Accumulators are used in wind turbines for hydraulic yaw and pitch control and system brakes. They also serve as an emergency power storage device for hydraulic pitch systems acting as a brake in extreme wind conditions or power failure protecting the turbine from damage or destruction. Accumulators offer a consistent, reliable source of continuous power when moving or stabilizing the nacelle.
Accumulators are often times coupled with compressed gas charge cylinders to supply economical, responsive energy to adjust the angles of the blades into the wind to optimize energy production. Use of Steelhead Composites lightweight composite accumulators and gas charge vessels reduce the overall weight of the nacelle thus reducing installation costs for onshore or offshore wind farms and can significantly reduce maintenance costs by virtually eliminating the need for a turbine crane.
RELATIVE WEIGHT COMPARISON OF ASSEMBLED ACCUMULATORS
Steelhead Composite accumulators also have a larger diameter 12 inches (30.5 cm) and can be up to 10 feet (3 meters) in length with pressures ranging from 3,000 psi (207 bar) to 6,000 psi (414 bar). This flexibility allows for greater design flexibility, fewer accumulators in a space, further reducing the weight at a notable cost savings.
WIND TURBINE APPLICATIONS
Emergency energy reserve
Power storage for emergency operations
Thermal compensation of hydraulic fluid
The composite construction of Steelhead Composites accumulators reduces weight to one-third to one-quarter of steel accumulators. The lighter construction results in much lower installation and maintenance costs. In addition, the benign leak-before-burst failure mode of high pressure composite accumulators ensure safety on board of wind turbine nacelles.
In wind power applications, the accumulators must provide necessary hydraulic energy during emergency stops, while the weight of hydraulic equipment must be minimized.
Ref. “Modeling Hydraulic Accumulators for use in Wind Turbines”, H. B. Hansen and P. W. Rasmussen, The 13th Scandinavian International Conference on Fluid Power, SICFP2013, June 3-5, 2013, Linköping, Sweden
Steelhead Composite lightweight high pressure accumulators are available in sizes ranging from 5 gal (19 L) to 30 gal (113 L) with pressure rating of 6000 psi (414 bar) to meet the needs of power and energy storage requirements of hydraulics for wind turbine applications.