CFD prediction of combustion in a swirl combustor

A numerical simulation has been performed to study the biogas combustion in a burner with premixed flame developed under a high intensity small-scale turbulent environment, corresponding to high Karlovitz conditions. The CFD simulations were validated against experimental data for burner running with methane (measured temperatures along the radiant tube and CO emission). The biogas combustion was compared with methane combustion and influence of excess air on combustion was observed. It has revealed that the combustion of biogas with excess air of 1.15 is similar to combustion of methane with same excess air, except the CO concentration which is lower for biogas. Increasing the excess air for biogas combustion leads to the change of flame front position, temperature distribution and higher CO concentration. (paper)