gt24 and gt26 gas turbines

5/27/2018 GT24 and GT26 Gas Turbines

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GT24/GT26SEQUENTIAL COMBUSTION

GAS TURBINES

GAS PRODUCT SOLUTIONS

POWER


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A WIDEPORTFOLIO FOR

GAS POWERSOLUTIONS:

GAS TURBINES

GENERATORS

HEATEXCHANGERS

PUMPS

AUTOMATIONAND CONTROL

SERVICES

25percent of the worlds

power productioncapacity depends on

Alstom technology

52,000employees around theworld in 70 countries

100years of industryleading expertise

With our recognised expertise

all over the power generation

market, we are able to find

solutions to the challenges

of today.

CLEAN POWER TODAY!We recognise the need to improve theenvironmental balance of legacy plantswhile increasing adoption of new cleanenergy solutions.

Alstom is a global leader in power generation with a portfolio of products

covering all fuel types. From fossil and biomass to nuclear and renewables,

close to 25% of the worlds power production capacity depends on Alstom

technology and services. Whether in design, manufacture, procurement orservicing, Alstom is setting the benchmark for innovative technologies that

provide clean, efficient, flexible and integrated power solutions. Alstom can

supply anything from single components to complete turnkey power plants.

Our Plant Integrator approach and power automation and control solutions

ensure the optimisation of all elements to derive the maximum lifetime value

from all our customers investments.

Alstom has more than 100 years of experience in engineering, procurement

and construction (EPC) of new power plants. But our engineers are also

experts in retrofitting, modernising and servicing existing plants. With

operations in 70 countries, Alstom is close to customers all over the world,ensuring rapid responses and service excellence at all times.

Welcome to Alstom


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Alstoms gas turbines stand out

for their high overall efficiency,

superior availability and enhanced flexibility

GT24/GT26Gas turbines

in a class of their ownThe GT24 and GT26 solutionsrepresent an exceptionally successful approach to heavy-duty combined-cycletechnology: many of their major components and subsystems have performed outstandingly for years in a number of

applications, ranging from electrical power generation in base load, intermediate or peak duty, to industrial use such as

in paper mills, district heating or desalination plants.

Utilities, independent power producers and merchant power generatorshave to faceunprecedented change, from deregulation to tougher competition, shifting consumption trends and more stringent

emissions legislation. They also need to ensure reliability of supply yet reduce the cost per kilowatt hour of producing

electricity. Raising efficiency remains a constant challenge. Finally, flexibility to fuel gas composition must be included intimes of global transport of fuel gas.

Alstom has addressed all of these challenges. The result is the compact GT24 (60 Hz) and GT26 (50 Hz) sequential

combustion gas turbines, solutions that lower the kilowatt-hour cost combined with high availability by raising the

efficiency in combined-cycle operation.

Environmental emissions are optimisedthanks to Alstoms unique, sequential combustion technology,which burns the fuel in two, dry low-NOx combustor stages. The GT24/GT26 can do all this with conventional firing

temperatures and burners that are robust enough to cope with the wide fuel gas compositions now seen. Whats more,

in addition to increasing their efficiency levels and power density, the operational flexibility of GT24/GT26 gas turbines is

significantly improved and their turndown capability is unique, making them ideally suited to todays markets.


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Key benefits

Competitive kilowatt hourIn combined-cycle applications, the GT24/GT26 is capable of

producing high efficiency over a wide load range, using proven

gas turbine technology.

High availabilityConventional turbine inlet temperatures, a uniform annular

temperature profile, a maintenance-free, welded rotor and a

simple and robust EV burner all help to reduce maintenance

needs and therefore improve availability.

High power densityHigh power density designs lead to smaller components.

Compared with Alstoms medium-class gas turbines, the GT24/GT26

provides up to 60% more output for the same footprint.

GT24/GT26Right technology,

The highly efficient GT24/GT26:the result of extensive experienceand evolutionary development.

