Blade manufacturer molds 1,000th set of 37-m blades
August 9, 2011 by Paul Dvorak
Filed under Construction, Turbine Blades, Wind Power News
MFG Texas is part of the Molded Fiber Glass Companies, based in Ashtabula, Ohio that has been manufacturing wind turbine components since 1988.
The Molded Fiber Glass Companies (MFG), a manufacturer of wind turbine components, says its company plant in Gainesville, Texas celebrated the shipment of its 1,000th set of 37-meter composite wind blades. Located 60 miles north of Dallas in the wind-farm hotbed of the USA, the 155,000-ft2 facility has been manufacturing wind blades since 1997 and employs about 200 skilled workers.
The shipment marking the 1,000th set milestone was comprised of 37-m blades for a 1,500-kW turbines. This factory has also produced another 500 sets of other blades ranging from 24 to 34m.
Today, wind turbine components comprise one of the company’s largest business segments. The company has two factories building wind blades, two factories building nacelles, and one factory building spinners. The company has wind component manufacturing facilities in Ohio, South Dakota, California, Alabama, and Texas.
“Consider this,” says MFG Director of Sales for Wind Energy Gary Kanaby, “these blades collectively have generated on the order of 4,234,000,000 kWh of electricity.” MFG’s newest 325,000 ft2 blade facility in Aberdeen, South Dakota, opened in 2007, and is the most advanced facility of its kind, they say, with an automated spray booth and robotic root drilling.
MFG
http://www.moldedfiberglass.com/
Planning Maintenance for Wind Turbine Blades
July 21, 2011 by Windpower Engineering
Filed under Editorial, Maintenance, Maintenance & operations
Like stately giants, utility wind turbines are appearing further afield and offshore. As designers tackle the job of building longer, heavier, higher performing turbine blades, wind-farm operators and owners are faced with a different challenge– keeping aging blades in optimum condition.
Traditionally, less attention has been paid to the repair and upkeep of turbine blades versus other components. Instead, preventive maintenance programs have focused on the internal mechanics of turbines due to the predictability of their maintenance requirements. Typical preventive maintenance plans for internal components fall into 3, 6, and 12-month work schedules. By nature, blade repairs are more difficult to plan. Blade damage can arise in manufacturing, transportation, and tower construction and erection. However, maintenance issues more often occur in the field from leading-edge erosion, weather, and other factors. A lack of predictability and historical data complicates preventive maintenance for blades.
A maintenance technician from Wind Energy Services Company sands the substrate of a blade before applying a surface coat.
Commercial turbines can have tip speeds of over 200 miles per hour. At these speeds, rain drops can take on the impact of small stones, and blowing sand has the erosion power of a plasma cutter. Studies have shown blade roughness and accumulated debris on the blades can reduce wind turbine performance by 5 to 30%. Blades that aren’t working efficiently can also create vibration that contributes to gearbox failures.
While Composites One distributes composites and materials for blades and their repair, those who apply them have an entirely personal and unique perspective to the task–which is worthy of broader exposure. Hence, this article.
To minimize downtime and boost energy-capture efficiency, it’s critical to adopt practices early on, including implementing a preventive maintenance program and identifying problem areas. “Return on investment for wind turbines is a long cycle so any downtime has significant impact on the owner,” says Dave Smith, power generation manager for Composites One. “Repairs must be made quickly and cost effectively.”
Gary Kanaby, director of sales for Texas-based Wind Energy Services Company (WES) agrees. “A planned maintenance program can mean the difference between a small repair and damage that incurs the cost of an outside crew, crane rental, and the loss of energy sales while the turbine is down,” he says. “Leading-edge damage affects air foil and air flow around the blade and can cause up to a 5% energy loss.” Kanaby explains that uncorrected erosion will lead to cracking, splitting of the blade tip, and blade separation. Efficiency can be improved by restoring the leading edge to its original airfoil specs.
