为了解地下高温低氧环境下的煤燃烧特性,研究低于空气氧体积分数情况下气体氛围对干燥煤燃烧的影响情况,对褐煤及焦煤2种煤样进行了热重实验,通过分析TG曲线及DTG曲线,求出各燃烧阶段特征温度值,并对最大失重速率温度和燃尽温度与氧体积分数数据进行拟合.结果表明:氧体积分数越高,达到最大升温速率时温度越低;在氧体积分数极低情况下,不同煤质煤燃尽温度接近,燃尽温度与煤质无关,随氧体积分数增大,燃尽温度不断降低,在氧体积分数高于一定值以后,燃尽温度趋于稳定;干燥褐煤较干燥焦煤更易于燃烧.此结果对防治高温低氧地下煤火现象,以及煤矿火灾有指导作用.
To get more knowledge about the characteristics of coal combustion under low oxygen concentra- tion conditions,thermogravimetric experiments were carried out using two kinds of coal samples (lignite coal and coking coal), in atmospheres with oxygen concentration below that in the air. Via analyzing the TG-DTG data obtained from the experiments, the characteristic temperatures of the coal samples during the whole combustion process can be calculated. Moreover, the relationship between the special tempera- tures and oxygen concentration, like the maximum mass loss rate temperature and burnout temperature, was fitted. The results show that,the temperature corresponding to the maximum mass loss rate point de- creases with the increasing oxygen concentration,which has been described as a linear relationship. With an ultra low oxygen concentration, the burnout temperature of different coals is close to each other, indicating the burnout temperature has no relationship with the coal quality. With an increase in the oxygen concen- tration, the burnout temperature decreases, and when the oxygen concentration is higher than a certain val- ue,the burnout temperature tends to be stable. The dry lignite is easier to be ignited than the dry coking coal. The results has a certain instruction for prevention and treatment of high temperature and low oxygen underground coal mine fire phenomenon.