Aerial mooring system

Abstract

The invention relates to an aerial mooring system which comprises a rotor, a main shaft and a driving unit. The rotor has buoyancy, the buoyancy can balance the dead weight of the system, and the rotor can freely rotate around the main shaft under stress; the two ends of the main shaft are symmetrically connected to a high-altitude acting module, and the driving unit is used for adjusting the rotating speed and / or the rotating direction of the rotor; and the total counter weight of the rotor and the driving unit is symmetrically distributed on the main shaft. According to the scheme, the Magnus effect serves as the principle, any needed lift force can be obtained by adjusting the rotating speed and / or the rotating direction of the rotor, the lift force, the lift-drag ratio and the traction angle of the air mooring system can be flexibly controlled, and the air mooring system is not limited by the altitude. Compared with traditional mooring systems such as helium balloons, the situation that the lift-drag ratio is reduced due to the increase of the altitude or the increase of the wind speed is avoided, and the situation that the traction angle cannot be controlled is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of high-altitude wind energy utilization, and in particular to an aerial mooring system. Background Art

[0002] High-altitude wind energy contains huge energy. Compared with conventional wind power generation, using high-altitude wind energy to do work can obtain more stable and lower-cost electricity. Working sails / working parachutes are commonly used aerial working systems that use high-altitude wind energy. During use, a tethered system is usually required as a lift guide to bring it to the required altitude before starting work. The setting of the tethered system is extremely critical to the stable launch and continuous work of the aerial working system.

[0003] CN101852178A discloses a high-power umbrella-type wind power generation system, in which a kite or a helium balloon is used as a mooring system to lift the balance parachute and the working parachute group to a suitable height, and then each working parachute group is deployed against the wind to do work or play a corresponding purpose. CN111114737A discloses a hybrid lift high-altitude mooring system, including an aerostat, a lift wing, a mooring cable, and a mooring cable retracting device fixed to the ground. In addition, there is also a prior art that uses a multi-rotor drone as a mooring system to provide lift.

[0004] Among the aforementioned and similar tethered systems, kites, airships and other tethered systems are rarely used because of the difficulty of flight control; and drones have limited lift and poor endurance, and are generally only used in small and short-term floating applications. Helium balloons are a more commonly used tethered system due to their simple structure and easy control, but the lift-to-drag ratio of helium balloons is uncontrollable. In particular, lift decreases with increasing altitude, while wind resistance increases with increasing wind speed. In actual applications, it is very easy to lower the pitch angle of the aerial work system relative to the ground, which is very unfavorable to the work safety and work power output. Summary of the invention

[0005] The purpose of the present disclosure is to provide an aerial tethering system with a controllable lift-to-drag ratio.

[0006] To achieve the above objectives, the present disclosure adopts the following technical solutions:

[0007] An aerial tethering system includes a rotor, a main shaft, and a drive unit;

[0008] The rotor has its own buoyancy, which can balance the deadweight of the system, and the rotor can rotate freely around the main axis under the force;

[0009] Both ends of the main shaft are symmetrically connected to the high-altitude work module, and the driving unit is used to adjust the speed and / or direction of the rotor;

[0010] The total weight of the rotor and the drive unit is symmetrically distributed on the main shaft.

[0011] Preferably, both ends of the main shaft are symmetrically connected to the high-altitude working module in a Y shape through traction ropes.

[0012] Preferably, the driving unit comprises a main driving motor, an energy storage module and a power generation module;

[0013] The power generation module is used to convert wind energy into electrical energy, the energy storage module is used to store the electrical energy and supply power to the main drive motor, and the main drive motor is used to adjust the rotation speed and / or direction of the rotor.

[0014] More preferably, the power generation module comprises at least one first fan and at least one second fan respectively arranged on both sides of the rotor, the first fan and the second fan are respectively connected to generator motors, and the generator motors are connected to the energy storage module.

[0015] More preferably, the first blower and the second blower are Darrieus blowers;

[0016] The blades of the first fan and the second fan are in a symmetrical or asymmetrical arc-shaped structure, and the number of the blades does not exceed 5.