Visual inspection is the simplest form of preventive maintenance and can be conducted using a camera with a telescopic lens of at least 400 mm, or high-powered binoculars. Joshua Crayton is blade services manager for Rope Partner, which provides turbine maintenance, repair, and inspection services throughout its locations in California, Texas, Canada, and Germany. He says regular inspections are especially important in windy seasons and following lightning storms. “Operators and owners are inheriting their wind farm assets and the responsibility of maintaining blades that are no longer covered by the OEM warranty,” he says. “Like any business, wind farm owners and operators typically run a lean staff and may not have an experienced maintenance technician in-house. Partnering with a service company can help them design a long-term, post warranty, preventive maintenance plan.”
According to Crayton, a maintenance plan should be initiated before the warranty period expires. “A thorough internal and external blade inspection should be scheduled in the warranty period,” he says. “Once owners and operators take over care of a wind farm, these inspections should take place every two years. Personnel can conduct simple ground inspections while on-site, but there is no substitution for a close, visual examination performed uptower.” Trained personnel using standard rope access systems offer an efficient, cost effective, environmentally friendly approach that enables complete 360° access to the tower, nacelle, and blades.
Crayton says consultation can still offer practical insights for wind-farm owners with the capbility to perform blade inspection and repairs in-house. “There are many different types of blades in the field,” he says. “Each construction type carries its own inherent flaws and issues. Consultants can give wind-farm owners an understanding of what to look for. A defect that may be potentially catastrophic for one type of blade may not be as serious for another.” Water ingress, for example, will not have the same impact on a blade core made from polymer foams as it would a blade built predominantly with a balsa-wood core.
Over the last year Crayton’s crew has begun to see an increase in requests from owners and operators for internal and external blade inspection on a site-wide basis. “When we make repairs we are always trying new products to find more efficient ways to get the turbine up and running faster,” he adds. For small fixes such as minor pitting or cleaning debris off blades, technicians can use a variety of abrasives, cleaning solutions, and fillers.
Structural repairs are more often made in the field. Products, such as the Renuvo line from Gurit, allow for prepreg patching right on the blade.
Jim Sadlo, wind energy market development manager for 3M, says some wind farm owners monitor their blades using high-speed telephoto cameras. “The stop action images offer enough clarity to reveal problem areas such as leading edge erosion and other defects on the blade,” he says. Typically, the next step is a visual blade inspection by a service company who analyzes the scope of work and determines the required materials. Wind farms, especially those in Northern climates, have a short window of opportunity to complete repairs. For example, restoring surface damage can require a number of steps. The crew usually masks off the portion of the blade surrounding the work area. A plastic film attached to masking tape works effectively and is easy to haul uptower, says Sadlo. The defective portion of the blade is cut out and then ground using ceramic grinding abrasives. The area has to be rebuilt with fabric and resin according to OEM criteria for strength, density, and structural soundness. After placing the last layer of fabric, filler helps restore the blade’s aerodynamic shape. Several epoxies and polyurethanes are available in easy-to-handle cartridges that offer short cure times. A repair technician can begin sanding in as little as 30 minutes.
Once the repaired section is sanded and painted, wind protection tape can be applied and the tape’s edges sealed and beveled to create optimal aerodynamic characteristics. Sadlo says the tape can also act as a shock absorber to lessen the impact of flying debris such as bugs or hail. This wind protection tape has a new option that allows for easy installation while the blade is vertical. The center section of the tape’s liner can be removed separately from the rest of the liner, making it easier to align to the blade edge and apply the tape from the middle.
When looking for advice on maintenance or repair products, the following companies can offer both materials and expertise.
Resins that cure quickly with UV light instead of heat also help reduce the time crews have to wait between repair steps. David Cripps, global account manager for Gurit Wind Energy says such resins broaden the window for repairs in colder climates because they can be used at temperatures as low as freezing. Available in a paste or prepreg patch, the resin paste can be used on its own to make small repairs. If a laminate must be restored to its original condition, the resin paste can also be used as a primer or wetting agent to help bond the new prepreg–a relatively dry material–to the blade surface. Once the prepreg patch is applied, additional paste can smooth the surface. “With the prepreg method, the amount of resin in the laminate is highly controlled for an accurate fiber-resin ratio,” he says.
