管道式油水分离系统分离特性研究

Investigation on the separation performance for pipeline oil-water separation system

管道式油水分离系统由T型管路和柱型旋流器组成,综合采用离心、膨胀和重力分离等原理,是一种新型的分离装置,具有分离效率高、占地面积小等优点。该文采用数值模拟和现场实验的方法对管道式分离系统的流场特征和分离性能进行了系统的研究,分别考虑了入口流速、含油率和分流比等参数对分离系统的影响。数值模拟研究中,采用欧拉-欧拉多相流模型和雷诺应力湍流模型,结果显示设计的管道式油水分离系统可以有效的实现油水两相的快速分离,对含油率为5%和25%的来液,在总分流比约为50%时,水中含油率可以分别降至0.025%和0.7%。现场实验采出液的温度为40oC,体积含油率范围为6%-25%,原油密度为902 kg/m3,黏度为130 mPa·s。在现场实验流速为2.0 m/s-3.5 m/s的范围内,生产液经设计的实验系统处理后,水中含油率可低于600 mg/L。

Pipeline oil-water separation system is a new-style equipment including series of T-junction pipes and cylindrical cyclones, which using the separation theory of gravity, centrifugation, expanding. The system is the high separation efficiency and small volume so as to improve the processing and decrease the area. In this paper, the flow field characteristic and separation performance of the system have been investigated in detail by using CFD and in-site experiments, which including the influences of inlet velocity, oil rate and the split ratio on the separation system. The Euler-Euler model and Reynolds-Stress model are used in the numerical simulation. In the field experiments, the temperature of fluid is 40~C, and the oil volume fraction of mixtures in the range of 6%-25%. The density of crude oil is 902 kg/m3 and zero shear viscosity is 130 mPas. It is shown that the system can achieve a rapid separation and the oil volume fraction of 5% and 25% in fluid can fall to 0.025% and 0.7% respectively, when the total separation ratio is about 50%. The results show that, using the pipeline separation system, the oil volume fraction can be decreased to below 600 mg/L in the velocity range of 2.0-3.5 m/s when the total separatopn ratio is below 40%.