含甲烷供气条件下煤氧化特性的综合实验研究

发布时间：2018-04-21 01:30

本文选题：含甲烷气体 + 气体输出装置　；参考：《中国矿业大学》2015年硕士论文

【摘要】：煤自燃和瓦斯是影响煤矿安全的主要灾害,在对高瓦斯易自燃煤层进行开采时,会有大量的瓦斯涌出,而采空区漏风流中含有一定量的瓦斯,氧气浓度也低于正常大气中的氧气浓度,煤自燃发火也是在该气体环境中发生。本文以阳煤集团石港煤矿为例,对其含甲烷供气条件下煤低温氧化特性进行实验研究。针对高瓦斯采空区中含有氧气、氮气和甲烷的实际情况,需配制含有易燃易爆气体的混合气体,提出了四种设计方案并对其进行分析优化,研制了含甲烷气体配比及输出实验装置。通过对实验装置进行参数优化实验,确定了最佳实验参数,验证了该装置的设计合理性和安全性,为煤低温氧化实验的进行提供了保障。开展了含甲烷供气条件下煤低温氧化产物实验,理论上分析了氧化产物的生成规律及煤低温氧化的过程,解释煤低温氧化过程中氧化产物的变化规律。得到在低氧高甲烷浓度的风流中,煤氧化产物的初始生成温度有“延迟效应”,氧化产物生成的初始温度滞后,为预测采空区煤自燃提供了参考依据。在符合石港煤矿实际情况的含瓦斯气体环境中,优选出了煤自燃早期预报的标志性气体。结果表明CO和C2H4气体可作为高瓦斯采空区煤自燃的指标气体。采用红外光谱仪分析了含甲烷供气条件下煤低温氧化过程中官能团种类和数量的变化规律。氧氮比较高时,高浓度的甲烷对含氧官能团的变化有抑制作用;随氧氮比例降低,含氧官能团反应也受到抑制,但甲烷体积分数对含氧官能团的数量变化无明显影响,脂肪烃官能团的生成速率随氧氮比降低而减小。芳环则相对稳定,基本不受氧气和甲烷浓度的影响。随氧化温度的升高,各基团种类和数量的变化是导致气体产物生成和变化规律的根本原因所在。论文研究成果为石港煤矿自燃过程的预测预报提供有力依据,利于制定有效的防灭火措施,并为采空区遗煤的自燃特性及煤的氧化反应机理研究提供新的角度。
[Abstract]:Spontaneous combustion of coal and gas are the main disasters that affect the safety of coal mine. When the coal seam with high gas is easy to burn, there will be a large amount of gas gushing out, and there is a certain amount of gas in the leaking air flow in the goaf. The oxygen concentration is also lower than that in the normal atmosphere, and the spontaneous combustion of coal also occurs in the gas environment. This paper takes Shigang Coal Mine of Yangshan Coal Group as an example to study the characteristics of coal oxidation at low temperature under the condition of methane supply. In view of the fact that there are oxygen, nitrogen and methane in high gas goaf, it is necessary to prepare the mixed gas containing flammable and explosive gas. Four design schemes are put forward and analyzed and optimized. An experimental device for the proportion and output of methane gas was developed. Through the parameter optimization experiment of the experimental device, the optimum experimental parameters are determined, and the design rationality and safety of the device are verified, which provides the guarantee for the low temperature oxidation experiment of coal. Experiments were carried out on the low temperature oxidation products of coal under the condition of methane supply. The formation law of the oxidation products and the process of coal low temperature oxidation were analyzed theoretically, and the variation law of the oxidation products in the low temperature oxidation process of coal was explained. In the air flow with low oxygen and high methane concentration, the initial formation temperature of coal oxidation product has "delay effect" and the initial temperature of oxidation product formation lags behind, which provides a reference for predicting coal spontaneous combustion in goaf. In accordance with the actual situation of Shigang coal mine gas environment, the early prediction of coal spontaneous combustion of the iconic gas is selected. The results show that CO and C2H4 gas can be used as index gas of coal spontaneous combustion in high gas goaf. The variety of functional groups in the process of coal oxidation at low temperature under the condition of methane supply was analyzed by infrared spectrometer. When oxygen and nitrogen were high, the changes of oxygen functional groups were inhibited by high concentration of methane, and the reaction of oxygen functional groups was inhibited with the decrease of oxygen nitrogen ratio, but the volume fraction of methane had no significant effect on the changes of the number of oxygen functional groups. The formation rate of functional groups of aliphatic hydrocarbons decreased with the decrease of oxygen to nitrogen ratio. Aromatic rings are relatively stable and are not affected by the concentration of oxygen and methane. With the increase of oxidation temperature, the change of group species and quantity is the fundamental reason for the formation and variation of gas products. The research results provide a powerful basis for the prediction and prediction of spontaneous combustion process in Shigang coal mine, which is conducive to the formulation of effective fire prevention measures, and provides a new angle for the study of spontaneous combustion characteristics and oxidation reaction mechanism of coal left over in goaf.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD752.2

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