煤粉粒度对元宝山褐煤燃烧特性的影响

为了给实际工程应用中煤粉粒度的确定提供参考,采用热重分析的方法,研究煤粉粒度对元宝山褐煤燃烧特性的影响.对燃烧热重曲线特征参数分析表明,粒度减小,煤粉着火提前、燃尽时间缩短;粒度减小,可燃指数C和综合燃烧指数S增加,表明煤粉燃烧性能得到改善;用Coats-Redfern方法求解燃烧反应的动力学参数,燃烧反应动力学分析表明,元宝山褐煤的热天平燃烧反应为一级反应;在最大燃烧速度对应温度前后燃烧过程分成两个阶段;粒度减小,各段燃烧反应的表观活化能和质量平均表观活化能均降低.减小煤粉粒度对改善煤粉燃烧性能是有利的.

Influence of coal particle size on the combustion characteristics of yuanbaoshan lignite

To support the choice of the particle size for practical industrial use,the thermogravimetric analysis was used to investigate the influence of particle size on the combustion characteristics of Yuanbaoshan lignite.The analysis of the combustion characteristic parameters of thermogravimetric curve indicates that with the decrease of the particle size,the ignition of the pulverized coal is advanced and the time for burnout is shortened,this means the increase of the combustible indices C and synthetic combustion indices S,which shows that the combustibility of the coal is improved.The method of Coats-Redfern was used to obtain the kinematic parameters.It shows that the TG combustion reaction of Yuanbaoshan lignite is one-order reaction.The total process can be considered as two seperated stages,one is before the maximum burning velocity and the other is after that.As the particle size decreases,the apparent activation energy for both of the two stages and the weight average apparent activation energy decrease.The study indicates that the decrease of the particle size of the pulverized coal can improve the conbustibility.