Hydrodynamic Model for the Gas Flow in Circulating Fluidized Bed Reactors

2002 ◽  
Vol 41 (24) ◽  
pp. 5983-5989 ◽  
Author(s):  
Charlotte Vandewalle ◽  
Jan Baeyens ◽  
Anna Claerbout
Keyword(s):  
Fluidized Bed ◽  
Hydrodynamic Model ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Fluidized Bed Reactors

scholarly journals Modelling of indirect steam gasification in circulating fluidized bed reactors

2018 ◽  
Vol 171 ◽  
pp. 10-19 ◽  
Author(s):  
Kari Myöhänen ◽  
Juha Palonen ◽  
Timo Hyppänen
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Steam Gasification ◽  
Fluidized Bed Reactors

CFD-DEM Modeling of CO2 Capture using Alkali Metal-Based Sorbents in a Bubbling Fluidized Bed

2014 ◽  
Vol 12 (1) ◽  
pp. 441-449 ◽  
Author(s):  
Zhonglin Zhang ◽  
Daoyin Liu ◽  
Yaming Zhuang ◽  
Qingmin Meng ◽  
Xiaoping Chen
Keyword(s):  
Fluidized Bed ◽  
Gas Flow ◽  
Fluidized Bed Reactors ◽  
Solid Sorbents ◽  
Bubbling Fluidized Bed ◽  
Shrinking Core ◽  
Simulation And Experiment ◽  
Kinetics Simulation ◽  
Reaction Processes ◽  
Back Mixing

Abstract This paper describes a CFD-DEM modeling of CO2 capture using K2CO3 solid sorbents in a bubbling fluidized bed, which takes into heat transfer, hydrodynamics, and chemical reactions. Shrinking core model is applied in reaction kinetics. Simulation and experiment results of bed pressure drop and CO2 concentration in the reactor exit agree well. Instantaneous dynamics as well as time-averaged profiles indicate detailed characteristics of gas flow, particle motion, and chemical reaction processes. The simulation results show an obvious core-annular flow and strong back-mixing flow pattern. CO2 concentration decreases gradually along the bed height, while regards on the lateral distribution CO2 concentration near the wall is lower than that in the middle zone where gas passes through faster. The effect of bubbles on CO2 reaction is two-sided: it can promote mixing which strengthens reaction, while it can be a short pass of gas which is not beneficial to reaction. The simulation is helpful for further understanding and optimal design of fluidized bed reactors of CO2 capture.

Dynamic simulation of the circulating fluidized bed loop performance under the various operating conditions

2019 ◽  
Vol 233 (7) ◽  
pp. 901-913 ◽  
Author(s):  
Seongil Kim ◽  
Sangmin Choi ◽  
Jari Lappalainen ◽  
Tae-Ho Song
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Heat Transfer Rate ◽  
Dynamic Simulation ◽  
Transfer Rate ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Operating Conditions ◽  
Temperature Behavior ◽  
Furnace Temperature

In a circulating fluidized bed boiler, the large thermal mass and flow characteristics of the solids strongly affect the transient response of the circulating fluidized bed loop temperature, which determines the heat transfer rate to steam flow. Therefore, it is essential to interpret the dynamic response of the solid behavior in the circulating fluidized bed loop for the stable and efficient operation of the circulating fluidized bed boiler. In this study, the dynamic simulation of the solid behavior along with the flue gas flow in a circulating fluidized bed loop was performed by applying the core-annulus approach for the solid-gas flow inside the furnace and selected models for other physical phenomena of the fluidized bed. The circulating fluidized bed loop of a commercial boiler was selected as the target system. Especially, the model simulates the characteristics of the solid behavior, such as the local solid mass distribution, and the solid flow inside the furnace and the circulating solid according to the various operating conditions. These aspects are difficult to measure and quantify in a real power plant. In this paper, the simulated furnace temperature behavior as the representative performance parameter of the circulating fluidized bed loop was discussed along with the qualitative operation experiences reported in the literature. The operating conditions include the feed rate of fuel and air, the particle size, the solid inventory and the solid circulation rate. Furnace temperature behavior was reproduced through the simulation for each operating case in the literature and was analyzed with the solid behavior along with the combustion rate and heat transfer rate of the circulating fluidized bed loop. The simulation enables quantitative evaluation of the effect of the solid behavior on the temperatures of the furnace and return part in the various operating conditions.

A hydrodynamic model of loop seal with a fluidized standpipe for a circulating fluidized bed

Particuology ◽  
2018 ◽  
Vol 36 ◽  
pp. 50-58 ◽  
Author(s):  
Changjin Li ◽  
Zheng Zou ◽  
Hongzhong Li ◽  
Qingshan Zhu
Keyword(s):  
Fluidized Bed ◽  
Hydrodynamic Model ◽  
Circulating Fluidized Bed

Hydrodynamic and kinetic modelling of circulating fluidized bed reactors applied to a modified Claus plant

1996 ◽  
Vol 51 (24) ◽  
pp. 5251-5262 ◽  
Author(s):  
David M.J. Puchyr ◽  
Anil K. Mehrotra ◽  
Leo A. Behie ◽  
Nicolas Kalogerakis
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Kinetic Modelling ◽  
Fluidized Bed Reactors

Internally Circulating Fluidized Bed Reactor Using m-ZrO2 Supported NiFe2O4 Particles for Thermochemical Two-Step Water Splitting

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Nobuyuki Gokon ◽  
Hiroki Yamamoto ◽  
Nobuyuki Kondo ◽  
Tatsuya Kodama
Keyword(s):  
Fluidized Bed ◽  
Water Splitting ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Thermal Reduction ◽  
Input Power ◽  
Light Irradiation ◽  
Bed Temperature ◽  
N2 Flow Rate

A windowed internally circulating fluidized bed reactor was tested using m-ZrO2-supported NiFe2O4(NiFe2O4/m-ZrO2) particles as redox material for thermochemical two-step water splitting to produce hydrogen from water. The internally circulating fluidized bed of NiFe2O4/m-ZrO2 particles is directly heated by solar-simulated Xe light irradiation through a transparent quartz window mounted on top of the reactor. A sun simulator with three Xe lamps at laboratory scale has been newly installed in our laboratory for testing the fluidized bed reactor. The input power of incident Xe light can be scaled up to 2.6 kWth. Temperature distributions within the fluidized bed are measured under concentrated Xe light irradiation with an input power of 2.6 kWth. Hydrogen productivity and reactivity for the fluidized bed of NiFe2O4/m-ZrO2 particles are examined using two different reactors under the N2 flow rate and flow ratio, which yield a higher bed temperature. The feasibility of successive two-step water splitting using the fluidized bed reactor is examined by switching from N2 gas flow in the thermal reduction step to a steam/N2 gas mixture in the water decomposition step. It is confirmed that hydrogen production takes place in the single fluidized bed reactor by successive two-step water splitting.

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