Improved materials, such as coatings, are helping wind farm owners and operators maximize the resistance of their blades to the elements and extend service life. Applied to the blade’s exterior by the OEM, these newer coatings can also be reapplied uptower to facilitate a repair. Martin Schoning, sales manager for Bergolin, says the products are fast drying and environmentally friendly. “The blade’s leading edge takes the brunt of damage from erosion, weather elements, and airborne particulates,” he says. “Re-application of the right coating is a key step to increasing the blade’s resistance to abrasion and erosion.”
The need for products that can be used in the field under less than ideal conditions is a component of preventive maintenance. “Turbine downtime costs a lot of money,” says Alistair Smith, technical sales manager for Mankiewicz. “Paints and top coats offer abrasion resistance and absorb some of the energy from sand, hail or any other element that hits the surface. The products must dry fast and last a long time. Delivery systems also have to make the products easy to handle, transport, and use uptower.”
As the industry grows, regular inspection and maintenance of blades, along with products that can support fast fixes are becoming critical tools for minimizing costs associated with reduced efficiency and downtime. “The blade is really the ‘engine’ of the turbine,” says Smith, “it’s the component that is capturing and producing energy. Planned maintenance can keep blades in peak performance which directly translates to kilowatts sold.”
Marcy Offner
Composites One
Arlington Heights, IL
www.compositesone.com
WPE
Wind Turbine Reliability – The Importance of Highly Reliable Pitch Control and Blade Sensing Systems
July 20, 2011 by Windpower Engineering
Filed under Condition Monitoring, Construction, Maintenance, Maintenance & operations, Towers, Uncategorized, Webinars, Wind Safety
Increase Turbine Reliability
In this 40 minute webinar, learn how two common hazards can hamper a wind turbine’s production. Wind-turbine owners and operators may experience a significant reduction of generated power, reducing overall turbine efficiency, if they don’t take into account:
- Blade Icing
- Failed Slip Rings Issues
- Increased Reliability
In this free webinar, we explore how Moog Blade Sensing Ice Detection Systems can monitor the load of each blade, providing real-time data indicating presence and level of ice build-up. We also examine key challenges with transmitting power and data signals from the nacelle through slip rings to the pitch-control system. Costly downtime can be eliminated by using fiber-brush technology and rugged mechanical components in the slip ring. Moog representatives show how they designed a slip ring that addresses these requirements for reliability and maintainability and thereby reduces a wind turbine’s overall operating cost.
Composite structural sizing software improves with new design and manufacturing features
May 11, 2011 by Paul Dvorak
Filed under Materials, Turbine Blades, Wind Power News
HyperSizer’s design and manufacturing capabilities are appropriate for optimizing composite-driven designs in a variety of industries including wind turbine blades, ship superstructures, and high-speed railcars.
HyperSizer v6 structural sizing and analysis software can help reduce structure weight while maintaining strength and improving manufacturability, especially for complex composite and metallic designs. Developed and proven at NASA, the software—the first commercialized by the agency—has a track record of 20% weight reduction in high-profile government and commercial aerospace projects.
Composites have gained wide acceptance and validation in aerospace applications while accelerating growth in a variety of industries. Their weight-to-strength properties promote fuel efficiency and allows hitting energy targets without impacting durability. “One of the biggest roadblocks to effective composite design is the inability of engineers to adequately explore optimized layups simultaneously with other design variables,” says Collier Research President Craig Collier. “This results in design inefficiencies and compromises.”
To address the issues, HyperSizer works with FEA solvers in a continuous, iterative loop, conducting trade studies and examining millions of potential design candidates down to the ply, even element level. The software ensures structural integrity through an extensive suite of failure analysis predictions that are validated to test data. The tool also enhances manufacturability by minimizing ply drops, identifying and controlling laminate transition drop/add boundaries, and defining best ply shapes and patterns. Hypersizer can be used from preliminary design to final analysis.
New features in HyperSizer v6 include:
- Manufacturability optimization – To help design for efficient manufacturing, the software can now identify, define, and control ply-count compatibility, laminate sequencing, interleaving, and ply-drop minimization. This results in fewer processing steps, cost-effective layups, and a faster turnaround in the mold.
- Post-buckling analyses – Automated compression, shear, and compression-shear post-buckling analyses have been added. These are based on complex NASA-developed methods that serve as the foundation for metal aircraft design. Integrated with flexural-torsional buckling, these let engineers cut weight in aluminum skin airframes. Such analyses, difficult to perform with nonlinear FEA alone, have been extended to composite material systems as well.
