生物质与煤混烧灰电团聚相互作用的模拟研究

SIMULATION STUDIES ON ELECTRICITY AGGLOMERATION INTERACTION OF BIOMASS/COAL CO-COMBUSTION ASH

研究生物质与煤混烧灰在除尘器内部的电团聚相互作用对于实现其细颗粒减排具有十分重要的意义。针对不同掺混比例的生物质燃料玉米秸杆与无烟煤混烧灰,基于Fluent软件,利用颗粒群平衡模型(PBM),通过自定义函数(UDF)功能导入电团聚核函数,计算颗粒在除尘器内部的团聚情况,分析其团聚效果。研究结果表明:电团聚对于细颗粒具有显著的作用,并且团聚效率随着颗粒粒径的增大而逐渐提高。同时,当颗粒体积分数为1.4%,流场流速为1 m/s时,考虑到实际条件,生物质掺混比为10%,电团聚效果最优。因此,对于掺烧生物质的燃煤锅炉,在常规除尘器前或电除尘器前级电场,利用电凝并技术实现细颗粒团聚后高效捕集是十分有效的手段。

Studying electricity agglomeration interaction of co-firing biomass / coal ash in ESP for achieving emission reduction of fine particle is very significant. For different co-combustion ratio of corn stalk biomass fuels and anthracite,basing on Fluent software,the paper utilized particle balance model( PBM) and user defined function( UDF) to import electricity agglomeration kernel,calculated the particle coalescence situation in ESP and analyzed electricity aggregation efficiency. The produced data show that electricity agglomeration is significant for fine particle,and the agglomeration efficiency strength with the increasing of particle size. Meanwhile,considering the actual conditions,when the co-combustion ratio is 10%,the electricity agglomeration has the optimal effect under 1. 4% particle volume fraction and 1. 0 m / s flow rate. Therefore,it’s a very effective mean for mixing biomass burning coal boilers to utilize electricity agglomeration technology in front of conventional precipitator or ESP to realize emission reduction of fine particle.