An oscillating float sea wave energy hydraulic collection system and hydraulic energy conversion system

Abstract

The utility model relates to a kind of oscillating float sea wave energy hydraulic acquisition system and hydraulic energy conversion system, and acquisition system includes floater, three-section variable-diameter push-pull rod, upper and lower double oil cylinder, one-way valve group and guide rail guide wheel guiding mechanism etc., the buoyancy of floater heaving motion can be efficiently converted into hydraulic energy with gravity;Conversion method is through energy storage tank buffer pressure pulsation, and uses multiple-gear hydraulic motor parallel connection scheme, according to system pressure automatically switches different specifications motor work, realizes the efficient, stable conversion of sea wave energy in 0.3~4m wave height range.The utility model is reliable in structure, energy capture efficiency is high, self-adaptability is strong, output is stable, significantly improves the comprehensive performance and economy of wave energy power generation device.

Description

Technical Field

[0001] This utility model relates to the field of marine renewable energy technology, to the collection and utilization of marine energy, and particularly to an oscillating buoy wave energy hydraulic collection system and hydraulic energy conversion system. Background Technology

[0002] Wave energy, as a widely distributed and abundant renewable energy source, has become a research hotspot both domestically and internationally. However, wave energy power generation technology still faces problems such as low conversion efficiency, poor device reliability, high operation and maintenance costs, and poor grid-connected power quality. In particular, the energy harvesting section of oscillating float-type wave energy devices often suffers from low energy capture efficiency due to unreasonable structural design, resulting in a mismatch between the float's heave motion and the hydraulic cylinder's stroke and thrust. Furthermore, the hydraulic system has poor adaptability under wide wave conditions, with large output pressure fluctuations, directly affecting the stable operation of the generator.

[0003] In existing technologies, hydraulic wave energy devices mostly employ single-cylinder single-acting or double-acting structures, which suffer from problems such as piston rod instability, easy seal damage, and poor response to small to medium-sized waves. Furthermore, the multi-stage hydraulic energy conversion systems lack adaptive control mechanisms for different sea conditions, leading to a sharp drop in system efficiency when wave height changes, making it difficult to achieve stable power output. Therefore, there is an urgent need for a hydraulic wave energy acquisition and conversion system that is structurally reliable, has high energy conversion efficiency, possesses adaptive capabilities, and can output power stably. Utility Model Content

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide an oscillating float wave energy hydraulic acquisition system and hydraulic energy conversion system. This system can convert the rising force of the float when it is buoyed by the rising waves and the falling force caused by the weight of the float when it sinks into hydraulic energy. It can also ensure that the stroke of the hydraulic cylinder is within the control range when the float moves up and down. This solves the problems of low energy conversion efficiency, large hydraulic output pulsation, poor system adaptability and easy damage of key components in the prior art.

[0005] The purpose of this utility model is achieved as follows: A hydraulic wave energy harvesting system using an oscillating buoy includes: Floats are used to capture wave energy; The push-pull rod has a three-section variable diameter structure, consisting of an upper section, a middle section, and a lower section from top to bottom, with the upper and lower sections having a larger diameter than the middle section; the top of the float is connected to the bottom surface of the push-pull rod. The upper and lower oil cylinders are connected vertically, allowing the push-pull rod to pass through and reciprocate. The upper section of the push-pull rod moves up and down in the upper oil cylinder, the lower section moves up and down in the lower oil cylinder, and the middle section moves between the upper and lower oil cylinders. The upper inlet check valve and the upper outlet check valve are installed on the upper part of the upper cylinder; The lower inlet check valve and the lower outlet check valve are installed on the upper part of the lower cylinder; The low-pressure inlet pipe connects to the inlet of the upper inlet check valve and the lower inlet check valve; The high-pressure outlet pipe connects to the outlets of the upper outlet check valve and the lower outlet check valve. A solenoid valve is connected in parallel to both ends of the lower inlet check valve; The upper and lower guide rails are fixed to the upper and lower parts of the float, respectively; The upper fixed frame and the lower fixed frame are arranged above the float and surround the upper and lower oil cylinders. The top of the upper oil cylinder is fixed to the upper fixed frame. The lower fixed frame is arranged below the float. The guide wheel assembly is installed inside the upper and lower fixed frames and works with the upper and lower guide rails to constrain the movement trajectory of the float.

[0006] Furthermore, the total length of the push-pull rod is designed based on the maximum wave height. The maximum wave height determines the maximum amplitude of the float, so the lengths of the upper, middle, and lower sections of the push-pull rod are matched with the maximum amplitude of the float.

[0007] Furthermore, all three sections of the push-pull rod are composed of seamless tubing, and the wall thickness of the push-pull rod is 8~15mm.

[0008] Furthermore, the inner diameter of the upper and lower hydraulic cylinders is 40-60 mm larger than the outer diameter of the corresponding section of the push-pull rod.

[0009] Furthermore, one end of the low-pressure inlet pipe is connected to the upper inlet check valve and the lower inlet check valve, and the other end is connected to the high-level oil tank; one end of the high-pressure outlet pipe is connected to the upper outlet check valve and the lower outlet check valve, and the other end is connected to the storage tank.

[0010] Furthermore, four upper guide rails are provided above the float. The four upper guide rails are arranged around the outside of the upper and lower oil cylinders and distributed at the four corners of the square. A protective partition is provided between two adjacent upper guide rails, so that the push-pull rods installed inside the float and the upper and lower oil cylinders installed on the fixed frame are hidden inside and not corroded by splashing seawater.

[0011] Furthermore, the upper fixed frame is a cubic frame structure, and the upper fixed frame is provided with two sets of upper guide wheels. One set of upper guide wheels is located at the bottom of the upper fixed frame, and the distance between the two sets of upper guide wheels exceeds the maximum stroke of the push-pull rod. Each set of upper guide wheels includes eight upper guide wheels, and two upper guide wheels are evenly distributed on the inner wall of the upper fixed frame. Each upper guide wheel corresponds to the outer side of an upper guide rail, that is, each upper guide rail corresponds to two upper guide wheels. The upper guide rail and the upper guide wheels cooperate to constrain the horizontal movement of the float.

[0012] Furthermore, when collecting wave energy with a wave height of 2.5 meters or more, a cylindrical lower guide rail is installed below the float. A lower fixing frame is provided on the outside of the lower guide rail. The lower fixing frame is a square frame structure. At least one lower guide wheel is provided on each of the four inner walls of the lower fixing frame. The lower guide wheel surrounds the lower guide rail. The lower guide rail and the lower guide wheel cooperate to constrain the up and down movement of the lower guide rail. Furthermore, a connecting fixing frame is provided on one side of the upper fixing frame and the lower fixing frame. The side of the connecting fixing frame is F-shaped, and the bottom end of the support rod of the connecting fixing frame is connected to the lower fixing frame to form an upper and lower balance.

[0013] A hydraulic energy conversion system for an oscillating buoy wave energy hydraulic acquisition system, based on the aforementioned oscillating buoy wave energy hydraulic acquisition system, includes an energy storage tank, an overflow valve A, an electric valve assembly, a hydraulic motor assembly, a low-pressure storage tank, an overflow valve B, and a high-level oil tank. Multiple high-pressure outlet pipes of the aforementioned oscillating buoy wave energy hydraulic acquisition system are connected to the energy storage tank. An electric valve assembly and a hydraulic motor assembly are installed between the energy storage tank and the low-pressure storage tank. The energy storage tank is connected to the high-level oil tank via overflow valve A, and the low-pressure storage tank is connected to the high-level oil tank via overflow valve B. The high-level oil tank is connected to the low-pressure inlet pipes of multiple acquisition units. The electric valve group includes at least three electric valves, and the hydraulic motor group includes multiple hydraulic motors, each corresponding to one of the electric valves. The corresponding electric valves and hydraulic motors are connected as a group, and multiple groups of electric valves and hydraulic motors are arranged in parallel between the energy storage tank and the low-pressure liquid storage tank.

