An outdoor unit

Abstract

The application relates to the air conditioning technical field, in particular to an outdoor unit, which comprises a shell, a compressor, an exhaust pipe and a silencer; the silencer comprises a first silencing part for absorbing middle-low frequency noise, a second silencing part for absorbing high frequency noise, which is connected in series with the first silencing part; and a silencing unit is arranged on the inner wall of the silencer. The silencer absorbs the middle-low frequency noise through the first silencing part, and the second silencing part mainly eliminates the high frequency noise; in combination with the silencing units of various specifications on the inner wall, a wide-band and multi-level silencing system is formed. The pulsation transmission sound generated by the compressor exhaust pipe under different working conditions is effectively covered, the noise transmission to the indoor is reduced, the interference on the daily life of the user is reduced, and the use comfort is improved.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and more particularly to an outdoor unit. Background Technology

[0002] An air conditioner is a device that regulates indoor ambient temperature. Its refrigeration cycle system uses a compressor to drive the refrigerant through a phase change cycle between the outdoor heat exchanger, expansion valve, and evaporator. The compressor compresses the low-pressure gaseous refrigerant into a high-temperature, high-pressure gas, which is then transported to the outdoor heat exchanger through the exhaust pipe to dissipate heat and liquefy. The gas is then depressurized through the expansion valve to form a low-temperature, low-pressure gas-liquid mixture, which finally absorbs heat and evaporates in the evaporator to achieve cooling. During operation, the compressor, as the power source, generates intermittent high-pressure airflow in the exhaust pipe through its periodic intake, compression, and exhaust actions. This causes periodic pressure fluctuations within the pipe, resulting in airflow pulsation.

[0003] When airflow pulsation noise is transmitted to the indoor side through the piping system, it differentiates into two significant types of noise: one is the low-to-mid-frequency transmission sound, originating from the continuous excitation of the pipes by pulsating pressure, manifesting as a muffled low-frequency hum; the other is the high-frequency howling sound, caused by turbulence disturbances generated by high-speed airflow at pipe bends, valves, and other locations, presenting a sharp and piercing high-frequency sound. In high-efficiency inverter air conditioners, to adapt to the wide range of load adjustment needs, the compressor needs to frequently start and stop in the high-frequency range, further widening the noise spectrum, and its noise becomes a pain point affecting the user's quiet experience.

[0004] The single-muffler solution commonly used in the industry today has significant limitations. Traditional reactive mufflers are only effective against low-to-mid-frequency noise in specific frequency bands, while simple structures combining reactive and resistive properties are limited to narrow-band high-frequency noise reduction, neither of which can achieve full coverage of a wide spectrum of noise. Some improved solutions attempt to add porous sound-absorbing materials to the inner wall of the muffler to extend the noise reduction frequency band, but oil and grease carried by the refrigerant in the air conditioning system gradually clog the pores of the material, causing the noise reduction performance to degrade significantly over time, making it difficult to meet the long-term stable quiet operation requirements. Utility Model Content

[0005] This application addresses, to at least some extent, one of the technical problems in the related art.

[0006] Therefore, this application provides an outdoor unit.

[0007] To achieve the above objectives, this application adopts the following technical solution: Firstly, an outdoor unit is provided, comprising: shell; The compressor, housed within a casing, is used to compress low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant, providing circulation power for the refrigerant; the compressor includes an exhaust port for discharging the high-temperature, high-pressure gaseous refrigerant. An outdoor heat exchanger is used to cool gaseous refrigerant into liquid refrigerant through heat dissipation; the outdoor heat exchanger includes an air inlet for inputting gaseous refrigerant. An exhaust pipe, connecting the exhaust port and the air inlet, is used for the refrigerant to flow between the compressor and the outdoor heat exchanger; A muffler, connected to the compressor's exhaust pipe at one end near the compressor, is used to absorb the pulsating noise generated by the compressor's exhaust pipe. The silencer includes: The first noise-absorbing section is used to absorb low-to-mid frequency noise; the first noise-absorbing section includes: Expansion cavity, used for sound attenuation; An inlet pipe is used for the gaseous refrigerant to enter the expansion chamber; The outlet pipe is used to output the gaseous refrigerant from the expansion chamber; The inlet pipe and the outlet pipe are respectively disposed at both ends of the expansion cavity; The cross-sectional area of ​​the expansion cavity is larger than the cross-sectional areas of the inlet pipe and the outlet pipe; A second noise-absorbing section, used to absorb high-frequency noise, is connected in series with the first noise-absorbing section; the second noise-absorbing section includes: Main pipeline; The first resonant cavity surrounds the outside of the main pipe; Multiple connecting holes are distributed on the wall of the main pipe; the first resonant cavity is connected to the main pipe through the connecting holes; A silencing unit is disposed on the inner wall of the silencer; the silencing unit includes: The second resonant cavity is used to convert sound energy into heat energy through air vibration for noise reduction; The neck connects the second resonant cavity to the external environment and is used to conduct sound.

