生物质颗粒度对燃烧特性影响

Affection on combustion character of biomass particle size

以稻壳为例考察了不同稻壳粒径对热解及燃烧特性、传热系数、焦炭燃烧的影响,利用TG/DTG6200热重差热分析仪对不同颗粒度稻壳粉做了热解实验,得到了不同的TG、DTG、DTA曲线。结果表明,稻壳颗粒度越小,其挥发分析出温度越低,析出时间越短,传热系数增大,升温速率增大,有利于燃烧,但过小的颗粒度同时增大了散热损失,当粒径低于临界尺度时,易出现熄火现象。焦炭燃烧过程受粒径大小的影响,粒径减小,燃烧反应速率加快,燃烧时间缩短,有利于燃烧。

The experiments chose paddy hull as feedstock and carried out research work mainly on the combustion process,and discussed the effects of different particle size on pyrolysis and combustion,heat tranefer coefficient,and coke combustion.The pyrolysis experiments is done in the TG/DTG6200 instrument with three different particle sizes of rice hulls((8～10),0.5～2 nm and 0.01～0.05 mm) and abtained TG,DTG,DTA curve.Some conclusions were drawn as follows:the particle size(d) is smaller and the eduction temperature of the volatile component is lower the heat tranefer coefficient is more,but its heat lost is more too.Flameout phenomenon is easy occurred while particle size is less than critical perticle size;The coke combustion rate is also faster and combustion time is shorter if the particle size is smaller,which is favorable to combustion.