Wave energy conversion device and evaluation method therefor

Abstract

A wave energy conversion device, comprising a fluid flow channel which is configured to convert wave energy transmitted to the fluid flow channel into pneumatic energy; an energy conversion system which is connected to the fluid flow channel, is configured to convert the pneumatic energy converted by the fluid flow channel into electric energy, and comprises an air turbine, wherein the air turbine comprises a flow channel wall, two groups of flow guide blades and a group of rotor blades; and a pressure relief system which is connected to the fluid flow channel, is configured to control the pressure of an air chamber in the fluid flow channel, and comprises a valve disk, a valve seat, an elastic unit, a control rod and a connection tube, the control rod being fixedly connected to the valve seat, the control rod being movably connected to the valve disk and the control assembly, and the control assembly being deployed on a surface of the connection tube and configured to dynamically adjust, on the basis of sea conditions of the wave energy conversion device, an initial length of the elastic unit by means of the control rod so as to control opening threshold values corresponding to the valve disk.

Description

Wave energy conversion device and evaluation method thereof

[0001] Related applications

[0002] The present application claims priority to the Chinese patent application No. 202410475117.9, filed on April 19, 2024, and entitled "Wave energy conversion device and evaluation method", the contents of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of ocean wave energy utilization, in particular to a wave energy conversion device and an evaluation method thereof. BACKGROUND

[0004] With the development of science and technology, the demand for energy is increasing. In this case, the development and utilization of new energy, such as solar energy, tidal energy, geothermal energy, wave energy, etc., are attracting much attention.

[0005] Taking wave energy as an example, wave energy has the characteristics of high energy density, wide distribution, and renewable energy. In related technologies, wave energy is converted by a wave energy conversion device to generate electric energy through a series of energy conversion, so as to realize the conversion of wave energy. However, once the wave of the environment where the wave energy conversion device is located is too large, it may threaten the safety of the wave energy conversion device. SUMMARY

[0006] Therefore, it is necessary to provide a wave energy conversion device and an evaluation method thereof to improve the safety of the wave energy conversion device in view of the above technical problems.

[0007] In a first aspect, the application provides a wave energy conversion device, comprising a fluid flow channel, an energy conversion system and a pressure relief system. The fluid flow channel is configured to convert wave energy transferred to the fluid flow channel into pneumatic energy. The energy conversion system is connected to the fluid flow channel and configured to convert the pneumatic energy converted by the fluid flow channel into electrical energy. The energy conversion system comprises an air turbine, which comprises a flow channel wall, two groups of guide vanes and a group of rotor vanes. The profile line of the cross section of each guide vane comprises an elliptical arc segment and a straight line segment, and the straight line segment is arranged along the tangent direction of the circle around the rotation axis at the end point of the straight line segment. The profile line of the cross section in the axial direction of each rotor vane comprises an elliptical arc segment on the suction side and a circular arc segment on the pressure side. The number of each group of guide vanes is 14-24. The pressure relief system is connected to the fluid flow channel and configured to control the pressure of the air chamber in the fluid flow channel. The pressure relief system comprises a valve flap, a valve seat, an elastic unit, a control rod and a connecting pipe. The valve flap is connected to the valve seat through the elastic unit. The valve flap is also connected to the air chamber through the connecting pipe. The control rod is fixedly connected to the valve seat, and the control rod is movably connected to the valve flap and a control assembly, respectively. The control rod is a telescopic rod. The valve flap has multiple corresponding opening thresholds. The control assembly is arranged on the surface of the connecting pipe and configured to dynamically adjust the initial length of the elastic unit through the control rod to control the corresponding opening threshold of the valve flap according to the sea conditions of the wave energy conversion device. The control assembly has multiple adjustment lengths of the initial length of the elastic unit.

[0008] In one of the embodiments, the valve flap is in an open state when the pressure of the air chamber exceeds the opening threshold. The valve flap is in a closed state when the pressure of the air chamber does not exceed the opening threshold.

[0009] In one of the embodiments, the energy conversion system comprises an air turbine and a power generation assembly, and the air turbine is connected to the power generation assembly. The air turbine is configured to convert the pneumatic energy converted by the fluid flow channel into mechanical energy. The power generation assembly is configured to convert the mechanical energy converted by the air turbine into electrical energy.

[0010] In one of the embodiments, the rotation speed of the rotor of the air turbine is the same as the rotation speed of the rotor of the generator.

[0011] In one of the embodiments, the air turbine further comprises a rotation axis and a rotor part. One group of guide vanes is uniformly distributed at the flow channel inlet of the flow channel wall, and the other group of guide vanes is uniformly distributed at the flow channel outlet of the flow channel wall. The one group of rotor vanes is uniformly distributed on the rotor part in the central region of the flow channel of the air turbine along the circumferential direction around the rotation axis.

[0012] In one of the embodiments, the profile of the cross section of the axial direction of the flow passage wall between the rotor blade and the guide blade comprises a 90° circular arc segment and straight line segments on both sides of the circular arc segment.

[0013] In one of the embodiments, the device further comprises one or more mooring systems, and the one or more mooring systems are connected to the wave-incident side of the wave energy conversion device.

[0014] In one of the embodiments, each mooring system comprises a floating ball connected to the wave-incident side of the wave energy conversion device through at least one elastic component.

[0015] In one of the embodiments, the fluid flow passage comprises a horizontal flow passage and a vertical flow passage in communication with each other, the vertical flow passage is arranged close to the wave-incident side of the wave energy conversion device, the mouth of the horizontal flow passage is arranged close to the wave-back side of the wave energy conversion device, the cross-sectional area of the horizontal flow passage is equal to that of the vertical flow passage, and a streamlined flow passage is arranged between the horizontal flow passage and the vertical flow passage.

[0016] In one of the embodiments, the fluid flow passage further comprises a plurality of partitions, and each partition is fixed vertically to the flow passage wall of the horizontal flow passage and the vertical flow passage.

[0017] In the second aspect, the application further provides a wave energy conversion device evaluation method, which comprises the following steps.

[0018] The mathematical model of the wave energy conversion device according to any one of the first aspect is constructed, and the mathematical model is a simulation equation for simulating the motion characteristics of the wave energy conversion device.

[0019] The mathematical model is solved to obtain the evaluation index value of the wave energy conversion device.

[0020] In one of the embodiments, the mathematical model is solved to obtain the evaluation index value of the wave energy conversion device, which comprises the following steps.

[0021] The mathematical model is discretized to obtain a numerical model. The discretization includes spatial discretization and temporal discretization.

[0022] Based on the numerical model, the time history curve of the wave energy conversion device is solved. The time history curve includes the corresponding relationship between the motion response and dynamic characteristics of the wave energy conversion device and time.

[0023] According to the time history curve, the evaluation index value of the wave energy conversion device is obtained.

[0024] In one of the embodiments, based on the numerical model, the time history curve of the wave energy conversion device is solved, which comprises the following steps.

[0025] The simulation time period is divided according to preset time steps, and a plurality of time points are determined.

[0026] The motion response value corresponding to each time point is obtained by using the numerical model.

[0027] A time course curve is constructed according to each time point and the motion response value corresponding to each time point.

[0028] In one embodiment, the motion response value corresponding to each time point is obtained by using the numerical model, including: for each time point, the numerical model is iteratively solved according to a preset iteration strategy until the numerical model satisfies a preset convergence condition, and the motion response value of each time point is obtained.

[0029] In one embodiment, the evaluation index value includes a power generation capability index value and a reliability index value of the wave energy conversion device.

[0030] In a third aspect, the present application further provides an evaluation device, which comprises a construction module and an operation module.

[0031] The construction module is configured to construct a mathematical model for the wave energy conversion device according to any one of the first aspect, and the mathematical model is a simulation equation for simulating the motion characteristics of the wave energy conversion device.

[0032] The operation module is configured to perform solution operation on the mathematical model to obtain the evaluation index value of the wave energy conversion device.

[0033] In a fourth aspect, the present application further provides a computer device, which comprises a memory and a processor, the memory stores a computer program, and the processor implements the steps of the wave energy conversion device evaluation method in any one of the embodiments of the second aspect when executing the computer program.

[0034] In a fifth aspect, the present application further provides a non-volatile computer readable storage medium, which stores a computer program, and the computer program implements the steps of the wave energy conversion device evaluation method in any one of the embodiments of the second aspect when executed by a processor.

[0035] In a sixth aspect, the present application further provides a computer program product, which comprises computer executable instructions, and the computer executable instructions implement the steps of the wave energy conversion device evaluation method in any one of the embodiments of the second aspect when executed by a processor.

[0036] The wave energy conversion device and the evaluation method thereof. The wave energy conversion device comprises a fluid flow channel, an energy conversion system, a pressure relief system and a control assembly. The fluid flow channel is used to convert wave energy transferred to the fluid flow channel into pneumatic energy. The energy conversion system is connected with the fluid flow channel and is used to convert the pneumatic energy converted by the fluid flow channel into electric energy. The energy conversion system comprises a flow channel wall, two groups of guide vanes and a group of rotor vanes. The profile line of the cross section of each guide vane comprises an elliptical arc segment and a straight line segment. The straight line segment is arranged along the tangent direction of the circle around the rotation main shaft at the end point of the straight line segment. The profile line of the cross section in the axial direction of each rotor vane comprises an elliptical arc segment on the suction side and a circular arc segment on the pressure side. The number of each group of guide vanes is 14-24. The pressure relief system is connected with the fluid flow channel and is used to control the pressure of the air chamber in the fluid flow channel. The pressure relief system comprises a valve clack, a valve seat, an elastic unit, a control rod and a connecting pipe. The valve clack is connected with the valve seat through the elastic unit. The valve clack is connected with the air chamber through the connecting pipe. The control rod is fixedly connected with the valve seat and is movably connected with the valve clack and the control assembly. The control rod is a telescopic rod. The valve clack has a plurality of corresponding opening thresholds. The control assembly is arranged on the surface of the connecting pipe and is used to dynamically adjust the initial length of the elastic unit through the control rod according to the sea conditions of the wave energy conversion device, so as to control the corresponding opening threshold of the valve clack. The control assembly has a plurality of adjustment lengths of the initial length of the elastic unit. In the device, the fluid flow channel converts wave energy into pneumatic energy, the energy conversion system converts the pneumatic energy converted by the fluid flow channel into electric energy, that is, wave energy is converted into electric energy through the fluid flow channel and the energy conversion system. In the process of converting wave energy into electric energy, the pressure relief system controls the pressure of the air chamber in the fluid flow channel, which is equivalent to considering the factor that the excessive wave affects the stability of the wave energy conversion device. The pressure of the air chamber in the fluid flow channel is adjusted in the normal pressure range through the pressure relief system, so as to ensure the safety of the wave energy conversion device. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments or the related art, the following will briefly introduce the drawings needed to be used in the embodiments or the related art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0038] Fig. 1 is a structural schematic diagram of a wave energy conversion device in an embodiment of the present application;

[0039] Fig. 2 is a structural schematic diagram of a pressure relief system in an embodiment of the present application;

[0040] Figure 3 is a schematic diagram of a pressure relief system according to another embodiment of the present application;

[0041] Figure 4 is a front view of an air turbine according to an embodiment of the present application;

[0042] Figure 5 is a top view of an air turbine according to an embodiment of the present application;

[0043] Figure 6 is a schematic diagram of a wave energy conversion device according to another embodiment of the present application;

[0044] Figure 7 is a schematic diagram of a mooring system according to an embodiment of the present application;

[0045] Figure 8 is a schematic diagram of a wave energy conversion device according to yet another embodiment of the present application;

[0046] Figure 9 is a flowchart of an evaluation method according to an embodiment of the present application;

[0047] Figure 10 is a flowchart of an index obtaining step according to an embodiment of the present application;

[0048] Figure 11 is a flowchart of a curve constructing step according to an embodiment of the present application;

[0049] Figure 12 is a flowchart of an evaluation method according to another embodiment of the present application;

[0050] Figure 13 is a flowchart of an evaluation method according to yet another embodiment of the present application;

[0051] Figure 14 is a comparison diagram of turbine steady efficiency curves according to an embodiment of the present application;

[0052] Figure 15 is a schematic diagram of device performance parameter curves according to an embodiment of the present application;

[0053] Figure 16 is a block diagram of an evaluation device according to an embodiment of the present application;

[0054] Figure 17 is a diagram of the internal structure of a computer device according to an embodiment of the present application.

[0055] Explanation of reference numerals: 10 wave energy conversion device; 11 fluid flow channel; 12 energy conversion system; 121 air turbine; 1211 guide vane; 1212 rotor blade; 13 pressure relief system; 1311 valve flap; 1312 elastic unit; 1313 valve seat; 1314 control rod; 1315 connecting pipe; 14 mooring system; 141 anchor; 142 chain section; 143 buoy; 144 elastic assembly; 15 main buoyancy tank; 16 auxiliary buoyancy tank. DETAILED DESCRIPTION

[0056] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should fall within the scope of protection of the present application.

[0057] The terms used herein are only used to describe specific embodiments of the present application and are not intended to limit the present application. The terms "comprise", "include" and the like used herein indicate the presence of the stated features, steps, components and / or operations, but do not exclude the presence or addition of one or more other features, steps, components or operations.

