A vortex-induced oscillation-based energy harvester

Abstract

The present invention discloses an energy harvester based on vortex-induced oscillation. By providing a rotating base, a support column, an energy harvesting column, and a contact-separation friction generator, after water flows through the energy harvester, the energy harvesting column is induced to swing, thereby driving the contact-separation friction generator to swing up and down, causing the vertical contact-separation structure within the contact-separation friction generator to convert part of the swinging mechanical energy of the energy harvesting column into electrical energy, thereby achieving the purpose of fully collecting the vibration energy of the water flow and efficiently converting it into electrical energy, filling the current technical gap in the field of vortex-induced vibration in fluid energy collection. By providing an MFC piezoelectric sheet, its deformation can be utilized to convert part of the swinging mechanical energy of the energy harvesting column into electrical energy. By providing a turntable friction generator, the rotational mechanical energy of the support column can be converted into electrical energy, further reducing energy loss. The present invention realizes the efficient collection of water kinetic energy from all directions by simultaneously utilizing piezoelectric and triboelectric modules, and has high working efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation, and in particular to an energy harvester based on vortex-induced oscillation. Background Art

[0002] In recent years, with the rapid development of integrated circuits and micro-electromechanical systems, the demand for wireless sensors has been increasing. However, traditional wireless sensor power supply methods represented by chemical batteries have many disadvantages such as short service life, high maintenance costs and environmental problems. In order to find the best solution for the power supply of the Internet of Things, people are committed to collecting energy from the environment, such as solar energy, wind energy, water energy, vibration energy, etc., so that the equipment can be self-powered and operate sustainably. Water energy, as a low-cost renewable clean energy, has received widespread attention. Among them, the use of vortex-induced vibration for fluid energy collection is one of the current research hotspots. Experiments have shown that in terms of energy capture effect, the performance of the flow-oriented oscillating cylinder is the best, far higher than that of the translational cylinder, but few researchers have studied vortex-induced oscillation. Therefore, the present invention proposes an energy harvester based on vortex-induced oscillation to fully collect the vibration energy of the water flow and efficiently convert it into electrical energy, filling the current technical gap in the field of vortex-induced vibration in the field of fluid energy collection. Summary of the Invention

[0003] The purpose of the present invention is to provide an energy harvester based on vortex-induced oscillation to fully collect the vibration energy of water flow and efficiently convert it into electrical energy, filling the current technical gap in the field of vortex-induced vibration in fluid energy collection.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides an energy harvester based on vortex-induced oscillation, comprising:

[0006] A vortex-induced oscillation module comprises a rotating base, a support column and an energy-harvesting column, wherein one end of the support column is connected to the rotating base, and a flow vane is provided on the support column, and the flow vane is used to drive the support column to rotate under the impact of the water flow; the energy-harvesting column is connected to the support column through an elastic cantilever beam, and the elastic cantilever beam is arranged at an angle to the support column, and the energy-harvesting column is used to contact the water flow and swing relative to the support column under the action of the kinetic energy of the water flow;

[0007] The energy-harvesting column includes a plurality of first energy-harvesting columns and a plurality of second energy-harvesting columns, any one of the first energy-harvesting columns and any one of the second energy-harvesting columns are connected to the support column through the elastic cantilever beam, and the ends of any one of the first energy-harvesting columns and any one of the second energy-harvesting columns are connected to a triboelectric module; wherein the diameter of the first energy-harvesting column is greater than the diameter of the second energy-harvesting column.

[0008] Optionally, the triboelectric module includes a contact-separation type triboelectric generator, which includes a closed shell and a vertical contact-separation structure arranged in the closed shell, the closed shell is connected to the end of the energy-capturing column, the vertical contact-separation structure includes a first electrode plate, a second electrode plate and an elastic member, the first electrode plate and the second electrode plate are arranged in parallel and spaced apart, the first electrode plate and the second electrode plate are connected by the elastic member, and metal electrodes are provided on the back surfaces of the first electrode plate and the second electrode plate. The contact-separation type triboelectric generator can swing with the energy-capturing column so that the metal electrode on the first electrode plate and the metal electrode on the second electrode plate are vertically contacted and separated, thereby converting the kinetic energy of the water flow into electrical energy.

[0009] Optionally, the elastic cantilever beam is a wavy elastic cantilever beam, one end of which is connected to the support column, and the other end is connected to the energy-harvesting column; an MFC piezoelectric sheet is provided on the wavy elastic cantilever beam, and the wavy elastic cantilever beam can be deformed under the swinging action of the energy-harvesting column, so that the MFC piezoelectric sheet is deformed and the swinging mechanical energy of the energy-harvesting column is converted into electrical energy.

