Combined noise reduction module, noise reduction wall and installation method for air-cooled transformer type equipment

Abstract

The application discloses a combined noise reduction module for air-cooled transformer equipment, a noise reduction wall and a mounting method, and belongs to the technical field of power facilities. The noise reduction module comprises an A-type module and a B-type module. The A-type module and the B-type module are both hollow cavities with open front ends and closed rear ends which are welded from stainless steel plates. Rectangular holes are arranged on the side walls of the noise reduction module to form sound absorption cavities when the A-type module and the B-type module are stacked. I-grade sound absorption bodies and II-grade sound absorption bodies are arranged in the side walls of the noise reduction module. Copper resonance membranes and titanium resonance membranes are arranged on the I-grade sound absorption bodies and the II-grade sound absorption bodies respectively to reduce the noise of the air-cooled transformer equipment. The application realizes the absorption of the core frequency components in the noise of the air-cooled transformer and the fan by means of sound absorption material parameter optimization, resonance membrane half-invasion needle fixation and noise reduction modules, thereby realizing the noise reduction of the air-cooled transformer equipment.

Description

Technical Field

[0001] This application relates to the field of power facility technology, specifically to a combined noise reduction module, noise reduction wall, and installation method for air-cooled transformer equipment. Background Technology

[0002] In power facilities such as substations, the noise of air-cooled transformers during operation is characterized by the following: In addition to the noise from the vibration of the transformer core and windings (mainly at frequencies of 100, 200, 300, 400, and 500 Hz), the starting and operation of the cooling fan adds further noise to the transformer's noise level. The fan noise energy is mostly distributed in the 600-1000 Hz range. Therefore, the start-up of the cooling fan significantly alters the overall noise level and spectral characteristics of the transformer. However, current noise reduction measures such as sound barriers have shortcomings in the following three aspects: 1. Only sound insulation was considered, without considering sound absorption design; 2. Sound absorption was considered, but the absorption of the prominent low-frequency components in the transformer body noise was not specifically addressed. 3. The absorption of low-frequency noise components in the transformer body was considered, but the absorption of new characteristic frequency components generated after the fan starts was not considered. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a combined noise reduction module, noise reduction wall, and installation method for air-cooled transformer equipment.

[0004] The present invention adopts the following technical solution.

[0005] The first aspect of the present invention discloses a combined noise reduction module for air-cooled transformer equipment. The noise reduction module includes an A-type module and a B-type module. Both the A-type module and the B-type module are hollow cavities with open front ends and sealed rear ends, which are welded from stainless steel plates. Rectangular holes are provided on the side walls of the noise reduction module, which are connected to form a sound-absorbing cavity when multiple A-type modules and B-type modules are stacked. The noise reduction module has a Class I sound absorber and a Class II sound absorber inside its sidewall. The Class I and Class II sound absorbers are respectively provided with a copper resonant membrane and a titanium resonant membrane, which are used to reduce noise in air-cooled transformer equipment.

[0006] Preferably, the type A module is an octagonal prism structure, with rectangular holes pre-reserved in the top, bottom, left, and right side walls of its eight side walls; the type B module is a cuboid structure, with rectangular holes pre-reserved in all four side walls.

[0007] Preferably, the Class I and Class II sound absorbers are synergistically optimized polyurethane-metal sound absorbers. The Class I sound absorber is in close contact with the inner wall of the rear end of the module, and the Class II sound absorber is closer to the front end of the module. The distance between the Class II sound absorber and the inner wall of the rear end of the noise reduction module is equal to the cavity depth of the two types of modules. .

[0008] Preferably, the cavity depth of the two types of modules From equation (1): (1) in For the speed of sound, The primary target sound absorption frequency, is a coefficient.

