Comparative Analysis Of CFD Models Of Gas-Solid Fluidized Bed And Experimental Verification

CFD tool has been widely used in the research of gas-solid fluidized bed because of thelower cost. Many gas-solid CFD models have been put forth by academic researcherswhich would result in much confusion. In order to choose appropriate closure models toprovide the basis for the further combustion research, the influence of adopting differentclosure models on the flow of gas and solid phase has been analyzed and compared in thispaper, and a set of cold flow experiments have been carried on in the95KW gas-solidfluidized bed to valid the numerical simulation results. The experimental value was used tomake a comparison with the simulation result.The hydrodynamic of the gas-solid fluidized bed was studied numerically by usingEulerian-Eulerian approach in Fluent6.3. The comparison analysis on various closuremodels in Fluent included turbulence model, drag force model, restitution coefficient,granular viscosity model, and radial distribution function. It can be concluded that theradial distribution function has minimal impact on the flow of two phases.Moreover, considering this fluidized bed would be use to carry on oxyfuel combustionexperiment later, the impact of the initial bed height and CO₂proportion in the CO₂/O₂mixed gas on the hydrodynamics of the bed has be discussed at this work. The changing ofdensity and viscosity of the mixed gas influenced the gas-solid phase flow significantly.Dimensionless analysis, gas and particle flow profiles of velocity, volume fraction, bedexpansion ratio, and bed pressure drop for different closure models and operationconditions were obtained in the simulations.