contamination control for wind turbinesjacksr7/gradworkshopwind09/asmegradstud… · 10µ=talcum...
TRANSCRIPT
Contamination ControlFor Wind Turbines
ASMEGraduate Student Workshop
October 2009
Bill NeedelmanChief Science AdvisorDonaldson Company, Inc
Study by Professor E. Rabinowicz, MIT
Loss of Usefulness
Obsolescence
(15%)
Surface Degradation
(70%)
Accidents
(15%)
Corrosion
(20%)
Mechanical Wear
(50%)
Abrasion AdhesionFatigue
“Six to seven percent of the Gross National Product is required
just to repair the damage caused by mechanical wear.”
Note: Currently ~$1 trillion
Wind TurbineReliability & Performance
• 25 % of Cost of Ownership of Wind Turbines is Maintenance
• Reliability Problems
Gearbox > Blades > Generators
• 80% Of Operating Problems Due to GBX
Mostly Gearbox Repair & Replacement
• Bearings are #1 Cause of Gearbox Failures
• Most Gearbox Warrantees ~2 Years,
Costly Repairs Start ~4th Year
• 90% Anticipated Energy Production
5% GBX, 3% Wind, 2% All Others
Hard Particle DamageBearing Fatigue
0.001
0.01
0.1
1
40 50 60 70 80 90 100 110 120 130
Debris Particle Size
Life Relative to Non-Dented Bearings
Hard Ductile (e.g. T15 & 52100 Steel) Hard Rigid (e.g. Al2O3 & SiC) Hard Friable (e.g. TiC)
Ref: Kotzalas & Needelman, AWEA Wind Power Conf, 2008
Outline
• Problems Caused by Oil Contamination
• Particle Filters
• Water Contamination Control
• Best Practices
• Benefits & Conclusions
Types of Contaminants
Particles - Hard & Soft
Water
Air/Gases
Fuels, Acids, Glycols
What is a MICRON ?What is a MICRON ?
40µµµµ
100 µµµµ
10
µµµµ
1µµµµ
PARTICLE SIZE
100µ=Grain of table salt
40µ=Lower limit of visibility
10µ=Talcum powder
2µ=Bacteria
Unit of Measurement
1 Millionth of a Meter (micrometer)
Or .000039"
µ = Micron Symbol
MICRON
70µ=Typical human hair diameter
The Particle Zoo
21/20/18
TOO DIRTY TO
EVALUATE
23/22/20
19/17/1518/16/14
26/24/22
20/19/17 16/15/13
15/14/1221/20/1821/20/18
Major Types & Sources of Hard Particle Contaminants in Wind Turbines
• Hard Particles
– Manufacturing Swarf
• Machine Chips, Casting Sand, Grinding Debris, Abrasives
– Internal Wear Debris
• Gear Tooth Wear
– Internal Corrosion Products
• Rust, Aluminum Oxide
– Environmental Grit
• Airborne Mineral Dust, Sand
Bath Tub Model
Hard Particle Problems
• Rolling Contact Fatigue
• Abrasive Wear & Erosion
• Lubricant Oxidation
Abrasive Wear
Adhesive Wear
Rolling Contact Fatigue
Mechanical Wear By Hard Particles
All Three Forms of Wear
Result in Loss of Clearance,
Rough Surfaces, and
Greater Friction
Gear Tooth ContactsSliding
Contacts
Rolling
Contact
Gear Friction Increases As Gear Tooth Surface Roughens
16
Rolling Contact Fatigue: Surface Origin Spalls
Initiation point
Roller Path
Spalled
Area
Load
Dynamic Fluid Film
Thickness (µm)
Older Bearings Failed BySub-surface Initiated Fatigue Spalling
Slag Inclusion
In Steel
Particles & Surface Initiated Fatigue
Particle CaughtParticle Caught
LoadLoad
Particles & Surface Initiated Fatigue
LoadLoad
Surface Dented,
Crack Initiation
Surface Dented,
Crack Initiation
Particles & Surface Initiated Fatigue
LoadLoad
Crack Propagation
Cracks Spread
With Repeated Cycles
Crack Propagation
Cracks Spread
With Repeated Cycles
Particles & Surface Initiated Fatigue
Fatigue Spall Crater Forms
Hard Particles Released
Fatigue Spall Crater Forms
Hard Particles Released
LoadLoad
SpallSpallSpall
The ChallengeCleaner Gear OilDrier Gear Oil
Same For Hydraulic Fluids
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Element Design����
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DT Steel Std
Collapse High Collapse
DT Steel
Coreless
1 Outer Wrap n/a n/a n/a
2 Support Mesh (2)
epoxy coated
steel for
support and
spacing
stainless steel
for support and
spacing
epoxy coated
steel for
support and
spacing
3 Flow Control Layers (2)
synthetic layers
to strengthen
media
synthetic layers
to strengthen
media
synthetic layers
to strengthen
media
4 Synteq® Media
thin glass-fiber
media for
performance
thin glass-fiber
media for
performance
thin glass-fiber
media for
performance
Filter Media Types
- Cellulose
- Synthetic (Glass Fiber)
- Wire Mesh
Pressure Loss Across A Filter Element(∆∆∆∆P)
Pressure Loss ∝∝∝∝ Flow Rate
X Viscosity
X Tortuosity
Gear Oil Oils: High Viscosity
Gear Boxes: Moderate Flow Rates
Fine Filters: High Tortuosity
Pore StructureGraded Pore Filter Media
State-Of-The Art Filter Media
Conventional Media
Resin Bonded
