A wind turbine that fully absorbs random wind energy

Abstract

The present invention discloses a wind turbine that fully absorbs random wind energy, and belongs to the technical field of wind turbines. The wind turbine includes vertically mounted blades and a rotating shaft, a torsion spring, a limiting device, a fixing device, and a tower. The blades and the rotating shaft of the system disclosed in the present invention are designed to be vertically mounted; the bottom of the rotating shaft is flexibly connected to the generator shaft, and the two are fixed in the fixing device. One or more torsion springs are used to elastically connect the fixing device and the wind turbine tower to form an elastic tower. Under the action of pulsating wind, the rotating wind turbine generates a pulsating lateral force; the lateral force pushes the torsion spring to deflect, and makes full use of the pulsation of the wind to store and release angular energy, so that the wind turbine as a whole is in a dynamic equilibrium state with a small vibration with the wind direction, thereby improving the inflow wind condition of the wind turbine.

Description

Technical Field

[0001] The invention relates to wind power generation technology, in particular to a wind turbine capable of fully absorbing random wind energy, belonging to the technical field of wind turbines. Background Art

[0002] As environmental issues become increasingly prominent, people are paying more and more attention to the use of renewable energy. Among them, wind energy resources are abundant, widely distributed, and pollution-free, and wind power generation has become an important way to achieve this. In recent years, the installed capacity of wind power has grown rapidly. As of the end of 2020, the cumulative installed capacity of wind power in my country has reached 281.72GW. By 2030, the total installed capacity of wind power and solar power generation will reach more than 1.2 billion kilowatts. The wind power industry has a good development prospect.

[0003] However, wind is random, which is manifested in the fact that wind speed fluctuates and wind direction fluctuates from left to right. For conventional wind turbine units, wind energy is mainly captured by blade rotation. Due to the heavy weight of wind turbine blades and other reasons, it is difficult to sensitively sense the randomness of wind speed changes, so it is particularly difficult to capture the wind energy generated by sudden high wind speeds. During the rotation of the wind turbine, the wind turbine overcomes the damping magnetic resistance of the generator and rotates, and the wind turbine dynamic torque and magnetic resistance are balanced; but when the wind speed suddenly decreases, the balance is quickly broken, the speed decreases, and the wind energy utilization rate decreases. The overall performance is: wind turbine energy capture is not sensitive to sudden increases in wind speed pulsation, but is more sensitive to sudden decreases. However, the heavier the blade weight, the less obvious the sensitivity to sudden increases; although the sensitivity to sudden decreases in speed is also decreasing due to the influence of kinetic energy, the total cost increases significantly due to the increase in mass. Increasing the weight of the blade is opposite to the direction of blade design. The blade design should minimize the weight under the condition that the structural reliability is met.

[0004] Conventional horizontal-axis wind turbines basically ignore the change in wind speed when the wind direction fluctuates left and right. Although horizontal-axis wind turbines have yaw devices, they are mainly used for long-term wind direction changes; instantaneous left and right fluctuations directly cause conventional horizontal-axis wind turbines to always have a yaw angle, which has a great impact on this type of wind turbine, equivalent to the wind turbine always being in a state of not facing the wind, the swept area is reduced, and the efficiency will decrease. Currently, the market mainly has horizontal-axis wind turbines. Vertical-axis wind turbines are not restricted by wind direction and can absorb wind energy from any wind direction.

[0005] In terms of overall pulsating wind, conventional horizontal-axis wind turbines can neither effectively sense changes in wind speed nor adjust the yaw angle in time to absorb wind energy; although conventional vertical-axis wind turbines are not restricted by wind direction, they cannot quickly sense wind direction.

