Wet gas metering using a vortex cross-correlation meter based on fluctuating pressure measurement

Abstract

A solution for wet gas metering was developed with a vortex meter by using pressure sensors and correlation technology. For the fluctuating pressure measurement, the micro pressure sensors, especially the probe-transducer systems, were designed to acquire reliable vortex signals. For the experiments, an annular mist flow loop with a film metering system was established, and the tests were conducted on various pressure, gas velocity and liquid flowrate conditions. Then, the dimensionless convection velocity, named convection coefficient, and the peak value of the normalized cross-correlation function, named correlation coefficient were calculated. A piecewise function was developed for the convection coefficient with modified Weber number where the segmentation was determined by the correlation coefficient. Finally, the wet gas measurement model was developed and realized by iterative algorithm. Under the present conditions, the ±5% error bands contain 91% of the relative errors for gas flowrate prediction, the mean absolute percentage error is 2.54%, and the uncertainty of gas flowrate prediction is 2.85%. The primary advantage of the proposed method is that the convection coefficient is almost independent of liquid fraction, no extra systems are necessary for watercut measurement, hence providing a cost-effective solution for wet gas metering.