Novel phononic crystal vibration isolator for transformer substation and installation method of novel phononic crystal vibration isolator

Abstract

The invention relates to a novel phononic crystal vibration isolator for a transformer substation and an installation method thereof.The phononic crystal vibration isolator comprises phononic crystal unit cells, the phononic crystal unit cells are arranged in a 6 * 6 mode to obtain the novel phononic crystal vibration isolator, and each phononic crystal unit cell comprises a scatterer, a base plate and a rubber cushion layer; the base body plate comprises an upper base body plate and a lower base body plate, a scattering body is installed between the upper base body plate and the lower base body plate, and rubber cushion layers are installed between the lower surface of the upper base body plate and the upper surface of the scattering body and between the upper surface of the lower base body plate and the lower surface of the scattering body. Secondary noise caused by equipment vibration can be effectively reduced, and it is ensured that normal operation and maintenance of the transformer substation do not affect resident life.

Description

Technical Field

[0001] This application relates to the field of vibration reduction and noise reduction of substation reactors, and particularly to a novel phononic crystal vibration isolator for substations and its installation method. Background Art

[0002] As an indispensable part of the power system, substations undertake important tasks such as voltage transformation, power reception and distribution, power flow control, and voltage regulation. With the further increase in the level of urbanization, the electricity consumption of urban residents is increasing day by day. To meet the daily electricity demand, substations have to be built in the urban electricity load center, ultimately resulting in the substations being too close to residential areas. Excessive vibration and structural secondary noise will greatly affect people's work and life, and in the long run, it will affect physical and mental health.

[0003] The noise sources of substations are usually the secondary noise caused by the vibration of substation equipment and environmental noise. Among them, environmental noise is transmitted through the air, so it can be relatively easily isolated and reduced in noise by using sound barriers and other means. However, the secondary noise caused by substation equipment is transmitted to the structure through the ground, so special equipment needs to be designed for isolation and noise reduction. Summary of the Invention

[0004] The purpose of the embodiments of this application is to provide a novel phononic crystal vibration isolator for substations and its installation method, which can effectively reduce the secondary noise caused by equipment vibration and ensure that the normal operation and maintenance of the substation will not affect the lives of residents.

[0005] To achieve the above purpose, this application provides the following technical solutions:

[0006] In the first aspect, the embodiments of this application provide a novel phononic crystal vibration isolator for substations, including phononic crystal unit cells. The phononic crystal unit cells are arranged in a 6×6 pattern to obtain the novel phononic crystal vibration isolator. The phononic crystal unit cell includes a scatterer, a base plate, and a rubber cushion layer. The base plate includes an upper base plate and a lower base plate. The scatterer is installed between the upper base plate and the lower base plate. Rubber cushion layers are installed between the lower surface of the upper base plate and the upper surface of the scatterer and between the upper surface of the lower base plate and the lower surface of the scatterer.

[0007] The upper base plate and the lower base plate are made of aluminum alloy thin plates with a side length of 40 mm and a thickness of 3 mm.

[0008] The scatterer is a lead layer, with a shape of symmetric hourglass up and down, a maximum radius of 15 mm, a minimum radius of 12 mm, and a height of 20 mm.

[0009] The rubber cushion layer is a rubber ring layer with a radius of 15 mm and a thickness of 5 mm.

[0010] The distance between the scatterers of the phononic crystal unit cell is 10 mm.

[0011] In a second aspect, an installation method for a novel phononic crystal vibration isolator for a substation provided by an embodiment of the present application includes the following specific steps:

[0012] Assembly of the lower base plate and the rubber cushion layer: Clean the installation surface, remove oil stains and rust, and apply epoxy resin glue to enhance adhesion. Place the rubber cushion layer at the center position of the lower base plate, ensuring that the center of the circle is aligned with the center of the base plate. Use a positioning mold (such as a circular template) to assist in positioning to avoid deviation. Gently press the rubber cushion layer to make it initially fit with the lower base plate.