[0010] Optionally, the MFC piezoelectric sheets are provided at both ends of the wavy elastic cantilever beam, and any one of the MFC piezoelectric sheets is in a “C” shape.

[0011] Optionally, the metal electrode is a gold electrode; the surface of one of the gold electrode on the first electrode plate and the gold electrode on the second electrode plate is coated with a PDMS back electrode, and the surface of the other is provided with a plurality of gold nanoparticles.

[0012] Optionally, the support column is vertically arranged up and down, and the lower end of the support column is connected to the rotating base; the crest of the wavy elastic cantilever beam protrudes toward the upper end or lower end of the support column to drive the energy-capturing column to swing up and down.

[0013] Optionally, the closed shell is a rectangular closed shell, the first electrode plate and the second electrode plate are arranged up and down in the rectangular closed shell, and the first electrode plate and the second electrode plate are both rectangular electrode plates that slide with the inner wall of the rectangular closed shell.

[0014] Optionally, the number of the first energy harvesting columns and the second energy harvesting columns is the same, all the first energy harvesting columns and all the second energy harvesting columns are evenly distributed in a circle centered on the support column, and the first energy harvesting columns and the second energy harvesting columns are staggered at intervals.

[0015] Optionally, the first energy-capturing column and the second energy-capturing column in a stationary state are both perpendicular to the support column, the first energy-capturing column and the second energy-capturing column are both arranged close to the upper end of the support column, and the flow vane is arranged close to the rotating base.

[0016] Optionally, the triboelectric module also includes a turntable triboelectric generator, which includes a cylindrical box body and a circular box cover, the cylindrical box body is connected to the upper end of the support column by a connecting shaft, and a first group of aluminum electrodes and a second group of aluminum electrodes are arranged at intervals on the inner bottom surface of the cylindrical box body, the first group of aluminum electrodes and the second group of aluminum electrodes are radially distributed, the first group of aluminum electrodes and the second group of aluminum electrodes have opposite polarities, and the first group of aluminum electrodes and the second group of aluminum electrodes are staggered, and an FEP film is arranged above the first group of aluminum electrodes and the second group of aluminum electrodes as a friction layer; the circular box cover is sealed and rotatably matched with the upper opening of the cylindrical box body, and a third group of aluminum electrodes is arranged on the lower surface of the circular box cover, the third group of aluminum electrodes are radially distributed and in contact with the FEP film; the cylindrical box body is used to rotate relative to the circular box cover driven by the support column to convert the kinetic energy of the water flow into electrical energy.

[0017] Optionally, the rotating base includes a base lower cover and a base upper cover rotatably connected to the base lower cover via a bearing; the support column is connected to the base upper cover.

[0018] Compared with the prior art, the present invention has achieved the following technical effects:

[0019] The energy harvester based on vortex-induced oscillation proposed in the present invention has a novel and reasonable structure. By setting a rotating base, a support column, an energy harvesting column and a contact-separation friction generator, the energy harvesting column can be induced to swing after the water flows through the energy harvester, thereby driving the contact-separation friction generator to swing up and down, causing the vertical contact-separation structure in the contact-separation friction generator to convert part of the swinging mechanical energy of the energy harvesting column into electrical energy, thereby achieving the purpose of fully collecting the vibration energy of the water flow and converting it into electrical energy efficiently, filling the current technical gap in the field of vortex-induced vibration in fluid energy collection.

[0020] In some technical solutions disclosed herein, multiple energy harvesters are installed around the perimeter of the support column, enhancing the structural stability of the harvester while also improving its efficiency in collecting and converting kinetic energy from the water. At least one energy harvester column oscillates up and down at varying flow rates and directions, enhancing the harvester's adaptability to varying water flow environments and, consequently, its energy harvesting characteristics and overall energy conversion performance in these environments.

[0021] In some technical solutions disclosed in the present invention, an MFC piezoelectric sheet is provided on each elastic cantilever beam. When the energy-harvesting column swings up and down, it applies a lateral force to the elastic cantilever beam, causing the elastic cantilever beam to undergo elastic deformation, thereby causing the MFC piezoelectric sheet on the elastic cantilever beam to deform and convert part of the swinging mechanical energy of the energy-harvesting column into electrical energy, further reducing energy loss and improving the collection and utilization rate of water kinetic energy.

[0022] In some technical solutions disclosed in the present invention, a turntable-type friction generator is also arranged on the top of the support column. When the energy-harvesting column swings under the action of the kinetic energy of the water, the flow vane drives the support column to rotate under the action of the kinetic energy of the water. During this process, the cylindrical box body of the turntable-type friction generator rotates with the support column relative to the circular box cover, so that the turntable-type friction generator converts the rotational mechanical energy of the support column into electrical energy, further reducing energy loss and improving the collection and utilization rate of the kinetic energy of the water.

