Review, implementation and validation of physical models in the FLICA code for application to LWR and SFR
Dipartimento
INGEGNERIA
Corso di studi
INGEGNERIA NUCLEARE
Relatori
relatore Prof. Ambrosini, Walter correlatore Ing. Forgione, Nicola relatore Dott. Bucci, Matteo correlatore Prof. Oriolo, Francesco
Parole chiave
boiling heat transfer
CHF
correlation
critical heat flux
DFFB
DNB
dryout
friction multiplier
IAFB
post critical heat flux
sodium pressure drop
TB
Data inizio appello
28/11/2011
Consultabilità
Non consultabile
Data di rilascio
28/11/2051
Riassunto
This work has been performed during a stage of nine months, carried out at the Commissariat à l’ ́énergie atomique et aux énergies alternatives (CEA), in Saclay, France. The work aims at improving the capabilities of the FLICA-OVAP code. FLICA-OVAP is a three-dimensional code for two-phase thermal-hydraulic analysis. It is oriented to several reactor types; it can be employed for safety analysis and design of light water reactors, liquid metal reactors and gas cooled reactors. The work consists in improving the FLICA code correlation database, by the review, the implementation and the validation of physical models to enable the FLICA-OVAP code to analyses properly heat transfer phenomena in the post critical heat flux region for light water reactors and the two-phase pressure drops in sodium fast reactors. These two subjects are treated separately in Part I and Part II of this work, respectively. In the first part, an extensive literature review has been performed, in order to understand the physics of the phenomenon and to identify the more appropriate correlations. Then, selected correlations have been implemented and validated against an extensive experimental database consisting of 219 tests, performed with boiling water flowing upward in a vertical tube heated by an uniform and constant heat flux. In the second part, correlations to estimate the two-phase flow multipliers and the slip ratio in sodium boiling channels have been reviewed, implemented and validated against experimental and analytical data, provided respectively by the Kottowski and Savatteri database, and an analytical model developed on the CAST3M platform. The analysis is performed for two-phase sodium up-flow in a vertical tube heated by a uniform and constant heat flux. The results obtained in both first and second part of this thesis are in good agreement with reference data. It confirms the suitability of the correlations implemented.
