Vertical-axis wind turbine counter-rotating self-protection device and offshore vertical-axis wind power generation system

Abstract

The present application provides a vertical-axis wind turbine counter-rotating self-protection device and an offshore vertical-axis wind power generation system. The vertical-axis wind turbine counter-rotating self-protection device includes two first bevel gears arranged coaxially and oppositely in the horizontal direction; two second bevel gears arranged coaxially and oppositely in the vertical direction, wherein the lower second bevel gear is fixedly connected coaxially with the vertical-axis wind turbine located below it; a rotational speed synchronization unit for switching the rotational speeds to be the same when the difference in rotational speeds between the two vertical-axis wind turbines is greater than a preset threshold; and a housing for accommodating the rotational speed synchronization unit, the first bevel gears, and the second bevel gears, and enabling the two first bevel gears and the two second bevel gears to rotate meshingly with each other. The technical solution of the present application can lock the rotational speeds in time when the rotational speed difference between the two vertical-axis wind turbines is large, eliminate the torque applied to the floating platform base, and effectively improve the safety and stability of the offshore wind power generation system.

Description

Technical Field

[0001] This application belongs to the technical field of wind power generation, and further relates to the technology of vertical-axis wind turbine power generation. Specifically, a self-protection device for counter-rotating vertical-axis wind turbines and an offshore vertical-axis wind power generation system using the above device are provided. Background Art

[0002] As an important part of new energy technologies, wind power generation technology has the advantages of continuous power generation process and less environmental restrictions. In particular, its installation is not restricted by conditions such as land or sea, and continuous power generation on the sea surface can be achieved. In recent years, with the increasing saturation of shallow sea development, offshore wind power has begun to move towards the open ocean and deep sea, and deep-sea floating wind turbine power generation systems have received more and more attention from the academic and industrial circles.

[0003] Wind power generation systems can be divided into two categories: horizontal-axis wind turbines and vertical-axis wind turbines according to the layout direction of the turbine rotation axis in space. Compared with horizontal-axis wind turbines, the rotation axis of the wind wheel of vertical-axis wind turbines is perpendicular to the horizontal plane and the center of gravity is relatively low, and its performance is more in line with the development trend of large-scale offshore wind turbines.

[0004] An important problem faced by deep-sea floating vertical-axis wind turbine power generation systems during power generation is that when the wind speed is relatively high, due to its large own mass, at high rotational speeds, on the one hand, a large torque will be exerted on the offshore floating platform, thereby increasing the tension of the mooring system, and its structural strength and stiffness will gradually decay, which will in turn pose serious safety hazards to the wind turbine and the platform and affect the operation efficiency of the wind turbine. To solve the above problems, two vertical-axis wind turbines can be set up and the two wind turbines can rotate in opposite directions to form torques in opposite directions to offset the effects on the floating platform and the mooring system, thereby realizing the stable operation of the system.

[0005] However, due to the complex and changeable wind field conditions in the open ocean, when there are large differences in wind force and wind direction at different heights from the sea level, the rotational speeds of the two counter-rotating wind turbines may be significantly different, thus unable to achieve the stability of the floating platform; in addition, when the sea surface wind speed is too high, the force on the wind turbine blades is too large, which also greatly increases the risk of blade breakage. Therefore, there is an urgent need for a device that protects the coaxial counter-rotating deep-sea vertical-axis power generation system and can achieve the stable and safe operation of the power generation system under complex and changeable wind field conditions. Summary of the Invention

[0006] To solve the problems existing in the above-mentioned prior art, the purpose of this application is to provide a self-protection device for counter-rotating vertical-axis wind turbines and an offshore vertical-axis wind power generation system using the self-protection device, which can achieve the stability of the floating platform and the mooring system under complex wind field conditions, thereby realizing safe and stable wind power generation.

[0007] The first aspect of the embodiments of the present application provides a vertical-axis wind turbine counter-rotating self-protection device, which is connected between two coaxial counter-rotating vertical-axis wind turbines and includes:

[0008] Two first bevel gears arranged coaxially and oppositely in the horizontal direction; two second bevel gears arranged coaxially and oppositely in the vertical direction, wherein the lower second bevel gear is fixedly connected coaxially with the vertical-axis wind turbine below it; a speed synchronization unit for making the speeds of the two vertical-axis wind turbines switch to be the same when the speed difference between the two vertical-axis wind turbines is greater than a preset threshold; a housing for accommodating the speed synchronization unit, the first bevel gears and the second bevel gears, and enabling the two first bevel gears and the two second bevel gears to rotate meshingly with each other.

