PGE Conference Paper TVB 31-05-2011 FINAL[1]

8/14/2019 PGE Conference Paper TVB 31-05-2011 FINAL[1]

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POWER

THE NEXT GENERATION ALSTOM GT26THE PIONEER IN

OPERATIONAL FLEXIBILITY

CONFERENCE PAPER



2 | Power-Gen Europe in Milan, Italy, 7–9 June 2011© ALSTOM 2011. All rights reserved. Information contained in this document is indicative only. No representation or warranty is given or should be relied on that it is complete or correct orwill apply to any particular project. This will depend on the technical and commercial circumstances. It is provided without liability and is subject to change without notice. Reproduction, useor disclosure to third parties, without express written authority, is strictly prohibited.

Paper presented at Power-Gen Europe in Milan, Italy, 7–9 June 2011

The Next Generation Alstom GT26The Pioneer in Operational FlexibilityMatthias Hiddemann, Frank Hummel, Jürg Schmidli

Alstom PowerPablo Argüelles Tuñón

hc energía, Oviedo, Spain

Abstract ................................................................................................................................3

1. Introduction ..........................................................................................................................41.1 Market Requirements .........................................................................................................41.2 GT26 Upgrade Evolution .....................................................................................................5

2. Upgrade Feature & Benets ..................................................................................................62.1 Overview .............................................................................................................................6

2.2 Compressor .........................................................................................................................72.3 SEV Combustion System ....................................................................................................82.4 Low Pressure turbine ..........................................................................................................82.5 Operation Concept ..............................................................................................................9

3. Validation ...........................................................................................................................103.1 Validation Strategy ............................................................................................................103.2 Compressor validation ......................................................................................................103.3 Turbine validation ..............................................................................................................113.4 Compressor validation ......................................................................................................12

3.4.1 Rig testing ...............................................................................................................123.5 SEV-Burner validation ......................................................................................................12

3.5.1 Rig testing ...............................................................................................................123.5.2 Engine validation in the Alstom Test Power Plant ...................................................12

4. Retrotability ......................................................................................................................13

5. Summary ...........................................................................................................................13

6. Bibliography .......................................................................................................................14



Power-Gen Europe in Milan, Italy, 7–9 June 2011 | 3

The Next Generation Alstom GT26The Pioneer in Operational Flexibility

© ALSTOM 2011. All rights reserved. Information contained in this document is indicative only. No representation or warranty is given or should be relied on that it is complete or correct orwill apply to any particular project. This will depend on the technical and commercial circumstances. It is provided without liability and is subject to change without notice. Reproduction, useor disclosure to third parties, without express written authority, is strictly prohibited.

AbstractIn order to reduce the cost of electricity in today’s challenging market environment and to reduce the CO2 emissions, highall-round efciency (base-load and part-load) is one of the key drivers regarding today’s gas turbine development. Whileintroducing new products and/or upgrades, the market expectation is to maintain a high level of reliability and availability.The rapid push globally for CO2-free technologies such as renewable power is seeing a signicant change in the roleof CCPP’s. The servicing of the traditional “energy” markets is being replaced by serving more the “capacity” markets,providing an increasing role in grid load balancing support - with high cycling and part load operation being more the norm.

To meet these goals and market challenges, the next evolutionary upgrade package for the GT26 sequential combustion gasturbine has been developed. Already in the 90’s with the launch of the GT26 gas turbine Alstom has realized the importanceof higher part load efciency and fast start-up capabilities. From its beginning this gas turbine technology has thereforeincorporated features, like multiple variable compressor guide vanes and sequential combustion, which set a new industrystandard regarding operational exibility.

