CN104868785B - A cylindrical vortex-induced vibration power generation device with built-in piezoelectric beams - Google Patents

Abstract

A cylindrical vortex-induced vibration power generation device with built-in piezoelectric beams, relating to a power generation device, an electromechanical conversion device for converting flow-induced vibration generated by a fluid flowing around a blunt body into electric energy, the power generation device includes a cylinder, a piezoelectric Electric chip, metal sheet, support structure, piezoelectric chip is bonded on both sides of the metal sheet to form a bimorph piezoelectric beam and placed inside the cylinder. The plane of the piezoelectric beam is parallel to the axial direction of the cylinder and the direction of incoming flow. The periodic vibration of the cylinder caused by vortex shedding when flowing around the cylinder drives the piezoelectric cantilever beam to vibrate. The base can be fixed on the bottom of the ocean or river or on the pipe wall of the water flow or airflow pipe, thereby converting the kinetic energy of the fluid into electrical energy. The device has a simple structure and can be started under low flow conditions.

Description

A cylindrical vortex-induced vibration power generation device with built-in piezoelectric beams

technical field

The invention relates to a power generating device, in particular to a cylindrical vortex-induced vibration power generating device with built-in piezoelectric beams.

Background technique

As an underwater extension of land-based wireless sensor networks, underwater wireless sensor networks can be used in data collection, pollution monitoring, disaster prevention, marine resource survey, underwater auxiliary navigation and positioning, remote underwater control, anti-submarine central warfare, etc. The economy and national defense play an important role. Since underwater sensor networks are mostly deployed on the seabed, their maintenance and replacement costs are high, so underwater wireless sensor networks need a stable, reliable, portable and long-term energy supply. However, the current marine power generation technology using wave and tidal power generation cannot be realized on the seabed or the equipment is too large to be suitable for underwater wireless sensor networks. Therefore, the power supply problem has become one of the technical bottlenecks of underwater wireless sensor networks.

Vortex-induced vibration is the most common physical phenomenon in nature. It exists widely in fluid motion, especially in the seabed environment with relatively small flow velocity. Moreover, this vibration persists without artificially increasing the excitation. It is a fluid One of the harvestable energy sources. Piezoelectric vibration energy harvesting technology is a technology that uses piezoelectric materials or devices to convert environmental vibration energy into electrical energy. Due to its simple structure, high energy density and electromechanical conversion efficiency, no electromagnetic interference, easy to manufacture, no pollution, and easy to implement Miniaturization, long life and other characteristics have been widely researched and applied. If piezoelectric materials are used to convert vortex-induced vibration energy into electrical energy, it can provide a solution to the power supply problem of underwater wireless sensor networks.

Contents of the invention

The object of the present invention is to provide a cylindrical vortex-induced vibration power generation device with a built-in piezoelectric beam, and an energy collection structure in which the piezoelectric cantilever beam is axially placed inside a flexible thin-walled cylinder. The structure utilizes the periodic bending vibration of the flexible cylinder caused by the vortex shedding formed when the fluid flows around the cylinder, thereby driving the vibration of the piezoelectric cantilever beam to generate electric energy.

The purpose of the present invention is achieved through the following technical solutions:

A cylindrical vortex-induced vibration power generation device with a built-in piezoelectric beam, which uses the vortex shedding generated when the fluid flows around the cylinder to drive the cylinder to vibrate perpendicular to the direction of the incoming flow, and drives the piezoelectric sheet to generate flexural vibration, thereby Convert kinetic energy into electrical energy; the device includes a thin-walled cylinder, a rectangular metal sheet, a piezoelectric wafer, an electrode lead groove, a support rod and a base; two piezoelectric wafers are respectively bonded on both sides of the metal substrate, and the electrodes of the piezoelectric wafer are connected in series , forming a bimorph piezoelectric beam. The piezoelectric beam is connected with the support rod through the bottom surface of the thin-walled cylinder and placed inside the cylinder. The plane of the piezoelectric beam is parallel to the axial direction of the cylinder and the direction of fluid flow. The electrode leads pass through the groove of the support rod from the The base is drawn out to access the energy harvesting circuit; the base is fixed on the bottom of the ocean, river or on the pipe wall of the water flow or airflow pipeline.

The cylindrical vortex-induced vibration power generation device with built-in piezoelectric beams, the cylinder is a thin-walled cylinder, the length of the cylinder is more than three times its diameter, the length of the metal substrate is equal to the length of the cylinder, and the width of the metal substrate is approximately equal to the inside diameter of the cylinder.

The cylinder vortex-induced vibration power generation device with built-in piezoelectric beams, the diameter and length of the cylinder are adjusted according to the incoming flow velocity.

