The combustion characteristics of the Xiaolongtan lignite and Jiaozuo anthracite chars in O2/CO2 were investigated by using a thermogravimetric analyzer.On the basis of the key relationship between the reaction rate and the pore surface area of coal chars,the effective reaction surface area of coal chars during the combustion was revised in a small increment of time,and a stochastic differential equation is solved by means of differential increment analysis method.Finally,a modified discrete random pore model was constructed to analyze the combustion characteristics of the Xiaolongtan lignite and Jiaozuo anthracite chars in O2/CO2 at different temperatures.By comparing the modified model with the existing discrete random pore model,it is found that the modified model has a better prediction results during the whole combustion process of coal chars,while the values predicted by the existing discrete random pore model show a larger deviation from the experimental data at the later combustion stage.%以小龙潭褐煤和焦作无烟煤作为研究对象,采用热重分析仪对煤焦的O2/CO2燃烧特性进行研究.以燃烧过程中煤焦颗粒反应速率与孔隙表面积之间的关键关系为切入点,对燃烧过程中非常小时间微元内的焦颗粒有效反应面积进行修正,并采用微元分析法求解随机微分方程,最终建立了预测煤焦O2/CO2燃烧特征的改进离散随机孔模型,并将此模型用于分析不同温度下小龙潭褐煤焦和焦作无烟煤焦的O2/CO2燃烧特性.通过与现有离散随机孔模型的比较发现,所提出的改进离散随机孔模型在整个燃烧阶段均能够得到较好的预测结果,而离散随机孔模型在燃烧后阶段的预测值与热重实验数据有较大偏差.
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