[0023] In some technical solutions disclosed in the present invention, by integrating a rotating base, a support column, an MFC piezoelectric sheet, a contact-separation friction generator and a turntable friction generator, it is possible to simultaneously utilize piezoelectric and friction electric modules to efficiently collect kinetic energy of water from all directions and convert the kinetic energy of water into electrical energy, thereby realizing efficient collection and conversion of kinetic energy of water, with high working efficiency and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of the overall structure of the vortex-induced oscillation energy harvester disclosed in an embodiment of the present invention;

[0026] Figure 2 A top view of an energy harvester based on vortex-induced oscillation disclosed in an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of the decomposed structure of the vortex-induced oscillation energy harvester disclosed in an embodiment of the present invention;

[0028] Figure 4 A schematic structural diagram of an elastic cantilever beam disclosed in an embodiment of the present invention;

[0029] Figure 5 A schematic structural diagram of a contact-separation type friction generator disclosed in an embodiment of the present invention;

[0030] Figure 6 A schematic diagram of the exploded structure of the vertical contact-separation structure disclosed in an embodiment of the present invention;

[0031] Figure 7 This is a schematic structural diagram of a rotary disc type friction generator disclosed in an embodiment of the present invention;

[0032] Figure 8 This is a schematic structural diagram of the rotating base disclosed in an embodiment of the present invention.

[0033] Wherein, the accompanying drawings are marked as follows:

[0034] 100. Energy harvester based on vortex-induced oscillation;

[0035] 1. Rotating base; 11. Base lower cover; 12. Bearing; 121. Bearing outer ring; 122. Cage; 123. Rotating ball; 124. Bearing inner ring; 13. Base upper cover; 131. Strip groove; 2. Support column; 3. Flow vane; 4. Elastic cantilever beam; 41. MFC piezoelectric piece; 42. Plug; 5. First energy-capturing column; 51. First connecting shaft; 52. First strip jack; 6. Second energy-capturing column; 61. Second connecting shaft; 62. Second strip jack; 7. Contact-separation friction generator Motor; 71. Enclosed shell; 72. First electrode plate; 73. Second electrode plate; 74. Elastic member; 741. First spring; 742. Second spring; 743. Third spring; 744. Fourth spring; 75. Metal electrode; 76. PDMS back electrode; 77. Gold nanoparticles; 8. Rotating disk friction generator; 81. Cylindrical box body; 82. Round box cover; 83. First set of aluminum electrodes; 84. Second set of aluminum electrodes; 85. FEP film; 86. Third set of aluminum electrodes; 9. Connecting shaft. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] One of the purposes of the present invention is to provide an energy harvester based on vortex-induced oscillation to fully collect the vibration energy of water flow and efficiently convert it into electrical energy, filling the current technical gap in the field of vortex-induced vibration in fluid energy collection.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0039] like Figures 1 to 3 As shown, this embodiment provides an energy harvester 100 based on vortex-induced oscillation, which mainly includes a vortex-induced oscillation module and a triboelectric module, wherein the vortex-induced oscillation module includes a rotating base 1, a support column 2 and an energy harvesting column, the support column 2 is vertically arranged up and down, and its bottom end is connected to the top of the rotating base 1, and a flow direction indicator 3 is provided on the support column 2, which is arranged to face the flow and can drive the support column 2 to rotate under the impact of the water flow; the energy harvesting column is a cylindrical energy harvesting column, which is connected to the support column 2 through an elastic cantilever beam 4, and the elastic cantilever beam 4 is arranged at an angle to the support column 2, and the energy harvesting column is distributed on the periphery of the support column 2. On the one hand, the energy harvesting column is used to contact the water flow and swing relative to the support column 2 under the action of the kinetic energy of the water flow, and the elastic cantilever beam 4 is used to reset the energy harvesting column, so that the energy harvesting column can realize reciprocating swing under the joint action of the kinetic energy of the water flow and the elastic cantilever beam 4; on the other hand, the energy harvesting column and the elastic cantilever beam 4 also serve as a facing flow structure to provide a certain power for the rotation of the support column 2. The above-mentioned friction electric module includes a contact-separation friction generator 7, which includes a closed shell 71 and a vertical contact-separation structure arranged in the closed shell 71, and the closed shell 71 is connected to the end of the energy-capturing column; the vertical contact-separation structure specifically selects a vertical contact-separation mode, which is a common working mode of the existing friction nanogenerator. The vertical contact-separation structure includes a first electrode plate 72, a second electrode plate 73 and an elastic member 74, and the first electrode plate 72 and the second electrode plate 73 are arranged in parallel and spaced apart. The first electrode plate 72 and the second electrode plate 73 are connected by the elastic member 74, and the back surfaces of the first electrode plate 72 and the second electrode plate 73, that is, the surfaces of the first electrode plate 72 and the second electrode plate 73 close to each other are A metal electrode 75, preferably a gold electrode, is provided. The contact-and-separation triboelectric generator 7 can swing with the energy-harvesting column. During this swing, the first and second electrode plates 72, 73 overcome the elastic force of the elastic member and approach each other, causing the metal electrodes 75 on the first and second electrode plates 73 to contact each other. Positive and negative charges form on the contact surfaces. Correspondingly, during this swing, the first and second electrode plates 72, 73 separate under the elastic force of the elastic member, causing the metal electrodes 75 on the first and second electrode plates 73 to separate from each other. A small air gap forms between the two metal electrodes 75, generating an induced potential difference between the two electrodes. As the contact-and-separation triboelectric generator 7 swings with the energy-harvesting column, the first and second electrode plates 72, 73 undergo reciprocating contact and separation, thereby converting the kinetic energy of the water into electrical energy. Specifically, this conversion process involves first converting the kinetic energy of the water into the mechanical energy of the energy-harvesting column's swing, which is then converted into electrical energy by the contact-and-separation triboelectric generator 7.

