A computational particle fluid-dynamics simulation of hydrodynamics in a three-dimensional full-loop circulating fluidized bed: Effects of particle-size distribution--颗粒学报PARTICUOLOGY

Zhang, H., & Lu, Y. (2020). A computational particle fluid-dynamics simulation of hydrodynamics in a three-dimensional full-loop circulating fluidized bed: Effects of particle-size distribution. Particuology, 49, 134-145. https://doi.org/10.1016/j.partic.2019.02.004

A computational particle fluid-dynamics simulation of hydrodynamics in a three-dimensional full-loop circulating fluidized bed: Effects of particle-size distribution

Hang Zhang, Youjun Lu ^*

State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an 710049, Shaanxi, China

10.1016/j.partic.2019.02.004

Volume 49, April 2020, Pages 134-145

Received 3 June 2018, Revised 23 December 2018, Accepted 19 February 2019, Available online 2 July 2019, Version of Record 26 February 2020.

E-mail: yjlu@mail.xjtu.edu.cn

Highlights

• CPFD model was applied to simulate 3D full-loop CFB.

• EMMS/matrix drag model was compared with the Gidaspow drag model.

• Numerical model was validated by comparison with experimental data.

• Influence of particle-size distribution on hydrodynamics of 3D full-loop CFB was investigated.

Abstract

A computational particle fluid-dynamics model coupled with an energy-minimization multi-scale (EMMS) drag model was applied to investigate the influence of particle-size distribution on the hydrodynamics of a three-dimensional full-loop circulating fluidized bed. Different particle systems, including one monodisperse and two polydisperse cases, were investigated. The numerical model was validated by comparing its results with the experimental axial voidage distribution and solid mass flux. The EMMS drag model had a high accuracy in the computational particle fluid-dynamics simulation of the three-dimensional full-loop circulating fluidized bed. The total number of parcels in the system (Np) influenced the axial voidage distribution in the riser, especially at the lower part of the riser. Additional numerical simulation results showed that axial segregation by size was predicted in the two polydisperse cases and the segregation size increased with an increase in the number of size classes. The axial voidage distribution at the lower portion of the riser was significantly influenced by particle-size distribution. However, radial segregation could only be correctly predicted in the upper region of the riser in the polydisperse case of three solid species.

Graphical abstract

Keywords

Circulating fluidized bed; Computational particle fluid dynamics; Particle-size distribution; Energy-minimization multiscale model; Three-dimensional full-loop simulation

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