- Panel Concepts – Two novel, damage-tolerant composite architectures are now available, providing more structural sizing variables and optimization flexibility: Prseus is a Boeing, NASA, and Air Force Research Lab-developed dry-fabric woven material poltruded rod structure, while “reinforced core sandwich” is an alternative sandwich panel similar to foam sandwich. Specialized analyses for both these panel concepts have been implemented and correlated to test data established for accurate strength predictions.
Serving as the analysis hub and automating data transfer during design and manufacturing cycles, HyperSizer integrates with FEA software, such as Nastran and Abaqus, and with composite CAD tools, such as Catia and FiberSIM. HyperSizer ensures that design and analysis departments are kept current and working with the same design data.
“Given the increasing emphasis on more complex materials, engineers must improve and automate their design processes to reach higher levels of efficiency,” says Collier. “It’s no longer good enough to spot-check. Each part must be examined as a system. HyperSizer lets engineers more fully explore the entire design space.”
“It’s challenging to cut weight while maintaining strength and controlling cost,” says Tom Ashwill, technical leader in Sandia National Laboratories Wind Energy Technology Department. “HyperSizer has the capability to systematically optimize placement of a variety of different materials throughout the blade to maximize load resistance and minimize weight and thus cost.”
Collier Research Corporation
www.hypersizer.com
Materials and design methods look for the 100-m blade
May 10, 2011 by Windpower Engineering
Filed under Editorial, Mechanical Components, Turbine Blades, Turbine Design
Craig Collier
President
Collier Research Corp.
hypersizer.com
Tom Ashwill
Technical Leader
Wind Energy Technology Department,
Sandia National Laboratories
windpower.sandia.gov/
Commercial wind-turbine blades have historically relied on fiberglass as a primary material. In 2010, a Sandia National Laboratories’ report estimated annual U.S. industry usage for utility-grade turbine blades at over 70,000 metric tons. As designers build bigger blades in an effort to boost power production and cost efficiency, material systems are evolving to account for the increasing weight and additional gravitational stresses. Engineers are now looking to high-performance composites for greater strength and lighter weight at competitive prices. But consider that a typical 1.5-MW blade is 33 to 40-m long, weighs up to eight tons, and can have composite layups as thick as 4-in. at the root. Now you begin to grasp the engineering challenge inherent in designing an efficient, cost-effective composite blade.
The blade planforms with major material regions are for Sandia’s three wind-blade prototypes: CX-100 (carbon experimental), TX-100 (twist-bend experimental), and BSDS (blade system design studies). (Illustration from Sandia National Laboratories’ Materials and Innovations for Large Blade Structures: Research Opportunities in Wind Energy Technology, AIAA- 2009-2407, May 2009)
Since the early 2000s, Sandia’s Wind Energy Technology Department has been conducting prototype projects to develop and evaluate a variety of innovations for wind blades, including new material systems, more efficient structural architectures, load alleviation methods, and thicker airfoils for increased structural performance. A program currently underway at the government lab explores the design of a 100-m blade (potentially for a 13.2-MW turbine) targeted for offshore use and asks the difficult design and material-system questions that accompany increasing blade length.
The cutaway of Sandia’s BSDS (blade system design studies) prototype shows a few internal details. Carbon is used for the primary load-bearing spars with a sandwich-style fiberglass construction for the blade skins and shear-webs panels. In this configuration, the spar caps were primarily unidirectional carbon fibers and the skins were typically biaxial or triaxial fiberglass. (Illustration from Sandia National Laboratories’ Blade System Design Study Part II: Final Project Report (GEC), SAND2009-0686, May 2009)
To help answer some of the questions, Sandia will be working with Virginia-based Collier Research Corp., to apply its composite analysis and optimization software to large-blade-prototype designs. The software, HyperSizer, a NASA technology-transfer spinoff, has been used extensively by the space agency (in the ARES V launch vehicle and Composite Crew Module) and in aircraft to structurally size complex composite and metallic designs. The software complements finite-element analysis (FEA), working in a feedback loop with commercial codes to search for solutions that minimize weight, while maximizing strength and manufacturability—all issues critical to wind-turbine design.
