【作者】 鲍庆国；

【导师】 王德明；

【作者基本信息】 中国矿业大学 ， 安全技术及工程， 2014， 博士

【摘要】 我国东部矿区地下开采深度越来越大，地温逐渐升高，导致煤自燃灾害更加频繁发生。位于山东滕南矿区的枣矿集团田陈、滕东等矿的开采深度均已达到-900m，地温超过40℃，煤自然发火灾害尤为严重，迫切需要开展高地温环境中煤低温氧化特性及防灭火技术的研究。地温是煤的起始氧化温度，直接影响煤的自燃特性。本文采用程序升温法分别以20℃、30℃、40℃为起始温度模拟研究不同地温对煤自燃特性的影响，得到了煤不同起始温度氧化温升过程中耗氧量、耗氧速率以及交叉点温度的变化规律。研究表明：煤以不同起始温度氧化温升过程中，起始氧化温度越高，煤的耗氧量及耗氧速率越大，煤自燃的交叉点温度越低，其机理在于在高地温条件下，煤中参与化学反应的微观活性基团的数量增高，进而耗氧量以及耗氧速率高，温升速率快，交叉点温度低，更易自然发火。煤氧化产热是导致煤自燃的根本原因，动力学参数是决定煤低温氧化反应速率的主要因素。本文通过采用高精度微量热仪C80测试煤在氧化过程中的产热，研究了煤氧化温升过程中动力学特性参数的实时变化规律；基于此，采用热分析动力学方法，通过构建与求解煤在绝热环境中的热平衡方程，模拟了煤的自热温升过程，实现了不同地温环境中煤自热危险性的快速判定。研究表明：随着地温的升高，煤绝热氧化温升到70℃所用的时间明显降低，煤的自然危险性显著增加；采用热分析动力学模拟方法能够快速准确地模拟煤的自热温升过程，克服了现有实验室绝热氧化实验消耗时间长、成功率低的缺点。煤自燃的早期识别与预报是有效防治内因火灾的基础，而气体分析法是目前煤自燃早期预测预报应用最为广泛的方法。本文采用程序升温法分别以20℃、30℃、40℃为起始温度模拟研究不同地温环境中煤氧化过程气体产物的变化规律，得到了地温对煤自燃预测预报指标气体的影响。研究表明：随着煤起始氧化温度的升高，煤释放出的CO的浓度降低（20℃＞30℃＞40℃），而不同煤样释放出的烷烯烃气体的浓度的变化规律不同。采用CO的绝对生成量或格雷哈姆系数R2值作为预测预报煤自燃的指标气体时，随着矿井地温的升高，均需要降低临界判定指标值。为实现滕南矿区高地温矿井的安全开采，需要从抑制产热与降温两个角度出发采取措施，确定采用惰化技术抑制煤低温氧化过程和灌注流体介质降低易发火区域温度的治理思路，提出了堵漏降氧、惰化置换和泡沫快速降温的高效综合防治技术。研究表明：采用惰化技术防止煤自燃灾害时需要将遗煤周围环境中氧浓度降到5%及其以下。采用液态二氧化碳或液氮灌注技术治理煤自燃灾害时，其对高温区域的冷却降温作用有限，主要表现为对火区的惰化抑爆作用，而阻化及三相泡沫降温作用明显，能快速冷却高温火区。该综合防治技术已在滕南矿区顺利推广，为治理高地温环境的煤自燃灾害提供了可靠的技术保障。更多还原

