11 results about "Noise reduction coefficient" patented technology

The invention relates to the technical field of functional materials, in particular to a sound-absorbing metal plate and a preparation method and application thereof. According to the sound-absorbing metal plate provided by the invention, the metal panel, the functional inner core and the back plate are adopted, and the core is that the sound-absorbing structure of the functional inner core is utilized, so that the noise reduction coefficient is more than 0.95. Specifically, according to the sound-absorbing metal plate provided by the invention, ethylene-vinyl acetate and polyethylene glycol terephthalate are adopted as basic resin, and the pore structure of the functional inner core is controlled by utilizing the synergistic effect of the foaming agent and the cross-linking agent, so that the pore structure is more beneficial to efficient absorption and reduction of sound reflection. According to the sound-absorbing metal plate, the functional inner core is further arranged between the metal face plate and the back plate, the sound-absorbing function and the structural stability of the functional inner core are further enhanced, and the sound-absorbing metal plate provided by the invention achieves the optimal performance. The sound-absorbing metal plate provided by the invention has the advantages of favorable flame retardancy, favorable safety, decoration and beautification functions and favorable overall effect.

The invention relates to the technical field of noise pollution protection, in particular to a composite acoustic material for noise reduction and application of the composite acoustic material in large-scale oil-filled power transformation equipment. The composite acoustic material for noise reduction is composed of four parts, the side facing a sound source serves as a starting point, and the first part is a surface layer material in the direction away from the sound source step by step; the second part material is an acoustic function material; the third part is made of a backboard high-temperature-resistant heat-insulating material; and the fourth part is made of a sound insulation structure material. According to the composite acoustic material for noise reduction, the 100 Hz sound absorption coefficient is larger than 0.3, the noise reduction coefficient is not smaller than 0.75, and the original intention of low frequency, high efficiency and broadband effectiveness is met; the overall thickness is fixedly pressed to be 80 mm, the surface density is smaller than 36 kg / m < 2 >, the acoustic performance can reach that the sound insulation index is larger than 45 dB, the efficient sound insulation requirement on the premise of small thickness and light weight is met, and practical application value is achieved.

The invention relates to the field of high polymer material processing, in particular to a waterproof roll with a sound-absorbing function, which comprises a porous sound-absorbing layer, a bonding layer and a waterproof layer which are arranged from top to bottom, the thickness of the porous sound-absorbing layer is 2-5mm, the porosity of the porous sound-absorbing layer is 60-80%, the bonding layer is arranged between the porous sound-absorbing layer and the waterproof layer, and the waterproof layer is arranged between the bonding layer and the waterproof layer. The waterproof layer is a modified asphalt layer or a high-molecular polymer layer, and the porous sound absorption layer and the waterproof layer form a permanent composite structure through the bonding layer; in the invention, firstly, in the aspect of functionality, the special bonding layer is arranged between the porous sound-absorbing layer and the waterproof layer, so that collaborative optimization of acoustic performance and waterproof performance is realized, and test data show that according to the sound-absorbing performance, the average sound-absorbing coefficient of the porous sound-absorbing layer within the frequency band of 125-4000 Hz reaches 0.65 or above due to the gradient pore structure (the porosity is 60-80%, and the pore diameter is 0.1-2 mm) of the porous sound-absorbing layer; the noise reduction coefficient is larger than or equal to 0.70 and is increased by 300% or above compared with a traditional waterproof roll.

The invention provides an impedance silencing plate for a sound barrier capable of being combined and stacked in multiple layers, which comprises a sound facing surface, a sound backing surface and a plurality of impedance silencing units arranged between the sound facing surface and the sound backing surface, and each impedance silencing unit is a variable cross-section cavity which sequentially extends and penetrates from the sound facing surface to the sound backing surface. A plurality of rows of impedance noise elimination units are arranged on the noise elimination plate, noise is eliminated when passing through the impedance noise elimination units, the purpose of noise elimination and reduction is achieved, and experimental tests prove that the noise reduction coefficient of the impedance noise elimination plate reaches 0.95-1.0. According to the impedance silencing plate, the multiple layers of plates are stacked and combined into the impedance silencing plate, the manufacturing difficulty of the impedance silencing unit is reduced, the manufacturing efficiency of the impedance silencing plate is greatly improved, and the impedance silencing plate is wide in material source, easy to obtain, low in manufacturing cost, light in product weight, good in mechanical strength and fatigue resistance and high in application and popularization value.

The invention discloses a multi-layer composite noise reduction material used in transformer equipment insulating oil, application and an electric reactor, and belongs to the technical field of composite acoustic materials. The cork rubber insulation board is composed of cork rubber and insulation paper boards arranged at the two ends of the cork rubber. One insulating paper board is arranged on the inner wall of an oil tank of the power transformation equipment, the other insulating paper board is provided with a through hole, and a cavity connected with the through hole is arranged in the cork rubber. The structure of the perforated plate and the cavity is easy to form a Helmholtz resonance sound absorption structure, and the structure has a remarkable absorption effect on long-wavelength low-frequency noise. Therefore, the composite material can still achieve the excellent performance that the 100 Hz sound absorption coefficient is larger than 0.3 and the noise reduction coefficient is not smaller than 0.75 in the severe acoustic environment with high sound velocity and long wavelength in oil, and the bottlenecks that a conventional porous material is poor in sound absorption effect in oil and the design of a resonant cavity is harsh are effectively overcome.