[0014] Compared with the prior art, the beneficial effects of this utility model are: This invention provides a hydraulic energy harvesting system and a hydraulic energy conversion system for an oscillating float. The system allows the float to move vertically within upper and lower cylinders via a push-pull rod after being impacted by waves. When the waves rise, the buoyancy force generated by the float is directly converted into hydraulic energy through the vertical movement of the push-pull rod. When the waves recede, the float loses buoyancy, and its mass lowers the push-pull rod, directly converting gravity into hydraulic energy. This maximizes the conversion efficiency. It has the following specific advantages: (1) High-efficiency energy capture: The structure of double cylinder and variable diameter push-pull rod is adopted to directly convert the buoyancy and gravity of the float's heave motion into hydraulic energy. There is no lever angle loss, the conversion efficiency is high, and it is suitable for wave height range of 0.3~4m.

[0015] (2) Reliable structure and impact resistance: The three-section push-pull rod design avoids the problem of instability of long and thin rods; the combination of guide rail and guide wheel effectively suppresses float swaying, reduces lateral force, and extends the life of seals and components.

[0016] (3) Adaptive energy conversion: The multi-stage hydraulic motor parallel design automatically switches based on the pressure sensor signal, and can operate efficiently under wide wave conditions, especially improving the ability to capture high energy in low wave conditions.

[0017] (4) Stable output with protection mechanism: The energy storage tank buffers pressure pulses to ensure stable hydraulic motor speed; the solenoid valve can automatically trigger protection mode under harsh sea conditions to improve system survivability.

[0018] (5) High system integration and easy maintenance: modular design, key components are easy to repair, simple overall structure, low manufacturing cost, suitable for large-scale application. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the hydraulic data acquisition system of this utility model.

[0020] Figure 2 This is a side view of the hydraulic data acquisition system of this utility model.

[0021] Figure 3 for Figure 1 AA sectional view.

[0022] Figure 4 for Figure 2 BB cross-sectional view.

[0023] Figure 5 This is a schematic diagram of the hydraulic energy conversion system of this utility model.

[0024] in: Float 1, Connecting Fixing Frame 2, Upper Fixing Frame 3, Lower Fixing Frame 4, Upper Inlet Check Valve 5, Upper Outlet Check Valve 6, Lower Inlet Check Valve 7, Lower Outlet Check Valve 8, Low-Pressure Inlet Pipe 9, High-Pressure Outlet Pipe 10, Push-Pull Rod 11, Upper Cylinder 12, Lower Cylinder 13, Upper Guide Roller 14.1, Lower Guide Roller 14.2, Upper Guide Rail 15, Protective Seal Plate 16, Lower Guide Rail 17, Solenoid Valve 18, Seal 19, Energy Storage Tank 20, Overflow Valve A 21, Low-Pressure Electric Valve 22.1, Medium-Pressure Electric Valve 22.2, High-Pressure Electric Valve 22.3, Extremely High-Pressure Electric Valve 22.4, Low-Pressure Hydraulic Motor 23.1, Medium-Pressure Hydraulic Motor 23.2, High-Pressure Hydraulic Motor 23.3, Extremely High-Pressure Hydraulic Motor 23.4, Low-Pressure Storage Tank 24, Overflow Valve B 25, High-Level Oil Tank 26. Detailed Implementation

[0025] To better understand the technical solution of this utility model, a detailed description will be provided below in conjunction with relevant illustrations. It should be understood that the specific embodiments described below are not intended to limit the specific implementation of the technical solution of this utility model, but are merely possible implementations of the technical solution of this utility model. It should be noted that the descriptions of the positional relationships of the components herein, such as component A being located above component B, are based on the relative positions of the components in the illustrations and are not intended to limit the actual positional relationships of the components. Example 1

[0026] See Figure 1-4 , Figure 1 A schematic diagram of the structure of an oscillating float wave energy hydraulic acquisition system according to Embodiment 1 is shown. As shown in the figure, the oscillating float wave energy hydraulic acquisition system of this utility model includes a float 1, a connecting and fixing frame 2, an upper fixing frame 3, a push-pull rod 11, an upper oil cylinder 12, and a lower oil cylinder 13. The top of the float 1 is rigidly connected to the bottom surface of the push-pull rod 11. The upper oil cylinder 12 and the lower oil cylinder 13 are provided on the outside of the push-pull rod 11, and the upper oil cylinder 12 and the lower oil cylinder 13 are arranged vertically. An upper guide rail 15 is provided above the float 1, and a lower guide rail 17 is provided below it.

[0027] The float 1 is an energy harvesting component, and its shape, mass and size are designed according to the wave conditions of the target sea area.

[0028] The push-pull rod 11 is a three-section variable diameter rod, including an upper section, a middle section and a lower section, replacing the traditional piston and piston rod structure. The upper section of the push-pull rod 11 moves up and down in the upper cylinder 12, and the lower section of the push-pull rod 11 moves up and down in the lower cylinder 13. The diameter of the middle section of the push-pull rod 11 is smaller than the diameter of the upper and lower sections, and the middle section of the push-pull rod 11 moves between the upper cylinder 12 and the lower cylinder 13.

[0029] The total length of the push-pull rod 11 is designed based on the maximum wave height. In this embodiment, it is set that wave energy of 0.3~4.5m height is to be collected and the maximum amplitude of float 1 does not exceed 4m. Therefore, the length of each section of the upper, middle and lower sections of the push-pull rod 11 is 4m. To reduce weight, all three sections of the push-pull rod 11 are made of seamless tubing, and the wall thickness of the push-pull rod 11 is 8~15mm. In this embodiment, the wall thickness of the push-pull rod 11 is 11mm.

[0030] The top of the upper cylinder 12 is fixed on the upper fixing frame 3. The cylinder bodies of the upper cylinder 12 and the lower cylinder 13 are connected by a flange. The inner diameter of the upper cylinder 12 and the lower cylinder 13 is 40-60mm larger than the outer diameter of the corresponding section of the push-pull rod 11. The upper cylinder 12 has an upper inlet check valve 5 on one side of its top and an upper outlet check valve 6 on the other side of its top. The lower cylinder 13 has a lower inlet check valve 7 on one side of its top, located on the same side as the upper inlet check valve 5. The lower cylinder 13 has a lower outlet check valve 8 on the other side of its top. A low-pressure inlet pipe 9 connects the upper inlet check valve 5 and the lower inlet check valve 7. A high-pressure outlet pipe 10 connects the upper outlet check valve 6 and the lower outlet check valve 8. One end of the low-pressure inlet pipe 9 is connected to the upper inlet check valve 5 and the lower inlet check valve 7, and the other end is connected to the high-level oil tank 26. One end of the high-pressure outlet pipe 10 is connected to the upper outlet check valve 6 and the lower outlet check valve 8, and the other end is connected to the energy storage tank 20. When the push rod 11 rises, the upper inlet check valve 5 creates a negative pressure in the upper cylinder 12, forcing the upper inlet check valve 5 to open. Liquid from the low-pressure inlet pipe 9 enters the upper cylinder 12 through the upper inlet check valve 5. When the push rod 11 falls, the upper outlet check valve 6 creates a positive pressure in the upper cylinder 12, causing the upper outlet check valve 6 to open. High-pressure liquid in the upper cylinder 12 is then forced through the upper outlet check valve 6 towards the high-pressure outlet pipe 10. When the push rod 11 descends, the lower inlet check valve 7 creates a negative pressure in the lower cylinder 13, forcing the lower inlet check valve 7 to open. Liquid from the low-pressure inlet pipe 9 enters the lower cylinder 13 through the lower inlet check valve 7. When the push rod 11 rises, the lower outlet check valve 8 creates a positive pressure in the lower cylinder 13, causing the lower outlet check valve 8 to open. This allows the high-pressure liquid in the lower cylinder 13 to be forced through the lower outlet check valve 8 towards the high-pressure outlet pipe 10.

