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Effect of Packing Structure Evolution on the Flow Characteristics in a Binary Composite Packed Bed Based on DEM-CFD Method. Processes (Basel) 2023. [DOI: 10.3390/pr11030732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
Abstract
The evolution of mesoscale structures of particle packing in binary composite packed beds and their effects on flow characteristics and wall effects were investigated using the discrete element method (DEM) and computational fluid dynamics (CFD). The DEM model was used to build a series of randomly mixed packing structures of particles in accordance with the dynamic change of mass ratio between particles in two size ranges, which were then confirmed by the findings of an X-ray tomography (CT) scan. The results show that the packing structure of b25s75 was conducive to reducing the influence of wall effect in packed bed reactors. For b25s75, the dimensionless distance of radial porosity fluctuation from the wall is 0.3705, which is the smallest among the five packing models, indicating that this structure plays a suppressive role on the wall effect. In addition, the uniformity of velocity and temperature distributions in both the radial and axial directions of different packing structures were compared. The standard deviations of radial relative velocity distributions in the packed beds of b100, b75s25, b25s75 and s100 are 0.28, 0.178, 0.139 and 0.156, respectively, indicating that the stacking mode of b25s75 can make the fluid flow and the gas–solid interactions more uniform.
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Numerical simulation of convective heat transfer in packed bed using open-source computational fluid dynamics. POWDER TECHNOL 2023. [DOI: 10.1016/j.powtec.2023.118452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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3
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Weng J, Zhang Q, Yu J, Yu Q, Ye G, Zhou X. Radially layered configuration for improved performance of packed bed reactors. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2022.117917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Wang Y, Li X, Liang R, Zhu H, Liu F, Liu Y, Niu F. Simulation of a solid-phase oxygen control scheme in lead-bismuth eutectic system. NUCLEAR ENGINEERING AND DESIGN 2022. [DOI: 10.1016/j.nucengdes.2022.111821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Qu Y, Wang L, Lin X, Ling H, Bai Y, Zhang S, Chen H. Heat transfer characteristics of mixed convection in packed beds. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2022.117679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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6
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Amini Y, Shadman MM, Karimi-Sabet J. CFD simulation of flow distribution in the randomly packed bed Dixon ring. SEP SCI TECHNOL 2021. [DOI: 10.1080/01496395.2021.2009513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Younes Amini
- Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
| | - Mohammad Mahdi Shadman
- Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
| | - Javad Karimi-Sabet
- Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran, Iran
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Yang X, Wang S, Zhang K, He Y. Evaluation of coke deposition in catalyst particles using particle-resolved CFD model. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2020.116122] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Flow, heat, and mass transfer in fixed beds of catalyst particles are complex phenomena and, when combined with catalytic reactions, are multiscale in both time and space; therefore, advanced computational techniques are being applied to fixed bed modeling to an ever-greater extent. The fast-growing literature on the use of computational fluid dynamics (CFD) in fixed bed design reflects the rapid development of this subfield of reactor modeling. We identify recent trends and research directions in which successful methodology has been established, for example, in computer generation of packings of complex particles, and where more work is needed, for example, in the meshing of nonsphere packings and the simulation of industrial-size packed tubes. Development of fixed bed reactor models, by either using CFD directly or obtaining insight, closures, and parameters for engineering models from simulations, will increase confidence in using these methods for design along with, or instead of, expensive pilot-scale experiments.
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Affiliation(s)
- Anthony G Dixon
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA; ,
| | - Behnam Partopour
- Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA; ,
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Panyaram S, Xianchun W, Slivensky D, Hampton K, Wilhite B. Fixed bed structures for mono and poly-disperse mixtures of spherical particles using different loading methods. Chem Eng Sci 2019. [DOI: 10.1016/j.ces.2019.115165] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Zhang M, Dong H, Geng Z. Computational study of particle packing process and fluid flow inside Polydisperse cylindrical particles fixed beds. POWDER TECHNOL 2019. [DOI: 10.1016/j.powtec.2019.05.061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Guo Z, Sun Z, Zhang N, Ding M, Shi S. CFD analysis of fluid flow and particle-to-fluid heat transfer in packed bed with radial layered configuration. Chem Eng Sci 2019. [DOI: 10.1016/j.ces.2018.12.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Guo Z, Sun Z, Zhang N, Ding M, Bian H, Meng Z. Computational study on fluid flow and heat transfer characteristic of hollow structured packed bed. POWDER TECHNOL 2019. [DOI: 10.1016/j.powtec.2018.11.101] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Moghaddam E, Foumeny E, Stankiewicz A, Padding J. Fixed bed reactors of non-spherical pellets: Importance of heterogeneities and inadequacy of azimuthal averaging. CHEMICAL ENGINEERING SCIENCE: X 2019. [DOI: 10.1016/j.cesx.2019.100006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Abstract
Packed beds are widely used in industries and it is of great significance to enhance the heat transfer between gas and solid states inside the bed. In this paper, numerical simulation method is adopted to investigate the heat transfer principle in the bed at particle scale, and to develop the direct enhanced heat transfer methods in packed beds. The gas is treated as continuous phase and solved by Computational Fluid Dynamics (CFD), while the particles are treated as discrete phase and solved by the Discrete Element Method (DEM); taking entransy dissipation to evaluate the heat transfer process. Considering the overall performance and entransy dissipation, the results show that, compared with the uniform particle size distribution, radial distribution of multiparticle size can effectively improve the heat transfer performance because it optimizes the velocity and temperature field, reduces the equivalent thermal resistance of convection heat transfer process, and the temperature of outlet gas increases significantly, which indicates the heat quality of the gas has been greatly improved. The increase in distribution thickness obviously enhances heat transfer performance without reducing the equivalent thermal resistance in the bed. The result is of great importance for guiding practical engineering applications.
