Improved hydrodynamic characterisation of two-phase flow in gas-mixed anaerobic digester by CFD modelling
An effective biochemical conversion from biomass into biogas relies on a proper mixing in anaerobic digestion.In order to better evaluate the mixing behaviour inside gas-mixed digesters,clearer insight in hydrodynamic characteristics is very important.This study aimed to improve the hydrodynamic characterisation of gas-liquid flow in digesters by Computational Fluid Dynamics (CFD) modelling and to solve the phase interaction clearly and straightforward.A 2D axisymmetric computational domain was set up in accordance with a lab-scale experimental study.In this model set-up,a Eulerian-Eulerian two-phase method was used to solve the governing equations of each phase,and specific models were applied to account for phase interaction processes and turbulence.It was found that some influencing factors,including bubble size,phase interaction forces and liquid rheology,impacted significantly the flow pattern.The model was validated against the experimental data,and a good agreement was achieved.Moreover,the simulation predicted further concrete details of the flow field,and evaluated the mixing by tracking particle trajectories based on a Euler-Lagrange method.The importance of clear cognition and appropriate setting of phase interaction processes to successfully simulate a multiphase flow was unravelled in this study.The developed CFD model also enabled a more accurate characterisation of mixing in gas-mixed anaerobic digesters.
CFD anaerobic digestion hydrodynamic two-phase flow gasmixing
P.Wei H.Spanjers W.S.J.Uijttewaal J.B.van Lier M.deKreuk
Department of Water Management, Delft University of Technology, Stevinweg 1, 2628 CN Delft, The Neth Department of Hydraulic Engineering, Delft University of Technology, Stevinweg 1, 2628 CN Delft, The
国际会议
The 15th IWA World Conference on Anaerobic Digestion( 第15届IWA世界厌氧大会)
北京
英文
377-380
2017-10-17（万方平台首次上网日期，不代表论文的发表时间）