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.

Repair of Advanced Gas Turbine Blades

2007 ◽  
Author(s):  
Reiner Anton ◽  
Brigitte Heinecke ◽  
Michael Ott ◽  
Rolf Wilkenhoener
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
High Efficiency ◽  
High Reliability ◽  
Turbine Blades ◽  
Cost Effective ◽  
Complex Nature ◽  
Thin Wall ◽  
Advanced Technologies

The availability and reliability of gas turbine units are critical for success to gas turbine users. Advanced hot gas path components that are used in state-of-the-art gas turbines have to ensure high efficiency, but require advanced technologies for assessment during maintenance inspections in order to decide whether they should be reused or replaced. Furthermore, advanced repair and refurbishment technologies are vital due to the complex nature of such components (e.g., Directionally Solidified (DS) / Single Crystal (SC) materials, thin wall components, new cooling techniques). Advanced repair technologies are essential to allow cost effective refurbishing while maintaining high reliability, to ensure minimum life cycle cost. This paper will discuss some aspects of Siemens development and implementation of advanced technologies for repair and refurbishment. In particular, the following technologies used by Siemens will be addressed: • Weld restoration; • Braze restoration processes; • Coating; • Re-opening of cooling holes.

Flameholding Tendencies of Natural Gas and Hydrogen Flames at Gas Turbine Premixer Conditions

2014 ◽  
Author(s):  
Elliot Sullivan-Lewis ◽  
Vincent McDonell
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
High Reliability ◽  
Elevated Pressure ◽  
Inlet Temperature ◽  
Increased Risk ◽  
Wide Range ◽  
Lean Premixed

Ground based gas turbines are responsible for generating a significant amount of electric power as well as providing mechanical power for a variety of applications. This is due to their high efficiency, high power density, high reliability, and ability to operate on a wide range of fuels. Due to increasingly stringent air quality requirements, stationary power gas turbines have moved to lean-premixed operation. Lean-premixed operation maintains low combustion temperatures for a given turbine inlet temperature, resulting in low NOx emissions while minimizing emissions of CO and hydrocarbons. In addition, to increase overall cycle efficiency, engines are being operated at higher pressure ratios and/or higher combustor inlet temperatures. Increasing combustor inlet temperatures and pressures in combination with lean-premixed operation leads to increased reactivity of the fuel/air mixture, leading to increased risk of potentially damaging flashback. Curtailing flashback on engines operated on hydrocarbon fuels requires care in design of the premixer. Curtailing flashback becomes more challenging when fuels with reactive components such as hydrogen are considered. Such fuels are gaining interest because they can be generated from both conventional and renewable sources and can be blended with natural gas as a means for storage of renewably generated hydrogen. The two main approaches for coping with flashback are either to design a combustor that is resistant to flashback, or to design one that will not anchor a flame if a flashback occurs. An experiment was constructed to determine the flameholding tendencies of various fuels on typical features found in premixer passage ways (spokes, steps, etc.) at conditions representative of a gas turbine premixer passage way. In the present work tests were conducted for natural gas and hydrogen between 3 and 9 atm, between 530 K and 650K, and free stream velocities from 40 to 100 m/s. Features considered in the present study include a spoke in the center of the channel and a step at the wall. The results are used in conjunction with existing blowoff correlations to evaluate flameholding propensity of these physical features over the range of conditions studied. The results illustrate that correlations that collapse data obtained at atmospheric pressure do not capture trends observed for spoke and wall step features at elevated pressure conditions. Also, a notable fuel compositional effect is observed.

