A study on thermo-hydraulic instability of boiling natural circulation loop with a chimney (4th report, an analytical consideration of the stability and thermo-hydraulic characteristics in the chimney in high pressure)

Fumio Inada, Masahiro Furuya, Akira Yasuo

Research output: Contribution to journalArticle

Abstract

Thermo-hydraulic instabilities of a boiling natural circulation loop with a chimney under high pressure were investigated using linear stability analysis. Drift-flux model was used for two-phase flow model. The instability regions as well as the thermo-hydraulic characteristics in the chimney such as wavy feature were examined, which were compared with the characteristics in low pressure. Instability could occur when exit quality was relatively low, which was the same manner as the characteristics in low pressure. In high-pressure, void was generated near channel exit, and void wave propagated in the chimney. In low pressure, steam was generated only near the chimney exit due to gravity induced flashing, and single-phase enthalpy wave, that is, temperature wave propagated in single-phase flow region. Though flow could be very stable in the high pressure and high power condition, the decay ratio of higher mode could be larger than that of lower mode.

Original languageEnglish
Pages (from-to)511-518
Number of pages8
JournalNippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Volume68
Issue number666
DOIs
Publication statusPublished - 2002 Jan 1
Externally publishedYes

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Keywords

  • Boiler
  • Boiling
  • Chimney
  • Flashing
  • Multi-phase flow
  • Natural circulation
  • Stability
  • Thermal-hydraulic instability
  • Wave

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering

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