【作者】 李云波；

【导师】 张子敏； 张玉贵；

【作者基本信息】 河南理工大学 ， 安全技术及工程， 2011， 硕士

【摘要】 构造煤的低强度、高储能、快速解吸和低渗透性的特性是造成煤与瓦斯突出的根本原因,是造成瓦斯含量测算不准、瓦斯聚集致灾的重要原因,也是构造煤发育区煤层气难抽采的直接原因。本论文以构造煤瓦斯解吸初期特征为研究核心,立足于分析煤体结构物性差异,优化建立了构造煤瓦斯解吸初期实验装置,分别对鹤壁、平顶山构造煤和原生结构煤进行了瓦斯解吸初期特征实验室实验,得出了构造煤瓦斯解吸初期阶段解吸模式,分析了构造煤瓦斯解吸初期特征的影响因素,建立了构造煤瓦斯解吸数学模型,最后对瓦斯含量测定中的瓦斯损失补偿方法进行了探讨并进行了实际考察。本论文取得的主要结论如下:（1）同一地点的构造煤和原生结构煤吸附能力差别不大,但构造煤初期瓦斯解吸速度和解吸量远大于原生结构煤。在瓦斯解吸的0-3min内的瓦斯解吸量、解吸速度与解吸时间t呈现幂指数关系,解吸量曲线符合Q=At^b的形式,瓦斯速度曲线符合Vt=At-b形式。（2）构造煤初始瓦斯解吸速度大,解吸速度衰减快,但衰减率相差不大,构造煤和原生结构煤瓦斯解吸初期规律差异主要表现在第1min。构造煤第1min解吸速度V1在1.225⁴.197 ml/（g·min）,原生结构煤V₁速度在0.485³.683 ml/（g·min）,构造煤解吸速度是原生结构煤解吸速度的1.25².84倍;实验显示构造煤瓦斯解吸前10s、30s、1min、3min、10min瓦斯量占60min瓦斯解吸量的比例分别为:16%、24%、31%、45%和64%。（3）瓦斯解吸速度与解吸时间曲线总是呈现一下降的单调有限函数。粒度越大瓦斯解吸速度越小,吸附平衡压力越大解吸速度越大,且构造煤的瓦斯解吸初速度要大于原生结构煤,煤体破坏程度越高,粒度对瓦斯解吸初速度的影响越小。（4）将实验室测定的构造煤瓦斯解吸初期数据与现有的经验公式拟合比较后发现,构造煤瓦斯解吸的0-3min内的解吸规律与文特式拟合效果较好,即在双对数坐标下构造煤瓦斯解初期解吸量与解吸时间呈线性关系: Ln （V_t ） = BL n（t ）+ c。（5）依据实验结果,分析了影响构造煤初期解吸规律的因素。变质作用不但产生了气源,而且影响了煤中孔隙由大孔向中孔、小孔的演变,孔隙形状由开放孔向封闭孔的转变并伴随畸形孔的产生;煤粒中大孔、中孔的分布及连通性决定了瓦斯运移初期能力的强弱;此外,煤粒粒度越大瓦斯解吸速度和解吸量越小,衰减越慢,粒度与瓦斯解吸量之间符合关系式: Qt = ax²+ bx + c,且随解吸时间的增加,a、c值增加、b值减小;吸附平衡压力与瓦斯解吸速度V₁之间符合V₁ = B·P^k_p。（6）提出了构造煤瓦斯解吸曲线的分段函数数学模型。认为构造煤0-3min的瓦斯解吸特征公式为:经实验验证后效果较好,可作为工程应用。更多还原

【Abstract】 Tectonic coal with low intensity, high energy storage, rapid desorption and low permeability are caused to the coal and gas outburst. The characteristics of tectonic coal are the important reason of gas accumulation, which to cause the coal mine disasters, and that is the essence reason of can not determinate gas content accurately and difficult extract CBM directly.The research core is initial stage features of tectonic coal gas desorption,which based on the structure of coal. The test device has designed and experimental studies of initial stage features of gas desorption of Hebi, Pingdingshan tectonic coal and undeformed coal have been tested. Then analysed the influence factors and established the tectonic coal gas initial desorption model, at last discussed the gas loss compensation method in gas content determination.The main conclusions are as follows:（1） The adsorption ability of tectonic coal and undeformed coal in the same place, however, the ability of tectonic coal gas desorption in initial stage is far greater than undeformed coal. The desorption rate and relationship meet Q=At^-b and the desorption and desorption time curve consistent with V_t = At^b during the 0 to 3minutes.（2） Tectonic coal has large desorption speed and quick decline. Initial stage gas desorption of tectonic coal and undeformed coal differences mainly manifested at first minute. Tectonic coal gas desorption rate distribution range is 1.225 4.197 ml/ （g·min） which is 1.25².84 to undeformed coal,which desorption rate distribution range is 0.485³.683 ml/ （g ? min）. Experiments showed that construction of coal gas desorption before the 10s, 30s, 1min, 3min, 10min gas volume To 60min the proportion of the gas desorption, respectively: 16%, 24%, 31%, 45% and 64%.（3） The curve of initial stage gas desorption of tectonic coal and undeformed coal always formulated a monotonic decreasing function. The bigger particle size the lower desorption speed, the higher adsorption balance pressure the higher desorption speed, the higher the damage degree of coal the little more influence to desorption speed.（4） Compered determination data of features of with the existing empirical formula, 0-3minute of tectonic coal initial stage gas desorption laws are draw up to match effective Winter type. Initial stage features of tectonic coal gas desorption and desorption time showed linear relationship, fitting: Ln （V t ） = BL n（t ）+ cunder the bi-logarithm coordinates.（5） According to the experimental results, analysis the influence factors of tectonic coal initial desorption factors. Metamorphism not only produced gas but also reshaped the pore structure of tectonic coal, which transformed macropore to mesopore and micropore, and which from open hole to closed hole along with the produce deformity hole. Distribution characteristics of mesopore and micropore decide the ability of initial stage features of tectonic coal gas desorption. Between size and quantity of gas desorption with equation: Qt = ax²+ bx + c.With the increasing of desorption time, a c increased but b decreased. Between Adsorption gas balanced pressure and desorption speed meet: V₁ = B·P^k_p.（6） Puts forward the piecewise functions of tectonic coal gas desorption. And consider that the tectonic coal 0-3min gas desorption characteristics formula should be expressed as follows:Better effects after experimented, and can be used for engineering application.更多还原