Degradation Assessment of Gas Turbine Hot Gas Path Components

2016 ◽  
Vol 1133 ◽  
pp. 376-380
Author(s):  
Ahmad Afiq Pauzi
Keyword(s):  
Gas Turbine ◽  
Fuel Mixture ◽  
Operating Conditions ◽  
Research Project ◽  
Damage Mechanisms ◽  
Damage And Failure ◽  
Hot Gas ◽  
Failure Risk ◽  
Path Component ◽  
Damage Processes

Hot gas path component consists of components designed to burn air-fuel mixture in combustion section and provide hot gasses to the turbine section where mechanical power is produced. The aim of this research project is expected to improve the current practices of managing degradation of hot gas path components. Understanding the damage mechanisms is of great interest in reducing the damage and failure risk. In this research, a study was conducted on F-Class type gas turbine hot gas path components assembly. It involved extensive examination and testing of the components which had been in operations for 24,000 hours since the last shutdown. Various factors such as installation, operating conditions, hardness and material of constructions were also investigated. This paper reports the initial findings of the study of hot gas path components degradation. It describes the damage observed on the affected areas of the components and proposes the factors that contribute to the damage processes. Potential solutions for mitigating the damages are also discussed.

Development of Diagnostic Tools for Real Time Assessment of Gas Turbine Hot Gas Path Component Temperatures: A Preliminary Study

2002 ◽  
Author(s):  
Carlo Carcasci ◽  
Bruno Facchini ◽  
Francesco Grillo ◽  
Erio Benvenuti ◽  
Gianni Mochi
Keyword(s):  
Gas Turbine ◽  
Evaluation System ◽  
Information Needs ◽  
Effective Means ◽  
Operating Conditions ◽  
Design Stage ◽  
Diagnostic Tools ◽  
Hot Gas ◽  
Path Component ◽  
Wide Range

This paper outlines a part of the work under way at GE Oil and Gas – Nuovo Pignone to develop advanced diagnostic tools to evaluate gas turbine hot gas path components life on the basis of actual operating data continuously recorded by remote monitoring systems. The system aims at correlating component metal temperatures and stresses as a function of operating performance data measured through standard machine instrumentation. Monitored data is processed by a new inverse-cycle algorithm to evaluate gas-path temperatures and pressures. The generated gas path information needs then to be correlated to metal temperatures and stresses with precision suitable for input to algorithms evaluating creep, oxidation and hot corrosion damage. Typically, calculations of gas path data to metal temperatures and stresses are performed at the design stage for a limited number of critical operating conditions by using complex and sophisticated CFD and structural/thermal analysis computer codes. For applications to diagnostic, direct use of such tools for any monitored sets of data would be impracticable. On the other hand, they represent the most effective means for assessing hot gas path component temperatures with adequate accuracy, particularly on last generation engines with substantial turbine blade and nozzle cooling. The approach chosen and described herein consists in extensively using high level design tools over a wide range of turbine operating conditions and use the results to produce equations and maps linking field monitored data to component temperatures suitable for easy implementation into a life evaluation system. In the paper major aspects of the above work are reviewed and synthesized, and significant steps in the first application to a turbine first stage cooled blade are illustrated.

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.

Hot-Gas-Path Life Extension Options for the V94.2 Gas Turbine

2000 ◽  
Author(s):  
Gerhard Bohrenkämper ◽  
Herbert Bals ◽  
Ursel Wrede ◽  
René Umlauft
Keyword(s):  
Power Plant ◽  
Service Life ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Life Extension ◽  
Hot Gas ◽  
Maintenance Program ◽  
Path Component ◽  
Strategic Options

Gas turbine and combined cycle power plants are typically designed for a service life of over 30 years. If operated at base load in continuous duty, the gas turbine hot-gas-path components for example in a combined-cycle power plant need repair and replacement according to the maintenance program several times during plant life. Most of the hot components would reach the end of their service life, e.g. 100,000 equivalent operating hours (EOH), after 10 to 12 years. As this is well before the end of the overall plant service life defined in the power plant concept, such plant applications therefore necessitate life extension measures enabling to continuing operation beyond 100,000 EOH. This paper presents strategic options for hot-gas-path component life entension.

