Marimba type multi-oscillating water column wide-band wave energy capturing method and system

Abstract

The application relates to the technical field of wave energy capturing, and discloses a horizontal-xi-type multi-oscillation water column broadband wave energy capturing method and system. The method comprises the following steps: quantitatively designing the draft depth sequence of the front wall of each air chamber unit to obtain a natural resonance frequency sequence; collecting an air pressure time sequence and a water column oscillation amplitude time sequence to obtain a primary pneumatic power sequence; performing difference and spectrum analysis on the air pressure of adjacent air chamber units to obtain a beat frequency sequence and an air pressure difference amplitude sequence; setting a pneumatic piston in the gas phase area of the partition wall, performing resonance matching adjustment on the natural frequency of the piston gas spring system, converting the reciprocating motion into a secondary energy capturing power sequence, superimposing the primary pneumatic power sequence and the secondary energy capturing power sequence to obtain a system total energy capturing power. The application improves the full-band comprehensive energy capturing efficiency of the horizontal-xi-type multi-oscillation water column broadband wave energy capturing device and the output stability of the active power output device of each air chamber unit.

Description

Technical Field

[0001] This application relates to the field of wave energy capture technology, and in particular to a method and system for capturing broadband wave energy in a panpipe-shaped multi-oscillating water column. Background Technology

[0002] Wave energy, as a abundant and widely distributed marine renewable energy source, has become one of the most engineered wave energy utilization methods due to its simple structure, few moving parts, and low maintenance costs. The basic working principle of existing oscillating water column devices is as follows: waves are incident on the opening of the air chamber unit, driving the water column inside to oscillate vertically. The oscillation of the water column compresses the gas at the top of the air chamber, forming an alternating airflow. This alternating airflow drives a generator through an air turbine to output electrical energy. To further reduce construction costs and improve engineering practicality, researchers have proposed integrating the oscillating water column device with a nearshore breakwater structure to form an OWC-type breakwater with both wave dissipation and power generation functions. This has been experimentally verified in several coastal projects.

[0003] However, the hydrodynamic response of a single-chamber device is highly dependent on the matching degree between the chamber's natural resonant frequency and the incident wave frequency. It only exhibits high energy capture efficiency within a narrow frequency band near the natural resonant frequency. Once the incident wave frequency deviates from the resonant frequency, the energy capture efficiency drops sharply. To overcome these shortcomings, researchers have proposed arranging multiple chamber units with different drafts along the wave propagation direction. By using stepped drafts, the natural resonant frequencies of each chamber unit form a frequency sequence, covering a wide frequency spectrum of the target sea area. This is known as a panpipe-shaped multi-oscillating water column broadband wave energy capture device. Each chamber unit of this device is equipped with an independent power output device, which can maintain high energy capture efficiency across the entire frequency band under broadband wave conditions.

[0004] Because each chamber unit has a different inherent resonant frequency, under real irregular wave conditions, the water column oscillation of each chamber unit will inevitably have a phase difference and an amplitude difference in the time domain. This directly leads to a continuous transient pressure difference between the gas phase spaces of adjacent chamber units. In existing schemes, the partition walls between adjacent chamber units are completely sealed, and the energy contained in the transient pressure difference has no recovery mechanism and is lost entirely as heat dissipation, constituting secondary energy loss at the device level. Furthermore, the oscillation frequency of the transient pressure difference is the beat frequency formed by the difference in inherent resonant frequencies between adjacent chamber units. The beat frequency is much lower than the inherent resonant frequencies of each chamber unit. Existing schemes neither quantitatively extract this beat frequency characteristic nor utilize it as a design parameter, resulting in the problem of energy loss due to inter-chamber pressure difference remaining unresolved in existing multi-chamber oscillating water column devices. Summary of the Invention

[0005] This application provides a broadband wave energy capture method and system for panpipe-type multi-oscillating water columns, which solves the problems in existing panpipe-type multi-oscillating water column devices where transient air pressure difference energy between adjacent air chamber units cannot be recovered and is lost entirely as heat dissipation, as well as the problem that the beat frequency characteristics are not quantitatively extracted and utilized, resulting in long-term unavoidable energy loss between chambers. This improves the overall energy capture efficiency of the panpipe-type multi-oscillating water column broadband wave energy capture device across the entire frequency band and the output stability of the active power output device of each air chamber unit.

[0006] In a first aspect, this application provides a method for capturing broadband wave energy of a panpipe-shaped multi-oscillating water column, the method comprising: Step S1: Based on the wave spectrum data of the target sea area, the draft sequence of the front wall of each air cell unit arranged in a stepped manner along the wave propagation direction is quantitatively designed to obtain the inherent resonant frequency sequence of each air cell unit. Step S2: Based on the inherent resonant frequency sequence of each air chamber unit, the air pressure time sequence and water column oscillation amplitude time sequence of each air chamber unit are collected to obtain the primary aerodynamic power sequence of each air chamber unit; Step S3: Calculate the pressure difference between adjacent air chamber units in the air pressure time series of each air chamber unit and perform spectrum analysis to obtain the beat frequency sequence and air pressure difference amplitude sequence between adjacent air chamber units. Step S4: A pneumatic piston is installed in the gas phase region of the partition wall between adjacent air chamber units. Based on the beat frequency sequence and the air pressure difference amplitude sequence, the natural frequency of the piston air spring system composed of the pneumatic piston and the elastic air bladder is resonantly matched and adjusted using the inflation volume and initial inflation pressure of the elastic air bladders at both ends of the piston as adjustment parameters. This causes the pneumatic piston to reciprocate under the transient air pressure difference driven by the air pressure difference amplitude sequence. The reciprocating motion is converted into a secondary energy capture power sequence between adjacent air chamber units by a linear electromagnetic power output device. This sequence is then superimposed with the primary pneumatic power sequence of each air chamber unit to obtain the total energy capture power of the system.

[0007] Secondly, this application provides a panpipe-shaped multi-oscillating water column broadband wave energy capture system, the panpipe-shaped multi-oscillating water column broadband wave energy capture system comprising: The quantization module is used to quantify the draft sequence of the front wall of each air chamber unit arranged in a stepped manner along the wave propagation direction based on the wave spectrum data of the target sea area, so as to obtain the inherent resonant frequency sequence of each air chamber unit. The acquisition module is used to acquire the air pressure time series and water column oscillation amplitude time series of each air chamber unit based on the inherent resonant frequency sequence of each air chamber unit, so as to obtain the primary aerodynamic power sequence of each air chamber unit. The analysis module is used to calculate the pressure difference between adjacent air chamber units in the air pressure time series of each air chamber unit and perform spectrum analysis to obtain the beat frequency sequence and air pressure difference amplitude sequence between adjacent air chamber units. The superposition module is used to set up a pneumatic piston in the gas phase region of the partition wall between adjacent air chamber units. Based on the beat frequency sequence and the air pressure difference amplitude sequence, and using the inflation volume and initial inflation pressure of the elastic air bladders at both ends of the piston as adjustment parameters, the natural frequency of the piston air spring system composed of the pneumatic piston and the elastic air bladder is resonantly matched and adjusted. This causes the pneumatic piston to generate reciprocating motion under the transient air pressure difference driven by the air pressure difference amplitude sequence. The reciprocating motion is converted into a secondary energy capture power sequence between each adjacent air chamber unit by a linear electromagnetic power output device. This sequence is then superimposed with the primary pneumatic power sequence of each air chamber unit to obtain the total energy capture power of the system.

[0008] Thirdly, a panpipe-shaped multi-oscillating water column broadband wave energy capture device is provided, comprising: a memory and at least one processor, wherein the memory stores instructions; the at least one processor invokes the instructions in the memory to cause the panpipe-shaped multi-oscillating water column broadband wave energy capture device to execute the above-described panpipe-shaped multi-oscillating water column broadband wave energy capture method.

[0009] Fourthly, a computer-readable storage medium is provided, wherein instructions are stored therein, which, when executed on a computer, cause the computer to perform the above-described panpipe-shaped multi-oscillating water column broadband wave energy capture method.

[0010] The technical solution provided in this application quantifies the draft sequence of the front wall of each chamber unit arranged in a stepped manner along the wave propagation direction, enabling the inherent resonant frequency sequence of each chamber unit to form multi-mode coverage within the target frequency band, fundamentally overcoming the inherent defect of narrow bandwidth in single-chamber oscillating water column devices. Based on the inherent resonant frequency sequence of each chamber unit, the air pressure time series and the water column oscillation amplitude time series are synchronously acquired, and the primary aerodynamic power sequence of each chamber unit is obtained by multiplying the two at each time step and averaging all sampling points (i.e., discretized time integral averaging). This allows the energy capture contribution of each chamber unit near its respective resonant frequency to be independently quantified, avoiding the evaluation distortion problem caused by the power aliasing of each chamber in a multi-chamber system. Based on this, the pressure difference between adjacent air chamber units in the time series of air pressure of each air chamber unit is calculated and spectral analysis is performed to extract the beat frequency sequence and air pressure difference amplitude sequence between adjacent air chamber units. The transient air pressure difference between chambers, which was originally regarded as interference loss, is transformed into a quantifiable physical parameter, providing a clear input basis for the parameter design of the subsequent pneumatic piston secondary energy harvesting device. This transformation idea has never been proposed or realized in the design framework of existing multi-chamber oscillating water column devices.

