Oscillating based dual serial bluff body vortex-induced vibration regenerative energy harvesting system

Abstract

This invention discloses a regenerative energy harvesting system based on oscillating dual-series blunt body vortex-induced vibration, comprising a serial dual-blunt body vortex-induced vibration device 1, a speed-increasing gear set 2, and a generator system 3. The serial dual-blunt body vortex-induced vibration device 1 has two blunt bodies arranged in series and vertically along the ocean current flow direction, and telescopic swing arms 1-3 at both ends of them. The upstream blunt body has inner and outer layers, with the inner layer being a transmission shaft 1-1-1 and the outer layer being an upstream blunt body shell 1-1; the downstream blunt body is a downstream blunt body shell 1-2. The transmission shaft 1-1-1 and the downstream blunt body shell 1-2 are connected at their upper and lower ends by telescopic upper swing arm 1-3-2 and telescopic lower swing arm 1-3-1, respectively. The speed-increasing gear set 2 and the generator system 3 are arranged sequentially above the transmission shaft 1-1-1 and coaxially with it. This invention avoids the problems of self-locking and high friction that may exist in the linear vibration of a single object, reduces the impact of the water flow environment on the power generation system, and meets the requirements of high environmental adaptability.

Description

Technical Field

[0001] This invention belongs to the field of renewable energy technology, and in particular relates to a regenerative energy harvesting system based on oscillating dual-series blunt body vortex-induced vibration. Background Technology

[0002] A vast amount of low-grade flowing energy exists in nature but remains untapped. The average flow velocity of most small and medium-sized river tributaries is less than 1 m / s, and most hydroelectric turbines require a velocity of 1.5 m / s to achieve efficient power generation. Furthermore, many coastal areas of my country, especially in the north, have ocean currents with velocities around 1 m / s. This low flow velocity and shallow water depth result in a significant amount of unusable water resources, necessitating the development of new renewable energy harvesting systems suitable for low-flow-velocity conditions.

[0003] Extensive research in marine engineering has shown that when the flow velocity is low, the flow field formed behind marine risers, offshore platforms, cables, and bridges exhibits strong pulsating characteristics. This type of pulsating flow can cause the structure to produce periodic oscillating motion. By converting the kinetic energy of these vibrations into electrical energy, flow energy harvesting under low flow velocity conditions can be achieved.

[0004] While the concept of vortex-induced vibration energy harvesting is theoretically proven to harvest low-grade flow energy, it has encountered numerous engineering difficulties in the decade or so since its inception, hindering its widespread practical application. Therefore, it is necessary to propose new design solutions in the conceptual design phase to address the challenges of actual operation at a lower cost.

[0005] One of the challenges in vortex-induced vibration energy harvesting devices lies in the fact that most existing vibration devices involve vertical linear reciprocating vibration. Therefore, two parallel guide rails along the vertical direction are needed as a constraint and support mechanism, such as... Figure 1 As shown, the incoming flow direction is perpendicular to the paper. When the incoming flow impacts the cylinder perpendicularly, the cylinder moves back and forth in a straight line along the parallel double rails on both sides. Because the parallel double rails are mechanically prone to self-locking, and especially because underwater silt and other impurities easily accumulate on the rails, the friction during operation increases, reducing energy harvesting efficiency. Using high-precision rails and moving parts can solve the self-locking and friction problems to some extent, but the high manufacturing cost makes it difficult to widely promote this energy harvesting device.

[0006] The second challenge in vortex-induced vibration energy harvesting devices lies in the fact that the principle of vortex-induced vibration requires the vibration direction to be perpendicular to the incoming flow direction. Existing vibrating devices can only have their oscillators move in a fixed, single direction; for example, the oscillator can only move between two parallel vertical guide rails at a fixed position. While this is relatively easy to achieve in river channels, ocean currents change direction with the seasons. Because existing vibrating devices cannot change the oscillator's direction of motion with seasonal changes, and cannot consistently maintain the oscillator's vibration direction perpendicular to the incoming flow direction, they may fail to harvest energy efficiently in practical applications at certain times. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention proposes a regenerative energy harvesting system based on oscillation of a dual-series blunt body vortex-induced vibration. The aim is to avoid the self-locking problem caused by the slide rail of traditional vortex-induced vibration devices, and to enable the device to adapt to changes in flow direction, thereby achieving efficient recovery of fluid kinetic energy under various flow conditions.

[0008] To solve its technical problems, the present invention proposes the following technical solutions:

[0009] A regenerative energy harvesting system based on oscillating dual-series blunt body vortex-induced vibration is characterized by comprising a series dual-blunt body vortex-induced vibration device 1, a speed-increasing gear set 2, and a generator system 3. The series dual-blunt body vortex-induced vibration device 1 has two blunt bodies arranged in series and vertically along the ocean current flow direction, and telescopic swing arms 1-3 at both ends of them. The upstream blunt body has two layers, with the inner layer being a transmission shaft 1-1-1 and the outer layer being an upstream blunt body shell 1-1. The downstream blunt body is a downstream blunt body shell 1-2. The transmission shaft 1-1-1 and the downstream blunt body shell 1-2 are connected at their upper and lower ends by a telescopic upper swing arm 1-3-2 and a telescopic lower swing arm 1-3-1, respectively. The speed-increasing gear set 2 and the generator system 3 are arranged sequentially above the transmission shaft 1-1-1 and coaxially with the transmission shaft 1-1-1.

