Noise reduction structure and kitchen air conditioner

Abstract

The application relates to a noise reduction structure and a kitchen air conditioner. The noise reduction structure comprises an air duct assembly and an active noise reduction assembly; the air duct assembly comprises an evaporator, an air duct and an air outlet which are sequentially communicated, and the deflection angles of the air duct inlet and outlet are greater than or equal to 90 DEG; the active noise reduction assembly comprises a pickup and a loudspeaker corresponding to the pickup, the pickup is arranged at the outlet position of the evaporator, and the loudspeaker is arranged in the air duct; the pickup is arranged at the outlet of the evaporator to collect the original noise signal of the front-end element in real time, and the loudspeaker is arranged in the air duct to generate a reverse sound wave; on the one hand, the source noise reduction can be realized, that is, the sound wave is offset before the noise is distorted by the reflection of the air duct; on the other hand, the path synchronization can be realized, that is, the reverse sound wave is synchronized with the original noise to pass through the deflection air duct, and the phase mismatch problem caused by the sound wave scattering in the deflection air duct is avoided; thus, the precise and significant noise elimination effect is achieved.

Description

Technical Field

[0001] This invention relates to the technical field of kitchen air conditioning, and in particular to a noise reduction structure and a kitchen air conditioner. Background Technology

[0002] Kitchen air conditioners typically employ an integrated design, combining the refrigeration system and air ducts entirely within the main unit. The casing usually contains a compressor and two independent air supply systems, one for circulating cooling and the other for heat dissipation. This results in kitchen air conditioners typically having five noise sources: cooling exhaust (supply air), cooling intake (return air), heat dissipation intake (external circulation intake), heat dissipation exhaust (exhaust air), and vibration radiation from the casing.

[0003] Among them, the cooling circulation duct for indoor users generally adopts a bent pipe structure (such as between the evaporator outlet and the exhaust vent that supplies air to the room). The geometry of this duct will significantly aggravate the noise generated by airflow. More importantly, this bent pipe layout causes the strong noise source of the air outlet that is too close to the main unit to directly radiate sound into the room, becoming one of the most prominent noise sources perceived by users. As a result, the indoor noise sound pressure level of the existing whole unit generally exceeds 55dB, which seriously affects the acoustic comfort of the kitchen and adjacent areas. Summary of the Invention

[0004] Therefore, it is necessary to provide a noise reduction structure and kitchen air conditioner that can effectively reduce noise, addressing the current problem of excessive noise from kitchen air conditioners.

[0005] This application first provides a noise reduction structure, including an air duct assembly and an active noise reduction assembly; the air duct assembly includes an evaporator, an air duct and an exhaust port connected in sequence, and the deflection angle of the air duct inlet and outlet is greater than or equal to 90°; the active noise reduction assembly includes a microphone and a speaker corresponding to the microphone, the microphone is disposed on the outlet side of the evaporator and the speaker is disposed inside the air duct.

[0006] In one embodiment, the speaker is embedded in the inner wall of the air duct.

[0007] In one embodiment, the loudspeaker is disposed on the inner wall of the air duct on the outer side relative to its own deflection center.

[0008] In one embodiment, the angle between the speaker's sound-emitting surface and the plane where the exhaust vent is located is less than or equal to 45°.

[0009] In one embodiment, the sound-emitting surface of the loudspeaker is tangent to the inner wall of the air duct.

[0010] In one embodiment, the sound-emitting surface of the loudspeaker is directly opposite the air duct outlet.

[0011] In one embodiment, the active noise cancellation component includes a plurality of microphones disposed at the evaporator outlet along a first direction, the first direction being parallel to both the plane of the evaporator outlet and the plane of the exhaust vent.

[0012] In one embodiment, the active noise cancellation component includes a plurality of pickups arranged at equal intervals along the first direction.

[0013] In one embodiment, the distance between the pickup end of the microphone and the outlet end face of the evaporator is 2cm to 5cm.

[0014] This application also provides a kitchen air conditioner, including the aforementioned noise reduction structure.

