Liu Jun, Wang Zheng, Wang Qian, Zou Sicong, Yang Xinglong
School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000, China.
State Key Laboratory Cultivation Base for Gas Geology and Gas Control, Jiaozuo, Henan 454000, China.
ACS Omega. 2024 Jul 17;9(30):32777-32788. doi: 10.1021/acsomega.4c03161. eCollection 2024 Jul 30.
In order to address the challenges of high gas outburst in both the adjacent layers and the coal seam itself faced by large mining faces, a study on the three-dimensional extraction of gas from different sources at a large mining face was conducted. Based on the research on the instability and failure characteristics of the overlying strata during mining and the gas outburst characteristics at the large mining face, a source-separated three-dimensional gas extraction system was established. A comprehensive gas management model for the large mining face, involving the extraction of gas from different sources, has been proposed. This model is suitable for gas management at large mining faces where there is a high gas emission in the adjacent layers and a complex structure of the coal seam. Through numerical simulations using FLAC, the height of the "three zones" of the overlying strata and the range of the floor fracture zone at the large mining face were obtained, providing guidance for the layout of high-level drainage roadway, low-level drainage roadway, and floor drainage roadways. Following the coordinated layout of high-level drainage roadway, inclined high-level drainage roadway, and low-level drainage roadway, the reasonable optimization of gas extraction techniques in the coal seam, and the reasonable arrangement of floor rock predrainage roadways, the methane capture efficiency of the large 15115 mining face reached 87.5%. The methane concentrations at the upper corner and in the return airflow being below 0.8%. The methane concentration extracted from the coal seam boreholes is 2.9 times higher than that from the ordinary mining face after adopting "ordinary boreholes + large-diameter boreholes". This gas management model effectively addresses the gas-related challenges of the large mining face and improves the gas extraction rate, achieving harmonious mining and extraction of coal and methane.
为应对大采面面临的邻近层及煤层自身高瓦斯突出挑战，开展了大采面不同源瓦斯三维抽采研究。基于采动覆岩失稳破坏特征及大采面瓦斯突出特征研究，建立了源分离三维瓦斯抽采系统。提出了一种涉及不同源瓦斯抽采的大采面瓦斯综合管理模型。该模型适用于邻近层瓦斯涌出量大、煤层结构复杂的大采面瓦斯管理。通过FLAC数值模拟，得出大采面覆岩“三带”高度及底板破坏带范围，为高位、低位及底板抽放巷道布置提供指导。通过高位抽放巷道、倾斜高位抽放巷道及低位抽放巷道的协同布置，煤层瓦斯抽采技术合理优化，底板岩石预抽巷道合理布置，15115大采面瓦斯抽采效率达到87.5%。上隅角及回风巷瓦斯浓度低于0.8%。采用“普通钻孔+大直径钻孔”后，煤层钻孔瓦斯抽采浓度比普通采面高2.9倍。该瓦斯管理模型有效应对了大采面瓦斯相关挑战，提高了瓦斯抽采率，实现了煤与瓦斯的和谐开采。
