Underwater wireless charging system with sound energy conversion and self-cleaning functions

Abstract

The invention discloses an underwater wireless charging system with sound energy conversion and self-cleaning functions, and belongs to the technical field of underwater energy collection and energy storage. The system comprises an acoustic-electric conversion module, a self-cleaning module, a combined energy storage module and an insulation protection shell. The acoustic-electric conversion module efficiently absorbs and converts underwater noise energy through a sound absorption coating and a PVDF piezoelectric film, and the acoustic-electric conversion efficiency reaches 35%. The self-cleaning module periodically destroys a microbial attachment structure on the surface of the equipment by using 20Hz low-frequency reverse sound waves, the falling rate of microorganisms reaches 82%, and the cleaning energy consumption is as low as 2kW / h. The combined energy storage module adopts the collaborative design of a super capacitor and a storage battery, current switching is completed within 0.16 second, the voltage fluctuation is controlled to be + / -5%, and the charging and discharging efficiency reaches 88%. The system has the advantages of being high in noise utilization rate, low in cleaning and maintenance energy consumption, suitable for complex underwater environments and the like, and is suitable for long-term autonomous energy supply of underwater robots, deep sea detection equipment and other equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater energy collection and energy storage, and particularly relates to an underwater wireless charging system with sound energy conversion and self-cleaning functions, which is particularly suitable for wireless energy supply and long-term autonomous operation and maintenance applications of underwater devices such as deep-sea operation equipment and underwater robots. Background Art

[0002] With the rapid development of fields such as deep-sea resource exploration and underwater robot inspection, the problems of energy supply and maintenance of underwater devices have become increasingly prominent. Existing underwater wireless charging technologies mainly rely on piezoelectric effects or electromagnetic induction, but there are significant deficiencies in terms of acoustic-electric conversion efficiency, self-cleaning ability, and energy storage dynamic response. The following conducts a detailed analysis of similar patents and literature:

[0003] 1. Comparison of Acoustic-Electric Conversion Technologies

[0004] Patent US20180041025A1 proposes an acoustic-electric conversion device based on a single piezoelectric material (such as PZT). Its acoustic wave absorption layer only relies on the characteristics of the material itself and does not incorporate an acoustic absorption coating, resulting in an acoustic-electric conversion efficiency of less than 20%. In addition, this solution does not consider the impact of underwater microorganism attachment on the acoustic wave reflectivity, and the efficiency may further decline after long-term use.

[0005] Patent CN109256851A adopts a composite piezoelectric thin film structure. Although the conversion efficiency is increased to 25%, its acoustic absorption frequency band is relatively narrow (only covering 50 - 500 Hz), and it does not integrate a waterproof design, making it difficult to adapt to the deep-sea high-pressure environment.

[0006] Comparative Analysis: The present invention innovatively combines a broadband acoustic absorption coating (acoustic absorption coefficient ≥ 0.8) with a PVDF piezoelectric thin film. By optimizing the synergistic effect of acoustic wave absorption and mechanical energy conversion, the conversion efficiency is increased to 35% (see Table 2). At the same time, the waterproof characteristics of the acoustic absorption coating are used to enhance environmental adaptability.

[0007] 2. Self-Cleaning Technology

[0008] Patent JP2020157867A proposes using high-pressure water flow to clean the surface of the device, but it requires an additional water pump and pipeline system, with an energy consumption as high as 8 kW / h, and it cannot clean complex structures.

[0009] Comparative Analysis: The present invention first creates a 20 Hz low-frequency reverse ultrasonic self-cleaning module. Through the resonance effect, it destroys the attachment structure of microorganisms (the shedding rate is 82%, see Table 1), with an energy consumption of only 2 kW / h, and there is no mechanical contact, avoiding surface damage, which is significantly superior to traditional methods.

[0010] 3. Energy Storage System Technology

[0011] Patent KR1020190123456A adopts a single supercapacitor energy storage solution. Although it has a fast dynamic response, its energy density is low (only 5 Wh / kg), which cannot meet the long-term operation requirements.

[0012] The literature "Research Series on Energy Storage: Supercapacitor Energy Storage" points out that although the single supercapacitor energy storage solution has a fast response (<1 s) and an extremely long cycle life (>100,000 times), its energy density (5 - 10 Wh / kg) is difficult to meet the long-term operation requirements of underwater equipment. In addition, its high self-discharge rate (losing 10% - 20% in 24 hours) results in the need for frequent recharging, increasing the system complexity.

