Rotor Components Life Evaluation Validated by Field Operation Data

Since E class gas turbines manufactured by Ansaldo Energia are approaching their typical life limits for their planned life cycle (100.000 EOH or 3000 start up) a detailed approach has been developed and carried out in order to guarantee main components for a life extension. This approach has become very important in order to overcome the adopted conservative design approach developed in the seventies taking into account an “ideal reference engine” and therefore focusing on the real engine featured by its history and its component peculiarity. This paper presents a complete life analysis approach which includes experimental tests, FEM analysis and life prediction for the gas turbine model AE94.2, using the 170MW-class 3000 rpm.

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Generating axial compressor maps to zero speed

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650920976052 ◽

2020 ◽

pp. 095765092097605

Author(s):

Luis E Ferrer-Vidal ◽

Vassilios Pachidis ◽

Richard J Tunstall

Keyword(s):

Gas Turbines ◽

Axial Compressor ◽

Sensitivity Study ◽

Generation Process ◽

Performance Models ◽

Start Up ◽

Map Generation ◽

Industrial Gas Turbines ◽

Main Components ◽

Aviation Engines

Gas turbine performance models typically rely on component maps to characterize engine component performance throughout the operational regime. For the sub-idle case, the lack of reliable rig test data or inability to run design codes far from design conditions entails that component maps have to be generated from the extrapolation of existing data at higher speeds. This undermines the accuracy of whole-engine sub-idle performance models, at times impacting engine development and certification of aviation engines and the accuracy of start-up performance prediction in industrial gas turbines. One of the main components driving this issue is the core compression system, which can present operability concerns during light-up and which also sets the combustor airflow required for ignition. This paper presents, discusses, and draws on previous approaches to describe a method enabling the creation of sub-idle compressor maps from analytical and physical grounds. The method relies on the calculation of zero-speed and torque-free lines to generate a map down to zero speed along with analytical interpolation. A method for the interpolation process is described. A sensitivity study is carried out to assess the effects that different elements of the map generation process may have on the accuracy of the resulting performance calculation. Overall, a method for the generation of accurate, consistent maps from limited geometry data is identified.

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A Gas Turbine Cogeneration Plant With a Gross Electrical Efficiency of Over 50%

Volume 4: Heat Transfer; Electric Power ◽

10.1115/86-gt-215 ◽

1986 ◽

Author(s):

A. L. Broekhuizen ◽

R. R. van Lavieren ◽

P. Kamminga

Keyword(s):

Power Generation ◽

Gas Turbines ◽

High Efficiency ◽

District Heating ◽

Performance Tests ◽

Steam Turbines ◽

Electrical Efficiency ◽

Start Up ◽

Cogeneration System ◽

Main Components

District heating projects in the Netherlands are cogeneration projects with special emphasis on high-efficiency power generation. Together with their customer N.V. IJsselcentrale, Thomassen International B.V., designed a cogeneration system based on gas and steam turbines. The system has following main features: - the gross electrical efficiency of the system is over 50%, which is a highly remarkable achievement in power generation - the main components, 2 gas turbines, a steam turbine and one generator are mounted in line on a single shaft. Successful start up of the plant happened in November 1985, performance tests have shown the target of power generation with an efficiency of 50% is met.

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Life Prediction Model of Mineral Admixture Cement Based-Materials under Early Age CO2-Erosion

Coatings ◽

10.3390/coatings11040413 ◽

2021 ◽

Vol 11 (4) ◽

pp. 413

Author(s):

Saisai Wang ◽

Jian Chen ◽

Xiaodong Wen

Keyword(s):

