基于超声波的气液两相分层流液膜厚度及流量的非介入测量

Non-contact Measurement of Liquid Film Thickness and Flow Rate of Gas-liquid Two-phase Stratified Flow Based on Ultrasonic Wave

传统液膜厚度测量方法会干扰液膜流动进而引发测量偏差,为了克服传统测量方法的不足,提出了采用超声多普勒进行非介入式测量液膜厚度的新方法,通过超声多普勒流速仪测量气液界面回波信号,通过反射回波识别气液界面测得液膜厚度,通过对液膜速度分布曲线进行积分,还可获得液相质量流量。在气液两相流实验环道上开展了测试,液相折算速度范围为0.027~0.066 m/s,气相折算速度范围4.85~15.81 m/s。实验表明:液膜厚度的分辨率0.01 mm,液膜厚度最大测量误差4.32%,液膜质量流量最大误差5.0%。

Traditional liquid film thickness t methods will disturb the flow of liquid film and cause measurement error. In order to overcome this shortcoming,a novel non-contact liquid film thickness measurement method based on ultrasonic Doppler is pro- posed in this paper. It measures the echo signal from gas-liquid interface using acoustic doppler velocimeter （UDV） and determines the liquid film thickness according to the echo signal, and the mass flow rate of liquid phase can also be obtained by integrating of liquid film velocity profile along the uhrasonic beam. Experiments were carried out in an air-water two-phase flow loop. The superficial velocity of liquid phase was in the range of 0. 027 -0. 066 m/s and the superficial velocity of gas phase varied from 4.85 m/s to 15.81 m/s. The resolution of film thickness is 0.01mm. The maximum relative error of the liquid film thickness and the liquid mass flow rate is 4.32% and 5.0% respectively.