[0017] More preferably, the Darrieus type blower comprises two driving wheels which can rotate freely relative to the main shaft, the driving wheels are connected to the blades via active supporting arms respectively, and the active supporting arms can rotate freely relative to the blades.

[0018] Preferably, the pitch angles of the blades of the first fan and the second fan are fixed.

[0019] More preferably, at least one of the first fan and the second fan is provided with an adjustment mechanism for adjusting the pitch angle of the blade.

[0020] Preferably, one of the two driving wheels is provided with a first limiting sliding groove, and an eccentric cam fixedly mounted on the main shaft is provided on its side, and the eccentric cam is provided with a second limiting sliding groove;

[0021] The two ends of the traveling pin are respectively restricted to move in the first limiting slide groove and the second limiting slide groove, and the traveling pin is connected to the wing located on the same side thereof through a driven support arm, and the driven support arm can rotate freely relative to the wing and the traveling pin.

[0022] More preferably, the direction of the eccentric cam is adjustable.

[0023] The technical solution claimed in this disclosure mainly achieves the following beneficial effects:

[0024] 1) Based on the Magnus effect, any required lift can be obtained by adjusting the rotor speed and / or steering, and the lift, lift-to-drag ratio and towing angle of the aerial tether can be flexibly controlled without being restricted by altitude. Compared with traditional tethering systems such as helium balloons, it avoids the lift-to-drag ratio decreasing due to the increase in altitude or with the increase in wind speed, and avoids the inability to control the towing angle.

[0025] 2) The Darrieus wind turbine has high power conversion efficiency and can continuously provide the required power for the rotor and other electrical equipment in the mooring system. And because the pitch angle of the Darrieus wind turbine blades can be adjusted according to the actual changes in the high-altitude environment, it can maintain the best windward angle of attack, thereby maximizing the power generation efficiency.

[0026] 4) By adjusting the pitch angles of the Darrieus-type fan blades on both sides of the rotor, the tethered system can be deflected in a predetermined manner. When the adjustment of the fan blade pitch angle is combined with the adjustment of the rotor steering / speed, the tethered system can be further synchronized to achieve horizontal and vertical position transfer within a certain spatial range, which is beneficial for space obstacle avoidance or space maneuvering. Compared with tethered solutions such as helium balloons, this system can not only flexibly achieve space maneuvers, but also has a simple control method, a large control range, and more outstanding maneuverability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are merely embodiments of the present disclosure, and a person of ordinary skill in the art can obtain other drawings based on the provided drawings without paying any creative work.

[0028] Figure 1a It is a three-dimensional schematic diagram of the overall structure of the aerial mooring system.

[0029] Figure 1b It is a plan view of the overall structure of the aerial mooring system.

[0030] Figure 2 Schematic diagram of the Magnus effect.

[0031] Figure 3 Schematic diagram of adjusting the traction angle of the high-altitude working module for the aerial tethering system.

[0032] Figure 4a Schematic diagram of the symmetrical blades of a Darrieus type fan.

[0033] Figure 4b Schematic diagram of the asymmetric blades of a Darrieus type fan.

[0034] Figure 5 Schematic diagram of a Darrieus-type wind turbine with fixed blade pitch angle (4 blades).

[0035] Figure 6 Schematic diagram of a Darrieus-type wind turbine with variable blade pitch angle (4 blades).

[0036] Figure 7 Schematic diagram of changing the force direction of a Darrieus type blower by adjusting the angle of the eccentric cam.

[0037] Figure 8 Schematic diagram of adjusting the spatial orientation of the aerial tethering system.

