含瓦斯煤体一维渗透失稳数学模型

发布时间：2018-02-28 21:05

本文关键词： 渗透失稳数学模型数值分析构造煤　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：为了研究煤与瓦斯突出过程,把构造煤作为煤与瓦斯突出的物性基础,建立煤与瓦斯一维持续渗透失稳破坏的数学模型。基于已建立的一维渗透失稳判别式,假定煤壁背景气压以指数规律衰减,结合理想气体状态方程、气体运动方程(达西定律)和连续性方程建立含瓦斯煤体一维持续渗透失稳数学模型。采用有限差分法对所建立含瓦斯煤体一维持续渗透失稳数学模型进行求解,分析煤层初次失稳和持续分层失稳过程。计算结果表明:煤层渗透率越大、背景气压消散越慢,则失稳分层厚度越大,分层失稳间隔时间越大;煤壁背景气压消散速率越快,突出强度越大。为了研究煤壁背景气压消散速率对突出强度的影响,采用自制实验装备进行密闭门揭煤实验、砂砾石反滤层揭煤实验、金属栅栏揭煤实验和巷道无障碍揭煤实验。四种揭煤实验均采用经15MPa压力压实的煤样,煤样总质量为35kg,突出后的松散煤样质量分别为0.30kg、1.80kg、5.36kg和23.88kg,突出后的松散煤样质量占总质量比分别为0.85%、5.10%、15.3%和68.4%。实验结果表明:密闭门揭煤实验、反滤层揭煤实验、金属栅栏揭煤实验和巷道无障碍揭煤实验的突出强度依次升高。
[Abstract]:In order to study the process of coal and gas outburst, taking structural coal as the physical property foundation of coal and gas outburst, the mathematical model of one dimensional continuous seepage instability of coal and gas is established. Assuming that the background pressure of coal wall attenuates exponentially, combining with the equation of state of ideal gas, The gas motion equation (Darcy's law) and the continuity equation are used to establish the one-dimensional sustained permeability instability mathematical model of gas-bearing coal body. The finite difference method is used to solve the one-dimensional sustained permeability instability mathematical model of gas-bearing coal body. The calculation results show that the greater the permeability of coal seam, the slower the background pressure dissipation, the greater the thickness of unstable stratification, the longer the interval of stratification instability, the faster the velocity of atmospheric pressure dissipation in coal wall is. In order to study the effect of atmospheric pressure dissipation rate on the outburst strength of coal wall background, the self-made experimental equipment was used to test the closed door uncovering of coal and the sand gravel filter layer to uncover coal. The experiments of removing coal under metal fence and unobstructed coal in roadway are carried out. The four kinds of coal uncovering experiments are all coal samples compacted under 15MPa pressure. The total mass of coal sample is 35 kg, the mass of loose coal sample after outburst is 0.30 kg / 1.80 kg / kg 5.36 kg and 23.88 kg respectively, the ratio of the mass of outburst loose coal sample to the total mass is 0.85% 5.10% and 68.4% respectively. The outburst strength of metal fence uncovering coal experiment and roadway unobstructed coal uncovering experiment increased in turn.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD713

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