Hydraulic Circuit of Wave Energy Power Generation Device and Hydraulic System for Step-by-step Wave Energy Power Generation

Abstract

The present invention discloses a hydraulic circuit for a wave energy power generation device and a hydraulic system for step-by-step wave energy power generation. The on-off of the hydraulic circuit of the wave energy power generation device is realized through the cooperation control of a hydraulic cylinder, a rope and a reversing valve. The piston rod of the hydraulic cylinder is connected to the valve core rod of the reversing valve through the rope. The piston rod can pull the valve core rod through the rope, and when the piston rod is reset under the action of the accumulator, it can also push the valve core rod to reset. There is no power consumption during the movement process of the valve core rod in the reversing valve, and the movement of the valve core rod directly controls the on-off of the hydraulic reversing valve, thereby enabling the on-off of the entire hydraulic circuit of the wave energy power generation device without the participation of electric control. Compared with the prior art, the control method is simpler and the operation is more reliable. In the hydraulic system for step-by-step wave energy power generation, the generators of each stage of the hydraulic circuit generate electricity automatically and independently in sequence as the pressure of the hydraulic system changes, and without the participation of electric control, having the advantages of high hydraulic energy conversion efficiency, simple control method, no power consumption, adjustable working pressure range of the hydraulic circuit, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulics, and in particular to a hydraulic circuit for a wave energy power generation device and a wave energy step-by-step power generation hydraulic system. Background Art

[0002] Hydraulic wave energy power generation devices mostly adopt energy storage and intermittent power generation methods. That is, when the pressure of the hydraulic system reaches the maximum working pressure, the generator starts to generate electricity until the pressure of the hydraulic system drops to the minimum working pressure, and the generator stops generating electricity, and the hydraulic system recharges. In the hydraulic circuit of a wave energy power generation device, a pressure relay is often required to reverse the electromagnetic directional valve to control the on-off of the oil circuit, and thus control whether the generator generates electricity. This control method requires electricity participation. The prior art generally supplies power from land or through the self-generated power supply of the generator to ensure the operation of the wave energy power generation device, which is not only costly and environmentally unfriendly, but also, the wave energy power generation device generally operates unattended. If there is a power supply problem, its normal operation will be affected, and the reliability is poor. Summary of the Invention

[0003] The purpose of the present invention is to provide a hydraulic circuit for a wave energy power generation device and a wave energy step-by-step power generation hydraulic system to solve the problems that the hydraulic circuit of the existing wave energy power generation device requires power control, which is not only costly and environmentally unfriendly, but also has poor reliability.

[0004] To achieve the above object, the present invention provides the following solution: The present invention provides a hydraulic circuit for a wave energy power generation device, including: a hydraulic cylinder, a directional valve, and a power generation branch. The piston rod of the hydraulic cylinder divides the cylinder body of the hydraulic cylinder into a rod chamber and a rodless chamber. One of the rod chamber and the rodless chamber is used to be connected to a hydraulic oil source, and the other is connected to a piston rod reset member, and the piston rod reset member is used to provide a restoring force for the piston rod; the inlet of the directional valve is used to be connected to the hydraulic oil source, and the valve core rod of the directional valve is connected to the piston rod through a rope, so that the piston rod can pull the valve core rod to move in a first direction through the rope, and when the piston rod is reset, it can push the valve core rod to move in a second direction, and the second direction is coaxial and opposite to the first direction; the power generation branch includes a hydraulic directional valve and a hydraulic motor. The inlet of the hydraulic directional valve is used to be connected to the hydraulic oil source, the control port of the hydraulic directional valve is connected to the outlet of the directional valve, the outlet of the hydraulic directional valve is connected to the inlet of the hydraulic motor through a connecting oil circuit, the hydraulic motor is used to be connected to a generator, and the outlet of the hydraulic motor is connected to a first oil tank; the minimum opening pressure of the hydraulic directional valve is less than the set minimum working pressure of the wave energy power generation device; the valve core rod moves between the first direction and the second direction, which can control the on-off of the hydraulic directional valve, and thus control the start and stop of the generator.

[0005] Optionally, the piston rod reset member is an accumulator; and the accumulator is connected to the rodless cavity, and the rod chamber is configured to be connected to the hydraulic oil source.

[0006] Optionally, a flow control valve is further provided on the connection oil path.

[0007] Optionally, a first limit screw and a second limit screw are respectively provided at both ends of the cylinder block of the hydraulic cylinder to limit the movement range of the piston rod.