This paper is reporting for the rst time about the development steps of this upgrade, which evolved from the existingproven design with presently more than 4.0 million red hours across the GT24/GT26 eet. In order to demonstrate thedevelopment targets before market introduction, an in-depth validation program, following the Alstom Power productdevelopment process, has been performed and will be described, e.g.:

Extensive full engine testing in the Alstom Test Power Plant in Birr, Switzerland Thermal Paint test run of the hot gas path parts Compressor mapping in one of the world’s biggest compressor test rigs Sequential EnVironmental (SEV) burner testing in a high-pressure combustor test rig Use of state-of-the-art design tools and features, including aero-engine know-how based on the technology sharingagreement between Alstom Power and Rolls Royce plc.

Furthermore, the paper reports on the commercial operation experience of this upgrade to-date, in as far as the LowPressure (LP) turbine has already been implemented in a front-runner unit. This unit has been operating reliably for morethen 8’000 operating hours as of June 2011. All design targets regarding performance and emissions have been met. Theresults of the rst scheduled inspection of the hot gas path revealed that all stationary and rotating components were inexcellent condition.




1. Introduction1.1 Market Requirements

Power markets around the world are facing new challenges:Building new power generation plants to meet growingdemand means also having to take into considerationmore stringent global environmental standards. Increasingall-round efciency is one of the main market drivers forgas turbine and combined cycle development, so as tolower fuel consumption, and at same time produce loweremissions (NOx, CO etc.) with the ultimate goal of havinga reduction in the cost of electricity.

Further market requirements arise by the trend-shiftin structural set-up from one of regulated (closed) tode-regulated (open) power markets: the result of thisdevelopment is that many of the advanced gas-redcombined cycle power plants that where installed in thelate 1990’s and early 2000’s were specied and designedbased on base-load dispatch due to their relative highefciencies. Today they are being called on to operate undera wide ranging dispatch regime, including daily stop/startsand intermediate regimes, which was never foreseen at the

outset.

Operational exibility as a market requirement is thereforemore and more important in the gas-red power industry.OEM’s and Operators alike are re-dening the way suchpower plants should be designed and the load regimesthat have to be supported today and in the future. The

emergence and growth of renewable power, in particularwind-farms, also brings new challenges and opportunitiesfor power companies and grid operators. The increasinginstallation of power generation systems using renewableenergies like wind power and their dependency on ambientconditions calls for a balance with the reliable and rapidlyavailable power resources covering periods of suddensupply shortage, peak demands or simply following theautomated generation control over a wide range of relativeload. As a result, the efciency under part-load operationis even more important than the efciency at base-load inmany cases.

Additionally, today’s gas turbine equipment requiresincreased exibility in terms of natural gas used. Marketforecasts predict an increasing variation in the fuel gascomposition over the next decade. Already today, pipelinegases are seeing a higher uctuation as they may consistof combinations of multiple well supplies that are blendedand thus result in varying properties. Moreover power

plants might be supplied with gas from LNG terminals.Flexibility regarding the fuel gases used for gas turbinesis therefore a must. A precondition for this fuel exibility isa robust combustion system that does not need additionalmeasures like hardware change or fuel preheating, whicheither result in additional downtime for changing hardwareor which might have an impact on the efciency of thepower plant.






1.2 GT26 Upgrade Evolution

In the mid 1990s, Alstom introduced two scaled sequentialcombustion gas turbines - the GT24 for the 60 Hz marketand the GT26 for the 50 Hz market. Since then the advancedclass GT24/GT26 gas turbines have demonstrated that thistechnology platform does offer signicant advantages.Unprecedented operating exibility, superior part-loadefciency, low emissions over a wide load range with world-class levels of reliability and availability are characteristicsof these gas turbines.

