Study On Acoustic Emission Signal Characteristics And Measurement Model Of Gas-liquid Two Phase Flow Based On Porous Plate

The petrochemical industry has always been a hot topic in today’s society.Therefore,experts and scholars have never stopped exploring the petrochemical industry.In the multitudinous research for multiphase flow detection because of its importance and complexity is paid more and more attention,the detection of gas-liquid two-phase flow is a representative multiphase flow detection,so the analysis of gas-liquid two-phase flow has far-reaching significance for the future development of the petrochemical industry.In this paper,the acoustic emission detection technology and differential pressure are combined to construct a porous plate flow measuring device suitable for this study,and the quantitative detection is realized by using the dual parameter method of acoustic emission differential pressure combination.The shape design and simulation of the throttling porous plate are followed to design a new type of porous plate flow measurement device.In addition,the new device is calibrated for the single-phase outflow coefficient,and a measurement model for the vertical single-phase water outflow coefficient is established.The maximum relative error of the final calibrated outflow coefficient is 1.91%.The gas-liquid two-phase flow dynamic test of the device is performed in the vertical direction,and the test conditions are multiple operating point conditions in the vertical direction flow patterns(bubble flow,slug flow and transition flow pattern),and the differential pressure signal and acoustic emission signal are recorded simultaneously in the test.The wavelet packet decomposition algorithm is used to extract the energy characteristic values in the specific frequency band of the flow acoustic signal,and the phase-concentration measurement model for the two-phase flow under different flow patterns are established.The slug-flow and transition flow-pattern measurement model fitted the relative error of the liquid-phase retention rate absolute,and the maximum value is 4.8%.The bubbly flow phase-concentration measurement model fits to the upper absolute value of the liquid-to-liquid phase rate relative error of 1.8%.Combining the phase holdup model with the test differential pressure signal,and comparing empirical flow measurement models,it is found that the two-phase mass flow calculation formula deduced by the Bison(0.45)empirical model has a good ability to predict the test conditions.The relative error of the two-phase mass flow rate of the slug flow and its transition flow is predicted to be within 3%;The Bizon(0.45)model is modified under the bubble flow condition,and the revised measurement model predicts that the maximum error of two-phase mass flow is 1.98%.The two-phase mass flow measurement models based on different flow patterns have considerable prediction effect.