CN117418982B - A power generation device for ocean wave energy and ocean current energy - Google Patents

Abstract

The invention provides a power generation device for ocean wave energy and ocean current energy, which includes a buoy that provides resistance and buoyancy in the sea. The buoy is rotatably connected to a connecting rod, and the lower end of the connecting rod is fixedly connected to an anchor body. The anchor body is provided with Guide plate; a power generation mechanism is provided on the connecting rod, and the power generation mechanism is arranged between the buoy and the anchor body; the power generation mechanism includes a water flow channel arranged radially along the connecting rod and a piezoelectric fiber composite material MFC, and the piezoelectric fiber composite material MFC is provided On the connecting rod in the water flow channel, the piezoelectric fiber composite MFC is installed at the outlet end of the water flow channel; the connecting rod is provided with a limiter for limiting the position of the power generation mechanism and the buoy.

Description

A power generation device for ocean wave energy and ocean current energy

Technical field

The invention relates to the technical field of ocean power generation, and in particular to a power generation device for ocean wave energy and ocean current energy.

Background technique

Ocean energy is a renewable energy source contained in the ocean, including mechanical energy and thermal energy caused by tides and waves. Ocean energy also involves a wider category, including wind energy above the sea, solar energy on the sea surface and biomass energy in the sea. The largest proportions are wave energy and ocean current energy. The demand for ocean exploration is also becoming increasingly urgent, which requires the application of many offline wireless sensor nodes. These wireless sensor nodes are large in number and widely distributed, and most of them are offline. Therefore, how to realize their self-power Becoming particularly important, wave energy, current energy, etc. that are widespread in the ocean provide a large amount of energy and can be used as the main energy source for wireless sensing nodes. However, since existing methods utilize high-speed water flows, the energy of low-speed water flows, which accounts for the largest proportion and has the widest frequency range in the ocean wave energy and ocean current energy spectrum, is greatly wasted. Therefore, there is an urgent need to develop new technologies to efficiently develop and utilize them.

Currently, there are four main ways to use ocean wave energy and current energy to generate electricity. Although these two methods, the piston type based on hydraulic motors and the buoy type based on buoy vibration, have high power density, they can only be applied to the sea surface and cannot meet the self-power needs of wireless sensing devices in the sea and under the sea. Although the eel type based on membrane oscillation can be applied underwater, its power density is low. The vortex-induced vibration-based vortex type can be applied to the sea surface and underwater, has high power density, is easy to integrate, and can meet the needs of wireless sensing nodes. However, there are no materials and devices to develop this mode for ocean wireless sensing.

The principle of eddy current piezoelectric energy capture is to use the vortex induced force formed by Karman vortex induction to convert wave energy and ocean current energy into electrical energy through piezoelectric materials. It has the characteristics of large bandwidth and high energy conversion efficiency. Therefore, the vortex power generation device contains two parts: the bluff body that generates the vortex-induced force and the core piezoelectric material used to achieve energy conversion. Vortex-induced trapped energy power generation places high demands on piezoelectric materials: they must have low resonant frequency, wide trapped energy frequency range, high electrical output performance, large strain, and flexibility. Piezoelectric fiber composites (MFC) have both excellent piezoelectric properties and flexibility and can meet the above requirements. However, the vortex-induced vibration frequency generated by low-speed ocean currents is much lower than the resonant frequency of commonly used piezoelectric materials, resulting in low energy capture efficiency. It cannot capture the energy of low-speed ocean currents well, so how to design power generation devices and piezoelectric materials to match the vortex-induced frequency generated by low-speed ocean currents has become a technical difficulty that must be solved.

Contents of the invention

The present invention proposes a power generation device for ocean wave energy and ocean current energy to solve the technical problem that existing ocean energy power generation devices are difficult to match the vortex-induced frequency generated by low-speed ocean currents.

