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VoithTorqueConverterstartingsystemforgasturbinesMTCGeneratorStarterSystem2Reliability&Availability:ChoosingtheRightSystemisImportantGasturbinesareoftenstartedseveraltimesaday.Choosingtherightstartingsystemwillaffectthestart-upreliabilityofthegasturbine.Voithsuppliestorqueconverterstoallleadinggastur-binemanufacturersanditslicensees,tostartgastur-binesranginginpowerfrom20to270MW.ThecombinationofaninductionmotorwithaVoithtorqueconverterissyn-onymouswithtroublefreestart-ups,highreliability,andlongservicelife.Morethan3,500gasturbinestartersworldwideisoutstandingevidenceofourexperienceandknow-howinthisarea.WebelievenootherstartingsystemormethodequalsthereliabilityandavailabilityoftheVoithtorqueconvert-erstartingsystem.OurexceptionallyhighMTBF(meantimebetweenfail-ure)leadstoastatisticalreliabilityof99.97%.Wealsoknowofnootherstartingsystemthatmatchesthe35-yeardesignlifeoftheVoithtorqueconverter;andthiscomeswithaguar-anteedavailabilityofpartsandservicematchingthelifeofourmachines.Thecompactandrigiddesignofferstroublefreeoperationwhilemainte-nanceexpensesareataminimum.3Voithtorqueconvertersaredesignedandbuilttomeetcustomerrequirements.Noothertorqueconvertermanufactureroffersthisservice.Lowmaintenanceexpenses.“No-loadstarting”conditiononthestartingmotorbydecouplingthemotorfromtheloadthroughthe“workingoilshut-offvalve”feature.TheVoithtorqueconverterdecouplesthestartingmotorfromthegasturbinetraindur-inggasturbineoperationwithouttheneedforamechanicalclutchthroughourexclusive“workingoilshut-offvalve”feature.Smoothandstep-lessoutputspeed&torqueadjustmentofthetorqueconverter.Torsionalvibrationdampeningandshockfreepowertransmission;consequently,nostressappliedtoconnectedequipmentthusdeliveringlongservicelife.BenefitsSelectionChart;basedontheapplicationandspecificationtheappropriatetorqueconvertersizecanbedefined.GasTurbineConverterinputpowerPp[MW]ConverterinputspeednP[min-1]TorqueconverterforgasturbinestartingSynchronizationconverter400600100020004000600080000,4124102040100200400600SelectionChart4TorqueConverterFunctionandDesignMTMPTheheartofVoiths’hydrodynamictorqueconverterisitshydrauliccircuit;consistingofapump,turbine,andaguidewheelwithadjustableguidevanes(seepicturetotheright).Thisiscombinedinacommonhousingfilledwithhydraulicoil.Themechanicalenergyofthemotorisconvertedintohydraulicenergythroughthepumpwheel.Intheturbinewheelthesamehydraulicenergyisconvertedbackintomechanicalenergyandtransmit-tedtothegasturbine/generatorshaft.Theadjustablevanesoftheguidewheelregulatethemassflowinthecircuit.Atclosedguidevanes(smallmassflow)thepowertransmissionisatitsminimum.Withtheguidevanescompletelyopen(largemassflow),thepowertransmissionisatitsmaxi-mum.Commonly,aconstantspeeddriversuchasaninductionmotororadieselenginedrivesthepumpwheel(inputshaftofthetorqueconverter).Becauseofthechangeinmassflow(duetotheadjustableguidevanes)theturbinewheels’speedisvariableandcanbeadjustedtomatchthevariousoperatingpointsofthegasturbine.Atlowspeed,theturbinedevelopsitshighesttorque.Withincreasingtur-binespeed,outputtorquedecreases(seegraphtotheright).MT=TurbinetorqueMP=Pumptorque=Efficiency1=Turbinewheel2=Pumpwheel3=Massflow(oil)MTMPηηnT=0nT=nTmax.nT=nopt.nT=0nT=nTmax123GuideVanesPumpWheelTurbineWheelFig.above:Basicdesignhydrody-namictorqueconverterDependingonthedesignofthebladeshape,theturbine(output)torqueatthebreak-away(nT=0)pointistwototentimesthatofthepump(input)torque.Theguidevanesabsorbthetorquedifferentialbetweentheturbine(output)andthepump(input)andtransferittothefoundation.Byplacingtheguidevanesupstreamofthepumpwheel,thetorquerequirementofthepump(input)remainsconstantatagivenguidevanesetting,independentoftheloadontheturbine(output).Thatmeansanoverloadofthedriver(motororengine)isnotpossiblethroughthehydrauliccircuit.Whenthehydraulicfluidisremovedfromthetorqueconvertercircuit,thepump(input)is„uncoupled“fromtheturbine(output)andconsequently,thestartermotororengineisdisconnectedfromthegasturbine.0%SpeedTorque5M810711910436125RTMMTypicalStarterSystemP&IDiagram1Torqueconverter2Torqueconverterhousing3Fillanddrainvalve4Controlvalve(Fillinganddraining)5Guidevaneadjustment6Orificeplate7Workingoilsupply8Lubeoilandcoolingoilsupply9Workingoilreturn10Lubeoilandcoolingoilreturn11Lubeoiltankofgasturbine1Breakaway2Unfiredresistance3Purgepoint(airexchange).4Firingspeed5Accelerationresistancetoself-sustainedspeed6Self-sustainedspeedTypicalgastturbinestart-upcurveTypicalhighspeedsettingTypicallowspeedsetting100%TypicalGasTurbineStart-UpCurveThroughitscharacteristicofhightorqueatlowoutputspeed,thetorqueconverteristheidealgasturbinestarter.Withtheabundantaccelerationtorqueavailable,thegasturbinecanbequicklyacceleratedtoandaboveitsself-sustainedspeed,animportantrequirementofthestate-of-the-art,hightemperaturegasturbines.StartUpBreak-awayofthegasturbinethroughthetorqueconverterortheintegralturninggearAccelerationtopurgespeedAccelerationtofiringspeedAssistingthegasturbinetoandaboveselfsustainedspeedUncouplingthestartingsystemfromthegasturbineOtherFunctionsTurnin