Columnar triboelectric nanogenerator unit, swing amplitude controllable triboelectric nanogenerator device

Abstract

The present invention relates to a columnar triboelectric nanogenerator unit and a swing amplitude controllable triboelectric nanogenerator device. A columnar triboelectric nanogenerator unit includes a housing, a swing block, and a swing spring. The housing has a closed inner cavity, and a first electrode layer is adhered to the side wall surface of the inner cavity, and a dielectric film is adhered to the surface of the first electrode layer; an annular spacer is provided in the middle and lower sections of the side wall surface of the inner cavity to divide the inner cavity into an upper cavity and a lower cavity. The swing block is frustum-shaped, and the radial length of the top end of the swing block is smaller than that of the bottom end; the inside of the swing block is hollow and contains a cavity, and a steel ball is arranged in the cavity; a second electrode layer is provided on the outer wall surface of the swing block. The swing spring is coaxially arranged with the swing block. One end of the swing spring enters the upper cavity from the lower cavity and is connected to the outer bottom surface of the swing block, and the other end is connected to the bottom wall surface of the lower cavity. The present invention can adapt to the low-frequency ocean wave environment by setting the swing block to swing omnidirectionally from the top and the limited distance between the swing block and the housing.

Description

Technical Field

[0001] The present invention relates to the technical field of triboelectric nanogenerators, and particularly to a columnar triboelectric nanogenerator unit, a swing amplitude controllable triboelectric nanogenerator device, a self-powered wave height sensor, and a marine early warning system applying the self-powered wave height sensor. Background Art

[0002] As a renewable energy source, wave energy is one of the most ideal distributed energy sources for large-scale applications. Wave observation is of great significance for ocean engineering construction, ocean development, ocean transportation and shipping, ocean fishery, and aquaculture. The triboelectric nanogenerator is revolutionary in efficiently converting micro mechanical energy into electrical energy. Compared with other energy converters, it poses less environmental risk. By driving a swing structure to generate electricity through friction by waves, the purpose of utilizing wave energy is achieved. Due to its omnidirectionality, the swing structure is often used as an energy conversion device in wave energy collection devices. However, the low frequency of waves sometimes leads to a small swing range of the swing structure, limiting the output of the wave collection device, resulting in low output power and reducing the utilization rate of wave energy. Therefore, it is urgent to further improve this problem. Summary of the Invention

[0003] Based on this, in view of the problem that the low frequency of waves limits wave energy collection, it is necessary to provide a columnar triboelectric nanogenerator unit, a swing amplitude controllable triboelectric nanogenerator device, a self-powered wave height sensor, and a marine early warning system applying the self-powered wave height sensor.

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

[0005] A columnar triboelectric nanogenerator unit, which includes a housing, a swing block, and a swing spring.

[0006] The housing has a closed inner cavity, the inner cavity is cylindrical, and a first electrode layer is provided on the side wall surface of the inner cavity; a dielectric film is provided on the surface of the first electrode layer; an annular spacer is provided in the middle and lower section of the side wall surface of the inner cavity, and the annular spacer divides the inner cavity into an upper cavity and a lower cavity; the first electrode layer and the dielectric film are located in the upper cavity.

[0007] The swing block is arranged on the center line of the upper cavity, the shape of the swing block is frustum-shaped, the radial length of the top end of the swing block is less than that of the bottom end; the radial length of the bottom end of the swing block is less than the radial length of the inner wall surface of the annular spacer; the swing block is hollow inside and contains a cavity, and steel balls are arranged in the cavity; a second electrode layer is provided on the outer wall surface of the swing block.

[0008] The swing spring is coaxially arranged with the swing block, one end of the swing spring enters the upper cavity from the lower cavity and is connected to the outer bottom surface of the swing block, and the other end of the swing spring is connected to the bottom wall surface of the lower cavity.

[0009] Further, a buffer layer is bonded between the first electrode layer and the inner wall surface of the housing to expand the contact area between the swing block and the housing.

[0010] Further, the first electrode layer and the second electrode layer are made of a conductive material with a resistivity greater than...

[0011] Further, the dielectric film is made of a material with a different ability to bind electrons from the first electrode layer and the second electrode layer.

[0012] Further, the thickness of the first electrode layer and the second electrode layer is... -... mm, and the thickness of the dielectric film is... -... mm.

[0013] The present invention also includes a swing amplitude controllable triboelectric nanogenerator. The swing amplitude controllable triboelectric nanogenerator includes a float, at least one columnar triboelectric nanogenerator unit, and a swing amplitude regulating mechanism.

[0014] The columnar triboelectric nanogenerator unit uses the product mentioned above.

[0015] The swing amplitude regulating mechanism is used to adjust the swing amplitude of the columnar triboelectric nanogenerator unit under different degrees of external force; it includes a support plate, side springs, and a bottom spring; the number of support plates is three, and the three support plates are arranged equidistantly in a ring at the top of the float; one end of the side spring is fixedly connected to the inner wall surface of the support plate, and the other end extends towards the center line of the float and is connected to the columnar triboelectric nanogenerator unit; the bottom spring is coaxially arranged with the columnar triboelectric nanogenerator unit, one end is connected to the top of the float, and the other end is connected to the bottom of the columnar triboelectric nanogenerator unit.

[0016] Further, the support plate is made of a weather-resistant rigid material.

[0017] The present invention also includes a self-powered wave height sensor, which mainly includes a float, a housing, a swing block, a swing spring, a swing amplitude regulating mechanism, a signal acquisition module, and a data processing module.

[0018] The housing has a closed inner cavity, the inner cavity is cylindrical, and the side wall surface of the inner cavity is provided with a first electrode layer; a dielectric film is provided on the surface of the first electrode layer; a circular spacer is provided in the middle and lower section of the side wall surface of the inner cavity, and the circular spacer divides the inner cavity into an upper cavity and a lower cavity; the first electrode layer and the dielectric film are located in the upper cavity.

