Wave energy-wind energy power generation system attached to catenary mooring line and verification method

Abstract

The present application relates to the wave energy - wind power generation system and calibration method attached to the catenary mooring line, belong to the marine renewable energy power generation technical field. Solve the problem of complex structure, difficult to practical application of prior art. Including wind turbine, platform, catenary mooring and wave energy device, the middle part of the platform is provided with wind turbine, the two ends of catenary mooring are connected with platform and seabed respectively, the middle part of catenary mooring is provided with wave energy device. The wave energy device of the present application can not only convert energy, but also can replace the mass block on the catenary mooring line, the structure is ingenious, thereby saving cost, has broad application prospect.

Description

Technical Field

[0001] This invention relates to wave energy-wind energy power generation systems and verification methods, belonging to the field of marine renewable energy power generation technology. Background Technology

[0002] Offshore wind turbines have advantages such as large single-unit capacity, high power generation efficiency, and low environmental pollution, making them a current hot topic in clean energy research. However, the development of deep-water floating wind turbines still faces challenges, with high costs, harsh working environments, and negative platform damping hindering their development. Wave energy is a type of mechanical energy generated by wind and stored as potential and kinetic energy in short-period waves. Currently, common wave energy devices mainly include oscillating water column (OWC), float-type, and nodding duck type. These wave energy devices are generally used individually, resulting in low power generation efficiency and high costs.

[0003] Current research indicates that wind-wave combined power generation systems help reduce the pitching and swaying of floating wind turbine platforms, thereby improving the stability of the structural system. This is because the addition of wave energy or tidal energy devices reduces the wave load on the floating platform. To reduce the cost of wind-wave coupled power generation, wave energy devices are installed on catenary mooring lines. This not only solves the problem of counterweights on catenary mooring lines but also utilizes the heave motion of the catenary mooring lines to generate electricity.

[0004] For example, CN114645817A, an invention entitled "A Multi-Degree-of-Freedom Wave Energy Float Coupled with a Semi-Submersible Wind Turbine Power Generation System and Method," describes a power generation system comprising a semi-submersible platform. A wind turbine is installed at the center of the upper part of the platform, and a multi-degree-of-freedom wave energy float is installed on the semi-submersible platform surrounding the wind turbine. Both the wind turbine and the multi-degree-of-freedom wave energy float are controlled by a central control system. However, the multi-degree-of-freedom wave energy float operates in the heave and pitch directions. When waves in other directions are too large, the float cannot function, and there is a risk of damage to the piston rod and the float. Furthermore, the wave energy device involved in this application has a complex structure, is difficult to implement, and has excessively high engineering costs.

[0005] For example, publication number CN217873094U, entitled "A Floating Wave Energy Power Generation Device and a Wind-Wave Energy Combined Power Generation Platform," relates to the technical field of offshore renewable energy utilization devices. The wave energy power generation device includes a buoy and a wave energy utilization component fitted onto the outer surface of the buoy, which can generate electricity using wave energy. This application uses an air turbine generator for power generation. When waves are too large, the air vents are easily submerged underwater. An excessively large floating platform and high buoyancy cause instability of the wind turbine on top of the platform during operation. Therefore, the wave energy device in this application has low energy transfer efficiency and large structural vibrations, making it difficult to apply in practical engineering.

[0006] Therefore, it is urgent to propose a wave energy-wind energy generation system and verification method attached to a catenary mooring line to solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to address the problems of complex structures and difficulty in practical application of existing technologies, and to provide a wave energy-wind energy generation system and verification method attached to a catenary mooring line. A brief overview of the invention is provided below to offer a basic understanding of certain aspects of it. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention.

[0008] The technical solution of this invention:

[0009] A wave energy-wind energy power generation system attached to a catenary mooring line includes a wind turbine, a platform, a catenary mooring line, and a wave energy device. The wind turbine is located in the middle of the platform, the two ends of the catenary mooring line are connected to the platform and the seabed, respectively, and the wave energy device is located in the middle of the catenary mooring line.

[0010] Preferably, the wave energy device includes a column, a chassis, an accumulator, a ballast tank, a generator, a hydraulic cylinder, a lower spring, a mover, and an upper spring. The lower part of the wave energy device's outer shell is provided with a ballast tank. The upper part of the mover is connected to the upper side wall inside the wave energy device's outer shell through the upper spring. The lower part of the mover is connected to the chassis through the lower spring. The chassis is located inside the wave energy device's outer shell and is connected to it. The upper part of the ballast tank is connected to the hydraulic cylinder. The movable end of the hydraulic cylinder passes through a through hole in the middle of the chassis and is connected to the mover. The hydraulic cylinder's oil cylinder is connected to the accumulator, and the accumulator is connected to the generator.

