Bridge rubber expansion joint electrostatic power generation device and power generation method

Abstract

The invention discloses a bridge rubber expansion joint electrostatic power generation device and a power generation method, particularly relates to the technical field of bridge arrangement, and solves the problems that in the prior art, electronic systems, advanced road technologies and Internet of Things applications related to highway bridges are subjected to a rapid development stage and depend on stable and continuous power supply; however, corresponding power supply conditions are not provided in many areas such as outer suburbs. According to the technical scheme, the bridge rubber expansion joint is designed into a mechanism with an upper layer and a lower layer, the upper layer and the lower layer are made of engineering rubber, high polymer materials with different work functions are used for two contact faces to serve as electrodes, and the upper electrode and the lower electrode form a galvanic couple layer; under the rolling compaction of traffic flow of highways and bridges, continuous green electric energy output can be generated by the movement of the polymer electrodes.

Description

Technical Field

[0001] The invention relates to the technical field of bridge setting devices, and in particular to an electrostatic power generation device and a power generation method for a bridge rubber expansion joint. Background Art

[0002] Bridge expansion joints refer to expansion joints set between two beam ends, between beam ends and abutments, or at the hinged position of the bridge to meet the requirements of bridge deck deformation. The function of bridge expansion joints is to adjust the displacement and connection between the superstructure caused by vehicle loads and bridge construction materials. The material of bridge expansion joints is usually polymer engineering rubber. Because it is different from the road surface material, vehicles can easily produce the so-called "jumping platform" phenomenon on the expansion joints, which is an impact load for the expansion joints.

[0003] With the development of information technology, intelligence and environmental protection, electronic systems related to highway bridges, advanced road technologies and Internet of Things applications are experiencing a rapid development stage. They all rely on a stable and continuous power supply. However, in many areas such as the suburbs, there is no power supply condition, which has become a challenge.

[0004] On the one hand, the expansion joint bears the impact load of the car rolling over; on the other hand, the road needs electricity. In this regard, we thought of the phenomenon of static electricity - it usually occurs when two different materials are close enough, at this time, electrons will migrate between them and form an electric field. When people touch something, they often hear a crackling discharge sound, which is a typical and common static electricity effect. The theory of static electricity is relatively mature. At present, there is the so-called friction electrification phenomenon, which only increases the degree of contact and still does not exceed the scope of classical static electricity theory. Of course, with the development of many new materials, static electricity has also developed in some applications. It can be seen that the current electrode materials for electrostatic power generation are mostly polymer materials, which have stable physical and chemical properties and good economy. This is also the reason why we develop expansion joint electrostatic power generation technology.

[0005] The rubber expansion joints of bridges are set to meet the requirements of bridge deck deformation. Usually, expansion joints are set between the two beam ends, between the beam ends and the abutments, or at the hinged positions of the bridges. In the context of the rapid development of contemporary highway construction, the number of bridge expansion joints is increasing. How to effectively use the position of expansion joints to convert the rolling of vehicles on the expansion joints into electrical energy to supply power for road power facilities is an urgent problem to be solved. Summary of the invention

[0006] Therefore, the present invention solves the technical problem that the electronic systems, advanced road technologies and Internet of Things applications related to highway bridges in the prior art are undergoing a rapid development stage and they all rely on a stable and continuous power supply; however, in many areas such as remote suburbs, there are no corresponding power supply conditions; the present invention provides a bridge rubber expansion joint electrostatic power generation device and a power generation method, which are realized by combining two half-mold patches, and effectively utilize the position of the expansion joint to convert the rolling of the expansion joint by moving vehicles into electrical energy, thereby supplying road power facilities.

[0007] The present invention provides an electrostatic power generation device for a bridge rubber expansion joint, comprising a power generation layer arranged between abutments and abutment gaps; the power generation layer is used to convert the impact of a vehicle rolling over the power generation layer when the vehicle passes over the abutment into electric energy.

[0008] Furthermore, the power generation layer includes a first filling layer and a second filling layer arranged up and down, and the first filling layer and the second filling layer are connected by bolts; an upper electrode is arranged on the lower surface of the first filling layer; and a lower electrode is arranged on the upper surface of the second filling layer.

[0009] Furthermore, the upper electrode comprises an aluminum foil fixed on the lower surface of the first filling layer; and a first PET tape is provided on the lower surface of the aluminum foil.