[0038] Reference numerals:

[0039] 100-rotor; 101-main drive motor; 200-first fan; 201-first generator motor; 210-second fan; 211-second generator motor; 300-main shaft; 400-first tether arm; 410-second tether arm; 500-traction rope; 600-energy storage module; 700-driving wheel; 701-active arm; 711-first limiting slide; 800-eccentric cam; 801-second limiting slide; 900-travel pin; 901-driven arm. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and beneficial effects of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0041] The overall structure of the aerial mooring system provided in this embodiment is shown in FIG1 , and includes a rotor 100, a main shaft 300, and a drive unit. The rotor 100 has its own buoyancy, which can balance the deadweight of the entire system, and the rotor 100 can rotate freely around the main shaft 300 under force. Both ends of the main shaft 300 are symmetrically connected to the high-altitude working module (such as a working rope), and the drive unit is used to adjust the speed and / or direction of the rotor 100. The total weight of the rotor 100 and the drive unit is symmetrically distributed on the main shaft 100.

[0042] Among them, the rotor 100 in this embodiment is a Magnus effect rotor. Exemplarily, the rotor 100 is configured as a sealed cylinder (it can also be other suitable shapes), the surface of which is a lightweight, high-strength, radiation-resistant floating balloon material or other materials that meet the requirements, and a high-strength lightweight skeleton such as carbon fiber can be installed inside to maintain a certain rigidity. The hollow part of the rotor 100 is filled with helium or a helium-hydrogen mixture to maintain a certain self-floating ability of the rotor 100, which can basically balance the deadweight of the entire system. The rotor 100 is mounted on the main shaft 300 through a bearing. Driven by the drive unit, the cylindrical rotor 100 can rotate freely in both directions around the main shaft 100.

[0043] Figure 2 The figure shows the working principle of the Magnus effect rotor. According to the Kutta-Joukowski lift formula, when the incoming flow velocity is v ∞ When a fluid has a circulation flow around a cylinder, the lift L exerted by the fluid on the rotating cylinder with a length of b is the fluid density ρ, the incoming flow velocity v ∞ The product of the velocity circulation Γ, that is

[0044] L=-ρv ∞ Γb formula (1)

[0045] The direction of the lift is determined by the forward flow velocity vector v ∞ Determine by rotating 90° in the direction of the counter-circulation flow. Figure 2 The lift force on the cylindrical rotor shown is perpendicular to the incoming flow direction and upward. If the cylinder is reversed, the lift force is perpendicular to the incoming flow direction and downward. Therefore, according to the real-time air density and air flow rate, any target lift force can be obtained by adjusting the rotation speed and direction of the cylinder. At the same time, the drag contribution of the surrounding flow to the cylinder is 0, so the target lift-to-drag ratio can also be obtained by controlling the rotation speed of the cylinder.

[0046] In a preferred solution, the driving unit in this embodiment includes a main driving motor 101, an energy storage module 600 and a power generation module, the power generation module is used to convert wind energy into electrical energy, the energy storage module 600 stores the electrical energy and supplies power to the main driving motor 101, and the main driving motor 101 is used to adjust the speed and / or direction of the rotor 100. Exemplarily, the power generation module includes at least one first fan 200 and at least one second fan 210 respectively arranged at both ends of the rotor 100, the first fan 200 and the second fan 210 are respectively connected to the first generator motor 201 and the second generator motor 211, and the first generator motor 201 and the second generator motor 211 are connected to the energy storage module 600.

[0047] In this embodiment, the rotor 100, the main drive motor 101, the first fan 200, the first generator motor 201, the second fan 210, the second generator motor 211 and the energy storage module 600 are symmetrically mounted on the main shaft 300 according to the counterweight, that is, the weight at both ends is symmetrically distributed with the center point of the main shaft 300 as the reference. In the preferred solution, the first tether arm 400 and the second tether arm 410 are respectively provided at both ends of the main shaft 300, and the ends of the first tether arm 400 and the second tether arm 410 are respectively used to attach the traction rope 500. The traction rope 500 is symmetrically fixed on the first tether arm 400 and the second tether arm 410 in a Y shape, and the ends are used to tether the aerial work component. The main shaft 300 does not rotate with the rotor 100 under the action of the traction rope 500.