Advantage and effect of the present invention are:

Built-in piezoelectric beam cylinder vortex-induced vibration energy conversion device, including light cylinder, piezoelectric ceramic sheet, metal substrate, support rod and base. Among them, the piezoelectric ceramic sheet is pasted on both sides of the metal substrate with conductive adhesive and placed inside the light cylinder. The top of the metal substrate is fixed on the upper end cover of the cylinder, and the bottom end of the metal substrate is connected with the support rod and the lower end cover of the light cylinder. The position is fixed, the lower end of the support rod is fixed on the base, and the electrode leads of the piezoelectric sheet are led out from the inner groove of the support rod to the signal processing circuit in the base. The device is placed on the seabed or the bottom of a river, the axis of the cylinder is perpendicular to the direction of fluid flow, and the plane of the piezoelectric sheet and the metal substrate is parallel to the direction of fluid flow. When the fluid flow rate and the structural parameters of the cylinder in the device meet certain conditions, alternate vortex shedding will occur on both sides of the cylindrical surface of the cylinder, so that the cylinder will generate vortex-induced vibration perpendicular to the direction of the incoming flow, and then drive the piezoelectric plate to vibrate to generate electrical energy. In the energy conversion device, the piezoelectric beams are packaged inside the cylinder and do not directly contact the external fluid. This design structure increases the bending resistance of the cylinder in the downstream direction, and strengthens the energy of lateral vortex-induced vibration. It not only solves the problems of other structural fabrication difficulties, sealing and anticorrosion, but also enhances the resonance coupling between the piezoelectric beam and the circular tube. Thereby improving energy conversion efficiency.

Description of drawings

Fig. 1 is a structural schematic diagram of a vortex-induced vibration energy conversion device with a built-in piezoelectric beam cylinder;

Fig. 2 is the front view of the vortex-induced vibration energy conversion device of the built-in piezoelectric beam cylinder;

Fig. 3 is a top view of a vortex-induced vibration energy conversion device with a built-in piezoelectric beam cylinder;

Figure 4 is the general assembly diagram of the vortex-induced vibration energy conversion device for the built-in piezoelectric beam cylinder;

Fig. 5 is a cross-sectional view of a vortex-induced vibration energy conversion device with a built-in piezoelectric beam cylinder;

Figure 6 is a schematic diagram of the vortex-induced vibration of the cylinder.

In the drawings: 1. Cylinder 2. Metal substrate 3. Piezoelectric chip 4. Lead groove 5. Support rod 6. Base.

detailed description

The present invention will be described in detail below in conjunction with the embodiments shown in the accompanying drawings.

The built-in piezoelectric beam cylinder vortex-induced vibration energy conversion device includes a thin-walled cylinder 1, a rectangular metal sheet 2, a piezoelectric wafer 3, an electrode lead groove 4, a support rod 5, and a base 6; Adhesive on both sides of the metal substrate 2, weld the power leads to make the piezoelectric sheet electrodes connected in series to form a bimorph piezoelectric beam, place the piezoelectric beam in the cylinder along the axial direction, and fix it with the two ends of the cylinder, from the support The electrode wires are led out from the lead groove of the cylinder bracket and sealed at both ends of the cylinder. The plane of the piezoelectric beam is parallel to the axial direction of the cylinder and the direction of fluid flow. For the energy harvesting circuit, the base can be fixed on the bottom of the ocean or river or on the pipe wall of the water flow or airflow pipeline.

When the water flow or air flow around the cylinder, regular vortex shedding is formed on both sides of the cylinder, the cylinder is subjected to vortex pressure to generate vortex-induced vibration in the direction perpendicular to the incoming flow, thereby driving the piezoelectric beam to vibrate, and then using the piezoelectric wafer Convert kinetic energy to electrical energy. When the shedding frequency is close to the natural frequency of the cylinder, a higher energy conversion efficiency can be achieved.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (1)

1. a kind of cylinder vortex TRT of built-in piezoelectric beam, it is characterised in that the device utilizes fluid winding flow cylinder When produce vortex shedding driving cylinder vibrated perpendicular to direction of flow, drive piezoelectric patches produce flextensional vibrate so that Convert kinetic energy into electric energy；Described device includes thin cylinder（1）, rectangular metal sheet（2）, piezoelectric chip（3）, contact conductor Groove（4）, support bar（5）And base（6）；Two panels piezoelectric chip（3）Metal substrate is bonded in respectively（2）Both sides, piezoelectricity plate electrode Series connection, constitutes bi-morph piezo-electric beam, and piezoelectric beam is attached across thin cylinder with support bar（1）Bottom surface is placed in cylinder interior, piezoelectricity Liangping face is parallel with cylinder axial direction and fluid direction of flow, and contact conductor passes through support bar groove（4）From base（6）Draw, from And access energy collection circuit；On base fixation Yu Haiyang, rivers bottom or current, the tube wall of airflow line；The cylinder（1） For thin cylinder, drum length is more than the three times of its diameter metal substrates（2）Length is equal to drum length, and metal substrate is wide Degree and cylinder interior diameter approximately equal；The drum diameter and length are adjusted according to speed of incoming flow.