Silencing device, air conditioner and silencing control method

Abstract

The invention discloses a muffling device, an air conditioner and a muffling control method.The muffling device comprises a shell, an acoustic metamaterial structure and a sound conduction interface, the acoustic metamaterial structure is arranged in a muffling cavity of the shell and is constructed to be a continuous swirling flow channel capable of prolonging a sound wave propagation path in the muffling cavity, and the sound conduction interface is arranged in the shell; the sound conduction interface is arranged at the joint of the shell and the valve pipe. Noise firstly enters the shell through the sound conduction interface, so that sound wave reflection loss is avoided; in the silencing cavity, the continuous swirling flow channel of the acoustic metamaterial structure forces the propagation path of sound waves to be greatly prolonged in a limited space, so that low-frequency resonance noise is effectively inhibited; meanwhile, a physical closed environment provided by the shell isolates external aging factors, and the problems that a traditional rubber damping material loses efficacy due to hardening and the performance of sound insulation cotton is degraded are solved; according to the invention, the risk of new resonance caused by frequency deviation is fundamentally avoided, and synchronous control and long-term reliable noise elimination of low-frequency noise are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioners, and in particular relates to a silencer device, an air conditioner and a silencer control method. Background Art

[0002] In air conditioner outdoor units, the compressor, as the primary moving component, can generate vibration and noise. This noise is transmitted through the large and small valve pipes. When the compressor's operating frequency approaches the piping modal frequency, severe vibration and noise can occur. Furthermore, piping vibration can cause structural deformation, reducing system reliability. Therefore, controlling compressor piping vibration and noise is essential.

[0003] A common method for reducing pipeline vibration noise in the prior art is to add counterweights to the pipeline to reduce the pipeline modal frequency, thereby offsetting the compressor excitation frequency and the pipeline resonant frequency to avoid resonance. While adding counterweights can partially solve the vibration noise problem, it may cause resonance at other pipeline frequencies, resulting in low reliability and ineffectiveness. Another method is to add damping materials to the pipeline, such as rubber blocks, damping blocks, polyurethane, and other highly elastic materials, to dissipate pipeline vibration energy. However, in actual use, vibration-damping rubber pads are subject to various factors due to long-term exposure to the environment, resulting in the breakage of elastic molecular chains, destruction of cross-linking structures, and material aging. This causes the vibration-damping pads to harden, lose their original elasticity and softness, and lose their vibration-damping effect. Another method is to wrap the compressor pipeline system with sound insulation cotton. Although the sound insulation cotton can effectively reduce high-frequency noise, its noise reduction performance gradually decreases with the age of the air conditioner, and the sound insulation cotton is not very effective in reducing low-frequency noise. Therefore, there is an urgent need for a noise reduction device that can simultaneously control low-frequency noise and provide long-term stability. Summary of the Invention

[0004] In view of this, the present invention provides a silencer, an air conditioner and a silencer control method, which solve the technical problem that traditional silencers may cause frequency resonance and instability in other pipelines.

[0005] In order to solve the above problems, according to one aspect of the present application, an embodiment of the present invention provides a silencer device, which includes a shell, an acoustic metamaterial structure and a sound conduction interface. The shell has a silencer chamber inside, and the acoustic metamaterial structure is arranged in the silencer chamber and is constructed as a continuous vortex flow channel that can extend the sound wave propagation path in the silencer chamber. The sound conduction interface is arranged at the junction of the shell and the valve tube.

[0006] In some embodiments, the acoustic metamaterial structure includes a plurality of dispersed metamaterial units, and a Z-shaped flow channel is formed between adjacent metamaterial units; wherein the Z-shaped flow channel can cover the space within the anechoic chamber.

[0007] In some embodiments, the acoustic conductive interface includes an acoustic diaphragm and an acoustic film, and the acoustic film is embedded in the acoustic diaphragm;

[0008] And / or, the acoustic partition is an acrylic board, and the acoustic film is a PVDF film.

[0009] In some embodiments, there are two acoustic films, and the two acoustic films correspond to the pipe openings of the large valve pipe and the small valve pipe of the air conditioner outdoor unit respectively.

[0010] In some embodiments, the muffler device further comprises a porous attraction layer, wherein the porous attraction layer is filled in the muffler chamber;

[0011] And / or, the porous attraction layer is sound-absorbing cotton.

[0012] In some embodiments, the silencing device further includes a helium injection assembly, which is connected to the silencing chamber through an inflation port and is used to change the medium density in the silencing chamber.

