Please wait a minute...
JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE)
    
Numerical simulation of discrete particles in fluidized bed with immersed tube
REN Li-bo1,2, HAN Ji-tian1, ZHAO Hong-xia1
1. School of Energy and Power Engineering, Shandong University, Jinan 250061, China; 2. Shanghai Heat Transfer Equipment Limited Company, Shanghai 201508, China
Download:   PDF(1952KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

The parallel technique for computational fluid dynamics-discrete element method (CFD-DEM) coupling model was developed through user defined functions (UDFs) in the framework of secondary development based on message passing interface (MPI) platform of FLUENT software. The algorithm has good scalability and speed-up performance with the increase in the number of computing nodes. Numerical simulation of the particle mixing processes in the fluidized bed with immersed tube was conducted by the developed parallel CFD-DEM coupling model. The gas-solid hydrodynamics and particle mixing mechanism were explored, and the erosion properties of the immersed tube were surveyed. Simulation results show that the immersed tube causes bubble coalescence and breakage. The preferential path of bubble motion mainly lies around the tube rather than near the walls. The radial distribution of bubble phase becomes more homogeneous with superficial gas velocity increasing. The radial heterogeneities of the solid flow and distribution are exhibited. Both of the existence of immersed tube and the increase in superficial gas velocity are helpful for particle mixing and for decrease in the time for full mixing status. The erosion quantity mainly depends on the impact frequency and particle velocity.



Published: 06 June 2018
CLC:  TK 121  
Cite this article:

REN Li-bo, HAN Ji-tian, ZHAO Hong-xia. Numerical simulation of discrete particles in fluidized bed with immersed tube. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2015, 49(1): 150-156.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2015.01.022     OR     http://www.zjujournals.com/eng/Y2015/V49/I1/150


单沉浸管流化床内离散颗粒数值模拟

基于FLUENT软件信息传递模式的多点接口(MPI)并行计算平台,在二次开发框架内通过用户自定义函数(UDFs)文件发展计算流体力学-离散单元法(CFD-DEM)耦合并行算法.该算法具有随计算节点数增加的良好扩展性能和加速性能.采用该算法数值模拟了单沉浸管流化床内的颗粒混合过程,揭示了气固两相的运动特性和颗粒混合机制,考察了沉浸管的磨损特性.结果表明:沉浸管引起床内气泡的聚并和破碎,气泡主要绕沉浸管而非沿两侧壁向上移动,随着表观气速的增加,气相流场沿径向的分布更加均匀;颗粒宏观流动结构与分布呈现出明显的径向非均匀特性;沉浸管的存在和表观气速的增加均有助于颗粒混合,使颗粒达到完全混合的时间减少;颗粒撞击管壁的频次和冲刷速度是造成沉浸管磨损的主要原因.