[0008] In the above embodiments, the silencer of this application uses a first silencing section to specifically absorb low- and mid-frequency noise, and a second silencing section to focus on eliminating high-frequency noise. Combined with silencing units of various sizes on the inner wall, it forms a wide-band, multi-layered silencing system. This effectively covers the pulsating noise transmitted from the compressor exhaust pipe under different operating conditions, reduces noise transmission into the room, minimizes interference with users' daily lives, and improves user comfort.

[0009] In some embodiments of this application, the inner wall of the expansion cavity of the first silencing part and the inner wall of the first resonant cavity of the second silencing part are respectively provided with at least two specifications of silencing units; The volume of the second resonant cavity and / or the length of the neck of different specifications of anechoic units are different.

[0010] In the above embodiments, different specifications refer to different volumes of the second resonant cavity or different lengths of the neck cavity. In this application, the different sizes of the silencing units correspond to different inherent resonant frequencies. The two sizes can be specifically matched to the noise frequency characteristics of the expansion cavity and the first resonant cavity in their respective silencing scenarios. In the expansion cavity of the first silencing part, the two sizes of units can respectively enhance the absorption of noise at different subdivided frequencies in the mid-low frequency band, making up for the problem of insufficient silencing at specific frequencies by a single-size unit. In the first resonant cavity of the second silencing part, the two sizes of units can further broaden the coverage of high-frequency noise, ensuring that more frequency pulsating sound transmissions in the high-frequency band are effectively suppressed, thereby enabling the entire silencer to maintain a stable silencing effect in a wide frequency range from mid-low to high frequencies.

[0011] In some embodiments of this application, one end of the main pipe is connected to the inlet pipe.

[0012] In the above embodiments, the main pipe and the inlet pipe are directly connected, ensuring that the refrigerant enters the first silencing section after preliminary treatment in the second silencing section, thus creating a continuous and coordinated silencing process for low-frequency and high-frequency noise. This continuous silencing link prevents noise from escaping between the two silencing sections, ensuring that broadband noise is suppressed step-by-step and efficiently, thereby improving the consistency and stability of the overall silencing effect.

[0013] In some embodiments of this application, the length l of the expansion cavity is expressed as follows: , in, This refers to the wavelength of low-to-mid frequency noise.

[0014] In the above embodiments, low-to-mid-frequency noise is the main pulsating sound transmitted through the compressor exhaust pipe, characterized by its relatively long wavelength and concentrated energy. The wavelength and the length of the expansion cavity are both measured in meters, centimeters, or millimeters. According to acoustic principles, when the expansion cavity length is one-quarter of the target noise wavelength, a standing wave will form within the cavity. The incident and reflected sound waves interfere and cancel each other out, thus reducing the transmission loss of noise in this frequency band. This solution can specifically capture the core low-to-mid-frequency noise generated during compressor operation, reducing the transmission of this frequency band noise into the room.

[0015] In some embodiments of this application, the silencing unit is mounted on the inner wall of the muffler via a fixing plate.

[0016] The mounting plate can be pre-integrated with multiple silencer units to form a modular assembly, which is then installed as a whole onto the inner wall of the silencer. Modular assembly reduces assembly steps and positioning times, minimizes human error, and improves production efficiency. The standardized design of the mounting plate facilitates mass production, adapts to different sizes of silencer unit combinations, and enhances production flexibility.

[0017] In some embodiments of this application, the design relationship of the first resonant cavity of the second silencing part is as follows: , The natural frequency of the first resonant cavity in the formula c is the speed of sound of the refrigerant, G is the conductivity, and V is the volume of the first resonant cavity.

[0018] In the above embodiments, the high-frequency pulsating transmission frequency characteristics of the compressor exhaust pipe of this application are clearly defined, and the silencing principle of the first resonant cavity relies on the matching of its natural frequency with the target noise frequency. When the two are consistent, the resonance effect will significantly absorb sound energy, thereby achieving silencing. Through the relationship, the volume V and conductivity G of the first resonant cavity can be derived and designed in reverse based on the actual frequency f of the high-frequency noise, avoiding the frequency deviation problem caused by traditional empirical design and improving the silencing efficiency of high-frequency noise.

[0019] In some embodiments of this application, the inner and outer cross-sections of the second resonant cavity and the neck are both hexagonal. In the above embodiments, the hexagonal structure of this application has the characteristic of tight splicing, and the edges of adjacent units can fit together completely, allowing more noise reduction units to be arranged within the limited space of the muffler's inner wall. The mold design and molding process of the hexagonal structure are relatively mature, and the uniform corner dimensions facilitate standardized production. During assembly, the splicing and positioning of the hexagonal units is simpler, and the arrangement can be quickly completed by aligning the edges side by side, reducing manual adjustment time.

[0020] In some embodiments of this application, the design formula of the silencing unit is as follows: , In the formula, f3 represents the noise reduction frequency, S0 represents the exit cross-sectional area of ​​the neck, V0 represents the volume of the second resonant cavity, and L0 represents the neck length.

