Is it better to have 3 blades or 5 or 6 blades for wind power?

3 pieces are good. To put it simply, 3 leaves are easy to balance, but it is difficult to balance when there are too many leaves, and the cost is high.

At the rated wind speed, the power generated is proportional to the swept area of the wind wheel, i.e. a wind wheel with 200 blades and a wind wheel with 1 blade can produce the same power.

The advantage of multi-blades is the large torque conversion rate.

However, in terms of energy conversion rate, the efficiency of 4-blade and 5-blade fans is lower than that of 3-blade fans.

The main reason is that the multi-blade fan has a large resistance, which causes a considerable part of the turbulence that interferes with the rotation of the blades, thus reducing the energy conversion rate.

Therefore, it is much better to choose 3 leaves than 4 or 5 leaves. (Well, electric fan.)

That's the same thing); Secondly, the number of blades is too small, which will affect the efficiency of power generation.

From a single blade to a three-blade wind wheel, the solid ratio is small, it is a low solid wind wheel, and a 12-blade wind wheel has a high solid ratio, which is a high solid wind wheel. Looking at the three thin blades, it seems that most of the wind is missing, so why not use a multi-blade wind wheel to receive more wind energy. The left figure in Figure 3 is a schematic diagram of the air flow of the wind through the ordinary three blades, the speed of the air flow slows down after the work is done through the impeller, and the volume of the air flow increases.

Figure 3 on the right is a schematic diagram of the air flow of the wind through multiple blades, which greatly increase the resistance of the gas to pass, and the air flow will flow separately around the impeller to the rear, and only part of the air flow will do work through the impeller. Due to the high resistance, the wind speed through the blades will also decrease, so the actual wind power of the impeller is reduced, which is an important reason why multi-blade wind turbines do not get more wind energy.

Does the low-solidity and low-blade wind turbine leak most of the airflow? Neither is it. The operating speed of the low-solidity wind turbine is higher, and the linear speed of the blades is many times higher than the wind speed, which can sweep through most of the passing air flow, and only a small part does not pass through the blades, and most of the passing air flow pushes the blades to operate, and most of the wind energy is utilized.

How many blades are appropriate, a lot of experiments have been done at home and abroad, two, three and four blades are the common choice of wind turbines, and the most used is three blades. Of course, the choice of three blades is also due to the structural strength of the wind turbine, manufacturing costs, noise, appearance and other reasons.

Wind turbine blades 20 to 30 meters.

Generally speaking, there are 600 to 1000 kW wind turbines and 20 to 30 meter blades.

Wind power shortage let motor principle:

It is an electrical equipment that converts wind energy into mechanical energy and mechanical energy into electrical energy. Broadly speaking, it is a kind of heat energy utilization engine that uses the sun as the heat source and the atmosphere as the working medium. Wind power is powered by natural energy.

It is much better than diesel power generation. But if it is used in an emergency, it is still not as good as a diesel generator. Wind power is not considered a backup power source, but it can be used for a long time.

The principle of wind power generation is to use wind power to drive the windmill blades to rotate as soon as possible, and then increase the rotation speed through the speed increaser to promote the generator to generate electricity. According to current wind turbine technology, power generation can be started at a breeze speed of about three meters per second (the degree of the breeze).

Wind power is becoming a boom in the world because it has no fuel problems and does not produce radiation or air pollution. <>

The largest wind turbine blades are 80 meters.

The world's largest wind turbine is located in the Danish Maade – called V164 – manufactured and installed by Mitsubishi Vestas Offshore Wind Company.

The wind turbine is 220 meters tall (plus blade length) and is housed with 3 giant blades, each 80 meters long, which is longer than the Boeing 747.

The area swept by the leaves is even much larger than the "London Eye" in the United Kingdom, and it looks spectacular.

In addition to being the largest, it is also the most powerful wind turbine in the world, generating 260,000 kilowatt-hours of electricity in 24 hours under normal circumstances, enough to meet the electricity consumption of hundreds of households for one month.

The requirements for the blades are:

1. It has light density and the best fatigue strength and mechanical properties, and can withstand extreme harsh conditions such as storms and random loads.