Degradation Evaluation of the Gas Turbine Hot-Gas-Path Component

2005 ◽  
pp. 2266-2271
Author(s):  
Jine Sung Jung ◽  
S.Y. Chang ◽  
Keun Bong Yoo ◽  
Gee Wook Song ◽  
Min Sung Kang ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Hot Gas ◽  
Path Component ◽  
Degradation Evaluation

Life Management System for Hot-Gas-Path Components of Gas Turbines

1999 ◽  
Author(s):  
Yasushi Hayasaka ◽  
Nobuhiro Isobe ◽  
Shigeo Sakurai ◽  
Kazuhiko Kumata
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Management System ◽  
Residual Life ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Life Assessment ◽  
Hot Gas ◽  
Life Management ◽  
Residual Life Assessment

Recently the number of gas-turbine-powered combined-cycle plants has been increasing because of their efficiency and environmental compatibility. Gas turbine operating conditions are severe, especially for hot-gas-path components. To improve the reliability of such components and to extend their life, we have developed a life management system based on a residual-life-assessment method. The system makes possible integrated residual-life-assessment based on numerical analyses, material destructive-tests, nondestructive inspections, statistical analyses of field machine data, and the use of a database. To develop the system, the primary damage mechanism for each component is clarified and material degradation is evaluated. For nozzles, the system describes a method of predicting the maximum surface crack growth. The validity of the methods is verified by assessment of the inspection data. This paper also describes optimization of operating cost and RAM (reliability, availability and maintainability).

Degradation Evaluation of the Gas Turbine Hot-Gas-Path Component

2005 ◽  
Vol 297-300 ◽  
pp. 2266-2271
Author(s):  
Jine Sung Jung ◽  
S.Y. Chang ◽  
Keun Bong Yoo ◽  
Gee Wook Song ◽  
Min Sung Kang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gas Turbine ◽  
Coating Layer ◽  
Interdiffusion Zone ◽  
Hot Gas ◽  
Impact Tests ◽  
Path Component ◽  
Coating Layers ◽  
Degradation Evaluation

Degradation of the gas turbine hot-gas-path components, the 1st stage blades and vanes, serviced for a period was evaluated by measuring the mechanical properties. For this, tensile and impact tests on these gas turbine parts were performed. Microstructure of the substrate and coating layers were also observed. The mechanical properties of the serviced blades were degraded by about 30% comparing with those of unused ones. In terms of the microstructure, the dissolution of the secondary g’ phase and subsequent coarsening of precipitates were observed in the substrate. And the interdiffusion zone near the coating layer was disappeared.

Assessment and Prediction of Helmholtz Resonator Performance Within Gas Turbine Combustion Systems

2014 ◽  
Author(s):  
Jochen Rupp ◽  
Graham Peacock ◽  
Gavita Regunath ◽  
Jon Carrotte
Keyword(s):  
Gas Turbine ◽  
Performance Comparison ◽  
Operating Conditions ◽  
Noise Levels ◽  
Neck Length ◽  
Linear Absorption ◽  
Fluid Displacement ◽  
Hot Gas ◽  
Gas Turbine Combustion ◽  
Combustion Systems

This paper is concerned with the potential use of Helmholtz resonators to provide increased acoustic damping within aero gas turbine combustion systems. Experimental measurements were undertaken using a high intensity facility into which a three burner combustor sector (non-reacting) model could be incorporated. In this way the performance of various damper geometry combinations were assessed. The effect of incident noise levels was also considered along with the associated transition from linear absorption (i.e. where absorption is directly proportional to incident pressure magnitude) to nonlinear absorption (i.e. where the proportion of acoustic loss decreases with increasing noise levels). This complicates the performance comparison between different damping geometries and means care is required when relating laboratory to engine operating conditions. In addition, all the measurements were undertaken in the presence of fuel injectors and other realistic flow field features found within a combustion system and which could affect damping performance. Finally, experimental and numerical assessment was made of the noise levels at which ingestion of hot gas will occur into the resonator cavities with and without the presence of a purging flow. For the geometries investigated ingestion occurs when the fluid displacement in the neck during an acoustic cycle is approximately equal to, or greater than, the resonator neck length. The ratio of fluid displacement and neck length provides a limit for the noise levels at which hot gas is ingested into the cavity and hence the operating condition where damping performance and system mechanical integrity is significantly compromised.

scholarly journals Research of the operability of an air-fuel lubrication and cooling system of gas turbine engine rotor bearings