[0048] In the preferred solution, the first fan 200 and the second fan 210 use Darrieus type fans. Darrieus type fans are available in H-type, φ-type and triangular types. The Darrieus type fan has a simple structure, and its vertical design is insensitive to changes in wind direction, and can adapt well to changes in wind direction. At the same time, the Darrieus type fan has a high wind energy conversion efficiency. When the tip speed ratio reaches about 4, the power coefficient of the Darrieus type fan with fixed blades can reach 0.4 or even higher. However, the starting performance of the Darrieus type fan is relatively poor. Generally, it is difficult to achieve self-rotation by relying on lift when the tip speed ratio is below 3. Therefore, an external force is required to drive its tip speed ratio to the starting speed to maintain its self-rotation. This embodiment does not limit the type of Darrieus type fan, but an H-type fan is preferred. The airfoil angle of the H-type fan can be changed through a variable pitch design, and a certain speed ratio increase and maneuvering control can be achieved.

[0049] In this embodiment, the first generator motor 201 can obtain electric energy from the energy storage module 600 to drive the first fan, i.e., the first Darrieus fan, to reach the starting speed. When the first Darrieus fan achieves stable self-rotation under the action of lift, the first generator motor 201 switches to the power generation mode, converts the rotational kinetic energy of the first Darrieus fan into electric energy and stores it in the energy storage module 600, thereby continuously supplying power to the main drive motor 100 and other electrical devices of the system. Similarly, the second generator motor 211 obtains electric energy from the energy storage module 600 to drive the second fan, i.e., the second Darrieus fan, to reach the starting speed. When the second Darrieus fan achieves stable self-rotation under the action of lift, the second generator motor 211 switches to the power generation mode, converts the rotational kinetic energy of the second Darrieus fan into electric energy and stores it in the energy storage module 600, continuously supplies power to various electrical devices of the system (necessary monitoring modules such as GPS, altitude sensor, wind speed sensor, communication module, etc.), and realizes the self-sufficiency of system energy.

[0050] In this embodiment, since the weight of the entire mooring system is evenly distributed along the main shaft 300, under the action of high-altitude wind, the main shaft 300 will always remain basically horizontal with the ground and perpendicular to the airflow direction. In the initial stage of lift-off, the rotor 100 is filled with helium or a helium-hydrogen mixture, so it can drive the system to float and rise to a certain height and autonomously align with the wind direction. According to formula (1), when the incoming wind speed increases or the rotor speed is increased, the lift can be increased. Therefore, according to the preset lift demand and traction angle demand, the system controls the main drive motor 101 to adjust the speed or direction of the rotor 100 in real time based on the real-time monitored wind speed, altitude and GPS data, so as to achieve the predetermined target lift or lift-to-drag ratio and traction angle, and guide the traction rope 500 to tow the aerial work module to a predetermined altitude and spatial position.

[0051] In such Figure 3 In the parachute-ladder combined high-altitude wind power generation system shown, the lift can be increased and the traction angle α can be increased by increasing the clockwise rotation speed of the rotor 100; the lift can be reduced and the traction angle α can be reduced by stopping or reversing the rotor 100. In other similar applications, the lift and traction angle can also be controlled on demand through the solution of the embodiment of the present invention.

[0052] In the preferred solution, in order to improve the power generation efficiency of the first wind turbine 200 and the second wind turbine 210 as much as possible and optimize their weight and size structure, suitable wind turbine airfoils can be selected according to different usage scenarios, and there is no limitation on this. FIG4 shows two preferred airfoils, wherein Figure 4a The NACA0018 airfoil shown is an airfoil with excellent aerodynamic performance among common symmetrical airfoils. Figure 4b What is shown is the NACA4418 airfoil. Compared with the symmetrical airfoil, this arc-shaped airfoil performs better in terms of dynamic characteristics such as earthquake resistance. As needed, some local shape optimization designs can also be made to the airfoil to achieve a higher tip speed ratio and power generation efficiency. Among them, the number of blades of the first fan 200 and the second fan 210 is preferably designed to be 3 to 4, and no more than 5. Too many or too few are not conducive to improving the power generation efficiency. The installation of the blades must be evenly distributed on the rotating circumference of the fan to ensure that the center of gravity of the fan is located on the axis of the main shaft 300.

