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Koizumi, Yasuo; Yoshizawa, Shota*
Proceedings of the ASME 2014 International Mechanical Engineering Congress and Exposition (IMECE 2014) (DVD-ROM), 7 Pages, 2014/11
The enhancement of drop wise condensation heat transfer by functionalizing a heat transfer surface was examined for 0.1 MPa steam. A gold-plated surface was used to produce the drop wise condensation. Rectangular-grooved heat transfer surfaces were adopted to functionalize the heat transfer surface. The size of the grooves were 2 mm 2 mm 2 mm, 3 mm 3 mm 3 mm and 2 mm 3 mm 2 mm (depth top width bottom width), respectively. The heat flux of the grooved surface was larger than that of the plain gold-plated surface. When the groove size was 2 mm 2 mm 2 mm and the top parts and the walls of grooves were plated with gold, the heat transfer rate augmentation was highest; the augmentation rate was 1.53. Since to increase the width of the top part of the grooves tended to bring the quality of the surface structure close to the plain surface, it was not right direction. It was also implied that to make summits and troughs on the surface to collect condensate tended to expose the summit part to steam more, which might result in the heat transfer augmentation.
Kondo, Masaya; Nakamura, Hideo; Anoda, Yoshinari; Saishu, Sadanori*; Obata, Hiroyuki*; Shimada, Rumi*; Kawamura, Shinichi*
Proceedings of 10th International Conference on Nuclear Engineering (ICONE 10) (CD-ROM), 9 Pages, 2002/00
no abstracts in English
Yonomoto, Taisuke; Otsu, Iwao; Svetlov, S.*
Proceedings of 3rd Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-3), p.521 - 528, 2002/00
A research project is being conducted at the Japan Atomic Energy Research Institute on thermal hydraulics for the future reactor systems. The present paper provides the belief description of the project, followed by two recent topics: the natural circulation in the PWR loop and the condensation heat transfer for a passive cooling system. For the first topic, we discuss the importance of the modeling of the nonuniform flow behavior among SG U-tubes for the assessment of the long-term decay heat removal systems relying on the SG secondary side cooling. Such a system is planned to be used in APWR+, a Japanese next-generation PWR. The condensation heat transfer was investigated using the data obtained at the SPOT test facility in Russia. The results have shown that the measured heat transfer rates on the inner surface of the tube consisting of several bends and short straight sections can be predicted using the existing correlations with the accuracy of several percentage, although the correlations are based typically on the data taken using relatively long straight tube.
Kunugi, Tomoaki; Takase, Kazuyuki; Kurihara, Ryoichi; Seki, Yasushi;
Fusion Engineering and Design, 42, p.67 - 72, 1998/00
Times Cited Count:12 Percentile:68.41(Nuclear Science & Technology)no abstracts in English
; Koizumi, Yasuo; Osakabe, Masahiro; ; Tasaka, Kanji
86-WA/NE-8, p.1 - 6, 1986/00
no abstracts in English