A4 Conference proceedings

Numerical study of direct contact condensation of steam on stable interface in a BWR suppression pool test facility


Publication Details
Authors: Patel Giteshkumar, Tanskanen Vesa, Rintala Ville, Hyvärinen Juhani
Publication year: 2015
Language: English
Related Journal or Series Information: International Topical Meeting On Nuclear Reactor Thermal Hydraulics
Title of parent publication: 16th International Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-16) Chicago, IL, August 30 - September 4 2015
Start page: 3176
End page: 3189
ISBN: 978-0-89448-722-4
JUFO-Level of this publication: 1
Open Access: Not an Open Access publication

Abstract
The analysis of direct contact condensation (DCC) phenomena occurring in a suppression pool of BWRduring steam discharge into sub-cooled water is interesting both from the numerical phase change modellingand the nuclear reactor safety points of view. This paper presents the computational fluid dynamics (CFD) simulations of a special case of low-Reynolds number DCC mode possible in suppression pools, in whichthe low-Reynolds number DCC corresponds to the steam. The presented CFD calculations were conductedby employing the Eulerian two-fluid approach of the OpenFOAM CFD solver. The interfacial heat transferin these simulations was modelled by using the DCC model based on the surface divergence theory. Thetest STB-31 of the POOLEX facility of Lappeenranta University of Technology was used as a reference. Inthis test, the condensation was limited to only occur on a stable steam-water interface by applying very lowsteam mass flux and thermal insulation of the blowdown pipe. The results of OpenFOAM CFD solver werecompared with the previously simulated results of the NEPTUNE_CFD code and with some preliminaryresults of the TransAT code. The influence of grid refinement on the DCC phenomena was assessed basedon a grid convergence index. Moreover, the significance of reference bubble diameter in large interfacedrag modelling was studied considering various diameters. The sensitivity of sub-cooling rate on the DCC phenomenon was studied with different pool temperatures as well. The simulation results indicate that theimplemented surface divergence model predicts the condensation rate quite accurately in this special case.

Last updated on 2017-22-03 at 14:02