[0009] Further, the speed synchronization unit includes a speed monitoring module, a speed synchronization mechanism and a control module; the speed monitoring module is used to monitor the speed of each vertical-axis wind turbine in real time; the control module controls the speed synchronization mechanism to switch from a separated state to a locked state when the speed difference between the two vertical-axis wind turbines is greater than a preset threshold; when the speed synchronization mechanism is in the separated state, the speeds of the two vertical-axis wind turbines are independent of each other, and when the speed synchronization mechanism is in the locked state, the speeds of the two vertical-axis wind turbines remain the same.

[0010] Further, the speed synchronization mechanism includes a lower synchronization shaft, a sliding shaft and an upper synchronization shaft arranged coaxially from bottom to top; the lower synchronization shaft is fixedly connected coaxially with the upper second bevel gear, the upper synchronization shaft is fixedly connected coaxially with the vertical-axis wind turbine above it, and the sliding shaft is slidably connected axially relative to the lower synchronization shaft; when the sliding shaft does not contact the upper synchronization shaft, the speed synchronization mechanism is in the separated state, and when the sliding shaft contacts the upper synchronization shaft and their speeds are the same, the speed synchronization mechanism is in the locked state.

[0011] Preferably, the outer peripheral surface of the lower synchronization shaft has a radially protruding limiting block; the lower part of the sliding shaft has a chute cooperating with the limiting block for enabling the sliding shaft to slide up and down axially relative to the lower synchronization shaft.

[0012] Preferably, a plurality of elastic and telescopic limiting pins are arranged circumferentially at the upper end of the sliding shaft; the lower end of the lower synchronization shaft has a plurality of limiting grooves cooperating with the limiting pins.

[0013] Preferably, the sliding shaft is made of a magnetic material; the control module includes a control chip, a power supply unit and an electromagnetic coil, and the electromagnetic coil generates a magnetic attraction force on the sliding shaft when powered by the power supply unit.

[0014] Preferably, the outer peripheral surface of the limiting pin and the inner wall of the limiting groove have a micro-undulating structure.

[0015] Preferably, a thin-film pressure sensor is provided on the outer peripheral surface of the limit pin and / or inside the limit groove.

[0016] Preferably, the rotational speed synchronization unit further includes a deceleration module for reducing the rotational speed of the vertical-axis wind turbine with a relatively high rotational speed.

[0017] A second aspect of the embodiments of the present application provides an offshore vertical-axis wind power generation system, including a floating platform base, a fixed bracket, two vertical-axis wind turbines, and a plurality of generating motors. The two vertical-axis wind turbines are coaxially arranged from bottom to top with opposite rotational directions. The rotating shaft of the lower vertical-axis wind turbine is rotatably received in the floating platform base, and the floating platform base floats on the sea surface and is limited by an anchor chain.

[0018] The above-mentioned vertical-axis wind turbine counter-rotating self-protection device is connected between the upper and lower vertical-axis wind turbines for switching their rotational speeds to be the same when the rotational speed difference between the two vertical-axis wind turbines is greater than a preset threshold; the fixed bracket is fixedly connected to the floating platform base and the outer shell of the vertical-axis wind turbine counter-rotating self-protection device; the generating motor generates electricity under the drive of the first bevel gear.

[0019] The vertical-axis wind turbine counter-rotating self-protection device provided by the embodiments of the present application realizes the synchronization of the rotational speeds of the upper and lower counter-rotating vertical-axis wind turbines through an intermeshing bevel gear transmission system and a rotational speed synchronization unit. Among them, after the bevel gear transmission system changes the rotation direction of the lower vertical-axis wind turbine, through the rotational speed synchronization unit that can be switched between a separated state and a locked state, the regulation of the rotational speeds of the two counter-rotating vertical-axis wind turbines is realized, thereby ensuring that the rotational speeds are locked in time when the rotational speed difference between the two vertical-axis wind turbines is large, so that the torques of the two cancel each other out, thereby eliminating the influence on the stability of the floating platform base and effectively improving the safety and stability of the offshore wind power generation system. Description of the Drawings

[0020] Figure 1 It is a side view of an existing coaxial counter-rotating offshore vertical-axis wind power generation unit;

[0021] Figure 2a It is a schematic structural diagram of an offshore vertical-axis wind power generation system according to an embodiment of the present application;

[0022] Figure 2b It is a top view of an offshore vertical-axis wind power generation system according to an embodiment of the present application;

[0023] Figure 3 It is an exploded view of a vertical-axis wind turbine counter-rotating self-protection device according to an embodiment of the present application;

[0024] Figure 4Internal structure side view of the vertical axis fan counter-rotating self-protection device according to an embodiment of the present application;

[0025] Figure 5 Schematic diagram of the lower synchronous shaft according to an embodiment of the present application;