[0013] In some embodiments, the helium injection assembly includes a helium storage tank, an inflation pump body, a controller, and an acoustic sensor. The acoustic sensor is arranged at the inflation port to sense the noise frequency inside the silencing cavity. The helium storage tank is connected to the inflation pump body, and the inflation pump body is connected to the controller. The controller is configured to adjust the injection amount of helium according to the noise frequency.

[0014] According to another aspect of the present application, an embodiment of the present invention provides an air conditioner, which includes a large valve tube, a small valve tube and the above-mentioned silencer, and the shell of the silencer is installed on the side panel of the air conditioner and covers the large valve tube and the small valve tube.

[0015] According to another aspect of the present application, an embodiment of the present invention provides a noise reduction control method, which uses the above-mentioned noise reduction device and includes:

[0016] The acoustic conduction interface receives the noise transmitted by the valve tube;

[0017] The noise enters the anechoic chamber inside the shell and propagates along the continuous swirling flow channel of the acoustic metamaterial structure, consuming sound energy through multiple reflections.

[0018] In some embodiments, the noise reduction control method further includes:

[0019] injecting helium into the anechoic chamber to change the density of the medium in the chamber;

[0020] Detecting the noise frequency in the anechoic chamber;

[0021] The helium injection amount is adjusted according to the detected noise frequency so that the maximum noise reduction frequency of the noise reduction device matches the detected noise frequency.

[0022] In some embodiments, adjusting the helium injection amount includes:

[0023] Call the pre-stored data on the relationship between helium density and anechoic frequency;

[0024] determining a target helium density based on the detected noise frequency and the corresponding relationship data;

[0025] Controlling the inflation pump to adjust the amount of helium injected so that the density of the medium in the cavity reaches the target density;

[0026] The corresponding relationship data is generated by the following steps: establishing an acoustic model based on the structural parameters of the silencer and the initial helium density; calculating the silencer performance under different helium densities through parametric scanning to obtain the variation pattern of the maximum silencer frequency with the helium density.

[0027] Compared with the prior art, the muffler of the present invention has at least the following beneficial effects:

[0028] The silencer device provided by the present invention includes a shell, an acoustic metamaterial structure and a sound conduction interface. The shell has a silencer chamber inside. The acoustic metamaterial structure is arranged in the silencer chamber and is constructed as a continuous vortex flow channel that can extend the sound wave propagation path in the silencer chamber. The sound conduction interface is arranged at the junction of the shell and the valve tube.

[0029] In the present invention, the valve tube serves as a transmission channel for vibration noise, and the sound waves it generates are first efficiently coupled through the sound conduction interface into the closed sound-absorbing chamber inside the shell, avoiding the loss of sound wave reflection; in the chamber, the continuous vortex flow channel of the acoustic metamaterial structure forces the sound wave to greatly extend the propagation path in a limited space, significantly increasing the interaction time and distance between the sound wave and the structure, and continuously converting the sound energy into heat energy and dissipating it through enhanced sound scattering, interference and viscous friction effects, thereby effectively suppressing low-frequency resonant noise; at the same time, the physically closed environment provided by the shell isolates external aging factors, so that the sound absorption performance of the acoustic metamaterial structure can be maintained stably for a long time, overcoming the problems of hardening failure of traditional rubber damping materials and performance degradation of sound insulation cotton; in addition, the structure actively attenuates broadband sound energy without changing the modal frequency of the pipeline, fundamentally avoiding the risk of new resonance caused by frequency offset, and realizing synchronous control of low-frequency noise and long-term reliable sound absorption.

[0030] The air conditioner provided by the present invention is designed based on the above-mentioned silencer device. Its beneficial effects can be found in the beneficial effects of the above-mentioned silencer device, which will not be described in detail here.

[0031] The noise reduction control method provided by the present invention is designed based on the above-mentioned noise reduction device. Its beneficial effects can be found in the beneficial effects of the above-mentioned noise reduction device, which will not be described in detail here.