[0019] The swing block is arranged on the center line of the upper cavity, the shape of the swing block is frustum-shaped, the radial length of the top end of the swing block is less than that of the bottom end; the radial length of the bottom end of the swing block is less than the radial length of the inner wall surface of the circular spacer; the swing block is hollow inside and contains a cavity, and steel balls are arranged in the cavity; a second electrode layer is provided on the outer wall surface of the swing block.

[0020] The swinging spring is coaxially arranged with the swinging block. One end of the swinging spring enters the upper cavity from the lower cavity and is connected to the outer bottom surface of the swinging block, and the other end of the swinging spring is connected to the bottom wall surface of the lower cavity.

[0021] The swing amplitude regulating mechanism is used to adjust the swing amplitude of the columnar triboelectric nanogenerator under the action of different degrees of external force; it includes a support plate, a side spring, and a bottom spring; the number of support plates is three, and the three support plates are arranged in an equidistant ring at the top of the float; one end of the side spring is fixedly connected to the inner wall surface of the support plate, and the other end extends towards the center line of the float and is connected to the columnar triboelectric nanogenerator, so as to absorb the potential energy during swinging and convert it into elastic potential energy for release, and resonate with the columnar triboelectric nanogenerator; the bottom spring is coaxially arranged with the columnar triboelectric nanogenerator, one end is connected to the top of the float, and the other end is connected to the bottom of the columnar triboelectric nanogenerator.

[0022] The signal acquisition module is used to collect the current signal between the first electrode layer and the second electrode layer in real time.

[0023] The data processing module is used to obtain the wave height at the corresponding moment according to the electrical signal collected at any moment and a preset "electrical signal - wave height" function, and the "electrical signal - wave height" function is used to characterize the mapping relationship between the electrical signal and the wave height during the detection of the wave height sensor.

[0024] In one of the embodiments, the method for establishing the "electrical signal - wave height" function includes the following steps:

[0025] S1. Place the wave height sensor in the experimental water tank, preset a wave height range, select multiple wave height values within the wave height range, and collect the electrical signals generated by the wave height sensor at different wave height values to obtain a set of discrete experimental data;

[0026] S2. Preset a number of repetitions, repeat step S1, obtain multiple sets of discrete experimental data, and process the multiple sets of discrete experimental data to obtain a set of reliable data sets. The method for obtaining the data set includes the following steps:

[0027] S2.1. Obtain the multiple electrical signals corresponding to any one wave height value in the multiple sets of discrete experimental data, form an original signal set, calculate the difference between the median value of the original signal set and each electrical signal in the original signal set one by one to obtain the signal difference;

[0028] S2.2. Compare each signal difference with a preset error value;

[0029] S2.3. When the signal difference is greater than the error value, delete the electrical signals of the original signal set corresponding to the signal difference, and the remaining electrical signals of the original signal set form a precise signal set;

[0030] S2.4. Calculate the average value of the precise signal set to obtain a reliable signal value;

[0031] S2.5. Repeat step S2.1 to calculate the reliable signal value corresponding to each wave height value. The wave height values and their corresponding reliable signal values form a data set;

[0032] S3. Establish a reference coordinate system with the wave height as the x - coordinate and the electrical signal as the y - coordinate. Mark the wave height values and their corresponding reliable signal values in the data set on the reference coordinate system to obtain a set of discrete points. Connect adjacent discrete points to establish an "electrical signal - wave height" function.

[0033] The present invention also includes a marine early warning system, which includes a plurality of wave height sensors matched with the seabed, a plurality of Gps positioning modules, a wireless communication module, at least one audible and visual alarm, and a server.

[0034] The wave height sensors adopt the self - powered wave height sensors mentioned above.

[0035] Each Gps positioning module corresponds to each wave height sensor one by one to obtain the position information of each wave height sensor.

[0036] The wireless communication module is used to transmit the data collected by the wave height sensors and Gps positioning modules to a server.

[0037] An audible and visual alarm is arranged in the marine monitoring workstation to give an alarm according to the warning signal of a server.

[0038] The server is used to receive the data signal transmitted by the wireless communication module, process the data signal to obtain the wave height information and the corresponding position information of the wave height sensors; it is also used to judge whether the wave height information is within a preset reasonable range; otherwise, it sends a warning signal and controls the audible and visual alarm to give an alarm.

[0039] The technical solution provided by the present invention has the following beneficial effects:

[0040] 1. The present invention sets a swing block that can swing in all directions. It swings with the fluctuation of the waves for energy conversion, converting micro - mechanical energy into electrical energy. Moreover, the matching of the swing block with the circular inner cavity of the inner wall of the shell can expand the contact area and improve the energy conversion effect. In addition, the frustum - shaped setting of the swing block makes the radial length of its top smaller than that of its bottom, which is more conducive to its swinging starting from the top, fitting the inner wall of the shell, reducing the longitudinal vibration phenomenon, and improving the lateral swing of the swing block. The all - around swing of the swing block from the top and the limited distance between the swing block and the shell, that is, the limited swing amplitude, can also adapt to the low - frequency ocean wave environment and still work in the non - linear ocean wave environment, providing a new way for energy collection;

[0041] 2. The present invention provides a swing amplitude control mechanism that can regulate the swing amplitude of the columnar triboelectric nanogenerator unit, reduce the phenomenon of excessive swing amplitude of the columnar triboelectric nanogenerator unit, shorten the swing amplitude period, improve the energy conversion effect, and also reduce the occurrence of the situation where the columnar triboelectric nanogenerator unit directly topples to one side;

[0042] 3. The present invention can judge the corresponding water wave height through the current value of triboelectric power generation. It not only realizes self-power supply through its own power generation, reduces the demand for external power sources, but also can realize the function of wave height sensing and know the wave height of the water flow at the location;

[0043] 4. The marine warning system provided by the present invention can make a judgment based on the obtained water wave height as a reference, facilitating timely warning, thereby achieving the purpose of monitoring water flow. When the device is placed at sea, it can realize marine monitoring and warning, and the self-power supply function is also convenient for laying at sea, making full use of wave energy and reducing energy waste. Brief Description of the Drawings

[0044] Figure 1 It is a schematic structural diagram of a columnar triboelectric nanogenerator unit according to Embodiment 1 of the present invention;

