Numerical simulation of soot combustion process in a bubbling fluidized bed with segregation behavior

2015 ◽  
Vol 11 (1) ◽  
pp. 140-150
Author(s):  
Hanbin Zhong ◽  
Xingying Lan ◽  
Jinsen Gao
AIChE Journal ◽  
2018 ◽  
Vol 64 (11) ◽  
pp. 3857-3867 ◽  
Author(s):  
Hadrien Benoit ◽  
Renaud Ansart ◽  
Hervé Neau ◽  
Pablo Garcia Triñanes ◽  
Gilles Flamant ◽  
...  

2018 ◽  
Vol 338 ◽  
pp. 664-676 ◽  
Author(s):  
Wang Lin ◽  
Qi Guoli ◽  
Li Zhenjie ◽  
Liu Songsong ◽  
Muhammad Hassan ◽  
...  

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 785
Author(s):  
Zdzisław Adamczyk ◽  
Magdalena Cempa ◽  
Barbara Białecka

The aim of this study was to examine the physico-chemical and phase characteristics of ash obtained in the process of the combustion of Polish poultry manure in a laboratory reactor with a bubbling fluidized bed. Three experiments, differing in the grain size and morphology of the raw material, the method of its dosing and the type of fluidized bed, were carried out. The contents of the main chemical components and trace elements in the obtained ash samples were determined using WDXRF, and the phase composition was examined through the XRD method. The morphology and the chemical composition of grains in a given micro-area using the SEM/EDS method were also investigated. The highest concentration of phosphorus (from 28.07% wt. to 29.71% wt. as P2O5 equivalent), the highest proportion of amorphous substance (from 56.7% wt. to 59.0% wt.) and the lowest content of unburned organic substance (LOI from 6.42% to 9.16%) (i.e., the best process efficiency), was obtained for the experiment in which the starting bed was quartz sand and poultry manure was fed to the reactor in the form of pellets. It has been calculated that in this case, the amorphous phase contains more than half of the phosphorus. The method of carrying out the combustion process has a significant impact on the phase composition and, consequently, on the availability of phosphorus.


2013 ◽  
Vol 17 (4) ◽  
pp. 1163-1179
Author(s):  
Milica Mladenovic ◽  
Stevan Nemoda ◽  
Mirko Komatina ◽  
Dragoljub Dakic

The paper deals with the development of mathematical models for detailed simulation of lateral jet penetration into the fluidized bed (FB), primarily from the aspect of feeding of gaseous and liquid fuels into FB furnaces. For that purpose a series of comparisons has been performed between the results of in-house developed procedure- fluid-porous medium numerical simulation of gaseous jet penetration into the fluidized bed, Fluent?s two-fluid Euler-Euler FB simulation model, and experimental results (from the literature) of gaseous jet penetration into the 2D FB. The calculation results, using both models, and experimental data are in good agreement. The developed simulation procedures of jet penetration into the FB are applied to the analysis of the effects, which are registered during the experiments on a fluidized pilot furnace with feeding of liquid waste fuels into the bed, and brief description of the experiments is also presented in the paper. Registered effect suggests that the water in the fuel improved mixing of fuel and oxidizer in the FB furnace, by increasing jet penetration into the FB due to sudden evaporation of water at the entry into the furnace. In order to clarify this effect, numerical simulations of jet penetration into the FB with three-phase systems: gas (fuel, oxidizer, and water vapour), bed particles and water, have been carried out.


Author(s):  
Christian Mueller ◽  
Anders Brink ◽  
Mikko Hupa

Solid fuels currently used for energy production in thermal power plants are characterized by a large variety ranging from different coals to biomasses and wastes. This manifold of fuels offers opportunities to the energy producers and nowadays many power plants do not fire single fuels but fuel mixtures. While this procedure may lead to overall economic and environmental advantages it is very demanding for the boiler operators to maintain boiler performance and availability and to meet emission limits. The development of mathematical models that are capable of predicting the combustion behavior of fuel mixtures and provide guidelines for operators and manufacturers has been a challenge over the last years. Since bubbling fluidized beds are frequently used for firing fuel mixtures and especially biomass mixtures, current CFD based BFB models, such as the A˚bo Akademi Furnace Model, have been used widely over the last years to predict emission tendencies and ash deposition behavior. However, due to the complexity of the processes during combustion of fuel mixtures and the combustion process in the bubbling fluidised bed itself, the models are characterized by strong simplifications. This is especially true for the description of the lower part of the furnace, the region of fuel intake and bubbling bed. Recently, the A˚bo Akademi Furnace Model has been extended by a more detailed description of the fuel conversion by considering the combustion of individual biomass particles and a first simplified approach describing heat and mass transfer processes between the bubbling bed and the freeboard. Both submodels guarantee a closed mass and energy balance over the bed-freeboard region. In the current study the new submodels have been used to investigate the combustion conditions in a 290 MW bubbling fluidized bed boiler firing peat and forest residue. Clear differences in the simulation results for the both fuels can be found with regard to the specific combustion characteristics, the location of the main combustion zone and the total heat generated during combustion.


2021 ◽  
Vol 190 ◽  
pp. 116812
Author(s):  
M. Díaz-Heras ◽  
J.I. Córcoles ◽  
J.F. Belmonte ◽  
J.A. Almendros-Ibáñez

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