Coupled Thermomechanical Fatigue Tests for Simulating Load Conditions in Cooled Turbine Parts

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Roland Mücke ◽  
Klaus Rau
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Thermomechanical Fatigue ◽  
Fatigue Tests ◽  
Material Behavior ◽  
Hot Gas ◽  
Numerical Predictions ◽  
Aisi 316 ◽  
Aisi 316 L ◽  
Load Conditions

Modern heavy-duty gas turbines operate under hot gas temperatures that are much higher than the temperature capability of nickel superalloys. For that reason, advanced cooling technology is applied for reducing the metal temperature to an acceptable level. Highly cooled components, however, are characterized by large thermal gradients resulting in inhomogeneous temperature fields and complex thermomechanical load conditions. In particular, the different rates of stress relaxation due to the different metal temperatures on hot gas and cooling air exposed surfaces lead to load redistributions in cooled structures, which have to be considered in the lifetime prediction methodology. In this context, the paper describes coupled thermomechanical fatigue (CTMF) tests for simultaneously simulating load conditions on hot and cold surfaces of cooled turbine parts (Beck et al., 2001, “Experimental Analysis of the Interaction of Hot and Cold Volume Elements During Thermal Fatigue of Cooled Components Made From AISI 316 L Steel,” Z. Metallkunde, 92, pp. 875–881 and Rau et al., 2003, “Isothermal Thermo-mechanical and Complex Thermo-mechanical Fatigue Tests on AISI 316 L Steel—A Critical Evaluation,” Mater. Sci. Eng., A345, pp. 309–318). In contrary to standard thermomechanical fatigue (TMF) testing methods, CTMF tests involve the interaction between hot and cold regions of the parts and thus more closely simulates the material behavior in cooled gas turbine structures. The paper describes the methodology of CTMF tests and their application to typical load conditions in cooled gas turbine parts. Experimental results are compared with numerical predictions showing the advantages of the proposed testing method.

Coupled Thermo-Mechanical Fatigue Tests for Simulating Load Conditions in Cooled Turbine Parts

2011 ◽  
Author(s):  
Roland Mu¨cke ◽  
Klaus Rau
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Mechanical Load ◽  
Fatigue Tests ◽  
Temperature Fields ◽  
Hot Gas ◽  
Mechanical Fatigue ◽  
Numerical Predictions ◽  
Temperature Capability ◽  
Load Conditions

Modern heavy-duty gas turbines operate under hot gas temperatures that are much higher than the temperature capability of nickel superalloys. For that reason, advanced cooling technology is applied for reducing the metal temperature to an acceptable level. Highly cooled components, however, are characterised by large thermal gradients resulting in inhomogeneous temperature fields and complex thermo-mechanical load conditions. In particular, the different rates of stress relaxation due to the different metal temperatures on hot gas and cooling air exposed surfaces lead to load redistributions in cooled structures, which have to be considered in the lifetime prediction methodology. In this context, the paper describes Coupled Thermo-Mechanical Fatigue (CTMF) tests for simultaneously simulating load conditions on hot and cold surfaces of cooled turbine parts, Refs [1, 2]. In contrary to standard Thermo-Mechanical Fatigue (TMF) testing methods, CTMF tests involve the interaction between hot and cold regions of the parts and thus more closely simulates the material behaviour in cooled gas turbine structures. The paper describes the methodology of CTMF tests and their application to typical load conditions in cooled gas turbine parts. Experimental results are compared with numerical predictions showing the advantages of the proposed testing method.

Coal-Water Slurry Testing of an Industrial Gas Turbine

1992 ◽  
Author(s):  
R. A. Wenglarz ◽  
C. Wilkes ◽  
R. C. Bourke ◽  
H. C. Mongia
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Water Injection ◽  
Department Of Energy ◽  
Combustion System ◽  
Hot Gas ◽  
Water Slurry ◽  
Coal Water Slurry ◽  
Burning Coal ◽  
Industrial Gas Turbine

This paper describes the first test of an industrial gas turbine and low emissions combustion system on coal-water-slurry fuel. The engine and combustion system have been developed over the past five years as part of the Heat Engines program sponsored by the Morgantown Energy Technology Center of the U.S. Department of Energy (DOE). The engine is a modified Allison 501-K industrial gas turbine designed to produce 3.5 MW of electrical power when burning natural gas or distillate fuel. Full load power output increases to approximately 4.9 MW when burning coal-water slurry as a result of additional turbine mass flow rate. The engine has been modified to accept an external staged combustion system developed specifically for burning coal and low quality ash-bearing fuels. Combustion staging permits the control of NOx from fuel-bound nitrogen while simultaneously controlling CO emissions. Water injection freezes molten ash in the quench zone located between the rich and lean zones. The dry ash is removed from the hot gas stream by two parallel cyclone separators. This paper describes the engine and combustor system modifications required for running on coal and presents the emissions and turbine performance data from the coal-water slurry testing. Included is a discussion of hot gas path ash deposition and planned future work that will support the commercialization of coal-fired gas turbines.

