Sensitivity Study of the South Texas Project Power Plant Steady-State Simulations Using RELAP5-3D Coupled With Dakota

2012 ◽  
Author(s):  
O. A. Rodriguez ◽  
R. Vaghetto ◽  
Y. A. Hassan
Keyword(s):  
Steady State ◽  
Power Plant ◽  
Uncertainty Quantification ◽  
National Laboratory ◽  
Sandia National Laboratory ◽  
Sensitivity Study ◽  
South Texas ◽  
Normal Operation ◽  
Inlet Temperature ◽  
The South

A RELAP5-3D input deck of the South Texas Project (STP) power plant was created in order to study the thermal-hydraulic behavior of the plant during normal operation (steady-state) and during a Loss of Coolant Accident (LOCA). It is important to study the sensitivity of selected output parameters such as the total coolant mass flow rate, the peak clad temperature, the secondary pressure, as a function of specific input parameters (reactor nominal power, vessel inlet temperature, steam generators primary side heat transfer coefficient, primary pressure etc.) in order to identify the variables that play a role in the uncertainty of the thermal-hydraulic calculations. RELAP5-3D, one of the most used best estimate thermal-hydraulic system codes, was coupled with DAKOTA, developed by Sandia National Laboratory for Uncertainty Quantification and Sensitivity Analysis in order to simplify the simulation process and the analysis of the results. In the present paper, the results of the sensitivity study for selected output parameters of the steady-state simulations are presented. The coupled software was validated by repeating one set of simulations using the RELAP5-3D standalone version and by analyzing the simulation results with respect of the physical expectations and behavior of the power plant. The thermal-hydraulic parameters of interest for future uncertainty quantification calculations were identified.

scholarly journals Auxiliary feedwater system risk-based inspection guide for the South Texas Project nuclear power plant

1993 ◽  
Author(s):  
J.D. Bumgardner ◽  
J.R. Nickolaus ◽  
N.E. Moffitt ◽  
B.F. Gore ◽  
T.V. Vo
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
South Texas ◽  
The South ◽  
System Risk

Long-Term Microturbine Exposure of an Advanced Alloy for Microturbine Primary Surface Recuperators

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Wendy J. Matthews ◽  
Karren L. More ◽  
Larry R. Walker
Keyword(s):  
Steady State ◽  
National Laboratory ◽  
Operating Conditions ◽  
Normal Operation ◽  
Operating Environment ◽  
Protective Oxide ◽  
Oak Ridge ◽  
Steady State Operation ◽  
Alloy Oxidation

Haynes alloy HR-120 (Haynes and HR-120 are trademarks of Haynes International, Inc.) forms a protective oxide scale when exposed to the harsh operating environment of a microturbine primary surface recuperator. Primary surface recuperators manufactured from HR-120 are currently in use on the Capstone C65 MicroTurbine (MicroTurbine is a registered trademark of Capstone Turbine Corporation). Long-term microturbine tests of this alloy are currently being conducted at an elevated turbine exit temperature (∼100°F higher than that in a normal operation) at Capstone Turbine Corporation. Alloy samples that have been tested under steady-state microturbine operating conditions are removed after predetermined exposure intervals for characterization by Capstone Turbine Corporation in collaboration with Oak Ridge National Laboratory. Such evaluations include the characterization of surface oxide scales and the associated alloy compositional changes following a steady-state operation ranging from 1800 h to 14,500 h. Results from the microstructural and compositional analyses of these long-term steady-state engine-tested HR-120 samples are used to illustrate the progression of alloy oxidation in the microturbine operating environment.

Primary Surface Recuperator Alloy Oxidation: A Comparison of Accelerated Engine Testing to Field Operation

2010 ◽  
Author(s):  
Wendy J. Matthews ◽  
Karren L. More ◽  
Larry R. Walker
Keyword(s):  
Steady State ◽  
Oxide Scale ◽  
National Laboratory ◽  
Normal Operation ◽  
Protective Oxide ◽  
Oak Ridge ◽  
Alloy Oxidation ◽  
Test Engine ◽  
Engine Testing

The Capstone C65 MicroTurbine Primary Surface Recuperator (PSR) core has been manufactured from Haynes alloy HR-120 since 2005. When exposed to the harsh operating environment of the microturbine PSR, HR-120 forms a protective oxide scale that is resistant to the effects of the water vapor present in the exhaust gas. Long-term accelerated microturbine testing, with samples in a modified PSR with a removable aft dome, is on-going at an elevated Turbine Exit Temperature (TET) ∼100°F higher than normal operation. The elevated TET test engine is operated at steady state conditions and the engine is shut down at pre-determined intervals for sample removal. Material characterization of the elevated TET samples has been carried out by Capstone Turbine Corporation in collaboration with Oak Ridge National Laboratory. The surface oxide scale formation and associated alloy compositional changes have been evaluated for elevated TET samples with operating lives ranging from ∼1,800 – ∼26,500 hours. In addition, field operated HR-120 recuperators have been sectioned and samples have been evaluated for operating lives ranging from ∼5,500 – ∼18,000 hours. Results from the microstructural and compositional analyses of both the long-term steady-state elevated TET HR-120 samples, and the field operated HR-120 recuperator samples, will be presented and compared.

