A Method to Evaluate the Impact of Power Demand on HPT Blade Creep Life

2011 ◽  
Author(s):  
W. Mohamed ◽  
S. Eshati ◽  
P. Pilidis ◽  
S. Ogaji ◽  
P. Laskaridis ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Thermal Analyses ◽  
Peak Load ◽  
Quantitative Relationship ◽  
Simulation Software ◽  
Power Demand ◽  
Creep Life ◽  
Turbine Engine ◽  
The Impact

Peak load operation requires gas turbines to operate at high firing temperature with consequence reduction in the useful lives of components. This paper studies the quantitative relationship between gas turbine power setting and the hot gas-path components’ life consumption. A 165MW gas turbine engine is modelled and investigated in this study. A comparative lifing model, which performs stress and thermal analyses, estimates the minimum creep life of components using the parametric Larson Miller method. This lifing model was integrated with in-house performance simulation software to simulate the engine performances at design point and off-design conditions. The results showed that the combined effect of the operating environment and the power demand could have significant impact on blade creep life. Predicting this impact will aid gas turbine users in the decision making processes associated with gas turbine operation.

scholarly journals Prediction and Analysis of Impact of Thermal Barrier Coating Oxidation on Gas Turbine Creep Life

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
E. A. Ogiriki ◽  
Y. G. Li ◽  
Th. Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Thermal Barrier ◽  
Creep Life ◽  
Premature Failure ◽  
Turbine Engine ◽  
Oxidation Rates ◽  
The Impact

Thermal barrier coatings (TBCs) have been widely used in the power generation industry to protect turbine blades from damage in hostile operating environment. This allows either a high turbine entry temperature (TET) to be employed or a low percentage of cooling air to be used, both of which will improve the performance and efficiency of gas turbine engines. However, with continuous increases in TET aimed at improving the performance and efficiency of gas turbines, TBCs have become more susceptible to oxidation. Such oxidation has been largely responsible for the premature failure of most TBCs. Nevertheless, existing creep life prediction models that give adequate considerations to the effects of TBC oxidation on creep life are rare. The implication is that the creep life of gas turbines may be estimated more accurately if TBC oxidation is considered. In this paper, a performance-based integrated creep life model has been introduced with the capability of assessing the impact of TBC oxidation on the creep life and performance of gas turbines. The model comprises of a thermal, stress, oxidation, performance, and life estimation models. High pressure turbine (HPT) blades are selected as the life limiting component of gas turbines. Therefore, the integrated model was employed to investigate the effect of several operating conditions on the HPT blades of a model gas turbine engine using a creep factor (CF) approach. The results show that different operating conditions can significantly affect the oxidation rates of TBCs which in turn affect the creep life of HPT blades. For instance, TBC oxidation can speed up the overall life usage of a gas turbine engine from 4.22% to 6.35% within a one-year operation. It is the objective of this research that the developed method may assist gas turbine users in selecting the best mission profile that will minimize maintenance and operating costs while giving the best engine availability.

Prediction and Analysis of Impact of TBC Oxidation on Gas Turbine Creep Life

2015 ◽  
Author(s):  
E. A. Ogiriki ◽  
Y. G. Li ◽  
Th. Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Prediction Models ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Creep Life ◽  
Premature Failure ◽  
Turbine Engine ◽  
Oxidation Rates ◽  
The Impact

Thermal Barrier Coatings (TBC) have been widely used in the power generation industry to protect turbine blades from damage in hostile operating environment. This allows either a high Turbine Entry temperature (TET) to be employed or a low percentage of cooling air to be used, both of which will improve the performance and efficiency of gas turbine engines. However, with continuous increases in turbine entry temperature aimed at improving the performance and efficiency of gas turbines, TBCs have become more susceptible to oxidation. Such oxidation has been largely responsible for the premature failure of most TBCs. Nevertheless, existing creep life prediction models that give adequate considerations to the effects of TBC oxidation on creep life are rare. The implication is that the creep life of gas turbines may be estimated more accurately if TBC oxidation is considered. In this paper, a performance-based integrated creep life model has been introduced with the capability of assessing the impact of TBC oxidation on the creep life and performance of gas turbines. The model comprises of a thermal, stress, oxidation, performance, and life estimation models. High Pressure Turbine (HPT) blades are selected as the life limiting component of the gas turbine. Therefore the integrated model was employed to investigate the effect of several operating conditions on the HPT blades of a model gas turbine engine using a Creep Factor approach. The results show that different operating conditions can significantly affect the oxidation rates of TBCs which in turn affect the creep life of HPT blades. For instance, TBC oxidation can speed up the overall life usage of a gas turbine engine from 4.22% to 6.35% within one year operation. It is the objective of this research that the developed method may assist gas turbine users in selecting the best mission profile that will minimize maintenance and operating costs while giving the best engine availability.

