Numerical Simulation and Experimental Study of a Full-Scale Mild Combustion Chamber

Over the past four decades, gas turbine combustion has been dedicated to achieving low emissions, resulting in numerous advancements in combustion technologies. MILD combustion, a relatively promising new technology with unique characteristics, has garnered extensive research and attention in the last twenty years. However, applying MILD combustion to gas turbines remains a significant challenge due to limited space and high heat release rates per unit. Currently, most MILD combustion experiments are conducted on a laboratory scale. To address this issue, we conducted full-scale MILD combustion experiments under pressure test conditions in this study. NOx data were obtained at different outlet temperatures (1473 K–1773 K) under experimental conditions of 1.5 bar pressure and air inlet temperature at about 423K and 510K. These results were compared with previous lab-scale research data. The findings indicate that while the NOx emission data for full-scale experiments increased relative to lab-scale studies, it still remained below 10 ppm@15%O2 during operating conditions, demonstrating the low NOx emission potential of MILD combustion. This outcome can be attributed primarily to the adiabatic state of the full-scale combustion chamber’s process and relatively poor mixing effects between fuel and air as well as flue gas and unburned reactants due to size enlargement. These findings have significant implications for designing full-scale MILD combustion chambers in gas turbine engines.