[0011] Preferably, the wave energy device further includes a column, a connector, and a sliding shaft. Symmetrical sliding shafts are provided on both sides of the chassis. The sliding shafts are installed inside the outer shell of the wave energy device through the column. A connector is provided on the side of the mover 14. The connector is slidably connected to the sliding shaft.

[0012] Preferably, the wave energy device further includes a stiffness converter, and the stiffness converter is installed on the chassis.

[0013] Preferably, the wave energy device further includes a piston rod, the two ends of which are connected to the bottom center of the mover and the movable end of the hydraulic cylinder respectively via universal joints.

[0014] Preferably, the wave energy device further includes an interface, which is located at the upper middle part of the outer shell of the wave energy device, and the two ends of the steel chain are respectively connected to the interface and the catenary mooring.

[0015] Preferably, the platform is a semi-submersible platform with three external cylinders arranged in a circumferential array on the platform, and each external cylinder is connected to a corresponding catenary mooring.

[0016] Preferred: The wind turbine includes blades, nacelle, hub and tower. The tower is mounted on the central cylinder of the platform, the nacelle is mounted on the top of the tower, the hub is connected to the nacelle, and three blades are equidistantly arranged around the hub.

[0017] Preferred configuration: also includes cables and a power control center, with the generator, engine room, and power control center electrically connected, and the control center outputting electrical energy to the outside world through cables.

[0018] A verification method for wave energy-wind power generation systems attached to catenary mooring lines includes the following steps:

[0019] Step 1: Calculate the linear relationship between PTO load and speed;

[0020] Step 2: Parameter setting;

[0021] Step 3: Analyze the results and verify their reasonableness.

[0022] The present invention has the following beneficial effects:

[0023] The wave energy device and the integrated power generation system of the catenary mooring line of the present invention can be used on deep-sea floating platforms. The power generated by the wave energy device can charge various deep-sea submersibles, reducing the power supply cost in deep-sea areas.

[0024] The wave energy device and the integrated power generation system of the catenary mooring line of the present invention can be used in deep-sea floating wind power generation mechanisms. The coupled power generation method improves power generation efficiency and reduces economic costs.

[0025] The wave energy device of the present invention has a stiffness converter installed inside, which can adjust the output of stiffness, reduce the frequency of the structure, and avoid resonance between the wave energy device and the catenary mooring line and the semi-submersible platform.

[0026] The wave energy device of the present invention can both convert energy and replace the mass block on the catenary mooring line. It has an ingenious structure, thereby saving costs and has broad application prospects.

[0027] This invention improves the quality and safety of the output electrical energy by enhancing the stability of the wave energy device. Attached Figure Description

[0028] Figure 1 This is a front view of a wave energy-wind energy generation system attached to a catenary mooring line.

[0029] Figure 2 This is a top view of a wave energy-wind energy generation system attached to a catenary mooring line.

[0030] Figure 3 This is an external outline diagram of a wave energy device;

[0031] Figure 4 This is a diagram of the internal structure of a wave energy device when the mover is at rest;

[0032] Figure 5 This is a diagram of the internal structure of a wave energy device during the motion of a moving part.

[0033] Figure 6 These are the vertical displacement time-history curves of the three wave energy devices corresponding to the three catenary mooring lines;

[0034] Figure 7 These are the vertical force diagrams for the three moving parts;

[0035] Figure 8 These are (a) sway, (b) sway, and (c) heave diagrams of a semi-submersible platform with a mass block and a wave energy device added to the catenary, respectively.

[0036] Figure 9 These are (d) roll, (e) pitch, and (f) bow diagrams of a semi-submersible platform with mass blocks and wave energy devices added to the catenary, respectively.

[0037] In the diagram: 1-Interface; 2-Column; 3-Connector; 4-Sliding shaft; 5-Chassis; 6-Stiffness converter; 7-Accumulator; 8-Ballast tank; 9-Generator; 10-Hydraulic cylinder; 12-Piston rod; 13-Lower spring; 14-Motor; 15-Upper spring; 16-Blade; 17-Nacelle; 18-Hub; 19-Tower; 20-Semi-submersible platform; 21-Cattail mooring; 22-Wave energy device; 23-Cable; 24-Power control center; 25-Steel chain. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0039] Specific implementation method one: Combining Figure 1-5 This embodiment describes a wave energy-wind energy power generation system attached to a catenary mooring line, comprising a wind turbine, a platform 20, a catenary mooring line 21, and a wave energy device 22. The wind turbine is located in the middle of the platform 20, and the two ends of the catenary mooring line 21 are connected to the platform 20 and the seabed, respectively. The wave energy device 22 is located in the middle of the catenary mooring line 21. The integrated power generation system of the wave energy device and the catenary mooring line of this invention can be used on deep-sea floating platforms. The electricity generated by the wave energy device can charge various deep-sea submersibles, reducing the power supply cost in deep-sea environments. The integrated power generation system of the wave energy device and the catenary mooring line of this invention can also be used in deep-sea floating wind power generation mechanisms. The coupled power generation method improves power generation efficiency and reduces economic costs.