[0021] In the above embodiments, this application designs the silencing unit through this relational design, which can achieve coverage of subdivided frequencies, flexibly adapt to multi-size requirements and changes in operating conditions, and at the same time improve R&D efficiency and mass production stability, providing technical support for wide-band, high-efficiency and reliable silencing of silencers.

[0022] In some embodiments of this application, the silencing unit is integrally formed with the inner wall of the muffler.

[0023] In the above embodiments, the curved or irregular inner wall of the muffler expansion cavity and the first resonant cavity can be integrally formed to fit its contour, so that the muffler unit can make full use of the space of the inner wall and avoid the space waste caused by insufficient adaptability in the split installation.

[0024] In the above embodiments, according to the noise reduction frequency relationship of the noise reduction unit, S0 and L0 are the core parameters that directly affect the noise reduction frequency f3. Increasing S0 or decreasing L0 can shift the noise reduction frequency to higher frequencies, while decreasing S0 or increasing L0 can adjust the frequency to lower frequencies. This control method does not require changing the volume V0 of the second resonant cavity, and can achieve precise matching of different subdivided frequencies while maintaining the overall compact structure of the unit.

[0025] Secondly, an outdoor unit is provided, including: shell; The compressor, housed within a casing, is used to compress low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant, providing circulation power for the refrigerant; the compressor includes an exhaust port for discharging the high-temperature, high-pressure gaseous refrigerant. An outdoor heat exchanger is used to cool gaseous refrigerant into liquid refrigerant through heat dissipation; the outdoor heat exchanger includes an air inlet for inputting gaseous refrigerant. An exhaust pipe, connecting the exhaust port and the air inlet, is used to transfer gaseous refrigerant; Cooling fan, used to dissipate heat from the outdoor heat exchanger; A muffler, connected to the compressor's exhaust pipe at one end near the compressor, is used to absorb the pulsating noise generated by the compressor's exhaust pipe. The silencer includes: The first noise-absorbing section is used to absorb low-to-mid frequency noise; the first noise-absorbing section includes: Expansion cavity, used for sound attenuation; An inlet pipe is used for the gaseous refrigerant to enter the expansion chamber; The outlet pipe is used to output the gaseous refrigerant from the expansion chamber; The inlet pipe and the outlet pipe are respectively disposed at both ends of the expansion cavity; The cross-sectional area of ​​the expansion cavity is larger than the cross-sectional area of ​​the inlet pipe and larger than the cross-sectional area of ​​the outlet pipe. A second noise-absorbing section, used to absorb high-frequency noise, is connected in series with the first noise-absorbing section; the second noise-absorbing section includes: Main pipeline; The first resonant cavity surrounds the outside of the main pipe; Multiple connecting holes are distributed on the wall of the main pipe; the first resonant cavity is connected to the main pipe through the connecting holes; A noise reduction unit is disposed on the inner wall of the first noise reduction section or the second noise reduction section; the noise reduction unit includes: The second resonant cavity is used to convert sound energy into heat energy through air vibration for noise reduction; The neck connects the second resonant cavity to the external environment and is used to conduct sound.

[0026] In the above embodiments, the various sizes of silencing units of this application can be flexibly arranged on the inner wall of the first or second silencing section according to the actual noise characteristics. When there are subdivided noise peaks in the low-to-medium frequency band, units of appropriate size can be arranged on the inner wall of the expansion cavity; when the high-frequency noise frequency is dispersed, corresponding units can be added to the inner wall of the first resonant cavity. The silencer can adapt to the noise changes under different operating conditions of the compressor and maintain a stable silencing effect in dynamic conditions.

[0027] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the internal structure of the outdoor unit provided in an embodiment of this application; Figure 2 This is an enlarged view of the installation position of the muffler provided in the embodiments of this application.

[0030] Figure 3 This is a schematic diagram of the overall structure of the muffler provided in the embodiments of this application; Figure 4 This is a cross-sectional view of the muffler provided in the embodiment of this application; Figure 5 This is a cross-sectional view of the second noise reduction section of the muffler provided in the embodiment of this application; Figure 6 This is a cross-sectional view of the first sound-absorbing section of the muffler provided in the embodiment of this application; Figure 7 This is an enlarged view of the arrangement of the noise reduction units provided in the embodiments of this application; Figure 8 This is an internal structural diagram of the noise reduction unit provided in the embodiments of this application; Figure 9 This is a schematic diagram of the overall structure of the muffler provided in the embodiments of this application; Figure 10 This is an enlarged view of the installation of the silencing unit provided in the embodiments of this application; In the above figures: 1. First silencing section; 10. Inlet pipe; 11. Outlet pipe; 12. Expansion chamber; 2. Second silencing section; 20. Main pipe; 21. First resonant cavity; 211. Inner wall; 212. Fixing plate; 22. Connecting hole; 3. Noise-absorbing unit; 30. Second resonant cavity; 31. Neck; 4. Muffler; 5. Compressor; 6. Exhaust pipe. Detailed Implementation