[0026] Figure 6a Schematic diagram of the limiting groove of the sliding shaft in the ejected state according to an embodiment of the present application;

[0027] Figure 6b Top view of the sliding shaft according to an embodiment of the present application;

[0028] Figure 6c Bottom view of the sliding shaft according to an embodiment of the present application;

[0029] Figure 6d For Figure 6a Cross-sectional view;

[0030] Figure 7a Schematic diagram of the limiting groove of the sliding shaft in the compressed state according to an embodiment of the present application;

[0031] Figure 7b For Figure 7a Cross-sectional view;

[0032] Figure 8a Bottom view of the upper synchronous shaft according to an embodiment of the present application;

[0033] Figure 8b C-C cross-sectional view of the upper synchronous shaft according to an embodiment of the present application;

[0034] Figure 9a Schematic diagram of the speed synchronization mechanism in the separated state according to an embodiment of the present application;

[0035] Figure 9b Schematic diagram of the speed synchronization mechanism in the misaligned state according to an embodiment of the present application;

[0036] Figure 9c Schematic diagram of the speed synchronization mechanism in the locked state according to an embodiment of the present application.

[0037] Reference numerals in the figure

[0038] 1: Floating platform base, 1': Floating platform base, 11: Floating platform bracket, 12: Base, 13: Floating platform, 14: Anchor chain, 2: Fixed bracket, 21: Vertical fixed rod, 22: Horizontal fixed rod, 31: Vertical axis wind turbine, 31': Vertical axis wind turbine, 311: Rotating shaft, 312: Blade, 313: Connecting arm, 32: Vertical axis wind turbine, 32': Vertical axis wind turbine, 321: Rotating shaft, 322: Wind turbine, 323: Connecting arm, 4: Self-protection device for counter-rotating vertical axis wind turbines, 4': Self-protection device for counter-rotating vertical axis wind turbines, 41: First bevel gear, 41': First bevel gear, 411: Coupling, 42: Second bevel gear, 42': Second bevel gear, 43: Rotational speed synchronization mechanism, 431: Lower synchronization shaft, 4311: Limit block, 432: Sliding shaft, 4321: Groove, 4322: Slide groove, 4323: Limit pin, 4324: Spring, 433: Upper synchronization shaft, 4331: Limit groove, 44: Rotational speed monitoring module, 441: Inductive probe, 451: Power supply module, 452: Electromagnetic coil, 461: Lower part of the housing, 462: Upper part of the housing, 471: Lower transmission shaft, 472: Upper transmission shaft, 5: Generator, 5': Disk generator, 61: Bearing, 62: Bearing, 63: Bearing. Detailed implementation manners

[0039] Hereinafter, the present application will be further described based on preferred implementation manners with reference to the accompanying drawings.

[0040] In addition, for the convenience of understanding, various components in the drawings are enlarged or reduced, but this is not intended to limit the protection scope of the present application.

[0041] In the description of the embodiments of the present application, it should be noted that if terms such as "upper", "lower", "inner", "outer", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the products in the embodiments of the present application are usually placed. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. In addition, in the description of the present application, in order to distinguish different units, terms such as first and second are used in this specification, but these are not limited by the manufacturing order and should not be construed as indicating or implying relative importance. In the detailed description and claims of the present application, their names may be different.

[0042] The terms used in this specification are for the purpose of describing the embodiments of the present application, but are not intended to limit the present application. It should also be noted that unless otherwise clearly specified and defined, the terms "arranged", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present application can be specifically understood.

[0043] Figure 1 Fig. shows a side view of an existing coaxial counter-rotating offshore vertical-axis wind turbine generator, as Figure 1 shown. The wind turbine generator includes a floating platform base 1', two vertical-axis wind turbines 31', 32', and a disk generator 5'. Among them, the two vertical-axis wind turbines 31', 32' are arranged coaxially up and down and rotate relative to the floating platform base 1' in different rotation directions. The stator part and the rotor part of the disk generator 5' are fixedly connected to the opposite rotating shafts of the two vertical-axis wind turbines 31', 32' respectively, and rotate in counter-rotation under the drive of the two rotating shafts, so as to realize power generation.