[0053] In this embodiment, the first fan 200 and the second fan 210 may adopt a fixed blade pitch angle design, such as Figure 5As shown. This structural design is simple to install. For most common airfoil designs, lift can be generated at an angle of attack of 0 to 15 degrees. In particular, a larger lift and less drag can be generated at an angle of attack of 8 to 13 degrees. The Darrieus type wind turbine with a fixed wing pitch angle is more suitable for airspace with relatively stable wind speeds, so that a stable angle of attack can be maintained to drive the motor to generate electricity. When the wind speed changes greatly, the speed must be adjusted through the real-time coordination of the first generator motor 201 and the second generator motor 211 to prevent the wind turbine from stalling due to a sudden drop in the tip speed ratio when it is suddenly subjected to a large wind force.

[0054] In a more preferred solution, the first fan 200 and the second fan 210 can be designed with a blade pitch angle that is periodically variable, so as to maximize the power generation efficiency. This configuration can use a cam push rod or an eccentric wheel to periodically adjust the blade angle of attack, which is not limited here. In the exemplary structure, Figure 6 The figure shows a design that uses an eccentric cam 800 and a driven arm 901 to achieve periodic changes in the pitch angle of the wing. This configuration can adjust the pitch angle only through a mechanical structure, has a simple structure, does not require additional electromechanical control, and has a lower starting speed.

[0055] Specifically, Figure 6 As shown, the Darrieus type fan includes two driving wheels 700 that can rotate freely relative to the main shaft 300, and the driving wheels 700 are connected to the wing pieces through active support arms 701, and the active support arms 701 can rotate freely relative to the mounting shaft on the wing piece. One of the driving wheels 700 is provided with a first limiting slide groove 711, and an eccentric cam 800 fixedly mounted on the main shaft 300 is provided on its side, and the eccentric cam 800 is provided with a second limiting slide groove 801. The two ends of the travel pin 900 are respectively limited to move in the first limiting slide groove 711 and the second limiting slide groove 801, and the travel pin 900 is connected to the side of the corresponding wing piece through a driven support arm 901, and the driven support arm 901 can rotate freely relative to the mounting shaft on the wing piece and the travel pin 900.

[0056] When the blade is affected by the wind and generates lift, the active arm 701 drives the active wheel 700 to rotate, thereby driving the generator motor to generate electricity. Since the eccentric cam 800 is fixed on the main shaft 300, it does not rotate with the active wheel 700. The stroke of the walking pin 900 is controlled by the first limiting slide groove 711 on the active wheel 700 and the second limiting slide groove 801 on the eccentric cam 800 at the same time. The limiting slide groove can be exemplarily set as an annular slide groove. When the driven arm 901 rotates with the blade, due to the limitation of the first limiting slide groove 711 and the second limiting slide groove 801, the driven arm 901 can drive the blade to rotate periodically around the mounting axis of the active arm 701 on the blade within a predetermined angle range, thereby adjusting the pitch angle of the blade, obtaining the best windward angle of attack, and thus obtaining a lower starting speed and a greater wind energy conversion efficiency.

[0057] In a more preferred solution, the blade pitch angles of the first fan 200 and the second fan 210 can also be adjusted asymmetrically, and the horizontal balance state of the aerial mooring system will be broken under the active action of, for example, a motor. Under the further action of wind force, the mooring system will undergo a predetermined deflection, thereby realizing the maneuverable control of the spatial position of the aerial mooring system, which is beneficial to spatial obstacle avoidance or spatial maneuvering. In this case, the blade pitch angle of the fan can be precisely adjusted by a micromotor or mechanically, without specific limitation.

[0058] In a preferred embodiment, the eccentric cam 800 is preferably fixedly mounted on the main shaft 300 in an angle-adjustable manner, and the eccentric cam can be controlled by, for example, a micromotor, etc., and the specific method is not limited. Figure 7 The example shows the change in the force direction of the Darrieus type fan when the angle of the eccentric cam is actively adjusted. The direction of the eccentric cam 800 is adjusted by 180 degrees. Although the rotation direction of the vane does not change, the force direction of the fan changes by 180 degrees.

