scholarly journals INCORPORATION OF A TWO-FLUX MODEL FOR RADIATIVE HEAT TRANSFER IN A COMPREHENSIVE FLUIDIZED BED SIMULATOR PART II: NUMERICAL RESULTS AND ASSESSMENT

2003 ◽  
Vol 2 (2) ◽  
Author(s):  
J. A. Rabi ◽  
M. L. De Souza-Santos
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Fluidized Bed Reactors ◽  
Transfer Model ◽  
Temperature Profiles ◽  
Transfer Rates ◽  
Gas Phases ◽  
Flux Model

As shown in the first part of this paper, equations and considerations for a preliminary attempt to improve the treatment for radiative heat transfer of a previous comprehensive simulation program were presented. For that, the two-flux radiative heat transfer model was applied. In this second part, the new version of that program was tested against steady-state operations of real equipment. Numerical simulations were carried for two different fluidized-bed reactors: a coal-fed boiler and a wood-fed gasifier. Computational results obtained with that new version were compared with those obtained with the previous simulator version. Then, both sets of results were also compared with real operational data. Special attention was paid to the temperature profiles of each particle species present in the bed section – carbonaceous, limestone and inert – as well as to the radiative heat transfer rates between these solids. Effects on the temperature profiles of the gas phases – emulsion and bubbles – and on the equipment performance parameters were also investigated. Improvements related to the incorporation of two-flux model are assessed and discussed. New developments and extensions of this approach are indicated.

scholarly journals INCORPORATION OF A TWO-FLUX MODEL FOR RADIATIVE HEAT TRANSFER IN A COMPREHENSIVE FLUIDIZED BED SIMULATOR PART II: NUMERICAL RESULTS AND ASSESSMENT

2003 ◽  
Vol 2 (2) ◽  
pp. 49
Author(s):  
J. A. Rabi ◽  
M. L. De Souza-Santos
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Fluidized Bed Reactors ◽  
Transfer Model ◽  
New Developments ◽  
Transfer Rates ◽  
Gas Phases ◽  
Flux Model

As shown in the first part of this paper, equations and considerations for a preliminary attempt to improve the treatment for radiative heat transfer of a previous comprehensive simulation program were presented. For that, the two-flux radiative heat transfer model was applied. In this second part, the new version of that program was tested against steady-state operations of real equipment. Numerical simulations were carried for two different fluidized-bed reactors: a coal-fed boiler and a wood-fed gasifier. Computational results obtained with that new version were compared with those obtained with the previous simulator version. Then, both sets of results were also compared with real operational data. Special attention was paid to the temperature profiles of each particle species present in the bed section – carbonaceous, limestone and inert – as well as to the radiative heat transfer rates between these solids. Effects on the temperature profiles of the gas phases – emulsion and bubbles – and on the equipment performance parameters were also investigated. Improvements related to the incorporation of two-flux model are assessed and discussed. New developments and extensions of this approach are indicated.

Development of Radiative Heat Transfer Model for Pulverized Coal Combustion

2008 ◽  
Vol 34 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Toshimitsu Asotani ◽  
Toru Yamashita ◽  
Hiroaki Tominaga ◽  
Yoshinori Itaya ◽  
Shigekatu Mori
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Coal Combustion ◽  
Radiative Heat ◽  
Heat Transfer Model ◽  
Pulverized Coal ◽  
Transfer Model ◽  
Pulverized Coal Combustion

scholarly journals Conjugate Heat Transfer Characteristics in a Highly Thermally Loaded Film Cooling Configuration with TBC in Syngas

Aerospace ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 16
Author(s):  
Jing Ren ◽  
Xueying Li ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Radiative Heat ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Plate Temperature ◽  
Total Percentage ◽  
Barrier Coating

Future power equipment tends to take hydrogen or middle/low heat-value syngas as fuel for low emission. The heat transfer of a film-cooled turbine blade shall be influenced more by radiation. Its characteristic of conjugate heat transfer is studied experimentally and numerically in the paper by considering radiation heat transfer, multicomposition gas, and thermal barrier coating (TBC). The Weighted Sum of Gray Gases Spectral Model and the Discrete Transfer Model are utilized to solve the radiative heat transfer in the multicomposition field, while validated against the experimental data for the studied cases. It is shown that the plate temperature increases significantly when considering the radiation and the temperature gradient of the film-cooled plate becomes less significant. It is also shown that increasing percentage of steam in gas composition results in increased temperature on the film-cooled plate. The normalized temperature of the film-cooled plate decreases about 0.02, as the total percentage of steam in hot gas increases 7%. As for the TBC effect, it can smooth out the temperature distribution and insulate the heat to a greater extent when the radiative heat transfer becomes significant.

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