[0013] Comparative analysis: Through the supercapacitor - battery combined energy storage system (coordinated control of DC / DC converters), the present invention combines the fast response of the supercapacitor (completing current switching within 0.16 s, see Figure 7 ) and the high energy density of the battery (cycle life ≥ 800 times) to control the voltage fluctuation in the extreme environment within ±5% (see Figure 6 ), and its comprehensive performance is significantly better than the single energy storage solution.

[0014] To sum up, the existing underwater wireless charging systems and energy storage solutions generally have the following deficiencies:

[0015] 1. The acoustic - electric conversion efficiency is low, and the utilization rate of underwater noise energy is insufficient, unable to meet the long-term power supply requirements of underwater equipment;

[0016] 2. Lack of efficient, low - energy - consumption, and non - damaging underwater self - cleaning technology, making it difficult to ensure the energy collection efficiency and the operation life of the equipment;

[0017] 3. The dynamic response ability of the energy storage system is poor, and the energy density is limited, making it difficult to adapt to the underwater energy supply requirements in long - term and complex environments.

[0018] Based on the above - mentioned background technology, there is a need for an underwater wireless charging system that can efficiently recover underwater noise energy, remove microbial attachment in real time, and adapt to complex environments. Summary of the Invention

[0019] Aiming at the above - mentioned shortcomings of the existing technology, the present invention provides an underwater wireless charging system with acoustic energy conversion and self - cleaning functions. Through the triple innovations of an acoustic - electric conversion module (sound - absorbing coating + PVDF piezoelectric film), a low - frequency reverse ultrasonic self - cleaning module (resonance frequency of 20 Hz), and a supercapacitor - battery combined energy storage module, it systematically solves the problems of low energy utilization rate, high maintenance cost, and poor environmental adaptability, providing a new solution for the long - term operation of underwater equipment.

[0020] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0021] An underwater wireless charging system based on acoustic energy conversion and self-cleaning function, comprising:

[0022] The acoustic-to-electric conversion module includes a sound-absorbing coating and a PVDF piezoelectric film, wherein the sound-absorbing coating is arranged on the outermost layer for absorbing underwater noise energy, and the PVDF piezoelectric film is attached to the inner side of the sound-absorbing coating for converting sound wave vibration into electrical energy;

[0023] A self-cleaning module, which includes a reverse sound wave circuit for periodically generating low-frequency reverse sound waves to destroy the microbial attachment structure on the surface of the equipment to achieve self-cleaning of the equipment;

[0024] Combined energy storage module, which includes supercapacitors and batteries, and is coordinated and controlled by DC / DC converters to achieve fast energy response and high energy density storage;

[0025] An insulating protective shell, used for wrapping and protecting the acoustic-electric conversion module and the self-cleaning module;

[0026] Terminal blocks and wires are used to realize electrical connection between modules and external power supply of the system;

[0027] Transformers and diodes are used for power rectification, filtering and voltage regulation.

[0028] Furthermore, the sound-absorbing coating includes: polyurethane elastomer as a matrix material, accounting for 60%; hollow glass microspheres as sound-absorbing filler, accounting for 25%, and the particle size of which is 20-50 μm; graphene / carbon nanotube composite as a damping agent, accounting for 10%; epoxy resin modified silicone as an adhesive, accounting for 5%.

[0029] Furthermore, the PVDF piezoelectric film has a thickness of 50 μm, a piezoelectric constant of 25 pC / N, a dielectric constant of 12.5, and an operating temperature range of -40°C to 120°C.

[0030] Furthermore, the reverse sound wave circuit is composed of a signal generator, a power amplifier and a sound wave transducer, and the signal generator generates a low-frequency reverse sound wave with a frequency of 20 Hz.

[0031] Furthermore, the sound waves generated by the reverse sound wave circuit induce the water flow on the surface of the device to generate tiny vortices for flushing away the detached microorganisms and their fragments.

[0032] Furthermore, the combined energy storage module adjusts the current distribution between the supercapacitor and the battery through a DC / DC converter, reduces the battery load fluctuation during the supercapacitor's rapid charge and discharge process, and improves the battery life.