[0015] The aforementioned noise reduction structure, by placing a microphone at the evaporator outlet to collect the original noise signal of the front-end components in real time, and simultaneously arranging loudspeakers inside the air duct to generate anti-phase sound waves, can achieve noise reduction at the source, that is, cancel the sound waves before the noise is distorted by reflection from the bend; on the other hand, it can achieve path synchronization, that is, the anti-phase sound waves and the original noise pass through the deflection air path synchronously, avoiding the phase mismatch problem caused by sound wave scattering in the deflection air path; thus achieving a precise and significant noise reduction effect. Attached Figure Description

[0016] Figure 1 This is an axonometric view of one embodiment of the noise reduction structure of this application; Figure 2 for Figure 1 The front view; Figure 3 This is a diagram illustrating the active noise reduction effect of the exhaust vent in another embodiment of the noise reduction structure of this application.

[0017] Reference numerals: 10, evaporator; 20, air duct; 30, exhaust vent; 1, microphone; 2, loudspeaker. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0019] In the description of this invention, 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," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] In this invention, unless otherwise explicitly 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," "over," and "on top" of 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.

[0023] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0024] Please combine Figure 1 as well as Figure 2 As shown, this application firstly discloses a noise reduction structure, including an air duct assembly and an active noise reduction assembly; the air duct assembly includes an evaporator 10, an air duct 20 and an exhaust port 30 connected in sequence, and the deflection angle α of the air duct 20 inlet and outlet is greater than or equal to 90°; the active noise reduction assembly includes a microphone 1 and a speaker 2 corresponding to the microphone 1, the microphone 1 is disposed at the outlet of the evaporator 10 and the speaker 2 is disposed inside the air duct 20.

[0025] The deflection design based on the air duct 20 meets the requirements of thinness and bottom air outlet, but it will increase airflow resistance and cause vortex noise. In this application, a microphone 1 is set at the outlet of the evaporator 10 to collect the original noise signal of the front-end components in real time. At the same time, a loudspeaker 2 is arranged inside the air duct 20 to generate anti-phase sound waves. On the one hand, it can achieve source noise reduction, that is, the sound wave is canceled before the noise is distorted by the reflection of the bend. On the other hand, it can achieve path synchronization, that is, the anti-phase sound wave and the original noise pass through the deflection air path synchronously, avoiding the phase mismatch problem caused by the sound wave scattering in the deflection air path; thus achieving a precise and significant noise reduction effect.

[0026] Specifically, when the air duct 20 is a straight air duct, the deflection angle α of its inlet and outlet directions is 0 degrees. Based on this, by designing the deflection angle α of the air duct 20 to be greater than or equal to 90°, the air path design can meet the requirements of thin equipment and bottom air outlet. However, this deflection structure will increase airflow resistance, which will easily lead to vortex noise. In this application, by setting a microphone 1 at the outlet of the evaporator 10 and setting a loudspeaker 2 inside the air duct 20, the original noise at the source can be actively reduced to avoid the noise being reflected and amplified by the deflection air path inside the air duct 20 and radiated into the room.

[0027] More specifically, the microphone 1 located at the outlet of the evaporator 10 can collect the original noise signals generated by the compressor, fan and other components in front of the air duct assembly in real time, and use them as the reference input for the active noise reduction assembly; while the speaker 2 located inside the air duct 20 can generate an anti-phase sound wave with the same amplitude and opposite phase as the noise according to the algorithm, thereby canceling out the original noise.

[0028] It is worth mentioning that the deflected air duct 20 causes sound wave reflection and scattering. If a speaker is installed at the outlet of the air duct 20 in a traditional active noise cancellation structure, the anti-phase sound waves cannot be accurately canceled with the original noise due to the difference in their paths. However, in this application, the speaker 2 is placed inside the air duct 20, so that the anti-phase sound waves pass through the air duct 20 synchronously with the original sound waves, ensuring that the cancellation effect is not affected by the geometric structure.

[0029] Please combine Figure 1 as well as Figure 2 As shown, in some embodiments, the speaker 2 is embedded in the inner wall of the air duct 20. That is, the surface of the speaker 2 is flush with or recessed into the inner wall of the air duct 20.