【Abstract】 The mining depth is increasing in the east mining area and the groundtemperature gradually increased, leading to more frequent occurrence of coalspontaneous combustion hazard. The coal mining elevation of TianChen, TengDongmine in TengNan mining area have reached-900m and the ground temperaturereached more than40℃, coal spontaneous combustion disaster is particularly acute.But now there is little research about low temperature oxidation characteristics of coalin high ground temperature and fire suppression technology.Ground temperature is the initial oxidation temperature of the coal. This papersimulated the coal oxidation process with temperature-programmed method under thestarting temperature of20℃,30℃,40℃, and respectively obtained the variation ofthe oxygen consumption, oxygen consumption rate and junction temperature duringthe process of coal oxidation. Studies show that：the higher the initial oxidationtemperature, the larger oxygen consumption and oxygen consumption rate of coal,and this difference increases with increasing temperature; the higher initial oxidationtemperature, the lower temperature of junction temperature, and with the startingtemperature increased, the degree of increase of junction temperature decreasesgradually; the higher initial temperature, the more active groups react with oxygenunder the process of low-temperature oxidation of coal in any temperature, whichleads to higher oxygen consumption and oxygen consumption rate, higher heatproduction, quicker temperature rise rate, lower crossing point temperature.Low-temperature oxidation of coal heat is the root cause of spontaneouscombustion of coal, and activation energy and pre-exponential factor are the majordeterminant of low-temperature oxidation rate of coal. This paper used high-precisionmicro-calorimeter C80to test the thermal behavior of the oxidation process of coalsamples in three different temperatures rising rate, and accurately solved the changingrule of the kinetic parameters (activation energy and pre-exponential factor) in theprocess of low-temperature oxidation of coal. And also used kinetics based simulationmethod assess the risk of spontaneous combustion of coal in different groundtemperature environments. Researches show that: With the increase of groundtemperature, the time for coal to reach70℃during adiabatic oxidation quicklyreduces, and the risk of spontaneous combustion of coal gradually changes from noteasy spontaneous combustion to spontaneous combustion, and spontaneous combustion to easy spontaneous combustion; Based on accurately solving kineticparameters and the heat balance equation of coal in adiabatic environment, theself-heating process of coal from different temperature can be accurately simulatedusing the kinetics based simulation method, which can accurately judge the risk ofself-heating of coal in different ground temperature, and overcomes the drawbacks ofadiabatic oxidation experiment which tends to consume for long time and has lowsuccess rate.The effective prevention of spontaneous fire is based on the early recognitionand prediction of coal spontaneous combustion, and the gas analysis method is themost widely used in early prediction and forecasting of coal spontaneous combustion.This paper simulates the programmed oxidation process of coal respectively with20℃,30℃,40℃as the starting temperature, and obtains the variation of gas productsin the process of coal oxidation temperature rising with different initial temperature.The results show that: In the process of coal oxidation temperature rising withdifferent initial temperature, the higher the incipient oxidation temperature is, thelower the concentration of CO which coal releases at anytemperature(20℃>30℃>40℃); When using the absolute amount of CO production asthe index-gas to predict coal spontaneous combustion, we need to reduce the criticaldecision index value with the increase of mine ground temperature, otherwise the firepoint temperature of coal spontaneous combustion will be assessed too low and we’lldelay the best time to put out a fire; In the oxidation process of coal with differentinitial temperature, the coal lower incipient oxidation temperature is, the higher theGray Hamm Coefficient R2is at any temperature. With the underground temperatureincreasing, we need to reduce the critical decision index value. If we still uses the oldcritical indicators when underground temperature increasing, it will lead to prematurealarm and unnecessary panic.To achieve mining safety in high geothermal in TengNan mining area, theprevention of coal spontaneous combustion accident and governance of internal fireneed to take measures from the two aspects of the inhibition of heat production andpromote heat radiation. With the theoretical analysis and experimental research, thispaper determined the performance of the inerting-technology inhibit low-temperatureoxidation process of coal and the cooling performance of various governancetechnology of internal fire. Based on that, to make high-temperature mine miningsafely in TengNan mining area, this paper put forward integrated high efficiency comprehensive prevention and control technology which use foam to cooling rapidlyas the core, to plugging for oxygen reduction and inert replacement as assist. Theresults show that: When using the inerting technology to prevent coal spontaneouscombustion disasters, the oxygen concentration of coal left in the surroundingenvironment is needed to reduce to the following of5%. When the left ambientoxygen concentration around the coal is higher than5%, the reduction of oxygenconcentration can’t inhibit the oxidation process of coal obviously. Using liquidcarbon dioxide or nitrogen filling technique to governance coal spontaneouscombustion disaster, the cooling effect of the high temperature region is extremelylimited, the main effect is inerting and suppression on fire area. But the three-phasefoam flowing through high temperature point with the vaporization of water whichwill absorb a lot of heat, the cooling effect is very obvious, and it can coolinghigh-temperature fire area rapidly; The integrated high efficiency comprehensiveprevention and control technology which use foam to cooling rapidly as the core andto plugging for oxygen reduction and inert replacement as assist is promoted to use inTengNan mining area smoothly, and the effect test verify the validity andpracticability of the comprehensive fire prevention and extinguishing technologyintegrated system.更多还原