Stability structure of low-quality density-wave oscillations in a natural circulation system at heating reactor conditions
Creators
- 1. Nuclear Engineering Lab., Swiss Federal Inst. of Technology, ETH Zentrum, Zurich (Switzerland)
Description
Non-linear behavior of two-phase flow instabilities in a natural circulation system with two parallel heated channels is investigated numerically. The present study draws emphasis on stability structure of density-wave oscillations (DWO) at low pressure and low quality conditions under which a typical integral heating reactor operates. Two transient modes, i.e., flow perturbation and exponential power change are employed to trigger unstable flow. The results indicate that exponential power reduction may lead two-phase flow from a stable to a conditionally stable operation region. The complicated stability structure has been found. The comparison of the nuemrical results with the available experimental data shows qualitatively quite good agreement. (orig.)
Abstract (German)
Das nicht-lineare Verhalten von Zweiphaseninstabilitaeten in einem Naturkreislauf mit zwei parallelen, geheizten Kanaelen wird numerisch untersucht. Insbesondere wird die Stabilitaetsstruktur von Dichtewellen-Oszillationen bei niedrigem Druck und niedrigem Dampfanteil analysiert, welches typische Betriebsbedingungen eines integrierten Heizreaktors sind. Zwei Transienten werden benutzt, um Stroemungsinstabilitaet auszuloesen, eine Durchsatzstoerung sowie eine exponentielle Leistungsaenderung. Die Ergebnisse zeigen, dass durch eine langsame exponentiale Leistungsreduktion der Stroemungszustand von einem absolut stabilen in einen bedingt stabilen Betriebsbereich zu ueberfuehren ist. Die komplizierte Stabilitaetsstruktur ist gefunden worden. Die numerischen Resultate stimmen mit den experimentellen Daten qualitativ recht gut ueberein. (orig.)Additional details
Publishing Information
- Journal Title
- Kerntechnik (1987)
- Journal Volume
- 62
- Journal Issue
- 4
- Journal Page Range
- p. 154-159.
- ISSN
- 0932-3902
- CODEN
- KERNEU
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- Germany
- INIS RN
- 28075947
- Subject category
- S21: SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; S21: SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS;
- Descriptors DEI
- BWR TYPE REACTORS; DISTRICT HEATING; HYDRAULICS; MECHANICAL VIBRATIONS; NATURAL CONVECTION; POOL TYPE REACTORS; PRIMARY COOLANT CIRCUITS; PROCESS HEAT REACTORS; REACTOR SAFETY; STEAM; TWO-PHASE FLOW
- Descriptors DEC
- CONVECTION; COOLING SYSTEMS; ENERGY TRANSFER; ENRICHED URANIUM REACTORS; FLUID FLOW; HEAT TRANSFER; HEATING; POWER REACTORS; REACTOR COMPONENTS; REACTOR COOLING SYSTEMS; REACTORS; SAFETY; THERMAL REACTORS; WATER COOLED REACTORS; WATER MODERATED REACTORS