[0045] Figure 2 Based on Figure 1 It is a schematic structural diagram of a swing amplitude controllable triboelectric nanogenerator device;

[0046] Figure 3 Based on Figure 2 It is a schematic structural diagram of the power transmission of the wave collection ability of the swing amplitude controllable triboelectric nanogenerator device;

[0047] Figure 4 Based on Figure 2 It is a schematic diagram of the working process of the swing amplitude controllable triboelectric nanogenerator device;

[0048] Figure 5 Based on Figure 2 It is a schematic diagram of the working charge transfer of the swing amplitude controllable triboelectric nanogenerator device;

[0049] Figure 6 Based on Figure 2 It is a schematic structural diagram of the straightening and natural bending states of the swing spring;

[0050] Figure 7 Based on Figure 2 It is an experimental result diagram of the swing angle of the swing block measured under different spring coefficients;

[0051] Figure 8 Based on Figure 2 It is a change trend diagram of the open circuit voltage, short circuit current, and transferred charge measured at different gravity positions of the swing block;

[0052] Figure 9 The graph of the changing trends of the open - circuit voltage, short - circuit current, and transferred charge measured at different bottom radii of the swing block based on Figure 2 ;

[0053] Figure 10 The graph of the changing trends of the open - circuit voltage, short - circuit current, and transferred charge measured at different weights of the swing block based on Figure 2 ;

[0054] Figure 11 The schematic diagram of the swinging angle of the driving seesaw of the swing - amplitude - controllable triboelectric nanogenerator based on Figure 2 ;

[0055] Figure 12 The graph of the changing trends of the open - circuit voltage, short - circuit current, and transferred charge of the swing - amplitude - controllable triboelectric nanogenerator at different swing angles from 5° to 30° based on Figure 2 ;

[0056] Figure 13 The schematic diagram of the changing swinging angles of the columnar triboelectric nanogenerator units with and without a swing - amplitude control mechanism based on Figure 2 ;

[0057] Figure 14 The graph of the changing trends of the open - circuit voltage, short - circuit current, and transferred charge of the columnar triboelectric nanogenerator units in two states of having and not having a swing - amplitude control mechanism based on Figure 2 ;

[0058] Figure 15 The graph of the changing trends of the load current, load voltage, and charging of a 4.7 μF capacitor of the swing - amplitude - controllable triboelectric nanogenerator at a wave height of 6 - 11 cm based on Figure 2 ;

[0059] Figure 16 The graph of the charging and discharging changing trends of the swing - amplitude - controllable triboelectric nanogenerator for different capacitors based on Figure 2 ;

[0060] Figure 17 The graph of the charging and discharging curve changes of the swing - amplitude - controllable triboelectric nanogenerator driving a 220 μF commercial capacitor based on Figure 2 ;

[0061] Figure 18 The schematic diagram of the application of the wave - energy - harvesting platform and network of the swing - amplitude - controllable triboelectric nanogenerator based on Figure 2 ;

[0062] Figure 19 The schematic diagram of the current values corresponding to different wave heights based on Figure 2 ;

[0063] Description of Main Component Symbols

[0064] 1. Housing; 11. First Electrode Layer; 12. Dielectric Film; 2. Swing Block; 21. Second Electrode Layer; 3. Swing Spring; 4. Buffer Layer; 5. Float; 6. Swing Amplitude Regulation Mechanism; 61. Support Plate; 62. Side Spring; 63. Bottom Spring.

[0065] The above description of main component symbols further elaborates on the present invention in conjunction with the accompanying drawings and specific embodiments. Specific Embodiments

[0066] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0067] Embodiment 1

[0068] The columnar triboelectric nanogenerator unit of the present invention solves the problem that the small swing range of the swing structure caused by the low frequency of existing ocean waves limits the ocean wave collection, and realizes the ocean wave collection even in low-frequency ocean waves. The present invention provides a swing block 2 that can swing in all directions, swings with the fluctuations of the ocean waves for energy conversion, and the matching of the swing block 2 with the circular inner cavity of the inner wall of the housing 1 can increase the contact area and improve the conversion effect. In addition, the frustum shape of the swing block 2 makes the radial length of its top smaller than that of its bottom, which is more conducive to its swinging starting from the top, fitting the inner wall of the housing 1, reducing the longitudinal vibration phenomenon, and improving the lateral swing of the swing block 2.

[0069] Such as Figure 1As shown in the figure, the columnar triboelectric nanogenerator unit mainly includes a housing 1, a swing block 2, and a swing spring 3. The housing 1 has a closed inner cavity to prevent other external factors from interfering with the frictional contact between the swing block 2 and the housing 1. Since the swing block 2 is frustum-shaped, in order to fit the swing block 2, the inner cavity of the housing 1 is set as a cylindrical shape, and a buffer layer 4, a first electrode layer 11, and a dielectric film 12 are adhesively bonded in sequence in the inner cavity. The buffer layer 4 is made of an elastic material, which can not only buffer the impact force of the swing block 2, but also deform under the impact of the swing block 2, so that when the swing block 2 collides with the inner wall of the housing 1, a larger contact area can be achieved. For the selection of the material of the buffer layer 4, it can be sponge. In order to reduce the possibility of the buffer layer 4, the first electrode layer 11, and the dielectric film 12 detaching under the action of gravity, and also to reduce the possibility of the swing block 2 shaking up and down in the inner cavity, an annular spacer is provided in the middle and lower part of the side wall surface of the inner cavity, dividing the inner cavity into an upper cavity and a lower cavity. The swing block 2, as well as the buffer layer 4, the first electrode layer 11, and the dielectric film 12 are all in the upper cavity. The annular spacer can support the buffer layer 4, the first electrode layer 11, and the dielectric film 12. At the same time, a small distance is maintained between the annular spacer and the swing block 2. The inner diameter of the annular spacer is smaller than the bottom diameter of the swing block 2. While not affecting the full swing of the swing block 2, when the swing block 2 vibrates longitudinally, it can block part of the vibration, enabling more ocean wave fluctuations to achieve the lateral swing of the swing block 2, making frictional contact with the inner cavity wall surface and generating electrical energy. A small distance is also maintained between the top of the swing block 2 and the inner cavity, but it does not affect the lateral swing of the swing block 2 and its contact with the inner cavity wall surface. The housing 1 and the annular spacer can be made of the same material, such as resin, so that they can be printed and formed by 3D printing.

