Impact of pressure on gas-solid hydrodynamics of Geldart B and D particles in a pressurized bubbling fluidized bed: A CFD-DEM study--颗粒学报PARTICUOLOGY

Zhu, X., Shi, Z., Song, G., Li, Y., Wang, H., Ocone, R., & Wang, Z. (2025). Impact of pressure on gas-solid hydrodynamics of Geldart B and D particles in a pressurized bubbling fluidized bed: A CFD-DEM study. Particuology, 96, 328-340. https://doi.org/10.1016/j.partic.2024.11.016

Impact of pressure on gas-solid hydrodynamics of Geldart B and D particles in a pressurized bubbling fluidized bed: A CFD-DEM study

Xiaoli Zhu^a *, Zhixin Shi^a, Guosheng Song^a, Yuehuan Li^b, Haigang Wang^c, Raffaella Ocone^d, Zhenbo Wang^a *

a College of New Energy, China University of Petroleum (East China), Qingdao, 266580, China
b The 41st Institute of the Sixth Academy of China Aerospace Science & Industry Corp, Hohhot, 010010, China
c Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing, 100190, China
d School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK

10.1016/j.partic.2024.11.016

Volume 96, January 2025, Pages 328-340

Received 23 October 2024, Revised 17 November 2024, Accepted 22 November 2024, Available online 6 December 2024, Version of Record 12 December 2024.

E-mail: zhuxiaoli@upc.edu.cn; wangzhb@upc.edu.cn

Highlights

• CFD-DEM simulations reveal the impact of pressure on hydrodynamics in a pressurized bubbling fluidized bed.

• Pressure and particle size significantly affect minimum fluidization velocity, bubble behavior, and particle dynamics.

• Higher pressures lead to smaller, denser bubbles, enhancing gas-solid interaction in PBFB systems.

• Larger particles create fewer but larger bubbles, leading to vertical slugs and increased bed height.

Abstract

Pressurized fluidized beds have gained considerable interest in industrial applications due to their superior performance and efficiency compared to atmospheric fluidized beds. However, the mechanisms through which pressure influences the hydrodynamic behavior of different particle types remain insufficiently explored, hindering the scale-up, optimization, and broader adoption of this technology. To address this gap, CFD-DEM simulations were performed on a pseudo-2D pressurized bubbling fluidized bed using Geldart B and D particles. The effects of pressure, particle size, and initial bed height on key flow characteristics, including minimum fluidization velocity, particle dynamics (i.e., particle velocity and volume fraction distribution), and bubble behavior (i.e., bubble diameter, aspect ratio, density) were comprehensively examined. Results showed that the minimum fluidization velocity decreases with increasing pressure and increases with particle size, with greater sensitivity at lower pressures. Higher pressures lead to smaller bubble diameters, higher bubble aspect ratios, and denser bubble populations, resulting in concentrated particle distribution in the lower bed and more uniform radial dispersion. In contrast, larger particles create fewer, larger bubbles or slugs, and increase the overall bed height. These high-fidelity simulations offer valuable insights for optimizing the performance of pressurized fluidized beds in industrial processes.

Graphical abstract

Keywords

CFD-DEM; Pressurized bubbling fluidized bed; Minimum fluidization velocity; Particle dynamics; Bubble behavior

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