阅读说明：本技术 一种全阻流式微风风力机技术 (Full-choking breeze wind turbine technology ) 是由 郭鹏 于 2020-12-18 设计创作，主要内容包括：贝茨定律(Betz’ Law),是近代风力发电领域的基础理论,但贝茨定律在推导过程中存在一些谬误；谬误1：贝茨定律假设了“理想风轮”结构,但在理论推导过程中只考虑了气流对理想风轮的作用力,而未考虑理想风轮对气流的反作用力,这导致推导结果与客观事实不符；谬误2：基于伯努利定理可知,流管直径变小则流体流速增加,风力机叶片面积扩大等同于气流流管直径变小,因此风力机叶片面积越大则受叶轮影响的气流流速越快,而贝茨定律在推导过程中并未考虑到理想风轮对气流的流速、流向等造成的影响,因而推导出的结果与客观事实不符；因为上述谬误,本发明跳出贝茨定律范畴,基于“理想风轮”概念重新设计了一种全阻流式微风风力机技术。(Betz 'Law is a basic theory in the field of modern wind power generation, but Betz' Law has some spurious phenomena in the derivation process; spurious 1: the structure of an ideal wind wheel is assumed by Betz law, but only the acting force of the airflow on the ideal wind wheel is considered in the theoretical derivation process, and the reaction force of the ideal wind wheel on the airflow is not considered, so that the derivation result is inconsistent with objective facts; spurious 2: based on Bernoulli's theorem, the flow velocity of fluid is increased when the diameter of the flow pipe is reduced, and the enlargement of the area of the wind turbine blade is equal to the reduction of the diameter of the flow pipe of the airflow, so that the larger the area of the wind turbine blade is, the faster the flow velocity of the airflow influenced by the impeller is, and the influence of an ideal wind wheel on the flow velocity, the flow direction and the like of the airflow is not considered in the derivation process by the Betz's law, so that the derived result is inconsistent with objective facts; due to the above-mentioned spurious, the invention jumps out of the scope of the Betz law, and redesigns the technology of the full-choke type breeze wind turbine based on the concept of the ideal wind wheel.)

1. A full-choke breeze wind turbine technology is characterized in that:

the circular sheet is designed on the basis of an ideal wind wheel concept proposed by the Betz law, the circular sheet capable of completely blocking airflow in the range of the impeller is used as an impeller main body structure, the circular sheet is perpendicular to the incoming airflow of the wind direction, the windward side can completely block the incoming airflow in the range of the impeller, and secondary flow is generated on the windward side of the impeller;

the wind-facing surface of the impeller main body structure and the outer edge of the impeller are provided with a plurality of guide vanes, the guide vanes and the impeller main body form a hollow concave surface structure, and after incoming flow is captured by the concave surface structure, formed secondary flow is ejected from the gaps of the guide vanes to form jet flow, and the jet flow can make the impeller receive reaction force to drive the impeller to rotate;

the jet flow of the airflow ejected from the guide vane gaps wraps the air on the outer edge of the impeller away from the impeller under the action of centrifugal force to form a diffusion type wake flow field;

the impeller structure is equivalent to a flow tube structure, the windward side of the impeller structure is a flow tube inlet, the gap between the guide vanes is a flow tube outlet, the total area of the flow tube outlet is smaller than that of the flow tube inlet, and the flow velocity of fluid in the flow tube range can be improved by narrowing the flow tube based on Bernoulli's law, so that higher airflow velocity is obtained to push the guide vanes to displace, and the impeller is driven to rotate;

the wind turbine structure includes: the novel impeller structure comprises an impeller (100), a middle shaft (101), a truss (104), a tension structure (105), a skin (106), a pull rope (107) and a guide vane (206), wherein the truss (104) and the impeller (100) are integrated into an integral structure.

2. The technology of the wind turbine of the full-choke type breeze as claimed in claim 1, wherein the structure of the guide vane (206) is a variable angle vane structure, when the wind speed in the nature is low, the vane is perpendicular to the impeller, the vane gap is narrow, the airflow is extruded from the narrow gap, the faster flow velocity is obtained, and the wind energy utilization rate is high; when the wind speed is higher, the wing pieces are unfolded, the gaps of the wing pieces are increased, the airflow velocity is relatively reduced, the wind energy utilization rate is lower, and the impeller is protected from being destroyed by strong wind.

3. The technology of the wind turbine of the full-choke breeze according to claim 1, wherein the structure of the impeller (100) is a tension structure (105) which is composed of a truss (104), a skin (106) and a pull rope (107), the truss (104), the skin (106) and the pull rope (107) are made of elastic materials, the impeller structure is subjected to pressure-bearing deformation when the wind turbine encounters strong wind, and the impeller structure recovers after the strong wind.

4. The technique as claimed in claim 1, wherein when the guide vanes (206) are disposed at the outer edge of the impeller, the radius of the impeller substantially corresponds to a labor-saving lever structure, and the known low-speed wind energy is a low-density energy.

5. The technique as claimed in claim 1, wherein the guide vanes (206) are arranged in such a manner that the gap in the direction of the incoming airflow is wider and the gap in the direction of the outgoing airflow from the impeller is narrower, and the flow velocity of the airflow between the blade gaps is increased by the narrow tube effect after the airflow passes through the guide vane gaps.

6. The technology of the wind turbine of the full-choke type breeze, as claimed in claim 1, wherein the guide wing panel (206) is designed as a concave cambered structure, and based on the principle of the circular flow of the curved path, the guide wing panel with the concave cambered structure can absorb the energy of the airflow while changing the airflow direction.

7. The technology of a wind turbine with full choke flow of the type of the small breeze as claimed in claim 1, wherein the guide vanes (206) can be fixed on the outer edge of the impeller or can be relatively independent, and the relatively independent guide vanes can directly drive the device to do work.

Technical Field

The invention belongs to the subject of hydromechanics and the field of wind energy utilization, in particular to a technology of a full-choke type breeze wind turbine designed based on an ideal wind wheel concept proposed in the Betz theory; the invention relates to a technology which applies Bernoulli's theorem and lever effect, accelerates the flow of air current by utilizing the pressure difference resistance of the windward side and the leeward side of an impeller, and generates a diffusion type wake flow field behind an ideal wind wheel so as to drive the impeller to rotate and drive equipment to do work; the wind turbine refers to various related technologies for directly or indirectly utilizing wind energy, such as wind power generation, wind water lifting, wind power grinding, wind power driven water oxygenation, wind power driven compressors and the like.