[0009] Preferably, the synergistic optimization method for the polyurethane-metal sound absorber includes the following steps: Step 1: Based on the geometric dimensions of the acoustic testing system, select the prepared polyurethane-metal medium as the original, standard volume medium, and measure the porosity of the polyurethane matrix as the reinforcing material and the thickness of the metal deposition layer as the matrix material as the original physical parameters. Step 2: Construct the polyurethane-metal dielectric model under the above standard volume based on the measured original physical parameters, and combine it with the acoustic test system model to form the polyurethane-metal dielectric acoustic property test model. Step 3: With the goal of achieving the best overall sound absorption effect in the 100-1000Hz range under low load conditions for air-cooled transformer equipment, the porosity of the polyurethane matrix and the thickness of the metal deposition layer are obtained by using the polyurethane-metal dielectric model described in Step 2. Step 4: Based on the optimal parameters of the medium obtained in Step 3, prepare a standard volume of polyurethane-metal medium again, and complete the sound absorption effect test using an acoustic testing system.

[0010] Preferably, the sound absorption effect test includes: If the test results do not meet the overall optimal sound absorption effect of 100-1000Hz, return to the polyurethane-metal dielectric model in step 2 for correction and repeat the optimization process in the route. If the test results satisfy the condition that the overall sound absorption effect in the 100-500Hz range is optimal and that the sound absorption effect in the 100-500Hz range is better than that in the 600-1000Hz range, then the porosity and the thickness of the metal deposition layer are established as the optimal medium parameters.

[0011] Preferably, the Class I and Class II sound absorbers are respectively provided with copper resonant membranes and titanium resonant membranes. A copper resonant membrane is attached to the inner side of the Class II sound absorber of the Type A module and the outer side of the Class I sound absorber of the Type B module; a titanium resonant membrane is attached to the outer side of the Class I sound absorber of the Type A module and the inner side of the Class II sound absorber of the Type B module.

[0012] Preferably, both the copper resonant diaphragm and the titanium resonant diaphragm are fixed to the sidewalls of the corresponding Class I and Class II sound absorbers by a folding and brazing process, following the fold lines and brazing points.

[0013] Preferably, the copper resonant membrane and the titanium resonant membrane are fixed to the surface of the corresponding Class I and Class II sound absorbers using a semi-invasive needle punching process.

[0014] Preferably, the rectangular hole is provided with a rectangular hole sealing rubber plug and a rectangular hole conductive rubber sleeve, which are used to adjust the volume of the sound absorption cavity after the A-type module and the B-type module are stacked.

[0015] The second aspect of the present invention discloses a noise reduction wall, comprising a combined noise reduction module for air-cooled transformer equipment as described in the first aspect, wherein a plurality of the A-type modules and B-type modules are stacked to form a noise reduction wall according to the distribution characteristics of the sound field of the air-cooled transformer equipment on its four sides.

[0016] Preferably, the upper part of the noise reduction wall is provided with a stainless steel equalizing cover to mitigate potential electric field distortion caused by the installation of the sound-absorbing wall; the rear part of the noise reduction wall is sprayed with water-based anti-rust adhesive and composite polymer resin paint; microphones and fixed brackets are arranged on both sides of the noise reduction wall for real-time measurement data feedback to the noise monitoring system; grounding cables are attached to the rear part of the noise reduction wall and the stainless steel equalizing cover, which are connected to the substation grounding grid to ensure equipment safety.

[0017] A third aspect of the present invention discloses an installation method for installing a noise-reducing wall as described in the second aspect, comprising the following steps: After the air-cooled transformer equipment, which is the target of noise reduction, is put into operation, a noise analysis system is used to set up measurement points around the equipment to obtain the spectral characteristics and spatial distribution data of the noise of the transformer equipment itself when the cooling fan is not running, as well as the spectral characteristics and corresponding spatial distribution characteristics data when the noise level is the highest when the cooling fan is running. Based on the obtained spectral characteristic data of the transformer equipment noise when the cooling fan is not running, the parameters of polyurethane-metal are optimized using a collaborative optimization method. Based on the obtained spectral characteristics and corresponding spatial distribution characteristics of the highest noise level under the operating conditions of the cooling fan, the semi-invasive needle-punching points of the copper resonant membrane and titanium resonant membrane in the A-type module and B-type module, as well as the stacking length, stacking height, rectangular holes and top envelope of the A-type module and B-type module, were adjusted to establish the installation method of the noise reduction wall. After the noise reduction wall body is installed, a noise monitoring system is used to feed the measurement data back to the noise monitoring system in real time to complete the real-time monitoring of the noise level of air-cooled transformer equipment and the real-time analysis of the noise reduction effect of the noise reduction wall.

