阅读说明：本技术 一种基于箱梁振动的悬臂式压电俘能装置 (Cantilever type piezoelectric energy harvesting device based on box girder vibration ) 是由 曹茂森 胡帅涛 张鑫 李帅 于 2020-06-30 设计创作，主要内容包括：本发明提供了一种基于箱梁振动的悬臂式压电俘能装置,该俘能装置应用于箱梁式的桥梁结构上,包括多个悬臂式压电俘能发电单元,所述悬臂式压电俘能发电单元包括一个能在一定范围内弯曲变形的刚性有机材料板,多个能够随刚性有机材料板的弯曲变形而伸缩的压电薄膜等。本发明将多个悬臂式压电俘能发电单元通过电线串联起来,内置于防水封装材料中,安装在箱梁结构侧面、下表面与内部,将环境动荷载引起的桥梁振动机械能转化为电能,当产生电能富余时能够及时进行存储,保证桥梁系统的持续供电,为桥梁结构提供一种全新的环保绿色能源。(The invention provides a cantilever type piezoelectric energy harvesting device based on box girder vibration, which is applied to a box girder type bridge structure and comprises a plurality of cantilever type piezoelectric energy harvesting power generation units, wherein each cantilever type piezoelectric energy harvesting power generation unit comprises a rigid organic material plate capable of bending deformation within a certain range, a plurality of piezoelectric films capable of stretching along with the bending deformation of the rigid organic material plate and the like. According to the invention, a plurality of cantilever type piezoelectric energy harvesting and generating units are connected in series through electric wires, are arranged in a waterproof packaging material, and are arranged on the side surface, the lower surface and the inside of a box girder structure, so that bridge vibration mechanical energy caused by environmental dynamic load is converted into electric energy, the electric energy can be stored in time when surplus electric energy is generated, the continuous power supply of a bridge system is ensured, and a brand-new environment-friendly green energy source is provided for the bridge structure.)

1. The cantilever type piezoelectric energy harvesting device is applied to a box girder type bridge structure and is characterized by comprising a plurality of cantilever type piezoelectric energy harvesting and generating units which are sequentially connected in series, wherein the cantilever type piezoelectric energy harvesting and generating units are distributed and installed on the side surface and the lower surface of the box girder and inside the box girder and are away from a bridge bearing end by a certain distance to be used for collecting mechanical energy of box girder structure vibration and converting the mechanical energy into electric energy to store or supply power for electric equipment.

2. The cantilever type piezoelectric energy harvesting device based on box girder vibration is characterized in that the cantilever type piezoelectric energy harvesting power generation unit has five main structures, which are sequentially from bottom to top: the flexible waterproof organic material cantilever comprises a rigid organic material cantilever substrate, a first electrode layer, a PVDF piezoelectric thin film layer, a second electrode layer and a flexible waterproof organic material layer, wherein the first electrode layer and the second electrode layer cover the upper side surface and the lower side surface of the PVDF piezoelectric thin film layer respectively; the PVDF piezoelectric thin film layer and the electrode layer are completely wrapped between the rigid organic material cantilever substrates by the flexible waterproof organic material layer to form a sealed waterproof space.

3. The cantilever type piezoelectric energy harvesting device based on box girder vibration of claim 1, wherein a weight block capable of moving along the axial direction of the cantilever is nested on the periphery of the cantilever type piezoelectric energy harvesting and generating unit, and the natural frequency of the cantilever type piezoelectric energy harvesting and generating unit is changed by adjusting the position of the weight block to increase the amplitude, so that the energy harvesting efficiency is increased.

4. The box beam vibration-based cantilever type piezoelectric energy harvesting device according to claim 2, wherein the rigid organic material cantilever substrate is made of a rigid organic material capable of bending deformation within a certain range, and the PVDF piezoelectric thin film layer can stretch and contract along with the bending deformation of the rigid organic material cantilever substrate.

5. The box beam vibration-based cantilever type piezoelectric energy harvesting device according to claim 2, wherein the first and second electrode layers are made of phosphor copper, and the PVDF piezoelectric thin film layers are rectangular in shape and are distributed on the rigid organic material cantilever substrate in parallel and uniformly.

6. The box beam vibration-based cantilevered piezoelectric energy harvesting device of claim 1, wherein the spacing between adjacent cantilevered piezoelectric energy harvesting power generation units is 10 cm.