[0008] The present invention also provides a hydraulic system for step-by-step wave energy power generation, which includes a hydraulic cylinder, a reversing valve, a primary power generation branch and a secondary power generation branch. The piston rod of the hydraulic cylinder divides the cylinder body of the hydraulic cylinder into a rod chamber and a rodless chamber. One of the rod chamber and the rodless chamber is used to be connected to a hydraulic oil source, and the other is connected to a piston rod resetting member, and the piston rod resetting member is used to provide a restoring force for the piston rod; the liquid inlet of the reversing valve is used to be connected to the hydraulic oil source, and the valve core rod of the reversing valve is connected to the piston rod through a rope, so that the piston rod can pull the valve core rod to move in a first direction through the rope, and when the piston rod resets, it can push the valve core rod to move in a second direction, and the second direction is coaxial and opposite to the first direction; the primary power generation branch includes a primary hydraulic reversing valve, a primary hydraulic motor and a primary sequence valve. The liquid inlet of the primary hydraulic reversing valve is used to be connected to the hydraulic oil source, the control port of the primary hydraulic reversing valve is connected to the liquid outlet of the reversing valve, the liquid outlet of the primary hydraulic reversing valve is connected to the liquid inlet of the primary hydraulic motor through a primary connection oil circuit, the liquid outlet of the primary hydraulic motor is connected to the liquid inlet of the primary sequence valve, and the primary hydraulic motor is used to be connected to a primary generator; the minimum opening pressure of the primary hydraulic reversing valve is less than the minimum working pressure of the set wave energy power generation device; the liquid outlet of the primary sequence valve is connected to a second oil tank, and the control port of the primary sequence valve is connected to the liquid outlet of the primary hydraulic reversing valve; the valve core rod moves between the first direction and the second direction, and can control the on-off of the primary hydraulic reversing valve, and further control the start and stop of the primary generator; the secondary power generation branch includes a secondary hydraulic reversing valve and a secondary hydraulic motor. The liquid inlet of the secondary hydraulic reversing valve is connected to the liquid outlet of the primary hydraulic reversing valve, the liquid outlet of the secondary hydraulic reversing valve is connected to the liquid inlet of the secondary hydraulic motor through a secondary connection oil circuit, and the secondary hydraulic motor is used to be connected to a secondary generator; when only one group of the secondary power generation branch is provided, the minimum closing pressure of the secondary hydraulic reversing valve is equal to the minimum opening pressure of the primary sequence valve; when multiple groups of the secondary power generation branch are provided, all the secondary power generation branches are arranged in sequence along the oil flow direction of the liquid outlet of the primary hydraulic reversing valve, and in addition to the secondary power generation branch located at the most downstream of the oil flow direction, secondary sequence valves are also provided in the remaining secondary power generation branches. The liquid inlet of any one of the secondary sequence valves is connected to the liquid outlet of the corresponding secondary hydraulic motor, the liquid outlet of any one of the secondary sequence valves is connected to the second oil tank, and the control port of any one of the secondary sequence valves is connected to the liquid outlet of the primary hydraulic reversing valve;Among them, the lowest closing pressure of the secondary hydraulic directional valve in the secondary power generation branch located at the uppermost upstream of the oil flow direction is equal to the lowest opening pressure of the primary sequence valve. The lowest opening pressure of any secondary sequence valve is equal to the lowest closing pressure of the secondary hydraulic directional valve in the adjacent secondary power generation branch downstream of it. The lowest opening pressure of any secondary sequence valve is greater than the lowest opening pressure of the secondary sequence valve in the secondary power generation branch downstream of it.;

[0009] Optionally, there are two groups of secondary power generation branches.

[0010] Optionally, the piston rod reset member is an accumulator.

[0011] Optionally, flow control valves are also provided on the primary connection oil circuit and any secondary connection oil circuit.

[0012] Optionally, a first limit screw and a second limit screw are respectively provided at both ends of the cylinder block of the hydraulic cylinder to limit the movement range of the piston rod.

[0013] The hydraulic circuit of the wave energy power generation device proposed by the present invention has achieved the following technical effects compared with the prior art: The on-off of the circuit is realized through the cooperation control of the hydraulic cylinder, the rope and the directional valve. The piston rod of the hydraulic cylinder is connected to the valve core rod of the directional valve through the rope. The piston rod can pull the valve core rod through the rope, and when the piston rod is reset under the action of the accumulator, it can also push the valve core rod to reset. There is no power consumption during the movement process of the valve core rod in the directional valve, and the movement of the valve core rod directly controls the on-off of the hydraulic directional valve, so that the on-off of the entire hydraulic circuit of the wave energy power generation device does not require electronic control participation. Compared with the prior art, the control method is simpler, and the hydraulic circuit runs more reliably in the unattended working mode, which is beneficial to improving the power generation efficiency and operation reliability of the wave energy power generation device.

[0014] In some technical solutions of the invention, through the arrangement of the first limit screw and the second limit screw, and the arrangement of the simple connection structure of the rope, the adjustment of the working pressure range of the hydraulic circuit can be realized, making the application method and application range of the hydraulic circuit of the wave energy power generation device more flexible.

[0015] The wave energy step-by-step power generation hydraulic system proposed by the present invention has the advantages that the generators of each level of hydraulic circuit generate electricity automatically and independently in sequence as the pressure of the hydraulic system changes, and no electronic control is required, with high hydraulic energy conversion efficiency, simple control method, no power consumption, adjustable working pressure range of the hydraulic circuit, etc. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of the hydraulic circuit of the wave energy power generation device disclosed in the embodiments of the present invention.

[0018] Figure 2 It is a schematic diagram when the primary generator of the wave energy step-by-step power generation hydraulic system disclosed in the embodiments of the present invention is in the power generation state.

[0019] Figure 3 It is a schematic diagram when the secondary generator of the wave energy step-by-step power generation hydraulic system disclosed in the embodiments of the present invention is in the power generation state.

[0020] Figure 4 It is a schematic diagram when the final-stage generator of the wave energy step-by-step power generation hydraulic system disclosed in the embodiments of the present invention is in the power generation state.

[0021] Figure 5 It is a schematic diagram when the final-stage generator of the wave energy step-by-step power generation hydraulic system disclosed in the embodiments of the present invention stops generating electricity.