[0059] In another exemplary solution, the eccentric cam of the first Darrieus fan and the eccentric cam of the second Darrieus fan are adjusted to opposite directions, and then the Darrieus fans are driven to rotate actively by the first generator motor 201 and the second generator motor 211, so that the horizontal deflection of the mooring system can be achieved. Under the action of the wind in the air, the system will reach a balanced state again. If viewed from the air, the mooring system will deflect horizontally at a certain angle relative to the ground base, thereby realizing the maneuverable control of the aerial position change. The deflection effect is as follows: Figure 8 Obviously, the deflection angle is related to the wind speed and the driving speed of the generator motor.

[0060] On the basis of adjusting the horizontal deflection, such as Figure 3As shown, if the rotation speed and / or rotation direction of the rotor 100 is adjusted synchronously, the mooring system can also realize vertical maneuvering adjustment at the same time, that is, the mooring system will be able to realize horizontal and vertical position transfer synchronously within a certain spatial range. Compared with traditional mooring schemes such as helium balloon mooring systems, the mooring system in this embodiment can not only flexibly realize spatial maneuvers, but also has a simple control method, a large control range, and more outstanding maneuverability.

[0061] The embodiments described above are merely illustrative descriptions of the present disclosure and are not intended to limit the scope of the present disclosure. Without departing from the design spirit of the present disclosure, various modifications and improvements made to the technical solutions of the present disclosure by ordinary technicians in this field should all fall within the protection scope determined by the present disclosure.

Claims

1. An aerial mooring system, characterized in that: It includes a rotor, a main shaft and a drive unit; The rotor has its own buoyancy, which can balance the deadweight of the system, and the rotor can rotate freely around the main axis under the force; Both ends of the main shaft are symmetrically connected to the high-altitude work module, and the driving unit is used to adjust the speed and / or direction of the rotor; The total weight of the rotor and the drive unit is symmetrically distributed on the main shaft.

2. The aerial mooring system according to claim 1, characterized in that: The two ends of the main shaft are symmetrically connected to the high-altitude working module in a Y shape through traction ropes.

3. The aerial mooring system according to claim 1, characterized in that: The drive unit includes a main drive motor, an energy storage module and a power generation module; The power generation module is used to convert wind energy into electrical energy, the energy storage module is used to store the electrical energy and supply power to the main drive motor, and the main drive motor is used to adjust the rotation speed and / or direction of the rotor.

4. The aerial mooring system according to claim 3, characterized in that: The power generation module includes at least one first fan and at least one second fan respectively arranged on both sides of the rotor, the first fan and the second fan are respectively connected to a generator motor, and the generator motor is connected to the energy storage module.

5. The aerial mooring system according to claim 4, characterized in that: The first blower and the second blower are Darrieus blowers; The blades of the first fan and the second fan are in a symmetrical or asymmetrical arc-shaped structure, and the number of the blades does not exceed 5.

6. The aerial mooring system according to claim 5, characterized in that: The Darrieus type blower comprises two driving wheels which can rotate freely relative to the main shaft, and the driving wheels are connected to the blades through active supporting arms respectively, and the active supporting arms can rotate freely relative to the blades.

7. The aerial mooring system according to claim 6, characterized in that: The pitch angles of the blades of the first fan and the second fan are fixed.

8. The aerial mooring system according to claim 6, characterized in that: At least one of the first fan and the second fan is provided with an adjustment mechanism for adjusting the pitch angle of the blade.

9. The aerial mooring system according to claim 8, characterized in that: One of the two driving wheels is provided with a first limiting sliding groove, and an eccentric cam fixedly mounted on the main shaft is provided on its side, and the eccentric cam is provided with a second limiting sliding groove; The two ends of the traveling pin are respectively restricted to move in the first limiting slide groove and the second limiting slide groove, and the traveling pin is connected to the wing located on the same side thereof through a driven support arm, and the driven support arm can rotate freely relative to the wing and the traveling pin.

10. The aerial mooring system according to claim 9, characterized in that: The direction of the eccentric cam is adjustable.

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