沿空留巷下综放工作面采空区瓦斯运移及抽采特征研究

Goaf gas migration and extraction characteristics of in fully mechanized top coal caving face with gob-side entry retaining

以古汉山矿1604综放工作面为研究对象,采取风量测定法及示踪气体法相结合的手段,分析了沿空留巷及“Y”型通风条件下采空区漏风及瓦斯运移规律,并结合抽采浓度及流量变化,分析了高位巷瓦斯抽采特征及影响因素,提出了针对性优化措施。结果表明:沿空留巷段漏风加大了采空区瓦斯涌出量及涌出范围,采空区瓦斯为工作面瓦斯涌出主要来源,漏风作用进一步增大了采空区瓦斯治理难度;高位巷布置在裂隙带下部,在一定程度上改变了采空区风流流动方向、削弱了采空区瓦斯涌出强度,但持续增大高位巷抽采流量,抽采纯量提高有限,当抽采流量在20~25m^(3)/min时,抽采浓度整体较高;采取有效措施减少沿空留巷段漏风并合理控制高位巷抽采流量,将有效降低漏风对抽采瓦斯的稀释作用,提高抽采浓度,实现抽采效率和效果最大化。

Taking 1604 fully mechanized top coal caving face as the research object,the law of air leakage and gas migration in goaf under the condition of gob-side entry retaining and“Y”ventilation is analyzed by air volume measurement and tracer gas method,and combining with the variation of extraction concentration and flow,the characteristics and influencing factors of gas extraction in high level roadway are analyzed,and targeted optimization measures are put forward.The results show that:the air leakage in the roadway section along the goaf increases the amount and range of gas emission in the goaf,and the gas in the goaf is the main source of gas emission in the working face,and the air leakage further increases the difficulty of gas control in the goaf;the high-level roadway is arranged at the lower part of the fracture zone,which changes the air flow direction of the goaf and weakens the gas emission intensity of the goaf,but the extraction flow of the high-level roadway continues to increase,and the improvement of the extraction purity is limited,the extraction concentration is relatively high when the extraction flow is 20~25 m^(3)/min;the mine adopts effective measures to reduce air leakage in the retained roadway along the goaf and reasonably control the extraction flow of the high level roadway,which will weaken the dilution effect of air leakage on the extracted gas,improve the extraction concentration and maximize the extraction efficiency and effect.