[0022] Among them, the reference numerals are: 100, hydraulic circuit of the wave energy power generation device; 200, wave energy step-by-step power generation hydraulic system; 1, hydraulic cylinder; 2, piston rod; 3, rod chamber; 4, rodless chamber; 5, hydraulic oil source; 6, accumulator; 7, reversing valve; 8, spool rod; 9, rope; 10, hydraulic reversing valve; 11, hydraulic motor; 12, generator; 13, first oil tank; 14, second oil tank; 15, flow control valve; 16, first limit screw; 17, second limit screw; 18, primary hydraulic reversing valve; 19, primary hydraulic motor; 20, primary sequence valve; 21, primary flow control valve; 22, primary generator; 23, secondary hydraulic reversing valve; 24, secondary hydraulic motor; 25, secondary sequence valve; 26, secondary flow control valve; 27, secondary generator; 28, final-stage hydraulic reversing valve; 29, final-stage hydraulic motor; 30, final-stage flow control valve; 31, final-stage generator; 32, pressure gauge; 33, coupling. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] One of the purposes of the present invention is to provide a hydraulic circuit for a wave energy power generation device to solve the problems of the hydraulic circuit of the existing wave energy power generation device, which requires electric control, not only has high cost, is not environmentally friendly, but also has poor reliability.

[0025] Another purpose of the present invention is to provide a hydraulic system for step-by-step wave energy power generation. In addition to solving the problems of the hydraulic circuit of the existing wave energy power generation device, which requires electric control, not only has high cost, is not environmentally friendly, but also has poor reliability, it can also improve the hydraulic energy conversion efficiency in the hydraulic circuit of the entire wave energy power generation device.

[0026] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0027] Embodiment 1

[0028] As Figure 1 shown, this embodiment provides a hydraulic circuit 100 for a wave energy power generation device, which mainly includes a hydraulic cylinder 1, a directional control valve 7, and a power generation branch. The piston rod 2 of the hydraulic cylinder 1 divides the cylinder body of the hydraulic cylinder 1 into a rod chamber 3 and a rodless chamber 4. One of the rod chamber 3 and the rodless chamber 4 is used to be connected to a hydraulic oil source 5, and the other is connected to a piston rod reset member, and the piston rod reset member is used to provide a restoring force for the piston rod 2; the inlet port of the directional control valve 7 is used to be connected to the hydraulic oil source 5, and the spool rod 8 of the directional control valve 7 is connected to the piston rod 2 through a rope 9, so that the piston rod 2 can pull the spool rod 8 to move in the first direction through the rope 9, and when the piston rod 2 is reset, it can push the spool rod 8 to move in the second direction, and the second direction is coaxial and opposite to the first direction; the power generation branch includes a hydraulic directional control valve 10 and a hydraulic motor 11. The inlet port of the hydraulic directional control valve 10 is used to be connected to the hydraulic oil source 5, the control port of the hydraulic directional control valve 10 is connected to the outlet port of the directional control valve 7, the outlet port of the hydraulic directional control valve 10 is connected to the inlet port of the hydraulic motor 11 through a connecting oil passage, the hydraulic motor 11 is used to be connected to a generator 12, and the outlet port of the hydraulic motor 11 is connected to a first oil tank 13; the spool rod 8 moves between the first direction and the second direction, which can control the on-off of the hydraulic directional control valve 10, and further control the start and stop of the generator 12.

[0029] In this embodiment, a sequence valve may be further provided in the above power generation branch. The inlet of the sequence valve is connected to the outlet of the hydraulic motor 11, and the outlet of the sequence valve is connected to the first oil tank 13; the control port of the sequence valve is connected to the outlet of the hydraulic pilot operated directional valve 10. However, generally, one set of power generation branches is provided, and this set of power generation branches is connected to a set of generators, which can realize the power generation operation of a single-stage and single-group generator. In this case, it is preferably not to provide a sequence valve in the power generation branch.

[0030] In this embodiment, the piston rod reset member may be a structure such as a spring or an accumulator. As a preferred solution, the piston rod reset member in this embodiment is set as the accumulator 6. The accumulator 6 is connected to the rodless cavity 4, and the rod chamber 3 is used to be connected to the hydraulic oil source 5.

[0031] In this embodiment, a flow control valve 15 is further provided on the connection oil path between the hydraulic pilot operated directional valve 10 and the hydraulic motor 11. The flow control valve 15 can control the rotational speed of the generator 12.

[0032] In this embodiment, the above-mentioned directional valve 7 is a two-position three-way sliding directional valve.

[0033] In this embodiment, a first limit screw 16 and a second limit screw 17 are respectively provided at both ends of the cylinder block of the hydraulic cylinder 1. The first limit screw 16 and the second limit screw 17 are both arranged parallel to the piston rod 2 and are used to limit the moving range of the piston rod 2 in the cylinder block of the hydraulic cylinder 1. The first limit screw 16 and the second limit screw 17 are respectively screwed into the cylinder block of the hydraulic cylinder 1 from the outside. As Figure 1 shown, the hydraulic cylinder 1 is located at the left end of the directional valve 7, and the first limit screw 16 and the second limit screw 17 are respectively located at the left and right ends of the hydraulic cylinder 1; by adjusting the length of the first limit screw 16 screwed into the cylinder block of the hydraulic cylinder 1 and the length of the rope 9, the maximum working pressure of the hydraulic circuit can be changed, and by adjusting the length of the second limit screw 17 screwed into the cylinder block of the hydraulic cylinder 1, the length of the rope 9, and the relative distance between the hydraulic cylinder 1 and the directional valve 7, the minimum working pressure of the hydraulic circuit can be changed.

[0034] The working process and working principle of the above-mentioned wave energy power generation device hydraulic circuit 100 will be specifically described below.