[0031] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0034] Additionally, if the meaning of "and / or" in the text is that it includes three parallel options, taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0035] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0036] It should be noted that an air conditioner is a device that regulates indoor ambient temperature. Its refrigeration cycle system uses a compressor to drive the refrigerant through a phase change cycle between the outdoor heat exchanger, expansion valve, and evaporator: the compressor compresses the low-pressure gaseous refrigerant into a high-temperature, high-pressure gas, which is then transported to the outdoor heat exchanger through the exhaust pipe to dissipate heat and liquefy. The gas is then depressurized through the expansion valve to form a low-temperature, low-pressure gas-liquid mixture, which ultimately absorbs heat and evaporates in the evaporator to achieve cooling. During operation, the compressor, as the power source, generates intermittent high-pressure airflow in the exhaust pipe through its periodic intake, compression, and exhaust actions, causing periodic pressure fluctuations within the pipe and resulting in airflow pulsation.

[0037] When airflow pulsation noise is transmitted to the indoor side through the piping system, it differentiates into two significant types of noise: one is the low-to-mid-frequency transmission sound, originating from the continuous excitation of the pipes by pulsating pressure, manifesting as a muffled low-frequency hum; the other is the high-frequency howling sound, caused by turbulence disturbances generated by high-speed airflow at pipe bends, valves, and other locations, presenting a sharp and piercing high-frequency sound. In high-efficiency inverter air conditioners, to adapt to the wide range of load adjustment needs, the compressor needs to frequently start and stop in the high-frequency range, further widening the noise spectrum, and its noise becomes a pain point affecting the user's quiet experience.

[0038] The single-muffler solution commonly used in the industry today has significant limitations. Traditional reactive mufflers are only effective against low-to-mid-frequency noise in specific frequency bands, while simple structures combining reactive and resistive properties are limited to narrow-band high-frequency noise reduction, neither of which can achieve full coverage of a wide spectrum of noise. Some improved solutions attempt to add porous sound-absorbing materials to the inner wall of the muffler to extend the noise reduction frequency band, but oil and grease carried by the refrigerant in the air conditioning system gradually clog the pores of the material, causing the noise reduction performance to degrade significantly over time, making it difficult to meet the long-term stable quiet operation requirements.

[0039] Based on this, this application proposes an outdoor unit that, by connecting a first silencer and a second silencer in series and setting a silencer unit on the inner wall of the two silencers, enables the silencer to have a wider frequency range of silencer and a higher noise reduction, thereby solving the problem of pulsating airflow noise in the compressor exhaust pipe.

[0040] In the following, embodiments of this application will be described in detail with reference to the accompanying drawings.

[0041] As attached Figures 1 to 10 As shown, Figure 2 for Figure 1 The enlarged view at point A shows an illustrative embodiment of the outdoor unit in this application, which includes a housing for securing and protecting internal components.

[0042] The outdoor unit includes a compressor 5, which is installed inside the casing and is used to compress low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant to provide circulation power for the refrigerant; the compressor 5 includes an exhaust port for discharging the high-temperature, high-pressure gaseous refrigerant.

[0043] The outdoor unit includes an outdoor heat exchanger, which is used to cool the gaseous refrigerant into liquid refrigerant through heat dissipation; the outdoor heat exchanger also includes an air inlet for introducing the gaseous refrigerant.

[0044] The outdoor unit includes an exhaust pipe 6, which connects the exhaust port and the air inlet, and is used to transfer gaseous refrigerant between the compressor and the outdoor heat exchanger.

[0045] The outdoor unit includes a cooling fan, which is used to dissipate heat from the outdoor heat exchanger.

[0046] The outdoor unit includes a muffler 4, which is connected to the exhaust pipe 6 of the compressor 5, near one end of the compressor 5, and is used to absorb the pulsating sound generated by the exhaust pipe 6 of the compressor 5.

[0047] like Figure 4 and Figure 6As shown, the silencer 4 includes a first silencing section 1 for absorbing low-to-mid frequency noise; the first silencing section 1 includes: an expansion cavity 12 for silencing; an inlet pipe 10 for gaseous refrigerant to enter the expansion cavity 12; and an outlet pipe 11 for gaseous refrigerant to leave the expansion cavity 12; wherein the inlet pipe 10 and the outlet pipe 11 are respectively located at both ends of the expansion cavity 12; the cross-sectional area of ​​the expansion cavity 12 is larger than the cross-sectional area of ​​the inlet pipe 10 and larger than the cross-sectional area of ​​the outlet pipe 11. like Figure 4 and Figure 5 As shown, the silencer 4 includes a second silencing part 2, which is used to absorb high-frequency noise and is connected in series with the first silencing part 1. The second silencing part 2 includes: a main pipe 20 for refrigerant airflow; a first resonant cavity 21, which is a cavity surrounding the outside of the main pipe 20; and multiple connecting holes 22 distributed on the wall of the main pipe 20. The first resonant cavity 21 is connected to the main pipe 20 through the connecting holes 22.

