Numerical investigation of supercritical water flow in a 2x2 rod bundle under non-uniform heat flux

Research output: Chapters, Conference Papers, Creative and Literary WorksRGC 32 - Refereed conference paper (with host publication)peer-review

1 Scopus Citations
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Author(s)

  • Marcin Rowinski
  • Yeng Ch. Soh
  • Timothy J. White
  • Ching Ch. Chieng
  • Jiyun Zhao

Related Research Unit(s)

Detail(s)

Original languageEnglish
Title of host publication2016 24th International Conference on Nuclear Engineering
PublisherAmerican Society of Mechanical Engineers (ASME)
PagesV005T15A012
Volume5
ISBN (print)9780791850053
Publication statusPublished - Jul 2016

Conference

Title2016 24th International Conference on Nuclear Engineering, ICONE 2016
PlaceUnited States
CityCharlotte
Period26 - 30 June 2016

Abstract

Generation III/III+ nuclear reactors operate with working fluid under subcritical conditions (Tc = 647K, pc = 22.115MPa). The efficiency, limited by the ratio of source and sink temperatures, is restricted by operating below the critical temperature. The supercritical water reactors (SCWRs) are able to rise efficiency limit while operating at the supercritical conditions. The amount of energy carried by working fluid is higher leading to potential efficiency improvement of nearly 30% above current nuclear stations. Therefore, rendering nuclear energy as one of the most efficient decarbonized electrical energy sources with efficiency of 45% and capacity factor of ca. 90%. Typical capacity factors of competing wind turbines and solar PV cells reaches 45% and 15% while the efficiencies 50% and 45%, respectively.

In a subcritical reactor a uniform heat flux is generated due to relatively constant fuel moderation. However, due to a change of density during transition from sub- to supercritical conditions, the fuel moderation is uneven along the fuel rod and results in a non-uniform heat generation. The literature on SCWR neutronics suggests higher heat generation at the fuel channel entrance. In this paper we simulated for the first time such non-uniform heat flux generated in a SCWR, we analyze the impacts of such flux on the working medium flow and suggest ways to mitigate negative impacts of non-uniform heat flux.

The study was conducted with use of Computational Fluid Dynamics (CFD) software. Obtained results show that the shape of heat flux curve along the channel highly influences the wall temperature distribution along the fuel channel. The differences in maximum wall temperatures can be up to 200K for different curve's shape. Moreover, the maximum wall temperature is always higher than in default case i.e. when uniform heat flux is applied. It is possible to control the wall temperature distribution by adjusting the shape of heat flux along the axis. Such adjustment can be made by using different enrichment levels along the fuel rod axis, unfortunately any change in power distribution caused rapid temperature increase at the upstream location.

Research Area(s)

  • Supercritical water, SCWR, CFD, GIF, PRESSURE WATER

Citation Format(s)

Numerical investigation of supercritical water flow in a 2x2 rod bundle under non-uniform heat flux. / Rowinski, Marcin; Soh, Yeng Ch.; White, Timothy J. et al.
2016 24th International Conference on Nuclear Engineering. Vol. 5 American Society of Mechanical Engineers (ASME), 2016. p. V005T15A012 ICONE24-60204.

Research output: Chapters, Conference Papers, Creative and Literary WorksRGC 32 - Refereed conference paper (with host publication)peer-review