[0006] Based on the above analysis, the present invention is based on the principles of aerodynamics and structural mechanics, and designs a wind power generation device that can automatically respond to wind and fully absorb the high wind energy of pulsating wind. When the wind speed changes and the wind direction changes, the device can use this method to store high wind speed wind energy and release angular energy at low wind speeds, thereby achieving the purpose of utilizing pulsating wind energy. Summary of the invention

[0007] The purpose of the present invention is to address the deficiencies of the above-mentioned background technology and to provide a wind turbine that fully absorbs random wind energy, fully utilizes the high wind energy brought by the sudden increase in pulsating wind speed, and at the same time increases the wind energy capture rate when the wind speed suddenly decreases. It can also sense the pulsating wind of any wind direction during the entire wind energy absorption process, thereby solving the technical problem that the existing wind turbines cannot effectively utilize the pulsating wind.

[0008] The present invention adopts the following technical solutions to achieve the above-mentioned invention object:

[0009] A wind turbine that fully absorbs random wind energy includes: blades, support wings, a main shaft, a torsion spring, a limit device, a generator, a fixing device, and a tower. The blades are installed vertically to the main shaft, and the support wings are used to connect the blades to the main shaft. The blades are vertically installed on the main shaft through the support wings to form a wind energy capture device; the blades are designed with an airfoil, and the chord of the airfoil is perpendicular to the length direction of the support wings; the main shaft is connected to the output shaft of the generator through an elastic coupling, the bottom end of the main shaft is rigidly fixed in the fixing device, and the fixing device is connected to the tower.

[0010] Furthermore, the number of blades usually used is 3 to 5 or more, and the ratio of the product of the blade chord length and the number of blades to twice the length of the supporting wing is greater than 0.5 and less than 1.

[0011] Furthermore, a torsion spring is used to connect the bottom of the fixing device and the top of the tower, one end of the torsion spring is connected to the bottom of the fixing device, and the other end is fixedly connected to the top of the tower; a limiting device is provided inside the torsion spring to limit its maximum deflection angle.

[0012] Furthermore, the elastic force of the torsion spring satisfies the requirement that the flow thrust generated by the wind wheel at a pulsating wind speed above the local average wind speed can cause it to deform. The torsion spring can also be replaced by other hollow elastic materials, which also meet the requirement that elastic deformation occurs at a wind speed greater than the starting wind speed, and a deformation limit device can be installed inside.

[0013] Taking into account the relationship between the force-bearing area of ​​the blade and its wind-catching capacity, the angle at which the torsion spring drives the fan as a whole to shake shall not be greater than 10°. While ensuring that the force-bearing area is not affected, the wind speed passing through the blade is increased, thereby improving the wind energy utilization rate of the blade and the working efficiency of the fan.

[0014] Furthermore, the torsion spring can be replaced by a plurality of small torsion springs or flexible hollow pipes installed in parallel. Accordingly, a limiting device is installed in each small torsion spring or flexible hollow pipe, and the overall requirement is that the minimum deflection force of each small torsion spring or flexible hollow pipe is equal to the minimum lateral force generated by the rotation of the blades under the local average wind speed.

[0015] In order to ensure that the wind turbine can always be in a dynamic balance state of "elastic vibration" during operation, the torsion spring has strong rigidity and is fixed between the tower and the base through a fixing device. The length is about 10% of the tower height. The center lines of the fixing device, limit device, torsion spring and tower coincide with each other to achieve better control and vibration.

[0016] The torsion spring can store and release angular energy. It is fixed between the tower and the fixing device, so that the entire energy conversion part on the upper part of the spring and the tower form a flexible connection. The rotating blades generate lateral force in the flow direction under the action of wind. This lateral force pushes the entire blade part on the upper part of the spring to tilt with the wind direction.

[0017] Under pulsating wind conditions, the wind speed fluctuates, and the lateral force on the entire power generation device also fluctuates. Under the action of the pulsating lateral force, the torsion spring continuously swings back and forth in the lateral direction.

[0018] When the wind direction changes, the vertically installed blades are not restricted by the wind direction. After the blades are installed, they rotate in one direction and can receive the pulsating lateral force of the flow direction generated by the pulsating wind in any direction to change the swing direction.

