EXPERIMENTAL STUDIES OF DROPLET HEAT TRANSFER FROM HOT METAL SURFACES

Persistent Link:
http://hdl.handle.net/10150/281960
Title:
EXPERIMENTAL STUDIES OF DROPLET HEAT TRANSFER FROM HOT METAL SURFACES
Author:
Plein, Howard George
Issue Date:
1980
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The boiling of water droplets on hot metal surfaces is studied experimentally and mathematically in order to establish the conditions necessary for droplets to enter a film boiling mode. The subsurface temperature history within a plate undergoing droplet boiling on the surface is measured. A numerical model of the heat transfer in the plate is then used to deduce from these data the following characteristics of droplet boiling: (1) the effective heat transfer coefficient between water droplet and plate during the initial transient forming the spherical droplet, (2) the apparent time period needed to establish the droplet in the film boiling mode, and (3) the minimum plate surface temperature reached during the initial formation of the boiling droplet. The effective heat transfer coefficient, formation time, and minimum surface temperature are sufficient to develop a calculation method which predicts the minimum initial plate temperature necessary for a water droplet to enter film boiling. This numerical conduction model accounts for the influence of plate material, plate thickness, oxidation of the plate surface, the boundary condition on the plate lower surface, and the size of the droplet. The prediction method is successfully used to estimate the minimum film boiling temperature for brass, graphite, Pyrex, copper, aluminum, stainless steel, and Zircalloy II. The findings of the experiments and numerical studies are applied to the rewetting phase of a loss-of-coolant-accident in a light water reactor. This application, in turn, provides explanations for some of the phenomena observed in studies of the prequench heat transfer within rod bundles including the effect of multiple droplet impacts, and suggests possible reasons for some of the difficulties experienced in attempts to establish the effective rewetting temperature on reactor fuel rod surfaces.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Film boiling.; Nucleate boiling.; Nuclear liquid drop model.; Heat -- Transmission.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Nuclear Engineering
Degree Grantor:
University of Arizona
Advisor:
Brehm, Richard L.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleEXPERIMENTAL STUDIES OF DROPLET HEAT TRANSFER FROM HOT METAL SURFACESen_US
dc.creatorPlein, Howard Georgeen_US
dc.contributor.authorPlein, Howard Georgeen_US
dc.date.issued1980en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe boiling of water droplets on hot metal surfaces is studied experimentally and mathematically in order to establish the conditions necessary for droplets to enter a film boiling mode. The subsurface temperature history within a plate undergoing droplet boiling on the surface is measured. A numerical model of the heat transfer in the plate is then used to deduce from these data the following characteristics of droplet boiling: (1) the effective heat transfer coefficient between water droplet and plate during the initial transient forming the spherical droplet, (2) the apparent time period needed to establish the droplet in the film boiling mode, and (3) the minimum plate surface temperature reached during the initial formation of the boiling droplet. The effective heat transfer coefficient, formation time, and minimum surface temperature are sufficient to develop a calculation method which predicts the minimum initial plate temperature necessary for a water droplet to enter film boiling. This numerical conduction model accounts for the influence of plate material, plate thickness, oxidation of the plate surface, the boundary condition on the plate lower surface, and the size of the droplet. The prediction method is successfully used to estimate the minimum film boiling temperature for brass, graphite, Pyrex, copper, aluminum, stainless steel, and Zircalloy II. The findings of the experiments and numerical studies are applied to the rewetting phase of a loss-of-coolant-accident in a light water reactor. This application, in turn, provides explanations for some of the phenomena observed in studies of the prequench heat transfer within rod bundles including the effect of multiple droplet impacts, and suggests possible reasons for some of the difficulties experienced in attempts to establish the effective rewetting temperature on reactor fuel rod surfaces.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectFilm boiling.en_US
dc.subjectNucleate boiling.en_US
dc.subjectNuclear liquid drop model.en_US
dc.subjectHeat -- Transmission.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineNuclear Engineeringen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorBrehm, Richard L.en_US
dc.identifier.proquest8017767en_US
dc.identifier.oclc7641596en_US
dc.identifier.bibrecord.b13474893en_US
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