Elastically hinged tandem hydrofoil power plant and method

Abstract

The present application belongs to the field of hydroelectric power generation facilities, and discloses a kind of elastic hinged series hydrofoil power generation equipment and method, the elastic hinged series hydrofoil power generation equipment includes elastic hinged mechanism and two oscillating hydrofoil power generation devices, each oscillating hydrofoil power generation device includes support frame, generator, slide rail, sliding block, hydrofoil and bidirectional damping mechanism, one end of hydrofoil is used to extend into water flow, the other end of hydrofoil is equipped with connecting shaft, connecting shaft is rotatably installed on sliding block and is connected with generator, and bidirectional damping mechanism is fixedly connected with sliding block;Two hydrofoils are connected by elastic hinged mechanism, and the elastic hinged mechanism includes first tension spring and two hinge pieces, and the first tension spring is hinged on the hydrofoil.The elastic hinged mechanism of the present application elastically connects two hydrofoils, can better adapt to the change of water flow and the coupling effect between each other, more fully utilizes the energy in water flow, expands the effective working flow velocity range of power generation equipment, and improves the total energy capture amount per unit water area.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hydroelectric power generation facilities, and more particularly relates to a flexible hinged series hydrofoil power generation device and method. BACKGROUND

[0002] Among numerous renewable energy sources, water flow energy has great development potential as a clean, renewable and widely distributed energy source. A high-efficiency generator at low flow rate can be applied to offshore low-speed tidal current energy, natural low-speed river current energy, and also to abyssal low-speed ocean current energy development. Oscillating hydrofoil water flow energy generator has become a research hotspot in recent years because it can generate electricity at low flow rate. Series oscillating hydrofoil generator further improves the energy capture efficiency at low flow rate through the interaction of regular limit cycle oscillation movement under the action of water flow, tail vortex evolution and flow field change between series hydrofoils.

[0003] In the development history of series oscillating hydrofoil generator, the connection mode between hydrofoils plays a key role in energy capture. Although certain achievements have been made through years of research and practice, there are still many problems to be solved.

[0004] In the prior art, some series hydrofoil generators use gear to rigidly connect the hydrofoils, use gear structure to capture water flow energy, and improve the energy conversion efficiency to a certain extent. However, when the hydrofoils reverse the direction of movement, due to the characteristics of rigid connection of the gear, when the direction of movement changes suddenly, a huge reversing force acts on the gear structure, resulting in serious energy loss and seriously affecting the durability of the device. In order to solve the problems caused by rigid connection, an invention using hydraulic structure to connect the hydrofoils appears, which uses liquid metal magnetic fluid to generate electricity and realizes the connection and energy transmission between the hydrofoils through hydraulic structure. However, the hydraulic structure connection mode has obvious disadvantages, the structure is complex, and the energy transmission needs to pass through multiple stages of hydraulic cavity-rod cavity-hydraulic cylinder, resulting in serious energy loss. The sealing, reliability and response speed of the hydraulic system also face challenges, and problems such as hydraulic oil leakage and system failure are prone to occur in actual application, affecting the normal operation and power generation efficiency of the power generation device. In addition, there is an invention using a single pile + connecting column to connect the hydrofoils, which captures water flow energy through the pitching and rotating movement of the hydrofoils. However, this connection mode limits the degrees of freedom of the series hydrofoils, seriously affecting the energy capture effect. The hydrofoils cannot fully adapt to the changes of water flow and the coupling between each other during the movement, resulting in insufficient energy capture and limiting the wide application of series hydrofoils in water flow energy generation field.

[0005] In addition to the above connection problems, the existing series oscillating hydrofoil generator also faces many challenges in terms of effective working flow rate, overall energy capture efficiency, and total energy capture per unit water area. In terms of effective working flow rate, most existing devices require relatively high flow rates to achieve effective energy conversion, and their performance decreases significantly under low flow rate conditions, which cannot meet the wide application requirements in different water areas and different flow rate environments. For example, in some offshore areas, low-speed sections of rivers, and low-speed ocean current areas of deep-sea bottoms, the flow rate is low, and the existing devices have low power generation efficiency in these areas, making it difficult to achieve effective energy development.

[0006] In terms of overall energy capture efficiency, the energy conversion efficiency of the existing series oscillating hydrofoil generator still needs to be improved. Due to the limitations of the connection mode between the hydrofoils, the motion coupling mechanism, and the energy transfer process, a large amount of energy is wasted, and the energy lost by the hydrofoils due to flow separation during the hydrofoil reversing process cannot be effectively recovered, further reducing the overall energy capture efficiency of the device.

[0007] In addition, in terms of total energy capture per unit water area, the existing technology also has deficiencies. In order to ensure the efficient energy capture of the rear hydrofoil, a large spacing between the front and rear hydrofoils is usually required, which makes it impossible to arrange enough hydrofoils in a limited water area, thereby limiting the total energy capture in a unit water area. For example, the optimal working spacing of two hydrofoils without hinges is large, resulting in low water area utilization efficiency and failing to fully utilize the energy capture potential of series hydrofoils in a unit water area. SUMMARY

[0008] In view of the above defects or improvement needs of the prior art, the present application provides a flexible hinge series hydrofoil power generation device and method, which has a large effective working flow rate range, high overall energy capture efficiency, and large total energy capture per unit water area.

[0009] To achieve the above-mentioned purpose, according to one aspect of the present application, a flexible hinge series hydrofoil power generation device is provided, which comprises a flexible hinge mechanism and two oscillating hydrofoil power generation devices arranged in sequence along the flow direction, wherein:

[0010] Each of the oscillating hydrofoil power generation devices comprises a support frame, a generator, a slide rail, a slide block, a hydrofoil and a bidirectional damping mechanism, the bidirectional damping mechanism, the generator and the slide rail are all installed on the support frame, the slide block is slidingly installed on the slide rail, one end of the hydrofoil is used to extend into water flow, the other end of the hydrofoil is provided with a connecting shaft, the connecting shaft is rotatably installed on the slide block and connected with the generator, so as to drive the generator to generate electricity, and the bidirectional damping mechanism is fixedly connected with the slide block, so as to provide damping force for the first direction movement and the second direction movement opposite to the first direction of the hydrofoil.

