Experimental studies in a single-phase parallel channel natural circulation system: preliminary results
-
K. Bodkha
Abstract
Natural circulation systems find extensive applications in industrial engineering systems. One of the applications is in nuclear reactor where the decay heat is removed by natural circulation of the fluid under off-normal conditions. The upcoming reactor designs make use of natural circulation in order to remove the heat from core under normal operating conditions also. These reactors employ multiple vertical fuel channels with provision of on-power refueling/defueling. Natural circulation systems are relatively simple, safe and reliable when compared to forced circulation systems. However, natural circulation systems are prone to encounter flow instabilities which are highly undesirable for various reasons. Presence of parallel channels under natural circulation makes the system more complicated. To examine the behavior of parallel channel system, studies were carried out for single-phase natural circulation flow in a multiple vertical channel system. The objective of the present work is to study the flow behavior of the parallel heated channel system under natural circulation for different operating conditions. Steady state and transient studies have been carried out in a parallel channel natural circulation system with three heated channels. The paper brings out the details of the system considered, different cases analyzed and preliminary results of studies carried out on a single-phase parallel channel system.
Kurzfassung
Naturumlaufsysteme finden vielseitige Anwendungen in der industriellen Sytemtechnik. Eine der Anwendungen betrifft Kernreaktoren, wo die Zerfallswärme unter abnormalen Betriebsbedingungen durch Naturumlauf beseitigt wird. Neue Reaktorauslegungen nutzen den Naturumlauf um auch die im Reaktorkern während normaler Betriebsbedingungen entstehende Wärme abzuleiten. Diese Reaktoren nutzen vertikale Brennstoffkanäle beim Brennelementwechsel bzw. der Entladung von Brennelementen aus dem Reaktor. Naturumlaufsysteme sind relativ einfach, sicher und zuverlässig im Vergleich zu Systemen mit Zwangsumlauf. Naturumlaufsysteme sind jedoch anfällig gegenüber unerwünschten Strömungsinstabilitäten. Das Vorhandensein paralleler Kanäle unter Naturumlauf macht das System komplizierter. Um das Verhalten eines Parallelkanalsystems zu bestimmen wurden Untersuchungen für einphasige Naturumlaufströmungen in einem multiplen vertikalen Kanalsystem durchgeführt. Ziel dieses Betrags ist es, das Strömungsverhalten von parallel erwärmten Kanälen bei Naturumlauf unter verschiedenen Bedingungen zu untersuchen. Untersuchungen zum stationären und transienten Zustand wurden mit drei erwärmten Kanälen durchgeführt in einem Parallelkanalsystem mit Naturumlauf. Der Beitrag beschreibt die Einzelheiten des betrachteten Systems, die verschiedenen analysierten Fälle sowie die Ergebnisse der durchgeführten Untersuchungen.
References
1 Chato, J. C.: Natural convection flows in parallel-channel systems. Journal of Heat Transfer85 (1963) 339–34510.1115/1.3686122Search in Google Scholar
2 Zvirin, Y.: The onset of flows and instabilities in a thermosyphon with parallel loops. Nuclear Engineering and Design92 (1986) 217–22610.1016/0029-5493(86)90248-7Search in Google Scholar
3 Takeda, T.; Kawamura, H.; Seki, M.: Natural circulation in parallel vertical channels with different heat inputs. Nuclear Engineering and Design104 (1987) 133–14310.1016/0029-5493(87)90294-9Search in Google Scholar
4 Yahalom, R.; Bein, M.: Boiling thermal hydraulic analysis of multichannel low flow. Nuclear Engineering and Design53 (1979) 29–3810.1016/0029-5493(79)90037-2Search in Google Scholar
5 Todreas, N. E.; Kazimi, M. S.: Nuclear systems II, Elements of Thermal Hydraulic Design, Hemisphere, New York (1990)Search in Google Scholar
6 Linzer, W.; Walter, H.: Flow reversal in natural circulation systems. Applied Thermal Engineering23 (2003) 2363–237210.1016/S1359-4311(03)00214-XSearch in Google Scholar
7 Gartia, M. R.; Pilkhwal, D. S.; Vijayan, P. K.; Saha, D.: Analysis of metastable regimes in a parallel channel single phase natural circulation system using RELAP5/MOD3.2. International Journal of Thermal Sciences 46 (2006) 1064–107410.1016/j.ijthermalsci.2006.11.016Search in Google Scholar
8 Chen, W. L.; Wang, S. B.; Twu, S. S.; Chung, C. R.; Pan, Chin: Hysteresis effect in a double channel natural circulation loop. International Journal of Multiphase Flow27 (2001) 171–18710.1016/S0301-9322(00)00018-5Search in Google Scholar
© 2016, Carl Hanser Verlag, München
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Stability analysis of the Korean prototype Generation-IV sodium-cooled fast reactor using linear frequency domain approach
- Validation of RELAP5 model of experimental test rig simulating the natural convection in MTR research reactors
- Steady state and transient analyses of MNSR reactor using RELAP5 code
- Protactinium-231 as a new fissionable material for nuclear reactors that can produce nuclear fuel with stable neutron-multiplying properties
- Assessment of pin-by-pin fission rate distribution within MOX/UO2 fuel assembly using MCNPX code
- Influence on rewetting temperature and wetting delay during rewetting rod bundle by various radial jet models
- Experimental and numerical investigation on natural convection heat transfer in nanofluids
- Experimental studies in a single-phase parallel channel natural circulation system: preliminary results
- Calculation of PDS-XADS core closed-loop transfer function by using feedback with the lumped-model
- Calculation of nuclear reactivity using the generalised Adams-Bashforth-Moulton predictor corrector method
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Stability analysis of the Korean prototype Generation-IV sodium-cooled fast reactor using linear frequency domain approach
- Validation of RELAP5 model of experimental test rig simulating the natural convection in MTR research reactors
- Steady state and transient analyses of MNSR reactor using RELAP5 code
- Protactinium-231 as a new fissionable material for nuclear reactors that can produce nuclear fuel with stable neutron-multiplying properties
- Assessment of pin-by-pin fission rate distribution within MOX/UO2 fuel assembly using MCNPX code
- Influence on rewetting temperature and wetting delay during rewetting rod bundle by various radial jet models
- Experimental and numerical investigation on natural convection heat transfer in nanofluids
- Experimental studies in a single-phase parallel channel natural circulation system: preliminary results
- Calculation of PDS-XADS core closed-loop transfer function by using feedback with the lumped-model
- Calculation of nuclear reactivity using the generalised Adams-Bashforth-Moulton predictor corrector method