Operational flexibilitySequential combustion means unrivalled operational flexibility,

including the ability to handle wide fluctuations in gas

compositions. With an operating range down to 20%, low-

load operation and low NOx emissions, the plant can meet allpower demands. And the GT24/GT26 is capable of switching

online between performance-optimised and maintenance-cost-

optimised modes.

Clean PowerSequential combustion technology is the industrys most

innovative platform for clean power generation, resulting in gas

turbines with low emissions and high efficiency.

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right product

Higher Performance,Cleaner Power

CLEAN POWER TODAY!

TheCHALLENGE

Industry has always sought to developa gas turbinewith higher efficiency. The traditional solution is to raise the firing

temperature at the turbine inlet.

This has drawbacks, however:it increases emissionsinto the atmosphere and subjects the entire gas turbine system to

higher temperatures and thermal stresses.

The usual resultis more frequent maintenance andreduced availability defeating the initial objective. For decades

conventional wisdom has decreed that efficiency cannot be

increased in any other way.

TheSOLUTION

There is another way.By injecting fuel into twocombustion systems in series, it is possible to increase output

and cycle efficiency without significantly increasing the emissions

at full and part load, since the firing temperature in the first

combustor can be kept relatively low, and the second combustor

does not make a substantial contribution to the level of engine

NOx emissions. This is called sequential combustion.

For more than 50 years,Alstom has been a pioneerin sequential combustion technology. Over the years, we have

made major system and component innovations, introduced

incrementally, with successive gas turbine models. These include

our industry-leading EV burners, annular combustion design and

solid welded rotor. In so doing, we have succeeded in uncoupling

emissions and efficiency through an inventive yet basic application

of elementary thermodynamics.

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Sequential combustion can be

visualised as a gas turbine comprising

two combustor-turbines in series,

where the exhaust gases from the first

turbine feed the combustor ofthe second.

An efficient 22-stage subsonic

compressor feeds combustion air into

the first combustor. Fuel is mixed with

the high-pressure air and burns in

the first combustor the annular EV

combustor. The hot gases drive the

single-stage high-pressure turbine.

Unlike conventional turbines, fuel isthen injected into a second burner

set and spontaneously ignites in the

following annular combustion zone,

the SEV (Sequential EV) combustor,

thereby reheating the air and further

expanding it through four low-pressure

turbine stages.

The temperature of the EV combustor is

maintained at a nearly constant level,

resulting in lower NOx emissions and

cleaner power.

1st-stage EV

combustorThe EV combustor has an

annular burner arrangement.

The GT24/GT26 gas turbines

are fitted with retractable

EV burners. Compared

with other combustor

arrangements, the annular

combustor distributes the

hot gas, circumferentially,

at a much more uniform

temperature.

SequentialAlternative approach,

Industry-leading burners

Vortexbreakdown

Sprayevaporation

Combustion air

LeanPremix Gas

RichPremix Gas

Premix Gas

Lean Premix Gasinjection holes

Ignition Flame front

Radial temperature uniformity is accomplished by pre-mixing compressor air with

the fuel in the EV burner, and by the absence of film cooling in the convection-cooled

combustor walls. This produces a single, uniform flame ring in the free space of the

EV combustion zone.

A key benefit is that the flame has no contact with the walls of the burner. These

design features distinguish the EV combustor significantly from other combustion

systems.

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Like all the best ideas, sequentialcombustion is based on a simpleconcept: the reheat principle.

2nd-stage SEV combustor

In the annular SEV combustor, the combustion process isrepeated as in the EV namely, vortex generation, fuel injection,

pre-mixing and flame stabilisation in a vortex. The SEV

combustor contains SEV burners distributed in a ring, followed

by an annular combustion zone surrounded by convection-

cooled walls.

Exhaust gas from the high-pressure turbine enters the SEV

combustor through the diffuser area. Combustion temperature

uniformity in the SEV, as in the EV, is achieved by the uniform

premixing of fuel with air in a swirling flow with high mixing

intensity. Each SEV burner contains four delta-shaped vortexgenerators on each burner wall in order to form four pairs of

vortices in the combustion air.

