The Hydac Group, based in Germany, is the world’s largest family-owned producer of hydraulic components and systems. Pronexos has worked with Hydac for several years now, applying our expertise in carbon fibre applications and other specialist industrial services to a range of interesting projects.
Pronexos and Hydac are currently collaborating on a project with the Flensburg University of Applied Sciences at the University of Augsburg to develop a new type of piston accumulator to be used in the next generation of wind turbines for wind power installations. Piston accumulators are a component in wind farm towers which enable very efficient energy transition from wind into electrical power, thus greatly improving the efficiency rating of the windmill.
The piston accumulator has some very specific properties which enable it to achieve this greater efficiency. “Inside the piston accumulator is a steel liner which has been produced by Pronexos using flow forming technology” explains Frank Wissink from Pronexos. “Our flow form technique produces a very stiff liner with a thin wall thickness. This steel liner is wrapped in carbon fibre, producing a reinforced tube that is both extremely strong and very lightweight. Weight is a big issue for the latest generation of windmills, which are much taller than previous ones and can generate up to 5mW of current.”
Despite its stiffness, the product is also required to be flexible enough to cope with high winds and harsh weather conditions. “The piston inside the tube is much stiffer than the tube itself, so we have to avoid the piston from jamming during movement because that will damage the system” explains Wissink. “This is one of the key challenges we have overcome. We have already qualified the material used for the construction of this prototype for series manufacturing by Pronexos.”
The project has so far produced a prototype which is currently in a testing phase at the University of Augsburg. “We are optimising the model, based on data from these trials” continues Wissink. “Achieving this innovative design is an iterative process that we believe will produce significant efficiency gains for the windmills. The commercial potential is massive, as the demand for more and more sustainable power generation continues. Wind turbine technology is advancing very quickly, just as subsidies are being withdrawn, so the drive to commercialise wind power is huge.”
Hydac are working with Pronexos because they value the combination of these two technologies under one roof. “Hydac see our high-tech capabilities and experience with flow-forming and carbon fibre as the ideal combination to partner with their expertise in hydraulics” concludes Wissink. “We are foging a successful long term partnership with Hydac that enables us to apply our expertise and capabilities in a range of different ways.”