Actually, there are single-blade and two-blade wind turbines. But the most common number of blades in modern wind turbines is three, the result of compromises between various aspects and parameters during the design process. These aspects include, but are not limited to: aerodynamics, energy conversion efficiency, manufacturing and maintenance costs, system reliability, noise and aesthetics. From a simple analysis of technical parameters, a larger number of blades can: 1) increase the mechanical torque; 2) increase the power output but at the same time: 3) reduce the maximum rotation speed 4) result in higher manufacturing and maintenance costs; is also more complex and difficult. Therefore, motors with a large number of blades are more suitable for operation in low-speed locations, such as water pumps and grain grinding motors. Wind turbines expectThis causes the blades to rotate at higher speeds, so the size of the generator located in the center of the blades (at the top of the tower) does not need to be large to meet the frequency requirements of the grid. Additionally, wind speeds generally increase at higher altitudes. As the wind turbine tower is very high, the blades are also very long (40 m-60 m*). There is a significant difference in wind speed between blades rotating to a high position and those rotating to a low position. If the generator has only two blades, then when the blades rotate so that one is in a higher position and the other is in a lower position, their stress is obviously not uniform enough, so a tower Stronger and more stable should be designed to hold the generator and blades. The three-blade generator can alleviate this imbalance to some extent, making it run more smoothly.Smooth means less noise and less wear. The number of blades of traditional wind turbine models in the industry is 3. This is the optimal result taking into account the action and comprehensive consideration of several factors. The main factor is optimization and the balance between aerodynamic efficiency and structural complexity, and the latter determines. the important indicator of manufacturing and maintenance costs. According to Betz's elementary momentum theory, fluid machines can theoretically capture up to 16/27 approximately 59.3% of the kinetic energy carried by the airflow flowing through a cross section. This theory determines the upper limit of the energy conversion efficiency of wind turbines.
The concept of the number of wind turbine blades - the strength of the wind turbine. The ratio between the total area of the wind turbine blades (projected in the direction of the wind) and the area where thewind passes through the rotor (swept surface of the rotor) is called solidity (or solidity ratio, volume ratio), and constitutes a reference data for wind turbines. ?
These are several types of horizontal axis wind turbines, with schematic diagrams showing four types of wind turbines: single blade, double blade, three blade and multi blade. The method of calculating solidity. of the wind turbine is as follows: S is each the projected surface of the blades in the direction of the wind, R is the radius of the wind wheel, B is the number of blades and σ is the realism ratio. σ=BS/πR2.
A wind turbine is an electrical device that converts wind energy into mechanical work, which causes the rotor to rotate and ultimately produces alternating current. Generally speaking, wind energy is also solar energy, so we can also say that a wind turbine is a generator using thermal energy that uses the sun as its source.rce of heat and the atmosphere as working fluid..