[0058] In the present application, unless otherwise explicitly specified and limited, the terms "mount", "fix" and the like should be understood in a broad sense. For those of ordinary skill in the art, the specific meaning of the above terms in the present application should be understood according to the specific circumstances.

[0059] All terms used herein, including technical and scientific terms, have the meanings commonly understood by one of ordinary skill in the art unless otherwise defined. It should be further understood that terms used herein have the same meanings as commonly understood by one of ordinary skill in the art unless otherwise defined, and should not be interpreted in an overly idealized or overly formal sense.

[0060] Wave energy is the highest grade and most widely distributed renewable energy in the ocean that has not yet been commercially developed by mankind. It is considered to be the hope of future energy for mankind. How to realize efficient and reliable wave energy conversion is a major scientific problem in the field of global renewable energy. Compared with other types of wave energy conversion devices, the aerodynamic wave energy conversion device has relatively higher efficiency and reliability. However, there are still deficiencies and challenges in improving efficiency, reliability, design optimization theory and other aspects of the aerodynamic wave energy conversion device, which has slowed down its industrial development. These deficiencies and challenges mainly include:

[0061] (1) High reliability is the first index element of the aerodynamic wave energy conversion device. Under high sea conditions, on the one hand, the whole device moves and the water in the air chamber oscillates violently, the pressure on the wall of the flow channel is too large, and the pressure in the air chamber of the device is too large, the aerodynamic energy input to the impact air turbine is excessive, which seriously affects the reliability of the flow channel, turbine rotor, generator and the whole device, so a corresponding pressure relief and load reduction system must be used to protect the safety of the device; on the other hand, the violent and large movement of the device causes the stress on the mooring system to be too large, which seriously affects the reliability and survivability of the mooring system and the whole device.

[0062] (2) The energy conversion efficiency of the aerodynamic wave energy conversion device is still low, and the wave frequency range that meets the high-efficiency energy capture is still narrow. The energy conversion process of the aerodynamic wave energy conversion device includes the following three stages in turn: the hull part converts wave energy into aerodynamic energy, the air turbine converts aerodynamic energy into rotational kinetic energy of the turbine rotor, and the generator converts the rotational kinetic energy into electrical energy. The improvement of the energy conversion efficiency of any stage will affect the overall energy conversion efficiency of the aerodynamic wave energy conversion device to varying degrees. In addition, through a large number of research and experiments, it is found that the introduction of some resonance mechanism may also broaden the frequency range of efficient energy capture of the wave energy conversion device.

[0063] Therefore, it is necessary to provide an air turbine with high reliability, high efficiency, compact axial and radial size, and the like. Meanwhile, the mooring system also affects the overall performance of the device, and on this basis, it is necessary to provide an efficiency-increasing wide-frequency mooring system suitable for the pneumatic wave energy conversion device to ensure the reliability of the mooring system.

[0064] (3) There may be a contradictory relationship between the high reliability and high efficiency of the pneumatic wave energy conversion device. If the threshold of the pressure relief and load reduction system is large, the power generation of the device is improved, but the generator of the device is in a high-power generation state for a long time under severe sea conditions and may exceed the rated power for a long time, affecting the reliability of the generator. If the threshold of the pressure relief and load reduction system is small, the safety of the turbine and generator is better protected, but the power generation of the device is affected, and the frequent opening / closing of the pressure relief and load reduction system also affects the reliability of the pressure relief and load reduction system and the overall device.

[0065] Under actual marine environment, the temporal and spatial distribution of waves, currents and wind conditions is irregular, and occasional large waves cause excessive pressure in the air chamber, but since the time is short, it will not affect the reliability of the generator (i.e., the generator is allowed to operate for a short time beyond the rated power), at this time, the pressure relief and load reduction system can not need to play a role, which not only helps to improve the power generation, but also improves the reliability of the pressure relief and load reduction system.

[0066] (4) The design optimization theory of the pneumatic wave energy conversion device is lacking. The sea trial test time cost and manpower and material resources cost of the pneumatic wave energy conversion device are quite huge. Under this circumstance, the numerical simulation result method is the most important means to study the performance and optimization of the pneumatic wave energy conversion device. However, due to the extreme complexity of the simulation of the pneumatic wave energy conversion device, it is necessary to consider the high-difficulty problems of multiple moving bodies, multiple physical fields, multiphase flow, strong nonlinearity, and the interaction between energy conversion stages. So far, although many experts and scholars have realized the importance of the coupling simulation of the pneumatic wave energy conversion device from the wave to the whole system, a corresponding theoretical model has not yet been established, and the design optimization theory of the pneumatic wave energy conversion device is lacking.

[0067] The numerical simulation of existing pneumatic wave energy converters only focuses on a certain stage of energy conversion, or uses a simplified model to describe the interaction between stages of energy conversion. The prediction model for the overall performance of the pneumatic wave energy converter basically uses the linear superposition method (see “An integrated numerical model for the chamber-turbine system of an oscillating water column wave energy converter (Liu et. Al, 2021)”). At the resonance point and its vicinity of the device, the simulation error of the device response amplitude is as high as 100%, and the simulation error of the energy conversion efficiency is as high as 30%. Therefore, the existing simulation method cannot accurately predict the energy conversion efficiency of each stage of the pneumatic wave energy converter and the overall performance of the device, and it is also difficult to provide a reliable analysis tool for optimizing the performance of the device.

[0068] In summary, the pneumatic wave energy converter in the related art has the problems of low reliability and low energy conversion efficiency, and lacks a theoretical optimization method for the wave energy converter. Based on this, the present application provides a threshold-adjustable automatic pressure relief load reduction system to protect the reliability of the wave energy converter in real time; a mooring system for the wave energy converter is constructed based on a high-strength elastic component to reduce the maximum stress of the mooring system and further improve the safety performance of the wave energy converter; and a radial inflow impulse air turbine is proposed, which has the characteristics of high reliability, high efficiency, compactness in both axial and radial directions, and improves the conversion efficiency of the wave energy converter. In addition, the present application also provides a wave-to-electricity full-system coupling simulation method for the pneumatic wave energy converter, which fills the gap in the design optimization theory of the wave energy converter.

[0069] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0070] In an exemplary embodiment, as shown in FIG. 1, a wave energy converter 10 is provided, which includes a fluid flow passage 11, an energy conversion system 12, and a pressure relief system 13. The fluid flow passage 11 is connected to the pressure relief system 13, and the fluid flow passage 11 is connected to the energy conversion system 12.

[0071] The fluid flow passage 11 is used to convert the wave energy transferred to the fluid flow passage 11 into pneumatic energy.

[0072] An energy conversion system 12 is configured to convert the pneumatic energy generated by the fluid flow channel 11 into electric energy.

[0073] A pressure relief system 13 is configured to control the pressure of the air chamber in the fluid flow channel 11.

[0074] As shown in FIG. 1, the wave energy conversion device 10 includes a fluid flow channel 11, an energy conversion system 12, and a pressure relief system 13. As shown in FIG. 1, the fluid flow channel 11 is connected to the energy conversion system 12 and the pressure relief system 13.

[0075] The fluid flow channel 11 includes a liquid flow channel and a gas flow channel. One end of the fluid flow channel 11 (the inlet of the liquid flow channel) is connected to a water body, and is configured to convert wave energy into pneumatic energy. The other end of the fluid flow channel 11 (the outlet of the gas flow channel) is connected to the energy conversion system 12, which is configured to convert the pneumatic energy generated by the fluid flow channel 11 into electric energy, such as converting the pneumatic energy into rotational kinetic energy, and then converting the rotational kinetic energy into electric energy.

[0076] In addition, during the energy conversion process of the wave energy conversion device 10, the fluid flow channel 11 is also connected to the pressure relief system 13. The pressure relief system 13 is configured to automatically open or close the valve according to the pressure of the air chamber in the gas flow channel of the fluid flow channel 11, so as to control the communication or closure between the fluid flow channel 11 and the atmosphere, and to control the pressure of the air chamber in the fluid flow channel 11.

[0077] In actual application scenarios, if the pressure of the fluid flow channel 11 in the wave energy conversion device 10 is too high, considering that the pneumatic energy input to the energy conversion system 12 is excessive, which affects the reliability of the wave energy conversion device 10, the fluid flow channel 11 needs to be connected to the atmosphere to reduce the pressure of the air chamber in the fluid flow channel 11; if the pressure of the fluid flow channel 11 in the wave energy conversion device 10 is within a preset threshold range, which means that the pneumatic energy of the energy conversion system 12 is insufficient to affect the reliability of the wave energy conversion device 10, at this time, the fluid flow channel 11 can be disconnected from the atmosphere, and no longer play a role in reducing the pressure of the air chamber in the fluid flow channel 11.

[0078] It should be noted that the wave energy conversion device 10 also has a mooring function. Based on this, please continue to refer to FIG. 1, the wave energy conversion device 10 in the embodiment of the present application also includes a mooring system 14, which is configured to fix the wave energy conversion device 10.

[0079] The mooring system 14 in the embodiment of the present application can be arranged on the wave-approaching side of the wave energy conversion device 10, or on the wave-avoiding side of the wave energy conversion device 10. The present application takes the mooring system 14 arranged on the wave-approaching side of the wave energy conversion device 10 in FIG. 1 as an example for description.

[0080] In the embodiment of the present application, the wave energy conversion device 10 comprises a fluid flow channel 11, an energy conversion system 12, and a pressure relief system 13. The fluid flow channel 11 is connected with the pressure relief system 13, and the fluid flow channel 11 is connected with the energy conversion system 12. The fluid flow channel 11 is used to convert the wave energy transferred to the fluid flow channel 11 into pneumatic energy. The energy conversion system 12 is used to convert the pneumatic energy obtained by the fluid flow channel 11 into electric energy. The pressure relief system 13 is used to control the air chamber pressure in the fluid flow channel 11. In the device, the fluid flow channel 11 converts the wave energy into pneumatic energy, and the energy conversion system 12 converts the pneumatic energy obtained by the fluid flow channel 11 into electric energy, that is, the wave energy is converted into electric energy through the fluid flow channel 11 and the energy conversion system 12. Moreover, in the process of converting the wave energy into electric energy, the pressure relief system 13 controls the air chamber pressure in the fluid flow channel 11, that is, considering the factor that the excessive wave influences the stability of the wave energy conversion device 10, the air chamber pressure in the fluid flow channel 11 is adjusted within the normal pressure range through the pressure relief system 13, thereby ensuring the safety of the wave energy conversion device 10.

[0081] Next, the structure and function of the fluid flow channel 11, the energy conversion system 12, the pressure relief system 13, and the mooring system 14 in the wave energy conversion device 10 will be described respectively.

[0082] In an exemplary embodiment, the fluid flow channel 11 comprises a horizontal flow channel and a vertical flow channel which are in communication with each other. The vertical flow channel is arranged close to the wave-approaching side of the wave energy conversion device 10, and the horizontal flow channel is arranged close to the wave-avoiding side of the wave energy conversion device 10. The cross-sectional area of the horizontal flow channel is equal to that of the vertical flow channel, and the horizontal flow channel and the vertical flow channel are connected by a streamlined flow channel.

[0083] Please continue to refer to FIG. 1. The fluid flow channel 11 can be an L-shaped flow channel, which specifically comprises a horizontal section and a vertical section which are in communication with each other. The end of the horizontal section away from the vertical section is the entrance of the fluid flow channel 11, and the entrance of the fluid flow channel 11 is completely immersed in the water body, and the entrance of the fluid flow channel 11 is located on the wave-avoiding side. The upper half of the vertical section is an air chamber.

[0084] In the embodiment of the present application, the cross-sectional area of the horizontal section of the fluid flow channel 11 is equal to that of the vertical section. In this case, the shape of the cross section of the horizontal section and the shape of the cross section of the vertical section of the fluid flow channel 11 are not limited, for example, the cross section of the horizontal section can be rectangular, pentagonal, or other streamlined shapes, and the cross section of the vertical section of the fluid flow channel 11 can be rectangular.

[0085] Please continue to refer to FIG. 1. In order to improve the flow field in the fluid flow channel 11, the upper and lower corners (i.e., the intersection of the horizontal flow channel and the vertical flow channel) inside the fluid flow channel 11 can be chamfered or rounded.

[0086] In an exemplary embodiment, the fluid channel 11 further comprises a plurality of partitions. Each partition is fixed vertically on the walls of the horizontal and vertical channels.

[0087] Inside the fluid channel 11, a plurality of vertical partitions are arranged at predetermined intervals, each of which is fixedly connected to the inner and outer walls of the channel, such as by welding. In an embodiment, the number of vertical partitions is 1-3.

[0088] Further, one end of the partition extends to the opening of the horizontal section of the fluid channel 11, and the other end extends to the free water surface position of the vertical section of the fluid channel 11.

[0089] In the embodiment of the present application, the vertical partition helps to guide the smooth flow of water in the vertical direction in the fluid channel 11, improving the energy capture efficiency of the wave energy conversion device 10; at the same time, the vertical partition strengthens the structural strength of the fluid channel of the device, and can also improve the safety of the wave energy conversion device 10 in complex sea conditions to some extent.

[0090] Next, the structure and function of the pressure relief system 13 in the wave energy conversion device 10 will be described.