Thermo-Fluid Modelling for Gas Turbines—Part I: Theoretical Foundation and Uncertainty Analysis

2009 ◽  
Author(s):  
Konstantinos G. Kyprianidis ◽  
Vishal Sethi ◽  
Stephen O. T. Ogaji ◽  
Pericles Pilidis ◽  
Riti Singh ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Simulation Software ◽  
System Level ◽  
Fluid Models ◽  
Performance Simulation ◽  
Turbine Performance ◽  
Aircraft System ◽  
The Impact ◽  
Made In

In this two-part publication, various aspects of thermo-fluid modelling for gas turbines are described and their impact on performance calculations and emissions predictions at aircraft system level is assessed. Accurate and reliable fluid modelling is essential for any gas turbine performance simulation software as it provides a robust foundation for building advanced multi-disciplinary modelling capabilities. Caloric properties for generic and semi-generic gas turbine performance simulation codes can be calculated at various levels of fidelity; selection of the fidelity level is dependent upon the objectives of the simulation and execution time constraints. However, rigorous fluid modelling may not necessarily improve performance simulation accuracy unless all modelling assumptions and sources of uncertainty are aligned to the same level. Certain modelling aspects such as the introduction of chemical kinetics, and dissociation effects, may reduce computational speed and this is of significant importance for radical space exploration and novel propulsion cycle assessment. This paper describes and compares fluid models, based on different levels of fidelity, which have been developed for an industry standard gas turbine performance simulation code and an environmental assessment tool for novel propulsion cycles. The latter comprises the following modules: engine performance, aircraft performance, emissions prediction, and environmental impact. The work presented aims to fill the current literature gap by: (i) investigating the common assumptions made in thermo-fluid modelling for gas turbines and their effect on caloric properties and (ii) assessing the impact of uncertainties on performance calculations and emissions predictions at aircraft system level. In Part I of this two-part publication, a comprehensive analysis of thermo-fluid modelling for gas turbines is presented and the fluid models developed are discussed in detail. Common technical models, used for calculating caloric properties, are compared while typical assumptions made in fluid modelling, and the uncertainties induced, are examined. Several analyses, which demonstrate the effects of composition, temperature and pressure on caloric properties of working mediums for gas turbines, are presented. The working mediums examined include dry air and combustion products for various fuels and H/C ratios. The errors induced by ignoring dissociation effects are also discussed.

Modeling and Simulation of Gas Turbine System on a Virtual Test Bed (VTB)

2012 ◽  
Author(s):  
Eshwarprasad Thirunavukarasu ◽  
Ruixian Fang ◽  
Jamil A. Khan ◽  
Roger Dougal
Keyword(s):  
Gas Turbine ◽  
Dynamic Modeling ◽  
Gas Turbines ◽  
Simulation Software ◽  
Performance Model ◽  
Simulation Environment ◽  
Test Bed ◽  
Turbine Engine ◽  
Virtual Test ◽  
Virtual Test Bed

Gas Turbine is a complex system and highly non linear in its overall performance. In order to study its impact on electric power quality under various load conditions, it is essential to create a high quality performance model of gas turbine to simulate its behavior in real time efficiently. This paper focuses on dynamic modeling of generic gas turbine model using alternate simulation environment for better feasibility. The model is developed on a virtual test bed which is an advanced dynamic simulation environment and can run a dynamic co-simulation effectively. The approach is by developing mathematical models of individual components of gas turbines and utilizing component performance map matching method to run the simulation. The paper discusses briefly about the VTB simulation environment and its use for dynamic modeling of gas turbine. The simulation studies carried out include design condition, off design condition and transient conditions. Working model of twin shaft turbine engine using compressor and turbine maps are validated with established gas turbine simulation software and results are shown.

scholarly journals The INVESTIGATION OF THE DYNAMIC CHARACTERISTICS OF TURBINE IMPELLER DISC OF GAS TURBINE ENGINE USING ANSYS SOFTWARE

2021 ◽  
Vol 3 (SI3) ◽  
pp. first
Author(s):  
THANH NGOC HUYNH ◽  
TOẢN QUỐC TRẦN ◽  
QUYẾT THÀNH PHẠM
Keyword(s):  
Gas Turbine ◽  
Dynamic Properties ◽  
Gas Turbine Engine ◽  
Simulation Software ◽  
Advanced Technology ◽  
Ansys Software ◽  
Engine Operation ◽  
Turbine Engine ◽  
The Impact ◽  
Turbine Impeller

