The hottest swing wing vertical shaft wind turbine

Swing wing vertical shaft wind turbine will popularize wind power

Abstract: because the cost of wind turbine is too expensive, the cost of wind power is 2/3 higher than that of thermal power, so although wind power is pollution-free, it can regenerate, which is a very ideal clean and sustainable energy, but it cannot be popularized. The swing wing vertical shaft wind turbine has been developed into a 250 Watt micro wind turbine with a power generation cost that is more than 20% lower than that of thermal power, and it is completely possible to further develop giant wind turbines with a power generation cost of more than 300 kW. This can widely promote wind power, change the world energy pattern dominated by thermal power, and greatly alleviate the harm of atmospheric pollution and warming. This paper discusses the characteristics of the wind turbine and analyzes the reasons for its low cost. Finally, it is hoped that the "ten pairs of samples loading and five" plan will discuss the policy issues of large-scale development of large, medium and small wind turbines

wind energy is pollution-free and renewable. It is an ideal clean and sustainable energy, but it is difficult to promote. At present, the electricity generated by global wind energy is negligible. According to the statistical data in September 1996, the wind power of California accounts for about 80% of the total wind power in the world, but it is only a little more than 1% of the total power generation of the state. Nowadays, thermal power accounts for about 80% of the world's energy pattern, and the rest is nuclear power and hydropower. The fundamental reason why wind power cannot be popularized is that the cost of wind turbines is too high. At present, wind power is about 5 cents per kWh, while thermal power is only 3 cents [1]

according to foreign data, wind power was 7 cents per kilowatt hour in 1981 and decreased to 5 cents per kilowatt hour in 1993 [1]. The US Energy Agency expects to reach 4 cents by 2000 [2]. The cost of wind power is difficult to reduce rapidly, which is mainly caused by the limitations of modern horizontal axis propeller wind turbines

swing wing vertical shaft wind turbine is a new kind of wind turbine. The recently developed 250 Watt micro wind turbine shows high technical and economic indicators, which makes the cost of wind power drop sharply to 2.4 cents, lower than that of thermal power. Under the control of the price law, wind energy has the conditions to be comprehensively promoted, so as to replace thermal power as the main energy in the new century

compared with similar products, the technical and economic indicators of the swing wing vertical shaft wind turbine have been increased by more than three times, as shown in the following table:

Product

capacity (watt) rated wind speed (M/s) weight (kg) price (yuan)

swing wing vertical shaft wind turbine 250 820800

China Southern Airlines star brand wind turbine 200 8115 2100

according to the service life of only 10 years and the full load rate of 18%, this product can generate electricity:

10 × three hundred and sixty-five × twenty-four × zero point one eight × 0.25=3945 (KWH)

therefore, it only costs 0.202 yuan per degree, equivalent to 2.4 cents, which is more than 20% cheaper than thermal power. If large and giant wind turbines are developed, the cost of wind power will be lower. There are internal reasons why the swing wing vertical shaft wind turbine can have such excellent technical and economic indicators. Compared with modern horizontal axis wind turbines, it has the following characteristics:

1) there is no need for an upwind mechanism

there is no problem of wind direction change in vertical axis wind turbines, so there is no need for an upwind mechanism. The horizontal axis wind turbine not only has to have an upwind mechanism, but also needs to move all wind turbines to the top of the tower, which is very inconvenient

2) simple and effective automatic aerodynamic layout

if the two wings of the aircraft are installed vertically on both sides, a vertical shaft wind turbine will be formed. Since the forces generated by the wind on the wings on both sides offset each other, the wind turbine will not start. At present, there are hundreds of design patents for vertical shaft wind turbines worldwide, including the use of additional airfoils and mechanical devices such as connecting rods and cams, which are quite complex and difficult to realize economically and effectively, with the exception of darrius vertical shaft wind turbines. But it will stop running when the wind blows, so it will not start by itself. Sandia National Laboratory of the U.S. Energy Agency specializes in the research and development of this kind of wind turbine. Existing products can compete with horizontal axis wind turbines, but they have not surpassed it

the swing wing vertical shaft wind turbine uses the aerodynamic principle to place the deflection axis of the wing in front of its aerodynamic center. Under the action of the wind, the wing automatically swings to the opposite side on both sides, thus generating torque in the same direction to drive the wind turbine to rotate together. Its structure is extremely simple. See Figure 1 for details

Fig. 1 function principle of swing wing vertical shaft wind turbine

Fig. 1 gives the top view of the wind turbine, and draws the vector diagram of velocity and aerodynamic force under the working state of the wings in the upwind and downwind positions. The wind comes from the left. When it is windward, the flow rate of the wing relative to the air flow is V1, and its action point, namely the aerodynamic center A1, is behind the deflection center, namely the fulcrum P1, so that the leading edge of the wing swings outward, and stops at the position shown by the positioning pin S1. The angle of attack at this time is α 1. The resultant force R1 of lift L1 and resistance D1 is generated correspondingly, and a driving torque f1r is generated on the vertical shaft of the wind turbine (R is the radius of the wind turbine); In the downwind, the aerodynamic force makes the leading edge of the wing swing inward and stop at the position of the locating pin S2. At this time, the angle of attack is α 2. The driving torque generated is f2r, which continues to drive the wind turbine to rotate

