煤矿井下封闭火区气体生成及变化规律实验研究

发布时间：2017-12-28 09:29

本文关键词：煤矿井下封闭火区气体生成及变化规律实验研究　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：矿井火灾是煤矿井下特别严重的灾害之一,也是瓦斯爆炸等矿井重大事故的主要诱因。我国每年因为矿井火灾及其引起的其他事故造成重大的资源浪费、环境污染和人员伤亡。因此研究矿井火灾发生以及熄灭的过程有着重大的意义。本文通过自行设计改装的煤矿井下封闭火区模拟实验装置,选用西山焦煤和平朔长焰煤两种煤样分析了从煤自燃到火区封闭后熄灭的整个过程。因为气体释放是煤燃烧主要外在表现特征之一,因此本文在煤自燃阶段分别研究了程序升温和煤体自热两个阶段的气体生成变化规律及关联性。在火区封闭后熄灭阶段主要分析了几种气体的释放变化规律及关联性研究,并对适合作为观测封闭火区熄灭情况的几种指标气体应用灰色理论作与温度的关联性研究。得出以下几个主要结论:(1)在煤低温氧化过程中耗氧速率在某个临界温度点之前,随着温度增加有逐渐增大的趋势,在某个临界温度点后耗氧速率跨越式增大。这说明,在煤的自燃过程中,耗氧速率伴随着煤温的增大而增高,当煤体临界温度到达某个点是时出现耗氧速率跳越是变大的现象,这个温度点是煤自燃达到剧烈阶段的临界点。(2)在煤自燃20℃到500℃的过程中,煤样复合反应可能呈现阶段性,20℃—80℃、80℃—180℃、180℃—300℃、300℃—500℃。80℃左右这个温度点是煤体从缓慢氧化阶段到较为激烈氧化的过渡点,180℃左右是煤体由较为激烈氧化阶段到激烈氧化阶段的转折点,300℃左右为煤体的燃点。(3)在煤低温氧化过程中CO/△O_2值随温度为稳定的线性增长趋势。CO/CO_2值随的增加温度在整体趋势上增大,在80℃之前CO/CO_2值随温度增加平稳,80℃之后开始急剧增加。在煤低温氧化过程中CO_2浓度至少是CO浓度的5倍。(4)在本实验条件下,从250℃到30℃温度下降的过程中H_2浓度、CO浓度、指CH_4释放量,H_2与CO差值都呈现指数下降的趋势。在封闭火区C_2H_4和C_2H_6的浓度随温度的降低总体为下降的趋势,在130℃左右时两种煤样C_2H_4的释放量已经为零,在110℃以后两种煤样C_2H_6释放量变为零。(5)通过对两种煤样进行灰色关联性分析得出西山焦煤第一指标气体为CO,第二为H_2,第三为CO/CO_2值,第四为H_2与CO差值,C_2H_4和C_2H_6排在最后。平朔长焰煤第一为CO/CO_2值,第二为CO,第三为H_2与CO差值、第四为H_2,第四第五为C_2H_6和C_2H_4。
[Abstract]:Mine fire is one of the most serious disasters in coal mine, and it is also the main cause of major accidents such as gas explosion. Every year, mine fire and other accidents caused by mine cause great waste of resources, environmental pollution and casualties. Therefore, it is of great significance to study the process of mine fire and the process of extinguishing. This paper designed and modified coal mine closed fire zone simulation experiment device, analyzes the whole process from spontaneous combustion of coal to fire extinguished after closed selection of Xishan Coal and Pingshuo Coal long flame coal two. Because gas emission is one of the main external characteristics of coal combustion. In this paper, the gas generation and change rules and correlation in two stages of programmed heating and coal self heating are studied in the stage of coal spontaneous combustion. In the closed fire extinguished after the stage mainly analyzes several gases variation and association studies, and the application of several index theory for gas sealed fire extinguished the grey observation and correlation of temperature. The following conclusions are drawn: (1) in the process of low temperature oxidation of coal, the oxygen consumption rate increases gradually with the increase of temperature before a critical temperature point, and at a critical temperature point, the oxygen consumption rate increases by leaps and bounds. This shows that, in the process of coal spontaneous combustion, the oxygen consumption rate with the increase of coal temperature increases, when the coal temperature reaches a point when there is oxygen consumption rate jump is larger, the temperature is the critical point of spontaneous combustion of coal reached intense stage. (2) during the process of 20 to 500 degrees coal spontaneous combustion, the coal sample reaction may be staged at 20, 80, 80, 180, 180, 300, and 500. The temperature point at 80 C is the transition point from the slow oxidation stage to the more intense oxidation stage. About 180 C is the turning point of the coal from the intense oxidation stage to the intense oxidation stage, and the ignition point of the coal is about 300 C. (3) in the process of coal oxidation at low temperature in the CO/ Delta O_2 value temperature stable linear growth trend. The increasing temperature of the CO/CO_2 value increases in the overall trend, and the CO/CO_2 value increases steadily with the temperature before 80 C, and then increases sharply after 80. In the process of low temperature oxidation of coal, the concentration of CO_2 is at least 5 times that of the concentration of CO. (4) under the experimental conditions, H_2 concentration, CO concentration, CH_4 release and H_2 and CO difference showed an exponential decline from 250 to 30 C. The concentration of C_2H_4 and C_2H_6 in closed fire zone decreases with temperature for the overall downward trend, at about 130 DEG C when the release amount of two coal samples of C_2H_4 has zero in 110 C two coal samples of C_2H_6 release quantity zero. (5) through the grey correlation analysis of two kinds of coal samples, it is concluded that the first index gas of Xishan coking coal is CO, the second is H_2, third is CO/CO_2 value, fourth is the difference between H_2 and CO, C_2H_4 and C_2H_6 are at the end. In the long flame coal first for CO/CO_2 value, the second CO, third H_2 and fourth CO difference, H_2, fourth and fifth for C_2H_6 and C_2H_4.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD752

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