NUMERICAL INVESTIGATION ON COMBUSTION CHARACTERISTICS AND EMISSIONS OF HYDROGEN/METHANE BLENDS IN FLAMESHEET COMBUSTOR

Flamesheet is a novel head-end combustor component design that can accommodate up to 40% H-2 in volume fraction while maintaining a low NOx emission at 9 ppm. It is compatible with many popular combustors, including 501F DLN, 7F DLN 2.6, and 7F DLN 2.6+. This study used a numerical investigation to examine the combustion characteristics of methane blended with hydrogen at various compositions in a lean premixed swirling flame in a W501F Flamesheet combustor. The volume of hydrogen enrichment ranged from 0 to 40%. A numerical approach using the partially premixed flamelet model and turbulent SST k-omega model was adopted to simulate the Flamesheet combustor. The flamelet-generated manifold was used to analyze the effect of hydrogen enrichment and equivalent ratio on flame operation, temperature distribution, CO and CO2 emissions, and species concentrations. The operating principle of this Flamesheet model was described, and details of flow characteristics and heat transfer were discussed. The results show that the Flamesheet combustor can operate stably with up to 40% hydrogen. The outlet temperature can be maintained at a constant by controlling the equivalent ratio as the hydrogen concentration increases. The effect of adding hydrogen on species concentrations was also discussed in detail.