[0032] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 1 is a schematic structural diagram of a muffler device provided by an embodiment of the present invention;

[0035] Figure 2 is a perspective view of a muffler provided by an embodiment of the present invention;

[0036] Figure 3 1 is a schematic diagram of the structure inside a shell of a muffler device provided by an embodiment of the present invention;

[0037] Figure 4 This is a bottom-view perspective view of a muffler provided by an embodiment of the present invention;

[0038] Figure 5 1 is a schematic structural diagram of a porous attraction layer in a muffler device provided by an embodiment of the present invention;

[0039] Figure 6 1 is a schematic structural diagram of a helium storage tank in a muffler device provided by an embodiment of the present invention;

[0040] Figure 7 This is a principle block diagram of a helium storage tank in a muffler device provided by an embodiment of the present invention;

[0041] Figure 8 This is a schematic structural diagram of a muffler provided by an embodiment of the present invention in combination with a side panel of an air conditioner;

[0042] Figure 9is a structural schematic diagram of an air conditioner provided by an embodiment of the present invention;

[0043] Figure 10 This is a control flow chart of a noise reduction control method provided by an embodiment of the present invention.

[0044] in:

[0045] 1. Shell; 2. Acoustic metamaterial structure; 21. Metamaterial unit; 3. Acoustic conduction interface; 31. Acoustic diaphragm; 32. Acoustic film; 4. Valve tube; 41. Large valve tube; 42. Small valve tube; 5. Porous attraction layer; 6. Helium injection assembly; 61. Helium storage tank; 62. Inflatable pump body; 63. Controller; 64. Acoustic sensor; 7. Side panel. DETAILED DESCRIPTION

[0046] To further illustrate the technical means and effects employed by the present invention to achieve its intended objectives, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention is provided in conjunction with the accompanying drawings and preferred embodiments. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0047] In the description of the present invention, it should be clarified that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence; the terms "vertical", "transverse", "longitudinal", "front", "back", "left", "right", "up", "down", "horizontal", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention, and do not mean that the devices or elements referred to must have a specific direction or position, and therefore cannot be understood as limiting the present invention.

[0048] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0049] Example 1

[0050] This embodiment provides a muffler device, such as Figure 1-8As shown, the silencing device includes a shell 1, an acoustic metamaterial structure 2 and a sound conduction interface 3. The shell 1 has a silencing chamber inside. The acoustic metamaterial structure 2 is arranged in the silencing chamber and is constructed as a continuous vortex flow channel that can extend the sound wave propagation path in the silencing chamber. The sound conduction interface 3 is arranged at the junction of the shell 1 and the valve tube 4.

[0051] As a component of the compressor pipeline, the valve tube 4 is directly connected to the shell 1 at the joint via the acoustic conduction interface 3, forming an interface for sound wave transmission. The shell 1 contains an internal anechoic chamber. The acoustic metamaterial structure 2 is fixedly installed in this chamber and is designed with a continuously convoluted flow channel. Therefore, the acoustic metamaterial structure 2 is completely located within the internal space of the shell 1. The acoustic conduction interface 3 is located at the junction of the shell 1 and the valve tube 4, ensuring that sound waves can be efficiently transmitted from the valve tube 4 to the anechoic chamber of the shell 1 for subsequent processing. Among them, the role of the shell 1 is to provide a sealed anechoic chamber, serving as a physical container for accommodating the acoustic metamaterial structure 2 and isolating it from external environmental interference. The role of the acoustic metamaterial structure 2 is to significantly extend the propagation path of the sound wave within the chamber through the design of its internal continuous convoluted flow channel, increase the interaction time between the sound wave and the structure, and thus promote the dissipation of sound energy. The role of the acoustic conduction interface 3 is to optimize the transmission efficiency of the sound wave from the valve tube 4 to the shell 1, reduce the reflection loss of the sound wave at the joint, and ensure that vibration noise is effectively introduced into the anechoic chamber.

[0052] During the specific working process, the vibration noise sound waves generated by the valve tube 4 are first efficiently coupled into the silencing chamber of the shell 1 through the sound conduction interface 3; in the silencing chamber, the sound waves are guided to the continuous vortex flow channel of the acoustic metamaterial structure 2, which forces the sound waves to repeatedly return and propagate, extending the path length and increasing the propagation distance of the sound waves in a limited space; this extended path design enhances the interference, scattering and friction effects of the sound waves, causing the sound energy to be gradually converted into heat energy and attenuated, ultimately reducing the noise level; at the same time, the closed structure of the shell 1 prevents the leakage of sound waves, ensuring that the silencing process is efficiently completed in the chamber.

