Wave energy capturing and wave absorbing integrated device based on Helmholtz resonance principle

Abstract

The wave energy capturing and wave absorbing integrated device based on the Helmholtz resonance principle comprises a dike body, the dike body is sequentially provided with a front baffle, a front air chamber, a middle air chamber, a rear air chamber and a rear baffle in the wave incidence direction, and a three-stage series type wave absorbing structure is jointly formed; a front gas-guide tube and a rear gas-guide tube are respectively arranged at the tops of the front gas chamber and the rear gas chamber, and the front gas-guide tube, a top gas cavity of the middle gas chamber and the rear gas-guide tube are respectively connected with a confluence header pipe through pipelines; a one-way air inlet valve and a one-way exhaust valve are arranged on the top of each air chamber and each air guide pipeline; the air outlet end of the confluence header pipe is connected with a one-way air turbine. On the premise that the physical size of the structure and the construction cost are not remarkably increased, the wave absorbing frequency band can be effectively widened, particularly the wave absorbing performance on long-period waves is remarkably improved, and therefore the defects of a traditional breakwater and a traditional OWC device in the aspects are overcome.

Description

Technical Field

[0001] This invention relates to the field of integrated development technology of marine renewable energy, and in particular to an integrated wave energy capture and wave damping device based on the Helmholtz resonance principle. Background Technology

[0002] In coastal and port engineering, breakwaters are critical infrastructure for resisting wave erosion, maintaining the stability of harbor waters, and protecting the coastline from erosion. Floating breakwaters have emerged as a new type of protective structure. Anchored to designated waters by a mooring system, they dissipate wave energy through the movement of the floating body and the structural design. Compared to fixed structures, they offer advantages such as environmental friendliness, mobility, and minimal impact on seabed topography. However, existing floating breakwaters still suffer from narrow effective wave-dissipating bandwidths and weak long-wave protection capabilities, requiring further improvement in reliability and effectiveness. Therefore, the development of new breakwater structures that can efficiently reduce long waves while maintaining stability is particularly urgent.

[0003] To more efficiently reduce wave energy, rather than simply reflecting it, some researchers have proposed combining wave energy conversion devices (WECs) with breakwaters. Among these, the oscillating water column (OWC) has been widely studied due to its simple structure, high reliability, and potential for both wave dissipation and wave energy generation. The working principle of a traditional OWC breakwater is as follows: wave motion drives a water column fixed to a cavity on the shore or semi-submerged sea surface to oscillate up and down, compressing the air inside the cavity and generating reciprocating airflow, which drives an air turbine to generate electricity. While traditional OWCs have great potential, in some shortwave conditions, most of the energy is reflected back, leading to reduced energy conversion efficiency and increased cost.

[0004] OWC (Overflow-Cooled Wave) devices perform well in handling waves near their natural frequency, but their response efficiency drops significantly when the wave frequency is outside this range. This is mainly because the natural frequency of the water column oscillation in a traditional OWC chamber is determined by structural parameters (such as chamber geometry and draft), making it unsuitable for varying wave conditions. When the incident wave frequency matches its natural frequency, the system resonates, achieving maximum energy capture and wave attenuation efficiency. However, long waves typically have frequencies significantly lower than the natural frequency of traditional OWC structures, leading to a substantial decrease in wave attenuation and energy absorption.

[0005] Furthermore, for an OWC (Overflow-of-Cell) wave energy device to achieve an ideal conversion efficiency, the incident wave frequency generally needs to match the device's resonant frequency. To improve the energy conversion efficiency and significantly expand the effective frequency response range, the concept of a multi-chamber OWC structure has been proposed. Current research results show that compared to single-chamber OWCs, multi-chamber OWCs offer significant improvements in both conversion efficiency and bandwidth. However, currently, multi-chamber OWC structures are mostly used in stationary devices, and their application in floating OWCs remains relatively limited.