[0040] In this embodiment, Figure 1 、 Figure 3 and Figure 4 As shown, the elastic cantilever beam 4 is preferably a wavy elastic cantilever beam, or an "S" shaped elastic cantilever beam, such as Figure 4 As shown, the wavy elastic cantilever beam includes two crests and two troughs, and the crests on the wavy elastic cantilever beam protrude toward the upper end of the support column 2, and the troughs protrude toward the lower end of the support column 2, thereby driving the energy capture column to swing up and down. Figure 4 As shown, an MFC piezoelectric sheet 41 is provided on the wavy elastic cantilever beam. The wavy elastic cantilever beam can be deformed under the swinging action of the energy-harvesting column, thereby causing the MFC piezoelectric sheet 41 to deform and convert part of the swinging mechanical energy of the energy-harvesting column into electrical energy. As a preferred embodiment, MFC piezoelectric sheets 41 are provided at both ends of the wavy elastic cantilever beam. The MFC piezoelectric sheets 41 at both ends of the wavy elastic cantilever beam are both "C"-shaped and are both located on the upper surface of the wavy elastic cantilever beam. The above-mentioned MFC piezoelectric sheet 41 can be a macro-fiber composite material MFC piezoelectric sheet, which is a durable new material that solves the defects of traditional piezoelectric materials, is conducive to improving the durability of the device, and extends the service life of the device.

[0041] In this embodiment, the energy harvesting column includes a plurality of first energy harvesting columns 5 and a plurality of second energy harvesting columns 6. Figures 1 to 3 As shown, any first energy-capturing column 5 and any second energy-capturing column 6 are connected to the support column 2 through an elastic cantilever beam 4, and the ends of any first energy-capturing column 5 and any second energy-capturing column 6 are connected to a contact-separation friction generator 7; wherein, the diameter of the first energy-capturing column 5 is greater than the diameter of the second energy-capturing column 6, and the number of the first energy-capturing columns 5 and the second energy-capturing columns 6 is the same, all the first energy-capturing columns 5 and all the second energy-capturing columns 6 are evenly distributed in a circle with the support column 2 as the center, and the first energy-capturing columns 5 and the second energy-capturing columns 6 are staggered and arranged at intervals. Figure 2 , which is a schematic diagram of four first energy harvesting columns 5 and four second energy harvesting columns 6 arranged alternately, wherein the eight energy harvesting columns, four large and four small, are arranged alternately and symmetrically.

[0042] Furthermore, in this embodiment, a cylindrical insert is fixedly provided at the upper end of the support column 2, and a plurality of elongated sockets are provided on the sidewall of the cylindrical insert; accordingly, each first energy-capturing column 5 and each second energy-capturing column 6 are cylindrical, and one end face of each first energy-capturing column 5 and each second energy-capturing column 6 is respectively provided with a first strip socket 52 and a second strip socket 62. Plugs 42 with rectangular cross-sections are respectively extended outwards from both ends of the wavy elastic cantilever beam, and the plugs 42 are adapted to the first strip sockets 52 and the second strip sockets 62. The wavy elastic cantilever beam is inserted into the elongated socket of the cylindrical insert through the plug 42 at one end, thereby realizing the connection between the wavy elastic cantilever beam and the support column 2, and the wavy elastic cantilever beam is inserted into the first strip socket 52 or the second strip socket 62 through the plug 42 at the other end, thereby realizing the connection between the wavy elastic cantilever beam and the first energy-capturing column 5 or the second energy-capturing column 6. In order to improve the connection strength, the plug 42 and the corresponding socket can be glued together after being plugged into each other.

