油水两相流在石油工业过程中十分常见,对其流动过程参数(如流量与含率)的准确测量一直受其流态的复杂性限制而成为科学研究与工业应用中亟待解决的重要课题。差压法是常用的流量测量手段,作为差压式流量计的一种,V型内锥式流量计结合两相流动模型可实现两相流流量的测量。电学法通过测量两相混合物电学性质(如电导率与介电常数)的变化实现分相含率的测量。本文采用等效直径比0.65的V型内锥式流量计结合环形电导式传感器阵列实现50mm内径水平管道中油水两相流总流量、含率与分相流速的测量,针对油水两相流特性修正Chisholm分相流差压测量关系式实现油水两相流质量流量的测量,并利用环形电导式传感器阵列实现含水率与质量含油率的测量。实验结果表明,油水两相流含水率测量的平均相对误差为8.1%,质量含油率的平均相对误差为13.7%,基于修正关系式与含水率、质量含油率测量结果的油水质量流量测量平均相对误差为4.4%,油相与水相表观流速的平均相对误差分别为3.2%与15.7%。本工作为进一步提高油水两相流过程参数的测量精度打下基础。
Oil-water two-phase flow is commonly encountered in petroleum industrial processes, and due to its inherent complexity, accurate measurement of the process parameters (flow rate and phase concentration) has been a challenge task to be solved urgently. As a branch of differential pressure (DP) flow meter, V-cone flow meter can measure two-phase flow based on the pressure difference before and after the cone body in conjunction with certain two-phase flow model. The electrical sensitivity based phase concentration measurement method detects the change of electrical property of two-phase mixture and determines the phase concentration. The experiment described in this paper was conducted on a 50 mm inner diameter horizontal pipe, the oil-water two-phase flow was measured using a V-cone meter with 0.65 diameter ratio, the flow rate was determined; and a set of conductivity rings were used to determine the phase concentration. The Chisholm measurement equation is modified according to the oil-water flow features. The average relative errors of water holdup and oil mass fraction measurements are 8.1% and 13.7%, respectively. Using the modified measurement equation, the average relative error of oil-water mass flow rate measurement is 4.4%; the average relative errors of the superficial velocities of oil and water are 3.2% and 4.6%, respectively. This research work lays a foundation for further improving the precision of oil-water two-phase flow measurement.