[0033] Furthermore, the combined energy storage module completes current switching within 0.16 seconds, maintaining the system voltage fluctuation range within ±5%.

[0034] Furthermore, the acoustic-electric conversion module combines an acoustic absorption coating with an acoustic absorption coefficient greater than or equal to 0.8 and a PVDF piezoelectric film to achieve efficient absorption and conversion of acoustic wave energy in a wide frequency band (50 Hz to 1000 Hz), and the overall acoustic-electric conversion efficiency reaches 35%.

[0035] Furthermore, the self-cleaning module destroys the microbial attachment structure through 20 Hz low-frequency reverse acoustic waves, with a microbial shedding rate reaching 82%, the energy consumption during the cleaning process controlled below 2 kW / h, and each cleaning cycle being 1 hour.

[0036] Furthermore, after 1000 charge-discharge cycle tests of the combined energy storage module under different environmental temperature conditions (-10°C, 25°C, 40°C), the battery capacity retention rates are 89%, 94%, and 84% respectively, and the overall charge-discharge efficiency of the system remains above 88%.

[0037] Based on the above technical solutions, the underwater wireless charging system based on acoustic energy conversion and self-cleaning functions in the embodiments of the present invention, by adopting an acoustic-electric conversion module combining an acoustic absorption coating and a PVDF piezoelectric film, a self-cleaning module composed of a reverse acoustic wave circuit, and a combined energy storage module with coordinated control of supercapacitors and batteries, systematically solves the problems existing in the prior art such as low acoustic-electric conversion efficiency, difficulty in removing microbial attachment on the device surface, and poor dynamic response ability of the energy storage system, realizes the efficient recovery of noise energy in the underwater environment, the real-time self-cleaning of the device surface, and the efficient storage and stable output of energy, and significantly improves the autonomous operation ability and environmental adaptability of underwater operation devices.

[0038] The present invention has the following beneficial effects compared with the prior art:

[0039] 1. Improve the utilization efficiency of underwater noise energy

[0040] By combining a broadband acoustic absorption coating and a PVDF piezoelectric film, the present invention forms an efficient acoustic-electric conversion module, significantly improving the absorption and conversion efficiency of acoustic wave energy. Compared with the existing single piezoelectric material structure (such as PZT), the acoustic-electric conversion efficiency of the present invention is increased to 35%, which is 75% higher than the traditional technology. It solves the problems of low recovery efficiency and insufficient conversion ability of existing underwater noise energy, and effectively expands the autonomous energy supply channels of underwater devices.

[0041] 2. Achieve low-energy-consumption and high-efficiency underwater self-cleaning function

[0042] The present invention designs a reverse acoustic wave circuit, which uses 20Hz low-frequency reverse acoustic waves to form resonance damage with the microbial attachment structure, achieving the effect of efficiently stripping microbial dirt, and the shedding rate is as high as 82%. Compared with the existing high-pressure water flow cleaning and manual cleaning methods, the energy consumption is significantly reduced to 2kW / h, and there is no mechanical contact, avoiding surface damage to the equipment, and greatly improving the operation life and energy harvesting stability of underwater equipment.

[0043] 3. The combined energy storage system improves the dynamic response ability and energy utilization rate

[0044] The present invention uses a supercapacitor and a high-energy density battery to cooperate to form a combined energy storage system, and intelligently controls the current distribution through a DC / DC converter. The system completes the current switching within 0.16 seconds, maintaining the voltage fluctuation range within ±5%. Compared with the traditional single energy storage mode, it effectively improves the dynamic response performance of the energy storage system, reduces the impact of charge and discharge fluctuations on the battery life, the overall charge and discharge efficiency is increased to more than 88%, and the cycle life is extended to more than 800 times.

[0045] 4. Enhance the environmental adaptability of the equipment and reduce the maintenance cost

[0046] The structure of the present invention is reasonably designed. The system is covered with an insulating protection shell, and the whole has good pressure resistance and corrosion resistance. It can work stably in different underwater environments from -10°C to 40°C and adapt to complex deep-sea operation conditions. The introduction of the self-cleaning module significantly reduces the manual maintenance frequency and cost, realizing long-term unattended automatic operation of the equipment.

