摘要
综放工作面回采过程中采空区遗煤自然发火是矿井生产过程中经常出现的自然灾害。由于复杂的地质及漏风情况,其危险性增大,而合理的防治措施是避免事故发生的关键。因此,以孔庄煤矿7465工作面为研究对象,首先利用Fluent软件模拟采空区压注二氧化碳后风压场分布、氧气与二氧化碳浓度场分布,数值模拟结果表明:压注二氧化碳在一定程度上可以减小采空区漏风量,稀释氧气体积分数、减小自燃区面积、惰化采空区。其次开展了采空区注浆、注氮、注二氧化碳的现场试验,并对3种措施的防灭火效果进行了对比分析。结果表明:采空区每日进行注浆后,各测点CO浓度呈下降趋势最终稳定在300×10^(-6)左右;对采空区注氮4 d后,各测点CO浓度下降至100×10^(-6)以下,在停止注氮后CO呈上升趋势,采空区出现复燃;最终向现场连续压注5 d,累计压注150 t左右二氧化碳之后,采空区发火得到有效治理,采空区CO浓度降至50×10^(-6)左右,工作面、回风流和上隅角未检测到C_(2)H_(4)气体。对比注浆、注氮技术,验证二氧化碳防灭火技术具有灭火速度快、不易复燃、现场适用性强的优势。对采空区遗煤自然发火灾害防治有重要的指导作用。
The natural combustion of the left coal in goaf in the process of fully mechanized caving face is a natural disaster that often appears in the process of mine production.Due to the complicated geology and air leakage,the risk of coal spontaneous combustion in goaf increases,and reasonable prevention and control measures are the key to avoid accidents.Therefore,taking the 7465 working face of Kongzhuang Coal Mine as the research object,Fluent software is firstly used to simulate the distribution field of wind pressure,oxygen and carbon dioxide concentration field after CO_(2) injection in the goaf.The results of numerical simulation show that CO_(2) injection can reduce air leakage,dilute oxygen volume fraction,reduce spontaneous combustion area and inert goaf.Secondly,field tests of goaf grouting,nitrogen injection and CO_(2) injection were carried out,and the fire prevention and extinguishing effects of the three measures were compared and analyzed.The results show that after daily grouting in the goaf,the CO concentration at each measuring point shows a downward trend and finally stabilates at about 300×10^(-6).After injecting nitrogen into the goaf for 4 days,CO concentration at each measuring point decreased to less than 100×10^(-6),after nitrogen injection was stopped,CO showed an upward trend,and the goaf reignited.Finally,the goaf combustion was effectively controlled after continuous injection of about 150 tons of carbon dioxide for 5 days.After the completion of pressure injection,the CO concentration in the goaf decreased to about 50×10^(-6),and no C_(2)H_(4) gas was detected in the working face,return air flow and upper corner.Compared with grouting and nitrogen injection technology,it is verified that carbon dioxide fire prevention technology has the advantages of fast fire suppression,not easy to relapse,and strong on-site applicability.It has an important guiding effect on the prevention and control of coal spontaneous combustion in goaf.
作者
王国芝
姜奎
王怡
姚向东
吴奎斌
WANG Guozhi;JIANG Kui;WANG Yi;YAO Xiangdong;WU Kuibin(College of Safety and Environmental Engineering,Shandong University of Science and Technology,Qingdao 266590,Chi-na;Ventilation Department of Jiangsu Branch of Shanghai Datun Energy Co.,Ltd.,Xuzhou 221600,China)
出处
《金属矿山》
CAS
北大核心
2021年第10期214-220,共7页
Metal Mine
关键词
综放工作面
采空区
自然发火
CO_(2)防灭火
数值模拟
指标气体
fully mechanized caving face
goaf
spontaneous combustion
CO_(2)fire prevention
numerical simulation
in-dex gas