[0011] The two hydrofoils of the two oscillating hydrofoil power generation devices are connected through the elastic hinged mechanism, the elastic hinged mechanism comprises a first tensile spring and two hinge pieces, each end of the first tensile spring is hingedly connected with one of the hydrofoils through one of the hinge pieces, so that when the hydrofoils rotate and move along the length direction of the slide rail, the first tensile spring exerts elastic force on the two hydrofoils and rotates around the center line of the hinge piece.

[0012] Preferably, each of the hinge pieces is installed on the side edge of the hydrofoil.

[0013] Preferably, the center line of the first tensile spring in the straightened state is collinear with the center line of each of the hinge pieces, the center line of each of the hinge pieces is perpendicular to the length direction of the hydrofoil, and the center lines of the two hinge pieces of the elastic hinged mechanism are collinear.

[0014] Preferably, the first tensile spring is in a relaxed state before the hydrofoil drives the first tensile spring to deform.

[0015] Preferably, the elastic hinged mechanism has a plurality of and they are arranged along the length direction of the hydrofoil.

[0016] Preferably, the chord length of each of the hydrofoils is L.

[0017] The distance between the two hydrofoils is 1.5L-2L when each of the hydrofoils is perpendicular to the direction of water flow.

[0018] Preferably, the bidirectional damping mechanism comprises a second tensile spring, and the second tensile spring is in a pre-tensioned state before the hydrofoil connected with the second tensile spring moves.

[0019] Preferably, the hydrofoil connects the generator through a belt transmission mechanism, the belt transmission mechanism comprises a belt and two belt pulleys rotatably installed on the support frame, one of the belt pulleys is installed on the rotor shaft of the generator, and the belt is fixedly installed on the slide block, so as to drive the belt to move when the slide block moves along the slide rail, thereby driving the belt pulleys to rotate and drive the generator to generate electricity.

[0020] Preferably, the displacement of each water wing along the length direction of the slide rail changes approximately in a sinusoidal manner with time, and the rotation angle of each water wing also changes approximately in a sinusoidal manner with time.

[0021] According to another aspect of the present application, a power generation method of the elastic hinged series water wing power generation device is also provided, comprising the following steps:

[0022] 1) arranging two oscillating water wing power generation devices in sequence along the water flow direction and fixing them on the shore, and connecting their water wings through the elastic hinged mechanism, wherein each oscillating water wing power generation device comprises a support frame, a generator, a slide rail, a slide block, a water wing and a bidirectional damping mechanism, the bidirectional damping mechanism, the generator and the slide rail are installed on the support frame, the slide block is slidingly installed on the slide rail, one end of the water wing extends into the water flow, the other end of the water wing is provided with a connecting shaft which is rotatably installed on the slide block and connected with the generator, and the bidirectional damping mechanism is fixedly connected with the slide block to provide damping force for the first direction movement of the water wing and the second direction movement opposite to the first direction;

[0023] 2) under the action of the water flow, the water flow impacts the two water wings in sequence, in the water wing swing process, the slide block slides along the slide rail with the water wing, and the water wing drives the rotor shaft of the generator to rotate, so as to realize the power generation of the generator; at the same time, the bidirectional damping mechanism provides damping force in the water wing swing process, autonomously adjusts the transverse movement amplitude and frequency of the series water wing, optimizes the motion state of the water wing, improves the energy capture, and the elastic hinged mechanism assists the swing of each water wing by continuously generating elastic deformation and restoring elastic deformation, so as to repeatedly utilize the energy lost by turning each water wing, and improve the energy capture efficiency of each water wing.

[0024] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0025] 1) The elastic hinged series hydrofoil power generation device of the present application connects two oscillating hydrofoil power generation devices through an elastic hinge mechanism. The hydrofoils swing under the impact of water flow, driving the sliding block to move along the sliding rail, and then driving the generator rotor shaft to rotate and generate electricity. The bidirectional damping mechanism provides damping force during the swing of the hydrofoils, and can independently adjust the lateral movement amplitude and frequency of the series hydrofoils, so that they can better adapt to changes in water flow and optimize the motion state, thereby improving energy capture. At the same time, the elastic hinge mechanism continuously deforms and recovers, assisting the swing of the hydrofoils, and reusing the energy lost by turning each hydrofoil between the two hydrofoils, improving the overall energy capture efficiency. Compared with traditional rigid connection or hydraulic connection, the energy conversion efficiency is greatly improved, and the energy in the water flow can be more fully utilized, especially at low flow rates, and high power generation efficiency can also be achieved, expanding the effective working flow rate range and improving the total energy capture amount per unit water area.

[0026] 2) The elastic hinged series hydrofoil power generation device of the present application has a certain elastic connection between the two hydrofoils, which can better adapt to changes in water flow and mutual coupling. When facing water flow of different flow rates and directions, the hydrofoils can more flexibly adjust the motion state to maintain good energy capture effect. In addition, the parameters of the elastic hinge mechanism (such as the stiffness and pre-tension of the first tension spring) can be adjusted and optimized according to the actual working conditions, so that the device can better adapt to different water environments and water flow conditions, and has strong universality and adaptability.

[0027] 3) The elastic hinged series hydrofoil power generation device of the present application has a lower effective working flow rate: the present application uses an elastic hinge mechanism to realize series connection of hydrofoils. During operation, through the elastic coupling effect of the elastic hinge mechanism, the effective angle of attack of each hydrofoil is increased, the lift coefficient of the hydrofoil is increased, and the lift of the hydrofoil motion is enhanced, so that normal power generation can be realized at a smaller flow rate. Laboratory physical test results show that, compared with existing series connection methods of hydrofoils, the dimensionless effective working flow rate of the series connection equipment using the elastic hinge mechanism of the present application is 3.07, which is 14.3% lower than the existing reported 3.58; indicating that the present application can generate electricity normally at a lower flow rate.

