Heat transfer of supercritical water in annuli with spacers

Hu, Zhiyuan; Gu, Haihua

doi:10.1016/j.ijheatmasstransfer.2017.12.056

Cited by 12 publications

(2 citation statements)

References 21 publications

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“…Because of the strong variation of the thermophysical properties in the area near the pseudocritical point, the characteristics of supercritical water heat transfer are quite different from FIGURE 1 | Pressure-temperature diagram of water, reprinted from Pioro and Mokry (2011) with permission of IntechOpen. subcritical water (Shitsman, 1963;Cheng et al, 2003Cheng et al, , 2007Hu and Gu, 2018;Xiao et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Diameter Effect on the Wall Temperature Behaviors During Supercritical Water Heat Transfer Deterioration in Circular Tubes and Annular Channels

Cheng

Yanlin²,

Wang

et al. 2019

Front. Energy Res.

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Diameter effect on heat transfer deterioration (HTD) for supercritical water upward flow in circular tubes and annular channels at low mass flux and high heat flux was studied numerically based on validated turbulence model. When the same boundary conditions were applied, i.e., mass flux, heat flux, and inlet temperature, it was observed that for circular tubes the first peak of wall temperature moves upstream and its magnitude increases at first then decreases as tube diameter increases, the second peak moves downstream as tube diameter increases. For annular channels with a fixed inner diameter, HTD is suppressed with small outer diameter, while HTD occurs gradually as outer diameter increases. The phenomenon agrees with previous experiment studies. The mechanism was analyzed based on fully developed turbulent velocity profiles at the heated sections inlet. Increasing inner diameter for circular tubes or outer diameter for annular channels will result in the decrease of maximum velocity and velocity gradient in the near heated wall region, which makes velocity profile in this region much easier to be flattened by the buoyancy. Then an M-shaped axial velocity profile is formed, which will significantly decrease the Reynolds shear stress and the turbulent kinetic energy and hence impair the heat transfer and cause HTD. At the same flow conditions, HTD is much easier to occur in circular tubes than in annular channels with the same hydraulic diameters.

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Section: Introductionmentioning

confidence: 99%

Diameter Effect on the Wall Temperature Behaviors During Supercritical Water Heat Transfer Deterioration in Circular Tubes and Annular Channels

Cheng

Yanlin²,

Wang

et al. 2019

Front. Energy Res.

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“…(2018) carried out both experimental and numerical studies in a smooth vertical tube at supercritical pressures investigating effects of specific heat ratio, buoyancy and acceleration parameters on heat transfer using ultra-supercritical water and found out SST k-ω turbulence model could predict heat transfer in enhanced and deteriorated heat transfer regimes, enhance heat transfer and deteriorated heat transfer are caused by effects of buoyancy and integral of specific in the boundary layer, non-uniform heat application could delay heat transfer deterioration occurrence in comparison with uniform heat application, and SST k-ω turbulence model could not accurately predict heat transfer in the deteriorated heat transfer regime and therefore need improvement. Hu and Gu (2018) performed an experimental study investigating heat transfer to water at supercritical pressures in annuli with spacers. It was found that blockage ratio, dimensionless distance, local enthalpy, heat flux, mass flux, pressure, and Reynolds number are the main parameters influencing heat transfer downstream from spacers at supercritical conditions.…”

Section: Introductionmentioning

confidence: 99%

Assessment of heat transfer correlations in the sub-channels of proposed rod bundle geometry for supercritical water reactor

Debrah

Shitsi

Chabi

et al. 2019

Heliyon

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There are heat transfer correlations for heat transfer analysis in single tube geometries after several experimental and theoretical heat transfer studies in these single tube geometries. This is not the case for heat transfer analysis in rod bundle geometry with regard to proposed square fuel assembly of the Supercritical-Water-Cooled Reactor (SCWR) European Atomic Energy (EURATOM) design. Thus limited heat transfer studies exist on rod bundle geometry at supercritical pressures. Heat transfer correlations with accurate prediction capabilities of coolant and wall temperatures will be helpful in carrying out heat transfer studies at supercritical pressures. This paper presents the performance of twelve selected heat transfer correlations assessed on the 1/8th bare square fuel assembly of the SCWR EURATOM design using Simulation of Turbulent flow in Arbitrary Regions Computational Continuum Mechanics C ++ based code (STAR-CCM + CFD code). The obtained numerical results were compared with the results obtained by Waata numerical experimentation. Overall, the Cheng et al. correlation provided the most satisfying prediction for the wall temperatures in all the sub-channels and captured closely Wataa's Numerical data. The maximum wall temperature was obtained in sub-channel 9, the hottest sub-channel and exceeded the design limit 620 °C by 60 °C for the Cheng correlation. The difference in temperature between the hottest and coldest sub-channels 9 and 1 respectively was approximately 80 °C. It was found that Cheng correlation is best suited for heat transfer prediction in rod bundle geometry at supercritical pressures with regard to the proposed square fuel assembly of the SCWR EURATOM design. It was also found that the different numerical tools adopted for this study and Waata study were able to capture the trends of normal, enhanced and deteriorated heat transfer regimes normally observed at supercritical pressures. Nevertheless, experimental investigations involving rod bundles adopted in this study should be conducted to validate the results obtained numerically and address the inconsistency of the conclusions drawn when compared with Waata data and other similar studies.

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Numerical Investigation of Mass Redistribution in Supercritical Water-Cooled Reactor Flow Channels

Zhao

Chen

Sun

et al. 2021

Advances in Heat Transfer and Thermal Engineering

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Heat transfer of supercritical water in annuli with spacers

Cited by 12 publications

References 21 publications

Diameter Effect on the Wall Temperature Behaviors During Supercritical Water Heat Transfer Deterioration in Circular Tubes and Annular Channels

Diameter Effect on the Wall Temperature Behaviors During Supercritical Water Heat Transfer Deterioration in Circular Tubes and Annular Channels

Assessment of heat transfer correlations in the sub-channels of proposed rod bundle geometry for supercritical water reactor

Numerical Investigation of Mass Redistribution in Supercritical Water-Cooled Reactor Flow Channels

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