[0048] like Figure 7 , Figure 8 and Figure 10 As shown, Figure 10 for Figure 5 The enlarged view at point B shows that the muffler 4 includes a silencing unit 3, which comes in various sizes and is mounted on the inner wall 211 of the muffler 4. The silencing unit 3 includes: a second resonant cavity 30 for converting sound energy into heat energy through air vibration to achieve sound attenuation; and a neck 31 connecting the second resonant cavity 30 to the external environment for conducting sound.

[0049] The silencer 4 uses the first silencing section 1 to specifically absorb low- and mid-frequency noise, and the second silencing section 2 to focus on eliminating high-frequency noise. Combined with the various sizes of silencing units 3 on the inner wall 211, it forms a wide-band, multi-layered silencing system. This effectively covers the pulsating noise transmitted from the compressor 5's exhaust pipe 6 under different operating conditions, reducing noise transmission into the room, minimizing interference with the user's daily life, and improving user comfort.

[0050] In some embodiments, the first silencing part 1 is configured as an expansion silencer 4, and the second silencing part 2 is a first resonant cavity 21 type silencer 4. The expansion cavity 12 of the first silencing part 1 achieves silencing through the difference in cross-sectional area, resulting in a simple structure. The first resonant cavity 21 of the second silencing part 2 is arranged around the main pipe 20 and combined with the design of the connecting hole 22, which can efficiently absorb high-frequency noise while minimizing airflow obstruction, reducing pressure loss of refrigerant during transmission, and ensuring the operating efficiency of the air conditioning system. The silencer 4 is connected in series at the end of the exhaust pipe 6 near the compressor 5, achieving maximum silencing effect. Its compact layout can adapt to the limited installation space inside the outdoor unit without significantly modifying the existing equipment structure, facilitating production and assembly.

[0051] The silencer 4 minimizes airflow obstruction, reducing energy loss during refrigerant transfer and ensuring that the high-temperature, high-pressure refrigerant discharged from the compressor 5 can efficiently enter the outdoor heat exchanger, maintaining the cooling / heating efficiency of the air conditioning system. By reducing pulsating noise transmission, it reduces long-term fatigue damage to the exhaust pipe 6, compressor 5, and other components caused by noise vibration, helping to extend the overall service life of the outdoor unit and reduce maintenance costs.

[0052] In some embodiments of this application, the inner wall 211 of the expansion cavity 12 of the first silencing part 1 and the inner wall 211 of the first resonant cavity 21 of the second silencing part 2 are each provided with at least two specifications of silencing units 3. The two different specifications refer to the different volumes of the second resonant cavities and the different lengths of the neck cavity. Furthermore, the silencing units 3 are also mounted on the inner wall 211 by a fixing plate 212. In the manufacturing process, the silencing units are first mounted on the fixing plate 212 and then attached to the inner wall 211.

[0053] The mounting plate can be pre-integrated with multiple silencer units to form a modular assembly, which is then installed as a whole onto the inner wall of the silencer. Modular assembly reduces assembly steps and positioning times, minimizes human error, and improves production efficiency. The standardized design of the mounting plate facilitates mass production, adapts to different sizes of silencer unit combinations, and enhances production flexibility.

[0054] In the above embodiments, the frequency and amplitude of the noise generated by the exhaust pipe 6 of the compressor 5 will change under different operating conditions. Two sizes of silencer units 3 can increase the adaptability of the silencer 4 to changes in operating conditions. When the noise frequency shifts due to changes in operating conditions, the two sizes of units can respectively cover the frequency range before and after the shift. In dynamically changing noise environments, the silencer 4 can maintain a good noise reduction effect, avoiding the problem of decreased noise reduction performance of traditional single-size units when operating conditions fluctuate.

[0055] like Figure 9 As shown, in some embodiments, one end of the main pipe 20 is connected to the inlet pipe 10 or the outlet pipe 11. The length of the connecting pipe between the main pipe 20 and the inlet pipe 10 or the outlet pipe 11 can be determined according to the actual working conditions. Figure 7 Disconnect the connecting pipe and omit its length. If the main pipe 20 is connected to the inlet pipe 10, the first silencer 1 is located behind the second silencer 2, and the refrigerant airflow first flows through the second silencer 2 and then through the first silencer 1; if the main pipe 20 is connected to the outlet pipe 11, the first silencer 1 is located in front of the second silencer 2, and the refrigerant airflow first flows through the first silencer 1 and then through the second silencer 2. Both connection sequences of the first silencer 1 and the second silencer 2 can achieve noise reduction.