[0010] Furthermore, the lower electrode comprises a copper foil fixed on the upper surface of the second filling layer; a second PET tape is arranged on the upper surface of the copper foil; and a PTFE film is arranged on the upper surface of the second PET tape.

[0011] Furthermore, the lower end of the bolt is fixed to the second filling layer, and the upper end thereof passes through the first filling layer; a spring is sleeved on the surface of the bolt, so that the second filling layer can be pressed down and reset.

[0012] Furthermore, the spring is located between the first filling layer and the second filling layer, so that when the first filling layer is not subjected to downward pressure, the spring can drive the first filling layer to return to its original position.

[0013] Furthermore, the aluminum foil and the copper foil are both bonded to the first filling layer and the second filling layer by double-sided adhesive.

[0014] Furthermore, the first filling layer and the second filling layer are both engineering rubber.

[0015] Furthermore, the aluminum foil corresponds to the copper foil up and down, thereby achieving contact between the upper and lower electrodes.

[0016] The present invention also provides a power generation method based on the above-mentioned bridge rubber expansion joint electrostatic power generation device, comprising the following steps:

[0017] S1: When the vehicle passes over the abutment, the first filling layer between the abutments is rolled to make the first filling layer move downward;

[0018] S2: The first filling layer moves downward, and the upper electrode on its lower surface contacts the lower electrode on the upper surface of the second filling layer to generate electrical energy output.

[0019] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0020] 1. The present invention designs the bridge rubber expansion joint into a two-layer structure. The upper and lower layers are made of engineering rubber. The two contact surfaces use polymer materials with different work functions as electrodes. The upper and lower electrodes form an electric dipole layer. When the car rolls over, the static electricity voltage is related to the distance and speed of the electric dipole layer, as well as the rolling time. The voltage and vehicle speed have a nonlinear growth relationship. In this way, the movement of the polymer electrode will generate continuous green power output as long as the traffic flow of the highway bridge rolls over the expansion joint.

[0021] 2. The electrostatic power generation device of the present invention can convert the kinetic energy of the vehicle into rapid contact between the upper layer and the lower layer structure when the vehicle is rolling over. On the other hand, the contact surface uses polymer materials with different work functions as electrodes to form an electric double layer, thereby generating electrostatic power generation. The voltage is related to the distance between the layers, the speed, and the width of the rolling time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the power generation layer of the present invention;

[0025] Figure 3 This is a schematic diagram of the bridge rubber expansion joint and wheel rolling;

[0026] Figure 4 It is a schematic diagram of the contact between two metals;

[0027] Figure 5 It is a schematic diagram of the experimental device of the present invention;

[0028] Figure 6 Schematic diagram of two loading methods in the experiment of the present invention;

[0029] Figure 7is a curve diagram of voltage variation over time when two fingers are pressed in the experiment of the present invention;

[0030] Figure 8 This is a curve diagram of the voltage variation over time of a 500-gram mass block in free fall in the experiment of the present invention;

[0031] Fig. 9 The figure is a curve diagram of the electrostatic power generation voltage of the device of the present invention at different vehicle speeds.

[0032] Description of reference numerals:

[0033] 1. First filling layer; 2. Second filling layer; 3. Bolts; 4. Aluminum foil; 5. First PET tape; 6. Copper foil; 7. Second PET tape; 8. PTFE film; 9. Spring; 10. Double-sided tape; 11. Power generation layer. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] This embodiment provides an electrostatic power generation device for a bridge rubber expansion joint, such as Figure 1 to Figure 2As shown. It mainly includes a power generation layer 11 arranged between the abutments and the gap between the abutments; the power generation layer 11 is used to convert the impact of the vehicle rolling over the power generation layer 11 when it passes over the abutment into electrical energy. The power generation layer 11 includes a first filling layer 1 and a second filling layer 2 arranged up and down, and a bolt 3 is arranged between the first filling layer 1 and the second filling layer 2; an upper electrode is arranged on the lower surface of the first filling layer 1; and a lower electrode is arranged on the upper surface of the second filling layer 2. The upper electrode includes an aluminum foil 4 fixed on the lower surface of the first filling layer 1; a first PET tape 5 is arranged on the lower surface of the aluminum foil 4. The lower electrode includes a copper foil 6 fixed on the upper surface of the second filling layer 2; a second PET tape 7 is arranged on the upper surface of the copper foil 6; and a PTFE film 8 is arranged on the upper surface of the second PET tape 7. The lower end of the bolt 3 is fixed to the second filling layer 2, and its upper end passes through the first filling layer 1; a spring 9 is sleeved on the surface of the bolt 3. The spring 9 is between the first filling layer 1 and the second filling layer 2. The aluminum foil 4 and the copper foil 6 are connected to the first filling layer 1 and the second filling layer 2 respectively through double-sided adhesive 10. The first filling layer 1 and the second filling layer 2 are both engineering rubber. The aluminum foil 4 corresponds to the copper foil 6 up and down. The length of the power generation layer 11 is the lane width, and the width of the power generation layer 11 is 70 mm. Considering the position of the bolt 3 and the spring 9, the width of the upper electrode and the lower electrode are both 50 mm; the first filling layer 1 and the second filling layer 2 are both made of the engineering rubber in Table 1 below; the diameter of the bolt 3 is 10 mm, and the diameter of the hole through which the bolt 3 passes through the first filling layer 1 and the second filling layer 2 is 12 mm; the spring wire φ=0.5 mm; the upper electrode and the lower electrode form an electric double layer, and the distance between the upper electrode and the lower electrode is 2 mm.

[0036] Table 1: Material constants of engineering rubber

[0037]

[0038] When the vehicle is rolling over, the kinetic energy of the vehicle can be converted into the rapid contact between the first filling layer 1 and the second filling layer 2. On the other hand, the contact surface uses polymer materials with different work functions to generate electrostatic power generation. The rapid contact between the first filling layer 1 and the second filling layer 2, this distance change h is the distance between the upper electrode and the lower electrode, v is the vehicle speed, and d is the expansion joint width. For example, the vehicle speed is 60km / h, the expansion joint width is 70mm, and the distance between the upper and lower layers is h=2mm, then the maximum value of the downward pressure speed is 0.21m / sec, and the electric pulse width Δt=0.00083.

[0039] According to the surface charge per unit area σ formula of the electric double layer:

[0040]

[0041] Wherein, φ is the work function, ε is the dielectric constant, λ is the penetration depth of the charge, q=1.6x10-19 coulomb, subscripts 1 and 2 represent two solids, and their units and values ​​are shown in Table 2 below.

[0042] The voltage of the electrostatic double layer under impact:

[0043]

[0044] In the formula, the distance between the upper and lower layers is h, which changes rapidly with the vehicle speed v. is the average speed of the downward pressure, Δt is the time of the car rolling-time pulse width. Coefficient k = 6073541.1, ε0 is the vacuum medium constant, ε r is the relative dielectric constant of the selected material.

[0045] Determine the electrostatic generation voltage corresponding to different vehicle speeds, such as Fig. 9 As shown, the relationship between the electrostatic power generation voltage of the device and the vehicle speed satisfies the nonlinear equation:

[0046] U(v)=0.0026v 3 +0.0011v;

[0047] It can be seen that the device of the present invention can stably generate electricity at different vehicle speeds.

[0048] Embodiment 2:

[0049] First, when two different solid materials come into contact, it is generally believed that when the contact distance reaches or is less than 25x10-10 meters, one material will transfer electrons to the other material, and the one that loses the electron will be positively charged, and the one that gains the electron will be negatively charged. As for the role of friction, it is to increase the contact area of ​​the two substances when the distance is less than 25 angstroms (1 angstrom = 1x10-10 meters). This is the reason why two solids carry static electricity when they are separated after contact.

[0050] like Figure 4 As shown, when two different metals A and B come into contact, an electric potential difference is generated. This potential difference is generally between a few tenths of a volt and several volts, and there is a series, namely: (+) aluminum, zinc, tin, cadmium, lead, antimony, bismuth, brass, mercury, iron, steel, copper, silver, gold, platinum, palladium, MnO2, PbO2 (-), when the front and back solids come into contact, the former is positively charged and the latter is negatively charged. On both sides of the solid contact surface, equal and opposite charge layers are formed, which are called electric double layers. Since the distance between the contact surfaces is very small (less than 25 angstroms) when the contact potential difference is formed, the capacitance between the unit contact area is very large. Therefore, although there is only a few volts of contact potential difference, the charge density on both sides of the electric double layer is very large. If the contact surfaces are separated at the same time and comprehensively to minimize the backflow of charges on both sides, both solids will have strong charges after separation.

