化工进展
化工進展
화공진전
CHEMICAL INDUSTRY AND ENGINEERING PROGRESS
2014年
6期
1403-1407
,共5页
碟片式离心机%离心分离%流场%数值模拟
碟片式離心機%離心分離%流場%數值模擬
설편식리심궤%리심분리%류장%수치모의
disc centrifuge%centrifugation%flow%numerical simulation
碟片式离心机内的流场难以直接测量,采用计算流体力学(CFD)技术可以更加直观地展现碟片式离心机内部流场特征。本文以DRS 230\4-00-99型碟片式离心机为研究对象,基于N-S方程和标准k-ε两方程湍流模型,利用 Fluent 流体动力学分析软件模拟了碟片间隙的内部流场。结果表明,模拟得出的速度分布和压力分布符合碟片式离心机的内部理论基本规律。液体在碟片间隙内存在旋转滞后现象,但由于碟片间隙较小,液体旋转滞后较小。说明碟片间隙小,不仅可以减小颗粒的沉降距离,有利于提高分离效率,同时还能减小液体滞后。模拟同时发现,等距离碟片间隙中液体流量及压力降呈现不均匀分布,离入口位置越近,碟片间隙中液体流量及压力降越大,在前三层尤为明显。这些发现为碟片式离心机两相分离的模拟研究提供了参考依据,对优化碟片式离心机的结构设计具有重要的指导意义。
碟片式離心機內的流場難以直接測量,採用計算流體力學(CFD)技術可以更加直觀地展現碟片式離心機內部流場特徵。本文以DRS 230\4-00-99型碟片式離心機為研究對象,基于N-S方程和標準k-ε兩方程湍流模型,利用 Fluent 流體動力學分析軟件模擬瞭碟片間隙的內部流場。結果錶明,模擬得齣的速度分佈和壓力分佈符閤碟片式離心機的內部理論基本規律。液體在碟片間隙內存在鏇轉滯後現象,但由于碟片間隙較小,液體鏇轉滯後較小。說明碟片間隙小,不僅可以減小顆粒的沉降距離,有利于提高分離效率,同時還能減小液體滯後。模擬同時髮現,等距離碟片間隙中液體流量及壓力降呈現不均勻分佈,離入口位置越近,碟片間隙中液體流量及壓力降越大,在前三層尤為明顯。這些髮現為碟片式離心機兩相分離的模擬研究提供瞭參攷依據,對優化碟片式離心機的結構設計具有重要的指導意義。
설편식리심궤내적류장난이직접측량,채용계산류체역학(CFD)기술가이경가직관지전현설편식리심궤내부류장특정。본문이DRS 230\4-00-99형설편식리심궤위연구대상,기우N-S방정화표준k-ε량방정단류모형,이용 Fluent 류체동역학분석연건모의료설편간극적내부류장。결과표명,모의득출적속도분포화압력분포부합설편식리심궤적내부이론기본규률。액체재설편간극내존재선전체후현상,단유우설편간극교소,액체선전체후교소。설명설편간극소,불부가이감소과립적침강거리,유리우제고분리효솔,동시환능감소액체체후。모의동시발현,등거리설편간극중액체류량급압력강정현불균균분포,리입구위치월근,설편간극중액체류량급압력강월대,재전삼층우위명현。저사발현위설편식리심궤량상분리적모의연구제공료삼고의거,대우화설편식리심궤적결구설계구유중요적지도의의。
Flow field in the disc centrifuge is difficult to measure directly. Computational fluid dynamics(CFD)technology can be used to show the internal flow field characteristics of a disc centrifuge more intuitively. Based on the N-S equation and the standard two equation k-ε turbulent model,Fluent was used to simulate the flow in a DRS 230\4-00-99 disc centrifuge,including three-dimensional velocity and pressure. Results showed that the simulation of velocity distribution and pressure distribution agreed with the theory of internal basic law of disc centrifuge,rotation of liquid between the discs existed hysteresis,which was small because of small gap in disc. The disc centrifuge not only reduced the sedimentation distance of particles,but also improved the separation,and reduced rotation of liquid hysteresis. At the same time,the liquid flow rate and pressure drop were not evenly distributed in equidistance disc gap. Near the entrance position,the flow rate and pressure drop were greater,particularly in the first three layers. These findings could provide the reference for two-phase flow simulation of the disc centrifuge and have an important guidance for the centrifuge structure optimization design.