[0031] A sealing ring is provided at the connection between the upper cylinder 12 and the lower cylinder 13 to seal the middle section of the push-pull rod 11 and the two cylinders. A seal 19 is provided between the top of the upper cylinder 12 and the upper section of the push-pull rod 11, and a seal 19 is provided between the bottom of the lower cylinder 13 and the lower section of the push-pull rod 11.

[0032] A solenoid valve 18 is also provided between the lower inlet check valve 7 and the low-pressure inlet pipe 9. One end of the solenoid valve 18 is connected to the lower inlet check valve 7, and the other end is connected to the low-pressure inlet pipe 9. When the solenoid valve 18 is open, it is in normal working condition. When the waves are too large and the float amplitude is too large, the solenoid valve 18 is automatically closed by the automatic control system, so that the float can only float and cannot sink, thereby realizing the system overload protection.

[0033] Four upper guide rails 15 are provided above the float 1. The four upper guide rails 15 are arranged around the outside of the upper oil cylinder 12 and the lower oil cylinder 13, and are distributed at the four corners of the square. The upper guide rails 15 are square in shape. A protective sealing plate 16 is provided between two adjacent upper guide rails 15, so that the push-pull rod installed on the float and the upper and lower oil cylinders installed on the fixed frame are hidden inside and not corroded by splashing seawater.

[0034] The upper fixed frame 3 is a cubic frame structure. The upper fixed frame 3 is provided with two sets of upper guide wheels 14.1. One set of upper guide wheels 14.1 is located at the bottom of the upper fixed frame 3. The distance between the two sets of upper guide wheels 14.1 exceeds the maximum stroke of the push-pull rod 11. Each set of upper guide wheels 14.1 includes eight upper guide wheels 14.1. Two upper guide wheels 14.1 are evenly distributed on the inner wall of the upper fixed frame 3. Each upper guide wheel 14.1 corresponds to the outer side of an upper guide rail 15. That is, each upper guide rail 15 corresponds to two upper guide wheels 14.1. The upper guide rail 15 and the upper guide wheels 14.1 cooperate to constrain the horizontal movement of the float, ensure the vertical movement of the push-pull rod, and reduce lateral force and seal wear.

[0035] Below the float 1 is a cylindrical lower guide rail 17. The lower guide rail 17 is surrounded by a lower fixing frame 4. The lower fixing frame 4 is a square frame structure. Each of the four inner walls of the lower fixing frame 4 is provided with a lower guide wheel 14.2. The four lower guide wheels 14.2 surround the lower guide rail 17. The lower guide rail 17 cooperates with the lower guide wheels 14.2 to constrain the up and down movement of the lower guide rail 17, and plays the same role as the upper fixing frame 3.

[0036] A connecting fixing frame 2 is provided on one side of the upper fixing frame 3 and the lower fixing frame 4. The side of the connecting fixing frame 2 is F-shaped and includes a support rod and two horizontal bars vertically arranged on the support rod. One horizontal bar is located at the top of the support rod, and the other end is located at the middle of the support rod. The outer ends of the two horizontal bars are respectively connected to the upper and lower ends of the upper fixing frame 3. The bottom end of the support rod of the connecting fixing frame 2 is connected to the lower fixing frame 4 to form a balance between the upper and lower parts.

[0037] When only wave energy with a wave height of less than 2.5 meters needs to be collected, there is no need to install the lower fixing frame 4, because the upper fixing frame is sufficient for guidance, so there is no need for the lower fixing frame and connecting frame; if you design and manufacture your own platform, power generation vessel, etc., there is no need for the connecting frame; if this system is installed independently on fishing boats, existing offshore platforms, etc., and when you need to collect wave energy with a wave height of more than 2.5 meters, the connecting fixing frame 2 is required, and the connecting fixing frame 2 can be fixedly installed on the ship and platform.

[0038] See Figure 5 , Figure 5A schematic diagram of the hydraulic energy conversion system of Embodiment 1 is shown. As shown in the figure, the hydraulic energy conversion system of the oscillating float wave energy hydraulic acquisition system of this utility model includes an energy storage tank 20, an overflow valve A21, an electric valve assembly, a hydraulic motor assembly, a low-pressure storage tank 24, an overflow valve B25, and a high-level oil tank 26. Multiple high-pressure outlet pipes 10 of the aforementioned oscillating float wave energy hydraulic acquisition system are connected to the energy storage tank 20. An electric valve assembly and a hydraulic motor assembly are installed between the energy storage tank 20 and the low-pressure storage tank 24. The energy storage tank 20 is connected to the high-level oil tank 26 via the overflow valve A21. The low-pressure storage tank 24 is connected to the high-level oil tank 26 via the overflow valve B25. The high-level oil tank 26 is connected to multiple low-pressure inlet pipes 9 of the aforementioned oscillating float wave energy hydraulic acquisition system.

[0039] The electric valve assembly includes a low-pressure electric valve 22.1, a medium-pressure electric valve 22.2, a high-pressure electric valve 22.3, and an ultra-high-pressure electric valve 22.4. The hydraulic motor assembly includes a low-pressure hydraulic motor 23.1, a medium-pressure hydraulic motor 23.2, a high-pressure hydraulic motor 23.3, and an ultra-high-pressure hydraulic motor 23.4. One end of the low-pressure electric valve 22.1 is connected to the energy storage tank 20, and the other end is connected to one end of the low-pressure hydraulic motor 23.1. The other end of the low-pressure hydraulic motor 23.1 is connected to the low-pressure liquid storage tank 24. One end of the medium-pressure electric valve 22.2 is connected to the storage tank 24. One end of the energy storage tank 20 is connected to one end of the medium-pressure hydraulic motor 23.2, and the other end of the medium-pressure hydraulic motor 23.2 is connected to the low-pressure storage tank 24. One end of the high-pressure electric valve 22.3 is connected to the energy storage tank 20, and the other end is connected to one end of the high-pressure hydraulic motor 23.3. The other end of the high-pressure hydraulic motor 23.3 is connected to the low-pressure storage tank 24. One end of the ultra-high-pressure electric valve 22.4 is connected to the energy storage tank 20, and the other end is connected to one end of the ultra-high-pressure hydraulic motor 23.4. The other end of the ultra-high-pressure hydraulic motor 23.4 is connected to the low-pressure storage tank 24.

[0040] This utility model discloses a hydraulic energy conversion method for an oscillating buoy wave energy hydraulic acquisition system, based on the aforementioned oscillating buoy wave energy hydraulic acquisition system and hydraulic energy conversion system, including the following: High-pressure oil enters the energy storage tank through the high-pressure outlet pipe, smoothing out pressure pulsations; The relief valve A is set to the maximum system pressure, which is set to 18MPa in this embodiment. It releases pressure when the pressure exceeds the limit. The electric valve assembly controls the oil circuits leading to hydraulic motors of different specifications, and the control system automatically switches the oil circuits according to the pressure value in the energy storage tank. When the pressure is ≥4MPa, the low-pressure electric valve 22.1 is opened, and the low-pressure hydraulic valve 23.1 is driven. When the pressure is ≥7MPa, close the low-pressure electric valve 22.1, open the medium-pressure electric valve 22.2, and drive the medium-pressure hydraulic motor 23.2; When the pressure is ≥13MPa, close the medium-pressure electric valve 22.2, open the high-pressure electric valve 22.3, and drive the high-pressure hydraulic motor 23.3; When the pressure is ≥16MPa, the ultra-high pressure electric valve 22.4 is opened, which, together with the high pressure electric valve 22.3, drives the ultra-high pressure hydraulic motor 23.4 to cope with extremely high fluctuations.

