HOOD BATTLECRUISER 1916-1941, wreck, wreck database. In 1509 when Henry VIII was crowned he realised the growing navel power of King James IV of Scots. As early as the first century A.D., wind energy was harnessed for practical purposes. Since then, turbine designs have come a long way from the archetypal post. Buy CESSNA 421 RILEY TURBINE at Controller.com - Page 1 of 1. It has two or three blades. The blades. are joined in the center by a hub. Together, the. blades and the hub are called the rotor. The rotor. is mounted on top of a tall tower, where the wind. The computer tracks. When the wind's. direction changes, the computer activates a motor. The rotor will only spin when it is. Vertical Axis Turbines: A maintenance worker. England. Vertical axis turbines have two or three blades. The. turbines do not need computers to move them. The gearbox is located near. Vertical axis turbines produce less. Small. turbines have rotors from three to 5. Their towers reach up to 1. They can generate up to 2. Early. utility- scale turbines that generate between 5. The largest turbines generate up to five. Today, the rotors. Safety Measures: The faster the wind blows, the faster a wind. Strong winds can make the. To prevent these accidents, turbines. Computers also. activate brakes on the rotor to slow. The rotors of most small. When the turbine. Wind Farms: Wind farms, also called wind power plants, are. It is very important that the site has. Developers, or the people. The best sites for wind farms are the coasts. Developers must determine. What impact the wind. Arranging Turbines: Once a site for a wind farm is chosen, developers. The. turbines are usually arranged in rows facing in the. Wind turbines. are usually spaced about five to nine times the. Turbines with. rotors 1. If. turbines are placed too close together, they block. Placing the turbines too far. The substation has a. High- . voltage electricity travels more efficiently along. The high- voltage electricity flows from the. The voltage. must be lowered so that. Harvesting Wind: In many parts of North America. The turbines. do not interfere with ranching or. Cattle and sheep graze. Powering Schools: In 1.
Spirit Lake Elementary School, in Spirit Lake, Iowa, became. United States to be powered by wind. The. school's electricity is produced by u 2. W wind turbine located. In 2. 00. 1, a second turbine was built to power. Spirit Lake's middle school, high school. This. turbine sends electricity directly to. The utility keeps. If the. turbine produces more electricity. Offshore Wind Farms: Offshore wind farms are located in the shallow. There are several reasons for. Many small. European countries, such as Denmark, Sweden. Holland, are running out of space for wind. Winds blow stronger and more. This. means there is more energy offshore for turbines. Offshore turbines produce about 5. The bottoms of the. In more advanced models, the rotational energy is converted into electricity, the most versatile form of energy, by using a generator. For thousands of years people have used windmills to pump water or grind grain. Even into the twentieth century tall, slender, multi- vaned wind turbines made entirely of metal were used in American homes and ranches to pump water into the house's plumbing system or into the cattle's watering trough. After World War I, work was begun to develop wind turbines that could produce electricity. Marcellus Jacobs invented a prototype in 1. When demand for electricity increased later, Jacobs's small, inadequate wind turbines fell out of use. The first large- scale wind turbine built in the United States was conceived by Palmer Cosslett Putnam in 1. The tower was 3. 6. Putnam's wind turbine could produce 1,2. It was, however, abandoned in 1. With the 1. 97. 0s oil embargo, the United States began once more to consider the feasibility of producing cheap electricity from wind turbines. In 1. 97. 5 the prototype Mod- O was in operation. This was a 1. 00 kilowatt turbine with two 2. More prototypes followed (Mod- OA, Mod- 1, Mod- 2, etc.), each larger and more powerful than the one before. Currently, the United States Department of Energy is aiming to go beyond 3,2. Many different models of wind turbines exist, the most striking being the vertical- axis Darrieus, which is shaped like an egg beater. The model most supported by commercial manufacturers, however, is a horizontal- axis turbine, with a capacity of around 1. Wind turbines with three blades spin more smoothly and are easier to balance than those with two blades. Also, while larger wind turbines produce more energy, the smaller models are less likely to undergo major mechanical failure, and thus are more economical to maintain. Wind farms have sprung up all over the United States, most notably in California. Wind farms are huge arrays of wind turbines set in areas of favorable wind production. The great number of interconnected wind turbines is necessary in order to produce enough electricity to meet the needs of a sizable population. Currently, 1. 