[0011] Furthermore, this application sets up a pneumatic piston in the gas phase region of the partition wall between adjacent air chamber units. The inflation volume of the elastic air bladders at both ends of the piston and the initial inflation pressure are used as adjustment parameters to resonate and match the natural frequency of the piston air spring system. This makes the natural frequency of the piston air spring system precisely match the beat frequency between the corresponding adjacent air chamber units. The pneumatic piston generates reciprocating motion in a resonant state under the drive of transient air pressure difference. The reciprocating motion is converted into a secondary energy capture power sequence between each adjacent air chamber unit by a linear electromagnetic power output device. The total energy capture power of the system is obtained by superimposing it with the primary pneumatic power sequence of each air chamber unit. The core contribution of the aforementioned resonance matching adjustment mechanism lies in the fact that the beat frequency, as the difference between the inherent resonant frequencies of two adjacent chambers, is much lower than the inherent resonant frequencies of each chamber. The piston gas spring system achieves precise tracking of this low-frequency beat frequency by adjusting the parameters of the elastic airbag, enabling the inter-chamber pressure difference energy, which is inherently generated in broadband multi-chamber systems but has never been utilized, to undergo a secondary conversion in terms of physical mechanism. At the same time, the reciprocating motion of the piston absorbs the inter-chamber pressure difference, which objectively plays a role in balancing the pressure of adjacent chambers, reducing the negative impact of inter-chamber airflow interference on the stable operation of the active power output device of each air chamber unit, and realizing the synergy of secondary energy capture and interference suppression. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of one embodiment of the panpipe-shaped multi-oscillating water column broadband wave energy capture method in this application; Figure 2 This is a schematic diagram illustrating the convergence process of the inherent resonant frequency deviation of each air chamber unit in the embodiments of this application as a function of the number of iterations; Figure 3 This is a schematic diagram comparing the primary aerodynamic power sequence of each air chamber unit with the secondary energy capture power sequence between adjacent air chamber units in the embodiments of this application. Detailed Implementation

[0014] This application provides a panpipe-type multi-oscillating water column broadband wave energy capture method and system. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data used can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein. Furthermore, the terms "comprising" or "having" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0015] For ease of understanding, the specific process of the embodiments of this application is described below. Please refer to [link / reference]. Figure 1 One embodiment of the panpipe-shaped multi-oscillating water column broadband wave energy capture method in this application includes: Step S1: Based on the wave spectrum data of the target sea area, the draft sequence of the front wall of each air cell unit arranged in a stepped manner along the wave propagation direction is quantitatively designed to obtain the inherent resonant frequency sequence of each air cell unit. Specifically, the spectral data of the target sea area is derived from measured JONSWAP spectra. Peak frequencies and effective bandwidth are extracted from these data to determine the high-frequency and low-frequency boundaries of the target frequency band. The design principle for the natural resonant frequency sequence of each air chamber unit is as follows: the target frequency band is uniformly divided into N sub-bands, with the natural resonant frequency of each air chamber unit corresponding to the center frequency of a sub-band. The difference in natural resonant frequencies between adjacent air chamber units is the frequency step size. The draft sequence of the front wall is calculated inversely from the oscillating water column resonance condition. Specifically, the designed natural resonant frequency, cross-sectional area of ​​the air chamber cavity, and additional mass correction coefficient of each air chamber unit are substituted into the oscillating water column resonance condition relationship. The equivalent volume parameter of the water column is the product of the cross-sectional area of ​​the air chamber cavity and the draft of the front wall. The draft of the front wall of each air chamber unit is obtained by inversely solving the equivalent volume parameter of the water column. The additional mass correction coefficient is determined by the ratio of the air chamber opening width to the draft using a preset empirical method.

[0016] Step S2: Based on the inherent resonant frequency sequence of each air chamber unit, the air pressure time sequence and water column oscillation amplitude time sequence of each air chamber unit are collected to obtain the primary aerodynamic power sequence of each air chamber unit; Specifically, the gas pressure time series of each gas chamber unit is acquired by a gas pressure sensor installed in the gas phase space at the top of the gas chamber, with a sampling frequency no less than 20 times the highest frequency of the target frequency band to satisfy the Nyquist sampling theorem. The water column oscillation amplitude time series is acquired by a liquid level elevation sensor installed at the free liquid surface of the water column in each gas chamber unit. The signals from both types of sensors are acquired synchronously under the same clock reference to eliminate time deviation. The instantaneous gas volumetric flow rate series of each gas chamber unit is obtained by multiplying the time difference fraction of the water column oscillation amplitude time series by the cross-sectional area of ​​the gas chamber cavity. The primary aerodynamic power series of each gas chamber unit is obtained by multiplying the instantaneous gas volumetric flow rate series by the gas pressure time series moment by moment, summing the values ​​at all sampling points within the acquisition period, and dividing by the number of sampling points (i.e., the discretized time integral average). The acquisition period is taken as an integer multiple of the inherent resonance period of each gas chamber unit to eliminate period truncation error.

[0017] Step S3: Calculate the pressure difference between adjacent air chamber units in the air pressure time series of each air chamber unit and perform spectrum analysis to obtain the beat frequency sequence and air pressure difference amplitude sequence between adjacent air chamber units. Specifically, the transient pressure difference time series between adjacent air chamber units is obtained by subtracting the pressure time series of adjacent air chamber units time by time. The beat frequency is physically defined as the difference between the inherent resonant frequencies of two adjacent air chamber units, i.e., the low-frequency envelope oscillation frequency generated after the superposition of the pressure oscillations of the two chambers. A fast Fourier transform is performed on the transient pressure difference time series, and the frequency corresponding to the peak power spectral density is extracted as the measured beat frequency. The sliding time window length is taken as an integer multiple of the beat frequency period to ensure spectral resolution. Half of the peak-to-peak value within the window is the pressure difference amplitude. The pressure difference amplitude and the measured beat frequency together constitute the pressure difference amplitude sequence and the beat frequency sequence.

[0018] Step S4: A pneumatic piston is installed in the gas phase region of the partition wall between adjacent air chamber units. Based on the beat frequency sequence and the air pressure difference amplitude sequence, the natural frequency of the piston air spring system composed of the pneumatic piston and the elastic air bladder is resonantly matched and adjusted using the inflation volume and initial inflation pressure of the elastic air bladders at both ends of the piston as adjustment parameters. This causes the pneumatic piston to reciprocate under the transient air pressure difference driven by the air pressure difference amplitude sequence. The reciprocating motion is converted into a secondary energy capture power sequence between adjacent air chamber units by a linear electromagnetic power output device. This sequence is then superimposed with the primary pneumatic power sequence of each air chamber unit to obtain the total energy capture power of the system.

[0019] Specifically, the physical structure of the piston-gas spring system is as follows: a pneumatic piston slides within a closed air passage, with an elastic air bladder connected to each end of the piston. The gas sealed within the elastic air bladder is compressed or expanded under the piston's displacement, generating an equivalent spring restoring force. The stiffness of the elastic air bladder gas spring is determined by three parameters: the initial inflation volume of the air bladder, the initial inflation pressure, and the cross-sectional area of ​​the pneumatic piston. The initial inflation volume and initial inflation pressure are adjustment parameters. By adjusting these two parameters, the natural frequency of the piston-gas spring system is perfectly matched with the beat frequency between corresponding adjacent air chamber units. The matching condition is that the natural frequency of the piston-gas spring system equals the beat frequency between adjacent air chamber units. Under resonant matching conditions, the reciprocating motion amplitude of the pneumatic piston driven by transient air pressure difference reaches its maximum. The optimal damping coefficient of the linear electromagnetic power output device is taken as half of the critical damping coefficient of the piston-gas spring system. Under this damping condition, the piston has the highest absorption rate of transient air pressure difference energy. The converted secondary energy-capturing power sequence is superimposed with the primary pneumatic power sequence of each air chamber unit to obtain the total energy-capturing power of the system.

[0020] In one specific embodiment, step S1 includes: Based on the measured spectral data of the target sea area, the peak frequency and effective bandwidth of the target frequency band are extracted to obtain the frequency boundary sequence of the target frequency band; Based on the target frequency band frequency boundary sequence, the design inherent resonant frequency of each air chamber unit is determined. The design inherent resonant frequency of each air chamber unit, the cross-sectional area of ​​the air chamber cavity and the additional mass correction coefficient are substituted into the resonance condition relationship of the oscillating water column. The equivalent volume parameters of the water column are solved inversely. Based on the equivalent volume parameters of the water column, the water draft sequence of the front wall of each air chamber unit is obtained. Substitute the water depth sequence of the front wall of each air chamber unit into the resonance condition relationship of the oscillating water column, perform forward calculation on the natural resonance frequency of each air chamber unit, and compare and verify the forward calculation result with the designed natural resonance frequency of each air chamber unit to obtain the natural resonance frequency sequence of each air chamber unit. The inherent resonant frequency sequence of each air chamber unit is compared one by one with the frequency boundary sequence of the target frequency band. The draft sequence of the front wall of the air chamber unit that exceeds the target frequency band boundary is iteratively corrected to obtain the inherent resonant frequency sequence of each air chamber unit that is completely covered and matched with the target frequency band.