[0041] The low-pressure storage tank provides back pressure of approximately 0.5 MPa to the hydraulic motor. This pressure is maintained by the overflow valve B, and the return oil enters the high-level oil tank to ensure smooth fluid flow.

[0042] Float 1 is impacted by the crests of ocean waves, generating a lateral impact force and a vertical upward buoyancy. We aim to collect the vertical upward buoyancy by using the push-pull rod 11 to move up and down within the upper and lower hydraulic cylinders, compressing the oil in the cylinders and converting it into hydraulic energy. To reduce the lateral oscillation of the float cylinders caused by the lateral impact and to ensure the normal operation of the push-pull rod 11 and the upper and lower hydraulic cylinders, a fixed frame is installed. Guide wheels are installed within the fixed frame. The guide wheels guide the up and down movement of the upper guide rail 15 and lower guide rail 17 mounted on float 1, and protect the push-pull rod 11 and the upper and lower hydraulic cylinders from damage. The push-pull rod 11 moves upward under the buoyancy of the float 1, and the oil in the lower cylinder 13 is pressurized and exits the cylinder body through the lower outlet check valve 8. At the same time, the upper cylinder 12 is deficient in oil, creating a vacuum and negative pressure that opens the upper inlet check valve 5 to allow oil to enter and fill the cylinder. When the float 1 sinks, the push-pull rod 11 is pulled downward, causing oil to exit from the upper cylinder 12 and oil to enter from the lower cylinder 13. This action is repeated to obtain hydraulic energy at various pressures. The hydraulic energy obtained by the push-pull rod 11 enters the energy storage tank 20 for storage. Then, the automatic control system redistributes the hydraulic energy in the energy storage tank 20 to the hydraulic motor through an electric valve, so that the hydraulic motor can optimally convert the hydraulic energy into mechanical energy to drive the generator to generate electricity.

[0043] Working principle: Wave energy harvesting technologies come in a variety of forms. Based on the installation method, they can be divided into fixed and floating types. Based on the working principle, they can be divided into several categories such as oscillating body type, oscillating water column type, and wave-surpassing type.

[0044] Compared to oscillating water column and wave-overtaking types, my country has focused more on oscillating body technology in its research on wave energy. There are many types of oscillating bodies, among which the following are representative devices: Duck-type wave energy generator: The device consists of a main shaft, a duck-shaped body, and an underwater support. The duck-shaped body swings up and down under the action of waves to capture wave energy. The wave energy drives the hydraulic system to do work and store energy, which in turn drives the generator to generate electricity.

[0045] Nezha Wave Energy Generation Device: A floating point absorption linear power generation wave force device. This device adopts a double cylindrical floating structure. The oscillating float is butterfly-shaped. The straight cylinder in the middle of the float is rigidly connected to the underwater damping plate. The oscillating motion of the float drives the linear generator inside the straight cylinder to generate electricity.

[0046] Eagle-type wave energy generator: To overcome the shortcomings of the canard series devices, the Guangzhou Institute of Energy combined the canard device with a semi-submersible barge to develop the Eagle-type wave energy conversion device. The device mainly consists of an Eagle-type wave-absorbing float, an energy conversion system, and a semi-submersible hull. The "Eagle-type No. 1" wave energy generator adopts a combination of hydraulic and direct-drive power generation systems.

[0047] Wave energy harvesting, specifically the oscillating system method, extracts energy by having a single buoy perform work as it is propelled by the waves. If the buoy's work is achieved through up-and-down motion, its rise is due to the buoyancy exerted by the rising wave crests, while its descent occurs when it loses buoyancy at a wave trough and is pushed downwards by its own weight. Waves are categorized as nearshore and offshore, and include wind waves and swells. Their size, length, and location are never repeated, which makes it difficult to directly generate electricity from the mechanical energy harvested by a single buoy. Therefore, the industry generally converts this energy into hydraulic energy for storage before power generation.

[0048] There are various forms of devices that convert the mechanical energy harvested from ocean waves into hydraulic energy to generate electricity. These include: a duck-like device where the head swings up and down, causing the body to rotate and generate hydraulic energy; an eagle-like device where a hydraulic cylinder piston extends and retracts to generate hydraulic energy; and a device where a float oscillates up and down, rotating via a rack and pinion mechanism and then a rope driving a pulley to drive a hydraulic system. However, these devices all have drawbacks. For example, the duck-like device's up-and-down swing angle and distance are limited, restricting energy harvesting; excessive rotation angles can cause the head to flip and be damaged; and the hydraulic system, being completely submerged in seawater, is susceptible to corrosion, affecting its lifespan. The eagle-like device, being a four-bar linkage, alters the direction of the force exerted by the waves on the float, reducing the force transmitted to the hydraulic cylinder and lowering the wave energy conversion efficiency. As for the hydraulic system driven by the float rotating via a rack and pinion mechanism and then a rope driving a pulley, the additional energy conversion step further reduces the wave energy conversion efficiency.

[0049] Based on the above analysis of the advantages and disadvantages of several oscillating hydraulic energy acquisition methods, the best way to improve the efficiency and reliability of hydraulic energy acquisition is to directly transmit the force of the oscillating float's up-and-down movement to the hydraulic cylinder, that is, to transmit it vertically to the hydraulic cylinder. However, this involves the stroke and pressure of the hydraulic cylinder. According to the stroke and force of the float to the piston rod of the hydraulic cylinder, conventional hydraulic cylinders cannot meet the requirements because the force provided by the float meets the diameter of the hydraulic cylinder, but the piston rod cannot meet the requirements. The reason is that if the piston rod is too thin and the stroke is too long, it will cause instability.

[0050] Therefore, this utility model provides an oscillating float wave energy hydraulic harvesting system and hydraulic energy conversion system, which maximizes the conversion of the force exerted on the float by the waves into hydraulic energy, i.e., a first-level energy conversion. It satisfies the requirement that both the upward force exerted on the float by the buoyancy of the rising waves and the downward force caused by the weight of the float when it sinks be converted into hydraulic energy. It also ensures that the stroke of the hydraulic cylinder caused by the up-and-down movement of the float is within a controlled range, especially ensuring that the piston rod meets the relationship between stroke, pressure, and its own strength to prevent instability. After obtaining the hydraulic energy converted from the oscillating float, it is necessary to consider that the final hydraulic energy can stabilize the generator speed, improve power generation efficiency and power output. Therefore, the system and method of this utility model can combine the energy collected by multiple floats and use automatic control to control the energy storage device, hydraulic motor, etc., to maximize the efficiency of hydraulic energy in generating electricity for the generator.

[0051] This utility model provides an oscillating float wave energy hydraulic acquisition system, including a float, a push-pull rod, upper and lower oil cylinders, upper inlet and outlet check valves, lower inlet and outlet check valves, low-pressure inlet pipe, high-pressure outlet pipe, solenoid valve, upper guide rail, lower guide rail, fixing frame and guide wheel; The diameter of the push-pull rod is, in principle, unrestricted. The set diameter only needs to satisfy the mechanical relationship between the maximum force exerted by the float on the push-pull rod and the rod's stroke. In other words, the minimum diameter of the middle section of the push-pull rod must meet mechanical performance requirements. The diameter of the lower section of the push-pull rod is set based on the force exerted by the float and the set system hydraulic pressure. Given the force and system pressure, the force the push-pull rod must withstand can be obtained. Calculated in kilograms of force per square centimeter, the bearing area of ​​the lower section of the push-pull rod can be calculated. The formula for calculating the diameter is: the sum of the bearing area of ​​the middle section of the push-pull rod and the bearing area, divided by π, squared, and then multiplied by 2. The diameter of the upper section of the push-pull rod is set based on the total weight of the float and the system hydraulic pressure. The bearing area can be calculated based on the downward force of the float's gravity and the hydraulic pressure, and then the diameter can be calculated in the same way as the lower section.

