Performance of Ammonia/Methane Combustion in an RQL Combustor

To gain a comprehensive understanding of the combustion characteristics of CH4-enhancing NH3 combustion in an industrial RQL gas turbine combustor, a numerical study was conducted using the CFD-CRN method. The study investigated flow and temperature distributions, flame structures, and NOx formation characteristics. Two methods of introducing CH4 were examined: premixing with NH3 before burning, and direct introduction in the inner swirl stage without premixing with NH3. The results revealed that NH3 combustion displayed a longer flame and higher NOx emissions compared to methane combustion. NOx was mainly generated at the flame front and the primary combustion zone. The addition of CH4 was found to increase combustion efficiency without significantly altering the flow and temperature distributions. Direct introduction of CH4 showed higher combustion efficiency compared to the premixing method. Moreover, the addition of CH4 contributed to an increase in NOx emissions. The direct introduction of CH4 in the inner swirl stage demonstrated promising results for NH3 combustion. This approach enhanced combustion efficiency and reduced NOx emissions without requiring fuel premixing systems.