[0028] 4) The elastic hinged series hydrofoil power generation device of the present application has higher overall energy capturing efficiency: the elastic hinged mechanism is used to realize the series connection between the hydrofoils, and in the movement process, the energy lost by the front hydrofoil due to the reversing movement can be stored through the deformation of the elastic hinged mechanism, and the stored energy is then transmitted through the structure to assist the reversing and energy capturing movement of the rear hydrofoil; similarly, the energy lost by the rear hydrofoil due to the reversing movement can also be stored by the elastic hinged mechanism, and the stored energy can assist the reversing and energy capturing movement of the front hydrofoil, and finally through the store-release bidirectional coupling gain function of the elastic connection structure, the energy lost by the hydrofoil turning is repeatedly used between the two hydrofoils through the bidirectional coupling function, and the energy capturing efficiency of each hydrofoil is improved. Laboratory physical test results show that the energy capturing efficiency of the front hydrofoil is 42%, which is 33% higher than the existing series hydrofoil device efficiency of 31.5%; the energy capturing efficiency of the rear hydrofoil is 35%, which is 180% higher than the existing series hydrofoil device efficiency of 12.5%; and the overall energy capturing efficiency of the two hydrofoils is 213% higher than the existing series hydrofoil device.

[0029] 5) The elastic hinged series hydrofoil power generation device of the present application has larger total energy capturing amount per unit water area: for two hydrofoils arranged in front and rear, the wake generated by the movement of the front hydrofoil will affect the energy capturing effect of the rear hydrofoil, and in order to ensure the efficient energy capturing of the rear hydrofoil, the spacing between the two hydrofoils is usually set to 9 times the chord length of the hydrofoil; the two hydrofoils are connected together through the elastic structure, the "store-release" function of the elastic structure for the energy lost by the hydrofoil turning realizes the bidirectional coupling gain of the reversing energy, improves the energy capturing efficiency of a single hydrofoil, and also realizes the close arrangement of the two hydrofoils, so that more hydrofoils can be arranged in a unit water area, thereby realizing the effect of larger total energy capturing amount per unit water area. Laboratory test results show that the optimal working spacing of the two hydrofoils of the present application is 1.5 times the chord length of the hydrofoil, at this time, the energy capturing efficiency of the two hydrofoils is 77%, the optimal working spacing of the two hydrofoils without hinge is 9 times the chord length of the hydrofoil, and the energy capturing efficiency of the two hydrofoils is 44%, and the total energy capturing amount per unit water area of the present application is 1049% higher than that of the existing device. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a perspective view of the elastic hinged series hydrofoil power generation device in the present application;

[0031] Figure 2 is a front view of the elastic hinged series hydrofoil power generation device in the present application;

[0032] Figure 3 is a side view of the elastic hinged series hydrofoil power generation device in the present application;

[0033] Figure 4 is a top view of the elastic hinged series hydrofoil power generation device in the present application;

[0034] Figure 5 Figure 8 is a schematic view of the oscillating hydrofoil power generation device in the present application after removing a part of the structure;

[0035] Figure 6 Figure 9 is a graph showing the relationship between the rotation angle and the lateral displacement of the front hydrofoil and time under the action of water flow; wherein the red curve is the curve of the rotation angle changing with time, and the black curve is the relationship curve of the lateral displacement changing with time;

[0036] Figure 7 Figure 10 is a graph showing the relationship between the rotation angle and the lateral displacement of the rear hydrofoil and time under the action of water flow; wherein the red curve is the curve of the rotation angle changing with time, and the black curve is the relationship curve of the lateral displacement changing with time;

[0037] Figure 8 Figure 11 is a graph showing the relationship between the rotation angle and the lateral displacement of the front hydrofoil and time under the action of water flow when the front hydrofoil and the rear hydrofoil are not hinged by the first extension spring; wherein the red curve is the curve of the rotation angle changing with time, and the black curve is the relationship curve of the lateral displacement changing with time;

[0038] In all the drawings, the same reference signs represent the same technical features, specifically:

[0039] 1, oscillating hydrofoil power generation device; 2, elastic hinge mechanism; 3, belt transmission mechanism; 4, support frame; 5, bidirectional damping mechanism; 6, generator; 101, front hydrofoil; 102, rear hydrofoil; 201, hinge; 202, first extension spring; 7, sliding block; 8, sliding rail; 301, belt; 302, pulley. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0041] REFERENCE Figures 1-8 An elastic hinge series hydrofoil power generation device, comprising an elastic hinge mechanism 2 and two oscillating hydrofoil power generation devices 1 arranged in sequence along the direction of water flow, wherein:

[0042] Each of the oscillating hydrofoil power generation devices 1 comprises a support frame 4, a generator 6, a slide rail 8, a slide block 7, a hydrofoil and a bidirectional damping mechanism 5, the bidirectional damping mechanism 5, the generator 6 and the slide rail 8 are all mounted on the support frame 4, the slide block 7 is slidingly mounted on the slide rail 8, one end of the hydrofoil is used to extend into the water flow, the other end of the hydrofoil is provided with a connecting shaft, the connecting shaft is rotatably mounted on the slide block 7 and connected with the generator 6, so as to drive the generator 6 to generate electricity, the connecting shaft is preferably rotatably mounted on the slide block 7 through a bearing, and the bidirectional damping mechanism 5 is fixedly connected with the slide block 7, so as to provide damping force for the first direction movement of the hydrofoil and the second direction movement opposite to the first direction.

[0043] The generator 6 preferably has a transmission, and the transmission ensures high power generation efficiency of the generator 6 through the gear transmission ratio inside the transmission. The support frame 4 is preferably a double-body shape with "inverted L-shaped" two ends and a recess in the middle. The support frame 4 provides stability for the overall device. The belt transmission mechanism 3 and the generator 6 are responsible for converting the water flow energy captured by the series hydrofoil into electrical energy; the bidirectional damping mechanism 5 optimizes the crosswise movement of the hydrofoil by relying on its own elasticity. The two hydrofoils are respectively a front hydrofoil 101 and a rear hydrofoil 102, and the water flow passes through the front hydrofoil 101 and the rear hydrofoil 102 in turn.

[0044] The length directions of the two hydrofoils of the two groups of hydrofoil assemblies are parallel to each other, the two hydrofoils of the two groups of hydrofoil assemblies are connected together through the elastic hinged mechanism 2, and the two hydrofoils and the elastic hinged mechanism 2 connecting them together form a series hydrofoil; the elastic hinged mechanism 2 comprises a first tensile spring 202 and two hinge pieces 201, each end of the first tensile spring 202 is hingedly connected to one of the hydrofoils through one of the hinge pieces 201, so that when the hydrofoils rotate and move along the length direction of the slide rail, the first tensile spring 202 exerts elastic force on the two hydrofoils and rotates around the center line of the hinge piece 201. The hinge piece 201 can adopt a commonly used hinged structure, such as a structure in which the inner and outer rings can rotate relative to each other, or a pin shaft rotatably mounted on the hydrofoil.