[0091] In an exemplary embodiment, referring to FIG. 2, the pressure relief system 13 comprises a valve disc 1311, a valve seat 1313, an elastic unit 1312, a control rod 1314, and a connecting pipe 1315, the valve disc 1311 is connected to the valve seat 1313 through the elastic unit 1312, and the valve disc 1311 is also connected to the air chamber through the connecting pipe 1315; the control rod 1314 is fixedly connected to the valve seat 1313, and the control rod 1314 is movably connected to the valve disc 1311 and a control assembly;

[0092] The control assembly is used to dynamically adjust the initial length of the elastic unit 1312 through the control rod 1314 to control the corresponding opening threshold of the valve disc 1311.

[0093] Wherein, the control rod 1314 can be a telescopic rod, the elastic unit 1312 can be a spring or other elastic system, and the initial state of the elastic unit 1312 is a compressed state, and the initial length is the compression length of the elastic unit 1312 in the compressed state.

[0094] Please continue to refer to FIG. 2, the dashed line on the inner wall of the connecting pipe 1315 in FIG. 2 represents a flat surface with a gap, and the control assembly can be installed on the flat surface. In this way, the control assembly deployed on the surface of the connecting pipe 1315 can be connected to the control rod 1314 to flexibly adjust the upward / downward movement of the control rod 1314, thereby controlling the initial length of the elastic unit 1312 to be shorter / longer, and further controlling the corresponding opening threshold of the valve disc 1311 to be increased / decreased.

[0095] In actual scenarios, the control component can control the control rod 1314 in the pressure relief system 13 to move downward when it is monitored that the wave energy conversion device 10 is in or is about to be in a severe sea state, so that the initial length of the elastic unit 1312 is lengthened to reduce the opening threshold of the valve disc 1311.

[0096] Further, the control component can control the control rod 1314 in the pressure relief system 13 to move upward when it is monitored that the wave energy conversion device 10 is converted from the severe sea state to the normal sea state, so that the initial length of the elastic unit 1312 is shortened or returns to the initial compressed length to increase the opening threshold of the valve disc 1311.

[0097] It should be noted that the control component can also be connected with the elastic unit 1312 to directly adjust the initial length of the elastic unit 1312.

[0098] In addition, in the embodiment of the application, the control component can adjust the initial length of the elastic unit by the control rod 1314 to have multiple adjustment lengths, that is, the valve disc 1311 can have multiple opening thresholds, and the embodiment of the application does not limit this.

[0099] In an exemplary embodiment, when the pressure in the air chamber exceeds the opening threshold, the valve disc 1311 is in an open state to perform the pressure relief and load reduction action.

[0100] When the pressure in the air chamber does not exceed the opening threshold, the valve disc 1311 is in a closed state to stop performing the pressure relief and load reduction action.

[0101] Further, the pressure relief principle of the pressure relief system 13 is described. Under normal conditions, as shown in FIG. 2, the valve disc 1311 is closed under the action of the gravity of the valve disc 1311 and the elastic pressure. When the pressure in the air chamber reaches the threshold, the gas pressure acting on the valve disc 1311 is greater than the sum of the gravity and the elastic pressure of the valve disc 1311, the valve disc 1311 moves upward (toward the valve seat) and opens, as shown in FIG. 3, at this time, the air chamber is in communication with the atmosphere, which plays a role in pressure relief and load reduction and protects the components in the energy conversion system 12.

[0102] It should be noted that, in combination with FIGS. 2 and 3, when the connecting pipe 1315 is fixed at a specific position, the distance between the valve seat 1313 and the upper surface of the connecting pipe 1315 will change with the extension and contraction of the control rod 1314. For example, the control rod 1314 is shortened, the length of the elastic unit 1312 is shortened, and the distance between the valve seat 1313 and the connecting pipe 1315 is increased. Moreover, the height of the valve disc 1311 rising is the same as the distance between the valve disc 1311 and the upper surface of the connecting pipe 1315 (i.e., the gap of the gas flow movement).

[0103] The structure and function of the energy conversion system 12 in the wave energy conversion device 10 will be described below.

[0104] In an exemplary embodiment, the energy conversion system 12 comprises an air turbine 121 and a power generation assembly connected with the air turbine.

[0105] The air turbine 121 is used to convert the pneumatic energy obtained from the fluid flow channel 11 into mechanical energy.

[0106] The power generation assembly is used to convert the mechanical energy obtained from the air turbine 121 into electrical energy.

[0107] In an exemplary embodiment, the rotational speed of the rotor of the air turbine 121 is the same as that of the rotor of the power generation assembly.

[0108] The air turbine 121 can be an impulse air turbine with self-regulating characteristics. FIG. 4 is a structural schematic diagram of the air turbine 121. As shown in FIG. 4, the air turbine 121 comprises guide vanes 1211 and rotor vanes 1212. In actual application, regardless of whether the air flow direction in the flow channel of the air turbine 121 is inflow or outflow, the air acting moment on the rotor vanes 1212 of the air turbine 121 is always in the same direction, i.e., the rotor vanes 1212 of the air turbine 121 always rotate in one direction, so as to facilitate the air turbine 121 to fully convert the pneumatic energy into mechanical energy, thereby improving the overall energy conversion efficiency of the wave energy conversion device 10.

[0109] In addition, the height of the flow channel inlet of the air turbine 121 and the free water surface in the air chamber satisfy certain vertical distance requirements, i.e., under the operating conditions of the wave energy conversion device 10, the water body in the fluid flow channel 11 will not flow back into the turbine flow channel.

[0110] Optionally, the impulse air turbine is connected with the air chamber through a flow channel with a streamlined profile, or the upper edge wall of the flow channel inlet below the turbine coincides with the top edge wall of the air chamber, to realize the fixed connection between the device hull part and the impulse air turbine.

[0111] The power generation assembly can be a direct-drive generator. Through the rotating magnetic field formed by the permanent magnet, the rotor is caused to rotate, thereby generating an induced electromotive force. Through the processing of electrical equipment such as rectifiers, the mechanical energy is finally converted into electrical energy.

[0112] In the wave energy conversion device 10, the power generation assembly is coaxially connected with the turbine rotor 121 and has the same rotational speed, so as to facilitate the power generation assembly to fully utilize the mechanical energy converted by the air turbine 121, thereby improving the conversion efficiency of the mechanical energy into electrical energy.

[0113] In one exemplary embodiment, please continue to refer to Fig. 4, the air turbine 121 comprises a flow passage wall, two groups of guide vanes 1211 and rotor vanes 1212.

[0114] The two groups of guide vanes 1211 are evenly distributed at the flow passage inlet of the flow passage wall, and the other group of guide vanes is evenly distributed at the flow passage outlet of the flow passage wall.

[0115] The rotor vanes 1212 are evenly distributed in the central region of the flow passage of the air turbine 121 along the axial direction.

[0116] The air turbine 121 is an impulse air turbine, which comprises a flow passage wall, two groups of guide vanes 1211, a turbine rotor part (including a hub) and rotor vanes 1212 fixed on the rotor part (hub) and a rotating main shaft.

[0117] The flow passage of the air turbine 121 is like a region formed by rotating a letter U with a certain thickness one round, which can be divided into guide vanes 1211, a flow passage wall (a transition section) and rotor vanes 1212. Further, please refer to Fig. 5, which is a top view of the air turbine 121, from which it can be seen that the guide vanes 1211 of the air turbine 121 are evenly distributed at the flow passage inlet of the flow passage wall. It should be noted that the air turbine 121 is a symmetrical structure, that is, the top view and the bottom view of the air turbine 121 arranged vertically along the axial direction (i.e. the direction of the rotating main shaft) are the same, therefore, the other group of guide vanes 1211 of the air turbine 121 in the embodiment of the present application are evenly distributed near the flow passage outlet of the flow passage wall.

[0118] The two groups of guide vanes 1211 are fixedly connected with the flow passage wall of the air turbine 121 and are evenly and symmetrically distributed near the flow passage inlet and the flow passage outlet along the circumferential direction, and each guide vane 1211 has an equal thickness in cross section.

[0119] In one embodiment, please continue to refer to Fig. 4 or Fig. 5, the profile line of the cross section of each guide vane 1211 in the air turbine 121 is composed of an elliptical arc segment and a shorter straight line segment, and the straight line segment is arranged along the tangent direction of the circle around the rotating main shaft at the end point of the straight line segment.

[0120] The turbine rotor part is arranged in a cylindrical region at the central position of the flow passage along the axial direction, and the rotor vanes 1212 are evenly arranged on the rotor part along the circumferential direction.

[0121] In one embodiment, the profile line of the cross section of each rotor vane 1212 in the air turbine 121 along the axial direction (i.e. the direction of the rotating main shaft) is an elliptical arc segment on the suction side and a circular arc segment on the pressure side, that is, the profile line of the cross section of each rotor vane 1212 in the air turbine 121 along the axial direction presents a crescent shape.

[0122] In one embodiment, the profile of the cross section in the axial direction of the transition section between the rotor blade 1212 and the guide vane 1211 in the air turbine 121 comprises a 90° circular arc section and straight line sections on both sides of the circular arc section.

[0123] Under normal working conditions, the airflow enters the air turbine 121 from the inlet of the U-shaped flow channel in the radial direction, is guided by the guide vanes 1211 and the flow channel wall, and then flows into the rotor blade 1212 at a certain angle to drive the rotor blade 1212 in the air turbine 121 to rotate. After that, the airflow flows out of the turbine outlet through the other set of guide vanes 1211.

[0124] In one embodiment, the number of rotor blades 1212 on the turbine rotor part of the air turbine 121 is 26-34, and the hub ratio is 0.60-0.75.

[0125] In one embodiment, if the corresponding radius of the outer wall of the flow channel at the position of the rotor blade 1212 of the air turbine 121 is R, the semi-major axis of the elliptical arc of the guide vane 1211 is 0.40R-0.65R, and the semi-minor axis is 0.26R-0.34R; the length of the straight line section of the guide vane 1211 is 0.03R-0.06R; the number of guide vanes 1211 is 14-24; the radius of the inner wall of the circular arc part of the transition section is 0.45R-0.55R, and the length of the straight line part is 0.20R-0.30R.

[0126] In the embodiments of the present application, the guide vanes 1211 in the impulse air turbine 121 are fixed, and there are no moving parts except the rotor blades 1212, so the structure is simple and the reliability is high. The flow passage cross section between the rotor blade 1212 of the air turbine 121 and the downstream guide vane 1211 continuously increases, and the airflow velocity gradually decreases, so the aerodynamic loss occurring at the downstream guide vane 1211 is reduced, thereby improving the turbine efficiency and having high efficiency characteristics. At the same time, the transition section of the air turbine 121 has relatively small radial and axial dimensions. On the one hand, the overall air turbine 121 is compact in the axial and radial directions, has high cost performance, and is more conducive to the fixed connection between the air turbine 121 and the fluid flow channel 11 of the wave energy conversion device 10; on the other hand, the air turbine 121 has relatively small weight, which is conducive to improving the stability of the wave energy conversion device 10.

[0127] In the actual application scenario of the wave energy conversion device 10, especially when the wind and wave are large, the mooring capacity of the wave energy conversion device 10 is also crucial. In the embodiment of the present application, the mooring system 14 is used to fix the wave energy conversion device 10 at a specific position, such as the seabed, the shore, etc. In general, in order to maintain the balance of the wave energy conversion device 10, the mooring system 14 is arranged on the wave-approaching side of the wave energy conversion device 10, and the counterweight system is fixed on the wave-avoiding side of the wave energy conversion device 10. Of course, the mooring system 14 can also be fixed at other positions on the wave-avoiding side of the wave energy conversion device 10, and the embodiment of the present application does not limit this.

[0128] In an exemplary embodiment, the wave energy conversion device further comprises one or more mooring systems 14; each mooring system 14 is connected to the wave-approaching side of the wave energy conversion device 10.

[0129] Among them, the mooring system 14 is used to fix the wave energy conversion device 10 at a specified position.

[0130] Taking the wave energy conversion device 10 comprising three mooring systems 14 as an example, please refer to FIG. 6, which is a top view of the wave energy conversion device 10, each mooring system 14 can be fixed on the vertical section of the fluid flow channel 11 of the wave energy conversion device 10, and the fixed positions of different mooring systems 14 are different. In the embodiment of the present application, one end of the mooring system 14 is fixed on the wave energy conversion device 10, and the other end can be fixed on the seabed, which means that the wave energy conversion device 10 can be parked on the sea surface.

[0131] In the actual scenario, one or more mooring systems 14 can also be arranged on the wave-avoiding side of the wave energy conversion device 10, and the mooring system 14 here can be a separate anchor and chain, or a new type of mooring system 14 comprising an elastic component, so as to improve the reliability and survivability of the wave energy conversion device 10. Based on this, the structure and function of the mooring system 14 will be further described below.

[0132] In an exemplary embodiment, as shown in FIG. 7, which is a top view of a mooring system 14, the mooring system 14 comprises an anchor 141, a chain 142, a floating ball 143 and two elastic components 144.

[0133] Among them, the floating ball 143 of the mooring system 14 is connected to the wave-approaching side of the wave energy conversion device 10 through at least one elastic component 144.