[0013] Assembly of the scatterer and the rubber cushion layer: Use a positioning mold (with a spacing of 10 mm) to vertically place the hourglass-shaped lead scatterer (with a height of 20 mm) on the rubber cushion layer, ensuring that the upper and lower symmetry axes coincide with the center line of the base plate. Check the scatterer spacing layer by layer, and use a rubber hammer to fine-tune the position to avoid misalignment between the lead body and the rubber cushion layer.

[0014] Installation of the upper base plate: Place another rubber cushion layer on the top of the lead scatterer, ensuring that the center of the circle is aligned with the center of the base plate. Cover the upper base plate on the rubber cushion layer and gently press it to make it initially fit. Use a positioning mold to ensure alignment between the upper and lower base plates to avoid misalignment.

[0015] Arrangement of multiple unit cells: Multiple units need to be combined (6×6 array). Repeat the above steps, and keep the edge spacing between adjacent unit cells at 10 mm. Fix them with connecting pieces through the reserved hole positions on the base plate. Use a level to check the overall flatness, and add shims for fine-tuning if necessary.

[0016] Installation of the reactor: Lift the reactor onto the support, adjust the position and level of the reactor, and connect the upper base plate of the phononic crystal vibration isolator to the reactor body with bolts to ensure a firm connection. Conduct system commissioning and testing to ensure that the replaced reactor works properly, and complete the installation of the reactor.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] In the present invention, the base and the scatterer are connected by rubber, and a damping system can be formed during the force application process, which can play a certain vibration reduction effect.

[0019] The present invention uses a lead layer scatterer, which not only improves the overall durability of the vibration isolator but also maintains a certain stiffness, and together with the rubber, it plays a dual vibration isolation effect.

[0020] The present invention adopts two or more unit cells arranged periodically to form a vibration isolator. This design can broaden the vibration isolation frequency band and is beneficial to achieving wide-band vibration isolation of the structure.

[0021] By designing the structure of the phononic crystal into an hourglass shape, the present invention improves the vibration isolation effect of the vibration isolator within a specific frequency range, effectively reducing the secondary structure noise caused by equipment in the substation and enhancing the safety and comfort of the substation structure. The vibration isolator is small in size, and the durability and vibration isolation performance of its materials have been fully verified, demonstrating the great potential of the phononic crystal vibration isolator in the field of vibration and noise reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0023] Figure 1 Schematic diagram of the overall structure of the embodiment of the present application;

[0024] Figure 2 Schematic diagram of the phononic crystal unit cell of the embodiment of the present application;

[0025] Figure 3 Schematic cross-sectional view of the embodiment of the present application; Figure 4 Vibration isolation effect diagram of the phononic crystal vibration isolator of the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0027] The term "comprising", "including" or any other variant thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0028] The purpose of the present application is to provide a new type of phononic crystal isolator for a substation, including a phononic crystal unit cell, wherein the phononic crystal unit cell is arranged in a 6×6 manner to obtain a new type of phononic crystal isolator, wherein the phononic crystal unit cell includes a scatterer 3, a substrate plate 1 and a rubber pad 2, wherein the substrate plate 1 includes an upper substrate plate and a lower substrate plate, wherein the scatterer 3 is installed between the upper substrate plate and the lower substrate plate, and the rubber pad 2 is installed between the lower surface of the upper substrate plate and the upper surface of the scatterer 3 and between the upper surface of the lower substrate plate and the lower surface of the scatterer.

[0029] The upper substrate plate and the lower substrate plate are made of aluminum alloy thin plates with a side length of 40 mm and a thickness of 3 mm.

[0030] The scatterer is a lead layer, and its shape is an hourglass symmetrical type, with a maximum radius of 15 mm, a minimum radius of 12 mm, and a height of 20 mm.

[0031] The rubber cushion layer is a rubber ring layer with a radius of 15 mm and a thickness of 5 mm.

[0032] The scatterer spacing of the phononic crystal unit cell is 10 mm.

