Noise reduction air duct and range hood

Abstract

The invention relates to the technical field of kitchen electric equipment, and discloses a noise reduction air duct and a range hood. The noise reduction air channel comprises a first flow guide plate, a second flow guide plate and a third flow guide plate. The second guide plate is arranged on one side of the first guide plate, and a first flow channel is defined by the second guide plate and the first guide plate. The third flow guide plate is arranged on the other side of the first flow guide plate, and a second flow channel is defined by the third flow guide plate and the first flow guide plate. Wherein the length of the first flow channel and the length of the second flow channel meet the following formula: # imgabs0 # noise sound waves are transmitted in from the end parts of the same sides of the first flow channel and the second flow channel, and are transmitted out from the end parts of the other sides of the first flow channel and the second flow channel to be converged. According to the noise reduction air duct and the range hood, noise can be reduced, and a user can conveniently use and install the noise reduction air duct.

Description

Technical Field

[0001] The present application relates to the technical field of kitchen appliances, for example, to a noise reduction air duct and a range hood. Background Art

[0002] At present, when using range hoods, users are often bothered by the noise of range hoods, which affects the user's cooking experience. When the back pressure of the range hood increases, the fan speed increases, and the noise becomes more obvious.

[0003] In the related art, the fan speed is reduced by increasing the impeller size and the overall width of the fan, thereby reducing the range hood noise.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

[0005] In the related art, after increasing the impeller size and the overall width of the fan, in order to accommodate the large-sized fan, the overall size of the range hood main box needs to be expanded, but the cabinet space is limited, which brings inconvenience to the user's use and installation.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0007] In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key / critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

[0008] The embodiments of the present disclosure provide a noise reduction air duct and a range hood to solve the problem in the related art of reducing the range hood noise by increasing the impeller size and the overall width of the fan, which causes inconvenience to users in use and installation.

[0009] In some embodiments, a noise reduction air duct is provided, comprising: a first guide plate; a second guide plate, disposed on one side of the first guide plate, and defining a first flow channel with the first guide plate; a third guide plate, disposed on the other side of the first guide plate, and defining a second flow channel with the first guide plate; wherein the length of the first flow channel and the length of the second flow channel satisfy the following formula:

[0010]

[0011] Wherein, Ld is the length of the first flow channel, in m; Lc is the length of the second flow channel, in m; λ is the wavelength of the noise sound wave, in m; k is a positive odd number; the noise sound wave is transmitted from the end of the first flow channel and the second flow channel on the same side, and is transmitted from the end of the other side of the first flow channel and the second flow channel and then merged.

[0012] Optionally, the first guide plate, the second guide plate and the third guide plate are all arc-shaped structures and are concentrically arranged, and the first guide plate, the second guide plate and the third guide plate have the same curvature and different radii.

[0013] Optionally, Ld=a·(r1+r2) / 2; Lc=a·(r1+r3) / 2; wherein a is the radian of the first guide plate, the second guide plate and the third guide plate, and the unit is rad; r1 is the radius of the first guide plate, and the unit is m; r2 is the radius of the second guide plate, and the unit is m; r3 is the radius of the third guide plate, and the unit is m.

[0014] Optionally, λ=v / f; wherein λ is the wavelength of the sound wave of the noise, in m; v is the speed of sound, in m / s; and f is the frequency of the noise, in Hz.

[0015] In some embodiments, a range hood is provided, comprising: a noise reduction air duct as described in any of the previous embodiments.

[0016] Optionally, the range hood further includes a fan; the fan is located above the noise reduction air duct; wherein the parameters of the fan and the size of the noise reduction air duct satisfy the following formula:

[0017]

[0018] Wherein, a is the radian of the first guide plate, the second guide plate and the third guide plate, unit: rad; r2 is the radius of the second guide plate, unit: m; r3 is the radius of the third guide plate, unit: m; n is the rated speed of the fan, unit: rpm; N is the number of blades of the fan, unit: piece; k is a positive odd number.

[0019] Optionally, the relationship between the frequency of the noise generated by the fan and the parameters of the fan satisfies the following formula: f=n·N / 60; wherein f is the frequency of the noise, in Hz.