Off Design Performance Map Similarity Study of Radial Type Turbomachinery in Supercritical CO2 Brayton Cycle

2015 ◽  
Author(s):  
Seong Kuk Cho ◽  
Jekyoung Lee ◽  
Jeong Ik Lee
Keyword(s):  
Critical Point ◽  
Pressure Ratio ◽  
National Laboratory ◽  
Sandia National Laboratory ◽  
Power Conversion ◽  
Design Tool ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Performance Map ◽  
The Future

A supercritical carbon dioxide (S-CO2) Brayton cycle has received attention as one of the future power conversion systems because of its high thermal efficiency at relatively low turbine inlet temperature. However, the design process of the S-CO2 compressor is known to be difficult because the fluid properties vary significantly near the critical point. This paper discusses about the design methodology of a S-CO2 compressor on the basis of the existing design practice and performance map of Sandia National Laboratory, which is the only reported experimental data for the S-CO2 compressor. Five parameters are mainly used for verifying the turbomachinery similarity. When all of 5 parameters coincide with the prototype and the conceptually designed turbomachinery, similar performance can be assumed. As a result, the data of SNL are insufficient to design a single stage compressor which is able to compress from near critical point to 20MPa. The optimum cycle pressure ratio is reported to be around 2.6∼2.7 in the previous S-CO2 Brayton cycle research works. The minimum number of stages is required at least two to utilize the existing data in the compressor design. So this study focuses on two main purposes. The first is to check whether the SNL data can be extended for the larger scale S-CO2 system. Second, the performance map obtained from KAIST_TMD, which is from an in-house code developed by the Korea Advanced Institute of Science and Technology (KAIST) research team, was compared to the SNL data, so that KAIST_TMD can be used as a design tool for a larger scale S-CO2 power conversion system in the future.

Uncertainty Quantification of a Fluidized Bed Reactor

2019 ◽  
Author(s):  
V. M. Krushnarao Kotteda ◽  
Anitha Kommu ◽  
Vinod Kumar ◽  
William Spotz
Keyword(s):  
Sensitivity Analysis ◽  
Uncertainty Quantification ◽  
National Laboratory ◽  
Sandia National Laboratory ◽  
Computational Cost ◽  
Wide Range ◽  
Input Parameters ◽  
Fluidizing Agent ◽  
Uncertain Input ◽  
Biomass Particles

Abstract Fluidized beds are used in a wide range of applications in gasification, combustion, and process engineering. Multiphase flow in such applications involves numerous uncertain parameters. Uncertainty quantification provides uncertainty in syngas yield and efficiency of coal/biomass gasification in a power plant. Techniques such as sensitivity analysis are useful in identifying parameters that have the most influence on the quantities of interest. Also, it helps to decrease the computational cost of the uncertainty quantification and optimize the reactor. We carried out a nondeterministic analysis of flow in a biomass reactor. The flow in the reactor is simulated with National Energy Technology Laboratory’s open source multiphase fluid dynamics suite MFiX. It does not possess tools for uncertainty quantification. Therefore, we developed a C++ wrapper to integrate an uncertainty quantification toolkit developed at Sandia National Laboratory with MFiX. The wrapper exchanges uncertain input parameters and critical output parameters among Dakota and MFiX. We quantify uncertainty in key output parameters via a sampling method. In addition, sensitivity analysis is carried out for all eight uncertain input parameters namely particle-particle restitution coefficient, angle of internal friction, coefficient of friction between two-phases, velocity of the fluidizing agent at the inlet, velocity of the biomass particles at the inlet, diameter of the biomass particles, viscosity of the fluidizing agent, and the percentage of nitrogen/oxygen in the fluidizing agent.

scholarly journals HCCI Intelligent Rapid Modeling by Artificial Neural Network and Genetic Algorithm

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
AbdoulAhad Validi ◽  
Jyh-Yuan Chen ◽  
Akbar Ghafourian
Keyword(s):  
Genetic Algorithm ◽  
Chemical Kinetics ◽  
National Laboratory ◽  
Sandia National Laboratory ◽  
Chemical Mechanism ◽  
Inlet Temperature ◽  
First Case ◽  
Crank Angle ◽  
Inlet Conditions ◽  
Rapid Modeling

A Dynamic model of Homogeneous Charge Compression Ignition (HCCI), based on chemical kinetics principles and artificial intelligence, is developed. The model can rapidly predict the combustion probability, thermochemistry properties, and exact timing of the Start of Combustion (SOC). A realization function is developed on the basis of the Sandia National Laboratory chemical kinetics model, and GRI3.0 methane chemical mechanism. The inlet conditions are optimized by Genetic Algorithm (GA), so that combustion initiates and SOC timing posits in the desired crank angle. The best SOC timing to achieve higher performance and efficiency in HCCI engines is between 5 and 15 degrees crank angle (CAD) after top dead center (TDC). To achieve this SOC timing, in the first case, the inlet temperature and equivalence ratio are optimized simultaneously and in the second case, compression ratio is optimized by GA. The model’s results are validated with previous works. The SOC timing can be predicted in less than 0.01 second and the CPU time savings are encouraging. This model can successfully be used for real engine control applications.

