| Project/Area Number |
03650169
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | IBARAKI UNIVERSITY |
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Principal Investigator |
KAWAMATA Masaaki (1993) IBARAKI UNIVERSITY, FACULTY OF ENGINEERING, ASSISTANT, 工学部, 助手 (70007631)
神永 文人 (1991-1992) 茨城大学, 工学部, 助教授 (80114015)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMOTO Yoshizo IBARAKI UNIVERSITY, FACULTY OF ENGINEERING, PROFESSOR, 工学部, 教授 (10194408)
川又 正昭 茨城大学, 工学部, 助手 (70007631)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1993: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1991: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | HEAT PIPE / THERMOSYPHON / BOILING / CONDENSATION / DECAY HEAT / 限界熱流束 / ヒ-トパイプ / 限界熱流来 |
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| Research Abstract |
The purpose of this study is to obtain basic features of a heat pipe to be applied to a decay heat removal system. Experimental studies to investigate heat transfer behaviors of the heat pipe present the foolowing findings :
(1) Heat transfer coefficient in a evaporator section of the heat pipe is two or three times higher than one on a horizontal heat transfer surface due to bubble agitation effect. A new correlation is presented by modification of Kutateladze's nucleate boiling correlation in terms of an additional two parameters, a density ratio of liquid and vapor and a surface roughness.
(2) A Wall temperature at an adiabatic section of the heat pipe is less than a saturation temperature corresponding to a system pressure in the heat pipe.
(3) A fill charge ratio of a working fluid gives a negligible effect on maximum heat transfer rate. A correlation presented by Ueda-Miyasita can predict the maximum heat transfer rate within 20% error. This correlation is recommended to be used for heat transfer calculation in the heat pipe.
(4) A heat transfer correlation to a turbulent film presented by Uehara give a better prediction for a heat transfer coefficient in a condenser section of the heat pipe than the Nusselt correlation used in current heat transfer calculations. But deviation between measured and predicted values is still large since effects of countercurrent vapor flow and entrainment and deposition of droplets affect the heat transfer particularly in the case of a high fill charge ratio.
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