What are the applications of wind power?

As a clean and renewable energy, wind energy has attracted more and more attention from countries around the world. Its potential is huge. The global wind energy is about 2.74×109MW, of which the available wind energy is 2×107MW, which is 10 times larger than the total amount of water energy that can be developed and utilized for wind power generation on the earth. Wind has been used by people for a long time - mainly for pumping water, grinding flour, etc. through windmills. Now, people are interested in how to use wind to generate electricity.

Introduction to wind power generation

Wind is a new energy source with great potential. People may still remember that in the early 18th century, a violent wind swept across Britain and France, destroying Four hundred wind mills, eight hundred houses, one hundred churches, more than four hundred sailing ships, thousands of people were injured, and a quarter of a million trees were uprooted. Just for uprooting trees, the wind generates 10 million horsepower (i.e. 7.5 million kilowatts; one horsepower is equal to 0.75 kilowatts) in a few seconds! Some people have estimated that the wind resources that can be used to generate electricity on the earth are about It has 10 billion kilowatts, which is almost 10 times the current hydropower generation capacity in the world. Currently, the world's energy from burning coal each year is only one-third of that provided by wind in a year. Therefore, domestic and foreign governments attach great importance to the use of wind power to generate electricity and develop new energy sources.

Attempts to use wind power to generate electricity began as early as the beginning of this century. In the 1930s, Denmark, Sweden, the Soviet Union and the United States applied rotor technology from the aviation industry and successfully developed some small wind power devices. This kind of small wind turbine is widely used in windy islands and remote villages. The cost of generating electricity is much lower than that of a small internal combustion engine. However, the power generation capacity at that time was relatively low, mostly below 5 kilowatts.

At present, it is understood that foreign countries have produced 15, 40, 45, 100, and 225 kilowatt wind turbines. In January 1978, the United States built a 200-kilowatt wind turbine in the town of Clayton, New Mexico. Its blades were 38 meters in diameter and the power generation was enough to power 60 households. In the early summer of 1978, a wind power generation device was put into operation on the west coast of Jutland, Denmark. Its power generation reached 2,000 kilowatts. The windmill was 57 meters high. 75% of the power generated was sent to the power grid, and the rest was supplied to a nearby school. .

In the first half of 1979, the United States built another windmill for power generation in the world in the Blue Ridge Mountains of North Carolina. This windmill is ten stories high, and the diameter of the windmill steel blades is 60 meters; the blades are installed on a tower-shaped building, so the windmill can rotate freely and obtain power from any direction; when the wind speed is more than 38 kilometers per hour, the power generation capacity is also Up to 2000 kilowatts. Since the average wind speed in this hilly area is only 29 kilometers per hour, the windmill cannot move at all. It is estimated that even if it operates only half of the year, it will be able to meet 1% to 2% of the electricity needs of seven North Carolina counties.

How to use wind power to generate electricity?

We convert the kinetic energy of the wind into mechanical energy, and then convert the mechanical energy into electrical energy. This is wind power generation. The equipment required for wind power generation is called a wind turbine. This kind of wind turbine can be roughly divided into three parts: wind wheel (including tail rudder), generator and iron tower. (Large-scale wind power stations basically do not have tail rudders, and generally only small ones (including household ones) have tail rudders)

The wind wheel is an important component that converts the kinetic energy of the wind into mechanical energy. It consists of two (or more) propeller-shaped impellers. When the wind blows towards the blades, aerodynamic force is generated on the blades to drive the wind wheel to rotate. The blade material requires high strength and light weight. Currently, it is mostly made of fiberglass or other composite materials (such as carbon fiber). (There are also some vertical wind wheels, S-shaped rotating blades, etc., which have the same function as conventional propeller-type blades)

Since the speed of the wind wheel is relatively low, and the magnitude and direction of the wind force often change, This in turn makes the speed unstable; therefore, before driving 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, and then connected to the generator. In order to keep the wind rotor always aligned with the wind direction to obtain maximum power, a tail rudder similar to a wind vane needs to be installed behind the wind rotor.