7. The box beam vibration-based cantilever type piezoelectric energy harvesting device is characterized in that when the cantilever type piezoelectric energy harvesting and generating unit is installed on a box beam web, one side of the fixed end of the cantilever is directly and fixedly bonded on the surface of the web; when the cantilever type piezoelectric energy harvesting power generation unit is arranged on the inner surface and the outer surface of the box girder bottom plate and the inner surface of the box girder top plate, firstly, one side of the fixed end of the cantilever is fixedly bonded on a base vertical to the cantilever, and then one end of the base is fixedly bonded on the box girder; namely: the cantilever type piezoelectric energy harvesting and generating unit is always kept horizontal.

8. The cantilever type piezoelectric energy harvesting device based on box girder vibration of claim 1, wherein a plurality of cantilever type piezoelectric energy harvesting and generating units are connected in series through wires to form a power supply circuit, the power supply circuit is sequentially connected with a voltage stabilizing rectifier, an energy storage device and a transformation device, the voltage stabilizing rectifier, the energy storage device and the transformation device are connected to an output port of the power supply circuit through wires, and the output port of the power supply circuit is connected to electric equipment.

9. The cantilever-type piezoelectric energy harvesting device based on box girder vibration of claim 1, wherein the power supply circuit is encapsulated by a high polymer flexible waterproof insulating material.

10. The box beam vibration-based cantilevered piezoelectric energy harvesting device of claim 1, wherein the electrical equipment comprises health monitoring systems, damping systems, lighting devices and traffic signs of the bridge structure.

Technical Field

The invention discloses a cantilever type piezoelectric energy harvesting device based on box girder vibration, and particularly relates to the field of energy harvesting devices for bridge structures.

Background

When an automobile or a train runs on a bridge, vibration energy can be transmitted into the bridge through a road surface or a track, in a highway and railway dual-purpose bridge, the transmission of the vibration can be stronger, and in addition, the disturbance of the environment can also cause the vibration of the bridge to different degrees.

The problem of energy conservation and environmental protection is widely raised nowadays, the power supply of bridge facilities is closely related to environmental protection, and the application of clean energy sources such as solar energy, wind energy and the like in traffic facilities is increasingly wide at present, but the clean energy sources are limited by the size and the arrangement requirements, and can only be used as accessory facilities on a small scale, and the energy supply of the facilities in the closed structure such as a box girder is difficult to some extent. Accordingly, there is a need for energy supply equipment that can be used more widely and that can be integrated with the transportation facility structure itself.

The conventional small energy harvesting device mainly adopts three forms, namely a piezoelectric type, an electromagnetic type and an electrostatic type, and through previous research and development, the energy density of piezoelectric conversion is several times that of electrostatic and electromagnetic conversion. Therefore, the piezoelectric material is effective in collecting energy in bridge vibration, and can generate enough power for small-sized electrical appliances, so that the application of the piezoelectric energy harvesting device in collecting and recycling bridge vibration energy becomes possible.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the limitation of difficult energy supply in the box girder, the cantilever type piezoelectric energy harvesting device based on bridge vibration is provided, and the vibration deformation of the bridge structure can be utilized to provide electric energy.

In order to solve the technical problems, the invention adopts the technical scheme that:

the invention provides a cantilever type piezoelectric energy harvesting device based on box girder vibration, which is applied to a box girder type bridge structure and comprises a plurality of cantilever type piezoelectric energy harvesting and generating units which are sequentially connected in series, wherein the cantilever type piezoelectric energy harvesting and generating units are distributed and arranged on the side surface and the lower surface of a box girder and in the box girder and are arranged at positions away from the end of a bridge support by a certain distance and used for collecting mechanical energy of box girder structure vibration and converting the mechanical energy into electric energy for storage or supplying power for electric equipment.

Furthermore, the cantilever type piezoelectric energy harvesting power generation unit based on box girder vibration provided by the invention has a main structure comprising five layers, which are sequentially from bottom to top: the flexible waterproof organic material cantilever comprises a rigid organic material cantilever substrate, a first electrode layer, a PVDF piezoelectric thin film layer, a second electrode layer and a flexible waterproof organic material layer, wherein the first electrode layer and the second electrode layer cover the upper side surface and the lower side surface of the PVDF piezoelectric thin film layer respectively; the PVDF piezoelectric thin film layer and the electrode layer are completely wrapped between the rigid organic material cantilever substrates by the flexible waterproof organic material layer to form a sealed waterproof space.