[0052] The upper and lower cylinders are two connected cylinder bodies, each with the same length as the push-pull rod. The inner diameter of the cylinder should ideally be 40-60mm larger than the outer diameter of the push-pull rod. The upper cylinder has a sealing ring installed at its upper part to seal the upper diameter of the push-pull rod and externally. A sealing ring is installed at the connection point of the two cylinders to seal the middle diameter of the push-pull rod and to seal the area between the two cylinders. The lower cylinder has a sealing ring installed at its lower part to seal the lower diameter of the push-pull rod and externally. The upper cylinder has an upper inlet check valve on one side and an upper outlet check valve on the other side. The lower cylinder also has a lower inlet check valve and a lower outlet check valve.

[0053] One end of the low-pressure inlet pipe is connected to the upper and lower inlet check valves, and the other end is connected to the low-pressure oil tank. One end of the high-pressure outlet pipe is connected to the upper and lower outlet check valves, and the other end is connected to the high-pressure energy storage tank.

[0054] The upper guide rail is connected and installed above the float, constrained by the guide wheel installed on the fixed frame. Together with the lower guide rail, it plays a directional protection role for the up and down movement of the float, reducing the lateral amplitude of the push rod and hydraulic cylinder caused by the float. The lower guide rail is round and is connected and installed below the float, serving the same function as the upper guide rail.

[0055] The mounting bracket consists of an upper mounting bracket, a lower mounting bracket, and a connecting mounting bracket. The upper mounting bracket is connected to and installed with an upper hydraulic cylinder. Two sets of guide wheels are installed inside the upper mounting bracket. One set of guide wheels is installed at the bottom of the bracket, and the other set is installed above the first set. The distance between them should be greater than the maximum stroke of the push-pull rod. These two sets of guide wheels mainly reduce the sway of the float guide rail when it moves up and down with the wave force, so that its movement trajectory is kept as close as possible to the center line of the push-pull rod hydraulic cylinder, thereby improving the service life of the push-pull rod and the seal, as well as the force conversion efficiency.

[0056] A set of guide wheels is installed inside the lower fixed frame. This set of guide wheels constrains the up and down movement of the lower guide rail and plays the same role as the upper fixed frame.

[0057] The upper cylinder converts the weight of the float into energy via a push-pull rod as the float descends. Because the upper diameter of the push-pull rod is larger than the middle diameter, the volume of the upper cylinder decreases. Since liquid is incompressible, the resulting high-pressure liquid is discharged from the outlet check valve to the high-pressure outlet pipe. The lower cylinder converts the buoyancy generated when the float rises into energy via a push-pull rod as the float moves upward. In the lower cylinder, the lower diameter of the upward-moving push-pull rod is larger than the middle diameter, causing the cylinder volume to decrease and creating high pressure. The pressurized high-pressure liquid is then forced through the outlet check valve to the high-pressure outlet pipe for discharge. In the upper and lower hydraulic cylinders, the push-pull rod moves upward under the influence of the float. In the lower cylinder, the larger diameter portion of the push-pull rod enters the cylinder, reducing its volume and creating positive pressure. The pressurized liquid is then discharged through a one-way valve. In the upper cylinder, the larger diameter portion of the push-pull rod moves out of the cylinder, while the smaller diameter portion enters, increasing its volume and creating negative pressure. This negative pressure opens the inlet one-way valve, drawing in liquid. When the float descends, its weight causes the push-pull rod to move downward. At this time, the liquid in the upper cylinder is pressurized and discharged through the one-way valve, while the lower cylinder is under negative pressure and draws in liquid through the one-way valve. The diameter and length of the push-pull rod are not limited, satisfying the relationship between its stroke and force. Reasonable dimensions can be determined based on the float's buoyancy, weight, stroke, and the set system pressure, maximizing the conversion of the buoyancy and weight into hydraulic energy. During the compression of the liquid by the push-pull rod, the work done by the push-pull rod is directly proportional to the upward force provided by the float, with no changes in angle or torque, maximizing energy conversion efficiency.

[0058] The upper and lower guide rails are designed to withstand the impact of waves on the float from front to back and side to side. They reduce planar swaying after the float is hit by waves, ensure smooth movement of the push-pull rod within the upper and lower hydraulic cylinders, and reduce wear on the seals, thus extending service life. The upper guide rail has a square frame structure. The four corners of the frame contact the guide wheels mounted on the mounting bracket, while the remaining portion is enclosed by a thin protective plate. This conceals the push-pull rod mounted on the float and the upper and lower hydraulic cylinders mounted on the mounting bracket, preventing them from being corroded by splashing seawater.

[0059] This utility model provides a hydraulic energy conversion system for an oscillating float wave energy hydraulic acquisition system, which includes a high-pressure outlet pipe, a storage tank, an overflow valve A, electric valve 1, electric valve 2, electric valve 3, electric valve 4, hydraulic motor 1, hydraulic motor 2, hydraulic motor 3, hydraulic motor 4, a low-pressure storage tank, an overflow valve B, and a high-level oil tank.

[0060] The high-pressure outlet pipe is the pipeline through which the high-pressure oil compressed by the push-pull rod in the upper and lower cylinders flows to the reservoir via the upper and lower outlet check valves. The reservoir is designed to buffer the pulsating high-pressure oil from the hydraulic cylinder when it enters the hydraulic motor, thus stabilizing the motor speed. The larger the energy storage space of the reservoir, the more stable the motor speed. The more energy collected by the floats, the more stable the speed. For example, receiving energy collected by dozens of floats can make the motor speed both stable and increase the power more stably.

[0061] Overflow valve A controls the maximum pressure of the liquid storage tank. For example, if the system is designed to have a maximum pressure of 18 MPa, the overflow valve will automatically release pressure to the maximum pressure when the pressure exceeds this limit.

[0062] Electric valves 1-4 are controlled by an automatic control device to distribute flow to hydraulic motors 1-4 respectively, effectively converting the energy collected by the float at different wave heights. Control is primarily based on pressure sensors, supplemented by level sensors. Electric valve 1 and hydraulic motor 1 are set for the minimum wave height (0.3~0.5m) collected by the float; electric valve 2 and hydraulic motor 2 are set for 0.5~1m; and electric valve 3 and hydraulic motor 3 are set for 1~1.5m wave heights. When the wave height exceeds 1.5m, electric valve 4 opens, activating hydraulic motor 4. The electric valves then perform the following actions: The procedure is as follows: when the pressure inside the storage tank exceeds 4 MPa, electric valve 1 opens, which also starts hydraulic motor 1, and the other valves close; when the pressure exceeds 7 MPa, electric valve 2 opens, and electric valves 1, 3, and 4 close; when the pressure exceeds 13 MPa, electric valve 3 opens, and electric valves 1, 2, and 4 close; when the pressure exceeds 16 MPa, electric valve 4 opens, electric valve 3 remains open, and electric valves 1 and 2 close. In other words, electric valves 1 and 2 are for converting low- and medium-pressure energy through low- and medium-pressure motors, while electric valves 3 and 4 are for converting high-pressure energy through high-pressure motors 3 and 4.

[0063] The low-pressure reservoir is designed for hydraulic motors because the motor requires back pressure during operation, which is around 0.5 MPa. Therefore, a reservoir is needed to maintain this pressure. The pressure is maintained by the relief valve B, which is also a pressure regulating valve. When adjusted to 0.5 MPa, the pressurized liquid flowing out of the valve is forced into the high-level oil tank. Setting up a high-level oil tank can make the liquid entering the cylinder more reliable and smooth.

