Life-Refurbishment of Service-Degraded Gas Turbine Buckets

2004 ◽  
Author(s):  
Yomei Yoshioka ◽  
Daizo Saito ◽  
Kazutoshi Ishibashi ◽  
Junji Ishii ◽  
Atsuhiko Izumi ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Low Cycle Fatigue ◽  
Hot Isostatic Pressing ◽  
Development Program ◽  
Charpy Impact ◽  
Turbine Rotor ◽  
Fatigue Properties ◽  
Maintenance Cost ◽  
Life Consumption ◽  
Non Destructive

Various methods have been developed, and used in practice, to reduce the maintenance cost of gas turbine hot parts by extending the replacement life. The life-refurbishment process by Hot Isostatic Pressing (HIP) is one of our accomplishments for the buckets retired due to the scheduled life and was confirmed to rejuvenate the microstructures and the tensile, Charpy impact, creep and low cycle fatigue properties to a condition equivalent to or even better than the new ones under the development program. According to above mentioned accomplishments, a number of HIP refurbished buckets were reinstalled in a Chubu Electric Power Co. Inc. (CEPCO) 1100°C-class gas turbine rotor on December 1999 and operated successfully for 2 years under the joint program. Those buckets also served for destructive and non-destructive evaluations after operation. From those tests, we reconfirmed the reliability of the HIP refurbished buckets and also validated that the life-consumption rate was the same as new ones.

scholarly journals 2MW Class High Efficiency Gas Turbine IM270 for Co-Generation Plants

1996 ◽  
Author(s):  
Hideo Kobayashi ◽  
Shogo Tsugumi ◽  
Yoshio Yonezawa ◽  
Riuzou Imamura
Keyword(s):  
Gas Turbine ◽  
High Efficiency ◽  
Mechanical Design ◽  
Development Program ◽  
Gas Turbine Engine ◽  
Maintenance Cost ◽  
Turbine Engine ◽  
Generation Plant ◽  
Emission Regulation ◽  
Heavy Duty Gas Turbine

IHI is developing a new heavy duty gas turbine engine for 2MW class co-generation plants, which is called IM270. This engine is a simple cycle and single-spool gas turbine engine. Target thermal efficiency is the higher level in the same class engines. A dry low NOx combustion system has been developed to clear the strictest emission regulation in Japan. All parts of the IM270 are designed with long life for low maintenance cost. It is planned that the IM270 will be applied to a dual fluid system, emergency generation plant, machine drive engine and so on, as shown in Fig.1. The development program of IM270 for the co-generation plant is progress. The first prototype engine test has been started. It has been confirmed that the mechanical design and the dry low NOx system are practical. The component tuning test is being executed. On the other hand, the component test is concurrently in progress. The first production engine is being manufactured to execute the endurance test using a co-generation plant at the IHI Kure factory. This paper provides the conceptual design and status of the IM270 basic engine development program.

AGT101 Advanced Gas Turbine Technology Update

1986 ◽  
Author(s):  
G. L. Boyd ◽  
J. R. Kidwell ◽  
D. M. Kreiner
Keyword(s):  
Gas Turbine ◽  
Technology Development ◽  
Development Program ◽  
Turbine Rotor ◽  
Test Time ◽  
Inlet Temperature ◽  
Metal Foil ◽  
Steady State Operation ◽  
Full Speed ◽  
Engine Testing

The Garrett/Ford Advanced Gas Turbine Technology Development Program, designated AGT101, has made significant progress during 1985 encompassing ceramic engine and ceramic component testing. Engine testing has included full speed operation to 100,000 rpm and 1149C (2100F) turbine inlet temperature, initial baseline performance mapping and ceramic combustor start and steady state operation. Over 380 hours of test time have been accumulated on four development engines. High temperature foil bearing coatings have passed rig test and a thick precious metal foil coating selected for engine evaluation. Ceramic structures have been successfully rig tested at 1371C (2500F) for over 27 hours. Interface compatibility testing conducted during these runs indicate RBSN-to-RBSN or SASC-to-SASC result in “sticking” — however, RBSN-to-SASC in either planar or line contact show no evidence of sticking. Ceramic combustor rig tests have demonstrated acceptable lightoffs using either a conventional ignitor or a commercially available glow plug. Operation to 1371C (2500F) combustor discharge temperatures have also been demonstrated. Ceramic turbine rotor fabrication efforts have continued at ACC and Ford. Kyocera and NGK-Locke also have been working on the rotor. Several rotors have been received and are currently undergoing final machining and qualification tests. Testing of the all-ceramic AGT101 engine is currently scheduled for late 1985.

scholarly journals Status of the Automotive Ceramic Gas Turbine Development Program: Year 3 Progress

1994 ◽  
Author(s):  
Takane Itoh ◽  
Hidetomo Kimura
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Test ◽  
Development Program ◽  
Turbine Rotor ◽  
Maximum Speed ◽  
Inlet Temperature ◽  
Test Rig ◽  
Thermal Test ◽  
The Individual

