含微小颗粒气流横掠圆管束表面的沉积特性

Deposition characteristics of tube bundles in particulate cross-flow

基于欧拉-拉格朗日粒子追踪模型和干燥粒子的沉积机制,采用Fluent-CFD软件和自编微粒沉积用户程序对含微小颗粒的气流横掠3×3阵列圆管束表面的粒子沉积特性进行数值研究。研究结果表明:随着粒径或进气气流速度增加,颗粒在管束表面的碰撞率增加,但黏附率降低;管排方式对小粒径颗粒影响较小,对大粒径颗粒影响较大;当粒子直径达到某一值后,尽管对壁面的碰撞能力加剧,但几乎不形成沉积。

Based on Euler-Lagrangian particle tracking module and dry particle deposition mechanism, a numerical simulation was made to predict the fine-particle deposition on the tube bundles with 3×3 array arrangement in a particulate cross-flow by using Fluent-CFD software and user-defined functions（UDFs）, taking particles transport, sticking and detachment processes into consideration. The results show that when the particle diameter or inlet gas velocity increases, the particle impact efficiency on the tube-bundles is enhanced while the sticking efficiency is weakened. In relation to small particles, the deposition rate of the large particles is greatly influenced by the arrangement of tube bundles. For larger particles, although the impact capacity is significantly enhanced, almost no deposition occurs.