Background

Wind energy is a green, environment-friendly and renewable new energy technology. In the world, almost all people have a wind power generator structure consisting of 3 elongated blades in mind as far as wind power generation is concerned. The wind power generator composed of 3 elongated blades is called a horizontal axis lifting wind power generator in academia, and the theoretical basis of the design of the wind power generator is derived from Betz' Law.

The betz theory is derived from several betz hypotheses, but it is found in research that the multiple hypotheses in the betz hypothesis do not conform to the objective natural law in the real environment, even contrary to the fact.

It is proposed in betz theory that the assumed ideal impeller structure of a wind turbine is an impeller structure consisting of infinite multiple blades, and this impeller structure is called an "ideal wind wheel". If the wind turbine wheel, which is assumed by Betz theory, is reduced in real-world environments and consists of countless blades, the resulting wheel is actually a solid disk. It is assumed in betz theory that this solid disc does not create resistance to wind (airflow) that passes through it and leaves a portion of the kinetic energy on the disc to drive it into rotation. This assumption clearly does not follow the objective natural laws in real world environments.

According to Newton's third law of motion, the force and reaction between two interacting objects are always equal in magnitude and opposite in direction, acting on the same line. If the ideal wind wheel and wind force (airflow) are considered as two objects, when the airflow exerts force on the impeller, the impeller also necessarily exerts a reaction force with opposite direction and equal force on the airflow. Obviously, the derivation process of the betz theory only considers the acting force of the airflow on the impeller and neglects the reaction force of the impeller on the airflow.

Refer to fig. 1 and 2;

FIG. 1 is a plot of the "ideal rotor" airflow field of a wind turbine in Betz's theory.

FIG. 2 is a diagram of a wind turbine impeller airflow field produced by simulating an "ideal wind wheel" structure in a real environment.

As can be seen from the comparison between fig. 1 and fig. 2, the ideal wind wheel flow field environment assumed by betz theory is quite different from the real "ideal wind wheel" flow field environment. The main difference is that the ideal wind wheel assumed by the Betz theory is in the range of a flow pipe taking the diameter of the impeller as a boundary, and the ideal wind wheel ignores the airflow field outside the range of the impeller. The range of the air flow which can be influenced by the ideal wind wheel in the real environment comprises 'two-part flow field in the impeller range and out of the impeller range'.

In fact, the research on the structure similar to an ideal wind wheel in the modern hydrodynamics field is very mature, but the related research results cannot be applied to the field of wind power generation. For example, the book by Wanghua Master, hydrodynamics I understand (ISBN/ISSN: 978-7-118-09847-1), the sixth section 6.7.1, section I, the viscous shear flow (page 169), discusses the behavior of ideal rotor-like structures in airflow (wind).

In a real environment, an ideal wind wheel is substantially equivalent to a circular flat plate which flows vertically. It can be known by analysis that the pressure at the center of the circular flat plate facing the fluid is equal to the total pressure of the incoming flow. After being stopped, the fluid can accelerate along the radial direction, the pressure is correspondingly reduced, the fluid bypasses the outer edge of the flat plate, is driven by the main flow outside the range of the flat plate and flows along the flow direction again. Based on the concept of "streamline pressure equality parallel to the line", the pressure of the fluid behind the plate is approximately equal to the pressure of the fluid just bypassing the plate, which is less than the static pressure of the incoming flow because the velocity of the fluid bypassing the plate is greater than the velocity of the flow. It can be seen that, for the plate, the head-on pressure is close to the total pressure of the incoming flow, and the back pressure is smaller than the static pressure of the incoming flow, so we can judge that the resistance acting on the plate should be slightly larger than the product of the dynamic pressure of the incoming flow and the area of the plate (experiments prove that the plate resistance in the flow is about 1.1 times of the value). This resistance caused by differential pressure is known as differential pressure resistance or form resistance in engineering terms. The specific flow field label can refer to the content shown in the 169 drawing in the book.

Fig. 3 is a view of the range of the gas flow tube assumed in betz theory (radial cross section of the gas flow field).

Fig. 4 is a range diagram of airflow flow pipes (radial section diagram of airflow field) of the range of influence of the ideal wind wheel structure on the airflow according to the real environment. The area indicated by the numeral 100 is an area within the range of the impeller (the range of an ideal wind wheel), the area indicated by the numeral 1 is an area within the range of an airflow field which is not affected by the impeller, and the area indicated by the numeral 2 is an area outside the range of the impeller and within the area of the airflow field which is affected by the impeller.

The flow field of the air flow in the range of the impeller and the flow field of the air flow outside the range of the impeller are included in the flow field structure shown.

In subsequent researches, the calculation result of the Betz theory in subsequent deduction and the real environment generate errors after the airflow field range is wrongly assumed. Particularly, after the ideal wind wheel assumed by the Betz theory is restored in a real environment, the value measured through experiments is different from the value deduced by the Betz theory.

The betz theory is derived based on the betz hypothesis, and when the betz hypothesis does not accord with the objective natural law, the conclusion derived from the hypothesis which does not accord with the objective natural law cannot necessarily obtain the correct result which accords with the objective real law.

Practice (experiment) is the only standard to check the truth. In the related literature search process, a search is carried out by taking a Betz theory experiment as a key word, and the derivation process of the experiment evidence Betz theory related to the Betz theory is hopefully found.

Unfortunately, only a great number of the derivation processes of the betz theory have been found by using a search engine since the betz theory was proposed to date for over a century, and relevant records or documents of ideal wind wheel concepts proposed by experimentally confirmed betz theory have not been found. That is, the Betz theory responsible for the abnormal-odor in the field of wind power generation has been a theory that has not been verified by a lot of experiments.

In recent years, with the development of wind energy utilization technology, the phyllodulin (BEM) theory has become a mainstream theory in the field of wind power generation.

The phylline (BEM) theory refers to the division of a wind turbine blade into many micro-segments in the spanwise direction. The blade theory simplifies the wind turbine blade into a finite number of blades which are formed by radially overlapping, so that the three-dimensional aerodynamic characteristics of the wind wheel can be obtained by radially integrating the aerodynamic characteristics of the blades. It can be seen from the above that, the core concept of the modern wind power generator is only aware of the influence of the airflow (wind) on the impeller, neglects the influence of the impeller on the airflow, and neglects the influence of the airflow outside the range of the impeller on the impeller.

The largest drawback of the wind power generator designed based on the betz theory is that the design has high requirements on the wind power environment. There is a large percentage of land areas in the world today with annual average wind speeds of no more than 5 meters per second, and even in many areas wind speeds of 3 meters per second 80% of the time of the year. Such areas are considered as unsuitable for the development of wind power generation technology. Experts have shown that the energy density of wind energy with a wind speed of 3 meters per second is too low to be of value. However, it can be found by calculation that wind energy, as well as solar energy, is a low-density energy source, and if the wind energy is effectively and reasonably utilized, great economic benefits can be brought.