[0035] The hydraulic oil source 5 is connected to the inlet of the hydraulic cylinder 1 composed of the cylinder block of the hydraulic cylinder and the piston rod 2, the inlet of the directional valve 7 composed of the valve body of the directional valve and the spool rod 8, and the inlet of the hydraulic pilot operated directional valve 10. A mechanical pressure gauge 32 is installed at the outlet of the hydraulic oil source 5 to observe the pressure of the hydraulic circuit in real time. The first limit screw 16 and the second limit screw 17 are respectively provided at both axial end faces of the cylinder block of the hydraulic cylinder 1 to limit the moving distance of the piston rod 2; the rodless cavity 4 of the hydraulic cylinder 1 is connected with an accumulator 6 to store oil and provide a restoring force for the piston rod 2. As Figure 1As shown, the hydraulic cylinder 1 and the reversing valve 7 are both horizontally placed and arranged side by side left and right. The piston rod 2 of the hydraulic cylinder 1 and the valve core rod 8 are coaxially arranged. Circular holes for fixing the rope 9 are provided at the ends of the piston rod 2 and the valve core rod 8 that are close to each other. The piston rod 2 and the valve core rod 8 are connected by a soft and inelastic rope 9. The two ends of the rope pass through the circular holes on the piston rod 2 and the valve core rod 8 respectively and are tied and fixed. When the piston rod 2 moves in the direction away from the reversing valve 7, that is, moves to the left, the rope 9 can be straightened first, and then the valve core rod 8 is driven to move left by the straightened rope 9; conversely, when the piston rod 2 moves in the direction close to the reversing valve 7, that is, moves to the right, when the piston rod 2 moves to the right, the valve core rod 8 is pushed to move right by direct contact to realize the reset of the valve core rod 8 to the right.

[0036] The reversing valve 7 is a "two-position three-way" reversing slide valve. The valve core rod 8 moves left and right in the reversing valve body to control the on-off of the hydraulic reversing valve 10. The liquid outlet of the reversing valve 7 is connected to a single set of power generation branch circuits. In this power generation branch circuit, the liquid outlet of the hydraulic reversing valve 10 is connected to the liquid inlet of the flow control valve 15, the liquid outlet of the flow control valve 15 is connected to the liquid inlet of the hydraulic motor 11, the hydraulic motor 11 is connected to the generator 12 through the coupling 33, and the liquid outlet of the hydraulic motor 11 is connected to the first oil tank 13.

[0037] The hydraulic circuit 100 of the above wave energy power generation device controls the on-off of the hydraulic reversing valve 10 through the accumulator 6, the hydraulic cylinder 1, the first limit screw 16, the second limit screw 17, the rope 9 and the reversing valve 7, so that the wave energy power generation device starts generating electricity when the pressure in the hydraulic circuit reaches the set maximum working pressure and stops generating electricity when it reaches the set minimum working pressure. The specific working process is as follows:

[0038] When the pressure in the hydraulic circuit reaches the set maximum working pressure, as Figure 1 shown, the piston rod 2 of the hydraulic cylinder 1 moves to the left limit position and is limited by the first limit screw 16. The valve core rod 8 is pulled by the traction force of the rope 9 and moves to the right working position. The control port of the hydraulic reversing valve 10 is connected to the hydraulic oil source 5. Since the minimum opening pressure of the hydraulic reversing valve 10 is less than the set minimum working pressure of the wave energy power generation device, the hydraulic reversing valve 10 is in the left-position passage state at this time, and the hydraulic oil source 5 starts to output high-pressure oil, and the generator 12 starts generating electricity; as the pressure in the hydraulic circuit continuously decreases, under the action of the pressure oil of the accumulator 6, the piston rod 2 gradually moves to the right. When the pressure in the hydraulic circuit gradually decreases to the set minimum working pressure, the piston rod 2 of the hydraulic cylinder 1 moves to the right limit position and is limited by the second limit screw 17. The valve core rod 8 is reset to the left working position by the thrust of the piston rod 2. The control port of the hydraulic reversing valve 10 is connected to the first oil tank 13, so that the hydraulic reversing valve 10 is in the right-position open state, and the hydraulic circuit 100 of the wave energy power generation device does not form a passage, and the generator 12 stops generating electricity.

[0039] It can be seen that for the hydraulic circuit 100 of the wave energy power generation device proposed in this technical solution, the on-off of the circuit is realized by the cooperation control of the hydraulic cylinder, the rope and the reversing valve. The piston rod of the hydraulic cylinder is connected to the spool rod of the reversing valve through the rope. The piston rod can pull the spool rod through the rope, and when the piston rod is reset under the action of the accumulator, it can also push the spool rod to reset. There is no power consumption during the movement of the spool rod in the reversing valve, and the movement of the spool rod directly controls the on-off of the hydraulic reversing valve, so that the on-off of the entire hydraulic circuit 100 of the wave energy power generation device does not require the participation of electric control. Compared with the prior art, the control method is simpler, and the hydraulic circuit runs more reliably in the unattended working mode.

[0040] In addition, through the arrangement of the first limit screw and the second limit screw, combined with the arrangement of the simple connection structure of the rope, the adjustment of the working pressure range of the hydraulic circuit can be realized, making the application method and application range of the hydraulic circuit 100 of the wave energy power generation device more flexible.