[0070] For the swing block 2, the diameter of the swing block 2 gradually increases from top to bottom, and it is hollow inside and filled with steel balls to control the weight and center of gravity of the swing block 2. The arc-shaped setting of the outer wall surface of the swing block 2 matches the circular inner cavity of the housing 1. In addition, in order to achieve triboelectrification, a second electrode layer 21 is adhesively bonded to the outer surface of the swing block 2. The second electrode layer 21 cooperates with the first electrode layer 11 and the dielectric film 12. Therefore, when the swing block 2 is in full contact with the inner cavity of the housing 1, more current can be generated. In order to cooperate with the full swing of the swing block 2, the swing block 2 and the inner cavity are connected by a swing spring 3. The swing block 2 and the swing spring 3 are coaxially arranged on the center line of the inner cavity. The swing block 2 is above and the swing spring 3 is below. The swing spring 3 cooperates with the full swing of the swing block 2 to collect the energy of irregular water waves. In addition, thanks to the elasticity of the spring, the swing structure can generate a resonance effect without being coupled with the external driving frequency. The swing of the swing block 2 in the inner cavity constitutes a contact-separation mode.

[0071] For the first electrode layer 11 and the second electrode layer 21, materials with the same structure can be used, but there needs to be a difference in the ability to bind electrons between the first electrode layer 11 and the second electrode layer 21 and the dielectric film 12, so as to achieve triboelectrification. The first electrode layer 11 and the second electrode layer 21 need to have a small internal resistance and large ductility, and at the same time, the resistivity is greater than 1.5, so as to converge the current to maintain a large current output. Therefore, the materials of the first electrode layer 11 and the second electrode layer 21 are preferably metal foils, such as copper foil, aluminum foil, zinc foil, etc. The dielectric film 12 uses a low dielectric constant insulator to reduce the capacitance, and an FEP film can be selected.

[0072] The columnar triboelectric nanogenerator unit of this embodiment can transmit and convert the captured mechanical energy into electrical energy, adapt to the low-frequency ocean waves of non-linear ocean waves, and effectively collect the ocean wave energy.

[0073] Embodiment 2

[0074] As Figure 2 shown, this embodiment introduces a swing amplitude controllable triboelectric nanogenerator device. On the basis of Embodiment 1, a float 5 and a swing amplitude control mechanism 6 are added. The float 5 is used to carry the columnar triboelectric nanogenerator unit and the swing amplitude control mechanism 6. The float 5 needs to be able to float on the water surface and fluctuate with the ocean waves, and has a certain role in capturing ocean waves. Therefore, the material of the float 5 can be selected to be light in mass, such as foam plastic. The swing amplitude control mechanism 6 can control the swing amplitude range of the columnar triboelectric nanogenerator unit, reduce the swing amplitude period of the columnar triboelectric nanogenerator unit, and increase the contact separation frequency between the housing 1 and the swing block 2 inside the columnar triboelectric nanogenerator unit.

[0075] The specific structure of the swing amplitude control mechanism 6 is described below: It mainly includes a support plate 61, side springs 62, and a bottom spring 63. The number of support plates 61 and side springs 62 is the same, and the bottom spring 63 is located at the center of the float 5. The support plate 61 needs to be made of a rigid material, and at the same time, it needs to have a certain weather resistance to meet the use in the natural environment for a long time. Since it needs to be in contact with seawater or other water flows for a long time, it also needs to have a certain chemical stability, and acrylic materials can be selected. The support plate 61 can be elastically coupled with the side springs 62, and the settings of the bottom spring 63 and the side springs 62 can increase the swing frequency of the columnar triboelectric nanogenerator unit. However, the support plate 61 plays a limiting role with the swing of the columnar triboelectric nanogenerator unit, preventing the swing range from being too large, extending the swing period, or even falling to one side. For the number of support plates 61, three are preferably selected and distributed in a triangular shape to form a stable structure. For the shape of the support plate 61, when the outer shape of the housing 1 is cylindrical, the shape of the support plate 61 can be selected as an arc to fit the housing 1 better. The swing amplitude control mechanism 6 can absorb the potential energy during swinging and convert it into elastic potential energy for release, so that the columnar triboelectric nanogenerator unit resonates.

[0076] This embodiment can achieve the collection of blue energy, where the blue energy refers to the water energy of the ocean. This embodiment can be placed on the water surface to collect the energy of water waves, increase the adjustment and resonance of the swing amplitude control mechanism 6, further improve the energy collection efficiency, and also has a certain effect of eliminating water sieves.

[0077] In actual application, the power transmission mechanism of this embodiment is as Figure 3 shown. The energy of ocean waves is transmitted to the float 5, then to the swing amplitude control mechanism 6, and finally to the columnar triboelectric nanogenerator unit. The working process of collecting wave energy is as Figure 4 shown. When the device floats on the sea, the columnar triboelectric nanogenerator unit is in an independent state ( Figure 4 -I). Since ocean waves propagate from the right to the device and will tilt to the left, at this time, the columnar triboelectric nanogenerator unit inside the device reaches a fully contacting state ( Figure 4 -II). Then the wave enters the device, and the columnar triboelectric nanogenerator unit transfers to a fully separated state ( Figure 4 -III). The leftward propagation of ocean waves will cause the device to tilt to the left. At the same time, the swing amplitude control device cooperates to make the columnar triboelectric nanogenerator unit fully contact again ( Figure 4 -IV). Since the ocean waves will leave the device, the entire device will return to its initial state. Therefore, the device will generate two contact-separation processes in one ocean wave. The working mechanism of the internal columnar triboelectric nanogenerator unit is as Figure 5 shown. It is based on the triboelectrification and electrostatic induction effects. Here, take the dielectric film 12 using FEP film, and the first electrode layer 11 and the second electrode layer 21 using copper foil as an example. First, the dielectric FEP film and the copper electrode are uncharged. When they come into contact with each other, static charges are generated through triboelectrification.