[0044] Figure 1 The coaxial counter-rotating offshore vertical-axis wind turbine generator shown is limited by an anchoring system formed by multiple anchor chains, and can be applied to offshore wind power generation in deep sea / ocean. However, the above-mentioned offshore generator still has operation and safety defects in the actual power generation process. The main reason is that the fixing method of the deep sea / ocean offshore generator is significantly different from that of the land-based or shallow sea generator. It can only limit the floating platform base 1' through an anchoring system composed of flexible anchor chains. In addition to the undulation of the floating platform base 1' caused by the sea surface waves, the axial rotation of the vertical-axis wind turbines 31', 32' will additionally generate a reverse torque on the floating platform base 1', and further exert a force on the anchoring system. Although the counter-rotation of the two vertical-axis wind turbines 31', 32' can cancel out the torque to a certain extent, due to the complex and changeable sea surface wind field in the ocean / deep sea area, when the wind speed, wind force, etc. change violently with height, the rotational speeds of the upper and lower vertical-axis wind turbines 31', 32' may have a large difference, resulting in poor torque cancellation effect, so that the anchoring system is subjected to a large tension and affects the stability of the floating platform base 1'.

[0045] Therefore, the present application provides a vertical-axis wind turbine counter-rotation self-protection device and an offshore vertical-axis wind power generation system using this device through embodiments to achieve safe and stable offshore power generation in deep sea / ocean.

[0046] Figure 2a Fig. shows a schematic structural diagram of an offshore vertical-axis wind power generation system provided according to some embodiments of the present application. Figure 2bIt is a top view of the wind power generation system. Figure 3 It is Figure 2a an explosion diagram of the vertical axis wind turbine counter-rotating self-protection device in

[0047] As shown in Figure 2, Figure 3 the power generation system includes a floating platform base 1, a fixed bracket 2, two vertical axis wind turbines 31, 32 and a plurality of power generation motors 5. In addition, the power generation system further includes a vertical axis wind turbine counter-rotating self-protection device 4, wherein the vertical axis wind turbines 31, 32 are coaxially rotatably connected through the vertical axis wind turbine counter-rotating self-protection device 4 from bottom to top.

[0048] Specifically, in the embodiment shown in Figure 2, the floating platform base 1 includes a Y-shaped floating platform bracket 11 and a base 12 fixed to the upper end of the floating platform bracket 11. The three support feet of the floating platform bracket 11 are respectively connected to three floating platforms 13, and the floating platforms 13 float on the sea surface by the buoyancy of the floating platforms 13. The lower part of each floating platform 13 is connected to the top end of an anchor chain 14, and the anchor claw (not shown in the figure) connected to the bottom end of the anchor chain 14 is driven into the seabed to limit the entire floating platform base 1.

[0049] As shown in Figure 2, the rotating shaft 311 of the lower vertical axis wind turbine 31 is rotatably accommodated in the base 12. Specifically, in some embodiments, a shaft hole is opened inside the base 12, and a suitable bearing 61 is selected according to the outer diameter of the rotating shaft 311 of the vertical axis wind turbine 31 and the inner diameter of the above shaft hole. The rotating shaft 311 is firmly installed in the base 12 by an interference fit method and can rotate smoothly around its axis.

[0050] As shown in Figure 2, the rotating shaft 311 of the vertical axis wind turbine 31 is circumferentially and equally spacedly connected to three groups of blades 312 through a connecting arm 313, and the rotating shaft 321 of the vertical axis wind turbine 32 is circumferentially and equally spacedly connected to three groups of blades 322 through a connecting arm 323. The orientations of the blades 312 and 322 are opposite. When there is a wind field on the sea surface, the blades 312, 322 drive the vertical axis wind turbines 31, 32 to rotate in opposite directions around their respective rotating shafts 311, 321. The above implementation method of realizing the counter-rotation of the vertical axis wind turbine by setting different orientations of the blades is already known to those skilled in the art and will not be elaborated here. In addition, Figure 2 only schematically shows the composition and implementation method of the vertical axis wind turbines 31, 32. In the specific implementation process, those skilled in the art can flexibly select the specification parameters such as the axial length, blade shape, and number of blade groups of each vertical axis wind turbine according to the design index.

[0051] Further, in the embodiments of the present application, as shown in FIG. 2, the vertical-axis wind turbines 31 and 32 are connected by a vertical-axis wind turbine counter-rotating self-protection device 4. The fixed brackets are fixedly connected to the floating platform base 1 and the outer shell of the vertical-axis wind turbine counter-rotating self-protection device 4 through the vertical fixing rods 21 and the horizontal fixing rods 22 respectively. The vertical-axis wind turbine counter-rotating self-protection device 4 is used to make the rotational speeds of the two vertical-axis wind turbines 31 and 32 the same when the difference between their rotational speeds is greater than a preset threshold value.

[0052] The structure and working mode of the vertical-axis wind turbine counter-rotating self-protection device are described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0053] As described above, Figure 3 shows an exploded view of the vertical-axis wind turbine counter-rotating self-protection device 4 provided by some preferred embodiments of the present application. Figure 4 shows a side view of the internal structure of the vertical-axis wind turbine counter-rotating self-protection device 4. For clearer display, in Figure 3 、 Figure 4 the outer shell of the vertical-axis wind turbine counter-rotating self-protection device 4 is sectioned.

