Research Article
Assessing the Role of Particles in Radiative Heat Transfer during Oxy-Combustion of Coal and Biomass Blends
Table 2
Summary of physical models employed in the CFD simulations.
| Physical models | Primary modeling option | Other modeling options explored in the sensitivity analysis |
| Coal devolatilization | The two competing rates (Kobayashi) model | |
| Biomass devolatilization | The two competing rates (Kobayashi) model | Constant devolatilization rate (20 sec−1) |
| Gas-phase chemistry | Two steps: (1) char oxidation to CO, (2) CO oxidation to CO2 | |
| Gas-phase radiative property | Perry (5 gg) [11]* | |
| Turbulence | Realizable k-ε | |
| Radiative transport equation solver | Discrete ordinates method (angular resolution, theta × phi: 3 × 3) | |
| Particle radiative property | Variable and (Table 1)* | Constant and (corresponding to that of char in cf. Table 2); |
| Particle scattering phase function | Anisotropic (forward scattering) | Isotropic scattering |
| Fuel particle size distribution (PSD) at inlet | Rosin-Rammler distributions (Figure 1) (8 diameter intervals) | Rosin-Rammler distributions (Figure 1) (40 diameter intervals) |
| Particle swelling coefficient (during devolatilization) | 1 (no change in particle diameter during devolatilization) | 1.5 (particle diameter increases by 50% during devolatilization) |
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These models were implemented as User-Defined Functions (UDFs) in ANSYS FLUENT.
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