Primary Surface Recuperator Alloy Oxidation: A Comparison of Accelerated Engine Testing to Field Operation

2010 ◽  
Vol 133 (4) ◽  
Author(s):  
Wendy J. Matthews ◽  
Karren L. More ◽  
Larry R. Walker
Keyword(s):  
Steady State ◽  
Oxide Scale ◽  
National Laboratory ◽  
Normal Operation ◽  
Protective Oxide ◽  
Oak Ridge ◽  
Alloy Oxidation ◽  
Test Engine ◽  
Engine Testing

The Capstone C65 Microturbine primary surface recuperator (PSR) core has been manufactured from Haynes alloy HR-120 since 2005 (Microturbine is a registered trademark of Capstone Turbine Corporation; Haynes and HR-120 are trademarks of Haynes International, Inc.). When exposed to the harsh operating environment of the microturbine PSR, HR-120 forms a protective oxide scale that is resistant to the effects of the water vapor present in the exhaust gas. Long-term accelerated microturbine testing with samples in a modified PSR with a removable aft dome is ongoing at an elevated turbine exit temperature (TET) ∼100°F higher than normal operation. The elevated TET test engine is operated at steady-state conditions, and the engine is shut down at predetermined intervals for sample removal. Material characterization of the elevated TET samples has been carried out by Capstone Turbine Corporation in collaboration with Oak Ridge National Laboratory. The surface oxide scale formation and associated alloy compositional changes have been evaluated for elevated TET samples with operating lives ranging from ∼1800 h to ∼26,500 h. In addition, field-operated HR-120 recuperators have been sectioned and samples have been evaluated for operating lives ranging from ∼5500 h to ∼18,000 h. Results from the microstructural and compositional analyses of both the long-term steady-state elevated TET HR-120 samples and the field-operated HR-120 recuperator samples will be presented and compared.

Long-Term Microturbine Exposure of an Advanced Alloy for Microturbine Primary Surface Recuperators

2008 ◽  
Author(s):  
Wendy J. Matthews ◽  
Karren L. More ◽  
Larry R. Walker
Keyword(s):  
Steady State ◽  
National Laboratory ◽  
Operating Conditions ◽  
Normal Operation ◽  
Operating Environment ◽  
Protective Oxide ◽  
Oak Ridge ◽  
Steady State Operation ◽  
Alloy Oxidation

Haynes Alloy HR-120 forms a protective oxide scale when exposed to the harsh operating environment of a microturbine primary surface recuperator. Primary surface recuperators manufactured from HR-120 are currently in use on the Capstone C65 MicroTurbine. Long-term microturbine tests of this alloy are currently being conducted at an elevated turbine exit temperature (∼100F° higher than normal operation) at Capstone Turbine Corporation. Alloy samples that have been tested under steady-state microturbine operating conditions are removed after pre-determined exposure intervals for characterization by Capstone Turbine Corporation in collaboration with Oak Ridge National Laboratory. Such evaluations include characterization of surface oxide scales and the associated alloy compositional changes following steady-state operation ranging from 1,800 – 14,500 hours. Results from the microstructural and compositional analyses of these long-term, steady-state engine-tested HR-120 samples are used to illustrate the progression of alloy oxidation in the microturbine operating environment.

Control of an adiabatic continuous reactor by feeding catalyst

1980 ◽  
Vol 45 (11) ◽  
pp. 2903-2918 ◽  
Author(s):  
Josef Horák ◽  
Zina Valášková ◽  
František Jiráček
Keyword(s):  
Steady State ◽  
Reaction Temperature ◽  
Continuous Reactor ◽  
Control Element ◽  
Inlet Temperature ◽  
Switching Cycle ◽  
Point Temperature ◽  
Set Point ◽  
Constant Rate ◽  
Laboratory Reactor

Algorithms have been presented, analyzed and experimentally tested to stabilize the reaction temperature at constant inlet temperature and composition of the feed by controlled dispensing of the catalyst. The information for the control element is the course of the reaction temperature. If the temperature of the reaction mixture is below the set point, the catalyst is being fed into the reactor at a constant rate. If the reaction temperature is higher the catalyst dispenser is blocked; dispensing of the catalyst is not resumed until the set point temperature has been reached again. The amount of catalyst added is a function of the duration of the switching cycle. The effect has been discussed of the form of this function on the course of the switching cycle. The results have been tested experimentally on a laboratory reactor controlled in an unstable steady state.

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