Characteristics of air leakage and gas migration in goaf of pillarless coal mining face

doi:10.16265/j.cnki.issn1003-3033.2024.11.1721

Abstract

Abstract:

To understand the characteristics of goaf air leakage and gas migration in different mining periods of Y-type ventilation working face without coal pillar mining, 97312 working face in Sihe No.2 coal mine of Jinneng Holding Equipment Manufacturing Group Co., Ltd. was selected. The sulfur hexafluoride (SF₆) tracer gas approach was used to determine the air leakage area distribution, air leakage type, and air leakage volume of 97312 working face and the roadways under different connectivity states with the adjacent 97311 working face goaf. The air leakage flow field distribution and gas migration characteristics in the goaf area were analyzed by numerical simulation. The results showed that 97312 working face had four air leakage areas of positive pressure-negative pressure-positive pressure-negative pressure along the wind direction. The main air intake roadway 97222 had positive pressure leakage. The air return roadway 97224 had mainly negative pressure air leakage along the gob-side entry retaining section, but positive pressure leakage was prone to occur near the extraction pipe and in the area where the roadway was severely deformed. After connectivity with the adjacent goaf area, an additional air leakage path was created. Moreover, the connection status with the adjacent goaf affected the internal air leakage flow field and gas migration of the goaf. Air leakage from the 97311 goaf area carried gas to the 97312 goaf, causing an increase in gas volume fraction in the 97312 goaf, working face, and the gob-side entry retaining section of the 97224 roadway. After the closure of the 97311 working face, the gas volume fraction near the connected goaf area decreased.

Key words: pillarless, coal mining face, air leakage in goaf, gas migration, Y-type ventilation, gob-side entry retaining, connection state of goaf

CLC Number:

X936

ZHANG Zunguo, ZHANG Honghu, TANG Chao, YUAN Xinli, CHEN Yongqiang. Characteristics of air leakage and gas migration in goaf of pillarless coal mining face[J]. China Safety Science Journal, 2024, 34(11): 119-130.