[0019] The continuous swinging process is a process of energy storage and energy release. The energy storage process is: under the high wind speed of the pulsating wind, the rotating blades react slightly, the speed increases slightly, and the captured energy also increases slightly, but the wind energy of the high wind speed cannot be completely captured. The excess energy is stored by pushing the spring and changing into spring elastic force; when the pulsating wind is at a low wind speed, the rotating blades should reduce the speed quickly under the "brake" effect of the motor magnetic resistance; but at this time, the spring rebounds and releases energy due to the reduction of the lateral force, and the rotating blades move in the opposite direction of the wind direction as a whole, generating additional wind speed, which increases the wind speed entering the rotating blades at low wind speeds. Therefore, the rotating blades will not reduce the captured energy due to the reduction of the pulsating wind speed, and the pulsating wind energy can be captured.

[0020] The blades adopt a large chord length design and a multi-blade design, with more than 3 to 5 blades. The ratio of the product of the blade chord length and the number of blades to twice the length of the support wing is greater than 0.5 and less than 1. Because the large chord length and multi-blade design make the blades easier to start, the lateral force generated is greater and it is more sensitive to changes in pulsating wind speed.

[0021] The torsion spring will also cause the blade swept area to change during the swing process, mainly the change of the blade height projection. The energy output of the blade is proportional to the cube of the wind speed and is proportional to the blade height. Therefore, considering the advantages and disadvantages of reduced swept area and increased wind speed, the maximum swing amplitude is designed to be 10°, and the maximum angle is limited by the limit device.

[0022] The torsion spring responds differently to the duration and size of the pulsating wind speed. Rapid changes in wind speed will cause the spring to quickly store and release energy. If the pulsating wind speed changes slowly, the torsion spring will change smoothly and have less impact on the overall situation.

[0023] The implementation of the elastic device enables the wind turbine to always be in a dynamic equilibrium state of "micro-elastic vibration" during operation, converting the pulsating wind energy, maximizing the collection and utilization of wind energy by the blades, and achieving better wind energy utilization.

[0024] The present invention adopts the above technical solution and has the following beneficial effects:

[0025] (1) Absorb and store pulsating wind and high-speed wind energy. Under high wind speeds, the overall structure of the wind turbine is subjected to a large wind load, but the mass of the blades causes inertia. Although the speed increases, it is difficult to immediately increase it to the required speed to absorb the excess wind energy. At this time, under the action of the elastic device, the blade part tilts slightly, and the elastic device stores excess energy.

[0026] (2) The energy stored under low wind speed is released, and the wind turbine continues to output high energy. If there is no torsion spring, when the wind speed decreases, the torque generated by the wind turbine decreases, and the magnetic resistance of the motor will quickly reduce the speed. In the present invention, the torsion spring rebounds, pulling the wind turbine back to its original position or even tilting it in the opposite direction, generating additional wind speed, increasing the wind speed of the blades, and improving the work capacity of the blades.

[0027] (3) The present invention enhances the smoothness of the wind turbine output, reduces the fluctuation of the wind turbine output curve, and achieves a more stable power output.

[0028] (4) Before starting, the wind energy capture device does not reduce the wind sweeping area, which is conducive to starting; after starting, it absorbs the pulsating wind energy and outputs electrical energy steadily. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the three-dimensional structure of the wind turbine of the present invention.

[0030] Figure 2 It is a cross-sectional view of a wind turbine blade according to the present invention.

[0031] Figure 3 (a) is a high wind speed marked diagram, and Figure 3 (b) is a horizontal force analysis diagram of the overall structure of the wind turbine under high wind speed shown in Figure 3 (a).

[0032] Figure 4 (a) is a small wind speed marked diagram, and Figure 4 (b) is a horizontal force analysis diagram of the overall structure of the wind turbine under small wind speed shown in Figure 4 (a).

