NUMERICAL SIMULATION OF TEMPERATURE FIELD IN STRATIFIED CORIUM AND EVALUATION OF NUCLEAR REACTOR WALL MELTING DURING SEVERE ACCIDENT

1998 ◽  
Author(s):  
Leonid A. Dombrovsky ◽  
Yuri Albertovich Zeigarnik
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Nuclear Reactor ◽  
Severe Accident ◽  
Reactor Wall

Liquid Film Flow on Vertical and Successive Inclined Plate Modeling Flow Channel of Molten Control Rod in Severe Accident

2018 ◽  
Author(s):  
Yutaro Hihara ◽  
Hideaki Monji ◽  
Yutaka Abe ◽  
Susumu Yamashita ◽  
Hiroyuki Yoshida
Keyword(s):  
Numerical Simulation ◽  
Liquid Film ◽  
Nuclear Reactor ◽  
Flow Channel ◽  
Severe Accident ◽  
Inclined Plate ◽  
Basic Study ◽  
Simulation Code ◽  
Energy Agency ◽  
Modeling Flow

When a severe accident of a nuclear reactor occurs, decommissioning work becomes important task. In the decommissioning work of a boiling water reactor after the severe accident, estimation of the sedimentation place of the molten debris is important. However, the technique to estimate exactly the sedimentation place has not been enough developed. Therefore, the detailed and phenomenological numerical simulation code named “JUPITER” is under development for predicting the molten core behavior in JAEA (Japan Atomic Energy Agency). The comparison between experimental and numerical results is necessary to clarify the validity of the numerical analysis code. The study provides the experimental data to examine the numerical simulation code. As a basic study to examine the numerical simulation code, a liquid film flowing in a modeling flow channel was studied by using water. The flow was visualized, and the flow data were obtained by image processing.

scholarly journals Three Dimensional Numerical Simulation on Nuclear Reactor Interior Flow and Temperature Field of a 1000MW Unit

2013 ◽  
Vol 6 (11) ◽  
pp. 2019-2026
Author(s):  
Jian-Quan Liu ◽  
Bao-Min Sun ◽  
Zhu-San Li ◽  
De-Liang Zhang ◽  
Ling-Yun Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Nuclear Reactor ◽  
Three Dimensional ◽  
Interior Flow

Numerical Simulation on Improving NOx Reduction Efficiency of SNCR by Regulating the 3-D Temperature Field in a Furnace

2013 ◽  
Vol 807-809 ◽  
pp. 1505-1513 ◽  
Author(s):  
Amir A.B. Musa ◽  
Xiong Wei Zeng ◽  
Qing Yan Fang ◽  
Huai Chun Zhou
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Removal Efficiency ◽  
Pulverized Coal ◽  
Measuring System ◽  
Optimum Temperature ◽  
Utility Boiler ◽  
Coal Particles ◽  
Injection Zone ◽  
Reduction Efficiency

The optimum temperature within the reagent injection zone is between 900 and 1150°C for the NOX reduction by SNCR (selective non-catalytic reduction) in coal-fired utility boiler furnaces. As the load and the fuel property changes, the temperature within the reagent injection zone will bias from the optimum range, which will reduces significantly the de-NOX efficiency, and consequently the applicability of SNCR technology. An idea to improve the NOX reduction efficiency of SNCR by regulating the 3-D temperature field in a furnace is proposed in this paper. In order to study the new method, Computational fluid dynamics (CFD) model of a 200 MW multi-fuel tangentially fired boiler have been developed using Fluent 6.3.26 to investigate the three-fuel combustion system of coal, blast furnace gas (BFG), and coke oven gas (COG) with an eddy-dissipation model for simulating the gas-phase combustion, and to examine the NOX reduction by SNCR using urea-water solution. The current CFD models have been validated by the experimental data obtained from the boiler for case study. The results show that, with the improved coal and air feed method, average residence time of coal particles increases 0.3s, burnout degree of pulverized coal increases 2%, the average temperature at the furnace nose decreases 61K from 1496K to 1435K, the NO emission at the exit (without SNCR) decreases 58 ppm from 528 to 470 ppm, the SNCR NO removal efficiency increases 10% from 36.1 to 46.1%. The numerical simulation results show that this combustion adjustment method based on 3-D temperature field reconstruction measuring system in a 200 MW multi-fuel tangentially fired utility boiler co-firing pulverized coal with BFG and COG is timely and effective to maintain the temperature of reagent injection zone at optimum temperature range and high NOX removal efficiency of SNCR.