[0043] Furthermore, in this embodiment, the other ends of the first energy harvesting column 5 and the second energy harvesting column 6 are connected to the first connecting shaft 51 and the second connecting shaft 61 respectively, and the first energy harvesting column 5 and the second energy harvesting column 6 are connected to the corresponding contact-separation type friction generator 7 through the first connecting shaft 51 and the second connecting shaft 61 respectively. Figure 1 As shown, one end of the first connecting shaft 51 is sleeved onto the exterior of the first energy-harvesting column 5, and the two can be threaded, welded, or plugged together. The other end of the first connecting shaft 51 is preferably welded or bonded to the contact-and-split triboelectric generator 7. Correspondingly, one end of the second connecting shaft 61 is sleeved onto the exterior of the second energy-harvesting column 6, and the two can be threaded, welded, or plugged together. The other end of the second connecting shaft 61 is preferably welded or bonded to the contact-and-split triboelectric generator 7.

[0044] In this embodiment, it is preferred that the first energy-capturing column 5 and the second energy-capturing column 6 in the static state are both arranged perpendicular to the length direction of the support column 2, that is, the first energy-capturing column 5 and the second energy-capturing column 6 in the static state are both parallel to the upper surface of the rotating base 1, and the first energy-capturing column 5 and the second energy-capturing column 6 are both arranged close to the upper end of the support column 2, and the flow vane 3 is arranged close to the rotating base 1. In this specific solution, in order to improve the flow-facing performance of the support column 2, the support column 2 and the flow vane 3 both adopt a plate-like structure with a flat flow-facing surface, and the flow vane 3 can be a rectangular plate, a circular plate or other special-shaped plate. As a preferred solution, the support column 2 and the flow vane 3 both adopt a rectangular plate-like structure, and the flow vane 3 and the support column 2 are an integrally formed structure, and the flow vane 3 is perpendicular to the support column 2.

[0045] In this embodiment, both the first and second energy harvesting columns 5, 6 are enclosed cylindrical structures. Accordingly, to improve the lifespan and reliability of the energy harvester, each elastic cantilever beam 4 is waterproofed, for example, by coating the exterior of each elastic cantilever beam 4 with a waterproof membrane such as TPU or PVC. In this embodiment, the MFC piezoelectric plates 41 at each end of the elastic cantilever beam 4 and the vertical contact-separation structure of the contact-separation triboelectric generator 7 together form a piezoelectric-triboelectric combined energy harvester. Under the elastic force of the elastic cantilever beam 4, this piezoelectric-triboelectric combined energy harvester exhibits significant up-and-down swing deformation and produces a high output voltage.

[0046] In this embodiment, Figure 3 、 Figure 5 and Figure 6 As shown, the closed shell 71 is preferably a rectangular closed shell to ensure its waterproof performance; the length direction of the rectangular closed shell in the static state is parallel to the support column 2. The first electrode plate 72 and the second electrode plate 73 are arranged up and down in the rectangular closed shell, and the first electrode plate 72 and the second electrode plate 73 are both rectangular electrode plates that slide with the inner wall of the rectangular closed shell. In the static state, the first electrode plate 72 and the second electrode plate 73 are respectively located at the top and bottom of the rectangular closed shell, and at most one of the first electrode plate 72 and the second electrode plate 73 is connected to the rectangular closed shell. When the rectangular closed shell swings up and down with the corresponding energy capture column, the first electrode plate 72 and the second electrode plate 73 can approach each other, thereby achieving contact between the gold electrodes on the first electrode plate 72 and the second electrode plate 73. After contact occurs, the first electrode plate 72 and the second electrode plate 73 can be separated from each other under the action of the elastic member 74.

[0047] In this embodiment, Figure 6 As shown, the first electrode plate 72 is located above the second electrode plate 73. The surface of the gold electrode on the first electrode plate 72 is coated with a PDMS back electrode 76, and the surface of the gold electrode on the second electrode plate 73 is provided with a plurality of gold nanoparticles 77. The first electrode plate 72 and the second electrode plate 73 are preferably made of PMMA (organic glass) structure. PMMA substrate material has the advantages of high strength, light weight, easy processing and low cost.