[0078] More specifically, when the internal Cu electrode contacts the FEP film, the triboelectric effect makes the FEP film negatively charged and the internal Cu electrode positively charged ( Figure 5 -I). As the internal Cu electrode gradually separates from the FEP film, the positive charges flow from the internal Cu electrode to the external Cu electrode through the external circuit, respectively shielding the local electric fields of the non-mobile negative charges on the FEP film ( Figure 5 -II). Since the internal Cu electrode is completely separated from the corresponding FEP film, all the positive charges will be driven to the external Cu electrode ( Figure 3 -III). Since the FEP film approaches the internal Cu electrode again, the positive charges on the external Cu electrode will transfer to the internal Cu electrode, generating a reverse current in the load ( Figure 5 -IV). Therefore, when ocean waves continuously drive the device to work, a continuous stream of ocean wave energy will be converted into electrical energy by the device.

[0079] Experimental Test

[0080] To more clearly demonstrate the performance of the device in this embodiment, performance tests are also conducted on the device. From multiple perspectives such as the swing angle and electrical output performance, optimization parameters of the product are obtained to enable the device to reach the optimal state when working.

[0081] The swing of the swing block 2 is the most important factor affecting the performance of the entire device. Therefore, a seesaw can be used for testing during the experiment because the working state of the offshore device is similar to that on the seesaw. During the test, the device is fixed on the seesaw for a swing experiment. The columnar triboelectric nanogenerator unit can be experimented first, such as Figure 6 shown, which shows the swing spring 3 in a bent state ( Figure 6 -a) and a natural bent state ( Figure 6 -b).

[0082] Since the bending of the swing spring 3 can be used to evaluate its swing effect, in order to optimize the parameters, springs with different spring coefficients are selected for the swing experiment. The experimental results are as shown in Figure 7 wherein, the swing angle of the No. 6 experimental spring is the largest, and the maximum swing angle is about 67°. Therefore, this spring can be selected for actual use. Through the experiment, the swing spring 3 with a length of 45 mm, a wire diameter of 0.8 mm, and a wire diameter of 10 mm can be finally adopted.

[0083] Based on the above spring, an experiment is conducted on the swing block 2 to test the influence of the center of gravity of the swing block 2 on the device. The center of gravity position of the swing block 2 is changed, and the electrical output performance at different center of gravity positions is as shown in Figure 8 wherein, Figure 8 -a is the change trend diagram of the open-circuit voltage at different center of gravity positions, Figure 8 -b is the change trend diagram of the transferred electric power at different center of gravity positions, Figure 8 -c is the change trend diagram of the short-circuit current at different center of gravity positions. The electrical output performance includes open-circuit voltage, short-circuit current, and transferred charge. The results show that when the center of gravity position of the swing block 2 is above, the electrical output performance reaches the maximum values of 72 V, 23 nC, and 5.1 μA.

[0084] To maximize the contact area, when the top radius is 5 mm, the influence of the bottom radius of the swing block 2 on the contact area is investigated. As shown in Figure 9 are the electrical output performances at different bottom radii from 18 mm to 22 mm, wherein, Figure 9 -a is the change trend diagram of the open-circuit voltage at different bottom radii, Figure 9 -b is the change trend diagram of the transferred charge at different bottom radii, Figure 9-c is the variation trend diagram of the short-circuit current under different bottom radii. When the bottom radius is 20 mm, the electrical output performance reaches the best, which is 97 V, 41 nC, and 8 mA.

[0085] In addition, the influence of the mass of the swing block 2 was also investigated. As Figure 10 shown, where Figure 10 -a is the variation trend diagram of the open-circuit voltage under different masses of the swing block, Figure 10 -b is the variation trend diagram of the transferred charge under different masses of the swing block, Figure 10 -c is the variation trend diagram of the short-circuit current under different weights of the swing block. The results show that as the mass of the swing block 2 increases, the output performance of the motor first increases and then decreases. When the mass of the swing block 2 is 42 g, the maximum short-circuit current reaches 8.9 μΑ, the open-circuit voltage is 140 V, and the transferred charge is 43 nC.

[0086] Due to the irregularity and randomness of ocean waves, when the device works on the sea surface with different wave heights and wave frequencies, different swing ranges will be generated. Figure 11 It is a schematic diagram of the driving seesaw swing angle, and the influence of the swing angle was also investigated. Figure 12 It shows the variation trend of the output performance at different swing angles from 5° to 30°. Among them, Figure 12 -a is the variation trend diagram of the open-circuit voltage at different swing angles, Figure 12 -b is the variation trend diagram of the transferred charge at different swing angles, Figure 12 -c is the variation trend diagram of the short-circuit current at different swing angles. The results show that the swing angle has little influence on the open-circuit voltage and the transferred charge. However, the swing angle has a greater influence on the short-circuit current. When the swing angle changes from 5° to 30°, the short-circuit current decreases from 10 mA to 6 mA. Because when the swing angle increases, the swing period becomes longer, increasing the contact separation time and affecting the current. This precisely proves that the device of this embodiment is suitable for the low-frequency ocean wave environment and can still work in the harsh ocean environment.

[0087] In order to verify the influence of the swing amplitude adjustment mechanism on the columnar triboelectric nanogenerator unit, experiments were carried out on the columnar triboelectric nanogenerator unit with and without the swing amplitude adjustment mechanism. The experimental effect diagrams are as Figure 13 shown. It can be seen that the swing angle of the columnar triboelectric nanogenerator unit with the swing amplitude control mechanism 6 is reduced, and the swing period is shortened.