Operating Experience of the GT13E2 at Kawasaki Gas Turbine Research Center

1999 ◽  
Author(s):  
Tatsuo Fujii ◽  
Takakazu Uenaka ◽  
Hitoshi Masuo
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Gas Flow ◽  
High Reliability ◽  
Operating Experience ◽  
Operational Reliability ◽  
Nox Emission ◽  
Research Center ◽  
Major Influence ◽  
Nox Emissions

The first Kawasaki-ABB GT13E2 gas turbine began operating at Kawasaki Gas Turbine Research Center (KGRC) in Sodegaura city, Japan in January 1994. This facility is a simple-cycle power station and is operated in DSS (Daily Start and Stop) operation mode as a peaking unit, and its output electricity is delivered to Tokyo Electric Power Company (TEPCO). The GT13E2 gas turbine at KGRC was manufactured jointly by Kawasaki Heavy Industries (KHI) and Asea Brown Boveri (ABB). KHI and ABB have a joint test program with this facility to research for high reliability, high performance and low emission for the GT13E2 and future gas turbines. The performance of the KGRC GT13E2 has been monitored continuously. It was found from these monitored data that the thermal efficiency has been maintained at a high level and could be recovered by compressor washing when the compressor was fouled. Several factors which influence NOx emissions were studied on the gas turbine, and it was found that atmospheric humidity has a major influence on NOx emissions. Also other factor such as the position of the variable inlet guide vanes (VIGV) and fuel gas flow through each burner of the combustor were adjusted to reduce NOx emission. As a result, NOx emission from the KGRC GT13E2 has been maintained at a very low level. Reliability, availability and maintainability (RAM) has been evaluated by Operational Reliability Analysis Program (ORAP®) of Strategic Power Systems, Inc. (SPS) in order to identify and improve RAM performance of the GT13E2 at KGRC. These analyses made it clear what kind of outage had an impact on the reliability, availability and starting reliability of the KGRC GT13E2 and appropriate actions have increased the starting reliability. This paper describes operating experiences of the KGRC GT13E2 including performance, emissions and RAM performance.

Development and Implementation of Repair Processes for Refurbishment of W501F, Row 1 Turbine Blades

2001 ◽  
Author(s):  
Richard Curtis ◽  
Warren Miglietti ◽  
Michael Pelle
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Turbine Blades ◽  
Combined Cycle ◽  
Cycle Basis ◽  
Repair Procedure ◽  
Crack Repair ◽  
Maintenance Requirements

In recent years, orders for new land-based gas turbines have skyrocketed, as the planning, construction and commissioning of new power plants based on combined-cycle technology advances at an unprecedented pace. It is estimated that 65–70% of these new equipment orders is for high-efficiency, advanced “F”, “G” or “H” class machines. The W501F/FC/FD gas turbine, an “F” class machine currently rated at 186.5 MW (simple cycle basis), has entered service in significant numbers. It is therefore of prime interest to owners/operators of this gas turbine to have sound component refurbishment capabilities available to support maintenance requirements. Processes to refurbish the Row 1 turbine blade, arguably the highest “frequency of replacement” component in the combustion and hot sections of the turbine, were recently developed. Procedures developed include removal of brazed tip plates, coating removal, rejuvenation heat treatment, full tip replacement utilizing electron beam (EB) and automated micro-plasma transferred arc (PTA), joining methods, proprietary platform crack repair and re-coating. This paper describes repair procedure development and implementation for each stage of the process, and documents the metallurgical and mechanical characteristics of the repaired regions of the component.

scholarly journals Operating Experience With Prototype Gas Turbines

1973 ◽  
Author(s):  
W. Endres
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
New Technologies ◽  
High Reliability ◽  
Operating Experience ◽  
The Past ◽  
Higher Power

Prototype gas turbines must have higher power and efficiency than their forerunners and therefore include new technologies and designs. A high reliability of the new gas turbine can be reached by careful evaluations of operating experience and by the choice of well proven elements for the new design. The first year’s operating experience with several prototype gas turbines, put into operation in the last decade, is given in the paper. It shows what kind of problems have been met in the past. All machines have given satisfactory service. This paper gives gas turbine users an assessment of the risks of running a prototype gas turbine.