[0041] Embodiment 2

[0042] As Figures 2 to 5As shown in the figure, this embodiment proposes a wave energy step-by-step power generation hydraulic system 200, specifically a hydraulic system capable of controlling the step-by-step automatic power generation of a wave energy device. It mainly includes a hydraulic cylinder 1, a reversing valve 7, a primary power generation branch and a secondary power generation branch. The piston rod 2 of the hydraulic cylinder 1 divides the cylinder body of the hydraulic cylinder 1 into a rod chamber 3 and a rodless chamber 4. One of the rod chamber 3 and the rodless chamber 4 is used to be connected to a hydraulic oil source 5, and the other is connected to a piston rod resetting member, and the piston rod resetting member is used to provide a restoring force for the piston rod 2; the liquid inlet of the reversing valve 7 is used to be connected to the hydraulic oil source 5, and the valve core rod 8 of the reversing valve 7 is connected to the piston rod 2 through a rope 9, so that the piston rod 2 can pull the valve core rod 8 to move in the first direction through the rope 9, and when the piston rod 2 resets, it can push the valve core rod 8 to move in the second direction, and the second direction is coaxial and opposite to the first direction. The primary power generation branch includes a primary hydraulic reversing valve 18, a primary hydraulic motor 19 and a primary sequence valve 20. The liquid inlet of the primary hydraulic reversing valve 18 is used to be connected to the hydraulic oil source 5, the liquid outlet of the primary hydraulic reversing valve 18 is connected to the liquid inlet of the primary hydraulic motor 19 through a primary connection oil circuit, the liquid outlet of the primary hydraulic motor 19 is connected to the liquid inlet of the primary sequence valve 20, and the primary hydraulic motor 19 is used to be connected to a primary generator 22; the liquid outlet of the primary sequence valve 20 is connected to a second oil tank 14, and the control port of the primary sequence valve 20 is connected to the liquid outlet of the primary hydraulic reversing valve 18. The valve core rod 8 moves between the first direction and the second direction, which can control the on-off of the primary hydraulic reversing valve 18, and further control the start and stop of the primary generator 22. The above-mentioned secondary power generation branch includes a secondary hydraulic reversing valve and a secondary hydraulic motor. The liquid inlet of the secondary hydraulic reversing valve is connected to the liquid outlet of the primary hydraulic reversing valve 18, the liquid outlet of the secondary hydraulic reversing valve is connected to the liquid inlet of the secondary hydraulic motor through a secondary connection oil circuit, and the secondary hydraulic motor is used to be connected to a secondary generator. When only one set of secondary power generation branches is provided, the minimum closing pressure of the secondary hydraulic reversing valve is equal to the minimum opening pressure of the primary sequence valve 20. At this time, the wave energy step-by-step power generation hydraulic system 200 has two power generation circuits.When multiple sets of secondary power generation branches are provided, all the secondary power generation branches are arranged in sequence along the oil flow direction of the outlet of the primary hydraulic directional control valve 18. And except for the secondary power generation branch located at the most downstream of the oil flow direction, that is, the last-stage power generation branch, secondary sequence valves are also provided in the remaining secondary power generation branches. The inlet of any secondary sequence valve is connected to the outlet of the corresponding secondary hydraulic motor, the outlet of any secondary sequence valve is connected to the second oil tank 14, and the control port of any secondary sequence valve is connected to the outlet of the primary hydraulic directional control valve 18. Among them, the lowest closing pressure of the secondary hydraulic directional control valve in the secondary power generation branch located at the most upstream of the oil flow direction is equal to the lowest opening pressure of the primary sequence valve 20, the lowest opening pressure of any secondary sequence valve is equal to the lowest closing pressure of the secondary hydraulic directional control valve in the adjacent secondary power generation branch downstream of it, and the lowest opening pressure of any secondary sequence valve is greater than the lowest opening pressure of the secondary sequence valve in the secondary power generation branch downstream of it; at this time, the wave energy step-by-step power generation hydraulic system 200 has more than three power generation circuits. In the above wave energy step-by-step power generation hydraulic system 200, the generators of each hydraulic circuit automatically generate electricity independently and successively as the pressure of the hydraulic system changes, and there is no need for electronic control to participate. It has the advantages of high hydraulic energy conversion efficiency, simple control method, no power consumption, adjustable working pressure range of the hydraulic circuit, etc.

[0043] In this embodiment, the piston rod reset member can be structures such as a spring or an accumulator. As a preferred solution, the piston rod reset member in this embodiment is set as the accumulator 6. The accumulator 6 is connected to the rodless cavity 4, and the rod chamber 3 is used to be connected to the hydraulic oil source 5.

[0044] In this embodiment, flow control valves are also provided on the above primary connection oil path and any secondary connection oil path to control the rotation speed of the generator in the corresponding power generation branch. Taking the example that two sets of secondary connection oil paths are provided, the flow control valve on the primary connection oil path is the primary flow control valve 21, the flow control valve in the secondary power generation branch adjacent to the primary power generation branch is the secondary flow control valve 26, and for the most downstream secondary connection oil path, which is used as the last-stage power generation branch, the flow control valve on it is the last-stage flow control valve 30.

[0045] In this embodiment, the above-mentioned reversing valve 7 is a two-position three-way reversing spool valve.

[0046] In this embodiment, a first limit screw 16 and a second limit screw 17 are respectively provided at both ends of the cylinder block of the hydraulic cylinder 1. The first limit screw 16 and the second limit screw 17 are both arranged parallel to the piston rod 2 and are used to limit the movement range of the piston rod 2 in the cylinder block of the hydraulic cylinder 1. The first limit screw 16 and the second limit screw 17 are respectively screwed into the cylinder block of the hydraulic cylinder 1 from the outside, such as Figure 1As shown in the figure, the hydraulic cylinder 1 is located at the left end of the reversing valve 7, and the first limit screw 16 and the second limit screw 17 are respectively located at the left and right ends of the hydraulic cylinder 1. By adjusting the length of the first limit screw 16 screwed into the cylinder body of the hydraulic cylinder 1 and the length of the rope 9, the maximum working pressure of the hydraulic circuit can be changed. By adjusting the length of the second limit screw 17 screwed into the cylinder body of the hydraulic cylinder 1, the length of the rope 9, and the relative distance between the hydraulic cylinder 1 and the reversing valve 7, the minimum working pressure of the hydraulic circuit can be changed.