In order to solve the above technical problems, the present invention provides a power generation device for ocean wave energy and ocean current energy. Its special feature is that it includes a submersible depth positioning device. The submersible depth positioning device includes a buoy and an anchor body. The buoy is rotatably connected to a connecting rod, the lower end of the connecting rod is fixedly connected to an anchor body, and the anchor body is provided with a guide plate; the connecting rod is provided with a power generation mechanism, and the power generation mechanism is arranged between the buoy and the buoy. between the anchor bodies; the power generation mechanism includes a water flow channel arranged radially along the connecting rod and a piezoelectric fiber composite material MFC, and the piezoelectric fiber composite material MFC is arranged on the connecting rod in the water flow channel, so The piezoelectric fiber composite material MFC is provided at the outlet end of the water flow channel; the connecting rod is provided with a limiter for limiting the position of the power generation mechanism and the buoy.

The diving depth positioning device includes a buoy and an anchor body. The buoy provides buoyancy in the sea. The radius of the buoy is 0.50m~2.00m. The height of the buoy is 0.2m~0.6m. The buoy and the connecting rod are connected through prestressed bolts. The position of the buoy on the connecting rod is fixed by adding a limiter at the connection between the rod and the buoy. The diameter of the connecting rod is 0.05m~0.1m, and the length of the connecting rod is 2m~3.5m. The power generation device is fixed with a prestressed bolt in the middle of the connecting rod. The position of the power generation device on the connecting rod is fixed with a limiter, and the anchor body is fixed with prestressed bolts under the connecting rod. The anchor body provides the gravity of the device in the sea, and works with the buoy to fix the position of the device in the sea. The quality of the anchor body The weight is 2kg~10kg. The guide device is fixed on the anchor body through prestressed bolts. The length of the guide plate is 1m~5m. The relevant parameters of the anchor body and buoy are calculated according to the gravity formula, buoyancy formula and Stokes formula. The specific radius and mass selection should be considered based on the actual application environment.

The connecting rod also serves as a bluff body in the power generation device to generate vortex-induced force and improve power generation efficiency.

The power generation device is mainly composed of a flow channel and a piezoelectric vibrator. The flow channel is fixed on the connecting rod through a limiter and a prestressed screw. The piezoelectric vibrator and the connecting rod are combined to form a cantilever beam structure.

When the direction of the ocean current changes, the flow channel inlet in the power generation device is consistent with the impact direction of the ocean current through the ocean current impacting the guide plate, thereby achieving the purpose of energy collection for multi-directional low-speed ocean currents. It is connected to the anchor body and also It can be used as a part of the counterweight of the overall device. The installation direction is consistent with the direction of the water flow channel, and the length is 1.00m~5.00m.

Preferably, the piezoelectric constant d33 of the piezoelectric fiber composite MFC is 700~800, and the interdigital electrodes are cathodes and anodes arranged alternately; the piezoelectric phase material of the piezoelectric fiber composite MFC is lead zirconate titanate. Ceramics; the polymer phase material of the piezoelectric fiber composite MFC includes DP270, DP460 or DP420; the material of the cantilever beam structural member of the piezoelectric fiber composite MFC includes stainless steel; the piezoelectric fiber composite MFC The base material of the beam structure of the cantilever beam includes aluminum, brass or copper.

Further, the length of the substrate of the piezoelectric fiber composite MFC is 0.01m~0.1m, the width is 0.005m~0.5m, and the thickness is 1mm~3mm; the piezoelectric phase of the cantilever beam of the piezoelectric fiber composite MFC is The length of the material is 0.01m~0.1m, the width is 0.005m~0.5m, and the thickness is 1mm~3mm; the length of the cantilever beam structure of the piezoelectric fiber composite material MFC is 0.01m~0.1m, and the width is 0.01m~0.1m. 0.005m~0.5m, with a thickness of 1mm~3mm; the total thickness of the cantilever beam of the piezoelectric fiber composite MFC is 3.5mm~5mm.

Further, when there is one power generation device, the radius of the buoy is 0.5m; the mass of the anchor body is 2kg; the diameter of the connecting rod is 0.05m; the length of the guide plate is 4m; The height of the water flow channel is 0.1m; the length of the piezoelectric fiber composite MFC is 0.01m, the width is 0.015m, and the thickness is 1mm. The total thickness of the cantilever beam of the piezoelectric fiber composite MFC is 3.5mm. The beam structural members of the cantilever beam have a length of 0.01m, a width of 0.015m, and a thickness of 1mm.

