沿空留巷开采中堵漏的必要性分析

Study on necessity to apply the plugging in mining of gob-side entry retaining

沿空留巷开采技术已在很多矿区得到广泛应用,在提高回采率、减少巷道掘进工程量的同时,却也加剧了采空区的漏风量。为了说明漏风给采空区防灭火工作造成的不利影响,强调堵漏在沿空留巷开采中应用的必要性,本文采用有限单元法对采空区速度场和氧浓度场进行了数值模拟,通过两者叠加划分出了自燃"三带",并在数学模型的建立过程中考虑了遗煤氧化及采空区瓦斯涌出对氧气的稀释作用。计算结果表明:堵漏前自燃带最大宽度为196m,平均宽度为110m;堵漏后自燃带最大宽度为70m,平均宽度为63m。由此可见,漏风点的存在对采空区"三带"影响较大,且对采空区防灭火十分不利。所以沿空留巷开采中采取堵漏措施是十分必要的。

It is popular to apply the plugging technology in mining of gob-side entry retaining. It can improve the recovery rate and reduce the tunnel heading amount. At the same time, it can also aggravate the air leakage of goaf. In order to explain the dangerous of air leakages and the necessary of plugging, the finite element method is applied to compute the distributions of seepage velocity field and oxygen concentration in this paper. The ＂ three zones＂ distribution of spontaneous combustion is respectively divided by using the superposition of the fields of seepage velocity and oxygen concentration. And the effect of coal oxidization and gas emission were considered in mathematical model. The computed results show that the maximum width is 196m, the average width is ll0m of spontaneous combustion zone before plugging, the values respectively turn to 70m and 63m after plugging. Therefore, the existence of leakages have great effect no the ＂three zones＂ distribution of spontaneous combustion, and it is very unfavorable to mine fire control. It is so necessary to apply the plugging measures in mining of gob-side entry retaining.