【作者】 王海生；

【导师】 高建良；

【作者基本信息】 河南理工大学 ， 安全技术及工程， 2010， 硕士

【摘要】 回采工作面采空区漏风对于采空区遗煤自燃发火和采空区瓦斯分布及其涌出有重要的影响。渗透率是解算采空区流场的关键参数,渗透率的变化对采空区的流场有很大的影响,而综采支架的存在,影响工作面向采空区的漏风。根据多孔介质渗流理论,利用计算流体力学软件Fluent,模拟了不同渗透率大小、不同渗透率分布及是否有综采支架三种情况下的采空区的流场,通过对采空区三带、漏风量、漏风风速等的比较,分析研究了采空区渗透率变化及采面是否有综采支架的不同情况对漏风流场解算结果的影响。结果表明采空区渗透率连续分布条件下的漏风分布与假设分段均匀分布和均匀分布条件下的漏风量、漏风风速分布和自燃三带的位置和宽度有很大的差别。当渗透率均匀分布时漏风量小,自燃带靠近工作面。而采空区分区处理时,由于渗透率在采空区分区界面上不连续,使速度在分区界面上产生跳跃;有综采支架时,工作面向采空区的漏风量过小,致使采空区的速度很小,自燃带靠近工作面。为了得到接近实际采空区的风流流动规律,解算采空区流场既要考虑综采支架,还要采用更能如实反映采空区岩石冒落和压实规律的渗透率分布。更多还原

【Abstract】 Air leakage from coal mining face to gob has great influence on gas distribution and emission as well as spontaneous combustion in waste. Permeability is a key factor to air leakage, its value and distribution influences greatly the distribution of air leakage. The mechanized support influence air leakage from working face to gob.According to the percolation theory of porous media, computational fluid dynamics software Fluent is applied respectively to simulate the distribution of air leakage in gob at various supposes of permeability distribution, permeability magnitude and mechanized support. The paper analyses the influence factors on leakage flow field solution, such as gob permeability and fully mechanized support. It shows that the quantity of air leakage and distribution of air velocity, three zones of spontaneous combustion vary largely under condition of different distributions of permeability, that is, continuous distribution, three uniform distribution zones and one even distribution zone. When gob permeability is one even distribution zone, quantity of air leakage is small and spontaneous combustion zone is close to the working face. In case of dividing the gob into three zones, in each zone the permeability distributing uniformly, it leads that the air leakage velocity jump at the boundary of zones because the permeability distribution is not continuous. When working face has mechanized support, air leakage quantity is small, velocity is low in goaf, and spontaneous combustion zone is more approach to working face. Therefore, distribution of permeability and mechanized support should be considered carefully as precise as possible in order to get the distribution in gob.更多还原