The main technology differentiator of Alstom’s GT24/GT26advanced-class gas turbines is the ‘sequential (2-stage)combustion’ principle, which was already rst introducedinto the market in 1948. The GT24/GT26 combustion systemis based on a well-proven Alstom combustion conceptusing the EV (EnVironmental) burner in a rst, annularcombustor followed by the SEV (Sequential EnVironmental)burner in the second annular combustion stage. The drylow NOx EV-burner has a long operating history and isused in the whole Alstom gas turbine range. Sequential

F L E X I B I L I T Y

P E R F O R M A N C E

High part load efficiencyHot start < 60 min.High fuel flexibility

*LLOC Low Load Operation Capability

High part load efficiencyHot start < 60 min.High fuel flexibility

High part load efficiencyHot start < 60 min.High fuel flexibilityLLOC*Superior part load emissions

378 MW Output57.0% Efficiency



Lower fuel consumption & reduced CO 2 production

1999

2002

2006

Today

Figure 1 – KA26 Performance and Flexibility evolution

combustion - ‘the reheat principle for gas turbines’ - hadalready been applied to earlier Alstom gas turbines by usingtwo side-mounted silo combustors. Integrating the conceptof dry low NOx EV-burner and sequential combustion intoa single-shaft gas turbine resulted in the GT24/GT26 – anadvanced-class GT-technology with high power density andlow emissions [1].

This Sequential Combustion combined with multiplevariable compressor guide vanes set a new industrystandard regarding part-load efciency and turn-downcapability. These two main contributors to operationalexibility were already introduced by Alstom in the 90’s,making Alstom the true pioneer.

The performance and exibility evolution of the GT26 untiltoday is shown in Figure 1.




Since the rst introduction, there have now been threeprevious performance increases on the GT26 engine:

1) In 1999, as part of the so called A-conguration to theB-conguration (Upgrade 1999)

2) In 2002, with the introduction of the rst compressorredesign (Upgrade 2002)

3) In 2006, a rating increase based on the secondcompressor upgrade together with a slight turbine inlettemperature increase (Upgrade 2006)

In 2002 the GT24/GT26 compressor was redesigned foran increased mass ow of 5%, with the goal of having asimilar increase in the combined cycle power output. Thiswas achieved through both, optimized airfoil design andre-staggering of the compressor blades. The result was adesign that required no change to the rotor and stator owpath contour. Compressor blade length and channel height,rotor and compressor vane xation grooves, as well asblade and vane material all remained unchanged.

The next modication of the GT26 compressor took place

in 2006. The GT26 compressor was re-staggered in thefront stages to increase the mass ow. Additionally, foroptimization of efciency and cooling air bleed conditions,some re-stagger was carried out in the high-pressurecompressor. However, the actual ow path as dened bythe outer casings and the rotor prole remained unchangedand this further upgrade is also fully retrotable into theearlier engines. Besides the re-staggering additionalmeasures to optimize the compressor blade clearance havebeen introduced to increase the compressor performance[2].

Besides the compressor upgrade, a stepped increase ofthe turbine inlet temperature for the LP turbine in orderto improve the gas turbine engine and plant efciencytook place. This step could be taken based on good eldexperience with the GT24 and GT26 eet in combinationwith additional hardware modications concerning ThermalBarrier Coating (TBC) and cooling in the LP turbine.

For additional efciency benets the cooling and leakageair consumption has been optimized. Using the eldexperience and data obtained from the GT26 Test Power

Plant, the cooling requirements in the SEV combustorcould be adjusted to have an optimum between lifetimeand efciency.

Meanwhile the Upgrade 2006 has achieved more than150’000 OH of commercial experience and the eetleader is expected to have its rst scheduled hot gas pathinspection end of 2011.

2. Upgrade Feature & Benets2.1 Overview

Based on this continued development experience a furtherevolutionary step for upgrading the GT26 gas turbinehas been achieved. The latest evolutionary step furtherenhances the key benets of this gas turbine and theassociated KA26 combined cycle power plants. In specicthis upgrade is designed for:

Higher performanceSuperior operational flexibility

Best-in-class all-round efficiency Turn-down-capability down to 40% and below Lifetime and Performance Optimized operation modes Leading robustness against natural gas compositionvariationReduced emissions

Low NOx emissions at base load with a uniquepart load characteristic resulting in decreased NOxemissions at very low loads

Low Load Operation Capability (“LLOC”), whereby thefull CCPP can be parked at a much reduced minimumload point (around 100 MW CCPP load) so as toprovide fast responding stand-by and significantlyreduced fuel consumption during such parking periods.






