三相卧螺离心机油水分离的CFD分析  

CFD Analysis for Three-phase Decanter Centrifuge for Oily Wastewater Separation

作　　者：姜杰[1] 温冬[1] 肖泽仪[1] 

机构地区：[1]四川大学,四川成都610065

出　　处：《流体机械》2017年第6期26-31,共6页Fluid Machinery

基　　金：2013年国家科技支撑计划项目(2013BAC12B01)

摘　　要：采用计算流体动力学(CFD)方法和计算软件FLUENT对分离含油废水的三相卧式螺旋卸料沉降离心机油水分离进行数值模拟。基于离心机转鼓结构与流体流动方式的简化进行物理建模,对离心机油水分离稳态进行分析,确定排水孔宽度以及溢流口轴向宽度对离心机油水分离效率的影响。模拟结果表明:在油相溢流口附近,油水两相的粘度差和速度差导致分层界面处存在摩擦剪切应力,从而导致部分水相跟随油相溢流。适当调节排水孔宽度增大该处流量可以提高离心机的油水分离效率;增大溢流口轴向宽度可以减缓流体溢流速度,减小油水两相之间的摩擦力,从而减少水相跟随油相溢流、提高离心机的油水分离效率。模拟方法和结果可以为三相卧螺离心机的结构设计提供更多参考。The numerical simulation for the oil/water separation in the drum of a three-phase decanter centrifuge in separating oily wastewater was performed by using CFD. Based upon the simplification of the fow field and the drum structure, a physcal mod-el for simulation was built, and the analysis under the steady-state of oil/water separation was carried out, and then the definite re-lation of the oil/water separation efficiency to the oil overflow mouth axial width and the water width was observed. The simulation results showed that viscosity and velocity differences between oil and water near the overflow mouth produced friction stress, which could further cause water following oil overflow near the water-oil interface. The proper adjustment of the drain hole width could improve flow rate, which would improve oil-water separation efficiency. Increasing overflow mouth axial width could slow the over-flow velocity of the fluid and then reduce the friction stress between oil and water and therefore water following oil overflow, which would improve the oil/water separation efficiency. The simulation method and results might be considered as a practical effort for structural design of a three-phase decanter centrifuge.

关 键 词：离心分离 多相流 数值模拟 模型简化 含油废水 分离效率 

分 类 号：TH123[机械工程—机械设计及理论] TQ051.8[化学工程]