Experimental Investigations on NOx Emission and Combustion Dynamics in an Axial Fuel Staging Combustor

Axial Fuel Staging(AFS) technology is an advanced low-emission combustion method in modern gas turbine, which divides the combustor into two axially arranged combustion zones. For revealing the characteristics of axial staged combustion, an industrial-grade combustor was designed and built. The distribution of temperature and velocity field in the combustor was presented with numerical simulation. And an Atmospheric Combustor Test Rig for axial staged combustion was built. The flow resistance characteristics of the combustor were measured at first. Then the effects of the equivalent ratio and the preheating temperature on the pollutant emission and combustion instability were investigated. The results show that the total pressure recovery coefficient in cold state is always above 98%; starting the secondary combustion at low load can reduce NO emissions by 50%, and can suppress the combustion oscillation amplitude of the combustor. At the design point with Φ=0.62 and preheating temperature=400°C, NO emission and CO emission are 15.68 and 4.22 mg/m~3(@15%O2).