Development of Capacitance Void Fraction Sensor Using X-ray Transmission Imaging

To improve capacitance-based void fraction measurement method in horizontal pipes, the correlation between the two-phase flow pattern in the pipe and the measured capacitance value was investigated by simultaneous measurement with X-ray imaging. The rectangular electrode pairs were placed above and below the horizontal pipe, and the capacitance between the electrodes was measured. X-ray transmission images were also taken at the same measurement position, and the void fraction was estimated. By synchronizing each measurement, the fluctuation of void fraction and capacitance was compared. As a result, the knowledge of the relationship between the measured capacitance and the flow structure was obtained.