Research on the measurement method of gas-water two-phase flow based on dual-sensor system

Abstract

Realizing the online accurate measurement of gas-water two-phase flow is of great significance for the natural gas industry. In this paper, a dual-sensor with the microwave resonant cavity sensor embedded in the throat of Venturi is proposed and both of the water volume fraction (WVF) and the separated flowrates of the two phases is attained by the method. To further improve the performance and the measurement accuracy of the sensor, a swirler is fixed inside the contraction section of the precession Venturi, which can regularize all flow patterns into spiral annular flow and reduce the influence caused by the nonuniform distribution of air and water. The microwave sensor response characteristics with WVF and Venturi over-reading (OR) characteristics have been researched through dynamic experiments, and the iteration method of OR model obtained by the precession Venturi and WVF model obtained by the microwave sensor is used to solve the gas and water flowrates respectively. The results show that gas phase flowrate relative error band of ±5% at a confidence probability of 86.08%, and Root Mean Square Error (RMSE) is 3.349%; while water flowrate relative error band of ±10% at a confidence probability of 87.70%, and RMSE is 9.680%, which suggests that the multi-sensor fusion technology provides a powerful solution for the measurement of separated flowrates of gas-water two-phase flow.