[0045] When the water flow passes through the series hydrofoil of the present application, under the fluid-structure coupling effect, the front hydrofoil 101 and the rear hydrofoil 102 respectively produce periodic oscillation around the connecting shaft, and reciprocating crosswise movement in the direction perpendicular to the water flow. The crosswise displacement and the pitch angle of the hydrofoil change with time, both of which change in a sinusoidal manner.

[0046] When the hydrofoil switches from transverse movement upstream to transverse movement downstream (or vice versa), the flow separates due to the sudden change in the direction of the hydrofoil movement, causing the surface boundary layer of the hydrofoil to separate from the wall surface, and forming periodic shedding trailing vortices at the trailing edge. The trailing vortices dissipate energy during generation, shedding and downstream transport, and according to the phase difference and relative position between the front hydrofoil 101 and the rear hydrofoil 102, positively or negatively affect the flow field in which the rear hydrofoil is located.

[0047] Compared with the traditional uncoupled series (energy is difficult to transfer between hydrofoils) or mechanically rigidly coupled series design (complex structure, limited degrees of freedom), the elastic hinge mechanism 2 constitutes a strong elastic coupling series structure with elastic hinge, which guarantees the transmission of dynamic load between hydrofoils and the freedom of hydrofoil movement, significantly suppresses the vortex energy dissipation of the traditional uncoupled series design, effectively avoids the energy capture performance limitation caused by the reduction of hydrofoil freedom in the traditional mechanically rigidly coupled design, and thus improves the energy capture efficiency of the device.

[0048] When the front hydrofoil 101 changes direction, the energy lost due to flow separation drives the elastic deformation of the first tensile spring 202 of the elastic hinge mechanism 2, and this elastic deformation stores the energy of the front hydrofoil 101 change direction as the elastic potential energy of the first tensile spring 202; when the rear hydrofoil 102 enters the change direction movement, the stored elastic potential energy is released to assist the rear hydrofoil 102 to change direction quickly; at the same time, part of the energy of the rear hydrofoil 102 change direction process is also converted into elastic potential energy stored in the first tensile spring 202, and then when the front hydrofoil 101 changes direction again, the energy stored in the first tensile spring 202 is released to assist the front hydrofoil 101 to change direction quickly. Thus, the elastic hinge mechanism 2 realizes the bidirectional coupling gain of the change direction energy between the series hydrofoils through its "storage-storing-release" bidirectional coupling gain function, significantly reduces the additional energy loss caused by rigid change direction and dead point problem in the traditional rigid coupling structure, and avoids the low energy transfer efficiency between hydrofoils in the uncoupled series.

[0049] Meanwhile, the introduction of the elastic hinge mechanism 2 makes the tandem hydrofoils and the strong elastic coupling system. Compared with the traditional uncoupling tandem design: the structure effectively suppresses the vortex mutual interference generated when the hydrofoils are close, allowing the compact arrangement of multiple hydrofoils; compared with the traditional mechanical rigid coupling structure: on the one hand, the elastic hinge mechanism 2 utilizes its elastic deformability to realize the "storage-release" bidirectional coupling gain of the reversing energy, reducing the energy loss of the hydrofoil reversing process; on the other hand, the elastic hinge mechanism 2 relies on its elastic hinge characteristics to autonomously adjust the motion configuration of the hydrofoil, obtain a larger equivalent attack angle and lift coefficient, improve the hydrofoil lift, and avoid the energy loss caused by the traditional mechanical rigid constraint. Therefore, the introduction of the elastic hinge mechanism 2 not only supports the arrangement of more hydrofoils in a unit water flow length, but also significantly improves the energy capture efficiency of a single hydrofoil, and ultimately significantly improves the total energy capture amount of the device per unit water flow.

[0050] Under low-speed water flow conditions, the elastic hinge mechanism 2 enables the front hydrofoil 101 and the rear hydrofoil 102 to obtain a more optimal system equivalent attack angle, realizing a high-lift hydrofoil configuration of "front hydrofoil 101-elastic hinge mechanism 2-rear hydrofoil 102". This configuration significantly increases the hydrofoil lift at low flow rates, effectively reduces the effective working flow rate threshold of the device, ensures the normal operation of the power generation equipment at low flow rates, and thus widens the effective working flow rate range of the power generation equipment.

[0051] Under normal flow rates, the relative position change between the tandem hydrofoils caused by the reciprocating motion of the hydrofoils drives the elastic hinge mechanism 2 to dynamically deform and store the energy of the deformation of the first tensile spring 202, and releases the energy at an appropriate time to optimize the hydrofoil motion response. At the same time, the tandem hydrofoils promote the hydrofoils to form a high-lift configuration, significantly improve the hydrofoil lift, and thus enhance the overall energy capture efficiency.

[0052] Under high-speed water flow conditions, compared with the rear hydrofoil 102 in the uncoupling tandem structure, which is easily disturbed by the wake vortex of the front hydrofoil 101 and falls into vortex-induced vibration lock, causing the energy capture motion of the rear hydrofoil 102 to be unstable or even stagnant; the introduction of the elastic hinge mechanism 2 between the two hydrofoils of the present application can break the vortex-induced vibration lock state of the rear hydrofoil 102 through the strong elastic coupling tandem of the elastic hinge mechanism 2, so that the device maintains effective energy capture motion in the high flow rate range, thereby widening the effective working flow rate range of the device.

[0053] In summary, when the present application works, the water flow drives the tandem hydrofoils to perform a self-sustaining limit cycle oscillation motion to capture energy. The elastic hinge mechanism 2 hinges the two hydrofoils to work cooperatively, which is the core design of the present application. The elastic hinge mechanism 2 of the present application has multiple functions:

[0054] 1) Through the elastic hinge design, the elastic coupling of the hydrofoils in series is realized, and the double freedom motion of the hydrofoils is ensured; in the running process, through the elastic coupling effect of the elastic hinge mechanism 2, the equivalent attack angle of each hydrofoil is improved, the lift coefficient of the hydrofoil is increased, and the lift of the hydrofoil motion is enhanced, so that normal power generation can still be realized at a smaller flow rate, and the effective working flow rate of the device is reduced.