New Media
Bi-Component
Thermoplastic B
Sheath
Bicomponent Binder Fiber
Thermoplastic A
Core
Glass
microfibers
Bi-Component Filter Medium
Bi-Component Filter MediumGlass
microfibers
Thermoplastic
binder
fiber
Field Data: GE 1.5 MW
Turbine #5
0
1000
2000
3000
4000
5000
6000
7000
12/1/08 1/1/09 2/1/09 3/4/09 4/4/09 5/5/09 6/5/09 7/6/09 8/6/09
Dates
Particles/ml
>4um
>6um
>14um
Hydac 10um
DT 5um XPNew 5 um
Current 10 um
Dissolved & Free Water
Free Water
Emulsified
Dissolved Water
Below
Saturation
Free Water
Bulk
Separation
Major Sources of Water Contaminationin Wind Turbines
• Water Vapor - Humidity
• Rain (Through Vents & Seals)
• New Oil
Oil Has A Relative Humidity (RH)
50% RH Oil
At Equilibrium
RH of Air
Equals
RH of Oil
(RH Oil = %Saturation)
Water
Molecules
50% RH Air
Humidification
Water moves from high relative humidity
to low relative humidity
0
10
20
30
40
50
60
70
80
0 8 16 24
T im e (H ou rs )
Moisture Content (% Saturation)
Mobil DTE PM 220
in contact with air
controlled at 90oF
& 80% RH
Problems Caused by Water Contaminationin Wind Turbines
• Rolling Contact Fatigue
• Adhesive Wear
• Additive Dumping
• Oil Oxidation
Water DamageBearing Fatigue
0.1
1
10
10 100 1000
Water Concentration in Lubricant (PPM)
Relative Fatigue Life
SAE 20 + R&O SAE 5 + EP (100/X)^0.6 Navy Data
Ref: Kotzalas & Needelman, AWEA Wind Power Conf, 2008
Water & Rolling Contact Fatigue
Oil + Dissolve Water Forced Into Cracks in the Contact Zone
LoadLoad
Water & Fatigue Crack Propagation
Hydrogen
Embrittlement
Loss of Fluid Film Lubrication& Adhesive Wear
Load
Low Viscosity
Water Not Able
To Support Load
Film Collapses
Dynamic Fluid
Film Thickness (um)
Water DamageAdditive Drop-Out
Fouled & Disabled Oil-Level Sensor
Water DamageAdditive Drop-Out
Courtesy COT-Puritech, Inc.
Fouled & Disabled Thermostat
Keeping Gear Oils & Hydraulic Fluids Dry in Wind Turbines
• Prevention
– Minimize Ingression
• Removal
– Rapid
Regenerable Breather Dryer
Inhalation ExhalationCaptures H2O Regenerates By
Releasing H2O
Ultrapac
ARV-3: P568790
ARV-10: P568791
Customer Supplied
Pressure Regulator
with Guage
(set to 100 psi)
Incoming
Compressed Air
Customer Supplied
Shut-off Valve
(Required for
maintenance of unit)
Customer Supplied
Shut-off Valve
Reservoir
Customer Supplied
Flow Meter
(Optional to adjust
compressed air
usage as required)
TRAP Breather with
Tee and Relief Valve
Orifice
ARV-3: P568606
ARV-10: P568799
(Must be installed for proper
operation of ARV)
Inlet
Port
Outlet
Port
Inlet & Outlet Installed On
Opposite Corners Ideal
Dry Air Blanket System
Dry Air Blanket System
Time
• Dry Air
• Dry Oil
• Humid Air
• Saturated Oil
• Purging
Humid Air
• Saturated Oil
• Dry Air
• Moisture
Desorbing
from Oil
Na12 [(AlO2)12(SiO2)12] x H2O - 10 Angstrom Molecular Sieve
Pressure Swing Adsorption Dryer
Dry Air Blanket Keeping Oil in Contact With Very Dry Air
0
10
20
30
40
50
60
70
80
0 8 16 24
Time (Hours)
Head Space Air Relative Humidity (%)
2
Reservoir Head Space Air
6
20
200
0
10
20
30
40
50
60
70
80
0.0 8.0 16.0 24.0
Time (Hours)
Oil Percent Saturation (%)
20
2
Reservoir Oil
200
6
Exchanges/hour
Best PracticesTotal Contamination Control Plan
1) Design
2) Roll-Off Cleanliness
3) Transportation
4) On-Site Storage
5) Clean Maintenance Practices
6) Ingression Prevention
7) Rapid Removal
Best Practices ForIngression Prevention & Rapid Removal
Inline Filter
ββββ5(c)=1000
Gearbox
Offline Filter
ββββ3(c)=1000
Offline Water
Absorption
Filter
Regenerable Breather
Dryer with 3 Micron Filter
Objectives: ISO 14/12/10
. 125 ppm max
Cooler
Dry Air
System
NASA/STLE Roller Bearing
Life Factors for Wind Turbines
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
0 5 10 15 20 25 30 35 40
Filter Rating Where ¬¬¬¬(C) = 1000
(Microns)
Bearing Life Factors
Adapted from Needelman & Zaretsky, STLE Annual Mtg. Proc. May 09
12 um10 um
8 um
5 um
2um
NASA/STLE ModelWater Contamination & Bearing Life
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
0 100 200 300 400 500 600
Water (ppm)
Relative Bearing Life
Maintaining Dry Oil
Estimated To Increase
Bearing Life ~200%
Current
Target
Conclusions
• Benefits Of Excellent Contam Control
– Greater Gearbox Reliability
–More Uptime, More Production
– Extended Warrantees
– Up To 5 Year Gear Oil Life
• Needed
– Coherent Contamination Control Plan
– Use Best Technologies & Practices
Thank You For Your Interest
__________________
Questions?
Comments?