[0134] It should be noted that FIG. 7 takes the mooring system 14 comprising two elastic components 144 as an example, which is only a schematic diagram of the mooring system 14, and in actual application, the elastic component 144 in the mooring system 14 can also be 1, 3, etc.

[0135] Optionally, the chain 142 includes catenary segments and lying segments, and the total length of the chain 142 can be 1.5-8.0 times the depth of the water.

[0136] In an actual mooring scenario, one end of the chain 142 is connected with the anchor 141 and fixed on the seabed, the other end of the chain 142 is fixed on the floating ball 143, the floating ball 143 is connected with two elastic components 144 respectively, and the other ends of the two elastic components 144 are fixed at different positions of the wave energy conversion device 10.

[0137] In terms of material, each elastic segment in the elastic component 144 can be a combined piece constructed according to the chain and spring / other elastic system, or can be a high-strength elastic rope.

[0138] In terms of quantity, the elastic component of a single set of mooring system 14 can be one, can be two arranged in a V shape, or can be more arranged in a scattered manner.

[0139] In terms of length, the horizontal length of each elastic component 144 is 2-3 times the length of the wave energy conversion device 10 (i.e., the distance from the floating ball 143 to the wave energy conversion device 10).

[0140] In the embodiment of the present application, the mooring system 14 adopts the mooring mode of the anchor 141, the chain segment 142, the floating ball 143, and the elastic component 144, which smoothes the mooring force of the mooring system 14 on the hull part of the wave energy conversion device 10, increases the surge response of the wave energy conversion device 10 under wave conditions, thereby achieving the effect of wide frequency and efficiency, and further improving the overall power generation performance of the wave energy conversion device 10. In addition, the combination of the floating ball 143 and the elastic component 144 (or the elastic energy absorbing component) reduces the maximum stress in the mooring system 14 to a certain extent, improves the reliability of the mooring system 14, and also improves the overall reliability and survivability of the wave energy conversion device 10 to a certain extent.

[0141] In an actual application scenario, in addition to the above-mentioned pressure relief system 13, fluid flow channel 11, power generation assembly, and air turbine 121, the wave energy conversion device 10 can also include a plurality of other components to further perfect the wave energy conversion device 10 and adapt to actual needs, such as sensors for monitoring device status, energy storage systems, monitoring systems, etc.

[0142] In an exemplary embodiment, the wave energy conversion device 10 can also include a buoyancy tank, an energy storage system, a power output system, a monitoring system, a counterweight, a sensor, etc.

[0143] In one embodiment, please refer to FIG. 8, which is a schematic diagram of the architecture of the wave energy conversion device 10. In FIG. 8, the buoyancy tank includes a main buoyancy tank 15 and a secondary buoyancy tank 16. Taking the L-shaped flow channel 11 as an example, the main buoyancy tank 15 can be arranged above the horizontal section of the L-shaped flow channel 11 and half-submerged in water, and the secondary buoyancy tank 16 can be arranged outside the vertical section of the L-shaped flow channel 11 and half-submerged or fully submerged in water. At this time, the mooring system 14 in the wave energy conversion device 10 can also be fixed to the secondary buoyancy tank 16.

[0144] In actual application, if the wave energy conversion device 10 includes the main buoyancy tank 15, the secondary buoyancy tank 16 can also not be arranged. In this regard, the embodiments of the present application are not limited.

[0145] The monitoring system includes information acquisition equipment (such as sensors, cameras, etc.), information transmission equipment, backend control equipment, storage equipment, and display equipment.

[0146] The energy storage system, the backend control and display equipment of the monitoring system, the counterweight, etc. are arranged inside the main buoyancy tank 15.

[0147] The sensors include but are not limited to the following sensors: (1) a liquid level sensor, which can be installed inside the air chamber and used to monitor the water level oscillation elevation in the L-shaped flow channel; (2) a vibration sensor, which can be installed on the base of the power generation assembly and used to monitor the water level vibration of the power generation assembly; (3) a temperature sensor, which can be installed on the surface of the generator and inside the main buoyancy tank 15 and used to monitor the temperature of the power generation assembly and the temperature inside the main buoyancy tank 15; (4) a flow sensor, which can be installed inside the flow channel of the air turbine 121 and used to monitor the gas volume flow; (5) a rotational speed sensor, which can be installed on the connecting shaft between the rotor of the air turbine 121 and the power generation assembly and used to monitor the rotational speed of the turbine rotor and the rotational speed of the power generation assembly; (6) a torque sensor, which can be installed on the connecting shaft between the rotor of the air turbine 121 and the power generation assembly and used to monitor the main torque provided by the turbine rotor to the power generation assembly.

[0148] In one embodiment, in order to monitor the running state of the wave energy conversion device 10 in real time, the data obtained by the above-mentioned sensors and the monitoring data obtained by the monitoring system can be uploaded to the cloud for remote viewing by the staff.

[0149] In combination with the above description of the structure of the wave energy conversion device 10, the working principle of the wave energy conversion device 10 can be summarized as follows: under the action of waves, currents, winds, etc., the wave energy conversion device 10 has six degrees of freedom motion, i.e., surge, sway, heave, roll, pitch and yaw, which causes the water body in the fluid flow channel 11 of the wave energy conversion device 10 to oscillate with the device, so that the water column in the liquid flow channel in the fluid flow channel 11 oscillates up and down, and the air pressure in the air chamber alternately changes between positive and negative; the top or side wall of the air chamber is connected with the atmosphere through the air flow channel in the fluid flow channel 11, and under the action of pressure difference, reciprocating air flow is formed in the air flow channel to drive the impact air turbine 121 installed in the air flow channel to rotate in one direction, and then drive the power generation assembly coaxially connected with the air turbine 121 to generate electricity, thereby realizing the conversion of wave energy into pneumatic energy, pneumatic energy into rotary mechanical energy, and rotary mechanical energy into electrical energy; at the same time, when the pressure in the air chamber in the fluid flow channel 11 is higher than the pressure threshold, the threshold-adjustable pressure relief system 13 installed above the air chamber is opened to play a role in pressure relief, load reduction, protection of the air turbine 121 and the power generation assembly.

[0150] It should be emphasized that the wave energy conversion device 10 in the embodiments of the present application can also be extended to a multi-air chamber pneumatic type, i.e., a plurality of the above-mentioned hull portions are connected in parallel to jointly constitute a wave energy primary energy conversion system, and the arrangement scheme of the secondary energy conversion system and the tertiary energy conversion system can adopt a multi-turbine multi-generator mode, a multi-turbine single-generator mode or a single-turbine single-generator mode.

[0151] The multi-chamber pneumatic wave energy converter 10 is greatly expanded in the width direction. A single set of device can capture wave energy in a larger range, greatly increasing the power output of a single set of device. The multi-chamber pneumatic wave energy converter 10 has N+6 degrees of freedom, where N represents the water column oscillation freedom of N chambers, and 6 represents the 6 degrees of freedom of the device itself, i.e. surge, sway, heave, roll, pitch and yaw. Since the movements of each degree of freedom generate oscillation waves in the flow channel with different frequencies, and these different frequency oscillation waves superimpose with the oscillation of the water column itself, when the wave energy is converted into pneumatic energy, the pneumatic energy exhibits a multi-peak feature in the period change curve, and the response of the device to the wave period width is widened, the efficiency of the wave energy conversion into pneumatic energy is increased, thereby producing an efficiency-increasing wide-frequency effect. The unit kilowatt cost of the multi-chamber pneumatic wave energy converter 10 is greatly reduced, which is embodied in the reduction of the transportation cost (i.e. from the shipyard to the working sea area), the mooring system cost, the power output system cost, the transparent cost and the generator cost (when using the multi-turbine single-generator mode or the single-turbine single-generator mode). Because under the condition of the same total installed capacity, compared with a single multi-chamber device, a plurality of single-chamber devices have higher transportation cost, more anchor mooring systems and power transmission cables, larger offshore construction and future operation and maintenance workload, and higher cost and operation and maintenance cost per kilowatt of installed capacity.

[0152] The above is a description of the structure of the wave energy converter. Considering the lack of reliable analysis models and theoretical basis for predicting the overall performance and optimizing the structure of the wave energy converter, the embodiments of the present application also provide a wave energy converter evaluation method, which provides a reliable analysis basis for the system design and optimization of the wave energy converter.

[0153] In an exemplary embodiment, as shown in FIG. 9, a wave energy converter evaluation method is provided, which includes the following steps S901 and S902.

[0154] S901, a mathematical model is constructed for the wave energy converter, and the mathematical model is a simulation equation for simulating the motion characteristics of the wave energy converter.

[0155] According to the functional type, the wave energy converter is divided into a hull system (fluid flow channel and buoyancy tank), an air turbine system, a power generation component system (generator), a pressure relief system and a mooring system. Then, according to the motion characteristics of each system, the control equation of each system is constructed, and finally, the above constructed equations are coupled to obtain the mathematical model of the wave energy converter.

[0156] In the embodiment of the present application, the mathematical model specifically includes the fluid motion equation, the hull motion equation, the turbine rotor motion equation, the pressure relief system control equation, the generator model control equation, the mooring system control equation, and the determination of the mathematical model boundary conditions and the mathematical model initial conditions.

[0157] Among them, the fluid motion equations are the continuity equation considering the compressibility of the fluid, the Reynolds-averaged Navier-Stokes equations, the turbulence model equations and the gas state equations; the hull motion equations, the turbine rotor motion equations and the pressure relief system control equations are Newton's second law equations.

[0158] Next, the specific construction process of the mathematical model is explained.

[0159] A Cartesian coordinate system O-x1x2x3 is defined, where the origin O coincides with the still water surface, the x1 axis is the wave propagation direction, the x2 axis is the wave crest line direction, and the x3 axis is vertically upward. Furthermore, a local coordinate system O′-x1′x2′x3′ is established at the center of mass of the pneumatic wave energy converter, moving with the device.

[0160] The fluid part includes water and gas. Its governing equations are the continuity equation and the Reynolds-averaged Navier-Stokes equations. The turbulence model equations are introduced and expressed as:

[0161] In the above formula, ρ is the fluid density; t is the time; the subscripts i, j, and k are dummy, and i = 1, j = 2, k = 3; u i The fluid along x i Speed ​​in direction; f i is the action on the fluid particles at x i The volume force in the direction; p is the relative pressure of the fluid; μ and μ t are the fluid dynamic viscosity coefficient and turbulent viscosity respectively; δ ij is the Kronecker function; K is the turbulent kinetic energy. t The SST K-Ω model or KE model can be used to solve it, which can be expressed as:

[0162] In the above formula (4), Ψ represents K and Ω, or K and E, depending on the selected turbulence model; σ Ψ is the model coefficient; G Ψ is the generated term of Ψ; Y Ψ is the dissipative term of Ψ. σ Ψ , G Ψ and Y Ψ The expressions are different in different models.

[0163] Optionally, the water phase is considered to be incompressible, and the compressibility of the gas phase can be neglected in small scale models or in rough calculations, in which case the equations (1)-(4) are closed. However, in large scale or full scale models, the compressibility of the gas phase must be considered, in which case a supplementary gas phase state equation is used to solve the gas phase density variation, expressed as: F(p, T a , p a ) = 0 Equation (5)

[0164] In the above equation (5), T a is the absolute temperature of the gas phase; p a is the density of the air phase.

[0165] Optionally, equation (5) is a general form of the gas phase state equation, and according to specific conditions, ideal gas state, real gas state equation, thermodynamic equation, etc. can be selected. The real gas state equation includes but is not limited to van der Waals equation, R-K equation, S-R-K equation, virial equation, etc.

[0166] The above equations (1)-(5) form a closed loop, and the fluid motion equation constructed thereby can be used to solve the flow velocity field, pressure distribution and density distribution of the fluid region.

[0167] wherein the ship part motion equation is the second law of Newton, expressed as:

[0168] In the above equation (6), M is a generalized mass matrix, which is a 6-order diagonal matrix corresponding to the 6 degrees of freedom of the ship part; and F are the generalized acceleration vector and the generalized force vector, respectively. Among them, the forces acting on the ship part include gravity G h , fluid pressure F p , fluid shear force F τ , rotor reaction force F r and mooring force F m , expressed as: G h = m h g Equation (7) F m = (-c m , 0, -c m sinh(u m2 )) Equation (11) F m = (-k s Δx cosφ s , 0, -(am s g+ks Δx sinφ s )) Formula (12)

[0169] In the above formula, m h is the mass of the hull part; g is the gravity acceleration vector; S d is the hull part wall surface; n is the unit normal vector of the hull wall surface area unit; I is a third-order unit tensor; τ represents the shear stress tensor acting on the hull wall surface area unit; represents the acceleration vector of the rotor.

[0170] It should be noted that there are two expressions of the mooring force F m , which correspond to different states of the mooring system: formula (11) is used when the mooring system component directly connected with the aerodynamic wave energy converter (such as the elastic section of the mooring system) is in a relaxed state, and formula (12) is used when the mooring system component directly connected with the aerodynamic wave energy converter (such as the elastic section of the mooring system) is in a state of tension and elastic deformation.

[0171] In the expression of F m , i.e. formula (11) and formula (12), c m , u m2 are the catenary model parameters of the mooring system; k s , m s and φ s are the stiffness coefficient, mass and the angle between the axis and the horizontal direction of the tensioned mooring system component, respectively; Δx is the deformation of the tensioned mooring system component; a is a proportional coefficient, which is related to the mass distribution of the mooring system itself; g is the gravity acceleration.

