垂直上升管中油气水三相流流型多尺度熵分析

为了研究垂直上升管中油气水三相流流动特性，本文利用纵向多极阵列电导式传感器（VMEA）和阵列电导探针组合测量方法在内径为125 mm多相流流动环中采集了油气水三相流电导波动信号，在定义6种油气水三相流流型基础上，绘制了4种油水混合液量下油气水三相流流型转换图，分析了含油率对流型转化及气相流速对油水相态逆转的影响.对水为连续相的5种流型VMEA传感器波动信号进行了多尺度熵分析，研究结果表明：含油率增加可使水包油段塞流在较低气相表观速度下产生；较低流速下的油水相态逆转可发生在油液比为0.9左右，气相流速增加使得逆转点向含油率低的方向偏移；多尺度熵细节可以刻画油气水三相流非线性动力学特性，而低尺度的多尺度熵变化率敏感地反映流型转变，是划分油气水三相流流型的有效准则.多尺度熵有助于理解油气水三相流流型非线性动力学特征.

Multi-scale entropy analysis of oil-gas-water three-phase flow patterns in vertical upward pipe

n order to study the flow property of oil-gas-water three-phase flow in vertical upward pipe, the conductance fluctuating signals of oil-gas-water flow in a 125 mm i.d. multiphase flow loop were acquired by using the combined measurement method of vertical multi-electrode array conductance sensor (VMEA) and mini-conductance probe array. Based on the determination of six three-phase flow patterns, the flow pattern maps for four total liquid mixture flow rates are constructed. Both the effect of the increase of oil in liquid volume fraction (fo) on flow pattern transition and the effect of superficial gas velocity (Usg) on the liquid inversion are discussed. Also the multi-scale entropy processing and analysis of conductance fluctuating signals acquired by VMEA sensor for five flow patterns with water as the continuous liquid are conducted. The study result indicates that the increase of fo makes oil in water type slug flow occur at lower Usg; for low flow velocity, the continuous liquid inversion occurs at about fo=0.9 and the increase of Usg makes the inversion point move to low oil volume fraction; the multi-scale entropy (MSE) detail describes the nonlinear dynamic characteristics of oil-gas-water flow patterns and the rate of MSE at low scales sensitively indicates the variation of flow patterns and can act as the efficient criterion of three-phase flow patterns identification. And multi-scale entropy is helpful to understand the nonlinear dynamic characteristics of oil-gas-water flow patterns.