Furthermore, the power generation device is mainly composed of a flow channel and a piezoelectric vibrator. The flow channel is fixed on the connecting rod through a stopper and a prestressed screw. The piezoelectric vibrator and the connecting rod are combined to form a cantilever beam structure. Among them, the flow channel is designed with a horn structure based on Bernoulli's principle. The purpose is to increase the sea current speed at the piezoelectric vibrator by changing the ratio of the flow channel entrance to the subsequent cross-sectional area, and further improve the Karman vortex shedding formed after impacting the connecting rod. frequency, the horn structure divides the water flow channel into a first flow channel and a second flow channel, the second flow channel is provided on the connecting rod, and the cross-sectional area of the first flow channel gradually decreases along the axial direction And connected with the second flow channel. The purpose is to increase the sea current velocity in the flow channel by changing the subsequent cross-sectional area of the flow channel inlet, and further increase the shedding frequency of the Karman vortex formed after impacting the bluff body. The height of the entrance of the first flow channel is 0.25m~1.50m; the height of the second flow channel is 0.10m~0.225m.

Furthermore, when the height at the entrance of the first flow channel is 0.25m, the height of the second flow channel is 0.1m; when the height at the entrance of the first flow channel is 0.7m, the height of the second flow channel The height of the flow channel is 0.15m; when the height of the first flow channel entrance is 1.5m, the height of the second flow channel is 0.225m; the radius of the buoy is 0.5m; the mass of the anchor body is 2kg; the diameter of the connecting rod is 0.05mm; the length of the guide plate is 4m; the length of the piezoelectric fiber composite MFC is 0.01m, the width is 0.015m, and the thickness is 1mm. The total thickness of the cantilever beam of the composite MFC is 3.5mm, and the length of the cantilever beam structural member is 0.01m, the width is 0.015m, and the thickness is 1mm.

Preferably, there are three connecting rods, and three power generating mechanisms are installed on the connecting rods. The connecting rods are arranged in a radial array of the buoy, and the spacing between adjacent connecting rods is 20 mm; the power generating mechanisms are arranged in an axial array of connecting rods, and the adjacent connecting rods are arranged in an axial array. The spacing is 20mm.

Further, the radius of the buoy is 0.6m; the mass of the anchor body is 10kg; the diameter of the connecting rod is 10mm; the length of the guide plate is 4m; the height of the first flow channel entrance is 0.25 m, the height of the second flow channel is 0.1m; the length of the piezoelectric fiber composite MFC is 0.01m, the width is 0.015m, and the thickness is 1mm. The total length of the cantilever beam of the piezoelectric fiber composite MFC is The thickness is 3.5mm, and the length of the cantilever beam structural member is 0.01m, the width is 0.015m, and the thickness is 1mm.

The anchor body in the above scheme provides gravity in the sea, and the buoy provides buoyancy matching the anchor body. The selection of various parameters is calculated through gravity, buoyancy and resistance calculation formulas, and the device is applied to different diving depth locations. The required counterweight mass is required to achieve the purpose of using it at all positions on the seabed. The expression is:

(1)

(2)

(3)

In the formula, Fg represents the gravity of the anchor body, m _object represents the weight of the counterweight, g represents the acceleration of gravity, F _b represents the buoyancy force of the anchor body, ρ _water represents the density of water, F _d represents the resistance of the anchor body in the water, eta represents the viscosity coefficient of water, R represents the length of the anchor body, and v represents the velocity of the counterweight relative to the water flow.

The above-mentioned first flow channel and second flow channel were designed based on Bernoulli's principle, and a "trumpet" type flow channel inlet was designed. By changing the cross-sectional area of the entrance flow channel and the cross-sectional area of the subsequent flow channel, the flow rate was increased. The purpose of the water flow velocity in the channel is to increase the vortex-induced vibration frequency by increasing the water flow velocity in the channel, consistent with the resonant frequency of the piezoelectric material, and improve the energy collection efficiency. The expression of Bernoulli's principle is:

(4)

In the formula, P ₁ represents the pressure at the entrance (Pa); v ₁ represents the flow rate of the fluid at the entrance (m/s); ρ represents the density of water (kg/m ³ ); h ₁ represents the depth at the entrance (m) ;P ₂ represents the pressure at the outlet (Pa); v2 represents the flow rate of the fluid at the outlet (m/s); h ₁ represents the depth at the outlet (m).