Asking material questions
In place of fiberglass, or glass fiber-reinforced polymer, blade designers are turning to carbon fiber-reinforced polymer for its superior weight-to-strength characteristics. Carbon fiber is already used extensively in the aerospace industry—in the Boeing 787, Airbus 350, Bombardier LearJet 85, and Goodrich engines—where higher strength, lower weight, and greater fuel efficiency are design goals.
A hypothetical model (left) is for a wind turbine blade with manually defined laminate zones showing rectangular layup sections based on generalized rules of thumb. Colors represent different zones. Note only a few sections in the blade root. In a detail of the blade root (right), HyperSizer software was used to redefine zones by surveying thousands of surface area shapes and sizes. While creating optimum zone shapes of laminate transitions, it also minimizes ply drops in zone transitions.
The question of when and where to substitute carbon for fiberglass in a wind blade is not simple. For one thing, even though carbon fiber is significantly stronger and stiffer than fiberglass, it is much more expensive. Also, an extensive library of glass and carbon fabrics and tapes with varied fiber orientation, strength, and rigidity, as well as a host of sandwich cores and hybrid laminates with diverse properties, makes materials decisions even more difficult for designers. Tremendous variation in internal loads along the length of a wind blade further amplifies the complexity of the material system design.
To help unravel design uncertainties, Sandia’s past prototype projects focused on the use of carbon fiber to control the loading scenarios of increasingly bigger blades. The CX-100 (carbon experimental) contained a full-length carbon spar cap – at the time a relatively new concept. The TX-100 (twist-bend experimental) used both a fiberglass spar cap that ran only half the length of the blade and unidirectional carbon fibers in the skins to passively shed aerodynamic loads through twist-bend coupling. The third prototype, the BSDS (blade system design studies), also used a full-length carbon spar cap, but experimented with airfoil shapes and dimensions of the root. The current 100-m blade study focuses on designing an all-fiberglass composite blade that can withstand international certification loads including operational, fatigue, and buckling, as well as manufacturability considerations.
While Sandia’s research is advancing blade technology and seeding industry innovation, there are still many gaps in knowledge and practice. Design areas ripe for innovation and optimization include material type, material placement, internal architecture (number of shear webs, spar cap thickness, and more), and airfoil planform. Where materials are concerned, because loads vary over a wind blade’s root, spar, shear webs, and free-flowing surface, it is difficult for a designer to know what shape to make a laminate zone, where to stop one zone and start another, or how to determine an optimum thickness of layups in different zones. It is also difficult (almost impossible) to manually calculate how to handle transitions between zones and where to position many individual ply drops and adds in a single blade. Resin and layup process variables introduce even more complexity and signal a need for additional design tools.
The ply-compatibility analysis conducted in HyperSizer quantifies how ply drops and adds are minimized along panel transitions.
Magnifying material answers
A material design model typically starts by mapping rectangular-shaped sections for the laminate zones, based on accumulated knowledge and rules of thumb. But the reality of buckling, bending, twisting, deflection, and aerodynamic loading is anything but regular. Software such as HyperSizer helps. Using blade-loading results from FEA, the software maps the laminate zones to more accurately represent the blade physics and then calculates a ply stacking sequence for each zone.
To accomplish this, FEA is first run to determine internal loads and deflections in the blade. Those loads are then imported into HyperSizer, which performs tradeoff studies, surveys thousands (or sometimes even millions) of candidate laminates, and exports the new material properties. Then the FEA model is rerun
As part of the analysis, the software performs a sizing optimization, failure-and-fatigue investigations, and weight-trade studies. It also calculates margins of safety (factors of safety) and best configurations for transition zones. Surveying designs in a ply-by-ply and even finite-element-by-element manner, the software leads users to customized laminate solutions early in a design process, using a wide variety of composite materials.
A typical analysis and optimization takes about four hours, while eliminating offline spreadsheets and manual calculations. The software can also exchange laminate specifications with CATIA and FiberSIM.
The three blade profiles provide scale for the 13.2 MW, 100-m prototype wind blade in development at Sandia National Laboratories Wind Energy Technology Department. Each colored patch on the blade model illustrates a laminate zone.