[0054] As shown in FIGS. 2 to 4, in the embodiments of the present application, the vertical-axis wind turbine counter-rotating self-protection device 4 is connected between two coaxial counter-rotating vertical-axis wind turbines 31 and 32, and includes two first bevel gears 41 and 41', two second bevel gears 42 and 42', a rotational speed synchronization unit, and an outer shell.

[0055] Specifically, as shown in FIGS. 2 to Figure 4 the outer shell includes a separable lower outer shell 461 and an upper outer shell 462, and a bearing structure for accommodating each bevel gear and the rotational speed synchronization unit is provided inside. Through holes for connecting the rotating shafts 311 and 321 are respectively formed at the lower end of the lower outer shell 461 and the upper end of the upper outer shell 462. After the assembly of each internal component is completed, the lower outer shell 461 and the upper outer shell 462 can be fixedly connected together by means of buckling, plugging, or flange connection to form a complete outer shell.

[0056] Further, as Figure 3 、 Figure 4As shown, two first bevel gears 41 and 41' are arranged oppositely coaxially in the horizontal direction, and are respectively connected to the generator 5 through couplings 411; two second bevel gears 42 and 42' are arranged oppositely coaxially in the vertical direction. Appropriate bearings 63 and 62 are selected according to the shaft diameters of the rotating shafts of the first bevel gears 41 and 41' and the second bevel gears 42 and 42', and are respectively assembled into the bearing structures in the housing, so that they can rotate relative to each other meshingly with respect to the housing, forming a set of bevel gear transmission systems. Obviously, the two first bevel gears 41 and 41' have the same rotational speed and opposite rotational directions, and the two second bevel gears 42 and 42' have the same rotational speed and opposite rotational directions. Among them, the lower second bevel gear 42 is fixedly connected coaxially with the vertical axis wind turbine 31 below it, and through the transmission of the above bevel gear transmission system, the rotational direction of the upper second bevel gear 42' becomes the same as the rotational direction of the vertical axis wind turbine 32, and the mechanical energy of the rotation of the vertical axis wind turbine 31 is converted into the electrical energy output by the generator 5. In addition, in some preferred embodiments, a speed increasing gearbox can also be provided between the first bevel gears 41 and 41' and the generator 5, so as to improve the output power of the generator 5.

[0057] The rotational speed synchronization unit is arranged between the above bevel gear transmission system and the vertical axis wind turbine 32, and is used to switch the rotational speeds to be the same when the difference in rotational speeds between the vertical axis wind turbines 31 and 32 is greater than a preset threshold. In some preferred embodiments of the present application, the rotational speed synchronization unit further includes a rotational speed monitoring module 44, a rotational speed synchronization mechanism 43 and a control module. Among them, the rotational speed monitoring module 44 is used to monitor the rotational speeds of the vertical axis wind turbines 31 and 32 in real time, and the control module controls the rotational speed synchronization mechanism 43 to switch from the separated state to the locked state when the difference in rotational speeds between the vertical axis wind turbines 31 and 32 is greater than a preset threshold.

[0058] Furthermore, as Figure 3 、 Figure 4 shown, the rotational speed synchronization mechanism 43 includes a lower synchronization shaft 431, a sliding shaft 432 and an upper synchronization shaft 433 arranged coaxially from bottom to top. The lower synchronization shaft 431 is fixedly connected coaxially with the upper second bevel gear 42', the upper synchronization shaft 433 is fixedly connected coaxially with the vertical axis wind turbine 32 above it, and the sliding shaft 432 is slidably connected axially relative to the lower synchronization shaft 431. When the sliding shaft 432 does not contact the upper synchronization shaft 433, the rotational speed synchronization mechanism 43 is in the separated state. At this time, the rotational speeds of the two vertical axis wind turbines 31 and 32 are independent of each other; when the sliding shaft 432 contacts the upper synchronization shaft 433 and their rotational speeds are the same, the rotational speed synchronization mechanism 43 is in the locked state. At this time, the rotational speeds of the two vertical axis wind turbines 31 and 32 remain the same.

[0059] Figure 5 shows a three-dimensional schematic diagram of the lower synchronization shaft 431 in some preferred embodiments. AsFigure 5 As shown, the lower synchronization shaft 431 may have the same diameter as the axle of the second bevel gear 42', and is coaxially and fixedly connected to the second bevel gear 42' by means such as welding or coupling connection. Its outer peripheral surface has a radially protruding limiting block 4311.

