1. Aeolian uplift:
Aeolian uplift has been widely used since ancient times.
2. Wind power generation:
Wind power generation generally has three modes of operation:
(1) It is an independent mode of operation, usually a small generator. is used to produce electricity. One or more households provide electricity, which uses batteries to store energy to ensure energy consumption when there is no wind.
(2) Wind power is combined with other electricity generation methods (such as diesel engine electricity generation) to provide electricity to a unit, a village or an island.
(3) Wind energy production is integrated into the conventional electricity grid to supply the large electricity grid. Often, dozens or even hundreds of wind turbines are installed in a wind farm, which constitutesue the main direction of development of wind power generation.
3. Sail to aid navigation:
In the development of today's motorboats, in order to save fuel and increase speed, ancient sails have been developed.
4. Wind heating:
With the improvement of people's living standards, the demand for thermal energy for household energy is increasing, especially in the high latitudes of Europe and North America. Drinking water is a large consumer of energy. In order to meet the thermal energy needs of households and small-scale industries, wind heating has been considerably developed.
Detailed information:
Advantages and disadvantages of wind energy
1. Advantages
Wind energy is a clean energy source. Wind power installationsWinds have become more advanced, mass production has reduced costs, and in the right places, wind power is now cheaper than other generators. Wind turbine installations are mostly non-three-dimensional installations that can protect land and ecology. Wind energy is a renewable, clean and environmentally friendly energy source. Wind power is energy efficient and environmentally friendly.
2. Disadvantages
The ecological problem with wind power is that it can disturb birds. For example, grouse in Kansas, USA, gradually disappeared after the emergence of wind turbines. The current solution consists of producing electricity at sea, which is more expensive but also more efficient.
In some regions, the profitability of wind energy production is insufficient and the wind is intermittent in many regions. What's worse is thate in places like Taiwan, there is less wind in summer and during the day. When energy demand is high, one must wait for the development of energy storage technologies such as compressed air.
Wind power generation requires a large amount of land to build wind farms to produce relatively large amounts of energy.
When wind power is generated, the wind turbine will make a lot of noise, so it is necessary to find open spaces to build.
Current wind production is not yet mature and there is still considerable room for development.
Baidu Encyclopedia-Wind Energy
Problems with wind turbines? I see that the wind turbine is very tall, with only three fan blades at the top, and the leaves are also thin. It is so tall, how can it be used to generate electricity throughthis in the wind?
The differences between horizontal axis and vertical axis wind turbines lie in the following aspects:
1. Design method
The design of horizontal axis wind turbine blades, The momentum-sheet element theory is commonly used, and the main methods include Glauert method, Wilson method, etc. However, because the blade element theory ignores the flow interference between each blade element, and at the same time ignores the airfoil resistance when designing blades using blade element theory, this simplification inevitably leads to inaccuracy in the results. This simplification has little impact. on the design of the blade shape, but has a greater impact on the wind energy utilization rate of the wind wheel. At the same time, the interference between the wind wheel blades is also very strong and the entire flux is very complex. It is impossible to obtain accurate results based on blade element theory alone.
The design of vertical-axis wind turbine blades was formerly based on the horizontal-axis design method and relied on blade element theory. Since the flow of vertical axis wind turbine is more complex than that of horizontal axis, it is a typical large separation unsteady flow and is not suitable for analysis and design using blade element theory. This is also an important reason for the vertical axis. The wind turbine has not been developed for a long time.
2. Wind power utilization rate
The wind power utilization rate of large horizontal axis wind turbines is mainly calculated by blade designers and is generally above 40%. As mentioned earlier, due to the flaws of the conception itself, the accuracy of the wind energy use calculated in this way is highly questionable. Of course, wind turbines at wind power plants will plot wind power curves based on measured wind speed and power output. However, the wind speed at that time is the wind speed measured by the anemometer on the back of the wind wheel. as the speed and power of the incoming wind. The curve is too high and needs to be corrected. After applying the correction method, the wind energy utilization rate of the horizontal axis will be reduced by 30-50%. Regarding the wind energy utilization rate of small horizontal axis wind turbines, the China Aerodynamic Research and Development Center has conducted relevant wind tunnel experiments, and the measured utilization rate is between 23% and 29%. %.
3. Structural characteristics
During a rotation, the blades of the wind turbine havehorizontal xe are affected by the combined effects of the force of inertia and gravity. The direction of the inertial force changes at. at any time. The direction of gravity remains unchanged, the blade is therefore subjected to an alternating load, which is very detrimental to the fatigue life of the blade. In addition, horizontal axis generators are placed at an altitude of tens of meters, which brings a lot of inconvenience to the installation, maintenance and inspection of generators.
The blades of the vertical axis wind turbine are much better stressed during rotation than those of the horizontal axis. Since the direction of the force of inertia and gravity always remains unchanged, the blades are subjected to a constant load. The fatigue life is longer than that of horizontal axis wind rotors. At the same time, the vertical axis generator can be placed under the wind wheel or on the ground for easy installation and maintenances.
4. Start-up wind speed
There is a consensus that the start-up performance of horizontal axis wind turbines is good. However, depending on the wind speed of small horizontal axis wind turbines driven. The China Aerodynamics Research and Development Center According to hole experience,The starting wind speed is generally between 4-5m/s, and the maximum reaches 5.9m/s. Such startup performance is obviously not satisfactory. There is also an industry consensus that the starting performance of vertical axis wind turbines is poor, especially for Darrieus Ф-type wind turbines, which have no self-starting capability, which is also a reason which limits the application of the vertical wind turbine. axis wind turbines. However, for the Darrieus type H wind wheel, the conclusion is the opposite. According to the author's research, as long as theaerodynamic profile and installation angle are correctly selected, fairly good starting performance can be obtained. Judging from tunnel experiments, the starting wind speed of this Darrieus type H-shaped wind rotor only needs 2 m/s. , which is better than the horizontal axis wind turbine mentioned above.
The location is high, so the wind is relatively strong and the wind speed is uniform.
As the blades are very long, the torque at the shaft (the directional force that turns the shaft) is very large. Many factors are considered in blade design. that of an airplane propeller, and the fluids are all taken into account. It was designed through mechanical research. To be honest, I haven't done much research into the many benefits of this form in fluids.
If the blade is too big, the blade itself will be easily damagedage and the torque will not increase but the forward thrust will increase, that is, the force to rotate the fan will not increase, but the force to rotate the fan will not increase. the force to topple the tower will increase, causing more harm than good.