The iron tower is the structure that supports the wind wheel, rudder and generator. It is generally built relatively high in order to obtain larger and more uniform wind force and to have sufficient strength. The height of the tower depends on the impact of ground obstacles on wind speed and the diameter of the wind wheel. It is generally in the range of 6-20 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 even operation, thereby converting mechanical energy into electrical energy.

How much wind power can be used to generate electricity?

Generally speaking, level 3 wind is valuable for utilization. However, from an economic and reasonable perspective, wind speeds greater than 4 meters per second are suitable for power 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; when the wind speed is 6 meters per second, Only 16 kilowatts; and 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.

In our country, there are already many successful medium and small wind power installations in operation.

my country is extremely rich in wind resources. The average wind speed in most areas is more than 3 meters per second, especially in the northeast, northwest, southwest plateau and coastal islands, the average wind speed is even higher; in some places, More than one-third of the year is windy. In these areas, the development of wind power generation is very promising.

The principle of wind power generation

The principle of wind power generation is to use wind power to drive the windmill blades to rotate, and then increase the speed of rotation through a speed increaser to prompt the generator to generate electricity. According to current windmill technology, power generation can start at a breeze speed of about three meters per second (the level of breeze). Wind power is forming a craze in the world, because wind power has no fuel problems and does not produce radiation or air pollution.

Wind power generation is very popular in countries such as Finland and Denmark; our country is also vigorously promoting it in the western region. The small wind power generation system is very efficient, but it is not composed of just one generator head, but a small system with certain technological content: wind turbine + charger + digital inverter. The wind turbine consists of a nose, a rotor, a tail, and blades. Each part is important, and the functions of each part are: the blades are used to receive wind power and convert it into electrical energy through the nose; the tail allows the blades to always face the direction of the wind to obtain the maximum wind energy; the swivel allows the nose to rotate flexibly to achieve The tail has the function of adjusting the direction; the rotor of the nose is a permanent magnet, and the stator winding cuts the magnetic lines of force to generate electrical energy.

Due to the unstable air volume, the wind turbine outputs alternating current of 13 to 25V, which must be rectified by the charger, and then the battery is charged, so that the electrical energy generated by the wind turbine is converted into chemical energy. . Then use an inverter power supply with a protection circuit to convert the chemical energy in the battery into AC 220V mains power to ensure stable use.

Usually people think that the power of wind power is completely determined by the power of the wind turbine, and they always want to buy a larger wind turbine, but this is incorrect. The current wind turbine only charges the battery, and the battery stores the electrical energy. The amount of electrical power people ultimately use is more closely related to the size of the battery. The size of the power mainly depends on the size of the air volume, not just the size of the machine head power. In the Mainland, small wind turbines are more suitable than larger ones. Because it is more easily driven by small winds to generate electricity, continuous small winds can provide greater energy than temporary strong winds. When there is no wind, people can still use the electricity brought by the wind normally. In other words, a 200W wind turbine can also be used with a large battery and an inverter to obtain a power output of 500W or even 1000W or even greater.

Using wind turbines means continuously turning wind energy into the standard mains electricity used by our families. The degree of savings is obvious. A family only needs 20 yuan of battery fluid for a year's electricity consumption. cost. The performance of today's wind turbines has been greatly improved compared to a few years ago. In the past, they were only used in a few remote areas. The wind turbine was connected to a 15W light bulb to directly use electricity, which would often damage the light bulb when it was bright and dark. Nowadays, due to technological advancement and the use of advanced chargers and inverters, wind power generation has become a small system with a certain technological content, and can replace normal commercial power under certain conditions. In mountainous areas, this system can be used to make a street light that costs nothing all year round; on highways, it can be used as a road sign at night; children in mountainous areas can study at night under fluorescent lamps; wind motors can also be used on the roofs of small high-rise buildings in cities, which is not only economical but also truly Green power. Wind turbines for home use can not only prevent power outages, but also add interest to life. In tourist attractions, border defenses, schools, military units and even backward mountainous areas, wind turbines are becoming a hot spot for people to purchase. Radio enthusiasts can use their own technology to serve people in mountainous areas in terms of wind power generation, allowing people to watch TV and lighting electricity in sync with the city, and also make themselves rich through labor.

