Simulation of the L-valve in the circulating fluidized bed with a coarse-grained discrete particle method--颗粒学报PARTICUOLOGY

Tang, R., Zou, Z., Xu, J., Wang, J., Zhu, Q., & Li, H. (2024). Simulation of the L-valve in the circulating fluidized bed with a coarse-grained discrete particle method. Particuology, 90, 266-280. https://doi.org/10.1016/j.partic.2023.12.009

Simulation of the L-valve in the circulating fluidized bed with a coarse-grained discrete particle method

Ruixiang Tang ^{a b}, Zheng Zou^{a b}, Ji Xu ^{a b}, Junwu Wang ^{a b c}, Qingshan Zhu ^{a b c *}, Hongzhong Li ^{a b c *}

a State Key Laboratory of Mesoscience and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing, 100190, China
b School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
c Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, China

10.1016/j.partic.2023.12.009

Volume 90, July 2024, Pages 266-280

Received 15 September 2023, Revised 29 November 2023, Accepted 19 December 2023, Available online 6 January 2024, Version of Record 29 January 2024.

E-mail: qszhu@ipe.ac.cn; hzli@ipe.ac.cn

Highlights

• Full-loop simulations were conducted to study the L-valve in a CFB.

• Solid flow characteristics can be accurately predicted by the simulations.

• The effects of operating parameters on solid flow characteristics were obtained.

• The effects of geometric parameters were studied for the optimization of L-valve.

Abstract

Stable and controllable solid flow is essential in circulating fluidized bed (CFB) systems. The L-valve is a typical non-mechanical valve that can provide flexible solid feeding. The investigation of the solid circulation rate and the hydrodynamic characteristics of the L-valve is crucial to its design and operation. The gas-solid flow in the L-valve of a full-loop CFB is studied with the coarse-grained discrete particle method (EMMS-DPM). Good agreements on the solid circulation rate and the pressure drop through the L-valve are achieved between the simulated and experimental data. The solid circulation rate increases linearly with the aeration velocity until the stable particle circulation of the CFB is destroyed. The flow patterns in the horizontal section of L-valve are gas-solid slug flow above the stationary solid layer and the moving solid layer, respectively. The effects of L-valve geometric parameters on the solid flow characteristics are also investigated. The results indicate that reducing the diameter and length of the horizontal section of L-valve can improve the solid transport efficiency, especially at low aeration velocity. Besides, the solid conveying capacity and flow stability are improved when the sharp bend of L-valve is modified to be a gradual bend.

Graphical abstract

Keywords

L-valve; Circulating fluidized bed; Full loop; Discrete particle method; Gas-solid flow

文章导读