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Molina-Herrera FI, Castillo-Araiza CO, Jiménez-Islas H, López-Isunza F. The Effect of Turbulence on Momentum and Heat Transport in Packed Beds with Low Tube to Particle Diameter Ratio. INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING 2018. [DOI: 10.1515/ijcre-2018-0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
This is a theoretical study about the influence of turbulence on momentum and heat transport in a packed-bed with low tube to particle diameter ratio. The hydrodynamics is given here by the time-averaged Navier-Stokes equations including Darcy and Forchheimer terms, plus a κ-ε two-equation model to describe a 2D pseudo-homogeneous medium. For comparison, an equivalent conventional flow model has also been tested. Both models are coupled to a heat transport equation and they are solved using spatial discretization with orthogonal collocation, while the time derivative is discretized by an implicit Euler scheme. We compared the prediction of radial and axial temperature observations from a packed-bed at particle Reynolds numbers (Rep) of 630, 767, and 1000. The conventional flow model uses effective heat transport parameters: wall heat transfer coefficient (hw) and thermal conductivity (keff), whereas the turbulent flow model includes a turbulent thermal conductivity (kt), estimating hw via least-squares with Levenberg-Marquardt method. Although predictions of axial and radial measured temperature profiles with both models show small differences, the calculated radial profiles of the axial velocity component are very different. We demonstrate that the model that includes turbulence compares well with mass flux measurements at the packed-bed inlet, yielding an error of 0.77 % in mass flux balance at Rep = 630. We suggest that this approach can be used efficiently for the hydrodynamics characterization and design and scale-up of packed beds with low tube to particle diameter ratio in several industrial applications.
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Moghaddam E, Foumeny EA, Stankiewicz AI, Padding JT. Rigid Body Dynamics Algorithm for Modeling Random Packing Structures of Nonspherical and Nonconvex Pellets. Ind Eng Chem Res 2018; 57:14988-15007. [PMID: 30449949 PMCID: PMC6237547 DOI: 10.1021/acs.iecr.8b03915] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/09/2018] [Accepted: 10/11/2018] [Indexed: 11/28/2022]
Abstract
Despite the common use of nonspherical catalyst pellets in chemical engineering applications, the packing structures of such pellets have not been as systematically studied and characterized as spherical packings. We propose a packing algorithm based on rigid body dynamics to simulate packing of nonspherical and possibly nonconvex pellets. The algorithm exerts a hard-body approach to model collision phenomena. The novelty is that the transition between moving and resting particles is controlled by a cutoff on the relative contact velocities, instead of artificially damping linear and angular velocities to stabilize the algorithm. The algorithm is used to synthesize packings of spheres, cylinders, and Raschig rings with tube-to-pellet diameter ratios 3-9.16. The packings are validated in terms of bulk porosity and radial void fraction distribution, finding satisfactory agreement with literature data. Denser packing structures are generated with high restitution coefficients and low friction coefficients. The confining tube walls play an important role, with highly fluctuating bulk porosities in narrow tubes.
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Affiliation(s)
- Elyas
M. Moghaddam
- Process & Energy Department, Delft University of Technology, 2628CB Delft, The Netherlands
| | - Esmail A. Foumeny
- Process & Energy Department, Delft University of Technology, 2628CB Delft, The Netherlands
| | - Andrzej I. Stankiewicz
- Process & Energy Department, Delft University of Technology, 2628CB Delft, The Netherlands
| | - Johan T. Padding
- Process & Energy Department, Delft University of Technology, 2628CB Delft, The Netherlands
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Wu Z, Wu Y, Tang S, Liu D, Qiu S, Su G, Tian W. DEM-CFD simulation of helium flow characteristics in randomly packed bed for fusion reactors. PROGRESS IN NUCLEAR ENERGY 2018. [DOI: 10.1016/j.pnucene.2018.07.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Li B, Ma M, Yu Y, Chen C, Zhou Z. Particle scale study on heat transfer of gas–solid spout fluidized bed with hot gas injection. PARTICULATE SCIENCE AND TECHNOLOGY 2018. [DOI: 10.1080/02726351.2018.1438547] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Bin Li
- School of Energy, Power and Mechanical Engineering, North China Electric Power University Baoding Campus, Baoding, China
| | - Mengxiang Ma
- School of Energy, Power and Mechanical Engineering, North China Electric Power University Baoding Campus, Baoding, China
| | - Yang Yu
- School of Energy, Power and Mechanical Engineering, North China Electric Power University Baoding Campus, Baoding, China
| | - Cuiling Chen
- School of Energy, Power and Mechanical Engineering, North China Electric Power University Baoding Campus, Baoding, China
| | - Zunkai Zhou
- School of Energy, Power and Mechanical Engineering, North China Electric Power University Baoding Campus, Baoding, China
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Guo Z, Sun Z, Zhang N, Ding M, Wen J. Experimental characterization of pressure drop in slender packed bed (1 Chem Eng Sci 2017. [DOI: 10.1016/j.ces.2017.08.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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20
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Effect of Gas Velocity Distribution on Heat Recovery Process in Packed Bed of Plate-Shaped Slag. ENERGIES 2017. [DOI: 10.3390/en10060755] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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