The 7 Technologies
THE X-STIFFENER™ – Bladena
Prevents twisting of the main and rear box of the blades.
Cracks on the leading and trailing edge are often found operation and expericially on larger blades. Experimental and theoretical modelling has proven that the installation of X-Stiffeners™ significantly reduces twisting and peeling stresses to a non-critical level.
The twisting and peeling stresses increase with the length of the blades in particular blades with large flat-backs can benefit from X-Stiffener™ installation. The installation of X-Stiffeners™ extends the lifetime of your blades.
The X-Stiffener™ connects the two sides of the blades like a cross in a bookshelf thereby avoiding deformation of the shear webs.
When rotating, the total load on the blade is comprised of the edgewise loading and aerodynamic forces caused by the wind, a so called combined loading scenario. The combined loading implies an alternating twisting, Cross Sectional Shear Distortion (CSSD) – of the blade which in turn cause critical peeling stresses in the bond lines.
Link to website: www.bladena.com
AEROX® – AHP LEP system
With the gradual increase in the size of wind turbine blades, Leading Edge Protection of the blade has become one of the most important challenges that lie ahead wind industry.
AEROX has developed the AHP technology with an outstanding performance delaying the appearance of damage in rain erosion tests compared with the industry standards.
The range of specific coatings AEROX AHP LEP is specifically designed for protecting the leading edge of wind turbine rotor blades. The AEROX AHP LEP range of products is very robust and reliable under industrial conditions of application. The characteristics of the different versions of AEROX AHP LEP have been modulated and adapted to the great variance of different environmental working conditions of the turbines, both on and off-shore.
Siemens Gamesa – Aerodynamic next generation blade retrofitable add-ons to increase AEP
A key concept to be competitive in the Wind Energy market is the aim to reduce the cost of wind energy generation. Increasing the cost effectiveness of energy generation process will increase the competitiveness.
The ability to design flow control devices for low-noise emission will have a large impact on the wind energy market, where noise emission regulations are every day more and more restrictive. Additionally, the design flow control devices which modify the aerodynamic behavior of the blade can be also used to increase performance, optimizing energy production and reliability.
The ability of reducing noise emissions at the same time as production is optimized is key to increase the competitiveness in the market.
Fully retrofitable add-ons also open a wide range of application, because of not only new turbines can be designed and manufactured with this new technology but also can be placed in many wind turbines located at wind farms along the world.
Cener – Vortex generators
Wind turbine blades size has scaled-up during last years due to wind turbine platform increase especially for offshore applications. The interest of wind turbine manufacturers in blade add-ons has risen to mitigate flow separation and blade loading. One type of add-ons is the vortex generators. Vortex generators are designed to create vorticity on the blade surface to mix high momentum zones in the upper part of the boundary layer with low momentum zones near the surface resulting in a velocity profile less prone to separation. CENER has more than 15 years of experience in the design and calculation of wind turbine blades, airfoils and add-ons as well as in performing CFD calculations. In the figure, a fully resolved CFD simulation of a rectangular pair of vortex generators is shown.
TNO – Cross sectional shear distortion sensor
TNO will perform cross sectional shear distortion measurements and failure monitoring of the X- stiffeners with application of advanced fibre optic sensors, based on fiber bragg gratings (FBG). The solution will be a very robust and durable sensor system which uses state of the art FBG technology. The cross sectional integration (or fixation) of these sensors into the wind turbine blades, in order to create robust yet reliable measurements, poses the main technological challenge. The final solution will measure, in real-time, the cross sectional shear distortion of the wind turbine blade, before and after the installation of the X-stiffeners.
TNO – Erosion sensor
TNO will demonstrate an innovative approach to detect leading edge erosion by incorporation of humidity FBG sensors under the top coating on the leading edge of the blade. The installation of humidity sensors near the tip of the wind turbine blade is made possible by using fiber optics which are insensitive to lightning strike. The integration of the humidity sensor with the AEROX LEP coating will provide real-time monitoring of the coating integrity.
ODSL – Metallic Leading Edge Erosion Protection
The ODB project will demonstrate a novel blade leading edge erosion protection system based on a nickel alloy insert. The use of nickel erosion protection strips is widespread in the helicopter industry (where tip speeds can be twice as fast as they are for wind turbine blades) but the technology has not been deployed on a turbine rotor blade to date. The inserts aim to eliminate the need for intervention related to leading edge erosion for the entire life of the turbine, whilst allowing the blade designer to achieve higher tip speeds. This will have several benefits – AEP would increase because aerodynamic losses related to leading edge erosion will be reduced and maintenance costs would decrease. The possibility of higher tip speeds would also have many benefits – two-bladed turbines would be more viable, while decreased torque for the same power output would reduce the turbine top head mass.