[0053] In this embodiment, the valve tube 4 serves as a transmission channel for vibration noise, and the sound waves it generates are first efficiently coupled into the closed anechoic chamber inside the shell 1 through the sound conduction interface 3, avoiding sound wave reflection loss; in the chamber, the continuous swirling flow channel of the acoustic metamaterial structure 2 forces the sound waves (especially low-frequency sound waves) to greatly extend the propagation path in a limited space, significantly increasing the interaction time and distance between the sound waves and the structure, and continuously converting the sound energy into heat energy and dissipating it through enhanced sound scattering, interference and viscous friction effects, thereby effectively suppressing low-frequency resonant noise; at the same time, the physically closed environment provided by the shell 1 isolates external aging factors (such as oxidation and temperature change), so that the anechoic performance of the acoustic metamaterial structure 2 can be maintained stably for a long time, overcoming the problems of hardening failure of traditional rubber damping materials and degradation of sound insulation cotton performance; in addition, the structure actively attenuates broadband sound energy without changing the pipeline modal frequency (such as the counterweight method), fundamentally avoiding the risk of new resonance caused by frequency offset, and realizing synchronous control of low-frequency noise and long-term reliable anechoic effect.

[0054] In a specific embodiment, the acoustic metamaterial structure 2 includes a plurality of dispersed metamaterial units 21, with adjacent metamaterial units 21 forming a Z-shaped flow channel; wherein the Z-shaped flow channel is capable of covering the space within the anechoic chamber. The structures of the dispersed metamaterial units 21 can be identical or different, and each metamaterial unit 21 includes one or more metamaterial plates to form multiple Z-shaped flow channels. The Z-shaped flow channel is an internally continuous space-filling curve with infinite length, achieving full planar coverage of a limited space.

[0055] The multiple metamaterial units 21 in the acoustic metamaterial structure 2 are arranged in a dispersed manner within the anechoic chamber, with adjacent units separated by specific angles to form continuous Z-shaped turning channels. This dispersed layout requires sound waves to repeatedly undergo sudden changes in direction (such as 90° or sharp angle turns) as they propagate within the channel, significantly increasing the frequency of collisions between the sound waves and the unit surfaces, thereby more efficiently dissipating sound energy through enhanced sound scattering and viscous resistance. At the same time, the multiple independent Z-shaped channels formed between adjacent metamaterial units 21 can provide segmented attenuation paths for noise in different frequency bands, avoiding localized energy accumulation caused by concentrated sound wave propagation and improving broadband anechoic capabilities.

[0056] The Z-shaped channel, through the dispersed arrangement of metamaterial units 21, covers the entire three-dimensional space of the anechoic chamber, ensuring that sound waves, regardless of where they enter the chamber, are forced to propagate within the Z-shaped channel. This full-coverage design eliminates the "short-circuit" region of sound waves in traditional straight channels (i.e., the area where sound waves directly penetrate without attenuation), forcing all sound waves to travel a maximum tortuous path length. At the same time, the Z-shaped channel achieves multiple returns of sound waves within the limited chamber volume, allowing low-frequency sound waves (with longer wavelengths) to self-cancel through phase interference during multiple turns, extending their residence time within the chamber and significantly improving the energy dissipation efficiency of low-frequency noise.

[0057] In a specific embodiment, the acoustic conduction interface 3 includes an acoustic baffle 31 and an acoustic film 32 , and the acoustic film 32 is embedded in the acoustic baffle 31 .

[0058] The acoustic baffle 31 serves as a rigid support structure fixed to the junction of the shell 1 and the valve tube 4. The acoustic film 32 is physically embedded and tightly fits within the preset through-hole or groove of the acoustic baffle 31, and the two form a composite interface layer. The acoustic baffle 31 provides structural stability and defines the boundary for sound wave transmission, while the acoustic film 32 completely covers the sound wave channel area in the baffle, ensuring that sound waves can only enter and exit the anechoic chamber through the film area. The function of the acoustic baffle 31 is to provide mechanical support and isolate the transmission of structural vibrations between the shell 1 and the valve tube 4, while restricting sound waves to directional transmission only through its central area. The function of the acoustic film 32 is to use its light, thin and flexible properties to achieve gradual acoustic impedance matching, reducing the interface reflection loss when sound waves are transmitted from the valve tube 4 to the air medium in the shell 1.

[0059] When acoustic baffle 31 and acoustic diaphragm 32 work together, broadband sound waves transmitted from valve tube 4 first strike diaphragm 32. Diaphragm 32 absorbs some of the high-frequency vibration energy through its elastic deformation. Its impedance matching properties allow mid- and low-frequency sound waves to efficiently penetrate the diaphragm and enter the anechoic chamber, significantly reducing interfacial reflections. Acoustic baffle 31 blocks the mechanical vibrations of valve tube 4 from being directly transmitted to housing 1, while maintaining the stability of the diaphragm's installation. These two elements work together to efficiently guide broadband sound waves and isolate vibrations, improving overall anechoic efficiency.