Furthermore, the cantilever type piezoelectric energy harvesting device based on box girder vibration is characterized in that a balancing weight capable of moving along the axial direction of a cantilever is nested on the periphery of the cantilever type piezoelectric energy harvesting and generating unit, and the natural frequency of the cantilever type piezoelectric energy harvesting and generating unit is changed by adjusting the position of the balancing weight so as to increase the amplitude, thereby increasing the energy harvesting efficiency.

Furthermore, the cantilever type piezoelectric energy harvesting device based on box beam vibration provided by the invention adopts a rigid organic material capable of bending deformation within a certain range as the rigid organic material cantilever substrate, and the PVDF piezoelectric thin film layer can stretch and contract along with the bending deformation of the rigid organic material cantilever substrate.

Furthermore, the cantilever type piezoelectric energy harvesting device based on box beam vibration provided by the invention has the advantages that the first electrode layer and the second electrode layer are made of phosphor copper, and the PVDF piezoelectric thin film layer is rectangular and is parallelly and uniformly distributed on the rigid organic material cantilever substrate.

Furthermore, the distance between adjacent cantilever type piezoelectric energy harvesting and generating units of the cantilever type piezoelectric energy harvesting device based on box girder vibration is 10 cm.

Furthermore, when the cantilever type piezoelectric energy harvesting and generating unit is arranged on a box beam web, one side of the fixed end of the cantilever is directly and fixedly bonded on the surface of the web; when the cantilever type piezoelectric energy harvesting power generation unit is arranged on the inner surface and the outer surface of the box girder bottom plate and the inner surface of the box girder top plate, firstly, one side of the fixed end of the cantilever is fixedly bonded on a base vertical to the cantilever, and then one end of the base is fixedly bonded on the box girder; namely: the cantilever type piezoelectric energy harvesting and generating unit is always kept horizontal.

Furthermore, the cantilever type piezoelectric energy harvesting device based on box girder vibration provided by the invention is characterized in that a plurality of cantilever type piezoelectric energy harvesting and generating units are connected in series through electric wires to form a power supply circuit, the power supply circuit is sequentially connected with a voltage stabilizing rectifier, an energy storage device and a transformation device, the voltage stabilizing rectifier, the energy storage device and the transformation device are connected to an output port of the power supply circuit through electric wires, and an output port of the power supply circuit is connected to electric equipment.

Furthermore, the cantilever type piezoelectric energy harvesting device based on box girder vibration provided by the invention has the advantage that a power supply circuit is packaged by adopting a high-molecular flexible waterproof insulating material.

Furthermore, the invention provides a cantilever type piezoelectric energy harvesting device based on box girder vibration.

Compared with the prior art, the invention adopting the technical scheme has the following beneficial effects:

the cantilever type piezoelectric energy harvesting and generating unit is connected in series through an electric wire, is arranged in a waterproof packaging material together with a power supply control device, is arranged on the side surface, the lower surface and the inside of a box girder structure, converts bridge vibration mechanical energy caused by environmental dynamic load into electric energy, supplies power to each electric device on a bridge or stores the electric energy through voltage stabilization and transformation treatment of a power supply control integrated system in the power supply device.

Drawings

Fig. 1 is a schematic cross-sectional view of a cantilever type piezoelectric energy harvesting power generation unit.

Fig. 2 is a schematic sectional view of the box girder structure.

Fig. 3 is a schematic diagram of five bonding modes of the cantilever type piezoelectric energy harvesting power generation unit and the box girder.

Fig. 4 is a schematic cross-sectional view of the present invention.

Fig. 5 is a schematic cross-sectional view of fig. 4 taken along line 1-1.

Fig. 6 is a schematic sectional view taken along line a-a of fig. 4.

Reference numbers in the figures: 1-a rigid organic material cantilever substrate; 2-a piezoelectric film; 3-an electrode layer; 4-a flexible waterproof organic material layer; 5-a balancing weight; 6-a base; 7-cantilever type piezoelectric energy harvesting and generating unit; 8-a wire; 9-high polymer waterproof insulation packaging; 10-a regulated rectifier; 11-a transformer; 12-an electrical energy storage device; 13-current output port; 14-box girder.

Detailed Description

The technical scheme of the invention is further explained in detail by combining the attached drawings:

it will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The invention provides a cantilever type piezoelectric energy harvesting device based on box girder vibration, which is applied to a box girder type bridge structure and comprises a plurality of cantilever type piezoelectric energy harvesting and generating units which are distributed on the side surface and the lower surface of a box girder and the part inside the box girder and at a distance of 3m away from a bridge support end, so that enough energy harvesting benefit can be obtained. The distance between adjacent cantilever type piezoelectric energy harvesting and generating units is 10 cm. The cantilever type piezoelectric energy harvesting and generating unit can be connected in series in a plurality of ways and generates electric energy along with the vibration of the bridge, mechanical energy of the vibration of the box girder structure is collected and is converted into electric energy to be stored or supplied to electric equipment, and the electric equipment comprises health monitoring equipment, a monitoring system, a damping system, an illuminating device, a driving sign and the like of the bridge structure.

