导叶式水力旋流器流场分布与分离效率研究

Study on Flow Field Distribution and Separation Efficiency of Guide-vane Hydrocyclone

为了研究油滴在流场内发生聚集和破碎的现象,采用CFD技术对油田现场使用的导叶式液-液旋流器进行数值模拟分析,并采用DPM模型追踪油滴在旋流管中的运动轨迹,探究油水两相分离过程。研究结果表明:随着压差比从1.5增大到2.0,旋流器的分离效率从34.12%提高到42.94%,但处理量从753.14 m^3/h下降至656.61 m^3/h,溢流比也从7.10上升到9.18;油滴破碎与流场中湍流强度有关,湍流强度越大的位置,直径大的油滴越容易破碎成小的油滴,影响油水分离效果;导叶式旋流器内从导叶流道出口处到小锥段湍流强度大于1,这些部位容易发生油滴破碎。所得结果可为水力旋流器的选型、现场调试及设计提供参考。

To study the phenomena of oil droplets agglomeration and breakage in the flow field,CFD technology was used to numerically simulate the guide-vane type liquid-liquid hydrocyclone applied in the oilfield. The DPM model was used to track the oil droplets trajectory in the hydrocyclone pipe to study the oil-water two-phase separation process. The analysis results show that,with the differential pressure ratio increasing from 1. 5 to 2. 0,the separation efficiency of the hydrocyclone increases from 34. 12% to 42. 94%,and the overflow ratio rises from7. 10 to 9. 18,but the treatment capacity decreases from 753. 14 m3/h to 656. 61 m3/h. The turbulence intensity in the flow field has an effect on the oil droplets breakage. High turbulence intensity makes the large diameter oil droplets easier to break into small oil droplets,thus impacting the oil-water separation effect. In the guide-vane type hydrocyclone,the turbulence intensity is higher than 1 from the guide vane flow passage exit to the small cone section,where oil droplets breakage is easier to happen. The study results can provide references for the selection,onsite commissioning and design of the hydrocyclone.