化工学报 ›› 2022, Vol. 73 ›› Issue (6): 2649-2661.doi: 10.11949/0438-1157.20211701

• 流体力学与传递现象 • 上一篇    下一篇

气固流化床启动阶段挡板内构件受力特性的CFD-DEM模拟

李铁男1,2(),赵碧丹2,3,赵鹏2,3,张永民1(),王军武2,3,4()   

  1. 1.中国石油大学（北京）重质油国家重点实验室，北京 102249
    2.中国科学院过程工程研究所多相复杂系统 国家重点实验室，北京 100190
    3.中国科学院大学化学工程学院，北京 100049
    4.中国科学院绿色过程制造创新研究院，北京 100190
  • 收稿日期:2021-11-29 修回日期:2022-03-11 出版日期:2022-06-05 发布日期:2022-06-30
  • 通讯作者: 张永民,王军武 E-mail:tnli@ipe.ac.cn;zhym@cup.edu.cn;jwwang@ipe.ac.cn
  • 作者简介:李铁男（1996—），男，硕士研究生，tnli@ipe.ac.cn
  • 基金资助:
    国家自然科学基金项目(21978295);中国科学院绿色过程制造创新研究院自主部署项目(IAGM-2019-A13)

CFD-DEM simulation of the force acting on immersed baffles during the start-up stage of a gas-solid fluidized bed

Tienan LI1,2(),Bidan ZHAO2,3,Peng ZHAO2,3,Yongmin ZHANG1(),Junwu WANG2,3,4()   

  1. 1.State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
    2.State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
    3.School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
    4.Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2021-11-29 Revised:2022-03-11 Published:2022-06-05 Online:2022-06-30
  • Contact: Yongmin ZHANG,Junwu WANG E-mail:tnli@ipe.ac.cn;zhym@cup.edu.cn;jwwang@ipe.ac.cn

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摘要：

流化床启动阶段内构件会受到较大的破坏性载荷冲击，为了保障流化床内构件的长周期可靠性，需要掌握这个阶段内构件在流化床内的受力特性。首先提出了一种统计内构件表面受力的方法，将微观颗粒-挡板作用信息转换为宏观挡板受力载荷信息。在此基础上采用CFD-DEM方法，统计分析了流化床启动阶段床层中水平挡板内构件的受力载荷特性。研究结果表明：CFD-DEM方法可半定量复现实验中启动阶段内构件表面受到的动态载荷信号，并复现了表观气速和颗粒粒径对挡板峰值载荷强度的影响规律。本研究证明了内构件表面受力载荷强度统计方法的正确性和CFD-DEM统计分析受力载荷的可行性。

关键词: 内构件, 介尺度结构, 流化床, CFD-DEM方法, 多相流, 数值模拟

Abstract:

In the start-up stage of a fluidized bed, the internal components will be impacted by a large destructive load. In order to ensure the long-term reliability of the internal components of the fluidized bed, it is necessary to master the force characteristics of the internal components in the fluidized bed at this stage. To this end, a method for statistically calculating the stress exerted on the internals from CFD-DEM simulation was proposed, and the simulation results were validated. It was found that the experimentally measured dynamic load impact can be reproduced semi-quantitatively, the effects of superficial gas velocity and particle properties on the load impact can also be predicted. Present study proved not only the correctness of the proposed statistical method, but also the feasibility of extracting the stress exerted on the internals using CFD-DEM method.

Key words: baffle, mesoscale structure, fluidized bed, CFD-DEM method, multiphase flow, numerical simulation

中图分类号: 

  • TQ 021.1

图1

密相床层中挡板表面与颗粒接触示意图(a)；等效为“虚拟平面”后颗粒碰撞接触图示(b)"

图2

三维方形冷模流化床实验装置示意图[11]"

图3

模拟采用的流化床几何结构"

表1

挡板床与自由床数值模拟参数"