It is known that the pressure difference resistance born by an impeller (an ideal wind wheel) can be obtained by the product of the dynamic pressure of wind incoming flow and the area of the impeller. It is known that at standard atmospheric pressure, the weight of air per cubic meter is about 1.29 kg. If the impeller surface area is 1 square meter, about 1.29 kg of air will pass through the impeller range per second when the wind speed is 1 meter per second. On the premise that the wind speed is unchanged, when the area of the impeller is increased to 2 square meters, 2.58 kilograms of air can pass through the impeller within the range of the impeller every second. By analogy, the larger the surface area of the impeller is, the faster the wind speed is, and the higher the kinetic energy which can be obtained by the impeller of the wind turbine is.

The table of figure 5 shows the total mass of air (in whole numbers during calculation) per second through the impeller at different wind speeds and different impeller diameters.

Knowing the flow velocity (wind speed), the fluid mass (1.29 kilograms per cubic meter), the resistance range (impeller surface area), and the total kinetic energy provided by the fluid (wind power) in the impeller range to the impeller by using a dynamic pressure calculation formula.

As can be seen from the table in fig. 5, taking an impeller with a diameter of 8 meters as an example, the circumference of the impeller is about 25 meters, and the area of the impeller is about 50 square meters (the area of a common large independent outdoor billboard is mostly 6 meters × 18 meters =108 square meters, and the area of the impeller with a diameter of 8 meters is only half of the area of the common large outdoor billboard). At a wind speed of 3 meters per second (2 winds), the total weight of air passing through the impeller per second is about 194 kilograms. The wind speed is 10 meters per second (5 wind), and the total weight of air passing through each second is about 647 kilograms. The kinetic energy of the airflow is enough to drive the wind turbine to work.

At the same time, too large an impeller is bound to face higher risks. Taking an 8-meter diameter rotor as an example, when the rotor is subjected to strong wind with the wind speed of 30 meters per second (11 grades of wind), the range of the rotor can bear 1942 kilograms of pressure per second. Therefore, the tower and the supporting structure of the wind turbine impeller structure also need to adopt completely new designs.

The present invention has been made in order to solve the above problems, and an object of the present invention is to provide a wind power generator which can efficiently use breeze and can enjoy free energy benefits from wind energy in a low wind speed region.

Disclosure of Invention

The traditional horizontal shaft lifting force type wind turbine has the problems of poor performance in a low wind speed environment and the like. In order to solve the problems, after the situation that the ideal wind wheel flow field assumed in the Betz theory is completely different from the ideal wind wheel flow field in the real environment is determined, the wind turbine impeller structure is redesigned based on the ideal wind wheel concept provided in the Betz theory.

In the betz theory, the number of blades of the "ideal wind wheel" is infinite, which means that the ideal wind wheel can completely block the airflow in the range of the impeller and change the airflow direction, so that the wind turbine developed by the concept of the "ideal wind wheel" can be called a "full-choked wind turbine". According to the betz theory, if the ideal wind wheel can utilize 100% of the kinetic energy generated by the airflow in the range of the impeller, the air losing the kinetic energy can be stagnated behind the impeller, and resistance is brought to the subsequent airflow. The above conclusion is drawn because the effect of the impeller on the wind flow is neglected by the betz theory, and the effect of the wind flow outside the range of the impeller on the wind turbine is neglected.

As shown in fig. 6, it is assumed that when the airflow encounters the impeller (ideal wind wheel), the kinetic energy of the airflow is completely absorbed by the impeller, and thus the airflow stagnates on the surface of the impeller. However, because the windward side and the leeward side of the impeller have pressure difference resistance, the windward side and the leeward side of the impeller have pressure difference. It is known that in natural environments, air flows spontaneously from a region of higher air pressure to a region of lower air pressure. Therefore, the air losing kinetic energy flows to the leeward side of the impeller spontaneously under the action of the pressure difference.

The relevant knowledge can be referred to in the book "hydrodynamics i understand, chapter six, section 6.7.1 (page 169) on flow resistance.

As shown in fig. 4, when the air losing kinetic energy flows out from the outer edge of the impeller, the position of the airflow is already shifted from the airflow range affected by the impeller to the airflow range not affected by the impeller (the area shown in the number 2). In the projection of the impeller boundary, the air losing kinetic energy leaves the impeller range, is mixed with the air outside the impeller range, is entrained by the air flow outside the impeller range which is not affected by the impeller (not absorbed by the kinetic energy of the impeller), and leaves the impeller range.

As shown in fig. 6, after leaving the impeller region, the air streams are mixed with the air streams outside the impeller region and leave the impeller region under the entrainment of the air streams outside the impeller region.

In betz theory, all "air flow" in the impeller region is considered to be ideal fluid, which is not affected by the impeller, and whose flow rate and direction are unchanged. This simplifies the equation calculation, but obviously does not conform to objective natural laws. As shown in fig. 6, when the airflow meets the impeller block, the flow direction and flow rate of the airflow will change inevitably. And it is clear that betz's theory neglects these changes and the consequences of these changes in the derivation process.

In the present invention, in order to describe more accurately the influence of the impeller (ideal wind wheel) on the airflow, the airflow is classified:

when wind energy (airflow) in natural environment is not influenced by the impeller and normally flows, the airflow is called as a type of airflow for convenience of description;

when one type of air stream impinges on the surface of the impeller, the air stream exerts an axial force on the impeller. Because the impeller is fixed on the tower, the axial static resultant force (also called structural strength) of the impeller is larger than the acting force of the airflow on the axial direction of the impeller, and therefore the impeller applies a continuous reacting force on the airflow impacting the impeller to cause the airflow to be stagnated. However, since the wind energy (airflow) is continuous, the subsequent airflow continuously applies an axial acting force to the front airflow, the impeller continuously applies a continuous reaction force to the airflow, the two forces extrude the airflow, so that the airflow flows from the surface of the impeller to the outer edge of the impeller (along the radial direction of the airflow), and the extruded airflow flows out from the outer edge of the impeller after passing through the impeller (ideal wind wheel) of the wind turbine. At this time, the airflow direction, the airflow velocity and the air density are all changed, and for convenience of description, the changed airflow is called as a second type of airflow in the invention;

when the second type of airflow leaves the range of the impeller and interferes with and mixes with the first type of airflow outside the range of the impeller to generate influence, the generated airflow is called as third type of airflow in the invention, and the third type of airflow generates a diffusion type wake flow field under the influence of the guide vanes.

