Piezoelectric generator with full-wind-direction excitation square column vibration
Technical Field
The invention relates to the field of clean energy power generation, in particular to a piezoelectric generator with a square column excited by full wind direction to vibrate.
Background
The working principle of the wind-induced vibration type generator mainly comprises three types: the electrostatic type, the electromagnetic type and the piezoelectric type need an external power supply to work, and the working mode has limited application scenes; strong magnetic fields exist around the electromagnetic system, and the electromagnetic system is difficult to use for some micro-electro-mechanical systems which are easily interfered by the magnetic fields; piezoelectric type is wider than electrostatic type and electromagnetic type application scenario, provides a better solution for the energy supply of micro-electro-mechanical system.
So far, the traditional piezoelectric type device for generating power by utilizing wind power mainly focuses on generating power by utilizing a single wind direction in a natural wind field, but the wind direction in the nature is uncertain, the speed and the size of the wind direction are difficult to accurately predict, and most of wind energy is difficult to effectively utilize only by utilizing the single wind direction. By looking up relevant data, research finds that: the flow-induced vibration of the square column generates an obvious fluid-solid coupling phenomenon along with the speed change of the air flow, and is particularly represented as the comprehensive action of vortex-induced vibration, galloping and other phenomena; simulating a square column streaming phenomenon through CFD and CSD, calculating a vortex-induced resonance phenomenon of a vertical single-degree-of-freedom vibration square column under the action of different wind speeds, theoretically explaining the vortex-induced vibration phenomenon of a square column rigid body in a flow field, simulating the vortex-induced vibration phenomenon of the square column rigid body under the condition of different wind speeds through designing the slenderness ratio of the square column rigid body and through a test method, and comparing an ideal slenderness ratio through experimental data to obtain the maximum amplitude of the vortex-induced vibration of the square column rigid body; the method is characterized in that a finite element volume method is adopted and Fluent software is combined to carry out vortex-induced vibration numerical simulation on the square column, and the frequency locking phenomenon of the square column vibration frequency at a certain wind speed is obtained by observing experimental data in the simulation process. In view of the research findings, the problem of energy supply of the existing micro-electromechanical system is combined, a piezoelectric power generation solution is provided by utilizing the all-direction wind in the nature, the most beneficial effects are that the all-direction wind in the nature can be fully utilized, the defect of power generation in a single wind direction is avoided, the captured natural wind energy is converted into the force for exciting the deformation of the ceramic piezoelectric plate through reasonable mechanical design, and finally the conversion from the all-direction wind energy to the electric energy is realized.
Disclosure of Invention
Aiming at the defect that the traditional wind power generation device only utilizes a single wind direction to generate power, the invention aims to provide a piezoelectric generator with a full wind direction exciting square column vibration, which can fully utilize all wind directions in the nature to generate power, greatly improve the utilization rate of wind energy and solve the power supply problem of a low-power consumption micro-electro-mechanical system.
The technical scheme of the invention is as follows: a piezoelectric generator for full wind-excited square column vibration, comprising: the device comprises a rigid body, a cylindrical pin, a polygonal connecting piece, a plurality of cantilever beams in circumferential array, a plurality of mass blocks, a plurality of piezoelectric sheets, a spring and a bottom plate; the cantilever beam is fixedly connected to the periphery of the polygonal connecting piece, the cantilever beams are arranged on the same horizontal plane and are spaced at the same angle, the lower portion of the rigid body is fixed to the upper surface of the bottom plate through a cylindrical pin and a spring, the tail end of the cantilever beam is provided with a mass block, the surface of the cantilever beam is attached with a piezoelectric sheet, and the cantilever beam and the piezoelectric sheet form a piezoelectric vibrator.
Furthermore, a polygonal connecting piece is arranged between the rigid body and the cylindrical pin, and the end face of the cantilever beam is fixedly connected with the side face of the polygonal connecting piece.
Furthermore, the connecting piece is a regular pentagon connecting piece, and the number of the cantilever beams is 5.
Further, the rigid body is a square column.
Furthermore, the piezoelectric patches are attached to the upper and lower surfaces of the cantilever beam.
Furthermore, the piezoelectric patch is attached to one end of the cantilever beam close to the polygonal connecting piece.