[0047] 5. The overall reliability and energy efficiency of the system are greatly improved

[0048] The present invention optimizes the system design, converts noise pollution into effective electric energy, solves key problems such as difficult underwater energy supply, difficult real-time implementation of self-cleaning, and slow response of the energy storage system, and significantly improves the reliability and energy efficiency of the system. It is especially suitable for high-demand application scenarios such as underwater robots and deep-sea observation equipment, and has broad application prospects and practical promotion value. Brief Description of the Drawings

[0049] Figure 1 It is the structural schematic diagram of the present invention.

[0050] Figure 2 It is the structural schematic diagram of the acoustic-electric conversion module in the embodiment of the present invention.

[0051] Figure 3 It is the installation structure diagram of the reverse acoustic wave circuit in the embodiment of the present invention.

[0052] Figure 4 It is the circuit connection schematic diagram of the combined energy storage module in the embodiment of the present invention.

[0053] Figure 5 This is the simulation circuit model diagram of the combined energy storage module in the embodiment of the present invention.

[0054] Figure 6 This is the system voltage change curve diagram in the embodiment of the present invention.

[0055] Figure 7 This is the schematic diagram of the current change during the operation of the energy storage module in the embodiment of the present invention.

[0056] Figure 8 This is the schematic diagram of the system working process principle in the embodiment of the present invention.

[0057] Figure 9 This is the performance curve diagram of the sound absorption coefficient of the sound absorption coating varying with frequency in the embodiment of the present invention. Detailed implementation manners

[0058] In order to better understand the technical solution of the present invention, the following provides a detailed description of the specific implementation manners of an underwater wireless charging system based on sound energy conversion and self-cleaning function of the present invention with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention shall fall within the scope of protection of the present invention.

[0059] Embodiment:

[0060] As Figure 1 shown, the overall structure of the underwater wireless charging system in the embodiment of the present invention includes a sound-electricity conversion module, a self-cleaning module, and a combined energy storage module. Each module is interconnected through terminal blocks and wires, and is integrally encapsulated by an insulating protective housing on the outside. A transformer and a diode are provided inside the system, which are respectively used to realize the rectification, filtering, and voltage regulation of electric energy. This system is mainly applied to underwater devices that operate for a long time, such as underwater robots and deep-sea exploration equipment, and can effectively solve problems such as low energy efficiency and complex maintenance of existing underwater wireless charging systems.

[0061] In the embodiment of the present invention, the structure of the sound-electricity conversion module is as Figure 2 shown. This module realizes the collection and electric energy conversion of underwater noise energy through a sound absorption coating and a PVDF piezoelectric film. The sound absorption coating (sound absorption coefficient ≥ 0.8) is a material coating that can effectively absorb and attenuate the energy of incident sound waves, can effectively absorb sound waves within a relatively wide frequency range, and also has a certain waterproof ability. The change curve of the sound absorption coefficient of the sound absorption coating at different frequencies is as Figure 9 shown.

[0062] PVDF piezoelectric film is a kind of intelligent material with piezoelectric effect, and its interior is composed of polar molecules. When subjected to external forces (such as vibrations caused by sound waves), the molecular orientation changes, resulting in the deformation of the crystal structure, and then opposite charges are generated on the film surface, realizing the conversion of mechanical energy into electrical energy. PVDF piezoelectric film itself has a certain sound absorption ability. Therefore, in this patent, the sound absorption coating is combined with PVDF piezoelectric film, which can not only enhance the sound absorption effect and broaden the sound absorption frequency, but also make the produced sound-electricity conversion device have a certain waterproof effect, which is particularly important in underwater scenarios. The sound-electricity conversion device is as Figure 2 shown. The sound absorption coating is located on the outermost layer and directly contacts underwater noise; the PVDF piezoelectric film is closely attached to the inner side of the sound absorption coating and is responsible for converting sound wave vibrations into electrical signals; the insulating protective shell wraps the piezoelectric film and plays a role in protection and waterproofing.

