油气混输泵压缩级内湍流强度及湍流耗散特性分析

Analysis of the Turbulent Flow Intensity and Dissipation Characteristics of an Oil-gas Multiphase Pump in Its Compression Stages

为了研究气液两相条件下油气混输泵压缩级内湍流强度和湍流耗散的分布规律,本文以螺旋轴流式油气混输泵为研究对象,采用CFD软件进行数值计算,得到从10%到70%含气率条件下油气混输泵压缩级内的湍流强度和湍流耗散特性。研究表明：气体越集中的位置也是介质流动越不均匀的位置;级间动静干涉作用、流动的不均匀性以及较大旋涡的出现均会导致湍流强度和湍流耗散程度的增加,且在压缩级内随着含气率的增加,湍流强度最大值先减小再增加,且低含气率下湍流强度最大值最大;油气混输泵压缩级内水力损失较大的区域主要集中在级间和导叶内以及叶轮进口区域。

In order to study the law governing the distribution of the turbulent flow intensity and dissipation inside the compression stages of an oil-gas muhiphase pump under the condition of a gas-liquid twophase flow, the software CFD was employed to conduct a numerical calculation with a spiral axial flow oilgas multiphase pump serving as the object of study and the turbulent flow intensity and dissipation characteristics of the oil-gas muhiphase pump in its compression stages were obtained under the condition of the air content ranging from 10% to 70%. The research results show that locations where gases are more concentrated are those where the flow of the working medium are not more uniform and any action of rotorstator interference between stages and presence of the non-uniformity of flows and relativeiy large vortexes can all lead to an increase of the said turbulent flow intensity and dissipation degree. With an increase of the air content in the compression stages, the maximum value of the turbulent flow intensity will first decrease and then increase. Furthermore, at a low air content, the maximum value of the turbulent flow intensity will be the maximum. The zones with relatively large hydraulic losses inside the compression stages of the oil-gas multiphase pump are mainly centralized at locations between stages, inside guide blades and at the inlet of the impeller.