Embed Size (px)
Citation preview
Blade Assets – Extend Life and Reduce Risks with Proactive Maintenance
Before We Start q This webinar will be available at
www.windpowerengineering.com & email
q Q&A at the end of the presentation
q Hashtag for this webinar: #WindWebinar
Moderator Presenter
Paul Dvorak Windpower Engineering
& Development
Aaron Wahlstrom Broadwind Energy
© 2015 Broadwind Services, LLC All rights reserved.
BLADE ASSETS – EXTEND LIFE AND REDUCE RISK WITH PROACTIVE MAINTENANCE
Our key topics § Important steps you can take to implement a proactive blade
maintenance program
§ Dramatically increase the lifecycle of blades and reduce down time
§ Common blade issues for all makes and models.
§ Importance of routine blade inspections to identify issues early
§ How impaired blades impact WTG reliability and performance
§ Comparison of leading edge protection solutions
Thinking like a wind farm owner, acting as your partner. © 2015 Broadwind Services, LLC All rights reserved.
§ Most comprehensive proactive GBX maintenance program
§ Borescope inspection
§ 4-‐‑phase oil change
§ Patent pending MW class GBX rebuilds executed entirely up-‐‑tower
§ 3-‐‑year rebuild warranty
We are the largest non-routine ISP in North America
§ BladeHD -‐‑ a stunning full profile map of suspect areas
§ BladenaTM -‐‑ strategic alliance to install D-‐‑stringTM technology
§ OEM factory support & authorized service provider
© 2015 Broadwind Services, LLC All rights reserved.
7
Awareness of blade damage is increasing
© 2015 Broadwind Services, LLC All rights reserved.
Panel Breathing Induced by Gravity Trailing edge panel breathing induced by gravity introduces peeling stresses in the bond lines
Breathing and peeling stresses are the root cause for cracks in the trailing edge region in the max chord area © 2015 Broadwind Services, LLC All rights reserved.
Turbines and blades are getting bigger!
Gravity forces on blades are cyclic § Pull down as the blade is on the way down § Pull in the opposite direction on the way up
This causes ‘breathing’ … independent of wind forces
Blade length L: from 20 m to ~100 m Gravity forces increase with L3
Bending moment increases with L4
e.g. for a 60 m blade: § Gravity forces are 27x larger § Bending moment is 81x larger … than for a 20 m blade and for a 100 m blade: 125x / 625x
Bigger blades = more risk © 2015 Broadwind Services, LLC All rights reserved.
Stronger blades – more energy
Typical 12 D-‐‑Strings installed in max chord area
Without D-‐‑Strings® installed
With D-‐‑Strings® installed
Red = high peeling stresses Blue = low peeling stresses
Damages typically seen due to trailing edge panel breathing – Eliminated by D-‐‑String®
Transverse cracks in the trailing edge panel
Hairline cracks in the trailing edge
Longitudinal cracks along the bond lines
Peeling stresses removed by D-‐‑String®
Simply stop breathing Blade panel deformations induced by edgewise gravity loads causes panel breathing
Without D-‐‑Strings
With D-‐‑Strings
>D-‐‑StringTM – simply effective!
Identify issues early § Prevent cosmetic issues from
spiraling into structural damage
§ Perform proactive planned maintenance at a fraction of the cost of blade replacement
§ Reduce unscheduled maintenance costs
§ Avoid media, insurance and community scrutiny
© 2015 Broadwind Services, LLC All rights reserved.
Everyday sources of blade damage and wear
© 2015 Broadwind Services, LLC All rights reserved.
Minor damage is the tip of the iceberg!
14
Minor gel-coat crack Investigation process Repair preparation
§ In-situ repair during inspection feasible
§ Can be multi-day project
© 2015 Broadwind Services, LLC All rights reserved.
§ Reduces energy capture
§ In-situ repair during inspection feasible
Leading edge erosion
cuts into energy capture
Moderate Edge Erosion w/ Structural Cracking
Severe Edge Erosion
Minor Edge Erosion
© 2015 Broadwind Services, LLC All rights reserved.
Cracks and
delamination
on leading
and trailing
edges
Severe edge damage can be catastrophic In-situ repair is feasible,
however typically one
week+ from date issue
found to repair
© 2015 Broadwind Services, LLC All rights reserved.
L/E Protection Tape /Paint PROs § Longer lifespan in most cases
§ Best on Polyester/Gelcoat blades
§ Nearly same application time
Considerations
§ Cost
§ Edge sealing
§ Cutting, splicing
§ Drag loss factor <1%*
Factory Paint L/E Protection PROs § Works for 1-1.5yrs on Epoxy Blades
§ Inexpensive
§ Bonds directly and wears predictably as original coating
Considerations
§ Polyester vs. Epoxy Construction
§ Current level of erosion
Several solutions - Pros & Cons
© 2015 Broadwind Services, LLC All rights reserved.
Carbon Blade Construction Unidirectional Fiber spar cap and box type construction
• Prepreg fabric spar cap • Pultruded square or sheet bonded spar cap bundle • Carbon structure manufactured as separate component
© 2015 Broadwind Services, LLC All rights reserved.
Lightning Strike Inspection
In-process Investigation & Repair
§ In-situ repair during annual inspection feasible
§ Multi-day project
© 2015 Broadwind Services, LLC All rights reserved.
20
Evaluation Process § Damage assessment
§ Repair feasibility
§ Repair method
§ Access method
Considerations
§ Standards
§ Blade type
§ Mfg. specs.
Investigation Techniques § Visual (ground or in-air) § Acoustic § Tap test § Infrared imaging § Thermography § Ultra-sound § Lightning system continuity check § Bond line measurements
Blade Damage Evaluation & Techniques
© 2015 Broadwind Services, LLC All rights reserved.
ü Poor aerodynamics & pitch errors
ü Reduced service life of gearbox due to blade vibrations
ü Overloaded pitch control drive motors
ü Shut down during icing & high winds
ü Downtime waiting for repairs during peaks
ü Overburdened lean onsite O&M teams
ü Increased repair costs for crane access to repair blade
ü Inflated cost of the needed repair
Delayed maintenance impacts your bottom line!
© 2015 Broadwind Services, LLC All rights reserved.
Proactive Blade Maintenance Checklist ü Scheduled periodic inspections during non-peak season
ü Repairs are smaller and a fraction of cost of blade replacement
ü Improved reliability and performance through aerodynamic efficiency
ü No lost revenue due to down time waiting for unscheduled repair
ü Build a blade performance database to project future costs
Partner with a service provider who will customize a solution to meet your unique operating conditions.
>Over 10,000 blades serviced.
© 2015 Broadwind Services, LLC All rights reserved.
Questions? Paul Dvorak Windpower Engineering & Development [email protected] Twitter: @windpower_eng
Aaron Wahlstrom Broadwind Energy [email protected]
Thank You q This webinar will be available at
www.windpowerengineering.com & email
q Tweet with hashtag #WindWebinar
q Connect with Windpower Engineering & Development
q Discuss this on the EngineeringExchange.com