The rotating blades of a compressor or turbine in a gas turbine engine are made up of blades installed on the impeller disc. In particular, the impeller disc needs to be designed, manufactured, and installed to ensure its reliability and safety regarding the strict standards. If damage occurs during the operating process of the impeller disc, it will not only damage the motor but also endanger operators and other equipment. To increase the service time of the engine as well as shorten the production cost, gas turbine manufacturers around the globe are constantly improving technology. In which the monolithic casting impeller is an advanced technology that helps bring down the impeller mass, increasing its life by reducing the shock force on the connection the blades to the rotating disc. Nevertheless, this type of monolithic casting impeller disc reduces its damping effectiveness, which causes the oscillation force to increase significantly. In order to resolve this problem, it is necessary to look into these factors affecting the oscillation of the impeller disc. This paper presents the factors that affect the oscillation of the impeller disc through the study of the dynamic properties of its constituent components. The specific oscillation of the impeller disc, its own oscillation, as well as the impact of factors occurring during the operating of the disc was calculated by using ANSYS simulation software. By creating a three-dimensional model of the turbine blades in gas turbine engine ДP76, the individual oscillation values in a variety of engine operation modes were calculated to compare with the actual value while the engine is operating. The results have good agreement with the measured values. This affirms the advantages and prospects in applying ANSYS software to the design and manufacture of the turbine impeller disc.

scholarly journals Chemically Recuperated Gas Turbines for Offshore Platform: Energy and Environmental Performance

2021 ◽  
Vol 13 (22) ◽  
pp. 12566
Author(s):  
Oleg Bazaluk ◽  
Valerii Havrysh ◽  
Oleksandr Cherednichenko ◽  
Vitalii Nitsenko
Keyword(s):  
Carbon Dioxide ◽  
Gas Turbine ◽  
Steam Reforming ◽  
Carbon Dioxide Emissions ◽  
Gas Turbines ◽  
Offshore Platforms ◽  
Turbine Engine ◽  
Wobbe Index ◽  
Gas Turbine Cycle ◽  
The Impact

Currently, offshore areas have become the hotspot of global gas and oil production. They have significant reserves and production potential. Offshore platforms are energy-intensive facilities. Most of them are equipped with gas turbine engines. Many technologies are used to improve their thermal efficiency. Thermochemical recuperation is investigated in this paper. Much previous research has been restricted to analyzing of the thermodynamic potential of the chemically recuperated gas turbine cycle. However, little work has discussed the operation issues of this cycle. The analysis of actual fuel gases for the steam reforming process taking into account the actual load of gas turbines, the impact of steam reforming on the Wobbe index, and the impact of a steam-fuel reforming process on the carbon dioxide emissions is the novelty of this study. The obtained simulation results showed that gas turbine engine efficiency improved by 8.1 to 9.35% at 100% load, and carbon dioxide emissions decreased by 10% compared to a conventional cycle. A decrease in load leads to a deterioration in the energy and environmental efficiency of chemically recuperated gas turbines.

scholarly journals Research on the influence of fuel gas on energy characteristics of a gas turbine

2019 ◽  
Vol 124 ◽  
pp. 05063 ◽  
Author(s):  
G.E. Marin ◽  
B.M. Osipov ◽  
D.I. Mendeleev
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Thermodynamic Cycle ◽  
Working Fluid ◽  
Fluid Composition ◽  
Fuel Gas ◽  
Turbine Engine ◽  
Equipment Operation ◽  
Turbine Efficiency ◽  
The Impact

The purpose of this paper is to study and analyze the gas turbine engine and the thermodynamic cycle of a gas turbine. The article describes the processes of influence of the working fluid composition on the parameters of the main energy gas turbines, depending on the composition of the fuel gas. The calculations of the thermal scheme of a gas turbine, which were made using mathematical modeling, are given. As a result of research on the operation of the GE PG1111 6FA gas turbine installation with various gas compositions, it was established that when the gas turbine is operating on different fuel gases, the engine efficiency changes. The gas turbine efficiency indicators were determined for various operating parameters and fuel composition. The impact of fuel components on the equipment operation is revealed.

Demonstration of a Semi-Closed Cycle, Turboshaft Gas Turbine Engine

2000 ◽  
Author(s):  
Peter L. Meitner ◽  
Anthony L. Laganelli ◽  
Paul F. Senick ◽  
William E. Lear
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Gas Turbine Engine ◽  
Exhaust Gas ◽  
Test Results ◽  
Closed Cycle ◽  
Turbine Engine ◽  
The Impact

