Uncertainty analysis was used to investigate the precision property of detailed chemical kinetic models.A general-purpose algorithm for assessing and evaluating the impact of uncertainties in chemical kinetic models is presented.The method was also validated through analysis of different kinetic mechanisms applied in the process of modeling NOx emission in methane flame. The algorithm,which provided a basis for further studies,was more efficient and general compared with other methods.
ZHAO Ran ,LIU Hao,HU Han,YAN ZhiQiang,WANG XiaoFeng, KONG FanHai&QIU JianRong State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China
An experimental and numerical study of the NOx formation and reduction process in a designed coal combustion furnace under both traditional air atmosphere and O2/CO2 atmosphere was conducted, in an attempt to explore the chemistry mechanism of the experimentally observed NOx suppression under high CO2 concentration atmospheres. A simplified ‘chemically oriented’ approach, computational fluid dynamics (CFD)-chemical kinetics modeling method, was validated and used to model the experimental process. The high CO2 concentration’s chemical effect on NO reduction has been studied, and the differences in NOx reaction behaviors between O2/CO2 atmosphere and air atmosphere were analyzed by detailed chemical kinetic model. On the basis of investigations through elementary chemical reactions, it can be concluded that high CO2 concentration plays an important role on NOx conversion process during oxy-fuel combustion. Moreover, the dominant reaction steps and the most important reactions for NO conversion under different atmospheres were discussed. Under O2/CO2 atmosphere, the main active sequence for NO reaction includes: NO→N→N2, and the main active path for NO reaction under air atmosphere is through N2→N→NO.
ZHAO Ran, LIU Hao, HU Han, ZHONG XiaoJiao, WANG ZiJian, XU ZhiYing & QIU JianRong State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, 430074, China