Numerical Simulation Of Gas-liquid Two-phase Flow In A Curved Flow Channel Of A Trickle Bed

Trickle bed is widely used in petroleum and chemical industry fields.At present,most hydrodynamic properties of trickle bed are studied mainly on macro-bed scale,and few studies focused on hydrodynamic characteristics on local scale.Therefore,it is necessary to study the hydrodynamics in the pores of the bed.Since the structure of inter-particle pores is complex and uncertain,it is difficult to study the hydrodynamic characteristics by experimental methods.Therefore,the CFD simulation method was used to study the hydrodynamics in the pores of the bed.Firstly,the bed pores were transformed into capillary bundle model utilizing the distribution characteristics of bed porosity;secondly,the appropriate solution model was selected,the corresponding boundary conditions and operating conditions were determined according to the actual conditions;finally,the simulation results are analyzed by comparing with the literature data.This study mainly simulated two-phase flow in straight and curving capillary.The influences of liquid phase fraction,superficial velocity,physical parameters,and geometric structure on the two-phase flow were investigated in the numerical simulation of the straight capillary tube,the changes of liquid holdup,pressure drop with time were explained.In the numerical simulation of the curving capillary,the effect of geometric factors including curvature capillary diameter,curvature angle,curvature radius,same curvature arc length on the two-phase flow,the changes of pressure drop and liquid holdup corresponding to different geometric models were studied.The study indicated that inlet liquid fraction is the most important factor for liquid holdup,the superficial velocity and physical properties mainly affects the capillary force,the influence of the geometric structure on the flow regime is obvious;pressure drop changes depend on the scale and shape of slug or large droplets,as well as the concavity of gas-liquid interface in the capillary,the gas-liquid two-phase flow by homogeneous feeding did not show obvious periodicity.