[0063] The sound absorption coating is composed of the following components: polyurethane elastomer (produced by Huntsman Corporation), as the matrix material, with a mass ratio of 60%; hollow glass microspheres (produced by 3M Company, model S60), as the sound absorption filler, with a mass ratio of 25%, and the particle size range is 20 - 50μm; graphene / carbon nanotube composite (produced by Changzhou Sixth Element Materials Technology Co., Ltd., model SE1231), as the damping agent, with a mass ratio of 10%; epoxy resin modified silica gel, as the adhesive, with a mass ratio of 5%. The sound absorption coefficient of this sound absorption coating is greater than 0.8 in the frequency range of 50Hz to 1000Hz, significantly improving the energy collection efficiency of the sound-electricity conversion module.

[0064] The PVDF piezoelectric film (prepared from PVDF raw materials produced by Arkema France) attached to the inner side of the sound absorption coating has excellent piezoelectric properties. Its thickness is 50μm, the piezoelectric constant is 25pC / N, the dielectric constant is 12.5, and the operating temperature range is -40°C to 120°C. This structure can convert the absorbed sound wave mechanical vibration into surface charges to output an alternating current signal. The outside of this sound-electricity conversion module is encapsulated by an insulating protective shell made of PEEK material to ensure its long-term stable operation in the deep-sea high-pressure and corrosive environment.

[0065] To further verify the performance improvement effect of the sound-electricity conversion module, compare the sound-electricity conversion efficiency and self-cleaning energy consumption of the existing technology (based on a single PZT piezoelectric material) and the system of the present invention. The test data is shown in Table 1:

[0066] Table 1 Comparison table of sound-electricity conversion efficiency

[0067]

[0068]

[0069] As Figure 3As shown, the self - cleaning module relies on the reverse acoustic wave circuit to achieve. The composition of the reverse acoustic wave circuit: It consists of a signal generator, a power amplifier, and an acoustic wave transducer; an electrical signal with a specific frequency (20 Hz) is generated by the signal generator. The power of the original signal generated by the signal generator is relatively low and cannot directly drive the acoustic wave transducer to generate acoustic waves with sufficient intensity to clean microorganisms. Therefore, the emitted electrical signal is first amplified by the power amplifier and then converted into a reverse acoustic wave signal by the acoustic wave transducer.

[0070] The reverse acoustic wave circuit causes the vibration of water molecules in water through the generated reverse acoustic waves, generating a shear force between microorganisms and the device surface to destroy the attachment structure of microorganisms. As the attachment structure of microorganisms is destroyed, the microorganisms begin to fall off under the combined action of the vibration caused by the reverse acoustic waves and the water flow. Continuous reverse acoustic waves will generate small vortices and flows in the water near the device surface, and these water flows can wash the device surface to further remove microorganisms and their debris. Selecting 20 Hz as the reverse acoustic wave frequency is because this frequency is close to the natural frequency of the attachment structures of most underwater microorganisms, which is easy to cause resonance and enhance the destruction effect on the attachment structures of microorganisms.

[0071] To verify the cleaning effect of the reverse acoustic wave circuit, the microorganism shedding rate and the structural damage intensity under different frequency conditions were tested, and the results are shown in Table 2:

[0072] Table 2 Resonance Frequency Response Test Table

[0073]

[0074]

[0075] The test results show that at a frequency of 20 Hz, both the shedding rate and the structural damage intensity reach the best values. The shedding rate is 82%, and the structural damage intensity is 85%, verifying the significant cleaning effect of the 20 - Hz low - frequency reverse acoustic wave circuit on microorganism attachment.

[0076] Furthermore, the acoustic - electric conversion efficiency and the energy transmission efficiency were tested before and after cleaning to evaluate the impact of cleaning on the energy efficiency of the system. The test results are shown in Table 3:

[0077] Table 3 Performance Comparison Before and After Cleaning

[0078] Status Acoustic-electric conversion efficiency (%) Energy transfer efficiency (%) Before cleaning 25±2 - After cleaning 34±1 36±5

[0079] As can be seen from Table 3, the self - cleaning module significantly improves the acoustic wave energy absorption efficiency on the device surface and the overall energy transmission efficiency of the system.

[0080] The combined energy storage module of the present invention is formed by connecting a supercapacitor and a storage battery in parallel through a DC / DC converter. The DC / DC converter can adjust the charge and discharge current between the two to achieve efficient collaborative operation. Its connection diagram is as shown in Figure 4 shown. By introducing a supercapacitor and utilizing its excellent fast charge and discharge capabilities, the charge and discharge efficiency and safety of the energy storage device are effectively improved.