2. The elasticity of the blade, the inertia of rotation and the characteristic curve of its vibration frequency are normal, and the load transmitted to the entire power generation system has good stability, and it shall not be pulled off and fly out under the action of centrifugal force in the case of loss of control (speed), nor shall it be broken under the action of wind pressure, nor shall it produce a strong resonance that causes the entire wind turbine within the range below the speed of the flying car.

3. The material of the blade must ensure that the surface is smooth to reduce wind resistance, and the rough surface will also be affected by the wind"Tearing"。

4. Do not produce strong electromagnetic interference and light reflection.

5. Excessive noise is not allowed.

6. Good corrosion resistance, ultraviolet radiation and lightning strike performance.

7. The cost is low and the maintenance cost is the lowest.

The weight is about 6-20 tons blades.

For the fan, the blade length is 34-45m, and the corresponding tower height (hub height is 65-100m), and the blade length is proportional to the corresponding hub height. But it is not a strong one-to-one correspondence. Weight approx. 6-8 tons blades.

2MW fan, blade length range: 48-59 meters, corresponding to hub height 80-100 meters. Weight approx. 8-15 tons blades.

3MW fan, blade length range: 44-59 meters, corresponding to hub height 80-110 meters. Weight approx. 8-15 tons blades.

5MW wind turbine and above, blade length range: 62-75 meters, corresponding to the hub height of 100-110 meters. The weight is about 15-20 tons blades.

Wind power advantages:

1. The construction period of wind power plants is short, the installation time of a single unit is only a few weeks, the construction period of 50,000 kilowatt capacity wind farm is about half a year to one year, and the wind turbine assembly mode is flexible.

2. In the wind turbines that are more and more applied to modern technology, the reliability of wind turbines is getting higher and higher. The life of the unit can be up to 20 years. At present, the cost per unit of installed capacity of medium-sized wind turbines is close to that of thermal power, and lower than that of oil and nuclear power.

If you calculate the cost of transportation into coal power and the costs associated with environmental protection, then wind power** is the cheapest energy source.

3. The operation and maintenance of wind turbines are simple, and their own automation level is high. The actual footprint of wind turbines is small, and wind power generation can be complementary to other energy power generation forms such as photovoltaics, hydropower lifting, etc., or it can be operated separately, which is very advantageous for decentralized layout. <>

The size of the wind turbine blades are: wind turbine, the blade length is 34 to 45 meters. 2MW fan, blade length range:

Forty-eight to fifty-nine meters 3MW wind turbine, blade length range: forty-four to fifty-nine meters. 5MW fan and mold wheel should be above and above, and the blade length range:

Sixty-two to seventy-five meters.

On a 600 kW wind turbine, each rotor blade is measured approximately 20 meters in length.

A wind turbine is an electrical equipment that converts wind energy into mechanical work, and the mechanic drives the rotor to rotate and finally outputs alternating current. Broadly speaking, wind energy is also solar energy, so it can also be said that wind turbines are a kind of thermal energy utilization generators that use the sun as the heat source and the atmosphere as the working medium.

The blade diameter is the sweep diameter. The mainstream blade type is 126 110 114, etc., and the corresponding blade sizes are 68m, 54m, 56m; The largest wind turbine blades are now more than 70 meters in diameter, equivalent to the wingspan of a Boeing aircraft.

Extended Materials

1. Application characteristics.

Various. A wide range of resins, curing agents, and modifier systems can be adapted to almost every application, and can range from very low viscosity to high melting point solids.

Easy to cure. With a wide range of curing agents, epoxy systems can be cured in the temperature range of almost 0 180.

Strong adhesion. The presence of polar hydroxyl and ether bonds inherent in the molecular chain of epoxy resin gives it high adhesion to various substances. Epoxy cures with low shrinkage and low internal stress, which also contributes to improved adhesion strength.

Low shrinkage. The reaction between the epoxy resin and the curing agent used is carried out by direct addition reaction or ring-opening polymerization of the epoxy group in the resin molecule, and no water or other volatile by-products are released. Compared to unsaturated polyester resins and phenolic resins, they show very low shrinkage (less than 2%) during curing.

Mechanical properties. The cured epoxy resin system has excellent mechanical properties.