[0055] 2) The elastic characteristics of the elastic hinge mechanism 2 are used to realize the "storage-releasing" bidirectional coupling gain of the energy between the series hydrofoils, the energy lost by the hydrofoil turning is repeatedly used between the two hydrofoils through the bidirectional coupling function, and the energy capture efficiency of each hydrofoil is improved. Further improve the overall energy capture efficiency of the device.

[0056] 3) The elastic hinge mechanism 2 and the series hydrofoils form a strong elastic coupling system, through the storage-releasing bidirectional coupling gain function of the elastic connection structure, the negative influence of vortex between the hydrofoils is reduced, and the layout density of the hydrofoils is improved. While improving the energy capture efficiency of a single hydrofoil, the close arrangement of two hydrofoils is also realized, thereby realizing the effect of larger total energy capture per unit water area.

[0057] In addition, the connection mode of the first tensile spring 202 hinged on the hydrofoil is also very important, and the main functions are as follows: 1) flexible motion coupling: the hinged first tensile spring 202 can rotate around the center line of the hinge 201 when the hydrofoil swings under the impact of the water flow. This degree of freedom of rotation can adapt to the complex motion state of the hydrofoil in the water flow, including rotation around its own axis and transverse motion along the vertical direction of the water flow. For example, when the hydrofoil swings around the connecting shaft under the action of the water flow, the hinged first tensile spring 202 can adjust its position and force direction accordingly with the change of the rotation angle of the hydrofoil, thereby ensuring the coordination between the deformation process of the first tensile spring 202 and the motion process of the hydrofoil. 2) Improve energy transmission and utilization efficiency: if the first tensile spring 202 is not hinged on the hydrofoil, but adopts other fixed modes, the deformation direction of the first tensile spring 202 will deviate from the motion direction of the hydrofoil, resulting in the dissipation of part of the energy in the form of invalid lateral force, etc., reducing the energy transmission and utilization efficiency. 3) Adapt to the motion trajectory of the hydrofoil: the motion and force of the hydrofoil in the water flow are relatively complex. The hinged first tensile spring 202 can better follow the motion trajectory of the hydrofoil, so that the elastic hinge mechanism 2 can effectively play a role in the whole motion process. For example, in the process of transverse motion and rotation, the motion speed and direction of the hydrofoil at different positions will change, and the hinged first tensile spring 202 can flexibly adapt to these changes, ensuring that the elastic connection between the hydrofoils is always in the best working state.

[0058] If the first tensile spring 202 is not hingedly connected to the hydrofoils but is fixedly connected to the hydrofoils, the following adverse effects will occur: 1) Motion coupling disorder: When the hydrofoils oscillate in the water flow, the force generated by the deformation of the first tensile spring cannot effectively match the direction and speed of the motion of the hydrofoils, which will cause the loss of coordination between the lateral movement and rotational movement of the hydrofoils, and the motion of the two hydrofoils will interfere with each other. For example, the oscillation of the front hydrofoil 101 can transmit an inappropriate force to the rear hydrofoil 102 through the non-hingedly connected first tensile spring 202, causing the direction and speed of the motion of the rear hydrofoil 102 to change abruptly, thereby destroying the motion rules of the two hydrofoils. 2) Deviation of the motion trajectory from the sinusoidal law: The sinusoidal motion trajectory is the ideal state of the interaction between the hydrofoils and the water flow and the coordinated work of the elastic hinge mechanism 2 (refer to the approximate sinusoidal curves of the rotation angle and lateral displacement of the hydrofoils versus time in Figure 6 、 Figure 7 , Figure 6 、 Figure 7 , where the curve with larger peaks and smaller troughs is the rotation angle versus time curve). When the first tensile spring 202 is not hingedly connected to the two hydrofoils, the motion trajectory of the hydrofoils will be disturbed by unreasonable forces. Such disturbing forces will cause the displacement and rotation angle of the hydrofoils versus time curve to deviate from the sinusoidal law, showing a chaotic curve shape (refer to the rotation angle and lateral displacement versus time curve of the front hydrofoil under the action of the water flow in Figure 8 , and the rear hydrofoil is similar to the front hydrofoil). Chaotic motion trajectory will cause the interaction between the hydrofoils and the water flow to be unstable, for example, the hydrofoils may exhibit excessive oscillation or stagnation at certain positions, affecting the continuous capture of the water flow energy by the hydrofoils, and thus affecting the stability and efficiency of power generation. Figures 6-8 , where the horizontal coordinate represents time t in seconds, and the vertical coordinate values of the rotation angle and lateral displacement have been mathematically transformed, the rotation angle θ is calculated by the formula: θ = θ sensor •π / 180°; the lateral displacement h is calculated by the formula: h = h sensor / c . Wherein, θ sensor is the angle data directly read by the angle sensor connected to the connecting shaft, h sensor is the displacement data directly read by the displacement sensor connected to the slider, θ is radian, h is the dimensionless displacement data, c is the chord length of the hydrofoil.

[0059] The hydrofoil is prone to excessive swing or vibration due to changes in water flow speed and direction. The bidirectional damping mechanism 5 effectively suppresses excessive swing by providing a damping force opposite to the direction of the hydrofoil movement, allowing the hydrofoil to move within a stable range and reducing energy waste. The bidirectional damping mechanism 5 makes the hydrofoil movement more stable and regular, avoiding excessive or insufficient frequency and irregular vibration, and improving energy conversion efficiency.

[0060] During the swing of the hydrofoil, the bidirectional damping mechanism 5 can dynamically adjust the size of the damping force according to the speed and direction of the hydrofoil movement, thereby achieving energy balance control of the hydrofoil system. When the speed of the hydrofoil movement is fast, the bidirectional damping mechanism 5 will provide a larger damping force to absorb excess kinetic energy and prevent the hydrofoil from deviating from the movement trajectory due to excessive speed. When the speed of the hydrofoil movement is slow, the bidirectional damping mechanism 5 will appropriately reduce the damping force to allow the hydrofoil to swing more easily, thereby maintaining the energy stability of the entire system. The bidirectional damping mechanism 5 precisely controls the movement state of the hydrofoil to ensure that the hydrofoil always interacts well with the water flow, thereby improving energy conversion efficiency. The adjustment of the damping force allows the hydrofoil to move more smoothly, reduces energy loss, and ensures that the kinetic energy of the water flow can be maximized to mechanical energy and transmitted to the generator 6.

