Prediction of Critical Heat Flux in Water-Cooled Plasma Facing Components Using Computational Fluid Dynamics

Youchison, D.L.; Ulrickson, M.; Bullock, James H.

doi:10.13182/fst11-a12348

Cited by 20 publications

(5 citation statements)

References 14 publications

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“…Several recent papers have been presented in the literature, which make use of advanced CFD modelling to predict the thermal performance of HVs for ITER with water [12][13][14][15]. These results are generally in agreement with experimental results from thermal studies at various high heat flux research institutes.…”

Section: (G)) It Is Found That the Vortex Stability Of The Mast Model...supporting

confidence: 59%

Potential for improvement in high heat flux HyperVapotron element performance using nanofluids

2013

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HyperVapotron (HV) elements have been used extensively as high heat flux beam stopping components in nuclear fusion research facilities. These water-cooled heat exchangers use a boiling heat transfer mechanism and so are inherently limited by their critical heat flux (CHF). The use of a nanofluid as the coolant, instead of water, promises to enhance the heat transfer performance of the HV and increase the CHF by a factor of 2 or 3, which would lead to a step-change improvement in the power handling capability. This paper reports on computational and experimental analyses which have indicated mechanisms for the enhanced thermal performance of nanofluids. A molecular dynamics simulation code has been developed which has identified heat transfer augmentation mechanisms that depart from classical thermodynamics associated with the presence of nanoparticles. In addition, an experiment has been conducted which uses particle image velocimetry to measure the flow field in a full-scale HV. Past studies have yielded qualitative experimental results, but the measurements reported here provide quantitative data to aid the understanding of the initial flow field inside the HV (i.e., before a heat flux is applied). Further, the experiment is conducted using both water and Al2O3–water nanofluid as the flow medium. Thus, these velocity measurements offer a first indication for potentially enhanced heat transfer in HV devices when nanofluids are used as the coolant. The improved understanding of the HV flow regime and the cooling advantage of nanofluids could assist the design of advanced high heat flux components for future fusion machines.

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Section: (G)) It Is Found That the Vortex Stability Of The Mast Model...supporting

confidence: 59%

Potential for improvement in high heat flux HyperVapotron element performance using nanofluids

2013

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“…The potential for an increase of energy efficiency in these centres by use of boiling based removal of hardware generated heat is evident when one takes into account that currently non-efficient chilled air cooling technique consumes half of the aforementioned electricity amount [21]. Another novel technical utilization of boiling is related to the water-cooled fusion reactors in which the cooling components are exposed to plasma and, therefore, to one-sided heating with extremely high heat flux rates (e. g. in ITER * , that is just an experimental device, heat loads as high as 5 MW/m 2 are expected according to [22]). Further, the understanding of new aspects of boiling phenomena in conditions of low gravity is indispensable for the design of cooling systems in powerful electronic packages for space applications [23].…”

Section: Urgency For More Accurate Modelling Of Boiling Heat Transfermentioning

confidence: 99%

Boiling heat transfer modelling: A review and future prospectus

Ilić¹,

Petrović

Stevanović

2019

Therm sci

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This paper reviews the current status of boiling heat transfer modelling, discusses the need for its improvement due to unresolved intriguing experimental findings and emergence of novel technical applications and outlines the directions for an advanced modelling approach. The state-of-the-art of computational boiling heat transfer studies is given for: macro-scale boiling models applied in two-fluid liquid-vapour interpenetrating media approach, micro-, meso-scale boiling computations by interface capturing methods, and nano-scale boiling simulations by molecular dynamics tools. Advantages, limitations and shortcomings of each approach, which originate from its grounding formulations, are discussed and illustrated on results obtained by the boiling model developed in our research group. Based on these issues, we stress the importance of adaptation of a multi-scale approach for development of an advanced boiling predictive methodology. A general road-map is outlined for achieving this challenging goal, which should include: improvement of existing methods for computation of boiling on different scales and development of conceptually new algorithms for linking of individual scale methods. As dramatically different time steps of integration for different boiling scales hinder the application of full multi-scale methodology on boiling problems of practical significance, we emphasise the importance of development of another algorithm for the determination of sub-domains within a macro-scale boiling region, which are relevant for conductance of small-scale simulations.

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“…The 3D, steady state, incompressible flow model, with the - SST turbulence closure [8] and "all y+" wall treatment is adopted. The VOF multiphase flow model is chosen, with the Rohsenow model [9], [10] on in case of boiling onset. Temperature-dependent material properties are used, with the water properties evaluated at 9 bar, and the saturation temperature evaluated at the pressure computed at the heat load peak position (6.9 bar, giving Tsat = 164 °C).…”

Section: Th Modelmentioning

confidence: 99%