[0088] Experiments were carried out on the device under the external stimulation in the actual water waves. The results show that the device of this embodiment can still resonate after the trigger stops. In addition, when testing the wave height from 6 cm to 11 cm, regardless of whether there is the swing amplitude control mechanism 6, its output performance is as Figure 14 shown, where Figure 14 -a is the comparison diagram of the open-circuit voltage data with and without the swing amplitude control mechanism under the wave height test, Figure 14-b is a comparison chart of transferred charge data with and without the swing amplitude control mechanism under wave height tests. Figure 14 -c is a comparison chart of short-circuit current data with and without the swing amplitude control mechanism under wave height tests. The results show that after installing the swing amplitude control mechanism 6, the open-circuit voltage, short-circuit current, and short-circuit transferred charge are all significantly improved. When the support plate 61 is made of acrylic material, it combines the rigidity of the arc-shaped acrylic material and the elasticity of the spring, enabling swing amplitude adjustment and resonance, and improving the output performance. In addition, the output performance of the device in actual water waves can obtain an output power about 2.5 - 3 times. Importantly, the swing amplitude control mechanism 6 is not only applicable to the device of this embodiment, but also applicable to all swinging structures.

[0089] To further test the performance of the device of this embodiment, the influence of different resistors on the device of this embodiment was carried out. The load current and voltage of the devices with different resistors at different wave heights (6 cm - 11 cm). As Figure 15 shown in a, the results show that: the load current of the device decreases with the increase of the external load resistance, while the load voltage of the device increases with the increase of the external load resistance. The peak power of the device at different wave heights is as Figure 15 shown in b. As the wave height increases from 6 cm to 11 cm, the maximum power of the device increases from 0.5 mW to 1.4 mW. In addition, by charging a 4.7 mF capacitor, the output performance of the SSC-TENG system at different wave heights was studied, as Figure 15 shown in c. Within the working time of 60 s, the voltage of the capacitor was charged from 3.6 - 7 V within the wave height range of 6 cm - 11 cm. In addition, through Figure 16 it is shown that for capacitors with a higher rated capacitance, the device can effectively achieve relevant charging tasks under the same driving conditions. The charge and discharge curve of a 220 μF commercial capacitor is as Figure 17 shown.

[0090] When collecting ocean wave energy, multiple columnar triboelectric nanogenerator units can be placed on the same large float 5 to form an energy collection platform, or a large energy collection network can be directly composed of multiple devices, as Figure 18 shown.

[0091] For the results of the above experimental tests, when preparing the device of this embodiment, the following dimensions can be adopted: the top diameter of the housing 1 is 50 mm, the height is 90 mm, a FEP film and a copper film with a thickness of 0.08 mm, and a sponge with a thickness of 2 mm are placed inside the housing 1. The inner diameter of the support plate 61 is 80 mm, the thickness is 5 mm, the length is 100 mm, and the radian is 1.26 radians. The length of the bottom spring 63 is 50 mm, the wire diameter is 1 mm, and the diameter is 10 mm. The length of the side spring 62 is 20 mm, the wire diameter is 0.4 mm, and the diameter is 9 mm. For a float 5 matched with one device, a foam plastic with a diameter of 25 mm and a height of 5.6 mm is used.

[0092] Example 3

[0093] This embodiment provides a self-powered wave height sensor that can sense the wave height of water flow. It mainly includes a housing 1, a swing block 2, a swing spring 3, a swing amplitude control mechanism 6, a float 5, a signal acquisition module, and a data processing module. The housing 1, the swing block 2, and the swing spring 3 can form the columnar triboelectric nanogenerator unit in Embodiment 1 or Embodiment 2, which is used to achieve self-power supply in this embodiment. The swing amplitude control mechanism 6 has the same structure as the swing amplitude control mechanism 6 in Embodiment 2. The signal acquisition module can collect the current signal between the first electrode layer 11 and the second electrode layer 21 in real time. The data processing module can obtain the wave height at the corresponding moment according to the electric signal collected at any moment and a preset "electric signal - wave height" function. The "electric signal - wave height" function is used to characterize the mapping relationship between the electric signal and the wave height during the detection process of the wave height sensor. Different wave heights correspond to different electric signals. Here, the electric signal can be a current value. The device in this embodiment obtains the corresponding wave height value by collecting different current values, achieving the purpose of measuring the wave height of water flow.

[0094] For the establishment of the height parameter comparison table, the following steps are adopted:

[0095] The method for establishing the "electric signal - wave height" function includes the following steps:

[0096] S1. Place the wave height sensor in an experimental water tank, preset a wave height range, select multiple wave height values within the wave height range, and collect the electric signals generated by the wave height sensor at different wave height values to obtain a set of discrete experimental data.

[0097] For the experimental water tank, water waves of different heights can be generated. By fixing the wave height, the corresponding electric signal can be obtained. The wave height difference between adjacent wave height values can be 0.1 cm.

[0098] S2. Preset a number of repetitions, repeat step S1, obtain multiple sets of discrete experimental data, and process the multiple sets of discrete experimental data to obtain a set of reliable data sets. The number of experiments is at least 10 times. Conducting multiple experiments can reduce the existence of errors and avoid the occurrence of accidental events affecting the accuracy of the experiment. Therefore, in order to obtain more accurate experimental data, multiple experiments are required to reduce the possibility of accidental data affecting the overall data. The method for obtaining the data set includes the following steps:

[0099] S2.1. Obtain multiple electric signals corresponding to any one wave height value in multiple sets of discrete experimental data to form an original signal set. Calculate the difference between the median value of the original signal set and each electric signal in the original signal set to obtain the signal difference.

[0100] S2.2. Compare each signal difference with a preset error value. The error value can be obtained through multiple experiments or can be an empirical value.

[0101] S2.3. When the signal difference is greater than the error value, delete the electrical signals in the original signal set corresponding to the signal difference. The remaining electrical signals in the original signal set form a precise signal set. Different experimental error factors result in different experimental results, and there are also deviations. Exclude data with large errors and remove data with large individual differences to avoid affecting the accuracy of the overall data.

[0102] S2.4. Calculate the average value of the precise signal set to obtain a reliable signal value.

[0103] S2.5. Repeat step S2.1 to calculate the reliable signal value corresponding to each wave height value. The wave height value and its corresponding reliable signal value form the data set.