3) automatic unloading in case of extreme wind

the fins of the swing wing vertical shaft wind turbine can automatically follow the oar in case of catastrophic extreme wind, so that the angle of attack is zero, so that the load on the fins is almost completely relieved, and it will automatically recover after the strong wind. This makes the wind turbine's strength calculation wind speed drop from more than 50 meters/second to 25 meters/second, and the wind pressure is reduced by more than four times, so the whole wind turbine can be designed very lightweight, greatly reducing the cost. This is fully reflected in the weight of the wind turbine in Table 1

4) simple and effective constant speed device controlled by centrifugal force

the speed regulating device of swing wing vertical shaft wind turbine is very simple and effective. Because the locating pin when the wing deflects is controlled by centrifugal force, when the speed exceeds the quota, the locating pin moves inward to reduce the angle of attack, so as to reduce the driving torque and make the wind turbine return to the rated speed, and vice versa. The experimental results show that when the wind speed or load changes, the wind turbine speed remains constant. This is conducive to the setting of generator frequency

5) adopt pin gear speed increase

the speed of wind turbine itself is very low, and it must increase by more than ten times before it can be used to drive the generator, so the generator is extremely bulky and uneconomical. The cost of high transmission ratio speed-up gearbox is very expensive. Therefore, we use the pin gear drive to increase the speed and solve the problem at the first level. Using the roller body of the rolling bearing as the pin tooth is very cheap, which greatly reduces the price of the speed increasing mechanism. The mechanical efficiency of the pin gear group is poor, but this can be compensated by increasing the diameter of the wind turbine and the length of the wing. The cost of the latter is small, and the overall technical and economic indicators can be greatly improved

6) advanced process design

in product design, new processes such as cold processing of sheet metal, resistance welding, plastic, bonding, glass fiber reinforced plastics, etc. should be used as much as possible, so as to facilitate mass production, improve production efficiency, significantly reduce production costs, and try to ensure interchangeability, make maintenance and assembly convenient, so as to facilitate after-sales service

due to the above characteristics, the swing wing vertical shaft wind turbine has outstanding performance

popularizing wind energy to replace thermal power can greatly improve air pollution and mitigate the harm of climate warming, which is certainly a cause worth pursuing. The high economic benefits of swing wing vertical shaft wind turbines have turned the price law, which was originally a constraint, into a powerful driving force. Relying on the market, wind energy development can be popularized by itself, without a large amount of national investment. However, the guidance and support of the government is also very important. There are three aspects that need attention:

first, the large-scale promotion of small wind turbines as energy-saving devices

small and micro wind turbines can be widely promoted if they are adopted by families. Therefore, the overall capacity of developing and utilizing large-scale wind energy resources is very considerable. As an energy-saving measure, it is worthy of attention

the independent operation of small wind turbines has the problem of energy storage. This can be solved by battery, so that when there is no wind, electricity can be used, and when there is wind, electricity can be stored. Due to the high price, difficult maintenance and greatly increased power cost, the battery is not popular, which makes it difficult to popularize small-scale wind power and achieve the purpose of large-scale energy conservation. Now most villages in China have been electrified. In order to enable small wind turbines to hang up, so as to ensure power supply when there is no wind, basically every city has our machines. When there is wind, we can feed back the electric energy to the electricity for storage. In this way, the cost of electricity can be greatly reduced, which is welcomed by the majority of users, and this has no loss to the power plant. However, this technology urgently needs to solve the problem of electric energy feedback, which also increases the difficulty of electric control. But in order to save energy, it is worth trying. I hope the government can advocate and regulate it

the second is the problem of giant wind turbines

the giant wind turbine is originally connected with electricity, so there is no such problem. However, the supercomputer has yet to be developed. Even if it passes the test report of fire-resistant Class B1, we are ready to develop a 3kW minicomputer first, and then develop a 300kW supercomputer after gaining experience. This requires a certain amount of human and financial resources, but also the support of the government

the third is to cultivate a technical force

wind power generation is a highly comprehensive engineering technology, involving many disciplines such as aerodynamics, structural mechanics, aircraft manufacturing technology, mechanical manufacturing technology, electrical engineering and automatic control. Majors can be set up in qualified colleges and universities, only graduate students can be recruited, and a group of technical talents can be trained to further develop the engineering technology of wind power generation

references

1, "high tech windmill's future burns bright" r&d magazine, Aug. 1992, p38

2, "harnessingt2020 will reach 1.5 million tons of he wind" IEEE spectrum Nov.1995,p78. (end)