Modeling And Numerical Analysis Of Gas-liquid Flow Reactor Based On Cfd-pbm Coupled Model

Two-phase flow reaction is widely used in nature,petrochemical industry,energy and power industry,aerospace industry,biomedicine industry and food processing industry.It is difficult and complicated to study the two-phase flow reaction because of the interaction between two phases and the random variable phase interface distribution.Therefore,it is difficult to accurately describe the evolution mechanism and kinematics characteristics of twophase flow reaction by using traditional analytical methods.In recent years,software simulation has become a new way to study two-phase flow.In the two-phase flow reaction,the kinetic behavior of the discrete phase is the focus of the study.In the reactor,the nucleation,growth,coalescence,fragmentation and extinction of the discrete phase and the interaction between the discrete phases will have a direct impact on the mass transfer,heat transfer and the occurrence and conduct of the reaction between the two phases.Therefore,understanding the discrete phase behavior of mixed phase from the mechanism is the key to explore the reaction process and control optimization of the reaction system.In this paper,the gas-liquid two-phase flow was numerically simulated in different mixing processes on ANSYS18.0 platform,and the model parameters were modified according to the experimental measurement data,and the gas-liquid mixing process and discrete phase behavior characteristics were deeply explored.First of all,through the simulation of the movement of a single particle in the micro channel,this paper explores the process of the growth of a single particle and the stress and tension deformation in the micro channel.Gas and liquid channels were constructed respectively,and a periodic input signal was set at the channel entrance by using the multi-fluid VOF model to observe the different dynamic characteristics of droplets and bubbles as discrete phases.Then,the flow field in the airlift reactor and venturi scrubber is simulated numerically.Airlift reactor is an efficient multiphase reactor,which is widely used in bioengineering,energy and chemical industry.The reaction device makes use of the density difference of the gas after entering to realize the circulation flow.Venturi scrubber is also a typical gas-liquid phase reaction device,which can provide higher mass transfer coefficient and stronger mixing effect.It is widely used in the processes of hydrogenation,chlorination and tail gas absorption.In the process of operation,the liquid is atomized and sprayed into the reactor and mixed with the gas under the action of high pressure.In the simulation process,PBM model was used to verify the adaptability of different discrete methods and the fragmentation polymerization model to different reaction devices.Finally,by combining the simulation results and experimental data,the most suitable numerical simulation method for different types of reactions and different reactors is proposed.