[0060] The acoustic baffle 31 is made of acrylic. Using acrylic significantly improves structural stability and environmental adaptability. Acrylic's high rigidity and lightweight properties effectively prevent mechanical vibrations transmitted by the valve tube 4 from diffusing into the housing 1. Its dense molecular structure and water absorption rate of less than 0.3% make it more resistant to deformation than metal in the high-temperature, high-humidity environment of the air conditioner's outdoor unit. It resists corrosion or creep over long periods of use, ensuring a reliable seal at the sound transmission interface. Furthermore, the acrylic's acoustic impedance closely matches that of the metal valve tube, reducing interfacial reflection losses.

[0061] The acoustic film 32 is a PVDF film. The use of PVDF (polyvinylidene fluoride) film for the acoustic film 32 enables efficient broadband acoustic energy conduction and selective dissipation. PVDF material exhibits a unique piezoelectric effect. When sound waves act on the film, its molecular chain polarization structure converts some of the high-frequency vibration energy into electrical energy for dissipation. The film's thickness of 0.1-0.3mm ensures a transmittance of over 92% for low- and medium-frequency sound waves (100-1000Hz), while its impedance gradient reduces the sound wave reflectivity to below 8%. PVDF's exceptional weather resistance overcomes the hardening and failure issues of traditional rubber materials.

[0062] In a specific embodiment, there are two acoustic films 32 , and the two acoustic films 32 correspond to the pipe openings of the large valve tube 41 and the small valve tube 42 of the air conditioner outdoor unit respectively.

[0063] Dual acoustic films 32 are used to correspond to the pipe orifices of the large valve tube 41 and the small valve tube 42 respectively, and precise noise reduction is achieved through targeted matching design: for the low-frequency noise mainly transmitted by the large valve tube 41, a higher surface density should be used to enhance the transmittance of low-frequency sound waves; the medium and high-frequency noise generated by the small valve tube 42 is processed by a thin PVDF film, and part of the high-frequency energy is converted into heat energy dissipation through the molecular chain piezoelectric effect; the independent operation of the dual films can avoid the mutual interference of the sound waves of the large and small pipes at the interface to generate secondary noise, and at the same time match the differentiated pipe mouth vibration characteristics to improve the overall sound energy transmission efficiency, and when a single film is damaged, it will not affect the noise reduction function of the other pipe.

[0064] In a specific embodiment, the muffler device further includes a porous attraction layer 5 , and the porous attraction layer 5 is filled in the muffler chamber.

[0065] The porous attraction layer 5 fills the anechoic chamber and is evenly distributed within the Z-shaped channel gaps of the acoustic metamaterial structure 2 and the remaining space within the chamber, forming a three-dimensional sound absorption network that covers the entire cavity. This arrangement increases frictional resistance during sound wave propagation through the complex pore channels within the porous structure, dissipating sound energy into heat and producing a particularly significant absorption effect on mid- and high-frequency noise. Simultaneously, it works in synergy with the Z-shaped channel of the acoustic metamaterial structure 2 to further enhance energy attenuation while extending the sound wave path, thus addressing the shortcomings of simple structural anechoics in the high-frequency range.

[0066] The porous attraction layer 5 is made of sound-absorbing cotton. Using sound-absorbing cotton as the porous attraction layer 5 fully utilizes its porous sound-absorbing properties. The interwoven fiber pores within the porous attraction layer increase friction damping during sound wave propagation, effectively dissipating mid- and high-frequency noise energy. Furthermore, the sound-absorbing cotton is filled into a sealed anechoic chamber, avoiding the environmental aging issues associated with traditional exposed use. Protected by the shell 1, its performance remains stable over the long term. It complements the Z-shaped flow channel of the acoustic metamaterial structure 2, which extends the sound wave path to suppress low-frequency noise, while the sound-absorbing cotton focuses on absorbing high-frequency sound energy. The two work together to achieve full-band noise reduction. Furthermore, the low cost and easy filling of the sound-absorbing cotton enhance the feasibility of this solution.

[0067] In a specific embodiment, the silencing device further includes a helium injection assembly 6 , which is connected to the silencing chamber through an inflation port and is used to change the medium density in the silencing chamber.