Electrical properties. The cured epoxy resin system is an excellent insulating material with high dielectric properties, surface leakage resistance, and arc resistance.

Chemical stability. In general, cured epoxy systems have excellent resistance to alkalis, acids, and solvents. Like other properties of cured epoxy systems, chemical stability depends on the resin and hardener used.

Proper selection of epoxy resins and curing agents can give them special chemically stable properties.

Dimensional stability. The combination of these properties gives epoxy resin systems outstanding dimensional stability and durability.

Mold resistant. The cured epoxy system is resistant to most molds and can be used in harsh tropical conditions.

2. The material of wind turbine blades.

Blades are an industry with high certainty, large market capacity and clear profit model in wind power components.

With the easing of the tight supply and demand situation, the wind power blade industry will also undergo a transformation from a group of heroes to several powers, and China's wind power blade industry is experiencing an industry reshuffle and integration.

With the expansion of the scale of the wind turbine blade market, the cost and selling price will fall, but the cost of enterprises with scale, technology and cost advantages will decline faster than the selling price, and the profit will exceed the average. The future industry competition pattern requires manufacturers to expand their scale, reduce costs, and maintain certain advantages in technology.

Epoxy resin is an organic polymer compound that contains two or more epoxy groups in the molecule, and their relative molecular weight is not high except for a few.

The molecular structure of epoxy resin is characterized by the presence of active epoxy groups in the molecular chain, which can be located at the end, middle or in a cyclic structure of the molecular chain. Because the molecular structure contains active epoxy groups, they can cross-link with various types of curing agents to form insoluble, non-meltable polymers with a three-way network structure.

The blades of wind turbines are still relatively large, generally tens of meters, between 30 and 50 for small ones, between 50 and 80 for large ones, and for more than 100 meters.

The blades of a wind turbine are about three meters long, and if you add the rotating part, it should be five meters

I have seen the blades of wind power generation from Douyin, and they are pulled by large trucks, and the blades should be quite long, and they should be twenty or thirty meters! Anyway, it's quite long, I don't know how much.

Most of them are forty meters, and the height is ninety meters.

Large megawatt blade beams may be designed with a mix of carbon and glass, and the housing web is generally made of fiberglass fabric.

In addition to LM, mainstream wind turbine blade manufacturers at home and abroad, such as Vestas, Siemens, Gamesa, etc., are epoxy resin systems; Relying on its own understanding of the interface bonding ability between resin and glass fiber fabric, LM uses polyester resin, which has fast bonding speed, no need for heating in the post-curing process, and high mold turnover efficiency;

The diameter of the blade is not professional, it should be the diameter of the sweep. The mainstream blade type is 126 110 114, etc., and the corresponding blade sizes are 68m, 54m, 56m;

01 To put it simply, in order to improve the wind energy conversion efficiency of the wind turbine, theoretically the fewer the number of fan blades, the higher the speed under the kinetic rate, and then considering the requirements of the stability of the center of gravity, the three blades are the most practical horizontal axis wind turbines in practice.

Now new energy is the hottest topic, it can be said that the eyes of the world are now paying attention to the environmental protection of new energy or the development of new new energy.

New energy, on the other hand, is an energy source that can be continuously regenerated and does not affect our ecological environment, such as wind energy.

Wind energy is a goal that the world is all concerned about now, and wind turbines are a model of using wind energy to the extreme.

Maybe speaking of this, many friends may not know what a wind turbine is, but it is actually very easy to understand, for example, the windmills with three leaves that we usually see in flat and open places, they are a kind of wind turbine.

The principle of the generator is also very simple, that is, the wind power brought to us by nature is converted into a kind of mechanical energy, and then through some technical problems, the mechanical energy is converted into kinetic energy, so that we have an inexhaustible supply of electrical energy.

The largest wind turbine in the world is currently in existence, and its leaf length can reach about 164 meters, and each blade reaches 32 tons.

This is too huge for our country, the cost is too huge, there is no way to popularize it everywhere, and at the same time, in the case of increasing the number of blades and increasing the cost, in fact, the electricity has not increased much.

Relatively speaking, the cost performance is still more suitable for the wind turbine of the three leaves. So all things considered, we decided to go with the three-leaf windmill, which is arguably the best design.