[0172] It should be emphasized that the expression of the mooring force F m is not only applicable to the mooring system in the embodiments of the present application, but also applicable to the traditional anchor chain mooring method and the mooring system using anchor chain, floating ball and chain.

[0173] In addition, in the expression of the mooring force F m above, only a single mooring system component directly connected with the wave energy converter is considered, and the arrangement direction of the mooring system component coincides with the x1 direction.

[0174] If multiple mooring system components are considered to be directly connected with the device, the mooring force generated by each mooring system component needs to be calculated according to the expression of F m and superimposed; if other arrangement directions of the mooring system component are considered, the mooring force obtained from the expression of F m needs to be decomposed in the Cartesian coordinate system O-x1x2x3.

[0175] The moment on the hull part is fluid pressure F p , fluid shear force F τ , and rotor reaction force F r , and mooring force F m The sum of the cross products of each force vector and the distance vector to the center of mass of the hull part is added to obtain T h = r p × F p + r τ × F τ + r r × F r + r m × F m Equation (13)

[0176] In the above equation (13), r p , r τ , r r , and r m are the distance vectors of the fluid pressure, the fluid shear force, the rotor reaction force, and the mooring force to the center of mass of the hull part, respectively.

[0177] One end of the turbine flow passage is open to the air chamber of the hull part, and the other end is open to the atmosphere. The turbine as a whole is fixed to the hull part and moves with the hull part in 6 degrees of freedom, and its motion equation is Newton's second law. At the same time, the turbine rotor rotates unidirectionally about the rotation axis of the rotor relative to the hull part, and its motion is described in the local coordinate system O'-x1'x2'x3' as follows:

[0178] In the above equation (14), I is the moment of inertia of the turbine rotor along the x3' direction; is the angular acceleration of the turbine rotor along the x3' direction; n d is the driving torque along the x3' direction due to the pressure difference between the suction side and the pressure side of the rotor blade; n g is the damping torque along the x3' direction applied to the turbine rotor by the generator; n f ' is the bearing friction torque and other resistance torque along the x3' direction experienced by the turbine rotor when it rotates.

[0179] The pressure relief system is a threshold-adjustable automatic pressure relief system installed above the air chamber of the hull part, and the motion equation of its valve is Newton's second law. At the same time, the valve of the threshold-adjustable automatic pressure relief system moves in one degree of freedom along the x3' direction relative to the hull part, and is expressed as:

[0180] In the above equation (15), m vIt is the quality of the valve disc of the automatic pressure relief system with adjustable threshold; is the acceleration of the valve disc along the x3′ direction; F p ' is the supporting force exerted on the valve disc by the gas in the air chamber (along the x3' direction); G v ′ is the component of the valve disc’s own gravity along the x3′ direction; k v It is the elastic coefficient of the spring or other elastic system between the valve disc and the valve seat; and are the initial length of the spring or other elastic system and the actual length at the current moment, and they must satisfy F f ' is the damping force along the x3' direction when the valve disc moves. It should be noted that during the opening of the valve disc, F f ′>0, during the valve disc closing process F f ′<0;F N ′ is the support force exerted on the valve disc along the x3′ direction.

[0181] When the valve disc is closed and the pressure in the air chamber is less than or equal to the threshold of the automatic pressure relief system, the air chamber pressure is insufficient to drive the valve disc to move. At this time, the valve disc is stationary relative to the local coordinate system O′-x1′x2′x3′, and its acceleration is 0, the formula (15) F f ′=0, and F p ′、G v ′ and F N ' reaches equilibrium; once the pressure in the air chamber is greater than the threshold of the automatic pressure relief system, the valve disc begins to open. At this time, the formula (15) F N '=0; then Increase in F p ' decreases, the valve disc begins to close until

[0182] It should be noted that the above formula (15) It can be adjusted according to the actual sea conditions to achieve the effect of automatic pressure relief with adjustable threshold, which is expressed as:

[0183] In the above formula (16), H is the wave height; They are There are m selectable adjustment values.

[0184] Preferably, considering that reliability is often the most important factor in the design process of an actual pneumatic wave energy conversion device, frequent adjustment of the initial length of the spring or other elastic system between the valve flap and the valve seat of the automatic pressure relief system is not conducive to the reliability of the device as a whole. Therefore, the value of m in formula (16) is recommended to be m=2, or m=3, that is, when the device faces the most severe sea conditions for reliability challenges, the threshold of the pressure relief system is appropriately adjusted to ensure the safe operation of the entire device; in other safer working conditions, the threshold of the automatic pressure relief system remains unchanged. However, if only the mathematical model of the automatic pressure relief system with an adjustable threshold is considered, m in formula (16) is not restricted here, and even It can be expressed as a continuous function of H.

[0185] Alternatively, if the function of an automatic pressure relief system with adjustable threshold is realized from the perspective of a mathematical model, the k in formula (15) can also be adjusted. v .

[0186] Alternatively, when the formula (15) and k v When it is fixed, the corresponding automatic pressure relief system can be an automatic pressure relief system with a fixed threshold.

[0187] The power generation component can be a direct-drive generator, where the generator rotor is coaxially connected to the turbine rotor and has exactly the same rotational angular velocity. The main torque of the generator is provided by the turbine rotor, and the resistance torque of the generator includes air resistance, mechanical friction, and electromagnetic resistance during the operation of the generator rotor. At the same time, the generator will apply a damping torque n' to the turbine rotor. g . n′ g It is related to the speed of the generator rotor, that is, the speed of the turbine rotor, and is expressed as: n′ g =F(ω′ R ) Formula (17)

[0188] The governing equation of the mooring system is the catenary equation or Hooke's law, which corresponds to the chain segment and elastic segment of the mooring system being in a relaxed state and in a taut state respectively. The catenary equation is expressed as: 1m =a m u m +b m sinh(u m )+α m Formula (18)

[0189] In the above formulas (18) and (19), x 1m is the x1 coordinate of the catenary element; x3m is the x3 coordinate of the catenary line element; a m and b m are integral constants, depending on the position of the two end points of the catenary and the mass of the catenary; u m is the catenary curve parameter; a m and b m are model parameters.

[0190] where a m , b m and u m are given by: sinh(u m ) = tan(φ m ) Equation (23)

[0191] In the above Equations (20)-(23), λ 0m and L eq are the unit length mass and the slack length of the catenary under no force condition; K m is the stiffness of the catenary; u m1 and u m2 are the u m values at the points where the catenary is connected to the seabed and to the aerodynamic wave energy converter, respectively; φ m is the inclination angle of the catenary curve.

[0192] When the chain or elastic segment of the mooring system is in slack state, the mooring force of the catenary on the device is represented by: F m = (-c m , 0, -c m sinh(u m2 )) Equation (24)

[0193] When the chain or elastic segment of the mooring system is in tension state, its mooring force on the device is solved according to Hooke's law, and is represented by: F m = (-k s Δx cosφ s , 0, -(am s g + k s Δx sinφ s ) Equation (25)

[0194] It should be noted that when the mooring system includes a floating ball, the equation of motion of the floating ball also needs to be considered. The control equation of the floating ball motion is Newton's second law, and the forces acting on the floating ball include its own gravity, fluid pressure, fluid shear force and mooring force on both sides.

[0195] The boundary of the mathematical model includes the inlet boundary, the outlet boundary, the bottom boundary, the top boundary, the side wall boundary, the fluid-structure interface (between the fluid and the ship body, the turbine and the float ball), and the gas-liquid interface (between the water phase and the gas phase) of the overall calculation domain.

[0196] The boundary condition of the inlet boundary is set as a velocity inlet. The velocity of the water phase at the inlet boundary considers the wave speed and the flow speed of the water flow, and the velocity of the gas phase at the inlet boundary is considered as the wind speed, which is expressed as:

[0197] In the above formula (26), u w1 and u w3 are the velocities of the wave in the x1 direction and the x3 direction, respectively, which are solved according to the wave theory; u c is the flow speed of the water flow; u wind is the wind speed; and ζ is the x3 coordinate of the interface between the water phase and the gas phase.

[0198] Alternatively, the spatio-temporal distribution of the wave speed at the inlet can be solved according to the micro-amplitude wave theory, or according to the high-order Stokes wave theory, the irregular wave theory or other wave theories. The spatial distribution and the time variation of the flow speed of the water flow and the wind speed can be considered, that is, u c = u c (x1, x2, x3, t), u wind = u wind (x1, x2, x3, t).

[0199] The boundary condition of the outlet boundary is set as a pressure outlet, and the specific pressure distribution is not limited, for example, the pressure distribution of the water phase at the outlet boundary satisfies the static pressure distribution of the water phase, and the pressure of the gas phase at the outlet boundary is 0, which is expressed as:

[0200] In the above formula (27), p w is the density of the water phase.

[0201] The boundary condition of the bottom boundary is set as a no-slip wall. The no-slip wall means that the force and the velocity of the fluid unit and the structural unit on the boundary are equal, which is expressed as:

[0202] In the above formula (28), u s is the velocity vector of the structural unit on the boundary; u is the velocity vector of the fluid unit on the boundary; p s is the fluid force vector acting on the structural unit on the boundary; and p is the structural reaction force vector acting on the fluid unit on the boundary. It should be particularly noted that for the bottom boundary, u s = u = 0.

[0203] The boundary condition of the top boundary is set as a pressure outlet. The overall calculation domain is high enough so that the water phase cannot splash to the top boundary, and thus only the gas phase passes through the top boundary. The pressure distribution at the top boundary is 0, i.e., free outflow.

[0204] The boundary condition of the side wall boundary is set as a no-slip wall, which is represented by formula (28). It needs to be particularly pointed out that, for the side wall boundary, u s = u = 0.

[0205] The boundary condition of the fluid-solid interface is set as a no-slip wall, which is represented by formula (28).

[0206] The water phase and the gas phase are immiscible at the gas-liquid interface. In the fluid control volume in the region where the gas-liquid interface is located, the water phase and the gas phase share the velocity field and the pressure field, and the equivalent fluid density and the dynamic viscosity are represented as:

[0207] In the above formula (29), γ is the volume fraction of water, and the value range is 0≤γ≤1; μ w and μ a are the dynamic viscosities of the water phase and the gas phase, respectively.

[0208] The initial condition of the mathematical model refers to the motion conditions of the fluid, the ship body part, the turbine rotor, and the buoy of the mooring system in the calculation domain at time t = 0. The six-degree-of-freedom displacement and velocity of the ship body part, the turbine rotor, and the buoy of the aerodynamic wave energy conversion device are all 0 at the initial moment, and the wave, the flow, and the wind are at a position before propagating to the wave-encountering surface of the aerodynamic wave energy conversion device.

[0209] Alternatively, to save calculation time, the initial condition can be set as the wind, the wave, and the flow just propagating to the front of the wave-encountering side of the aerodynamic wave energy conversion device.

[0210] S902, the mathematical model is solved to obtain the evaluation index value of the wave energy conversion device.

[0211] According to the preset solving algorithm, the mathematical model is solved to obtain the operation result of the mathematical model. Then, the operation result is taken as the real running result of the wave energy conversion device under the initial condition, and the power generation capacity index value and the reliability index value of the wave energy conversion device are evaluated as the evaluation index value of the wave energy conversion device.

[0212] It needs to be noted that, in addition to the power generation capacity index value and the reliability index value of the wave energy conversion device, other evaluation parameters can also be included to represent the performance of the wave energy conversion device in multiple dimensions, and the embodiments of the present application do not limit this.

[0213] In the embodiments of the present application, a mathematical model is constructed for the wave energy conversion device, the mathematical model is a simulation equation for simulating the motion characteristics of the wave energy conversion device, and then the mathematical model is solved to obtain the evaluation index value of the wave energy conversion device. In this method, the motion characteristics in the wave energy conversion device are simulated, and the energy conversion stages and the interaction between the energy conversion stages are comprehensively considered to improve the evaluation of the power generation capacity and reliability of the wave energy conversion device, and to provide an optimization direction for the wave energy conversion device in terms of conversion efficiency and reliability.

[0214] In order to simulate the motion characteristics of the wave energy conversion device in a real scenario as much as possible, the simulation equation in the mathematical model is usually continuous in time and space. In this case, the overall calculation domain of the mathematical model can be divided into a finite number of grid cells, the control equation in the mathematical model is converted into a discrete equation between the function values to be solved at the nodes of the continuous grid cells by mathematical principles, and then the mass, momentum and energy conservation equations of each grid cell are solved.

[0215] In an exemplary embodiment, as shown in FIG. 10, the mathematical model is solved to obtain the evaluation index value of the wave energy conversion device, including steps S1001, S1002 and S1003.

[0216] S1001, the mathematical model is discretized to obtain a numerical model, wherein the discretization includes spatial discretization and temporal discretization.

[0217] The step of obtaining the numerical model can include three steps: establishing a set of high-quality grids, determining a numerical solution method, and establishing a reasonable and feasible interface condition. In the embodiments of the present application, the purpose of establishing a set of high-quality grids is to discretize the mathematical model in space; the purpose of determining the numerical solution method is to discretize the mathematical model in time after discretization; and considering that the grid size of the two sub-regions connected by the interface remains basically the same during the grid establishment process, a reasonable and feasible interface condition also needs to be established.

