A numerical study of the NO x emission characteristics of methane counterflow flame under direct-fired supercritical oxyfuel combustion condition

摘要: The direct fired supercritical carbon dioxide (sCO2) power cycle using CO2 as a working fluid is recently highlighted not only because it has a high thermal efficiency with small machinery footprints but also because it can ideally capture CO2 up to 99%. Since N2 can infiltrate the combustor of the cycle mainly because natural gas has impurity in its chemical composition, this paper investigates the effects of N2 amount in the fuel stream on the NOX emissions characteristics at supercritical conditions of the sCO2 power cycle.In this study, 1-D numerical simulations of nonpremixed counterflow methane flame are performed using OPPDIF code [1] with real gas effects [2]. San Diego mechanism [3] with NOx sub mechanism [4] is adopted because its validation range covers the relatively high pressure condition. All simulations are conducted with the boundary condition that inlet temperature of fuel and oxidizer side are …