Understanding dry-out mechanism in rod bundles of boiling water reactor
| Autor: | Dinesh K. Chandraker, Sumana Ghosh, Liril D. Silvi, Arup Kumar Das |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Fluid Flow and Transfer Processes
Work (thermodynamics) Materials science Nuclear fuel Mechanical Engineering 02 engineering and technology Mechanics Heat transfer coefficient Nuclear reactor 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Rod 010305 fluids & plasmas law.invention Condensed Matter::Soft Condensed Matter Physics::Fluid Dynamics Heat flux law 0103 physical sciences Volume of fluid method Boiling water reactor 0210 nano-technology |
| Zdroj: | International Journal of Heat and Mass Transfer. 177:121534 |
| ISSN: | 0017-9310 |
| DOI: | 10.1016/j.ijheatmasstransfer.2021.121534 |
| Popis: | Present work reports numerical understanding of interfacial dynamics during co-flow of vapor and liquid phases of water inside a typical Boiling Water Reactor (BWR), consisting of a nuclear fuel rod bundle assembly of 7 pins in a circular array. Two representative spacings between rods in a circular array are used to carry out the simulation. In literature, flow boiling in a nuclear reactor is dealt with mechanistic models or averaged equations. Hence, in the present study using the Volume of Fluid (VOF) based multiphase model, a detailed numerical understanding of breaking and making in interfaces during flow boiling in BWR is targeted. Our work will portray near realistic vapor bubble and liquid flow dynamics in rod bundle scenario. Constant wall heat flux for fuel rod and uniform velocity of the liquid at the inlet patch is applied as a boundary condition. The saturation properties of water are taken at 30 bar pressure. Flow boiling stages involving bubble nucleation, growth, merging, local dry-out, rewetting with liquid patches, and complete dry-out are illustrated. The dry-out phenomenon with no liquid presence is numerically observed with phase fraction contours at various axial cut-sections. The quantification of the liquid phase fraction at different axial planes is plotted over time, emphasizing the progressive dry-out mechanism. A comparison of liquid-vapor distribution for inner and outer rods reveals that the inner rod's dry-out occurs sooner than that of the outer rod. The heat transfer coefficient to identify the heat dissipation capacity of each case is also reported. |
| Databáze: | OpenAIRE |
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