In the following sections the measures to achieve theseupgrade features are described and the benets arehighlighted. The GT26 upgrade contains evolutionary

modications on following core GT components:

Compressor SEV (2nd stage) combustorLP Turbine

Figure 2 shows the major areas of development that tookplace for the latest upgrade. The modied Compressorallows a further increase in mass-ow for higher engineperformance at improved operational exibility and highefciency.

The LP Turbine is optimized for high efciency and allowsfor exible operation at increased inspection intervals of upto 30%.

The SEV combustion system is improved for increasedfuel exibility at yet lower emissions. To accommodatethe evolutionary compressor upgrade, the surroundingstructural parts are modied as well. Again, an evolutionaryapproach was done for design modications to these

parts. In the following chapters the modications for eachcomponent are described. In chapter 3 the validation

for each of these components and the entire engine isdescribed in detail.

2.2 Compressor

The Compressor upgrade results in an increased compressorinlet mass-ow at high compressor efciency over awide range of ambient and load ranges. The compressorarchitecture is based on the 22-stage well-proven designof the current GT26 engine. The outer annulus is increasedto match the mass-ow increase. The compressor bladingis designed using design tools developed by Rolls Royce,with whom Alstom has an unlimited technology sharingagreement. The state of the art blade design for maximumefciency over a wide load range is using Controlled DiffusionAirfoils (CDA). To increase the part-load performance evenfurther, the variable vane row count has been increasedfrom three to four.

LP Turbine:- Airfoil prole optimisation- Leakage reduction- Enhanced cooling scheme

SEV Combuster:- Optimised SEV burner- Improved sealing- Leakage reduction

Compressor:- Increased mass ow- Optimised blade design- Increased turn-down ratio

Figure 2 – Overview of major areas of evolutionary designmodications

Figure 3 – Compressor cross-section with four variableguide vanes




2.3 SEV Combustion System

The SEV Combustion System architecture and structural

parts remains unchanged to the current GT26. Modicationsare introduced with a modied SEV burner, SEV lance andfuel injection as well as improved seals to reduce leakagesinto the combustion chamber. The burner modicationsensure a better mixing of the fuel with the airow resultingin lower emission values over a wide operation range andfuel gas composition. The combustion system is designedto be able to operate over a wider Wobbe Index (WI) rangeand higher hydrocarbon content (e.g. ethane, propane andbutane, abbreviated C2+) than the current GT26.

As with the earlier GT26 upgrades, the combustion systemwill maintain its superior NOx emissions characteristic. Itwill achieve emission values below 25 vppm NOx at 15%O2 dry over a GT load range from 100% down to 40% andbelow, as well as at the low load parking point.

2.4 Low Pressure turbine

The upgrade package includes an improved LP turbine. The

High Pressure (HP) turbine remains unchanged.

The benets of the modied LP turbine are (i) highercomponent efciency and (ii) the ability to switch on-linebetween two operation modes thereby offering an increasein scheduled maintenance intervals by up to 30%, resulting inhigher availability and lower maintenance costs. To achievethis, all four LP turbine stages contain airfoils with optimizedproles and cooling schemes. The shroud design wasimproved to reduce the over-tip leakages. In addition thevane-part count per row is reduced from the current GT26to minimize the hot gas surface, which requires cooling.The turbine outlet annulus is increased to accommodatethe higher hot gas mass-ow delivered by the upgradedcompressor.

Figure 6 shows as an example the vane and blade parts forstages 1 and 3. 3D airfoil proling has been applied throughoutall stages to achieve a high aerodynamic efciency. As withthe compressor, the turbine was designed using the RollsRoyce design tools under a technology sharing agreement.