Fuel is then injected through an air-cooled fuel lance, distributed with four jets into the vortex pairs such that it forms a perfect

fuel/air mixture prior to combustion. The fuel jet is surrounded by cool carrier-air that delays spontaneous ignition until the fuel/air

mixture has reached the combustion zone.

Here, the mixture ignites spontaneously and, as in the EV combustion occurs in a single, stable flame ring, operating across its entire

load range.

The EV and SEV do not require any parts replacement prior to HGPI (Hot Gas Path Inspection), C inspection. This mechanical

simplicity determines the high reliability and availability of the GT24/GT26 design.

combustion:optimised design

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High powerdensity

The sequential combustion concept results in a gas turbine

with extremely high power density enabling the smaller bladedimensions of GT24/GT26 machines. The five rows of turbine

blades are anchored in fir-tree slots.

Air from the compressor cools the high-pressure turbine stage

and the first three low-pressure turbine stages utilising a

combination of film- and convection-cooling techniques.

Maximisedperformance

The cooling air for the hot gas path components is taken fromfour extraction points along the compressor. Air from two of

these secondary airflows is used directly, while the two other

streams are cooled by heat exchangers (once-through coolers)

before entering the hot gas path components.

The heat rejected is recovered in the water-steam cycle, which

maximises the performance of the GT24/GT26 in combined

cycle applications. In simple cycle applications, the cooling is

achieved by quenching water, which is introduced directly into

the secondary air stream.

Its beauty lies

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Maintenance-free welded rotor

There is no need to destack and re-stack

during the rotor lifetime.

Alstoms welded rotor was first introduced

in 1929 for steam turbines and the concept

has been used successfully in Alstom gas and

steam turbines ever since.

The welded rotor design eliminates

maintenance work such as restacking and

disk replacement during the service life of the

rotor in any major overhaul of the gas turbine.

in its simplicity

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Performance

Although a large amount of the total unit fuel is burned in the

SEV combustor, very little additional NOx (at 15% O2) is formed

in the SEV combustor, mainly due to the low oxygen content of

the incoming air.

At full load, approximately half of the total amount of fuel is

burnt in the first-stage EV combustor. Initial expansion occurs in

the single-stage high-pressure turbine (HPT). The high-pressure

turbine exhaust gas enters entirely into the second combustor.

The remaining fuel is introduced and burnt in the second

reheat combustor (the SEV combustor).

Efficiency only equaled

by its reliability

The second expansion occurs in a four-stage low-pressure

turbine (LPT). At over 600C, the exhaust gas temperatures are

ideal for combined cycle applications.

The GT24/GT26 achieves low NOx emission levels, not only

at full load, but also down to low-part loads. This is due

to the operation concept that maintains the EV combustor

temperature at a nearly constant level. Furthermore, the SEV

combustor produces only little additional NOx.

The EV/SEV burners also enable dry low NOx combustion withdifferent grades of natural gases, and the use of liquid fuel as

back-up.

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with unique track record

Alstom is the pioneer of operational flexibility. We are the

pioneer in introducing the low load concept, which means

that the plant can be parked at 20% load during periods of low

demand during part-load operation. Efficiency of our plant stays

virtually constant from 100% down to 80% load and even at the

lowest load, emissions stay within statutory limits.

The proven output and efficiency are being offered from an

existing and well-proven technology platform. This gas turbine

technology has over 15 years operating experience with more

than 4.5 million operating hours.

The GT24/GT26 gas turbine is still the only advanced-class

turbine with sequential combustion and proven technology

to deliver:

Low Cost of Electricity

High All-round Efficiency

Exceptional Operational Flexibility

Performance and operational flexibility,

with a unique track record

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PowertrainarrangementsAlstom has extensive experience with both single- and multi-shaft powertrain arrangements, in all types of operating regimes frombase load to daily start & stop.

