Wind energy is booming. This field of regenerative electricity generation contributed approximately 7% nationally in Germany in 2007 alone and more than 80,000 workers have found employment in this industry to this day. Wind power has therefore developed into an important economy sector. In this country more than 19,000 wind turbines provide a total power output of over 22,000 megawatts (MW).
All over the world, there is a strong demand for large wind power stations of the multi-megawatts class in order to realize the generation of clean CO2-free electricity. The German manufacturer Fuhrländer has made a name for itself in the 2.5 megawatt class with their newly designed drive concept, which is the first one to work without the heavy main shaft. Apart from this, the concept has other special features which make wind power even more economic. The FL 2500 by Fuhrländer can be adjusted to varying conditions at different locations with three rotor sizes of 80, 90 and 100 meters as well as with hub heights of up to 160 meters.
Collection of measurement data
The “Condition Monitoring System” which is used for the comprehensive monitoring of the FL 2500 works with acoustic sensors that are positioned at the main bearing, the transmission and at the generator. Here a wideband record of acceleration is created. The measurement values which are collected and saved are available for further assessment and/or reporting. The evaluation includes the rotor’s rotational speed, the effective power generated and the wind speed as well as a complete set of kinematic data. Reports are created automatically which give information on the measurement data, evaluate this data and show irregularities.
Furthermore, the FL 2500 is equipped with high-performance safety technology which can be included in the system according to the customer’s wishes. Part of this is the optional fire alarm system which increases the system security even more.
Fires under control
Luckily, fires in wind turbines are rare. They can be caused by lightning, electrical malfunctions or overheated surfaces. In cases like these, the firefighters are often left with only one option: to let the unit burn down “in a controlled manner” since their ladders can usually only reach to a height of 40 meters. Modern turbines such as the Fuhrländer FL 2500, however, reach heights of 160 meters. With a rotor diameter of 90 meters, the turbine in Laasow reaches an overall height of 205 meters. Even during the construction of the FL 2500, great importance was attached to preventive fire protection in order to keep such a fire scenario from occurring in the first place. The protective measures according to VdS 3523 encompass— among other things—the risk analysis according to the EU machine guideline as well as a comprehensive lightning protection concept, the minimization of flammable materials and the reduction of possible ignition sources. The installed fire recognition system provides information to the power control system and automatically creates a notification should any event occur. Subsequently both the shutdown of the wind turbine as well as the actuation of the extinguishing device are initiated. For this purpose, the turbine at the Laasow location in Spreewald has been secured with releasing control equipment and two aspirating smoke detectors for room and/or switch cabinet monitoring. In the case of a fire the triggering of various extinguishing systems in the switch cabinets and the turbine room is provided for. Considering the technical safety measures in the Laasow wind turbine, an undisturbed operation can be expected for many years to come.
