固定床反应器环形分布器内流场模拟与流体均布性能分析

Simulation and Distribution Performance Analysis of Annular Distributor in Multitubular Fixed-Bed Reactor

环形分布器是实现列管式固定床反应器壳程换热介质均匀流动的重要部件。采用计算流体力学方法分析了环形分布器内的静压分布规律,并考察了环形分布器的结构形式,如进口数目、出口数目等因素对流体均布效果的影响。通过计算发现,均匀开孔时,在其它结构参数和进口总流量保持不变的情况下,出口数目对流体均布的影响不是单调的,一定范围内减少出口数目有利于流体均布;增加进口数目有利于环形分布器内各个出口的流体均布。对模拟结果进行分析发现,当总压降与穿孔压降的比值U在0.95～1.06之间时,均匀开孔即能满足流体均布的要求。

Annular distributor plays an important role in achieving uniform distribution in the shell of multitubular fixed-bed reactor. The static pressure distribution characteristics and the influence of the structure parameters of annular distributor such as inlet number and outlet number on the uniform performance were analyzed based on the calculated fluid dynamic （CFD）method. The simulation results showed that when outlets of the same size were opened, and other structure parameters and import condition kept un- changed,decreasing outlet number in a certain range and increasing inlet number were beneficial to uni- form distribution of fluid inside the annular distributor. Moreover, according to the pressure characteristics in annular distributor,the fluid distribution depends on the pressure drop of main channel and the pressure drop of outlets. Based on simulation results, U was defined as the ratio of the pressure drop of outlets to the total pressure drop between inlet and outlet. If U was at 0. 95-1. 06, that means the fluid has been uniformly distributed even outlets of the same size were opened.