NUMERICAL STUDY OF EFFECT OF PITCH TO ROD DIAMETER RATIO ON HEAT TRANSFER TO SUPERCRITICAL WATER IN 2×2 ROD BUNDLE

2020 ◽  
Author(s):  
SURESH SAHU ◽  
Abhijeet M. Vaidya
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Numerical Study ◽  
Diameter Ratio ◽  
Rod Bundle

Experimental studies on heat transfer to supercritical water in 2×2 rod bundle with two channels

2015 ◽  
Vol 291 ◽  
pp. 212-223 ◽  
Author(s):  
H.Y. Gu ◽  
Z.X. Hu ◽  
D. Liu ◽  
Y. Xiao ◽  
X. Cheng
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Experimental Studies ◽  
Rod Bundle

Heat Transfer to Supercritical Water in Vertical Annular Channel and 3-Rod Bundle

2009 ◽  
Author(s):  
V. G. Razumovskiy ◽  
Eu. N. Pis’mennyy ◽  
A. Eu. Koloskov ◽  
I. L. Pioro
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Supercritical Water ◽  
Annular Channel ◽  
Heat Fluxes ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Rod Bundle ◽  
Temperature Regimes ◽  
Outside Diameter

The results of heat transfer to supercritical water flowing upward in a vertical annular channel (1-rod channel) and tight 3-rod bundle consisting of the tubes of 5.2-mm outside diameter and 485-mm heated length are presented. The heat-transfer data were obtained at pressures of 22.5, 24.5, and 27.5 MPa, mass flux within the range from 800 to 3000 kg/m2·s, inlet temperature from 125 to 352°C, outlet temperature up to 372°C and heat flux up to 4.6 MW/m2 (heat flux rate up to 2.5 kJ/kg). Temperature regimes of the annular channel and 3-rod bundle were stable and easily reproducible within the whole range of the mass and heat fluxes, even when a deteriorated heat transfer took place. The data resulted from the study could be applicable for a reference estimation of heat transfer in future designs of fuel bundles.

Nonuniform heat transfer of supercritical water in a tight rod bundle – Assessment of correlations

2017 ◽  
Vol 110 ◽  
pp. 570-583 ◽  
Author(s):  
Han Wang ◽  
Qincheng Bi ◽  
Linchuan Wang ◽  
Laurence K.H. Leung
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Rod Bundle

Numerical study of heat transfer to supercritical water in an inclined tube

2021 ◽  
pp. 1-21
Author(s):  
Siyang Wang ◽  
Yafei Xin ◽  
Tiantian Niu ◽  
Yinlong Li ◽  
Dong Yang
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Numerical Study ◽  
Inclined Tube

An Analysis of Heat Transfer to Axial Dispersed Flow between Rod Bundles under Reactor Emergency Cooling Conditions

1980 ◽  
Vol 102 (3) ◽  
pp. 508-512 ◽  
Author(s):  
S. Wong ◽  
L. E. Hochreiter
Keyword(s):  
Heat Transfer ◽  
Diameter Ratio ◽  
Circular Pipe ◽  
Rod Bundles ◽  
Dispersed Flow ◽  
Rod Bundle ◽  
Cooling Conditions ◽  
Flow Heat ◽  
Square Array ◽  
The Heat Transfer Coefficient

Analysis is carried out for dispersed flow heat transfer under reactor emergency cooling conditions. The present formulation explicitly reveals an extra dependence of the heat transfer coefficient and Nusselt number on the mean vapor temperature for droplet dispersed flow which is not found in single phase flow heat transfer. The heat transfer results obtained from three different geometries—an infinite square array of cylindrical rods, an annulus and a circular pipe—are compared; all have the same hydraulic diameter. It is found that, within the framework of the present analysis, results for the annulus and the rod bundles agree well when the pitch-to-diameter ratio is 1.5 or greater. The circular pipe is in general a poor approximation for rod bundle geometries except at a pitch-to-diameter ratio of about 1.3 which is typical of present day light water reactor fuel assemblies.

