COMBUSTION SYSTEM

The combustion system is of the can-annular, reverseflow type, with six cans mounted on the compressordischarge case. It is derived from the GE PowerSystems DLN2 combustor design installed on “F”Class machines. Current operation is with gaseous fuel but futuredevelopment will include liquid fuel capability. Ineach combustion can there are a 4+1 fuel nozzles.The fuel nozzles contain premixing tube, where fuelgas and air mix together before the primary burningzone, and a central body, with a diffusion fuel gas cir-cuit. The combustor operates in diffusion mode atlow loads (less than 50%), and in premixed mode athigher loads with a 25 PPM NOx initial target. Thefuel gas delivery system is provided with multiple gascontrol valves to distribute the fuel to the differentgas circuits. Accurate split is required during premixoperation to ensure both low emissions and lowcombustion dynamic.

HP TURBINE

The axial flow, two-stage reaction type HP Turbine,was designed to deliver high efficiency over a broadpower range. It consists of two turbine wheels, firstand second stage turbine nozzle assemblies, and tur-bine casings. Both stages of HPT nozzles are aircooled (convection and film) by compressor dis-charge air flowing through each vane. Both stages ofHPT buckets are cooled by compressor air flowingthrough the dovetail and shanks into the buckets.

LP TURBINE

The power turbine uses the same heavy duty designas that used in the LM2500+. The mechanical struc-ture is the same, however the flow-path profile andairfoils were redesigned because of the higher airflowrequired.

The MS5002E Compressor Rotor

• Output Shaft 30 MW• SC Efficiency 36,4%• LPT Shaft Speed 6100 rpm• Exhaust Temperature 523 °C• NOx Emission 25 ppm

Nominal Performance

GE Power SystemsOil & GasNuovo Pignone S.p.A.via F. Matteucci, 2 50127 Firenze - ItalyTel. +39/055423211 Fax +39/0554232800gepower.com /geoilandgasinfo.geoil&gas@np.ge.com

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FSFL, DLN tuning, LP turbine mapping etc.), toaddress all potential areas of machine risks and tocover all aspects necessary for validation of thedesign. The data relevant to test objectives (rotordy-namics, performance, aeromechanics, combustion,

operability, thermo-mechanical assessment, auxil-iaries validation etc.) will be collected, processed andanalyzed during test execution, using thoroughly vali-dated GE Oil & Gas software and quality assessmentprocesses.

MS5002EA new 2-shaft heavy duty

GAS TURBINE

GE Power SystemsOil & Gas

The MS5002E, the latest addition to theGE Oil & Gas family of gas turbines, is a30MW-class machine designed for highefficiency, low environmental impactand high reliability. The MS5002E will beavailable in both single-and dual-shaftversions to cover power generation andmechanical drive applications.This latest machine was developed inresponse to Customer demand for amachine in the 30 MW range with lowfuel consumption, reduced emissionsand high availability and reliability.In order to guarantee high reliabilityand availability the MS5002E has a con-servative firing temperature with respectto the state-of-the-art.High efficiency was achieved throughthe use of Advanced design tools to opti-mize airfoils, clearances, leakages andthe distribution of cooling flows.The MS5002E offers NOx emission levelsdown to 25 ppm (intro) through the useof a dry-low emission combustion systemderived from the GE Power SystemsDLN2 combustion technology.The design of the MS5002E is being vali-dated through an extensive test programthat included a full scale test of the axialcompressor, full scale rotordynamic test-ing and full testing of the gas turbine sys-tem.The MS5002E single-and dual-shaft30MW-class machine represents a world-class engineering achievement to pro-vide Customers with a high efficiency,low emissions machine with outstandingreliability matched for Oil & GasIndustry applications.

COMPRESSOR

The compressor is a 11-stage, high pressure ratio(17:1), axial flow design scaled-up directly from theGE10 gas turbine. At the nominal operating speed of7455 rpm, the airflow is 96 Kg/sec. The inlet guidevanes (IGV) and the first and second stage statorblades have hydraulically actuated variable vanes.There are two bleed ports located along the flow-path: the 4th stage bleed is used for LP turbinewheel cooling and bearing sealing the 7th stagebleed is used for cooling and for surge control duringstart-up/shut-down. As in the GE10 the compressorrotor has one forward stub shaft, six discs and fivespacers, and one aft stub shaft, all packed togetherby 26 tie bolts. The compressor casings are horizon-tally split for on-site maintenance. The air inlet casingsupports Bearing #1, a combined tilting-pad journaland thrust bearing. Casing materials are cast iron forthe inlet case, nodular cast iron for the intermediatecase and cast steel for the compressor dischargecase.

AUXILIARIES

The MS5002E package design is similar to that usedin other mature GE Oil & Gas gas turbines. As withthe existing MS5002D, the base that supports thetwo separate structural-steel frames; one for the gasturbine engine and one for the auxiliaries. The gas turbine is mounted on its baseplate bymeans of two forward supports, flexible in the axialdirection, and two rear support legs. The enginebaseplate has approximately the same footprint asthat of the MS5002D and contains both inlet andexhaust plenums. These plenums, with small modifi-cations, are suitable for both vertical and lateral ori-entation. The auxiliary baseplate contains the lubeoil system and reservoir, hydraulic oil system, startingsystem with rotor turning device and the fuel gasskid. This modular design permits different installa-tion configurations, for optimization of the plant lay-out to meet Customer requirements. The MS5002Euses the SPEEDTRONIC Mark VI control system,currently used on all GE gas turbine models.