[0056] The main pipe 20 of the second silencer 2 is directly connected to the inlet pipe 10 or outlet pipe 11 of the first silencer 1. Furthermore, the airflow passing through the second silencer before the first silencer provides better noise reduction. This makes the refrigerant flow path between the first silencer 1 and the second silencer 2 smoother, avoiding turbulence or throttling phenomena that might occur with complex connection structures. It also reduces pressure loss of the refrigerant during transmission, allowing the high-temperature, high-pressure gaseous refrigerant to be transferred from the compressor 5 exhaust port to the outdoor heat exchanger, ensuring the cooling / heating efficiency of the air conditioning system and reducing energy consumption increases caused by excessive pressure loss.

[0057] In some embodiments, the connection structure between the main pipe 20 and the inlet pipe 10 or outlet pipe 11 can be achieved through integral molding or simple fixed connection, without the need for complex connectors or sealing components. This simplifies the production and assembly process of the silencer 4, reduces assembly time and the number of parts, lowers production errors and costs, and is more conducive to large-scale production.

[0058] In the above embodiments, the main pipe 20 is directly connected to the inlet pipe 10 or the outlet pipe 11. The refrigerant can first flow through the first silencing section 1 and then enter the second silencing section 2, or first flow through the second silencing section 2 and then enter the first silencing section 1. Both paths can reduce and silence mid-low frequency and high frequency noise. The continuous silencing link avoids noise escape between the two silencing sections, effectively suppresses wide-band noise, and improves the consistency and stability of the overall silencing effect.

[0059] In some embodiments of this application, the length l of the expansion cavity is expressed as follows: , in, This refers to the wavelength of low-to-mid frequency noise.

[0060] It should be noted that the main pulsating noise transmission path of the compressor 5's exhaust pipe 6 is low-to-mid frequency noise, which is characterized by a longer wavelength and more concentrated energy. When the length of the expansion cavity 12 is set to 1 / 4 of the target noise wavelength, a stable standing wave field can be formed within the cavity. At this time, the incident sound wave and the reflected sound wave interfere and cancel each other out, reducing the transmission loss of noise in this frequency band. This solution can accurately suppress the core low-to-mid frequency noise generated by the compressor 5 during operation and reduce the propagation of this frequency band noise into the room.

[0061] The noise reduction principle of the expansion cavity 12 is based on the impedance mismatch caused by the abrupt change in the cross-sectional area of ​​the pipe. When the noise wavelength and the cavity length form a specific proportional relationship, the noise reduction frequency response of the expansion cavity 12 to the mid-low frequency band is steeper, and it can form a significant noise reduction peak in the target frequency band. This works in synergy with the structural feature that the cross-sectional area of ​​the expansion cavity 12 is larger than that of the inlet and outlet pipes 10, thus avoiding the problem of weakened mid-low frequency noise reduction effect caused by unreasonable cavity length design.

[0062] When compressor 5 is running at variable frequency, the wavelength of low- and mid-frequency noise fluctuates regularly with frequency changes, but the wavelength range of the core frequency band remains relatively stable. The quarter-wavelength design can cover the mainstream wavelength of the core range, and can maintain effective suppression of low- and mid-frequency noise when the operating conditions fluctuate slightly. This avoids the problem of reduced noise reduction effect when the frequency shifts due to a fixed cavity length, and improves the stability of silencer 4 in different operating modes.

[0063] In some embodiments of this application, the design relationship of the first resonant cavity 21 of the second noise-absorbing part 2 is as follows: , The natural frequency of the resonant cavity in the formula c is the speed of sound of the refrigerant, G is the conductivity, and V is the volume of the first resonant cavity. By adjusting the conductivity G and the volume V of the first resonant cavity 21, the natural frequency of the first resonant cavity 21 can be actively set to match the target noise frequency generated by the compressor 5 during operation. When the noise frequency matches the natural frequency of the first resonant cavity 21, the first resonant cavity 21 will absorb sound energy through resonance. The incident sound wave and the reverse sound wave generated by resonance will interfere and cancel each other out, thereby reducing the transmission of noise in this frequency band into the room.

[0064] Furthermore, the outdoor unit's internal space is compact, and the area around the exhaust pipe 6 often contains cooling fans, heat exchanger pipes, etc., so the volume design of the first resonant cavity 21 must be limited by the installation space. The design formula of the first resonant cavity 21 provides a parametric design approach. When the installation space restricts the volume V, the target natural frequency f2 can be maintained by adjusting the conductivity G; conversely, if G is difficult to adjust due to structural and technological limitations, frequency matching can also be achieved by optimizing the volume V.

[0065] In some embodiments, the internal and external cross-sections of the second resonant cavity 30 and the neck 31 are both hexagonal. The hexagonal structure of this application allows for close fitting with adjacent units, increasing the number of silencing units 3 arranged on the inner wall 211. The hexagonal structure facilitates mold design and injection molding, improving manufacturing efficiency and reducing production costs during mass production. The symmetrical design simplifies the assembly process between components, ensuring a proper fit between the second resonant cavity 30 and the neck 31.

