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Watanabe, Hironori; Tamai, Hidesada; Sato, Takashi; Shibata, Mitsuhiko; Mitsutake, Toru*
Flow Measurement, p.95 - 106, 2012/03
In Boiling Water Reactor (BWR), reactor power, fuel conversion ratio and reactor cooling capacity changes by the void fraction in the core. We have developed a capacitance method (C method) to measure the void fraction under the condition of high temperature and high pressure of 7MPa, simulating reactor. This C method is based on the principle that the capacitance in the two-phase flow is a function of void fraction. Using this method, we can measure void fractions in real time, at all region of void fractions, and with a small error of measurement, which was not realized by usual techniques up to now.
Watanabe, Hironori; Mitsutake, Toru*; Shibata, Mitsuhiko; Takase, Kazuyuki
Nihon Kikai Gakkai Rombunshu, B, 76(769), p.1379 - 1385, 2010/09
The electro void fraction meter (Capacitance type meter) was applied to high temperature and high pressure condition measurement with various shapes of flow conduits such as rod bundle and pipe geometries. The principle of the meter is that the electrical capacitance of a gas liquid two phase flow changes with the void fraction. High frequency power supply enables to measure the electrical capacitance of the ion exchanged water with even though conductivity of pure water. It was confirmed by steam water boiling two phase flow experiments that void fraction can be obtained in real time way. Void fraction ranging from 0 to 0.9 at maximum was successfully measured under steam water boiling two phase flow conditions of 2 MPa through 18 MPa pressure.
Watanabe, Hironori; Mitsutake, Toru*; Kakizaki, Sadayuki*; Takase, Kazuyuki
Nihon Kikai Gakkai Rombunshu, B, 75(751), p.155 - 157, 2009/03
Capacitance type electro-void fraction meters with various shapes of electrodes were developed for two-phase flow measurement in tubes of 1mm in the smallest diameter. Ring and wire- type electrodes were applied to measure void fraction. The principle of the meter is that the electrical capacitance of a gas-liquid two-phase flow changes with void fraction. A high-frequency power supply enables to measure the low electrical capacitance of the water including pure water. It was confirmed by the air-water two-phase flow experiments that void fraction can be obtained in real time way every 50 millisecond. Void fraction in the experiment ranged from 0 to higher than 0.9. The void fraction was correlated with the electric capacitance by a linear function for the ring-electrode and hyperbolic function for the opposite wires-electrode under the atmospheric condition.
Watanabe, Hironori; Mitsutake, Toru*; Kakizaki, Sadayuki*; Takase, Kazuyuki
Nihon Kikai Gakkai Rombunshu, B, 74(742), p.1257 - 1262, 2008/06
Misawa, Takeharu; Onuki, Akira; Mitsutake, Toru*; Katsuyama, Kozo; Misawa, Susumu*; Nagamine, Tsuyoshi; Nakamura, Yasuo; Akimoto, Hajime
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 8 Pages, 2007/04
Mitsutake, Toru*; Katsuyama, Kozo*; Misawa, Takeharu; Nagamine, Tsuyoshi*; Kureta, Masatoshi*; Matsumoto, Shinichiro*; Akimoto, Hajime
JAERI-Tech 2005-034, 55 Pages, 2005/06
JAERI-Tech-2005-034.pdf:7.76MB
In tight-lattice bundles with about 1mm gap between rods, a rod displacement might affect thermal-hydraulic characteristics. The inside-structure observation of the simulated seven-rod bundle of RMWR was made with the high-energy X-ray CT of JNC. The CT view assured that the rod position was almost the same as expected by design. In the heat transfer experiments, all thermocouples on the center rod showed almost simultaneous BT-induced temperature increase and on the same axial heights showed quite similar time-variation behaviors in the vapor cooling heat transfer regime. It showed that the effect of the geometrical asymmetry was small on the BT characteristics. The calculated critical power by subchannel analysis with the input of the CT measured rod position was smaller by about 5% than that with the designed rod position. It concluded that the error in the calculated critical power was attributable not to the asymmetry in the rod position, but to the models in the subchannel analysis code.
Mitsutake, Toru*; Akimoto, Hajime; Misawa, Takeharu; Kureta, Masatoshi*; Katsuyama, Kozo*; Nagamine, Tsuyoshi*; Matsumoto, Shinichiro*
Proceedings of 4th World Congress on Industrial Process Tomography, Vol.1, p.348 - 353, 2005/00
An inside-structure observation of a tight-lattice 7-rod bundle was made, using the high-energy X-ray computer tomography(CT) apparatus. The two-dimensional configurations of all rods were obtained at seventy-six axial height positions over the whole length of the bundle. The measured results of the rod positions showed small rod position displacements, about 0.5 millimeters at maximum, from the lattice positions. Based on these measured rod position displacement results, the flow area, equivalent hydraulic diameter, rod-rod clearance, and rod-shroud clearance were calculated. The effect of rod position displacement on critical power was estimated by a sub-channel analysis. The result showed that the rod position displacement effect has only a small effect on critical power calculations. The calculated critical power still overestimated the measured value.
Katsuyama, Kozo; Misawa, Susumu*; Mitsutake, Toru*; Misawa, Takeharu; Nagamine, Tsuyoshi; Nakamura, Yasuo; Onuki, Akira; Akimoto, Hajime
no journal, ,
no abstracts in English
Watanabe, Hironori; Mitsutake, Toru*; Kakizaki, Sadayuki*; Takase, Kazuyuki
no journal, ,
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.
Watanabe, Hironori; Mitsutake, Toru*; Kakizaki, Sadayuki*; Sekine, Katsunori*; Takase, Kazuyuki
no journal, ,
no abstracts in English
