217 results about "Noise generation" patented technology

The invention relates to a wind noise modeling method and system based on machine learning and application, and belongs to the field of marine acoustics and environmental noise modeling, and the method comprises the steps of data preprocessing and feature extraction, hybrid network model building, hybrid network model training and verification. According to the method, a hybrid network model of multiple linear regression and a multi-layer perceptron is constructed based on a known physical mechanism of wind noise and two main noise generation mechanisms of surface turbulence and bubble oscillation, a linear relation and a non-linear relation are modeled respectively, outputs of the two models are integrated through a weighted fusion strategy, and a multi-layer perceptron model is constructed. Smooth transition modeling from a low-wind-speed linear relation to a high-wind-speed nonlinear relation is achieved.

The invention discloses an anisotropic noise generation method based on local tensor integral field feature modulation, and is applied to the technical field of computer texture generation. The method comprises the following steps: step 1, constructing a global tensor field of spatial anisotropy intensity and direction; step 2, calculating local tensor integral features in a support domain based on the support domain of a Gabor noise kernel function, the local tensor integral features including principal direction features and anisotropic ratio features; step 3, calculating a curvature penalty factor based on the deviation between the local tensor integral feature and the center tensor of the seed point; step 4, based on the local tensor integral features, performing weighted correction on the frequency domain center frequency and Gaussian envelope parameters of the Gabor kernel function; and step 5, generating a final noise texture based on the corrected kernel function. The Gabor kernel function parameter is subjected to weighted correction through the local tensor integral feature and the curvature penalty factor, modulation of the kernel function direction under the high-curvature tensor field is achieved, spectrum leakage, texture fracture and artifacts caused by inconsistent direction changes in the kernel function can be reduced, and the robustness of the kernel function is improved. Therefore, the topological continuity and the simulation fidelity of the anisotropic noise texture at the complex structure are improved.

This utility model belongs to the technical field of sewage treatment equipment, and provides an open channel ultraviolet disinfection device, including a mounting plate, a disinfection box, a cleaning frame, brushes, connecting ropes, and a drive mechanism. The mounting plate has multiple vertically penetrating and parallel strip-shaped mounting holes, and through holes are respectively opened at the four corners of the mounting plate. The lower end of the disinfection box passes through the corresponding strip-shaped mounting holes. The disinfection box contains multiple ultraviolet lamps. The cleaning frame is vertically movable and positioned below the mounting plate. The brushes are connected to the cleaning frame, and one end of the connecting rope passes through the corresponding through hole and connects to the cleaning frame. This utility model uses a drive mechanism to move the connecting ropes to achieve the lifting and lowering of the cleaning frame, thereby cleaning the lower end of the disinfection box. Because there are four connecting ropes, the cleaning frame is evenly stressed when the drive mechanism drives the connecting ropes, preventing the cleaning frame from tilting and ensuring stable lifting and lowering operation, thus reducing noise generation.

According to the shell module, the examination couch and the scanning equipment, the shell module comprises a shell assembly and a sliding rail assembly, the shell assembly comprises a plurality of shells, the multiple shells are sequentially arranged in a sleeving mode, and any two adjacent shells in the multiple shells are in sliding connection through the sliding rail assembly in the vertical direction. In other words, the shell assembly can guide the movement of the two adjacent shells in the vertical direction through the sliding rail assembly, so that the shell assembly can only move in the vertical direction. In this way, the situation that in the movement process of the whole shell module, due to the fact that the shell modules are subjected to external force, the shells between different layers rub against one another, noise, abnormal sounds or jamming are generated is avoided, and the use experience of the examining table with the shell module is improved.