[0048] In this embodiment, the elastic member 74 includes four springs, namely a first spring 741, a second spring 742, a third spring 743 and a fourth spring 744. Figure 5 and 6As shown, a first spring 741, a second spring 742, a third spring 743, and a fourth spring 744 are respectively connected to the four corners of the first electrode plate 72 and the second electrode plate 73, thereby forming a spring-supported separation structure. The springs allow the first electrode plate 72 and the second electrode plate 73 to easily separate when the external force is removed. In practice, in addition to the aforementioned spring-supported separation structure, the vertical contact-separation structure of the contact-separation triboelectric generator 7 can also adopt a spacer structure, an arch structure, and a multi-layer stacked structure. These structures can all achieve a vertical contact-separation mode of the triboelectric generator. In this mode, when the gold electrodes on the two electrode plates contact each other, positive and negative charges are formed on the two contacting surfaces. When they separate, a small air gap is formed between the two surfaces, and an induced potential difference is generated between the two gold electrodes. The spring-supported separation structure selected in this embodiment allows the two friction layers of the triboelectric generator (TENG) to easily separate when the external force is removed. Compared with other vertical contact-separation structures, it has the advantages of simple structure and very high power output.

[0049] In this embodiment, in order to further improve the utilization rate of flow kinetic energy, a turntable friction generator 8 is further provided in the triboelectric module. The turntable friction generator 8 includes a cylindrical box body 81 and a circular box cover 82. The cylindrical box body 81 is connected to the upper end of the support column 2 through a connecting shaft 9. The inner bottom surface of the cylindrical box body 81 is provided with a first group of aluminum electrodes 83 and a second group of aluminum electrodes 84. Figure 7As shown, the first group of aluminum electrodes 83 is a radial disc structure, and the second group of aluminum electrodes 84 is a disc with radial disc-shaped hollow holes. The polarities of the first group of aluminum electrodes 83 and the second group of aluminum electrodes 84 are opposite, and the first group of aluminum electrodes 83 is just embedded in the radial disc-shaped hollow holes of the second group of aluminum electrodes 84. The first group of aluminum electrodes 83 and the second group of aluminum electrodes 84 are fixed to the inner bottom surface of the cylindrical box body 81; an FEP film 85 is provided above the first group of aluminum electrodes 83 and the second group of aluminum electrodes 84 as a friction layer. Accordingly, the FEP film 85 has the same radial shape as the first group of aluminum electrodes 83. The FEP film 85 of the radial disc structure is connected to the circular cover 82, which is sealed and rotatably engaged with the upper opening of the cylindrical box body 81. The lower surface of the circular cover 82 is provided with a third set of radially distributed aluminum electrodes 86 in contact with the FEP film 85. The cylindrical box body 81 is driven by the support column 2 to rotate relative to the circular cover 82 to convert the kinetic energy of the water into electrical energy. This conversion process is supposed to be that the kinetic energy of the water is first converted into the rotational mechanical energy of the support column 2, and then the rotary disc-type triboelectric generator 8 converts the rotational mechanical energy into electrical energy. In the above-mentioned rotary disc-type triboelectric generator 8, both the cylindrical box body 81 and the circular cover 82 are preferably made of acrylic. The aforementioned turntable triboelectric generator 8 is a conventional non-contact, independently rotating disc-shaped triboelectric generator (FRD-TENG). In actual operation, to ensure that the circular cover 82 remains stationary relative to the cylindrical body 81, a fixed bracket can be installed near the installation site of the energy harvester to connect to the top surface of the circular cover 82. The circular cover 82 and the cylindrical body 81 can also be connected by a bearing structure. In addition to the above solution, in actual operation, through the relevant structural configuration, the circular cover 82 can rotate in the opposite direction relative to the cylindrical body 81 while the cylindrical body 81 rotates, thereby also achieving triboelectric power generation.

[0050] In this embodiment, Figure 8 As shown, the rotating base 1 includes a base lower cover 11 and a base upper cover 13 rotatably connected to the base lower cover 11 via a bearing 12. The base upper cover 13 is provided with a strip groove 131, and the support column 2 is plugged into the strip groove 131. To improve the connection strength, the support column 2 and the strip groove 131 can also be glued together after plugging. In actual operation, the base lower cover 11 is fixed to a corresponding position underwater. When the support column 2 is affected by the water flow, the support column 2 can drive the base upper cover 13 to rotate relative to the base lower cover 11. The bearing 12 is a conventional bearing structure, which includes a bearing outer ring 121, a retaining frame 122, a rotating ball 123, and a bearing inner ring 124. The specific structure and working principle are not repeated here. In this embodiment, the bearing outer ring 121 of the bearing 12 is connected to the base lower cover 11, and the bearing inner ring 124 is connected to the base upper cover 13.