[0033] Figure 5 Pulsating wind speed v , schematic diagrams of output curves of a conventional wind turbine and the wind turbine of the present invention.

[0034] Figure 6 This is a schematic diagram of a wind turbine vibrating at a certain angle with multiple degrees of freedom.

[0035] Explanation of the numbers in the figure: 1. blade, 2. support wing, 3. main shaft assembly, 4. generator, 5. fixing device, 6. torsion spring, 7. limit device, 8. tower. DETAILED DESCRIPTION

[0036] The technical solution of the invention is described in detail below with reference to the accompanying drawings.

[0037] like Figure 1 As shown, the wind turbine of the present invention comprises: vertically mounted blades 1, support wings 2, main shaft 3, generator 4, fixing device 5, torsion spring 6, limit device 7 and tower 8; before starting the wind speed, the wind flows through the blades 1, the lateral force is small, which is smaller than the designed elastic force of the torsion spring 6, and the torsion spring 6 does not deform; at this time, the maximum wind sweeping area of ​​the blades is also met, which is convenient for starting.

[0038] like Figure 2 As shown in the figure, the airfoil design adopted by the blade generates tangential force under the condition of wind flow, driving the blade to rotate. After the starting wind speed, the blade rotates and forms a cylindrical shape. The lateral force increases and is greater than the elastic force of the torsion spring. The torsion spring is slightly deformed and slightly deflected in the flow direction.

[0039] As shown in Figure 3 (a) and Figure 3 (b), under high wind speed, the wind turbine is subjected to a large wind load as a whole, and the lateral force on the overall structure of the wind turbine is F Greater than the spring torque N , the fan as a whole produces a certain inclination to store excess energy.

[0040] As shown in Figure 4 (a) and Figure 4 (b), as the wind speed decreases, the wind load on the wind turbine decreases, and the lateral force F Smaller, spring torsional force N Greater than lateral force F The torsion spring pulls the fan back to its original position or even shakes it in the opposite direction, releasing energy and generating torque or rotational force, which increases the relative speed of the blades. The actual wind energy captured by the blades increases, the working capacity of the blades is improved, and the utilization rate of wind energy is improved.

[0041] like Figure 5 As shown, they are the pulsating wind speed v (size and direction are uncertain), schematic diagram of the output curve of an ordinary wind turbine and the wind turbine of the present invention. Because the wind turbine continues to increase with the wind speed, the rotation speed fails to increase in time to capture more wind energy, and some energy will not be fully utilized. Under the action of the elastic device of the present system, when the wind speed gradually decreases from the highest point, the elastic device begins to continuously release energy, continuously adding an additional speed to the wind turbine, increasing the rotation speed of the wind turbine, greatly improving the utilization rate of wind energy by the wind turbine, and enhancing the smooth output characteristics of the wind turbine, among which the improvement is most obvious and effective at the lowest wind speed. Comparing the output curves before and after the installation of the elastic device, the output curve of the wind turbine of the present invention is relatively flatter, and the difference between the maximum output and the minimum output is reduced, which greatly improves the working efficiency of the wind turbine.

[0042] like Figure 6 As shown in the figure, in the process of continuous increase and decrease of the fluctuating wind speed, the process of lateral force change and decrease in Figure 3 (a) and Figure 4 (a) will be repeated. In strong winds, the wind turbine increases slightly, and the torsion spring deforms to store the excess wind energy that is not absorbed; in weak winds, the torsion spring rebounds to release energy, generating additional wind speed, and the actual wind speed entering the wind turbine increases, and the wind turbine continues to accelerate or does not decelerate. This process continues in the next fluctuation of the fluctuating wind.

