受限空间小型急冷塔内喷雾蒸发的数值模拟  

NUMERICAL SIMULATION ON SPRAY EVAPORATION PROCESS FOR SMALL-SCALE QUENCH TOWER IN LIMITED SPACE

作　　者：李文俊 郑成航[1] 王伊凡 赵中阳 刘昶 吴卫红[1] 刘少俊 LI Wenjun;ZHENG Chenghang;WANG Yifan;ZHAO Zhongyang;LIU Chang;WU Weihong;LIU Shaojun(National Environmental Protection Coal-fired Air Pollution Control Engineering Technology Center,State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学能源清洁利用国家重点实验室国家环境保护燃煤大气污染控制工程技术中心,杭州310027

出　　处：《环境工程》2022年第4期50-56,78,共8页Environmental Engineering

基　　金：国家重点研发计划项目(2016YFC0203706);国家自然科学基金项目(U1609212,51621005)。

摘　　要：针对受限空间内小型急冷塔冷却水蒸发过程,运用计算流体力学(CFD)进行数值模拟,基于涡壳进气型急冷塔研究了喷嘴雾化粒径、喷射速度、喷射角度等喷嘴运行参数对急冷塔内蒸发过程的影响机制。结果表明:随着液滴粒径的增大,液滴蒸发时间、轴向以及径向蒸发距离均随之显著上升,粒径由40μm增大至80μm时蒸发时间增加了293%;当液滴喷射速度增加时,液滴的蒸发时间、轴向以及径向蒸发距离均有所下降,但增大至一定程度后其影响作用减弱;随着液滴喷射角度的增大,液滴蒸发时间及轴向蒸发距离减小,而径向蒸发距离无显著变化。因此,在急冷塔尺寸受限时选用70μm以下的小雾化粒径喷嘴能够直接有效提升急冷塔的运行安全性。同时,与均匀进气型急冷塔相比,采用涡壳进气型急冷塔以及喷嘴成切圆布置方式能够在急冷塔上部形成湍流强化区域,喷嘴雾化粒径为80μm时,轴向安全裕度可提升7%。该模拟结果可为小型化急冷塔的工程应用提供优化设计方案与运行指导参考。Aiming at small-scale quench tower in limited space,the effect of operation parameters of spray nozzle on the evaporation process was studied by using computational fluid dynamics(CFD),such as atomization droplet size,jet relocity and spray angle.The results showed that with the increase of the droplet size,the evaporation time,axial and radial evaporation distance of the droplet increased accordingly,and the evaporation time increased by 293%when droplet size increased from 40μm to 80μm.When the jet velocity of droplet increased,the evaporation time,axial and radial evaporation distance of the droplet decreased,but the effect was weakened when the jet velocity increased to a certain value.The increase of spray angle caused the decrease of the evaporation time and axial evaporation distance of the droplet,but there was no obvious trend on the radial evaporation distance.The small atomizing droplet size nozzle below 70μm could directly and effectively improve the operation safety.By comparison,it was found that a turbulence intensified area was formed in the upper part of the quench tower with volute inlet,and that led to better cooling characteristic and operational safety than quench tower with upper vertical inlet,when the space of quench tower was limited.The axial safety margin could be increased by 7%with a droplet size of 80μm.The simulation results could provide optimal design scheme and operation guidance for engineering application of miniaturized quench tower.

关 键 词：受限空间 急冷塔 涡壳进气 蒸发特性 数值模拟 

分 类 号：X701[环境科学与工程—环境工程]