,2019,44(4):1188-1196. LI Yang,ZHANG Yugui,ZHANG Lang,et al.Characterization on pore structure of tectonic coals based on the method of mercury intrusion,carbon dioxide adsorption and nitrogen adsorption[J].Journal of China Coal Society,2019,44(4):1188-1196.
[15]	李希建,薛海腾,陈刘瑜,等.贵州地区突出煤层微孔结构及对瓦斯流动特性的影响[J].煤炭科学技术,2020,48(10):67-74. LI Xijian,XUE Haiteng,CHEN Liuyu,et al.Micropore structure of outburst coal seam in Guizhou Area and its effect on gas flow[J].Coal Science and Technology,2020,48(10):67-74.
[16]	LI Yonghua,LU Gaoqing,RUDOLPH V.Compressibility and fractal dimension of fine coal particles in relation to pore structure characterisation using mercury porosimetry[J].Particle and Particle Systems Characterization,1999,16(1):25-31.