Level 8
Wind force refers to the force of the wind blowing on objects. Generally, the wind force is divided into 18 levels according to the different phenomena caused by the wind blowing on objects on the ground or on the water surface, the minimum being level 0 and the maximum being level 17.
In terms of meteorology, wind is generally divided into twelve levels according to its strength:
1 Level 0 wind is also called calm wind.
2. Level 2 wind is called light breeze, the leaves make a slight sound, and the face is windy.
Level 3 and 4 winds are called gentle breezes. Tree branches shake, which can blow dust and paper onto the ground.
Level 4 and 6 winds are strong, large branches sway, power lines whir, and it is difficult to walk with an umbrella.
Winds of levels 5 and 8 are called strong winds. The brindisTrees can be broken and the resistance to walking in the wind is very great.
6. Level 10 winds are called squall winds and are rare on land. They can uproot trees and cause serious damage to buildings.
7. Winds above level 12 are called typhoons or hurricanes, which are extremely destructive and rarely seen on land.
Principles of wind power generation
Convert the kinetic energy of wind into mechanical kinetic energy, and then convert the mechanical energy into kinetic energy electric. is the production of wind energy. The principle of wind power generation is to use wind energy to rotate the blades of the wind turbine, then use a speed multiplier to increase the rotation speed to induce the generator to produce electricity. According to current wind turbine technology, the production of electricityity can start at a breeze speed of around three meters per second (the degree of breeze). Wind energy is becoming a craze worldwide because it does not require the use of fuel and does not produce radiation or air pollution.
The devices needed to produce wind energy are called wind turbines. This type of wind turbine can be roughly divided into three parts: the wind wheel (including the tail rudder), the generator and the iron tower. (Large-scale wind power plants basically do not have tail rudders. Generally, only small power plants (including domestic types) have tail rudders.)
The wind wheel is a component important which converts the kinetic energy of the wind. in mechanical energy. It consists of two (or more) propeller-shaped wheels. When the wind blows towards the blades, an aerodynamic force is generated on the blades to maketurn the wind wheel. The blade material requires high strength and light weight. Currently, it is mainly made of fiberglass or other composite materials (such as carbon fiber). (There are also vertical wind turbines, S-shaped rotating blades, etc., which have the same function as conventional propeller-type blades)
Since the speed of the wind turbine is relatively weak and the magnitude and direction of the wind force often changes, making the speed unstable. Therefore, before operating the generator, a gearbox must be attached to increase the speed to the rated speed of the generator, and a speed regulating mechanism must be added; to keep the speed stable, then connected to the generator. In order to keep the wind rotor always aligned with the wind direction to obtain maximum power, a similar tail ruddere a weather vane must be installed behind the wind rotor.
The iron tower is the structure that supports the wind wheel, rudder and generator. It is usually built relatively high in order to obtain a greater and more uniform wind force and to have sufficient force. Effect of tower height on wind speed due to ground obstaclesIt depends on the sound situation and the diameter of the wind wheel, which is generally between 6 and 20 meters.
The function of the generator is to transfer the constant rotation speed obtained from the wind wheel to the power generation mechanism through increased speed for uniform operation, thereby converting mechanical energy into electrical energy .
For a 1.5 MW wind turbine, the generator spins about 1,800 times per minute, generates 1,500 kilowatt hours of electricity per hour, and the turbine spins about 18 times per minute. minute. This is directlyrelated to the unit's ability.
Generally speaking, level 3 winds are valuable. However, from an economic and reasonable point of view, wind speeds above 4 meters per second are suitable for electricity generation.
According to measurements, a 55 kilowatt wind turbine has an output power of 55 kilowatts when the wind speed is 9.5 meters per second; when the wind speed is 8 meters per second, the power is 38 kilowatts; wind speed When the wind speed is 6 meters per second, it is only 16 kilowatts; when the wind speed is 5 meters per second, it is only 9.5 kilowatts. It can be seen that the stronger the wind force, the greater the economic benefits.
Detailed information
A wind turbine is an electrical device that converts wind energy into mechanical work. Mechanical work causes the rotor to rotate and pultimately produces an alternative production. current. Wind turbines generally consist of components such as a wind wheel, a generator (including devices), a steering (tail), a tower, a speed-limiting safety mechanism, and an energy storage device.
The operating principle of a wind turbine is relatively simple. The wind wheel rotates under the influence of the wind. It converts the kinetic energy of the wind into the mechanical energy of the wind wheel shaft. driving the wind wheel shaft to produce electricity. Generally speaking, wind energy is also solar energy, so we can also say that a wind turbine is a thermal energy generator that uses the sun as a heat source and the atmosphere as a heat fluid. work.
For many centuries, wind turbines, like hydraulic machines, have played an important role in the development of productivity as a source of energy intended to replace human and animal energy. The widespread application of electromechanical power in modern times and the discovery of oil deposits in the Middle East in the 1950s slowed the development of wind turbines.
In the early 1970s, due to the “oil crisis”, energy shortages appeared. People have become aware of the instability and limitations of conventional fossil energy supplies, so the search for clean and renewable energy has become a key issue in the modern economy. world. an important subject. As a renewable and non-polluting natural energy source, wind energy has once again attracted attention.
Reference documents:
Baidu Encyclopedia - Wind Turbine