The Need for Standards to Promote Low Emission, High Efficiency Gas Turbine Facilities

1999 ◽  
Author(s):  
Manfred Klein
Keyword(s):  
Gas Turbine ◽  
High Efficiency ◽  
Operating Experience ◽  
Cost Effective ◽  
District Energy ◽  
Low Emission ◽  
Carbon Dioxide Co2 ◽  
Prevention Methods ◽  
Environmental Permitting

Gas turbine cogeneration and district energy plants can provide significant environmental improvements to the long term mix of energy production, in terms of low air pollutants and greenhouse gases. This paper is intended to discuss the fundamental need to integrate plant efficiency considerations into the environmental permitting rules to address all air issues at the same time, as described in the 1992 Canadian gas turbine emission guideline. The paper also compares the relevant air emissions, primarily nitrogen oxides (NOx) and carbon dioxide (CO2), from modern gas turbine plants, and the Canadian operating experience with cost-effective emission prevention methods.

2-Stage Air Filtration for Gas Turbine Naval Applications

2019 ◽  
Author(s):  
Gianluca de Arcangelis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Turbine Blades ◽  
Water Repellency ◽  
Air Filtration ◽  
Compressor Blades ◽  
Reduced Pressure ◽  
Filtration System ◽  
Offshore Oil

Abstract Traditional air filtration systems for Gas Turbine Naval applications consist of 3 stages: 1st vane separator + pocket filter + 2nd vane separator. The 2nd vane separator is required to drain out droplets formed by the traditional pocket filter during its coalescing function. Further to technological advancements in the water repellency of filter media, as well as leak-free techniques, it is now possible to implement a pocket filter that avoids leaching water droplets downstream. This enables the elimination of the 3rd stage vane separator in the air filtration system. The result is a suitable 2-stage air filtration system. The elimination of the 3rd stage vane separator provides the obvious following advantages: • Reduced pressure drop • Reduced weight • Reduced foot-print • Reduced cost Latest technological advancements in water repellency and high efficiency melt-blown media also allow the attainment of higher performance such as: • Increased efficiency against water droplet and salt in wet state • Increased efficiency against dry salt and dust This results in higher cleanliness of the Gas Turbines with benefits in terms of compressor fouling, compressor blades corrosion and turbine blades hot erosion. Higher performance also results in simplified maintenance as technicians need only focus on the replacement of the elements as opposed to the cleaning and overhauling of the intake duct. The paper goes through the engineering challenges of evolving from a 3-stage to 2-stage filtration system. The paper provides data from testing at independent laboratories with results that back the claims. Furthermore, reference is made to Offshore Oil & Gas installations and testing that have proven successful with independently measured data.

Researches Concerning Kerosene-to-Landfill Gas Conversion for an Aero-Derivative Gas Turbine

2010 ◽  
Author(s):  
Jeni A. Popescu ◽  
Valeriu A. Vilag ◽  
Romulus Petcu ◽  
Valentin Silivestru ◽  
Virgil Stanciu
Keyword(s):  
Carbon Dioxide ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
High Reliability ◽  
Landfill Gas ◽  
Combustion Process ◽  
Injection System ◽  
Cfd Simulations ◽  
Numerical Approaches

The aero-derivative gas turbine represents an advanced solution for technologic transfer from aeronautics to industrial applications, including high efficiency, reduced dimensions and high reliability. The paper, as result of a research project, is focused on an application using an aero-derivative gas turbine as an installation for CO2 rich landfill gas valorization. The paper also presents the potential for landfill gas production in Romania, in the context of the requirements imposed by the environmental laws. A calculation is realized based on demographic statistics, showing the most suitable areas in the country for obtaining the landfill gas. The first part is dedicated to a comparative examination of classical liquid fuel, kerosene, and two gaseous fuels, methane and landfill gas with equal volume ratio of methane and carbon dioxide, analyzed from the point of view of their combustion performances in the gas turbine, with the help of CEA program developed by NASA. Considering the nowadays utilization of CFD simulations for design purpose in many activity fields from the engineering domain, the results provided by the CEA program, along with the ones provided by the gas turbine’s producer, were considered input data for the numerical approaches of the combustion process of methane and landfill gas in the known combustion chamber using a commercial CFD code. The main goal of the CFD applications is to determine the optimum geometric configuration of the new injection system in order to obtain a stabilized process and high performances in safety conditions, for low working regimes and nominal regime, as defined by experimental data and producer’s recommendations. Previous successful experimentations on test bench following the combustion simulation of methane gas and the encouraging results from the CFD simulations lead to new experimentations of the gas turbine working on landfill gas in order to validate the numerical approaches, activity described in the third part of the paper. A technological fueling scheme was designed, the geometrical adjustments were made according to previous simulations and the landfill gas was simulated using a homogenization device installed on the fuel line for a forced mixing of the two non-reactive substances, methane and carbon dioxide. The gas turbine was prepared and instrumented for bench testing and stable working was obtained for speeds of 27–63% of the nominal one. The conclusions are related to the execution of an installation allowing experimentation of gas turbines working on landfill gas and future researches focusing on tests for higher working regimes.

