反应器类型对流动影响的数值模拟

Numerical Simulation on Flow Characteristics of Different Reactors

在油?氢气体系中使用欧拉?欧拉双流体模型考察了温度703.15 K和压力11 MPa下气升式环流反应器和鼓泡床反应器对气液两相流动的影响.结果表明,环流反应器中气含率和轴向液速沿导流筒径向存在突增现象,环流反应器中气含率在径向0?0.5和0.75?1时明显大于鼓泡床反应器,在径向0.5?0.75处前者的平均气含率比后者高约6%;环流反应器中上升管内环流液速明显大于鼓泡床反应器,且在下降区有所增强,环流反应器平均轴向液速比鼓泡床反应器高约21%;反应器尺寸较小时环流反应器和鼓泡床反应器的流动特性相差不大,反应器体积放大过程中前者的流动特性优于后者的趋势逐渐明显.

Euler-Euler two-flow model was applied to study the effects of gas lift type loop reactor and bubble column bed reactor on the hydrodynamics under oil-hydrogen system when temperature and pressure were 703.15 K and 11 MPa, respectively. The numerical simulation results show that there exists an excursion phenomenon in gas holdup and axial liquid velocity along the radial guide tube direction in the loop reactor. The gas holdup at the radial location of 0-0.5 and 0.75-1 in ALR is obvious bigger than that in BCR, the gas holdup in ALR at the radial location of 0.5-0.75 is smaller than that in BCR due to wall effect, the overall gas holdup in ALR is 6% higher than that in BCR by. The axial liquid velocity in the riser of loop reactor is greater than that in the bubble column reactor, the trend in the dropper is bigger, the overall axial liquid velocity in ALR is 21% higher than that in BCR. The flow characteristics are similar when their reactor size is small. The trend is gradually obvious that the flow characteristic of loop reactor is better than that of bubble column reactor in the scale-up process of reactor volume.