COMBUSTION ANALYSIS OF A CAN COMBUSTOR WITH CH4/NH3 BLENDED FUELS FOR A MICRO GAS TURBINE

Ammonia has been proposed as a hydrogen carrier and a potential alternative fuel to achieve low-carbon emissions. Due to its high ignition energy, limited flammable range, and low heating value compared to hydrogen and typical hydrocarbon fuels, it is challenging to sustain stable ammonia combustion. Blending ammonia with natural gas can increase the possibility of combustion applications. This work is to investigate the combustion performance of a micro gas turbine combustor with CH4/NH3 fuel blends. Results indicated the flame temperature declined with increasing NH3 mole fractions at constant fuel flow rates due to lower heating value of ammonia. To maintain the same power output with increasing NH3 contents, the mass flow rates of the fuel blends were raised, which pushed the flame downstream and resulted in severe temperature fluctuation at combustor exit. At higher NH3 fractions, the high-temperature regions shrank again because of lower residence time for any significant reactions. NOx emission was increased due to fuel-NOx production with NH3 addition. However, the non-monotonic trend of NO emission indicated a competition between thermal-NO and fuel-NO productions. Further considerations of flame stabilization and dilution strategy are essential for the implementation of the fuel blends in this micro gas turbine.