水平油水两相流流型对阻抗式含水率计的影响研究

实验研究了水平条件下20mm管径油水两相流的流动特性对阻抗式含水率计测量的影响.首先利用阻抗式含水率计测量不同含水率和流量条件下的混合物电阻率,并使用高速摄像记录对应的流型特征,进而分析流型对测量值的影响.通过对低、高流量分别采用电学和流体动力学模型分析后发现:低流量下混合物电阻率的主要影响因素是油水两相之间的速度滑脱,采用双流体动力学模型能有效地反映其变化规律.而高流量下(水包油分散流时)速度滑脱很小可以忽略,油水两相的空间结构对混合物电阻率的影响是问题的关键.近似绝缘的油滴分散在导电的水中形成的含孔导体电阻率高于实心导体,适用的电学模型是Maxwell电阻率模型.

Study of the Influence of Horizontal Oil-Water Two-Phase Flow Pattern on the Impedance Moisture Meter

The influence of horizontal oil-water two-phase flow pattern on the measurement of impedance moisture meter was exprementially studied in a 20mm diameter acrylic pipe. Resistivity of oil-water mixture was measured by impedance moisture meter first under condition of different moisture contents and flow rates, and the corresponding flow patterns were recorded by a high-speed camera to analyze the influence of flow patterns on the measurement. It is demonstrated that at low flow rate (stratified flow), the remarkable velocity slip between oil and water plays a dominant influence on mixture resistivity. This phenomenon can be explained by two-fluid dynamic model. While at the high flow rate (dispered flow), the slippage between oil and water can be ignored. The mixture resistivity mostly depends on the mixture spatial structure. Then Maxwell electric model was adopted to calcualte the water cut. Above result is approaching to the known results calculated by the single phase flow rate before mixed.