[0060] Figures 6a to 6d Stereoscopic schematic views, top views, bottom views, and sectional views taken along the B-B direction of the sliding shaft 432 are respectively shown in some preferred embodiments. As Figures 6a to 6d shown, the lower part of the sliding shaft 432 has a groove 4321 and a sliding groove 4322 that cooperate with the cylinder of the lower synchronization shaft 431 and the limiting block 4311, enabling the sliding shaft 432 to slide up and down axially relative to the lower synchronization shaft 431.

[0061] Furthermore, as Figure 6d shown, a plurality of limiting pins 4323 are circumferentially arranged at the upper end of the sliding shaft 432, and a spring 4324 is arranged at the lower part of each limiting pin 4323, enabling the limiting pin 4323 to elastically expand and contract relative to the upper end of the sliding shaft 432.

[0062] Figures 6a to 6d In [reference], the limiting pins 4323 of the sliding shaft 432 are in a popped-up state. When it receives a downward pressure from above, it presents a compressed state as shown in Figure 7a 、 7b .

[0063] Figure 8a 、 Figure 8b Bottom views and sectional views taken along the C-C direction of the upper synchronization shaft 433 are respectively shown in some preferred embodiments. As Figure 8a and 8b shown, the lower end of the upper synchronization shaft 433 has a plurality of limiting grooves 4331 that cooperate with the limiting pins 4323 of the sliding shaft 432.

[0064] In the embodiments of the present application, the upper synchronization shaft 433 is coaxially and fixedly connected to the rotating shaft 321 of the vertical-axis fan 32. Specifically, the diameter of the upper synchronization shaft 433 can be set to be the same as that of the rotating shaft 321, and the upper synchronization shaft 433 and the rotating shaft 321 are directly fixedly connected through a coupling, a flange plate, etc.

[0065] In addition, in some preferred embodiments, as Figure 3 、 Figure 4 shown, a lower transmission shaft 671 and an upper transmission shaft 672 may be additionally provided, and the rotating shaft 311 and the second bevel gear 42 are fixedly connected through the lower transmission shaft 671, and the upper synchronization shaft 433 and the rotating shaft 321 are fixedly connected through the upper transmission shaft 672.

[0066] In some preferred embodiments of the present application, the sliding shaft 432 is made of a material such as metal with magnetic sensing characteristics. The control module includes a control chip, a power supply unit 451, and an electromagnetic coil 452. Specifically, as Figure 3 , Figure 4 shown, the power supply unit 451 can be a battery module controlled by a control chip (not shown in the figure) and is disposed in the upper drive shaft 472; the electromagnetic coil 452 is circumferentially disposed in the upper synchronous shaft 433 and is electrically connected to the power supply unit 451. When the power supply unit 451 supplies power to the electromagnetic coil 452 under the control of the control chip, the electromagnetic coil 452 generates a magnetic suction force on the sliding shaft 432, causing it to slide upward along the axis.

[0067] In some preferred embodiments of the present application, as shown in FIG. 2, a vertical axis wind turbine counter-rotating self-protection device 4' can be further connected above the vertical axis wind turbine 32, and the mechanical energy of the rotation of the vertical axis wind turbine 32 is converted into electrical energy output by the motor 5 through the motor 5 assembled therein (obviously, the vertical axis wind turbine counter-rotating self-protection device 4' provided here only uses the bevel gear transmission system therein for wind turbine power generation without the need for speed monitoring).

[0068] Figures 9a to 9c shows the process of the speed synchronization mechanism transitioning from the separated state to the locked state under the control of the control module. As Figures 9a to 9c shown, the speed monitoring module 44 respectively monitors the speeds of the sliding shaft 432 and the upper synchronous shaft 433 in real time through two induction probes 441, thereby obtaining the speed data of the vertical axis wind turbine 31 and the vertical axis wind turbine 32. When the speed difference between the two vertical axis wind turbines 31 and 32 is less than a preset threshold, the torque difference generated by the two vertical axis wind turbines 31 and 32 on the floating platform base 1 is relatively small, and the floating platform base 1 is relatively stable. At this time, as Figure 9a shown, the control module controls the power supply unit 451 not to supply power to the electromagnetic coil 452, and the sliding shaft 432 is in a separated state from the upper synchronous shaft 433 under the action of gravity; when the speed monitoring module 44 monitors that the speed difference between the two vertical axis wind turbines 31 and 32 is greater than the preset threshold, the torque difference generated by the two vertical axis wind turbines 31 and 32 on the floating platform base 1 will have a non-negligible impact on the floating platform base 1. At this time, the control module supplies power to the electromagnetic coil 452 through the power supply unit 451, so that the electromagnetic coil 452 generates a magnetic suction force on the sliding shaft 432. When the magnetic suction force is greater than the gravity of the sliding shaft 432, the sliding shaft 432 will slide upward along the axis, and its upper end face gradually contacts the lower end face of the upper synchronous shaft 433. When the limit groove 4331 of the upper synchronous shaft 433 is not aligned with the limit pin 4323 of the sliding shaft 432, as Figure 9bAs shown, the limit pin 4323 is pressed downward to within the upper end face of the sliding shaft 432; since the rotational speeds of the sliding shaft 432 and the upper synchronizing shaft 433 are different, the relative positions of the limit pin 4323 and the limit groove 4331 will change continuously until they are aligned. At this time, as Figure 9c shown, the limit pin 4323 pops into the limit groove 4331 under the action of the spring 4324. At this time, the rotational speed synchronization mechanism 43 is in a locked state, and the rotational speeds of the lower synchronizing shaft 431, the sliding shaft 432, and the upper synchronizing shaft 433 are kept consistent. Furthermore, the rotational speeds of the two vertical-axis wind turbines 31 and 32 are made consistent. At this time, the torques generated by the vertical-axis wind turbines 31 and 32 relative to the floating platform base 1 are equal in magnitude and opposite in direction, so they cancel each other out, effectively eliminating the impact on the floating platform base 1 and improving the stability and safety of the power generation system.