[0018] Compared with the prior art, the beneficial effects of the present invention include at least the following: 1. This invention addresses noise control for air-cooled transformer equipment by considering a comprehensive approach of sound absorption and insulation. It utilizes stainless steel and sound-insulating rubber on the outside of the noise reduction module as a sound insulation structure, and Class I and Class II sound absorbers, copper and titanium resonant membranes, and sound-absorbing cavities whose volume can be controlled by rectangular holes and conductive plugs within the Type A and Type B modules as sound absorption structures. By combining these sound absorption and insulation phase structures, the overall low-frequency sound absorption and noise control effect is improved. 2. This invention fully considers the frequency characteristics of the sound source equipment and takes into account the noise of the device itself and the noise of the fan separately; the distance between the Class II sound absorber and the inner wall of the rear end of the module is... The design, synergistic optimization of the two core parameters of the polyurethane-metal sound absorber inside the A-type and B-type modules (porosity and metal deposition thickness), adjustment of the number of semi-intrusive needle points of the copper and titanium resonant membranes, and volume control of the sound absorption cavity achieve targeted absorption of the main frequency components in the body noise and fan noise. Attached Figure Description

[0019] Figure 1 These are the front and side views of the Type A and Type B modules in this invention; Figure 2 This is a schematic diagram showing the positions of the Class I and Class II sound absorbers in this invention; Figure 3 This is a schematic diagram of the copper resonant membrane and the titanium resonant membrane in this invention; Figure 4 This is a schematic diagram of the acupuncture points in this invention, where (a), (b), and (c) are the 1st, 3rd, and 4th semi-invasive acupuncture points in the type A module, respectively, and (d) and (e) are the 1st and 2nd semi-invasive acupuncture points in the type B module, respectively. Figure 5 This is a schematic diagram of the rubber stopper and rubber sleeve in this invention; Figure 6 This is a front view of the noise-reducing wall in this invention; Figure 7This is a side view of the noise-reducing wall in this invention; Figure 8 This is a flowchart of the parameter optimization method in this invention.

[0020] In the picture: 1. Type A module; 2. Type B module; 3. Rectangular hole; 4. Sound absorption cavity; 5. Sound insulation rubber; 6. Stainless steel plate; 7. Class I sound absorber; 8. Class II sound absorber; 9. Copper resonant diaphragm; 10. Titanium resonant diaphragm; 11. Folding line; 12. Brazed joint; 13. Needle-punched point; 14. Rectangular hole sealing plug; 15. Rectangular hole conductive sleeve; 16. Top-to-top sealing rubber teeth; 17. Air-cooled transformer; 18. Stainless steel equalizing cover; 19. Water-based rust-preventive adhesive; 20. Composite polymer resin paint; 21. Microphone and mounting bracket; 22. Grounding cable. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this invention.

[0022] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0026] like Figure 1-5 As shown, Embodiment 1 of the present invention provides a combined noise reduction module for air-cooled transformer equipment. The noise reduction module includes: a type A module 1 and a type B module 2, which are used to form a solid noise reduction wall when stacked.

[0027] Both the Type A module 1 and the Type B module 2 are hollow cavity structures welded from 2.5mm stainless steel plates 6, with an open front end and a sealed rear end. A 25mm thick sound-insulating rubber 5 is adhered to the bottom of the rear end, which is recycled from waste silicone rubber insulator skirts.

[0028] The type A module 1 is an octagonal prism structure, with rectangular holes 3 reserved in the top, bottom, left, and right side walls of its eight side walls; the type B module 2 is a cuboid structure, with rectangular holes 3 reserved in the four side walls of its four side walls.

[0029] The rectangular holes in the type B module correspond to the rectangular holes in the type A module when stacked, which facilitates the connection of the sound-absorbing cavity 4 after the type A and type B modules are stacked.

[0030] It is worth noting that if the rectangular holes are too small, they will affect the sound absorption effect after forming a large connected cavity; if they are too large, they will affect the structural strength after the modules are stacked. Preferably, the rectangular holes 3 of the type A module and the type B module are both 120mm×85mm.