[0033] Installation Method

[0034] Assembly of lower base plate and rubber pad: Clean the mounting surface, remove oil and rust, and apply epoxy resin glue to enhance adhesion. Place the rubber pad in the center of the lower base plate, ensuring that the center of the circle is aligned with the center of the base plate. Use a positioning mold (such as a circular template) to assist in positioning to avoid offset. Lightly press the rubber pad to make it initially fit with the lower base plate.

[0035] Assembling the scatterer and rubber cushion: Use a positioning mold (spacing 10mm) to vertically place the hourglass-shaped lead scatterer (height 20mm) on the rubber cushion, ensuring that the upper and lower symmetry axes coincide with the center line of the substrate. Check the scatterer spacing layer by layer, and use a rubber hammer to fine-tune the position to avoid misalignment between the lead body and the rubber cushion.

[0036] Upper substrate installation: Place another rubber pad on top of the lead diffuser, ensuring that its center is aligned with the center of the substrate. Place the upper substrate over the rubber pad and press gently to make it fit. Use a positioning mold to ensure that the upper and lower substrates are aligned to avoid misalignment.

[0037] Multi-unit arrangement: multiple units are required (6×6 array), repeat the above steps, keep the distance between the edges of adjacent units at 10mm, and fix them with connecting pieces through the reserved holes on the base plate. Use a level to check the overall flatness and add fine-tuning gaskets if necessary.

[0038] Reactor installation: Lift the reactor onto the support, adjust the position and level of the reactor, connect the base plate of the phononic crystal vibration isolator to the reactor body with bolts to ensure a firm connection, conduct system debugging and testing to ensure the normal operation of the replaced reactor, and complete the installation of the reactor.

[0039] Based on the support structure of the above embodiment, the specific vibration reduction effect is calculated as follows:

[0040] 1. Calculate the equivalent mass m eff

[0041] Calculation of the volume of the lead scatterer (the hourglass shape is approximated as two truncated cones):

[0042]

[0043] Lead density ρ Pb = 11340 kg / m 3 Then:

[0044] m eff = ρ Pb V Pb = 11340×1.92×10 -5 = 0.218 kg

[0045] 2. Equivalent stiffness

[0046] The stiffness of the vibration isolator is dominated by the shear stiffness of the rubber cushion. Rubber elastic modulus E r = 1 Mpa, cushion area A = π×15 2 = 706.9 mm 2 Thickness t = 5 mm, then:

[0047]

[0048] 3. Calculate the center frequency of the local resonance band gap

[0049] The local resonance band gap is determined by the equivalent mass-spring system of the lead scatterer and the rubber cushion, and the center frequency is approximately:

[0050] 4. Calculate the vibration isolation effect

[0051] The vibration isolation effect is evaluated by the transmission ratio. Within the local resonance band gap, TL is approximately:

[0052]

[0053] The motion equation of the system is: The solution is:

[0054]

[0055] Thus, the transmissibility is obtained as follows:

[0056]

[0057] where m eff = 0.218 kg, k eff = 141372 N / m, ω n = 805 rad / s → f n = 128 Hz, and the rubber damping ratio ζ = 0.1.

[0058] Taking the target frequency f n = 128 Hz (the center of the bandgap) as an example, when ω = ω n = 804 rad / s, ω / ω n = 1 (the resonance point) is substituted into the transmissibility formula:

[0059]

[0060] The vibration equivalent value Z vibration level is used as the evaluation quantity. In the frequency range of 80 Hz - 200 Hz, the Z vibration level is approximately reduced by 10 - 25 dB.