[0021] Specifically, the bandwidth is the width of the frequency range where the spectral density exceeds half of the peak spectral density. The lowest and highest frequencies of this range are determined as the lower and upper boundaries of the target frequency band frequency boundary sequence, respectively. These two boundary values ​​together constitute the target frequency band frequency boundary sequence. The target frequency band is uniformly divided into N sub-bands between the upper and lower boundaries according to the number of air chamber units N. The center frequency of each sub-band is the design natural resonant frequency of the corresponding air chamber unit. The resonance condition relationship of the oscillating water column is established based on linear wave theory, describing the quantitative relationship between the natural angular frequency of the water column in the air chamber and the cross-sectional area of ​​the air chamber cavity, the equivalent volume parameter of the water column, and the additional mass correction factor. Specifically, the square of the natural angular frequency is equal to the product of the gravitational acceleration and the cross-sectional area of ​​the air chamber cavity divided by the sum of the equivalent volume parameter of the water column and the additional mass correction factor, where the equivalent volume parameter of the water column is the product of the cross-sectional area of ​​the air chamber cavity and the draft of the front wall. The physical meaning of the water column equivalent volume parameter is the volume of the water column participating in the oscillation within the air chamber. It directly determines the magnitude of the water column's equivalent inertia. The greater the draft, the larger the water column equivalent volume parameter and the lower the natural resonant frequency. This is the physical basis for the panpipe-type multi-oscillating water column device to cover a wide frequency spectrum through stepped drafts. The additional mass correction coefficient reflects the extra inertial contribution generated by the accompanying motion of the water at the air chamber opening during oscillation. Its value is determined by the ratio of the air chamber opening width to the draft of the front wall through a preset empirical method. This empirical method can be obtained in advance through water tank model tests or numerical simulations. The correction coefficient increases with the increase of the ratio of the opening width to the draft. Substituting the design natural resonant frequency, the cross-sectional area of ​​the air chamber cavity, and the additional mass correction coefficient into the resonance condition relationship of the oscillating water column, the water column equivalent volume parameter is solved inversely. Based on the ratio of the water column equivalent volume parameter to the cross-sectional area of ​​the air chamber cavity obtained from the inverse solution, the draft sequence of the front wall of each air chamber unit is obtained. The aforementioned inverse solution process and the subsequent forward calculation and verification of the draft depth sequence of the front wall of each air chamber unit are two independent calculation steps with opposite directions. The former uses the design natural resonance frequency as a known quantity to solve for the unknown equivalent volume parameters of the water column, while the latter uses the draft depth of the front wall obtained from the inverse solution as a known quantity to calculate the natural resonance frequency and compare it with the design natural resonance frequency for verification. This is used to verify the correctness of the inverse calculation design results, rather than using the forward calculation results as new unknown parameters to continue to be substituted into subsequent calculations.

[0022]

[0023]

[0024]

[0025] In the formula, ω is the natural angular frequency of the air cell unit (rad / s); The acceleration due to gravity is taken as 9.8 m / s². 2 A is the cross-sectional area of ​​the air chamber (m²).2 V is the equivalent volume parameter of the water column (m). 3 V = A·d; d is the draft of the front wall of the air chamber unit (m); Additional mass correction factor (m) 3 (with dimensions consistent with V), is determined by the ratio of the air chamber opening width to the draft depth through a preset empirical method, which can be obtained in advance through water tank model tests or numerical simulations; The resonant frequency (Hz) of the air chamber unit.

[0026] Substitute the water depth sequence of the front wall of each air chamber unit into the above-mentioned oscillating water column resonance condition relationship for forward calculation verification. Calculate the natural angular frequency of each air chamber unit in turn. Divide the natural angular frequency obtained by forward calculation by twice pi to obtain the natural resonance frequency of each air chamber unit. Take the absolute value of the difference between the natural resonance frequency of each air chamber unit and the center frequency of the corresponding sub-band in the target frequency band frequency boundary sequence. Set the deviation judgment threshold to 5% of the effective bandwidth of the target frequency band. The basis for setting this threshold is that when it is lower than this threshold, the interval between the natural resonance frequencies of adjacent air chamber units can still ensure continuous coverage of the target frequency band without energy capture blind spots. When it is higher than this threshold, there will be uncovered frequency intervals between the natural resonance frequencies of adjacent air chamber units, resulting in the incident wave energy in the frequency interval not being effectively captured by any air chamber unit. For air chamber units whose forward calculation deviation exceeds the threshold, the draft of the front wall of the air chamber unit is adjusted step by step using the ratio of the deviation to the partial derivative of the resonance condition relationship of the oscillating water column with respect to the draft as the correction step size. After each adjustment, the forward calculation verification is performed again by substituting into the resonance condition relationship of the oscillating water column until the deviation of the inherent resonance frequency of all air chamber units from the center frequency of the corresponding sub-band does not exceed the threshold. This is used as the termination condition for iteration, and the inherent resonance frequency sequence of each air chamber unit that is completely matched with the target frequency band is output.

[0027] Figure 2 This is a schematic diagram illustrating the convergence process of the inherent resonant frequency deviation of each air chamber unit in the embodiments of this application as a function of the number of iterations.

[0028] In the figure, the horizontal axis represents the number of iterations, and the vertical axis represents the deviation between the inherent resonant frequency of each air cell unit and the center frequency of the corresponding sub-band. The four broken lines correspond to the deviation convergence trajectories of air cell 1, air cell 2, air cell 4, and air cell 5, respectively. The horizontal dashed line represents the convergence threshold, which corresponds to five percent of the effective bandwidth of the target frequency band. As can be seen from the figure, the deviation of the inherent resonant frequency of each air cell unit decreases monotonically with the increase of the number of iterations. After the eighth to tenth iterations, the deviation of all air cell units simultaneously drops below the convergence threshold, the iterative correction process terminates, and the output is a sequence of inherent resonant frequencies of each air cell unit that completely matches the target frequency band.

[0029] In one specific embodiment, step S2 includes: Based on the inherent resonant frequency sequence of each air chamber unit, the sampling frequency of the air pressure sensor in the gas phase space at the top of each air chamber unit is set, and the air pressure sensor in the gas phase space at the top of each air chamber unit is synchronously triggered and sampled based on the same hardware clock reference. The air pressure time series of each air chamber unit is synchronously acquired to obtain the air pressure time series of each air chamber unit. The instantaneous air pressure value in the air pressure time series of each air chamber unit is synchronously paired with the output value of the liquid level sensor at the free liquid surface of the water column in the corresponding air chamber unit, and the oscillation amplitude time series of the water column of each air chamber unit is extracted to obtain the oscillation amplitude time series of the water column of each air chamber unit. The time series of water column oscillation amplitude of each air chamber unit is time-differenced, that is, the difference of water column oscillation amplitude between two adjacent sampling times is divided by the sampling time interval. The time series of water column oscillation velocity of each air chamber unit is calculated, and the time series of water column oscillation velocity of each air chamber unit is multiplied by the cross-sectional area of ​​the air chamber cavity of each air chamber unit at each time step to obtain the instantaneous gas volume flow rate sequence of each air chamber unit. The instantaneous gas volumetric flow rate sequence of each air chamber unit is multiplied by the gas pressure time sequence of each air chamber unit at each sampling time to obtain the instantaneous aerodynamic power of each air chamber unit. The instantaneous aerodynamic power is the product of the gas pressure in the air chamber and the instantaneous gas volumetric flow rate at the corresponding sampling time. The instantaneous aerodynamic power of each air chamber unit is summed at all sampling points within the acquisition period and then divided by the number of sampling points within the acquisition period to obtain the primary aerodynamic power sequence of each air chamber unit. The summation and division by the number of sampling points is the equivalent realization of the time integral averaging of instantaneous aerodynamic power under discrete sampling conditions.

[0030] Specifically, the sampling frequency of the pressure sensor is determined based on the highest natural resonant frequency in the natural resonant frequency sequence of each air chamber unit. The sampling frequency is set to twenty times the highest natural resonant frequency of the target frequency band. This multiple is based on the Nyquist sampling theorem, which requires that the sampling frequency be no less than twice the highest frequency of the sampled signal. A multiple of twenty allows for sufficient frequency margin while satisfying the sampling theorem, eliminating the interference of aliasing errors on the pressure time series. The pressure sensor in the gas phase space at the top of each air chamber unit and the liquid level sensor at the free surface of the water column in the corresponding air chamber unit are triggered for sampling under the same hardware clock reference. The sampling times of the two types of sensors are strictly aligned, and the instantaneous pressure value and the output value of the liquid level sensor form a one-to-one pairing data at each sampling time, eliminating the phase error introduced by the sampling time deviation. The output value of the liquid level sensor is the instantaneous elevation of the free surface of the water column in each air chamber unit relative to the still water surface. The time series of this elevation is the time series of the oscillation amplitude of the water column in each air chamber unit, reflecting the vertical oscillation process of the water column in each air chamber unit under the action of waves.

[0031] The water column oscillation velocity time series is calculated by time difference of the water column oscillation amplitude time series. Specifically, the difference in water column oscillation amplitude between two adjacent sampling times is divided by the sampling time interval to obtain the water column oscillation velocity corresponding to that sampling time. This difference operation is performed time-by-time to obtain the water column oscillation velocity time series for each gas chamber unit. The cross-sectional area of ​​the gas chamber cavity is the horizontal cross-sectional area of ​​the gas chamber cavity, which physically represents the area of ​​the gas-liquid interface during water column oscillation. The product of the water column oscillation velocity and the cross-sectional area of ​​the gas chamber cavity is the gas volume passing through the gas-liquid interface per unit time, i.e., the instantaneous gas volumetric flow rate of each gas chamber unit (denoted by q(t)). The above multiplication operation is performed time-by-time to obtain the instantaneous gas volumetric flow rate time series q(t) for each gas chamber unit. The instantaneous gas volumetric flow rate series of each gas chamber unit is multiplied by the gas pressure time series of each gas chamber unit at each sampling time to obtain the instantaneous aerodynamic power of each gas chamber unit, which physically represents the instantaneous power exerted by the gas pressure inside the gas chamber on the gas passing through the gas-liquid interface. The acquisition period is taken as an integer multiple of the inherent resonance period of each air chamber unit. This value is based on the fact that summing the instantaneous aerodynamic power at the sampling points corresponding to an integer number of resonance periods can eliminate the period truncation error and avoid the power calculation deviation caused by the non-integer period of the sampling interval. The instantaneous aerodynamic power of each air chamber unit is summed at all sampling points within the acquisition period and then divided by the number of sampling points within the acquisition period to obtain the aerodynamic power sequence of each air chamber unit. This summation and division by the number of sampling points is the equivalent realization of the time integral average of instantaneous aerodynamic power under discrete sampling conditions.

