1Adopted forWind Power Management classhttp://www.icaen.uiowa.edu/~ie_155/by Andrew KusiakIntelligent Systems Laboratory2139 Seamans CenterThe University of Iowa Iowa City, Iowa 52242 – [email protected]: 319-335-5934 Fax: 319-335-5669http://www.icaen.uiowa.edu/~ankusiakGasTOPS Confidential © 2008Oil Debris Condition MonitoringFor Wind Turbine GearboxesPresented by : Richard DupuisAWEA Wind Power Asset Management WorkshopJanuary 2008, San Diego, CACorporate Profile• Advanced products and services for Machinery Condition Assessment and Control• Supplier of MetalSCAN Oil Debris Monitoring technology since 1995GasTOPS Confidential © 2008• Aviation, Defense, Energy and Marine sectors• Founded in 1979• Four locations:– Ottawa, Ontario (head office)– Halifax, Nova Scotia (field office)– Victoria, British Columbia (field office)– Pensacola, Florida (GasTOPS, Inc.)What’s the Problem ?GasTOPS Confidential © 2008Gearbox FailuresGasTOPS Confidential © 20082Typical Wind Turbine Gearbox ArrangementGasTOPS Confidential © 2008Overview• How can the problem be managed• Condition Monitoring Theory & FeasibilityGasTOPS Confidential © 2008• Oil Debris Monitoring (ODM) method - principle of operation• Why Bearings & Gears Fail• Validation of ODM method for condition monitoringHow to deal with the problem ?• Conduct root cause investigations of gearbox problems• Continue to make design modifications to gearboxes and their system interfacesGasTOPS Confidential © 2008gy• Operators/owners must seek solutions to manage the problemHow can the problem be managed ?• Adopt Condition Monitoring (CM) • Avoid “Failure” Event– Contain the damageGasTOPS Confidential © 2008–Reduce repair time & costs significantly• Minimize Business Interruption– Schedule repair support on-site before shutdown– Minimize lost revenue & penalties3Condition Monitoring Theory : P-F CurvePOTENTIAL FAILUREGOODGasTOPS Confidential © 2008• Need to have a: ‘Condition Indicator’ (CI) FAILUREBADCM Technical Feasibility Criteria• CI must detect the potential failure (P)• CI must identify the degree of damage towards failure (F)GasTOPS Confidential © 2008• P-F interval must provide adequate time for the organization to proactively plan• P-F curve must be consistent for the failure mode •Metallic debris from bearing or gearbox sump• Sensor includes 3-coil assemblyOil Debris Monitoring (ODM) -Principle of OperationGasTOPS Confidential © 2008•Metallic debris from bearing or gearbox sump flows past the field coils creating a disturbance signal in the sense coil• Signal characteristics define: - particle size based upon signal amplitude - type (Fe or NFe) based upon signal directionHow does ODM satisfyGasTOPS Confidential © 2008the CM criteria ?4Why Bearings/Gears Fail?• Most bearings/gears are damaged in-service due to stress concentrations that arise from:– Physical / dimensional discrepancies -….Misapplication, Mishandling, DefectsGasTOPS Confidential © 2008pp g– Overrolling of debris -….Contaminants in lube oil– Corrosion pitting -….Chemical interactionsValidation of ODM method• Bearing and Gear component damage - research data• Engine and Gearbox damage - rig test dataGasTOPS Confidential © 2008• Fielded Applications damage – field dataBearing and Gear ComponentGasTOPS Confidential © 2008Component Damage ResearchBearing Damage Research (NRC)• Observations:– Early damage is series of ‘particle bursts’• Rig data from over 40 bearings (2” to 18” in diameter; ball and roller)Later damage is more progressiveParticle Size60008000cles> 200 umParticle Size60008000cles> 200 umParticle SizeGasTOPS Confidential © 2008– Particle size distribution is independent of bearing size–Later damage is more progressive…Rate is dependent on load and speed…Quantity is dependent on size of bearing• Conclusions:– Quantity correlates to ‘degree of damage’– Quantity + Rate correlates to ‘remaining life’*0 20 40 60 80 100 120020004000Elapsed Time [%]Number of Partic> 500 um> 400 um> 350 um> 300 um> 250 um> 700 um>200 um>700 um0 20406080100120020004000Elapsed Time [%]Number of Partic> 500 um> 400 um> 350 um> 300 um> 250 um> 700 umReference document: “Rolling Element Bearing Failure Detection with ODM (Oil Debris Monitor) On-line Oil Debris Sensor”, NRCC doc. – IMR-MCM-CTR-0205• Seeded fault test data from gear rig monitored by ODMGear Damage Research (NASA)GasTOPS Confidential © 2008Reference document: “Integrating Oil Debris and Vibration Gear Damage Detection Technologies Using Fuzzy Logic”, NASA/TM –2002-211126Increasing damage on gear tooth Bearing Prognostics Research (AFRL)• Seeded fault test on bearing test rig• 52100 and M50NiL bearing steels• ODM used to monitor debris quantityGasTOPS Confidential © 20080204060801001201401601802000.0E+00 1.0E+07 2.0E+07 3.0E+07 4.0E+07 5.0E+07CyclesMass Loss(mg)314 ksi300 ksi278 ksi250 ksiquantityReference document: “ISHM presentation by Dr. Nelson Forester, Aug 11/05”AFRL Observations-1. Higher stress = quicker damage progression2. Mass loss is repeatable for constant stressEngine and GearboxDamageGasTOPS Confidential © 2008Damage Rig TestsGas Turbine F119 (F22 Aircraft) Bearing Damage – Test Data (P&W)700080009000Bearing ReplacedGasTOPS Confidential © 2008• New engine run on test stand• Damage due to mis-assembly• Bearing highly overstressed• NO SECONDARY DAMAGE occurred01000200030004000500060000 2 4 6 8 10 12 14 16OPERATING TIME (Hrs.)PARTICLE COUNTSBearing Replaced(5 operating hours later)Initial Damage Occurs6Bell 206 Helicopter Gearbox Bearing Damage – Test Data (DSTO)• Rig test of two B206 main rotor gearboxes at DSTO test facilityCumulative Fe Mass - Bell 206 Main Rotor Gearbox Overload Trial100.00200.00300.00400.00500.00600.00Fe Mass (mg)Test #1GasTOPS Confidential © 2008gearboxes at DSTO test facility• 150% overload stress test• Test #1 & 2 teardowns showed damage limited to planet bearingData is presented by permission from the Australian Defense Science & Technology Organization 05010 015 02002503003504004505005506000 102030405060708090Ope r at in g Hour s0.000.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00 180.00Operating HoursTest #2Apache Helicopter GearboxBearing Damage – Test Data (NAVAIR)GasTOPS Confidential © 2008• Rig test of AH-64 drive-train at USNavy Patuxent River