събота, 20 декември 2014 г.

Abcs Wind Turbine Maintenance Idaho

By Stacey Burt


A windsturbine with their harvests the energy of winds rotor, converts it into electrical energy and feeds it into power grid. Also use the designations winds power plant, sometimes winds power converter (CHP), colloquially windsturbine or winds mill (wind turbine maintenance Idaho). Small plants that can be economically isolated operation are treated under winds generator; winds-driven pumps.

Like all machines can not reach windsturbines, the theoretical maximum. Aerodynamic losses resulting from air friction on the leaves, by vortices at the blade tips and swirl in wake of rotor. In modern systems, these losses reduce the power coefficient of cp, Betz 0.593 on cP equals 0.4 to 0.5. Of above 320 W / m ie up to 160 W / m expected. A rotor with 113 m diameter (10,000 m) is then 1.6 megawatts to shaft. To calculate the power at the mains addition, the efficiencies of all mechanical and electrical parts must still be considered.

Analog increased the average hub height and power ratings up to first half of 2014 to 113 m and 2.65 MW and a rotor diameter of 97 m, with significant differences due to regional winds speeds. Modern windsturbines have become weak rotor diameter to about 130 meters and hub heights up to 150 meters, the total amount of investment shall not exceed 200 m far in most cases. In offshore area (as of 2013) systems with a rotor diameter of 170 meters in test mode.

The Dane Poul la Cour came in 1900 through systematic experiments - among others aerodynamic airfoil in winds tunnels - the concept of speed engine, in which only a few blades sufficient to exploit the energy of flow over the entire rotor surface. During the First World War, over 250 plants of this type in Denmark were in operation. In other countries winds engines were built for decentralized power generation in early 20th century. With the widespread electrification in interwar period, many ofse plants disappeared, equipped with DC generators and battery saving winds engines were not compatible with the AC power grid since.

A winds assessment based on the frequency distribution windspeed for a location is the optimal choice of rated windspeed (usually 1.4 to 2 times the mean windspeed) or given plant data to estimate the energy produced per year, industry-standard specified as a full load hours (quotient of anticipated or actually achieved annual amount of power installed capacity).

Not all newly installed systems are in new locations: Partial old plants are dismantled and replaced by more powerful what is referred to as repowering. Within winds farms decreases, as a rule, the number of plants, while at the same time increase installed capacity and yield significantly. The density of kinetic energy of flow increases as the square of winds speed v and also depends on the air density.

The exported also to thousands in 1980s in US plants had three rigid rotor blades (= no rigid blade angle adjustment) and a grid-connected inverter without phase machine with one or two fixed speeds. The capacity limitation was performed by flow separation. Archetype of this very successful concept was designed by Johannes Juul and in 1957 commissioned in Gedser windsturbine. It worked reliably up to its preliminary decommissioning in 1966 and was in late 1970s put back into service for a joint test program by scientists and NASA .

Their rated power, sometimes called the installed capacity reaches a windsturbine at the rated windsspeed. In capacity of plant is kept constant in order to avoid overloading. At very high windsspeeds (storm), the system is completely switched off. With a slight crescent shape in outer region of rotor blades soft gusts from the blade tips to leeward. The associated distortion of sheets reduces the angle of attack and therefore the winds load. Accordingly, material can be saved




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