A Gas-Liquid Flowmeter Combining Vertical and Horizontal Pressure Fluctuations Induced by Local Void Fraction Variations

Abstract

Two AC signals generated by two sensors mounted in two elbows at the ends of vertical and horizontal branches of a metering pipe are simultaneously recorded and analyzed. The AC signals are mainly due to fluctuations in stagnation-pressure caused by the local oscillations of local void fraction and to transport velocity of the gas-liquid flow. Features extracted from stochastic interpretation of the two signals are strongly related to gas and liquid flowrates. Laboratory and field testing of the new meter demonstrated that, for the same gas and liquid flowrates, probability distribution functions (PDF) determined from statistical analysis of “vertical” and “horizontal” AC signals are unique. For broad ranges of gas-liquid ratios, features extracted from the PDF are linearly related to gas and liquid flowrates.