[0040] Specific Implementation Method Two: Combining Figure 1-5 This embodiment describes a wave energy-wind power generation system attached to a catenary mooring line. The wave energy device 22 is a ballast water regulating wave energy device. The wave energy device 22 includes a chassis 5, an accumulator 7, a ballast tank 8, a generator 9, a hydraulic cylinder 10, a lower spring 13, a mover 14, and an upper spring 15. The ballast tank 8 is located at the lower part of the outer shell of the wave energy device 22. The structure is kept balanced by regulating the ballast water in the ballast tank. The upper part of the mover 14 is connected to the upper side wall inside the outer shell of the wave energy device 22 via the upper spring 15, and the lower part of the mover 14 is connected to the chassis 5 via the lower spring 13. The chassis 5 is located inside the outer shell of the wave energy device 22 and... The wave energy device 22 is fixedly connected to the outer shell, and the upper part of the ballast tank 8 is fixedly connected to the hydraulic cylinder 10. The movable end of the hydraulic cylinder 10 passes through the through hole in the middle of the chassis 5 and is connected to the mover 14. The oil cylinder of the hydraulic cylinder 10 is connected to the accumulator 7, and the accumulator 7 is connected to the generator 9. The accumulator 7 and the generator 9 are located inside the outer shell of the wave energy device 22. When the movable end of the hydraulic cylinder 10 moves vertically, it causes the hydraulic oil to be exchanged between the accumulator 7 and the generator 9. When the hydraulic oil flows into the generator 9, it drives the generator to do work and generate electrical energy. The wave energy device of the present invention can perform energy conversion and can also replace the mass block on the catenary mooring line, thereby saving costs and having broad application prospects.

[0041] Specific implementation method three: Combining Figure 1-5This embodiment describes a wave energy-wind power generation system attached to a catenary mooring line. The wave energy device 22 further includes columns 2, connectors 3, and sliding shafts 4. A mover 14 is installed between two parallel columns 2. Symmetrical sliding shafts 4 are arranged on both sides of the chassis 5. The sliding shafts 4 are fixedly installed inside the outer shell of the wave energy device 22 through the columns 2. A connector 3 is fixedly installed on the side of the mover 14. The connector 3 is a sliding sleeve and is slidably connected to the sliding shaft 4. The upper part of the ballast tank 8, i.e., inside the wave energy device, contains two vertically parallel columns 2, a generator 9, and an energy storage device 7. This invention improves the stability of the wave energy device, resulting in higher quality and safer output power.

[0042] Specific implementation method four: Combination Figure 1-5 This embodiment describes a wave energy-wind power generation system attached to a catenary mooring line. The wave energy device 22 further includes a stiffness converter 6, which is mounted on the chassis 5. The stiffness converter 6 is installed on the chassis 5, and by adjusting the stiffness converter 6, the stiffness output of the wave energy device 22 can be changed, thereby adjusting the stiffness of the upper and lower springs of the mover 14 to avoid structural resonance. The bottom of the wave energy device 22 is provided with a ballast tank 8, and the balance of the wave energy device 22 is adjusted by ballast water.

[0043] Specific Implementation Method Five: Combining Figure 1-5 This embodiment describes a wave energy-wind power generation system attached to a catenary mooring line. The wave energy device 22 further includes a piston rod 12, with both ends of the piston rod 12 connected to the bottom center of the mover 14 and the movable end of the hydraulic cylinder 10 via universal joints. When the catenary mooring line 21 is subjected to wind and waves, it undergoes a swaying motion, thereby converting the vertical motion of the mover 14 into the vertical displacement of the piston rod 12. The hydraulic cylinder 10 is connected to the accumulator 7, which is connected to the generator 9 via a pipeline. The vertical reciprocating motion of the piston rod 12 drives the piston at the movable end of the hydraulic cylinder to move in the cylinder, causing the hydraulic oil to be transferred between the generator 9, the hydraulic cylinder 10, and the accumulator 7, thereby driving the generator to perform work.