[0010] The upstream blunt shell 1-1 acts as a vortex generator, producing a flowing vortex structure. This flowing vortex structure originates from the surface of the upstream blunt shell 1-1. During the vortex generation process, the upstream blunt shell 1-1 remains essentially stationary. The fluid passes through the upstream blunt shell 1-1 and splits into two parts, forming an alternating vortex structure. The downstream blunt shell 1-2 acts as an oscillator, induced by the flowing vortex propagated from the upstream blunt shell 1-1, resulting in continuous circular oscillation. The vibration of the downstream blunt shell 1-2 drives the rotation of the transmission shaft 1-1-1. The oscillation of the downstream blunt shell 1-2 is transmitted to the transmission shaft 1-1-1 of the upstream blunt shell 1-1 through the extendable and retractable swing arm 1-3-1. The transmission shaft 1-1-1 then transmits the oscillation to the speed-increasing gear set 2. The speed-increasing gear set 2 accelerates the rotation and inputs it into the generator system 3. The generator system 3 converts kinetic energy into electrical energy for output, thus completing the entire energy conversion process.

[0011] Further, the upstream blunt shell 1-1 includes an upstream cylindrical shell, an upstream elliptical shell, a rounded upstream triangular prism shell, a rounded upstream square prism shell, or other rounded upstream polyhedral structure shells; the downstream blunt shell 1-2 includes a downstream cylindrical shell, a downstream elliptical shell, a rounded downstream triangular prism shell, a rounded downstream square prism shell, or other rounded downstream polyhedral structure shells.

[0012] Furthermore, the downstream blunt shell 1-2 undergoes continuous circular oscillation, which manifests as a single-degree-of-freedom reciprocating oscillation. The driving force and restoring force of the motion are both generated by the flow vortex propagating from the upstream blunt shell 1-1 acting on the surface of the downstream blunt shell.

[0013] Furthermore, the height and diameter of the upstream blunt shell 1-1 and the downstream blunt shell 1-2 are determined according to the energy output level and the actual flow environment: when the energy output is at the watt level, its height is on the order of meters, and when the energy output is at the kilowatt level, its height is on the order of tens of meters.

[0014] Furthermore, the telescopic swing arms 1-3 are used to match different flow velocities and water depths. The optimal bluff body spacing is different under different flow velocities. If the water depth is insufficient to drive vibration, the torque is increased by adjusting the spacing to ensure vortex-induced vibration.

[0015] Furthermore, the telescopic swing arm 1-3 includes a telescopic upper swing arm 1-3-2 and a telescopic lower swing arm 1-3-1. Each of the telescopic upper swing arm 1-3-2 or the telescopic lower swing arm 1-3-1 is composed of three parts: two stainless steel plates with toothed racks on one side and one stainless steel plate with toothed racks on both sides. The length of the swing arm can be changed by adjusting the meshing position of the toothed racks, and ultimately the distance between the two blunt bodies can be adjusted from 1.5 times the maximum diameter to 5 times the maximum diameter.

[0016] Furthermore, the upstream blunt body shell 1-1 is provided with a through hole 1-1-3 for connecting the flange and a through hole 1-1-4 for connecting the transmission shaft connecting sleeve near the top end; the upstream blunt body shell 1-1 and the fixed flange are fixed together through the through hole 1-1-3 for connecting the fixed flange; the upstream blunt body shell 1-1 and the transmission shaft connecting sleeve 1-1-2 are fixed together through the through hole 1-1-4 for connecting the transmission shaft connecting sleeve.

[0017] Furthermore, a slot 1-1-5 is provided at the connection between the surface of the upstream blunt shell 1-1 and the telescopic upper swing arm 1-3-2. This slot 1-1-5 is used to ensure that the downstream blunt shell 1-2 does not directly contact the upstream blunt shell 1-1 when the direction of most ocean currents is stable. Therefore, the swing of the downstream blunt shell 1-2 will not cause the upstream blunt shell 1-1 to rotate, and will not affect the upstream blunt shell 1-1 from generating a flow vortex structure.

[0018] Furthermore, the outer surface of the transmission shaft 1-1-1 connecting sleeve near the lower end is machined with an annular groove 1-1-2-1 for matching the fixing flange. The annular groove 1-1-2-1 is used to embed two semi-circular flanges 4. The outer surface below the annular groove 1-1-2-1 of the transmission shaft connecting sleeve 1-1-2 is also provided with a plurality of circumferentially spaced threaded holes 1-1-2-2 for connecting the shaft connecting sleeve. The plurality of circumferentially spaced threaded holes 1-1-2-2 are used to fix with the upstream blunt body shell 1-1.

