【作者】 李希建；

【导师】 林柏泉；

【作者基本信息】 中国矿业大学 ， 安全技术及工程， 2013， 博士

【摘要】 瓦斯灾害不仅是贵州也是全国煤矿面临的重大灾害之一，随着矿井开采深度的增加，瓦斯灾害越来越严重，严重地制约了煤炭工业的持续健康发展。瓦斯灾害是个复杂问题，煤与瓦斯突出机理至今还没有完全清楚。一般认为，煤的物理力学特性、煤层瓦斯和地应力是影响瓦斯灾害的三个重要方面，而每个方面又由许多因素综合作用。本文采用理论分析、物理实验和数值模拟相结合的方法对贵州突出煤的物理化学特性进行了研究，并提出了基于突出煤理化特性的瓦斯防治技术。通过对贵州突出煤的形成及分布规律分析，确定了合理的煤样选取点。研究认为受聚煤盆地、沉积环境、成煤条件、地质运动、控煤构造等因素影响，贵州主要富煤区为六盘水煤田、织纳煤田、黔北煤田、兴义煤田，其赋存煤层大多数为煤与瓦斯突出煤层。通过现场观测及实验室测试分析，从工业分析、元素分析、大分子结构分析及破坏类型、显微结构、孔隙结构、比表面积等几个方面，获得了贵州突出煤的物理化学特性。发现贵州突出煤多为破坏强烈的Ⅲ类煤，平行层理面存有晶体物质，层理面和节理面均有孔隙或裂隙，孔径基本上在0～10nm之间。孔径为3～5nm的微孔在煤样中最为丰富，为瓦斯主要吸附空间。系统地研究了煤对甲烷吸附的分子模拟理论，提出了煤对甲烷吸附的分子模拟算法。针对贵州突出煤对甲烷吸附的特点，提出采用狭缝孔物理模型和微孔填充吸附机理相结合的吸附模型，以及巨正则系统的Monte Carlo理论研究煤的甲烷分子模拟，并通过粒子的插入与删除实现煤对甲烷分子的吸附与解吸过程，获得了孔隙、温度、灰分、水分等对甲烷吸附的影响规律。开发了专门针对煤对瓦斯吸附的分子模拟软件，验证分析表明模拟得到的吸附等温线与实验基本吻合。利用开发的分子模拟软件，以现场与实验室测定的数据为基础，对不同条件下的瓦斯吸附情况进行模拟。模拟结果表明，煤的孔隙率、灰分、水分与温度等对煤的吸附特性均有影响，其中灰分影响最大。研究成果为从分子角度预测煤的吸附特性提供了一种新的途径，并提高了分子模拟技术研究煤吸附瓦斯特性的可靠性，可为预测煤层瓦斯压力、瓦斯含量等瓦斯参数提供理论基础。更多还原

【Abstract】 Gas disaster is not only the major disaster in Guizhou province but also in thewhole country. Coal mining disasters become more and more serious as the miningdepth increases. The gas disasters severely impact the safety of coal mining industry.Gas disaster is a complicated problem and the coal and gas outburst mechanism is stillnot completely clear. But, it is generally believed that the physical properties of coal,the gas in coal seam and the ground stress are the three major factors that impact thegas disaster. However, every factor is synthetically influenced by the many combinedfactors. This paper investigates the physicochemical properties of the outburst coal inGuizhou province by the method of theoretical analysis, physical experiments andnumerical simulation. The gas prevention and control technology is proposed basedon the physicochemical properties of outburst coal.The locations of experiment samples were determined by analyzing theformation and distribution law of the outburst coal in Guizhou province. SinceGuizhou province is influenced by the coal accumulating basin, the sedimentaryenvironment, the coal forming conditions, the geological movements, the coalcontrolling structures and other factors. Its major coal rich zones are Liupanshui coalfield, Zhina coal field, Qinbei coal field, Xinyi coal field, whose coal seams aremostly the outburst coal seam.Through the aspects of industrial analysis, elemental analysis, macromolecularstructure analysis, destruction type, microstructure, pore structure, specific surfacearea, the physicochemical properties of the samples in Guizhou province wereattainted by the field test and laboratory test. The outburst coal of Guizhou province ismostly the strongly destructive type of class Ⅲ coal. There exists crystal substancesparallel to the stratification plane, and many pores or fractures exist in stratificationplanes and joint planes, whose apertures are generally between0~10nm. Amongthem, apertures between3~5nm are the most common, which are the most importantgas adsorption space.Adsorption theory and molecular simulation models were adopted to investigatethe properties of methane adsorption on the coal. According to the methane adsorptioncharacteristics of the outburst coal in Guizhou province, the molecular adsorptionmodel was adopted based on the physical model of slit pore and the adsorptionmechanism of microporous filling. Using the Monte Carlo simulation method in grandcanonical system, the adsorption and desorption of coal methane molecules was realized through the insertion and deletion of particles, and so were the influence lawof aperture, temperature, ash content, moisture and other factors on methaneabsorption.The software specifically for methane adsorption was developed. Comparing theresults of molecular simulation with physical test, the adsorption isotherms areconsistent. By using the molecular simulation software, the simulation of methaneadsorption was made under the conditions, in which the data were based on the fieldtest and laboratory test. Simulation results show that the porosity of the coal, thetemperature, the content of ash and water all have influence on the adsorptioncharacteristics of coal. Among them, the ash content is the most important one.From the aspect of molecular lever, the research results provided a new way tofrom the Angle of molecular predicting the adsorption characteristics of coal, andimproved the reliability of the molecular simulation technique, which could be used toprovide theoretical basis for forecasting gas pressure, gas content and other gasparameters.更多还原