[0044] Specific Implementation Method Six: Combination Figure 1-5 This embodiment describes a wave energy-wind energy generation system attached to a catenary mooring line. The wave energy device 22 further includes an interface 1, which is located at the upper middle part of the outer shell of the wave energy device 22. The two ends of the steel chain 25 are respectively connected to the interface 1 and the catenary mooring line 21.

[0045] Specific implementation method seven: Combining Figure 1-5This embodiment describes a wave energy-wind energy generation system attached to a catenary mooring line. Platform 20 is a semi-submersible platform. Three external cylinders are arranged in a circumferential array on the triangular platform 20. Each external cylinder is fixedly connected to a corresponding catenary mooring line 21. The three external cylinders are respectively connected to the catenary mooring line 21, and the tail of the mooring line is anchored to the seabed. The three catenary mooring lines are connected to three wave energy devices 22 by steel chains. The semi-submersible platform consists of four cylinders, a triangular float, and a heave plate. The central cylinder is connected to the three external cylinders through the triangular float, and the heave plate is installed at the bottom of the triangular float.

[0046] Specific implementation method eight: Combination Figure 1-5 This embodiment describes a wave energy-wind power generation system attached to a catenary mooring line. The wind turbine includes blades 16, a nacelle 17, a hub 18, and a tower 19. The tower 19 is mounted on the central cylinder of a platform 20, the nacelle 17 is mounted on top of the tower 19, and the hub 18 is connected to the nacelle 17. Three equidistant blades 16 are arranged circumferentially on the hub 18. The tower 19 of the wind turbine is mounted on the central cylinder of a semi-submersible platform 20, the nacelle 17 is mounted on top of the tower 19, and the hub 18 is connected to the nacelle 17. Finally, the three blades 16 are installed on the hub 18. After the wind turbine is installed and commissioned, it can be put into service. During service, the inflow wind speed at the operating wind speed generates aerodynamic force to drive the blades 16 to rotate. The blades 16 are connected to a low-speed bearing inside the nacelle 17. The low-speed bearing is connected to a high-speed shaft through gears, converting low-speed rotation into high-speed rotation. The high-speed shaft is connected to a generator inside the nacelle 17, and finally, the generator generates electricity.

[0047] Specific Implementation Method Nine: Combining Figure 1-5 This embodiment describes a wave energy-wind energy power generation system attached to a catenary mooring line. It also includes a cable 23 and a power control center 24. The power control center 24 is located inside a central cylinder. The generator 9 and nacelle 17 are electrically connected to the power control center 24. The control center 24 outputs electrical energy to the outside via the cable 23. The electrical energy generated by the wind power generation mechanism and the wave energy device 22 is all fed into the power control center 24. The electrical energy generated by the wave energy device 22 and the wind power generator is integrated by the control center 24 and then output via the cable.

[0048] Specific Implementation Method Ten: Combining Figure 1-9 This embodiment describes a verification method for a wave energy-wind power generation system attached to a catenary mooring line. Based on the aforementioned wave energy-wind power generation system, the method includes the following steps:

[0049] Step 1: Calculate the linear relationship between PTO load and speed;

[0050]

[0051] In the formula: F p Indicates the external power output load, c p Indicates the damping coefficient. α represents the vertical velocity of the mover, and α represents the velocity coefficient;

[0052] Step 2: Parameter setting;

[0053] The damping coefficient applied vertically is 90,000 N / (m / s). The wave energy device is installed 91.1 meters below the water surface, weighs 450 tons, and is designed to operate as Airy waves with a wave height of 6m, a period of 10s, a wind and wave direction of 0°, a turbulent wind speed of 11.4m / s, and an operating water depth of 130m.

[0054] Step 3: Analyze the results and verify their reasonableness;

[0055] The results of the computational analysis show that, Figure 6 Figure 7 As shown, the vertical displacement of the wave energy device facing the wave is approximately 20m, with a vertical force of less than 1kN. The vertical displacement of the other two wave energy devices is within 15m, with vertical forces ranging from 0kN to 25kN. Figure 8 Figure 9 As shown, the motion response of a semi-submersible platform with attached mass blocks and wave energy devices on a catenary mooring line was compared and analyzed. It can be found that both have little impact on the platform's motion. The semi-submersible platform's sway remains at about 20m, the roll is between (0.2°, 0.7°), the pitch fluctuates in the range of approximately (0°, 5.5°), and the heave is approximately between (-1.5m, 1.3m), indicating a reasonable design.