[0032]

[0033]

[0034]

[0035]

[0036] In the formula, This is a time series of water column oscillation velocity (m / s); The time series of water column oscillation amplitude (m); The sampling time interval (s); For instantaneous gas volumetric flow rate time series (m 3 / s); A is the cross-sectional area of ​​the air chamber (m²) 2 This refers to the horizontal cross-sectional area where the free surface of the water column is located. This application calculates the instantaneous gas volumetric flow rate using the water column displacement method, which is obtained by multiplying the velocity of the free surface of the water column by the cross-sectional area of ​​the gas chamber. The physical basis for this is that the free surface of the water column is the boundary of the gas movement within the gas chamber, and the surface moves at a velocity... When moving upwards, the volume of gas displaced within the cross-sectional area A of the air chamber is... According to the fluid continuity equation, this volumetric flow rate is equal to the volumetric flow rate of the gas discharged through the outlet pipe, that is... It is equal to the product of the airflow velocity inside the pipe and the cross-sectional area of ​​the pipe; since the cross-sectional area of ​​the air chamber is much larger than the cross-sectional area of ​​the water outlet pipe, according to the continuity equation, the airflow velocity inside the pipe is correspondingly much larger than the water column oscillation velocity. The two measurement paths are numerically equivalent. This application selects the water column displacement method because it only requires a liquid level elevation sensor to obtain the value, and there is no need to place a wind speed sensor inside the pipe, making the measurement method simpler. The time series of air chamber pressure (Pa); Instantaneous aerodynamic power (W); The formula represents the aerodynamic power (W); K is the number of sampling points in one acquisition cycle, and n is the sampling point number. It is obtained by summing the instantaneous aerodynamic power over all K sampling points within the acquisition period and dividing by K. It is the equivalent expression of the time integral average of instantaneous aerodynamic power under discrete sampling conditions. The product of the sampling time interval and the number of sampling points K is the acquisition period duration.

[0037] In one specific embodiment, step S3 includes: The pressure time series of adjacent air chamber units in each air chamber unit are subtracted at each sampling time, that is, the pressure value of the previous air chamber unit is subtracted from the pressure value of the next air chamber unit along the wave propagation direction. The transient pressure difference time series between each adjacent air chamber unit is calculated to obtain the transient pressure difference time series between each adjacent air chamber unit. The difference between the maximum and minimum values ​​of the transient pressure difference time series between each adjacent air chamber unit is extracted within a sliding time window as the peak-to-peak value. The peak-to-peak value is then divided by two. The pressure difference amplitude between each adjacent air chamber unit is statistically analyzed to obtain the pressure difference amplitude sequence. The transient pressure difference time series between each adjacent air chamber unit is input into the Fast Fourier Transform for spectral analysis. The square of the amplitude of each frequency component output by the Fast Fourier Transform is divided by the data length to obtain the power spectral density corresponding to each frequency component. The power spectral density reflects the energy proportion of each frequency component in the transient pressure difference time series. The power spectral density sequence between each adjacent air chamber unit is obtained by arranging them in frequency order. Based on the power spectral density sequence between each adjacent air chamber unit, the peak frequency of each power spectral density sequence is extracted and compared with the theoretical beat frequency obtained by subtracting adjacent frequencies from the inherent resonant frequency sequence of each air chamber unit. The theoretical beat frequency corresponding to the adjacent air chamber unit whose absolute value of the difference between the measured beat frequency and the theoretical beat frequency exceeds the threshold is marked and corrected to obtain the beat frequency sequence between adjacent air chamber units.

[0038] Specifically, the transient pressure difference time series between adjacent air chamber units is obtained by subtracting the pressure time series of adjacent air chamber units at each sampling moment. The subtraction direction is the difference between the pressure value of the previous air chamber unit and the pressure value of the next air chamber unit in the direction of wave propagation, maintaining the consistency of the sign of the difference to reflect the directionality of the pressure difference. The sliding time window length is taken as an integer multiple of the theoretical beat frequency period between adjacent air chamber units, specifically ten times the theoretical beat frequency period. This multiple is set based on the fact that the beat frequency period is much larger than the inherent resonance period of each air chamber unit. Taking ten times the beat frequency period as the window length can include a sufficient number of complete beat frequency oscillation cycles within the window, ensuring that the peak-to-peak value extraction result is stable and not affected by window truncation. Within each sliding time window, the peak-to-peak value is obtained by subtracting the maximum and minimum values ​​of the transient pressure difference time series between adjacent air chamber units. The peak-to-peak value is then divided by two to obtain the pressure difference amplitude within that window. The sliding step size is taken as a single sampling time interval. The windows are gradually slid and the above operation is repeated to arrange the pressure difference amplitudes within each window in chronological order, thus obtaining a pressure difference amplitude sequence. This sequence reflects the change process of the transient pressure difference amplitude between adjacent air chamber units over time.

[0039]

[0040]

[0041] In the formula, For the transient pressure difference time series (Pa) between the i-th and i+1-th air chamber units, the difference direction is along the wave propagation direction, from the air pressure of the previous air chamber to the air pressure of the next air chamber; , These are the time series of air pressures between two adjacent air chambers (Pa); a is the amplitude of the air pressure difference within the sliding time window (Pa), taken within the window. The window length is one-half the difference between the maximum and minimum values, and is ten times the theoretical beat frequency period.

[0042] The transient pressure difference time series between adjacent air chamber units is input into a Fast Fourier Transform (FFT). The data length L is the minimum of all values ​​that simultaneously satisfy the following two conditions: first, it is not less than the number of sampling points corresponding to the window length (i.e., ten times the beat frequency period); second, it is an integer power of 2. This satisfies the FFT's data length requirements and ensures sufficient frequency resolution. The frequency resolution is equal to the sampling frequency divided by the data length, and the frequency resolution must not be greater than one-tenth of the theoretical minimum beat frequency to ensure that the beat frequencies between adjacent air chamber units can be effectively distinguished. For each discrete frequency component output by the FFT, the square of the amplitude of the frequency component is divided by the data length to obtain the power spectral density value corresponding to that discrete frequency. The power spectral density values ​​corresponding to all discrete frequency components are arranged in ascending order of frequency to obtain the power spectral density sequence, which reflects the energy proportion of each frequency component in the transient pressure difference time series. The peak frequency of the power spectral density sequence is the frequency corresponding to the maximum power spectral density, i.e., the measured beat frequency. The measured beat frequency is compared one by one with the theoretical beat frequency obtained by subtracting the natural resonant frequencies of adjacent air chamber units in the natural resonant frequency sequence of each air chamber unit. The deviation threshold is set to 10% of the theoretical beat frequency value. The basis for setting this threshold is that when the deviation between the measured beat frequency and the theoretical beat frequency is lower than this threshold, the deviation is within the acceptable range of the resonance matching adjustment of the piston gas spring system and will not affect the accuracy of subsequent resonance matching adjustment. For adjacent air chamber units whose deviation exceeds the threshold, the measured beat frequency is used to replace the theoretical beat frequency for marking and correction. The corrected beat frequencies between adjacent air chamber units are arranged in the index order of adjacent air chamber unit pairs to obtain the beat frequency sequence between adjacent air chamber units.

[0043]

[0044]

[0045] In the formula, Power spectral density at frequency The value at; The discrete frequency components output by the Fast Fourier Transform (FFT) are given in Hz. Their values ​​are equal to the product of the frequency resolution and the corresponding frequency component index, and range from 0 to half the sampling frequency (Nyquist frequency) for L / 2 discrete frequency points. FFT(·) is the Fast Fourier Transform; L is the number of data points involved in the transformation, and is the minimum of all values ​​that simultaneously satisfy the following two conditions: first, it is not less than the number of sampling points corresponding to the window length; second, it is an integer power of 2. All discrete frequency components output by the Fast Fourier Transform are substituted into the above formula sequentially for calculation. Arranging the values ​​corresponding to each discrete frequency in frequency order constitutes the power spectral density sequence; measured beat frequency Pick The frequency corresponding to the peak value; The theoretical beat frequency (Hz) is obtained by the difference between the natural resonant frequencies of the i-th and i+1-th air chambers. , These are the natural resonant frequencies (Hz) of two adjacent air chambers, respectively. If | - |More than 0.1· Then the actual shooting frequency is used. Replace the theoretical beat frequency as input for subsequent designs.

