生物质与煤混烧灰湍流团聚相互作用的模拟研究

Simulation Studies on Turbulent Agglomeration Interaction of Biomass/Coal Co-combustion Ash

研究生物质与煤混烧灰的湍流团聚相互作用对于生物质混烧发电锅炉电除尘器入口前构建湍流聚并器具有十分重要的指导意义。针对生物质燃料玉米秸与无烟煤不同掺混比例的混烧灰,基于Fluent软件,利用颗粒群平衡模型(PBM),通过自定义函数(UDF)功能导入湍流团聚核函数,分析不同生物质掺比下混烧灰样细颗粒的湍流团聚效果。研究结果表明,湍流团聚对于微米级颗粒效果较亚微米级颗粒效果显著,湍流团聚效率随着粒径的增大而增大。同时,在不同生物质与煤混烧比下,当流场流速为1.5 m/s,生物质掺混比例越高,湍流团聚效果越佳。因此,对于燃煤锅炉掺杂生物质混烧可提高灰样的湍流团聚效率,在电除尘器入口前构建湍流聚并器是可行的。

Studying the interaction of co-firing biomass / coal ash in ESP for constructing turbulent coalescence device is very important to biomass co-firing power boilers. For the different co-combustion ratio of corn stalk biomass fuels and anthracite,researches the particle interaction under turbulent aggregation. Based on the Fluent software,and utilizing the particle balance model（ PBM） and user defined function（ UDF） to import the turbulent agglomeration kernel. The fine particle of different volume fraction and different flow field rate under turbulent aggregation are calculated,and analyzed the aggregation effect of different co-combustion ratio ash. The produce data show that turbulent agglomeration effect is significant for micron particle than sub-micron particle,and the agglomeration efficiency strength with the increasing of particle size. Meanwhile,with the improvement of biomass co-combustion ratio,the turbulent agglomeration has a better effect under 1. 5 m / s flow rate. Therefore,biomass co-combustion in coal-fired units can improve the efficiency of turbulent aggregation,and it is feasible to construct turbulent coalescence device in front of ESP entrance.