Study on Freezing of Water Flow inside Tubes

管内水流冻结研究

• 批准号: 59460153
• 负责人: OCHIFUJI Kiyoshi
• 金额: $ 4.03万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1984
• 资助国家: 日本
• 起止时间: 1984 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-59460153/
• 关键词: Freezing; Solidification; Tube; Coil; Water; Cooling; 層流; 乱流; 対流熱伝達率; 管閉塞; 氷点下

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.

本文从实验和理论两方面研究了管盘管内水流的降温和结冰问题。管道实验结果表明，沿水流方向的温度下降与静水温度随入口流动时间的变化基本一致。线圈实验的结果是，在接近表面结冰时，线圈中任意点的温度变化保持在0 C以上，当水因结冰而无法畅通时，温度变化立即降至0 C以下。从两个实验中得出的主要结论是，设备中任何地方的水温不应低于0 C，以保证水始终流动。在理论分析方面，利用层流和湍流中的热对流系数进行了实际的水温下降和结冰的计算。在一定条件下，该方法得到的结果与理论分析和实验数据基本吻合。考虑冻结时的压降和流量下降，进行了分析。还发现，当冷冻在管道或线圈中产生时，它会不断生长，直到关闭它们的部分。

项目成果

Kiyoshi Ochifuji; Katsunori Nagano; Makoto Nakamura: "The Analysis of Freezing in a Circular Tube Considering Pressure Drop with Freezing of Laminer Flow" Proceeding of annual meeting in the Society of Heating, Air-Conditioning and Sanitary Engineers of J

越藤清;

Kiyoshi Ochifuji; Katsunori Nagano: "The Analysis of Freezing of Quiescent Water in a Circular Tube with Initial Temperature Distribution" Proceeding of annual meeting in Architectural Institute of Japan. 719-720 (1986)

越藤清;

落藤澄,長野克則,中村真人: 空気調和・衛生工学会学術講演論文集. 65-68 (1986)

Sumi Rakufuji、Katsunori Nagano、Masato Nakamura：日本空调和卫生工程师学会学术讲座论文集 65-68 (1986)。

Kiyoshi Ochifuji: the Society of Heating,Air-Conditioning and Sanitary Engineers of Japan. A Guidoline for Prevention of Freezing, 1-127 (1982)

Kiyoshi Ochifuji：日本供暖、空调和卫生工程师协会。

落藤澄,新谷一之: 空気調和・衛生工学会北海道支部学術講演論文集. 21. 59-62 (1987)

Sumi Rakufuji、Kazuyuki Shintani：空调和卫生工程师协会北海道分会论文集，21. 59-62 (1987)。