[0068] Helium injection assembly 6 communicates with the silencing chamber via an inlet port located on the wall of housing 1. Its core function is to alter the density of the acoustic propagation medium by injecting helium into the sealed chamber. Specifically, the high-density gaseous environment created by helium injection increases the propagation impedance of sound waves within the Z-shaped flow channel, enhancing the scattering of low-frequency sound waves by the acoustic metamaterial structure 2. This allows longer-wavelength, low-frequency sound waves to experience more significant phase interference and energy attenuation with the same number of channel turns. Furthermore, the inert helium environment slows down the oxidative aging of the porous attracting layer 5, maintaining its stable sound absorption performance. This synergistically improves low-frequency noise reduction efficiency and extends the device's lifespan.

[0069] In a specific embodiment, the helium injection assembly 6 includes a helium storage tank 61, an inflation pump body 62, a controller 63 and an acoustic sensor 64. The acoustic sensor 64 is arranged at the inflation port to sense the noise frequency inside the silencing cavity. The helium storage tank 61 is connected to the inflation pump body 62, and the inflation pump body 62 is connected to the controller 63. The controller 63 is configured to adjust the injection amount of helium according to the noise frequency.

[0070] A helium storage tank 61 is fixed to the air conditioner's exterior unit bracket and connected to the inlet of the inflation pump body 62 via a gas pipe. The outlet of the inflation pump body 62 extends through the inflation pipe to the inflation port of the housing 1. An acoustic sensor 64 is embedded in the inner wall of the inflation port to directly contact the chamber gas. A controller 63 is electrically connected to the inflation pump body 62 and the acoustic sensor 64 via cables, forming a closed-loop control system. The acoustic sensor 64 collects noise data in real time and transmits it to the controller 63, which then sends helium flow adjustment instructions to the inflation pump body 62. The helium storage tank 61 stores high-pressure inert helium as a medium regulating gas source. The inflation pump body 62 precisely controls the helium injection volume and flow rate according to the instructions. The controller 63 analyzes the noise spectrum characteristics monitored by the acoustic sensor 64 and calculates the required helium injection parameters. The acoustic sensor 64 senses the sound pressure level and dominant frequency within the anechoic chamber in real time, providing a data basis for dynamic adjustment.

[0071] The acoustic sensor 64 continuously monitors the noise spectrum in the chamber. When a specific low-frequency resonance peak is detected (such as when the compressor excitation frequency is close to the pipeline modal frequency), the controller 63 immediately starts the inflation pump body 62 and extracts an appropriate amount of helium from the helium storage tank 61 and injects it into the chamber. After the helium is injected, the gas density in the chamber is increased, the sound wave propagation impedance is changed, and the original resonance frequency is shifted and thus out of the excitation frequency band. At the same time, the controller 63 dynamically adjusts the helium flow rate according to the noise attenuation feedback (if the resonance is not eliminated, the injection amount is increased) until the acoustic sensor 64 confirms that the main frequency of the noise has moved out of the danger zone, thereby achieving adaptive vibration cancellation.

[0072] The muffler device provided in this embodiment operates as follows: the vibration noise generated by the compressor is transmitted to the acoustic conduction interface 3 through the large valve tube 41 and the small valve tube 42. The acoustic diaphragm 31 blocks the transmission of mechanical vibration, while the acoustic film 32 efficiently guides the sound waves into the muffler chamber of the housing 1 through impedance matching. The acoustic metamaterial structure 2 within the muffler chamber forms a Z-shaped flow channel formed by multiple dispersed units, forcing the sound waves to repeatedly turn, significantly extending the propagation path to enhance the interference and dissipation of low-frequency sound energy. The porous attraction layer 5 filling the muffler chamber simultaneously absorbs mid- and high-frequency noise, forming a broadband attenuation. The helium injection assembly 6 monitors the noise frequency in real time through an acoustic sensor 64. Based on this, the controller 63 adjusts the inflation pump body 62 to draw helium from the helium storage tank 61 and inject it into the chamber, dynamically changing the medium density to shift the resonant frequency, ultimately achieving adaptive control of noise across the entire frequency band. This process ensures long-term stability while addressing the core issues of low-frequency resonance, material aging, and incomplete frequency band coverage.

[0073] Example 2

[0074] This embodiment provides an air conditioner, such as Figure 8 and Figure 9As shown, the air conditioner includes a large valve tube 41, a small valve tube 42 and the silencer described in Example 1. The shell 1 of the silencer is installed on the side panel 7 of the air conditioner and covers the large valve tube 41 and the small valve tube 42.

