Study On The Numerical Simulation Of The Three-Phase Loop Reactor In The Slurry-Bed Hydrogenation Process

The gas-lift loop reactor offers some advantages,such as fluid directional flow,no mechanical stirring as well as good mixing effect,so that it has better application prospect in the slurry-bed hydrogenation process.However,the fluid flow inside the three-phase gas-lift loop reactor is more complex,and the internal structure of the reactor also has an important influence on the flow of fluid inside the reactor.In this paper,the numerical model of gas-liquid-solid three phase mean as a continuous fluid?E/E/E?was established by using fluid calculation software Fluent 14.0 according to Euler-Euler double fluid model.It investigates the different solid particles and the artifacts in the reactor structure on the influence of the fluid state in heavy oil-hydrogen system by analyzing the gas holdup,circulation fluid velocity,particle velocity in the rising zone and the annulus,the particle deposition in the bottom of the reactor,which is in view of the volume of 78.5 L air-lift loop reactor.Some basically theoretical parameters for the design,amplification and optimization of operational condition of such reactors can be indicated.The effects of particle size,solid content and particle density on fluid flow in the reactor were studied.The results show that the particle deposition volume,gas holdup in the rising zone and the annulus increase,and the circulation fluid velocity and particle velocity in the rising zone and the annulus decrease with the increasing of particle size and particle density.The gas holdup,circulation fluid velocity and particle velocity will decrease with the increment of the solid content in the rising zone and the annulus,while inverse behaviors can be found for the trend of particle deposition.When the particle density was greater than 1200kg?m^-3 and the particle size was greater than 80?m,the sedimentation rate increased rapidly.The influence of the installation height,diameter as well as the length of the guide tube,the position of the nozzle and the angle of the nozzle on the fluid flow in the reactor were studied.The results show that the gas holdup,circulation fluid velocity and particle velocity are the highest in the rising zone and the annulus when the height ratio of the guide tube to the reactor is 0.06 and the particle deposition will increase with the increasing of the installation height of the guide tube.With the increase of the diameter of the guide tube and the angle of the nozzle,the gas holdup monotonously increases in the rising zone and the annulus,while the particle deposition,the circulation fluid velocity and particle velocity monotonously decrease in the rising zone and the annulus.The particle deposition,gas holdup,circulation fluid velocity and particle velocity monotonously increase with the increment of the length of the guide tube,when the ratio of the length of the guide tube to the height of the reactor is 0.6,the deposition rate tends to be stable.The particle deposition,gas holdup in the rising zone and the annulus increase,and the circulation fluid velocity and particle velocity in the rising zone and the annulus decrease with the increase of nozzle position.