Wind’s material future
There is currently no “best design” configuration for wind turbines. The engineering community is still searching for the right combinations of structural innovation and complementary material solutions.
But when Sandia’s prototype blade research first started in 2002, engineers didn’t even know if they could mix carbon fiber with glass fibers because their strength properties differed by a factor of three. Now they know a combination of advanced materials including carbon fiber, hybrid laminates, and sandwich cores of all material types can play important roles in blade design. Along the way they have accumulated more than 10,000 fatigue-test results for about 150 different composites, all of which can be downloaded into the software’s material database
Analysts at CompositeWorld’s 2009 Carbon Fiber Conference agreed with Sandia researchers’ findings about the value of new materials. They predicted that by 2014 wind blades will be consuming 35,000 to 50,000 metric tons of carbon fiber annually.
As wind technology matures, engineers are learning how to build longer, stronger, and lighter blades using the latest high-performance composites. Advanced analysis tools, such as HyperSizer, will accelerate that learning curve. The software’s track record in the aerospace industry has been weight reduction averaging 20%. Test cases on wind blades are yielding similar results.
WPE
Trends in blade maintenance
May 7, 2011 by Windpower Engineering
Filed under Maintenance, Maintenance & operations
Blades are the leading edge of a wind turbine so their aerodynamic surfaces carry critical shapes in a fluid (air) that seems bent on removing the shape. Blade tips often hit 180 mph, so it’s no surprise that sand, rain, and hail wear and damage their surfaces.
Trends in blade maintenance show up in two distinct areas: damage detection and repair.
“To gain initial baseline blade damage insight, we first suggest an on-ground visual examination of 10 to 20% of a site’s blades by using a scope and high-resolution camera in order to achieve a statistical handle on possible blade problems,” says Rope Partner Director of R&D and Business Development Chris Bley. “Depending on our findings we use rope access techniques to inspect the blades more closely. After gathering this baseline information, it’s possible to calculate trending, an indicator of how the blades are performing for particular locations.” One trend now is to conduct such inspections before turbines come out of warranty.
“More cautious owners/operators choose not to take a statistical approach before the expiration of warranty, they feel inspecting 100% of their blades from the ground and 10 to 20% on ropes is necessary to protect their valuable assets.” says Bley.
Should a closer inspection become necessary, technicians can use sonic devices to evaluate the damage. Ultrasonic units have been useful in these tasks but they require applying a water or gel (a couplant) to the blade surface and examining small areas – a few inches square – at a time. Recently, a more promising method uses light for a more in-depth diagnosis, over a larger area without contacting the blade.
The optical inspection method, shearography, has had widespread use in the aerospace and marine industries. “It’s laser based technique that lets us measure small surface deformation that are indicative of subsurface defects says Dantec Dynamics’ Matt Crompton. “The defects could result from manufacturing, weather, or fatigue. The unit works fast taking roughly 30 sec to sample an area about 1 ft2, and it’s highly repeatable. The device works well on glass or carbon-fiber constructions.”
The equipment works by subjecting a composite surface to a small stress, usually either a slight temperature rise of 1 or 2 degrees, or a small pressure change and then the laser light can measure sub-micron surface movements. The unit quickly detects flaws below the surface including wrinkling, delamination, and impact damage. There is no surface preparation required, and 150 ft2 can be scanned in an hour. It’s used in field and up tower for instant results,” he says. A structural engineer with knowledge of the blade’s construction and loading will have to decide how to treat the problem. The identified flaw could lead to cracking and ultimately blade failure.
Additional trends include using the data to predict which other blades from a lot might have a particular flaw. The idea being that early detection allows better and less costly repairs.
Because the best defense is a good offence, Rope Partner’s Bley suggests preventing blade wear by placing a durable polyurethane tape over its leading edge. 3M developed the clear rugged tape–difficult to pierce with a scissor point–for the leading edge of helicopter rotors. The material company is also wrapping up a study on how blade erosion negatively affects aerodynamics that cause turbulence which may reduce the overall turbine output. 3M will release the study at AWEA’s Windpower 2011. “Over the last decade, we’ve seen damage at sites across the globe due to leading-edge erosion when conducting inspections for wind turbine maintenance and repairs,” adds Bley. “At some sites, significant erosion occurred in a little as two years after installation.”