Prediction Model ◽

Life Prediction ◽

Experimental Tests ◽

Mineral Admixture ◽

Model Parameters ◽

Influence Coefficient ◽

Test Pieces ◽

Cement Based Materials ◽

Particle Group ◽

Life Prediction Model

Most of the existing models of structural life prediction in early carbonized environment are based on accelerated erosion after standard 28 days of cement-based materials, while cement-based materials in actual engineering are often exposed to air too early. These result in large predictions of the life expectancy of mineral-admixture cement-based materials under early CO2-erosion and affecting the safe use of structures. To this end, different types of mineral doped cement-based material test pieces are formed, and early CO2-erosion experimental tests are carried out. On the basis of the analysis of the existing model, the influence coefficient of CO2-erosion of the mineral admixture Km is introduced, the relevant function is given, and the life prediction model of the mineral admixture cement-based material under the early CO2-erosion is established and the model parameters are determined by using the particle group algorithm (PSO). It has good engineering applicability and guiding significance.

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A Study on Fatigue Life Evaluation of Pressure Vessel Made of ASME SA240-316L Material Using Numerical Analysis

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.893.1 ◽

2019 ◽

Vol 893 ◽

pp. 1-5 ◽

Cited By ~ 1

Author(s):

Eui Soo Kim

Keyword(s):

Finite Element ◽

Fatigue Life ◽

Pressure Vessel ◽

Life Prediction ◽

Pressure Vessels ◽

Physical Damage ◽

Element Analysis ◽

Internal Damage ◽

Life Evaluation ◽

Fatigue Life Evaluation

Pressure vessels are subjected to repeated loads during use and charging, which can causefine physical damage even in the elastic region. If the load is repeated under stress conditions belowthe yield strength, internal damage accumulates. Fatigue life evaluation of the structure of thepressure vessel using finite element analysis (FEA) is used to evaluate the life cycle of the structuraldesign based on finite element method (FEM) technology. This technique is more advanced thanfatigue life prediction that uses relational equations. This study describes fatigue analysis to predictthe fatigue life of a pressure vessel using stress data obtained from FEA. The life prediction results areuseful for improving the component design at a very early development stage. The fatigue life of thepressure vessel is calculated for each node on the model, and cumulative damage theory is used tocalculate the fatigue life. Then, the fatigue life is calculated from this information using the FEanalysis software ADINA and the fatigue life calculation program WINLIFE.

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Dynamic Simulation of Full Start-Up Procedure of Heavy Duty Gas Turbines

Volume 4: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; IGTI Scholar Award ◽

10.1115/2001-gt-0017 ◽

2001 ◽

Cited By ~ 1

Author(s):

J. H. Kim ◽

T. W. Song ◽

T. S. Kim ◽

S. T. Ro

Keyword(s):

Gas Turbines ◽

Guide Vane ◽

Inlet Guide Vane ◽

Stable Operation ◽

Heavy Duty ◽

Operating Characteristics ◽

Fully Implicit ◽

Start Up ◽

Full Speed ◽

Stage Characteristic

A simulation program for transient analysis of the start-up procedure of heavy duty gas turbines for power generation has been constructed. Unsteady one-dimensional conservation equations are used and equation sets are solved numerically using a fully implicit method. A modified stage-stacking method has been adopted to estimate the operation of the compressor. Compressor stages are grouped into three categories (front, middle, rear), to which three different stage characteristic curves are applied in order to consider the different low-speed operating characteristics. Representative start-up sequences were adopted. The dynamic behavior of a representative heavy duty gas turbine was simulated for a full start-up procedure from zero to full speed. Simulated results matched the field data and confirmed unique characteristics such as the self-sustaining and the possibility of rear-stage choking at low speeds. Effects of the estimated schedules on the start-up characteristics were also investigated. Special attention was paid to the effects of modulating the variable inlet guide vane on start-up characteristics, which play a key role in the stable operation of gas turbines.