[1] STEAM TURBINEAlstom steam turbines offer:

HP turbine shrink-ring design for sustained efciency and

fast start-up welded rotor design for fast start-up and low

maintenance

single-bearing design for compact arrangement

single axial and lateral-exhaust designs also available for lower

foundations and lower first costs.

[2] TURBOGENERATOR

Alstom turbogenerators demonstrate high efficiency, reliability

and availability with low maintenance requirements. According

to plant size and arrangement, both air-cooled TOPAIR and

hydrogen-cooled TOPGAS generators are available.

[3] GAS TURBINE

Alstom gas turbines - the core of any combined cycle plant.

[4] HEAT RECOVERY STEAM GENERATOR (HRSG)

Alstoms range of HRSGs provides:

both drum type and once-through technology

optimised cold-end.

Performance for maximised combined-cycle efficiency

high thermal exibility for fast start-up highly modularised design for fast site erection.

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1

The AlstomPowertrain

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How itworks

[1] COMPRESSED AIR

is fed into the EV burner, creating a

homogeneous, lean fuel/air mixture.

The vortex flow, induced by the shape

of the burner, breaks down at the EV

burner exit into the combustion zone,

forming a central recirculation zone.

[2] THE MIXTURE

ignites to form a single, low-tempera-

ture flame ring. The inner recirculation

zone stabilises the flame in the free

space within the combustion zone,

avoiding contact with the burner wall.

[3] THE HOT EXHAUST GAS,

low in oxygen content, exits the first

combustor and moves through the

high-pressure turbine stage before

entering the SEV burner.

[4] VORTEX GENERATORS

in the SEV burner enhance the mixing

process, while carrier air, injected with

the fuel at the SEV fuel lance, delays

spontaneous ignition until the mixture

enters the annular SEV combustion

chamber.

[5] IGNITION OCCURS

when the fuel reaches self-ignition

temperature in the free space of the

SEV combustor. The hot gas then con-

tinues its path into the low-pressure

turbine.

1 2 5

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Optimised designAlternative approach,

additional advantages

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Sequential combustionapplicationsCOMBINED-CYCLE

A combined-cycle power plant is an efficient and environmentally sound way

to generate electrical power. Sequential combustion provides optimum exhaust

temperatures for combined-cycle use, the main application for which the GT24

and GT26 have been developed.

The two combustors in the GT24/GT26 sustain high efficiency and low emissions

at part load operation through control of the inlet air flow by four rows ofvariable guide vanes.

This means the thermodynamic quality of the sequential combustion combined-

cycle remains nearly constant. As a result, the GT24/GT26 combined-cycle offers

high efficiency over the operational load range, with virtually constant efficiency

between 100% and 80% CCPP load.

This maximises the long-term value of GT24/GT26 power plants by significantly

broadening their operating flexibility a key success factor for todays

competitive power generation market.

Langage combined-cycle powerplant in Devon, UK.

REPOWERING WITH SEQUENTIAL COMBUSTION GAS TURBINES

Alstom has developed a hybrid plant concept combining conventional steam plants with the GT24/GT26. These plants combine operating

and dispatching flexibility with continuous fuel optimisation, low O&M costs and moderate capital investment.

The concept responds to the most critical requirements of modern power generation systems low generating costs, greater fuel mix

capabilities, operational flexibility and minimum environmental impact. It also enables extraordinary design flexibility by integrating high-

performance sequential-combustion gas-turbine technology with a wide range of existing or new conventional steam power plants.

Innovative concepts

100

CCP

PR

elative

Typical MSL

2%-4%

90 80 70 60 50 40

KA26

Single Combustor GT

Superior part-load efficiency

characteristic of the KA24/KA26 CCPP.

One distinct feature is the fact that the

plant efficiency stays nearly constant

from 100% down to 80% combined cycle,

a unique capability in the market.