[0061] Each bidirectional damping mechanism 5 of the oscillating hydrofoil power generation device 1 can be provided with multiple bidirectional damping mechanisms 5, which can be symmetrically arranged on both sides of the sliding block 7, such as rubber shock-absorbing blocks, springs, etc., to provide bidirectional damping force.

[0062] The specific effect of the bidirectional damping mechanism 5 on the swing frequency is as follows: increasing the damping force will reduce the hydrofoil swing frequency, making the hydrofoil move more smoothly and slowly, and reducing energy loss and mechanical fatigue caused by frequent and rapid swing; reducing the damping force will increase the hydrofoil swing frequency, allowing the hydrofoil to respond more quickly to changes in water flow, and quickly swing when the flow speed is high or the water flow kinetic energy is sufficient, thereby improving power generation efficiency. However, the damping force cannot be too small, as a too small damping force will result in excessive swing amplitude, affecting stability. The bidirectional damping mechanism 5 dynamically adjusts the damping force according to the speed and direction of the hydrofoil movement, allowing the swing frequency to be automatically optimized according to the flow speed and the movement state of the hydrofoil, thereby being in the best working range, improving power generation efficiency and equipment stability.

[0063] Further, each of the hinges 201 is mounted on the side edge of the hydrofoil.

[0064] The hinged piece 201 is installed at the edge of the hydrofoil, and the position is selected so that the elastic hinge mechanism 2 can more effectively transmit force and motion during the swing of the hydrofoil. The hinged piece 201 at the edge position can better adapt to the swing trajectory of the hydrofoil, making the motion of the hydrofoil under the action of the water flow more smooth and stable, reducing the torsional and bending stress concentration of the hydrofoil during the motion, and improving the structural strength and service life of the hydrofoil. At the same time, this arrangement is also conducive to optimizing the stress distribution of the entire device, making the stress between the components more uniform and reasonable, and enhancing the overall stability and reliability of the equipment.

[0065] The hinged piece 201 is arranged at the edge of the hydrofoil, which can make the elastic hinge mechanism 2 more coordinated with the motion of the hydrofoil, and ensure that the elastic hinge mechanism 2 can timely and effectively produce elastic deformation when the hydrofoil swings, and transfer and exchange energy between the two hydrofoils. In this way, the energy generated during the swing of the hydrofoil can be more fully utilized, and the energy loss during transmission can be reduced, thereby further improving the energy conversion efficiency of the entire power generation equipment.

[0066] Further, the center line of the first tensile spring 202 when stretched is collinear with the center line of each of the hinged pieces 201, and the center line of each of the hinged pieces 201 is perpendicular to the length direction of the hydrofoil, and the center lines of the two hinged pieces 201 of the elastic hinge mechanism 2 are collinear.

[0067] This collinear design ensures that the first tensile spring 202 mainly produces tensile or compressive deformation along its axis direction during the motion of the hydrofoil, optimizes the deformation direction of the first tensile spring 202, and more effectively stores and releases elastic potential energy. When the hydrofoil rotates around the connecting shaft, the first tensile spring 202 can effectively store and release elastic potential energy along its axis direction, thereby more efficiently converting the motion energy of the hydrofoil into elastic potential energy, and releasing it at the appropriate time to assist the swing of the hydrofoil, improving the energy conversion efficiency.

[0068] The collinear design helps to reduce the torsional and bending stress concentration of the hydrofoil during the motion. The first tensile spring 202 is arranged along the center line of the hinged piece 201, so that the stress of each part of the hydrofoil during the swing is more uniform and reasonable, reducing the instability of the vibration and swing amplitude of the hydrofoil due to uneven stress. This uniform stress distribution enhances the stability of the motion of the hydrofoil, so that the hydrofoil can swing more smoothly in the water flow, thereby improving the operation stability and power generation quality of the power generation equipment.

[0069] Further, the first tensile spring 202 is in a relaxed state before the hydrofoil drives it to deform, which makes the first tensile spring 202 not exert additional resistance or constraint force on the hydrofoil in the initial stage of the hydrofoil movement, thereby reducing the energy loss when the hydrofoil starts. The hydrofoil is easier to start swinging under the impact of water flow, which reduces the starting flow rate requirement of the device and enables the power generation equipment to start and generate power at a lower water flow speed. For example, under low flow conditions, the water flow impact on the hydrofoil is small, and if the first tensile spring 202 is in a pre-tightened state, the hydrofoil may need to overcome a large spring force to start moving, while the first tensile spring 202 in a relaxed state enables the hydrofoil to start more easily at low flow rate, widening the effective working flow rate range of the device. Since the first tensile spring 202 is in a relaxed state before the hydrofoil starts to move, the hydrofoil can more fully absorb the kinetic energy of the water flow and convert it into mechanical energy in the initial swinging stage. As the swinging amplitude of the hydrofoil gradually increases, the first tensile spring 202 starts to deform and store elastic potential energy. When the hydrofoil changes direction, the elastic potential energy stored in the first tensile spring 202 is released, assisting the hydrofoil to change direction quickly, thereby improving the movement efficiency and energy capture capacity of the hydrofoil. This design enables the hydrofoil to more effectively utilize the energy in the water flow during movement, reduces the waste of energy in the initial stage, and improves the energy conversion efficiency of the entire power generation equipment.

[0070] Further, the elastic hinge mechanism 2 is arranged along the length direction of the hydrofoil. By arranging multiple elastic hinge mechanisms 2 up and down, the overall stiffness and carrying capacity of the entire series hydrofoil in the direction perpendicular to the water flow can be significantly improved. Multiple elastic hinge mechanisms 2 share the various loads and moments generated during the swinging of the hydrofoil, avoiding problems such as deformation, fatigue or damage of a single elastic hinge mechanism 2 due to excessive force, enhancing the structural strength and reliability of the entire device, enabling it to adapt to larger scale hydrofoils and higher flow rate conditions, and improving the application range and power output capacity of the power generation equipment.