The cantilever type piezoelectric energy harvesting device is arranged on a box girder 14, and the structural section of the box girder is shown in figure 2. Fig. 3 is a schematic diagram of five bonding modes of the cantilever type piezoelectric energy harvesting power generation unit and the box girder. The cantilever type piezoelectric energy harvesting power generation unit is connected with the inner surface of the box beam bottom plate, (d) the cantilever type piezoelectric energy harvesting power generation unit is connected with the outer surface of the box beam bottom plate, and (e) the cantilever type piezoelectric energy harvesting power generation unit is connected with the inner surface of the box beam top plate. When the cantilever type piezoelectric energy harvesting and generating unit is arranged on a box girder web plate, one side of the fixed end of the cantilever is directly and fixedly bonded on the surface of the web plate; when the cantilever type piezoelectric energy harvesting power generation unit is arranged on the inner surface and the outer surface of the box girder bottom plate and the inner surface of the box girder top plate, firstly, one side of the fixed end of the cantilever is fixedly bonded on a base vertical to the cantilever, and then one end of the base is fixedly bonded on the box girder; that is, the cantilever type piezoelectric energy harvesting power generation unit is always kept horizontal.

As shown in fig. 4, the cantilever type piezoelectric energy harvesting device includes a plurality of cantilever type piezoelectric energy harvesting power generation units 7, wherein each cantilever type piezoelectric energy harvesting power generation unit is bonded with the box beam according to five bonding methods in fig. 3, the distance between every two cantilever type piezoelectric energy harvesting power generation units 7 is about 10cm, the number of cantilever type piezoelectric energy harvesting power generation units 7 is determined by the electric quantity required by the electric equipment, and the larger the number of cantilever type piezoelectric energy harvesting power generation units 7 is, the larger the electric quantity can be provided.

The structure of the cantilever type piezoelectric energy harvesting and generating unit 7 is shown in fig. 1, and the main structure can be divided into five layers, which are sequentially as follows: the cantilever comprises a rigid organic material cantilever substrate 1, an electrode layer 3, a PVDF piezoelectric thin film layer 2, an electrode layer 3, a flexible waterproof organic material layer 4 and a balancing weight which is nested at the periphery of the cantilever and can move along the axial direction of the cantilever, wherein the balancing weight can slide along the axial direction of the cantilever to adjust the self-vibration frequency of the cantilever type piezoelectric energy harvesting power generation unit, so that the self-vibration frequency of the cantilever of the power generation unit arranged at each part of a bridge is coupled with the vibration frequency of the bridge at the part, the amplitude of the cantilever is increased, and the energy harvesting efficiency is improved.

When the rigid organic material cantilever substrate is deformed under the action of bridge vibration, the piezoelectric film is driven to deform together, so that a polarization phenomenon occurs in the piezoelectric film, charges with opposite positive and negative polarities can be generated on the two opposite surfaces, the charges are collected through the electrode layers and output through a lead connected with the fixed end of the cantilever to form current, and wave energy is converted into electric energy by utilizing the piezoelectric effect.

Further, the force-electric coupling equation of the piezoelectric material is as follows:

wherein_iWhich is indicative of the overall strain,

is a coefficient of compliance, σ_jRepresenting stress, first term

Representing the stress σ when the electric field strength is zero or constant_jTo total strain_iContribution of (d)_kiIs the piezoelectric strain constant, E_kRepresents the electric field strength, which can be expressed in relation to the voltage as:

second item d_kiE_kRepresenting electric field versus total strain_iThe contribution of (c).

In this embodiment, the rigid organic material cantilever substrate is made of a rigid organic material capable of bending and deforming within a certain range, and the electrode layer 3 is made of phosphor copper. The PVDF piezoelectric thin film layer 2 is rectangular, 2mm in thickness and is distributed on the rigid organic material cantilever substrate 1 in parallel and uniformly; the thickness of the electrode layer 3 is 1mm, and the electrode layer is completely covered on the upper side surface and the lower side surface of the PVDF piezoelectric film layer 2; the thickness of the flexible waterproof organic material layer 4 is 5mm, and the PVDF piezoelectric thin film layer 2 and the electrode layer 3 are completely wrapped between the rigid organic material cantilever substrates 1 to form a sealed waterproof space; the thickness of the rigid organic material cantilever substrate is 1mm, and materials of all layers are bonded by strong glue. The PVDF piezoelectric thin film layer 2 can expand and contract with the bending deformation of the rigid organic material cantilever substrate 1.

