【作者】 王俊峰；

【导师】 靳钟铭； 邬剑明；

【作者基本信息】 太原理工大学 ， 采矿工程， 2010， 博士

【摘要】 煤炭是我国重要的基础能源和重要原料,是不可再生资源。煤炭自燃严重威胁着矿井的安全生产,而且造成资源大量浪费。然而,煤层自燃火灾发生于地下数百米深处,由于人员无法靠近以及火源的隐蔽性,给防灭火工作带来了巨大的困难。因此,自燃火源位置的精确探测一直是煤矿安全生产中的重大难题之一,也是一项世界性难题。地面同位素测氡法探测火源位置作为一种行之有效的技术已在自然发火严重的矿井进行了应用,但没有形成一个完善的理论;因此,深入研究煤地下自燃时覆岩中氡的运移规律及其影响因素,可进一步提高同位素测氡法探测煤层自燃火源位置的精度,可有效地解决矿井防灭火火源位置探测这一关键技术,具有重要的科学意义和应用价值。通过分析氡运移规律的影响因素,得出了自燃煤层覆岩中氡运移的基本原理,借助自行研制的国内外最大的煤自燃与测氡实验台,通过实验研究、理论分析、数值模拟、以及现场探测的方法,对煤地下自燃时覆岩中氡迁移机理、不同温度下和不同深度处氡的析出特征、不同地表条件下现场实际探测分析、以及对自燃煤层开采过程中采空区自燃危险区域模拟,结合地表探测分析氡的异常区域进行了系统的研究。主要研究内容及结果如下:(1)自燃煤层覆岩中氡异常形成的机理。从氡的产生、性质和来源入手,分析了煤自燃对覆岩中氡的影响,结合“geogas”理论的特点,提出了自燃煤层覆岩中氡异常形成的机理。(2)煤自燃与测氡实验台的研制。在分析煤自燃过程中覆岩中氡的迁移机理基础上,研制了国内外自动化程度最高的煤自燃与测氡实验台。该实验装置可模拟不同粒度、不同漏风强度下煤自燃的全过程,以及氡在不同射气介质、构造条件下的析出规律。(3)煤自燃生成气体与氡析出的相关性及实验台温度场的实验研究。通过煤自燃实验,得出煤自燃的特征温度及各特征温度下的标志气体与氡析出的关系;分析了自燃过程中各层位高温区域与时间的关系及中心测点高温区域与层位的关系和特点,为研究煤地下自燃时布置覆岩中测氡点的位置提供了参考。(4)煤自燃时覆岩中氡运移的实验研究。应用实验台研究了不同射气介质在煤自燃过程中氡的析出规律,得出不同孔隙率、不同温度以及不同位置及深度对氡析出率的影响及程度。(5)矿井自燃火灾中氡气探测的现场观测研究。给出了地面测氡技术探测自燃火源的探测工艺及野外原始数据的有效取值、分析方法;通过对4个典型条件下的现场探测,结合实际灭火工程效果,得出典型条件下地表氡异常与煤地下自燃的相互关系,为同类条件下的探测提供参考依据。(6)采空区自燃危险区域数值模拟及上覆地表氡的析出规律。通过对乌达矿区黄白茨矿1293长壁工作面采空区气体的长期观测,应用CFD模拟技术模拟了自燃危险区域,结合地表氡气探测技术,验证自燃危险区域一致性,同时为采空区自燃地面测氡法探测测场布置提供科学依据。更多还原

【Abstract】 Coal is an important basic energy and raw materials. More importantly, it is a non-renewable resource. The spontaneous combustion of coal, resulting in substantial waste of resources, threats to the safety of production. However, fire prevention has faced to great difficulties dut to the imperceptibility of fire and its hundred meters below under the ground. Therefore, it has been being a major worldwide problem to precisely detect the location of fire source. The measurement of radon isotope has been applied to many coal mines to detect fire source, but it is short of a complete theory. Therefore, radon migration law in overlying strata and its influencing factors are the keys to further enhance the precision of fire detection, showing the scientific significance and application value.The basic principle of radon migration was obtained on the basis of the analysis of the influcing factors on the radon migration. Using the largest self-developed spontaneous combustion of coal and radon laboratory bench, the migration mechanism of radon under overburden rock during the spontaneous combustion of coal underground, the characteristics of radon liberation at the different temperatures and in the different depth were systematically studied through experimental research, theoretical analysis and numerical simulation combined with on-site detection. The dangerous zone of the spontaneous combustion of coal in goaf was simulated. The abnormal regions of radon were analyzed according to detection on the ground.The main research contents and results are as follows:(1) The forming machnism of abnormal radon in overlying strata during the spontaneous combustion of coal. The forming machanism of abnormal radon was proposed on the basis of the combination of the effects of coal spontaneous combustion on radon in overlying strata and the "geogas" theory, according to the formation of radon, characteristics and sources.(2) The research and development of the spontaneous combustion of coal and radon bench. On the basis of the mechanism of radon migration, the spontaneous combustion of coal and radon bench was developed with the highest level of automation, which can be used to research the whole process of spontaneous combustion of coal with the different sizes and air leakage intensity, as well as radon libration laws in different media and under different construction conditions.(3) Research on the relationship between gases generated during the coal spontaneous combustion and the radon libration and the experiments on temperature field in the bench. The relationship between the index gases and the radon libration at the characteristic temperature was obtained. The relationship between the high temperature zones in different horizons and time and that between the high temperature zones in the centre measuring point and horizons, giving a guide for the arrangement of the radon measuring points during the coal spontaneous combustion.(4) Experiment of radon migration in overlying strata. The radon libration law in the different emanation media was studied during the spontaneous combustion of coal in the bench, giving out the effect of the porosity, temperature, position and depth on the radon libration.(5) On-site observation of the radon detection. The ground radon detection process, the data effective values and the analytical method were given. The relationship between the spontaneous combustion of coal underground and the abnormal radon amount on the ground through the on-site detection under four typical conditions, combined with the actual fire-fighting project results.(6) The numerical simulation of spontaneous combustion dangerous zone in goaf and the earth’s surface radon libration law. Through long-term observation on gases in goaf on Wuda mining 1293 longwall working face, the danger zone was simulated with CFD, suggesting the consistency of spontaneous combustion dangerous zone with the on-site observation.更多还原