化学工程
化學工程
화학공정
CHEMICAL ENGINEERING
2014年
8期
21-24
,共4页
中空纤维膜组件%动网格%振动%强化传质
中空纖維膜組件%動網格%振動%彊化傳質
중공섬유막조건%동망격%진동%강화전질
hollow fiber module%dynamic mesh%vibration%mass transfer enhancement
为提高中空纤维膜组件的传质效率，减轻浓差极化，运用计算流体力学软件Fluent动网格技术，以含氧水的除氧过程为研究对象，研究了振动特性对中空纤维膜组件管外传质的影响。研究结果表明：与静止的工况相比，振动能够使流体产生二次流，使得流动从层流转化为紊流，增强流体与膜组件以及中空纤维管壁面的碰撞，极大程度地减轻浓差极化现象，进而强化传质；随着振动频率和振幅的增大，膜组件出口处氧质量浓度降低，水中氧的清除率增大，传质效果变好；一定条件下振动工况比静止工况氧的清除率最高可以提高144％，固定振幅为6 mm振动频率从2．5 Hz增加到10 Hz时清除率提高76％；固定频率为2．5 Hz振幅由2 mm增加到6 mm时清除率提高10％，增大振动频率对于强化传质的效果要好于增大振幅。研究结果可以为实际的工程应用提供理论指导。
為提高中空纖維膜組件的傳質效率，減輕濃差極化，運用計算流體力學軟件Fluent動網格技術，以含氧水的除氧過程為研究對象，研究瞭振動特性對中空纖維膜組件管外傳質的影響。研究結果錶明：與靜止的工況相比，振動能夠使流體產生二次流，使得流動從層流轉化為紊流，增彊流體與膜組件以及中空纖維管壁麵的踫撞，極大程度地減輕濃差極化現象，進而彊化傳質；隨著振動頻率和振幅的增大，膜組件齣口處氧質量濃度降低，水中氧的清除率增大，傳質效果變好；一定條件下振動工況比靜止工況氧的清除率最高可以提高144％，固定振幅為6 mm振動頻率從2．5 Hz增加到10 Hz時清除率提高76％；固定頻率為2．5 Hz振幅由2 mm增加到6 mm時清除率提高10％，增大振動頻率對于彊化傳質的效果要好于增大振幅。研究結果可以為實際的工程應用提供理論指導。
위제고중공섬유막조건적전질효솔，감경농차겁화，운용계산류체역학연건Fluent동망격기술，이함양수적제양과정위연구대상，연구료진동특성대중공섬유막조건관외전질적영향。연구결과표명：여정지적공황상비，진동능구사류체산생이차류，사득류동종층류전화위문류，증강류체여막조건이급중공섬유관벽면적팽당，겁대정도지감경농차겁화현상，진이강화전질；수착진동빈솔화진폭적증대，막조건출구처양질량농도강저，수중양적청제솔증대，전질효과변호；일정조건하진동공황비정지공황양적청제솔최고가이제고144％，고정진폭위6 mm진동빈솔종2．5 Hz증가도10 Hz시청제솔제고76％；고정빈솔위2．5 Hz진폭유2 mm증가도6 mm시청제솔제고10％，증대진동빈솔대우강화전질적효과요호우증대진폭。연구결과가이위실제적공정응용제공이론지도。
In order to improve the mass transfer efficiency of hollow fiber modules and reduce the concentration polarization,the dynamic mesh of computational fluid dynamics software Fluent was used to study the characteristics of flow and mass transfer of a vibrating hollow fiber membrane module,and the effect of different vibration parameters on mass transfer performance was analyzed based on the process of removing oxygen from water.The numerical results show that vibration can cause secondary flow and the transition from laminar to turbulent flow, both of which enhance the collision between the fluid and the hollow fiber module and reduce the concentration polarization.So vibration is favorable to mass transfer enhancement.With the growth of vibration frequency and amplitude,the clearance rate of oxygen increases and the mass transfer performance gets better,whereas the outlet oxygen mass concentration decreases.Oxygen removal rate can be increased by 144% under a given vibration condition compared to no vibration.Oxygen removal rate is increased by 76% with the vibration frequency increased from 2.5 Hz to 10 Hz when the vibration amplitude is 6 mm,while it is only increased by 10%with the vibration amplitude increased from 2 mm to 6 mm when the vibration frequency is 2.5 Hz.Increasing the vibration frequency is more effective on the mass transfer enhancement than increasing the vibration amplitude.The results provide the theoretical guidance for practical engineering applications.
