Research On The Performance Of Different Distributors And Distributor Plates In Fixed Bed Hydrogenation Reactor

As the world’s crude oil demand continues to rise,the trend of heavy and degraded crude oil resources is becoming more and more obvious.How to efficiently transform and cleanly use heavy oil resources has become an urgent difficulty for world refining and chemical companies.As an internal component in the fixed-bed hydrogenation reactor,the gas-liquid distribution plate plays a vital role in the operation efficiency of the hydrogenation reactor.In this thesis,three different principles of distributors and distribution plates are simulated and optimized,aiming to provide a certain reference value for the development and reference of fixed-bed hydrogenation reactor distributors and distribution plates.In this thesis,Eulerian two-phase flow model and standard turbulence model are selected to verify the model of the distributor.The simulation results are in good agreement with the experimental results,which shows that the simulation can reflect the gas-liquid two-phase flow in the distributor,and proves the accuracy of the simulation results in this thesis.Then,taking the feed of industrial hydrogenation unit as raw material,the basic simulation research of aipiration type,overflow type and spray type distributor is carried out.The results show that the liquid distribution effect of overflow type distributor is better,and the distribution unevenness is 18.92 %.The actual working condition analysis results show that the three distributors and distributor plates have good applicability in residue hydrogenation,diesel hydrogenation and aviation coal hydrogenation,and can adapt to high viscosity oil products.The influence of gas load on the performance of the distributor and the distribution plate was analyzed.The results show that the increase of gas flow rate is beneficial to the uniform distribution of liquid phase in the aspiration type and overflow type distributor and the distribution plate,but unfavorable to the uniform distribution of liquid phase in the spray type distributor and the distribution plate.The structure of the distribution plate composed of three different principle distributors has been optimized.The optimal structure of the aspiration type distribution plate is equilateral triangle arrangement and 171 mm spacing.Compared with the basic configuration of the distributor,the distribution unevenness is reduced by 45.5%.The optimal structure of the overflow type distribution plate is equilateral triangle arrangement,128 mm spacing and 190 mm distance from the catalyst bed.Compared with the basic configuration of the distributor,the distribution unevenness is reduced by 28.8%.The optimal structure of the spray type distribution plate is square arrangement,105 mm spacing and 200 mm distance from the catalyst bed.Compared with the basic configuration of the distributor,the distribution unevenness is reduced by 51.7%.