[0031] Both the Type A module 1 and the Type B module 2 contain two polyurethane-metal sound absorbers with a thickness of 80-100mm. The one in close contact with the inner wall of the rear end of the module is a Class I sound absorber 7, and the one near the front end of the module is a Class II sound absorber 8. The distance between the Class II sound absorber and the inner wall of the rear end of the module is equal to the cavity depth of the two types of modules. .

[0032] The polyurethane-metal material was originally used for the adsorption of specific components in gases, but the inventors discovered that its porous structure is also suitable as a sound-absorbing material for noise control. As a sound-absorbing material, the greater its thickness, the better the sound absorption effect, but the cost also increases significantly with increasing thickness. Therefore, the thickness was set at 80-100mm, and the equivalent thickness of the sound-absorbing material was increased by the cavity design between the Class I and Class II sound absorbers in the Type A and Type B modules, thereby increasing the sound absorption effect while keeping costs under control.

[0033] Specifically, for a sound wave of a certain frequency entering the sound-absorbing cavity, since its sound pressure value is 0 at 1 / 4 wavelength from the rigid wall at the bottom of the cavity, and the air particles in the sound wave have the greatest kinetic energy at this time, if the polyurethane-metal sound-absorbing material is arranged at an odd multiple of 1 / 4 wavelength from the rigid wall at the bottom, the sound energy consumed by the friction damping effect of the polyurethane-metal sound-absorbing material will also reach its maximum. Therefore, the cavity depth at this time has the greatest sound absorption effect on the sound wave of that frequency.

[0034] Therefore, after determining the primary target acoustic absorption frequency, the cavity depth of the two types of modules... It can be obtained from equation (1): (1) in For the speed of sound, The primary target sound absorption frequency, is a coefficient.

[0035] Preferably, taking into account both the low-frequency noise suppression effect and the footprint of the combined noise reduction module, the inventors selected 300 Hz as the target sound absorption frequency, and The value is 0 ( If not set to 0, then the cavity depth of the two types of modules... The higher the value, the thicker the wall formed by the combination, and consequently, the larger the area occupied by the noise reduction module.

[0036] Therefore, let the speed of sound Take 343 m / s, Taking 300 Hz and substituting it into equation (1), the distance between the Class II sound absorber and the inner wall of the rear end of the module can be obtained, which is the cavity depth of the two types of modules. It is 285.83mm.

[0037] In order to achieve optimal sound absorption in the target frequency range and maximize sound absorption, such as Figure 8 As shown, this invention provides a synergistic optimization method for two core parameters of the polyurethane-metal sound absorbers inside the type A module 1 and type B module 2: porosity and metal deposition thickness, specifically including the following steps: Step 1: Based on the geometry of the acoustic testing system, a pre-prepared polyurethane-metal medium with a diameter of 100 mm and a thickness of 40 mm is selected as the original, standard volume medium. The porosity of the polyurethane matrix as the reinforcing material and the thickness of the metal deposition layer as the matrix material are measured as the original physical parameters.

[0038] Step 2: Construct the polyurethane-metal dielectric model under the above standard volume based on the measured original physical parameters, and combine it with the acoustic test system model to form the polyurethane-metal dielectric acoustic property test model. Specifically, the construction of the polyurethane-metal dielectric model under the standard volume based on the measured original physical parameters is carried out by using multiphysics simulation software and the LM multi-objective optimization algorithm to construct the polyurethane-metal dielectric model under the standard volume.

[0039] Step 3: With the goal of achieving the best overall sound absorption effect in the 100-1000Hz range under low load conditions for air-cooled transformers, the porosity of the polyurethane matrix and the thickness of the metal deposition layer are obtained by using the polyurethane-metal dielectric model described in Step 2.

[0040] Preferably, when multiple values ​​are obtained from the optimization of the polyurethane-metal dielectric model, the optimal value is selected based on the condition that the sound absorption effect of 100-500Hz should be better than that of 600-1000Hz.