[0006] Traditional floating breakwaters and traditional oscillating water column (OWC) devices have difficulty matching their inherent frequencies with low-frequency long waves when dealing with long-period waves, resulting in a decrease in wave dissipation and energy absorption efficiency; a single OWC structure can only maintain high efficiency within a narrow wave frequency range and cannot effectively adapt to sea conditions with a wide wave frequency range.

[0007] Therefore, in view of the problems existing in the prior art, it is a technical problem that needs to be solved by those skilled in the art to provide a new type of breakwater structure that can effectively broaden the wave-damping frequency band and significantly improve the wave-damping performance for long-period waves without significantly increasing the physical size of the structure and construction costs, thereby making up for the defects of traditional breakwaters and traditional OWC devices in the above-mentioned aspects. Summary of the Invention

[0008] In view of this, the present invention provides an integrated wave energy capture and wave attenuation device based on the Helmholtz resonance principle.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] An integrated wave energy capture and wave dissipation device based on the Helmholtz resonance principle includes a main body of the dike. The main body of the dike is provided with a front baffle, a front air chamber, a middle air chamber, a rear air chamber and a rear baffle in sequence along the wave incident direction, which together form a three-stage series wave dissipation structure.

[0011] The front air chamber and the rear air chamber are respectively provided with a front air guide pipe and a rear air guide pipe at their tops. The front air guide pipe, the top air chamber of the middle air chamber, and the rear air guide pipe are respectively connected to the manifold through pipes. A one-way air inlet valve and a one-way air outlet valve are provided at the top of each air chamber and on each air guide pipe. The outlet end of the manifold is connected to a one-way air turbine.

[0012] Preferably, the middle air chamber is a Helmholtz resonant cavity type oscillating water column (OWC) structure, including a neck channel located below the water surface and a sealed air chamber located above the neck channel, and the vertical length of the neck channel is adjustable.

[0013] Preferably, the vertical length of the neck channel is adjusted by a mechanical adjustment mechanism. The mechanical adjustment mechanism includes a turbine connected to a movable plate and a turbine rack meshing with the turbine. The turbine rack is located in a groove in the cavity wall. The movable plate meshes with the turbine rack, and the turbine meshes with the worm gear. By driving and controlling the worm gear to rotate, the turbine is driven to rotate along the turbine rack, causing the movable plate to move up and down, thereby changing the effective length of the neck channel.

[0014] Preferably, both the front air chamber and the rear air chamber are OWC air chamber structures with bottom openings;

[0015] Preferably, the draft of the front baffle is less than that of the rear baffle; the front baffle is used to attenuate short- and medium-period waves, and the rear baffle is used to block long waves and provide structural stability.

[0016] Preferably, the airflow generated by the front air chamber, middle air chamber and rear air chamber is rectified by a one-way valve group. Before entering the main manifold, the airflow is rectified by a one-way intake valve and a one-way exhaust valve respectively set on their respective airflow paths to ensure that the airflow entering the main manifold is in a single direction.

[0017] Preferably, the one-way valve group includes a first set of one-way air inlet valves disposed at the top of each air chamber and a second set of one-way exhaust valves disposed inside each air guide pipe.

[0018] Preferably, the device further includes a wave monitoring system, a gear track, a worm gear control system, and a turbine connecting rod;

[0019] The wave monitoring system is located on the front baffle, the worm gear control system is located on the upper left of the movable plate in the middle air chamber, the turbine is connected to the movable plate through the turbine connecting rod, the worm gear is connected to the movable plate through the turbine connecting rod, and the movable plate moves up and down vertically along the gear track.

[0020] A wave energy conversion method for an integrated wave energy capture and dissipation device based on the Helmholtz resonance principle, the method comprising:

[0021] By adjusting the length of the neck channel of the middle gas chamber, its resonant frequency is matched with the incident long-wave frequency to maximize energy capture efficiency.