The application provides a flow control method based on three-curved-surface fish scale bionic structure, comprising the following steps: S1, constructing a main structure of an impeller blade, including a suction surface e and a pressure surface f, and fish scale areas g with multiple fish scale bionic structure coupling elements arranged regularly are arranged on the suction surface e and the pressure surface f; S2, constructing and designing a single fish scale bionic structure coupling element, including a bottom surface adhering to a blade surface, a top surface in a fish scale structure, and a rear side cylindrical surface; the top surface comprises two groups of parallel fold surfaces, and each group of fold surfaces is composed of three quadrilateral surfaces; a space rectangular coordinate system is established with a front end point of the bottom surface as an origin, and the fish scale bionic structure coupling element is constructed in the space rectangular coordinate system; and S3, establishing multiple fish scale bionic structure arrangement rules. The application can improve the fluid flow characteristics of the blade surface and reduce noise generation based on the control of flow by bionic structure.

The expansion valve comprises a valve body assembly, a switch piece and a silencing assembly, the valve body assembly is provided with a valve port, a first side and a second side, and the valve port is located between the first side and the second side and communicates with the first side and the second side; the switch piece and the noise reduction assembly are arranged on the first side and / or the second side, the noise reduction assembly is connected to the valve body assembly, a channel is formed between the noise reduction assembly and the valve body assembly, the noise reduction assembly is provided with a porous noise reduction part, the switch piece is movably located between the noise reduction assembly and the valve port, and a first flow channel is formed between the switch piece and the valve body assembly; when the flowing direction of the working medium is from the valve port to the silencing assembly, the porous silencing part is closed by the switch piece; and when the flowing direction of the working medium is from the silencing assembly to the valve port, the porous silencing part is opened. According to the expansion valve, the problems that a refrigerant flowing through the valve port is prone to cavitation to generate noise, and bubbles are prone to being generated in the refrigerant before flowing through the valve port to generate noise can be solved.

The invention relates to a remote sensing image reverse editing method for a diffusion model, and belongs to the field of computer vision. The strong generation and editing capability of the diffusion model brings a series of potential safety hazards, and the image reverse editing technology aims at adding a layer of protective noise to an image, so that the diffusion model is difficult to output an ideal editing result. In order to solve the problems that an existing anti-editing technology is poor in effect on a remote sensing image and generally faces low efficiency and obvious protection traces, the invention provides an efficient and hidden protection scheme which comprises the following three steps: step 1, generating anti-editing disturbance based on hidden space high-frequency component suppression; step 2, noise generation network training based on single-time forward transmission; and step 3, concealment enhancement based on noise perception graph constraint. The method can effectively resist malicious image editing based on a diffusion model, is suitable for the field of remote sensing images, and gives consideration to safety, efficiency and image quality.

This invention provides a technology that reduces or cancels out the noise of massage devices using a different approach than conventional methods. [Solution] The massage device 100 comprises a sound signal output unit 21 and a speaker 3. The sound signal output unit 21 outputs an output sound signal that includes a suppression sound signal that weakens or cancels out noise generated from the device 100. The speaker 3 converts the output sound signal into sound and outputs the sound. The sound signal output unit 21 has a sound selection unit 211. Based on the noise generation conditions, the sound selection unit 211 selects a suppression sound signal from among a plurality of recorded sound signals pre-recorded as sound information 11 stored in the storage unit 1,902.

The application discloses a kind of class imbalance table data processing methods based on contrast constraint diffusion generation, belong to data processing technical field, it includes using binary classification table dataset to generate model training, obtain the generation model based on noise generation minority class's synthetic latent representation, generate model is randomly generated with several noise inputs, diffusion modeling branch is denoised to each noise and obtains the synthetic latent representation of minority class of each noise, using decoding module is decoded to each synthetic latent representation, obtains synthetic table sample;Data filtering is carried out to all synthetic table samples, then all synthetic table samples after filtering are merged with table dataset, and enhanced imbalance table data are obtained.The application introduces contrast learning branch in the process of generating minority class sample, effectively overcome the deficiency existing in class imbalance table data processing of existing oversampling method and general generation model.

