Range hood and noise reduction control method thereof

Abstract

The application relates to the technical field of kitchen appliances, and discloses an oil extractor hood and a noise reduction control method thereof. The oil extractor hood comprises a smoke collecting cavity, a wind channel structure, a flow guide structure and a noise reduction structure arranged in the smoke collecting cavity. The flow guide structure guides the airflow in the smoke collecting cavity to the wind channel structure, can block the airflow from escaping to the two sides of the wind channel air inlet, makes the airflow concentrate on the wind channel air inlet, effectively reduces the airflow turbulence degree of the wind channel air inlet, the noise reduction structure is arranged on the outer circumferential side of the wind channel structure, reasonably utilizes the outer circumferential side space of the wind channel structure, improves the space utilization rate of the oil extractor hood, the outer circumferential side space of the flow guide structure, the noise reduction structure and the wind channel structure forms a double-layer resonance sound absorption cavity, makes the airflow noise gradually weaken, and since the spacing between the noise reduction structure and the flow guide structure is adjustable, when the user selects different fan rotating speeds, the spacing between the noise reduction structure and the flow guide structure can be adjusted to make the noise of the oil extractor hood quickly reduce to the minimum value.

Description

Technical Field

[0001] This invention relates to the field of kitchen appliance technology, and in particular to a range hood and its noise reduction control method. Background Technology

[0002] Existing retractable range hoods suffer from turbulent flow and wasted space in some areas due to their lifting and duct structures. There is significant backflow near the inlet of the telescopic cavity, and the lateral space corresponding to the duct structure in the smoke collection cavity is an area of ​​unnecessary fluid movement. The existence of these two areas leads to high noise levels and affects the air performance of the retractable range hood. Summary of the Invention

[0003] Based on the above problems, the purpose of this invention is to provide a range hood and its noise reduction control method, which can reduce the noise of the range hood and improve the space utilization of the range hood.

[0004] To achieve the above objectives, the following technical solution is provided:

[0005] In a first aspect, the present invention provides a range hood, including a smoke collection chamber and an air duct structure, a flow guiding structure and a noise reduction structure disposed in the smoke collection chamber. The flow guiding structure is used to guide the airflow in the smoke collection chamber to the air duct structure, and the noise reduction structure is disposed on the outer periphery of the air duct structure. The distance between the noise reduction structure and the flow guiding structure is adjustable.

[0006] As an optional solution to the range hood provided by the present invention, it also includes a driving device, which is used to drive the noise reduction structure to move, so as to adjust the distance between the noise reduction structure and the airflow guiding structure.

[0007] As an optional solution for the range hood provided by the present invention, the driving device includes a driving component and a push rod. The driving component can push the noise reduction structure to move through the push rod, so as to adjust the distance between the noise reduction structure and the airflow guiding structure.

[0008] As an optional solution to the range hood provided by the present invention, a noise sensor is also included, which is used to measure the noise value of the range hood.

[0009] As an optional solution for the range hood provided by the present invention, a speed sensor is also included, which is used to measure the fan speed of the duct structure.

[0010] As an optional solution for the range hood provided by the present invention, the air guiding structure is provided with a clearance hole and a first noise reduction hole, and the clearance hole is connected to the air inlet of the air duct structure.

[0011] As an optional solution for the range hood provided by the present invention, the airflow guiding structure is provided with a sound-absorbing layer.

[0012] As an optional solution for the range hood provided by the present invention, the airflow guiding structure is an arc-shaped structure that is thick around the edges and thin in the middle.

[0013] As an optional solution to the range hood provided by the present invention, it also includes a telescopic cavity, which is movably connected to the smoke collection cavity.

[0014] Secondly, the present invention also provides a noise reduction control method for a range hood, used to control the aforementioned range hood. The noise reduction control method for the range hood includes the following steps:

[0015] Under different fan speeds, the preset distance between the noise reduction structure and the airflow guiding structure corresponding to the lowest noise value was obtained through experiments.