[0022] The aforementioned front air chamber is used for preliminary attenuation and energy conversion of medium and short waves;

[0023] The rear air chamber and the rear baffle are used to finally reduce and stabilize the residual wave energy, and some of the waves are reflected back to the middle air chamber for secondary energy capture.

[0024] The bidirectional alternating airflow generated in each air chamber is rectified into a unidirectional stable airflow through a one-way intake valve and a one-way exhaust valve, and then collected to jointly drive the unidirectional air turbine to generate electricity.

[0025] The present invention achieves the following technical effects compared to the prior art:

[0026] (1) The present invention, through the design of a Helmholtz resonant cavity with adjustable neck length, can actively adapt to the natural frequency of long waves, fundamentally solving the problem of low response efficiency of traditional oscillating water column devices to long-period waves, and significantly improving wave damping performance.

[0027] (2) This invention utilizes the series layout of the front, middle and rear three-stage air chambers and the unequal length baffle structure to form a wide-bandwidth, multi-stage collaborative wave-damping mechanism, which can effectively cope with complex and ever-changing sea conditions and broaden the wave-damping frequency band.

[0028] (3) The present invention integrates the bidirectional airflow generated by each air chamber into a unidirectional stable airflow through a one-way valve group and drives a unidirectional air turbine, which significantly improves the efficiency of energy recovery and output stability.

[0029] (4) The structure of the present invention achieves functional optimization through simple mechanical adjustment, avoiding the high cost and construction difficulties caused by increasing the structural size in the traditional solution. It has the advantages of structural compactness, functional adaptability and engineering economy, and has outstanding practical value and application prospects in the field of coastal protection and wave energy utilization. Attached Figure Description

[0030] Figure 1 A three-dimensional schematic diagram of the integrated device for breakwater-oscillating water column wave energy device;

[0031] Figure 2 Cross-sectional view of the integrated device for breakwater-oscillating water column wave energy generation;

[0032] Figure 3 This is a partial view of the movable plate area;

[0033] In the diagram: 1. Front baffle; 2. Front air chamber; 3. Middle air chamber (Helmholtz resonant cavity); 3a. Neck (adjustable part); 3b. Movable plate; 3c. Gear track; 4. Rear air chamber; 5. Rear baffle; 6. Front air guide pipe; 7. Rear air guide pipe; 8. Main manifold; 9. One-way intake valve; 10. One-way air turbine; 11. One-way exhaust valve inside the pipe; 12. Wave monitoring system; 13. Turbine rack; 14. Turbine; 15. Worm rod; 16. Worm rod control system; 17. Turbine connecting rod. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] like Figure 1-3 As shown, the present invention discloses an integrated wave energy capture and wave dissipation device based on the Helmholtz resonance principle, including a main body of the dike, which is usually composed of a pontoon and reinforced concrete. The main body of the dike is provided with a front baffle 1, a front air chamber 2, a middle air chamber 3, a rear air chamber 4 and a rear baffle 5 in sequence along the wave incident direction, which together form a three-stage series wave dissipation structure.

[0036] The front air chamber 2 and the rear air chamber 4 are respectively provided with a front air guide pipe 6 and a rear air guide pipe 7. The front air guide pipe 6, the top air chamber of the middle air chamber 3, and the rear air guide pipe 7 are respectively connected to the main manifold 8 through pipes.

[0037] One-way inlet valve 9 and one-way exhaust valve 11 are installed at the top of each air chamber and on each air guide pipe to regulate the bidirectional airflow generated in each air chamber into a stable airflow in a single direction.

[0038] The outlet of the manifold 8 is connected to a one-way air turbine 10, which is used to convert the kinetic energy of the stable airflow into mechanical energy or electrical energy.

[0039] The middle air chamber 3 is the key innovative part of the present invention, which constitutes a Helmholtz resonant cavity; it includes a neck 3a located below the design water level and a sealed air chamber located above the neck. The Helmholtz resonant cavity is connected to the air guide pipe through an opening at its top, and the vertical length of the neck channel 3a is adjustable.