This disclosure provides a compressor that suppresses noise generation by suppressing variations in the gap between the muffler and the bearing, for bearings having discharge holes. [Solution] A rotary compressor comprising: a shaft extending in a first direction; a motor that drives the shaft; a first bearing that supports the shaft and has a discharge hole through which compressed refrigerant is discharged; a cylinder that forms a cylinder chamber inside; a roller fixed to the shaft and rotating eccentrically in the cylinder chamber; and a muffler arranged to cover the discharge hole, wherein the motor, the muffler, the first bearing, and the cylinder are arranged in order along the first direction; the first bearing has a boss portion that supports the shaft and protrudes toward the muffler; the muffler has an opening through which the boss portion passes; and the positioning structure determines the position of the muffler relative to the first bearing such that the first bearing or the muffler has a gap with the opening around the entire circumference in the outer direction of the boss portion.

The invention provides a loudspeaker control method and electronic equipment, the electronic equipment comprises a loudspeaker, the loudspeaker comprises a voice coil, a rigidity adjusting assembly and a displacement monitoring assembly are arranged in the loudspeaker, and the displacement monitoring assembly is used for monitoring the rigidity adjusting assembly when the rigidity adjusting assembly moves. The method comprises the steps that when the displacement of the rigidity adjusting assembly relative to the balance position exceeds a first interval range or the moving speed of the rigidity adjusting assembly changes suddenly, an input signal of the voice coil is changed, and the input signal of the voice coil is used for driving the voice coil and the rigidity adjusting assembly to move. By adopting the loudspeaker, the problems of distortion, noise generation, incapability of rebounding and the like caused by overlarge amplitude of the vibrating diaphragm can be solved, the loudspeaker can be prevented from losing efficacy, the maximum capability of the loudspeaker can be effectively exerted, and the stability of the loudspeaker under large amplitude can be improved.

The invention discloses an analysis and prediction method for high-frequency noise of a pod propeller, and the method comprises the following steps: S1, obtaining flow field original data and corresponding high-frequency noise monitoring data of the pod propeller in a working state, and carrying out the preprocessing; and S2, constructing a flow field-noise coupling analysis framework based on the separation vortex model, and setting a time step length and a calculation frequency matched with actual working conditions. The invention relates to the technical field of ship propeller noise analysis and prediction. According to the pod propulsor high-frequency noise analysis and prediction method, flow field vortex structure characteristics can be captured by constructing a flow field-noise coupling analysis framework and processing the preprocessed flow field data, and the contribution degree of each vortex unit to the high-frequency noise is accurately calculated based on a vortex structure and noise generation correlation mechanism, so that the high-frequency noise analysis and prediction method is provided for the high-frequency noise analysis and prediction of the pod propulsor. The vortex units leading the noise source are screened, dynamic positioning of the high-frequency noise source is achieved by combining the space-time position information of the vortex units, and the source of noise generation can be deeply known.

This invention discloses an air-cooled energy-saving distribution transformer, including a transformer housing and an air-cooling device and a heat dissipation device disposed on one side of the transformer housing. The transformer housing is equipped with a noise reduction mechanism. The air-cooling device includes a cooling fan, a cooling block, a cooling plate, and a first heat dissipation fan. The heat dissipation device includes a heat dissipation window, and a second heat dissipation fan and a dustproof mechanism are disposed outside the heat dissipation window. The noise reduction mechanism includes a first honeycomb sound insulation board, sound insulation felt, sound insulation cotton, and a second honeycomb sound insulation board. This invention achieves the purpose of reducing the air temperature inside the transformer housing by setting up the air-cooling device, thereby enhancing the heat dissipation effect of the main body of the distribution transformer. The heat dissipation device dissipates the high temperature inside the transformer housing while the dustproof net adsorbs dust inside the transformer housing. The noise reduction mechanism absorbs the noise generated by the main body of the distribution transformer, reducing noise and thus minimizing the impact on the daily lives of surrounding residents.

