This study assesses the required fidelities in modeling particle radiative properties and particle size distributions (PSDs) of\ncombusting particles in Computational Fluid Dynamics (CFD) investigations of radiative heat transfer during oxy-combustion of\ncoal and biomass blends. Simulations of air and oxy-combustion of coal/biomass blends in a 0.5MWcombustion test facility were\ncarried out and compared against recent measurements of incident radiative fluxes. The prediction variations to the combusting\nparticle radiative properties, particle swelling during devolatilization, scattering phase function, biomass devolatilization models,\nand the resolution (diameter intervals) employed in the fuel PSD were assessed.While the wall incident radiative flux predictions\ncompared reasonably well with the experimental measurements, accounting for the variations in the fuel, char and ash radiative\nproperties were deemed to be important as they strongly influenced the incident radiative fluxes and the temperature predictions\nin these strongly radiating flames. In addition, particle swelling and the diameter intervals also influenced the incident radiative\nfluxes primarily by impacting the particle extinction coefficients. This study highlights the necessity for careful selection of particle\nradiative property, and diameter interval parameters and the need for fuel fragmentation models to adequately predict the fly ash\nPSD in CFD simulations of coal/biomass combustion.
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