Numerical Simulation Of Oxygen-enriched Combustion And NO_x Emission Characteristic Of Gas Boiler

As a kind of environmental conservation boiler, gas boiler develops quickly because of its high thermal efficiency and low emission of pollutants. And the technology of oxygen-enriched combustion can increase burning temperature, enhance heat transfer, reduce pollutants, save energy etc. Thus, if we combine the advantages of gas boiler and oxygen-enriched combustion, maybe we can get better results. But there are few researches about this project at present, and many problems need to be solved. So the task comes up. And the purpose of this thesis is to simulate oxygen-enriched combustion and NO_x emission characteristic of gas boiler.Based on the introduction and analyze of all kinds of models and calculation methods of fluid flow, heat and mass transfer, combustion process and NO_x emission, the thesis starts with the simulation of the burner using CFD software Star-CD, the result is satisfactory. And then it simulates the combustion process of gas boiler, getting the temperature field, component concentration field and NO_x distribution under different oxygen concentration. After further analysis, it finds out the relationship between NO_x emission and the temperature. Also gets how combustion efficiency and NO_x emission change with the oxygen concentration.Compared with the experimental results, they match each other by and large. It proves that the simulation is successful. In addition, the simulation method is less costly, much faster than experiments. Also it can predict the flow and combustion process, give much information that experiments can't. Consequently, the numerical simulation shows its active effects on the combustion improvement and the emission characteristic prediction as a new method of research.