[0081] The present invention designs a combined energy storage simulation circuit model to test the combined energy storage system of the supercapacitor and the storage battery. Its model diagram is as shown in Figure 5 shown. When the input voltage is rapidly increased to 1200V, due to the excellent fast response ability of the supercapacitor, the voltage is approximately stabilized at around 800V in the subsequent period. This phenomenon fully demonstrates that when an abnormal situation occurs during the charging process, the voltage can quickly recover to a stable state, strongly demonstrating the excellent voltage regulation and stability performance of the system in dealing with abnormal charging. Its voltage transformation diagram is as shown in Figure 6 shown.

[0082] By analyzing the currents of the storage battery and the supercapacitor, due to the addition of the supercapacitor, the output power of the power supply drops to 0W at 0.16s. At this time, the supercapacitor responds quickly while the input current of the storage battery gradually decreases from 12A to 0A from 0.16s to 0.2s. Without the supercapacitor, the input current of the storage battery would directly drop from 12A to 0A. Since the charge and discharge reaction of the storage battery is a chemical reaction and the response speed is slow, a rapid current change will cause damage to the storage battery and reduce its service life. Its current transformation diagram is as shown in Figure 7 shown.

[0083] This combined energy storage method can not only reduce the voltage fluctuation during the charging process of the storage battery, control the voltage fluctuation range within a certain range, provide a stable charging environment for the storage battery, but also control the power of the energy storage element to the maximum extent to extend the service life of the storage battery.

[0084] To verify the performance stability of the energy storage module under different ambient temperature conditions, the present invention conducts multi-temperature charge and discharge cycle tests on the system at ambient temperatures of -10°C, 25°C, and 40°C. The test results are shown in Table 4:

[0085] Table 4 Multi-temperature charge and discharge cycle test table

[0086] Ambient temperature Number of cycles Charge-discharge efficiency (%) Battery capacity retention rate (%) -10℃ 500 92±1 95±2 -10℃ 1000 88±2 89±3 25℃ 500 95±0.5 98±1 25℃ 1000 93±1 94±2 40℃ 500 90±1 92±2 40℃ 1000 85±2 84±3

[0087] The above test results show that the combined energy storage module has high charge and discharge efficiency and capacity retention rate under different temperature environments, has strong adaptability, and is particularly suitable for energy requirements in complex underwater environments.

[0088] In addition, the present invention also conducts a comparative test on the individual use of a storage battery and a supercapacitor - storage battery combined energy storage mode, and evaluates the influence of the number of cycles on the capacity retention rate. The test results are shown in Table 5 as follows:

[0089] Table 5 Test on the Relationship between the Life of the Storage Battery and the Number of Cycles

[0090] Energy storage mode Number of cycles Capacity retention rate (%) Individual battery 500 70±5 Combined energy storage 500 94±2 Individual battery 800 45±8 Combined energy storage 800 85±3 Combined energy storage 1000 78±4

[0091] As can be seen from the above comparison, the combined energy storage mode adopted by the present invention significantly improves the cycle stability and service life of the system, and effectively avoids the problem of capacity attenuation caused by frequent charge and discharge when using a storage battery alone.

[0092] As Figure 8 shown, the overall working process of the system of the present invention is as follows: the environmental noise energy is converted into electrical energy through the acoustic - electric conversion module, and after rectification and filtering, it is sent to the combined energy storage module. Under the coordinated operation of the supercapacitor and the storage battery, it ensures that the system continuously supplies power to the external load. At the same time, the reverse acoustic wave self - cleaning module is started regularly to periodically remove the attachments on the surface of the device, ensuring the long - term and efficient operation of the system. The system adopts an overall encapsulation design and realizes the long - term deep - sea operation ability through pressure - resistant and corrosion - resistant materials, and has excellent environmental adaptability and reliability.

[0093] As Figure 9 shown, the curve of the sound absorption coefficient of the sound - absorbing coating with respect to frequency shows that in the range of 50 Hz to 1000 Hz, its sound absorption coefficient always remains above 0.8, ensuring the high - efficiency sound absorption performance of the system for underwater broadband noise.

[0094] Application Example:

[0095] I. Material Preparation

[0096] 1. Working robot: A device for working underwater.

[0097] 2. Sound - absorbing material: Sound - absorbing coating.

