Numerical Study of High-Temperature Air Combustion Using Different Jet Nozzle

High-Temperature Air Combustion (HTAC) is an advanced combustion technology with the advantage of energy saving and low nitrogen oxide pollutant emission. A swirling burner was designed to further improve the HTAC performance and a numerical simulation was carried out based on CFD technology to investigate the combustion process of methane under different jet parameters. The RSM turbulence model was used to calculate the turbulent flow and EBU combustion model was used to calculate the combustion process of methane gas. DO radiation model was applied to simulate heat transfer between the furnace walls and the flue gas. A full mechanism of NOX production and reduction was considered, i.e. the thermal and prompt NOX, the N2O inter-media path to form NO and the NO reduction by reburning. Experimental data from published papers were used to validate the present model. Numerical results showed that a swirling burner could enhance there circulation of the flue gas in the furnace to enlarge low oxygen area, resulting in a more uniform temperature field with a lower temperature uniformity ratio, which determined the final low emission of NO.