According to the law of energy conservation, power generation calculation formula and energy collection efficiency formula, the energy collection efficiency of this device under different flow rates is calculated.

(5)

(6)

(7)

In the formula, E represents the kinetic energy of the fluid (J); ρ represents the density of water (kg/m ³ ); S represents the cross-sectional area of the flow channel (m ² ); t represents time (s); v represents the flow rate of the fluid (m /s); Q represents the collected energy (J); U represents the voltage generated by the power generation device (V); R represents the external resistance of the power generation device (Ω); eta represents the energy conversion efficiency.

Therefore, according to the empirical formula (8) of Taylor and Rayleigh, the vortex-induced vibration frequency of the device in water flow environments with different flow rates can be calculated, so that it matches the resonant frequency of the piezoelectric material in the device and improves the energy collection efficiency.

(8)

Where V represents the fluid flow rate, d represents the connecting rod diameter, and Re represents the Reynolds number at the current flow rate.

The beneficial effects of the present invention include at least:

1) Through the design of the guide device, the position of the flow channel entrance can be changed when the direction of the ocean current changes, thereby collecting the energy of the ocean current in any direction;

2) Through the design of buoys and anchors, the size, weight and material of the positioning device can be designed according to the application environment, so as to achieve positioning at any diving depth in the sea for energy collection and meet the integrated use of wireless sensors;

3) As an additional technical feature, the water flow channel part is designed based on Bernoulli's principle to increase the flow rate of low-speed water and increase the subsequent Karman vortex vibration frequency, thereby achieving an energy collection efficiency of 72.907%~79.99%.

4) As an additional technical feature, through the MFC structural design, the energy of vibrations with frequencies below 24.914Hz can be collected, and in conjunction with the flow channel design, the energy of lower-speed ocean currents can be collected.

Description of drawings

Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention;

Figure 2 is a diagram of the output voltage test results of Embodiment 1 of the present invention;

Figure 3 is a schematic structural diagram of Embodiment 2 of the present invention;

Figure 4 is a diagram of the output voltage test results of Embodiment 2 of the present invention;

Figure 5 is a schematic diagram of the output voltage test results of Embodiment 3 of the present invention;

Figure 6 is a schematic diagram of the output voltage test results of Embodiment 4 of the present invention;

Figure 7 is a schematic structural diagram of Embodiment 5 of the present invention;

Figure 8 is a diagram of the output voltage test results of Embodiment 5 of the present invention;

Figure 9 is a schematic diagram of the design principle of the flow channel structure according to the embodiment of the present invention;

Figure 10 is a perspective structural schematic diagram of the power generation mechanism according to the embodiment of the present invention;

In the picture: 1-buoy, 2-connecting rod, 3-anchor body, 4-guide plate, 5-water flow channel, 51-first flow channel, 52-second flow channel, 6-piezoelectric fiber composite material MFC, 7-limiter, 8-generating mechanism.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without any creative work fall within the protection scope of the present invention.

For convenience of explanation, only parts related to this embodiment are shown.

Example 1:

As shown in Figure 1, a power generation device for ocean wave energy and ocean current energy. When the flow channel design is not carried out in the embodiment of the present invention, the diving depth positioning device is designed: the radius of the buoy is 0.5m, and the anchor body mass is 2kg. The buoy and the anchor body are connected by a single connecting rod with a diameter of 0.05m. The length of the guide plate is 4m, and its length direction is consistent with the direction of fluid flow in the flow channel. The height range of the flow channel is 0.10m; the core power generation material is MFC, the medium piezoelectric phase material of MFC is one of PZT-4, PZT-5, and PZT-8, and the polymer phase material is one of DP270, DP460, and DP420. Its preferred dimensional parameters include a length of 0.01m, a width of 0.015m, and a thickness of 1mm; the preferred material of the beam structure of the MFC cantilever beam is stainless steel, and its preferred dimensional parameters include a length of 0.01m and a width of 0.01m. 0.015m, with a thickness of 1mm; the preferred total thickness of the MFC cantilever beam is 3.5mm.