[0218] First, establishing a high-quality grid includes six parts: determining a numerical solution region, determining a grid type, determining a grid encryption criterion, determining a grid transition criterion, controlling a grid quality, and determining a grid number.

[0219] Specifically, step a: determining a numerical solution region.

[0220] In the embodiments of the present application, the numerical solution region is determined as a numerical wave tank with a size of 12λ×8b×2h w , where λ is the wavelength, b is the width of the wave energy conversion device, and h wis the water depth.

[0221] In one embodiment, the distance from the wave-impingement wall of the wave energy conversion device to the inlet boundary of the numerical wave tank is 5λ.

[0222] Optionally, the size of the numerical solution region and the position of the device in the numerical solution region can be adjusted as appropriate.

[0223] Step b: determining the grid type.

[0224] In the embodiments of the present application, the grid structure is determined to be a hexahedral grid, but one or more corners of the hexahedral grid are cut at the boundary position to form a polyhedral grid.

[0225] Optionally, the grid structure can also adopt a tetrahedral grid or a combination of a hexahedral grid and a tetrahedral grid, but since the corresponding number of grids is more massive when adopting a tetrahedral grid structure, the numerical solution cost is higher, and the solution accuracy is relatively lower, it is difficult to effectively adapt to the solution of the complex aerodynamic wave energy conversion device full-system coupling model.

[0226] Step c: determining the grid refinement criterion.

[0227] In the embodiments of the present application, the grid refinement is performed on the model boundary (including the inlet boundary, the outlet boundary, the bottom boundary, the top boundary, the side wall boundary of the numerical wave tank, and the fluid-solid interface and the gas-liquid interface), the L-shaped flow passage region of the ship body part, the turbine flow passage region, the region involved in the movement of the ship body part, the region involved in the movement of the floating ball of the mooring system, and the region involved in the movement of the valve of the threshold-adjustable automatic pressure relief system. Specifically, to ensure the reliability of the wave sequence propagation in the numerical wave tank, the height of the grid refinement region of the gas-liquid interface is 1.5H-2.0H, where H is the wave height, and the grid size of the region satisfies The grid of the turbine flow passage region needs to be more refined, especially the region distributed by the rotor blades and the guide vanes, and at least 6 layers of grids should be distributed between the rotor blades. In particular, there is a small gap between the top end of the rotor blade and the inner wall of the turbine flow passage, and the discharge effect of the gap has an important influence on the turbine characteristics, so at least 2-3 layers of grids should be distributed in the thickness direction of the region to accurately depict the flow characteristics of the blade tip gap.

[0228] It should be noted that to ensure the reliability of the numerical solution result, the grid refinement criterion of the above-mentioned gas-liquid interface refinement region, turbine flow passage region and blade tip gap should be strictly implemented.

[0229] Step d: determining the grid transition criterion.

[0230] In one embodiment, the numerical solution region is distributed with different size grids, and the transition layer between adjacent size grids is at least 2-3 layers.

[0231] Step e: control the grid quality.

[0232] In the embodiments of the present application, the grid quality should be strictly controlled to ensure that the grid quality of all grids in the numerical solution region is higher than the preset minimum grid quality.

[0233] Optionally, the preset minimum grid quality can be selected as 0.05.

[0234] Step f: determine the number of grids.

[0235] In the embodiments of the present application, a set of high-quality grids is established according to steps a-e. Further, the final number of grids is determined through grid convergence analysis.

[0236] In one embodiment, the grid convergence criterion is selected as 0.5%-1.0%, that is, the changes of physical quantities such as ship body motion, air chamber pressure, impact air turbine rotor speed, anchor chain force, etc. obtained by using the device from wave to electric system coupling simulation method are all not more than 0.5%-1.0% with the continuous increase of the number of grids, at which time it is considered to meet the grid convergence requirement.

[0237] It should be noted that considering different hydrodynamic conditions, grid densification criteria, grid transition criteria, and grid convergence criteria, the final number of grids will also have a large difference. Research shows that when the requirements of steps a-f are strictly met, the number of established grids is not less than 4.5 million.

[0238] In the case of building grids, determining the numerical solution method includes determining the numerical method and determining the solving algorithm.

[0239] In the embodiments of the present application, for the fluid control equation in the mathematical model, the corresponding discrete method is determined as the finite volume method. Specifically, the finite volume method refers to integrating the fluid control equation in each grid control volume and a certain time interval to obtain a set of discrete equations. Based on the finite volume method, the discrete forms of formulas (1) and (2) are represented as:

[0240] In the above formulas (30) and (31), V is the control volume; A is the surface of the control volume; n i is the component of the control volume surface unit normal vector n in the x i direction; S u and s u are source terms.

[0241] When solving the discrete equations of fluid motion, the SIMPLE algorithm is used to couple the pressure and flow velocity, the second-order implicit format is used to process the time term, the Gauss least square method is used to process the gradient term, the second-order upwind format is used to process the convection term, the HRIC algorithm is used to capture the free surface, and the full y + wall treatment method is used to predict the flow and turbulence problems of the wall boundary layer. The full y+ wall treatment method is a hybrid treatment method, i.e., low y + wall treatment is used for fine grids, and high y + wall treatment is used for coarse grids.

[0242] For the control equations of the ship body part, the rotor of the impulse air turbine, the valve of the threshold-adjustable automatic pressure relief system, and the floating ball of the mooring system, the time-domain step-by-step integration method is used for discrete solution, such as the second-order precision trapezoidal format with good stability, which is represented as:

[0243] In the above formula (32)-formula (34), M -1 is the inverse matrix of the generalized mass matrix M; v(t-Δt), and x(t-Δt) are the generalized velocity, generalized acceleration and generalized displacement vector of the ship body part, the rotor of the impulse air turbine, the valve of the threshold-adjustable automatic pressure relief system, or the floating ball of the mooring system at the time (t-Δt); and Δt is the time step.

[0244] In one embodiment, the time step is selected as Δt=(1 / 2000)T~(1 / 10000)T, where T is the wave period. The size of the time step is mainly related to the grid size and the turbine rotor speed. Generally, the higher the turbine rotor speed, the smaller the selected time step. Further, the final time step size is determined by the time step convergence analysis.

[0245] Establishing reasonable and feasible interface conditions includes dividing the calculation region and setting the interface between the regions.

[0246] In this embodiment, the whole numerical solution region is divided into five sub-regions, which are a background region representing the entire numerical wave tank, an overlapping region 1 containing the ship body part of the air-driven wave energy conversion device and the impulse air turbine but not including the turbine rotor region, an overlapping region 2 containing the threshold-adjustable automatic pressure relief system, an overlapping region 3 containing the floating ball, and a rotor region where the turbine rotor is located. The background region is a static region, and the overlapping region 1, the overlapping region 2, the overlapping region 3, and the rotor region are all moving regions.

[0247] Optionally, if the device does not install an automatic pressure relief system or the valve of the threshold adjustable automatic pressure relief system is always closed, at this time, there is no need to set the overlapping area 2; if the device installs multiple automatic pressure relief systems, at this time, there are multiple independent overlapping areas 2 (which can be recorded as overlapping area 2-1, overlapping area 2-2, …).

[0248] Optionally, if the mooring system of the device adopts the traditional anchor chain mooring mode, that is, one end of the chain is connected with the anchor and fixed on the seabed, and the other end is fixed on the hull part of the device, at this time, there is no need to set the overlapping area 3; if the mooring system of the device contains multiple floating balls, at this time, there are multiple independent overlapping areas 3 (which can be recorded as overlapping area 3-1, overlapping area 3-2, …).

[0249] In the embodiment of the application, the interface between the background area and the overlapping area 1 adopts the overlapping grid interface; the interface between the background area and the overlapping area 3 adopts the overlapping grid interface; the interface between the overlapping area 1 and the overlapping area 2 adopts the overlapping grid interface; the interface between the overlapping area 1 and the rotor area adopts the internal in-situ interface; there is no direct data interaction between other sub-areas, and no interface condition needs to be set.

[0250] It should be noted that the overlapping grid interface and the internal in-situ interface realize the data interaction between two sub-areas that are physically connected, and in the process of establishing the grid, the grid size of the two sub-areas connected by the interface near the interface should be kept basically consistent.

[0251] S1002, based on the numerical model, solving the time history curve of the wave energy conversion device, the time history curve including the corresponding relationship between the motion response and dynamic characteristics of the wave energy conversion device and time.

[0252] In an exemplary embodiment, as shown in FIG. 10, based on the numerical model, the step of solving the time history curve of the wave energy conversion device includes steps S1101, S1102 and S1103.

[0253] S1101, dividing the simulation time period according to a preset time step to determine multiple time points.

[0254] Wherein, the size of the time step Δt is mainly related to the grid size and the turbine rotor speed. Generally, the higher the turbine rotor speed, the smaller the selected time step. Further, the final time step size is determined by time step convergence analysis. Usually, Δt=(1 / 2000)T~(1 / 10000)T, where T is the wave period.

[0255] Taking a simulation time period of 3 minutes and a preset time step of 0.001 second as an example, 180000 time points of the 0.001s, 0.002s, 0.003s,..., 3 minutes are determined for the preset time period.

[0256] S1102, obtain the motion response value corresponding to each time point of the numerical model.

[0257] For any time point in the plurality of time points, that is, for each time point, the numerical model is iteratively solved according to a preset iteration strategy until the numerical model satisfies a preset convergence condition, and the motion response value of each time point is obtained.

[0258] Please refer to FIG. 12, which is an iterative solution process of the wave energy conversion device from wave to electricity full system coupling simulation method provided by an embodiment of the present application, including the following steps S1201 to S1209.

[0259] S1201, obtain information at the interfaces of the overlapping grid and the internal in-situ interface.

[0260] S1202, iteratively solve the fluid motion equation.

[0261] S1203, obtain the velocity field, pressure field and density field information of the fluid region.

[0262] The fluid pressure and shear stress on the surfaces of the hull part of the pneumatic wave energy conversion device, the impinging air turbine, the threshold-adjustable automatic pressure relief system, the floating ball of the mooring system and other components are integrated to obtain the forces and moments acting on each part of the device.

[0263] S1204, determine whether the velocity field, pressure field and density field of the fluid region all satisfy the convergence condition.

[0264] If the convergence condition is not satisfied, the fluid motion equation is iteratively solved, and the process returns to S1002 until the convergence condition is satisfied.

[0265] S1205, if yes, the motion state of the hull part, the rotor of the impinging air turbine, the valve of the threshold-adjustable automatic pressure relief system, and the floating ball of the mooring system is solved by using the second-order precision trapezoidal format.

[0266] S1206, update the overlapping network.

[0267] Specifically, the positions of the overlapping region 1, the overlapping region 2, the overlapping region 3 and the rotor region are updated according to the solution result.

[0268] S1207, obtain the motion response value of the current time step.

[0269] S1208, determine whether the calculation of all time steps is completed.

[0270] S1209, if yes, the motion response value of the current time step is obtained.

[0271] If no, the iteration calculation of the next time step is continued until the motion response values of all time steps are obtained.

[0272] Further, the motion response and dynamic characteristics of the aerodynamic wave energy converter at the current time step are obtained. The motion response and dynamic characteristics include but are not limited to the force, acceleration, velocity and displacement of the ship body part and the floating ball of the mooring system in the 6 degrees of freedom in the Cartesian coordinate O-x1x2x3; the force of the mooring system; the opening and closing state of the valve of the threshold-adjustable automatic pressure relief system; the force and rotation of the impulse air turbine rotor in the local coordinate system O'-x1'x2'x3'(also the rotation of the direct-drive generator rotor); the free surface distribution, especially the spatial distribution of the water column elevation in the L-shaped flow channel in the local coordinate system O'-x1'x2'x3'; the pressure, velocity and density distribution of the water phase and gas phase in the fluid domain, especially the pressure distribution in the air chamber in the L-shaped flow channel and the flow velocity distribution in the impulse air turbine flow channel.

[0273] Further, the water power input power, the aerodynamic power, the turbine rotor mechanical power and the final output power of the device of the aerodynamic wave energy converter at the current time step are obtained. The water power input power P in,t , the aerodynamic power P pt , the turbine rotor mechanical power P rt and the final output power P out,t of the device are represented as: P in,t = S ω b Equation (35) P pt = Δp t Q t Equation (36) P rt = n' dt ω' Rt Equation (37) P out,t = n' gt ω' Rt Equation (38)

[0274] In the above formula, S ω is the energy density per unit width under the superposition of incident wave and water flow; Δp t is the air chamber pressure at the current moment; Q t is the air chamber volume flow at the current moment; n′ dt and n′ gt are the driving torque and the damping torque of the generator applied to the turbine rotor in the local coordinate system O′-x1′x2′x3′ at the current moment; ω′ Rt is the rotational speed of the turbine rotor (and the generator rotor) in the local coordinate system O′-x1′x2′x3′ at the current moment.

[0275] Optionally, the incident wave can be regular wave (including small amplitude wave, high-order Stokes wave), irregular wave, etc., and the expression of S ω is also different.

