The blade shape of ordinary wind turbines is an airfoil shape. This is because the design of the airfoil can use airflow to generate lift and convert wind energy into rotational force to drive the generator. The design of the airfoil blades usually refers to the aerodynamic principles in the aviation field, using a structure similar to that of an aircraft wing. Arc shape, this shape can generate greater lift when the wind blows over the blades, and convert wind energy into rotational kinetic energy. By rotating, the wind turbine generates electrical energy that is used to generate electricity. Different types of wind turbines may have slightly different blade designs to suit specific operating conditions and efficiency requirements.
Advantages of two-blade wind turbines over three-blade wind turbines
The blade diameter is not professional, it should be the sweep diameter. The mainstream blade shapes are 126/110/114, etc., and the corresponding blade sizes are 68m, 54m, and 56m; now the diameter of the largest wind turbine blade has exceeded 70 meters, which is equivalent to the wingspan of a Boeing aircraft.
When it comes to materials, it’s more complicated. Different parts of the blade have different materials. Generally speaking, three categories are used, carbon fiber and fiberglass as the outer surface, and balsa wood and foam as the core. material.
The other thing is the binder. Carbon fiber is ideal because it has better strength and is lighter, but it is also a problem because it is too expensive. Balsa wood is balsa wood. As for foam, there are relatively many types, but they are generally hard foam. 3A products account for 90% of the share in this area.
The main materials of wind turbine blades are fiberglass fabrics and reinforced resins.
Large-megawatt blade spar caps may use a carbon-glass hybrid design, and the shell webs generally use glass. Fiber fabric
In addition to LM, mainstream domestic and foreign wind turbine blade manufacturers such as VESTAS, SIEMENS, GAMESA, etc. all use epoxy resin systems; LM relies on its own understanding of the interface ability between resin and fiberglass fabric, Using polyester resin, the bonding speed is fast, the post-curing process does not require heating, and the mold turnover efficiency is high;
With 2 blades, the installation and transportation costs are lower than those with 3 blades. In addition, the tip speed ratio of the 2-blade is higher than that of the 3-blade. If it is used to generate electricity, the speed increase ratio of the gearbox is smaller than that of the 3-blade, so the cost of the gearbox is less.
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The hub structure of the 2-blade is special, with a seesaw structure, and the fatigue problem is more serious than that of the 3-blade. So each has its pros and cons.