The utility model discloses a cooling tower spray water noise reduction device. High-temperature circulating water is uniformly sprayed to the surface of filler through a water distribution system to form a water film or water drops, the water film or water drops fall into a water pool at the bottom of the cooling tower after the water temperature is reduced and collide with accumulated water in the water pool to generate noise, and the noise belongs to high-frequency noise and disturbs residents. The device comprises a cooling tower, a spray water buffer rack is placed at the bottom of the cooling tower, the spray water buffer rack comprises an upper buffer plate, a lower buffer plate and a buoy, the upper buffer plate and the lower buffer plate are connected and fixed through a plurality of stand columns, two circles of supporting legs are fixed at the bottom of the lower buffer plate, and the two circles of supporting legs are fixed at the bottom of the lower buffer plate. The bottoms of the supporting legs are fixed on the buoy; a water collecting hole is formed in the middle of the lower buffer plate and is connected with a water conduit. The cooling tower spray water noise reduction device is used for cooling tower spray water noise reduction.

The invention provides a large and medium-sized water surface ship radiation noise generation and control method, system and device covering a scale effect, and a storage medium, and belongs to the field of large and medium-sized water surface ship radiation noise prediction and analysis. The difference of contribution degrees of machinery, hydrodynamic force and propeller noise to underwater radiation noise in different navigation states is considered, a multi-modal noise separation method is adopted to separate coupling components, and a ship underwater radiation noise source is simplified into a noise source model along a ship body; a ship scale effect analysis and multi-resolution time-frequency analysis technology is introduced, and a generation mechanism of ship radiation noise is simplified into underwater radiation noise caused by shell vibration caused by the fact that a plurality of distributed low-frequency loads act on a ship structure; large and medium water surface ship radiation noise passing characteristic rules are disclosed, and a ship navigation state underwater radiation noise simulation theoretical model is established. According to the method, an effective means is provided for generation and control of underwater noise of the ship, and optimization of ship design and reduction of underwater radiation noise are facilitated.

This utility model relates to the field of scroll compressor technology, and particularly to an INJ tube mounting structure and a scroll compressor. The INJ tube mounting structure includes a silencer body mounted on the upper part of the fixed scroll plate of the scroll compressor, with a first through hole on the silencer body; an INJ tube body passing through the upper shell component of the scroll compressor, the INJ tube body passing through the first through hole; a positioning member mounted on the upper part of the fixed scroll plate, the bottom end of the INJ tube body inserted into the positioning member, the bottom end of the INJ tube body communicating with the compression chamber of the scroll compressor; and a sealing assembly disposed on the INJ tube body, the sealing assembly covering the upper part of the first through hole. This INJ tube mounting structure and scroll compressor can solve the problem of noise generated by airflow passing through the gap when the INJ tube passes through the silencer.

The application relates to an adjustable motor mounting rack for a new energy vehicle, and belongs to the technical field of motor mounting racks for new energy vehicles, which comprises a connecting base, the top surface of the connecting base is provided with T-shaped limiting grooves on the left side and the right side, the inner walls of the two T-shaped limiting grooves are jointly fixed with supporting groove blocks used for clamping fixation through sliding T-shaped limiting blocks, the inner wall of the supporting groove block is provided with an output motor used for rotary output, the top surface of the output motor is clamped with a protective cover block used for wrapping protection, the bottom surface of the protective cover block is provided with a plurality of connecting components used for fixed connection, the left and right surfaces of the connecting base are provided with sliding openings used for movement, the application can ensure that the output shaft position can be adjusted after the motor is fixed, the problem of dismounting and re-installing the motor is avoided, the fastening of the motor is more and more strong during the overall operation, the problem of motor loosening and noise generation is avoided, and even the normal use function of the motor can be directly affected.