[0276] S1103, constructing a time history curve according to each moment and the corresponding motion response value at each moment.

[0277] Taking each moment as the horizontal axis and the corresponding motion response value at each moment as the vertical axis, a time history curve of the wave energy conversion device in a preset time period is constructed.

[0278] S1003, obtaining an evaluation index value of the wave energy conversion device according to the time history curve.

[0279] According to the time history curve of the motion response and the power characteristics of the wave energy conversion device, evaluation index values in terms of power generation capacity index value and reliability index value are calculated.

[0280] The expression of the power generation capacity index value is as follows:

[0281] In the above formula (39), and are the average water dynamic performance, the average turbine performance, the average generator performance and the average overall performance of the device, and the corresponding expressions are as follows:

[0282] In the above formula, and are the average incident wave power, the average aerodynamic power, the average rotor mechanical power and the average output power (i.e. the average power generation power); t0 is the time when the numerical simulation reaches the dynamic balance stage, and the value is different in different examples; n is the number of wave periods corresponding to the data length selected when the data is averaged, and is usually an integer between 4-8.

[0283] It should be noted that the average hydrodynamic performance may also be characterized as the capture width ratio of the wave energy conversion device, and The calculation result can exceed 100%.

[0284] wherein the reliability index value is an index parameter for evaluating the wave energy conversion device to have the ability to work normally and continuously in a specific marine environment. When one or more of the parameters such as the rotational speed of the turbine rotor, the mooring force in the chain segment and / or the elastic segment of the mooring system, and the differential pressure force on the wall surface of the hull portion liquid flow passage (i.e., the difference between the pressures on the inside and outside of the wall surface) exceed the rated upper limit of the corresponding parameter for a long time during the simulation period, it will seriously affect the reliability index value of the wave energy conversion device.

[0285] In the embodiments of the present application, the greater the power generation capacity index value, the higher the energy conversion efficiency of the wave energy conversion device; the greater the reliability index value, the more reliable the wave energy conversion device. In actual scenarios, the power generation capacity index value and the reliability index value of the wave energy conversion device are calculated at the same time, and the power generation capacity index value is maximized under the condition that the reliability index value meets the actual demand.

[0286] In one scenario, the reliability index value can be one of two discrete values, such as 0 or 1 in 0 and 1. In this case, a reliability index value of 0 indicates that the wave energy conversion device is unreliable, and a reliability index value of 1 indicates that the wave energy conversion device is reliable.

[0287] In the embodiments of the present application, the reliability index value can be determined according to whether the physical parameters (including but not limited to rotational speed, mooring force, and differential pressure force) exceed the rated upper limit of the corresponding parameter: if one of the physical parameters exceeds the rated upper limit of the corresponding parameter, it means that the wave energy conversion device is in an unsafe operating state, and in this case the reliability index value is determined to be 0; if all physical parameters do not exceed the rated upper limit of the corresponding parameter, it means that the wave energy conversion device is in a safe and reliable operating state, and the reliability index value is determined to be 1.

[0288] Taking the rotational speed of the power generation assembly as the physical parameter, and the rated upper limit of the rotational speed being 700 revolutions per minute as an example, if the rotational speed of the power generation assembly in the wave energy conversion device exceeds 700 revolutions per minute during the simulation process, the reliability index value is determined to be 0; if the rotational speed of the power generation assembly during the simulation process does not exceed 700 revolutions per minute, the reliability index value is determined to be 1.

[0289] In one scenario, the reliability index value can be any value in the interval [0, 1], such as 0.1, 0.5, 0.9, etc. In this case, the closer the reliability index value is to 0, the less reliable the wave energy conversion device is, and the closer the reliability index value is to 1, the more reliable the wave energy conversion device is.

[0290] In the embodiments of the present application, the reliability index value can be determined according to the duration that the physical parameter (including but not limited to the rotating speed, the mooring force and the differential pressure force) exceeds the upper limit of the corresponding parameter rating, and the duration is negatively correlated with the reliability index value, that is, the longer the duration that the physical parameter exceeds the upper limit of the corresponding parameter rating, the lower the reliability index value; the shorter the duration, the higher the reliability index value. The purpose of such setting is to allow the part of the hardware in the wave energy conversion device to have certain pressure resistance in the actual running scene, for example, the power generation assembly allows short-time overload operation.

[0291] Still taking the rotating speed of the power generation assembly as the physical parameter and the upper limit of the rotating speed as 700 rpm as an example, the initial reliability index value is set as 1, and on the basis that the rotating speed of the power generation assembly in the wave energy conversion device exceeds 700 rpm, the duration t that the rotating speed exceeds 700 rpm is further monitored beyond , then the reliability index value n R is determined as follows: R n beyond =1-f(t

[0292] In the above formula (43), f(t beyond ) represents a function positively correlated with the duration t beyond , and the value range thereof is [0, 1]. In the simplest example, f(t beyond ) is linearly related to t beyond in a certain range, that is,

[0293] In the above formula (44), T0 represents the maximum duration that the rotating speed of the power generation assembly is allowed to exceed the upper limit thereof.

[0294] Further, by changing the water power incident conditions, the generator characteristics, the threshold of the threshold-adjustable automatic pressure relief system, the mooring mode and other parameters, the steps of the evaluation method shown in FIGS. 8-10 can be repeated to obtain the changes of the evaluation indexes of the power generation capacity and the reliability of the pneumatic wave energy conversion device under different conditions with the changes of the above water power incident conditions, the generator characteristics, the threshold of the threshold-adjustable automatic pressure relief system, the mooring system and other parameters, and the energy conversion mechanism of the pneumatic wave energy conversion device is deeply revealed.

[0295] In the embodiments of the present application, the numerical model easy to calculate is obtained by discretizing the mathematical model, then the time history curve is constructed according to the numerical model, the dynamic characteristics of the wave energy conversion device are visualized, and the evaluation index value determined based on the time history curve is more suitable for the actual running state of the wave energy conversion device.

[0296] In one exemplary embodiment, a simulation method of a wave energy conversion device is provided, comprising the following steps S1301 to S1305.

[0297] S1301, a mathematical model of full system coupling of the wave energy conversion device is established.

[0298] S1302, a numerical model of full system coupling of the wave energy conversion device is established.

[0299] S1303, based on numerical iteration solution, motion response and dynamic characteristics of the wave energy conversion device are obtained.

[0300] S1304, time history curves of the motion response and the dynamic characteristics are constructed.

[0301] S1305, according to the time history curves, evaluation index values of the wave energy conversion device are obtained.

[0302] Optionally, the structure parameters and other detailed designs of the wave energy conversion device are optimized, and the above S1301 to S1305 are repeatedly executed to obtain evaluation indexes of the wave energy conversion device under different conditions, and according to the structure parameters and the evaluation index values corresponding to the structure parameters, the energy conversion mechanism of the wave energy conversion device is revealed, and an optimization direction for improving the power generation capacity and reliability of the wave energy conversion device is provided.

[0303] In the embodiments of the present application, a comprehensive and complete simulation method of full system coupling of a wave energy conversion device from wave to electricity is provided to fill the gap of lack of reliable design optimization theory of the aerodynamic wave energy conversion device.

[0304] In one exemplary embodiment, a wave energy conversion device evaluation method is provided, comprising the following steps:

[0305] (1) a mathematical model is constructed for the wave energy conversion device.

[0306] The mathematical model is a simulation equation for simulating motion characteristics of the wave energy conversion device.

[0307] (2) the mathematical model is discretized to obtain a numerical model.

[0308] The discretization includes spatial discretization and temporal discretization.

[0309] (3) the simulation time period is divided according to a preset time step to determine a plurality of time points.

[0310] (4) For any time in the plurality of times, the numerical model is iteratively solved according to a preset iteration strategy until the numerical model satisfies a preset convergence condition, and a motion response value at each time is obtained.

[0311] (5) A time history curve is constructed according to each time and the motion response value corresponding to each time.

[0312] The time history curve is used to represent the corresponding relationship between the motion response and the dynamic characteristics of the wave energy conversion device and time.

[0313] (6) An evaluation index value of the wave energy conversion device is obtained according to the time history curve.

[0314] The evaluation index value includes a power generation capacity index value and a reliability index value in the wave energy conversion device.

[0315] In the embodiments of the present application, a mathematical model is constructed for the wave energy conversion device, the mathematical model is a simulation equation for simulating the motion characteristics of the wave energy conversion device, and then the mathematical model is solved to obtain the evaluation index value of the wave energy conversion device. In this method, the motion characteristics of the wave energy conversion device are simulated, and the interaction between the energy conversion stages and the energy conversion stages is comprehensively considered to improve the evaluation of the power generation capacity, reliability and other aspects of the wave energy conversion device, and to provide an optimization direction for the wave energy conversion device in terms of conversion efficiency, reliability and other dimensions.

[0316] In addition, it should be emphasized that the optimization method provided in the embodiments of the present application, including the steps of constructing a control equation and numerical solving, is universal, and is not only applicable to the performance prediction of the wave energy conversion device proposed in the embodiments of the present application, but also applicable to the performance prediction of all other forms of air-driven wave energy conversion devices. For example, devices without an automatic pressure relief system, devices with limited motion freedom, wave energy generation devices including a plurality of air-driven wave energy conversion devices fixedly connected to form a whole, in addition to this, wave energy generation devices with a part of the hull being a rear elbow pipe, a front elbow pipe or a center pipe; air turbines being radial impact air turbines, axial impact air turbines, Wells turbines and other types of wave energy generation devices; mooring methods using separate anchor chains, anchor chains + floating balls + chains for wave energy generation devices; pressure relief systems with fixed threshold values; wave energy generation devices including a wide range of torque-speed relationship generators. The only thing to note is that the simulation method uses an impact air turbine with fixed guide vanes for the air-driven wave energy conversion device, and for the impact air turbine with actively / passively rotating or sliding guide vanes, it has been proved that the reliability is very low in the actual marine environment, and the operation will be destroyed in a very short time, so it is not considered here.

[0317] It should be understood that, although the steps in the flowcharts involved in the above-described embodiments are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise explicitly stated herein, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least some of the steps in the flowcharts involved in the above-described embodiments can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be alternately or alternately executed with at least some of the other steps or steps or stages in other steps.

[0318] To further verify the performance parameters of the wave energy conversion device provided by the embodiments of the application, the application also conducts a plurality of comparative experiments, and the research shows that:

[0319] (1) The highest steady-state efficiency of the air turbine (radial inflow impeller air turbine) provided by the embodiments of the application is 68%, and the highest periodic average efficiency is 63%, which is increased by 35.8% and 31.5%, respectively, compared with the highest steady-state efficiency and the highest periodic average efficiency of the axial flow impeller air turbine with fixed guide vanes.

[0320] For specific results, see FIG. 14, which is a comparison diagram of turbine steady-state efficiency curves obtained by using the simulation method of the embodiments of the application. In FIG. 14, S1 is the steady-state efficiency curve of the radial impeller air turbine provided by the embodiments of the application, and S2 is the steady-state efficiency curve of the axial impeller air turbine. As can be seen from FIG. 13, under the same flow coefficient, the steady-state efficiency of the radial impeller air turbine provided by the application is greater than that of the axial impeller air turbine.

[0321] (2) Under regular wave conditions, the average overall performance of the new impeller air turbine aerodynamic wave energy conversion device provided by the embodiments of the application is the highest, which is increased by 20.6% compared with the highest average overall performance of the aerodynamic wave energy conversion device using the axial flow impeller air turbine with fixed guide vanes, proving the applicability and high efficiency of the new impeller air turbine provided by the embodiments of the application.

[0322] See FIG. 15, which is a curve diagram of the average hydrodynamic performance the average turbine performance and the average overall performance of the wave energy conversion device under the condition of the average power generation performance of the wave energy conversion device under regular wave conditions.

[0323] (3) Under irregular wave conditions, the average overall performance of the new impeller air turbine aerodynamic wave energy conversion device proposed in the application is the highest at 35%, which is 19.8% higher than the highest average overall performance of the aerodynamic wave energy conversion device using the guide vane fixed axial flow impeller air turbine, which again proves the applicability and high efficiency of the new impeller air turbine proposed in the application.

[0324] (4) Under the same hydrodynamic conditions, compared with the aerodynamic wave energy conversion device using the single anchor chain mooring method and the anchor chain + floating ball + chain mooring method, the average overall performance of the wave energy conversion device using the new mooring system (a synergistic wide-frequency mooring system suitable for the anchor chain-float-elastic component of the aerodynamic wave energy conversion device) proposed in the application is improved, and the maximum is increased by 12.5% and 3.2% respectively; at the same time, the high-efficiency energy capture interval of the aerodynamic wave energy conversion device using the new mooring system proposed in the application is widened by 46.8% and 10.5% compared with the high-efficiency energy capture interval of the aerodynamic wave energy conversion device using the single anchor chain mooring method and the anchor chain + floating ball + chain mooring method respectively, which proves the effectiveness of the new mooring system proposed in the application in terms of synergistic wide-frequency and improving the overall power generation capacity of the device. It should be noted that the water dynamic performance greater than 80% corresponds to the high-efficiency energy capture interval.