[0064] This invention efficiently converts the hydraulic energy collected by a float at wave heights of 0.3-4 meters into mechanical energy via a hydraulic motor, which then powers a generator. The collection and conversion of wave energy, especially low-energy wave energy at wave heights of 0.3-0.5 meters, is generally considered difficult in the industry, resulting in low energy levels and low efficiency. The technical solution provided by this invention addresses these problems: the push-pull rod driven by the float moves vertically up and down within the hydraulic cylinder, rising as far as the float can; the motor is equipped with low-pressure, low-flow, medium-pressure, medium-flow, and high-pressure, high-flow motors; the low-pressure, low-flow motor is specifically designed for collecting and converting low-energy waves at 0.3 meters. A float suitable for collecting low-energy wave energy is designed; an oversized float will not collect energy because low-energy waves have short wavelengths (e.g., a 0.3-meter wave has a wavelength of approximately 8 meters), and a large float will only exhibit planar oscillations under such conditions.

[0065] The process of a buoy harvesting wave energy is as follows: the buoy oscillates up and down with the rise and fall of the waves. The amplitude and distance of the buoy's oscillation are related to the buoy's mass, size, and shape. For buoys of the same size and shape, a larger mass buoy will rise a shorter distance than a smaller mass buoy because it has to overcome gravitational acceleration when rising. Floats of the same mass but different sizes and shapes will also rise a different distance because the buoy has a damping effect on the water when rising; a buoy with greater damping will rise less.

[0066] The float drives the push-pull rod to do work on the hydraulic cylinder. The greater the pressure in the hydraulic cylinder, the greater the reaction force on the push-pull rod. For example, at low pressure (4MPa) and high pressure (16MPa), the reaction force on the push-pull rod is one-quarter of that at high pressure. To overcome the reaction force of the push-pull rod, the float needs buoyancy, which is the mass and volume of water displaced by the float. The float can only rise after overcoming the reaction force. The greater the reaction force, the less the float rises until it stops moving. In a 0.3-meter wave, the float's maximum amplitude without mass is no more than 0.3 meters. With mass, it experiences upward acceleration and damping force, reducing its amplitude, for example, to 0.2 meters. However, this is the float's rising distance when unloaded. When the push-pull rod performs work on the hydraulic cylinder, it exerts a reaction force on the float. The greater the force, the greater the resistance to the float's ascent, and the smaller the rising distance. When the reaction force equals the float's buoyancy, the float will not move. For example, a 3-meter diameter float with an amplitude of 0.2 meters in a 0.3-meter wave height when unloaded has a maximum buoyancy of 1.5 * 1.5 * 3.14 * 0.2 * the specific gravity of water ≈ 1420 kg. If the reaction force of the push-pull rod reaches this value, the float will not move. If the reaction force on the push-pull rod is 710 kg, the float can rise 0.1 meters. However, the wave energy we need to collect is limited to waves with heights between 0.3 and 4 meters, primarily those between 1 and 2 meters in most sea conditions. To improve the efficiency of energy collection and conversion, the hydraulic cylinder pressure is set at 16 MPa, and the thrust of the push-pull rod is 3-4 kilograms. Since the dimensions of the hydraulic cylinder and push-pull rod cannot be changed, the only way to reduce the thrust on the push-pull rod is to adjust the system pressure, allowing for vertical travel. Therefore, the hydraulic energy to mechanical energy conversion method of this invention consists of multiple hydraulic motors with different flow rates and set pressure parameters. These motors are controlled by an automatic control system, which selects the appropriate motor based on the pressure from the pressure sensor, ensuring that the hydraulic energy collected by the float under different sea conditions is efficiently converted into mechanical energy.

[0067] The device of this utility model has a simple structure, high energy conversion efficiency, low production difficulty and economic cost, convenient maintenance, high degree of automation, and is conducive to widespread use.

[0068] The parameter data and energy acquisition algorithm in this embodiment are as follows: Oscillating buoys collect ocean wave energy by moving the buoy with the waves. The efficiency of energy collection depends on the size, shape, and mass of the buoy, as well as the height, wavelength, and period of the waves. The efficiency of collecting ocean wave energy is related to the distance the buoy travels, the volume of water displaced by the buoy, and the amount of work done by the buoy on the collection system.

[0069] The energy harvesting capabilities of oscillating buoys from ocean waves are conditional; they cannot harvest energy from waves that are too small, nor from waves that are too large. Therefore, currently, they can generally harvest energy from waves with a height of 0.3 to 4 meters. At a wave height of 0.3 meters, the wavelength is 7 to 8 meters and the period is 1.5 to 2 seconds; harvesting this energy using conventional methods is impossible. At a wave height of 4 meters, the wavelength is 124 meters and the period is 8 seconds. If a floating platform is used, the platform must be large enough; otherwise, the platform will be positioned between wave crests and troughs, preventing normal energy harvesting. To meet these conditions, the various parameters of this invention must be designed, and the data calculated and verified to ensure that the conditions are met.

[0070] The wave height in the East my country Sea and South China Sea is mostly between 1 and 1.5 meters per year. Therefore, the parameters for the data acquisition system design should be based on this, while also considering the acquisition of low-energy data with wave heights of 0.3 to 0.5 meters.

[0071] The oscillating float is butterfly-shaped; considering the collection of low-energy ocean wave energy, the diameter is Ø3.4m; the float itself, push-pull rod, and upper and lower guide rails weigh a total of 3100KG; the push-pull rod has three sections, upper, middle and lower, each 4m long, totaling 12m in length. The diameter can be designed as Ø108mm based on the middle section, Ø116mm based on the total weight of the float, and Ø120mm based on the buoyancy of the float.

[0072] The mid-section diameter is determined by the maximum thrust provided by the float to the push-pull rod and the maximum vertical stroke of the push-pull rod (4m). The maximum thrust is the highest pressure designed for the system: 18MPa × 10 × 21.4 (area of ​​Ø120 - area of ​​Ø108 = 21.4 cm²) = 3852 kg. According to mechanical calculations, the mid-section diameter of Ø108 mm and length of 4m already meet the thrust requirement. The thrust is more adequately borne by the lower Ø120 mm diameter section. If calculated using a conventional hydraulic cylinder piston, this cross-sectional area would translate to a piston diameter of 21.4 cm² ÷ (π) × 2 = Ø53 mm. The piston rod diameter would be even smaller, and the 4-meter stroke would not meet the requirements.

[0073] To meet the maximum thrust of 3852KG for the push-pull rod at 18MPA, the float needs to displace a certain volume of water to rise. Assuming the specific gravity of water is 1, the float needs to rise at least 3852 liters ÷ (1.7m × 1.7m × л) = 424mm. The designed thrust under normal conditions is 16MPA×10×21.4=3424KG, and the float rises a short distance of 3452÷(1.7×1.7×л)=380mm. When collecting data at wave heights of 0.6 to 1 m, the designed thrust is 10 MPa × 10 × 21.4 = 2140 kg, and the float's minimum ascent distance is 2140 ÷ (1.7 × 1.7 × л) = 236 mm. The design thrust for collecting data at wave heights of 0.3~0.5m is 4MPA×10×21.4=856KG, and the shortest lift distance on the float is 856÷(1.7×1.7×л)=94mm.

[0074] The float rises due to the buoyancy of the waves, which is related to the float's weight, the damping force of the water, and the wave period. Short-period waves cause the float to rise faster, resulting in a greater upward gravitational acceleration and damping force. If the wave period is long, the float rises very slowly, and this force can be ignored. The gravitational acceleration and damping force prevent the float from rising. Therefore, when collecting low-energy ocean wave energy at a height of 0.3~0.5m, due to the short wave period, the float must overcome an upward acceleration force and damping force of about 1000KG to rise. This means the float needs to displace about 1 cubic meter of water before it can rise, which translates to the float rising 1000÷1.7÷1.7÷л=110mm less.

[0075] Therefore, to collect the energy of 0.3 meters of ocean waves, only a low pressure of 4-5 MPa can be used. When the pressure is 4 MPa, the distance that the float does work upward on the push rod is 300-110-94=96mm; when the pressure is 8 MPa, it is 300-110-188=2mm. The float basically does not move when it moves up and down by 2mm.