2019 ◽  
Vol 18 (1) ◽  
pp. 55-66
Author(s):  
V. N. Klimov ◽  
D. Ya. Dud’ev ◽  
V. Ya. Sigaylo ◽  
N. I. Klimov ◽  
Yu. K. Mashkov
Keyword(s):  
Gas Turbine ◽  
Thermal State ◽  
Cooling System ◽  
Fuel Mixture ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Hollow Shaft ◽  
Friction Regime ◽  
Rotor Bearings

The article is devoted to the problem of ensuring the operability of air-fuel lubrication and cooling systems for gas turbine engine (GTE) rotor bearings. The paper considers one of the advanced designs of a GTE in which an air-fuel mixture obtained in a special mixer is fed to a bearing installed in the turbine support and then through a hollow shaft to the bearing of the compressor support and then directed to the engine input. It is difficult to implement such a GTE scheme because of the necessity to ensure the operability of bearings lubricated with an air-fuel mixture for a predetermined period of time. It is impossible to determine the thermal state of the bearings and the friction regime in them with sufficient accuracy. The solution of the problems requires carrying out experimental work to determine the coefficients of friction and convective heat transfer in the bearings, as well as their full service life under various operating conditions and parameters of the air-fuel mixture blown through the bearings. The paper presents the results of testing a 45-126205РЯ radial thrust bearing lubricated with an air-fuel mixture, МС-8П oil and a non-lubricated bearing of the same kind. The operability of the GTE rotor bearings lubricated with the air-fuel mixture is analyzed, the area of efficient application of the gas turbine engine with an air-fuel lubrication system is determined.

A test rig for investigations of gas turbine combustor cooling concepts under realistic operating conditions

2008 ◽  
Vol 222 (2) ◽  
pp. 169-177 ◽  
Author(s):  
T Behrendt ◽  
Ch Hassa
Keyword(s):  
Gas Turbine ◽  
Gas Flow ◽  
Leading Edge ◽  
Test Sample ◽  
Operating Conditions ◽  
Test Rig ◽  
Hot Gas ◽  
Elevated Pressures ◽  
Low Emission

In the current paper, a new test rig for the characterization of advanced combustor cooling concepts for gas turbine combustors is presented. The test rig is designed to allow investigations at elevated pressures and temperatures representing realistic operating conditions of future lean low emission combustors. The features and capabilities of the test rig in comparison to existing rigs are described. The properties of the hot gas flow are measured in order to provide the necessary data for a detailed analysis of the measured cooling effectivity of combustor wall test samples. Results of the characterization of the velocity and temperature distribution in the hot gas flow at the leading edge of the test sample at pressures up to p = 10 bar and global flame temperatures up to TF = 2000 K are presented.

1D Tool for Stator-Rotor Cavities Integrated Into a Fluid Network Solver of Heavy-Duty Gas Turbine Secondary Air System

2010 ◽  
Author(s):  
F. Bonzani ◽  
L. Bozzi ◽  
M. Mantero ◽  
A. Vinci ◽  
L. Innocenti ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Heavy Duty ◽  
Ambient Conditions ◽  
Hot Gas ◽  
Fluid Network ◽  
Air System ◽  
Air Flows ◽  
Secondary Air

In order to improve performance of heavy-duty gas turbines, in terms of efficiency and reliability, accurate calculation tools are required to simulate the SAS (Secondary Air System) and estimate the minimum amount of cooling and sealing air to ensure the integrity of hot gas path components. A critical component of this system is the cavity formed between coaxial rotating and stationary discs, that needs a sealing flow to prevent the hot gas ingestion. This paper gives a general overview of a 1D tool for the analysis of stator-rotor cavities and its integration into an “in-house” developed fluid network solver to analyse the behaviour of the secondary air system over different operating conditions. The 1D cavity solver calculates swirl, pressure and temperature profiles along the cavity radius. Thanks to its integration into the SAS code, the cavity solver allows estimation of sealing air flows, taking into account directly of the interaction between inner and outer extraction lines of blades and vanes. This procedure has been applied to the AE94.3A secondary air system and the results are presented in terms of sealing flows variation for the cavities of second and third vane on gas turbine load and ambient conditions. In some different load conditions, calculated secondary air flows are compared to experimental data coming from the AE94.3A Ansaldo fleet.

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