[0019] Furthermore, the upstream blunt shell 1-1 and the transmission shaft connecting sleeve 1-1-2 are connected by a fixed or non-fixed method. When the fixed method is used, a screw is inserted into the through hole 1-1-4 of the transmission shaft connecting sleeve for fixed connection. When the non-fixed method is used, it is not necessary to insert a screw into the through hole. The non-fixed method is used when the ocean current direction changes during seasonal changes. When the ocean current direction changes, the position of the slot on the upstream blunt shell 1-1 and the ocean current direction will form an angle, which may limit the normal swing range of the swing arm. In order not to affect the normal swing of the telescopic upper swing arm 1-3-2, the non-fixed method is used. When the ocean current direction changes, the swing arm can finely adjust the orientation of the slot 1-1-5 of the upstream blunt shell 1-1 by multiple small-intensity collisions with the upstream blunt shell 1-1 at the edge of the slot, so that the change of the ocean current direction can drive the upstream blunt shell 1-1 to rotate, thereby ensuring that the position of the slot on the upstream blunt shell 1-1 matches the ocean current direction and ensuring the movement space of the swing arm.

[0020] Furthermore, the speed-increasing gear set includes a large gear set 2-1, a small gear set 2-2, and a ratchet set 2-3; the small gear set 2-2 and the ratchet set 2-3 have the same diameter and number of teeth; the large gear set 2-1, the small gear set 2-2, and the ratchet set 2-3 each have a first large gear, a second large gear, a first small gear, a second small gear, a first ratchet, and a second ratchet arranged axially from bottom to top; wherein, the first large gear and the first ratchet mesh, the second large gear and the second small gear mesh, and the first small gear and the second ratchet mesh; the first ratchet and the second ratchet of the ratchet set ensure that the two reciprocating motions can only be transmitted to the generator in a single direction, thereby ensuring that the motion transmitted from the two ratchets to the generator shaft 3-1 is a rotation in a single direction.

[0021] Furthermore, the first and second ratchet wheels each have half a cycle of motion that can be transmitted to the generator shaft 3-1. When combined, they form a unidirectional rotation. Specifically, when the first ratchet wheel outputs power within half a cycle, the second ratchet wheel only rotates in the opposite direction without outputting energy to the generator during that half cycle; conversely, when the second ratchet wheel outputs power within half a cycle, the first ratchet wheel only rotates in the opposite direction without performing any work. The pinion gear set 2-2 is used to change the reciprocating rotation direction of the second ratchet wheel: the rotation directions of the first ratchet wheel and the large gear set 2-1 are opposite. Since the second ratchet wheel is indirectly in contact with the second large gear through the pinion gear set 2-2, its rotation direction is the same as that of the large gear set 2-1 and opposite to that of the first ratchet wheel. Therefore, the reciprocating rotation directions of the first and second ratchet wheels are always opposite, but the rotation of the ratchet wheel in only one direction can be transmitted to the generator shaft 3-1, ultimately enabling the generator to receive a continuous unidirectional rotational energy input. The gear ratio of the large gear set 2-1 to the pinion gear set 2-2 is 2 to 10.

[0022] Advantages and effects of the present invention

[0023] 1. Based on the working principle of vortex-induced vibration power generation, this invention designs a single-degree-of-freedom wake-induced vibration power generation device according to the principle of interaction between the wakes of flowing objects in a series. This method avoids the problems of self-locking and high friction that may exist in the linear vibration of a single object. By changing the linear vibration to a pendulum-like rotational oscillation, the friction is greatly reduced, making it suitable for initiating vibration at low flow velocities to generate electricity.

[0024] 2. This invention adopts a pendulum rotation motion mode, and the swing direction can adapt to the incoming flow direction, which reduces the impact of the water flow environment on the power generation system and meets the requirements of high environmental adaptability: by setting the rotating shaft to be perpendicular to the water surface, the influence of gravity on the pendulum is eliminated, and the equilibrium position of the oscillator can be at any angle, thus solving the problem of flow direction adaptation. Attached Figure Description

[0025] Figure 1This is a schematic diagram of an existing energy harvesting device based on dual-track linear motion in a single direction.

[0026] Figure 2 This is a schematic diagram of the dual-series blunt body vortex-induced vibration renewable energy harvesting device of the present invention.

[0027] Figure 3 This is an exploded view of the dual-series blunt body vortex-induced vibration renewable energy harvesting device of the present invention.

[0028] Figure 4 This is a schematic diagram showing the through holes and slots arranged on the upstream cylindrical shell of the present invention;

[0029] Figure 5 This is a schematic diagram of the transmission shaft connecting sleeve embedded in the fixed flange of the present invention;

[0030] Figure 6 A schematic diagram showing the annular groove formed in the transmission shaft connecting sleeve of the present invention;

[0031] Figure 7 This is a schematic diagram showing the shortest and longest states of the telescopic swing arm of the present invention;

[0032] Figure 8 This is a schematic diagram of the speed-increasing gear set of the transmission shaft connecting sleeve of the present invention.