[0030] By embedding the speaker 2 into the inner wall of the air duct 20, the protrusion structure on the inner wall of the air duct 20 is avoided. This prevents physical protrusions from interfering with the airflow path or the reverse sound field propagation path of the speaker 2, thus ensuring the airflow effect and the acoustic effect of the active noise cancellation components.

[0031] Specifically, if the speaker 2 protrudes from the inner wall of the air duct 20, it will disrupt the airflow path and form additional turbulence and vortices. This will not only increase wind resistance and airflow noise, but also cause sound wave distortion due to obstruction and reflection. The embedded structure maintains the geometric integrity of the inner wall of the air duct 20 and ensures the smoothness of the inner wall of the air duct 20. This not only prevents the possibility of generating additional turbulence and vortices, but also ensures the acoustic stability of the active noise cancellation component.

[0032] Preferably, the surface of the speaker 2 is flush with the inner wall of the air duct 20, which can ensure that the inner wall of the air duct 20 at the location of the speaker 2 maintains a smooth transition, thereby ensuring that the effective flow section in the air duct 20 has a smooth transition, preventing the local flow channel contraction and expansion at the location of the speaker 2 from affecting the airflow resistance and flow velocity, and thus ensuring that the air outlet effect of the air duct assembly is not affected by the speaker 2.

[0033] Furthermore, please combine Figure 1 as well as Figure 2 As shown, in some embodiments, the speaker 2 is disposed on the inner wall of the air duct 20 on the outer side relative to its own deflection center.

[0034] With the speaker 2 embedded in the air duct 20, it is placed on the inner wall of the air duct 20 on the outer side relative to its own deflection center, so that the physical space on the outer side of the air duct 20 can be used to meet the requirements of the sound wave radiation direction.

[0035] It is easy to understand that when the air duct 20 has a large angle of deflection, its inner space is restricted due to the compression caused by the curvature. If a speaker 2 is installed, the sound-emitting surface may be blocked or deflected. On the other hand, the outer inner wall has a more open space due to its gentle curvature, allowing the sound-emitting surface of the embedded speaker 2 to face directly towards the exhaust vent 30 (see reference). Figure 2The inner wall path of the air duct 20 where the speaker 2 is located is longer and unobstructed on the side facing the exhaust vent 30.

[0036] This configuration maintains the smooth airflow provided by the embedded speaker 2, while ensuring that the anti-phase sound waves generated by the speaker 2 can propagate unobstructed along the axis of the air duct 20 to the exhaust port 30, avoiding scattering or attenuation of the sound waves due to obstruction by the internal structure, and achieving precise coverage and cancellation of the anti-phase sound field inside the air duct.

[0037] Please combine Figure 1 as well as Figure 2 As shown, in some embodiments, the angle β between the sound-emitting surface of the speaker 2 and the plane where the exhaust vent 30 is located is less than or equal to 45°.

[0038] By limiting the angle β between the sound-emitting surface of the loudspeaker 2 and the plane where the exhaust vent 30 is located to be less than or equal to 45°, the main radiation direction of the anti-phase sound wave emitted by the loudspeaker 2 is limited to a small degree of deviation from the normal direction of the plane of the exhaust vent 30, so that the anti-phase sound wave generated by the loudspeaker 2 is more directly aligned with the air outlet axis of the exhaust vent 30.

[0039] It is understandable that if the included angle β is too large, the anti-phase sound wave will reflect more towards the wall of the air duct 20 or propagate in the opposite direction along the air duct 20, resulting in a reduction in the effective anti-phase sound energy reaching the exhaust vent 30 and a decrease in noise reduction efficiency. However, by controlling the included angle β to within 45°, the sound pressure level at the outlet of the air duct 20 of the anti-phase sound wave is attenuated less, the phase matching accuracy between the anti-phase sound wave and the original noise transmitted from the air duct 20 to the exhaust vent 30 is higher, the destructive interference effect is more sufficient, and the scattering and energy loss caused by the reflection of the air duct wall during the propagation of the sound wave are reduced.