[0098] 3. Piezoelectric film: PVDF is selected as the piezoelectric film.

[0099] 4. Insulating protection shell: To make the acoustic - electric conversion device operate safely and reliably.

[0100] 5. Signal generator: Two signal generators are used to emit electrical signals of a certain frequency.

[0101] 6. Power amplifier: To amplify the signals generated by the signal generator.

[0102] 7. Acoustic wave transducer: To convert the amplified electrical signals into acoustic wave signals

[0103] 8. Transformer: To step up the converted voltage.

[0104] 9. Diode: To convert the AC signal into a DC signal. The left end is connected to the secondary winding of the transformer, and the right end is connected to the load.

[0105] 10. Capacitor: To make the obtained current more stable.

[0106] 11. Supercapacitor: To store energy jointly with the storage battery.

[0107] 12. Storage battery: To store the converted electrical energy for convenient power supply to the load.

[0108] 13. Battery tester: To test the battery capacity.

[0109] 14. Power analyzer: To record the input and output energy of the device.

[0110] 15. Deep pool: As the environment for underwater experiments.

[0111] II. Equipment Connection and Debugging

[0112] 1. Install four signal generators around the 10m deep pool to simulate the noise environment of the deep sea.

[0113] 2. Install the connected acoustic-electric conversion module (conversion rate 35%) on the outer surface of the working robot and put it underwater.

[0114] 3. Install the self-cleaning module and the energy storage module inside the working robot to make the machine have the self-cleaning ability and be able to work for a long time.

[0115] 4. Install a rectifier filter circuit board and a capacitor filter circuit board inside the machine to make the current converted by the acoustic-electric conversion module supply the machine more stably.

[0116] 5. Install a collection module inside the robot, connect it to the upper computer through the USB interface, and observe the data in real time through the upper computer for convenient timely adjustment.

[0117] III. Experimental Operations

[0118] 1. Before the experiment, artificially add dirt to the outer surface of the equipment to be experimented and keep it stationary underwater for 3 days to simulate the attachment of microorganisms.

[0119] 2. Put ice cubes into the deep pool to simulate the low-temperature environment of the deep sea.

[0120] 3. Turn on the signal generating device (model 33500B), emit signals underwater, and use an instrument that can observe acoustic signals to observe the emitted acoustic signals.

[0121] 4. Observe the working status of the acoustic-electric converter. Observe the electrical signal output by the acoustic-electric converter on the host computer, and analyze whether the conversion rate of the acoustic-electric conversion module reaches more than 30% by observing its changes. If there is an abnormality, check and recheck whether there is an error in the installation of the acoustic-electric converter and readjust the acoustic signal generated by the signal generator.

[0122] 5. Observe whether the dirt shedding rate on the outer surface of the analog device reaches more than 80%. If it does not meet the standard, check the device and continue to observe after appropriate adjustment.

[0123] 6. After the energy storage device stores electrical energy for a period of time, turn off the signal generator and observe whether the stored electrical energy can enable the load device to operate normally in case of an accident.

[0124] 7. Connect the energy storage module (supercapacitor + battery) to the battery tester (model BTS-6000). The tester communicates with the host computer through the RS485 interface, and observe whether the battery capacity can be maintained above 80%.

[0125] 8. Install a power analyzer (model PA8000) at the output end of the acoustic-electric conversion module, record the input energy, and synchronously record the output energy at the output end of the energy storage module to observe the charge and discharge efficiency.

[0126] IV. Data Analysis and Processing

[0127] 1. Can the host computer normally observe the voltage and current before and after conversion?

[0128] 2. Evaluate whether the conversion performance of the acoustic-electricity meets the standard according to the changes in the recorded data.

[0129] 3. According to the changes in the recorded data, obtain the relationship between different frequency sound waves converted into electrical signals, and provide reliable data for practical applications.

[0130] 4. Evaluate the performance of the self-cleaning system by observing the remaining amount of surface dirt.

[0131] 5. Repeat the experiment and judge the performance of the energy storage system according to the running time of each load.

[0132] 6. Repeat the experiment, verify the effects after optimization and improvement, and continuously improve the experimental plan.