[0016] Adjust the distance between the noise reduction structure and the airflow guiding structure to the preset distance based on the currently selected fan speed.

[0017] As an optional solution to the noise reduction control method for range hoods provided by the present invention, the method further includes the following steps:

[0018] Under different noise levels, the target spacing between the noise reduction structure and the flow guiding structure corresponding to the lowest noise level was obtained through experiments.

[0019] Based on the currently measured noise value, the distance between the noise reduction structure and the flow guiding structure is adjusted from the preset distance to the target distance.

[0020] As an optional solution to the noise reduction control method for range hoods provided by the present invention, the method further includes the following steps:

[0021] Before adjusting the distance between the noise reduction structure and the flow guiding structure, initialize the distance between them to the initial distance.

[0022] The beneficial effects of this invention are as follows:

[0023] The range hood and its noise reduction control method provided by this invention guides the airflow in the smoke collection chamber to the duct structure through a flow guiding structure, which can prevent the airflow from escaping to both sides of the duct inlet, thus concentrating the airflow at the duct inlet and effectively reducing the degree of airflow turbulence at the duct inlet, thereby reducing the noise of the range hood. A noise reduction structure is set on the outer periphery of the duct structure, making reasonable use of the outer periphery space of the duct structure and improving the space utilization rate of the range hood. The flow guiding structure, the noise reduction structure, and the outer periphery space of the duct structure form a double-layer resonant sound absorption chamber, which gradually weakens the airflow noise. Since the distance between the noise reduction structure and the flow guiding structure is adjustable, the distance between the noise reduction structure and the flow guiding structure corresponding to the lowest noise value at different fan speeds can be determined through experiments. Therefore, when the user selects different fan speeds, the noise of the range hood can be quickly reduced to the lowest value by adjusting the distance between the noise reduction structure and the flow guiding structure, improving the user experience. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the range hood provided in a specific embodiment of the present invention;

[0026] Figure 2 This is a cross-sectional view of the range hood provided in a specific embodiment of the present invention from one perspective;

[0027] Figure 3 This is a cross-sectional view of the range hood provided in a specific embodiment of the present invention from another perspective;

[0028] Figure 4 This is a partial structural schematic diagram of the range hood provided in a specific embodiment of the present invention;

[0029] Figure 5 This is a top view schematic diagram of the airflow guiding structure in the range hood provided in a specific embodiment of the present invention;

[0030] Figure 6 This is a front view schematic diagram of the airflow guiding structure in the range hood provided in a specific embodiment of the present invention;

[0031] Figure 7 This is a cross-sectional view of the range hood provided in a specific embodiment of the present invention from another perspective.

[0032] In the picture:

[0033] 1. Smoke collection chamber; 2. Air duct structure; 3. Airflow guiding structure; 4. Noise reduction structure; 5. Drive device; 6. Noise sensor; 7. Controller; 8. Telescopic chamber;

[0034] 31. Clearance hole; 32. First noise reduction hole;

[0035] 41. Second noise reduction hole;

[0036] 51. Driving component; 52. Push rod;

[0037] 81. Smoke gathering plate; 82. Smoke inlet. Detailed Implementation

[0038] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., 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 the invention and for 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 the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0041] like Figures 1 to 7 As shown, this embodiment provides a range hood, which includes a smoke collection chamber 1 and an air duct structure 2, a flow guiding structure 3, and a noise reduction structure 4 disposed within the smoke collection chamber 1. The flow guiding structure 3 guides the airflow in the smoke collection chamber 1 to the air duct structure 2. The noise reduction structure 4 is disposed on the outer periphery of the air duct structure 2, and the distance between the noise reduction structure 4 and the flow guiding structure 3 is adjustable. It can be understood that the noise reduction structure 4 and the flow guiding structure 3 can move relative to each other to adjust their distance. For example, the noise reduction structure 4 can move while the flow guiding structure 3 remains stationary; or, both the noise reduction structure 4 and the flow guiding structure 3 can move. Since the flow guiding structure 3 needs to guide the airflow in the smoke collection chamber 1 to the air duct structure 2, and the air duct structure 2 is usually stationary, it is preferable that the flow guiding structure 3 remains stationary, and the distance between the noise reduction structure 4 and the flow guiding structure 3 is adjusted by the movement of the noise reduction structure 4.