[0104] S3. Establish a reference coordinate system with the wave height as the x - coordinate and the electrical signal as the y - coordinate. Mark the wave height values and their corresponding reliable signal values in the data set in the reference coordinate system to obtain a set of discrete points. Connect adjacent discrete points to establish the "electrical signal - wave height" function.

[0105] The height comparison table of the wave height and the corresponding current signal obtained through experiments is as Figure 19 shown. In actual use, if more precise measurement is required, select wave height points with smaller adjacent intervals and a larger number of wave height points within the same range, so as to establish a more precise function, and select an appropriate number of wave height points according to actual needs.

[0106] The self - powered wave height sensor provided in this embodiment not only generates electricity by itself to achieve self - power supply, reducing the demand for external power supplies, but also provides a new way for measuring the wave height of waves.

[0107] Embodiment 4

[0108] This embodiment provides a marine early warning system for marine monitoring, which can give an early warning when the wave height of sea waves is abnormal. The marine early warning system mainly includes a wave height sensor, a limit block, a Gps positioning module, a wireless communication module, an acoustic - optical alarm, and a server. The wave height sensor uses the product in Embodiment 3.

[0109] Limit blocks can be added to the system. The number of limit blocks can be the same as the number of wave height sensors, or it can be an integral unit. The shape of the limit block can be any kind and has a certain weight. The limit block can limit the wave height sensor by its own weight, or can be fixedly connected to other devices or objects to limit the wave height sensor. The wave height sensor and the limit block can be tied together. The function of the limit block is to limit the wave height sensor, so that the wave height sensor floats in the surrounding area of the limit block and will not float away with the fluctuations of the sea waves, but can swing with the fluctuations of the sea waves.

[0110] The number of Gps positioning modules is the same as the number of wave height sensors and is installed on the wave height sensors to obtain the positioning information of the wave height sensors. The wireless communication module transmits the data collected by the wave height sensors and Gps positioning modules to a server. The audible and visual alarm needs to be installed where there are offshore monitoring personnel so that the staff can hear the audible and visual alarm and take preventive measures in advance. The server not only receives the data signals transmitted by the wireless communication module and processes the data signals to obtain the wave height information and corresponding position information of the wave height sensors, but also can judge whether the wave height information is within a preset reasonable range; otherwise, it sends a warning signal and controls the audible and visual alarm to alarm.

[0111] The warning method in this embodiment includes the following steps:

[0112] Step 1. Collect data signals in real time.

[0113] Step 2. Process the data signals to obtain the wave height information and corresponding position information of the wave height sensors. Data processing includes processing and organizing the collected data to form the required data format. First, data cleaning is performed to screen and remove redundant and repeated data, supplement missing data, correct or delete incorrect data. Subsequently, data processing is carried out, and information extraction, calculation, grouping, conversion, etc. are performed on the data fields to make it into the final required data.

[0114] Step 3. Judge whether the wave height information is within a preset reasonable range. The preset reasonable range can be adjusted according to the actual situation, and is adjusted according to the different topographies of different regions, etc., so that the range conforms to the actual situation of the region and makes the warning effect more accurate.

[0115] Step 4. Otherwise, send a warning signal. The warning signal includes the wave height value and the corresponding position information, and controls the audible and visual alarm to alarm.

[0116] Sending a warning signal can be sent to related devices, and at the same time, the priority can be set. The number of devices to be sent is determined according to the magnitude of the value by which the wave height exceeds the preset reasonable range to reflect the urgency of the warning.

[0117] The system in this embodiment establishes an early warning system based on the wave height sensor in Embodiment 3, makes full use of wave energy, reduces energy waste, can adapt to the non-linear marine environment, and provides a new way for marine monitoring.

[0118] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0119] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A friction nanogenerator with controllable swing amplitude, which comprises a float (5), and is characterized in that, The swing amplitude controllable triboelectric nanogenerator further includes: At least one columnar triboelectric nanogenerator unit, which includes a housing (1), a swing block (2) in the shape of a frustum of a cone, and a swing spring (3) coaxially arranged with the swing block (2); the housing (1) has a closed inner cavity in the shape of a cylinder, and the side wall surface of the inner cavity is provided with a first electrode layer (11) with a dielectric film (12) on its surface. An annular partition is provided in the middle and lower section of the side wall surface of the inner cavity to divide the inner cavity into an upper cavity and a lower cavity; the first electrode layer (11) and the dielectric film (12) are located in the upper cavity; the swing block (2) is arranged on the center line of the upper cavity. The radial length of the top end of the swing block (2) is smaller than that of the bottom end, and the radial length of the bottom end is smaller than the radial length of the inner wall surface of the annular partition; the inside of the swing block (2) is hollow and contains a cavity with steel balls inside; the outer wall surface of the swing block (2) is provided with a second electrode layer (21); one end of the swing spring (3) enters the upper cavity from the lower cavity and is connected to the outer bottom surface of the swing block (2), and the other end is connected to the bottom wall surface of the lower cavity; and A swing amplitude adjustment mechanism (6) for adjusting the swing amplitude of the columnar triboelectric nanogenerator unit under different degrees of external force; the swing amplitude adjustment mechanism (6) includes a support plate (61), a side spring (62), and a bottom spring (63); the number of the support plates (61) is three, and the three support plates (61) are arranged in an equidistant ring at the top end of the float (5); one end of the side spring (62) is fixedly connected to the inner wall surface of the support plate (61), and the other end extends towards the center line direction of the float (5) and is connected to the columnar triboelectric nanogenerator unit; the bottom spring (63) is coaxially arranged with the columnar triboelectric nanogenerator unit, one end is connected to the top end of the float (5), and the other end is connected to the bottom end of the columnar triboelectric nanogenerator unit.

2. The swing amplitude controllable triboelectric nanogenerator according to claim 1, wherein The support plate (61) is made of weather-resistant rigid material.

3. The swing amplitude controllable triboelectric nanogenerator according to claim 1, characterized in that, A buffer layer (4) is bonded between the first electrode layer (11) and the inner side wall surface of the housing (1) to expand the contact area between the swing block (2) and the housing (1).

4. The swing amplitude controllable triboelectric nanogenerator according to claim 1, wherein, The first electrode layer (11) and the second electrode layer (21) are made of a conductive material with a resistivity greater than 1.

