The NO_x Emission Of The Air Rating And Oxygen-enriched Combustion By Numerical Simulation

The technology of oxygen-enriched combustion can increase burning temperature, enhance heat transfer; reduce pollutants, save energy etc. but because of the high flame temperature of the oxygen-enriched combustion, the NOx emission increase greatly. In the other words, the great NOx emission became the one of factors that the technology of oxygen-enriched combustion takes part in wider application. The technology of the air rating combustion take the air into burning at two times, the combustion is finished at two stages. It can avoid the high flame temperature. So the advantages of oxygen-enriched combustion and the air rating combustion, we maybe get better results. But there is little research about this project, and many problems need to be solved. So the task comes up. This thesis applies the method of computer numerical simulation, to research the NOx emission of the oxygen-enriched and the air rating combustion.Based on the introduction and analyze of all kinds of models and calculation methods of fluid flow, heat and mass transfer, combustion process and NOx emission, the thesis find the right way of numerical simulation to to research the NOx emission of the oxygen-enriched and the air rating combustion. Starts with the simulation of the burner using CFD software Fluent, the result is satisfactory.The oxygen concentration of the oxygen-enriched air, the rate of the first burning air and the second burning air, and the surplus air coefficient are effective on the NOx emission. Thus, the thesis simulates the different oxygen concentration, rate of the first burning air and the surplus air coefficient, how change is the NOx emission. After further analysis, it finds out the better ate of the first burning, the surplus air coefficient etc.