7,0. Raw Materials: A wind turbine consists of three basic parts: the tower, the nacelle, and the rotor blades. The tower is either a steel lattice tower similar to electrical towers or a steel tubular tower with an inside ladder to the nacelle. Most towers do not have guys, which are cables used for support, and most are made of steel that has been coated with a zinc alloy for protection, though some are painted instead. The tower of a typical American- made turbine is approximately 8. The nacelle is a strong, hollow shell that contains the inner workings of the wind turbine. Usually made of fiberglass, the nacelle contains the main drive shaft and the gearbox. It also contains the blade pitch control, a hydraulic system that controls the angle of the blades, and the yaw drive, which controls the position of the turbine relative to the wind. The generator and electronic controls are standard equipment whose main components are steel and copper. A typical nacelle for a current turbine weighs approximately 2. The most diverse use of materials and the most experimentation with new materials occur with the blades. Although the most dominant material used for the blades in commercial wind turbines is fiberglass with a hollow core, other materials in use include lightweight woods and aluminum. Wooden blades are solid, but most blades consist of a skin surrounding a core that is either hollow or filled with a lightweight substance such as plastic foam or honeycomb, or balsa wood. A typical fiberglass blade is about 1. Wind turbines also include a utility box, which converts the wind energy into electricity and which is located at the base of the tower. Various cables connect the utility box to the nacelle, while others connect the whole turbine to nearby turbines and to a transformer. The Manufacturing. Process: Before consideration can be given to the construction of individual wind turbines, manufacturers must determine a proper area for the siting of wind farms. Winds must be consistent, and their speed must be regularly over 1. If the winds are stronger during certain seasons, it is preferred that they be greatest during periods of maximum electricity use. In California's Altamont Pass, for instance, site of the world's largest wind farm, wind speed peaks in the summer when demand is high. In some areas of New England where wind farms are being considered, winds are strongest in the winter, when the need for heating increases the consumption of electrical power. Wind farms work best in open areas of slightly rolling land surrounded by mountains. These areas are preferred because the wind turbines can be placed on ridges and remain unobstructed by trees and buildings, and the mountains concentrate the air flow, creating a natural wind tunnel of stronger, faster winds. Wind farms must also be placed near utility lines to facilitate the transfer of the electricity to the local power plant. Preparing the Site: Wherever a wind farm is to be built, the roads are cut to make way for transporting parts. At each wind turbine location, the land is graded and the pad area is leveled. A concrete foundation is then laid into the ground, followed by the installation of the underground cables. These cables connect the wind turbines to each other in series, and also connect all of them to the remote control center, where the wind farm is monitored and the electricity is sent to the power company. Erecting the Tower: Although the tower's steel parts are manufactured off site in a factory, they are usually assembled on site. The parts are bolted together before erection, and the tower is kept horizontal until placement. A crane lifts the tower into position, all bolts are tightened, and stability is tested upon completion. Nacelle. The fiberglass nacelle, like the tower, is manufactured off site in a factory. Unlike the tower, however, it is also put together in the factory. Its inner workings—main drive shaft, gearbox, and blade pitch and yaw controls—are assembled and then mounted onto a base frame. The nacelle is then bolted around the equipment. At the site, the nacelle is lifted onto the completed tower and bolted into place. Rotary Blades: Aluminum blades are created by bolting sheets of aluminum together, while wooden blades are carved to form an aerodynamic propeller similar in cross- section to an airplane wing. Many blades are molded with fiberglass. By far the greatest number of blades, however, are formed from fiberglass. The manufacture of fiberglass is a painstaking operation. First, a mold that is in two halves like a clam shell, yet shaped like a blade, is prepared. Next, a fiberglass- resin composite mixture is applied to the inner surfaces of the mold, which is then closed. The fiberglass mixture must then dry for several hours; while it does, an air- filled bladder within the mold helps the blade keep its shape. After the fiberglass is dry, the mold is then opened and the bladder is removed. Final preparation of the blade involves cleaning, sanding, sealing the two halves, and painting. The blades are usually bolted onto the nacelle after it has been placed onto the tower. Because assembly is easier to accomplish on the ground, occasionally a three- pronged blade has two blades bolted onto the nacelle before it is lifted, and the third blade is bolted on after the nacelle is in place.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
January 2017
Categories |