Through the above device design, the energy collection efficiency test is carried out in the simulated flow channel. The fluid in the flow channel is water and the flow rate is 1m/s. As shown in Figure 2, the terminal voltage is 14V in the test results. When the external load is 2MΩ, the output The maximum power is 0.1mW, which can also meet the needs of powering micro wireless sensor nodes.

Example 2:

As shown in Figure 3, Figure 9 and Figure 10, a power generation device for ocean wave energy and ocean current energy. The embodiment of the present invention further designs the water flow channel 5 so that the cross-sectional area S1 of the first flow channel 51 is along the The axial direction gradually decreases to S2 and is connected to the second flow channel 52 to increase the flow rate from V ₁ to V ₂ . By designing the water flow channel 5, the water flow enters from the large cross-sectional area of the first flow channel 51, and then passes through the second flow channel 52. The flow rate of the water flow before and after passing through the flow channel will change according to Bernoulli's principle, and then passes through the second flow channel 52. The water flow will accelerate after the second flow channel 52.

The radius of the buoy is 0.5m, the mass of the anchor body is 2kg, the buoy and the anchor body are connected by a single connecting rod, and the diameter of the connecting rod is 0.05m. The length of the guide plate is 4m, and its length direction is consistent with the flow direction of the fluid in the flow channel. Its length direction is consistent with the flow direction of the fluid in the first flow channel 51 and the second flow channel 52. The entrance height range of the first flow channel 51 is 0.25m, and the height range of the second flow channel 51 is 0.25m. The height range of flow channel 52 is 0.10m; the core power generation material is piezoelectric fiber composite material MFC, the piezoelectric phase material in MFC is lead zirconate titanate ceramic, and the polymer phase material is one of DP270, DP460, and DP420 produced by 3M Company. , its preferred dimensional parameters include a length of 0.01m, a width of 0.015m, and a thickness of 1mm; the preferred material of the beam structure of the MFC cantilever beam is stainless steel, and its preferred dimensional parameters include a length of 0.01m, a width of 1mm is 0.015m and the thickness is 1mm; the total thickness of the preferred MFC cantilever beam is 3.5mm.

Through the above device design, the energy collection efficiency test is carried out in the simulated flow channel. The fluid in the flow channel is water and the flow rate is 1m/s. As shown in Figure 4, the terminal voltage is 24V in the test results. When the external load is 2MΩ, the output The maximum power is 0.335mW, which can also meet the needs of powering micro wireless sensor nodes.

Example 3:

The radius of the buoy is 0.5m, the mass of the anchor body is 2kg, the buoy and the anchor body are connected by a single connecting rod, and the diameter of the connecting rod is 0.05m. The length of the guide plate is 4m, and its length direction is consistent with the flow direction of the fluid in the flow channel. Its length direction is consistent with the flow direction of the fluid in the first flow channel 51 and the second flow channel 52. The entrance height of the first flow channel 51 is 0.7m, and the entrance height of the second flow channel is 0.7m. 52 height 0.15m; the core power generation material is piezoelectric fiber composite material MFC. The piezoelectric phase material in MFC is lead zirconate titanate ceramic. The polymer phase material is one of DP270, DP460 and DP420 produced by 3M Company. The preferred The dimensional parameters include a length of 0.01m, a width of 0.015m, and a thickness of 1mm; the preferred material of the beam structure of the MFC cantilever beam is stainless steel, and the preferred dimensional parameters include a length of 0.01m, a width of 0.015m, The thickness is 1 mm; the preferred total thickness of the MFC cantilever is 3.5 mm.

Through the above device design, the energy collection efficiency test is carried out in the simulated flow channel. The fluid in the flow channel is water and the flow rate is 1m/s. As shown in Figure 5, the terminal voltage is 29V in the test result. When the external load is 2MΩ, the output The maximum power is 0.421mW.