[0042] The airflow in the smoke collection chamber 1 is guided to the duct structure 2 by the flow guide structure 3, which prevents the airflow from escaping to both sides of the duct inlet, concentrating the airflow at the duct inlet and effectively reducing the turbulence of the airflow at the duct inlet, thus reducing the noise of the range hood. A noise reduction structure 4 is installed on the outer periphery of the duct structure 2, making reasonable use of the outer periphery space and improving the space utilization of the range hood. The flow guide structure 3, the noise reduction structure 4, and the outer periphery space of the duct structure 2 form a double-layer resonant sound-absorbing chamber, gradually weakening the airflow noise. Since the distance between the noise reduction structure 4 and the flow guide structure 3 is adjustable, experiments can be conducted to determine the distance between them that results in the lowest noise level at different fan speeds. Therefore, when users select different fan speeds, they can adjust the distance between the noise reduction structure 4 and the flow guide structure 3 to quickly reduce the noise of the range hood to the lowest value, improving the user experience.

[0043] To facilitate adjustment of the distance between the noise reduction structure 4 and the airflow guiding structure 3, the range hood may optionally include a drive device 5. The drive device 5 drives the noise reduction structure 4 to move, thereby adjusting the distance between the noise reduction structure 4 and the airflow guiding structure 3. The drive device 5 can be manually driven or automatically driven by a motor or other drive components, achieving automatic adjustment of the distance between the noise reduction structure 4 and the airflow guiding structure 3, thus improving the product's competitiveness. Multiple drive devices 5 can be provided to ensure even force distribution and smooth movement of the noise reduction structure 4.

[0044] Optionally, the driving device 5 includes a driving component 51 and a push rod 52. The driving component 51 can push the noise reduction structure 4 to move via the push rod 52, thereby adjusting the distance between the noise reduction structure 4 and the flow guiding structure 3. Using the push rod 52 to push the noise reduction structure 4 reduces the complexity of the movement and makes the movement of the noise reduction structure 4 smoother. The driving component 51 can be a motor, or a cylinder, hydraulic cylinder, or other driving element. To improve the smoothness of the movement of the noise reduction structure 4, guide rails or guide columns can also be provided to guide the movement of the noise reduction structure 4. The noise reduction structure 4 can be a plate-like structure, and the thickness of the noise reduction structure 4 does not exceed one-third of the thickness of the gaps on both sides. The material of the noise reduction structure 4 can be resin material or cut metal plate.

[0045] To facilitate the acquisition of the noise level of the range hood, the range hood may optionally include a noise sensor 6, which measures the noise level of the range hood. The noise sensor 6 can be positioned between the noise reduction structure 4 and the back panel of the smoke collection chamber 1, sensing the noise generated during the operation of the range hood. The noise sensor 6 is equipped with a high-sensitivity electret condenser microphone. When an object produces sound, the sound wave vibrates and displaces the electret diaphragm in the microphone, causing a change in the capacitor, thereby generating a small voltage corresponding to the change, realizing the conversion from optical signal to electrical signal.

[0046] To facilitate the acquisition of the fan speed of the duct structure 2, the range hood may optionally include a speed sensor, which measures the fan speed of the duct structure 2. The acquisition of the speed signal can be viewed as a speed measurement process for a rotating component. Eddy current speed sensors are reliable, provide strong signals, are easy to use for speed measurement, are reasonably priced, and are less affected by environmental factors. Based on these advantages, eddy current speed sensors are widely used in speed signal acquisition. The range hood also includes a controller 7, which receives signals from the noise sensor 6 and the speed sensor. After logical judgment, the controller adjusts the distance between the noise reduction structure 4 and the airflow guiding structure 3 to minimize the noise impact of the range hood.