[0041] Step 4: Based on the obtained optimal parameters of the medium, prepare a standard volume of polyurethane-metal medium again, and complete the sound absorption effect test using an acoustic testing system.

[0042] In a preferred but non-limiting embodiment of the present invention, step 4 includes: Step 4.1: If the test results do not meet the overall optimal sound absorption effect of 100-1000Hz, return to the polyurethane-metal dielectric model in Step 2 for correction and repeat the optimization process in the route. Step 4.2: If the test results satisfy the condition that the overall sound absorption effect in the 100-500Hz range is optimal and the sound absorption effect in the 100-500Hz range is more prominent, then the porosity and the thickness of the metal deposition layer are established as the optimal medium parameters.

[0043] like Figure 2-3As shown, a 0.01mm thick copper resonant membrane 9 is attached to the inner side of the Type A module Class II sound absorber 8 and the outer side of the Type B module Class I sound absorber 7; a 0.02mm thick titanium resonant membrane 10 is attached to the outer side of the Type A module Class I sound absorber 7 and the inner side of the Type B module Class II sound absorber 8. Both the copper resonant diaphragm 9 and the titanium resonant diaphragm 10 are fixed to the corresponding Class I and Class II sound absorber sidewalls by means of a folding and brazing process, with the resonant diaphragm fixed to the corresponding folding lines 11 and brazing points 12.

[0044] More preferably, the copper resonant membrane 9 and the titanium resonant membrane 10 are both fixed to the surface of the corresponding Class I and Class II sound absorbers using a semi-invasive needle punching process.

[0045] The number of semi-invasive needle puncture points 13 can be adjusted according to an increasing rule, and their positions can be set in a centrally symmetrical or axially symmetrical manner. The differentiated setting of the number and position of the semi-invasive needle puncture points 13 is jointly committed to the adaptation of the core target sound absorption frequency band and the maximum sound absorption.

[0046] Specifically, such as Figure 4 As shown in (a)-(c), firstly, the sound absorption performance of the type A sound absorption module was tested under the conditions of 1, 3 and 4 semi-intrusive needle puncture points, and the corresponding main transformer sound absorption frequency bands fA1, fA3 and fA4 were obtained. Secondly, such as Figure 4 (d)-(e) show the sound absorption performance of the B-type sound absorption module under the conditions of 1 and 2 semi-intrusive needle puncture points, respectively, and the corresponding main transformer sound absorption frequency bands fB1 and fB2 are obtained. The relationship between the differences in the number and location of different semi-invasive needle puncture points and the adaptation of the core target's sound absorption frequency band and the maximum sound absorption can be presented by the expression (2) of the natural frequency of the elastic structure: (2) in, These are the characteristic coefficients of the nth mode shape, which are related to the number and location of constraints and the mode shape. For the system's equivalent stiffness, the more internal fixed points there are and the more uniformly they are distributed, the better. The larger; To contribute to the equivalent mass of the vibration, internal constraints reduce the vibration area. Slightly lower.

[0047] As can be seen from the above formula, for the semi-invasive acupuncture fixation method, the stiffness improvement effect brought about by the increase in the number of acupuncture points always dominates. Therefore, the higher the number of acupuncture points, the higher the corresponding increase in resonance frequency.

[0048] Third, after the air-cooled transformer equipment was put into operation, the spectral characteristics and corresponding spatial distribution characteristics of the cooling fan at the highest noise level under operating conditions were measured on site. Finally, based on the spectral characteristics and corresponding spatial distribution characteristics of the cooling fan when the operating noise level is at its maximum, the combination of fA1, fA3, fA4 and fB1, fB2 is selected.

[0049] like Figure 5 As shown, the rectangular holes 3 in the type A module 1 and type B module 2 are based on sound-insulating rubber material recycled from waste silicone rubber insulator skirts. They are designed with a type rectangular hole sealing plug 14 and a type rectangular hole conductive sleeve 15. After the type A module 1 and type B module 2 are stacked to form a noise reduction wall, the volume of the sound absorption cavity 4 is adjusted, thereby focusing on the adaptation of the core target sound absorption frequency band and the maximum sound absorption.

