1986 Fiscal Year Final Research Report Summary
Study on Freezing of Water Flow inside Tubes
| Project/Area Number |
59460153
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
建築環境・環境工学
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| Research Institution | Hokkaido University |
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Principal Investigator |
OCHIFUJI Kiyoshi Hokkaido University Fac. of Engineering Professor, 工学部, 教授 (50001152)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOYAMA Shintaro Hokkaido University Fac. of Engineering Associate, 工学部, 助手 (90002279)
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| Project Period (FY) |
1984 – 1986
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| Keywords | Freezing / Solidification / Tube / Coil / Water / Cooling / 層流 / 乱流 / 対流熱伝達率 / 管閉塞 / 氷点下 |
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| Research Abstract |
Temperature drop and ice formation of water flow inside tubes and coils are investigated experimentally and theoretically.
The result of a tube experiment is that temperature drop along water flow almost agree with temperature variation of quiescent water on a function of flowing time from an inlet. The result of a coil experiment is that temperature variation at any point in a coil keeps above 0゜C during freezing near the surface and drops immediately below 0゜C, when water can not flows soothly due to ice formation. The main conclusion to be drawn from both experiments is that water temperature should not be less than 0゜C anywhere in the equipments for water to flow always.
In regard to theoretical analysis, the practical methods are conducted to obtain water temperature drop and ice formation using the coefficient of heat convection in laminar flow and turbulent flow. It is found that the results obtained by this method approximately agree with ones of theoretical analysis and experimental date under some conditions. The analyses in which the pressure drop and decrease of flow rate with freezing are considered is undertaken. It is also found that when freezing generates in tubes or coils, it is growing until it closes the section of them.
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