WPE
Longest turbine blades yet
February 11, 2011 by Kathleen Zipp
Filed under Mechanical Components, Turbine Blades
In a recent chat with turbine blade supplier LM Wind Power, I learned that the company will develop what they say is the “longest turbine blades ever produced.” The company is partnering with French Alstom, which provides power generation equipment services, to develop the blade designed to fit its 6-MW turbine for the European offshore market.
This blade will require more than 20,000 hours of work, focusing on aerodynamics, structural design, and production. Using glass fiber and polyester will enable the blades to be considerably light for their length. The blades will be tested in LM Wind Power’s wind tunnel. Prototype blades will be produced in the company’s Danish factory in Lunderskov, also currently manufacturing the LM 61.5-m blades, and will be ready for installation at Alstom prototype sites in Europe over the winter 2011 to 2012. LM Wind does not yet know if the blade will be offered in the U.S. Communications Specialist Lene Mi Ran Kristiansen says it will depend on Alstom’s plans. Most likely France, UK, and other North Sea markets are what they will focus on.
LM Wind Power's wind tunnel is used to verify the aerodynamic efficiency of the blades.
As for the turbine, Alstom reports its model has a large rotor diameter and 6-MW power output. The turbine’s weight also reduces installation and infrastructure costs. It features what Alstom calls “pure-torque technology” to protect the generator and improving its performance. The technology protects the turbine’s drive train by deflecting unwanted stresses from the wind safely to the tower. Only turning force, or torque, is transmitted to the generator thereby boosting the turbine’s reliability. Furthermore the turbine’s permanent magnet direct drive system enables a compact, lightweight design that reduces service costs and improves operating efficiency. The system’s low number of rotating parts increases reliability, to maximize turbine availability and further reduce maintenance costs.
Unfortunately, Communications Specialist Lene Mi Ran Kristiansen says Alstrom prefers not to share details of the blade’s length or rotor size due to the competitiveness of the offshore wind market. Roland Sundén, chief executive officer at LM Wind Power Group says the new blade builds on features developed for the company’s recent blade launch, the GloBlade, which offers an additional annual energy production of 4-5 % compared to standard blades.
Closed-molding demo (think blades) at Composites 2011 show, Feb 3-4
January 14, 2011 by Paul Dvorak
Filed under Manufacturing, Turbine Blades, Wind Power News
Talk to the mold doctors at COMPOSITES 2011, Feb 3-4, Ft. Lauderdale, Florida.
The Closed Mold Alliance and over 10 industry partners will host a comprehensive, ongoing demo of closed mold technology – in person, right on the show floor– during COMPOSITES 2011 in Fort Lauderdale, Florida. To be held in a specially designed staging area at Booth # 917, presentations will take place throughout the day both Thursday, February 3, and Friday, February 4.
At the event, manufacturers can watch work cells demonstrating three closed-mold processes – Light Resin Transfer Molding (Light RTM), the Vacuum Infusion Process (VIP), and Flex Molding –to produce replica wind turbine blades, a replica nacelle, and other production parts. Highlighting this event will be the latest technologies to enhance closed-mold production.
New this year will be the introduction of Temperature Controlled Molding to the Vacuum Infusion Process. Temperature Controlled Molding manages exotherm temperatures using Controlled Radical Polymerization (CRP) for composites. Temperature Controlled Molding was developed by TCM Composites, Andre Cocquyt, Arkema, and Cook Composites & Polymers.
“With a replica wind blade mold, we’ll demonstrate how Vacuum Infusion and Temperature Controlled Molding are ideal for parts that require superior flow characteristics, faster production times, enhanced physical properties, and extended gel times,” said Composites One Vice President of Marketing, Greg Shymske. “We’ve helped manufacturers see how closed mold is ideal for building a wide range of parts and now they will see system enhancements making it even easier to build parts more efficiently.”
Also new this year, will be Flex Molding Technology, recently introduced by Magnum Venus Plastech at JEC 2010. The program will feature a video demonstration of how to make a silicone bag using the Flex Mold Process. Afterwards a live demo using the same silicone bag will feature production of a replica wind blade. In addition, new Flex Molding Controls will be featured in all work cells. The Light RTM work cell will feature a replica nacelle and 10 to 12 parts will be manufactured daily.
