NUMERICAL SIMULATION ON HYDRODYNAMICS AND COMBUSTION IN A CIRCULATING FLUIDIZED BED UNDER O2/CO2 AND AIR ATMOSPHERES
Oxy-fuel circulating fluidized bed (CFB) combustion technology is in the stage of initial development for carbon capture and storage (CCS). Numerical simulation is helpful to better understanding the combustion process and will be significant for CFB scale-up. In this paper, a computational fluid dynamics (CFD) model was employed to simulate the hydrodynamics of gas-solid flow in a CFB riser based on the Eulerian-Granular multiphase model. The cold model predicted the main features of the complex gas-solid flow, including the cluster formation of the solid phase along the walls, the flow structure of up-flow in the core and downward flow in the annular region. Furthermore, coal devolatilization, char combustion and heat transfer were considered by coupling semi-empirical sub-models with CFD model to establish a comprehensive model. The gas compositions and temperature profiles were predicted and the outflow gas fractions are validated with the experimental data in air combustion. With the experimentally validated model being applied, the concentration and temperature distributions in O2/CO2 combustion were predicted. The model is useful for the further development of a comprehensive model including more sub-models, such as pollutant emissions, and better understanding the combustion process in furnace.
CFD comprehensive model multiphase flow combustion heat transfer O2/CO2 combustion
W.Zhou C.S.Zhao L.B.Duan C.R.Qu J.Y.Lu X.P.Chen
School of Energy and Environment, Southeast University, Nanjing, 210096, China
国际会议
第20届国际流化床燃烧会议(20th International Conference on Fluidized Bed Combustion)
西安
英文
883-888
2009-05-18（万方平台首次上网日期，不代表论文的发表时间）