[0047] Taking the case where two sets of secondary power generation branches are provided as an example, the working process and working principle of the above-mentioned wave energy step-by-step power generation hydraulic system 200 will be specifically described. At this time, the wave energy step-by-step power generation hydraulic system 200 has a three-stage power generation hydraulic circuit. The primary power generation branch is used as the first-stage power generation branch, and the other two sets of secondary power generation branches are respectively used as the second-stage power generation branch and the final (third-stage) power generation branch. Among them, the hydraulic reversing valve, hydraulic motor, sequence valve, flow control valve, and generator in the second-stage power generation branch are respectively called: the second-stage hydraulic reversing valve 23, the second-stage hydraulic motor 24, the second-stage sequence valve 25, the second-stage flow control valve 26, and the second-stage generator 27. The hydraulic reversing valve, hydraulic motor, flow control valve, and generator in the final (third-stage) power generation branch are respectively called: the final-stage hydraulic reversing valve 28, the final-stage hydraulic motor 29, the final-stage flow control valve 30, and the final-stage generator 31.

[0048] As Figures 2 to 5 As shown in the figure, the hydraulic oil source 5 is connected to the inlet of the hydraulic cylinder 1 composed of the cylinder body of the hydraulic cylinder and the piston rod 2, the inlet of the reversing valve 7 composed of the valve body of the reversing valve and the spool rod 8, and the inlet of the primary hydraulic reversing valve 18. A mechanical pressure gauge 32 is installed at the outlet of the hydraulic oil source 5 to observe the pressure of the hydraulic circuit in real time. The first limit screw 16 and the second limit screw 17 are respectively arranged at the axial two end faces of the cylinder body of the hydraulic cylinder 1 to limit the moving distance of the piston rod 2. The rodless cavity 4 of the hydraulic cylinder 1 is connected with an accumulator 6 to store oil and provide a restoring force for the piston rod 2. The hydraulic cylinder 1 and the reversing valve 7 are both placed horizontally and are arranged side by side left and right. The piston rod 2 of the hydraulic cylinder 1 is coaxially arranged with the spool rod 8. Round holes for fixing the rope 9 are arranged at the mutually approaching ends of the piston rod 2 and the spool rod 8. The piston rod 2 and the spool rod 8 are connected by a soft and inelastic rope 9. The two ends of the rope respectively pass through the round holes on the piston rod 2 and the spool rod 8 and are tied and fixed respectively. When the piston rod 2 moves in the direction away from the reversing valve 7, that is, moves to the left, the rope 9 can be straightened first, and then the straightened rope 9 drives the spool rod 8 to move leftward. On the contrary, when the piston rod 2 moves in the direction close to the reversing valve 7, that is, moves to the right, when the piston rod 2 moves to the right, it directly contacts and pushes the spool rod 8 to realize the rightward movement reset of the spool rod 8.

[0049] The reversing valve 7 is a "two-position three-way" reversing spool valve. The spool rod 8 moves left and right within the reversing valve body to control the opening and closing of the primary hydraulic reversing valve 18. The primary hydraulic reversing valve 18 serves as the main hydraulic reversing valve of the entire wave energy step-by-step power generation hydraulic system 200. Its liquid outlet is connected to the liquid inlet of the primary flow control valve 21, the liquid inlet of the secondary hydraulic reversing valve 23, the liquid inlet of the final-stage hydraulic reversing valve 28, the control port of the primary sequence valve 20, and the control port of the secondary sequence valve 25. The liquid outlet of the primary flow control valve 21 is connected to the liquid inlet of the primary hydraulic motor 19. The primary hydraulic motor 19 is connected to the primary generator 22 through a coupling 33. The liquid outlet of the primary hydraulic motor 19 is connected to the liquid inlet of the primary sequence valve 20. The liquid outlet of the primary sequence valve 20 is connected to the second oil tank 14. The liquid outlet of the secondary hydraulic reversing valve 23 is connected to the liquid inlet of the secondary flow control valve 26. The liquid outlet of the secondary flow control valve 26 is connected to the liquid inlet of the secondary hydraulic motor 24. The secondary hydraulic motor 24 is connected to the secondary generator 27 through a coupling 33. The liquid outlet of the secondary hydraulic motor 24 is connected to the liquid inlet of the secondary sequence valve 25. The liquid outlet of the secondary sequence valve 25 is connected to the second oil tank 14. The liquid outlet of the final-stage hydraulic reversing valve 28 is connected to the liquid inlet of the final-stage flow control valve 30. The liquid outlet of the final-stage flow control valve 30 is connected to the liquid inlet of the final-stage hydraulic motor 29. The final-stage hydraulic motor 29 is connected to the final-stage generator 31 through a coupling 33. The liquid outlet of the final-stage hydraulic motor 29 is connected to the second oil tank 14. Among them, the minimum opening pressure of the primary sequence valve 20 is equal to the minimum closing pressure of the secondary hydraulic reversing valve 23, and is greater than the minimum opening pressure of the secondary sequence valve 25. The minimum opening pressure of the secondary sequence valve 25 is equal to the minimum closing pressure of the final-stage hydraulic reversing valve 28.