[0076] Therefore, when converting hydraulic energy into mechanical energy, multiple pressure steps need to be set. The low-pressure, low-flow hydraulic motor 23.1 converts the energy collected at a wave height of about 0.5 meters. The energy collected at a wave height of about 0.8 meters is converted by the medium-flow, medium-pressure (7~12MPA) hydraulic motor 23.2. The high-flow, high-pressure energy collected at a wave height of more than 1 meter is converted by multiple high-flow, high-pressure hydraulic motors 23.3 and 23.4.

[0077] When the waves rise, they push the float upwards, performing work on the push-pull rod. As the waves fall, the float loses buoyancy and its weight pulls the push-pull rod downwards. The float's total weight is 3100 kg. The upper push-pull rod has a diameter of Ø116 mm, and the middle one has a diameter of Ø108 mm. The difference in their cross-sectional areas is 5.8 cm × 5.8 cm × 3.14 = 105.6 cm², 5.4 cm × 5.4 cm × 3.14 = 91.6 cm², and 105.6 - 91.6 = 14 cm². Using the system's maximum pressure of 18 MPa, the maximum resistance to the downward work of the push-pull rod is 14 cm² × 18 MPa × 10 = 2520 kg. The 3100 kg downward pull of the float on the push-pull rod is greater than the 2520 kg resistance.

[0078] The following calculations are performed based on the wave energy that the buoy can collect under several wave conditions and the mechanical power converted from that energy: When the float is in a wave of 0.3 meters and the system pressure is 4 MPa, the push-pull rod is pushed upwards by 96 mm. The calculated volume from the upper outlet check valve of the lower hydraulic cylinder is: 9.6 cm × 21.4 cm² = 205 cm³ = 0.205 liters. When the push-pull rod is pulled downwards, the volume from the upper outlet check valve of the upper hydraulic cylinder is: 9.6 cm × 14 cm² = 134 cm³ = 0.134 liters; totaling 0.205 + 0.134 = 0.339 liters. Assuming a wave period of 2 seconds, the float moves up and down 30 times per minute, resulting in a flow rate of 30 × 0.339 = 10.17 liters per minute. Referring to the table, the power of the low-pressure hydraulic motor (model 23.1) is 0.82 kW at 4 MPa and a flow rate of 10 liters per minute.

[0079] When the wave height becomes 0.5 meters, the increased volume of the one-way valve due to the increased stroke of the push-pull rod causes an increase in the flow rate of the low-pressure hydraulic motor 23.1, forcing the hydraulic system pressure to rise to 5 MPa. At 5 MPa, the thrust is 5 MPa × 10 × 21.4 = 1070 kg. The float rises a short distance of 1070 ÷ 1.7 ÷ 1.7 ÷ π = 118 mm. Therefore, the distance the float pushes upward is 500 - 110 - 118 = 272 mm = 27.2 cm. The volume is 27.2 × 21.4 = 582 cm³ = 0.582 liters. When it moves downwards, the upper cylinder presses out a volume of 27.2 × 14 = 381 cm³ = 0.381 liters. The total volume of the float moving up and down is 0.582 + 0.381 = 0.963 liters. The wave period is 2.5 seconds. Therefore, the float moves up and down 24 times per minute, which is 24 × 0.963 = 23 liters / minute. From the table, when the pressure is 5 MPa and the flow rate is 23 L / minute, the power of the hydraulic motor is 23.1 kWh, which is 2.35 kW.

[0080] When the wave height is around 0.8 meters, the stroke of the push-pull rod increases, causing an increase in flow. The hydraulic motor 23.1 cannot handle the flow quickly enough, resulting in a rise in hydraulic pressure. When the pressure exceeds 7 MPa, motor 23.2 automatically starts working, and motor 23.1 automatically shuts down. At 7 MPa, the resistance to the push-pull rod pushing upward is 7 MPa × 10 × 21.4 cm² = 1498 kg. The float rises a short distance of 1498 ÷ 1.7 ÷ 1.7 ÷ π = 165 mm. Therefore, the distance the float pushes upward is 800 - 110 - 165 = 525 mm = 52.5 cm. The volume is 52.5 × 21.4 = 1129 cm³ = 1.129 liters. When it moves downwards, the upper cylinder presses out a volume of 52.5 × 14 = 735 cm³ = 0.735 liters. The total volume of the float's up and down movement is 1.129 + 0.735 = 1.864 liters. The wave period is 3.4 seconds, so the float moves up and down 17.5 times per minute, which is 17.5 × 1.864 = 32.6 liters / minute. From the table, at 7 MPa and 32.6 L / minute, the power of the hydraulic motor 23.2 is 3.4 kW.

[0081] When the wave height is 1 meter, the flow rate continues to increase, and the pressure inside the cylinder can reach 10~12 MPa. Taking an average of 11 MPa, the weight is 11 × 10 × 21.4 = 2354 kg. The minimum rising distance of the float is 2354 ÷ 1.7 ÷ 1.7 ÷ π = 259 mm. Therefore, the distance the float pushes upward is 1000 - 110 - 259 = 631 mm = 63.1 cm. The volume is 63.1 × 21.4 = 1350 cubic meters. cm³ = 1.35 liters. When moving downwards, the upper cylinder presses out a volume of 63.1 × 14 = 883 cm³ = 0.883 liters. The total volume of the float moving up and down is 1.35 + 0.883 = 2.23 liters. The wave period is 4 seconds, so the float moves up and down 15 times per minute, which is 15 × 2.23 = 33.5 liters / minute. From the table, at 11 MPa and 33.5 L / minute, the power of the hydraulic motor at 23.2 is 6.7 KW.

[0082] When the wave height is 1.5 meters, the flow rate continues to increase, and the cylinder pressure can reach 16 MPa. 16 × 10 × 21.4 = 3440 kg. The float's minimum rising distance is 3440 ÷ 1.7 ÷ 1.7 ÷ π = 379 mm. Therefore, the float's upward thrust is 1500 - 110 - 379 = 1011 mm = 101.1 cm. The volume is 101.1 × 21.4 = 2163 cm³ = 2.163 liters. When the upper cylinder presses down, the volume is 101.1 × 14 = 1415 cm³ = 1.415 liters. The total volume of the float moving up and down is 2.163 + 1.415 = 3.58 liters. The wave period is 4.8 seconds, so the float moves up and down 12.5 times per minute, which is 12.5 × 3.58 = 44.7 liters / minute. From the table, at 16 MPa, the power of the hydraulic motor at 23.3 liters / minute is 14.6 kW.

[0083] When the wave height is 2 meters, the flow rate continues to increase, and the cylinder pressure exceeds 16 MPa. This causes hydraulic motors 23.4 to also activate and work together with 23-3, reducing the system pressure to 15 MPa. 15 MPa × 10 × 21.4 = 3210 kg. The float's minimum rising distance is 3210 ÷ 1.7 ÷ 1.7 ÷ π = 354 mm. Therefore, the float's upward thrust is 2000 - 110 - 354 = 1545 mm = 154.5 cm. The volume is 154.5 × 21.4 = 3. 306 cm³ = 3.306 liters. When moving downwards, the upper cylinder presses out a volume of 154.5 × 14 = 2163 cm³ = 2.163 liters. The total volume of the float moving up and down is 2.163 + 3.306 = 5.47 liters. The wave period is 5.6 seconds, so the float moves up and down 10.7 times per minute, which is 10.7 × 5.47 = 58.5 liters / minute. Looking up the table, at 15 MPa, the combined power of hydraulic motors 23.3 and 23.4 at 58.5 L / minute is 18.1 kW.

