Computational Fluid Dynamics–Discrete Element Model Simulation of Flow Characteristics and Solids’ Residence Time Distribution in a Moving Bed Air Reactor for Chemical Looping Combustion

2020 ◽  
Vol 59 (40) ◽  
pp. 18180-18192
Author(s):  
Yali Shao ◽  
Ramesh K. Agarwal ◽  
Jiageng Li ◽  
Xudong Wang ◽  
Baosheng Jin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Model Simulation ◽  
Flow Characteristics ◽  
Element Model ◽  
Chemical Looping Combustion ◽  
Discrete Element Model ◽  
Chemical Looping

scholarly journals MFIX-Exa: A path toward exascale CFD-DEM simulations

2021 ◽  
pp. 109434202110092
Author(s):  
Jordan Musser ◽  
Ann S Almgren ◽  
William D Fullmer ◽  
Oscar Antepara ◽  
John B Bell ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Element Model ◽  
Discrete Element Model ◽  
Software Framework ◽  
Chemical Reactors ◽  
Software Infrastructure ◽  
Fundamental Physics ◽  
Dem Simulations ◽  
Algorithmic Approaches

MFIX-Exa is a computational fluid dynamics–discrete element model (CFD-DEM) code designed to run efficiently on current and next-generation supercomputing architectures. MFIX-Exa combines the CFD-DEM expertise embodied in the MFIX code—which was developed at NETL and is used widely in academia and industry—with the modern software framework, AMReX, developed at LBNL. The fundamental physics models follow those of the original MFIX, but the combination of new algorithmic approaches and a new software infrastructure will enable MFIX-Exa to leverage future exascale machines to optimize the modeling and design of multiphase chemical reactors.

scholarly journals Validation of a Computational Fluid Dynamics Model for a Novel Residence Time Distribution Analysis in Mixing at Cross-Junctions

Water ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 733 ◽  
Author(s):  
Daniel Hernández-Cervantes ◽  
Xitlali Delgado-Galván ◽  
José Nava ◽  
P. López-Jiménez ◽  
Mario Rosales ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Distribution Analysis ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model

Review of Computational Fluid Dynamics Studies on Chemical Looping Combustion

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Yali Shao ◽  
Ramesh K. Agarwal ◽  
Xudong Wang ◽  
Baosheng Jin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Flow Process ◽  
Gas Leakage ◽  
Fuel Reactor ◽  
Energy Penalty

Abstract Chemical looping combustion (CLC) is an attractive technology to achieve inherent CO2 separation with low energy penalty. In CLC, the conventional one-step combustion process is replaced by two successive reactions in two reactors, a fuel reactor (FR) and an air reactor (AR). In addition to experimental techniques, computational fluid dynamics (CFD) is a powerful tool to simulate the flow and reaction characteristics in a CLC system. This review attempts to analyze and summarize the CFD simulations of CLC process. Various numerical approaches for prediction of CLC flow process are first introduced and compared. The simulations of CLC are presented for different types of reactors and fuels, and some key characteristics including flow regimes, combustion process, and gas-solid distributions are described in detail. The full-loop CLC simulations are then presented to reveal the coupling mechanisms of reactors in the whole system such as the gas leakage, solid circulation, redox reactions of the oxygen carrier, fuel conversion, etc. Examples of partial-loop CLC simulation are finally introduced to give a summary of different ways to simplify a CLC system by using appropriate boundary conditions.