MAINTAINABILITY

The MS5002E was designed for maintainability withspecial consideration given to:• Planned maintenance• Handling and lifting of gas turbine components

and main auxiliaries• Special maintenance tools• Location of boroscope ports for easy inspection• Enclosure access doors and openingsThe horizontally split gas generator casings and theremovable enclosure roof allow on-site mainte-nance. The power turbine is mounted on a specialframe that permits it to be moved axially on the base-plate. The module can be either disassembled direct-ly on the base, or can be removed for off-base main-

tenance. Combustors can be disassembled withoutremoval of the compressor discharge case and bear-ings 1, 3 and 4 are easily accessible for inspection.The general layout of the auxiliary baseplate ensuresgood accessibility to the most critical areas and com-ponents. An internal crane is provided for lifting ofmain auxiliaries lifting purposes.Filters and instrumentation racks are located outsideof the enclosure, to facilitate inspection and repair.

The planned maintenance intervals are:• 12,000 hrs - Combustion system inspection• 24,000 hrs - Hot gas path inspection• 36,000 hrs - Combustion system inspection• 48,000 hrs - Major inspection and overhaul• 60,000 hrs - Combustion system inspection• 72,000 hrs - Hot gas path inspection• 96,000 hrs - Major inspection and overhaul

TESTING PROGRAM

ROTORDYNAMIC TESTA full scale engine rotordynamic test was carried outto validate the lateral and torsional dynamic behav-ior of the entire engine. The test stand was com-posed of the engine (casings, supports, bearings androtors), two variable speed electric motors, gears,couplings and support frames. The rotors containedenlarged turbine discs to simulate blade masses, per-mitting normal speeds to be reached by reduction ofthe ventilation losses. The objective of the testingwas to validate the design with respect to:• steady state rotor and casing vibrations• transient vibrations• journal bearing behavior and performance• rotor critical speeds and modal damping

Rotordynamic test stand

This latest activity has been faced with the purposeof tuning the process and increase knowledge forfuture work. The test, preceded by rotors natural fre-quencies validation (free-free test) was completedsuccessfully. Test results confirmed, as predicted byanalysis, that there are no critical speeds within theHP or LP operating ranges and API 616 criteria andlimits in terms of damped unbalanced analysis andexperimental results were met. Rotor and casingvibration levels were found to be within acceptablelimits both within the normal operating range andduring transients (start-up, shut down).

COMBUSTION TESTPreliminary tests were performed at the GECorporate Research and Development Center, toassess the combustor behavior over the entire rangeof operation. Design validation tests were also per-formed in a GE Power Systems full-scale test rig usinga single can, full-scale combustor.The test program was carried out operating in bothdiffusion and premix modes. In the diffusion mode,the combustion system was tested for loads (from0% to 50%) of full load at different gas turbinespeeds and different ambient conditions.These tests showed low dynamics, excellent marginto lean blow out and metal temperatures as predict-ed by analysis. In the premix mode the combustionsystem test results showed low emission levels, wellbelow the target, and dynamics levels and lean blowout margin within the expected range and adequatefor gas turbine off design operation.Specific tests were also performed to verify ignitionand cross fire capability. During the productionphase, the test rig will be available to test the com-bustor performance with specific fuels as requiredfor customer applications.

COMPRESSOR TESTThe purpose of the compression testing was to evalu-ate both the mechanical behavior and the aerody-namic performance of the compressor. The maintest objectives were:• Define the axial compressor maps over the entire

operating range (from 80% to 110% of correctedspeed) and at low speed (from 20% to 75% of cor-rected speed) up to the surge limit.

• Assess the stator vane and rotor blade stresses andnatural frequencies through strain gage dataanalysis.

• Validate rotor and casing thermal models throughmetal temperature measurements and clearancemeter data.

The test rig developed based on prior GE Oil & GasExperience consisted of the compressor (inlet plenum,casings and rotor) driven by a LM2500/PGT25 gas tur-bine, an inlet system with air flow measurement tubes,an inlet throttle valve and a compressor air dischargesystem.The compressor was extensively instrumented withflowpath aerodynamic instrumentation (static pres-sure probes, total pressure and temperature multipleprobes) to measure the individual stage characteristics.

The test was successfully completed validating thecompressor design:• No compressor blade aero-mechanical issues iden-

tified and measured modal frequencies matchedprediction within 3%

• Compressor performance met both in terms ofmass flow and efficiency at design point and in offdesign conditions

• Extensive measurements close to the surge limitindicated a safe margin on compressor surge.

Clearance meter data were also taken to evaluaterotor-stator clearances both at steady state and duringtransients and to assess their impact on compressorperformance.

PROTOTYPE TESTA complete MS5002E prototype test is ongoing at theNuovo Pignone Massa facility, to validate the overallsystem (engine and auxiliaries).The prototype uses as the driven load the previouslytested MS5002E compressor.The test plan covers all critical operating phases(pre-start, crank, idle, diffusion FSFL, premixed

Compressor test rig