摘要
针对近距离煤层群开采过程中工作面瓦斯浓度频繁超限的问题,以重庆松藻矿区为例测试了煤体孔隙结构和吸附能力,现场对比了裂隙带高位抽采钻孔、高位抽采巷道和采空区抽采钻孔3种方法防治瓦斯超限效果。结果表明:煤体大孔与裂隙不发育,渗透率低,瓦斯预抽效果差,开采卸压导致工作面瓦斯超限。裂隙带高抽巷作用下平均瓦斯抽采量为12.6 m^3/min,平均瓦斯抽采体积分数为32.75%,与高位抽采钻孔相比分别提高了5倍和2.8倍。采空区抽采钻孔与冒落带连通导致工作面空气进入高抽巷,平均瓦斯抽采体积分数降低至28.19%,抽采量为11.38 m^3/d。高抽巷方法使工作面尾排瓦斯平均体积分数降低了63.2%,上隅角瓦斯平均体积分数降低了19.6%,杜绝了工作面瓦斯超限事故的发生,单月工作面推进效率平均提高了46.7%,10个月共抽采可直接利用瓦斯441.7万m^3,取得了良好的经济社会效益。
In order to prevent the gas overrun in the mining process of contiguous seams, the gas overrun mechanism was analyzed by the pore structure and adsorption capacity test of the coal in Songzao mining area of Chongqing.On-site tests were conducted to compare the effect of preventing gas overrun by the following three methods: high-level drainage borehole, high-level drainage roadway and gob drainage borehole.The results showed that the coal pores and fissures are not developed and the permeability is low,the gas pre-drainage effect is poor, and the mining pressure relief causes gas overrun.With the method of high level drainage roadway in fractured zone, the average amount of gas drainage was12.6 m3/min and average gas concentration was32.75%, which was 5 times and2.8 times higher than that of the high-level drainage borehole method. The drainage hole in the gob is connected with the falling belt, which causes the working face air to enter the high level drainage roadway. The average gas drainage concentration is thus reduced to28.19%, and the drainage volume is11.38 m3/d.The high level drainage roadway method reduce the average gas concentration in the tail of the working face by 63.2%, and the average concentration of the gas in the corner are reduced by19.6%. This prevented the occurrence of gas overrun accidents on the working face, and the average efficiency of single-month working face increased by46.7%. The total drainage of direct usable gas in ten months reached4.417 million m3, and achieved good economic and social benefits.
作者
杨枫
郑金龙
王联
YANG Feng;ZHENG Jinlong;WANG Lian(School of Civil Engineering, Southwest Jiaotong University, Chengdu 600041,China;Sichuan Province Transportation Department Highway Planning, Survey, Design and Research Institute,Chengdu 600041,China)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2019年第5期126-131,共6页
Coal Science and Technology
基金
国家科技重大专项资助项目(2016ZX05045)
国家自然科学基金资助项目(51804261)
关键词
高抽巷
瓦斯浓度
瓦斯纯量
近距离煤层
瓦斯超限
high level drainage roadway
gas concentration
gasamount
contiguous seams
gas overrun