my country's wind energy resources

1. Overview

my country is rich in wind energy resources. The exploitable wind energy reserves are about 1 billion kW, of which the onshore wind energy reserves are about 1 billion kW. 253 million kW (calculated based on data at a height of 10 meters above the ground on land), and the wind energy reserves that can be developed and utilized at sea are about 750 million kW, with a total of 1 billion kW. By the end of 2003, the national installed electricity capacity was approximately 567 million kW.

Wind is one of the pollution-free energy sources. And it is inexhaustible. For coastal islands, grassland pastoral areas, mountainous areas and plateau areas that are short of water, fuel and have inconvenient transportation, the use of wind power to generate electricity according to local conditions is very suitable and has great potential.

Introduction to my country’s independent intellectual property products in the wind power industry:

In the 1990s, my country’s independent power supply system mainly used horizontal axis wind turbines and solar photovoltaic systems to supply electricity. , mainly used in special occasions such as communication base stations, border posts, and island troops. It is mainly a set of logistics support systems for troops.

After a certain period of application, many problems were discovered. For example, equipment during a typhoon was seriously damaged; the noise was loud, affecting the normal rest of personnel; and interference with communication equipment caused some equipment to fail to operate normally. The occurrence of these problems affected the normal communication of the troops.

In 2001, in order to solve these problems, relevant units were convened for discussion. Shanghai Mosi Electronic Equipment Co., Ltd., a supporting manufacturer of military communication products, was also invited.

After the meeting, after a certain period of investigation and research, MUCE proposed to take on the important task of scientific research. The army leaders agreed and issued instructions that they must come up with technical solutions and prototypes as soon as possible.

With the cooperation of a group of experts from Xijun Electric, Xi'an Jiaotong University, Shanghai Fudan University, Shanghai Tongji University and other universities, Shanghai Mosi Electronic Equipment Co., Ltd. successfully developed the The world's first new (H-type) vertical axis wind turbine was successfully installed and tested, and basic data and practical experience were obtained. (This also became the birth date of the world's first new vertical axis wind turbine) In the following year, MUCE conducted numerous improvements and tests on the product. At the end of 2002, the product passed various tests and met all design requirements. .

From the end of 2002 to the present, MUCE has installed more than 60 sets of vertical axis wind turbines and wind-solar hybrid systems in the army, making immortal contributions to stabilizing national defense!

The wind-solar hybrid street light power supply system produced by Shenzhen Chengyuan Company is an emerging road lighting system that comprehensively utilizes solar and wind energy. A separate solar or wind energy heating system is difficult to utilize solar and wind energy resources around the clock due to time and geographical constraints. Solar energy and wind energy are highly complementary in time and geography. When the light is strong during the day, the wind is small. When the light is weak at night, the wind energy is enhanced due to the large changes in surface temperature. The complementarity between solar energy and wind energy in time is that of wind and light. The complementary street light power supply system is the best match in resource utilization. This system is energy-saving, environmentally friendly, renewable, inexhaustible, and will surely become the mainstream alternative to other road lighting systems in the future. When the system is working, the solar collector collects solar radiation energy to generate electricity (during the day), which is transmitted to the power control system through dedicated lines for storage and distribution. Wind turbines use wind energy around the clock, convert the wind energy into electrical energy, and then rectify it through the controller to charge the battery pack.

New wind energy conversion method - runoff two-wheel effect

Runoff two-wheel effect or two-wheel effect is a new wind energy conversion method.

