Mitigating NOx emissions from an ammonia-fueled micro-power system with a perforated plate implemented

[Display omitted] •A micro-combustor with a perforated plate applied is designed to mitigate NOx emission.•The NOx emission is significantly reduced in the presence of the perforated plate.•Reducing w or increasing l is shown to be associated with a lower NO generation.•Perforated plate material properties have little effect on the NO generation.•The pressure loss depends strongly on w, l and the material properties of the perforated plate. In this work, three-dimensional numerical simulations with a simplified reaction mechanism are conducted to investigate the effect of implementing a perforated plate in an ammonia-fueled micro-power systems on the NOx emission behavior. Detailed analyses on 1) the perforated plate hole dimensionless width w, dimensionless location l as well as the material property are performed. Results show that with an optimized perforated plate implemented, the NO emission is reduced by up to 73.3 % compared to those in the absence of perforated plates. The decrease is mainly due to the formation of a recirculation zone with a low flame temperature. Increasing w is shown to play a positive role in minimizing the NO generation, while l leads to a reverse trend resulting from the size variation of the recirculation zone. In contrast, the plate material has a negligible effect on NOx emissions. It is also shown that the pressure loss Ploss is varied non-monotonically with l, but monotonically with w and the NH3 volumetric flow rate. Furthermore, the conjugate heat transfer between the plate and combustion products has a certain impact on Ploss. The present work shed lights on reducing NOx emissions by implementing a well-designed perforated plate for practical micro-power systems.