Citation: | LI Zhenrong,TIAN Fuchao,WANG Gang,et al. Fractal characteristics of spontaneous combustion of gas-bearing coal under different temperature and adsorption pressure conditions[J]. Coal Science and Technology,2025,53(5):213−232. DOI: 10.12438/cst.2024-0354 |
The composite disaster of gas and coal spontaneous combustion in the goaf is increasingly becoming the main disaster pattern that restricts the safe production of mines. To study the disaster mechanism of the composite disaster of gas and coal spontaneous combustion, the experiments of low-temperature oxidation microstructure and thermal analysis of coal under different CH4 adsorption pressures were carried out in the paper by low-temperature liquid nitrogen adsorption, scanning electron microscopy and TG-FTIR testing methods, and a pore fractal calculation model was set up based on the fractal theory to investigate the influence of adsorbed CH4 on the pore structure and thermal stability of coal. The results showed that the adsorbed CH4 inhibited the thermal damage destruction of micropores by oxidation, thus a large number of micropores existed in gas-bearing coal and the pore morphology changed compared with the raw coal which was mainly medium- and large-porous; with the increase of adsorption pressure, the mass loss of coal samples in the stage of water loss and desorption was 4%, 2.9%, 3.2% and 3.2%, respectively, and CH4 occupied the adsorption sites of the coal oxygen reaction leading to the reduction of compounds involved in the oxidation reaction, and the active substances involved in the oxidation reaction decreased in the stage of oxidative weight gain, and the oxidative weight gain of the coal samples was 0.67%, 0.41% and 0.31%, respectively, and the spontaneous combustion of the gas-bearing coal in all stages of the characteristic temperature points lagged with the increase of adsorption pressure. A fractal model based on pore size distribution and CH4 adsorption/desorption process was established. The morphological inhomogeneity of the coal surface increased during the pre-oxidation period of low CH4 pressure, the gas adsorption capacity of the coal surface was elevated, the possibility of oxidation reaction increased, the risk of coal spontaneous combustion increased, and the ability of low gas to inhibit the spontaneous combustion of coal was weaker, and was correlated with the specific surface area of the primary pores. The research results investigated the influence of different residual gas contents on the spontaneous combustion characteristics of coal, further verified the accuracy of the continuous physical simulation platform for the whole process of adsorption-desorption-oxidation of gas-bearing coal competition under different adsorption pressures and temperatures, and provided basic support for the prevention and control of gas-fire coupling disaster in the composite disaster environment of the goaf.
[1] |
田富超,贾东旭,陈明义,等. 采空区复合灾害环境下含瓦斯煤自燃特征研究进展[J]. 煤炭学报,2024,49(6):2711−2727.
TIAN Fuchao,JIA Dongxu,CHEN Mingyi,et al. Research progress of spontaneous combustion of coal containing gas under the compound disaster environment in the goaf[J]. Journal of China Coal Society,2024,49(6):2711−2727.
|
[2] |
周福宝. 瓦斯与煤自燃共存研究(Ⅰ):致灾机理[J]. 煤炭学报,2012,37(5):843−849.
ZHOU Fubao. Study on the coexistence of gas and coal spontaneous combustion(Ⅰ):Disaster mechanism[J]. Journal of China Coal Society,2012,37(5):843−849.
|
[3] |
林柏泉,李庆钊,周延. 煤矿采空区瓦斯与煤自燃复合热动力灾害多场演化研究进展[J]. 煤炭学报,2021,46(6):1715−1726.
LIN Baiquan,LI Qingzhao,ZHOU Yan. Research advances about multi-field evolution of coupled thermodynamic disasters in coal mine goaf[J]. Journal of China Coal Society,2021,46(6):1715−1726.
|
[4] |
胡彪. 煤中多尺度孔隙结构的甲烷吸附行为特征及其微观影响机制[D]. 徐州:中国矿业大学,2022.
HU Biao. Characteristics of methane adsorption behavior with multi-scale pore structure in coal and its micro-influence mechanism[D]. Xuzhou:China University of Mining and Technology,2022.
|
[5] |
陈刘瑜,李希建,沈仲辉,等. 贵州北部突出煤的孔隙结构及分形特征研究[J]. 中国安全科学学报,2020,30(2):66−72.