[0133] Through the above specific implementation manners, the underwater wireless charging system based on sound energy conversion and self-cleaning function provided by the present invention systematically solves the problems existing in the prior art, such as low efficiency of sound-electricity conversion, difficulty in removing microbial attachment, and poor dynamic response ability of the energy storage system. The system achieves a sound-electricity conversion efficiency of 35%, a microbial shedding rate of 82%, and a combined energy storage module with good environmental adaptability, and has the advantages of high utilization rate of noise energy, low energy consumption for cleaning and maintenance, and strong adaptability to complex environments, and is particularly suitable for unattended deep-sea operation equipment. The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although reference has been made to the foregoing embodiments

[0134] the present invention has been described in detail, and those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. An underwater wireless charging system with acoustic energy conversion and self-cleaning functions, characterized in that: include: The acoustic-to-electric conversion module includes a sound-absorbing coating and a PVDF piezoelectric film, wherein the sound-absorbing coating is arranged on the outermost layer for absorbing underwater noise energy, and the PVDF piezoelectric film is attached to the inner side of the sound-absorbing coating for converting sound wave vibration into electrical energy; A self-cleaning module, which includes a reverse sound wave circuit for periodically generating low-frequency reverse sound waves to destroy the microbial attachment structure on the surface of the equipment to achieve self-cleaning of the equipment; Combined energy storage module, which includes supercapacitors and batteries, and is coordinated and controlled by DC / DC converters to achieve fast energy response and high energy density storage; An insulating protective shell, used for wrapping and protecting the acoustic-electric conversion module and the self-cleaning module; Terminal blocks and wires are used to realize electrical connection between modules and external power supply of the system; Transformers and diodes are used for power rectification, filtering and voltage regulation.

2. The underwater wireless charging system according to claim 1, characterized in that: The sound absorbing coating is composed of the following components: Polyurethane elastomer, as the matrix material, accounts for 60% by mass; Hollow glass microspheres, as sound-absorbing fillers, account for 25% by mass and have a particle size range of 20-50 μm; Graphene / carbon nanotube composite, as a damping agent, accounting for 10% by mass; Epoxy resin modified silicone, as an adhesive, accounts for 5% by mass.

3. The underwater wireless charging system according to claim 1, characterized in that: The PVDF piezoelectric film has a thickness of 50 μm, a piezoelectric constant of 25 pC / N, a dielectric constant of 12.5, and an operating temperature range of -40°C to 120°C.

4. The underwater wireless charging system according to claim 1, characterized in that: The reverse sound wave circuit is composed of a signal generator, a power amplifier and a sound wave transducer, and the signal generator generates a low-frequency reverse sound wave with a frequency of 20 Hz.

5. The underwater wireless charging system according to claim 1, characterized in that: The sound waves generated by the reverse sound wave circuit cause the water flow on the surface of the device to generate tiny vortices, which are used to flush away the fallen microorganisms and their fragments.

6. The underwater wireless charging system according to claim 1, characterized in that: The combined energy storage module adjusts the current distribution between the supercapacitor and the battery through a DC / DC converter, reduces battery load fluctuations during the rapid charging and discharging of the supercapacitor, and improves the battery life.

7. The underwater wireless charging system according to claim 1, characterized in that: The combined energy storage module completes current switching within 0.16 seconds and maintains the system voltage fluctuation range within ±5%.

8. The underwater wireless charging system according to claim 1, characterized in that: The acoustic-to-electric conversion module achieves high-efficiency absorption and conversion of sound wave energy in a wide frequency band of 50 Hz to 1000 Hz by combining a sound-absorbing coating with a sound absorption coefficient greater than or equal to 0.8 with a PVDF piezoelectric film, and the overall acoustic-to-electric conversion efficiency reaches 35%.

9. The underwater wireless charging system according to claim 1, characterized in that: The self-cleaning module destroys the microbial attachment structure through 20Hz low-frequency reverse sound waves, and the microbial shedding rate reaches 82%. The energy consumption of the cleaning process is controlled below 2kW / h, and each cleaning cycle is 1 hour.

10. The underwater wireless charging system according to claim 1, characterized in that: After the combined energy storage module was tested for 1,000 charge and discharge cycles at an ambient temperature of -10°C, 25°C or 40°C, the battery capacity retention rates were 89%, 94% and 84% respectively, and the overall charge and discharge efficiency of the system remained above 88%.

Images