5.

5. The swing amplitude controllable triboelectric nanogenerator according to claim 4, characterized in that, The dielectric film (12) is made of a material with a different ability to bind electrons from the first electrode layer (11) and the second electrode layer (21).

6. The swing amplitude controllable triboelectric nanogenerator according to claim 1, wherein The thickness of the first electrode layer (11) and the second electrode layer (21) is 0.001 - 0.08 mm, and the thickness of the dielectric film is 0.01 - 0.2 mm.

7. A self-powered wave height sensor, which comprises a float (5), characterized in that, The wave height sensor further includes: A housing (1) with a closed inner cavity, the inner cavity is in the shape of a cylinder, and the side wall surface of the inner cavity is provided with a first electrode layer (11); a dielectric film (12) is provided on the surface of the first electrode layer (11); an annular partition is provided in the middle and lower section of the side wall surface of the inner cavity, and the annular partition divides the inner cavity into an upper cavity and a lower cavity; the first electrode layer (11) and the dielectric film (12) are located in the upper cavity; The swing block (2) is arranged on the center line of the upper cavity. The swing block (2) is in the shape of a frustum of a cone, and the radial length of the top end of the swing block (2) is smaller than that of the bottom end; the radial length of the bottom end of the swing block (2) is smaller than the radial length of the inner wall surface of the annular spacer; the swing block (2) is hollow inside and contains a cavity, and steel balls are arranged in the cavity; a second electrode layer (21) is arranged on the outer wall surface of the swing block (2). The swing spring (3) is coaxially arranged with the swing block (2). One end of the swing spring (3) enters the upper cavity from the lower cavity and is connected to the outer bottom surface of the swing block (2), and the other end of the swing spring (3) is connected to the bottom wall surface of the lower cavity. The swing amplitude regulating mechanism (6) is used to adjust the swing amplitude of the columnar triboelectric nanogenerator under the action of different degrees of external force; the swing amplitude regulating mechanism (6) includes a support plate (61), a side spring (62), and a bottom spring (63); the number of the support plates (61) is three, and the three support plates (61) are arranged in an equidistant ring at the top end of the float (5); one end of the side spring (62) is fixedly connected to the inner wall surface of the support plate (61), and the other end extends towards the center line direction of the float (5) and is connected to the columnar triboelectric nanogenerator; the bottom spring (63) is coaxially arranged with the columnar triboelectric nanogenerator, one end is connected to the top end of the float (5), and the other end is connected to the bottom end of the columnar triboelectric nanogenerator. The signal acquisition module is used to acquire the electrical signal between the first electrode layer (11) and the second electrode layer (21) in real time. The data processing module is used to obtain the wave height at the corresponding moment according to the electrical signal acquired at any moment and a preset "electrical signal - wave height" function, and the "electrical signal - wave height" function is used to characterize the mapping relationship between the electrical signal and the wave height during the detection of the wave height sensor.

8. The self-powered wave height sensor according to claim 7, wherein The method for establishing the "electrical signal - wave height" function includes the following steps: S1. Place the wave height sensor in the experimental water tank, preset a wave height range, select multiple wave height values within the wave height range, and acquire the electrical signals generated by the wave height sensor at different wave height values to obtain a set of discrete experimental data. S2. Preset a number of repetitions, repeat step S1 to obtain multiple sets of discrete experimental data, and process the multiple sets of discrete experimental data to obtain a set of reliable data sets. The acquisition method of the data sets includes the following steps: S2.

1. Acquire multiple electrical signals corresponding to any wave height value in multiple sets of discrete experimental data to form an original signal set, and calculate the difference between the median value of the original signal set and each electrical signal in the original signal set to obtain a signal difference. S2.

2. Compare each signal difference with a preset error value. S2.

3. When the signal difference is greater than the error value, delete the electrical signals in the original signal set corresponding to the signal difference, and the remaining electrical signals in the original signal set form a precise signal set. S2.

4. Calculate the average value of the precise signal set to obtain a reliable signal value. S2.

5. Repeat step S2.1 to calculate the reliable signal value corresponding to each wave height value. The wave height value and its corresponding reliable signal value form the data set; S3. Establish a reference coordinate system with the wave height as the x - coordinate and the electrical signal as the y - coordinate. Mark the wave height value and its corresponding reliable signal value in the data set in the reference coordinate system to obtain a set of discrete points. Connect adjacent discrete points to establish the "electrical signal - wave height" function.

9. The self-powered wave height sensor according to claim 7, characterized in that, A buffer layer (4) is bonded between the first electrode layer (11) and the inner wall surface of the housing (1) to expand the contact area between the swing block (2) and the housing (1).

10. The self-powered wave height sensor according to claim 7, characterized in that, The first electrode layer (11) and the second electrode layer (21) are made of a conductive material with a resistivity greater than 1.

5.

11. The self-powered wave height sensor according to claim 10, characterized in that, The dielectric film (12) is made of a material with a different electron - binding ability from that of the first electrode layer (11) and the second electrode layer (21).

12. The self-powered wave height sensor according to claim 7, characterized in that, The thickness of the first electrode layer (11) and the second electrode layer (21) is 0.001 - 0.08 mm, and the thickness of the dielectric film is 0.01 - 0.2 mm.

13. An offshore early warning system, characterized in that, It includes: Multiple wave height sensors arranged to match the seabed; It uses the self - powered wave height sensor as described in any one of claims 7 - 12; Multiple Gps positioning modules, each Gps positioning module corresponding to each wave height sensor to obtain the position information of each wave height sensor; A wireless communication module for transmitting the data collected by the wave height sensors and Gps positioning modules to a server; At least one acoustic - optical alarm, which is set in the marine monitoring workstation and issues an alarm according to the warning signal from a server; A server for receiving the data signal transmitted by the wireless communication module, processing the data signal to obtain the wave height information and the corresponding position information of the wave height sensor; and also for judging whether the wave height information is within a preset reasonable range; otherwise, sending a warning signal and controlling the acoustic - optical alarm to give an alarm.

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