According to experiments, in the working process of the wind turbine, certain differences exist in the airflow flow speed, airflow direction, air density and the like of the first type airflow, the second type airflow and the third type airflow, and if the completely different airflows are unreasonable in a general way like in the Betz theory, the operation is not scientific.

The impeller structure is characterized in that the larger the diameter of the impeller, the larger the circumference and the larger the area of the impeller. For example, the circumference of the impeller is about 3.1 m for an impeller diameter of 1 m, and about 6.3 m for an impeller diameter of 2 m. Thus, the class two air flow, which loses kinetic energy, escapes from outside the impeller range, effectively creating a larger diffusible space. At the same time, the centrifugal force of the impeller rotation also affects the dissipation of the airflow.

The flow velocity of the jet flow of the air flow ejected from the guide vane gap is high, and based on the bernoulli principle, the faster the flow velocity, the smaller the fluid pressure. Thus, the jet flow in the guide vane gap entrains air at the outer edge of the impeller to a region far away from the impeller, and the related principle is similar to that of a bladeless fan.

The traditional wind turbine structure is influenced by the Betz theory, and the guidance idea of the design takes 'no influence on air flow permeability' and 'improvement of tip speed ratio' as the center of gravity. The core concept of the invention is based on Newton's law of motion, Bernoulli's theorem and lever effect, and utilizes the interaction between the airflow and the impeller to convert the kinetic energy of the airflow in the area where the impeller is located (including the area inside the impeller and the area outside the impeller) into mechanical energy for driving the mechanical structure to do work.

In my hydrodynamics, chapter six, section 6.7.1 (page 177), the figure notes the drag coefficients of several typical configurations at common reynolds numbers. The resistance coefficient of a 'zero-thickness circular plate' similar to an ideal wind wheel structure is about 1.17 (which is consistent with the experimental result), but compared with the resistance coefficient of an inverted hemispherical shell structure, the resistance coefficient of the inverted hemispherical shell structure can reach 1.42. It can be seen that the anti-hemispherical shell structure can obtain a larger drag coefficient, which means that the wind energy utilization rate of the structure is higher. However, the anti-hemispherical shell structure cannot directly utilize wind energy, for example, a common cup-type anemometer adopts a plurality of anti-hemispherical shell structures to form an impeller, and if the cup-type anemometer is not guided by a correct theory, the cup-type anemometer cannot be developed continuously.

The relationship between an ideal wind wheel structure and wind energy utilization is cleared, and correct theoretical guidance is found, so that the truly feasible impeller structure of the breeze wind turbine can be designed.

Based on the theoretical derivation, the wind turbine provided by the invention is composed of an impeller structure similar to an ideal wind wheel and a plurality of guide vanes. The guide vanes can be placed on an ideal wind wheel impeller and can also be relatively independent.

The impeller structure similar to an ideal wind wheel can obstruct the flow routes of all air flows flowing through the impeller range, force one type of air flow in the impeller range to change the advancing route, improve the air flow velocity and generate two types of air flows.

The two types of air flow generated by the impeller do not directly provide kinetic energy to the impeller by itself. At the moment, a flow guide device is required to be additionally arranged on the windward side of the impeller and the outer edge of the impeller, and the airflow kinetic energy is obtained by changing the airflow path. In early researches, I obtain the kinetic energy of airflow by adding a diversion trench structure on the surface of an impeller and apply for a patent of a diversion type wind turbine blade structure (ZL 2018102308354).

In subsequent researches, I find that the ideal wind wheel concept proposed in the Betz theory does not conform to the objective natural law, and the residual wind speed of the impeller structure similar to the ideal wind wheel is observed to be zero for many times in experiments, so I apply for a patent of a horizontal axis wake flow diffusion type wind turbine technology (ZL 2019113146521).

Based on the above technology, after a large number of experiments, I find that the spiral involute diversion trench structure has some disadvantages in the real environment. Although spiral involute guiding gutter can effectively utilize class II air current, if be in weather environment such as sleet, heavy snow, hail, the inside snow problem that can appear of guiding gutter, this can increase the weight of impeller self by a wide margin, can cause a large amount of adverse effects to impeller focus, impeller structure etc. when the impeller is high-speed rotatory. Meanwhile, the spiral involute diversion trench arranged on the surface of the impeller has the problems of relatively high manufacturing cost, high requirement on the strength of the impeller, large weight increase of the impeller, high later maintenance difficulty and the like.

In order to solve the problems, the structure of the spiral involute guide groove is optimized into a plurality of deformable guide vanes, and the guide vanes are utilized to absorb the kinetic energy of the second type of airflow on the surface of an impeller (an ideal wind wheel). When the impeller is in rainy or snowy weather, the influence of the rainy or snowy weather on the impeller can be solved by utilizing the deformation function of the guide vanes.

More importantly, experiments show that if the guide vanes are arranged in a mode of surrounding the outer edge of the impeller and a certain gap is left between the guide vanes, and the total area of the gap is smaller than the total area of the windward side of the impeller, the second type of airflow can be accelerated based on Bernoulli's law.

As shown in fig. 7, in the three views of the wind turbine impeller, a plurality of guide vanes are arranged on the outer edge of an ideal wind wheel, and a plurality of gaps are arranged among the guide vanes, so that when the incoming flow of the windward side of the impeller enters the concave surface of the impeller, the airflow is extruded to flow out from the gaps of the guide vanes. Because the total area of the windward side of the wind wheel is larger than the gaps of the guide vanes, the flow velocity of the airflow flowing out of the gaps of the guide vanes can be increased according to Bernoulli's theorem.

Based on the concept of "boundary layer separation", in order to rapidly separate the air flow from the impeller, the region of the guide vane located behind the impeller needs to be extended by a certain length of auxiliary vane.

The airflow flowing out of the gap of the guide vane at high speed forms jet flow and gives a reaction force to the impeller to push the impeller to rotate.

The ideal wind wheel structure adopted by the invention has the advantages that:

firstly, compared with the traditional wind turbine, the airflow can be diffused from the outer edge of the impeller, and a diffusion type wake flow field is formed behind the impeller. The diffusion type wake field refers to a diffusion type wake field generated at the rear part of the impeller by the wind turbine structure. The Betz theory suggests that the reason why the wind energy utilization rate of the wind turbine cannot exceed 59.3% is because if the kinetic energy of the airflow absorbed by the impeller of the wind turbine exceeds 59.3%, the air is stagnated behind the impeller of the wind turbine, and resistance is caused to the subsequent airflow. However, the betz theory ignores the possibility that the airflow will bypass the impeller, and as shown in fig. 6, the airflow will bypass the impeller after being blocked by the impeller. As the air stream bypasses the region of the impeller, fluid that loses kinetic energy from within the region of the impeller may be entrained by a type of air stream outside the region of the impeller and thereby leave the region of the impeller. One type of air flow outside the range of the impeller shares the kinetic energy of the two types of air flow losing kinetic energy in the range of the impeller and forms three types of air flow. Therefore, the two types of airflow which lose the kinetic energy do not stagnate and do not cause resistance to the subsequent airflow.