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that also lower costs

Gas turbines in action - project highlights

A GT26 merchant power plantapplication

Scottish Power Ltd selected theKA26-1 standard single-shaft designto build a combined-cycle power plantat Shoreham Harbour in the UnitedKingdom. The plant was completed inDecember 2000 and is managed on amerchant plant basis. It has operated atboth base load and intermediate duties.

The first GT26 single-shaft powerplant

Contact Energy in New Zealand is theowner of an Alstom turnkey 360 MWcombined-cycle power plant, featuringthe GT26 sequential combustion gasturbine.

Taranaki is arranged in a single-shaftconfiguration and represents the firststandardised reference plant solutionwith the GT26. This triple-pressurereheat combined-cycle plant has beenin continuous base load operation since

July 1998.

SHOREHAM / UK

TARANAKI / NEW ZEALAND

A GT26 fast-track project in Spain

The Cartagena project, a 1200 MWcombined-cycle power plant consistingof three independent blocks equippedwith dual-fuel GT26 gas turbines, wasawarded to Alstom in December 2003with a very aggressive timetable.

The first unit was finished within 25months, with the other units followingat one month intervals. This is a repeat

order for Gas Natural, which alreadyowns and operates two other GT26combined-cycle power plants in Spain.

Efficiency increase by 20%

Alstom won a contract with SpainsACS Group to provide power equipmentand services for the El Sauz combinedcycle power plant in Queretaro, one ofMexicos most industrialized states.

A new GT24 gas turbine to replace theexisting gas turbines and will retrofitthe steam turbine at the existing ElSauz gas-fired power plant, which hasbeen operating since 1981. This newcontract will add 25 years to El Sauzcombined cycle power plant and boost

its efficiency by 20%.

CARTAGENA / SPAIN

EL SAUZ / MEXICO

A GT24 in cogeneration application

Island Cogen is a 250 MW gas-firedcombined-cycle cogeneration powerplant at Campbell River in BritishColumbia, Canada. The plant is ownedby Calpine and delivers steam to anadjacent paper mill.

Superior reliability & availability

Road generating plant in Dayville,Connecticut, U.S.A. Lake Road is a792 MW combined-cycle generatingfacility based on three GT24 gas turbines.

The units have exhibited good startingreliability and high availabilities duringoperation. The Lake Road combined-cycle generating facility features dualfuel flexibility that utilizes natural gasas the primary combustion source anddistillate fuel oil as a backup. The plantentered commercial operations

in May 2002.

ISLAND COGEN / CANADA

LAKE ROAD / USA

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The AlstomPower Plant

Partnership throughout

In todays power generation and industrial markets, plant

owners and operators seek to establish long-term cooperation

with major Original Equipment Manufacturers. They look for

partners who are willing and able to develop solutions that will

increase production efficiency and reduce emissions throughout

the lifetime of their equipment.

As part of Alstoms commitment to providing complete

plant services for optimal performance, we are dedicated to

supporting you to cost-effectively maintain your gas turbine andcombined-cycle (GT/CC) power plants.

Our flexible and customised expert services cover solutions at

all stages of the plant lifecycle or if requested simply on single

components including:

New and improved parts

Reconditioning Services

Advice and operational support

Field service

Performance improvements

Service contracts

Services on other OEM gas turbines

In-depth serviceportfolio combined

with broad experienceLocated in Birr, Switzerland, the Alstom Power Plant providesa unique environment for maintaining the incomparable

advantages of the GT24/GT26 range, all within the proximity

of Alstoms R&D facility, gas turbine development department,

manufacturing plant and power plant. The latter is equipped

with a dual-fuel GT26 gas turbine, operating in simple-cycle

mode, connected directly to the 220 kV Swiss power grid.

As it is an Alstom facility, the turbines can be submitted

to a real-life comprehensive validation process that leaves

nothing out in terms of loads, limits or duration. The GT26 isoperated under real service conditions without any commercial

constraints. This includes fuel switch-over operation between

gas and oil. The power plant has oil storage sufficient to run the

GT26 for 12 hours at full-load.