[0046] In one specific embodiment, step S4 involves installing a pneumatic piston in the gas phase region of the partition wall between adjacent gas chamber units, including: The pressure difference amplitude sequence and the beat frequency sequence are input into the pneumatic piston cross-sectional area design process. Based on the spatial size constraints of the gas phase region of the partition wall of each adjacent air chamber unit, the cross-sectional area of ​​the pneumatic piston between each adjacent air chamber unit is designed to obtain the cross-sectional area sequence of the pneumatic piston between each adjacent air chamber unit. Based on the cross-sectional area sequence of the pneumatic piston between each adjacent air chamber unit, the initial inflation volume and initial inflation pressure of the elastic airbags at both ends of the pneumatic piston are set, and the stiffness of the elastic airbag air spring between each adjacent air chamber unit is calculated to obtain the stiffness sequence of the elastic airbag air spring between each adjacent air chamber unit. Substitute the stiffness sequence of the elastic air spring between each adjacent air chamber unit into the natural frequency calculation formula of the piston air spring system, set the natural frequency of the piston air spring system to be equal to the corresponding beat frequency value in the beat frequency sequence, and back-calculate the mass of the pneumatic piston between each adjacent air chamber unit to obtain the mass sequence of the pneumatic piston between each adjacent air chamber unit. Based on the mass sequence of the pneumatic pistons between adjacent air chamber units and the stiffness sequence of the elastic airbags between adjacent air chamber units, the natural frequency of the piston-air spring system between adjacent air chamber units is verified by forward calculation. The verification results are compared with the beat frequency sequence one by one. The inflation volume and initial inflation pressure of the elastic airbags corresponding to adjacent air chamber units with deviations exceeding the threshold are iteratively adjusted to obtain the parameter sequence of the piston-air spring system between adjacent air chamber units that perfectly matches the beat frequency sequence. The parameter sequence of the piston-air spring system includes the stiffness of the elastic airbags between adjacent air chamber units, the mass of the pneumatic piston, the cross-sectional area of ​​the pneumatic piston, and the initial inflation volume of the elastic airbag.

[0047] Specifically, the inputs to the pneumatic piston cross-sectional area design process are the pressure difference amplitude sequence and the beat frequency sequence. The design objective is to ensure that, under the spatial constraints of the partition wall's gas phase region, the driving force generated by the pneumatic piston under transient pressure difference is sufficient to overcome the sum of the piston's own inertia and the elastic restoring force of the elastic airbag. The spatial constraints of the partition wall's gas phase region are the upper limits on the pneumatic piston's cross-sectional area imposed by the partition wall's thickness and height; the pneumatic piston's cross-sectional area must not exceed the maximum usable cross-sectional area of ​​the partition wall's gas phase region. Under the premise of satisfying spatial constraints, the cross-sectional area of ​​the pneumatic piston is determined based on the ratio of the air pressure difference amplitude between each adjacent air chamber unit in the air pressure difference amplitude sequence to the target driving force. The target driving force is the minimum driving force required for the piston gas spring system to generate effective reciprocating motion under resonant matching conditions. This minimum driving force is determined by the product of the square of the product of the piston mass and the corresponding angular frequency of the beat frequency and the design reference value of the piston displacement amplitude. The design reference value of the piston displacement amplitude is taken as 10% of the air passage length. The basis for setting this ratio is that if it is lower than this ratio, the piston reciprocating motion amplitude is too small, resulting in insufficient output power of the linear electromagnetic power output device, and if it is higher than this ratio, the piston stroke exceeds the physical limit of the air passage.

[0048]

[0049]

[0050] In the formula, F is the target driving force (N); The mass of the pneumatic piston is (kg). In this step, the preset initial design value of the pneumatic piston mass is used. The beat frequency corresponds to the angular frequency (rad / s). =2π· x is the design reference value (m) for piston displacement amplitude. The air passage length (m) is used in this step to determine the pneumatic piston cross-sectional area. And the stiffness k of the elastic airbag air spring. Then, in the forward calculation and verification of the natural frequency of the piston air spring system, the mass of the pneumatic piston is calculated and iteratively corrected by k and m until the deviation between the natural frequency and the beat frequency sequence converges to within the threshold. That is, the closed-loop iterative solution of the piston mass from the preset initial value to the final design value is completed.

[0051] Divide the pressure difference amplitude between adjacent air chamber units by the target driving force to obtain the cross-sectional area of ​​the pneumatic piston between adjacent air chamber units. Under the constraint of not exceeding the maximum usable cross-sectional area of ​​the gas phase region of the partition wall, take the smaller value between the calculated value of the pneumatic piston cross-sectional area obtained by dividing the pressure difference amplitude between adjacent air chamber units by the target driving force and the upper limit of the constraint of the maximum usable cross-sectional area of ​​the gas phase region of the partition wall. Arrange them according to the index order of the adjacent air chamber unit pairs to obtain the sequence of pneumatic piston cross-sectional areas between adjacent air chamber units.

[0052]

[0053] In the formula, The cross-sectional area of ​​the pneumatic piston between adjacent air chamber units (m²) 2 F is the target driving force (N); a is the corresponding air pressure difference amplitude (Pa). The force on the pneumatic piston under transient air pressure difference driving is equal to the product of the air pressure difference amplitude and the piston cross-sectional area. Therefore, the piston cross-sectional area is obtained by dividing the target driving force by the air pressure difference amplitude. The maximum usable cross-sectional area (m²) of the gas phase zone of the partition wall 2 The upper limit of the spatial constraint is determined by the thickness and height of the partition wall. When the calculated piston cross-sectional area exceeds the upper limit, the upper limit is used as the value of the piston cross-sectional area, thereby ensuring that the pneumatic piston can be installed in the physical space of the gas phase region of the partition wall.

[0054] The stiffness of the elastic airbag gas spring is jointly determined by the initial inflation volume of the elastic airbag, the initial inflation pressure, and the cross-sectional area of ​​the pneumatic piston. Physically, it represents the ratio of the equivalent elastic restoring force to the displacement when the gas sealed within the elastic airbag is compressed or expanded under the action of the piston. Based on the ideal gas adiabatic compression process, the stiffness of the elastic airbag gas spring is equal to the product of the air adiabatic index and the initial inflation pressure, multiplied by the square of the pneumatic piston cross-sectional area, and then divided by the initial inflation volume. The air adiabatic index is taken as 1.4, a known physical property parameter of dry air at normal temperature and pressure. Both the initial inflation pressure and the initial inflation volume are adjustable parameters, and they jointly determine the stiffness of the elastic airbag gas spring. By adjusting the initial inflation pressure and the initial inflation volume, the stiffness of the elastic airbag gas spring can meet the resonance matching requirements. In a preferred embodiment, the initial inflation pressure is taken as standard atmospheric pressure, and in this case, the initial inflation volume is used as the main adjustment parameter for iterative adjustment.

[0055]

[0056] In the formula, The stiffness of the elastic airbag air spring (N / m); The adiabatic index of air is taken as 1.4 (a known physical property parameter of dry air at normal temperature and pressure). Initial inflation pressure (Pa); The cross-sectional area of ​​the pneumatic piston (m²) 2 ); Initial inflation volume (m³) 3 ).

[0057] The natural frequency of a piston-gas spring system is equal to the square root of the ratio of twice the stiffness of the elastic airbag gas spring to the mass of the pneumatic piston, divided by twice pi. The coefficient 2 in this formula originates from the fact that with two elastic airbags connected in series at both ends of the piston, the equivalent stiffness is twice that of a single gas spring. Substituting the elastic airbag gas spring stiffness sequence into the above natural frequency calculation formula, and setting the natural frequency of the piston-gas spring system to the corresponding beat frequency value in the beat frequency sequence, the pneumatic piston mass sequence between adjacent air chamber units is obtained by inversely solving for the pneumatic piston mass sequence between adjacent air chamber units. During forward calculation verification, the pneumatic piston mass sequence and the elastic airbag air spring stiffness sequence are substituted into the natural frequency calculation formula. The natural frequencies obtained from the forward calculation are compared with the beat frequency sequence one by one. The deviation threshold is set to five percent of the corresponding beat frequency value. The basis for setting this threshold is that when it is lower than this threshold, the degree of detuning between the natural frequency and the beat frequency of the piston air spring system is within 2% of the decrease in the resonance response amplitude, which does not affect the effective output of the secondary energy harvesting power. For adjacent air chamber units where the deviation exceeds the threshold, the initial inflation volume and / or the initial inflation pressure are adjusted step by step using the partial derivative of the natural frequency calculation formula with respect to the initial inflation volume and / or the initial inflation pressure as the step size. The forward calculation verification is repeated until all deviations do not exceed the threshold at the same time. The output is the piston air spring system parameter sequence between each adjacent air chamber unit that is completely matched with the beat frequency sequence.

[0058]

[0059]

[0060]

[0061] In the formula, The natural frequency (Hz) of the piston gas spring system; The stiffness of the elastic airbag air spring (N / m); Let fbeat be the mass of the pneumatic piston (kg); the physical source of the coefficient 2 in the formula is that each end of the pneumatic piston is connected to an elastic air bladder. When the piston reciprocates, the elastic restoring forces of the air bladders on both sides are superimposed along the direction of motion, and the equivalent total stiffness is twice the stiffness of a single air bladder. Therefore, the coefficient 2 appears in the formula for calculating the natural frequency of the system; fbeat is the beat frequency (Hz) between corresponding adjacent air chamber units; the third formula is the convergence criterion for forward calculation verification, and the deviation threshold is taken as 5% of the beat frequency value.

[0062] In one specific embodiment, step S4 involves adjusting the natural frequency of the piston-gas spring system composed of the pneumatic piston and the elastic airbag to achieve resonance matching based on the beat frequency sequence and the air pressure difference amplitude sequence, including: Substitute the parameter sequence of the piston-gas spring system between each adjacent air chamber unit and the gas pressure difference amplitude sequence into the optimal matching condition of linear damping, calculate the optimal damping coefficient of the linear electromagnetic power output device between each adjacent air chamber unit, and obtain the optimal damping coefficient sequence between each adjacent air chamber unit. Based on the optimal damping coefficient sequence between each adjacent air chamber unit, the steady-state displacement amplitude and steady-state velocity amplitude of the pneumatic piston between each adjacent air chamber unit under transient air pressure difference drive are calculated to obtain the steady-state motion parameter sequence of the pneumatic piston between each adjacent air chamber unit. Based on the steady-state velocity amplitude in the steady-state motion parameter sequence of the pneumatic piston between each adjacent air chamber unit, the optimal damping coefficient between each adjacent air chamber unit is multiplied by the square of the corresponding steady-state velocity amplitude, and half is taken as the average secondary energy capture power of the linear electromagnetic power output device between each adjacent air chamber unit in one beat frequency cycle, thus obtaining the secondary energy capture power sequence between each adjacent air chamber unit.