[0050] More preferably, the inner width of the rectangular hole conductive rubber sleeve 15 is 5mm (the thickness of two layers of stainless steel shell). In order to prevent possible sound leakage at the edge of the rectangular hole sealing rubber plug 14 and the rectangular hole conductive rubber sleeve 15, the inner edge of the rectangular hole conductive rubber sleeve is also designed with top-to-top sealing rubber teeth 16.

[0051] This invention achieves targeted absorption of the main frequency components of the cooling fan when the operating noise level is at its highest by selecting the combination of the semi-needle-punching points of the type A sound-absorbing module 1 and the type B sound-absorbing module 2, as well as the number and position of the rectangular holes.

[0052] Embodiment 2 of the present invention discloses a noise-reducing wall, such as Figure 6-7 As shown, it includes multiple noise reduction modules as described in Embodiment 1; the multiple Type A modules 1 and Type B modules 2, according to the distribution characteristics of the sound field of the air-cooled transformer 17 on its four sides, establish the stacking length, stacking height, and top envelope morphology of the Type A and Type B modules on the corresponding sides, thereby forming a rigorous noise reduction wall to improve the sound absorption efficiency of the sound-absorbing wall on that side, and thus focus on the adaptation of the core target sound absorption frequency band and the maximum sound absorption. Adaptive adjustment and overall design of material, module, and wall parameters. In a preferred but non-limiting embodiment of the present invention, a stainless steel equalizing cover 18 is provided on the upper part of the noise reduction wall to mitigate the potential electric field distortion caused by the installation of the sound-absorbing wall.

[0053] More preferably, a 2mm thick water-based anti-rust adhesive 19 and a 2mm thick composite polymer resin paint 20 are sprayed onto the rear part of the noise reduction wall. This serves two purposes: first, to improve the overall anti-rust level of the rear gap after the A and B type modules are stacked; and second, to further improve the overall sound insulation level of the noise reduction wall based on the 25mm sound insulation rubber 5 at the bottom of the A and B type modules.

[0054] In a preferred but non-limiting embodiment of the present invention, microphones and fixed brackets 21 are arranged on both sides of the noise reduction wall, and the measurement data is fed back to the noise monitoring system in real time to evaluate the noise level of the air-cooled transformer and to assist in calculating the noise reduction performance parameters such as the insertion loss of the noise reduction wall.

[0055] More preferably, the rear of the noise reduction wall and the stainless steel equalizing cover 18 are both connected to grounding cables 22, which are connected to the substation grounding grid. This is to promptly leak the charge induced on the noise reduction wall into the grounding grid, thereby ensuring the safety of the auxiliary microphone and noise level monitoring and analysis system.

[0056] Embodiment 3 of the present invention discloses an installation method for installing a noise-reducing wall as described in Embodiment 2, comprising the following steps: Step 1: After the air-cooled transformer equipment, which is the target of noise reduction, is put into operation, a noise analysis system is used to set up measurement points around the equipment to obtain the spectral characteristics and spatial distribution data of the noise of the transformer equipment itself when the cooling fan is not running, as well as the spectral characteristics and corresponding spatial distribution data when the noise level is the highest when the cooling fan is running.

[0057] The noise analysis system consists of 40 capacitor microphones.

[0058] Step 2: Based on the spectral characteristic data of the transformer equipment body noise when the cooling fan is not running, obtained in Step 1, the parameters of polyurethane-metal are optimized using a collaborative optimization method. Step 3: Based on the spectral characteristics and corresponding spatial distribution characteristics of the cooling fan at its highest noise level under the operating conditions obtained in Step 1, adjust the semi-intrusive needle-punching points, wall stacking length, stacking height, number and location of rectangular holes, and top envelope of the copper and titanium resonant membranes in the Type A and Type B modules to establish the installation method of the noise reduction wall body. Step 4: After the installation of the noise reduction wall body is completed, a noise monitoring system is used to measure the data and feed it back to the noise monitoring system in real time to complete the real-time monitoring of the noise level of air-cooled transformer equipment and the real-time analysis of the noise reduction effect of the noise reduction wall.