[0051] If the dielectric constants and penetration depths of the two solids are ∈1, λ1 and ∈2, λ2 respectively, the surface charge per unit area σ is obtained according to Gauss's theorem of electric field:

[0052]

[0053] Table 2: Work function, penetration depth and dielectric constant of polymer materials

[0054]

[0055] Where 1e·V.=1.6x10 -1 6 Coulomb.V, q=1.6x10 -19 Coulomb, ε0 is the dielectric constant of vacuum equal to 8.85x10 -12 Cullen.V -1 .rice -1 or farad / meter.

[0056] formula It can be seen that the surface charge and the work function of the solid have the greatest influence. Table 2 gives the work function, penetration depth and dielectric constant of several common polymer materials, which provides a reference for the next step of selecting electrode polymer materials;

[0057] On the other hand, the contact surface of the two electrodes forms an electric double layer. If it is treated as a parallel plate capacitor, the capacitance C per unit area is:

[0058]

[0059] Where εr is the relative dielectric constant of the medium in the gap between parallel plates, in farads per meter, and h is the distance between the plates.

[0060] Then, according to the formula

[0061] If h = 25 angstroms = 25 × 10 -10 m, the gap is vacuum, ∈ r =1, then we get C = 354 × 10 -3 Farad / meter 2 If h is increased to 1 mm, the capacitance is C1 = 8.85 × 10 -9 Farad / meter 2 , that is, the capacitance is reduced by 400,000 times. It can be seen that under the condition that the charge on both sides remains unchanged, the potential difference will increase by 400,000 times. This is why the weak contact potential difference becomes a very high electrostatic voltage.

[0062] Different from the above embodiment, this embodiment simulates the power generation process of the device described in embodiment 1 in the laboratory according to the above principle, using two glass fiber reinforced plastic plates instead of engineering rubber, the steel plate size is 100x100mm, the electrode size is 50x50mm, and the rest remains the same;

[0063] like Figure 3 As shown in the figure, the wheel on the rubber expansion joint is a pulse impact load. In order to approximately reflect this feature, we use two loading methods, such as Figure 6 Shown: I, two-finger press; II, 500g mass block free fall (falling height 20mm)

[0064] like Figure 5 As shown in the figure, the RIGOL DS4034 oscilloscope is used to measure the open circuit voltage. This is a multifunctional, high-performance digital oscilloscope with the following key features and performance indicators: bandwidth: 350MHz, sampling rate: up to 4GSa / s, number of analog channels: 4, memory depth: standard 140 million points, waveform capture rate per second: up to 110,000wfms / s, automatic measurement, record / playback / analysis functions.

[0065] Experiment I: Press the center of the fiberglass plate with two fingers at a pressure of about 10 Newtons, hold for about 1 second, and then release. Figure 7 The experimental results show that when the finger is pressed or released, there is a voltage, the voltage amplitude is about 3 volts, the voltage pulse width is 0.02 seconds when pressed, and the voltage pulse width is 0.04 seconds when released. There is no voltage output when the finger is pressed and kept still.

[0066] Experiment II: A 500-gram mass falls freely (falling from a height of 20 mm) onto the center of a fiberglass plate. It takes 0.063 seconds for the mass to fall onto the plate. The contact speed is 0.63 m / s, the distance between the two electrodes is 2 mm, and the time for the electrode movement is 0.0032 s. Figure 8 The experimental results show that the voltage range is 16 to -9 volts and the voltage pulse width is 0.1 second.

[0067] Experiments I and II show two points: electrode a: aluminum foil / PET tape and electrode b: PTFE film / double-sided tape / PET tape / copper foil can produce obvious output voltage under certain conditions; and the relative movement speed of the two electrodes has a huge impact on the voltage. If the speed is 0, there will be no voltage even if the two electrodes are in contact.

