A CV weighted method for oil-water two-phase flow of non-contact multi-frequency el7ectrical impedance tomography

Abstract

Electrical tomography (ET) technology has attracted extensive attention in the field of scientific research on oil-water two-phase flow due to its advantages of non-intrusion, non-radiation, and simple equipment structure. Affected by Maxwell-Wagner-Sillars (MWS) effect, more imaging information can be obtained by changing the excitation frequency, especially for the mixtures with conductive phases. In this paper, a CV (coefficient of variation )-weighted method of non-contact multi-frequency electrical impedance tomography (NM-EIT) system is carried out for water-oil two-phase flow imaging. Firstly, the frequency response of the measurement system is studied and the electrical impedance information of medium in the region of interest (RoI) is observed. Secondly, the measured electrical impedance information with with different excitation frequencies are weighted by CV method. Finally, combined with the classic image reconstruction algorithm, the simulation and static experiment are carried out to verify the reconstruction effect of the proposed method. The imaging accuracies under different frequencies and flow patterns are analyzed, and a measurement experimental platform is set up to verify the reconstruction effect of the proposed method. The experimental results show that the CV-based multi-frequency weighted method maintains a higher imaging accuracy than single-frequency imaging.