Experimental study of transient pool boiling heat transfer under exponential power excursion on plate-type heater
Thesis: S.M., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2015.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2015
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| Online Access: | http://hdl.handle.net/1721.1/97863 |
| _version_ | 1826209304823201792 |
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| author | Su, Guanyu, Ph. D. Massachusetts Institute of Technology |
| author2 | Jacopo Buongiorno and Thomas McKrell. |
| author_facet | Jacopo Buongiorno and Thomas McKrell. Su, Guanyu, Ph. D. Massachusetts Institute of Technology |
| author_sort | Su, Guanyu, Ph. D. Massachusetts Institute of Technology |
| collection | MIT |
| description | Thesis: S.M., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2015. |
| first_indexed | 2024-09-23T14:20:25Z |
| format | Thesis |
| id | mit-1721.1/97863 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T14:20:25Z |
| publishDate | 2015 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/978632023-02-26T03:09:50Z Experimental study of transient pool boiling heat transfer under exponential power excursion on plate-type heater Su, Guanyu, Ph. D. Massachusetts Institute of Technology Jacopo Buongiorno and Thomas McKrell. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Nuclear Science and Engineering. Thesis: S.M., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2015. Cataloged from PDF version of thesis. Includes bibliographical references (page 82). Conduction and single-phase convective heat transfer are well understood phenomena: analytical models [1] and empirical correlations [2] allow capturing the thermal behavior of plate-type fuels or heaters in contact with a single-phase coolant. On the other hand, transient boiling heat transfer is a scarcely studied and much less understood phenomenon. Although, earlier studies have shown that important features of the boiling curve (i.e. onset of nucleate boiling (ONB), nucleate boiling heat transfer coefficient, and critical heat flux (CHF)) in transient conditions. These parameters significantly differ from those at steady-state. The mechanisms by which these changes occur are not clear. Furthermore, some of the conclusions from different authors are quantitatively or qualitatively in disagreement with each other. This work studied transient pool boiling heat transfer phenomena under exponentially escalating heat fluxes on plate-type heaters, at the time scales of milliseconds typical of Reactivity Initiated Accidents (RIAs) in nuclear reactors. The investigation utilized state-of-the-art diagnostics such as Infrared (IR) thermometry and high-speed video (HSV), to gain insight into the physical phenomena and generate a database that could be used for development and validation of accurate models for transient boiling heat transfer. The tests with exponential power escalation periods ranging from 100 ms to 5 ms and subcoolings of OK (saturation), 25K and 75 K were conducted. The measured pre-ONB heat transfer coefficient agrees well with the theoretical predictions for transient conduction. The ONB and onset of significant void (OSV) temperature and heat flux were found to increase monotonically with decreasing period and increasing subcooling, as expected. The mechanistic ONB model of Hsu was able to predict the measured ONB temperature and heat flux. The transient pool boiling curves were measured up to fully developed nucleate boiling (FDNB). Generally two types of boiling curve were observed: with overshoot (OV) or without overshoot. Data show that, when an OV is present, the OV temperature increases monotonically with decreasing period and increasing subcooling. The present study clears the confusions (eg. the trend of ONB temperature and heat flux versus power period) in previous research, and sheds light to the mechanisms behind transient boiling heat transfer. This can ultimately reduce the uncertainty in both design and safety analyses of the research reactors especially under RIAs. by Guanyu Su. S.M. 2015-07-17T19:54:37Z 2015-07-17T19:54:37Z 2015 2015 Thesis http://hdl.handle.net/1721.1/97863 913785590 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 97 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Nuclear Science and Engineering. Su, Guanyu, Ph. D. Massachusetts Institute of Technology Experimental study of transient pool boiling heat transfer under exponential power excursion on plate-type heater |
| title | Experimental study of transient pool boiling heat transfer under exponential power excursion on plate-type heater |
| title_full | Experimental study of transient pool boiling heat transfer under exponential power excursion on plate-type heater |
| title_fullStr | Experimental study of transient pool boiling heat transfer under exponential power excursion on plate-type heater |
| title_full_unstemmed | Experimental study of transient pool boiling heat transfer under exponential power excursion on plate-type heater |
| title_short | Experimental study of transient pool boiling heat transfer under exponential power excursion on plate-type heater |
| title_sort | experimental study of transient pool boiling heat transfer under exponential power excursion on plate type heater |
| topic | Nuclear Science and Engineering. |
| url | http://hdl.handle.net/1721.1/97863 |
| work_keys_str_mv | AT suguanyuphdmassachusettsinstituteoftechnology experimentalstudyoftransientpoolboilingheattransferunderexponentialpowerexcursiononplatetypeheater |