[0047] Optionally, the flow guiding structure 3 is provided with an avoidance hole 31 and a first noise reduction hole 32. The avoidance hole 31 is connected to the air inlet of the duct structure 2. That is, the avoidance hole 31 is obtained by hollowing out the outer contour of the duct of the volute of the duct structure 2 on the flow guiding structure 3. The avoidance hole 31 fits into the duct enclosure of the volute, and there is no need for a fixed connection between the two. The avoidance hole 31 can be set with a certain chamfer and extend into the duct to ensure that the oil fumes can smoothly enter the duct after entering the smoke collection chamber 1. An arc-shaped windbreak structure can be set on the upper side of the duct inlet to block the upper space of the duct, so that the oil fumes can enter the duct to the maximum extent and be discharged, thereby improving the performance of the range hood. By avoiding the air inlet of the duct structure 2 through the avoidance hole 31, the flow guiding structure 3 will not affect the normal air intake of the duct inlet and will not cause interference in terms of structural design. The first noise reduction hole 32 consumes the sound energy of the airflow on both sides of the duct structure 2 by frictional heat generation, thereby reducing aerodynamic noise. The first noise reduction hole 32 can be a circular hole with a diameter of 2mm and a spacing of 8mm between two adjacent first noise reduction holes 32.

[0048] Optionally, the flow guiding structure 3 is provided with a sound-absorbing layer. The sound-absorbing layer can be sound-absorbing cotton, which is readily available, low in cost, and can effectively reduce noise. The flow guiding structure 3 has multiple first flanged protrusions, which, together with the flow guiding structure 3, form a limiting groove, within which the noise reduction layer is placed. The sound-absorbing cotton is precisely positioned within the limiting groove, eliminating the need for additional installation methods to fix it. The sound-absorbing layer can utilize high damping to convert mechanical vibrations into heat energy for dissipation, thereby achieving noise reduction. High-damping materials include multi-functional damping rubber sheets, magnesium alloys, titanium alloys, titanium coatings, composite boards, etc.

[0049] The noise reduction structure 4 is equipped with sound-absorbing cotton and a second noise reduction hole 41. A double-layer resonant cavity, consisting of sound-absorbing cotton-air-sound-absorbing cotton-air cross-combination, is formed between the noise reduction structure 4 and the airflow guiding structure 3, thereby improving the noise reduction capability of the range hood. The main material of the sound-absorbing cotton is porous fiber. The noise reduction principle of the sound-absorbing cotton is as follows: sound waves travel through the air. The sound-absorbing cotton has a multi-fiber structure. When sound waves pass through the sound-absorbing cotton, they are reflected and superimposed by countless fibers, converting sound wave energy into heat energy, weakening the sound wave intensity, and causing the sound to disappear. The noise reduction structure 4 is equipped with multiple second flanged protrusions, which, together with the noise reduction structure 4, form a limiting groove. The noise reduction layer is placed within the limiting groove. The sound-absorbing cotton is precisely positioned within the limiting groove, eliminating the need for additional installation methods to fix the sound-absorbing cotton. The porosity of the flow guiding structure 3 and the noise reduction structure 4 can be different. The smaller porosity has a significant effect on absorbing low-frequency noise, while the larger porosity has a significant effect on absorbing mid-to-high-frequency noise. This can effectively absorb noise peaks and avoid the operating risk frequencies of the range hood.

[0050] To facilitate the guidance of airflow from the smoke collection chamber 1 to the duct structure 2 by the guide structure 3, the guide structure 3 can optionally be an arc-shaped structure that is thicker around the edges and thinner in the middle. The arc design reduces airflow resistance, facilitates a better transition to the duct inlet, improves the uniformity of the flow field at the duct inlet, reduces airflow turbulence, and lowers aerodynamic noise. The guide structure 3 can be a plate-like structure, and its maximum thickness should not exceed the gap width between the duct structure 2 and the telescopic cavity 8, so as not to affect the expansion and contraction of the telescopic cavity 8.