[0033] In the diagram, 1: Serial double blunt body vortex-induced vibration device; 1-1: Upstream blunt body shell; 1-1-1: Transmission shaft; 1-1-2: Transmission shaft connecting sleeve; 1-1-2-1: Annular groove; 1-1-2-2: Threaded hole of shaft connecting sleeve; 1-1-3: Through hole of connecting flange; 1-1-4: Through hole of connecting transmission shaft connecting sleeve; 1-1-5: Slot; 1-2: Downstream blunt body shell; 1-3: Telescopic swing arm; 1-3-1: Telescopic lower swing arm; 1-3-2: Telescopic upper swing arm; 2: Speed-increasing gear set; 2-1: Large gear set; 2-1-1: Gear set input shaft; 2-2: Small gear set; 2-3: Ratchet set; 3: Generator system; 3-1: Generator shaft; 4: Fixed flange; 5: Bearing. Detailed Implementation

[0034] Design principle of the invention

[0035] 1. Design Principle of Double-Series Blunt Body Vortex-Induced Vibration: Based on the working principle of vortex-induced vibration power generation, this invention designs a single-degree-of-freedom wake-induced vibration power generation device according to the principle of interaction between the flow wakes of serial objects. Specifically, this invention cleverly utilizes the geographical characteristics of the upstream and downstream locations, placing cylindrical blunt shells upstream and downstream respectively. The upstream cylindrical shell is stationary, while the downstream cylindrical shell is movable. Because the upstream cylindrical shell is located upstream of the water flow, when the water flows past it, the upstream cylinder first divides the fluid into two parts. After the fluid separates, it forms an alternating vortex structure that acts on the downstream cylindrical shell, allowing the upstream cylindrical shell to act as a vortex generator to produce a flow vortex structure. This vortex structure originates from the surface of the upstream cylindrical shell. The downstream cylindrical shell is induced by the flow vortices propagating from the upstream cylinder, resulting in continuous oscillation along the circumferential direction. This method avoids the need for a oscillator (the oscillator is a cylinder moving linearly between two parallel tracks, such as...). Figure 1 As shown, linear vibration on a vertical parallel track may have problems such as self-locking and high friction. By changing the linear vibration to a pendulum-like rotational oscillation, the friction is greatly reduced, making it suitable for starting vibration at lower flow velocities to generate electricity.

[0036] 2. Adaptive Flow Direction Design Principle: The improvement of this invention lies in the fact that the oscillator's trajectory is not limited by a parallel track and can be adjusted accordingly with changes in ocean current direction. The upstream cylinder is set to a fixed position and perpendicular to the water surface, while the downstream cylinder is set to a non-fixed position, and the downstream cylinder oscillates in a circular motion due to the flow vortex structure generated by the upstream cylinder. This oscillation direction can adapt to the incoming flow direction and is not limited to any position on the circumference. When the ocean current direction changes, the direction of the ocean current flowing through the upstream cylinder also changes within an angle range of 0-360 degrees. Therefore, the direction of the flow vortex generated by the ocean current flowing through the upstream cylinder also changes, and the direction induced by the flow vortex propagated from the upstream cylinder on the downstream cylinder also changes. Since the oscillation position of the downstream cylinder is limited by the change in the vortex direction of the upstream cylinder vortex generator, and the change in the upstream vortex direction is in turn limited by the change in the ocean current direction, the equilibrium position of the oscillator's vibration can always remain basically consistent with the ocean current direction. This invention's adaptive flow direction design method reduces the impact of the water flow environment on the power generation system, meets the requirements of high environmental adaptability, and gets rid of the limitation of the oscillator's motion direction by the traditional double parallel track, so that the oscillator's equilibrium position can be at any angle, thus solving the problem of flow direction adaptation.

[0037] 3. Speed-increasing gear set design principle. The speed-increasing gear set design must simultaneously meet two conditions: low speed to high speed, and although the oscillation of the oscillator (downstream cylindrical shell) is reciprocating, the input to the generator is a unidirectional rotation, thus making the final output power curve smooth and facilitating subsequent rectification and transformer transmission. The design principle that ensures that only unidirectional motion can be ultimately transmitted to the generator is as follows: First, design three sets of gears: a large gear set, a small gear set, and a ratchet set. The ratchet set is used to connect the generator to output power; the large gear set, small gear set, and ratchet set work together to double the speed; the small gear set is used to change the direction of motion of one of the two ratchets; Second, design the ratchet set as two ratchets, one above the other, from bottom to top. The two ratchets rotate simultaneously but in opposite directions, and when one ratchet is outputting power to the generator in the current half-cycle, the other does not work in the current half-cycle. Furthermore, the driving force of the first ratchet comes from the first large gear and meshes with it, while the driving force of the second ratchet comes from the first small gear and meshes with it. Third, each of the large and small gear sets has two identical gears axially aligned and moving in the same direction. The first large gear transmits power to the second large gear, which meshes with the second small gear. The second small gear transmits power to the first small gear, and the movement of the first small gear determines the direction of movement of the second ratchet. Fourth, the first and second ratchet each have half a cycle of motion to handle the power output of the gear set. When combined, they form a single-direction rotation. Specifically, when the rotation direction of the first ratchet is the same as the rotation direction of the motor shaft, it outputs power to the motor within half a cycle, while the second ratchet simply idles in the opposite direction without performing any work. When the rotation direction of the second ratchet is the same as the rotation direction of the motor shaft, it outputs power to the motor within half a cycle, while the first ratchet simply idles in the opposite direction without performing any work.