ParameterValue
bed sizeLx ×Ly ×Lz /mm300×300×2200
baffle sizelx ×ly ×lz /mm60×300×10
particlemean Sauter particle diameter/μm595
density/(kg/m3)2906
voidage at the minimum fluidization condition0.47
minimum fluidization velocity/(m/s)0.33
sphericity0.86
coarse-graining ratio5
coarse-grained particle number3459863
restitution coefficient0.90
friction coefficient0.30
rolling friction coefficient0.01
characteristic velocity/(m/s)0.5
Young’s modulus/Pa1×108
Poisson’s ratio0.3
time step/s1×10-5
gasdensity/(kg/m3)1.2
viscosity/(Pa·s)1.8×10-5
superficial gas velocity/(m/s)0.4, 0.6, 0.9
operating pressure/Pa101325
gas grid size/mm10
time step/s1×10-4

图4

流化床启动阶段内构件所受载荷实验结果与CFD-DEM模拟结果比较"

表2

挡板床数值模拟参数"

ParameterValue
Young’s modulus/Pa1×1085×1081×1092×1093×1095×1091×1010
DEM-time step/s1×10-51×10-51×10-61×10-61×10-61×10-61×10-6
CFD-time step/s1×10-41×10-41×10-51×10-51×10-51×10-51×10-5

图5

不同颗粒杨氏模量下颗粒床层内挡板受到载荷随时间的变化"

图6

不同杨氏模量下颗粒最大重叠量与粒径比值随时间的变化"

图7

不同颗粒碰撞恢复系数(a)、滑动摩擦因数(b)、滚动摩擦因数(c)下颗粒床层内挡板受到载荷随时间的变化"

图8

不同表观气速下颗粒床层内挡板受到载荷随时间的变化"

图9

不同颗粒粒径床层启动阶段挡板受到载荷随时间的变化"