[0325] (5) Under the same hydrodynamic conditions (high sea state conditions), the maximum mooring force of the aerodynamic wave energy conversion device using the new mooring system proposed in the application is lower than that of the aerodynamic wave energy conversion device using the single anchor chain mooring method and the anchor chain + floating ball + chain mooring method, and the maximum is reduced by 212% and 156% respectively, which proves the effectiveness of the new mooring system proposed in the application in improving the reliability of the device.

[0326] (6) Under the conditions of normal sea state (wave height 1m in the embodiment of the application, corresponding to 3rd sea state), high sea state (wave height 4m in the embodiment of the application, corresponding to 5th-6th sea state) and extreme sea state (wave height 12m in the embodiment of the application, corresponding to 8th sea state), the maximum values of the air chamber pressure and the rotating speed of the turbine rotor of the air-driven wave energy conversion device equipped with the newly-proposed threshold-adjustable automatic pressure relief system are well controlled. Moreover, compared with the normal sea state, the incident wave energy is increased by more than 20 times under the high sea state, and the maximum pressure difference force on the wall surface of the L-shaped flow passage of the ship body part is only increased by 3.05 times; compared with the normal sea state, the incident wave energy is increased by more than 300 times under the extreme sea state, and the maximum pressure difference force on the wall surface of the L-shaped flow passage of the ship body part is only increased by 2.1 times, which proves the reliability of the air-driven wave energy conversion device itself and the effectiveness of the threshold-adjustable automatic pressure relief system proposed in the application in improving the reliability of the device.

[0327] (7) Further, the research results show that the natural frequencies of the six degrees of freedom motion of the wave energy conversion device provided in the embodiment of the application are different, so that each degree of freedom motion generates a water column oscillation wave in the flow passage, these water column oscillation waves generate superposition effect, thereby widening the frequency response width of the device and increasing the capture width ratio. The longitudinal motion of the device moored by the anchor chain and the floating ball mooring system contributes most to the capture width ratio of the device, and the contribution of the longitudinal motion to the capture width ratio accounts for 50% to 95% of the total capture width ratio under different sea states.

[0328] The above experimental researches show that, compared with the energy conversion device provided in the prior art, the air-driven wave energy conversion device provided in the embodiment of the application includes a ship body part, an impact air turbine, an automatic pressure relief load reduction system, a generator, a mooring system and other systems / equipment / components. The air-driven wave energy conversion device has the advantages of high reliability, high efficiency, compactness in axial and radial directions. The threshold-adjustable automatic pressure relief system can be remotely manually controlled or automatically controlled according to the actual sea state, thereby improving the reliability of the device under high sea state. The anchor chain-floating ball-elastic energy absorption component has the advantages of wide frequency and efficiency, and reducing the maximum stress in the mooring system.

[0329] Based on the same inventive concept, the embodiment of the application further provides an evaluation device for implementing the above-mentioned evaluation method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more evaluation device embodiments provided below can be referred to the limitations of the evaluation method in the above, which will not be described here again.

[0330] In an example embodiment, as shown in FIG. 16, a wave energy converter evaluation device is provided, comprising: a construction module 1601 and an operation module 1602.

[0331] The construction module 1601 is configured to construct a mathematical model for the wave energy converter, the mathematical model being a simulation equation simulating motion characteristics of the wave energy converter.

[0332] The operation module 1602 is configured to perform solution operation on the mathematical model to obtain an evaluation index value of the wave energy converter.

[0333] In an example embodiment, the operation module 1602 comprises a discrete processing unit, a curve construction unit, and an index acquisition unit.

[0334] The discrete processing unit is configured to perform discretization processing on the mathematical model to obtain a numerical model; the discretization processing comprises spatial discretization processing and time discretization processing.

[0335] The curve construction unit is configured to solve a time history curve of the wave energy converter based on the numerical model, the time history curve comprising a corresponding relationship between motion response and dynamic characteristics of the wave energy converter and time.

[0336] The index acquisition unit is configured to obtain the evaluation index value of the wave energy converter according to the time history curve.

[0337] In an example embodiment, the curve construction unit comprises a time division subunit, a response acquisition subunit, and a time history construction subunit.

[0338] The time division subunit is configured to divide a simulation time period according to a preset time step to determine a plurality of time points.

[0339] The response acquisition subunit is configured to obtain a motion response value corresponding to each time point of the numerical model.

[0340] The time history construction subunit is configured to construct the time history curve according to each time point and the motion response value corresponding to each time point.

[0341] In an example embodiment, the response acquisition subunit is specifically configured to, for any time point in the plurality of time points, perform iterative solution on the numerical model according to a preset iteration strategy until the numerical model satisfies a preset convergence condition to obtain the motion response value at the time point.

[0342] In an example embodiment, the evaluation index value comprises a power generation capability index value and a reliability index value in the wave energy converter.

[0343] Each of the modules in the above evaluation device can be implemented by software, hardware, and combinations thereof, in whole or in part. The above modules can be embedded in or independent of a processor in a computer device in hardware form, or stored in a memory in a computer device in software form, so as to be called and executed by a processor to perform the operations corresponding to the above modules.

[0344] In an exemplary embodiment, a computer device is provided, which can be a terminal, and an internal structure diagram thereof can be as shown in FIG. 17. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operating system and the computer program in the non-volatile storage medium to run. The input / output interface of the computer device is configured to exchange information between the processor and external devices. The communication interface of the computer device is configured to perform wired or wireless communication with external terminals, and the wireless communication can be achieved by WIFI, mobile cellular network, NFC (Near Field Communication), or other technologies. The computer program is executed by the processor to implement a wave energy conversion device evaluation method. The display unit of the computer device is configured to form a visually visible picture, which can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer overlaid on the display screen, or a key, trackball, or touchpad arranged on the shell of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0345] Those skilled in the art can understand that the structure shown in FIG. 17 is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the computer device to which the scheme of the present application is applied. A specific computer device can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0346] In an exemplary embodiment, a computer device is provided, which includes a memory and a processor, and the memory stores a computer program. The processor executes the computer program to implement the steps in the above wave energy conversion device evaluation method embodiments.

[0347] In an embodiment, a non-volatile computer readable storage medium is provided, which stores a computer program. The computer program is executed by a processor to implement the steps in the above wave energy conversion device evaluation method embodiments.

[0348] In one embodiment, a computer program product is provided, including computer-executable instructions that, when executed by a processor, implement the steps in the above-mentioned wave energy conversion device evaluation method embodiments.

[0349] It should be noted that the user information (including but not limited to user equipment information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant regulations.

[0350] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. Any reference to a memory, database or other medium used in the embodiments provided by the present application can include at least one of a non-volatile and volatile memory. The non-volatile memory can include a read-only memory (ROM), a magnetic tape, a floppy disk, a flash memory, an optical storage, a high-density embedded non-volatile memory, a resistive memory (ReRAM), a magnetoresistive random access memory (MRAM), a ferroelectric memory (FRAM), a phase change memory (PCM), a graphene memory, etc. The volatile memory can include a random access memory (RAM) or an external cache memory, etc. As an illustration but not limitation, the RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided by the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided by the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0351] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, as long as the combinations of technical features do not have contradictions, they shall be considered within the scope of the present disclosure.

[0352] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it shall not be understood as a limitation on the patent scope of the present application. It shall be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these shall be within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A wave energy converter, comprising: a fluid channel configured to convert wave energy transferred to the fluid channel into pneumatic energy; an energy conversion system connected to the fluid channel and configured to convert the pneumatic energy converted by the fluid channel into electrical energy; the air turbine comprising a channel wall, two sets of guide vanes and a set of rotor vanes; a cross-sectional profile of each of the guide vanes comprises an elliptical arc segment and a straight line segment, and the straight line segment is arranged along a tangent direction of a circle around a rotation axis at an end point of the straight line segment; a cross-sectional profile of each of the rotor vanes in an axial direction comprises an elliptical arc segment on a suction side and a circular arc segment on a pressure side; each set of the guide vanes has a number of 14-24; a pressure relief system connected to the fluid channel and configured to control a pressure of an air chamber in the fluid channel; the pressure relief system comprises a valve flap, a valve seat, an elastic unit, a control rod and a connecting pipe, the valve flap is connected to the valve seat through the elastic unit, the valve flap is further connected to the air chamber through the connecting pipe, the control rod is fixedly connected to the valve seat, and the control rod is movably connected to the valve flap and a control assembly, respectively, the control rod is a telescopic rod, the valve flap has a plurality of corresponding opening thresholds, the control assembly is disposed on a surface of the connecting pipe and configured to dynamically adjust an initial length of the elastic unit through the control rod to control the corresponding opening threshold of the valve flap according to a sea condition of the wave energy converter, and the control assembly has a plurality of adjustment lengths for adjusting the initial length of the elastic unit.

2. The apparatus of claim 1, wherein, the valve flap is in an open state corresponding to a case that the pressure of the air chamber exceeds the opening threshold, and the valve flap is in a closed state corresponding to a case that the pressure of the air chamber does not exceed the opening threshold.

3. The apparatus of claim 1 or 2, wherein, the energy conversion system comprises an air turbine and a power generation assembly, and the air turbine is connected to the power generation assembly; the air turbine is configured to convert the pneumatic energy converted by the fluid channel into mechanical energy; the power generation assembly is configured to convert the mechanical energy converted by the air turbine into the electrical energy.

4. The apparatus of claim 3, wherein, a rotation speed of a rotor of the air turbine is the same as a rotation speed of a rotor of the power generation assembly.

5. The apparatus of claim 3 or 4, wherein, the air turbine further comprises a rotation axis and a rotor part; one set of the guide vanes is uniformly distributed at a channel inlet of the channel wall, and the other set of the guide vanes is uniformly distributed at a channel outlet of the channel wall; the set of the rotor vanes is uniformly distributed on the rotor part in a central region of the channel of the air turbine along a circumferential direction around the rotation axis.

6. The apparatus of claim 5, wherein, a cross-sectional profile of the channel wall in an axial direction between the rotor vanes and the guide vanes comprises a 90° circular arc segment and straight line segments on both sides of the circular arc segment. 7.The device according to any one of claims 1-6, further comprising one or more mooring systems, and the one or more mooring systems are connected to a wave-approaching side of the wave energy converter.

8. The apparatus of claim 7, wherein, each mooring system comprises a floating ball connected to the wave-approaching side of the wave energy converter through at least one elastic assembly.

9. The device of any one of claims 1-8, wherein, The fluid flow channel comprises a horizontal flow channel and a vertical flow channel which are in communication with each other; the vertical flow channel is arranged close to the wave-approaching side of the wave energy conversion device, and the mouth of the horizontal flow channel is arranged close to the wave-receding side of the wave energy conversion device; the cross-sectional area of the horizontal flow channel is equal to that of the vertical flow channel; the horizontal flow channel and the vertical flow channel are connected by a streamlined flow channel.

10. The apparatus of claim 9, wherein, The fluid flow channel further comprises a plurality of partitions; each partition is fixed vertically on the flow channel wall of the horizontal flow channel and the vertical flow channel. 11.A method for evaluating a wave energy conversion device, comprising: constructing a mathematical model for the wave energy conversion device according to any one of claims 1-10, wherein the mathematical model is a simulation equation for simulating motion characteristics of the wave energy conversion device; solving the mathematical model to obtain an evaluation index value of the wave energy conversion device.

12. The method of claim 11, wherein, The solving of the mathematical model to obtain the evaluation index value of the wave energy conversion device comprises: discretizing the mathematical model to obtain a numerical model, wherein the discretization comprises spatial discretization and temporal discretization; solving a time history curve of the wave energy conversion device based on the numerical model, wherein the time history curve comprises a corresponding relationship between motion response and dynamic characteristics of the wave energy conversion device and time; obtaining the evaluation index value of the wave energy conversion device according to the time history curve.

13. The method of claim 12, wherein, The solving of the time history curve of the wave energy conversion device based on the numerical model comprises: dividing a simulation time period according to a preset time step to determine a plurality of time points; obtaining a motion response value corresponding to each time point of the numerical model; constructing the time history curve according to each time point and the corresponding motion response value.

14. The method of claim 13, wherein, The obtaining of the motion response value corresponding to each time point of the numerical model comprises: for each time point, iteratively solving the numerical model according to a preset iteration strategy until the numerical model satisfies a preset convergence condition, to obtain the motion response value of each time point.

15. The method according to any one of claims 11-14, characterized in that, The evaluation index value comprises a power generation capability index value and a reliability index value of the wave energy conversion device. 16.A device for evaluating a wave energy conversion device, comprising: a construction module configured to construct a mathematical model for the wave energy conversion device according to any one of claims 1-10, wherein the mathematical model is a simulation equation for simulating motion characteristics of the wave energy conversion device; an operation module configured to solve the mathematical model to obtain an evaluation index value of the wave energy conversion device. 17.A computer device, comprising a memory and a processor, wherein the memory stores a computer program. The processor, when executing the computer program, implements the steps of the method of any one of claims 11-15.

18. A non-transitory computer readable storage medium having stored thereon a computer program, the computer program comprising program instructions configured to cause a processor to perform the method of any one of claims 1-17. The computer program, when executed by the processor, implements the steps of the method of any one of claims 11-15.

19. A computer program product, comprising computer-executable instructions, characterized in that, The computer executable instructions, when executed by the processor, implement the steps of the method of any one of claims 11-15.

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