[1] MASOUMIFARD N, MOSTOUFI N, HAMIDI A A, et al. Investigation of heat transfer between a horizontal tube and gas-solid fluidized bed [J]. Powder Technology, 2008, 29(5): 1504-1511.
[2] LYCZKOWSKI R W, BOUILLARD J X, GAMWO L K, et al. Experimental and CFD analyses of bubble parameters in a variable-thickness fluidized bed [J]. Industrial and Engineering Chemistry Research, 2010, 49(11): 5166-5173.
[3] JOHANSSON K, NORLING R, HJORNHEDE A, et al. Hydrodynamics and steel tube wastage in a fluidized bed at elevated temperature [J]. Chemical Engineering Science, 2004, 59(1): 31-40.
[4] LI T W, DIETIKER J F, ZHANG Y M, et al. Cartesian grid simulations of bubbling fluidized beds with a horizontal tube bundle [J]. Chemical Engineering Science, 2011, 66(23): 6220-6231.
[5] DONG N H, ARMSTRONG L M, GU S, et al. Effect of tube shape on the hydrodynamics and tube-to-bed heat transfer in fluidized beds [J]. Applied Thermal Engineering, 2013, 60(1): 472-479.
[6] YUSUF R, HALVORSEN B, MELAAEN M C. Eulerian–Eulerian simulation of heat transfer between a gas-solid fluidized bed and an immersed tube-bank with horizontal tubes [J]. Chemical Engineering Science, 2011, 66(8): 1550-1564.
[7] RONG D G, HORIO M. Behavior of particles and bubbles around immersed tubes in a fluidized bed at high temperature and pressure: a DEM simulation [J]. International journal of Multiphase Flow, 2001, 27(1): 89-105.
[8] 虞育松,张衍国,李清海,等. 基于DEM的埋管鼓泡流化床内颗粒运动特性模拟[J].清华大学学报:自然科学版, 2012,52(1):72-76.
YU Yu-song, ZHANG Yan-guo, LI Qing-hai, et al. DEM simulation of the behavior of particles in a spout-fluid bed with immersed tubes [J]. Journal of Tsinghua University: Science and Technology, 2012,52(1):72-76.
[9] YANG S L, LUO K, FAN J R, et al. Particle-scale investigation of the hydrodynamics and tube erosion property in a 3-D bubbling fluidized bed with immersed tubes [J]. Industrial and Engineering Chemistry Research, 2014, 53 (17): 6896-6912.
[10] 杨世亮,罗坤,张科,等.三维流化床内埋管传热及磨损特性的LES-DEM研究[J]. 工程热物理学报,2013,34(11):15.
YANG Shi-liang,LUO Kun, ZHANG Ke, et al. LES-DEM study on heat transfer and erosion patterns of immersed tube in 3D fluidized bed [J]. Journal of Engineering  Thermophysics, 2013, 34(11): 15.
[11] 赵永志,江茂强,徐平,等.埋管流化床内传热行为的微观尺度模拟研究[J].浙江大学学报:工学版,2010,44(6):11781184.
ZHAO Yong-zhi, JIANG Mao-qiang, XU Ping, et al. Micro-scale simulation of heat transfer behavior in fluidized bed with immersed tube [J]. Journal of Zhejiang University: Engineering Science, 2010, 44(6): 1178-1184.
[12] MULLER C R, HOLLAND D J, SEDERMAN A J, et al. Granular temperature: comparison of magnetic resonance measurements with discrete element model simulations [J]. Powder Technology, 2008, 184(2): 241-253.
[13] MULLER C R, SCOTT S A, HOLLAND D J, et al. Validation of discrete element model using magnetic resonance measurements [J]. Particuology, 2009, 7(4): 297-306.
[14] FINNIE I. Erosion of surfaces by solid particles [J]. Wear, 1960, 3(2): 87-103.
[15] HOOMANS B P B, KUIPERS J A M, BRIELS W J, et al. Discrete particle simulation of bubble and slug formation in a two-dimensional gas-fluidized bed: a hard sphere approach [J]. Chemical Engineering Science, 1996, 51(1): 99-118.

[1] PAN Zhi-juan, HUANG Qun-xing, Moussa-Mallaye Alhadj-Mallah, WANG Jun, CHI Yong, YAN Jian-hua.
Effect of active carbon on microwave pyrolysis characteristics of petroleum sludge
[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2015, 49(6): 1166-1172.
[2] LOU Bin, XU Xu, WANG Wen-long, WANG Yu-fei, FAN Li-wu, YU Zi-tao. Natural convection heat transfer of aqueous nanofluids with carbon nanotubes in a rectangular enclosure[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2014, 48(12): 2196-2201.
[3] ZHOU Hao, RUI Miao, CEN Ke-fa. Study of flow in porous media by LES-LBM coupling method[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2012, 46(9): 1660-1665.
[4] XU He-wei, ZHOU Hao, CEN Ke-fa. Measure carbon content in fly ash by infrared reflection method[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2011, 45(5): 890-895.
[5] DIAO Jia-Pei, ZHOU Hao, CEN Ge-Fa. Radiation characteristics of syngas in  radiation waste heat boiler
at high temperature and high pressure
[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2010, 44(9): 1781-1786.
[6] WANG Hui, JIA Zhong-Yang, CA Ji-Cong, WANG Chao, DIAO Jia-Fei, NI Meng-Jiang. Experimental study of influencing factors on transmissivity of SiO2 nanofluids[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2010, 44(6): 1143-1148.