[0051] The specific working principle of the vortex-induced oscillation energy harvester 100 in this embodiment is as follows:

[0052] After the water flows through the energy harvester, it induces the first energy harvesting columns 5 and the second energy harvesting columns 6 to swing up and down, thereby driving the contact-separation friction generators 7 to swing up and down, causing the vertical contact-separation structure in the contact-separation friction generator 7 to convert part of the swinging mechanical energy of the energy harvesting column into electrical energy. At the same time, the up and down swinging of the first energy harvesting columns 5 and the second energy harvesting columns 6 applies a lateral force to the elastic cantilever beam 4, causing the elastic cantilever beam 4 to undergo elastic deformation, thereby causing the MFC piezoelectric piece 41 on the elastic cantilever beam 4 to deform and convert part of the swinging mechanical energy of the energy harvesting column into electrical energy. During the process of the first energy-capturing columns 5 and the second energy-capturing columns 6 swinging under the action of the kinetic energy of the water, the flow direction indicator 3 drives the support column 2 to rotate under the action of the kinetic energy of the water, and the first energy-capturing columns 5, the second energy-capturing columns 6 and the elastic cantilever beams 4 rotate with the support column 2. During this process, the cylindrical box body 81 of the turntable friction generator 8 rotates with the support column 2 relative to the circular box cover 82, so that the turntable friction generator 8 converts the rotational mechanical energy of the support column 2 into electrical energy.

[0053] It can be seen that the vortex-induced oscillation-based energy harvester 100 of this embodiment is specifically a rotatable piezoelectric-triboelectric energy harvester based on vortex-induced oscillation and having a variable diameter energy harvesting column, which is used to collect and convert the vibration energy of water flow into electrical energy. By integrating the rotating base, support column 2, MFC piezoelectric sheet 41, contact-separation friction generator 7 and turntable friction generator 8, it realizes the simultaneous use of piezoelectric and triboelectric modules to efficiently collect water kinetic energy from all directions and convert the water kinetic energy into electrical energy, thereby realizing efficient collection and conversion of water kinetic energy, high working efficiency and broad application prospects. Compared with the existing technology, the beneficial effects of this technical solution are as follows:

[0054] (1) The energy harvester of this technical solution is equipped with a rotatable rotating base, so that the entire energy harvester can simultaneously convert swinging mechanical energy and rotational mechanical energy into electrical energy, thereby improving the efficiency of the energy harvester in converting mechanical energy.

[0055] (2) The energy harvester of this technical solution, by providing eight energy harvesting columns ("four large and four small, staggered and bilaterally symmetrical"), not only enhances the structural stability of the energy harvester, but also improves the efficiency of collecting and converting the kinetic energy of the water. Under different flow rates and flow directions, the support column 2 rotates and at least one energy harvesting column swings up and down, enhancing the adaptability of the energy harvester to different water flow environments, thereby enhancing the energy harvesting characteristics and overall energy conversion performance of the energy harvester in water flow environments.

[0056] (3) In the energy harvester of this technical solution, the elastic cantilever beam 4 adopts a wave-shaped structure, which can achieve large swing deformation and greatly increase the output voltage.

[0057] (4) The energy harvester of this technical solution, through the provision of the turntable friction generator 8, not only greatly improves the flexibility of the energy harvester operation, but also improves the durability and stability of the energy harvester and reduces energy loss.

[0058] (5) The energy harvester of this technical solution can be used in a variety of environments and can collect and convert the vibration energy contained in air flow, wave fluctuations, etc. into electrical energy.

[0059] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description. It is intended that all changes that fall within the meaning and range of equivalents of the claims be included in the present invention, and any reference signs in the claims should not be construed as limiting the claims to which they relate.

[0060] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A vortex-induced oscillation energy harvester, characterized in that: include: The vortex-induced oscillation module includes a rotating base, a support column and an energy-harvesting column. One end of the support column is connected to the rotating base. A flow vane is provided on the support column. The flow vane is used to drive the support column to rotate under the impact of water flow. The energy-harvesting column is connected to the support column via an elastic cantilever beam, and the elastic cantilever beam is arranged at an angle to the support column. The energy-harvesting column is used to contact the water flow and swing relative to the support column under the action of the kinetic energy of the water flow; The energy-harvesting column includes a plurality of first energy-harvesting columns and a plurality of second energy-harvesting columns, any one of the first energy-harvesting columns and any one of the second energy-harvesting columns are connected to the support column through the elastic cantilever beam, and the ends of any one of the first energy-harvesting columns and any one of the second energy-harvesting columns are connected to a triboelectric module; wherein the diameter of the first energy-harvesting column is greater than the diameter of the second energy-harvesting column.