[0056] To verify the rationality of this invention, a model was designed in OrcaFlex. The wave energy device was installed 91.1 meters below the water surface, weighing 450 tons. The operating conditions were designed as follows: Airy waves with a height of 6m, a period of 10s, a wind direction of 0°, a turbulent wind speed of 11.4m / s, and a working water depth of 130m. The results of coupled analysis using OpenFAST and OrcaFlex show that the vertical displacement of the wave energy device facing the wave is approximately 20m, with a vertical force of less than 1kN. The vertical displacement of the other two wave energy devices is within 15m, with vertical forces ranging from 0kN to 25kN. The semi-submersible platform exhibits a sway of approximately 20m, a roll between 0.2° and 0.7°, a pitch fluctuation within approximately 0° and 5.5°, and a heave between approximately -1.5m and 1.3m.

[0057] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not describe the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wave energy-wind energy generation system attached to a catenary mooring line, characterized in that: It includes a wind turbine, a platform (20), a catenary mooring (21) and a wave energy device (22). The wind turbine is installed in the middle of the platform (20), the two ends of the catenary mooring (21) are connected to the platform (20) and the seabed respectively, and the wave energy device (22) is installed in the middle of the catenary mooring (21). The wave energy device (22) includes a chassis (5), an accumulator (7), a ballast tank (8), a generator (9), a hydraulic cylinder (10), a lower spring (13), a mover (14), and an upper spring (15). The lower part of the outer shell of the wave energy device (22) is provided with a ballast tank (8). The upper part of the mover (14) is connected to the upper side wall inside the outer shell of the wave energy device (22) through the upper spring (15). The lower part of the mover (14) is connected to the chassis (5) through the lower spring (13). The chassis (5) is located inside the outer shell of the wave energy device (22) and is connected to the outer shell of the wave energy device (22). The upper part of the ballast tank (8) is connected to the hydraulic cylinder (10). The movable end of the hydraulic cylinder (10) passes through the through hole in the middle of the chassis (5) and is connected to the mover (14). The oil cylinder of the hydraulic cylinder (10) is connected to the accumulator (7). The accumulator (7) is connected to the generator (9).

2. The wave energy-wind energy generation system attached to a catenary mooring line according to claim 1, characterized in that: The wave energy device (22) also includes a column (2), a connector (3) and a sliding shaft (4). The chassis (5) is provided with symmetrical sliding shafts (4) on both sides. The sliding shafts (4) are provided inside the shell of the wave energy device (22) through the column (2). The side of the mover (14) is provided with a connector (3), and the connector (3) is slidably connected to the sliding shaft (4).

3. The wave energy-wind energy generation system attached to a catenary mooring line according to claim 2, characterized in that: The wave energy device (22) also includes a stiffness converter (6), which is mounted on the chassis (5).

4. The wave energy-wind energy generation system attached to a catenary mooring line according to claim 1, characterized in that: The wave energy device (22) also includes a piston rod (12), the two ends of which are connected to the bottom center of the mover (14) and the movable end of the hydraulic cylinder (10) respectively through universal joints.

5. The wave energy-wind energy generation system attached to a catenary mooring line according to claim 1, characterized in that: The wave energy device (22) also includes an interface (1), which is located at the upper middle part of the outer shell of the wave energy device (22). The two ends of the steel chain (25) are connected to the interface (1) and the catenary mooring (21) respectively.

6. The wave energy-wind energy generation system attached to a catenary mooring line according to any one of claims 1-5, characterized in that: The platform (20) is a semi-submersible platform. Three external cylinders are arranged in a circumferential array on the platform (20), and one external cylinder is connected to a corresponding catenary mooring (21).

7. The wave energy-wind energy generation system attached to a catenary mooring line according to claim 6, characterized in that: The wind turbine includes blades (16), nacelle (17), hub (18) and tower (19). The tower (19) is mounted on the central cylinder of the platform (20). The nacelle (17) is mounted on the top of the tower (19). The hub (18) is connected to the nacelle (17). The hub (18) has three blades (16) arranged equidistantly around its circumference.

8. The wave energy-wind energy generation system attached to a catenary mooring line according to claim 7, characterized in that: It also includes a cable (23) and a power control center (24). The generator (9), the engine room (17) are electrically connected to the power control center (24), and the control center (24) outputs electrical energy to the outside world through the cable (23).

9. A verification method for a wave energy-wind energy generation system attached to a catenary mooring line, characterized in that: The wave energy-wind energy generation system attached to a catenary mooring line according to any one of claims 1-8 includes the following steps: Step 1: Calculate the linear relationship between PTO load and speed; In the formula: Indicates the external power output load. Indicates the damping coefficient. Indicates the vertical velocity of the mover. Indicates the velocity coefficient; Step 2: Parameter setting; Step 3: Analyze the results and verify their reasonableness.

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