[0050] The primary hydraulic reversing valve 18, the primary flow control valve 21, the primary hydraulic motor 19, the primary generator 22, the primary sequence valve 20, and the corresponding second oil tank 14 form the first-stage power generation hydraulic circuit. The secondary hydraulic reversing valve 23, the secondary flow control valve 26, the secondary hydraulic motor 24, the secondary generator 27, the secondary sequence valve 25, and the corresponding second oil tank 14 form the second-stage power generation hydraulic circuit. The final-stage hydraulic reversing valve 28, the final-stage flow control valve 30, the final-stage hydraulic motor 29, the final-stage generator 31, and the corresponding second oil tank 14 form the third-stage power generation hydraulic circuit. The power generation sequence of the generators in each hydraulic circuit is the primary generator 22, the secondary generator 27, and the final-stage generator 31. The rotational speeds of the primary generator 22, the secondary generator 27, and the final-stage generator 31 are controlled by the primary flow control valve 21, the secondary flow control valve 26, and the final-stage flow control valve 30 respectively.

[0051] The working principle of the above wave energy step-by-step power generation hydraulic system 200 with three hydraulic circuits is as follows:

[0052] During the power generation process of the wave energy power generation device, the hydraulic oil pressure provided by the hydraulic oil source 5 will continuously decrease. Therefore, the rated powers of the primary generator 22, the secondary generator 27, and the final-stage generator 31 decrease in sequence to match the continuously decreasing hydraulic energy input to the primary hydraulic motor 19, the secondary hydraulic motor 24, and the final-stage hydraulic motor 29, thereby improving the hydraulic energy conversion efficiency of the wave energy power generation device during the entire power generation process.

[0053] When the pressure of the hydraulic circuit reaches the set maximum working pressure, refer to Figure 2 , the piston rod 2 moves to the left extreme position and is limited by the first limit screw 16. The spool rod 8 moves leftward to the right-position working state under the traction force of the rope 9. The control port of the primary hydraulic directional valve 18 is connected to the hydraulic oil source 5. Since the minimum opening pressure of the primary hydraulic directional valve 18 is less than the minimum working pressure of the set wave energy power generation device, the primary hydraulic directional valve 18 is in the left-position passage state at this time. The hydraulic oil source 5 starts to output oil to the first-stage, second-stage, and third-stage power generation hydraulic circuits. Since the hydraulic circuit pressure is relatively high at first, the control ports of the primary sequence valve 20 and the secondary sequence valve 25 are affected by the high-pressure hydraulic oil, causing both the primary sequence valve 20 and the secondary sequence valve 25 to open. The control ports of the secondary hydraulic directional valve 23 and the final-stage hydraulic directional valve 28 are affected by the high-pressure hydraulic oil, causing both the secondary hydraulic directional valve 23 and the final-stage hydraulic directional valve 28 to be in the upper position and closed. Therefore, the second-stage and third-stage power generation hydraulic circuits do not form a passage, and the secondary generator 27 and the final-stage generator 31 do not generate electricity. The first-stage power generation hydraulic circuit forms a passage, and the primary generator 22 starts to generate electricity.

[0054] As the hydraulic circuit pressure continuously decreases, under the action of the pressure oil of the accumulator 6, the piston rod 2 gradually moves rightward. When the hydraulic circuit pressure gradually decreases below the minimum opening pressure of the primary sequence valve 20, refer to Figure 3 , the primary sequence valve 20 closes. Since the minimum closing pressure of the secondary hydraulic directional valve 23 is equal to the minimum opening pressure of the primary sequence valve 20, the pressure at the control port of the secondary hydraulic directional valve 23 also decreases below the minimum closing pressure. The secondary hydraulic directional valve 23 is in the lower position and opens. Therefore, the first-stage power generation hydraulic circuit does not form a passage, the primary generator 22 stops generating electricity, the second-stage power generation hydraulic circuit forms a passage, and the secondary generator 27 starts to generate electricity. The third-stage power generation hydraulic circuit still does not form a passage, and the final-stage generator 31 does not generate electricity.

[0055] As the hydraulic circuit pressure continues to decrease, under the action of the pressure oil of the accumulator 6, the piston rod 2 continues to move rightward. When the hydraulic circuit pressure gradually decreases below the minimum opening pressure of the secondary sequence valve 25, refer to Figure 4, the second-stage sequence valve 25 closes. Since the minimum closing pressure of the last-stage hydraulic directional valve 28 is equal to the minimum opening pressure of the second-stage sequence valve 25, the control port pressure of the last-stage hydraulic directional valve 28 also drops below the minimum closing pressure. The last-stage hydraulic directional valve 28 is in the lower position and opens. Therefore, the second-stage power generation hydraulic circuit does not form a path, the second-stage generator 27 stops generating electricity, the third-stage power generation hydraulic circuit forms a path, and the last-stage generator 31 starts generating electricity. The first-stage power generation hydraulic circuit still does not form a path, and the first-stage generator 22 does not generate electricity.

[0056] As the pressure of the hydraulic circuit continues to decrease, under the action of the pressurized oil of the accumulator 6, the piston rod 2 continuously moves to the right and contacts the spool rod 8. The spool rod 8 moves to the left under the thrust of the piston rod 2 to the left-position working state. Refer to Figure 5 , at this time, the pressure of the hydraulic circuit drops to the minimum working pressure. The piston rod 2 moves to the right extreme position and is limited by the second limit screw 17. The control port of the first-stage hydraulic directional valve 18 is connected to the second oil tank 14, making the first-stage hydraulic directional valve 18 in the right-position open circuit state. The hydraulic oil source 5 stops outputting hydraulic oil to each stage of the power generation hydraulic circuit. The last-stage generator 31 stops generating electricity. The hydraulic system of the wave energy power generation device starts storing energy again, and finally realizes the purpose that the generators in the first-stage, second-stage, and third-stage power generation hydraulic circuits generate electricity automatically step by step with the change of the hydraulic circuit pressure.

