| Project/Area Number |
09480103
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
エネルギー学一般・原子力学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
FUKUDA Kenji Kyushu Univ., Professor, 工学研究科, 教授 (90117234)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIMOTO Noboru Kyushu Univ., Assistant, 工学研究科, 助手 (60274510)
MORITA Kouji Kyushu Univ., Associate Professor, 工学研究科, 助教授 (40311849)
饒 燕飛 九州大学, 工学部, 助教授 (10243891)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1998: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1997: ¥3,300,000 (Direct Cost: ¥3,300,000)
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| Keywords | SBWR / INSTABILITY / GEYSERING / DENSITY WAVE OSCILLATION / DRIFT FLUX MODEL / CHIMNEY / 3-D SYSTEM / PARALLEL CHANNELS / ドリフトフラックスモデル / 自然循環型原子炉 / 3次元気液=相流 / 受動安全 / 安全性 / 核熱統合安全性 / 三次元気液二相流 / 安定性 |
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| Research Abstract |
To assure the passive-safety of the SBWR cooled by natural circulation its possible instabilities are examined with using a small scale experimental apparatus. This is a 1+3 dimensional system, composed of a glass container with three heater parallel channels, and a chimney volume on the top half of the container.
Experiments were performed for various number of channels to observe closely the instabilities : the geysering and the density wave oscillation. It was clarified that the geyserings are initiated either from the top or the bottom of the heated channels, with accelerated propagation of the boiling front due to the gravity-governed self-evaporation. On the other hand the feedback effect between the driving force of the natural circulation and the movement of the bubbles plays the dominant role. It was very often to observe these two type instabilities occur simultaneously. These observations were simulated with using a newly developed time-domain computer code.
Experiments were also performed with using a larger container with higher chimney volume. Although with a higher chimney, it was observed that the natural circulation flow rate unchanged. This was because, the secondary circulation in the chimney volume makes the pressure drop uniform, which declines the driving force of the natural circulation in the chimney part. This indicates that dividing of the chimney with several vertical segments is advisable. This observation was verified by analyses with a computer code using the drift-flux model.
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