[0040] The vertical length of the neck channel 3a is adjusted by a mechanical adjustment mechanism;

[0041] The mechanical adjustment mechanism includes a turbine 14 connected to a movable plate 3b and a turbine rack 13 meshing with the turbine 14. The turbine rack 13 is located in a cavity wall groove, shown as a dashed line in the figure.

[0042] The movable plate 3b meshes with the turbine rack 13, and the turbine 14 meshes with the worm gear 15. The worm gear control system 16 drives the motor to control the rotation of the worm gear 15, which in turn drives the turbine 14 to rotate along the turbine rack 13. Therefore, the movable plate 3b connected to the turbine 14 can be driven to rise and fall in the vertical direction, thereby continuously and accurately changing the actual effective length of the neck 3a.

[0043] This design allows for variable adjustment of the resonant frequency.

[0044] Both the front chamber 2 and the rear chamber 4 are OWC chamber structures with bottom openings; their bottom openings face the open sea and the harbor, respectively.

[0045] The front air chamber 2 is equipped with a front air guide pipe 6 at its top, and the rear air chamber 4 is equipped with a rear air guide pipe 7 at its top. The draft of the front and rear baffles (1,5) has been optimized and their lengths are different. The front baffle 1 is shorter to effectively attenuate medium and short waves, while the rear baffle 5 is longer to provide the last barrier against long waves and enhance structural stability. At the same time, the reflected waves can also be captured by the Helmholtz resonant cavity in the middle, so as to maximize the energy conversion efficiency.

[0046] The draft of the front baffle 1 is less than that of the rear baffle 5; the front baffle 1 is used to attenuate short- and medium-period waves, while the rear baffle 5 is used to block long waves and provide structural stability.

[0047] The airflow generated by the front air chamber 2, the middle air chamber 3 and the rear air chamber 4 is rectified by a one-way valve group. Before entering the main manifold 8, the airflow is rectified by the one-way intake valve 9 and the one-way exhaust valve 11 set on their respective airflow paths to ensure that the airflow entering the main manifold 8 is in a single direction.

[0048] The one-way valve assembly includes a first set of one-way inlet valves 9 located at the top of each air chamber and a second set of one-way exhaust valves 11 located inside each air guide pipe.

[0049] The device also includes a wave monitoring system 12, a gear track 3c, a worm gear control system 16, and a turbine connecting rod 17; used to automatically adjust the vertical length of the neck channel (3a) according to the real-time monitored wave frequency data, so that the resonant frequency of the middle air chamber (3) matches the wave frequency.

[0050] The wave monitoring system 12 is located on the front baffle 1, the worm gear control system 16 is located on the upper left of the movable plate 3b in the middle air chamber 3, the turbine 14 is connected to the movable plate 3b through the turbine connecting rod 17, the worm gear 15 is connected to the movable plate 3b through the turbine connecting rod 17, and the movable plate 3b moves up and down vertically along the gear track 3c.

[0051] This invention also discloses a wave energy conversion method for an integrated wave energy capture and wave attenuation device based on the Helmholtz resonance principle, the method comprising:

[0052] By adjusting the length of the neck channel 3a of the middle chamber 3, its resonant frequency is matched with the incident long-wave frequency to maximize energy capture efficiency.

[0053] The front air chamber 2 is used to perform preliminary attenuation and energy conversion of medium and short waves;

[0054] The rear air chamber 4 and the rear baffle 5 are used to finally reduce and stabilize the residual wave energy, and some of the waves are reflected back to the middle air chamber 3 for secondary energy capture.

[0055] The bidirectional alternating airflow generated in each air chamber is rectified into a unidirectional stable airflow by the one-way intake valve 9 and the one-way exhaust valve 11, and then converged to jointly drive the unidirectional air turbine 10 to generate electricity.

[0056] The core of this invention is to achieve efficient reduction and energy capture of broadband waves, especially long-period waves, by combining an adjustable Helmholtz resonant cavity with a multi-chamber synergistic wave-damping and power generation system.