[0063] Specifically, the physical meaning of the optimal matching condition for linear damping is the damping coefficient value condition corresponding to the maximum power extraction from the reciprocating motion of the pneumatic piston by the linear electromagnetic power output device under resonance matching conditions. This condition is derived from the power maximization of a single-degree-of-freedom forced vibration system under harmonic excitation. The optimal damping coefficient is equal to half of the critical damping coefficient of the piston-gas spring system. The critical damping coefficient is equal to twice the square root of the product of twice the stiffness of the elastic airbag gas spring and the mass of the pneumatic piston. This derivation result is a well-known conclusion in linear vibration theory. Substituting the stiffness of the elastic airbag gas spring and the mass of the pneumatic piston in the parameter sequence of the piston-gas spring system between each adjacent air chamber unit into the above critical damping coefficient calculation relationship, the critical damping coefficient between each adjacent air chamber unit is obtained. Then, half of each critical damping coefficient is taken and arranged according to the index order of the adjacent air chamber unit pairs to obtain the optimal damping coefficient sequence between each adjacent air chamber unit. The physical meaning of the optimal damping coefficient is the ratio of the damping force applied by the linear electromagnetic power output device to the pneumatic piston to the piston speed. This ratio determines the efficiency of the linear electromagnetic power output device in extracting energy from the reciprocating motion of the piston. The basis for taking half of the critical damping coefficient is that the system is in an underdamped resonance state and the power extraction efficiency is the highest at this time.

[0064]

[0065]

[0066] In the formula, The critical damping coefficient (N·s / m); The optimal damping coefficient is (N·s / m). Stiffness of a single elastic airbag air spring (N / m); Let K be the mass of the pneumatic piston (kg). An elastic air bladder is connected to each end of the piston. During reciprocating motion, the elastic restoring forces of the air bladders on both sides are superimposed along the direction of motion, resulting in an equivalent total stiffness that is twice the stiffness of a single air bladder, i.e., 2k. Substituting K=2k into the critical damping formula for a single-degree-of-freedom forced vibration system, we obtain... The physical origin of this coefficient 2 is the same as that of the coefficient 2 in the aforementioned formula for calculating the natural frequency of the piston gas spring system, both originating from the parallel superposition of two airbags.

[0067] The steady-state displacement amplitude is the peak displacement of the pneumatic piston when it reaches steady-state oscillation under the continuous drive of the harmonic pressure difference corresponding to the beat frequency. It is obtained by dividing the product of the corresponding pressure difference amplitude and the cross-sectional area of ​​the pneumatic piston in the pressure difference amplitude sequence by the product of the optimal damping coefficient and the angular frequency corresponding to the beat frequency, where the angular frequency corresponding to the beat frequency is equal to the beat frequency multiplied by twice pi. The steady-state velocity amplitude is obtained by the product of the steady-state displacement amplitude and the angular frequency corresponding to the beat frequency, reflecting the peak velocity of the pneumatic piston during steady-state oscillation. The steady-state displacement amplitude and steady-state velocity amplitude are arranged and combined according to the index order of adjacent air chamber unit pairs to form the steady-state motion parameter sequence of the pneumatic piston between adjacent air chamber units. The instantaneous secondary energy capture power is the product of the damping force applied to the pneumatic piston by the linear electromagnetic power output device at each sampling moment and the piston's instantaneous velocity. The damping force is equal to the product of the optimal damping coefficient and the piston's instantaneous velocity. Therefore, the instantaneous secondary energy capture power is equal to the product of the optimal damping coefficient and the square of the piston's instantaneous velocity. The average secondary energy capture power of the linear electromagnetic power output device between adjacent air chamber units is obtained by multiplying the optimal damping coefficient between each adjacent air chamber unit by the square of the corresponding steady-state velocity amplitude and taking half of the result. This average value is the result of time integration averaging of the instantaneous secondary energy capture power within the acquisition period. The integration period is taken as an integer multiple of the beat frequency period to eliminate period truncation error. Arranged according to the index order of adjacent air chamber unit pairs, the secondary energy capture power sequence between adjacent air chamber units is obtained. Each element in this sequence is the average secondary energy capture power obtained by time integration averaging of the instantaneous secondary energy capture power between the corresponding adjacent air chamber units within the acquisition period.

[0068]

[0069]

[0070]

[0071]

[0072] In the formula, The steady-state displacement amplitude of the pneumatic piston (m); The pressure difference amplitude (Pa); The cross-sectional area of ​​the pneumatic piston (m²) 2 ); The optimal damping coefficient is (N·s / m). The beat frequency corresponds to the angular frequency (rad / s); This represents the steady-state velocity amplitude (m / s) of the pneumatic piston, which is the peak velocity in each cycle after the piston's reciprocating motion reaches a steady state. The instantaneous velocity of the piston is (m / s). The corresponding instantaneous secondary energy harvesting power (W); Let be the average secondary energy harvesting power (W) over one beat frequency cycle. To avoid confusion between the concepts of "instantaneous" and "steady-state" velocity, the above two equations are respectively... The two different symbols, V (instantaneous velocity, which varies with time) and V (steady-state velocity amplitude, i.e., the peak value of steady-state oscillation), represent the instantaneous velocity. The calculation uses the peak velocity Vp and multiplies it by a factor of 1 / 2 to convert it into periodic average power. This factor of 1 / 2 is the average value of the square of the sine function over the time integral over one complete cycle, as shown in the formula. It is itself an analytical closed-form solution of the time integral average of the instantaneous secondary energy harvesting power under steady-state harmonic oscillation conditions, so there is no need to write the integral symbol separately in the formula.

[0073] Figure 3 This is a schematic diagram comparing the primary pneumatic power sequence of each air chamber unit and the secondary energy capture power sequence between adjacent air chamber units in the embodiments of this application. In the figure, the horizontal axis represents the air chamber unit number and the piston number of adjacent air chamber units, the vertical axis represents the power value, the diagonally filled bars represent the primary pneumatic power output by each air chamber unit through the main air turbine, and the cross-filled bars represent the secondary energy capture power output by the pneumatic pistons between adjacent air chamber units through the linear electromagnetic power output device. As can be seen from the figure, the primary pneumatic power corresponding to air chamber 2 is the highest at 510.0 W / m, and the secondary energy capture power corresponding to the pistons of air chambers 1-2 is 8.2 W / m. The secondary energy capture power is much smaller than the primary pneumatic power, which reflects the process of the secondary energy capture mechanism recovering and utilizing the residual energy originally dissipated in the pressure difference between the chambers.

[0074] In one specific embodiment, in step S4, the linear electromagnetic power output device converts the reciprocating motion into a secondary energy capture power sequence between adjacent air chamber units, which is then superimposed with the primary aerodynamic power sequence of each air chamber unit to obtain the total energy capture power of the system, including: The secondary energy capture power sequences between each adjacent air chamber unit are accumulated one by one according to the index order of the adjacent air chamber unit pairs. The sum of the secondary energy capture power sequences between each adjacent air chamber unit is calculated to obtain the total secondary energy capture power of the system. The aerodynamic power sequence of each air chamber unit is accumulated unit by unit according to the air chamber unit index order, and the sum of the aerodynamic power sequence of each air chamber unit is calculated to obtain the total energy capture power of the system in one step. The total energy capture power of the system is obtained by superimposing the total secondary energy capture power of the system and the total primary energy capture power of the system. The ratio of the total energy capture power of the system to the incident wave energy power of the target sea area is calculated, the energy capture width ratio of the system across the entire frequency band is evaluated, the energy capture width ratio of the system across the entire frequency band is compared with a preset threshold, and the draft sequence of the front wall corresponding to the air cell unit that is lower than the preset threshold is iteratively corrected to obtain the total energy capture power of the system.

[0075] Specifically, the secondary energy harvesting power sequence between adjacent air chamber units is accumulated pairwise according to the index order of the adjacent air chamber unit pairs. The index order is from the adjacent pairs formed by the first and second air chamber units along the wave propagation direction to the adjacent pairs formed by the (N-1)th and Nth air chamber units, for a total of N-1 pairs. The secondary energy harvesting power corresponding to the N-1 pairs is added sequentially to obtain the total secondary energy harvesting power of the system. The primary aerodynamic power sequence of each air chamber unit is accumulated unit-by-unit according to the air chamber unit index order from the first air chamber unit to the Nth air chamber unit, for a total of N air chamber units. The primary aerodynamic power corresponding to the N air chamber units is added sequentially to obtain the total primary energy harvesting power of the system.

[0076]

[0077]

[0078]

[0079] In the formula, denoted as the secondary energy capture power (W) between the i-th and i+1-th gas chamber units; The total secondary energy capture power (W) of the system is summed over N-1 adjacent gas chamber pairs. The primary aerodynamic power (W) of the i-th air chamber unit; The total energy capture power (W) of the system is summed over N gas chamber units; N is the total number of gas chamber units. The total energy capture power of the system is (W).

[0080] The total energy capture power of the system is obtained by directly adding the total secondary energy capture power and the total primary energy capture power of the system. It reflects the total output power of the panpipe-shaped multi-oscillating water column broadband wave energy capture device under the actual operating conditions in the target sea area. The incident wave energy power in the target sea area is calculated by the significant wave height, peak period, and seawater density of the target sea area according to the wave energy flow formula per unit width in linear wave theory. Specifically, it is calculated by multiplying the product of seawater density and the square of gravitational acceleration by the product of the square of significant wave height and the peak period, and then dividing by 32 times pi. All parameters are taken from measured data in the target sea area.

