低液量水平管气液两相分层流压力梯度和持液率研究

The pressure gradient and holdup in horizontal two-phase gas-liquid flows with low liquid loading

低液量气液两相分层流是长距离凝析天然气管线中一种常见流型,文章在大型多相流实验环道上进行了气液两相分层流实验,以动量平衡方程为流动机理分析基础,根据低液量气液两相流动特征,选取双圆环作为界面几何模型;优选气液相间摩擦系数,使低液量气液两相分层流压力梯度计算关系式闭合,计算了低液量分层流的压力梯度和持液率,并将模型预测值与实验实测数据进行了比较分析。在整个实验数据范围内,双圆环界面模型能够很好地预测低液量条件下气液两相分层流的压力梯度和持液率,因此建议在低液量的气液两相分层流中推荐采用双圆环界面模型预测压力梯度和持液率。

Low liquid loading gas/liquid flow is frequently encountered in condensate natural gas transmission through long distance pipelines. In this review the typical flow phenomena of low liquid loading gas/liquid pipe flow are described based on the experimental measurements and observations conducted by the large-scale multiphase experimental loop. Based on measurement and observation of flow pattern, the momentum equa- tions for stratified flow are developed on low liquid loading, double-circle surface model is selected to calculate pressure gradient and liquid holdup. In order to close the pressure gradient calculation relations, the correla- tions of gas-liquid interfacial fraction coefficient were optimized; and the proposed models for pressure gradient and liquid holdup predictions, and closure relationships developed were introduced and discussed. The pres- sure gradient and the holdup data were compared with predictions of the double-circle surface models. The model predicted the pressure gradient and holdup reasonably well. Overall the double-circle surface model was judged to be more robust.