[0057] The workflow of the power generation system is as follows:

[0058] When the water columns in the front chamber 2, middle chamber 3, and rear chamber 4 oscillate back and forth under wave excitation, they will compress and draw in the air in their respective chambers, generating bidirectional alternating airflow.

[0059] The front air guide pipe 6, the outlet at the top of the middle air chamber 3, and the rear air guide pipe 7 are each connected to a main manifold 8 via pipes. A set of one-way inlet valves 9 and one-way exhaust valves 11 are installed at the air outlet of each air chamber and inside each air guide pipe.

[0060] The ingenious arrangement of these one-way valves ensures that the airflow can be rectified and directed in a single direction in the manifold 8, regardless of whether the airflow direction is discharge (compression) or intake (suction).

[0061] Thus, the originally unstable bidirectional airflow generated by the three air chambers is integrated into a continuous and directionally stable high-speed airflow. This converged airflow eventually impacts the blades of the unidirectional air turbine 10, causing it to rotate at high speed, thereby driving the generator to generate electricity stably.

[0062] Example 1:

[0063] The working process of this device will now be explained using a port in my country that is troubled by long waves as an example:

[0064] Initial status and monitoring: The port area is equipped with a wave monitoring system;

[0065] One day, wave monitoring system 12 detected a group of long-period waves approaching.

[0066] Intelligent adjustment: The worm gear control system 16 calculates the optimal neck length H required for the middle air chamber 3 to achieve resonance based on the received wave frequency data and through a built-in algorithm.

[0067] Subsequently, the worm gear control system 16 controls the worm gear 15 to rotate, causing the turbine 14 to drive the movable plate 3b to descend via the gear track 3c, thereby precisely adjusting the effective length of the neck 3a to the preset value.

[0068] Synergistic wave damping and power generation:

[0069] First-stage wave damping: Long waves first reach the front baffle 1 and the front air chamber 2;

[0070] The front chamber 2 primarily attenuates and captures the energy of short and medium wave components, while allowing some long waves to pass through.

[0071] Core-level wave attenuation: Long waves enter the middle chamber 3 through the front chamber 2. At this point, the Helmholtz resonator, which has been adjusted to its optimal state, strongly resonates with the incident long waves. The water column inside the chamber has a huge amplitude, efficiently absorbing the core energy of the long waves and converting it into strong airflow waves. This is the most important process for attenuating long waves.

[0072] Final wave absorption and stabilization: Residual wave energy (which may include long waves and other frequencies that are not completely absorbed) passes through the middle air chamber 3 and enters the rear air chamber 4.

[0073] The rear air chamber 4 works in conjunction with the deeper-draft rear baffle 5 to dissipate and block residual energy, and to reflect some waves back to the front air chamber for energy conversion, ensuring calm in the harbor.

[0074] High-efficiency energy recovery: Throughout the process described above, the airflow generated by the three air chambers is rectified via the one-way exhaust valves 11 along their respective paths and converges into the main manifold 8, forming a stable, high-speed unidirectional airflow that efficiently drives the unidirectional air turbine 10 to continuously generate electricity. Compared to a traditional single OWC, its power generation and stability are greatly improved.

[0075] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An integrated wave energy capture and wave attenuation device based on the Helmholtz resonance principle, comprising a main body of a dike, characterized in that, The main body of the embankment is provided with a front baffle (1), a front air chamber (2), a middle air chamber (3), a rear air chamber (4) and a rear baffle (5) in sequence along the wave incident direction, which together form a three-stage series wave-damping structure; The front air chamber (2) and the rear air chamber (4) are respectively provided with a front air guide pipe (6) and a rear air guide pipe (7). The front air guide pipe (6), the top air chamber of the middle air chamber (3), and the rear air guide pipe (7) are respectively connected to the manifold (8) through pipes. A one-way air inlet valve (9) and a one-way air outlet valve (11) are provided on the top of each air chamber and on each air guide pipe. The outlet end of the manifold (8) is connected to a one-way air turbine (10).