[0069] It should be noted that when the rotational speed synchronization mechanism 43 is in a locked state, since the vertical-axis wind turbine with a higher rotational speed needs to "drive" the vertical-axis wind turbine with a lower rotational speed, while improving the stability of the floating platform base 1, a certain amount of power generation will inevitably be sacrificed. Therefore, when the wind field distribution in the vertical direction tends to be consistent, the rotational speed synchronization mechanism 43 should be restored to the separated state as soon as possible so that the two vertical-axis wind turbines 31 and 32 rotate independently to improve the power generation of the system. However, since the rotational speeds of the sliding shaft 432 and the upper synchronizing shaft 433 are the same when the rotational speed synchronization mechanism 43 is in a locked state, it is impossible to determine whether the sliding shaft 432 and the upper synchronizing shaft 433 can be separated again based on the rotational speed information obtained by the rotational speed monitoring module 44.

[0070] Although the distribution of the wind field can be obtained by additionally setting wind monitoring devices at different heights, the above settings will greatly increase the system cost and control complexity. Considering the two vertical-axis wind turbines in a locked state under inconsistent wind field conditions, there must be internal torsion between their two rotating shafts 311 and 321, and this torsion will be transmitted between the limit pin 4323 and the limit groove 4331 for locking. Therefore, the change of this torsion can be used to adaptively separate the rotational speed synchronization mechanism 43 from the locked state when the wind field areas are consistent.

[0071] In some preferred embodiments, a micro-undulating structure can be formed on the outer peripheral surface of the limit pin 4323 and the inner wall of the limit groove 4331 by means of sandblasting or coating a friction coating. This micro-undulating structure will generate a vertical frictional force when the limit pin 4323 enters the limit groove 4331, and this frictional force will change with the change of the torque between the two vertical-axis wind turbines. By adjusting specific parameters such as the roughness of the micro-undulating structure, the corresponding friction coefficient can be adjusted so that when the torque between the two vertical-axis wind turbines is greater than the preset design value, the frictional force of the upper synchronous shaft 433 on the sliding shaft 432 is greater than the gravity of the sliding shaft 432, so that the rotation speed synchronization mechanism 43 can be kept in the locked state without the need for the electromagnetic coil 452 to continuously generate magnetic suction, and when the above torque is less than the preset design value, the gravity of the sliding shaft 432 is used to realize its automatic separation from the upper synchronous shaft 433.

[0072] Through the above implementation manner, it can be ensured that after the self-protection device enters the locked state, according to the changes in the forces and torques of the vertical-axis wind turbines 31 and 32 under wind field conditions, the locked state can be automatically released under appropriate conditions, so that the two vertical-axis wind turbines can enter the independent rotational power generation state as soon as possible under the condition of meeting safety requirements, thereby effectively improving the power generation efficiency of the system.

[0073] In addition, in some other preferred embodiments, a thin-film pressure sensor can also be provided on the outer peripheral surface of the limit pin 4323 and / or inside the limit groove 4331, and the above thin-film pressure sensor is used to obtain an accurate torque value. The control module judges whether to stop the power supply to the electromagnetic coil 452 according to the situation of the above torque value to realize the separation of the sliding shaft 432 and the upper synchronous shaft 433.

