| Conductance sensor measurements are based on electrical characteristics of a two-phase flow measurement method, phase fraction measurement in gas-liquid two-phase flow mainly including conductance probe method, sectional multi-electrodes method and vertical annular electrodes method, and made a lot of progress at home and abroad. This paper proposes two measurement structures of internal-external electrodes conductance sensor based on sectional multi-electrodes method, include internal-external annular conductance sensor and multi-electrodes conductance sensor. Analyze characteristics of sensitivity field and phase fraction in gas-water two-phase flow measurement separately.The main achievements in this paper are as follows:1. Research on internal-external electrodes conductance sensor measure model and its equivalent circuit based on electrical conductivity measurement mechanism of two-phase flow. Relative calculation method of cross-sectional-averaged holdup is raised.2. Application of physical field coupling analysis software COMSOL to build internal-external electrodes conductance sensor model, grid partition, and simulation.3. Study on internal-external annular conductance sensor by COMSOL and MATLAB. Sensor optimization of the electric field such as uniformity, spatial sensitivity is proposed. By analysis of this configuration, the relationship of gas fraction and measuring voltage in laminar flow and dispersed flow are obtained, and prove this results by measurement.4. Study on multi-electrodes conductance sensor, uniformity, spatial sensitivity is analyzed. Make electrode measuring range clearly, the radius of bubble, gas fraction and electrode measuring range are got by COMSOL and MATLAB software and prove this results by measurement. |
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