The utility model discloses a magnetically controlled reactor which comprises a first installation support, the upper surface of the first installation support is connected with a group of iron core yoke frames, the outer surface of each iron core yoke frame is sleeved with a coil, and the two ends of each coil are electrically connected with electrode plates. According to the device, through the arrangement of the first mounting bracket, the second mounting bracket, the iron core yoke frame, the coil, the electrode plate, the sound insulation cover and the sound absorption plate, noise generated by a magnetostriction phenomenon can be uniformly absorbed by utilizing the sound absorption plate made of a polyester fiber material, and the noise is blocked by utilizing the sound insulation shell, so that noise reduction protection of the magnetically controlled reactor is realized, and the service life of the magnetically controlled reactor is prolonged. According to the magnetically controlled reactor, the problem that noise generated during work of the magnetically controlled reactor causes interference to the environment is solved, the heat dissipation assembly, the heat dissipation fan, the dust cover and the heat dissipation air holes are arranged, the heat dissipation fan can be used for blowing air into the sound insulation shell and discharging heat, air blowing cooling of the magnetically controlled reactor is achieved, and the magnetically controlled reactor can be safely and effectively used conveniently.

A system and method for controlling a VTOL aircraft to minimize acoustic noise. In a hover mode, the aircraft may be controlled to utilize a blade pitch angle and corresponding angle of attack range which minimizes variations in the boundary layer separation location to a point or narrow region, which reduces noise generation. The propeller blades used in the system are configured to have a reduced or no shift of the point of flow separation on the airfoil as a function of angle of attack during the hover mode. The blade design may trade off overall blade efficiency in exchange for the reduced noise during hover.

This invention relates to the field of shock absorber technology, specifically to a composite noise-absorbing and vibration-damping chassis for heat pumps. The chassis includes a chassis body with a frame fixedly mounted on its bottom surface. It also includes a compressor vibration damping seat and a noise-dampening cover. The compressor vibration damping seat is fixedly mounted on the upper surface of the chassis body. The noise-dampening cover has a rectangular, hollow, bottomless structure and is detachably mounted on the outside of the compressor vibration damping seat. The compressor vibration damping seat in this invention can achieve both rigid and flexible connections. Therefore, a rigid connection can be used during transportation to maintain the stability of the compressor, while a flexible connection can be used during use to reduce resonance and thus reduce noise generation.

The utility model discloses an intelligent sound box, which is used for solving the problem that a sound post assembly of an existing intelligent sound box is easy to generate noise in a reciprocating motion process. The intelligent sound box of the utility model comprises a sound box housing, a sound post assembly and a driving assembly. The sound box shell is internally provided with the driving assembly, and the driving assembly is connected with the sound post assembly to drive the sound post assembly to reciprocate relative to the sound box shell along a first direction; and the driving assembly is connected with a noise reduction assembly.

The utility model relates to the technical field of composite doors and windows, in particular to a composite door and window with a noise reduction function, which comprises a composite door and window, a fixing frame is fixedly connected to the front side of the composite door and window, a noise reduction plate is slidably connected to the inner side of the fixing frame, and a plurality of threaded grooves are formed in the bottom of the noise reduction plate. According to the utility model, through the arrangement of the fixing frame, the noise reduction plate, the threaded groove, the mounting plates, the mounting holes, the mounting bolts, the handle, the fixing plate, the insertion grooves, the sliding grooves and the plug pins, when noise is generated outside, the wooden sound absorption plate and the polyurethane foam layer can absorb the noise outside; the hollow rubber bag can provide support for the polyurethane foam layer and further absorb noise, the polyester fiber sound insulation plate can isolate the noise, and the design of the noise reduction plate and the connecting component thereof can reduce vibration transmission so as to reduce the noise, so that the indoor quietness is improved.