[0074] In addition, in some cases where the wind field changes violently, there may be a situation where the rotational speed difference between the two vertical-axis wind turbines increases sharply, making it difficult for the limit pin 4323 to enter the limit groove 4331. Therefore, in some preferred embodiments, the rotational speed synchronization unit further includes a deceleration module. The deceleration module can be a brake pad surrounding the outside of the rotating shafts 311 and 321, and a braking operation is performed on the vertical-axis wind turbine with a larger rotational speed according to the rotational speed information obtained by the rotational speed monitoring module 44 to reduce its rotational speed, so that the limit pin 4323 can more easily enter the limit groove 4331.

[0075] The above has made a detailed introduction to the specific implementation manners of the present application. For those skilled in the art of this technology, without departing from the principle of the present application, several improvements and modifications can still be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A self-protection device for contra-rotating vertical-axis wind turbines, which is connected between two coaxial contra-rotating vertical-axis wind turbines, and is characterized in that, Comprising: Two first bevel gears arranged coaxially and oppositely in the horizontal direction; Two second bevel gears arranged coaxially and oppositely in the vertical direction, wherein the lower second bevel gear is fixedly connected coaxially with the vertical axis fan located below it; A rotational speed synchronization unit for switching the rotational speeds of two vertical axis fans to be the same when the difference in rotational speeds between the two vertical axis fans is greater than a preset threshold; A housing for accommodating the rotational speed synchronization unit, the first bevel gears, and the second bevel gears, and enabling the two first bevel gears and the two second bevel gears to rotate meshingly with each other; The rotational speed synchronization unit includes a rotational speed monitoring module, a rotational speed synchronization mechanism, and a control module; The rotational speed monitoring module is used to monitor the rotational speed of each vertical axis fan in real time; The control module controls the rotational speed synchronization mechanism to switch from a separated state to a locked state when the difference in rotational speeds between the two vertical axis fans is greater than a preset threshold; When the rotational speed synchronization mechanism is in the separated state, the rotational speeds of the two vertical axis fans are independent of each other, and When the rotational speed synchronization mechanism is in the locked state, the rotational speeds of the two vertical axis fans remain the same; The rotational speed synchronization mechanism includes a lower synchronization shaft, a sliding shaft, and an upper synchronization shaft arranged coaxially from bottom to top; The lower synchronization shaft is fixedly connected coaxially with the upper second bevel gear, the upper synchronization shaft is fixedly connected coaxially with the vertical axis fan located above it, and the sliding shaft is slidably connected axially relative to the lower synchronization shaft; When the sliding shaft does not contact the upper synchronization shaft, the rotational speed synchronization mechanism is in the separated state, and When the sliding shaft contacts the upper synchronization shaft and their rotational speeds are the same, the rotational speed synchronization mechanism is in the locked state; The outer peripheral surface of the lower synchronization shaft has a radially protruding limiting block; The lower part of the sliding shaft has a sliding groove cooperating with the limiting block for enabling the sliding shaft to slide up and down axially relative to the lower synchronization shaft; A plurality of elastically telescopic limiting pins are arranged circumferentially at the upper end of the sliding shaft; The lower end of the lower synchronization shaft has a plurality of limiting grooves cooperating with the limiting pins; The sliding shaft is made of a magnetic material; The control module includes a control chip, a power supply unit, and an electromagnetic coil, and the electromagnetic coil generates a magnetic attraction force on the sliding shaft when powered by the power supply unit.

2. The vertical axis fan counter-rotating self-protection device according to claim 1, wherein: The outer peripheral surface of the limiting pin and the inner wall of the limiting groove have a micro-undulating structure.

3. The vertical axis fan counter-rotating self-protection device according to claim 1, wherein: A thin film pressure sensor is arranged on the outer peripheral surface of the limiting pin and / or inside the limiting groove.

4. The vertical axis fan counter-rotating self-protection device according to claim 1, wherein: The rotational speed synchronization unit further includes a deceleration module for reducing the rotational speed of the vertical axis fan with a larger rotational speed.

5. An offshore vertical axis wind power generation system, comprising a floating platform base, a fixed bracket, two vertical axis wind turbines and a plurality of generating motors. The two vertical axis wind turbines are coaxially arranged from bottom to top with opposite rotation directions. The rotating shaft of the lower vertical axis wind turbine is rotatably received in the floating platform base. The floating platform base floats on the sea surface and is limited by anchor chains. It is characterized in that: A vertical axis wind turbine counter-rotation self-protection device as described in claim 1 is connected between the upper and lower vertical axis wind turbines, and is used to make their rotation speeds switch to the same when the rotation speed difference between the two vertical axis wind turbines is greater than a preset threshold; The fixed bracket is fixedly connected to the floating platform base and the outer shell of the vertical axis wind turbine counter-rotation self-protection device; The generating motor generates electricity under the drive of the first bevel gear.

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