煤结构破坏分解产生CO规律、机理及煤自燃指标修正研究

发布时间：2018-05-03 00:42

本文选题：次生CO + 产生规律　；参考：《河南理工大学》2016年硕士论文

【摘要】：一氧化碳(CO)是煤自燃气体产物之一,也是目前我国大多数煤矿用来预报煤自然发火的标志气体。然而诸多煤矿现场观测结果发现CO经常异常超限但并未发生煤自燃情况,因此有效辨识井下CO气体来源,了解其产生规律,将对提高井下煤自燃预报准确度有着重要指导意义。论文利用自行设计的煤体破碎实验平台,以内蒙长焰煤为研究对象,从煤样质量和电机转速两方面研究了因煤结构破坏分解产生CO(S-CO)产生规律及温度变化规律,结果表明:在煤样破碎过程中,各工况S-CO出现时间和温升开始变化时间受煤样质量和电机转速影响不明显,但是在电机转速从15000r/min降低到10000r/min时,S-CO和温升出现时间会分别明显推迟50s和70s左右,各工况S-CO平均产生速率和最大浓度均随着电机转速和煤样质量增加而增加,温升随电机转速增加变化明显,受煤样质量影响并不明显。S-CO浓度变化过程可随破碎时间分为无S-CO产生阶段、S-CO呈线性增长阶段和S-CO呈类指数增长阶段。对各工况破碎后煤样继续开展红外光谱实验,结合傅里叶变换红外光谱法研究了S-CO产生机理,通过对煤体破碎过程中表面官能团及化学键变化情况分析,认为S-CO主要产生于破碎初期煤结构破坏引发的羧酸、醚、过氧化物断裂和破碎后期随着刀片做功内能增大,羧基、杂氧键、过氧键、醚键、羟基等含氧官能团活化分解释放S-CO。通过对煤体破碎实验数据算术分析,研究了实验条件下各工况S-CO绝对产生量和平均产生速率,推导出S-CO绝对产生量与煤样质量之间量化关系式。利用最小二乘法对S-CO平均产生速率和温升进行了相关性分析,R2为0.8633,表明S-CO平均产生速率和温升的相关性较强。建立了开采工作面S-CO浓度计算模型,推导出开采过程中S-CO浓度计算方法,并利用计算公式对工作面CO浓度和CO浓度变化速率进行修正。
[Abstract]:Carbon monoxide (CO) is one of the products of coal spontaneous combustion, and it is also the symbol gas used to predict the spontaneous combustion of coal in most coal mines in China. However, many coal mine field observation results show that CO often exceeds the limit, but no spontaneous combustion of coal occurs. Therefore, it is important to identify the underground CO gas source and understand its production law, which will be of great significance to improve the prediction accuracy of underground coal spontaneous combustion. In this paper, based on the experimental platform of coal fragmentation designed by ourselves and taking long flame coal in Inner Mongolia as the research object, the law of CO-S-CO-producing and the law of temperature change due to the decomposition of coal structure are studied from two aspects of coal sample quality and motor speed. The results show that in the process of coal sample crushing, the time of S-CO appearance and the change time of temperature rise are not obviously affected by coal sample quality and motor speed. However, when the speed of motor is reduced from 15000r/min to 10000r/min, the emergence time of S-CO and temperature rise will be obviously delayed about 50s and 70s, respectively. The average rate and maximum concentration of S-CO in each working condition will increase with the increase of motor speed and coal sample mass. The temperature rise changes obviously with the increase of motor speed, and the change process of S-CO concentration is not obviously affected by coal sample mass. The change process of S-CO concentration can be divided into linear growth stage and S-CO exponential growth stage with breaking time. The infrared spectrum experiments were carried out on the coal samples after crushing under various conditions. The mechanism of S-CO production was studied by means of Fourier transform infrared spectroscopy. The changes of surface functional groups and chemical bonds in the process of coal crushing were analyzed. It is considered that S-CO mainly comes from carboxylic acid, ether, peroxide breakage and late breakage caused by coal structure destruction in the early stage of crushing. The activation decomposition of carboxyl, hetero, superoxide, ether, hydroxyl and other oxygen-containing functional groups releases S-COs with the increase of the energy in the blade work. Based on the arithmetic analysis of the experimental data of coal body crushing, the absolute production rate and the average production rate of S-CO under different conditions are studied, and the quantitative relationship between the absolute production of S-CO and the quality of coal sample is derived. The correlation analysis between the average rate of S-CO production and temperature rise was carried out by using the least square method. The R2 was 0.8633, which indicated that the average production rate of S-CO had a strong correlation with temperature rise. The calculation model of S-CO concentration in mining face is established, the calculation method of S-CO concentration in mining process is deduced, and the change rate of CO concentration and CO concentration in working face are modified by using the calculation formula.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD752.2

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