If at present there are many more advanced methods of generating energy, then before wind turbines were used almost everywhere. Of course, they are used now, but the number has significantly decreased. To understand the principle of their work, it is important to know that the wind is a form of solar energy.
general description
Wind turbines operate using wind currents. But why exactly is the wind capable of generating electricity? This phenomenon occurs due to the fact that there is an uneven heating of the earth’s atmosphere, the structure of the planet’s surface is irregular, and also because it rotates. Wind turbines, or wind generators, are able to convert the kinetic energy of the wind into mechanical energy , which can later be used for some other tasks.
How exactly do these devices generate electrical energy using ordinary wind? In fact, everything is quite simple. The principle of operation of such a turbine is the exact opposite of the fan. Under the influence of wind force, the blades rotate near the wind turbine, which, in turn, cause the shaft to rotate, connected to a generator that produces electrical energy.
Types of turbines
There are several types of various turbines. Engineers distinguish two main categories that are currently used. The first category is horizontally axial, and the second category is vertically axial. The first type of wind turbine has the most common design, which includes two or three blades. Units with three blades work on the principle of "against the wind." The elements themselves are installed so that they look at the wind.
One of the largest turbines in the world is GE Wind Energy. The power of this device is 3.6 megawatts. It is worth noting that the larger the turbine, the more efficient it is. In addition, the ratio of benefits and price also improves with an increase in the size of the unit.
General turbine performance
The first indicator by which a device is selected is power. If we take "service" turbines, then their power can start from 100 kW and reach several mW. It is also important to note that both vertical and horizontal wind turbines can be grouped. Such groups are most often called wind farms. The purpose of such sites is the wholesale supply of electricity to the desired facility.
If we talk about small single turbines, the power of which is lower than 100 kW, then they are most often used to supply electricity to private houses, telecommunication antennas or to supply energy to water pumps. It is worth noting that small turbines in size can also be used in conjunction with diesel generators, batteries or solar panels. Such a system is called a hybrid. They are used in places where there is no other way to connect to the electrical network.
The advantages of vertical turbines
Currently, it is much more often used exactly the vertical type of devices. This is justified by the fact that the vertical type has several advantages over horizontal ones.
The load on the towers of the vertical type will act more evenly, which gives such an opportunity as a simpler creation of a larger construction in its dimensions. In addition, to install the rotor on this type of turbine, there is no need for additional equipment. An important advantage that increases work efficiency is that the blades of vertical turbines can be made twisted - in the form of a spiral. This is very important, since in this case wind energy will affect them both at the input and at the output, which, of course, increases the efficiency of the installation.
One of the most important advantages of vertical turbines is that when installed, it makes no sense to adjust the axis to the wind flow. This type of device will work with a wind flow blowing from either side.
Bolotov Wind Rotor Turbine
This setting stands out from the rest of the devices. For normal operation of the turbine there is no need to adapt it to various kinds of weather conditions. The wind power element of this design is able to perceive the wind from any side, without carrying out any tuning operations. In addition, this type of station does not require turning the tower when the wind direction changes. Another advantage of vertical wind turbines (VAWT - a wind farm with a vertically located generator shaft) is that they have a special design that allows you to work with wind flows of any power. It is possible to work even with stormy gusts. It is possible to select the number of installation modules. The output power of the turbine will depend on their number. That is, by changing the number of modules, you can change the power of the unit, which is very convenient. Another advantage is that the wind-driven structural element is assembled in such a way that allows the conversion with high efficiency of kinetic energy to mechanical.
Dimensions of the Biryukov and Blinov wind turbine
This device has a two-story rotor with a diameter of 0.75 m. The height of this element is 2 m. Under the influence of fresh wind, such a rotor was able to completely unwind the rotor of an asynchronous shaft with a power of up to 1.2 kW. The turbine could withstand wind power without breakdowns up to 30 m / s.
It is worth talking about why the wind turbine is considered the achievement of two scientists. The thing is that in the 60s. in the USSR, scientist Biryukov patented a rotary wind generator with a KIEV of 46%. However, somewhat later, engineer Blinov was able to use the same design, but with an indicator of 58% KIEV.
Hyperboloid type turbines
The hyperboloid type wind turbines were based on the ideas of such an engineer as Vladimir G. Shukhov.
The features of this type of turbine include the fact that it has a larger working area of the wind flow. If we compare this indicator with other categories of devices, then the hyperboloid type shows the results 7-8% better, if you count from the swept area. This indicator is valid for those types in which the working area of the wind flow is winged. If we compare this type, for example, with the Daria and Savonius turbines, the difference will be 40-45%.
The special properties of this category of units also include the fact that they are able to work with ascending air currents. This is very productive if you install a generator near a lake, swamp, on a hillside, etc.
The pluses of such turbines include the fact that the contact line of the active layer of air that washes the hyperboloid will be 1.6 times longer than that of a similar cylinder rotating as a rotary type wind generator. Naturally, this leads to the conclusion that the efficiency will be the same as many times.
disadvantages
Despite the many advantages and features of these turbines, they also have a number of some disadvantages.
The negative factors include the fact that when the blades of the generator rotate against wind flows, this type of generator will incur significant losses, which, in turn, will lead to a decrease in operating efficiency by about half. The decrease in this indicator is very noticeable when comparing vertical turbines with horizontal ones that do not have such losses.
Another drawback will be that the vertical wind generator must be very long. If you place it close to the ground, where the wind speed is much lower than at high altitude, then there may be problems with starting the rotor, which needs a push to start work. By itself, it does not start at all. You can, of course, install special towers to raise the blades higher, but the lower part of the rotor will still be too low.
Other disadvantages include the fact that in winter icicles will form on the blades of wind generators. It is also worth noting the large amount of noise that turbines emit during operation. Some of the facilities are even capable of producing harmful infrasound during their operation. It causes vibration, due to which glass, windows, dishes can rattle.
Interesting fact: RimWorld wind turbines were used as a source of energy.