[0059] Specifically, after the installation of the noise reduction wall body is completed, a microphone and a fixed bracket 21 are installed at the geometric center of each of the inner and outer sides of the wall. The microphone probe is 1.5 meters above the ground and more than 0.5 meters away from the noise reduction wall body. The measurement data is fed back to the noise monitoring system in real time to complete the real-time monitoring of the noise level of air-cooled transformer equipment and the real-time analysis of the noise reduction effect of the noise reduction wall.

[0060] The noise reduction module and wall of this invention are applicable to transformer-type equipment (including AC transformers, reactors and converter transformers) cooled by fans. Specifically, they can be used to control audible noise from air-cooled transformers in 110 kV and above fully outdoor, semi-indoor, and fully indoor substations. The absorption of core frequency components in the noise of the air-cooled transformer body and the fan is achieved through four levels of methods: optimization of polyurethane-metal sound-absorbing material parameters, semi-intrusive needle-punching gradient fixing process of resonant membrane, volume connection-shutdown control of noise reduction cavity, and differentiated stacking of noise reduction modules.

[0061] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0062] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0063] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0064] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A combined noise reduction module for air-cooled transformer equipment, the noise reduction module comprising: Type A module (1) and Type B module (2), characterized in that: Both the A-type module (1) and the B-type module (2) are hollow cavities with open front ends and sealed rear ends, welded from stainless steel plates (6). The side walls of the noise reduction modules are provided with rectangular holes (3) for connecting to form sound-absorbing cavities (4) when multiple A-type modules (1) and B-type modules (2) are stacked. The noise reduction module has a Class I sound absorber (7) and a Class II sound absorber (8) inside its side wall. The Class I sound absorber (7) and the Class II sound absorber (8) are respectively provided with a copper resonant membrane (9) and a titanium resonant membrane (10) for noise reduction of air-cooled transformer equipment.

2. The combined noise reduction module for air-cooled transformer equipment according to claim 1, characterized in that: The type A module (1) is an octagonal prism structure, and rectangular holes (3) are reserved in the top, bottom, left and right side walls of its eight side walls; the type B module (2) is a cuboid structure, and rectangular holes (3) are reserved in the four side walls of its four side walls.

3. The combined noise reduction module for air-cooled transformer equipment according to claim 1, characterized in that: The Class I sound absorber (7) and Class II sound absorber (8) are synergistically optimized polyurethane-metal sound absorbers. The Class I sound absorber (7) is close to the inner wall of the rear end of the module, and the Class II sound absorber (8) is close to the front end of the module. The distance between the Class II sound absorber and the inner wall of the rear end of the noise reduction module is the cavity depth of the two types of modules. .

4. The combined noise reduction module for air-cooled transformer equipment according to claim 3, characterized in that: The cavity depth of the two types of modules From equation (1): （1） in For the speed of sound, The primary target sound absorption frequency, is a coefficient.

5. The combined noise reduction module for air-cooled transformer equipment according to claim 3, characterized in that: The synergistic optimization method for the polyurethane-metal sound absorber includes the following steps: Step 1: Based on the geometric dimensions of the acoustic testing system, select the prepared polyurethane-metal medium as the original, standard volume medium, and measure the porosity of the polyurethane matrix as the reinforcing material and the thickness of the metal deposition layer as the matrix material as the original physical parameters. Step 2: Construct the polyurethane-metal dielectric model under the above standard volume based on the measured original physical parameters, and combine it with the acoustic test system model to form the polyurethane-metal dielectric acoustic property test model. Step 3: With the goal of achieving the best overall sound absorption effect in the 100-1000Hz range under low load conditions for air-cooled transformer equipment, the porosity of the polyurethane matrix and the thickness of the metal deposition layer are obtained by using the polyurethane-metal dielectric model described in Step 2. Step 4: Based on the optimal parameters of the medium obtained in Step 3, prepare a standard volume of polyurethane-metal medium again, and complete the sound absorption effect test using an acoustic testing system.

