Přístupnostní navigace
E-application
Search Search Close
Master's Thesis
Author of thesis: Ing. Kateřina Koudelková
Acad. year: 2025/2026
Supervisor: Ing. Jakub Elcner, Ph.D.
Reviewer: Mgr. Jan Frélich
This thesis is focused on a CFD analysis of thermohydraulic processes in a horizontal steam generator of a nuclear power plant equipped with a VVER-440/213 reactor, with a specific focus on the phenomenon of temperature stratification during an SGTR (steam generator tube rupture) accident. The objective of this thesis is to simulate the behavior of the secondary coolant in the affected steam generator during the application of emergency procedure E-3, when heat flux reversal occurs and subsequent temperature stratification forms, which plays an important role in maintaining the pressure difference between the affected and unaffected steam generators. ANSYS Fluent software was used for the simulation, with boundary conditions derived from the RELAP5 system code (RELEDU-4.3 model). The work includes a parametric study of the effect of water level height on the intensity of stratification and the efficiency of steam condensation at the water surface. The simulation results confirm the formation of a stable stratified water layer above the tube bundle, which effectively isolates the heat exchange bundle from the steam space. The analysis revealed the nonlinear nature of steam condensation, and it was found that raising the water level above 600 mm yields only minimal benefits in terms of heat removal and condensation.
VVER-440, steam generator, CFD, ANSYS Fluent, SGTR, temperature stratification, porous medium, Dual Cell Heat Exchanger
Date of defence
11.06.2026
Result of the defence
Defended (thesis was successfully defended)
Grading
A
Process of defence
Studentka seznámila zkušební komisi s výsledky své diplomové práce. Oponent práce doktor Elcner přečetl posudek vedoucího práce. Posudek oponenta přečetl předseda komise prof. Katovský. Následovaly odpovědi na dotazy oponenta, tyto byly správně vypořádány. Doplňující otázky položili doc. Baláš, doktor Kracík, doc. Zácha a doktor Radil. Studentka odpověděla na všechny předložené dotazy s občasnou mírnou pomocí tazatelů.
Language of thesis
Czech
Faculty
Fakulta elektrotechniky a komunikačních technologií
Department
Department of Electrical Power Engineering
Study programme
Nuclear Power Engineering (MPC-JAE)
Composition of Committee
prof. Ing. Karel Katovský, Ph.D. (předseda) Ing. Štěpán Foral, Ph.D. (místopředseda) Ing. Lukáš Radil, Ph.D. (člen) Ing. Petr Kracík, Ph.D. (člen) doc. Ing. Marek Baláš, Ph.D. (člen) doc. Ing. Pavel Zácha, Ph.D. (člen) Ing. Ota Fišera, Ph.D. (člen)
Supervisor’s reportIng. Jakub Elcner, Ph.D.
Grade proposed by supervisor: A
Reviewer’s reportMgr. Jan Frélich
Grade proposed by reviewer: A
Responsibility: Mgr. et Mgr. Hana Odstrčilová