[0040] Furthermore, in some embodiments, the sound-emitting surface of the loudspeaker 2 is tangential to the inner wall of the duct 20. This arrangement allows the outer edge contour of the loudspeaker 2 to smoothly transition with the inner wall surface of the duct 20, avoiding structural abrupt changes such as protrusions or grooves around the loudspeaker 2. From a fluid dynamics perspective, the tangential arrangement can minimize the disturbance of the airflow within the duct 20 by the loudspeaker 2, suppress additional turbulent noise and vortex shedding caused by structural abrupt changes, thereby avoiding the introduction of new airflow-generated noise sources while actively reducing noise. At the same time, this smooth transition structure is also convenient for processing, manufacturing, and assembly, which is beneficial for consistency control in mass production.

[0041] In one specific embodiment, the loudspeaker 2 is located on the inner wall of the deflection section of the air duct 20, and the angle between the sound-emitting surface of the loudspeaker 2 and the plane where the exhaust port 30 is located is 45°.

[0042] Furthermore, in some embodiments, the sound-emitting surface of the speaker 2 is directly opposite the outlet of the air duct 20, that is, the sound-emitting surface of the speaker 2 is parallel to the plane where the outlet of the air duct 20 is located, and the included angle β is 0°.

[0043] This arrangement ensures that the main radiation axis of speaker 2 faces directly towards the outlet end of duct 20. The anti-phase sound wave propagates along the axial direction of duct 20, forming a direct superposition relationship with the original noise propagating in the same direction. In other words, the sound-emitting surface of speaker 2 faces the same direction as the reflection of the original noise at the location of speaker 2, ensuring that the propagation paths of the anti-phase sound wave and the original noise are highly coincident. This improves the real-time performance and matching accuracy of active noise cancellation, effectively reduces the risk of noise distortion caused by geometric deflection, and makes the overall noise cancellation more accurate.

[0044] In addition, this configuration ensures that the main energy of the anti-phase sound wave propagates directionally along the airflow direction of the duct 20, avoiding reflection loss of the sound wave on the inner wall of the duct 20 due to the tilt of the sound-generating surface. This ensures that the generated anti-phase sound wave and the original noise remain coaxial on the propagation path, reducing energy attenuation caused by sound wave scattering during the cancellation process and improving the sound energy conversion efficiency of the active noise cancellation component.

[0045] Furthermore, in some embodiments, the projection of the sound-emitting surface of the speaker 2 along the plane perpendicular to the outlet of the air duct 20 is entirely within the outlet range of the air duct 20.

[0046] Since the sound-emitting surface is parallel to the plane where the air duct 20 is located, by limiting the projection of the sound-emitting surface along the direction perpendicular to the plane where the air duct 20 is located to be completely within the outlet range of the air duct 20, it can be ensured that the anti-phase sound waves emitted by the sound-emitting surface of the speaker 2 radiate directly into the room along the axis of the air duct 20 through the air duct 20 and the exhaust vent 30, so as to avoid the situation where the anti-phase sound waves are refracted or reflected in the air duct 20, resulting in energy loss or inability to accurately cancel the original noise.

[0047] Please combine Figure 1 as well as Figure 2 As shown, in some embodiments, the active noise cancellation component includes a plurality of microphones 1, which are disposed at the outlet of the evaporator 10 along a first direction, which is parallel to both the plane of the evaporator 10 outlet and the plane of the exhaust vent 30.

[0048] By placing multiple microphones 1 along the first direction at the outlet of the evaporator 10, spatial sampling optimization of the noise source is achieved.

[0049] Specifically, due to the deflection structure of the duct 20, the sound waves are scattered unevenly within the bend, making it difficult for a single microphone 1 to cover wideband noise signals. However, by arranging multiple microphones 1 along this first direction, the airflow noise in different regions of the evaporator 10 outlet section can be captured simultaneously, effectively avoiding modal distortion caused by sound wave reflection within the bend duct 20. This provides a full-band, high-precision reference input for the generation of anti-phase sound waves by the loudspeaker 2, significantly improving the adaptability of the active noise reduction component of this application under complex flow field conditions.

[0050] Furthermore, please combine Figure 1 as well as Figure 2 As shown, in some embodiments, the active noise cancellation component includes a plurality of microphones 1 arranged at equal intervals along a first direction.

