Premixed moderate or intense low-oxygen dilution (MILD) combustion from a single jet burner in a laboratory-scale furnace

Impacts of initial conditions on the characteristics of premixed moderate or intense low-oxygen dilution (MILD) combustion from a single jet burner in a laboratory-scale furnace are investigated through Reynolds-averaged Navier- Stokes (RANS) modeling and experiments. Different initial conditions examined include the area of the nozzle (A), equivalence ratio ((I)), thermal input (P), and initial dilution of reactants (f). Very low emissions of NOx, CO, and H-2 are measured for the MILD conditions when the furnace is operated under the premixed mode. The numerical results have shown that premixed MILD combustion can occur at the present furnace and burner system only when Re exceeds a critical value (Re-c). When Re >= Re-c, a stable MILD combustion can be established, irrespective of the variation of A, Phi, or f. The diagram of the stability limits for the premixed MILD combustion based on the furnace temperature and recirculation rate is also presented.