Further, an operating method of the piezoelectric generator with the square column vibrating under full wind excitation comprises the following implementation steps:
the method comprises the following steps: the wind in the nature has a certain direction and magnitude at a certain moment, and when the wind blows the device, the square column rigid body generates vortex-induced vibration to a certain degree under the excitation of the wind;
step two: the spring at the bottom of the regular pentagon connecting piece can swing in the same direction as wind due to the vortex-induced vibration of the cylinder, and the swing amplitude is larger when the wind speed is larger;
step three: due to the swinging of the spring, the cantilever beam on the windward side can lift up at a small angle, the cantilever beam on the leeward side can tilt at a small angle, and meanwhile, the tail end mass block of the cantilever beam is driven to lift up and tilt to a certain degree;
when the wind direction changes at the next moment, the steps from one to three are repeated, so that wind energy in all directions in the nature can be fully utilized, and electric energy is continuously output.
The invention has the beneficial effects that:
the invention provides a piezoelectric generator for exciting square column vibration in a full wind direction, which is characterized in that a square column rigid body is selected through software analysis to convert wind energy into vortex-induced vibration of the square column to the maximum extent, 5 cantilever beams are selected and fixed on the side surfaces of a regular pentagonal connecting piece, and a piezoelectric sheet is adhered to one side, close to the regular pentagonal connecting piece, of each cantilever beam to obtain the maximum bending deformation. The device has the advantages of simple structure, easy miniaturization, high reliability and the like, can be widely applied to places such as valley basins with high difficulty in erecting power transmission cables, and supplies power for low-power-consumption equipment.
Drawings
FIG. 1 is a three-dimensional schematic view of a full wind power plant.
Fig. 2 is a schematic diagram of the central part of the full wind direction power generation device.
FIG. 3 is a schematic diagram of a cantilever, a piezoelectric plate and a mass.
Detailed Description
The device is further described with reference to fig. 1 to 3, and comprises a square column rigid body 1, a cylindrical pin 2, a regular pentagonal connecting piece 3, 5 circumferential arrays of cantilever beams 4, 5 mass blocks 5, 5 pairs of piezoelectric sheets 6, a spring 7 and a bottom plate 8. The specific connection mode is as follows: 4 terminal surfaces of cantilever beam of 5 circumference arrays fix on regular pentagon connecting piece 3 side, the terminal surface is fixed at regular pentagon connecting piece 3 upper surface under the square column rigid body 1, regular pentagon connecting piece 3 lower part is fixed at the bottom plate upper surface through cylindric lock 2 and spring 7, 5 cantilever beam 4 of circumference array pastes piezoelectric patches 6 on the upper and lower surface near 3 one end of pentagon connecting piece, piezoelectric patches 6 do not completely cover the upper and lower surface of cantilever beam 4, 1 quality piece 5 is fixed respectively to 4 terminal upper surfaces of cantilever beam of 5 circumference arrays, cantilever beam 4 constitutes piezoelectric vibrator with piezoelectric patches 6.
The device has the following specific implementation mode: under the excitation of the wind in all directions of the nature, the square column rigid body 1 generates vortex-induced vibration to a certain degree, the regular pentagonal connecting piece 3 is connected with the spring 7 at the bottom through the cylindrical pin 2, the spring 7 generates swinging in a certain direction under the excitation, the cantilever beams 4 of the circumferential array can generate upward lifting and downward tilting at a certain angle due to being connected with the spring 7, the swinging of the cantilever beams 4 excites the tail end mass block 5, the cantilever beams 4 can generate bending deformation to a certain degree due to the inertia force of the mass block 5, thereby the piezoelectric sheets 6 adhered to the upper surface and the lower surface of the cantilever beams 4, which are close to the pentagonal connecting piece 3, are caused to generate maximum bending deformation, the power generation power of the piezoelectric sheets is in direct proportion to the bending deformation degree, the piezoelectric effect of the ceramic crystal is utilized to output voltage, and the process of finally converting the wind energy.
The working principle of the invention is as follows: the initial kinetic energy of the device is wind energy in all directions in nature, the wind energy is converted into vibration of a square column rigid body through mechanical structure design under the excitation of all directions of wind in the nature, the spring swings in a universal mode, the swing of the cantilever beam excites the tail end mass block, the cantilever beam generates bending deformation to a certain degree by utilizing the inertia force of the mass block, then the bending deformation of the piezoelectric plate is caused, and voltage is output by utilizing the piezoelectric effect.