Secondly, the center axis (101) of the wind turbine impeller is positioned at the center (circle center) of the impeller, and in the traditional wind turbine impeller structure (a small three-blade wind turbine impeller), airflow linearly passes through the impeller, and the generated kinetic energy cannot be concentrated (refer to a phyllotactic theory). The structure of the impeller of the wind turbine can cause all airflow in the range of the impeller to flow away from the outer edge of the impeller, and the impeller structure is actually a wheel shaft structure in terms of the structure. The known wheel axle is a lever system with an axle center as a fulcrum and a radius as a rod. Therefore, the wheel axle can change the torque of the torsion, thereby achieving the purpose of changing the size of the torsion. Therefore, the wind turbine impeller provided by the invention can be used for substantially amplifying the torque of low-speed wind energy.

Wind energy is essentially a large area, low density, range of energy sources. The impeller of the wind turbine in the real environment can receive the acting force applied to the impeller by wind power every second no matter how large the diameter of the impeller is, and every square centimeter in the range of the impeller. The traditional wind driven generator excessively pursues the rotating speed of an impeller, and pursues the tip speed ratio, so that the low rotating speed and the high torque are neglected, and the wind driven generator can be driven to work. For example, the mature wind water elevator technology uses a low-speed and high-torque wind impeller structure to work. The impeller structure (ideal wind wheel) of the invention concentrates the kinetic energy of the airflow in the impeller range, and amplifies the torque generated by the kinetic energy with low density by using the wheel shaft, thereby obtaining the power output with high torque and low rotating speed.

The wind turbine impeller structure can concentrate airflow in the impeller range to the outer edge of the impeller and improve the airflow velocity in the impeller range, thereby achieving the purpose of efficiently utilizing wind energy in the impeller range. According to experiments, the wind turbine provided by the invention has better performance in a low wind speed environment.

In the present invention, as set forth in claim 2, the angle of the guide vane is variable:

as shown in fig. 8, the guide vanes are at 90 degrees to the impeller when the wind speed is low. At the moment, the guide vanes are erected to change the impeller into an inwards concave container, and gaps exist among the guide vanes. The area of the gap is smaller than the total area of the windward side of the impeller, and the airflow velocity is increased based on Bernoulli's law.

As shown in fig. 9, when the wind speed is high, the guide vanes deform into a cambered surface structure under the influence of wind force, and the second type of air flow in the range of the impeller is concentrated on the outer edge of the impeller and is "squeezed out" from the gaps of the guide vanes to drive the impeller to rotate at a high speed. In the experiment, after the guide vane is deformed into an arc-shaped structure, the jet flow generated by the vane gap can bring larger torque for the impeller, and the specific test result shows that the impeller of the wind turbine has excellent performance at the moment.

As shown in fig. 10, when the wind speed is very high, the guide vanes are completely unfolded, gaps between the guide vanes are enlarged, and the excessive air flow can directly escape through the outer edge of the impeller. At the same time, the centrifugal force created by the high speed rotation of the impeller provides additional tension to the impeller structure. Like 'turning handkerchief' in acrobatic performance, the centrifugal force generated by the high-speed rotation of the impeller can bring extra support strength to the impeller and resist the influence of strong wind on the impeller of the wind turbine.

When the wind turbine impeller encounters rain and snow weather, the guide vane is actively unfolded, so that the problem that gaps of the guide vane exist in rain and snow accumulation is solved, and the problems that extra burden and gravity center shift are brought to the impeller by rain and snow are solved.

The deformation range of the guide vanes is not limited to a vertical deformation angle, and other angles can be adopted for deformation according to design requirements, and the main purpose of the guide vanes is to adjust the airflow direction through the deformation of the guide vanes, change the wind energy utilization rate of the impeller and automatically eliminate the influence on the impeller caused by rain and snow weather when necessary.

The deformation of the guide vane is not influenced by adopting different angles, appearances and modes.

Compared with the traditional horizontal shaft lifting type wind driven generator, the wind turbine impeller has larger volume, and the self weight of the impeller is inevitably increased if the wind driven generator impeller is made of rigid materials such as traditional glass fiber reinforced plastics, aluminum alloy and the like. In order to effectively reduce the self weight of the wind turbine impeller and improve the strength of the impeller, the wind turbine impeller adopts a tension integral structure design, and the wind turbine impeller structure is manufactured by utilizing structures such as a truss, a pull rope, a skin and the like.

The integral tension structure is a technology for supporting a three-dimensional space by using a support rod and a pull rope. The three-dimensional structure is characterized in that a truss is used as a supporting structure, and a pull rope and a skin are used for traction, so that the three-dimensional structure is formed. Common folding umbrellas are typically of a tensioned monolithic construction.

As shown in fig. 11, the windward side of the ideal wind wheel structure of the present invention adopts an integral tension structure, the central axis of the impeller and the truss are used as supports (the truss is fused with the impeller structure), and the traction rope is used to provide tension to ensure the stability of the integral structure of the impeller.

The larger the impeller area, the more the number of traction ropes needs to be, depending on the design requirements. The impeller is of a symmetrical structure, and the pressure borne by the windward side of the impeller can be decomposed by utilizing the traction rope. Based on the principle of conservation of angular momentum, the impeller rotates at high speed to play a role similar to a gyroscope, and the impeller is assisted to keep balance. Centrifugal force generated in the rotation process of the impeller provides extra tension for the impeller and resists the influence of strong wind on the impeller.

Although the umbrella-shaped wind turbine impeller designed by adopting the tension structure can resist the wind speed of 30 meters per second, if a hurricane of 50 meters per second is encountered, the wind turbine still has destructive effects. As mentioned above, the impeller structure of the present invention is composed of a truss, a rope, and a skin structure. As can be seen from the structure of the impeller of the wind turbine, the impeller of the wind turbine has a structure very similar to that of the folding umbrella. The structure of the middle shaft of the impeller of the wind turbine is similar to that of an umbrella handle of an umbrella, the truss of the wind turbine is similar to that of an umbrella frame of the umbrella, and the structure of the skin of the impeller of the wind turbine is similar to that of umbrella cloth of the umbrella. If one wants to protect against wind turbine damage in a hurricane, the structure described in the patent "a breeze wind turbine blade Structure (ZL 201510478505.3)" may be used. When a hurricane comes, the wind turbine skin is detached from the truss as described in the patent "a breeze wind turbine blade structure (ZL 201510478505.3)" and flies with the wind in a flag-like manner. After hurricane, the connection between the skin structure and the umbrella stand is restored, and the wind power is continuously and effectively utilized.