[0057] Most existing hydraulic wave energy power generation devices only use one generator in the entire working pressure range. This will lead to the inability to maintain a high conversion efficiency during the conversion of hydraulic energy into electrical energy, which is not conducive to the full utilization of hydraulic energy. To solve this problem, the above-mentioned wave energy step-by-step power generation hydraulic system 200 is proposed in this technical solution. Through the mutual combination of hydraulic directional valves with different minimum closing pressures and sequence valves with different minimum opening pressures, the generators in each stage of the hydraulic circuit generate electricity independently in sequence, improving the hydraulic energy conversion efficiency of the wave energy power generation device, which is conducive to outputting more electrical energy. At the same time, no electrical equipment such as electromagnetic directional valves and pressure relays is used during the output of hydraulic oil by the hydraulic oil source and the power generation process of each stage of the hydraulic circuit. The entire power generation process does not require electricity participation, simplifies the control method, saves electrical energy, and also has the advantages such as the adjustable working pressure range of the hydraulic circuit.

[0058] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0059] Specific examples are used in the present invention to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A wave energy step-by-step power generation hydraulic system, characterized in that, It includes a hydraulic cylinder, a directional control valve, a primary power generation branch and a secondary power generation branch. The piston rod of the hydraulic cylinder divides the cylinder body of the hydraulic cylinder into a rod chamber and a rodless chamber. One of the rod chamber and the rodless chamber is used to be connected to a hydraulic oil source, and the other is connected to a piston rod return member, and the piston rod return member is used to provide a restoring force for the piston rod; the inlet of the directional control valve is used to be connected to the hydraulic oil source, and the spool rod of the directional control valve is connected to the piston rod through a rope, so that the piston rod can pull the spool rod to move in a first direction through the rope, and when the piston rod is reset, it can push the spool rod to move in a second direction, and the second direction is coaxial and opposite to the first direction; the primary power generation branch includes a primary hydraulic directional control valve, a primary hydraulic motor and a primary sequence valve. The inlet of the primary hydraulic directional control valve is used to be connected to the hydraulic oil source, the control port of the primary hydraulic directional control valve is connected to the outlet of the directional control valve, the outlet of the primary hydraulic directional control valve is connected to the inlet of the primary hydraulic motor through a primary connection oil circuit, the outlet of the primary hydraulic motor is connected to the inlet of the primary sequence valve, and the primary hydraulic motor is used to be connected to a primary generator; the minimum opening pressure of the primary hydraulic directional control valve is less than the minimum working pressure of the set wave energy power generation device; the outlet of the primary sequence valve is connected to a second oil tank, and the control port of the primary sequence valve is connected to the outlet of the primary hydraulic directional control valve; the spool rod moves between the first direction and the second direction, and can control the on-off of the primary hydraulic directional control valve, and further control the start and stop of the primary generator; the secondary power generation branch includes a secondary hydraulic directional control valve and a secondary hydraulic motor. The inlet of the secondary hydraulic directional control valve is connected to the outlet of the primary hydraulic directional control valve, the outlet of the secondary hydraulic directional control valve is connected to the inlet of the secondary hydraulic motor through a secondary connection oil circuit, and the secondary hydraulic motor is used to be connected to a secondary generator; when only one set of the secondary power generation branch is provided, the minimum closing pressure of the secondary hydraulic directional control valve is equal to the minimum opening pressure of the primary sequence valve; when multiple sets of the secondary power generation branch are provided, all the secondary power generation branches are arranged in sequence along the oil flow direction of the outlet of the primary hydraulic directional control valve, and in addition to the secondary power generation branch located at the most downstream of the oil flow direction, secondary sequence valves are also provided in the remaining secondary power generation branches. The inlet of any one of the secondary sequence valves is connected to the outlet of the corresponding secondary hydraulic motor, the outlet of any one of the secondary sequence valves is connected to the second oil tank, and the control port of any one of the secondary sequence valves is connected to the outlet of the primary hydraulic directional control valve;Among them, the lowest closing pressure of the secondary hydraulic directional control valve in the secondary power generation branch located at the most upstream of the oil flow direction is equal to the lowest opening pressure of the primary sequence valve, the lowest opening pressure of any secondary sequence valve is equal to the lowest closing pressure of the secondary hydraulic directional control valve in the adjacent secondary power generation branch downstream of it, and the lowest opening pressure of any secondary sequence valve is greater than the lowest opening pressure of the secondary sequence valve in the secondary power generation branch downstream of it.; 2. The wave energy step-by-step power generation hydraulic system according to claim 1, characterized in that, There are two sets of the secondary power generation branches provided.

3. The wave energy step-by-step power generation hydraulic system according to claim 1 or 2, characterized in that The piston rod reset member is an accumulator.

4. The wave energy step-by-step power generation hydraulic system according to claim 1 or 2, characterized in that, Flow control valves are also provided on the primary connecting oil path and any one of the secondary connecting oil paths.

5. The wave energy step-by-step power generation hydraulic system according to claim 1 or 2, characterized in that A first limit screw and a second limit screw are respectively provided at both ends of the cylinder block of the hydraulic cylinder to limit the movement range of the piston rod.

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