[0068] Experiments show that: according to the principle of electrostatic charging performance, the work function of polymer solids and the distance h between the electric double layers are two important factors for the expansion joint electrostatic power generation device. For a double-layer rubber expansion joint with electrodes, when a car runs over it, the kinetic energy of the car will be partially converted into the rapid contact of the upper layer with the lower structure. The distance between the upper and lower layers is h, which changes rapidly with the vehicle speed v. Therefore, the electrostatic power generation voltage under the car's running over is not only related to h, see the formula And the average pressure

[0069] speed The rolling time is related to the time pulse width Δt. Therefore, the present invention proposes a static electricity generation formula for a double-layer rubber expansion joint subjected to automobile rolling:

[0070]

[0071] Among them, the coefficient k = 6073541.1 is determined according to two conditions: ① when the distance between the upper and lower layers h = 0, Umax = 0; ② for test 2, h = 0.002 meters, = 0.63 meters / second Δt = 0.1 seconds, σ is determined by the formula Calculate, it is the surface charge per unit area of ​​the electric double layer.

[0072] Based on the above work and findings, the rubber expansion joint is designed into two layers, each with a pair of electrodes. The continuous flow of traffic on the highway bridge will generate continuous power output, and its voltage satisfies the formula

[0073] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A bridge rubber expansion joint electrostatic power generation device, characterized in that: It comprises a power generation layer (11) arranged between the gaps between abutments; the power generation layer (11) is used to convert the impact of a vehicle rolling over the power generation layer (11) when the vehicle passes over the abutment into electric energy.

2. The electrostatic power generation device for bridge rubber expansion joints according to claim 1 is characterized in that: The power generation layer (11) comprises a first filling layer (1) and a second filling layer (2) arranged one above the other, wherein a bolt (3) is provided between the first filling layer (1) and the second filling layer (2); an upper electrode is provided on the lower surface of the first filling layer (1); and a lower electrode is provided on the upper surface of the second filling layer (2).

3. The electrostatic power generation device for bridge rubber expansion joints according to claim 2 is characterized in that: The upper electrode comprises an aluminum foil (4) fixed on the lower surface of the first filling layer (1); a first PET tape (5) is provided on the lower surface of the aluminum foil (4).

4. The electrostatic power generation device for bridge rubber expansion joints according to claim 3 is characterized in that: The lower electrode comprises a copper foil (6) fixed on the upper surface of the second filling layer (2); a second PET tape (7) is arranged on the upper surface of the copper foil (6); and a PTFE film (8) is arranged on the upper surface of the second PET tape (7).

5. The electrostatic power generation device for bridge rubber expansion joints according to claim 4 is characterized in that: The lower end of the bolt (3) is fixed to the second filling layer (2), and the upper end thereof passes through the first filling layer (1); a spring (9) is sleeved on the surface of the bolt (3).

6. The electrostatic power generation device for bridge rubber expansion joints according to claim 5 is characterized in that: The spring (9) is located between the first packing layer (1) and the second packing layer (2).

7. The electrostatic power generation device for bridge rubber expansion joints according to claim 6 is characterized in that: The aluminum foil (4) and the copper foil (6) are respectively connected to the first filling layer (1) and the second filling layer (2) via double-sided adhesive tape (10).

8. The electrostatic power generation device for bridge rubber expansion joints according to claim 7 is characterized in that: The first filling layer (1) and the second filling layer (2) are both engineering rubber.

9. The electrostatic power generation device for bridge rubber expansion joints according to claim 8, characterized in that: The aluminum foil (4) and the copper foil (6) correspond to each other vertically.

10. A power generation method based on the electrostatic power generation device for bridge rubber expansion joints according to any one of claims 1 to 9, characterized in that The steps include: S1: When a vehicle passes over the abutment, the first filling layer (1) between the abutments is rolled over, so that the first filling layer (1) moves downward; S2: the first filling layer (1) moves downward, and the upper electrode on its lower surface contacts the lower electrode on the upper surface of the second filling layer (2) to generate electrical energy output; S3: The electrostatic generation voltage is not only related to the distance between the upper and lower electrodes, but also to the average speed of the upper and lower electrodes, the vehicle rolling time-time pulse width, and satisfies the following electrostatic generation formula for double-layer rubber expansion joints subjected to vehicle rolling: In the formula, the distance between the upper and lower electrodes is h, which changes rapidly with the vehicle speed v. is the average speed of downward pressure, Δt is the vehicle rolling time-time pulse width; The coefficient k = 6073541.1, ε0 is the vacuum medium constant, ε r is the relative dielectric constant of the selected material; S4: The nonlinear relationship between the electrostatic generation voltage and the vehicle speed is as follows: U(v) = 0.0026v 3 +0.0011v.

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