[0081]

[0082] In the formula, ρ is the incident wave energy power over the target sea area, expressed per unit span (W / m); ρ is the seawater density (kg / m³). 3 ), take 1025kg / m 3 g is the acceleration due to gravity (9.8 m / s²). 2 ); Significant wave height (m); The peak period (s) is used, and all parameters are taken from measured data in the target sea area. The primary aerodynamic power of each air chamber in this application... Total system capture power All values ​​are calculated based on the spanwise unit width of the air chamber unit (W / m), and... Since the units are the same, the two can be directly compared to obtain the dimensionless energy capture width ratio.

[0083] The physical meaning of the system's full-band energy capture width ratio is the ratio of the system's total energy capture power to the incident wave energy power of the target sea area. This ratio reflects the comprehensive capture efficiency of the panpipe-shaped multi-oscillating water column broadband wave energy capture device for incident wave energy across the entire frequency band. The value ranges from 0 to 1, with a larger value indicating a higher degree of utilization of incident wave energy by the device. The preset threshold is set to 0.5. This value is based on the fact that the peak energy capture width ratio of existing single-chamber oscillating water column devices at the resonant frequency is approximately 0.4 to 0.5. This invention, through the synergistic effect of multi-chamber stepped resonance and secondary energy capture by pneumatic pistons, requires a full-band energy capture width ratio higher than the peak level of existing single-chamber devices to demonstrate the technical superiority of this invention. Therefore, the preset threshold is set to 0.5. When the system's full-band energy capture bandwidth ratio is lower than a preset threshold, iterative correction of the front wall draft sequence is triggered. The correction target is determined as follows: the absolute value of the deviation between the inherent resonant frequency of each air chamber unit and the center frequency of its corresponding sub-band is compared one by one. The air chamber unit with the largest absolute deviation is selected as the air chamber unit to be corrected. This air chamber unit has the lowest energy capture efficiency in the corresponding sub-band because its inherent resonant frequency deviates the farthest from the center of the target sub-band, and its contribution to the system's full-band energy capture bandwidth ratio is also the smallest. The front wall draft of the air chamber unit to be corrected is adjusted in the direction of reducing the above deviation. The adjustment step size is the deviation of the inherent resonant frequency of the air chamber unit divided by... The partial derivative of the natural resonant frequency with respect to the draft of the front wall in the resonance condition formula of the oscillating water column reflects the change in natural resonant frequency caused by a unit change in draft. Dividing the deviation by the partial derivative of the natural resonant frequency with respect to the draft of the front wall is equivalent to converting the frequency deviation into the corresponding draft adjustment amount using a first-order linear approximation. This is the standard application of Newton's iteration method in single-variable optimization problems. After adjustment, the entire calculation process from the calculation of the natural resonant frequency sequence of each air chamber unit to the evaluation of the system's full-band energy capture width ratio is re-executed until the system's full-band energy capture width ratio is not lower than the preset threshold. The total energy capture power of the system after closed-loop verification is then output.

[0084]

[0085] In the formula, CWR is the system's full-band energy capture bandwidth ratio (dimensionless, ranging from 0 to 1). The total energy capture power of the system is (W / m). The incident wave energy power (W / m) in the target sea area. When the CWR is lower than the preset threshold of 0.5, the forewall draft sequence iterative correction is triggered.

[0086] The panpipe-shaped multi-oscillating water column broadband wave energy capture method in this application has been described above. The panpipe-shaped multi-oscillating water column broadband wave energy capture system in this application is described below. One embodiment of the panpipe-shaped multi-oscillating water column broadband wave energy capture system in this application includes: The quantization module is used to quantify the draft sequence of the front wall of each air chamber unit arranged in a stepped manner along the wave propagation direction based on the wave spectrum data of the target sea area, so as to obtain the inherent resonant frequency sequence of each air chamber unit. The acquisition module is used to acquire the air pressure time series and water column oscillation amplitude time series of each air chamber unit based on the inherent resonant frequency sequence of each air chamber unit, so as to obtain the primary aerodynamic power sequence of each air chamber unit. The analysis module is used to calculate the pressure difference between adjacent air chamber units in the air pressure time series of each air chamber unit and perform spectrum analysis to obtain the beat frequency sequence and air pressure difference amplitude sequence between adjacent air chamber units. The superposition module is used to set up a pneumatic piston in the gas phase region of the partition wall between adjacent air chamber units. Based on the beat frequency sequence and the air pressure difference amplitude sequence, and using the inflation volume and initial inflation pressure of the elastic air bladders at both ends of the piston as adjustment parameters, the natural frequency of the piston air spring system composed of the pneumatic piston and the elastic air bladder is resonantly matched and adjusted. This causes the pneumatic piston to generate reciprocating motion under the transient air pressure difference driven by the air pressure difference amplitude sequence. The reciprocating motion is converted into a secondary energy capture power sequence between each adjacent air chamber unit by a linear electromagnetic power output device. This sequence is then superimposed with the primary pneumatic power sequence of each air chamber unit to obtain the total energy capture power of the system.

[0087] This invention also provides a panpipe-shaped multi-oscillating water column broadband wave energy capture device, which can be a server. The panpipe-shaped multi-oscillating water column broadband wave energy capture device includes a processor, memory, display screen, input device, network interface, and database connected via a system bus. The processor, designed as a computer, provides computing and control capabilities. The memory of the panpipe-shaped multi-oscillating water column broadband wave energy capture device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the panpipe-shaped multi-oscillating water column broadband wave energy capture device stores the data corresponding to this embodiment. The network interface of the panpipe-shaped multi-oscillating water column broadband wave energy capture device is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements the above-described method.

[0088] The present invention also provides a computer-readable storage medium, which can be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium, wherein the computer-readable storage medium stores instructions that, when the instructions are executed on a computer, cause the computer to perform the steps of the panpipe-shaped multi-oscillating water column broadband wave energy capture method.

[0089] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0090] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a panpipe-shaped multi-oscillating water column broadband wave energy capture device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0091] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for capturing broadband wave energy of a panpipe-shaped multi-oscillating water column, characterized in that, The method includes: Step S1: Based on the wave spectrum data of the target sea area, the draft sequence of the front wall of each air cell unit arranged in a stepped manner along the wave propagation direction is quantitatively designed to obtain the inherent resonant frequency sequence of each air cell unit. Step S2: Based on the inherent resonant frequency sequence of each air chamber unit, the air pressure time sequence and water column oscillation amplitude time sequence of each air chamber unit are collected to obtain the primary aerodynamic power sequence of each air chamber unit; Step S3: Calculate the pressure difference between adjacent air chamber units in the air pressure time series of each air chamber unit and perform spectrum analysis to obtain the beat frequency sequence and air pressure difference amplitude sequence between adjacent air chamber units. Step S4: A pneumatic piston is installed in the gas phase region of the partition wall between adjacent air chamber units. Based on the beat frequency sequence and the air pressure difference amplitude sequence, the natural frequency of the piston air spring system composed of the pneumatic piston and the elastic air bladder is resonantly matched and adjusted using the inflation volume and initial inflation pressure of the elastic air bladders at both ends of the piston as adjustment parameters. This causes the pneumatic piston to reciprocate under the transient air pressure difference driven by the air pressure difference amplitude sequence. The reciprocating motion is converted into a secondary energy capture power sequence between adjacent air chamber units by a linear electromagnetic power output device. This sequence is then superimposed with the primary pneumatic power sequence of each air chamber unit to obtain the total energy capture power of the system.

2. The panpipe-shaped multi-oscillating water column broadband wave energy capture method according to claim 1, characterized in that, Step S1 includes: Based on the measured spectral data of the target sea area, the peak frequency and effective bandwidth of the target frequency band are extracted to obtain the frequency boundary sequence of the target frequency band; Based on the target frequency band frequency boundary sequence, the design inherent resonant frequency of each air chamber unit is determined. The design inherent resonant frequency of each air chamber unit, the cross-sectional area of ​​the air chamber cavity and the additional mass correction coefficient are substituted into the resonance condition relationship of the oscillating water column. The equivalent volume parameters of the water column are solved inversely. Based on the equivalent volume parameters of the water column, the water draft sequence of the front wall of each air chamber unit is obtained. Substitute the water depth sequence of the front wall of each air chamber unit into the resonance condition relationship of the oscillating water column, perform forward calculation on the natural resonance frequency of each air chamber unit, and compare and verify the forward calculation result with the designed natural resonance frequency of each air chamber unit to obtain the natural resonance frequency sequence of each air chamber unit. The inherent resonant frequency sequence of each air chamber unit is compared one by one with the frequency boundary sequence of the target frequency band. The draft sequence of the front wall of the air chamber unit that exceeds the target frequency band boundary is iteratively corrected to obtain the inherent resonant frequency sequence of each air chamber unit that is completely covered and matched with the target frequency band.

