Experimental and numerical investigation on ultra-high intensity premixed LPG- air combustion in a novel porous stack burner

In the present study, the experimental and numerical investigations are conducted to study the flame stabilization of premixed LPG/air mixtures in a zirconia-based stack porous media burner with 10 PPI foams at higher thermal inputs of 16.63, 19.95 and 23.28 kW under fuel-rich conditions. A detailed chemical model with 67 species and 475 elementary reactions is developed and implemented to elucidate the chemical aspect in the present work. Flame morphology, effects of PM on flame temperature and its reaction zone, intermediate species, heat release rates, and major emissions like NOx and CO are analysed to design an ultra-high intensity burner for mini-gas turbine applications. At 16.63 kW, the peak of OH radicals increased by 92.58 times on gradually shifting the equivalence ratio, φ from 2.18 to 1.21. Chain branching reaction ((R1) H + O2 ↔ O + OH) accounts for consuming 5–10% of the combustion heat, and its contribution percentage slightly predominant towards stoichiometry due to more O2 availability that accelerates the chain branching reaction. Flame temperature and the residence time are the dominant factors affecting CO and NOx formations. NOx emission levels are found to be significant in both the high thermal input cases of 16.63 and 19.95 kW. © 2023