Increased efciency- Airfoil prole optimisation

Reduced losses- Improved shrouds

Optimised cooling- Reduced number of vanes 1, 2 and 4

Figure 5 – Modications to the Low Pressure turbine

Vane 1 Blade 1 Vane 3 Blade 3

Figure 6 – Turbine parts for stage 1 and stage 3 of theimproved Low Pressure turbine

Improvedsealing

SEV burner SEV lance

Figure 4 – Modications to the SEVcombustion system






2.5 Operation Concept

With this upgrade the unique Alstom exible operation

concept, already available for the GT24 and for Alstom’sconventional class gas turbine GT13E2, is introduced forthe GT26. It allows with one set of hardware the on-lineselection between a “Lifetime Optimized” operation modewith extended inspection intervals and a “PerformanceOptimized” operation mode for maximum output/efciencyto meet variable market requirements, while the plant isconnected to the grid. The inspection interval criteria areshown in Figure 7 – compared with the Upgrade 2006an increase of around 30% can be achieved, resultingin a corresponding increased availability and reducedmaintenance cost.

The operation concept of the GT26 is shown in Figure 8.The basic operation concept to load the GT by increasingthe ring temperature of the rst combustor to its designvalue, to ignite the second combustor (self-ignition) andthen open the VIGV’s remains unchanged from the currentGT26.

As part-load operation is today more important due to

increasing power generation from renewables, the GT26,which since its initial introduction in the mid 1990’s hasdemonstrated superior part-load efciency, offers a furtherincrease of efciency for operation below base-load.

The operator has the option to run during high part loadoperation in the Performance Optimized mode, as shownin Figure 9. In this mode the ring temperature is increased– as a result a higher exhaust gas temperature is achievedfor better combined-cycle performance.

In the Lifetime Optimized mode, the ring- and the exhaust-

temperature are lower, resulting in a small reduction inperformance compared to the Performance Optimized mode.Hence the interval between the GT26 type C inspections (hotgas path inspections) is extended by up to 30%.

This feature offers a further increase in the degree ofoperational exibility delivered by the GT26 and thecorresponding KA26 combined cycle products from Alstom.

+30% increase

Operating Hours

C y c

l i c E v e n

t s ( s t a r t / s

t o p ,

t r a n s

i e n

t s )

Figure 7 – Longer inspection intervals with latestGT26 upgrade

PO*L O*

123

Relative GT Load

GT Exhaust Temperature

SEV Combustor Temperature

VGV Position

0%

SEV Ignition~10% Load

EV Combustor Temperature1

2

3

123 123


SEV Ignition~10% Load

EV Combustor Temperature1

2

3

* LO: Lifetime Optimised mode PO: Performance Optimised mode

Figure 8 – Operation concept

Relative GT Load

GT ExhaustTemperature


VIGV Position

50%

EV Combustor Temperature

LO* PO*

LO* PO*

Lifetime o ptimised

Perform ance optimised

Lifetimeoptimised

Performanceoptimised

GT ExhaustTemperature


VIGV Position

EV Combustor Temperature

GT Load

LO* PO*GT Load

T I T 2

Lifetime o ptimised

Perform ance optimised

T e

x h

Lifetimeoptimised

Performanceoptimised

Extra part load efficiency

* LO: Lifetime Optimised modePO: Performance O timised mode

Figure 9 – Operation concept detail at high part-load




3. Validation3.1 Validation Strategy

In order to ensure fully validated and highly reliable productsAlstom is using a Product Development Quality (PDQ)process. This process denes at a very early stage duringthe design phase for each component, the appropriatevalidation measure to reduce risk to a minimum level.

The PDQ process has been applied for the GT26 upgradepackage with regard to the validation: For each componentvarious validation steps have been performed such asdesign feature validation (to validate the cooling channeldesign), component validation, full engine validation in theAlstom GT26 Test Power Plant and eld monitoring. In thechapters below, the major validation steps and validationunits are described in more detail.

3.2 Full-Engine validation

The full upgrade package has been implemented in theGT26 Test Power Plant in Birr, Switzerland. A dedicatedtest campaign started in March 2011. Full load has alreadybeen achieved and Alstom is currently optimizing theoperation concept further.