[0066] In some embodiments, the design formula for the noise reduction unit 3 is as follows: , In the formula, f3 represents the noise reduction frequency, S0 represents the exit cross-sectional area of ​​the neck, V0 represents the volume of the second resonant cavity, and L0 represents the neck length.

[0067] The noise frequency of compressor 5 may fluctuate slightly under different operating conditions. The parameters of the silencer unit 3 can be adjusted to adapt to the new noise frequency by using preset correlations between S0 and L0 and the frequency. When a slight increase in high-frequency noise is detected, the length L0 of the neck 31 can be reduced or the outlet cross-sectional area S0 can be increased to synchronize the noise reduction frequency, preventing a disconnect in the noise reduction effect due to fluctuations in operating conditions and improving the stability of the silencer 4 in dynamic environments.

[0068] In some embodiments, the silencing unit 3 is integrally formed with the inner wall 211 of the muffler 4.

[0069] In the above embodiments, the curved or irregularly shaped inner wall 211 of the expansion cavity 12 and the first resonant cavity 21 of the muffler 4 is integrally formed to fit its contour, allowing the silencing unit 3 to fully utilize the space of the inner wall 211 and avoiding space waste caused by insufficient adaptability in split installations. The integral formation of the silencing unit 3 and the inner wall 211 results in a more uniform stress distribution, avoiding the risk of fatigue fracture caused by stress concentration at connection points in split installations. Under long-term exposure to refrigerant impact and vibration loads, the overall structure is less prone to cracking or deformation, extending the overall service life of the muffler 44 and reducing equipment maintenance costs.

[0070] In some embodiments, an outdoor unit is provided, including a housing for protecting and securing internal components.

[0071] The outdoor unit includes a compressor 5, which is installed inside the casing and is used to compress low-temperature, low-pressure gaseous refrigerant into high-temperature, high-pressure gaseous refrigerant to provide circulation power for the refrigerant; the compressor 5 includes an exhaust port for discharging high-temperature, high-pressure gaseous refrigerant.

[0072] The outdoor unit includes an outdoor heat exchanger, which is used to cool the gaseous refrigerant into a liquid refrigerant through heat dissipation; the outdoor heat exchanger includes an air inlet for introducing the gaseous refrigerant.

[0073] The outdoor unit includes an exhaust pipe 6, which connects the exhaust port and the air inlet, and is used for the flow of gaseous refrigerant between the compressor and the outdoor heat exchanger.

[0074] The outdoor unit includes a cooling fan, which is used to dissipate heat from the outdoor heat exchanger.

[0075] The outdoor unit includes a muffler 4, which is connected to the exhaust pipe 6 of the compressor 5, near one end of the compressor 5, and is used to absorb the pulsating sound generated by the exhaust pipe 6 of the compressor 5.

[0076] The silencer 4 includes a first silencing section 1, which is used to absorb low- and mid-frequency noise. The first silencing section 1 includes: an inlet pipe 10 for the gaseous refrigerant to enter the first silencing section 1; an expansion cavity 12 for the silencing area; and an outlet pipe 11 for the gaseous refrigerant to leave into the expansion cavity 12. The inlet pipe 10 and the outlet pipe 11 are respectively located at both ends of the expansion cavity 12. The cross-sectional area of ​​the expansion cavity 12 is larger than the cross-sectional area of ​​the inlet pipe 10 and larger than the cross-sectional area of ​​the outlet pipe 11. The silencer 4 includes a second silencing part 2, which is used to absorb high-frequency noise and is connected in series with the first silencing part. The second silencing part 2 includes: a main pipe 20 for the passage of refrigerant gas; a first resonant cavity 21 surrounding the outside of the main pipe 20; and multiple connecting holes 22 distributed on the wall of the main pipe 20. The first resonant cavity 21 is connected to the main pipe 20 through the connecting holes 22. The silencer 4 includes various sizes of silencer units 3, which are disposed on the inner wall 211 of the first silencer 1 or the second silencer 2. The silencer unit 3 includes: a second resonant cavity 30 for converting sound energy into heat energy through air vibration to perform noise reduction; and a neck 31 connecting the second resonant cavity 30 to the external environment for conducting sound.

[0077] Various sizes of silencing units 3 can be flexibly arranged on the inner wall 211 of the first silencing section 1 or the second silencing section 2 according to the actual noise characteristics: when there are subdivided noise peaks in the low and medium frequency bands, units of appropriate size can be arranged on the inner wall 211 of the expansion cavity 12; when the high frequency noise frequency is dispersed, corresponding units can be added to the inner wall 211 of the first resonant cavity 21. The silencer 4 can adapt to the noise changes of the compressor 5 under different operating conditions, ensuring a stable silencing effect in dynamic conditions.