2. The energy harvester based on vortex-induced oscillation according to claim 1, characterized in that: The friction electric module includes a contact-separation type friction generator, which includes a closed shell and a vertical contact-separation structure arranged in the closed shell. The closed shell is connected to the end of the energy-capturing column. The vertical contact-separation structure includes a first electrode plate, a second electrode plate and an elastic member. The first electrode plate and the second electrode plate are arranged in parallel and spaced apart. The first electrode plate and the second electrode plate are connected by the elastic member. Metal electrodes are provided on the back surfaces of the first electrode plate and the second electrode plate. The contact-separation type friction generator can swing with the energy-capturing column so that the metal electrode on the first electrode plate and the metal electrode on the second electrode plate are vertically contacted and separated, thereby converting the kinetic energy of the water flow into electrical energy.

3. The energy harvester based on vortex-induced oscillation according to claim 1, characterized in that: The elastic cantilever beam is a wavy elastic cantilever beam, one end of which is connected to the support column, and the other end is connected to the energy-harvesting column; an MFC piezoelectric sheet is provided on the wavy elastic cantilever beam, and the wavy elastic cantilever beam can be deformed under the swinging action of the energy-harvesting column, so that the MFC piezoelectric sheet is deformed and the swinging mechanical energy of the energy-harvesting column is converted into electrical energy.

4. The energy harvester based on vortex-induced oscillation according to claim 3, characterized in that: The MFC piezoelectric sheets are provided at both ends of the wavy elastic cantilever beam, and any one of the MFC piezoelectric sheets is in a "C" shape.

5. The energy harvester based on vortex-induced oscillation according to claim 2, characterized in that: The metal electrode is a gold electrode; one of the gold electrode on the first electrode plate and the gold electrode on the second electrode plate is coated with a PDMS back electrode, and the other is provided with a plurality of gold nanoparticles on the surface.

6. The energy harvester based on vortex-induced oscillation according to claim 2 or 5, characterized in that: The support column is vertically arranged up and down, and the lower end of the support column is connected to the rotating base; the crest of the wave-shaped elastic cantilever beam protrudes toward the upper end or lower end of the support column to drive the energy capture column to swing up and down.

7. The energy harvester based on vortex-induced oscillation according to claim 6, characterized in that: The closed shell is a rectangular closed shell, the first electrode plate and the second electrode plate are arranged up and down in the rectangular closed shell, and the first electrode plate and the second electrode plate are both rectangular electrode plates that slide with the inner wall of the rectangular closed shell.

8. The energy harvester based on vortex-induced oscillation according to claim 7, characterized in that: The number of the first energy harvesting columns and the second energy harvesting columns is the same, all the first energy harvesting columns and all the second energy harvesting columns are evenly distributed around the support column, and the first energy harvesting columns and the second energy harvesting columns are staggered at intervals.

9. The energy harvester based on vortex-induced oscillation according to claim 8, characterized in that: The first energy harvesting column and the second energy harvesting column in a stationary state are both perpendicular to the support column. The first energy harvesting column and the second energy harvesting column are both arranged close to the upper end of the support column, and the flow vane is arranged close to the rotating base.

10. The energy harvester based on vortex-induced oscillation according to claim 6, characterized in that: The triboelectric module also includes a turntable triboelectric generator, which includes a cylindrical box body and a circular box cover. The cylindrical box body is connected to the upper end of the support column by a connecting shaft. The inner bottom surface of the cylindrical box body is provided with a first group of aluminum electrodes and a second group of aluminum electrodes at intervals. The first group of aluminum electrodes and the second group of aluminum electrodes are both radially distributed. The polarities of the first group of aluminum electrodes and the second group of aluminum electrodes are opposite, and the first group of aluminum electrodes and the second group of aluminum electrodes are staggered. An FEP film is provided above the first group of aluminum electrodes and the second group of aluminum electrodes as a friction layer; the circular box cover is sealed and rotatably matched with the upper opening of the cylindrical box body, and a third group of aluminum electrodes is provided on the lower surface of the circular box cover. The third group of aluminum electrodes is radially distributed and in contact with the FEP film; the cylindrical box body is used to rotate relative to the circular box cover driven by the support column to convert the kinetic energy of the water flow into electrical energy.

11. The vortex-induced oscillation energy harvester according to any one of claims 1 to 5, characterized in that: The rotating base includes a base lower cover and a base upper cover rotatably connected to the base lower cover via a bearing; the support column is connected to the base upper cover.

Images