Abstract:
The complex vibration phenomenon occurs in the downhole environment of the gas-liquid hydrocyclone, which affects the flow field in the hydrocyclone. In order to study the influence of vibration on hydrocyclone separation, the characteristics of the flow field in the downhole gas-liquid hydrocyclone were analyzed and studied under the condition of vibration coupling. Based on Computational Fluid Dynamics (CFD), Computational Solid Mechanics Method (CSM) and fluid-solid coupling method, a fluid-solid coupling mechanical model of a gas-liquid cyclone is established. It is found that under the condition of vibration coupling, the velocity components in the three directions of the hydrocyclone flow field change obviously. The peak values of tangential velocity and axial velocity decrease, and the asymmetry of radial velocity increases. The distribution regularity of vorticity and turbulence intensity in the overflow pipe becomes worse. Among them, the vorticity intensity of the overflow pipe is obviously enhanced, and the higher turbulence intensity near the wall occupies more area distribution range. The gas-liquid separation efficiency of the hydrocyclone will decrease with the increase of the rotational speed of the screw pump, and the degree of reduction can reach more than 10%. However, this effect will decrease with the increase of the rotational speed of the screw pump, so the excitation effect caused by the rotational speed has a maximum limit on the flow field.
摘要:
气液旋流器的井下环境中会出现复杂的振动现象,影响水力旋流器内的流场。为了研究振动对水力旋流器分离的影响,在振动耦合条件下,对井下气液旋流器的流场特性进行了分析和研究。基于计算流体动力学(CFD)计算固体力学方法(CSM)和流固耦合方法,建立了气液旋流器的流固耦合力学模型。发现在振动耦合条件下,水力旋流器流场三个方向的速度分量变化明显。切向速度和轴向速度的峰值减小,并且径向速度的不对称性增加。溢流管内涡度和湍流强度的分布规律变差。其中,溢流管的涡度强度明显增强,壁附近湍流强度越高,占据的面积分布范围越大。水力旋流器的气液分离效率会随着螺杆泵转速的增加而降低,还原程度可达10%以上。然而,这种效应会随着螺杆泵转速的增加而减小,因此,由转速引起的激励效应对流场具有最大限制。