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

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 NO_x 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 NO_x emissions. It is also shown that the pressure loss P_loss 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 P_loss. The present work shed lights on reducing NO_x emissions by implementing a well-designed perforated plate for practical micro-power systems.