Abstract:

In order to analyze the flow field and performance change regulations of hydrocyclone caused by the blocked problem in downhole, the downhole inverted cone hydrocyclone was used as the study object, and the flow field characteristics and separation performance of the hydrocyclone were analyzed in six different blocked conditions by combining numerical simulation and experiment, and a quantitative characterization method of flow field asymmetry was proposed to clarify the change of the flow field and the average offset unsymmetry of the hydrocyclone under different blocked conditions. The results showed that in condition of three closely neighboring flow channels blocked, the average offset unsymmetry rates of both tangential and axial velocities produced maximum values of 67.82% and 34.99%. Compared with the non-blocked condition, the average pressure drop increases and the separation efficiency decreased in all six different blocked conditions, and working condition six in condition of four closely neighboring flow channels blocked, the average pressure drop was the largest and the separation efficiency was the smallest. The separation performance analysis under different blocked conditions was carried out, and the average error between the simulation results and the experimental results was 1.22%, which reflected a good consistency and proves the accuracy of the numerical simulation results.

Key words: computational fluid dynamics, numerical analysis, two-phase flow, hydrocyclone, velocity field

摘要：

为研究水力旋流器在井下出现堵塞问题而产生的流场及性能变化规律，以井下倒锥式水力旋流器为研究对象，采用数值模拟与实验相结合的研究方法，对旋流器在六种不同堵塞工况下的流场特性及分离性能进行深入分析，并提出一种流场不对称性的定量表征方法，明确其在不同堵塞工况下旋流场变化及平均偏移不对称情况。结果表明，在三条紧邻流道堵塞的工况中，切向速度及轴向速度的平均偏移不对称率均产生最大值分别为67.82%和34.99%；相对于无堵塞工况，六种不同堵塞工况的平均压降均有所上升，分离效率均有所下降，其中工况六在四条紧邻流道堵塞的工况中，平均压降最大，分离效率最小。通过实验开展不同工况下的分离性能分析，实验结果与模拟结果的平均误差为1.22%，呈现出较好的一致性，为本文数值模拟方法的准确性提供了验证。

关键词: 计算流体力学, 数值模拟, 两相流, 水力旋流器, 速度场