[0020] Optionally, the range hood further includes: a first shell, in which the fan is arranged; a second shell, which is connected to the bottom of the first shell; and a noise reduction air duct is arranged in a space defined by the first shell and the second shell.

[0021] Optionally, the range hood further comprises: an external oil net, arranged at the smoke inlet of the second shell.

[0022] Optionally, the range hood also includes: an inner oil net, arranged at the smoke outlet of the second shell, the inner oil net being provided with strip slits corresponding to the first guide plate, the second guide plate and / or the third guide plate respectively, for the first guide plate, the second guide plate and / or the third guide plate to pass through the inner oil net.

[0023] Optionally, the range hood further comprises: a check valve, which is arranged in the first shell and communicated with the exhaust port of the fan.

[0024] The noise reduction air duct and range hood provided by the embodiments of the present disclosure can achieve the following technical effects:

[0025] In the noise reduction air duct provided by the embodiment of the present disclosure, noise sound waves enter from the ends of the first flow channel and the second flow channel on the same side, and the difference between the length of the second flow channel and the length of the first flow channel is an odd multiple of λ / 2 (λ is the wavelength of the noise sound waves), so that the phases of the noise sound waves after they are transmitted from the ends on the other side of the first flow channel and the second flow channel differ by π, and the noise sound waves converge after being transmitted from the ends on the other side of the first flow channel and the second flow channel, and part of the energy of the sound waves at the confluence cancels each other out, thereby achieving noise reduction.

[0026] The range hood provided in the embodiment of the present disclosure can reduce noise and facilitate user use and installation without increasing the impeller size of the fan and the overall width of the range hood by providing a noise reduction air duct.

[0027] The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

[0029] Figure 1 is a structural schematic diagram of a noise reduction air duct provided by an embodiment of the present disclosure;

[0030] Figure 2 It is a schematic diagram of the noise reduction principle of the noise reduction air duct provided by an embodiment of the present disclosure;

[0031] Figure 3 is a side view schematic diagram of a range hood provided by another embodiment of the present disclosure;

[0032] Figure 4 is a three-dimensional schematic diagram of a range hood provided by another embodiment of the present disclosure;

[0033] Figure 5 is a schematic diagram of the external structure of a range hood provided by another embodiment of the present disclosure;

[0034] Figure 6 It is a schematic diagram of the arrangement relationship between the noise reduction air duct and the fan provided in another embodiment of the present disclosure.

[0035] Reference numerals:

[0036] 100: noise reduction air duct; 101: first guide plate; 102: second guide plate; 103: third guide plate; 104: first flow channel; 105: second flow channel;

[0037] 200: range hood; 201: fan; 202: first shell; 203: second shell; 204: outer oil net; 205: inner oil net; 206: check valve. DETAILED DESCRIPTION

[0038] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0039] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0040] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0041] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0042] Unless otherwise stated, the term "plurality" means two or more.

[0043] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0044] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0045] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other.

[0046] Combination Figures 1 to 4 , Figure 6 As shown, an embodiment of the present disclosure provides a noise reduction air duct 100. The noise reduction air duct 100 includes a first guide plate 101, a second guide plate 102 and a third guide plate 103. The second guide plate 102 is arranged on one side of the first guide plate 101. The second guide plate 102 and the first guide plate 101 define a first flow channel 104. The third guide plate 103 is arranged on the other side of the first guide plate 101. The third guide plate 103 and the second guide plate 102 are respectively located on opposite sides of the first guide plate 101. The third guide plate 103 and the first guide plate 101 define a second flow channel 105. Among them, the length of the first flow channel 104 and the length of the second flow channel 105 satisfy the following formula:

[0047]

[0048] Wherein, Ld is the length of the first flow channel 104, in m. Lc is the length of the second flow channel 105, in m. λ is the wavelength of the sound wave of the noise, in m. k is a positive odd number. The sound wave of the noise enters from the end of the first flow channel 104 and the second flow channel 105 on the same side, and passes out from the end of the other side of the first flow channel 104 and the second flow channel 105 and then merges.

