Study On Flow Characteristics Of Gas-liquid Two-phase Flow Based On Ultrasonic Technology

Gas-liquid two phase flow exists widely in industrial processes, due to the interaction between the two phases, it makes two phase flow with complex flow characteristics, two-phase flow patterns as an important parameter has been the two-phase study key. In this paper, the use of ultrasonic nondestructive testing technology flow of gas-liquid two-phase study, the contents and results are as follows:The establishment of simulation model by using Wave2000 Plus ultrasound simulation software, the simulation analysis of the echo signal and residual signal transmission in different bubble radius using reflection and transmission method, the results show that: With the emergence of gas bubbles in the pipe, bubble echo signal amplitude is positively correlated with the bubble radius, away from the emission source tube wall echo signal amplitude and transmission signal negatively related to the bubble radius and draws a conclusion that wall echo signal amplitude as the characteristic parameter in the reflection method, the ratio of signal attenuation as characteristic quantities in transmission method used for the study of gas-liquid two-phase flow pattern identification.Build a two-phase flow in vertical tubes ultrasonic test system, by regulating and controlling the flow of gas and liquid, forming a stable bubbly flow, slug flow, annular flow in the vertical pipe, the system can be separately collected ultrasonic signal and image tube in the flow pattern using the reflection method and transmission method. Finally, the two methods to get the signal acquisition comparative analysis and probability density distribution, the results showed that:(1)Reflection method: Bubble flow, bubble echo signal amplitude is positively correlated with the bubble radius, away from the emission source tube wall echo signal amplitude is negatively related to the bubble radius, after the calculation of the probability distribution, the wall surface echo signal amplitude as the characteristic quantity of sample distribution in high amplitude range, with growth of bubble sample distribution range extending to low amplitude. Slug flow, the wall echo signals appear periodically, part of the sample distribution in the very low range, another part of the distribution in high amplitude range. Annular flow, the sample distribution in the very low range.(2)Transmission method: Bubble flow, transmission signal negatively related to the bubble radius, after the calculation of the probability distribution, the attenuation ratio as the characteristic quantity of sample distribution in low attenuation rang. Slug flow, the samples appeared two kinds of distribution, a part of the distribution in the high attenuation ratio range, another part of the distribution in the low attenuation range. Annular flow, the sample distribution in high attenuation range.The two methods can effectively identify the flow pattern of gas-liquid two-phase in the vertical pipe, compared with reflection method, transmission method is more simple and practical application. Finally, by using the attenuation ratio obtained flow char.