Investigation on combustion characteristics and energy efficiency improvement of H2/NH3 fueled micro power generator with bluff body and porous media

To optimize the combustion performance and energy conversion efficiency of micro-power generators, the NH3 3 addition and porous media (PM) are employed. Coupling effects of H2/NH3 2 /NH 3 blending ratios and PM configurations on combustion characteristics and thermal performance are analyzed under different operating conditions. The experimental results demonstrate that a small blended fraction of NH3 3 significantly influences the flame regime of H2/NH3/air 2 /NH 3 /air combustion, and the reaction kinetics analysis indicates that the blended NH3 3 modifies the step and sensitivity of reactions for the formation and consumption of key radicals and heat release, leading to an important augment of burner thermal performance. PM markedly enhances the stability of flames and improves heat transfer within the combustion chamber. The average wall temperature of the combustor equipped with PM exceeds that of free flame by 117 K. This temperature differentialce is noted at m f = 2.66 x 10-5-5 kg/s and m N = 20%. Furthermore, these effects are amplified with increasing input energy and appropriate PM porosity, and the combustion with 20% NH3 3 blending and porous media insertion obtains the highest radiation power 35.65 W at m f = 3.461 x 10-5-5 kg/s. This observation offers crucial guidance for the design and optimization of micro power generation systems, thereby enhancing their efficiency and performance.