单颗粒海藻生物质在流化床内燃烧试验与数值模拟

NUMERICAL INVESTIGATION AND EXPERIMENT OF A SINGLE SEAWEED PARTICLE COMBUSTION IN FLUIDIZED BED

在小型流化床试验台上研究海藻颗粒(条浒苔)的流化床燃烧试验,条浒苔颗粒在流化床中先进行脱水和挥发分的燃烧;接着发生焦炭燃烧,其燃烧过程符合缩核模型,炭核由外向内逐层燃烧,灰层半径几乎不变。通过对不同燃烧时间收集的焦炭颗粒剖面的SEM扫描电镜观察,进一步确定燃烧过程,发现随着燃烧的进行,颗粒内孔隙增大,微孔表面粗糙,局部甚至出现融化。最后建立条浒苔单颗粒在流化床内燃烧的数学模型,模拟结果与试验对比基本符合。

The fluidized bed combustion of seaweed particles （Enteromorpha clathrata） was studied in a bench scale combustor. When Enteromorpha clathrata particles were put into the fluidized bed, dehydration and the release and com- bustion of volatile happened, followed by burning char that accorded with the shrinking core model. The carbon burnt lay- er by layer from outside to inside the nuclear, while the ash layer was almost constant radius. SEM analysis was used to study the cross-sections of Enteromorpha clathrat particles at different fluidization times. With the combustion of EN parti- cle, the pores inside the particle increase. The micro-pore surface appeared rough, and even partial happened to melt. At last, the mathematical model for the fluidized bed combustion of Enteromorpha clathrata single particle was established. The simulation resulted generally consistent with the experiments.