Noun interpretation

Impeller: the horizontal axis wind power generator is a mature wind energy utilization device and is characterized in that the horizontal axis wind power generator is of a wheel-shaped structure consisting of a plurality of blades. The impeller in the present invention was developed based on the hypothetical "ideal wind wheel" structure proposed in betz theory. As stated in betz theory, the blades of an ideal wind wheel are infinite in their impeller range, which is essentially a solid disk. The solid disc is preferably of a complete solid disc structure, but in consideration of technical construction difficulty, a disc structure consisting of a plurality of fins or an impeller structure consisting of a tension structure and a skin can be selected as necessary.

Wheel shaft: as the name implies, a system consisting of a "wheel" and an "axle". The system can rotate around a coaxial line, and is equivalent to a lever system taking an axis as a fulcrum and a radius as a rod. Therefore, the wheel axle can change the torque of the torsion, thereby achieving the purpose of changing the size of the torsion.

Front and rear of the impeller: the 'wind-facing' function is the basic function of modern wind turbines, and most of the current horizontal-axis wind turbines have the wind-facing function. In the field of wind turbines, when a horizontal shaft wind turbine works, airflow is perpendicular to a rotating plane of an impeller. At this time, the wind comes forward of the impeller. The direction deviating from the impeller is the rear part of the impeller after the wind power passes through or bypasses the impeller.

The rotation direction of the impeller: in the field of wind power generation, a mode that wind power drives an impeller to rotate and then the impeller drives a generator to generate power is often adopted. Most often the impeller rotates clockwise (or counterclockwise). In the rotation process of the impeller, the advancing direction of the blades is the front, and the reverse direction is the rear.

Axial and radial of the impeller: in the betz theory, the natural environment of the wind turbine is assumed to be an airflow pipe structure, and the diameter of the impeller is taken as the pipe diameter of the airflow pipe. However, in the present invention, it is found that the range of the flow field of the air flow that can be influenced by the impeller includes the range inside the impeller and the range outside the impeller, and thus the diameter of the flow tube is enlarged to "all the ranges of the air flow influenced by the impeller include the range inside the impeller and the range outside the impeller". Therefore, the axial direction and the radial direction of the flow pipe are the same as Betz theory. The flow tube of the present invention differs from the flow tube of the betz theory in whether the flow tube range contains the flow field of the gas flow outside the impeller range that is affected by the impeller.

Inside and outside the impeller: in the present invention, the impeller is a disc-like structure. The center point (circle center) of the disc-shaped structure is the center of the impeller, and the maximum circumference line of the impeller is the outer edge of the impeller.

Front and back of impeller: in the invention, the windward side of the impeller is the front side, and the leeward side of the impeller is the back side.

Blade head end and tail end: in the present invention, the impeller can be composed of several blades. The part close to the center of the impeller is the head end of the blade, and the part close to the outer edge of the impeller is the tail end of the blade.

And (3) airflow classification: in betz theory, the airflow over the impeller is considered a constant mean value, which is not scientific. In the present invention, the flow direction and the flow velocity of the air flow (wind power) within the range of the wind turbine cannot be generally known. Some areas have high airflow speed, some areas have low airflow speed, some areas have intersection with the plane of the impeller, and some areas have forward airflow along the surface of the impeller. For ease of description, airflow within the confines of a wind turbine is hereby generally classified;

referring to fig. 6: when wind energy (airflow) in the natural environment of the wind turbine is not influenced by the impeller and normally flows, the airflow is called a type of airflow (indicated by a numeral 1 in the figure) for convenience of description;

when one type of airflow impacts the surface of the impeller, the airflow exerts an acting force on the impeller, because the impeller is fixed on the tower, the strength of the impeller is higher than the acting force exerted by the airflow on the impeller, therefore, the impeller can apply a counterforce to the airflow impacting the impeller, and because the wind energy (airflow) is continuous, the subsequent airflow can apply an acting force to the front airflow, the impeller applies reaction force to the airflow, the two forces extrude the airflow in the previous stage, the airflow is caused to flow from the surface of the impeller to the outer edge of the impeller, after the extruded air flow passes through the spiral involute guide groove formed by the guide wing pieces, flows out from the blade gap or the blade outer edge, the airflow direction, the airflow speed and the air density are changed at the moment, for convenience of description, the modified airflow is referred to as a second type of airflow (indicated by numeral 2 in the figure);

when the two types of air flow interfere with, mix with and affect the one type of air flow, the resulting air flow (turbulent flow) is referred to as the three types of air flow in the present invention (indicated by numeral 3 in the figure).

Circulation of the curved road: the curve circulation principle, also known as curve circulation water and sand shunting principle, is commonly used for hydrological analysis of river curves. Air and water belong to Newtonian fluids, and most calculation formulas are communicated. When the fluid encounters a bend, the inertial force of the fluid itself is transferred to the wall of the bend forming the bend.

The narrow tube effect: the "narrow tube effect" is also called canyon effect, and like the wind in canyons is always stronger than plain wind, the wind force in narrow zones between high buildings in cities is also particularly strong, and disasters are easily caused. The throat effect tends to occur where the airflow passes from a wider area into a narrower area, which results in an increased airflow velocity and thus a higher airflow velocity. The throat effect belongs to a concrete expression example of Bernoulli's theorem.

Spiral involute diversion trench: in the early stage, the experiment shows that the wind energy utilization rate of the wind driven generator is obviously increased after the guide grooves are additionally arranged on the surface of the blade of the wind driven generator. The inventor therefore applies for a patent "flow-guiding wind turbine blade structure (ZL 2018102308354)". However, there is no perfect theoretical guidance at the time, so that the guide slots are only used as an attachment on the blades of the wind turbine. In subsequent research and development, the relation between the diversion trench technology and the air flow and the relation between the impeller and the flow field are further improved. In the invention, the early spiral involute diversion trench is optimized into a plurality of diversion fin structures with variable angles, and the problem that the gravity center of the impeller is shifted because rain and snow are easily accumulated in the spiral involute diversion trench in rainy and snowy weather is solved.

Flow guide fins: the 'ideal wind wheel' structure of the wind turbine is developed based on the ideal wind wheel concept proposed by the Betz hypothesis in the Betz theory. The ideal rotor is actually a solid disc that completely shields the air flow in the region of the impeller. This results in an ideal wind wheel in which the air flow can only bypass the impeller. To make efficient use of these flows, a number of guide vane structures are provided on the impeller. The guide wing plate obtains the self kinetic energy of the second type air flow by blocking the normal flow of the second type air flow and transfers the kinetic energy to the impeller structure so as to drive the impeller to rotate and further push the equipment to do work.