Example 4:

The radius of the buoy is 0.5m, the mass of the anchor body is 2kg, the buoy and the anchor body are connected by a single connecting rod, and the diameter of the connecting rod is 0.05m. The length of the guide plate is 4m, and its length direction is consistent with the flow direction of the fluid in the flow channel. Its length direction is consistent with the flow direction of the fluid in the first flow channel 51 and the second flow channel 52. The entrance height of the first flow channel 51 is 1.5m, and the entrance height of the second flow channel is 1.5m. 52 height is 0.225m; the core power generation material is piezoelectric fiber composite material MFC. The piezoelectric phase material in MFC is lead zirconate titanate ceramic. The polymer phase material is one of DP270, DP460 and DP420 produced by 3M Company. The preferred The dimensional parameters include a length of 0.01m, a width of 0.015m, and a thickness of 1mm; the preferred material of the beam structure of the MFC cantilever beam is stainless steel, and the preferred dimensional parameters include a length of 0.01m, a width of 0.015m, The thickness is 1 mm; the preferred MFC cantilever beam has a total thickness of 3.5 mm.

Through the above device design, the energy collection efficiency test is carried out in the simulated flow channel. The fluid in the flow channel is water and the flow rate is 1m/s. As shown in Figure 6, the terminal voltage is 21V in the test result. When the external load is 2MΩ, the output The maximum power is 0.221mW.

Example 5:

As shown in Figure 7, a power generation device for ocean wave energy and ocean current energy. The embodiment of the present invention further increases the number of power generation mechanisms 8, and builds the power generation mechanism 8 by connecting multiple connecting rods 2. The connecting rods 2 are arranged There are three, and three power generating mechanisms 8 are provided on the connecting rod 2.

The specific structural design is as follows: the radius of buoy 1 is 0.6m, the mass of anchor body 3 is 10kg, buoy 1 and anchor body 3 are connected by connecting rod 2, the connecting rods are arranged in an array, the diameter of connecting rod 2 is 10mm, and adjacent connections are The distance between poles 2 is 20mm. The length of the guide plate 4 is 4m, and its length direction is consistent with the direction of fluid flow in the first flow channel 51 and the second flow channel 52; the power generation mechanisms 8 are arranged in an array on the connecting rod 2, and the distance between adjacent power generation mechanisms 8 is 20mm. The height range of the first flow channel 51 is 0.25m, and the height range of the second flow channel 52 is 0.10m; the core power generation material is piezoelectric fiber composite material MFC, and the medium piezoelectric phase material of MFC is lead zirconate titanate ceramic and polymer phase material. It is one of the DP270, DP460, and DP420 produced by 3M Company. Its preferred dimensional parameters include a length of 0.01m, a width of 0.015m, and a thickness of 1mm; the dimensional parameters of the beam structure of the MFC cantilever beam: the length is 0.01 m, the width is 0.015m, and the thickness is 1mm; the total thickness of the preferred MFC cantilever beam is 3.5mm.

Through the above device design, the energy collection efficiency test is carried out in the simulated flow channel. The fluid in the flow channel is water and the flow rate is 1m/s. As shown in Figure 8, the terminal voltage is 205.4V in the test results. When the external load is 2MΩ, The maximum output power is 3.34mW, which can also meet the demand for powering micro wireless sensor nodes, and the output power is further increased.

The technical features of the above embodiments can be combined in any way. To simplify the description, all possible combinations of the technical features in the above embodiments are not described. They only express the preferred embodiments of the present invention. The descriptions thereof It is more specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. As long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope of this specification.

It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the patent of the present invention should be determined by the appended claims.

