Investigation of the flame structure and nitrogen oxides formation in lean porous premixed combustion of natural gas/hydrogen blends

摘要

The effect of the natural gas to H_2 ratio on the flame structure and NO_x formation in lean premixed porous combustion was determined by combining Comsol and Premix codes. The thermal pathway was of secondary importance while the NNH, N_2O and prompt pathways were the most important routes involved in NO formation. H_2 enrichment resulted in the penetration of the combustion zone into the porous burner and in the decrease of the importance of the prompt pathway, which leads to the decrease of NO formation. The chemical effect of NO recirculation was also investigated.