Influence of turbulent mixing intensity on the MILD combustion and the pollutant formation

Moderate or intense low-oxygen dilution (MILD) combustion has been acknowledged as one of the most interesting combustion technologies to meet both the targets of high process efficiency and low pollutant emissions. Therefore, the potential for its implementation in gas turbine combustors is investigated in recent research activities. In the MILD combustion regime, we find that the characteristic times of kinetics and turbulence become comparable and the two phenomena are coupled with each other. In this work, a partially stirred reactor is applied to investigate the influence of the turbulent mixing intensity on the combustion process as well as its impact on NOx formation. The proposed model is based on a combination of simple turbulent mixing approach with a detailed chemistry sub-model for methane oxidation and NOx formation. The computational results demonstrate that the combustion processes as well as the pollutant formation are very sensitive to the mixing intensity. However, the total NOx emissions after complete combustion are seen to be only slightly influenced by the mixing intensity.