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Life Prediction of Power Turbine Components for High Exhaust Back Pressure Applications: Part I — Disks

Volume 7A: Structures and Dynamics ◽

10.1115/gt2015-43333 ◽

2015 ◽

Author(s):

Dipankar Dua ◽

Brahmaji Vasantharao

Keyword(s):

Steady State ◽

Secondary Flow ◽

Gas Turbines ◽

Life Prediction ◽

Creep Damage ◽

Back Pressure ◽

System Level ◽

Cyclic Life ◽

Power Turbine ◽

The Impact

Industrial and aeroderivative gas turbines when used in CHP and CCPP applications typically experience an increased exhaust back pressure due to pressure losses from the downstream balance-of-plant systems. This increased back pressure on the power turbine results not only in decreased thermodynamic performance but also changes power turbine secondary flow characteristics thus impacting lives of rotating and stationary components of the power turbine. This Paper discusses the Impact to Fatigue and Creep life of free power turbine disks subjected to high back pressure applications using Siemens Energy approach. Steady State and Transient stress fields have been calculated using finite element method. New Lifing Correlation [1] Criteria has been used to estimate Predicted Safe Cyclic Life (PSCL) of the disks. Walker Strain Initiation model [1] is utilized to predict cycles to crack initiation and a fracture mechanics based approach is used to estimate propagation life. Hyperbolic Tangent Model [2] has been used to estimate creep damage of the disks. Steady state and transient temperature fields in the disks are highly dependent on the secondary air flows and cavity dynamics thus directly impacting the Predicted Safe Cyclic Life and Overall Creep Damage. A System-level power turbine secondary flow analyses was carried out with and without high back pressure. In addition, numerical simulations were performed to understand the cavity flow dynamics. These results have been used to perform a sensitivity study on disk temperature distribution and understand the impact of various back pressure levels on turbine disk lives. The Steady Sate and Transient Thermal predictions were validated using full-scale engine test and have been found to correlate well with the test results. The Life Prediction Study shows that the impact on PSCL and Overall Creep damage for high back pressure applications meets the product design standards.

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FEM Analysis of Contact for Converter Spherical Hinge

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.365-366.331 ◽

2013 ◽

Vol 365-366 ◽

pp. 331-334

Author(s):

Xue Ping Ren ◽

Jian Da Gao

Keyword(s):

Numerical Simulation ◽

Thermal Stress ◽

Optimum Design ◽

Theoretical Basis ◽

Fem Analysis ◽

Structure Design ◽

Coupling Field ◽

Main Components ◽

Spherical Hinge

The role of converter spherical hinge is one of the main components, combined with practical work and With help of FEM, Thermal Stress coupling field of spherical washer can been obtained through numerical simulation. The result supplies substantial theoretical basis for further structure design and optimum design of mechanism.

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Operational Tests Results of the Naval Gas Turbines Operated by the Polish Navy

Zeszyty Naukowe Akademii Marynarki Wojennej ◽

10.2478/sjpna-2018-0005 ◽

2018 ◽

Vol 212 (1) ◽

pp. 85-103

Author(s):

Bogdan Pojawa

Keyword(s):

Gas Turbines ◽

Technical Condition ◽

Naval Academy ◽

Energy Research ◽

Idle Mode ◽

Load Variations ◽

Start Up ◽

Operational Diagnostics ◽

Operational Tests ◽

Near Future

Abstract This article is a continuation to the theme of the article Operational diagnostics synthesis of the naval gas turbines operated by the Polish Navy published in SJ of PNA No. 1/2017. This article presents examples of results of energy research carried out by the Polish Naval Academy in the years 1985–2016, for the purpose of operational diagnostics of this type of engine, operated by the Polish Navy. The research conducted since 1985 covered four types of naval gas turbines (DE 59, DR 76, DR 77 and LM 2500), with a total of 24 engines. Currently in operation there are four LM 2500 type engines. In the near future, another LM 2500 engine will commence operations, along with a project 661M patrol ship. The energy research covers the engine start-up process, their operation in idle mode and within the whole range of load variations, as well as the process of engine stopping. The article presents examples of characteristics specific to the above processes, determined based on the results of studies of individual types of engines. Currently ongoing studies allow for constructing strategies for naval gas turbines, operated in the Polish Navy, according to technical condition.

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