[0051] By further defining multiple microphones 1 arranged at equal intervals along a first direction, this design targets the noise energy distribution characteristics (typically approximately uniform) of the evaporator 10 outlet cross section, eliminating acoustic monitoring blind spots through equally spaced sampling.

[0052] Specifically, the equidistant arrangement ensures that the original noise is captured uniformly, avoiding the synthesis error of antiphase sound waves caused by differences in the density of sampling points. Especially for high-frequency noise with shorter wavelengths (which is easily affected by scattering in curved channels), the equidistant pickups 1 can effectively suppress the spatial aliasing effect in the sound cancellation process, so that the cancellation sound field generated by the loudspeaker 2 forms a uniform coverage on the cross-section of the air duct 20, improving the global suppression capability of broadband noise.

[0053] Furthermore, please combine Figure 1 as well as Figure 2 As shown, in some embodiments, the active noise cancellation component includes three microphones 1 arranged at equal intervals along a first direction, and three speakers 2 corresponding to the three microphones 1 are disposed in the air duct 20.

[0054] In one specific embodiment, three microphones 1 are equally spaced along the first direction at the outlet of the evaporator 10, the air duct 20 is a 90° bend, and three loudspeakers 2 are correspondingly arranged inside it. The sound-emitting surface of the loudspeaker 2 faces the outlet of the air duct 20 (that is, the sound-emitting surface is parallel to the plane where the outlet of the air duct 20 is located, and the projection of the sound-emitting surface along the axis of the air duct 20 is completely located inside the outlet of the air duct 20). A kitchen air conditioner with the aforementioned noise reduction structure was placed on a table in a regular room. A 1-meter-long straight flexible hose (with sound insulation optimization treatment) was connected to the return air vent, while a rectangular acrylic tube of approximately 1 meter long was connected to the exhaust vent for sound insulation. A sound pressure sensor was placed at a position of 300.5 meters from the exhaust vent to measure noise. The test results are as follows. Figure 3 As shown, the noise reduction at 8kHz and 2kHz is 6.7dBA and 8.1dBA, respectively.

[0055] In other words, in the above specific embodiments, the noise reduction structure can effectively reduce low- and medium-frequency noise during the operation of the whole machine.

[0056] Of course, in some other embodiments, the number of microphones 1 and speakers 2 can be adjusted according to factors such as space size, equipment cost, and noise reduction requirements, as long as the noise reduction effect can be guaranteed. This application will not go into detail here.

[0057] In some embodiments, the distance between the pickup end of the pickup 1 and the outlet end face of the evaporator 10 is 2cm to 5cm.

[0058] If the distance between the two is less than 2cm, the microphone 1 is too close to the outlet fin area of ​​the evaporator 10, and the diaphragm is easily affected by the splashing of water droplets condensed on the fin surface, resulting in random pulse noise interference in the acquired signal; the vibration of the evaporator 10 is directly transmitted to the microphone 1 through the air gap, causing structural vibration noise coupling and reducing the signal-to-noise ratio; in addition, if the gap between the microphone 1 and the fin end is too narrow, additional local flow resistance will be formed, resulting in airflow acceleration and backflow, causing local eddies and airflow pulsation, increasing aerodynamic resistance and causing a decrease in airflow, while forming an additional aerodynamic noise source near the microphone 1.

[0059] If the distance between the two is greater than 5cm, the microphone 1 is far away from the original noise source, and the direct sound signal will experience sound pressure level attenuation as the distance increases, especially the attenuation in the high frequency band is more significant. The change in the acoustic path length between the microphone 1 and the loudspeaker 2 leads to a reduction in the phase margin of the closed-loop feedback system, affecting the real-time performance and accuracy of the generation of anti-phase sound waves. In addition, a long unconstrained expansion airflow zone is formed between the microphone 1 and the outlet of the evaporator 10. The airflow forms a free shear layer and a recirculation zone due to the sudden expansion of space, which easily generates turbulent pulsation and vortex shedding noise. Additional aerodynamic noise is mixed into the acquired signal, while increasing the total pressure loss in the duct 20.