Together with the Product Support organisation and the GT

development department, the Power Plant means Alstom

can ensure seamless implementation of evolutionary product

improvements based on actual GT24/GT26 fleet experience.

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AMERICASDanvilleRichmondRichmondRichmondJupiterJupiter

JupiterSao Paulo

EUROPEBadenBadenBadenAshbyBirrKarlovac

MIDDLE EAST / ASIA PACIFICDubaiDubaiDubaiRabighKuala LumpurKuala Lumpur

Reconditioning Workshop

Execution CentreProduct Centre

Field Service Network

We are whereour customers are

the plants lifecycle

Alstoms footprint and broad industry expertise enables us to support you in an efficient

and responsive manner around the world. With a network of over 60 Local ServiceCentres in 70 countries, there is always a dedicated Service manager close at hand and

available around the clock to respond to your needs.

2 GT/CC product centres

4 GT/CC execution centres 7 GT reconditioning workshops

7 eld service network

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Services

ServiceContractsAlstoms service contracts are tailored to meet all your operational, maintenance and support requirements. Whether you prefer a

Long Term Agreement (LTA) or an Operation & Maintenance (O&M) contract with Alstoms comprehensive, yet flexible agreements,

you can be sure of a win-win situation.

Partnerships for performanceLong-term agreements are based on framework contracts that define prices and conditions in advance. Besides offering preferentialconditions for high quality parts and services, the LTA reduces administrative efforts and simplifies planning. The scope of services and

equipment covered, as well as the contract duration and risk sharing, can be adapted perfectly to your needs.

LTAs offer many immediate advantages:

Fixed preferential prices for parts and services

Flexible scope to suit operative strategy

Extendable scope to include almost any aspect of plant operations

Alstoms operation and maintenance contracts let plant owners devise completely new management strategies by outsourcing risks

and responsibilities. Take advantage of performance and availability guarantees through tailored agreements that perfectly suit your

required service and equipment scope.

Alstoms O&M contracts are fee-based agreements that:

Mitigate risks

Leverage Alstoms extensive experience in plant asset management

Can be adapted to suit your business strategy

Plant SupportCentreTM

Expert support around-the-clockAlstoms Plant Support Center (PSC) offers fast and comprehensive technical support solutions to keep plants competitive. Besides

remote monitoring and diagnostic services, the PSC provides 24/7 operation support and direct access to a global network of

technical experts who assist in troubleshooting, assessment and re-commissioning and analyse equipment trends.

Besides practical experience, our plant operation experts rely on comprehensive and proprietary knowledge management tools. If

required, they can also call in Alstom experts with specific engineering know-how and fleet-wide experience to assist with operational

support or more detailed investigations.

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TPW/BPROB/GSTRBN1

2/eng/THP/06.12/FR/7691ALSTOM2012.Allrightsreserved.In

formationcontainedinthisdocumentisindicativeonly.Norepresentationorwarrantyisgivenorshouldbereliedonthatitiscompleteorcorrectorwillapplytoanyparticularproject.This

willdependonthetechn

icalandcommercialcircumstances.Itisprovidedwithoutliabilityandissubjecttochangewithoutnotice.Reproduction,useordisclosuretothirdparties,withoutexpresswrittenauthority,isstrictlyproh

ibited.Photocredits:2007BryonPaulMcCartney|

www.atelier-mccartney.com,Alstomandothers.Layoutandrealisation:LesditionsStratgiques

Alstom contributes to the protection of the environment.This brochure is printed on environmentally-friendly paper.

Alstom (Switzerland) LtdBrown Boveri Strasse 7CH-5401 BadenPhone: +41 56 205 6923

www.alstom.com/power

gt24 and gt26 gas turbines

Documents

power automation

power generationmarket

turnkey power plants

alstoms gas turbines

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clean power today

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