1 卢天雄. 流化床反应器[M]. 北京: 化学工业出版社, 1986.
Lu T X. Fluidized Bed Reactor [M]. Beijing: Chemical Industry Press, 1986.
2 Wang Y, Jin Y, Wei F. Effect of internal tubes and baffles[M]// Handbook of Fluidization and Fluid-Particle Systems. Boca Raton: CRC Press, 2003: 171-199.
3 Zhang Y M. baffles and aids to fluidization[M]// Essentials of Fluidization Technology. Wiley-VCH, 2020: 431-455.
4 刘对平. 气固流化床挡板内构件受力特性的实验研究[D]. 北京: 中国石油大学(北京), 2019.
Liu D P. Experimental study on forces acting on baffles immersed in gas-solid fluidized beds[D]. Beijing: China University of Petroleum, 2019.
5 Kennedy T C, Donovan J E, Trigas A. Forces on immersed tubes in fluidized beds[J]. AIChE Journal, 1981, 27(3): 351-357.
6 Hosny N, Grace J R. Transient forces on tubes within an array in a fluidized bed[J]. AIChE Journal, 1984, 30(6): 974-976.
7 Grace J R, Hosny N. Forces on horizontal tubes in gas fluidised beds[J]. Chemical Engineering Research and Design, 1985, 63(3): 191-198.
8 Nagahashi Y, Grace J, Lim K, et al. The mechanism of buffeting force on tubes immersed in gas-fluidized beds[J]. Transactions of the Japan Society of Mechanical Engineers Series B, 1998, 64(625): 2964-2970.
9 Nagahashi Y, Grace J R, Lim K S, et al. Dynamic force reduction and heat transfer improvement for horizontal tubes in large-particle gas-fluidized beds[J]. Journal of Thermal Science, 2008, 17(1): 77-83.
10 Liu D P, Zhang S H, Wang R Y, et al. Dynamic forces on a horizontal slat immersed in a fluidized bed of fine particles[J]. Chemical Engineering Research and Design, 2017, 117: 604-613.
11 Liu D P, Zhang S H, Zhang Y M, et al. Forces on an immersed horizontal slat during starting up a fluidized bed[J]. Chemical Engineering Science, 2017, 173: 402-410.
12 Liu D P, Zhang Y M, Yuan Y S, et al. Effect of particle properties on forces on an immersed horizontal slat during start-up of a fluidized bed[J]. Chemical Engineering Research and Design, 2020, 159: 105-114.
13 Liu D P, Zhang Y M, Zhang S H, et al. Effect of structure parameters on forces acting on baffles used in gas-solids fluidized beds[J]. Particuology, 2022, 61: 111-119.
14 Higashida K, Rai K, Yoshimori W, et al. Dynamic vertical forces working on a large object floating in gas-fluidized bed: discrete particle simulation and Lagrangian measurement[J]. Chemical Engineering Science, 2016, 151: 105-115.
15 Yan L, Liu H Z, Li F, et al. Dynamic characteristics of the large particles inside the fluidized bed with an inclined air distribution plate[J]. Powder Technology, 2020, 367: 632-642.
16 Nagahashi Y, Takeuchi H, Grace J R, et al. Dynamic forces on an immersed cylindrical tube and analysis of particle interaction in 2D-gas fluidized beds[J]. Advanced Powder Technology, 2018, 29(12): 3552-3560.
17 崔树稳, 刘伟伟, 朱如曾, 等. 关于非均匀系统局部平均压力张量的推导及对均匀流体的分析[J]. 物理学报, 2019, 68(15): 293-300.
Cui S W, Liu W W, Zhu R Z, et al. On the derivation of local mean pressure tensor for nonuniform systems and the analysis of uniform fluid[J]. Acta Physica Sinica, 2019, 68(15): 293-300.
18 Chapman S, Cowling T G. The Mathematical Theory of Non-Uniform Gases: an Account of the Kinetic Theory of Viscosity[M]. 2nd ed. New York: Cambridge University Press, 1970.
19 Gidaspow D. Multiphase Flow and Fluidization, Continuum and Kinetic Theory Descriptions[M]. New York: Academic Press, 1994.
20 Rao K K, Nott P R. An Introduction to Granular Flow[M]. Cambridge: Cambridge University Press, 2008.
21 Zhao B D, He M M, Wang J W. Multiscale kinetic theory for heterogeneous granular and gas-solid flows[J]. Chemical Engineering Science, 2021, 232: 116346.
22 Babic M. Average balance equations for granular materials[J]. International Journal of Engineering Science, 1997, 35(5): 523-548.
23 Zhu H P, Yu A B. Averaging method of granular materials[J]. Physical Review E, 2002, 66(2): 021302.
24 Mehrabadi M M, Nemat-Nasser S, Oda M. On statistical description of stress and fabric in granular materials[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1982, 6(1): 95-108.
25 Goldhirsch I. Stress, stress asymmetry and couple stress: from discrete particles to continuous fields[J]. Granular Matter, 2010, 12(3): 239-252.
26 Weinhart T, Thornton A R, Luding S, et al. From discrete particles to continuum fields near a boundary[J]. Granular Matter, 2012, 14(2): 289-294.
27 Ries A, Brendel L, Wolf D E. Coarse graining strategies at walls[J]. Computational Particle Mechanics, 2014, 1(2): 177-190.
28 Oda M, Nemat-Nasser S, Mehrabadi M M. A statistical study of fabric in a random assembly of spherical granules[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1982, 6(1): 77-94.