[0051] Optionally, the range hood also includes a telescopic cavity 8, which is movably connected to the smoke collection cavity 1. When the range hood is working, the telescopic cavity 8 extends out of the smoke collection cavity 1 relative to it. The telescopic cavity 8 is equipped with a smoke inlet 82 and a smoke gathering plate 81. Opening the smoke gathering plate 81 exposes the smoke inlet 82, allowing for the extraction of indoor fumes. When the range hood stops working, the telescopic cavity 8 retracts out of the smoke collection cavity 1 relative to it, reducing the space occupied by the range hood.

[0052] This embodiment also provides a noise reduction control method for a range hood, which is used to control the range hood described above. The noise reduction control method includes the following steps: under different fan speeds, the preset distance between the noise reduction structure 4 and the airflow guiding structure 3 corresponding to the lowest noise value is obtained through experiments; according to the currently selected fan speed, the distance between the noise reduction structure 4 and the airflow guiding structure 3 is adjusted to the preset distance.

[0053] Understandably, different fan speeds can be divided into several levels for user convenience, and these speeds can also be infinitely adjustable. By fitting the discrete value of the distance between the noise reduction structure 4 and the airflow guiding structure 3 at the lowest noise level, a continuous value for the distance between these two structures at different fan speeds is obtained. Based on the fan speed information input from the speed sensor to the controller 7, the controller outputs the distance between the noise reduction structure 4 and the airflow guiding structure 3 at the lowest noise level for the corresponding fan speed. This allows the controller 7 to send a control signal to the drive device 5, which in turn moves the noise reduction structure 4, ensuring the distance between the noise reduction structure 4 and the airflow guiding structure 3 reaches the preset value. The real-time noise information input from the noise sensor 6 to the controller 7 is compared with experimental values, providing feedback for PID control adjustment and correction of the distance between the noise reduction structure 4 and the airflow guiding structure 3.

[0054] The airflow in the smoke collection chamber 1 is guided to the duct structure 2 by the flow guide structure 3, which prevents the airflow from escaping to both sides of the duct inlet, thus concentrating the airflow at the duct inlet and effectively reducing the airflow turbulence at the duct inlet, thereby reducing the noise of the range hood. The noise reduction structure 4 is set on the outer periphery of the duct structure 2, making reasonable use of the outer periphery space of the duct structure 2 and improving the space utilization of the range hood. The flow guide structure 3, the noise reduction structure 4, and the outer periphery space of the duct structure 2 form a double-layer resonant sound absorption chamber, which gradually weakens the airflow noise. Since the distance between the noise reduction structure 4 and the flow guide structure 3 is adjustable, the distance between the noise reduction structure 4 and the flow guide structure 3 corresponding to the lowest noise value under different fan speeds can be determined by experiment. Therefore, when the user selects different fan speeds, the noise of the range hood can be quickly reduced to the lowest value by adjusting the distance between the noise reduction structure 4 and the flow guide structure 3, improving the user experience.

[0055] Optionally, the noise reduction control method for a range hood further includes the following steps: under different noise levels, experimentally obtain the target distance between the noise reduction structure 4 and the airflow guiding structure 3 corresponding to the lowest noise level; based on the currently measured noise level, adjust the distance between the noise reduction structure 4 and the airflow guiding structure 3 from a preset distance to the target distance. After the range hood has been used for a period of time, a lot of grease and other impurities will accumulate inside, and the noise will increase significantly. The theoretical distance between the noise reduction structure 4 and the airflow guiding structure 3 cannot achieve the lowest noise level under the current fan speed. Therefore, it is necessary to introduce the currently measured noise level as the main reference factor for adjusting the distance between the noise reduction structure 4 and the airflow guiding structure 3, and correct the distance between the noise reduction structure 4 and the airflow guiding structure 3. This can better reduce the noise level of the range hood, thereby improving the user experience. In some embodiments, the distance between the noise reduction structure 4 and the airflow guiding structure 3 can be corrected by comprehensively considering the fan speed and noise level in a weighted proportion.