The utility model provides a medical oxygen generator's noise reduction device, the medical oxygen generator's noise reduction device includes Y-type air inlet pipe, Y-type air inlet pipe includes straight pipe portion and Y-type pipe portion, straight pipe portion one end is connected with the second slip pipe of Y-type pipe portion, straight pipe portion one end is equipped with the first slip pipe that connects with the Y-type pipe portion, the first slip pipe is equipped with the second slip pipe, the second slip pipe is equipped with the second slip pipe, and the second slip pipe is equipped with the second slip pipe. The second sliding pipe is sleeved with the first sliding pipe in a sliding mode, a buffering corrugated pipe part is integrally formed on the first clamping ring, and the other end of the buffering corrugated pipe part is connected with the second clamping ring on the straight pipe part. When airflow enters and gathers along the two pipe ends of the Y-shaped pipe part, the second sliding pipe and the first sliding pipe can slide when the airflow gathers and impacts, and the buffering corrugated pipe part can play a role in damping and buffering, so that vibration noise generated by airflow gathering is reduced, and the service life of the air conditioner is prolonged. A plurality of lubricating oil storage annular grooves used for being filled with solid lubricating oil are formed in the inner wall of the first sliding pipe, so that sliding between the first sliding pipe and the second sliding pipe is smoother, and noise generated by sliding is avoided.

The invention relates to the technical field of data enhancement, and discloses an infrastructure resource library data enhancement method, system and device based on artificial intelligence and a medium, comprising: constructing an infrastructure contract format and a noise knowledge engine, obtaining contract data, initiating through an adversarial noise generation agent, and based on the infrastructure contract format and the noise knowledge engine, obtaining the contract data; generating antagonism data under the fact constraint; and constructing a target contract key clause identification model to obtain a contract identification result and a loss value, generating an instant reward signal or a delay penalty signal of the adversarial noise generation agent, and performing strategy updating on the adversarial noise generation agent. According to the method, a closed-loop online data enhancement architecture based on fact constraint and antagonistic learning is introduced, so that the fidelity and rationality of generated data are remarkably improved, the efficiency and pertinence of data enhancement are greatly improved, and co-evolution of a data generator and a data learner is realized.

The invention discloses a noise reduction windscreen wiper strip and a processing method, the noise reduction windscreen wiper strip comprises a rubber strip main body and at least one supporting piece, and the supporting piece is arranged in the rubber strip main body and used for reducing noise generated when the rubber strip main body wipes glass by increasing the strength of the rubber strip main body. The supporting piece is arranged in the rubber strip body, the supporting piece is used for enhancing the attribute of the windscreen wiper strip, the strength of the windscreen wiper strip is enhanced, the windscreen wiper strip is not prone to generating noise due to inertia when the direction of the windscreen wiper is changed, and therefore the noise reduction effect is achieved. The supporting piece is arranged in the rubber strip main body, so that high-frequency vibration or up-and-down shaking of the wiper strip during wiping can be prevented, the structural rigidity is increased, the inherent frequency is changed, resonance caused by friction between the wiper strip and glass and speed change is reduced, pressure distribution of the wiper strip is improved, pressure of all parts of the wiper strip is uniform, local deformation of the wiper strip is avoided, and the service life of the wiper strip is prolonged. And the fitting degree of the windscreen wiper strip and the glass surface is ensured, so that rainwater is ensured to be completely wiped.

The invention relates to a power network lightweight attack path generation method and system, and belongs to the technical field of attack path generation, and the method comprises the steps: obtaining the power network flow data of a target regional power grid in real time, carrying out the preprocessing, eliminating the sampling difference between heterogeneous devices, and obtaining the preprocessed time sequence aligned heterogeneous data; carrying out heterogeneous graph modeling based on the preprocessed time sequence aligned heterogeneous data to obtain a combined heterogeneous graph; wherein the heterogeneous graph modeling comprises the steps of extracting differentiated node features based on a source equipment type, and constructing edges with interaction features based on power business logic and a protocol type to form a protocol interaction element path; inputting the combined heterogeneous graph into a pre-trained potential attack path generation model to obtain a potential attack path probability; wherein the potential attack path generation model is obtained by performing joint adversarial training on the potential attack path generation model and the noise generation model; a suspicious path score is calculated based on the potential attack path probability, and an attack path is generated based on the suspicious path score.