2. The wave energy capture and wave attenuation integrated device based on the Helmholtz resonance principle according to claim 1, characterized in that, The middle air chamber (3) is a Helmholtz resonant cavity type oscillating water column OWC structure, including a neck channel (3a) located below the water surface and a sealed air chamber located above the neck channel, and the vertical length of the neck channel (3a) is adjustable.

3. The wave energy capture and wave attenuation integrated device based on the Helmholtz resonance principle according to claim 2, characterized in that, The vertical length of the neck channel (3a) is adjusted by a mechanical adjustment mechanism. The mechanical adjustment mechanism includes a turbine (14) connected to a movable plate (3b) and a turbine rack (13) meshing with the turbine (14). The turbine rack (13) is located in a cavity wall groove. The movable plate (3b) meshes with the turbine rack (13), and the turbine (14) meshes with the worm gear (15). By driving and controlling the worm gear (15) to rotate, the turbine (14) is driven to rotate along the turbine rack (13), causing the movable plate (3b) to move up and down, thereby changing the effective length of the neck channel (3a).

4. The wave energy capture and wave attenuation integrated device based on the Helmholtz resonance principle according to claim 1, characterized in that, Both the front air chamber (2) and the rear air chamber (4) are OWC air chamber structures with bottom openings.

5. The wave energy capture and wave attenuation integrated device based on the Helmholtz resonance principle according to claim 1, characterized in that, The draft of the front baffle (1) is less than that of the rear baffle (5); the front baffle (1) is used to attenuate short- and medium-period waves, and the rear baffle (5) is used to block long waves and provide structural stability.

6. The wave energy capture and wave attenuation integrated device based on the Helmholtz resonance principle according to claim 1, characterized in that, The airflow generated by the front air chamber (2), middle air chamber (3) and rear air chamber (4) is rectified by a one-way valve group. Before entering the main manifold (8), the airflow is rectified by a one-way inlet valve (9) and a one-way exhaust valve (11) set on their respective airflow paths to ensure that the airflow entering the main manifold (8) is in a single direction.

7. The wave energy capture and wave attenuation integrated device based on the Helmholtz resonance principle according to claim 6, characterized in that, The one-way valve group includes a first set of one-way inlet valves (9) located at the top of each air chamber and a second set of one-way exhaust valves (11) located inside each air duct.

8. The wave energy capture and wave attenuation integrated device based on the Helmholtz resonance principle according to claim 1, characterized in that, The device also includes a wave monitoring system (12), a gear track (3c), a worm gear control system (16), and a turbine connecting rod (17); The wave monitoring system (12) is located on the front baffle (1), the worm gear control system (16) is located on the upper left of the movable plate (3b) in the middle air chamber (3), the turbine (14) is connected to the movable plate (3b) through the turbine connecting rod (17), the worm gear (15) is connected to the movable plate (3b) through the turbine connecting rod (17), and the movable plate (3b) moves up and down vertically along the gear track (3c).

9. A wave energy conversion method for an integrated wave energy capture and dissipation device based on the Helmholtz resonance principle according to claims 1-8, characterized in that, The method includes: By adjusting the length of the neck channel (3a) of the middle air chamber (3), its resonant frequency is matched with the incident long wave frequency to maximize energy capture efficiency; The front air chamber (2) is used to perform preliminary attenuation and energy conversion of medium and short waves; The residual wave energy is finally reduced and stabilized by the rear air chamber (4) and the rear baffle (5), and some of the waves are reflected back to the middle air chamber (3) for secondary energy capture. The bidirectional alternating airflow generated in each air chamber is rectified into a unidirectional stable airflow through a one-way inlet valve (9) and a one-way exhaust valve (11), and then converged to drive the unidirectional air turbine (10) to generate electricity.

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