Under the ongoing seven-year program, designated “Research and Development of Automotive Ceramic Gas Turbine Engine (CGT Program)”, started in June 1990. Japan Automobile Research Institute. Inc. (JARI) is continuing to address the issues of developing and demonstrating the advantageous potentials of ceramic gas turbines for automotive use. This program has been conducted by the Petroleum Energy Center (PEC) with the financial support of MITI. The basic engine is a 100 kW, single-shaft regenerative engine having a turbine inlet temperature of 1350°C and a rotor speed of 110,000 rpm. In the third year of this program, the experimental evaluation of the individual engine components and various assembly tests in a static thermal test rig were continued. Exhaust emissions were also measured in a performance test rig for an initially designed pre-mixed, pre-vaporized lean (PPL) combustor. A maximum speed of 130,700 rpm was obtained during hot spin tests of delivered ceramic turbine rotors, which was almost the same level as during cold spin tests. A dynamic thermal test including a centrifugal compressor, a ceramic radial turbine rotor and all the ceramic stationary hot parts was initiated.

The Effect of Creep-Fatigue Interactions on Thermo-Mechanical Fatigue Life and Reliability Estimates for a Typical Gas Turbine Engine Component

2019 ◽  
Author(s):  
Esakki Muthu Shanmugam ◽  
Raghu V. Prakash
Keyword(s):  
Gas Turbine ◽  
Base Alloy ◽  
Low Cycle Fatigue ◽  
Creep Damage ◽  
Fatigue Curve ◽  
Turbine Rotor ◽  
Distribution Method ◽  
Turbine Engine ◽  
Linear Creep ◽  
Creep Fatigue

Abstract The low cycle fatigue-creep damage is the main parameter for the failures of gas turbine components under high temperature and cyclic loading. In this work, different combinations of Creep-Fatigue damage are introduced and checked for its impact on the Turbine life and its reliability. Linear and Non-Linear Creep-Fatigue combinations were considered as part of this work. The Turbine rotor under present study is made out of Nimonic-90 nickel base alloy forging. Weibull distribution method was used to study the reliability. It was found that, the reliability reduces from 99% to 25% when creep damage component is increased from 20% to 40% for a fixed Turbine life. The damage factor was found more in above linear Creep-Fatigue curve and less in below linear Creep-Fatigue curve.

scholarly journals Assessing the Condition of Gas Turbine Rotor Blades with the Optoelectronic and Thermographic Methods

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 31 ◽  
Author(s):  
Mariusz Bogdan ◽  
Józef Błachnio ◽  
Artur Kułaszka ◽  
Marcin Derlatka
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Degradation Process ◽  
Turbine Rotor ◽  
Visible Range ◽  
Engine Operation ◽  
Color Changes ◽  
Optoelectronic Method ◽  
Non Destructive ◽  
Destructive Methods

Gas turbines and their blades in particular might be damaged in the course of the aviation turbojet engine operation process. The degradation process of the blade microstructure is most evident from the change in the colour of its surface. This is assessed using the optoelectronic method. The article presents the concept of non-destructive methods, which are used to assess the degree of degradation of the alloy of a gas turbine blade. The proposed optoelectronic method is the basic method for the preliminary determination of color changes in the surface. Appropriate videoscopes or video-analyzers, capable of recording a test object in various electromagnetic wave ranges (infrared radiation, visible range), are used for this purpose. These preliminary results of the diagnosis make it possible to infer further studies of the blade. For accurate investigation of the state of the alloy microstructure, a non-destructive thermographic method (xenon flash pulsed thermography) was used. The results of studies of the degradation of the microstructure with the use of non-destructive methods were verified through the use of metallographic investigations. Appropriate metallographic specimens were created in order to recognize phase γ′ degradation (i.e., the phase strengthening the blade alloy). The results of the presented research allowed for an in-depth assessment of the degree of microstructure degradation of operated blades.

LCF Initiated - HCF Propagated Crack Life Estimation of Gas Turbine Bolts

2018 ◽  
Author(s):  
Amit K. Paspulati ◽  
Krishna Veluru ◽  
Kashinath Akki ◽  
Rohit Khattar ◽  
Sudeep Bosu ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Gas Turbine ◽  
High Cycle Fatigue ◽  
Low Cycle Fatigue ◽  
Evaluation Studies ◽  
Three Dimensional ◽  
Fatigue Loading ◽  
Turbine Rotor ◽  
Cycle Fatigue ◽  
Compressor Rotor

This paper discusses the methodology to calculate high cycle fatigue (HCF) crack propagation life of gas turbine bolts and compares two dimensional (2D) HCF crack propagation life to three dimensional (3D) HCF crack propagation life. Gas turbine bolts when exposed to fatigue loading are prone to crack initiation and propagation (structural failure) during operation. In such cases cracks mostly are initiated by low cycle fatigue (LCF) and propagated by HCF. Therefore in current illustration the authors have evaluated crack propagation primarily initiated by low cycle fatigue and propagated by high cycle fatigue. 2D and 3D fracture methodology approaches had been used for analytical evaluation. The authors conclude on the efficacy of both the methods based on the data from the field. The coupling joint bolts located in the engine mid-section, which are used to join compressor rotor with turbine rotor are being considered for crack evaluation studies. The coupling bolts located in mid-section are primarily loaded by high axial bolt pre-loads needed to keep the joint intact, as well as loaded in bending due to rotor gravity sag. The crack propagation life is evaluated and validated with field data using cracked bolt specimen from the field.