3. The panpipe-shaped multi-oscillating water column broadband wave energy capture method according to claim 1, characterized in that, Step S2 includes: Based on the inherent resonant frequency sequence of each air chamber unit, the sampling frequency of the air pressure sensor in the gas phase space at the top of each air chamber unit is set, and the air pressure sensor in the gas phase space at the top of each air chamber unit is synchronously triggered and sampled based on the same hardware clock reference. The air pressure time series of each air chamber unit is synchronously acquired to obtain the air pressure time series of each air chamber unit. The instantaneous air pressure value in the air pressure time series of each air chamber unit is synchronously paired with the output value of the liquid level sensor at the free liquid surface of the water column in the corresponding air chamber unit, and the oscillation amplitude time series of the water column of each air chamber unit is extracted to obtain the oscillation amplitude time series of the water column of each air chamber unit. The time series of water column oscillation amplitude of each air chamber unit is time-differenced, that is, the difference of water column oscillation amplitude between two adjacent sampling times is divided by the sampling time interval. The time series of water column oscillation velocity of each air chamber unit is calculated, and the time series of water column oscillation velocity of each air chamber unit is multiplied by the cross-sectional area of ​​the air chamber cavity of each air chamber unit at each time step to obtain the instantaneous gas volume flow rate sequence of each air chamber unit. The instantaneous gas volumetric flow rate sequence of each air chamber unit is multiplied by the gas pressure time sequence of each air chamber unit at each sampling time to obtain the instantaneous aerodynamic power of each air chamber unit. The instantaneous aerodynamic power is the product of the gas pressure in the air chamber and the instantaneous gas volumetric flow rate at the corresponding sampling time. The instantaneous aerodynamic power of each air chamber unit is summed at all sampling points within the acquisition period and then divided by the number of sampling points within the acquisition period to obtain the primary aerodynamic power sequence of each air chamber unit. The summation and division by the number of sampling points is the equivalent realization of the time integral averaging of instantaneous aerodynamic power under discrete sampling conditions.

4. The panpipe-shaped multi-oscillating water column broadband wave energy capture method according to claim 1, characterized in that, Step S3 includes: The pressure time series of adjacent air chamber units in each air chamber unit are subtracted at each sampling time, that is, the pressure value of the previous air chamber unit is subtracted from the pressure value of the next air chamber unit along the wave propagation direction. The transient pressure difference time series between each adjacent air chamber unit is calculated to obtain the transient pressure difference time series between each adjacent air chamber unit. The difference between the maximum and minimum values ​​of the transient pressure difference time series between each adjacent air chamber unit is extracted within a sliding time window as the peak-to-peak value. The peak-to-peak value is then divided by two. The pressure difference amplitude between each adjacent air chamber unit is statistically analyzed to obtain the pressure difference amplitude sequence. The transient pressure difference time series between each adjacent air chamber unit is input into the Fast Fourier Transform for spectral analysis. The square of the amplitude of each frequency component output by the Fast Fourier Transform is divided by the data length to obtain the power spectral density corresponding to each frequency component. The power spectral density reflects the energy proportion of each frequency component in the transient pressure difference time series. The power spectral density sequence between each adjacent air chamber unit is obtained by arranging them in frequency order. Based on the power spectral density sequence between each adjacent air chamber unit, the peak frequency of each power spectral density sequence is extracted and compared with the theoretical beat frequency obtained by subtracting adjacent frequencies from the inherent resonant frequency sequence of each air chamber unit. The theoretical beat frequency corresponding to the adjacent air chamber unit whose absolute value of the difference between the measured beat frequency and the theoretical beat frequency exceeds the threshold is marked and corrected to obtain the beat frequency sequence between adjacent air chamber units.

5. The panpipe-shaped multi-oscillating water column broadband wave energy capture method according to claim 1, characterized in that, Step S4, which involves installing a pneumatic piston in the gas phase region of the partition wall between adjacent gas chamber units, includes: The pressure difference amplitude sequence and the beat frequency sequence are input into the pneumatic piston cross-sectional area design process. Based on the spatial size constraints of the gas phase region of the partition wall of each adjacent air chamber unit, the cross-sectional area of ​​the pneumatic piston between each adjacent air chamber unit is designed to obtain the cross-sectional area sequence of the pneumatic piston between each adjacent air chamber unit. Based on the cross-sectional area sequence of the pneumatic piston between each adjacent air chamber unit, the initial inflation volume and initial inflation pressure of the elastic airbags at both ends of the pneumatic piston are set, and the stiffness of the elastic airbag air spring between each adjacent air chamber unit is calculated to obtain the stiffness sequence of the elastic airbag air spring between each adjacent air chamber unit. Substitute the stiffness sequence of the elastic air spring between each adjacent air chamber unit into the natural frequency calculation formula of the piston air spring system, set the natural frequency of the piston air spring system to be equal to the corresponding beat frequency value in the beat frequency sequence, and back-calculate the mass of the pneumatic piston between each adjacent air chamber unit to obtain the mass sequence of the pneumatic piston between each adjacent air chamber unit. Based on the mass sequence of the pneumatic pistons between adjacent air chamber units and the stiffness sequence of the elastic air springs between adjacent air chamber units, the natural frequency of the piston-air spring system between adjacent air chamber units is verified by forward calculation. The verification results are compared with the beat frequency sequence one by one. The inflation volume and initial inflation pressure of the elastic air springs corresponding to adjacent air chamber units with deviations exceeding the threshold are iteratively adjusted to obtain the parameter sequence of the piston-air spring system between adjacent air chamber units that perfectly matches the beat frequency sequence.

6. The panpipe-shaped multi-oscillating water column broadband wave energy capture method according to claim 5, characterized in that, Step S4 involves adjusting the natural frequency of the piston-gas spring system composed of the pneumatic piston and the elastic airbag according to the beat frequency sequence and the air pressure difference amplitude sequence, including: Substitute the parameter sequence of the piston-gas spring system between each adjacent air chamber unit and the gas pressure difference amplitude sequence into the optimal matching condition of linear damping, calculate the optimal damping coefficient of the linear electromagnetic power output device between each adjacent air chamber unit, and obtain the optimal damping coefficient sequence between each adjacent air chamber unit. Based on the optimal damping coefficient sequence between each adjacent air chamber unit, the steady-state displacement amplitude and steady-state velocity amplitude of the pneumatic piston between each adjacent air chamber unit under transient air pressure difference drive are calculated to obtain the steady-state motion parameter sequence of the pneumatic piston between each adjacent air chamber unit. Based on the steady-state velocity amplitude in the steady-state motion parameter sequence of the pneumatic piston between each adjacent air chamber unit, half of the product of the optimal damping coefficient between each adjacent air chamber unit and the square of the corresponding steady-state velocity amplitude is taken as the average secondary energy harvesting power of the linear electromagnetic power output device between each adjacent air chamber unit in one beat frequency cycle, thus obtaining the secondary energy harvesting power sequence between each adjacent air chamber unit.

7. The panpipe-shaped multi-oscillating water column broadband wave energy capture method according to claim 6, characterized in that, In step S4, the linear electromagnetic power output device converts the reciprocating motion into a secondary energy capture power sequence between adjacent air chamber units, which is then superimposed with the primary aerodynamic power sequence of each air chamber unit to obtain the total energy capture power of the system, including: The secondary energy capture power sequences between each adjacent air chamber unit are accumulated one by one according to the index order of the adjacent air chamber unit pairs. The sum of the secondary energy capture power sequences between each adjacent air chamber unit is calculated to obtain the total secondary energy capture power of the system. The aerodynamic power sequence of each air chamber unit is accumulated unit by unit according to the air chamber unit index order, and the sum of the aerodynamic power sequence of each air chamber unit is calculated to obtain the total energy capture power of the system in one step. The total energy capture power of the system is obtained by superimposing the total secondary energy capture power of the system and the total primary energy capture power of the system. The ratio of the total energy capture power of the system to the incident wave energy power of the target sea area is calculated, the energy capture width ratio of the system across the entire frequency band is evaluated, the energy capture width ratio of the system across the entire frequency band is compared with a preset threshold, and the draft sequence of the front wall corresponding to the air cell unit that is lower than the preset threshold is iteratively corrected to obtain the total energy capture power of the system.

8. A panpipe-shaped multi-oscillating water column broadband wave energy capture system, characterized in that, For implementing the panpipe-shaped multi-oscillating water column broadband wave energy capture method as described in any one of claims 1-7, the panpipe-shaped multi-oscillating water column broadband wave energy capture system comprises: The quantization module is used to quantify the draft sequence of the front wall of each air chamber unit arranged in a stepped manner along the wave propagation direction based on the wave spectrum data of the target sea area, so as to obtain the inherent resonant frequency sequence of each air chamber unit. The acquisition module is used to acquire the air pressure time series and water column oscillation amplitude time series of each air chamber unit based on the inherent resonant frequency sequence of each air chamber unit, so as to obtain the primary aerodynamic power sequence of each air chamber unit. The analysis module is used to calculate the pressure difference between adjacent air chamber units in the air pressure time series of each air chamber unit and perform spectrum analysis to obtain the beat frequency sequence and air pressure difference amplitude sequence between adjacent air chamber units. The superposition module is used to set up a pneumatic piston in the gas phase region of the partition wall between adjacent air chamber units. Based on the beat frequency sequence and the air pressure difference amplitude sequence, and using the inflation volume and initial inflation pressure of the elastic air bladders at both ends of the piston as adjustment parameters, the natural frequency of the piston air spring system composed of the pneumatic piston and the elastic air bladder is resonantly matched and adjusted. This causes the pneumatic piston to generate reciprocating motion under the transient air pressure difference driven by the air pressure difference amplitude sequence. The reciprocating motion is converted into a secondary energy capture power sequence between each adjacent air chamber unit by a linear electromagnetic power output device. This sequence is then superimposed with the primary pneumatic power sequence of each air chamber unit to obtain the total energy capture power of the system.

9. A panpipe-shaped multi-oscillating water column broadband wave energy capture device, characterized in that, The method includes a memory and a processor, wherein the memory stores a computer program that can run on the processor, and the processor executes the computer program to implement the panpipe-shaped multi-oscillating water column broadband wave energy capture method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is run by the processor, it causes the processor to execute the panpipe-shaped multi-oscillating water column broadband wave energy capture method as described in any one of claims 1 to 7.

Images