Two-dimensional CFD simulation of chemical reactions in tapered-in and tapered-out fluidized bed reactors

2019 ◽  
Vol 30 (1) ◽  
pp. 136-147
Author(s):  
Hossein Askaripour ◽  
Asghar Molaei Dehkordi
Keyword(s):  
Fluidized Bed ◽  
Chemical Reactions ◽  
Cfd Simulation ◽  
Fluidized Bed Reactors ◽  
Two Dimensional

Erosion Mechanism of Platen Heating Surfaces in CFB

2012 ◽  
Vol 472-475 ◽  
pp. 2287-2291 ◽  
Author(s):  
Jing Hui Song ◽  
Tao Wang ◽  
Xiao Ying Hu ◽  
Chang Qing Dong
Keyword(s):  
Fluidized Bed ◽  
Chemical Reactions ◽  
Maximum Velocity ◽  
Two Dimensional ◽  
Solid Flow ◽  
Flow Models ◽  
Erosion Mechanism ◽  
Heating Surfaces ◽  
X 24 ◽  
The Right

A two-dimensional numerical gas-solid flow models without chemical reactions is developed to simulate gas-solid flow in the fluidized bed boiler through MFIX software. Platen heating surfaces is considered in the upper of the furnace. Considering that velocity and concentration are the most factor effecting on erosion, there are three main area suffered serious erosion: (1) There is a maximum velocity at the position ( X = 57 cm, Y= 60 cm) on the right side of the wall, which will produce serious impact and erosion. (2) In the vicinity of position (X = 57 cm, Y= 140 cm) will suffer serious impact and tear. (3) As to the platen heating surfaces, the lower part which connect with flow is slightly wear and impacted. While the velocity on the right part is relatively large, especially in the corner of position (X = 24 cm, Y= 147 cm) reach a maximum.

scholarly journals Multi-scale CFD simulation of hydrodynamics and cracking reactions in fixed fluidized bed reactors

2015 ◽  
Vol 5 (4) ◽  
pp. 255-261 ◽  
Author(s):  
Jin H. Zhang ◽  
Zhen B. Wang ◽  
Hui Zhao ◽  
Yuan Y. Tian ◽  
Hong H. Shan ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Cfd Simulation ◽  
Fluidized Bed Reactors ◽  
Multi Scale

CFD Simulation of Pyrolysis of Lignite in a Downstream Fluidized Bed

2012 ◽  
Vol 457-458 ◽  
pp. 515-520 ◽  
Author(s):  
Yong Li Sun ◽  
Rong Zhang ◽  
Lv Hong Zhang ◽  
Ya Nan Zhang
Keyword(s):  
Fluidized Bed ◽  
Chemical Reactions ◽  
Coal Combustion ◽  
Cfd Simulation ◽  
Inert Gas ◽  
Combustion Model ◽  
Particle Track ◽  
Nitrogen Gas ◽  
Commercial Software ◽  
Injection Point

This paper works with the CFD simulation of the process of pyrolysis of lignite particles in a downstream fluidized bed, which actually means the particles would fall down from the injection point and escape the furnace from the bottom. The particle track is solved by using the Lagrangian approach, while the flow of the inert gas (nitrogen) is dealt with by the Eulerian approach. The heat transferred from the nitrogen gas to the surface of particle is computed by means of the famous Ranz-Marshall correlation. The chemical reactions are simulated using part of the coal combustion model inserted in the commercial software used.

Comparison of CFD Simulation and Simplified Modeling of a Fluidized Bed CO2 Capture Reactor

2016 ◽  
Vol 14 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Daoyin Liu ◽  
Zhonglin Zhang ◽  
Yaming Zhuang ◽  
Xiaoping Chen
Keyword(s):  
Fluidized Bed ◽  
Flow Model ◽  
Cfd Simulation ◽  
Plug Flow ◽  
Fluidized Bed Reactors ◽  
Cfd Model ◽  
Two Phase ◽  
Multiphase Cfd ◽  
Reactor Models ◽  
Dem Model

AbstractCO2 capture using solid sorbents in fluidized bed reactors is a promising technology. The multiphase CFD model is increasingly developed to study the reactors, but it is difficult to model all the realistic details and it requires significant computational time. In this study, both the multiphase CFD model (i.e., CFD-DEM model coupled with reaction) and the simplified reactor models (i.e., plug flow model and bubbling two-phase model) are developed for modeling a fluidized bed CO2 capture reactor. The comparisons are made at different gas velocities from fixed bed to fluidized bed. The DEM based model reveals a detailed view of CO2 adsorption process with particle flow dynamics, based on which the assumptions in the simplified models can be evaluated. The plug flow model predictions generally show similar trends to the DEM model but there are quantitative differences; thus, it can be used to determine the reactor performance limit. The bubbling two-phase model gives better predictions than the plug flow model because the effect of bubbles on the inter-phase mass transfer and reaction is included. In the future, a closer combination of the multiphase CFD simulation and the simplified reactor models will likely be an efficient design method of CO2 capture fluidized bed reactors.

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