[0038] 4. Design Principle of the Upstream Cylindrical Sleeve. The design challenge of the upstream cylindrical sleeve lies in the fact that it is not directly connected to the downstream cylindrical shell. Therefore, the oscillation of the downstream cylinder will not drive the upstream cylindrical sleeve to rotate in most cases, thus having little impact on the vortex generation process on the surface of the upstream cylinder. The vortex shedding process of the upstream cylindrical sleeve is close to that of a stationary, non-rotating cylinder. Under this condition, the downstream cylindrical shell needs to be connected to the rotating shaft inside the upstream cylindrical sleeve, and the upstream cylindrical sleeve needs to be designed with slots to accommodate the movement of the upper swing arm. Due to seasonal changes, the direction of ocean currents changes with the seasons. However, at this time, the slots will interfere with the left-right reciprocating oscillation of the retractable swing arm driven by the downstream cylindrical shell. Therefore, when the change in ocean current direction makes it possible for the downstream cylindrical shell to touch the edge of the slot, it is necessary to change the orientation of the slot on the upstream cylinder so that the orientation of the slot on the upstream cylinder changes with the change in ocean current direction. The change in the orientation of the upstream cylindrical slot is achieved by using a non-fixed connection between the upstream cylindrical shell and the upstream rotating shaft connecting sleeve. Because it is a non-fixed connection, the upstream cylindrical sleeve makes corresponding adjustments under the influence of the change in ocean current direction, and after rotation, the direction of the ocean current remains in the equilibrium position of the downstream swing.

[0039] Based on the above principles, this invention designs a regenerative energy harvesting system based on the oscillating vibration of a dual-series blunt body, such as... Figure 2 , Figure 3 As shown, its features include: a series double blunt body vortex-induced vibration device 1, a speed-increasing gear set 2, and a generator system 3; the series double blunt body vortex-induced vibration device 1 has two blunt bodies arranged in series and vertically along the ocean current flow direction and telescopic swing arms 1-3 at both ends; the upstream blunt body has two layers, the inner layer is the transmission shaft 1-1-1, and the outer layer is the upstream blunt body shell 1-1; the downstream blunt body is the downstream blunt body shell 1-2; the transmission shaft 1-1-1 and the downstream blunt body shell 1-2 are connected at their upper and lower ends by telescopic upper swing arm 1-3-2 and telescopic lower swing arm 1-3-1 respectively; the speed-increasing gear set 2 and the generator system 3 are arranged sequentially above the transmission shaft 1-1-1 and coaxially with the transmission shaft 1-1-1;

[0040] The upstream blunt shell 1-1 acts as a vortex generator, producing a flowing vortex structure. This flowing vortex structure originates from the surface of the upstream blunt shell 1-1. During the vortex generation process, the upstream blunt shell 1-1 remains essentially stationary. The fluid passes through the upstream blunt shell 1-1 and splits into two parts, forming an alternating vortex structure. The downstream blunt shell 1-2 acts as an oscillator, induced by the flowing vortex propagated from the upstream blunt shell 1-1, resulting in continuous circular oscillation. The vibration of the downstream blunt shell 1-2 drives the rotation of the transmission shaft 1-1-1. The oscillation of the downstream blunt shell 1-2 is transmitted to the transmission shaft 1-1-1 of the upstream blunt shell 1-1 through the extendable and retractable swing arm 1-3-1. The transmission shaft 1-1-1 then transmits the oscillation to the speed-increasing gear set 2. The speed-increasing gear set 2 accelerates the rotation and inputs it into the generator system 3. The generator system 3 converts kinetic energy into electrical energy for output, thus completing the entire energy conversion process.

[0041] Further, the upstream blunt shell 1-1 includes an upstream cylindrical shell, an upstream elliptical shell, a rounded upstream triangular prism shell, a rounded upstream square prism shell, or other rounded upstream polyhedral structure shells; the downstream blunt shell 1-2 includes a downstream cylindrical shell, a downstream elliptical shell, a rounded downstream triangular prism shell, a rounded downstream square prism shell, or other rounded downstream polyhedral structure shells.

[0042] Furthermore, the downstream blunt shell 1-2 undergoes continuous circular oscillation, which manifests as a single-degree-of-freedom reciprocating oscillation. The driving force and restoring force of the motion are both generated by the flow vortex propagating from the upstream blunt shell 1-1 acting on the surface of the downstream blunt shell.

[0043] Furthermore, the height and diameter of the upstream blunt shell 1-1 and the downstream blunt shell 1-2 are determined according to the energy output level and the actual flow environment: when the energy output is at the watt level, its height is on the order of meters, and when the energy output is at the kilowatt level, its height is on the order of tens of meters.

[0044] Furthermore, the telescopic swing arms 1-3 are used to match different flow velocities and water depths. The optimal bluff body spacing is different under different flow velocities. If the water depth is insufficient to drive vibration, the torque is increased by adjusting the spacing to ensure vortex-induced vibration.

[0045] Furthermore, the telescopic swing arm 1-3 includes a telescopic upper swing arm 1-3-2 and a telescopic lower swing arm 1-3-1. Each of the telescopic upper swing arm 1-3-2 or the telescopic lower swing arm 1-3-1 is composed of three parts: two stainless steel plates with toothed racks on one side and one stainless steel plate with toothed racks on both sides. The length of the swing arm can be changed by adjusting the meshing position of the toothed racks, and ultimately the distance between the two blunt bodies can be adjusted from 1.5 times the maximum diameter to 5 times the maximum diameter.

