Study on the thermal-hydraulics characteristics of a boiling two-phase natural circulation loop with nanofluids
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A. K. Nayak
and M. R. Gartia
Abstract
In this paper, we present the steady state and stability behaviour of a boiling two-phase natural circulation loop with a small concentration of Al2O3 nanofluids. For this, experiments were conducted in a natural circulation loop at different operating powers, pressures, and water levels in the steam drum. The test results revealed that while the steady state natural circulation behaviour is similar, however, the buoyancy induced flow rates are found to be relatively higher with nanofluids than with water alone. In addition, with nanofluids, the amplitudes of the boiling induced Type I instabilities are found to be significantly reduced, However, the Type II instabilities are found to appear at relatively lower power with addition of nanofluids as compared to that with water alone. The most interesting result is that with addition of nanofluids, the amplitudes of Type II instabilities are found to get suppressed with increase in power similar to that of low quality Type I instability.
Kurzfassung
In der vorliegenden Arbeit wird das Stabilitätsverhalten im stationärer Zustand beim Naturumlauf für Zweiphasenströmung mit einer geringen Konzentration von Al2O3 Nanoflüssigkeiten untersucht. Dazu wurden Experimente durchgeführt in einem Naturumlaufkreislauf bei verschiedenen Betriebsleistungen, Druckverhältnissen und Wasserfüllständen im Dampfsammler. Die Ergebnisse zeigen, dass, während das Verhalten des Naturumlaufs im stationären Zustand unverändert bleibt, die durch Auftrieb induzierten Strömungsgeschwindigkeiten mit Beimischung von Nanoflüssigkeiten etwas höher sind als mit Wasser allein. Des Weiteren sind bei Nanoflüssigkeiten die Amplituden der durch das Sieden induzierten Typ I Instabilitäten signifikant reduziert. Im Vergleich zum reinen Wassermedium treten die Typ II Instabilitäten jedoch beim Zusatz von Nanoflüssigkeiten bereits bei relativ niedrigen Leistungen auf. Das interessanteste Ergebnis ist, dass mit dem Zusatz von Nanoflüssigkeiten die Amplituden der Typ II Instabilitäten unterdrückt werden mit steigender Leistung, ähnlich wie die von Typ I Instabilitäten niedriger Qualität.
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© 2008, Carl Hanser Verlag, München
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Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Development and validation of the pressure surge computer code DYVRO mod. 3
- Simulation model of a nuclear power plant turbine
- Study on the thermal-hydraulics characteristics of a boiling two-phase natural circulation loop with nanofluids
- The effect of combination of different materials on neutron absorption in a nuclear research reactor spent fuel pool
- Re-evaluation of the criticality experiments of the “Otto Hahn Nuclear Ship” reactor
- Potential advantages and disadvantages of sequentially building small nuclear units instead of a large nuclear plant
- Radiological consequences of potential sabotage attack to storage casks on the ISFSI site
- Unified treatment of the P(λ)n approximation to solve the reflected slab criticality problem with strong anisotropy
- A comparative study on classical polynomial approximations to the transport equation in spherical media albedo problems
- Solution of half space and slab albedo problems for linearly anisotropic scattering with the modified FN method
- Study of the effect of anisotropic scattering on the critical slab problem in neutron transport theory using Chebyshev polynomials