The Alstom Test Power Plant is connected to the Swissgrid. It is dedicated for upfront testing of upgrades in allkinds of operation regimes, i.e. from base-load to extremeoff-design conditions, before products are released to themarket.

Special instrumentation techniques applied are shownin Figure 12. For this test and validation campaign,Alstom has installed more than 4’000 of additional test-instrumentation on top of standard to ensure maximumengine performance monitoring under all operatingconditions.

Figure 10 – Validation steps according to Alstom’sPDQ process

Thermal Paintsfor hot gas path

Strain gauge Pyrometers Telemetry

5-hole Probe

Hot Gas Rakes

Kiel Heads

Figure 12 – Special instrumentation overview forGT Test Power Plant

Figure 11 – GT26 Test Power Plant






3.3 Turbine validation

The turbine component validation was done in three-steps.As a rst-step, the turbine internal cooling schemes andtheir internal heat transfer was validated in an in-housetest facility using Perspex models and thermo-sensitiveliquid crystal measurement technique (Figure 13).

The second-step of turbine component validation was doneduring two engine test campaigns in the GT26 Test PowerPlant. The rst test campaign was a dedicated thermal paintrun for the improved hot gas parts (Figure 14). The secondcampaign was a performance and mapping test campaignto validate the LP Turbine performance characteristic overthe entire range of operating conditions.

Based on the good results from the tests in the Test PowerPlant, the LP turbine hardware was released for a front-runner operation in a commercial KA26 unit in Spain. Boththe performance and emission guarantees were met. Thisfront-runner saw its rst scheduled inspection in September2010 at 5’529 OH, 45 starts. This inspection showed theLP turbine to be in excellent condition. Figure 15 showspictures from the borescope inspection. As of June 2011 theturbine has accumulated more than 8’000 OH.

The customer (hc energía) is very satised with the resultsof the upgraded LP Turbine. Pablo Argüelles Tuñón, GeneralManger Combined Cycle Power Plants, and Juan MiguelHerranz Martínez, Power Station Manager, had this to sayduring the validation phase: “For years, we have developeda strong and effective working relationship with Alstom.For that reason, we considered that this upgrade would bea good opportunity to make our plant more competitive,improving its efciency and power output without

jeopardizing the plant reliability. From the “operational”

point of view, this upgrade has improved the power outputand efciency of the plant. From the “maintenance” point ofview, it has introduced the opportunity to extend the normalhot gas path inspection intervals by up to 30%, which meansincreased availability and reduced maintenance costs forthe plant. The performance guaranteed values has beenexceeded and Alstom has shown a very high commitmentand cooperation throughout the validation period.”

Figure 14 – GT26 Test Power Plant – Thermal Paint Testof the LP turbine

Figure 13 – Internal heat transfer validation usingthermo-sensitive liquid crystals and Perspex models

Blade 1 Blade 2

Vane 1 Vane 2

Figure 15 – Low Pressure turbine frontrunner A-typeinspection borescope pictures




3.5 SEV-Burner validation

SEV-Burner validation was done in a two-step approach.

The rst step was to carry out a single burner test. Thesecond step was full engine tests in the Alstom Test PowerPlant.

3.5.1 Rig Testing

Figure 17 shows the single burner high-pressure test rig.The test bed is used to measure and analyze the mixing andemission behavior, to check the ame stability limits andthe acoustic behavior. Parameter variations are done forinlet and outlet boundary conditions, and in particular forvarious fuel types (varying LHV, C2+). The instrumentationon the rig contains more than 500 measurement locationsfor temperatures, pressures, acoustics, emissions andame positioning.

3.5.2 Engine validation in the Alstom TestPower Plant

Out of the single burner test rig different burner lancecongurations were selected for full-engine tests at the

Alstom Test Power Plant in Birr, Switzerland. In a test seriesthe best conguration was selected for implementation inthe GT26. This conguration was then mapped for the fulloperating concept and a large ambient range.

