Numerical study on the thermal stratification characteristics in the upper plenum of sodium-cooled fast reactor (SFR)

2020 ◽  
Vol 138 ◽  
pp. 107222
Author(s):  
Mingjun Wang ◽  
Jing Chen ◽  
Dalin Zhang ◽  
Jing Zhang ◽  
Wenxi Tian ◽  
...  
Keyword(s):  
Fast Reactor ◽  
Thermal Stratification ◽  
Numerical Study

The Role of Turbulence Models for Predicting a Thermal Stratification

2006 ◽  
Vol 128 (4) ◽  
pp. 656-662 ◽  
Author(s):  
Seok-Ki Choi ◽  
Seong-O Kim
Keyword(s):  
Liquid Metal ◽  
Thermal Stratification ◽  
Transport Model ◽  
Numerical Study ◽  
Turbulence Models ◽  
Liquid Metal Reactor ◽  
Temporal Oscillation ◽  
Elliptic Relaxation ◽  
Shear Stress Transport Model

A numerical study of the evaluation of turbulence models for predicting the thermal stratification phenomenon is presented. The tested models are the elliptic blending turbulence model (EBM), the two-layer model, the shear stress transport model (SST), and the elliptic relaxation model (V2-f). These four turbulence models are applied to the prediction of a thermal stratification in an upper plenum of a liquid metal reactor experimented at the Japan Nuclear Cooperation (JNC). The EBM and V2-f models predict properly the steep gradient of the temperature at the interface of the cold and hot regions that is observed in the experimental data, and the EBM and V2-f models have the capability of predicting the temporal oscillation of the temperature. The two-layer and SST models predict the diffusive temperature gradient at the interface of a thermal stratification and fail to predict a temporal oscillation of the temperature. In general, the EBM predicts best the thermal stratification phenomenon in the upper plenum of the liquid metal reactor.

scholarly journals The circulation of the Persian Gulf: a numerical study

2005 ◽  
Vol 2 (3) ◽  
pp. 129-164 ◽  
Author(s):  
J. Kämpf ◽  
M. Sadrinasab
Keyword(s):  
United Arab Emirates ◽  
Persian Gulf ◽  
Thermal Stratification ◽  
Numerical Study ◽  
Three Dimensional ◽  
Detailed Comparison ◽  
Mass Properties ◽  
Inverse Estuary ◽  
The Persian Gulf ◽  
Autumn And Winter

Abstract. We employ a three-dimensional hydrodynamic model (COHERENS) to study the circulation and water mass properties of the Persian Gulf, which is a large inverse estuary. Our findings suggest that the Persian Gulf experiences a distinct seasonal cycle in which a Gulf-wide cyclonic overturning circulation establishes in spring and summer, but this disintegrates into mesoscale eddies in autumn and winter. Establishment of the Gulf-wide circulation coincides with establishment of thermal stratification and strengthening of the baroclinic exchange circulation through the Strait of Hormuz. The latter is associated with winter cooling of extreme saline (>45 psu) water in shallow regions along the coast of United Arab Emirates. To validate the model results, we present a detailed comparison with observational evidence.

scholarly journals NUMERICAL ANALYSIS OF THERMAL STRATIFICATION IN THE UPPER PLENUM OF THE MONJU FAST REACTOR

2013 ◽  
Vol 45 (2) ◽  
pp. 191-202 ◽  
Author(s):  
SEOK-KI CHOI ◽  
TAE-HO LEE ◽  
YEONG-IL KIM ◽  
DOHEE HAHN
Keyword(s):  
Numerical Analysis ◽  
Fast Reactor ◽  
Thermal Stratification

An Unsteady Analysis on Thermal Stratification in the SCS Piping Branched Off the RCS Piping

2003 ◽  
Author(s):  
Kwang-Chu Kim ◽  
Man-Heung Park ◽  
Hag-Ki Youm ◽  
Sun-Ki Lee ◽  
Tae-Ryong Kim ◽  
...  
Keyword(s):  
Temperature Difference ◽  
Thermal Stratification ◽  
Nuclear Power ◽  
Cooling System ◽  
Numerical Study ◽  
Outer Wall ◽  
Maximum Temperature ◽  
Rear Side ◽  
Maximum Temperature Difference ◽  
Starting Point

A numerical study is performed to estimate on an unsteady thermal stratification phenomenon in the Shutdown Cooling System (SCS) piping branched off the Reactor Coolant System (RCS) piping of Nuclear Power Plant. In the results, turbulent penetration reaches to the 1st isolation valve. At 500sec, the maximum temperature difference between top and bottom inner wall in piping is observed at the starting point of horizontal piping passing elbow. The temperature of coolant in the rear side of the 1st isolation valve disk is very slowly increased and the inflection point in temperature difference curve for time is observed at 2700sec. At the beginning of turbulent penetration from RCS piping, the fast inflow generates the higher temperature for the inner wall than the outer wall in the SCS piping. In the case the hot-leg injection piping and the drain piping are connected to the SCS piping, the effect of thermal stratification in the SCS piping is decreased due to an increase of heat loss compared with no connection case. The hot-leg injection piping affected by turbulent penetration from the SCS piping has a severe temperature difference that exceeds criterion temperature stated in reference. But the drain piping located in the rear compared with the hot-leg injection piping shows a tiny temperature difference. In a viewpoint of designer, for the purpose of decreasing the thermal stratification effect, it is necessary to increase the length of vertical piping in the SCS piping, and to move the position of the hot-leg injection piping backward.

Numerical Study on the Main Coolant Pump of Sodium-Cooled Fast Reactor

2015 ◽  
Author(s):  
Sungho Ko ◽  
Yeon-tae Kim
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Fast Reactor ◽  
Numerical Study ◽  
Pressure Rise ◽  
Head Loss ◽  
Computational Domain ◽  
Coolant Pump ◽  
Pump Head

A numerical study was conducted to predict the performance curve of a downscaled model of the main coolant pump for a sodium-cooled fast reactor and to reduce the head loss by the optimization of the diffuser blade. The ANSYS CFX program was utilized to obtain flow characteristics inside the pump as well as the overall pressure rise across the pump operating on- and off-design points. Computational domain was divided into several blocks to achieve high grid quality effectively and 7.5 million nodes were used totally to resolve small leakage flows as well as the flow inside the rotating impeller. The corresponding experiment was conducted to validate CFD computed results. The comparison between the CFD and experimental data shows excellent agreement in terms of mass flow rate and head rise on and near design operating points. The DOE (design of experiments) and RSM (response surface method)[1] were utilized to reduce the head loss by the diffuser blade in the pump. The diffuser blade was defined as four geometric parameters for DOE. The analysis of 25 cases was made to solve the output parameters for all design points which are defined by the DOE. RSM was fitting the output parameter as a function of the input parameters using regression analysis techniques. The optimized model increased the total pump head on the design point and the low mass flow rate point, but total pump head on 130% of operating mass flow rate was reduced than the initial model.

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