CHEN Liuyu,LI Xijian,SHEN Zhonghui,et al. Pore structure and fractal characteristics of outburst coal in northern Guizhou[J]. China Safety Science Journal,2020,30(2):66−72.
|
[6] |
郭勇义,高亚斌,曹敬,等. 基于修正压汞法的不同瓦斯含量煤样孔隙结构及分形特征研究[J]. 中国矿业大学学报,2023,52(6):1075−1083.
GUO Yongyi,GAO Yabin,CAO Jing,et al. Study on pore structure and fractal characteristics of coal samples with different gas content based on modified MIP[J]. Journal of China University of Mining & Technology,2023,52(6):1075−1083.
|
[7] |
王磊,刘怀谦,谢广祥,等. 含瓦斯煤孔裂隙结构精细表征及强度劣化机制[J]. 岩土力学,2021,42(12):3203−3216.
WANG Lei,LIU Huaiqian,XIE Guangxiang,et al. Fine characterization of the pore and fracture structure and strength degradation mechanism of gas bearing coal[J]. Rock and Soil Mechanics,2021,42(12):3203−3216.
|
[8] |
田富超, 李振榕, 李帅魁, 等. 高温高压条件下含瓦斯煤解吸-自燃演化特性研究[J]. 煤炭科学技术,2024,52(7):101−113.
TIAN Fuchao, LI Zhenrong, LI Shuaikui, et al. Study on evolutionary characteristics of desorption-spontaneous combustion of gas-bearing coal under high temperature and pressure conditions[J]. Coal Science and Technology,2024,52(7):101−113.
|
[9] |
田富超,李振榕,梁运涛,等. 智能型含瓦斯煤竞争吸附解吸氧化模拟平台及试验方法:CN117007462A[P]. 2023−11−07.
|
[10] |
王俏,王兆丰,代菊花,等. 高温高压吸附后焦煤的孔隙结构变化特性[J]. 安全与环境学报,2021,21(6):2602−2608.
WANG Qiao,WANG Zhaofeng,DAI Juhua,et al. Pore structure changing features of the coking coal due to the adsorption of high temperature and high pressure[J]. Journal of Safety and Environment,2021,21(6):2602−2608.
|
[11] |
王玲玲,王兆丰,霍肖肖,等. 高温高压下煤孔隙结构的变化对瓦斯吸附特性的影响[J]. 中国安全生产科学技术,2018,14(12):97−101.
WANG Lingling,WANG Zhaofeng,HUO Xiaoxiao,et al. Influence of pore structure change on gas adsorption characteristics of coal under high temperature and high pressure[J]. Journal of Safety Science and Technology,2018,14(12):97−101.
|
[12] |
MA L,GUO R Z,GAO Y,et al. Study on coal spontaneous combustion characteristics under methane-containing atmosphere[J]. Combustion Science and Technology,2019,191(8):1456−1472. doi: 10.1080/00102202.2018.1531286
|
[13] |
邓军,周佳敏,白祖锦,等. 瓦斯对煤低温氧化过程微观结构及热反应性的影响研究[J]. 煤炭科学技术,2023,51(1):304−312.
DENG Jun,ZHOU Jiamin,BAI Zujin,et al. Effect of gas on microstructure and thermal reactivity of coal during low temperature oxidation[J]. Coal Science and Technology,2023,51(1):304−312.
|
[14] |
张玉涛,张园勃,李亚清,等. 低瓦斯气氛下煤氧化热效应和关键基团演变特性[J]. 中国矿业大学学报,2021,50(4):776−783.
ZHANG Yutao,ZHANG Yuanbo,LI Yaqing,et al. Thermal effect of coal oxidation and evolution properties of key functional groups of coal oxidation at low gas atmospheres[J]. Journal of China University of Mining & Technology,2021,50(4):776−783.
|
[15] |
张玉涛,路旭,李亚清,等. 低甲烷气氛下褐煤的低温氧化特性研究[J]. 安全与环境学报,2024,24(2):517−524.
ZHANG Yutao,LU Xu,LI Yaqing,et al. Study on low temperature oxidation characteristics of lignite in low methane atmosphere[J]. Journal of Safety and Environment,2024,24(2):517−524.
|
[16] |
刘超,郑万成,张镭,等. 瓦斯对煤自燃过程中官能团演变的影响[J]. 能源与环保,2021,43(7):148−155.
