Research On Dual-Wavelength Optical Detection Method For Gas-Liquid Two-Phase Flow In Small Channel

Gas-liquid two-phase flow has a wide range of applications in the mixed transportation of petroleum,aerospace power cycle,refrigeration cycle and other fields.With the development of industrial equipment towards miniaturization,interest has arisen during recent years for the gas-liquid two-phase flow in small channels.Measuring the parameters can not only provide reference for scientific research,but also effectively guide manufacturing.In this dissertation,the use of dual-wavelength laser based on the principle of scattering represents a promising way to measure the phase distribution of gas-liquid two-phase flow in a small channel.In this dissertation,a small-channel gas-liquid two-phase flow detection method based on the principle of dual-wavelength scattering is proposed.The light intensity distribution after phase flow is studied,the influence of the position and size of bubbles in the liquid on the refraction of two different wavelengths of light is studied.Using Trace Pro and MATLAB software,the propagation process of light of different wavelengths in the gas-liquid two-phase flow is simulated,and the light intensity distribution of the transmitted light under different bubble positions and sizes in the gas-liquid two-phase flow is obtained through the simulation,and the key points are extracted.parameters,and establish a simulation database of the relationship between key parameters and the position and size of bubbles.On this basis,the variation law of dual-wavelength characteristics caused by phase distribution is studied.The inversion model is established by neural network,support vector regression and gradient boosting decision tree,and the established intelligent learning algorithm is trained by using the simulation database,and the results of several intelligent algorithms are compared.The results show that the prediction results of the neural network model are in good agreement with the simulation data,the absolute error is within ±0.05 mm,and the relative error is within the range of ±5%,which is suitable for the measurement of gas-liquid two-phase flow.On this basis,the measurement accuracy of the dual-wavelength scattering method proposed in this dissertation is compared with the existing single-wavelength method.The results show that the dualwavelength scattering method has higher accuracy.A dual-wavelength measurement system for vertically ascending gas-liquid twophase flow in a small channel was built.A glass rod was used to simulate bubbles to conduct static experiments to verify the accuracy of the dual-wavelength gas-liquid two-phase flow detection method.Dynamic experiments were carried out with an injection platform,which verifies the effectiveness of this method in the measurement of phase distribution parameters in actual gas-liquid two-phase flow.