Numerical Analysis of the Flow and Heat Transfer in the Sub-Channel of Supercritical Water Reactor

2013 ◽  
Author(s):  
Ajoy Debbarma ◽  
K. M. Pandey
Keyword(s):  
Heat Transfer ◽  
Fuel Assembly ◽  
Supercritical Water ◽  
High Performance ◽  
Flow Distribution ◽  
Diameter Ratio ◽  
Light Water Reactor ◽  
Water Reactor ◽  
Fuel Rod ◽  
Gap Width

Research activities are ongoing for High performance light water reactor (HPLWR) with square double rows fuel assembly to develop nuclear power plants with the purpose to achieve a high thermal efficiency and to improve their economical competitiveness. However, there is still a big deficiency in understanding and prediction of heat transfer in supercritical fluids. This paper evaluates three-dimensional turbulent flow and convective heat transfer in a single-phase and steady-state sub-channel of HPLWR by using general computational fluid dynamics code, Ansys 14 Fluent. The major concern using supercritical water as work fluid is the heat transfer characteristics due to large variations of thermal properties of supercritical water near pseudo-critical line. In order to ensure the safety of operation in High performance light water reactor (HPLWR), heat transfer deterioration (HTD) must be avoided. Numerical results prove that the RNG k-e model with the enhanced near-wall treatment obtained the most satisfactory prediction and lead to satisfactory simulation results. The HPLWR Square fuel assembly has many square-shaped water rods, Out of four types of sub-channels; three sub-channels SC-1, SC-2 and SC-3 are investigated (adjacent to the side of the moderator flow channels (SC-1) (moderator tube and assembly gap), central sub-channels formed by four fuel rods (SC-2), adjacent to the corner of the moderator tube (SC-3). Since coolant flow distribution in the fuel assembly strongly depends on the gap width between the fuel rod and water rod, fuel rod pitch to diameter ratio 1.1–1.4 with 8mm diameter are considered for simulation. Sub-channel analysis clarifies that coolant flow distribution becomes uniform when the gap width is set to 1.0 mm. was less than 620°C. Effects of various parameters, such as boundary conditions and pitch-to-diameter ratios, on the mixing phenomenon in sub-channels and heat transfer are investigated. The effect of pitch-to-diameter ratio (P/D) on the distributions of surface temperature and heat transfer coefficient (HTC) in a sub-channel, it was found that HTC increases with P/D 1.1 first and then decreases with increasing P/D ratio. Apart from the basic geometry sub-channel, a square sub-channel with a wire-wrapped rod inside has been chosen to investigate the “wire effect”.

NUMERICAL INVESTIGATION OF HEAT TRANSFER TO SUPERCRITICAL WATER IN A 2 × 2 ROD BUNDLE WITH TWO CHANNELS

2018 ◽  
Vol 49 (2) ◽  
pp. 103-118
Author(s):  
Ibrahim Tahir ◽  
Waseem Siddique ◽  
Inamul Haq ◽  
Kamran Qureshi ◽  
Anwar Ul Haq Khan
Keyword(s):  
Heat Transfer ◽  
Numerical Investigation ◽  
Supercritical Water ◽  
Rod Bundle

Comparison of Three-Rod Bundle Data With Existing Heat-Transfer Correlations for Bare Vertical Tubes

2010 ◽  
Author(s):  
Krysten King ◽  
Amjad Farah ◽  
Sahil Gupta ◽  
Sarah Mokry ◽  
Igor Pioro
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Annular Channel ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Rod Bundle ◽  
Nuclear Systems ◽  
Heat Transfer Correlations ◽  
Vertical Tubes ◽  
Bare Tube

Many heat-transfer correlations exist for bare tubes cooled with SuperCritical Water (SCW). However, there is very few correlations that describe SCW heat transfer in bundles. Due to the lack of extensive data on bundles, a limited dataset on heat transfer in a SCW-cooled bundle was studied and analyzed using existing bare-tube correlations to find the best-fit correlation. This dataset was obtained by Razumovskiy et al. (National Technical University of Ukraine “KPI”) in SCW flowing upward in a vertical annular channel (1-rod channel) and tight 3-rod bundle consisting of tubes of 5.2-mm outside diameter and 485-mm heated length. The heat-transfer data were obtained at pressures of 22.5, 24.5, and 27.5 MPa, mass flux within a range from 800 to 3000 kg/m2s, inlet temperature from 125 to 352°C, outlet temperature up to 372°C and heat flux up to 4.6 MW/m2. The objective of this study is to compare bare-tube SCW heat-transfer correlations with the data on 1- and 3-rod bundles. This work is in support of SuperCritical Water-cooled Reactors (SCWRs) as one of the six concepts of Generation-IV nuclear systems. SCWRs will operate at pressures of ∼25MPa and inlet temperatures of 350°C.

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