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Study of countercurrent flow limitation in a horizontal pipe connected to an inclined one
TLDR
In this article, the effects of various geometrical parameters of the test section and of the inlet water flow rate on the onset of flooding, on the partial delivery of water and on the zero liquid penetration were investigated.Abstract:
Experiments with air and water in small hot leg reproductions were carried out aiming to acquire a better understanding of the countercurrent flow limitation (CCFL) in this geometry. The effects of various geometrical parameters of the test section and of the inlet water flow rate on the onset of flooding, on the partial delivery of water and on the zero liquid penetration were investigated. It was observed that while the onset of flooding is affected by the inlet water flow rate, the zero liquid penetration is independent of this flow rate. The results with partial delivery showed that, for a fixed air velocity, an increase in the horizontal length, or in the inclined length, of the flow channel leads to an increase of the water carried over by the air. On the other hand, in pipes with larger diameters the drag of the water is smaller. The experimental results showed small differences in the results for tests with inclination of the riser lower than 90 ◦ . For an inclination equal to 90 ◦ , the water carried by the air tends to be lower than in the others angles for a fixed air velocity. The study led also to a new correlation for the flooding.read more
Citations
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Journal ArticleDOI
Image-Processing-Based Study of the Interfacial Behavior of the Countercurrent Gas-Liquid Two-Phase Flow in a Hot Leg of a PWR
TL;DR: In this article, the interfacial behavior during countercurrent two-phase flow of air-water and steam-water in a model of a PWR hot leg was studied quantitatively using digital image processing of a subsequent recorded video images of the experimental series obtained from the TOPFLOW facility, Helmholtz-Zentrum Dresden Rossendorf e.V. (HZDR), Dresden, Germany.
Journal ArticleDOI
Numerical Simulation of Size Effects on Countercurrent Flow Limitation in PWR Hot Leg Models
TL;DR: In this article, the authors used the two-fluid model implemented in the CFD software FLUENT6.3.26 to investigate effects of shape of a flow channel and its size on CCFL (countercurrent flow limitation) characteristics in PWR hot leg models.
Journal ArticleDOI
Effects of Liquid Properties on CCFL in a Scaled-Down Model of a PWR Hot Leg
TL;DR: In this article, the effects of liquid properties on countercurrent flow limitation (CCFL) in a PWR hot leg were investigated in a 1/15 scaled-down model of the hot leg using air/water and air/glycerol-water solutions as working fluids.
DissertationDOI
Experimentelle Untersuchung der Tropfenabscheidung einer horizontalen, entgegengerichteten Wasser/Luft-Schichtenströmung
TL;DR: In this article, a detailliertere Beschreibung der auftretenden Stromungsphanomene bei gleichzeitig verbesserter Skalierbarkeit.
TRACE Analysis of LOCA Transients Performed on FIX-II Facility
TL;DR: In this paper, the simulation results show that TRACE model can well reproduce the transient thermal-hydraulic behaviors under different LOCA situations, and sensitivity analysis are also performed to investigate the influence of particular models and parameters, including counter current flow limitation (CCFL) model, choked flow model, insulator in the steam dome, K-factor in the test section, and pump trip, on the results.
References
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Journal ArticleDOI
Experimental Study of Counter-Current Two-Phase Flow in Horizontal Tube Connected to Inclined Riser
TL;DR: In this article, the authors used the Wallis-type correlation (J g * 1/2+mJ i *1/2=C) to determine the CCFL characteristics of air-water and saturated steam-water flow in hot legs of PWRS.
Journal ArticleDOI
Scale effects on countercurrent gas-liquid flow in a horizontal tube connected to an inclined riser
TL;DR: The scale effects of a flow path under countercurrent flow limitation (CCFL) in a horizontal tube connected to an inclined riser have been studied in this article, where an analytical model with a two-fluid model was developed based on flow observation results in small scale experiments and then assessed with various scale experiments under various pressures.
Journal ArticleDOI
Flooding in an elbow between a vertical and a horizontal or near-horizontal pipe
TL;DR: In this article, the authors measured the flooding limits in countercurrent air-water flow through pipe elbows consisting of an upper vertical leg and a lower leg which is horizontal or slightly inclined, and found that flooding is caused by unstable wave formation (slugging) at the hydraulic jump which forms in the lower pipe limb close to the bend.
Journal ArticleDOI
Two-phase countercurrent flow in a model of a pressurized water reactor hot leg
TL;DR: In this article, the experimental data of the countercurrent flow limitation (CCFL) for gas and liquid in a horizontal pipe with a bend are investigated. And the authors show that the onset of flooding appears simultaneously with the slugging of unstable waves that are formed at the crest of hydraulic jump.
Journal ArticleDOI
Assessment of RELAP5/MOD3.2.2γ Against Flooding Database in Horizontal-to-Inclined Pipes
Hyoung Tae Kim,Hee Cheon No +1 more
TL;DR: In this article, the authors used the RELAP5/MOD3.2 data bank for the assessment of counter-current flow limitation (CCFL) in horizontal-to-inclined pipes simulating a PWR hot leg.