When the PVDF piezoelectric thin film layer 2 is subjected to the vibration load action of the box girder 14, the rigid organic material cantilever substrate 1 deforms, the polarization phenomenon can occur inside the PVDF piezoelectric thin film layer 2, charges with opposite positive and negative polarities can occur on two opposite surfaces, the charges are transmitted through the electrode layer 3 to form current, and the device discharges outwards.

The cantilever type piezoelectric energy harvesting and generating units 7 are connected in series through the wires 8 to form a power supply circuit, and the wires play a role in connecting each cantilever type piezoelectric energy harvesting and generating unit 7, the voltage stabilizing rectifier 10, the transformer 11, the electric energy accumulator 12, the circuit output port 13 for connecting electric equipment and transmitting current, as shown in fig. 5. And the power supply circuit is packaged by adopting a high-molecular flexible waterproof insulating material to form the cantilever type piezoelectric energy harvesting device.

The power supply circuit further comprises a voltage stabilizing rectifier 10, a transformer 11 and an energy storage device 12, the voltage stabilizing rectifier 10, the transformer 11 and the energy storage device 12 are connected to an output port 13 of the power supply circuit through an electric wire 8, and a current output port 13 of the power supply circuit is connected to electric equipment, as shown in fig. 5, the electric equipment mainly refers to electric equipment on a bridge, and specifically comprises health monitoring equipment, a monitoring system, a damping system, an illuminating device, a driving sign and the like of the bridge structure. The voltage stabilizing rectifier 10, the transformer 11, the electric energy accumulator 12 and a circuit output port 13 connected with electric equipment are connected with each cantilever type piezoelectric energy harvesting and generating unit 7 through the electric wire 8, and are connected with external electric equipment through the circuit output port 13 to supply power for the external electric equipment, and the energy storage device stores surplus electric energy.

The power supply circuit is packaged by a high-molecular flexible waterproof insulating material 9 to form a cantilever type piezoelectric energy harvesting device, the cantilever type piezoelectric energy harvesting device is installed on the side face, the lower surface and the inner part of the box girder beyond 3m from the girder support seat end, and the contact face of the cantilever type piezoelectric energy harvesting device and the box girder 14 is fixed by a high-strength adhesive, as shown in fig. 6.

The fixed end of the cantilever type piezoelectric energy harvesting power generation unit 7 is adhered to the box beam 14 or the base 6 through a flat extension surface integrated with the rigid organic material cantilever substrate, an enough contact surface is provided for the use of an adhesive, the cantilever type piezoelectric energy harvesting power generation unit 7 can be firmly fixed on the side surface, the lower surface and the inside of the box beam, the current output port 13 is arranged on one side of the cantilever type piezoelectric energy harvesting power generation unit 7, the space of wiring is arranged on the same side of the friction type electrostatic unit 7, and the situation that the power generation effect and the stability of the whole system are influenced due to the fact that the internal wiring is wound in a staggered mode in vibration is prevented, as shown in figure 6.

The piezoelectric energy harvesting material can convert mechanical energy generated by bridge vibration generated under the action of environmental load into electric energy according to the mechanical-electrical conversion characteristics of the piezoelectric energy harvesting material, and the electric energy is collected and utilized to provide electric energy for each electric facility on the bridge, so that the aim of changing harm into benefit is fulfilled. The box girder structure is used extensively, if can carry out rational utilization to the mechanical energy that box girder structure vibration produced, can provide the power consumption for this structural multiple equipment completely, will richen surplus electric quantity save in, can guarantee this continuous power supply from the energy supply system.

The cantilever type piezoelectric energy harvesting device is simple in structure, easy to process and manufacture, convenient to miniaturize and integrate, low in limitation of energy collection and application working environment of materials, high in efficiency, green and environment-friendly, capable of generating great economic benefits due to development and utilization of related technologies, capable of providing assistance for building a resource-saving society, and capable of having certain market potential and economic value.

The above description is provided to explain in detail embodiments of the present invention by referring to the figures. Furthermore, it should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention is described in detail with reference to examples, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.