A semi-closed cycle, turboshaft gas turbine engine was assembled and tested under a cooperative program funded by the NASA Glenn Research Center with support from the U.S. Army. The engine, called HPRTE (High Pressure, Recuperated Turbine Engine), features two distinct cycles operating in parallel; an “inner,” high pressure, recuperated cycle, in which exhaust gas is recirculated, and an “open” through-flow cycle. Recuperation is performed in the “inner,” high pressure loop, which greatly reduces the size of the heat exchanger. An intercooler is used to cool both the recirculated exhaust gas and the fresh inlet air. Because a large portion of the exhaust gas is recirculated, significantly less inlet air is required to produce a desired horsepower level. This reduces the engine inlet and exhaust flows to less than half that required for conventional, open cycle, recuperated gas turbines of equal power. In addition, the reburning of the exhaust gas reduces exhaust pollutants. A two-shaft engine was assembled from existing components to demonstrate concept feasibility. The engine did not represent an optimized system, since most components were oversized, and the overall pressure ratio was much lower than optimum. New cycle analysis codes were developed that are capable of accounting for recirculating exhaust flow. Code predictions agreed with test results. Analyses for a fully developed engine predict almost constant specific fuel consumption over a broad power range. Test results showed significant emissions reductions. This document is the first in a series of papers that arc planned to be presented on semi-closed cycle characteristics, issues, and applications, addressing the impact of recirculating exhaust flow on combustion and engine components.

Impact of Operating and Health Conditions on Aero Gas Turbine: Hot Section Creep Life Using a Creep Factor Approach

2010 ◽  
Author(s):  
M. F. Abdul Ghafir ◽  
Y. G. Li ◽  
R. Singh ◽  
K. Huang ◽  
X. Feng
Keyword(s):  
Gas Turbine ◽  
Impact Analysis ◽  
Influencing Factor ◽  
Operating Conditions ◽  
Health Conditions ◽  
Creep Life ◽  
Turbine Engine ◽  
Model Engine ◽  
Life Consumption ◽  
The Impact

A thorough assessment of component life is very important to ensure both the safety and economics of gas turbine operation. As a component’s life given by OEM is based on certain ambient and operating conditions, its actual life may vary substantially when the ambient, operating and engine health conditions change. Therefore possessing knowledge on how those conditions affect actual component life will be valuable in making informed maintenance decisions, maximising operation effectiveness and cutting down operating costs. In this paper, an impact analysis on component creep life due to different operating and engine health conditions using an introduced Creep Factor is performed, which aims to provide useful insights on the relationship between gas turbine performance change and hot section component’s creep life. As the Creep Factor is defined as the ratio between the actual creep life and a reference creep life at a user-defined condition, the magnitude of the impact can be quantified with the change of the Creep Factor. The developed creep life analysis approach was applied to a model single spool turboshaft gas turbine engine operated at various operating and health conditions. A physics-based model combined with the Creep Factor approach was then used to estimate the creep life variation of the high pressure turbine of the model engine. The results showed that for a clean engine, the change in the rotational speed has given the highest impact on the creep life consumption. Also the presence of blade cooling and component degradation is seen to significantly reduce the blade’s creep life and as the degradation effects are combined, the degree of reduction increases even more. It also shows that the Creep Factor is good indicator of creep life consumption and provides a good technique to rank the influencing factor according to the threat they imposed.

Life assessment of a high temperature probe designed for performance evaluation and health monitoring of an aero gas turbine engine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Benny George ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Performance Evaluation ◽  
Gas Turbine ◽  
Health Monitoring ◽  
Gas Turbine Engine ◽  
Life Assessment ◽  
Exhaust Gas ◽  
Cycle Fatigue ◽  
Creep Life ◽  
Turbine Engine ◽  
Engine Components

AbstractTemperature probes of different designs were widely used in aero gas turbine engines for measurement of air and gas temperatures at various locations starting from inlet of fan to exhaust gas from the nozzle. Exhaust Gas Temperature (EGT) downstream of low pressure turbine is one of the key parameters in performance evaluation and digital engine control. The paper presents a holistic approach towards life assessment of a high temperature probe housing thermocouple sensors designed to measure EGT in an aero gas turbine engine. Stress and vibration analysis were carried out from mechanical integrity point of view and the same was evaluated in rig and on the engine. Application of 500 g load concept to clear the probe design was evolved. The design showed strength margin of more than 20% in terms of stress and vibratory loads. Coffin Manson criteria, Larsen Miller Parameter (LMP) were used to assess the Low Cycle Fatigue (LCF) and creep life while Goodman criteria was used to assess High Cycle Fatigue (HCF) margin. LCF and HCF are fatigue related damage from high frequency vibrations of engine components and from ground-air-ground engine cycles (zero-max-zero) respectively and both are of critical importance for ensuring structural integrity of engine components. The life estimation showed LCF life of more than 4000 mission reference cycles, infinite HCF life and well above 2000 h of creep life. This work had become an integral part of the health monitoring, performance evaluation as well as control system of the aero gas turbine engine.

Sign in / Sign up

Export Citation Format

Share Document