The Lean Mean Closed Mold Machine at COMPOSITES 2011 will also showcase a new micro-infused resin technology that can be used in closed molding. From Australian company MIRteq, the technology uses a resin with a modified polymer structure making it safer for the environment. Access to the technology is available exclusively through Composites One.
All closed mold demonstrations will feature Magnum Venus Plastech (MVP), meter/mix equipment manufacturer with expertise in closed mold and a member of the Closed Mold Alliance. The program will also be presented with assistance Alliance member RTM North Technologies, North America’s leading Light RTM expert. Composites One is also a member of the Closed Mold Alliance.
Throughout the event, industry experts from the Alliance, along with the Composites One Closed Mold Team, will be on hand to answer questions about Light RTM, Flex Molding, VIP, discuss equipment and materials, and help manufacturers learn how to put closed mold to work in their operation. This is the seventh consecutive year that Composites One and its partners have presented live demonstrations of closed mold processes at a major trade show event.
The live demonstrations at COMPOSITES 2011 are the culmination of a joint effort between Composites One, the Closed Mold Alliance and its supplier partners: Airtech Advanced Materials Group, Airex Baltek, Arkema, Cook Composites & Polymers, Chemtrend, Chomarat, ITW Plexus, Kit Concepts, Magnum Venus Plastech, MIRteq, Owens Corning, Progress Plastiques, RTM North, Syrgis, TCM Composites, Vectorply, Wacker Silicones. Composites Manufacturing and Composites Technology are the official media sponsors of the event.
“The support of our suppliers has been crucial in the development of the Closed Mold Alliance,” added Shymske. “As a result Composites One and the Closed Mold Alliance can offer manufacturers a complete turn-key to successful closed mold conversion.”
For more information, visit the demo at booth #917 at COMPOSITES 2011.
Composites One
Material promises a better blade
January 12, 2011 by Paul Dvorak
Filed under Materials, Turbine Blades, Wind Power News
Although turbine blades have been getting longer, they must be sleek, light, and resilient to wear and tear as they spin through the wind. To assist the elongation of the blade is Owens Corning. They say their Ultrablade fabric treated with epoxy resin can help improve blade aerodynamics and strength, without sacrificing length.
According to the company, the material can increase blade length by 6% and stiffness by 205. It could also allow blade thickness to decrease by 6%, total blade weight by 5%, and lessen the weight of its carbon-fiber spars by 18%. Added up, Owens Corning says turbine designers could take almost a metric ton of reinforcement and resin from a 2-MW turbine, when compared with similarly sized blades of standard E-glass.
Designers can use a combination of several improved properties in different areas of a blade. They can choose to increase blade length for any given weight while keeping thrust constant and assuring sufficient tower clearance.
At lower wind speeds, weight-saving Ultrablade fabric can help increase a blade’s aerodynamic lift, torque, and energy capture. The end-result will be higher annual energy production from optimised blade designs using high-performance fabrics.
Owens Corning
Core product approved for turbine blades
December 13, 2010 by Kathleen Zipp
Filed under Mechanical Components, Turbine Blades
Tycor W fiber reinforced composite sandwich core products have have earned a Certificate of Approval by Germanischer Lloyd (GL) for use in the manufacture of composite wind turbine blades. GL is an international design certification agency for the wind industry. In addition, the certification includes the design and manufacture of products at WebCore’s Miamisburg, Ohio manufacturing facility.
The manufacturer’s ability to offer Tycor W in standard grades gives designers and manufacturers the flexibility to optimize blade designs and have the option to use the material throughout the blade. The composite core material combines fiber reinforcements, such as E-glass roving or mat, with closed-cell, low density foam in an engineered architecture. Tycor W enables improved performance and quality while significantly reducing cost and weight. The product has been in use for over two years in utility-class wind turbine blades. The GL certificate of approval qualifies Tycor W for use with additional 1.5 to 3.0-MW turbines that have blade lengths in the 40 to 60-m range.
WebCore www.webcoreonline.com
