Study of countercurrent flow limitation in a horizontal pipe connected to an inclined one

Navarro, Moysés A.

doi:10.1016/j.nucengdes.2005.02.010

Cited by 62 publications

(43 citation statements)

References 5 publications

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“…This kind of hysteresis in CCFL characteristics has also been observed in countercurrent flows in a vertical pipe 14) of D ¼ 0:032 m and a simulated hot leg 8) of D ¼ 0:054 m. However, flow patterns and the mechanism of the hysteresis have not been well understood yet.…”

Section: Outline Of Air-water Testsmentioning

confidence: 56%

“…It is, therefore, necessary to understand the detailed characteristics of a countercurrent flow in the hot leg for developing a reliable model for predicting the flow. Although a number of experiments have been carried out on the countercurrent flow limitation, CCFL, in the hot leg, [3][4][5][6][7][8][9][10] two-phase flow patterns in the hot leg geometry have not been observed. Detailed knowledge on flow patterns in the inclined pipe and elbow in the hot leg under countercurrent flow conditions, therefore, has not been reported.…”

Section: Introductionmentioning

confidence: 99%

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Countercurrent Gas-Liquid Flow in a PWR Hot Leg under Reflux Cooling (II) Numerical Simulation of 1/15-Scale Air-Water Tests

Minami

Murase²,

Tomiyama

2010

Journal of Nuclear Science and Technology

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When reflux cooling is executed in the case of loss of residual heat removal systems under mid-loop operation of PWR, steam generated in the reactor core and water condensed in the steam generator may form a complicated countercurrent flow in the hot leg. Numerical simulations of air-water countercurrent flows in a 1/15-scale model of the hot leg are carried out in this study to examine the capability of predicting two-phase flow patterns and CCFL characteristics in the hot leg. A three-dimensional two-fluid model implemented in FLUENT6.3.26 is used in the simulations. Good agreements between measured and predicted flow patterns and CCFL characteristics are obtained by using an appropriate set of correlations for the interfacial friction coefficient in the momentum equation of the two-fluid model.

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Section: Outline Of Air-water Testsmentioning

confidence: 56%

Section: Introductionmentioning

confidence: 99%

Countercurrent Gas-Liquid Flow in a PWR Hot Leg under Reflux Cooling (II) Numerical Simulation of 1/15-Scale Air-Water Tests

Minami

Murase²,

Tomiyama

2010

Journal of Nuclear Science and Technology

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“…A number of experiments have been carried out on the countercurrent flow limitation (CCFL) in the hot leg. [3][4][5][6][7][8] On the other hand, reported observations of flow patterns are limited and have been made only for horizontal pipes 9) or under cocurrent flow conditions. 10) Detailed knowledge on flow patterns in the inclined pipe and the elbow in the hot leg under countercurrent flow conditions has not been reported.…”

Section: Introductionmentioning

confidence: 99%

Countercurrent Gas-Liquid Flow in a PWR Hot Leg under Reflux Cooling (I) Air-Water Tests for 1/15-Scale Model of a PWR Hot Leg

Minami¹,

Nishiwaki²,

Nariai³

et al. 2010

Journal of Nuclear Science and Technology

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In the case of loss of residual heat removal systems under mid-loop operation during shutdown of a PWR plant, reflux cooling by a steam generator (SG) is expected, and steam generated in the reactor core and water condensed in the SG form a countercurrent flow in a hot leg. The flow is highly complicated because the hot leg consists of a horizontal pipe, an elbow, and an inclined pipe. In this study, a scale model of the PWR hot leg (1/15th of the actual plant size) is used to investigate flow patterns and characteristics of countercurrent flow limitation (CCFL). The following conclusions are obtained.

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“…Navaro [16] studied countercurrent flow limitation in a horizontal pipe connected to an inclined one. He investigated the effect of various geometrical parameters of the test section on the onset of flooding, on the partial delivery of water and on the zero liquid penetration.…”

Section: Introductionmentioning

confidence: 99%

An experimental investigation on the effect of middle length and inclination angle of S-shaped channel on two-phase flow patterns

Azadi

Gheisari

Ansari

2014

Experimental Thermal and Fluid Science

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An experimental investigation is conducted to study the effect of middle length and inclination angle of an S-shaped channel on adiabatic two-phase flow patterns. To study this effect, three channel lengths of 0.25, 0.50, and 1.00 m, and four bends at the angles of 22.5˚, 45˚, A dimensionless analysis of obtained flow pattern maps is also carried out. It is shown that effect of geometry changes along S-shaped pipeline on two-phase flow pattern transitions is determined by either inclination angle or elevation difference between two horizontal lines. The explained flow mechanisms, obtained flow pattern maps and the transition lines can be used to predict the particular flow pattern that will be established for a given mass flux, inclined length and angle along pipelines.

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Study of countercurrent flow limitation in a horizontal pipe connected to an inclined one

Cited by 62 publications

References 5 publications

Countercurrent Gas-Liquid Flow in a PWR Hot Leg under Reflux Cooling (II) Numerical Simulation of 1/15-Scale Air-Water Tests

Countercurrent Gas-Liquid Flow in a PWR Hot Leg under Reflux Cooling (II) Numerical Simulation of 1/15-Scale Air-Water Tests

Countercurrent Gas-Liquid Flow in a PWR Hot Leg under Reflux Cooling (I) Air-Water Tests for 1/15-Scale Model of a PWR Hot Leg

An experimental investigation on the effect of middle length and inclination angle of S-shaped channel on two-phase flow patterns

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