[0046] Furthermore, such as Figure 4As shown, the upstream blunt body shell 1-1 has a through hole 1-1-3 for connecting the flange and a through hole 1-1-4 for connecting the transmission shaft connecting sleeve near its top end; the upstream blunt body shell 1-1 and the fixed flange are fixed together through the through hole 1-1-3 for connecting the fixed flange; the upstream blunt body shell 1-1 and the transmission shaft connecting sleeve 1-1-2 are fixed together through the through hole 1-1-4 for connecting the transmission shaft connecting sleeve.

[0047] Supplementary Note 1:

[0048] 1. For example Figure 4 , Figure 5 , Figure 6 As shown, the fixed flange consists of two semi-circular flanges fastened into an annular groove 1-1-2-1. The two semi-circular flanges have threaded holes that mate with the through holes 1-1-3 on the upstream cylindrical shell. The two semi-circular fixed flanges and their inner surfaces are not fixedly connected. When the direction of the ocean current changes with seasonal variations, the current causes a slight rotation of the upstream bluffing shell and the fixed flanges. Because the inner surface of the fixed flanges and the annular groove are not fixedly connected, they can rotate with the slight rotation of the upstream bluffing shell.

[0049] 2. The ocean current will cause the upstream blunt shell and the fixed flange to rotate slightly. This slight rotation will occur for a considerable period of time after the ocean current direction changes due to seasonal changes. When the ocean current direction does not change relatively, the upstream blunt shell 1-1 will drive the fixed flange 4 to remain basically stationary during the eddy current process.

[0050] Furthermore, such as Figure 4 As shown, a slot 1-1-5 is provided at the connection between the surface of the upstream blunt shell 1-1 and the telescopic upper swing arm 1-3-2. This slot 1-1-5 is used to ensure that the downstream blunt shell 1-2 does not directly contact the upstream blunt shell 1-1 when the direction of most ocean currents is stable. Therefore, the swing of the downstream blunt shell 1-2 will not cause the upstream blunt shell 1-1 to rotate, and will not affect the upstream blunt shell 1-1 from generating a flow vortex structure.

[0051] Supplementary Note 2:

[0052] like Figure 4 As shown, the width of the slot 1-1-5 should be greater than the range of circumferential swing or vibration of the downstream cylindrical shell. In this way, the vibration of the oscillator will only swing within the arc range of the slot, and will not transmit the force of the vibration to the upstream cylindrical shell and cause the upstream cylindrical shell to swing together.

[0053] Furthermore, such as Figure 6As shown, the outer surface of the transmission shaft 1-1-1 connecting sleeve near the lower end is machined with an annular groove 1-1-2-1 for matching the fixing flange. The annular groove 1-1-2-1 is used to embed two semi-circular flanges 4. The outer surface below the annular groove 1-1-2-1 of the transmission shaft connecting sleeve 1-1-2 is also provided with a plurality of circumferentially spaced threaded holes 1-1-2-2 for connecting the shaft connecting sleeve. The plurality of circumferentially spaced threaded holes 1-1-2-2 are used to fix the shaft connecting sleeve to the upstream blunt body shell 1-1.

[0054] Furthermore, the upstream blunt shell 1-1 and the transmission shaft connecting sleeve 1-1-2 are connected by a fixed or non-fixed method. When the fixed method is used, a screw is inserted into the through hole 1-1-4 of the transmission shaft connecting sleeve for fixed connection. When the non-fixed method is used, it is not necessary to insert a screw into the through hole. The non-fixed method is used when the ocean current direction changes during seasonal changes. When the ocean current direction changes, the position of the slot on the upstream blunt shell 1-1 and the ocean current direction will form an angle, which may limit the normal swing range of the swing arm. In order not to affect the normal swing of the telescopic upper swing arm 1-3-2, the non-fixed method is used. When the ocean current direction changes, the swing arm can finely adjust the orientation of the slot 1-1-5 of the upstream blunt shell 1-1 by multiple small-intensity collisions with the upstream blunt shell 1-1 at the edge of the slot, so that the change of the ocean current direction can drive the upstream blunt shell 1-1 to rotate, thereby ensuring that the position of the slot on the upstream blunt shell 1-1 matches the ocean current direction and ensuring the movement space of the swing arm.

[0055] Supplementary Note 3:

[0056] like Figure 6 As shown in the illustration, the fixed connection method is only one approach presented in this embodiment, and it is not mandatory. In practical applications, a non-fixed connection method can be used regardless of whether the ocean current direction changes or not. This is because changes in ocean current direction only occur with seasonal variations. When there are no seasonal changes or changes in ocean current direction, even a non-fixed connection method can keep the upstream cylinder in a essentially static state. In other words, when the ocean current direction is relatively fixed and does not change, even a non-fixed connection method can maintain the ocean current direction perpendicular to the oscillation direction of the oscillator, thereby achieving high-efficiency power generation.

[0057] Furthermore, such as Figure 8As shown, the speed-increasing gear set includes a large gear set 2-1, a small gear set 2-2, and a ratchet set 2-3; the small gear set 2-2 and the ratchet set 2-3 have the same diameter and number of teeth; the large gear set 2-1, the small gear set 2-2, and the ratchet set 2-3 each have a first large gear, a second large gear, a first small gear, a second small gear, a first ratchet, and a second ratchet arranged axially from bottom to top; wherein, the first large gear and the first ratchet mesh, the second large gear and the second small gear mesh, and the first small gear and the second ratchet mesh; the first ratchet and the second ratchet of the ratchet set ensure that the two reciprocating motions can only be transmitted to the generator in a single direction, thereby ensuring that the motion transmitted from the two ratchets to the generator shaft 3-1 is a rotation in a single direction.

