CFD Design And Optimization Of Integrated MBR Ship Domestic Sewage Treatment Device

The pollution problem of ship wastewater without discharging standard,it has aroused widespread concern in the field of social and related research.According to the current ship sewage treatment equipment and the research of the ship sewage treatment methods,a new type of ship sewage treatment equipment has been designed,which combine the anaerobic and aerobic MBR parts,form an upflow attached growth reactor.In order to analyze the internal flow of the equipment,use CFD to establish two dimensional model,on this basis,the three-dimensional numerical simulation is used to optimize the structure of the device,and beneficial to control environmental parameters in the later stage of reactor.The process of two dimensional numerical model,firstly,respective to construct the upper and lower models,based on the methods of multiphase flow Euler model and k-? turbulence model,Carry out the simulation of phase distribution and flow field in the reactor,explore the simulation methods.The results show that introduction of porous model and set the viscosity model and drag model,it can be applied to the simulation of the reactor.Secondly,in the whole model,in order to fully reflect the actual state,refine the aeration structure,based on the decomposition model,establish a set of simulation methods suitable for this reactor.The results show that the phase distribution is relatively uniform and velocity is stable,flow field is better than the decomposition model,however,the limitation of space makes the difference between simulation results and real situation.In order to verify the efficiency of the basic model,such as multiphase flow Euler model and k-? turbulence model,experiments were carried out using bottled sludge,and compare the actual movement of sludge with the simulation results,it is found that the movement trend of each phase is basically the same,it can better reflect the basic change of solid,liquid and gas phases in the bottle,so the method is feasible.In the three dimensional model,establish the three dimensional model of reactor,optimize three structures include the distance between the bottom end of the aeration head to the upper end of the water distribution area(H1),the distance between the outlet port to the upper end of the water distribution area(H2)and the inner diameter of the guide tube(D).By comparing the simulation results of each structural parameter,when(?)H1=0.6m,the solid matter is reasonably distributed in the aerobic and anaerobic zones and the velocity distribution is uniform,which is better to the stability of the flow field.When H2=1.345m,the flow field in the reactor has certain regularity,which is beneficial to the utilization ratio of the reactor space.When D=0.195m,the solid phase has the better improved by the bottom of the gas phase,there is a certain regularity in the speed variation and the symmetry of the left and right ends of the membrane module,which can better for the stability of flow field and the mixing of phases.