Second-Generation Low-Emission Combustors for ABB Gas Turbines: Tests Under Full-Engine Conditions

Abstract

An experimental rig was constructed which made it possible to research the influence of air mass flow, pressure, preheating temperature, and fuel/air ratio on the behavior of a full-scale burner. Because the investigations were carried out in the high pressure test facility at the DLR in Cologne, and not in a real gas turbine, the parameters could be varied independently of one another. Based on these systematic measurements, it is possible to predict flame stability limits and emissions for any gas turbine under any operating condition. For example, it can be shown that NOx emissions from the GT8 with ABB’s new second-generation premixing burners will not exceed 25 ppm (for 15% O2) and COwet will be less than 8 ppm at full load (16 bar, 420°C). In addition, the data measured were compared to results obtained from correlations frequently used, such as that NOx is proportional to p0.5. It was shown that this equation is too optimistic even if the flame type remains unchanged.