A1 Journal article (refereed), original research

Effective momentum induced by steam condensation in the oscillatory bubble regime


Publication Details
Authors: Gallego-Marcos Ignacio, Kudinov Pavel, Villanueva Walter, Puustinen Markku, Räsänen Antti, Tielinen Kimmo, Kotro Eetu
Publisher: Elsevier
Publication year: 2019
Language: English
Related Journal or Series Information: Nuclear Engineering and Design
Volume number: 2019
Issue number: 350
Start page: 259
End page: 274
Number of pages: 16
ISSN: 0029-5493
eISSN: 1872-759X
JUFO-Level of this publication: 3
Open Access: Not an Open Access publication

Abstract

The spargers used in Boiling Water Reactors (BWR) discharge steam from the primary coolant system into a pool of water. Direct steam condensation in subcooled water creates sources of heat and momentum determined by the condensation regimes, called “effective sources” in this work. Competition between the effective sources can result in thermally stratification or mixing of the pool. Thermal stratification is a safety concern in BWRs since it reduces the steam condensation and pressure suppression capacity of the pool. In this work, we present semiempirical correlations to predict the effective momentum induced by steam condensation in the oscillatory bubble regime, relevant for the operation of spargers in BWRs. A Separate Effect Facility (SEF) was designed and built at LUT, Finland, in order to provide the necessary data. An empirical correlation for the effective momentum as a function of the Jakob number is proposed. The Kelvin Impulse theory was also applied to estimate the effective momentum based on information about the bubble dynamics. To do this, new correlations for the bubble collapse frequencies, maximum bubble radius, velocities, pressure gradient and heat transfer coefficient are proposed and compared to available data from the literature. The effective momentum induced by sonic steam jets appears to be constant in a wide range of studied Jakob number. However, further experimental data is necessary at larger Jakob numbers and steam mass fluxes.


Last updated on 2020-20-03 at 10:03

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