Forced and mixed convection heat transfer to supercritical CO{sub 2} vertically flowing in a uniformly-heated circular tube

Journal Article · Mon Nov 15 00:00:00 EST 2010 · Experimental Thermal and Fluid Science

DOI:https://doi.org/10.1016/J.EXPTHERMFLUSCI.2010.06.001· OSTI ID:21350396

Bae, Yoon-Yeong; Kim, Hwan-Yeol ^[1]; Kang, Deog-Ji ^[2]

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1. Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea)
2. Korea Hydro and Nuclear Power Co. Ltd., 216 Kori, Jangan-eup, Gijang-gun, Busan 619-711 (Korea)

An experiment of heat transfer to CO{sub 2}, which flows upward and downward in a circular tube with an inner diameter of 6.32 mm, was carried out with mass flux of 285-1200 kg/m{sup 2} s and heat flux of 30-170 kW/m{sup 2} at pressures of 7.75 and 8.12 MPa, respectively. The corresponding Reynolds number at the tube test section inlet ranges from 1.8 x 10{sup 4} to 3.8 x 10{sup 5}. The tube inner diameter corresponds to the equivalent hydraulic diameter of the fuel assembly sub-channel, which is being studied at KAERI. Among the tested correlations, the Bishop correlation predicted the experimental data most accurately, but only 66.9% of normal heat transfer data were predicted within {+-}30% error range. The Watts and Chou correlation, which is claimed to be valid for both the normal and deteriorated heat transfer regime, showed unsatisfactory performance. A significant decrease in Nusselt number was observed in the range of 10{sup -6}<Gr{sub b}/Re{sub b}{sup 2.7}<2 x 10{sup -5} before entering a serious heat transfer deterioration regime. The heat transfer deteriorated when the value of the buoyancy parameter Gr{sub b}/Re{sub b}{sup 2.7} exceeded 2.0 x 10{sup -5} close to the Jackson and Hall's criterion. As soon as the heat transfer deteriorated, it entered a new regime and did not return to a normal heat transfer regime, although the value of buoyancy parameter Gr{sub b}/Re{sub b}{sup 2.7} reduced below the deterioration criterion 2.0 x 10{sup -5}. It may justify the requirement of developing separate correlations for the normal and deterioration regimes, as proposed in this paper. (author)

• OSTI ID: 21350396
• Journal Information: Experimental Thermal and Fluid Science, Vol. 34, Issue 8; Other Information: Elsevier Ltd. All rights reserved; ISSN 0894-1777
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
22 GENERAL STUDIES OF NUCLEAR REACTORS
CONVECTION
CARBON DIOXIDE
TUBES
EXPERIMENTAL DATA
FORCED CONVECTION
CORRELATIONS
PRESSURE RANGE MEGA PA 01-10
NUSSELT NUMBER
REYNOLDS NUMBER
FUEL ASSEMBLIES
HEAT FLUX
DATA COVARIANCES
MASS
PERFORMANCE
SUPERCRITICAL STATE
REACTOR COOLING SYSTEMS
Supercritical pressure
Vertical flow