[0043] like Figure 6 As shown, it is the fan torsion angle θ Schematic diagram of the overall structure of the fan after the torsion spring is turned on. During the swinging process, the torsion spring will also cause the blade swept area to change, mainly the change of the blade height projection. The energy output of the blade is proportional to the cube of the wind speed and is proportional to the blade height. Taking into account the mutual influence of the blade force area and the wind catching ability, the angle at which the torsion spring drives the overall structure of the fan to produce a small swing should be controlled within 10°, that is, under the premise of ensuring that the force area is not greatly affected to the greatest extent, the wind speed flowing through the blade is increased through the small vibration of the fan with multiple degrees of freedom, thereby improving the wind energy utilization rate of the blade and the working efficiency of the fan.

[0044] The torsion spring responds differently to the duration and magnitude of the pulsating wind speed. The faster the wind speed fluctuates, the faster the spring swings, and the greater the additional wind speed generated.

[0045] It can be seen that under the action of the elastic device, the wind turbine tilts slightly as a whole to store energy at high wind speeds; at low wind speeds, the wind load decreases, the device releases energy, the wind turbine as a whole swings in the opposite direction, the wind speed of the wind turbine inflow increases, and high-energy power generation continues. Under the action of wind pulsation, the elastic device vibrates repeatedly at a fixed value, and the wind turbine is always in a state of multi-degree-of-freedom small-amplitude vibration, continuously storing and releasing energy, thereby capturing pulsating wind energy.

[0046] In summary, under the condition that the wind turbine operating conditions are relatively complex, the wind turbine of the present invention fully utilizes the pulsation of the incoming wind, so that the overall structure of the wind turbine is always in a dynamic micro-vibration balance, and fully absorbs wind energy.

Claims

1. A wind turbine that fully absorbs random wind energy, characterized in that: include: At least three vertically mounted blades, at least three supporting wings, a main shaft, a generator, a fixing device, a torsion spring and a tower, wherein the bottom of the tower is fixed on the ground, the top of the tower is connected to one end of the torsion spring, the other end of the torsion spring is connected to the bottom of the fixing device, the bottom end of the main shaft is fixed in the fixing device, the output shaft of the generator is flexibly connected to the main shaft, each vertically mounted blade is installed on the main shaft at equal intervals through a supporting wing, a limiting device is installed in the torsion spring, and the limiting device limits the maximum deflection angle of the torsion spring to be less than or equal to 10°; the torsion spring is replaced by a plurality of small torsion springs or flexible hollow pipes installed in parallel, one end of each small torsion spring or flexible hollow pipe is connected to the top of the tower, the other end of each small torsion spring or flexible hollow pipe is connected to the bottom of the fixing device, a limiting device is installed in each small torsion spring or flexible hollow pipe, and the minimum deflection force of each small torsion spring or flexible hollow pipe is equal to the minimum lateral force generated by the rotation of the wind turbine under the local average wind speed; Under high-speed pulsating wind, the blades rotate to capture high-speed wind energy, and the high-speed wind energy not captured by the rotating blades pushes the torsion spring to convert it into spring force; under low wind speed of pulsating wind, the torsion spring rebounds to release energy, and the rotating blades as a whole move in the opposite direction of the wind direction to generate additional wind speed.

2. A wind turbine that fully absorbs random wind energy according to claim 1, characterized in that: The length of the torsion spring is 10% of the height of the tower, and the center lines of the fixing device, the limiting device, the torsion spring and the tower coincide with each other.

3. A wind turbine that fully absorbs random wind energy according to claim 1, characterized in that: The minimum deflection force of the torsion spring is greater than or equal to the lateral force generated by the rotation of the blades at the local average wind speed.

4. A wind turbine for fully absorbing random wind energy according to claim 1, characterized in that: The length of the vertically mounted blades satisfies the relationship between the lateral force generated by rotation and the minimum deflection force at the local average wind speed.

5. A wind turbine that fully absorbs random wind energy according to claim 1, characterized in that: The number of vertically mounted blades is 3 to 5, and the ratio of the product of the blade chord length and the number of blades to twice the length of the supporting wing is greater than 0.5 and less than 1.

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