煤的热天平燃烧反应动力学特性的研究

AN EXPERIMENTAL STUDY ON THE CHEMICAL REACTION KINETICS OF COAL BY THERMOGRAVIMETRY ANALYSIS

采用热天平获得同一种煤在不同升温速率下的TG、DTG曲线,可求出燃烧速率、燃烧温度随燃烬度的变化曲线,根据两个不同升温速率下的数据,可计算出化学动力学参数活化能和指前因子随燃烬度的变化曲线。根据实验数据计算得到四个煤种的反应动力学参数随燃烬度变化的曲线,并预测其中一种煤在第三个升温速率下的燃烧速率随燃烬度的变化曲线,计算结果与实验结果符合较好。用此模型预测了在不同的恒定温度下试验煤种的煤粉燃烧速率随燃烬度的变化趋势。

TG, DTG curves under different temperature increasing rates for an identical coal by a thermal balance TGA7 can be obtained, and the curves of the combustion rates and the temperatures varied with the burnout ratio can then be got. By the experimental data under two temperature increasing rates, the curves of the apparent activation energy and the pre-exponential factor varied with the burnout ratio can be calculated. The curves of and for four coals were obtained by the method, and the combustion rate varied with the burnout ratio for one coal under a third temperature increasing rate was calculated, which agreed well with the experimental results. The change trends of the combustion rates for the four coals under different constant temperature levels were predicted.