Figures/Tables 13

Fig.1

Fig.2

Fig.3

Table 1

Table 2

Table 3

Fig.4

Fig.5

Table 4

Fig.6

Fig.7

Fig.8

Fig.9

References 20

[1]	何满潮, 马新根, 牛福龙, 等. 中厚煤层复合顶板快速无煤柱自成巷适应性研究与应用[J]. 岩石力学与工程学报, 2018, 37(12): 2 641-2 654.
	HE Manchao, MA Xin'gen, NIU Fulong, et al. Adaptability research and application of rapid gob-side entry retaining formed by roof cutting and pressure releasing with composite roof and medium thick coal seam[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(12): 2 641-2 654.
[2]	杨红运, 刘延保, 李勇, 等. 近距离煤层群切顶留巷覆岩应力及变形响应研究[J]. 矿业安全与环保, 2022, 49(1): 8-13, 19.
	YANG Hongyun, LIU Yanbao, LI Yong, et al. Study on strata stress and deformation response of contiguous seams under cutting roof for entry retaining[J]. Mining Safety & Environmental Protection, 2022, 49(1): 8-13, 19.
[3]	闫肃. 深部厚硬顶板厚煤层切顶成巷综采工作面采空区漏风规律研究[D]. 淮南: 安徽理工大学, 2021.
	YAN Su. Research on the law of air leakage in the goaf of fully mechanized coal mining face in deep thick hard roof thick coal seam[D]. Huainan: Anhui University of Science and Technology, 2021.
[4]	王琰, 周建, 王元. 高地温综放工作面采空区漏风规律研究[J]. 煤炭科学技术, 2020, 48(增2): 155-158.
	WANG Yan, ZHOU Jian, WANG Yuan. Study on air leakage law of goaf in fully mechanized top coal caving face with high ground temperature[J]. Coal Science and Technology, 2020, 48(S2): 155-158.
[5]	赵文彬, 刘方顺, 石新岩, 等. 放顶煤工作面立体自燃带动态变化特性研究[J]. 中国安全科学学报, 2022, 32(3): 65-74. doi: 10.16265/j.cnki.issn1003-3033.2022.03.009
	ZHAO Wenbin, LIU Fangshun, SHI Xinyan, et al. Research on dynamic change characteristics of three-dimensional spontaneous combustion zone in caving coal face[J]. China Safety Science Journal, 2022, 32(3): 65-74. doi: 10.16265/j.cnki.issn1003-3033.2022.03.009
[6]	王炯, 刘鹏, 姜健, 等. 切顶卸压沿空留巷回采工作面Y型通风漏风规律研究[J]. 采矿与安全工程学报, 2021, 38(3): 625-633.
	WANG Jiong, LIU Peng, JIANG Jian, et al. Y-shaped ventilation air leakage law of working face of gob-side entry retaining by cutting roof to release pressure[J]. Journal of Mining & Safety Engineering, 2021, 38(3): 625-633.
[7]	杜云飞. 切顶卸压留巷Y型通风模式下采空区漏风特性研究[D]. 焦作: 河南理工大学, 2018.
	DU Yunfei. Study on the characteristics of air leakage in the goal under a Y type ventilation system using cutting roof and release pressure method mining[D]. Jiaozuo: Henan Polytechnic University, 2018.
[8]	LI Tengteng, WU Bing, LEI Baiwei, et al. Study on air leakage and gas distribution in goaf of Y-type ventilation system[J]. Energy Sources Part A Recovery Utilization and Environmental Effects, 2020, 46(1):8632-8 645.
[9]	李艳昌, 靖泽浩, 贾进章. 切顶卸压沿空留巷“Y”型通风模式下采空区漏风规律研究[J]. 自然灾害学报, 2022, 31(3): 184-189.
	LI Yanchang, JING Zehao, JIA Jinzhang. Study on the air leakage law of goaf under the "Y" ventilation mode of gob-side entry retaining with roof cutting and pressure relief[J]. Journal of Natural Disasters, 2022, 31(3): 184-189.
[10]	ZHOU Xihua, JING Zehao, LI Yanchao. Research on controlling gas overrun in a working face based on gob-side entry retaining by utilizing ventilation type "Y"[J]. Scientific Reports, 2023, 13(1):DOI:10.1038/s41598-023-36464-y.
[11]	MT/T 845—1999, 煤矿巷道用SF₆示踪气体检测漏风技术规范[S].
	MT/T 845-1999, Technical specification of leakage detection with SF₆ tracer gas in roadways of coal mines[S].
[12]	杨明, 高建良, 冯普金. U型和Y型通风采空区瓦斯分布数值模拟[J]. 安全与环境学报, 2012, 12(5): 227-230.
	YANG Ming, GAO Jianliang, FENG Pujin. Numerical simulation of gas distribution in goaf with U-type and Y-type ventilation[J]. Journal of Safety and Environment, 2012, 12(5): 227-230.
[13]	陶远, 秦汝祥, 庞文华. U型综采工作面采空区流场数值模拟[J]. 煤矿安全, 2014, 45(1): 186-188,191.
	TAO Yuan, QIN Ruxiang, PANG Wenhua. Numerical simulation of goaf flow field for U-type fully mechanized working face[J]. Safety in Coal Mines, 2014, 45(1): 186-188,191.
[14]	陈向军, 刘金钊, 司朝霞, 等. 切顶卸压留巷开采模式下工作面及采空区内风流运移特性[J]. 河南理工大学学报:自然科学版, 2020, 39(6): 1-9.
	CHEN Xiangjun, LIU Jinzhao, SI Zhaoxia, et al. Characteristics of air flow in working face and goaf under the mining mode of pressure relief by roof cutting of retaining gateway[J]. Journal of Henan Polytechnic University :Natural Science, 2020, 39(6): 1-9.
[15]	王春霞, 艾德春, 杨付领, 等. 风帘对采空区漏风及工作面瓦斯分布的影响[J]. 煤炭技术, 2019, 38(6): 101-102.
	WANG Chunxia, AI Dechun, YANG Fuling, et al. Influence of wind curtain on distribution of air leakage in gob and gas in working face[J]. Coal Technology, 2019, 38(6): 101-102.
[16]	杨永亮. 110工法工作面采空区漏风及煤自燃与瓦斯复合灾害研究[D]. 青岛: 青岛理工大学, 2023.
	YANG Yongliang. Study on air leakage and coal spontaneous combustion and gas compound disaster in the mining area of 110 working face[D]. Qingdao: Qingdao University of Technology, 2023.
[17]	刘宇. 采空区瓦斯与自燃灾害关联3D数值模拟研究[D]. 阜新: 辽宁工程技术大学, 2014.
	LIU Yu. Three-dimensional numerical simulation research on correlation of gas and spontaneous combustion disaster in goaf[D]. Fuxin: Liaoning Technical University, 2014.
[18]	CARMAN P C. Permeability of saturated sands, soils and clays[J]. The Journal of Agricultural Science, 1939, 29(2): 263-273.
[19]	高光超, 李宗翔, 张春, 等. 基于三维“O”型圈的采空区多场分布特征数值模[J]. 安全与环境学报, 2017, 17(3): 931-936.
	GAO Guangchao, LI Zongxiang, ZHANG Chun. Numerical simulation for multi-field distribution characteristic features of the goaf based on 3D "O" type circle[J]. Journal of Safety and Environment, 2017, 17(3): 931-936.
[20]	国家安全监管总局, 国家煤炭安监局, 国家能源局, 等. 建筑物、水体、铁路及主要井巷煤柱留设与压煤开采规范[L]. 2017-05-17.