[0071] Multiple elastic hinge mechanisms 2 are arranged along the length direction of the hydrofoil, which can be more evenly distributed in the length direction of the hydrofoil, enabling the hydrofoil to obtain effective elastic force assistance at all positions during swinging. This uniform distribution of elastic support can make the movement of the hydrofoil more stable, reduce the vibration and deformation of the hydrofoil during movement, and improve the operation stability and power generation quality of the power generation equipment. At the same time, multiple elastic hinge mechanisms 2 can more fully absorb and utilize the energy lost during the turning of the hydrofoil, and more effectively transfer and recover energy between two hydrofoils, further improving the energy recovery effect and power generation efficiency of the entire system.

[0072] Further, the length of each hydrofoil is L.

[0073] The distance between the two water wings is 1.5L-2L when each water wing is perpendicular to the water flow direction.

[0074] The distance range is set based on the comprehensive consideration of fluid mechanics principles and energy capture optimization. The appropriate distance can ensure that the rear water wing can still obtain sufficient energy for capture in the wake formed after the water flow passes through the front water wing, while avoiding the problems of mutual interference, energy competition and vortex interaction between the water wings due to too small distance, and preventing the waste of water space and the reduction of the number of water wings per unit water area due to too large distance. By reasonably setting the distance between the water wings, more water wings can be arranged in a limited water area, improving the total energy capture amount per unit water area, while enabling the entire series water wing system to work better in cooperation, achieving efficient utilization and maximum capture of energy.

[0075] Further, the bidirectional damping mechanism 5 includes a second tension spring, and the second tension spring is in a pre-tension state before the water wing moves.

[0076] The second tension spring in the bidirectional damping mechanism 5 is in a pre-tension state before the water wing moves, which enables the bidirectional damping mechanism 5 to have a certain damping force reserve at the initial moment. When the water wing starts to swing under the action of the water flow, the pre-tensioned second tension spring can immediately generate damping force, more effectively inhibiting the excessive swing and vibration of the water wing, making the movement of the water wing more stable and controllable, reducing the shaking and impact of the water wing during movement, and improving the operation stability and reliability of the power generation equipment. The bidirectional damping mechanism 5 in this pre-tension state can better adapt to the movement of the water wing in different directions, ensuring that effective damping force can be provided during the movement of the water wing in the first direction and the second direction opposite to the first direction, and realizing precise control and stable support of the movement of the water wing.

[0077] The pre-tensioned second tension spring can dynamically adjust the size and direction of the damping force according to the movement speed and direction of the water wing, thereby autonomously adjusting the transverse movement amplitude and frequency of the series water wing. Through this real-time energy adjustment effect, the movement state of the water wing is better matched with the water flow conditions, and the energy capture effect of the water wing is optimized. When the water flow speed changes or the water wing is disturbed, the bidirectional damping mechanism 5 with the pre-tensioned second tension spring can respond and adjust more quickly, ensuring that the water wing is always in an optimal movement state, and improving the energy conversion efficiency and stability of the entire power generation equipment under different working conditions.

[0078] Further, the hydrofoils and the generator 6 can be directly connected or connected through a gear mechanism, in which case the generator 6 needs to be installed on the sliding block 7, but this will increase the burden of the hydrofoil transverse movement, resulting in a decrease in power generation efficiency. The hydrofoils of the present application are preferably connected to the generator 6 through a belt transmission mechanism 3 and the sliding block 7, the belt transmission mechanism 3 comprising a belt 301 and two pulleys 302 rotatably mounted on the support frame 4, one of which is mounted on the rotor shaft of the generator 6, and the belt 301 is fixedly mounted on the sliding block 7 to drive the belt 301 to move when the sliding block 7 moves along the slide rail 8, thereby rotating the pulley 302 to drive the generator to generate electricity.

[0079] The cooperation of the belt 301 and the pulley 302 can effectively convert the linear reciprocating motion of the hydrofoil into the rotational motion of the rotor shaft of the generator 6, achieving efficient power transmission. Compared with direct connection or gear transmission, the belt transmission mechanism 3 can to some extent buffer and absorb the impact and vibration during the movement of the hydrofoil, reduce energy loss, improve transmission efficiency, and thus improve the output power and power generation efficiency of the generator 6.

[0080] Further, the displacement of each hydrofoil along the length direction of the slide rail 8 changes approximately sinusoidally with time, and the rotation angle of each hydrofoil also changes approximately sinusoidally with time. This motion law design makes the movement of the hydrofoil more in line with the dynamics of the water flow. The sinusoidal displacement and rotation angle can make the interaction between the hydrofoil and the water flow more coordinated during the swinging process, reducing the acceleration discontinuity and inertial force impact of the hydrofoil during the movement. This smooth motion law is beneficial to improve the energy capture efficiency of the hydrofoil, because the hydrofoil can more effectively perform periodic acceleration and deceleration in the water flow, thereby more fully absorbing the kinetic energy in the water flow and converting it into mechanical energy to be transmitted to the generator 6 for power generation.

[0081] According to another aspect of the present application, a power generation method of an elastic hinged series hydrofoil power generation device is also provided, comprising the following steps:

[0082] 1) Two oscillating hydrofoil power generation devices 1 are arranged in sequence along the direction of water flow and fixed on the shore, and their hydrofoils are connected together through elastic hinged mechanism 2, wherein each oscillating hydrofoil power generation device 1 comprises support frame 4, generator 6, sliding rail 8, sliding block 7, hydrofoil and bidirectional damping mechanism 5, the bidirectional damping mechanism 5, generator 6 and sliding rail 8 are installed on the support frame 4, the sliding block 7 is slidingly installed on the sliding rail 8, one end of the hydrofoil extends into the water flow, the other end of the hydrofoil is rotatably installed on the sliding block 7 and connected with the generator 6, and the sliding block 7 is fixedly connected with the bidirectional damping mechanism 5 to provide damping force for the first direction movement of the hydrofoil and the second direction movement opposite to the first direction; by arranging the two oscillating hydrofoil power generation devices 1 in sequence along the direction of water flow and connecting the two hydrofoils through the elastic hinged mechanism 2, the water flow can impact the two hydrofoils in sequence to cause the swing of the hydrofoils. In the swing process of the hydrofoils, the sliding of the sliding block 7 on the sliding rail 8 and the connection of the hydrofoil with the generator 6 realize the efficient conversion of mechanical energy into electrical energy. At the same time, the cooperation of the bidirectional damping mechanism 5 and the elastic hinged mechanism 2 can autonomously adjust the motion state of the hydrofoil, optimize the energy capture process and improve the power generation efficiency. This systematic power generation method makes the entire power generation process more orderly and efficient, can fully play the advantages of the elastic hinged series hydrofoil power generation equipment, and realizes the effective utilization and stable output of water flow energy.