[0078] The first silencing section 1 absorbs low-to-mid-frequency noise primarily through the expansion cavity 12 structure. The second silencing section 2 eliminates high-frequency noise through the combination of the first resonant cavity 21 and the main pipe 20. Furthermore, silencing units 3 of various sizes further reduce noise in subdivided frequency bands. This covers the main frequency range of the pulsating sound transmitted by the exhaust pipe 6 of the compressor 5, avoiding the problem of insufficient silencing capacity in specific frequency bands by traditional single-structure silencers 4, and reducing the overall noise level of the outdoor unit during operation.

[0079] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. An outdoor unit characterized by comprising: include: shell; The compressor is housed within the casing; An outdoor heat exchanger is used to cool gaseous refrigerant into liquid refrigerant through heat dissipation. The exhaust pipe is used for the refrigerant to flow between the compressor and the outdoor heat exchanger; A muffler, connected to the exhaust pipe at one end near the compressor, is used to absorb the pulsating sound generated by the compressor's exhaust pipe. The silencer includes: The first noise-absorbing section is used to absorb low-to-mid frequency noise; the first noise-absorbing section includes: Expansion cavity, used for sound attenuation; An inlet pipe is used for the gaseous refrigerant to enter the expansion chamber; The outlet pipe is used to output the gaseous refrigerant from the expansion chamber; The inlet pipe and the outlet pipe are respectively disposed at both ends of the expansion cavity; The cross-sectional area of ​​the expansion cavity is larger than the cross-sectional areas of the inlet pipe and the outlet pipe; A second noise-absorbing section, used to absorb high-frequency noise, is connected in series with the first noise-absorbing section; the second noise-absorbing section includes: Main pipeline; The first resonant cavity surrounds the outside of the main pipe; Multiple connecting holes are distributed on the wall of the main pipe; the first resonant cavity is connected to the main pipe through the connecting holes; A noise reduction unit is disposed on the inner wall of the silencer; the noise reduction unit includes: The second resonant cavity is used to convert sound energy into heat energy through air vibration for noise reduction; The neck connects the second resonant cavity to the external environment and is used to conduct sound.

2. The outdoor unit according to claim 1, characterized by The inner wall of the expansion cavity and the inner wall of the first resonant cavity are each provided with at least two specifications of silencing units. The volume of the second resonant cavity and / or the length of the neck of different specifications of anechoic units are different.

3. The outdoor unit according to claim 1, characterized in that, One end of the main pipe is connected to the inlet pipe.

4. The outdoor unit according to claim 1, characterized by The length l of the expansion cavity is expressed as follows: , wherein, is the wavelength of the mid-low frequency band noise.

5. The outdoor unit according to claim 1, characterized by The silencing unit is mounted on the inner wall of the muffler via a fixing plate.

6. The outdoor unit according to claim 1, characterized by The design formula for the first resonant cavity of the second anechoic section is: ， The natural frequency of the first resonant cavity in the formula c is the speed of sound of the refrigerant, G is the conductivity, and V is the volume of the first resonant cavity.

7. The outdoor unit according to claim 1, characterized by The inner and outer cross sections of the second resonant cavity and the neck are both set to hexagonal.

8. The outdoor unit according to claim 1, characterized by The design formula for the silencing unit is: ， In the formula, f3 represents the noise reduction frequency, S0 represents the exit cross-sectional area of ​​the neck, V0 represents the volume of the second resonant cavity, and L0 represents the neck length.

9. The outdoor unit according to claim 1, characterized by The silencing unit is integrally formed with the inner wall of the muffler.

10. An outdoor unit characterized by comprising: include: shell; The compressor is located inside the casing; An outdoor heat exchanger is used to cool gaseous refrigerant into liquid refrigerant through heat dissipation. The exhaust pipe is used for the refrigerant to flow between the compressor and the outdoor heat exchanger; A muffler, connected to the exhaust pipe at one end near the compressor, is used to absorb the pulsating sound generated by the compressor's exhaust pipe. The silencer includes: The first noise-absorbing section is used to absorb low-to-mid frequency noise; the first noise-absorbing section includes: Expansion cavity, used for sound attenuation; An inlet pipe is used for the gaseous refrigerant to enter the expansion chamber; The outlet pipe is used to output the gaseous refrigerant from the expansion chamber; The inlet pipe and the outlet pipe are respectively disposed at both ends of the expansion cavity; The cross-sectional area of ​​the expansion cavity is larger than the cross-sectional area of ​​the inlet pipe and larger than the cross-sectional area of ​​the outlet pipe. A second noise-absorbing section, used to absorb high-frequency noise, is connected in series with the first noise-absorbing section; the second noise-absorbing section includes: Main pipeline; The first resonant cavity surrounds the outside of the main pipe; Multiple connecting holes are distributed on the wall of the main pipe; the first resonant cavity is connected to the main pipe through the connecting holes; A noise reduction unit is disposed on the inner wall of the first noise reduction section or the second noise reduction section; the noise reduction unit includes: The second resonant cavity is used to convert sound energy into heat energy through air vibration for noise reduction; The neck connects the second resonant cavity to the external environment and is used to conduct sound.

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