Investigation of Flow Instabilities Near the Rim Cavity of a 1.5 Stage Gas Turbine

2009 ◽  
Author(s):  
M. Rabs ◽  
F.-K. Benra ◽  
H. J. Dohmen ◽  
O. Schneider
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Gas Turbines ◽  
Flow Instabilities ◽  
Navier Stokes ◽  
Flow Rates ◽  
Air Mass ◽  
Hot Gas ◽  
Path Modelling ◽  
Mass Flow Rates

The present paper gives a contribution to a better understanding of the flow at the rim and in the wheel space of gas turbines. Steady state and time-accurate numerical simulations with a commercial Navier-Stokes solver for a 1.5 stage turbine similar to the model treated in the European Research Project ICAS-GT were conducted. In the framework of a numerical analysis, a validation with experimental results of the test rig at the Technical University of Aachen will be given. In preceding numerical investigations of realistic gas turbine rim cavities with a simplified treatment of the hot gas path (modelling of the main flow path without blades and vanes), so called Kelvin-Helmholtz vortices were found in the area of the gap when using appropriate boundary conditions. The present work shows that these flow instabilities also occur in a 1.5 stage gas turbine model with consideration of the blades and vanes. Therefore, several simulations with different sealing air mass flow rates (CW 7000, 20000, 30000) have been conducted. The results show, that for high sealing air mass flow rates Kelvin-Helmholtz Instabilities are developing. These vortices significantly coin the flow at the rim.

Repair of Advanced Gas Turbine Blades

2005 ◽  
Author(s):  
Julie McGraw ◽  
Reiner Anton ◽  
Christian Ba¨hr ◽  
Mary Chiozza
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
High Reliability ◽  
Turbine Blades ◽  
Base Material ◽  
Operating Experience ◽  
Cost Effective ◽  
Directionally Solidified ◽  
Hot Gas

In order to promote high efficiency combined with high power output, reliability, and availability, Siemens advanced gas turbines are equipped with state-of-the-art turbine blades and hot gas path parts. These parts embody the latest developments in base materials (single crystal and directionally solidified), as well as complex cooling arrangements (round and shaped holes) and coating systems. A modern gas turbine blade (or other hot gas path part) is a duplex component consisting of base material and coating system. Planned recoating and repair intervals are established as part of the blade design. Advanced repair technologies are essential to allow cost-effective refurbishing while maintaining high reliability. This paper gives an overview of the operating experience and key technologies used to repair these parts.

Development of Risk-Based Maintenance Software for Gas Turbines

2007 ◽  
Author(s):  
Tomoharu Fujii ◽  
Terutaka Fujioka ◽  
Chris Ablitt ◽  
Julian Speck ◽  
Brian Cane
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Damage Mechanism ◽  
Risk Assessments ◽  
Inspection Planning ◽  
Risk Matrix ◽  
Hot Gas ◽  
Path Component ◽  
Software Risk ◽  
Maintenance And Inspection

Risk-based maintenance software has been developed to perform risk-based maintenance and inspection planning on gas turbine hot gas path components. The software allows the user to easily prepare a risk matrix, plotting every active damage mechanism for each hot gas path component. Based on the result of the risk assessments the components can be ranked, allowing inspection plans to be focused and prioritized and aiding the user to identify the most appropriate and effective risk mitigating activity within the software. Risk assessments are performed on a component-by-component basis, with the software’s scope including all combustor and turbine hot gas path components. The software also contains comprehensive help documents to aid the user in identifying and assessing peculiar damage mechanisms and prescribing the most effective inspection methods for gas turbines.

Robust Optimization of the HPT Blade Cooling and Aerodynamic Efficiency

2016 ◽  
Author(s):  
Kirill A. Vinogradov ◽  
Gennady V. Kretinin ◽  
Kseniya V. Otryahina ◽  
Roman A. Didenko ◽  
Dmitry V. Karelin ◽  
...  
Keyword(s):  
Robust Optimization ◽  
Gas Turbine ◽  
Film Cooling ◽  
Gas Turbines ◽  
Leading Edge ◽  
Operational Parameters ◽  
Cooling Effectiveness ◽  
Aerodynamic Efficiency ◽  
Hot Gas ◽  
Blade Tip