[0058] Furthermore, the first and second ratchet wheels each have half a cycle of motion that can be transmitted to the generator shaft 3-1. When combined, they form a unidirectional rotation. Specifically, when the first ratchet wheel outputs power within half a cycle, the second ratchet wheel only rotates in the opposite direction without outputting energy to the generator during that half cycle; conversely, when the second ratchet wheel outputs power within half a cycle, the first ratchet wheel only rotates in the opposite direction without performing any work. The pinion gear set 2-2 is used to change the reciprocating rotation direction of the second ratchet wheel: the rotation directions of the first ratchet wheel and the large gear set 2-1 are opposite. Since the second ratchet wheel is indirectly in contact with the second large gear through the pinion gear set 2-2, its rotation direction is the same as that of the large gear set 2-1 and opposite to that of the first ratchet wheel. Therefore, the reciprocating rotation directions of the first and second ratchet wheels are always opposite, but the rotation of the ratchet wheel in only one direction can be transmitted to the generator shaft 3-1, ultimately enabling the generator to receive a continuous unidirectional rotational energy input. The gear ratio of the large gear set 2-1 to the pinion gear set 2-2 is 2 to 10.

[0059] Supplementary Note 4:

[0060] 1. The "design principle of the speed-increasing gear set" is explained in point 3 of the design principle of this invention;

[0061] 2. The two ratchet wheels in the ratchet assembly must rotate simultaneously but in opposite directions. Secondly, of the two ratchet wheels rotating in opposite directions, one must be working while the other is not. "Working" means its motion is ultimately transmitted to the generator; "not working" means the ratchet's rotation is idle and its motion cannot be transmitted to the generator. Thirdly, the working ratchet wheel is either the lower first ratchet wheel or the upper second ratchet wheel. Regardless of which ratchet wheel it is, the working ratchet wheel must rotate in the same direction as the motor. This ensures that even if the oscillator's trajectory is reciprocating, the force transmitted from the ratchet wheel to the motor remains consistent.

[0062] It should be emphasized that the above specific embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to the above embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A regenerative energy harvesting system based on oscillating dual-series blunt body vortex-induced vibration, characterized in that: The device includes a series double blunt body vortex-induced vibration device (1), a speed-increasing gear set (2), and a generator system (3). The series double blunt body vortex-induced vibration device (1) is provided with two blunt bodies arranged in series and vertically along the ocean current flow direction and telescopic swing arms (1-3) at both ends of them. The upstream blunt body has two layers, the inner layer being a transmission shaft (1-1-1) and the outer layer being an upstream blunt body shell (1-1). The downstream blunt body is a downstream blunt body shell (1-2). The transmission shaft (1-1-1) and the downstream blunt body shell (1-2) are connected at their upper and lower ends by a telescopic upper swing arm (1-3-2) and a telescopic lower swing arm (1-3-1), respectively. The speed-increasing gear set (2) and the generator system (3) are arranged sequentially above the transmission shaft (1-1-1) and coaxially with the transmission shaft (1-1-1). The upstream blunt shell (1-1) acts as a vortex generator, producing a flow vortex structure. This flow vortex structure originates from the surface of the upstream blunt shell (1-1). During the vortex generation process, the upstream blunt shell (1-1) remains essentially stationary. The fluid passes through the upstream blunt shell (1-1) and is divided into two parts, forming an alternating vortex structure. The downstream blunt shell (1-2) acts as an oscillator, induced by the flow vortex propagating from the upstream blunt shell (1-1), resulting in continuous circular oscillation. -2) The vibration drives the rotation of the transmission shaft (1-1-1): the swing of the downstream blunt shell (1-2) is transmitted to the transmission shaft (1-1-1) of the upstream blunt shell (1-1) through the telescopic lower swing arm (1-3-1), and then the transmission shaft (1-1-1) transmits the swing to the speed-increasing gear set (2), the speed-increasing gear set (2) accelerates the rotation and inputs it into the generator system (3), the generator system (3) converts the kinetic energy into electrical energy output, thus completing the entire energy conversion process; The telescopic swing arm (1-3) is used to match different flow velocities and water depths. The optimal bluff body spacing is different under different flow velocities. If the water depth is insufficient to drive vibration, the torque is increased by adjusting the spacing to ensure vortex-induced vibration. The upstream blunt body shell (1-1) has a through hole (1-1-3) for connecting the flange and a through hole (1-1-4) for connecting the transmission shaft connecting sleeve near its top end; the upstream blunt body shell (1-1) and the fixed flange (4) are fixed together through the through hole (1-1-3) for connecting the fixed flange; the upstream blunt body shell (1-1) and the transmission shaft connecting sleeve (1-1-2) are fixed together through the through hole (1-1-4) for connecting the transmission shaft connecting sleeve. The outer surface of the transmission shaft connecting sleeve (1-1-2) near its lower end is machined with an annular groove (1-1-2-1) for matching the fixing flange (4). The annular groove (1-1-2-1) is used to embed two semi-circular fixing flanges (4). The outer surface below the annular groove (1-1-2-1) of the transmission shaft connecting sleeve (1-1-2) is also provided with a plurality of circumferentially spaced threaded holes (1-1-2-2). The plurality of circumferentially spaced threaded holes (1-1-2-2) are used to be fixedly connected with the upstream blunt body shell (1-1). The telescopic swing arm (1-3) includes a telescopic upper swing arm (1-3-2) and a telescopic lower swing arm (1-3-1). Each of the telescopic upper swing arm (1-3-2) or the telescopic lower swing arm (1-3-1) consists of three parts: two stainless steel plates with toothed racks on one side and one stainless steel plate with toothed racks on both sides. The length of the telescopic swing arm can be changed by adjusting the meshing position of the toothed racks. The upstream blunt shell (1-1) and the transmission shaft connecting sleeve (1-1-2) are connected in a non-fixed manner. The non-fixed manner is used when the ocean current direction changes during seasonal changes. When the ocean current direction changes, the position of the slot on the upstream blunt shell (1-1) and the ocean current direction will form an angle, which may limit the normal swing range of the telescopic upper swing arm. In order not to affect the normal swing of the telescopic upper swing arm (1-3-2), a non-fixed manner is adopted. When the ocean current direction changes, the telescopic upper swing arm can finely adjust the orientation of the slot (1-1-5) of the upstream blunt shell (1-1) by multiple small-intensity collisions with the upstream blunt shell (1-1) at the edge of the slot. This allows the change in the ocean current direction to drive the upstream blunt shell (1-1) to rotate, so as to ensure that the position of the slot (1-1-5) on the upstream blunt shell (1-1) matches the ocean current direction and ensure the movement space of the telescopic upper swing arm. When using a fixed connection method, insert the screw into the through hole (1-1-4) of the connecting sleeve of the transmission shaft for fixed connection; when using a non-fixed connection method, it is not necessary to insert the screw into the through hole.

