Ultrasound-Based Parameter Measurement For Gas-Liquid Two-Phase Flow

The main work in this paper is achieved the detection of film thickness,cross-sectional phase fraction,the gas-liquid interface dynamic monitoring and the gas-liquid interface flow rate by using ultrasonic echo reflection method.And the measured gas-liquid interface shape can reflect the changes of two-phase flow pattern.The specific work in this paper is as follows:(1)Analyzed the theoretical feasibility of using ultrasonic principle to detect the film thickness,cross-sectional phase fraction,the gas-liquid interface flow rate,and so on.And designed an overall research scheme.(2)Developed a detection system for the two-phase flow parameter based on the ultrasonic principle,and designed an experimental data processing software to extract the first wave arrival time automatically,analyze signal correlation processing and so on.(3)Obtained the film thickness detection correction model through the film thickness detecting experiment taken under static condition using ultrasonic detection system,and eliminated the error influence caused by the transducer installation,time delay and so on.Completed the detection of dynamic film thickness and the average film thickness,crosssectional phase fraction of stratified flow.(4)Designed a scheme of using a single ultrasonic transducer mounted on the bottom of the pipe for the stratified smooth/wavy flow,slug flow and plug flow pattern monitoring.And the research indicates that the detected dynamic gas-liquid interface shape can reflect the variation of the flow pattern;for annular flow regime detecting,a scheme of using two probes installed on the top and bottom of the pipe was proposed,but due to limitations of the experimental conditions,the experimental study did not complete.(5)Obtained average flow velocity of the gas-liquid interface by using correlation technology.Calculated the correlation character of the dynamic wave monitoring signal received by the two probes installed on the upstream and downstream to obtain the time delay.And then get the flow velocity of the gas-liquid interface.According to the gas-liquid interface velocity and film thickness detected,proposed a method to calculate the liquid flow rate.