WindEnergy 2018

•••4••• Innovationen Messe-Rundgang zur Anzeigen-Spezial WindEnergy Hamburg Safer screw connections Seamless monitoring by using ultrasound methods Wind farms at sea are exposed to extreme environmental con- ditions from storms, waves, the salty atmosphere and saltwater. As a consequence, threaded con- nections may loosen over time, or even break. This does not only affect heavy components such as rotor blades, but also more light- weight structures, e. g. ladders used by maintenance personnel. Damaged screws can mean acute danger to life. There is no stand- ardised, universally applicable, nondestructive method that al- lows inspecting screws installed in the field for their operational reli- ability. For safety reasons, so far, screws have either been replaced early, or re-tightened. In addition, the maintenance or replacement of screws in the maritime environment is associ- ated with high expenditures of money and time. Expensive spe- cial vessels with the appropriate maintenance personnel must be deployed for several days. And if work below the water’s surface is necessary, each dive is a risk for the industrial divers. Engineers and scientists from the Fraunhofer IZFP and the IfW are developing a robust and versa- tile ultrasound method that can be used to inspect the preload force of screws installed, without requiring prior calibration. The correct preload force holds parts and components fastened with threaded connections together and is thus of essential signifi- cance in safety-critical areas. The presented method can be used to test said preload force directly and without knowing the original status of the threaded connec- tion. “Based on the speed of two types of ultrasound waves, we plan to determine the exact ten- sion status of the screw using an adapted method. The slower the two types of ultrasound waves move through the screws, the higher the preload force, i. e., changes in preload force can still be measured even years after the screw was installed,” explained Michael Becker, project lead engi- neer at the Fraunhofer IZFP. After its successful development and testing, the ultrasound method is to be standardised and qualified for universal application. This, in combination with systems devel- oped by the Fraunhofer IZFP ear- lier for ultrasound-based preload- force detection for industrial use, would allow seamless monitoring of the entire lifecycle of threaded connections. Screws connections of wind energy plants must be regularly inspected in order to safe lives. Photo: Rainer Sturm / pixelio.de Continued from page 1 Egal ob zur Blattwinkel- messung, Windrichtungs- nachführung, Drehzahl- regelung oder Signal- und Leistungsübertragung – Kübler hat stets die richtige Lösung. Mit langjähriger Erfahrung in der Branche können Kunden auf kom- petente Beratung und zu- verlässige Produkte zählen. NebenDrehgebern und Sen- soren zur Anlagenregelung bietet Kübler ein umfang- reiches Portfolio an Sicher- h e i t s - D r e h - gebern und Schleifringen. Diese sind ideal kombinierbar und bieten zu- sammen vie- le Vorteile für Windanlagen- regelung und -überwachung. Halle B6 Stand 382 Kübler: Drehgeber und Schleifringe Deepwater EU bring exten- sive cathodic protection ex- perience gained from over 30 years in the offshore energy sector to the rene- wables market. The latest remote controllable power supply units offer the opera- tor complete confidence in the integrity of their asset and the operation of their ICCP system. With proven products for both retrofit and new build applications for external and internal corrosion prevention and monitoring. Multiple exter- nal retrofit systems have been installed, typically in less than 72 hours, reinsta- ting protection where there were insufficient sacrificial or failing close mounted ICCP systems. See us in Hall B7, booth 643 Offshore Corrosion Specialists