This invention discloses an active noise reduction control method, device, air conditioner, and storage medium for an air conditioner, belonging to the field of air conditioning technology. The method includes: acquiring a noise reduction coefficient from each of multiple designated locations within the air conditioner to other designated locations when the air conditioner is off; collecting real noise data generated at each designated location based on the noise reduction coefficient; performing noise reduction processing on a noise reduction module corresponding to the designated location based on the real noise data; acquiring the noise change rate of the real noise data within a preset time period, and determining whether abnormal noise exists based on the noise change rate; and generating a noise anomaly alert when abnormal noise is detected. The method provided by this invention can be applied to energy-saving air conditioners. By calibrating the noise reduction coefficient and collecting real noise data, targeted noise reduction processing can be achieved, thereby improving the overall noise reduction effect; simultaneously, timely maintenance can be performed by identifying abnormal noise.

The invention discloses a metal sound absorber sound barrier design method and device, equipment, a medium and a product, and relates to the technical field of noise control, and the method comprises the steps: determining a target frequency band based on a target sound source; establishing a thermal viscosity-pressure acoustic coupling simulation model of the sound barrier; establishing a model database; scanning the sound barrier thermal viscosity-pressure acoustic coupling simulation model based on the data of the model database, and establishing a simulation database; comparing the sound absorption coefficient obtained by the simulation database with the sound absorption coefficient obtained by the existing theoretical model, and if a deviation exists, correcting the sound absorption coefficient of the simulation database; the maximum noise reduction coefficient and the maximum maximum effective sound absorption bandwidth in the target frequency band serve as optimization targets, and the optimal design parameters and expected performance of the metal sound absorber sound barrier are obtained. Core parameters such as the double-layer distance, the back cavity depth and the micropore diameter can be flexibly adjusted based on the target vibration frequency band, and it is guaranteed that the performance of the sound absorber is optimal.

The utility model discloses an ardealite noise barrier plate, and relates to the technical field of road engineering. A plurality of first concave holes are formed in the surface of the side, close to the road, of the ardealite noise barrier plate at intervals, first micro holes and second micro holes are formed in the ardealite noise barrier plate, and the hole diameter of the first concave holes is larger than that of the first micro holes; and the aperture of the first micropores is larger than that of the second micropores. The first concave holes, the first micropores and the second micropores which are different in aperture are formed, and the aperture of the first micropores is larger than that of the second micropores, so that absorption of low-frequency sound waves can be improved through the first concave holes, absorption of medium-frequency sound waves can be improved through the first micropores, and absorption of high-frequency sound waves can be improved through the second micropores; furthermore, broadband sound absorption is achieved through the multi-stage pore structure, the noise reduction coefficient of the phosphogypsum noise barrier plate is increased, and the sound absorption effect of the phosphogypsum noise barrier plate is improved.

The invention discloses a foam silicate particle sound absorption material and a preparation method thereof, and belongs to the technical field of sound absorption materials. The sound absorption material comprises the following components in parts by weight: 100 parts of foamed silicate particles, 20-30 parts of organic glue and 3-5 parts of mineral fibers. The foam silicate particle sound absorption material is high in strength, silicate particles are excellent in weather resistance, freeze-thaw resistance and fireproof performance, small holes exist between individual particles of the formed sound absorption material, the foam silicate particles are of a porous structure, the viscous internal friction, heat conduction and relaxation effects of the sound absorption material are further improved, and the sound absorption material has a good sound absorption effect. The sound absorption effect can be further improved, the noise reduction coefficient NRC can stably reach 0.75 or above, the noise reduction coefficient NRC can reach 0.80 or above through process matching, and the outdoor acoustic sound absorption material is a high-quality outdoor acoustic sound absorption material superior to sound absorption materials in the market.

The invention relates to collagen nanofiber and lignin composite sponge with an aperture-adjustable layered porous structure, preparation of the collagen nanofiber and lignin composite sponge and application of the collagen nanofiber and lignin composite sponge as a sound absorption material, and belongs to the technical field of noise pollution treatment. The main raw materials of the sound-absorbing sponge are collagen and lignin, collagen nanofiber sponge is used as a framework, and after lignin is doped, the composite sound-absorbing sponge (CLS) with a multi-stage layered pore structure with a loose upper layer and a compact lower layer is formed. Based on the structure, the material shows high porosity (gt; compared with the prior art, the material provided by the invention has the advantages that the material has excellent low-frequency sound absorption performance (the sound absorption coefficient in the frequency range of 2000-6300Hz exceeds 0.9), light weight (10mg / cm < 3 >) and wide-frequency range sound absorption characteristic (the sound absorption coefficient in the frequency range of 2000-6300Hz exceeds 0.9), and meanwhile, the material has extremely excellent low-frequency sound absorption performance, and the noise reduction coefficient NRC of a sample under the thickness of 30mm reaches 0.64 and is far better than that of a natural sound absorption material and a commercial acoustic material which are reported at present.