【作者】 王阳；

【导师】 来兴平； 邓军；

【作者基本信息】 西安科技大学 ， 采矿工程， 2009， 硕士

【摘要】 我国的煤炭产量和消费量均居世界首位,但煤层自燃现象却比较严重,严重威胁着煤矿的安全生产,不仅可以造成工作面、矿井封闭与停产,还可能引发瓦斯、煤尘、水煤气爆炸或火烟毒化矿井,酿成人员伤亡的恶性事故。煤自然发火过程可分为潜伏期、自热期和自燃期(或风化期)三个阶段,潜伏期是煤低温氧化蓄热阶段,自热期为加速氧化升温阶段,其转变温度点称为临界温度。研究临界温度及其特性对煤低温自然发火过程及其机理的深入研究具有重要实际意义。本文以灵武矿区2号煤层煤样为研究对象。首先,根据煤自燃机理分析,阐述了煤氧复合的反应过程及自燃实质,即煤自然发火主要是由于煤氧复合,放出热量,在一定蓄热环境下引起升温的过程,临界温度是煤自燃发火过程中的突变温度点;其次,利用XK-IV型大型煤自然发火实验台模拟2号煤层煤样低温氧化自然发火过程,得出煤体温度的变化规律,据临界温度的定义和宏观表现,推算出煤样的耗氧速度、放热强度、升温速率、反应物CO、CO2气体产生率等煤自燃特性参数及其与煤体温度的变化规律,在此基础上,提出煤样临界温度的确定方法,得出2号煤样临界温度,以及煤样在临界温度时的煤自燃特性参数及其变化率。最后,将原煤样破碎成不同粒度,采用水(空气)浴程序升温实验装置,分别在相同实验条件下对煤样进行程序升温氧化实验,根据实验结果,分析煤样粒度对临界温度及自燃特性参数的影响规律。通过煤自然发火过程中的关键突变温度点—临界温度及其特性的研究,对深入认识煤自燃过程,定量表征煤自燃倾性,具有一定的理论指导意义。更多还原

【Abstract】 The production and consumption of coal all play the leading role in the world, but coal spontaneous combustion seriously threatens the production safety of coal mines, and leads to working face closing, even ceasing production, it also can cause gas, coal dust and water gas explosion or smoke and flame which envenom coal mines and fatalities. Coal spontaneous combustion can be devided into three periods: latent period, self-heating period and spontaneous ignition period or efflorescence period. Latent period is the low temperature heat accumulating step, self-heating period is accelerating oxidation and temperature increasing step, the temperature changing point is called critical temperature. It’s significant to research the critical temperature and characteristics for deeper research on procedures and mechanism of coal spontaneous combustion under low temperature.Taking coal No.2 as experimental sample, first, expatiate on procedures and essence of coal oxidation and spontaneous combustion according to coal spontaneous combustion mechanism analysis, it is because coal oxidation releases heat which accumulates in suitable environment and cause temperature increasing, then comes spontaneous combustion, critical temperature is the sudden changing point in coal spontaneous combustion. Then, XK-IV coal spontaneous combustion experiment system is used to simulate coal No.2 sample’spontaneous combustion procedures, coal temperature relationship is figured out, according to definition of critical temperature and macro performance, relationships bwtween coal spontaneous combustion characteristic parameters and coal temperature are worked out, such as O2 consumption rates, heat releasing intensity, temperature increasing rate, CO and CO2 generating rates etc. Based on that, method for determing coal critical temperature is raised, the critical temperature, characteristic parameters and their changing rates of coal NO.2 under critical temperature are figured out. Finally, original coal sample is breaked up into different grain diameters, water or air temperature programming experiments are carried out in same experimental conditions, according to experiment results, the influence of coal grain diameter on critical temperature and characteristic parameters of coal are analysed.According to the research on key temperature changing point in coal spontaneous combustion-critical temperature and its characters, this research is theoretically significant for deep understanding on coal spontaneous combustion procedures and tokening coal spontaneous combustion tendency quantitatively.更多还原