Experimental and numerical investigation of the thermomechanical load on a turbine housing in a radial turbocharger

2021 ◽  
pp. 095440702110521
Author(s):  
Shaolin Chen ◽  
Hong Zhang ◽  
Liaoping Hu ◽  
Guangqing He ◽  
Fen Lei ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Fatigue Life ◽  
Simulation Analysis ◽  
Simulation Method ◽  
Testing Temperature ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Monitoring Point ◽  
Turbine Housing

The fatigue life of turbine housing is an important index to measure the reliability of a radial turbocharger. The increase in turbine inlet temperatures in the last few years has resulted in a decrease in the fatigue life of turbine housing. A simulation method and experimental verification are required to predict the life of a turbine housing in the early design and development process precisely. The temperature field distribution of the turbine housing is calculated using the steady-state bidirectional coupled conjugate heat transfer method. Next, the temperature field results are considered as the boundary for calculating the turbine housing temperature and thermomechanical strain, and then, the thermomechanical strain of the turbine housing is determined. Infrared and digital image correlations are used to measure the turbine housing surface temperature and total thermomechanical strain. Compared to the numerical solution, the maximum temperature RMS (Root Mean Square) error of the monitoring point in the monitoring area is only 3.5%; the maximum strain RMS error reached 11%. Experimental results of temperature field test and strain measurement test show that the testing temperature and total strain results are approximately equal to the solution of the numerical simulation. Based on the comparison between the numerical calculation and experimental results, the numerical simulation and test results were found to be in good agreement. The experimental and simulation results of this method can be used as the temperature and strain (stress) boundaries for subsequent thermomechanical fatigue (TMF) simulation analysis of the turbine housing.

Numerical Simulation of Corium Jet Breakup During Fuel-Coolant Interaction Based on the ALISA Test Performed at KROTOS Test Facility

2018 ◽  
Author(s):  
Pei Shen ◽  
Wenzhong Zhou
Keyword(s):  
Numerical Simulation ◽  
Steam Explosion ◽  
Field Method ◽  
Severe Accident ◽  
Phase Field Method ◽  
Test Facility ◽  
Jet Breakup ◽  
Jet Behavior ◽  
Jet Fragmentation ◽  
Explosion Test

Steam explosion is one of the consequences of fuel-coolant interactions in a severe accident. Melt jet fragmentation, which is the key phenomenon during steam explosion, has not been clarified sufficiently which prevents the precise prediction of steam explosion. The focus of this paper is on the numerical simulation of the melt jet behavior falling into a coolant pool in order to get a qualitative and quantitative understanding of initial premixing stage of fuel-coolant interaction. The objective of our first phase is the simulation of the fragmentation process and the estimation of the jet breakup length. A commercial CFD code COMSOL is used for the 2D numerical analysis employing the phase field method. The simulation condition is similar to our steam explosion test supported by the ALISA (Access to Large Infrastructure for Severe Accidents) project between European Union and China, and carried out in the KROTOS test facility at CEA, France. The simulation result is in relatively good agreement with the experimental data. Then the effect of the initial jet velocity, the jet diameter and the instability theory are presented. The preliminary data of melt jet fragmentation is helpful to understand the premixing stage of the fuel-coolant interaction.

Experimental Investigation on Dependence of Decontamination Factor on Aerosol Number Concentration in Pool Scrubbing Under Normal Temperature and Pressure

2018 ◽  
Author(s):  
HaoMin Sun ◽  
Shinichi Machida ◽  
Yasuteru Sibamoto ◽  
Yuria Okagaki ◽  
Taisuke Yonomoto
Keyword(s):  
High Performance ◽  
Nuclear Reactor ◽  
Experimental System ◽  
Decontamination Factor ◽  
Number Concentration ◽  
Severe Accident ◽  
Measurement Instruments ◽  
Aerosol Number Concentration ◽  
Real Phenomenon ◽  
Validation Tests

During a severe accident of a nuclear reactor, radioactive aerosols may be released from degraded nuclear fuels. Pool scrubbing is one of the efficient filters with a high aerosol removal efficiency, in other words a high decontamination factor (DF). Because of its high performance, many pool scrubbing experiments have been performed and several pool scrubbing models have been proposed. In the existing pool scrubbing experiments, an experimental condition of aerosol number concentration was seldom taken into account. It is probably because DF is assumed to be independent of aerosol number concentration, at least, in the concentration where aerosol coagulation is limited. The existing pool scrubbing models also follow this assumption. In order to verify this assumption, we performed a pool scrubbing experiment with different aerosol number concentrations under the same boundary conditions. The test section is a transparent polycarbonate pipe with an inner diameter of 0.2 m. 0.5 μm SiO2 particles were used as aerosols. As a result, DF was increasing as decreasing the aerosol number concentration. In order to ensure a reliability of this result, three validation tests were performed with meticulous care. According to the results of these validation tests, it was indicated that DF dependence on the aerosol concentration was not because of our experimental system error including measurement instruments but a real phenomenon of the pool scrubbing.

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