环状流液滴夹带率测量方法及分析

针对气液两相环状流液膜参数溯源问题，设计了一种液膜在线提取装置和基于液膜质量流量测量的夹带率测量方法。该装置利用超声波测距传感器对储液箱液位进行实时监测并反馈至控制系统，利用单片机控制抽气泵开关实现对环状流多孔渗水介质管段内外差压调节控制液膜析出速率，使用换向器实现计量和废液管路切换并记录两次切换之间的时间间隔。利用精密电子天平对取出液膜进行称重测量，结合记录时间和液相质量流量计测量结果实现液膜质量流量和液滴夹带率等参数的测量。在小口径高精度气液两相流模拟装置进行了75组实流验证实验，并结合两种典型夹带率模型预测结果对测量系统进行了科学评价。研究结果表明，液膜质量流量和液滴夹带率测量结果可溯源，测量准确度高，为研究气液两相环状流液膜流动特性提供了一种可靠的实验测试方法。

Measurement method and analysis of droplet entrainment in annular flow

In view of the lack of traceability method for liquid film parameters measurement of gas-liquid two-phase annular flow, an online liquid film extraction device and an entrainment rate measurement method based on liquid film mass flow measurement were designed in the present paper. Liquid film extraction device used ultrasonic ranging sensor to monitor the liquid level of the liquid storage tank in real time and feedback to the control system. In order to make the liquid film extraction rate controllable, the single chip controlled the switch of the pumping pump to adjust the internal and external differential pressure. By using a commutator, metering and waste pipeline switching could be achieved and the time interval between the two switches could be recorded. The extraction liquid film could be weighed by the liquid film mass flow measurement module with a high precision electronic balance. Combined with the above time interval and the measurement results of liquid mass flow meter, the liquid film mass flow rate and droplet entrainment could be measured. 75 Groups of real flow verification experiments were carried out in the small-diameter high-precision gas-liquid two-phase flow simulation device, and the measurement system was evaluated scientifically by analyzing the predictive results of two typical entrainment rate models. The results showed that the measurement results of liquid film mass flow rate and droplet entrainment were traceable with high measurement accuracy, which provides a reliable experimental test method for the study of liquid film flow characteristics in gas-liquid two-phase annular flow.