Modeling of CWM droplet combustion. Final report
The objective of the present study was to develop a one-dimensional, unsteady state model for coal-water mixture droplet combustion, and to compare the characteristic times for the various processes, such as water vaporization, devolatilization and char oxidation with available experimental data. A water film surrounding a spherical coal particle is considered to undergo vaporization by heat transfer from the hot air. After the water vaporization is complete, devolatilization begins. This process is assumed to be kinetically controlled. Water vaporization and devolatilization processes are modeled by using a hybrid Eulerian-Lagrangian method to obtain the properties of the gas-phase and the condensed-phase. An explicit finite difference scheme is used to solve the Eulerian gas-phase equation where as a Runga-Kutta scheme is employed to solve the Lagrangian condensed-phase equations. The predicted characteristic times for water vaporization is in good agreement with values proposed in the literature. At the present time there is insufficient data to draw any conclusions on the model. Methods are proposed to refine the simple kinetic model which takes into account pore diffusion and mass transfer for devolatilization and char oxidation. 9 references, 12 figures.
- Research Organization:
- Pandalai Coatings Co., Brackenridge, PA (USA)
- DOE Contract Number:
- AC22-82PC50052
- OSTI ID:
- 5162127
- Report Number(s):
- DOE/PC/50052-T1; ON: DE84009755
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHARS
OXIDATION
FUEL SLURRIES
COMBUSTION
WATER
DEVOLATILIZATION
EVAPORATION
COAL
DROPLETS
FINITE DIFFERENCE METHOD
HEAT TRANSFER
LAGRANGE EQUATIONS
MATHEMATICAL MODELS
MIXTURES
ONE-DIMENSIONAL CALCULATIONS
WATER VAPOR
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
DIFFERENTIAL EQUATIONS
DISPERSIONS
ENERGY SOURCES
ENERGY TRANSFER
EQUATIONS
FLUIDS
FOSSIL FUELS
FUELS
GASES
HYDROGEN COMPOUNDS
ITERATIVE METHODS
MATERIALS
NUMERICAL SOLUTION
OXYGEN COMPOUNDS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLES
PHASE TRANSFORMATIONS
PYROLYSIS PRODUCTS
SLURRIES
SUSPENSIONS
THERMOCHEMICAL PROCESSES
VAPORS
014000* - Coal
Lignite
& Peat- Combustion