Experimental study on feasibility of capacitance void fraction meters

Watanabe, Hironori; Mitsutake, Toru*; Kakizaki, Sadayuki*; Takase, Kazuyuki

The electro-void fraction meter (Capacitance Type meter) is practical for high void fraction measurement. It can be used with various shapes of flow conduits such as round, rectangular and rod-bundle geometries. The principle of the meter is that the electrical capacitance of a gas-liquid two-phase flow changes with respect to the void fraction. High-frequency power supply enables to measure the void fraction of the pure water. It was confirmed by an air-water two-phase flow experiment that void fraction can be obtained in real time by measuring the capacitance of the two-phase flow. Void fraction ranging from 0 to more than 0.9 in a 37-rod bundle was successfully measured under 7MPa pressure conditions.