97224巷	97224巷与97312面距离/m			n/%
	采空区连通前	采空区连通后	97311封闭后	n/%
	(0,150]	(0,200]	(0,200]	5
	(150,250]	(200,300]	(200,400]	6
	(250,280]	(300,330]	(400,600]	8
	(280,320]	(330,370]	(600,800]	12
97222巷	采空区连通后97222巷与 97311面距离/m	n/%	97311工作面封闭后 97222巷与97311面距离/m	n/%
	(0,300}	5	(0,100}	5
	(300,530}	4	(100,570}	1.5
	(530,570}	1.5	-	-

开采时期	几何名称	长×宽×高/(m×m×m)	几何名称	长×宽×高/(m×m×m)
采空区连通前	97222巷	50×5×2.6	97312采空区	320×215×40
	97224巷	370×5×2.6	顶板高位钻孔抽采孔	0.113×0.113
	97312工作面	220×5×1.65	采空区埋管抽采孔	0.457×0.457
采空区连通后	97222巷	580×5×2.6	97311采空区	570×175×40
	97224巷	470×5×2.6	97312采空区	370×215×40
	97311工作面	175×4×1.9	顶板高位抽采孔	0.113×0.113
	97312工作面	220×5×1.65	采空区埋管抽采孔	0.457×0.457
97311工作面封闭后	97222巷	150×5×2.6	97311采空区	570×170×40
	97224巷	860×5×2.6	97312采空区	800×215×40
	97311工作面	170×4×1.9	顶板高位抽采孔	0.113×0.113
	97312工作面	220×5×1.65	采空区埋管抽采孔	0.475×0.475

回采时期	97222巷进风量/ (m³·min^-1)	97224巷进风量/ (m³·min^-1)
采空区连通前	1 174	725
采空区连通后	1 664	628
97311工作面封闭后	1 252	1 205

开采时期	校验点	现场瓦斯体积分数	模拟瓦斯体积分数	误差
采空区连通前	97312工作面回风隅角	0.22~0.26	0.22~0.27	0.01
采空区连通前	97224巷尾	0.20	0.19	0.01
采空区连通后	97312工作面进风隅角	0.06~0.08	0.06~0.07	0.01
	97224巷胶带机头	0.04	0.04	0
	97224巷尾	0.20~0.38	0.20~0.34	0.04
97311工作面封闭后	97224巷沿空留巷段距离97312 工作面300m	0.20	0.25	0.05
97311工作面封闭后	97224巷沿空留巷段距离97312 工作面600m	0.30	0.27	0.03