A Novel Gas Turbine Product Line for Onsite Generation and Combined Heat and Power Between 400 kWe and 1.6 MWe

2004 ◽  
Author(s):  
George L. Touchton ◽  
Alexandr Belokon ◽  
Mikhail Senkevych ◽  
V. Belyaev
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Size Range ◽  
Cost Effective ◽  
Combined Heat And Power ◽  
Product Line ◽  
Operating Characteristics ◽  
Capital Costs ◽  
Reciprocating Engines

In theory gas turbines have inherent advantages for on-site power generation and combined heat and power production in the size range from 50 kWe to 5 MWe. These include low maintenance costs, low vibration, low emissions impact, and ease of remote operation. They also have the potential for high efficiency and low capital costs. In practice they have failed to seriously challenge reciprocating engines dominant market position, despite many recent attempts by established corporations and innovative start-ups. The authors analyze the reasons for this, and discuss the performance goals that gas turbines (or any other new product) must meet in order to challenge and displace the incumbent technology. They then describe a novel gas turbine product line designed specifically to meet this specification in the size range from 400 kW to 1.6 MW. The design is a “clean sheet” of paper approach uniquely fusing industrial gas turbine and aero engine technologies and practices. Fully commercial, cost effective components and technology are applied throughout. The result is a family of machines, which have efficiencies, capital costs, emissions impact, and operating characteristics that make them directly competitive with reciprocating engines across the board. The authors base the features and operating characteristics of the machines on thermodynamic analysis, and component, and system designs prepared by Salut [Appendix A].

Overhaul and Uprate of Industrial Gas Turbines by an Alternate Service Provider

2010 ◽  
Author(s):  
Michel Arnal
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Rate ◽  
Cost Effective ◽  
Advanced Technology ◽  
General Electric ◽  
Extensive Experience ◽  
Hot Gas ◽  
Before And After ◽  
Industrial Gas Turbines

This paper reviews specific methods used by Wood Group Gas Turbine Services for boosting power output and improving heat rate for existing industrial gas turbines. The methods employed allow operators to make the most of existing equipment as a cost-effective alternative to the replacement of a complete engine. The article summarizes experience with the service and uprate of General Electric Frame 6B gas turbines using the company’s Advanced Parts Manufacture (APM™) turbine parts. A comparison of output and heat rate before and after service allows estimates of the performance improvement for individual components and combinations of hot gas path parts. Such comprehensive upgrades can be implemented only in older generation gas turbines that are part of a model line which the original equipment manufacturer (OEM) has redesigned. An ideal example of such a gas turbine model is the General Electric Frame 6B series. Wood Group Gas Turbine Services has extensive experience in overhauling and uprating the complete range of Frame 6B gas turbines. The company’s replacement parts have been installed in all stages of the hot gas path both as complete sets and in stages in combination with OEM parts in neighboring stages. Examples of components which can be upgraded include: • Turbine vanes and blades; • Combustion Lines and transition pieces; • Heat shields / shroud blocks; • Seals and clearances. All of these can be installed to increase the engine firing temperature and improve performance. The performance data is corrected to ISO conditions to enable a fair and meaningful comparison. The different configurations employed for the overhauls also permit estimates of the contribution of the replacement parts to the overall improvement in performance. Design details of the advanced technology parts are described as needed to provide understanding for the improvements in engine efficiency.

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