[0061] Traditional floor vibration reduction technologies generally have the problem of poor vibration reduction effect and are difficult to meet more vibration reduction requirements. Compared with traditional vibration isolators, phononic crystal vibration isolators have the characteristic of vibration transmission attenuation. Therefore, in a specific frequency range, the floating floor with phononic crystal vibration isolators has better vibration reduction and noise reduction effects. Moreover, phononic crystal vibration isolators can achieve precise control of the frequency range with enhanced vibration reduction effect through parameter optimization, so as to meet the vibration reduction and noise reduction requirements of more projects. The vibration of the main transformer and reactor vibration sources is mainly vertical. And since the equipment vibration is excited by alternating current, there are obvious peaks at 50 Hz and its multiples, especially more obvious at 100 Hz and 200 Hz. The structure of the phononic crystal determines the position and width of its bandgap, thus affecting the frequency range of its sound insulation and vibration reduction. This solution adopts a hourglass-shaped phononic crystal structure, and combines a thinner rubber layer and a thicker lead layer into an hourglass-shaped resonance unit attached to the thin panel, and a sound insulation frequency band in the medium and low frequencies can be obtained.

[0062] The above are only the embodiments of the present application and are not used to limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A novel phonon crystal vibration isolator for a substation, characterized in that, It includes a phononic crystal unit cell. The phononic crystal unit cells are arranged in a 6×6 pattern to obtain a new type of phononic crystal vibration isolator. The phononic crystal unit cell includes scatterers, a base plate, and a rubber cushion layer. The base plate includes an upper base plate and a lower base plate. Scatterers are installed between the upper base plate and the lower base plate. Rubber cushion layers are installed between the lower surface of the upper base plate and the upper surface of the scatterers and between the upper surface of the lower base plate and the lower surface of the scatterers.

2. A novel phonon crystal vibration isolator for a substation according to claim 1, characterized in that, The upper base plate and the lower base plate are made of aluminum alloy thin plates with a side length of 40 mm and a thickness of 3 mm.

3. The novel phonon crystal vibration isolator for a substation according to claim 1, characterized in that, The scatterer is a lead layer, with a shape of upper and lower symmetric hourglass, a maximum radius of 15 mm, a minimum radius of 12 mm, and a height of 20 mm.

4. A novel phonon crystal vibration isolator for a substation according to claim 1, characterized in that, The rubber cushion layer uses a rubber ring layer with a radius of 15 mm and a thickness of 5 mm.

5. A novel phonon crystal vibration isolator for a substation according to claim 1, characterized in that, The scatterer spacing of the phononic crystal unit cell is 10 mm.

6. An installation method for a new type of phononic crystal vibration isolator for a substation, characterized by comprising the following specific steps: Assembly of the lower base plate and the rubber cushion layer: Clean the installation surface, remove oil stains and rust, apply epoxy resin glue to enhance adhesion, place the rubber cushion layer at the center position of the lower base plate, ensure that the center of the circle is aligned with the center of the base plate, use a positioning mold for auxiliary positioning to avoid deviation, and gently press the rubber cushion layer to make it initially fit with the lower base plate; Assembly of the scatterer and the rubber cushion layer: Use a positioning mold to vertically place the hourglass-shaped lead scatterer on the rubber cushion layer, ensure that the upper and lower symmetry axes coincide with the center line of the base plate, check the scatterer spacing layer by layer, and use a rubber hammer to finely adjust the position to avoid misalignment between the lead body and the rubber cushion layer; Installation of the upper base plate: Place another rubber cushion layer on the top of the lead scatterer, ensure that the center of its circle is aligned with the center of the base plate, cover the upper base plate on the rubber cushion layer, gently press it to make it initially fit, use a positioning mold to ensure the alignment of the upper and lower base plates to avoid misalignment, and complete the assembly of the phononic crystal unit cell; Arrangement of multiple unit cells: Repeat the above steps to achieve the arrangement of multiple phononic crystal unit cells in a 6×6 array, with a spacing of 10 mm between the edges of adjacent unit cells. Fix them with connecting pieces through the reserved hole positions on the base plate. Use a level to check the overall flatness, and add shim sheets as needed to form a phononic crystal vibration isolator; Installation of the reactor: Hoist the reactor onto the support, adjust the position and levelness of the reactor, connect the upper base plate of the phononic crystal vibration isolator to the reactor body with bolts to ensure a firm connection, conduct system debugging and testing to ensure the normal operation of the replaced reactor, and complete the installation of the reactor.

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