[0056] Optionally, the noise reduction control method for the range hood further includes the following steps: before adjusting the distance between the noise reduction structure 4 and the airflow guiding structure 3, initialize the distance between the noise reduction structure 4 and the airflow guiding structure 3 to an initial distance. When the range hood starts, initialize the noise reduction structure 4 to its initial position. At this time, the distance between the noise reduction structure 4 and the airflow guiding structure 3 is the initial distance, so that each adjustment of the distance between the noise reduction structure 4 and the airflow guiding structure 3 is based on the same reference position. When the operating state of the range hood changes, resulting in a change in noise or a change in motor speed, the drive device 5 first pushes or pulls the noise reduction structure 4 back to its initial position, and then readjusts the appropriate position of the noise reduction structure 4 according to the original settings. The current position of the noise reduction structure 4 can be measured by a displacement sensor, thereby facilitating the initialization of the noise reduction structure 4 to its initial position.

[0057] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A range hood characterized by, The device comprises a smoke collecting cavity (1), a wind channel structure (2), a flow guide structure (3) and a noise reduction structure (4) arranged in the smoke collecting cavity (1), the flow guide structure (3) is used for guiding the airflow in the smoke collecting cavity (1) to the wind channel structure (2), the noise reduction structure (4) is arranged on the outer circumferential side of the wind channel structure (2), the distance between the noise reduction structure (4) and the flow guide structure (3) is adjustable, the outer circumferential side space of the flow guide structure (3), the noise reduction structure (4) and the wind channel structure (2) forms a double-layer resonance sound absorption cavity, and the porosities of the flow guide structure (3) and the noise reduction structure (4) are different.

2. The hood according to claim 1, characterized in that, The device further comprises a driving device (5) used for driving the noise reduction structure (4) to move so as to adjust the distance between the noise reduction structure (4) and the flow guide structure (3).

3. The hood according to claim 2, characterized in that, The driving device (5) comprises a driving member (51) and a push rod (52), the driving member (51) is capable of moving the noise reduction structure (4) through the push rod (52) so as to adjust the distance between the noise reduction structure (4) and the flow guide structure (3).

4. The hood according to claim 1, characterized in that, The device further comprises a noise sensor (6) used for measuring the noise value of the range hood.

5. The hood according to claim 1, characterized in that, The device further comprises a rotating speed sensor used for measuring the rotating speed of the fan of the wind channel structure (2).

6. The hood according to claim 1, characterized in that, The flow guide structure (3) is provided with an avoiding hole (31) and a first noise reduction hole (32), the avoiding hole (31) is communicated with the air inlet of the wind channel structure (2).

7. The hood according to claim 1, characterized in that, The flow guide structure (3) is provided with a sound absorption layer.

8. The hood according to claim 1, characterized in that, The flow guide structure (3) is an arc-shaped structure with thick periphery and thin middle.

9. The hood according to claim 1, characterized in that, The device further comprises a telescopic cavity (8) movably connected with the smoke collecting cavity (1).

10. A noise reduction control method for a range hood, the method comprising: The device is used for controlling the range hood as claimed in any one of claims 1-9, and the noise reduction control method of the range hood comprises the following steps. In different fan rotating speed conditions, the preset distance between the noise reduction structure (4) and the flow guide structure (3) corresponding to the lowest noise value is respectively obtained through experiments; According to the currently selected fan rotating speed, the distance between the noise reduction structure (4) and the flow guide structure (3) is adjusted to the preset distance.

11. The range hood noise reduction control method of claim 10, wherein, The device further comprises the following steps: In different noise value conditions, the target distance between the noise reduction structure (4) and the flow guide structure (3) corresponding to the lowest noise value is respectively obtained through experiments; According to the currently measured noise value, the distance between the noise reduction structure (4) and the flow guide structure (3) is adjusted from the preset distance to the target distance.

12. The range hood noise reduction control method of claim 10, wherein, The device further comprises the following steps: Before adjusting the distance between the noise reduction structure (4) and the flow guide structure (3), the distance between the noise reduction structure (4) and the flow guide structure (3) is initialized to an initial distance.

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