Simulation of aggregation effects on co-fired biomass-coal ash in an electrostatic precipitator--颗粒学报PARTICUOLOGY

Lu, J., Yang, Z., Xu, B., Zhou, Z., & Sun, C. (2020). Simulation of aggregation effects on co-fired biomass-coal ash in an electrostatic precipitator. Particuology, 50, 120-126. https://doi.org/10.1016/j.partic.2019.07.006

Simulation of aggregation effects on co-fired biomass-coal ash in an electrostatic precipitator

Jianyi Lu ^{a b *}, Zhe Yang ^b, Bingyi Xu ^b, Zhiyong Zhou ^b, Chenxi Sun ^b

a MOE Key Laboratory of Resources and Environmental Systems Optimization, Beijing 102206, China
b School of Environment Science and Engineering, North China Electric Power University, Baoding 071003, China

10.1016/j.partic.2019.07.006

Volume 50, June 2020, Pages 120-126

Received 16 January 2019, Revised 28 May 2019, Accepted 31 July 2019, Available online 26 September 2019, Version of Record 7 April 2020.

E-mail: lujianyi@tsinghua.org.cn

Highlights

• A population balance model simulated particle aggregation in an electroprecipitator.

• Optimum conditions for particle aggregation effects were studied and determined.

• Electrical aggregation was evident for both micron- and submicron-sized particles.

• Particle aggregation was mainly determined by electrical aggregation.

Abstract

Aggregation of fine ash into larger particles benefits fly ash removal in an electrostatic precipitator. Thermal aggregation, turbulent aggregation, and electrical aggregation of fine ash (derived from co-firing of biomass fuel and anthracite coal) was simulated under different conditions in an electrostatic precipitator. A population balance model and user-defined function in Fluent were assumed to obtain aggregation kernel functions and calculate the aggregation effects on the co-combusted particles. The results show that electrical aggregation had an obvious effect on both micron- and submicron-sized particles. For submicron particles, the effect of thermal aggregation is about ten times greater than turbulent aggregation. Meanwhile, for micron-sized particles, turbulent aggregation is about seven times greater than thermal aggregation. Therefore, particle aggregation in the electrostatic precipitator mainly occurs because of electrical aggregation, supplemented by thermal aggregation and turbulent aggregation. When the flow velocity is 1.0 m/s, particle volume fraction is 1.4%, and biomass co-firing ratio is 10%, the effects of all three aggregation processes on ash particles are optimized.

Graphical abstract

Keywords

Co-combustion; Aggregation; Population balance model (PBM); Dust removal; Electrostatic precipitator (ESP)

文章导读