LIU Chao,ZHENG Wancheng,ZHANG Lei,et al. Influence of gas on evolution of functional groups during coal spontaneous combustion[J]. China Energy and Environmental Protection,2021,43(7):148−155.
|
[17] |
XU Q,YANG S Q,TANG Z Q,et al. Optimum oxidation temperature of coal bed for methane desorption in the process of CBM extraction[J]. Fuel,2020,262:116625. doi: 10.1016/j.fuel.2019.116625
|
[18] |
MANDELBROT B B,WHEELER J A. The fractal geometry of nature[J]. American Journal of Physics,1983,51(3):286−287. doi: 10.1119/1.13295
|
[19] |
QI L L,TANG X,WANG Z F,et al. Pore characterization of different types of coal from coal and gas outburst disaster sites using low temperature nitrogen adsorption approach[J]. International Journal of Mining Science and Technology,2017,27(2):371−377. doi: 10.1016/j.ijmst.2017.01.005
|
[20] |
MOU P W,PAN J N,NIU Q H,et al. Coal pores:Methods,types,and characteristics[J]. Energy & Fuels,2021,35(9):7467−7484.
|
[21] |
ZHAO D F,GUO Y H,WANG G,et al. Characterizing nanoscale pores and its structure in coal:Experimental investigation[J]. Energy Exploration and Exploitation,2019,37(4):1320−1347. doi: 10.1177/0144598719831397
|
[22] |
LI Y B,SONG D Y,LIU S M,et al. Evaluation of pore properties in coal through compressibility correction based on mercury intrusion porosimetry:A practical approach[J]. Fuel,2021,291:120130. doi: 10.1016/j.fuel.2021.120130
|
[23] |
WANG W D,LIU Z,ZHANG M R,et al. Experimental study on fractal characteristics of adsorption pore structure of coal[J]. Processes,2023,11(1):78.
|
[24] |
LU G W,WANG J L,WEI C T,et al. Pore fractal model applicability and fractal characteristics of seepage and adsorption pores in middle rank tectonic deformed coals from the Huaibei coal field[J]. Journal of Petroleum Science and Engineering,2018,171:808−817. doi: 10.1016/j.petrol.2018.07.074
|
[25] |
ZOU G G,SHE J S,PENG S P,et al. Two-dimensional SEM image-based analysis of coal porosity and its pore structure[J]. International Journal of Coal Science & Technology,2020,7(2):350−361.
|
[26] |
SUN L L,ZHANG C,WANG G,et al. Research on the evolution of pore and fracture structures during spontaneous combustion of coal based on CT 3D reconstruction[J]. Energy,2022,260:125033. doi: 10.1016/j.energy.2022.125033
|
[27] |
任少魁,秦玉金,贾宗凯,等. 不同煤阶煤孔隙结构分形表征及其对甲烷吸附特性的影响[J]. 煤矿安全,2023,54(5):175−181.
REN Shaokui,QIN Yujin,JIA Zongkai,et al. Fractal characterization of pore structure of coal with different ranks and its effect on methane adsorption characteristics[J]. Safety in Coal Mines,2023,54(5):175−181.
|
[28] |
FAN L L,MENG X L,ZHAO J Q,et al. Pore Structure evolution and fractal analysis of Shenhua non-caking coal during low-temperature oxidation[J]. Energy Sources,Part A:Recovery,Utilization,and Environmental Effects,2022,44(3):6856−6867.
|
[29] |
CHEN Y L,WANG X L,HE R. Modeling changes of fractal pore structures in coal pyrolysis[J]. Fuel,2011,90(2):499−504. doi: 10.1016/j.fuel.2010.10.016
|
[30] |
CAI Y D,LIU D M,YAO Y B,et al. Fractal characteristics of coal pores based on classic geometry and thermodynamics models[J]. Acta Geologica Sinica-English Edition,2011,85(5):1150−1162. doi: 10.1111/j.1755-6724.2011.00547.x
|
[31] |
FEI H,HU S,XIANG J,et al. Study on coal chars combustion under O2/CO2 atmosphere with fractal random pore model[J]. Fuel,2011,90(2):441−448. doi: 10.1016/j.fuel.2010.09.027
|
[32] |
李祥春,高佳星,张爽,等. 基于扫描电镜、孔隙−裂隙分析系统和气体吸附的煤孔隙结构联合表征[J]. 地球科学,2022,47(5):1876−1889.