3.4 Compressor validation

3.4.1 Rig Testing

During the mapping of a GT compressor when the engineis connected to the grid, the operating line from idle to fullload can be validated. In order to gain a full compressor mapover the entire speed, ambient temperature and pressureratio range a full 22-stage scaled-rig was built and tested.The scaled-rig includes bleed slots and inlet and outletgeometry and all variable rows as the full-scale GT26. Ontop of compressor mappings, upfront start-up optimizationsfor start-up power and time were undertaken. The mappingof the compressor was carried out up to the surge limit, farbeyond the GT26 operating line requirements. The rig isone of the world’s largest axial compressor rigs for pressureratios above 30. The instrumentation scope for the rigincludes pressure taps throughout the compressor, bothsteady and transient temperature measurements, straingauges, tip timing and clearance measurements. Figure 16shows the assembled rig.

Figure 16 – Compressor scaled test rig Figure 17 – Single burner high-pressure test rig






4. RetrotabilityAs with all of the development steps in the evolution of

the GT26 since its initial introduction, Alstom ensures thatthe improvements to the engine can be offered as retrotupgrades to existing customers wherever possible. In thisrespect the LP turbine can be offered as a service upgradeto GT26 customers who ordered their engine from Upgrade2002 onwards.

5. SummaryAlstom’s position as the pioneer in operational exibilitycontinues.

The outcome of this latest GT26 upgrade is a provenadvanced-class gas turbine technology to furtherincrease the competitiveness for power plant operators.Moreover, the commonly known strengths of the GT26– long recognized and appreciated for its high all-roundoperational exibility and the high fuel exibility – havebeen further extended. More specically the capabilities of

the latest upgrade include:

More than 500 MW in a 1-on-1 combined-cycleconfiguration

More than 61% efficiency in single-shaft and multi-shaftcombined-cycles

Further increase of the already best-in-class part-loadefficiencyIncreased inspection intervals resulting in higheravailability and reduced maintenance costs

Switchable (on-line) operation modes to adjust the gasturbine performance according to market requirementsand thereby offering better inspection planning

Low Load Operation Capability for parking thecombined-cycle at around 100 MW and still meet theemission requirements

A minute reserve of more than 350 MW in 15 minutes Increased fuel flexibilityFast start-up times below 30 minutes

Alstom’s development philosophy is to attain the balancebetween providing the latest technology while maintainingthe proven levels of high availability and reliability based onan evolutionary approach.

The latest upgrade of the GT26 is a perfect example for thisapproach. Based on the basis of a well-proven gas turbine,Alstom has further developed the Compressor, the SEVCombustor and the LP turbine.

Validation is a key step within Alstom’s developmentprocess - for the latest upgrade the validation has beenperformed to the maximum extent:

Full-engine validation in the Alstom GT26 Test PowerPlant in Switzerland

Full testing of Compressor, SEV Combustor and LPturbine including thermal paint runs in various test rigs

Validation of the LP turbine operating commercially in aretrofitted unit for more than 8’000 operation hours

Alstom therefore follows its approach to release provenand fully validated products to the market and paves theground for further development of the GT26.




6. Bibliography[1] Superior fuel exibility for today’s and future

market requirements Douglas Pennell, Matthias Hiddemann, Peter FlohrPaper presented at Power-Gen Europe 2010

[2] A further uprate for Alstom’s Sequential CombustionGT26 Gas TurbineStephen Philipson, Michael Ladwig, Karin Lindvall,

Jürg SchmidliPaper presented at Power-Gen Europe 2006








Alstom Power

© ALSTOM 2011. All rights reserved. Informationcontained in this document is indicative only. Norepresentation or warranty is given or should berelied on that it is complete or correct or will apply

to any particular project. This will depend on thetechnical and commercial circumstances. It isprovided without liability and is subject to changewithout notice. Reproduction, use or disclosure tothird parties, without express written authority, isstrictly prohibited.

www.alstom.com/power

Documents

PGE Conference Paper TVB 31-05-2011 FINAL[1]