液—液旋流分离器内流场的数值模拟研究

Study on Numerical Simulation of Inner Field Flow in a Liquid-Liquid Hydrocyclone

用计算流体动力学(CFD)的数值方法,采用RSM模型对油水分离用液—液水力旋流器的流场进行了数值模拟。单相流场的模拟结果表明,旋流器内的流场结构是强旋转和非对称的三维结构,因而对旋流器的研究(无论是数值模拟还是实验测量)必须是基于三维的;旋流器上游区内流体紊流现象严重,两侧有循环流存在,这都对两相分离不利,应改进结构以改变这种流动形式;其模拟结果与他人实验结果吻合较好,说明该湍流模型和算法是可靠的。另外还对油—水两相流场进行了研究,初步揭示了液—液两相分离的现象,这都为进一步研究旋流器特性参数对分离效率的影响和旋流器的结构优化提供了参考。

The inner flow field in a liquid-liquid hydrocyclone for oil separation is simulated using numerical method of computational fluid dynamics (CFD) method on Reynolds stress model(RSM). The simulated results of single phase indicate that, the flow field is strongly swirrling and non-symmerical, so the study on the hydrocyclone must be on the basis of three dimensions (either to numerical simulation or to experiment). The upriver flow field is strongly turbulentand and the circulating flow occurs in either side which are all the disadvantages for phase separation. So, the strcture should be changed so as to change the flow form. The simulated results are consistant with experimental measurement other people already done, so the turbulent model and numerical method is reliable for use. Meantime, oil-water two phase flow field is also studied and reveals the phenomenon of liquid-liquid two phase separation. All of these will provide future study on influence of hydrocyclone’s parameters on separation efficiency and optimization of hydrocyclone.