[0075] The air conditioner achieves systematic noise reduction and reliability upgrade by integrating the silencer device of Example 1: the shell 1 of the silencer device covers the large valve tube 41 and the small valve tube 42 as a whole, so that the dual-pipe noise is efficiently introduced into the same silencer chamber through the differentiated thin films of the sound conduction interface 3, and the low-frequency sound wave path is synchronously extended in the Z-shaped flow channel of the acoustic metamaterial structure 2. Combined with the porous attraction layer 5 to absorb medium and high-frequency energy, the problems of insufficient low-frequency control and incomplete frequency band coverage in traditional solutions are completely solved; the helium injection component 6 dynamically adjusts the chamber medium density according to the real-time noise spectrum, actively shifts the resonant frequency, and avoids the risk of frequency imbalance caused by the counterweight method; at the same time, the closed environment of the shell 1 isolates external aging factors, ensuring that the performance of the metamaterial structure, sound-absorbing cotton and acoustic film is stable throughout the life cycle of the air conditioner, and ultimately achieving the dual goals of broadband noise reduction and long-term reliable operation.

[0076] Example 3

[0077] This embodiment provides a noise reduction control method, such as Figure 10 As shown, the noise reduction control method adopts the noise reduction device described in Example 1, including:

[0078] S1, the acoustic conduction interface 3 receives the noise transmitted by the valve tube 4;

[0079] S2, the noise enters the anechoic chamber in the housing 1, propagates along the continuous swirling flow channel of the acoustic metamaterial structure 2, and consumes sound energy through multiple reflections.

[0080] The noise reduction control method provided in this embodiment efficiently receives noise transmitted by the valve tube 4 through the acoustic conduction interface 3 and introduces it into the sealed noise reduction chamber of the housing 1. Within the chamber, the noise is forcibly guided to propagate through the continuous convoluted flow channel of the acoustic metamaterial structure 2. The multiple tortuous paths of the flow channel force the sound waves to undergo repeated reflection, interference, and scattering. During this process, the sound wave energy is continuously converted into heat energy and dissipated through air viscous friction and structural vibration. This method utilizes the physical path extension and energy conversion mechanism to effectively suppress low-frequency resonant noise without changing the pipeline modal frequency. It also avoids the aging or performance degradation problems of traditional materials and achieves stable and reliable broadband noise reduction.

[0081] In a specific embodiment, the noise reduction control method further includes:

[0082] S3, injecting helium into the anechoic chamber to change the medium density in the chamber;

[0083] S4, detecting the noise frequency in the anechoic chamber;

[0084] S5, adjusting the helium injection amount according to the detected noise frequency so that the maximum noise reduction frequency of the noise reduction device matches the detected noise frequency.

[0085] In this embodiment, helium is first injected into the anechoic chamber through the helium injection assembly 6. The density of helium is significantly lower than that of air, so as to reduce the density of the medium in the cavity, thereby changing the sound wave propagation speed and impedance characteristics, and causing the anechoic frequency characteristics of the acoustic metamaterial structure 2 to shift; secondly, the acoustic sensor 64 detects the main frequency of the noise in the chamber (i.e., the noise frequency in S4 above) in real time, and accurately identifies the resonance peak frequency that occurs during the operation of the compressor; finally, the controller 63 dynamically adjusts the helium injection amount according to the detected noise frequency. When the main frequency of the noise increases, the helium injection is reduced to maintain a higher medium density. When the main frequency decreases, the helium injection is increased to further reduce the density. Through continuous adjustment, the peak anechoic frequency of the anechoic device always tracks and matches the current main noise frequency, thereby achieving adaptive resonance suppression.

[0086] In a specific embodiment, in S5, adjusting the helium injection amount includes:

[0087] S51, calling pre-stored data on the correspondence between helium density and anechoic frequency;

[0088] S52, determining a target helium density based on the detected noise frequency and the corresponding relationship data;

[0089] S53, controlling the inflation pump to adjust the amount of helium injected so that the density of the medium in the cavity reaches the target density;

[0090] The corresponding relationship data is generated by the following steps: establishing an acoustic model based on the structural parameters of the silencer and the initial helium density; calculating the silencer performance under different helium densities through parametric scanning to obtain the variation pattern of the maximum silencer frequency with the helium density.

[0091] In this embodiment, the controller 63 calls a pre-generated database, which stores the mapping relationship between helium density and the peak silencing frequency of the silencing device; based on the real-time noise main frequency detected by the acoustic sensor 64, combined with the above mapping relationship, the target helium density value to be achieved is reversely calculated to align the device silencing peak frequency with the current noise main frequency; then the controller 63 sends an instruction to the inflation pump body 62, and accurately controls the density of the mixed gas in the chamber by increasing or decreasing the helium injection amount until the real-time medium density is equal to the target density value determined in S52, thereby completing the adaptive matching of the silencing frequency.