29 Jagota A, Dawson P R, Jenkins J T. An anisotropic continuum model for the sintering and compaction of powder packings[J]. Mechanics of Materials, 1988, 7(3): 255-269.
30 Oda M, Iwashita K. Study on couple stress and shear band development in granular media based on numerical simulation analyses[J]. International Journal of Engineering Science, 2000, 38(15): 1713-1740.
31 Hua L N, Zhao H, Li J, et al. Eulerian-Eulerian simulation of irregular particles in dense gas-solid fluidized beds[J]. Powder Technology, 2015, 284: 299-311.
32 Lu L Q, Xu J, Ge W, et al. EMMS-based discrete particle method (EMMS-DPM) for simulation of gas-solid flows[J]. Chemical Engineering Science, 2014, 120: 67-87.
33 Peng L, Xu J, Zhu Q S, et al. GPU-based discrete element simulation on flow regions of flat bottomed cylindrical hopper[J]. Powder Technology, 2016, 304: 218-228.
34 Zhong W Q, Zhang Y, Jin B S, et al. Discrete element method simulation of cylinder-shaped particle flow in a gas-solid fluidized bed[J]. Chemical Engineering & Technology, 2009, 32(3): 386-391.
35 Kruggel-Emden H, Rickelt S, Wirtz S, et al. A study on the validity of the multi-sphere discrete element method[J]. Powder Technology, 2008, 188(2): 153-165.
36 Oschmann T, Hold J, Kruggel-Emden H. Numerical investigation of mixing and orientation of non-spherical particles in a model type fluidized bed[J]. Powder Technology, 2014, 258: 304-323.
37 Lan B, Xu J, Zhao P, et al. Long-time coarse-grained CFD-DEM simulation of residence time distribution of polydisperse particles in a continuously operated multiple-chamber fluidized bed[J]. Chemical Engineering Science, 2020, 219: 115599.
38 兰斌, 徐骥, 刘志成, 等. 连续操作密相流化床颗粒停留时间分布特性模拟放大研究[J]. 化工学报, 2021, 72(1): 521-533.
Lan B, Xu J, Liu Z C, et al. Simulation of scale-up effect of particle residence time distribution characteristics in continuously operated dense-phase fluidized beds[J]. CIESC Journal, 2021, 72(1): 521-533.
39 Lan B, Xu J, Zhao P, et al. Scale-up effect of residence time distribution of polydisperse particles in continuously operated multiple-chamber fluidized beds[J]. Chemical Engineering Science, 2021, 244: 116809.
40 Ganser G H. A rational approach to drag prediction of spherical and nonspherical particles[J]. Powder Technology, 1993, 77(2): 143-152.
41 Wang J W, van der Hoef M A, Kuipers J A M. Why the two-fluid model fails to predict the bed expansion characteristics of Geldart A particles in gas-fluidized beds: a tentative answer[J]. Chemical Engineering Science, 2009, 64(3): 622-625.
42 Wang J W. Continuum theory for dense gas-solid flow: a state-of-the-art review[J]. Chemical Engineering Science, 2020, 215: 115428.
43 Wang J W, van der Hoef M A, Kuipers J A M. Coexistence of solidlike and fluidlike states in a deep gas-fluidized bed[J]. Industrial & Engineering Chemistry Research, 2010, 49(11): 5279-5287.
44 Jia Y, Zhang Y, Xu J, et al. Coarse-grained CFD-DEM simulation to determine the multiscale characteristics of the air dense medium fluidized bed[J]. Powder Technology, 2021, 389: 270-277.
45 Tsuji Y, Tanaka T, Ishida T. Lagrangian numerical simulation of plug flow of cohesionless particles in a horizontal pipe[J]. Powder Technology, 1992, 71(3): 239-250.
46 Tsuji Y, Kawaguchi T, Tanaka T. Discrete particle simulation of two-dimensional fluidized bed[J]. Powder Technology, 1993, 77(1): 79-87.
47 孙其诚, 金峰, 王光谦, 等. 二维颗粒体系单轴压缩形成的力链结构[J]. 物理学报, 2010, 59(1): 30-37.
Sun Q C, Jin F, Wang G Q, et al. Force chains in a uniaxially compressed static granular matter in 2D[J]. Acta Physica Sinica, 2010, 59(1): 30-37.
48 陈波, 童培庆. 瓮模型中多粒子动力学的研究[J]. 物理学报, 2005, 54(12): 5554-5558.
Chen B, Tong P Q. Dynamics of many particles in the urn model[J]. Acta Physica Sinica, 2005, 54(12): 5554-5558.
49 房明明. 循环流化床内稠密气固两相流动的DEM-LES模拟研究[D]. 杭州: 浙江大学, 2013.
Fang M M. DEM-LES investigation of dense as-solid two-phase flows in circulating fluidized beds[D]. Hangzhou: Zhejiang University, 2013.
50 王立军, 赵惠君, 武振超, 等. 颗粒滚动摩擦系数对颗粒堆内部受力的影响[J]. 东北农业大学学报, 2018, 49(3): 65-72.
Wang L J, Zhao H J, Wu Z C, et al. Effect of coefficient of rolling friction on internal force of particles pile[J]. Journal of Northeast Agricultural University, 2018, 49(3): 65-72.
51 赵永志, 程易, 郑津洋. 三方程线性弹性-阻尼DEM模型及碰撞参数确定[J]. 计算力学学报, 2009, 26(2): 239-244.
Zhao Y Z, Cheng Y, Zheng J Y. Three-equation linear spring-dashpot DEM model and the determination of contact parameters[J]. Chinese Journal of Computational Mechanics, 2009, 26(2): 239-244.
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