The application discloses a volute assembly, a fan assembly and an air treatment device. The volute assembly comprises two oppositely arranged side plates, at least one of which is provided with an air inlet through hole; a surrounding plate connected with the two side plates respectively, the two side plates and the surrounding plate cooperatively defining a mounting cavity, the surrounding plate being provided with an air outlet, the surrounding plate comprising a volute tongue arranged adjacent to the air outlet and an air duct plate arranged opposite to the volute tongue; and a convex rib arranged on the side plate and located in the mounting cavity. Thus, the convex rib is connected with the air duct plate to reduce the speed of airflow flowing to the air outlet, change the flow direction of part of the airflow, reduce the risk of airflow backflow, and reduce the problems of noise or abnormal sound caused by the impact of airflow backflow on the volute tongue, so as to reduce the noise of the volute assembly.

The utility model discloses a kind of cover assembly capable of reducing clutch driving disc noise, including gear and cover plate, the intermediate position of gear is equipped with protruding bearing sleeve;The outer periphery of bearing sleeve is equipped with washer, cover plate is successively sleeved in the upper surface of washer;Correspondingly, limit slot is opened in the contact place of cover plate and washer.Correspondingly, limit slot is opened in the contact place of cover plate and washer.The utility model uses the bearing sleeve of gear center as the positioning column of washer without changing the existing gear and cover structure, restricts the position of washer by the height of bearing sleeve, solves the inconvenient installation of washer and the situation that it is easily deviated in use, avoids the problem that noise is generated by washer deviation, solves the abnormal sound problem of cover with minimum technical improvement and lowest improvement cost.

The utility model discloses a low-noise circular cooling tower, which relates to the technical field of cooling towers and comprises a base, a tower body fixedly arranged at the top of the base, a connecting seat fixedly arranged at the top of the tower body, a sound insulation layer fixedly arranged on the outer side wall of the tower body, a water inlet pipe fixedly arranged in the connecting seat, and a water outlet fixedly arranged on the pipe wall of the water inlet pipe. And a first filler is fixedly arranged on the inner side wall of the connecting seat. According to the cooling tower, the sound insulation layer is adopted for sound insulation, the sound insulation cover is arranged on the outer side wall of the tower body so as to prevent noise from being too large when an existing cooling tower is used and avoid noise pollution from being easily generated, noise is reduced, it is guaranteed that working efficiency of workers is improved, and the noise reduction effect is achieved due to the fact that air circulation is needed on the lower side. No protection device is arranged near the cooling tower, so that small animals such as snakes and mice are prevented from easily falling into the water pool to pollute water in the water pool, and the isolation net is used for isolation, so that the cooling tower is very convenient to use.

The utility model discloses an air pipe noise reduction device of a heating ventilation air conditioner, the edge part of a mounting batten is rotatably connected with a sound-absorbing cotton plate, the edge part of the sound-absorbing cotton plate is rotatably connected to the inner side of a connecting seat through a movable shaft, and the outer side of the movable shaft is sleeved with a torsion spring; the flow speed of airflow is controlled through the staggered sound-absorbing cotton plates, the probability that noise is generated when the airflow passes through the installation inner box is reduced, and when the airflow pressure is large, the airflow pressure borne by the sound-absorbing cotton plates is relatively large through the installation battens, the connecting bases, the movable shafts and the torsion springs, so that the noise is reduced, and the noise is reduced. Therefore, the sound-absorbing cotton plate drives the torsion spring to twist and deflect, the air flow pressure is reduced and buffered, the phenomenon of backflow caused by the fact that the air flow cannot quickly pass through the air pipe due to the fact that the air flow pressure is large is avoided, the passing efficiency of the air flow is guaranteed, meanwhile, the contact face between the sound-absorbing cotton plate and the pressure air flow is increased, and the noise reduction effect is guaranteed.