Claims (4)

1. A power generation device for ocean wave energy and ocean current energy, characterized by: including a depth positioning device, the depth positioning device includes a buoy (1) and an anchor (3), and the buoy is rotatably connected There is a connecting rod (2), an anchor body (3) is fixedly connected to the lower end of the connecting rod (2), and a guide plate (4) is provided on the anchor body (3); A power generation mechanism (8) is provided on the connecting rod (2), and the power generation mechanism (8) is provided between the buoy (1) and the anchor body (3); The power generation mechanism (8) includes a water flow channel (5) arranged radially along the connecting rod (2) and a piezoelectric fiber composite material MFC (6). The piezoelectric fiber composite material MFC (6) is arranged on the On the connecting rod (2) in the water flow channel (5), the piezoelectric fiber composite material MFC (6) is arranged at the outlet end of the water flow channel (5); The piezoelectric constant d33 of the piezoelectric fiber composite material MFC (6) is 700~800, and the interdigital electrodes are cathodes and anodes arranged alternately; the piezoelectric phase material of the piezoelectric fiber composite material MFC (6) adopts zirconium Lead titanate ceramic; the polymer phase material of the piezoelectric fiber composite material MFC (6) includes DP270, DP460 or DP420; the material of the cantilever beam structure of the piezoelectric fiber composite material MFC (6) includes stainless steel ; The substrate material of the beam structural member of the piezoelectric fiber composite MFC (6) cantilever beam includes aluminum, brass or copper; The water flow channel (5) includes a first flow channel (51) and a second flow channel (52). The second flow channel (52) is provided on the connecting rod (2). The first flow channel (52) The cross-sectional area of 51) gradually decreases along the axial direction and is connected with the second flow channel (52); the connecting rod (2) is provided through the second flow channel (52); The height of the entrance of the first flow channel (51) is 0.25m~1.5m; the height of the second flow channel (52) is 0.1m~0.225m; The connecting rod (2) is provided with a limiter (7) for limiting the position of the power generation mechanism (8) and the buoy (1); The radius of the buoy (1) is 0.50m~2.00m; the height of the buoy (1) is 0.2m~0.6m; the diameter of the connecting rod (2) is 0.05m~0.1m; the connecting rod The length of (2) is 2m~3.5m; the mass of the anchor body (3) is 2kg~10kg; the length of the guide plate (4) is 1.00m~5.00m; the piezoelectric fiber composite material MFC ( The length of the substrate of 6) is 0.01m~0.1m, the width is 0.005m~0.5m, and the thickness is 1mm~3mm; the length of the piezoelectric phase material of the cantilever beam of the piezoelectric fiber composite material MFC (6) is 0.01m ~0.1m, the width is 0.005m~0.5m, and the thickness is 1mm~3mm; the length of the cantilever beam structural member of the piezoelectric fiber composite material MFC (6) is 0.01m~0.1m, and the width is 0.005m~ 0.5m, with a thickness of 1mm~3mm; the total thickness of the cantilever beam of the piezoelectric fiber composite material MFC (6) is 3.5mm~5mm. 2. A power generation device for ocean wave energy and ocean current energy according to claim 1, characterized in that when the height of the entrance of the first flow channel (51) is 0.25m, the second flow The height of the channel (52) is 0.1m; when the height of the entrance of the first flow channel (51) is 0.7m, the height of the second flow channel (52) is 0.15m; when the first flow channel (51) 51) When the height of the inlet is 1.5m, the height of the second flow channel (52) is 0.225m; the radius of the buoy (1) is 0.5m; the mass of the anchor body (3) is 2kg; The diameter of the connecting rod (2) is 0.05m; the length of the guide plate (4) is 4m; the length of the piezoelectric fiber composite material MFC (6) is 0.01m, the width is 0.015m, and the thickness is 1mm , the total thickness of the cantilever beam of the piezoelectric fiber composite material MFC (6) is 3.5mm, the length of the beam structural member of the cantilever beam is 0.01m, the width is 0.015m, and the thickness is 1mm. 3. A power generation device for ocean wave energy and ocean current energy according to claim 1, characterized in that: three connecting rods (2) are provided, and three power generating devices are provided on the connecting rod (2). Institutions (8). 4. A power generation device for ocean wave energy and ocean current energy according to claim 3, characterized in that: the connecting rods (2) are arranged along the radial array of the buoy (1). The spacing between adjacent connecting rods (2) is 20 mm; the generating mechanisms (8) are arranged in an axial array along the connecting rods (2), and the spacing between adjacent connecting rods (8) is 20 mm.