MODELING CHAR OXIDATION AS A FUNCTION OF PRESSURE ...
MODELING CHAR OXIDATION AS A FUNCTION OF PRESSURE ...
MODELING CHAR OXIDATION AS A FUNCTION OF PRESSURE ...
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5. Theoretical Developments.........................................................................................45<br />
The Observed Reaction Orders in Zone I and Zone II...................................................46<br />
Rough Sphere Combustion.............................................................................................50<br />
Bulk Diffusion vs. Knudsen Diffusion..........................................................................53<br />
Relationship between the Effectiveness Factor and the Second Effectiveness Factor...57<br />
Extended Resistance Equation (ERE).............................................................................60<br />
Various Mechanisms for the Carbon-Oxygen Reaction.................................................62<br />
Constant Fractional Reaction Order Issue.....................................................................65<br />
6. High Pressure Char Oxidation Model........................................................................69<br />
CBK Model....................................................................................................................69<br />
Single-Film Char Oxidation Submodel.....................................................70<br />
Statistical Kinetics and Properties...........................................................74<br />
Thermal Annealing Submodel...............................................................76<br />
The Ash Encapsulation Submodel..........................................................77<br />
HP-CBK Model Development......................................................................................78<br />
Kinetics ........................................................................................78<br />
Effective Diffusivity..........................................................................80<br />
Estimating S ext /S int Using Pore Structure Model...........................................82<br />
Thermodynamic and Transport Properties.................................................84<br />
Range of Reynolds Number.................................................................85<br />
7. Model Evaluation and Discussion..............................................................................87<br />
Graphite Flake Data.......................................................................................................88<br />
Rough Sphere Combustion Data....................................................................................90<br />
Results and Discussion.......................................................................92<br />
Large Particle Oxidation Data.........................................................................................95<br />
Pulverized Char Drop-Tube Data................................................................................103<br />
Approach......................................................................................104<br />
Results ........................................................................................109<br />
TGA and FFB Data-This Study..................................................................................111<br />
Results ........................................................................................115<br />
Summary......................................................................................................................117<br />
8. Summary and Conclusions.......................................................................................121<br />
Analytical Solutions of the Effectiveness Factors.......................................................121<br />
Theoretical Developments...........................................................................................122<br />
The Observed Reaction Order in Zone I and Zone II....................................122<br />
Rough Sphere Combustion.................................................................122<br />
Knudsen Diffusion and Molecular Diffusion.............................................123<br />
Second Effectiveness Factor and ERE ....................................................124<br />
Mechanisms ..................................................................................124<br />
HP-CBK Model...........................................................................................................125<br />
Principal Conclusions...................................................................................................127<br />
9. Recommendations....................................................................................................129<br />
References........................................................................................................................131<br />
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