This question is complex. At present, the dominant technology is vacuum resin transfer technology, which prepares each component separately, and then molds the high pressure sheet and low pressure sheet to form a whole. The details would take thousands of words. Vestas, LM, GE, Goldwind, Sany, AVIC Huiteng, etc. all use this technology. Siemens has integrated molding technology, that is, the high pressure sheet and the low pressure sheet are molded together, reducing the mold clamping process. Some blades, of relatively regular shape, are also formed by the winding method. Japan is also developing a thermoplastic blade that joins fibrous materials and solid resin, heats the mold to melt the resin, and cools it to form it.
How are wind turbine blades designed?
If the angle between the blades is 90°, what will be the effectelectricity production? When the wind acts at a right angle of 90° to a certain blade, it is 0° to the next blade. While the wind still acts on the first blade, it will also act on the second blade.
If the wind force at that time is different, one blade will be pushed forward, while the other blade will be stopped. This is not only detrimental to wind power generation, but also consumes more equipment. What can be concluded is that the interaction between the four blades is relatively large, which affects the result of their interaction and reduces the power. The blades of the two blades interfere with each other, and the interaction between them is also obvious, which is also undesirable. Therefore, the three-blade type is reasonable.
Wind turbine blades represent approximately 15 to 20% of the total cost of the wind turbine. Currently, the blades of theLarge wind turbines are mainly made of composite materials, and the content of composite materials generally exceeds. 80%. According to statistics, every 6% increase in the size of a wind turbine's blades can increase the amount of wind energy captured by 12%. The original intention of the blade design is to achieve a balance between dynamic efficiency and structural design. The choice of materials and processes determines the actual final thickness and cost of the blade. Structural designers play an important role in how to combine design principles and manufacturing processes, and must find the optimal solution between ensuring performance and reducing costs. Blade force analysis: Pushing on the blade causes the blade to rotate. The distribution of thrust is not uniform but proportional to the length of the blade. The thrust force experienced by the tip of the blade isgreater than that of the blade root. Beam design: The bending deformation caused by the self-weight of the blade and external thrust constitutes the main load of the blade. In order to improve bending performance, unidirectional fiber cloth is used along the length direction of the blade, as well as the upper and lower beams. the caps are connected by a shear web in the middle Separated as much as possible, the shear webs are made of bidirectional fiber fabric and foam (PET) cores laid diagonally to increase overall stiffness. Internal beam structure: In order to reduce production costs, some unnecessary materials can be removed from the design. Common blades adopt a hollow design. Foil Wrap: The main function of the foil wrap is to provide an aerodynamic shape. The sandwich structure of the sheet shell increases the rigidityyou. The sandwich structure consists of a fiberglass surface layer with a foam core material (PET) or balsa wood core material (BALTEK) in the middle. The sandwich structure is rigid enough to support bending loads while preventing debonding. distributed diagonally in the leaf shellThe fibers provide the necessary torsional rigidity. Blade Root Design: The blade root portion is usually designed to be round. At the same time, in order to meet maintenance and other needs, the blade roots are often connected by bolts to facilitate disassembly and assembly. Welded flange connections can be used for metal beams. Geometric size optimization design: without changing the geometric shape of the blade, the performance of the blade can be changed by adjusting the thickness of the spar cap, and the production cost can be reduced.re reduced. Thinner blades require thicker spars, which increases production costs. At the same time, the strength of the strip must be increased, but as the thickness becomes thinner, the total material consumption does not change significantly. In summary, optimal design of geometric dimensions requires careful consideration of many aspects such as fan design, load analysis, structural design and manufacturing cost to achieve the best results.