Secondary flow: in hydrodynamics, the concept of secondary flow is defined as follows: if the flow along a boundary is subjected to lateral pressure, causing a deflection parallel to the boundary, the fluid layer near the boundary will be deflected more than the fluid layer further from the boundary due to the lower velocity, which results in a secondary flow superimposed on the primary flow. Therefore, when the airflow directly impacts the surface of the impeller (ideal wind wheel), the airflow is blocked and stagnated by the impeller. But the gas losing kinetic energy continues to move and form a secondary flow due to the action of the subsequent gas flow and the reaction force of the impeller. As the impeller continues to rotate under the influence of wind and there is a pressure difference between the front and rear of the impeller, this causes these stagnant air streams to form secondary flows.

Stretching the integral structure: by tensegrity is meant a "self-supporting, self-stressing, spatial lattice structure of a set of continuous or discontinuous compression members and a set of continuous tension elements. Its characteristic is that it uses little material to support large-range space structure.

Drawings

The above and other objects and features of the present invention will become more apparent from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view of an air flow field assumed in the Betz theory, which can be seen in basic teaching materials on the Betz theory in all wind power generation fields;

FIG. 2 is a diagram of an airflow field after an air airflow meets an "ideal wind wheel" assumed by Betz theory in a real environment;

FIG. 3 is a cross-sectional view of a range of a flow tube assumed in Betz's theory, wherein a swept surface of the impeller is within the annular region, and the flow of air beyond the swept surface of the impeller is ignored during the derivation of Betz's theory;

fig. 4 is a sectional view of an airflow duct established based on "the range of airflows that can be affected" of an ideal wind wheel structure in a real environment, in which numeral 100 is an impeller (ideal wind wheel), numeral 2 is a class ii airflow, and numeral 1 is a class i airflow;

FIG. 5 is a table comparing impeller diameter with impeller surface area with total mass of air passing through the impeller in unit time, where the first row in the table is impeller diameter, the second row is impeller perimeter, the third row is impeller area, corresponding to different areas of the wind turbine impeller, and each column below corresponds to total mass of air passing through the impeller in units of kilograms per second;

fig. 6 is a flow field diagram measured based on an ideal wind wheel assumed by the betz theory in a real environment, and positions corresponding to various types of airflows are specified in detail in order to classify the airflows, where a numeral 1 represents a first type of airflow, a numeral 2 represents a second type of airflow, a numeral 3 represents a third type of airflow, a numeral 4 represents an air negative pressure region, and a numeral 100 represents an impeller;

fig. 7 is a three-view diagram of the structural model of the ideal wind wheel and the guide vanes in operation. The figure shows the specific structure of the impeller structure of the wind turbine in operation at different angles;

FIG. 8 is a cross-sectional flow field schematic view of a wind turbine impeller structure according to the present invention. In the figure, 100 denotes an impeller and 206 denotes guide vanes. The airflow is blocked by the impeller and concentrated towards the outer edge of the impeller, and then is extruded out from the gap of the guide vane to achieve the jet effect;

FIG. 9 is a cross-sectional view of the wind turbine impeller structure after the guide vane is deformed by wind force in the weather of high wind speed, and the guide vane is supported by an elastic material truss and deformed into a cambered surface by wind force. The second type of air flow flows along the inner edge of the cambered surface and is extruded out from the gaps of the guide vanes to form jet flow;

FIG. 10 is a cross-sectional view of the impeller structure of the wind turbine according to the present invention after the guide vanes are fully deployed when the wind speed is very high or when the wind turbine is rainy or snowy. After the impeller is unfolded, the gap between the guide vanes is increased, more airflow escapes from the gap between the guide vanes, the pressure born by the impeller of the wind turbine is reduced, and the impeller of the wind turbine is ensured to continue to work normally. When the wind turbine encounters extreme weather with extremely high wind speed such as hurricane and the like, the guide vane of the wind turbine impeller is completely unfolded, the wind turbine impeller yaws, the impeller is vertical to the wind direction, and airflow passes through the surface of the impeller and does not act on the surface of the impeller, so that the impeller can be protected from being damaged by strong wind;

FIG. 11 is a schematic view of a tensioned monolithic structure of a wind turbine blade wheel, wherein numeral 1 indicates a wind direction, numeral 100 indicates a blade wheel structure, numeral 101 indicates a center axis, numeral 107 indicates a pull rope, and numeral 206 indicates a guide vane;

fig. 12 is a schematic structural view of the wind turbine according to embodiment 1, in which numeral 1 is a wind direction, numeral 207 is a tower structure, and in the drawing, the impeller is disposed behind the tower, and the wind turbine automatically aligns wind by using the wind force, so that a wind aligning device is not required, the manufacturing cost is reduced, and the wind turbine is beneficial to popularization and use in a common household;

fig. 13 is a schematic structural diagram of the wind turbine according to embodiment 2, where numeral 1 is a wind direction, numeral 207 is a tower structure, and in the diagram, an impeller of the wind turbine is located in front of the tower, so that the tower does not obstruct airflow and the wind energy utilization rate of the wind turbine is affected.

The reference numbers illustrate:

a type 1 gas stream; 2, gas flow of the second type; 3, three types of airflow; 4 air negative pressure area; 100 impellers; 101 a central axis; 107 pull ropes; 206 guide vanes; 207 a tower;

the specific implementation mode is as follows:

specific example 1:

the wind turbine can be divided into an active wind turbine and a passive wind turbine according to design requirements. The active wind-aligning type wind turbine can utilize the motor to drive the impeller to actively search the wind direction to align the wind, and can also yaw the impeller when encountering strong wind to resist the strong wind. The passive wind-aligning wind turbine needs to adjust the direction of an impeller by wind power to align wind. The specific embodiment 1 is a passive convection wind turbine.

The wind turbine can be divided into a small wind turbine, a medium wind turbine, a large wind turbine and an ultra-large wind turbine according to the size of the impeller and the power. The wind turbine in the specific embodiment 1 is a small foldable wind turbine. The small foldable wind turbine has the advantage that the structure of the wind turbine impeller is similar to that of a folding umbrella. The wind turbine impeller is simple in structure and convenient to disassemble and assemble, and the wind turbine impeller can be folded in a folding mode like a folding umbrella structure, so that the wind turbine impeller is convenient to carry.