Constant rise of hot gas temperature is crucial for the creation of modern gas-turbines engines requiring considerable improvement of cooling configurations. A high pressure turbine blade is one of the most crucial and loaded details in gas-turbine engines. A HPT blade is affected by different operational deviations: stochastic fluctuations of inlet parameters and difference in operational parameters for manufactured engines. Combination of these factors makes the task of uncertainty quantification and robust optimization of the HPT blade relevant in modern science. The authors make an attempt to implement robust optimization to the HPT blade of the gas-turbine engine. The two most important areas of the cooling blade (the leading edge (LE) and the blade tip) were taken into account. The operational and the aleatoric uncertainties were analyzed. These uncertainties represent the fluctuations in the operational parameters and the random-unknown conditions such as the boundary values and or geometrical variations. Industrial HPT blade with a serpentary cooling system and film cooling at the LE was considered. Results of many engine tests were applied to construct probability density function distributions for operational uncertainties. More than 100 real gas-turbines were examined. The following operational uncertainties were reviewed: inlet hot gas pressure and temperature together with cooling air pressure. The tip gap was used as geometrical variation. Conjugate Heat Transfer computations were carried out for the temperature distribution obtained. Geometrical variations of the LE film cooling rows and the tip gap are variables in the robust optimization process. The authors developed a special technology for full parameterization of the LE film-cooling rows only by two parameters. A surrogate model technique (the response surface and the Monte-Carlo method) was applied for the uncertainty quantification and the robust optimization processes. The IOSO technology was employed as one of the robust optimization tools. This technology is also based on the widespread application of the response surface technique. Robust optimal solution (the Pareto set) between cooling effectiveness of the leading edge and the blade tip and aerodynamic efficiency was obtained as the result. At chosen point from the Pareto set (angle point) we calculated necessary levels of robust criteria characterized LE and blade tip cooling effectiveness and kinetic energy losses.

scholarly journals Assessment of Hot Gas Cleanup Technologies in Coal-Fired Gas Turbines

1990 ◽  
Author(s):  
Edward L. Parsons ◽  
Holmes A. Webb ◽  
Charles M. Zeh
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Department Of Energy ◽  
General Motors ◽  
Bench Scale ◽  
Hot Gas ◽  
The Status ◽  
Efficient Combustion ◽  
Westinghouse Electric ◽  
Technical Discussion

This paper reviews the status of in situ gas stream cleanup technologies which are an integral part of the direct coal-fired gas turbine systems being developed through the U.S. Department of Energy (DOE), Morgantown Energy Technology Center (METC). The technical discussion focuses on the proof-of-concept systems under development in the DOE/METC Advanced Coal-Fueled Gas Turbine Systems (ACFGTS) program initiated in 1986. In this program, Solar Turbines Inc., the Allison Gas Turbine Division of General Motors Corporation, and Westinghouse Electric Corporation have completed bench-scale tests of integrated combustion and hot gas cleanup systems in preparation for full-size subsystem tests. All these projects include the development of cleanup systems for contaminants resulting from the combustion of coal. These systems will both control emissions of pollutants and protect the turbine gas path from fouling, erosion, and corrosion. The bench-scale tests have demonstrated efficient combustion of coal-water slurries (CWS) and dry coal in high-pressure, short residence-time combustors. The tests have also yielded promising results in the abatement of nitrogen oxides (NOx) and volatile alkali and in the removal of ash and sulfur species from the hot gas streams.

Design and Analysis of a Real-Time Hot Gas Temperature Estimator for Heavy-Duty Gas Turbines

2015 ◽  
Author(s):  
Eric A. Müller ◽  
Adrian Ticǎ
Keyword(s):  
Real Time ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Gas Temperature ◽  
Heavy Duty ◽  
Component Level ◽  
Load Range ◽  
Hot Gas ◽  
Dynamic Tracking ◽  
Heavy Duty Gas Turbine

The knowledge about a relevant process and lifetime indicative quantity, such as the hot gas temperature, is crucial for the control of a gas turbine. Since this indicative process quantity usually cannot be directly measured, it has to be estimated. The paper describes a model-based method to accurately estimate in real-time the hot gas temperature of a heavy-duty gas turbine. The method follows a well-balanced trade-off between resulting prediction accuracy and involved computational complexity. It takes advantage of the capability of a component-level dynamic model to predict the system behaviour and of the capacity of a dynamic tracking filter to adapt to the current gas turbine conditions. In a simulation study, it is shown that the proposed design can provide an accurate hot gas temperature estimation over the entire gas turbine load range, along the gas turbine lifecycle, and during fast transient manoeuvres.

An Empirical Model for Predicting Crack Growth Behavior of Gas Turbine Stage 1 Nozzles

2002 ◽  
Author(s):  
Jenfu Yau ◽  
Hui Kuang
Keyword(s):  
Gas Turbine ◽  
Empirical Model ◽  
Gas Turbines ◽  
Monte Carlo Analysis ◽  
Management Plan ◽  
Maintenance Cost ◽  
Crack Growth Behavior ◽  
Multiple Cracks ◽  
Hot Gas ◽  
Stage 1

Expenditure of maintenance cost for gas turbines can be greatly reduced if the parts can be well managed during the service to avoid excessive fallout rate or unplanned forced outage. In order to achieve the optimum part life management plan, the ability to accurately predict the life capabilities and fallout rates of the life limiting components becomes very important. An empirical model for the stage 1 nozzle of F-class frame 9 GE gas turbine has been developed based on Weibull statistic analysis of measured crack dimensions at observed critical locations of the nozzle. The crack measurements were taken during the hot gas path inspections and data from several different machine units which had different operating histories were used to establish relationship between Weibull parameters and elapsed operation histories. The fallout rate as function operation history is predicted by performing a Monte Carlo analysis to account for the combined effects of multiple cracks.

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