[0092] The generation of the corresponding relationship data in S51 is based on acoustic modeling and calculation: First, an acoustic model is established based on the structural parameters of the silencer (such as the Z-shaped flow channel size, chamber volume) and the initial helium density. The core of the acoustic model is the Helmholtz equation. (where the wave number k = ω / c and the sound speed c = √(γP / ρ)). This equation controls the sound speed c through the medium density ρ, thereby affecting the sound propagation characteristics. The solution to the equation at different helium densities is then parametrically scanned to calculate the transmission loss curve and extract the peak anechoic frequency. Finally, a mapping database between helium density and anechoic peak frequency is established, allowing the controller to actively shift the resonant frequency by adjusting the density.

[0093] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous technical features can be freely combined and superimposed.

[0094] The above are merely preferred embodiments of the present invention and do not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A muffler, characterized in that: The silencer device includes a shell, an acoustic metamaterial structure, and a sound conduction interface. The shell has a silencer chamber inside. The acoustic metamaterial structure is arranged in the silencer chamber and is constructed as a continuous vortex flow channel that can extend the sound wave propagation path in the silencer chamber. The sound conduction interface is arranged at the junction of the shell and the valve tube.

2. The muffler device according to claim 1, characterized in that: The acoustic metamaterial structure includes a plurality of dispersed metamaterial units, and a Z-shaped flow channel is formed between adjacent metamaterial units; wherein the Z-shaped flow channel can cover the space in the anechoic chamber.

3. The muffler device according to claim 1, characterized in that: The acoustic conduction interface includes an acoustic diaphragm and an acoustic film, wherein the acoustic film is embedded in the acoustic diaphragm; And / or, the acoustic partition is an acrylic board, and the acoustic film is a PVDF film.

4. The muffler device according to claim 3, characterized in that: There are two acoustic films, which respectively correspond to the pipe openings of the large valve pipe and the small valve pipe of the air conditioner outdoor unit.

5. The muffler device according to claim 1, characterized in that: The muffler device further comprises a porous attraction layer, wherein the porous attraction layer is filled in the muffler chamber; And / or, the porous attraction layer is sound-absorbing cotton.

6. The muffler device according to claim 1, characterized in that: The silencing device further includes a helium injection assembly, which is communicated with the silencing chamber through an inflation port and is used to change the medium density in the silencing chamber.

7. The muffler device according to claim 6, characterized in that: The helium injection assembly includes a helium storage tank, an inflation pump body, a controller and an acoustic sensor. The acoustic sensor is arranged at the inflation port to sense the noise frequency inside the silencing cavity. The helium storage tank is connected to the inflation pump body, and the inflation pump body is connected to the controller. The controller is configured to adjust the amount of helium injected according to the noise frequency.

8. An air conditioner, characterized in that: The air conditioner includes a large valve pipe, a small valve pipe and the silencer according to any one of claims 1 to 7. The shell of the silencer is installed on the side panel of the air conditioner and covers the large valve pipe and the small valve pipe.

9. A noise reduction control method, characterized in that: The noise reduction control method adopts the noise reduction device according to any one of claims 1 to 7, comprising: The acoustic conduction interface receives the noise transmitted by the valve tube; The noise enters the anechoic chamber inside the shell and propagates along the continuous swirling flow channel of the acoustic metamaterial structure, consuming sound energy through multiple reflections.

10. The noise reduction control method according to claim 9, characterized in that: The noise reduction control method further comprises: injecting helium into the anechoic chamber to change the density of the medium in the chamber; Detecting the noise frequency in the anechoic chamber; The helium injection amount is adjusted according to the detected noise frequency so that the maximum noise reduction frequency of the noise reduction device matches the detected noise frequency.

11. The noise reduction control method according to claim 10, characterized in that: The adjusting of the helium injection amount comprises: Call the pre-stored data on the relationship between helium density and anechoic frequency; determining a target helium density based on the detected noise frequency and the corresponding relationship data; Controlling the inflation pump to adjust the amount of helium injected so that the density of the medium in the cavity reaches the target density; The corresponding relationship data is generated by the following steps: establishing an acoustic model based on the structural parameters of the silencer and the initial helium density; calculating the silencer performance under different helium densities through parametric scanning to obtain the variation pattern of the maximum silencer frequency with the helium density.

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