瓦斯安全抽采及其建模

为提高煤矿瓦斯抽采运行过程的安全性,围绕瓦斯抽采过程由于空气的导入而造成抽采区域煤自燃、抽采管网中瓦斯燃爆等潜在风险开展研究,明确给出了瓦斯安全抽采的概念,提出了瓦斯安全抽采的定量评价指标——抽采安全度,并通过联立煤层瓦斯抽采中气体扩散-渗流,煤-氧反应以及热量传输方程,定量描述了抽采过程中场流演化,建立了抽采安全度的计算模型。以盘江煤电山脚树矿瓦斯抽采工程为例,揭示了抽采负压、封孔质量、巷道卸压区渗透率、煤层瓦斯吸附特性及煤自燃特性等因素对抽采安全度的影响机理,给出了提高抽采安全度的技术措施。

A model of safe drainage of coal seam gas

While the gas drainage efficiency has attracted much attention，the importance of safe drainage should be recognized.Under the effect of gas drainage，air flows into the drainage borehole through fractures，providing sufficient oxygen for coal spontaneous combustion and making gas drainage concentration decline into the explosion scope.Based on the risk of coal spontaneous combustion induced by gas drainage and gas explosion in the drainage pipe，the concept of safe drainage was proposed，and the safety factor was defined to quantitatively evaluate the security of gas drainage.By establishing the seepage and diffusion of multicomponent gas，coal-oxygen reaction and heat transfer equations and analyzing the evolution of multicomponent gas flow，oxygen concentration and temperature field，the theoretical model for safe drainage of coal seam gas was built.Taking gas drainage project in Shanjiaoshu Mine of Panjiang Coal and Electricity Group as example，the influence of negative pressure，sealing quality，permeability of distressed zone，gas absorption speciality and coal spontaneous combustion characteristics on safety factor of gas drainage were studied，and some technical measures to ensure the safe drainage were given.