针对水连续油水分散流流速测量问题,提出了一种基于连续波超声多普勒的测量方法。测量传感器主要由一对中心频率为1 MHz的压电陶瓷超声换能器构成。发射探头向被测流体中发射连续的超声波,受到流体内运动的分散液滴散射后的声波被接收探头接收。根据多普勒效应,发射声波和接收声波的频率差与测量区域内散射体的运动速度成正比。由于分散相和连续相之间存在相对滑动,因此利用漂移模型对最终结果进行修正。对漂移模型中的参数进行基于油水两相流实际流动状态的理论分析,并通过实验数据计算漂移速度。实验结果表明,该测量模型对流型的依赖性很高,且漂移速度随着含水率的变化而改变,通过测量数据对该测量模型进行修正,最终结果的相对误差小于5%。
A superficial flow velocity measurement method for water continuous dispersed oil-water two-phase flow based on continuous wave ultrasonic Doppler(CWUD) is presented.The sensor includes a pair of ultrasonic transducers of 1 MHz center frequency.The ultrasonic wave was emitted into the fluid,and then received after being scattered by the dispersed phase.The frequency shift between the emitted and received signal is proportional to the scatters' moving velocity.A theoretical correlation based on drift-flux model was proposed to relate the drift velocity between the continuous phase and dispersed phase.The distribution parameter in drift-flux model was determined by theoretical analysis and the drift velocity was obtained by experiments.Dynamic experiments were performed in a horizontal plexiglas pipe.As shown in results,the characteristic of drift-flux model depends on the flow patterns,and the drift velocity of dispersed phase changes with the water fraction.By using the theoretical model,the finally results meet the reference total superficial flow velocity with a maximum relative error of 5%.