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

作　　者：Ruixiang Tang Zheng Zou Ji Xu Junwu Wang Qingshan Zhu Hongzhong Li 

机构地区：[1]State Key Laboratory of Mesoscience and Engineering,Institute of Process Engineering,Chinese Academy of Sciences,P.O.Box 353,Beijing,100190,China [2]School of Chemical Engineering,University of Chinese Academy of Sciences,Beijing,100049,China [3]Innovation Academy for Green Manufacture,Chinese Academy of Sciences,Beijing,100190,China

出　　处：《Particuology》2024年第7期266-280,共15页颗粒学报（英文版）

基　　金：the National Natural Science Foundation of China(grant No.22278404),and the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(grant No.21921005);the National Key Research and Development Program of China(grant No.2023YFC2908002);the State Key Laboratory of Multiphase Complex Systems(grant No.MESO-23-A03).

摘　　要：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.

关 键 词：L-valve Circulating fluidized bed Full loop Discrete particle method Gas-solid flow 

分 类 号：O35[理学—流体力学]