[0083] 2) Under the action of water flow, the water flow impacts the two hydrofoils in sequence, in the swing process of the hydrofoils, the sliding block 7 slides along the sliding rail 8 with the hydrofoil and the hydrofoil drives the rotor shaft of the generator 6 to rotate, thereby realizing the power generation of the generator 6; at the same time, the bidirectional damping mechanism 5 provides damping force in the swing process of the hydrofoil, autonomously adjusts the lateral displacement energy capture motion amplitude and frequency of the series hydrofoil, optimizes the motion state of the hydrofoil, improves the energy capture, and the elastic hinged mechanism 2 assists the swing of each hydrofoil by continuously producing elastic deformation and restoring elastic deformation, thereby repeatedly utilizing the energy lost by turning each hydrofoil between the two hydrofoils, and improving the energy capture efficiency of each hydrofoil.

[0084] Those skilled in the art will readily understand that the above description is only the preferred embodiment of the present application and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A flexible articulated series hydrofoil power generation device, characterized in that, It includes a flexible hinge mechanism and two oscillating hydrofoil power generation devices arranged sequentially along the water flow direction, wherein: Each of the aforementioned oscillating hydrofoil power generation devices includes a support frame, a generator, a slide rail, a slider, a hydrofoil, and a bidirectional damping mechanism. The bidirectional damping mechanism, the generator, and the slide rail are all mounted on the support frame. The slider is slidably mounted on the slide rail. One end of the hydrofoil is used to extend into the water flow, and the other end of the hydrofoil is equipped with a connecting shaft. The connecting shaft is rotatably mounted on the slider and connected to the generator to drive the generator to generate electricity. The bidirectional damping mechanism is fixedly connected to the slider to provide damping force for the hydrofoil's movement in a first direction and its movement in a second direction opposite to the first direction. The two hydrofoils of the two oscillating hydrofoil generators are connected together by the elastic hinge mechanism, which includes a first tension spring and two hinge members. Each end of the first tension spring is respectively hinged to one of the hydrofoils by one of the hinge members, so that when the hydrofoil rotates and moves along the length direction of the slide rail, the first tension spring applies a spring force on the two hydrofoils and rotates about the center line of the hinge member.

2. The elastically articulated series hydrofoil power generation device according to claim 1, characterized in that, Each of the aforementioned hinges is mounted on the side edge of the hydrofoil.

3. The elastically articulated series hydrofoil power generation device according to claim 1, characterized in that, When the first tension spring is taut, its centerline is collinear with the centerline of each of the hinge members. The centerline of each hinge member is perpendicular to the length direction of the hydrofoil. Furthermore, the centerlines of the two hinge members of the elastic hinge mechanism are collinear.

4. The elastically articulated series hydrofoil power generation device according to claim 1, characterized in that, Before the hydrofoil causes the first tension spring to deform, the first tension spring is in a relaxed state.

5. The elastically articulated series hydrofoil power generation device according to claim 1, characterized in that, There are multiple elastic hinge mechanisms, and they are arranged along the length of the hydrofoil.

6. The elastically articulated series hydrofoil power generation device according to claim 1, characterized in that, The chord length of each of the aforementioned hydrofoils is L; When each hydrofoil is perpendicular to the direction of water flow, the distance between the two hydrofoils is 1.5L to 2L.

7. The elastically articulated series hydrofoil power generation device according to claim 1, characterized in that, The bidirectional damping mechanism includes a second tension spring, which is in a pre-tensioned state before the hydrofoil connected to it moves.

8. The elastically articulated series hydrofoil power generation device according to claim 1, characterized in that, The hydrofoil is connected to the generator via a belt drive mechanism and the slider. The belt drive mechanism includes a belt and two pulleys rotatably mounted on the support frame. One of the pulleys is mounted on the rotor shaft of the generator. The belt is fixedly mounted on the slider so that it moves as the slider moves along the slide rail, thereby causing the pulley to rotate and drive the engine to generate electricity.

9. A flexible articulated series hydrofoil power generation device according to claim 1, characterized in that, The displacement of each hydrofoil along the length of the slide rail changes approximately sinusoidally over time, and the rotation angle of each hydrofoil also changes approximately sinusoidally over time.

10. A method for generating electricity using a flexible articulated series hydrofoil generator, characterized in that, Includes the following steps: 1) Two oscillating hydrofoil generators are arranged sequentially along the water flow direction and fixed to the bank. Their hydrofoils are connected together by an elastic hinge mechanism. Each oscillating hydrofoil generator includes a support frame, a generator, a slide rail, a slider, a hydrofoil, and a bidirectional damping mechanism. The bidirectional damping mechanism, the generator, and the slide rail are all mounted on the support frame. The slider is slidably mounted on the slide rail. One end of the hydrofoil extends into the water flow, and the other end of the hydrofoil is equipped with a connecting shaft, which is rotatably mounted on the slider and connected to the generator. The bidirectional damping mechanism is fixedly connected to the slider to provide damping force for the hydrofoil's movement in a first direction and in a second direction opposite to the first direction. 2) Under the action of water flow, the water flow impacts the two hydrofoils in sequence. During the oscillation of the hydrofoils, the slider carries the hydrofoils to slide along the slide rail and the hydrofoils drive the rotor shaft of the generator to rotate, thereby realizing the generation of electricity by the generator. At the same time, the bidirectional damping mechanism provides damping force during the oscillation of the hydrofoils, autonomously adjusts the amplitude and frequency of the transverse energy-harvesting motion of the series hydrofoils, optimizes the motion state of the hydrofoils, and improves energy harvesting. The elastic hinge mechanism assists each hydrofoil in oscillation by continuously generating elastic deformation and restoring elastic deformation, thereby reusing the energy lost by each hydrofoil in turning between the two hydrofoils and improving the energy harvesting efficiency of each hydrofoil.

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