Behavior of particle swarms at low and moderate Reynolds numbers using computational fluid dynamics—Discrete element model

2020 ◽  
Vol 32 (7) ◽  
pp. 073304
Author(s):  
Oladapo Ayeni ◽  
Shashank S. Tiwari ◽  
Chunliang Wu ◽  
Jyeshtharaj B. Joshi ◽  
Krishnaswamy Nandakumar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Element Model ◽  
Reynolds Numbers ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Particle Swarms

scholarly journals Optimization of a Continuous Hybrid Impeller Mixer via Computational Fluid Dynamics

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
N. Othman ◽  
S. K. Kamarudin ◽  
M. S. Takriff ◽  
M. I. Rosli ◽  
E. M. F. Engku Chik ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Operating Conditions ◽  
Impeller Speed ◽  
Transient Condition ◽  
Experimental Investigations ◽  
Rushton Turbine

This paper presents the preliminary steps required for conducting experiments to obtain the optimal operating conditions of a hybrid impeller mixer and to determine the residence time distribution (RTD) using computational fluid dynamics (CFD). In this paper, impeller speed and clearance parameters are examined. The hybrid impeller mixer consists of a single Rushton turbine mounted above a single pitched blade turbine (PBT). Four impeller speeds, 50, 100, 150, and 200 rpm, and four impeller clearances, 25, 50, 75, and 100 mm, were the operation variables used in this study. CFD was utilized to initially screen the parameter ranges to reduce the number of actual experiments needed. Afterward, the residence time distribution (RTD) was determined using the respective parameters. Finally, the Fluent-predicted RTD and the experimentally measured RTD were compared. The CFD investigations revealed that an impeller speed of 50 rpm and an impeller clearance of 25 mm were not viable for experimental investigations and were thus eliminated from further analyses. The determination of RTD using ak-εturbulence model was performed using CFD techniques. The multiple reference frame (MRF) was implemented and a steady state was initially achieved followed by a transient condition for RTD determination.

Computational Fluid Dynamics Modeling of Chemical Looping Combustion Process with Calcium Sulphate Oxygen Carrier

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Baosheng Jin ◽  
Rui Xiao ◽  
Zhongyi Deng ◽  
Qilei Song
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Combustion Products ◽  
Calcium Sulphate ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Dynamics Modeling ◽  
Fuel Reactor

To concentrate CO2 in combustion processes by efficient and energy-saving ways is a first and very important step for its sequestration. Chemical looping combustion (CLC) could easily achieve this goal. A chemical-looping combustion system consists of a fuel reactor and an air reactor. Two reactors in the form of interconnected fluidized beds are used in the process: (1) a fuel reactor where the oxygen carrier is reduced by reaction with the fuel, and (2) an air reactor where the reduced oxygen carrier from the fuel reactor is oxidized with air. The outlet gas from the fuel reactor consists of CO2 and H2O, while the outlet gas stream from the air reactor contains only N2 and some unused O2. The water in combustion products can be easily removed by condensation and pure carbon dioxide is obtained without any loss of energy for separation.Until now, there is little literature about mathematical modeling of chemical-looping combustion using the computational fluid dynamics (CFD) approach. In this work, the reaction kinetic model of the fuel reactor (CaSO4+ H2) is developed by means of the commercial code FLUENT and the effects of partial pressure of H2 (concentration of H2) on chemical looping combustion performance are also studied. The results show that the concentration of H2 could enhance the CLC performance.

Application of computational fluid dynamics (CFD) to ozone contactor optimization

2006 ◽  
Vol 6 (4) ◽  
pp. 9-16 ◽  
Author(s):  
J. Li ◽  
J. Zhang ◽  
J. Miao ◽  
J. Ma ◽  
W. Dong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Original Design ◽  
Computational Fluid Dynamics Cfd ◽  
Ozone Contactor

Many approaches have been used to model the performance and efficiency of ozone contactors based on some assumptions to characterize the backmixing in fluids. Recently, computational fluid dynamics (CFD) technique has been proposed to simulate and optimize ozone contactors by calculating residence time distribution of fluid. To improve the ozone contactor performance of Bijianshan Water Treatment Plant in Shenzhen in South China, CFD was used for simulation and development of new optimization measures. Results showed that the low depth/length ratio of the contactor chambers in the original design resulted in short circuiting and backmixing, with the T10/HRT being only 0.40. Installation of guide plates substantially reduced short circuiting and backmixing with a much higher T10/HRT (0.66), increased by 73% compared with the original design.

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