Investigation on lateral dispersion characteristics of fuel particles in dense phase zone of a large-scale circulating fluidized bed boiler under combustion conditions--颗粒学报PARTICUOLOGY

Yang, Z., Lu, X., Dong, Z., Zhang, R., Lu, J., Jue, J., . . . Li, J. (2023). Investigation on lateral dispersion characteristics of fuel particles in dense phase zone of a large-scale circulating fluidized bed boiler under combustion conditions. Particuology, 78, 62-72. https://doi.org/10.1016/j.partic.2022.10.002

Investigation on lateral dispersion characteristics of fuel particles in dense phase zone of a large-scale circulating fluidized bed boiler under combustion conditions

Zhongzhi Yang ^a, Xiaofeng Lu ^a *, Zhonghao Dong ^a, Rongdi Zhang ^a, Jiayi Lu ^b, Jiayi Jue ^c, Baosheng Meng ^c, Quanhai Wang ^a, Yinhu Kang ^a, Jianbo Li ^a

a Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing, 400044, China
b Dongfang Boiler Group Co., Ltd, Chengdu, 611731, China
c Geely Baikuang Group Co., Ltd, Guangxi, 533000, China

10.1016/j.partic.2022.10.002

Volume 78, July 2023, Pages 62-72

Received 6 July 2022, Revised 3 September 2022, Accepted 1 October 2022, Available online 22 October 2022, Version of Record 2 January 2023.

E-mail: xfluke@cqu.edu.cn

Highlights

Abstract

The dispersion characteristics of fuel particles in the dense phase zone in circulating fluidized bed (CFB) boilers have an important influence on bed temperature distribution and pollutant emissions. However, previous research in literature was mostly on small-scale apparatus, whose results could not be applied directly to large-scale CFB with multiple dispersion sources. To help solve this problem, we proposed a novel method to estimate the lateral dispersion coefficient (D_x) of fuel particles under partial coal cut-off condition in a 350 MW supercritical CFB boiler based on combustion and dispersion models. Meanwhile, we carried out experiments to obtain the D_x in the range of 0.1218–0.1406 m²/s. Numerical simulations were performed and the influence of operating conditions and furnace structure on fuel dispersion characteristics was investigated, the simulation value of D_x was validated against experimental data. Results revealed that the distribution of bed temperature caused by the fuel dispersion was mainly formed by char combustion. Because of the presence of intermediate water-cooled partition wall, the mixing and dispersion of fuel and bed material particles between the left and right sides of the furnace were hindered, increasing the non-uniformity of the bed temperature near furnace front wall.

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