6. The combined noise reduction module for air-cooled transformer equipment according to claim 5, characterized in that: The sound absorption effect test includes: If the test results do not meet the overall optimal sound absorption effect of 100-1000Hz, return to the polyurethane-metal dielectric model in step 2 for correction and repeat the optimization process in the route. If the test results satisfy the condition that the overall sound absorption effect in the 100-500Hz range is optimal and that the sound absorption effect in the 100-500Hz range is better than that in the 600-1000Hz range, then the porosity and the thickness of the metal deposition layer are established as the optimal medium parameters.

7. The combined noise reduction module for air-cooled transformer equipment according to claim 1, characterized in that: The Class I sound absorber (7) and Class II sound absorber (8) are respectively provided with a copper resonant membrane (9) and a titanium resonant membrane (10). A copper resonant membrane (9) is attached to the inner side of the Class II sound absorber (8) of the Type A module (1) and the outer side of the Class I sound absorber (7) of the Type B module (2); a titanium resonant membrane (10) is attached to the outer side of the Class I sound absorber (7) of the Type A module (1) and the inner side of the Class II sound absorber (8) of the Type B module (2).

8. The combined noise reduction module for air-cooled transformer equipment according to claim 7, characterized in that: The copper resonant membrane (9) and the titanium resonant membrane (10) are both fixed to the sidewalls of the corresponding Class I sound absorber (7) and Class II sound absorber (8) by brazing along the fold line (11) and through the brazing points (12).

9. The combined noise reduction module for air-cooled transformer equipment according to claim 8, characterized in that: The copper resonant membrane (9) and titanium resonant membrane (10) are fixed to the surface of the corresponding Class I sound absorber (7) and Class II sound absorber (8) using a semi-invasive needle punching process.

10. The combined noise reduction module for air-cooled transformer equipment according to claim 1, characterized in that: The rectangular hole (3) is provided with a rectangular hole sealing rubber plug (14) and a rectangular hole conductive rubber sleeve (15) for adjusting the volume of the sound absorption cavity (4) after the A-type module (1) and the B-type module (2) are stacked.

11. A noise-reducing wall, comprising a combined noise-reducing module for air-cooled transformer equipment as described in any one of claims 1-10, characterized in that: Multiple Type A modules (1) and Type B modules (2) are stacked to form a noise reduction wall according to the distribution characteristics of the sound field on the four sides of the air-cooled transformer equipment.

12. The noise-reducing wall according to claim 11, characterized in that: The upper part of the noise reduction wall is provided with a stainless steel equalizing cover (18) to smooth out the potential electric field distortion caused by the installation of the sound-absorbing wall; the rear part of the noise reduction wall is sprayed with water-based anti-rust glue (19) and composite polymer resin paint (20); microphones and fixed brackets (21) are arranged on both sides of the noise reduction wall for real-time measurement data feedback to the noise monitoring system; the rear part of the noise reduction wall and the stainless steel equalizing cover (18) are both connected to grounding cables (22) to the substation grounding grid to ensure equipment safety.

13. An installation method for installing a noise-reducing wall as described in any one of claims 11-12, characterized in that: Includes the following steps: After the air-cooled transformer equipment, which is the target of noise reduction, is put into operation, a noise analysis system is used to set up measurement points around the equipment to obtain the spectral characteristics and spatial distribution data of the noise of the transformer equipment itself when the cooling fan is not running, as well as the spectral characteristics and corresponding spatial distribution characteristics data when the noise level is the highest when the cooling fan is running. Based on the obtained spectral characteristic data of the transformer equipment noise when the cooling fan is not running, the parameters of polyurethane-metal are optimized using a collaborative optimization method. Based on the obtained spectral characteristics and corresponding spatial distribution characteristics of the highest noise level under the operating conditions of the cooling fan, the semi-invasive needle-punching points of the copper resonant membrane (9) and titanium resonant membrane (10) in the A-type module (1) and B-type module (2), as well as the stacking length, stacking height, rectangular hole (3) and top envelope of the A-type module (1) and B-type module (2) were adjusted to establish the installation method of the noise reduction wall. After the noise reduction wall body is installed, a noise monitoring system is used to feed the measurement data back to the noise monitoring system in real time to complete the real-time monitoring of the noise level of air-cooled transformer equipment and the real-time analysis of the noise reduction effect of the noise reduction wall.

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