O2/CO2气氛下煤粉燃烧反应动力学的试验研究

在热重分析仪上进行了模拟空气气氛及不同O2浓度(21%、30%、40%、80%)的O2/CO2气氛下3种不同品质煤粉(龙岩无烟煤、贵州烟煤、元宝山褐煤)的燃烧特性试验,确定了3种煤粉的燃烧特征参数并进行了动力学分析.结果表明,O2/CO2气氛下煤粉的燃烧分布曲线与O2/N2气氛下有明显不同,在相同O2浓度的条件下,O2/CO2气氛下煤粉燃烧速率低,燃尽时间长;随着O2浓度的增加,燃烧DTG曲线向低温区偏移,着火温度及燃尽温度降低,燃尽时间缩短,可燃性指数及燃尽指数明显提高;O2/CO2气氛下煤粉燃烧基本属于一级反应,动力学参数随燃烧气氛与煤质变化的不同有较大差异.

Kinetics of Pulverized Coal Combustion Under Mixed O2/CO2 Atmospheres

Experiments,for investigating combustion characteristics of three different ranks of pulverized coals concerning Longyan anthracite coal,Guizhou bituminous coal and Yuanbaoshan lignite coal,have been carried out on a thermogravimetric analyzer under simulated air atmospheres and mixed O_2/CO_2 atmospheres with different O_2 concentrations(21%,30%,40%,80%).The characteristic parameters of three pulverized coals have been determined and kinetically studied.Results show that profiles of pulverized coal combustion under mixed O_2/CO_2 atmospheres is obviously different from those under mixed O_2/N_2 atmospheres.With a same O_2 concentration,the burning rate and burnout time in the former atmosphere condition respectively get lower and longer than the latter one.Under mixed O_2/CO_2 atmospheres,with the rising concentration of O_2,DTG curves of coal combustion move to low temperature zones,resulting in lowered ignition and burnout temperature,shortened burnout time,obviously increased combustible and burnout indexes.Pulverized coal combustion under mixed O_2/CO_2 atmospheres is basically of the first order reaction,its kinetic parameters change significantly with the variation of combustion atmosphere and coal rank.