First of all, it is a double-wheel structure. Compared with the horizontal axial flow fan, it is radial flow. Like the existing vertical axis fan, the blades are arranged along the long axis and can be directly used. The single-wheel vertical axis wind rotor works by rotating due to the thrust of the wind. Because the blades on both sides of the shaft receive the wind force at the same time, the torques are opposite and cancel each other out, so the output torque is not large. Designed as a two-wheel structure and installed close together, running synchronously, the original dependence of the vertical axis torque output on the hydrodynamic shape of the blade is changed to the utilization of the vortex force generated by the rotation between the two wheels. The two wheels borrow force from each other and push each other. ; And the reverse wind flow blowing between the two wheels can block each other, and then distribute it to the outside of the two wheels in turn, so that the outside of the two wheels can get a superimposed wind flow, so that the outer edge linear speed of the two wheels can be high. Depending on the wind speed, the mutual assistance of the two-wheel structure actively utilizes the characteristics of the wind to produce the "two-wheel effect".

Compared with some single-wheel structure wind turbines, external shielding methods, movable pitch changes and other passive designs are used to reduce the impeller rotation reset resistance, which reflects the characteristics of actively utilizing wind power. Therefore, this invention not only has a practical effect and promotes the research and development of wind power utilization, but also has new fluid mechanics significance. It opens up a new space for the development of wind energy and is a basic invention. This two-wheel fan has simple design, easy manufacturing and processing, low rotation speed, lowered center of gravity, good safety, low operating cost and low maintenance. It has obvious characteristics such as ease of use and no noise pollution. It can be widely popularized and promoted to meet China's energy conservation and emission reduction needs, and has great market prospects.

Wind energy market overview

As a clean and renewable energy, wind energy has attracted more and more attention from countries around the world. Its potential is huge. The global wind energy is about 2.74×109MW, of which the available wind energy is 2×107MW, which is 10 times larger than the total amount of water energy that can be developed and utilized on the earth. China has large wind energy reserves and is widely distributed. The wind energy reserves on land alone are about 253 million kilowatts.

With the development of the global economy, the wind energy market has also developed rapidly. Global wind power capacity has doubled since 2004, and global installed wind power capacity expanded by 27% between 2006 and 2007. In 2007, there were 90,000 megawatts, and by 2010 this number will be 160,000 megawatts. It is expected that in the next 20-25 years, the world wind energy market will increase by 25% annually. With the advancement of technology and environmental protection, wind power generation will be able to compete with coal-fired power generation commercially.

During the "Tenth Five-Year Plan" period, China's grid-connected wind power developed rapidly. In 2006, China's cumulative installed wind power capacity reached 2.6 million kilowatts, becoming one of the major markets for the development of wind power after Europe, the United States and India. In 2007, my country's wind power industry continued its explosive growth trend. By the end of 2007, the country's cumulative installed capacity was approximately 6 million kilowatts. In August 2008, China's total installed wind power capacity reached 7 million kilowatts, accounting for 1% of China's total installed power generation capacity, ranking fifth in the world. This also means that China has entered the ranks of major renewable energy countries.

Since 2008, the domestic wind power construction boom has reached a fever pitch. By the end of 2008, the scale of wind power may reach 10 million kilowatts, and the cumulative installed capacity will reach 20 million kilowatts by 2010.

The development prospects of China's wind power and other new energy power generation industries are very broad. It is expected to maintain rapid development for a long time in the future. At the same time, profitability will also steadily increase as the technology gradually matures. The total profit of this industry will maintain rapid growth in 2009. After the rapid growth in 2009, the growth rate is expected to fall slightly in 2010 and 2011, but the growth rate will also reach more than 60%.

At the current stage of development of wind power, its cost performance is forming a competitive advantage with coal power and hydropower. The advantage of wind power is that every time the capacity is doubled, the cost drops by 15%. In recent years, the growth of world wind power has remained above 30%. With the localization of China's wind power installed capacity and the scale-up of power generation, the cost of wind power is expected to drop further. Therefore, wind power has begun to become a place for more and more investors to pursue gold.

The Prospects of Wind Power

China’s new energy strategy has begun to focus on vigorously developing wind power. According to national plans, in the next 15 years, the country's installed wind power capacity will reach 20 to 30 million kilowatts. Based on an equipment investment of 7,000 yuan per kilowatt of installed capacity, the future wind power equipment market will be as high as 140 billion yuan to 210 billion yuan.