Microstructure and Fatigue Properties of TiAl with Unique Layered Microstructure Fabricated by Electron Beam Melting

2018 ◽  
Vol 941 ◽  
pp. 1597-1602
Author(s):  
Ken Cho ◽  
Ryota Kobayashi ◽  
Takuma Fukuoka ◽  
Jong Yeong Oh ◽  
Hiroyuki Y. Yasuda ◽  
...  
Keyword(s):  
Electron Beam ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Crack Propagation ◽  
Electron Beam Melting ◽  
Low Cycle Fatigue ◽  
Hot Isostatic Pressing ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Cast Alloys

The effect of a unique layered microstructure consisting of duplex-like region and equiaxed γ grains (γ bands) on the fatigue properties of Ti-48Al-2Cr-2Nb alloy bars fabricated by electron beam melting (EBM) at an angle (θ) of 90° between the building direction and cylinder (loading) axis was investigated focusing on the layered microstructure and test temperature. We found the room temperature (RT) fatigue strength of the alloy bars fabricated at θ = 90° is higher than that of the bars fabricated at θ = 0°. Moreover, it is comparable to that of the cast alloys with hot isostatic pressing (HIP) treatment in low-cycle fatigue life region, even without HIP treatment. The high fatigue strength of the bars at RT is attributed to the γ band, which acts as a resistance for crack propagation directed perpendicular to the γ band. On the other hand, the fatigue strength of the bars at θ = 90° is lower than that of the bars at θ = 0° in low-cycle fatigue life region at 1023 K. This is because the γ bands dose not act as a resistance for crack propagation at 1023 K. Although the bars at θ = 90° exhibits low fatigue strength in the region at 1023 K, that value is comparable to that of HIP-treated cast alloys due to the fine grain size, which is one of the features for the alloys fabricated by the EBM.

Integrated Approach to Gas Turbine Rotor Condition Assessment and Life Management

2012 ◽  
Author(s):  
V. P. (Swami) Swaminathan ◽  
Gil J. Dean ◽  
John R. Scheibel
Keyword(s):  
Gas Turbine ◽  
Structural Engineering ◽  
Low Cycle Fatigue ◽  
Integrated Approach ◽  
Turbine Rotor ◽  
Life Assessment ◽  
Tensile Fracture ◽  
Materials Testing ◽  
Engineering Analysis ◽  
Turbine Disc

Turbine manufacturers place limits on the service life of gas turbine (GT) rotors/discs based on either the number of hours of operation or the number of start-stop cycles. A significant number of gas turbine rotors are either condemned or slated for replacement during a future outage. Some turbines experience premature cracking which results in the replacement of select rotor components. Examples of such cases are GE Frame 7EA compressor disc cracking, Frame 7FA/9FA turbine disc air-feed slot and post cracking, and Frame 6001B turbine disc rabbet cracking Many Alstom 11N and Siemens W-501 rotors and discs are also replaced based on design life limitations. This experience prompted EPRI, sponsored by gas turbine owners to conduct projects in this area. Under this program, TurboMet International and AccTTech,LLC conducted metallurgical evaluation of cracked discs to understand the crack initiation and propagation mechanisms, detailed structural engineering analysis to understand the root cause of cracking and developed solutions; and to provide recommendations to turbine owners to mitigate such failures. Condition and remaining life analysis of several turbine models was conducted using rigorous engineering analysis to provide objective technical recommendations to turbine users to safely extend the life of the rotors. This collective experience has result in guidelines for safe reinspection intervals to mitigate future risk. In order to obtain pertinent material properties needed for such detailed engineering analysis, retired rotors and discs were obtained from both compressor and turbine sections. Nondestructive examinations (NDE) and materials testing were conducted to assess component condition and mechanical properties such as tensile, fracture toughness, crack growth, creep, low-cycle fatigue, etc. This paper provides an overview of an integrated rotor condition and life assessment approach including several examples of component evaluations.

scholarly journals Status of the Automotive Ceramic Gas Turbine Development Program: Year 2 Progress

1993 ◽  
Author(s):  
Takane Itoh ◽  
Hidetomo Kimura
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Speed ◽  
Development Program ◽  
Turbine Rotor ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Turbine Engine ◽  
Basic Engine ◽  
Second Year

A seven-year program, designated “Research & Development of Automotive Ceramic Gas Turbine Engine (CGT Program)”, was started in June 1990 with the object of demonstrating the advantageous potentials of ceramic gas turbines for automotive use. This CGT-Program is conducted by PEC with the support of MITI. The basic engine is a 100-kW, single-shaft engine having a turbine inlet temperature of a 1350°C and a rotor speed of 110,000 rpm. During the second year of the program, experimental evaluation of the various components was started, including a centrifugal compressor, a radial turbine rotor, a high speed rotor system and initial ceramic hot parts. Cold and hot spin testing of ceramic rotors from three different ceramic suppliers was also initiated.

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