scholarly journals Experimental Validation of RELAP5 and TRACE5 for Licensing Studies of the Boron Injection System of Atucha II

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Alejandro I. Lazarte ◽  
William Fullmer ◽  
Martín Bertodano
Keyword(s):  
Heat Transfer ◽  
Nuclear Power ◽  
Experimental Validation ◽  
Injection System ◽  
Water Interface ◽  
Experimental Facility ◽  
Pressure Losses ◽  
Air Water Interface ◽  
Loss Of Coolant ◽  
Tank Level

This paper presents an experimental validation of RELAP5 and TRACE5 for licensing studies of the Atucha II-PHWR nuclear power plant. A scaled experimental facility, representing the boron injection system of Atucha II, was built. The system has a fundamental importance for loss of coolant accidents (LOCA) and anticipated transients without scram (ATWS). The experiment consists of the discharge of a tank that represents the boron tank filled with air or a mixture of air-water onto a discharge tank that represents the moderator tank. Both tanks are connected by a pipe which includes a valve and an orifice plate to model the pressure losses due to the fittings in the real system. The pressure and water level measured in the tanks are compared with the RELAP5 and TRACE5 predictions. The codes predict the pressure in the tanks accurately. However, both codes overpredict the heat transfer in the boron tank air-water interface which produces a greater expansion of the air which leads to a small discrepancy in the boron tank level prediction.

Comparison of Profiles and Fluxes of Heat and Momentum Above and Below an Air-Water Interface

1982 ◽  
Vol 104 (1) ◽  
pp. 34-39 ◽  
Author(s):  
B. M. Howe ◽  
A. J. Chambers ◽  
S. P. Klotz ◽  
T. K. Cheung ◽  
R. L. Street
Keyword(s):  
Heat Transfer ◽  
Surface Layer ◽  
Water Surface ◽  
Temperature Fields ◽  
Water Interface ◽  
Law Of The Wall ◽  
Air Water Interface ◽  
Total Energy Flux ◽  
Momentum And Heat Transfer ◽  
Water Surface Layer

The velocity and temperature fields on both sides of an air-water interface were examined experimentally in order to understand better the physical processes of momentum and heat transfer through the surface layers about the interface. An examination of temperature and velocity profiles plotted in “law-of-the-wall” coordinates leads to the conclusion that, both in the air and in the water, the mechanism of momentum transfer is affected by surface roughness changes, but the mechanism of heat transfer is not. In the water surface layer the velocity fluctuations due to the wave-related motions are of the same order as the purely turbulent motions. The turbulent components closely resemble those found in boundary layers over solid walls. The measured total energy flux from the interface agrees well with the measured single-phase, vertical heat transport through the water surface layer.

scholarly journals Small break loss of coolant accident of 200 cm² in cold leg of primary loop of Angra2 nuclear power reactor evaluation

2021 ◽  
Vol 9 (2B) ◽  
Author(s):  
EDUARDO MADEIRA BORGES ◽  
GAIANÊ SABUNDJIAN
Keyword(s):  
Heat Transfer ◽  
Nuclear Power ◽  
Nuclear Reactor ◽  
Power Reactor ◽  
Reactor Core ◽  
Flow Regimes ◽  
Nuclear Power Reactor ◽  
Primary Loop ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant

The aim of this paper is evaluated the consequences to ANGRA 2 nuclear power reactor and to identify the flow regimes, the heat transfer modes, and the correlations used by RELAP5/MOD3.2.gama code in ANGRA 2 during the Small-Break Loss-of-Coolant Accident (SBLOCA) with a 200cm2 of rupture area in the cold leg of primary loop. The Chapter 15 of the Final Safety Analysis Report of ANGRA 2 (FSAR-A2) reports this specific kind of accident. The results from this work demonstrated the several flow regimes and heat transfer modes that can be present in the core of ANGRA 2 during the postulated accident. The results obtained for ANGRA 2 nuclear reactor core during the postulated accident were satisfactory when compared with the FSAR-A2. Additionally, the results showed the correct actuation of the ECCS guaranteeing the integrity of the reactor core.

Experimental Modeling of Heat Transfer in a Continuous Casting Mould Model

2014 ◽  
Author(s):  
R. Kalter ◽  
B. W. Righolt ◽  
S. Kenjereš ◽  
C. R. Kleijn ◽  
M. J. Tummers
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Continuous Casting ◽  
Transfer Coefficient ◽  
Cooling Water ◽  
Working Fluid ◽  
Water Interface ◽  
Temperature Distributions ◽  
Air Water Interface ◽  
Continuous Casting Mould

Temperature distributions in a thin continuous casting mould model have been studied experimentally, using water as a working fluid. The mould model consists of two narrow walls and two broad walls. One of the broad walls of the mould model was cooled with cooling water of a fixed temperature. Inflow of two turbulent jets with a constant high temperature was from a bifurcated nozzle, submerged to a depth of 0.1 m below the air/water interface. The temperature drop over the mould was measured as a function of the temperature difference between the liquid flowing into the mould and the cooling water temperature. From these measurements the overall heat transfer coefficient and heat transfer coefficient due to convection in the mould were calculated. Temperature distributions at the cooled wall have been measured using thermochromic liquid crystal sheets, which have a specific color depending on the temperature. The shear layers of the two jets hit the cooled wall, leading to hot spot formation. The jets show a self-sustained oscillating behavior, leading to a non stationary temperature distribution at the cooled wall. Between the jets and the air/water interface, recirculation zones occur where the liquid cools down significantly, leading to large wall temperature differences in the mould.

scholarly journals The Latest Method for Surface Tension Determination: Experimental Validation

Proceedings ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 3
Author(s):  
Tomasz Janusz Teleszewski ◽  
Andrzej Gajewski
Keyword(s):  
Surface Tension ◽  
Experimental Validation ◽  
Experimental Results ◽  
Water Interface ◽  
Air Water Interface ◽  
Relative Differences

The newest method for determining surface tension is being validated, which is done for the air–water interface. Since the relative differences between the benchmark values and the experimental results are very small, the newest method seems to be validated in a positive way.

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