[0060] Therefore, by limiting the distance between the two to 2cm~5cm, the microphone 1 is positioned close to the original noise source but with an appropriate distance, which can obtain a high-fidelity direct sound signal, avoid interference from fin vibration and condensate splashing, and ensure the phase stability of the closed-loop feedback system. At the same time, it will not form an excessively narrow throttling gap between the microphone 1 and the fin, which would generate additional flow resistance and eddy noise, nor will it form an excessively long unrestrained expansion zone, which would lead to increased turbulence pulsation and pressure loss. It has no significant impact on the overall air volume and cooling capacity of the unit.

[0061] Preferably, the distance between the pickup end of the pickup 1 and the outlet end face of the evaporator 10 is 3cm.

[0062] Please combine Figure 1 as well as Figure 2 As shown, in some embodiments, the pickup end of the microphone 1 faces the evaporator 10, and the pickup end is provided with a windproof head.

[0063] By limiting the pickup end of the microphone 1 to face the evaporator 10 and adding a windproof head, it can be ensured that the microphone 1 can still output a high-fidelity reference signal stably under strong airflow conditions, thus ensuring the pickup accuracy of the microphone 1 from the signal source and avoiding the deterioration of the noise reduction effect due to the distortion of the pickup data.

[0064] Among them, the directional orientation towards the front noise source (such as compressor, fan, etc.) can maximize the signal-to-noise ratio of the original noise signal and avoid sound interference from reflections on the wall of the air duct 20. The windproof head is designed for the high-speed airflow at the outlet of the evaporator 10. The porous structure of the windproof head can attenuate wind noise interference caused by wind pressure pulsation (non-target noise reduction source) while maintaining the sound wave frequency response characteristics without distortion.

[0065] This application also provides a kitchen air conditioner, including the aforementioned noise reduction structure.

[0066] The aforementioned kitchen air conditioner can be controlled by a voice module, which is equipped with a controller, a voice receiving module, and a voice parsing module. The voice receiving module receives user commands, and the voice parsing module parses the commands. Based on the parsed commands, the controller controls the aforementioned kitchen air conditioner to perform corresponding operations, thereby realizing intelligent control of the kitchen air conditioner and improving the user experience.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A noise reduction structure, characterized in that, Including air duct components and active noise cancellation components; The air duct assembly includes an evaporator (10), an air duct (20), and an exhaust port (30) connected in sequence, and the deflection angle of the air duct (20) in the direction of the inlet and outlet is greater than or equal to 90°; The active noise cancellation component includes a microphone (1) and a speaker (2) corresponding to the microphone (1). The microphone (1) is located on the outlet side of the evaporator (10), and the speaker (2) is located inside the air duct (20).

2. The noise reduction structure according to claim 1, characterized in that, The loudspeaker (2) is embedded in the inner wall of the air duct (20).

3. The noise reduction structure according to claim 2, characterized in that, The loudspeaker (2) is located on the inner wall of the air duct (20) on the outer side relative to its own deflection center.

4. The noise reduction structure according to claim 3, characterized in that, The angle between the sound-emitting surface of the loudspeaker (2) and the plane where the exhaust vent (30) is located is less than or equal to 45°.

5. The noise reduction structure according to claim 4, characterized in that, The sound-emitting surface of the loudspeaker (2) is tangent to the inner wall of the air duct (20).

6. The noise reduction structure according to claim 4, characterized in that, The sound-emitting surface of the loudspeaker (2) is directly opposite the outlet of the air duct (20).

7. The noise reduction structure according to claim 1, characterized in that, The active noise reduction component includes a plurality of microphones (1), which are disposed at the outlet of the evaporator (10) along a first direction, the first direction being parallel to both the plane of the evaporator (10) outlet and the plane of the exhaust vent (30).

8. The noise reduction structure according to claim 7, characterized in that, The active noise cancellation component includes a plurality of pickups (1) arranged at equal intervals along the first direction.

9. The noise reduction structure according to claim 1, characterized in that, The distance between the pickup end of the pickup (1) and the outlet end face of the evaporator (10) is 2cm to 5cm.

10. A kitchen air conditioner, characterized in that, Includes the noise reduction structure as described in any one of claims 1 to 9.

Images