[0084] When the wave height is 2.5 meters, the flow rate continues to increase, and the cylinder pressure exceeds 16 MPa. Hydraulic motors 23.3 and 23.4 then operate together. 16 MPa × 10 × 21.4 = 3440 kg. The float's minimum upward distance is 3440 ÷ 1.7 ÷ 1.7 ÷ π = 379 mm. Therefore, the float's upward thrust is 2500 - 110 - 379 = 2011 mm = 201.1 cm, and the volume is 201.1 × 21.4 = 4304 cm³. =4.304 liters. When it moves downwards, the upper cylinder presses out a volume of 201.1 × 14 = 2815 cm³ = 2.815 liters. The total volume of the float moving up and down is 4.304 + 2.815 = 7.12 liters. The wave period is 6.4 seconds. Therefore, the float moves up and down 9.37 times per minute, which is 9.37 × 7.12 = 66.7 liters / minute. From the table, at 16 MPa, the combined power of hydraulic motors 23.3 and 23.4 is 21.8 kW when the flow rate is 66.7 L / minute.

[0085] To improve the efficiency of float-based energy collection, multiple floats, up to nearly a hundred, should be used. The hydraulic energy collected by each float should be collected into an energy storage tank, which will then distribute the energy to the various hydraulic motors. The number of hydraulic motors can also be increased to subdivide the pressure gradient. For example, one low-pressure motor, one medium-pressure motor, and two to four high-pressure motors can be set to subdivide the hydraulic energy between 13 and 18 MPa, so that the system always maintains a pressure of around 16 MPa, which is the optimal operating pressure for the hydraulic motors.

[0086] The above are merely specific application examples of this utility model and do not constitute any limitation on the scope of protection of this utility model. All technical solutions formed by equivalent transformations or equivalent substitutions fall within the scope of protection of this utility model.

Claims

1. An oscillating buoy sea wave energy hydraulic harvesting system, characterized in that, include: Float (1), used to capture wave energy; The push-pull rod (11) is a three-section variable diameter structure, consisting of an upper section, a middle section and a lower section from top to bottom, wherein the diameters of the upper and lower sections are larger than those of the middle section; the top of the float (1) is connected to the bottom surface of the push-pull rod (11); The upper cylinder (12) and the lower cylinder (13) are connected vertically to allow the push-pull rod (11) to pass through and reciprocate. The upper section of the push-pull rod (11) moves up and down in the upper cylinder (12), the lower section moves up and down in the lower cylinder (13), and the middle section moves between the upper cylinder (12) and the lower cylinder (13). The upper inlet check valve (5) and the upper outlet check valve (6) are installed on the upper part of the upper cylinder (12); The lower inlet check valve (7) and the lower outlet check valve (8) are installed on the upper part of the lower cylinder (13); The low-pressure inlet pipe (9) is connected to the inlet of the upper inlet check valve (5) and the lower inlet check valve (7); The high-pressure outlet pipe (10) is connected to the outlet of the upper outlet check valve (6) and the lower outlet check valve (8); Solenoid valve (18) is connected in parallel to both ends of the lower inlet check valve (7); The upper guide rail (15) and the lower guide rail (17) are fixed to the upper and lower parts of the float (1), respectively; The upper fixed frame (3) and the lower fixed frame (4) are arranged above the float (1) and surround the upper cylinder (12) and the lower cylinder (13). The top of the upper cylinder (12) is fixed on the upper fixed frame (3); the lower fixed frame (4) is arranged below the float (1). The guide wheel assembly is installed in the upper fixed frame (3) and the lower fixed frame (4), and cooperates with the upper guide rail (15) and the lower guide rail (17) to constrain the movement trajectory of the float (1).

2. The oscillating buoy wave energy hydraulic acquisition system according to claim 1, characterized in that: The total length of the push-pull rod (11) is designed based on the maximum wave height. The maximum wave height determines the maximum amplitude of the float (1). Therefore, the lengths of the upper, middle and lower sections of the push-pull rod (11) are matched with the maximum amplitude of the float (1).

3. A system according to claim 1, wherein: The three sections of the push-pull rod (11) are all made of seamless tubes, and the wall thickness of the push-pull rod (11) is 8~15mm.

4. A system according to claim 1, wherein: The inner diameters of the upper cylinder (12) and the lower cylinder (13) are 40-60 mm larger than the outer diameters of the corresponding sections of the push-pull rod (11).

5. A system according to claim 1, wherein: One end of the low-pressure inlet pipe (9) is connected to the upper inlet check valve (5) and the lower inlet check valve (7), and the other end is connected to the high-level oil tank (26); one end of the high-pressure outlet pipe (10) is connected to the upper outlet check valve (6) and the lower outlet check valve (8), and the other end is connected to the energy storage tank (20).

6. A system according to claim 1, wherein: The float (1) is provided with four upper guide rails (15) above it. The four upper guide rails (15) are arranged around the outside of the upper oil cylinder (12) and the lower oil cylinder (13) and distributed at the four corners of the square. A protective sealing plate (16) is provided between two adjacent upper guide rails (15).

7. A system according to claim 1, wherein: The upper fixed frame (3) is a cubic frame structure. The upper fixed frame (3) is provided with two sets of upper guide wheels (14.1). One set of upper guide wheels (14.1) is set at the bottom of the upper fixed frame (3). The distance between the two sets of upper guide wheels (14.1) exceeds the maximum stroke of the push-pull rod (11). Each set of upper guide wheels (14.1) includes eight upper guide wheels (14.1). Two upper guide wheels (14.1) are evenly distributed on the inner wall of the upper fixed frame (3). Each upper guide wheel (14.1) corresponds to the outer side of an upper guide rail (15). That is, each upper guide rail (15) corresponds to two upper guide wheels (14.1). The upper guide rail (15) and the upper guide wheel (14.1) cooperate to constrain the horizontal movement of the float.

8. A system according to claim 1, wherein: When collecting wave energy with a wave height of 2.5 meters or more, a cylindrical lower guide rail (17) is set below the float (1). A lower fixing frame (4) is provided on the outside of the lower guide rail (17). The lower fixing frame (4) is a square frame structure. At least one lower guide wheel (14.2) is provided on each of the four inner walls of the lower fixing frame (4). The lower guide wheel (14.2) surrounds the lower guide rail (17). The lower guide rail (17) cooperates with the lower guide wheel (14.2) to constrain the up and down movement of the lower guide rail (17).

9. The oscillating buoy wave energy hydraulic acquisition system according to claim 8, characterized in that: A connecting fixing frame (2) is provided on one side of the upper fixing frame (3) and the lower fixing frame (4). The side of the connecting fixing frame (2) is F-shaped, and the bottom end of the support rod of the connecting fixing frame (2) is connected to the lower fixing frame (4).

10. A hydraulic energy conversion system of an oscillating buoy sea wave energy hydraulic energy harvesting system, according to any one of the preceding claims 1 to 8, characterized in that: The system includes an energy storage tank (20), an overflow valve A (21), an electric valve assembly, a hydraulic motor assembly, a low-pressure storage tank (24), an overflow valve B (25), and a high-level oil tank (26). The high-pressure outlet pipe (10) of multiple oscillating float wave energy hydraulic acquisition systems is connected to the energy storage tank (20). An electric valve assembly and a hydraulic motor assembly are installed between the energy storage tank (20) and the low-pressure storage tank (24). The energy storage tank (20) is connected to the high-level oil tank (26) via the overflow valve A (21). The low-pressure storage tank (24) is connected to the high-level oil tank (26) via the overflow valve B (25). The high-level oil tank (26) is connected to the low-pressure inlet pipe (9) of multiple oscillating float wave energy hydraulic acquisition systems. The electric valve group includes at least three electric valves, and the hydraulic motor group includes multiple hydraulic motors, each corresponding to one of the electric valves. The corresponding electric valves and hydraulic motors are connected as a group, and multiple groups of electric valves and hydraulic motors are arranged in parallel between the energy storage tank (20) and the low-pressure liquid storage tank (24).

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