The hottest carbon fiber composites and wind turbi

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Carbon fiber composite materials and wind turbine blades

in wind turbine units, the components made of composite materials include blades, engine room covers, flow deflectors and other components, of which the largest amount is blades. Composite wind turbine blade is the key dynamic component of wind power generation system, which directly affects the performance of the whole wind power system. Therefore, the selection of blade materials and manufacturing process are very important for wind turbine blades

in the history of wind turbine development, blade materials have experienced wooden blades, bumenpi blades, aluminum alloy blades, etc. With the development of large-scale wind turbines, composite materials have been basically used in recent years. Using composite materials to manufacture wind turbine blades can make full use of the designability of composite materials to optimize the strength and stiffness of blades; For complex shape and surface requirements, the blade with complex shape, light weight and high strength can be made by using composite materials, which has good maintainability, short cycle and can be constructed on site; Because the composite material has the characteristics of high fatigue strength, low notch sensitivity, large internal damping and excellent weather resistance, excellent comprehensive properties can be obtained by using composite materials to manufacture fan blades

at present, composite material fan blades are mostly made of glass fiber as reinforcement and unsaturated polyester resin, epoxy resin or vinyl resin as matrix materials. However, with the continuous increase of blade length, this system can no longer meet the requirements in some occasions, so carbon fiber reinforced materials with better performance have entered the vision of blade producers

compared with glass fiber, the stiffness of carbon fiber is 3 times that of glass fiber, and the composite material made of carbon fiber is 2 times that of FRP. In addition, due to the small increase in the length of the blade, the weight of the blade also increases, and the use of carbon fiber composite material will greatly reduce the weight of the blade. Based on these points, the use of carbon fiber composites will be the development trend of blade manufacturing in the future

in foreign countries, many blade manufacturers have used carbon fiber materials to manufacture blades:

in the 61.5m long 5MW fan blades of LM company in Denmark, carbon fiber is used as reinforcing material in the parts with high requirements such as beams and flanges, and the quality of a single blade reaches 17.7 T

Jinan testing machine preparation and assembly process specification Vestas used carbon fiber material in the sample test of v-90 3.0MW fan blades. In addition, Vestas used carbon fiber in the field of 44m series blade main beam supporting V90 3.0MW fan. The blade weight is only 6T, the same as that of V80 2MW and 39m blades

gamesa uses carbon fiber in the manufacture of fan blades with diameters of 87m and 90m

nordex rotor, a German blade manufacturer, uses carbon fiber to make the whole main beam structure on the 5wm fan blade with a length of 56 meters

the 5MW blades of REpower company in Germany are made of carbon fiber and glass fiber. A single blade can make purified syngas into 18 tons of methanol, which can be used for precise market positioning, service and land use

carbon fiber is more expensive than glass fiber. At present, carbon fiber is mainly mixed with glass fiber in foreign countries. Carbon fiber is only used in the middle beam (especially the beam cover), front and rear edges and page surface of the blade

not only in foreign countries, but also in China, Nantong Dongtai group produced the first 2 MW wind turbine blade in China using carbon fiber material as blade main beam in August 2008, filling a gap in China's wind power industry. Carbon fiber has high elasticity and high strength. As a main beam, it has excellent fatigue strength and mechanical properties; At the same time, on the premise of ensuring the strength performance of the blade, the weight of the blade is reduced, the load of the blade on the whole machine is reduced, and the development direction of large-scale and lightweight blade is complied with

with the increase of the power of a single generator, the blade length is required to increase. Carbon fiber will play an important role in the blade. However, the high price of carbon fiber affects its wide application in wind power generation. Despite all this, major blade manufacturers around the world are conducting in-depth research on raw materials, process technology, quality control and other aspects in order to reduce costs and enable carbon fiber to be more applied in wind power generation. At present, the use of carbon fiber and glass fiber blend structure is a good way to reduce costs. With the emergence of large fiber bundles of carbon fiber, the price is significantly lower, which also provides a good opportunity for the application of fan blades

in the blade manufacturing process, traditional composite wind turbine blades are mostly manufactured by hand paste process. The main characteristics of the hand lay up process are manual operation, open mold forming, low production efficiency and low resin curing degree. It is suitable for the production of composite products with small batch size and low quality uniformity requirements. The other is the prepreg forming process: the fiber is first made into prepreg, which is laid on site, heated (or at normal temperature) and cured under pressure, with high production efficiency and good on-site working environment. Vestas and gamesa are using the prepreg forming process. The latest development of blade forming method is RTM, namely resin transfer molding method. The fiber preform is placed in the mold cavity, then the resin is injected, heated and pressurized. RTM is currently recognized as a low-cost manufacturing method in the world. There is still a high potential to develop for the re receiving and receiving operation of resources. The adoption of new forming and processing technology is also one of the ways to reduce costs

in addition, it is also necessary to reduce the cost of the mold. For large blade molds, the original metal materials can be replaced by composite materials. On the one hand, the blade length can be increased. On the other hand, because the mold and blade use the same materials, the thermal expansion coefficient of the mold material is basically the same as that of the blade material, and the precision and dimensional stability of the composite blades are better than those of the blade products made of metal molds

nowadays, carbon fiber materials are mainly used in aviation. But the application of carbon fiber will gradually increase. At present, the growth rate of the installed capacity of wind power generation in the world is accelerating. Large capacity wind turbines made of long blades with high carbon fiber content will become an inevitable trend. (end)

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