The wind turbine in the specific embodiment 1 adopts a wind turbine impeller with an impeller diameter of 2 meters, a guide vane width of 0.4 meter, an impeller circumference of 6.3 meters and an impeller surface area of about 3.1 square meters.

In the embodiment, the wind turbine is a small foldable wind turbine. The device is suitable for conditions such as self-driving camping, residents in coastal areas, greenhouse growers, tops of high-rise buildings, herdsman tent families and the like. For example, in the camping process, the foldable characteristic of the wind turbine can be utilized to support a wind turbine to provide power supply for the camp when the camping camp is constructed.

As can be seen from the table of FIG. 5, the wind turbine impeller of embodiment 1 has a mass of about 12 kg per second of airflow passing through the impeller at a wind speed of 3 meters per second (2-level wind). At wind speeds of up to 10 meters per second (5-level winds), the mass of air passing through the impeller per second is about 40 kilograms. At wind speeds of up to 30 meters per second (11 wind), the mass of air passing through the impeller per second is about 120 kg.

Therefore, as long as the wind turbine of the embodiment can start to work at the wind speed of 3 meters per second, the wind turbine still cannot be destroyed by strong wind at the wind speed of 30 meters per second, and the basic requirements of users can be met.

According to the actual measured data, the following steps are carried out:

under the natural environment with the wind speed of 3 meters per second (2-level wind), the rotating speed of the impeller is about 30 revolutions per minute;

under the natural environment of wind speed of 5 meters per second (4-level wind), the rotating speed of the impeller is about 50-80 revolutions per minute;

it is known that an impeller with a diameter of 2 meters and a radius of about 1 meter (1000 mm), an impeller center shaft with a diameter of 20 mm and a radius of 10 mm, has a torque amplification of about 100 times.

A speed change gear box with the ratio of 1:28.2 is additionally arranged behind the impeller to accelerate the rotating speed of the impeller of the wind turbine, so that the rotating speed of about 800-2200 revolutions per minute can be ensured while the sufficient torque output is ensured. A customized 3000W coreless disk type generator is arranged behind the gearbox, and can output electric energy for a long time. The storage battery pack is utilized to store the unstable electric energy of the wind turbine, and the energy is provided for the electric appliance through rectification and inversion.

In the specific experiment process, the height of the experimental tower is 2 meters, the distance between the axis of the impeller and the ground is 1.8 meters, a carbon fiber rod (made of high-strength fishing rod) is used as an impeller truss, and reinforced canvas is used as a skin of the wind turbine, so that the wind turbine impeller structure can be completed.

FIG. 12 is a sectional view of a wind turbine blade according to embodiment 1.

Specific example 2:

the specific embodiment 2 is an active wind-facing type wind turbine, and the wind-facing operation is performed by controlling the angle of the wind turbine by a motor.

In the specific embodiment 2, the design that the diameter of the impeller is 8 meters, the width of the guide vane is 1.6 meters, the circumference of the impeller is 25 meters, and the area of the impeller is about 50 square meters is adopted.

As can be seen from the table of FIG. 5, the mass of the airflow passing through the impeller per second in the range of the impeller of the wind turbine in embodiment 2 is about 194 kg at a wind speed of 3 meters per second (2-class wind). At wind speeds of up to 10 meters per second (5-grade wind), the mass of air passing through the impeller per second is about 647 kilograms. At wind speeds of up to 30 meters per second (11 wind grades), the mass of air passing through the impeller per second is about 1942 kg.

The known large-scale independent outdoor billboard has the area which is mostly 6 meters multiplied by 18 meters =108 square meters, the area of the impeller with the diameter of 8 meters is only half of the area of the common large-scale outdoor billboard, and the known large-scale outdoor billboard can survive under most natural wind conditions, so that the conclusion can be drawn that the impeller structure of the wind turbine in the specific embodiment has the same area and can also work for a long time under the natural wind conditions.

As shown in fig. 13, the wind turbine structure uses the wind alignment device to align the wind automatically on the windward side of the impeller, thereby effectively utilizing the wind energy. When meeting hurricane weather, the wind device automatically drifts, and hurricane damage to the wind machine is prevented.

Specific example 3:

the technique as claimed in claim 7, wherein the guide vanes (206) are fixed to the outer edge of the impeller or are relatively independent, and the relatively independent guide vanes can directly drive the device to do work.

In this embodiment, the guide vanes are relatively independent from the impeller (the ideal wind wheel shown in fig. 6). The impeller blocks the airflow to form the second type of airflow, the second type of airflow spreads to the outer edge of the impeller along the surface of the impeller, and the flow speed is increased.

A structure similar to a bearing is arranged on the outer edge of the impeller, and the bearing structure is divided into a bearing inner ring and a bearing outer ring.

The outer edge of the impeller is fixed with the inner ring of the bearing, and the guide vanes are fixed on the outer ring of the bearing. At the moment, the second type of airflow pushes the guide vanes to drive the bearing outer ring to rotate, and the bearing inner ring (impeller) is relatively static.

The outer ring of the bearing is provided with an annular rack (track), and the impeller is provided with one or more than one generator. The generator and the annular rack (track) are meshed by a gear.

When the second type of airflow pushes the guide vanes, the guide vanes drive the outer ring of the bearing to rotate. The bearing outer ring drives the annular rack (track) to rotate, and the annular rack drives the gear, so that the generator is driven to do work. At this time, the bearing inner ring (impeller) is relatively static.

Compared with the specific embodiment 2, the wind turbine structure is suitable for large wind turbine structures.

With the increase of the diameter of the impeller, the self weight of the impeller is greatly increased, and if the technical scheme that the impeller of the specific embodiment 2 rotates integrally is continuously adopted, a large amount of extra burden is caused on the impeller, and huge frictional resistance is brought to the middle shaft (101).

In the embodiment, the guide vanes are relatively independent, and the second type of air flow drives the guide vanes to rotate, so that the outer ring of the bearing is driven to move rapidly, the mechanical structure is driven to do work, and the pressure on the middle shaft is greatly reduced. Meanwhile, in the technical scheme, the impeller does not need to rotate, so that a more stable technical solution can be adopted for the connection mode of the impeller and the tower. For example, a technical solution similar to a tower crane or a radar is adopted.

When a large-sized or ultra-large-sized wind turbine needs to be designed, the embodiment is superior to the embodiment 2 in the aspects of practicability, implementation difficulty of technical schemes and the like.

Although the embodiments of the present invention have been described in detail above, those skilled in the art may make various modifications and alterations to the embodiments of the present invention without departing from the spirit and scope of the present invention. It will be understood that modifications and variations may occur to those skilled in the art, which modifications and variations may be within the spirit and scope of the present invention as defined by the appended claims.