2. The regenerative energy harvesting system based on oscillation of a dual-series blunt body vortex-induced vibration according to claim 1, characterized in that: The upstream blunt shell (1-1) includes an upstream cylindrical shell, an upstream elliptical shell, a rounded upstream triangular prism shell, or a rounded upstream square prism shell; the downstream blunt shell (1-2) includes a downstream cylindrical shell, a downstream elliptical shell, a rounded downstream triangular prism shell, or a rounded downstream square prism shell.

3. The regenerative energy harvesting system based on oscillation of a dual-series blunt body vortex-induced vibration according to claim 1, characterized in that: The downstream blunt shell (1-2) undergoes continuous circular oscillation, which manifests as a single-degree-of-freedom reciprocating oscillation. The driving force and restoring force of the motion are generated on the surface of the downstream blunt shell (1-2) by the flow vortex propagated from the upstream blunt shell (1-1).

4. The regenerative energy harvesting system based on oscillation of a dual-series blunt body vortex-induced vibration according to claim 1, characterized in that: The height and diameter of the upstream blunt shell (1-1) and the downstream blunt shell (1-2) are determined according to the energy output level and the actual flow environment: their height is on the order of meters when the energy output is at the watt level, and on the order of tens of meters when the energy output is at the kilowatt level.

5. The regenerative energy harvesting system based on oscillation of a dual-series blunt body vortex-induced vibration according to claim 1, characterized in that: The speed-increasing gear set includes a large gear set (2-1), a small gear set (2-2), and a ratchet set (2-3); the small gear set (2-2) and the ratchet set (2-3) have the same diameter and number of teeth; the large gear set (2-1), the small gear set (2-2), and the ratchet set (2-3) are each axially arranged from bottom to top. There are a first large gear, a second large gear; a first small gear, a second small gear; a first ratchet, and a second ratchet; wherein, the first large gear and the first ratchet mesh, the second large gear and the second small gear mesh, and the first small gear and the second ratchet mesh; the first ratchet and the second ratchet of the ratchet group (2-3) ensure that the two reciprocating motions can only be transmitted to the generator in a single direction, thereby ensuring that the motion transmitted from the two ratchets to the generator shaft (3-1) is a rotation in a single direction.

6. The regenerative energy harvesting system based on oscillation of a dual-series blunt body vortex-induced vibration according to claim 5, characterized in that: The first and second ratchet each have a half-cycle of motion that can be transmitted to the generator shaft (3-1). When combined, they form a unidirectional rotation. Specifically, when the first ratchet outputs power within half a cycle, the second ratchet simply rotates in the opposite direction without outputting energy to the generator during that half-cycle; conversely, when the second ratchet outputs power within half a cycle, the first ratchet simply rotates in the opposite direction without performing any work during that half-cycle. The small gear set (2-2) is used to change the reciprocating rotation direction of the second ratchet: the first ratchet and the large gear set ( The rotation direction of the second ratchet is opposite to that of the large gear set (2-1); since the second ratchet is indirectly in contact with the second large gear set (2-2) through the small gear set (2-2), the rotation direction of the second ratchet is the same as that of the large gear set (2-1) and opposite to that of the first ratchet; the reciprocating rotation directions of the first ratchet and the second ratchet are always opposite, but the rotation of the ratchet in only one direction can be transmitted to the generator shaft (3-1), so that the generator can obtain a continuous unidirectional rotational energy input; the tooth ratio of the large gear set (2-1) and the small gear set (2-2) is 2 to 10.

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