LI Xiangchun,GAO Jiaxing,ZHANG Shuang,et al. Combined characterization of scanning electron microscopy,pore and crack analysis system,and gas adsorption on pore structure of coal with different volatilization[J]. Earth Science,2022,47(5):1876−1889.
|
[33] |
YU B M,LEE L J,CAO H Q. A fractal in-plane permeability model for fabrics[J]. Polymer Composites,2002,23(2):201−221. doi: 10.1002/pc.10426
|
[34] |
李祥春,黄涛,陈小龙,等. 煤基质变形影响下含瓦斯煤渗透率动态变化规律[J]. 天然气工业,2020,40(1):83−87.
LI Xiangchun,HUANG Tao,CHEN Xiaolong,et al. Dynamic change laws of the permeability of coal containing gas under the effect of coal matrix deformation[J]. Natural Gas Industry,2020,40(1):83−87.
|
[35] |
吴世跃. 煤层气与煤层耦合运动理论及其应用的研究:具有吸附作用的气固耦合理论[D]. 沈阳:东北大学,2006.
WU Shiyue. Study on coupled motion theory of coalbed methane and coal seam and its application:Gas-solid coupling theory with adsorption[D]. Shenyang:Northeastern University,2006.
|
[36] |
LEE G J,PYUN S I,RHEE C K. Characterisation of geometric and structural properties of pore surfaces of reactivated microporous carbons based upon image analysis and gas adsorption[J]. Microporous and Mesoporous Materials,2006,93(1−3):217−225. doi: 10.1016/j.micromeso.2006.02.025
|
[37] |
THOMMES M,KANEKO K,NEIMARK A V,et al. Physisorption of gases,with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report)[J]. Pure and Applied Chemistry,2015,87(9−10):1051−1069. doi: 10.1515/pac-2014-1117
|
[38] |
张同浩,陈明义,田富超,等. 褐煤中CH4/O2/N2气体竞争吸附特性的分子模拟研究[J]. 矿业科学学报,2023,8(6):817−827.
ZHANG Tonghao,CHEN Mingyi,TIAN Fuchao,et al. Molecular simulation on competitive adsorption characteristics of CH4/O2/N2 gas in lignite[J]. Journal of Mining Science and Technology,2023,8(6):817−827.
|
[39] |
杨德金,杨胜强,季广瑞,等. 不同氧浓度下煤体低温氧化过程中物化参数变化规律研究[J]. 煤矿安全,2021,52(4):39−44.
YANG Dejin,YANG Shengqiang,JI Guangrui,et al. Variation of physicochemical parameters of coal during low temperature oxidation under different oxygen concentrations[J]. Safety in Coal Mines,2021,52(4):39−44.
|
[40] |
程远平,胡彪. 基于煤中甲烷赋存和运移特性的新孔隙分类方法[J]. 煤炭学报,2023,48(1):212−225.
CHENG Yuanping,HU Biao. A new pore classification method based on the methane occurrence and migration characteristics in coal[J]. Journal of China Coal Society,2023,48(1):212−225.
|
[41] |
朱建芳,申嘉辉,宋富美,等. 煤自燃机制的TG-FTIR研究[J]. 中国安全科学学报,2019,29(12):46−52.
ZHU Jianfang,SHEN Jiahui,SONG Fumei,et al. TG-FTIR study on coal spontaneous combustion mechanism[J]. China Safety Science Journal,2019,29(12):46−52.
|
[42] |
王继仁,邓存宝,单亚飞,等. 煤的自燃倾向性新分类方法[J]. 煤炭学报,2008,33(1):47−50.
WANG Jiren,DENG Cunbao,SHAN Yafei,et al. A new classifying method of the spontaneous combustion tendency[J]. Journal of China Coal Society,2008,33(1):47−50.
|
[43] |
郝建峰. 基于解吸热效应的煤与瓦斯热流固耦合模型及其应用研究[D]. 阜新:辽宁工程技术大学,2021.
HAO Jianfeng. Study on fluid-solid coupling model of coal and gas heat based on desorption thermal effect and its application[D]. Fuxin:Liaoning Technical University,2021.
|
[44] |
李子文,郝志勇,庞源,等. 煤的分形维数及其对瓦斯吸附的影响[J]. 煤炭学报,2015,40(4):863−869.
LI Ziwen,HAO Zhiyong,PANG Yuan,et al. Fractal dimensions of coal and their influence on methane adsorption[J]. Journal of China Coal Society,2015,40(4):863−869.
|