[0049] The noise reduction air duct 100 provided in the embodiment of the present disclosure defines a first flow channel 104 through the second flow guide plate 102 and the first flow guide plate 101, and defines a second flow channel 105 through the third flow guide plate 103 and the first flow guide plate 101, so that the first flow channel 104 and the second flow channel 105 are arranged side by side, thereby realizing the propagation of noise along the first flow channel 104 and the second flow channel 105. The noise sound waves are transmitted from the ends of the first flow channel 104 and the second flow channel 105 on the same side to the first flow channel 104 and the second flow channel 105, propagated in the first flow channel 104 and the second flow channel 105, and finally transmitted from the ends of the other sides of the first flow channel 104 and the second flow channel 105 and then merged, so as to realize noise reduction.

[0050] In the noise reduction air duct 100 provided in the embodiment of the present disclosure, noise waves enter from the ends of the first flow channel 104 and the second flow channel 105 on the same side, and the difference between the length of the second flow channel 105 and the length of the first flow channel 104 is an odd multiple of λ2, so that the phases of the noise waves after they are transmitted out from the ends on the other side of the first flow channel 104 and the second flow channel 105 differ by π, and the noise waves are transmitted out from the ends on the other side of the first flow channel 104 and the second flow channel 105 and merge, and part of the energy of the sound waves at the confluence cancels each other out, thereby achieving noise reduction.

[0051] Combination Figure 1 , Figure 3 , Figure 4 and Figure 6 As shown, in some embodiments, the first guide plate 101, the second guide plate 102 and the third guide plate 103 are all arc-shaped structures and are concentrically arranged. The first guide plate 101, the second guide plate 102 and the third guide plate 103 have the same arc and different radii.

[0052] In this embodiment, the first guide plate 101 is an arc-shaped structure, the second guide plate 102 is an arc-shaped structure, the first guide plate 101 and the second guide plate 102 are concentrically arranged, the curvature of the first guide plate 101 is equal to the curvature of the second guide plate 102, and the radius of the first guide plate 101 is different from the radius of the second guide plate 102, so as to achieve the second guide plate 102 and the first guide plate 101 to define an arc-shaped first flow channel 104.

[0053] In this embodiment, the first guide plate 101 is an arc-shaped structure, the third guide plate 103 is an arc-shaped structure, the first guide plate 101 and the third guide plate 103 are concentrically arranged, the curvature of the first guide plate 101 is equal to the curvature of the third guide plate 103, and the radius of the first guide plate 101 is different from the radius of the third guide plate 103, so as to achieve the third guide plate 103 and the first guide plate 101 to define an arc-shaped second flow channel 105.

[0054] In this embodiment, the second guide plate 102 is an arc-shaped structure, the third guide plate 103 is an arc-shaped structure, the second guide plate 102 and the third guide plate 103 are concentrically arranged, the curvature of the second guide plate 102 is equal to the curvature of the third guide plate 103, and the radius of the second guide plate 102 is different from the radius of the third guide plate 103, so as to realize the side-by-side arrangement of the arc-shaped first flow channel 104 and the arc-shaped second flow channel 105.

[0055] In this embodiment, the second guide plate 102 and the first guide plate 101 define an arc-shaped first flow channel 104, and the third guide plate 103 and the first guide plate 101 define an arc-shaped second flow channel 105, so as to achieve noise reduction while saving installation space. When the noise reduction air duct 100 is applied to the range hood 200, it can reduce noise without increasing the impeller size of the fan, and can also not increase the overall width of the range hood. The arc-shaped first flow channel 104 and the arc-shaped second flow channel 105 are arranged side by side, and the difference between the length of the second flow channel 105 and the length of the first flow channel 104 is an odd multiple of λ2, so that the noise sound wave enters the first flow channel 104 and the second flow channel 105 from the ends on the same side of the first flow channel 104 and the second flow channel 105, propagates in the first flow channel 104 and the second flow channel 105, and finally passes out from the ends on the other sides of the first flow channel 104 and the second flow channel 105 and merges, and part of the energy of the sound waves at the confluence cancels each other, thereby reducing noise.

[0056] Optionally, the curvature of the first guide plate 101 , the curvature of the second guide plate 102 , and the curvature of the third guide plate 103 are all a.

[0057] Combination Figure 1 , Figure 3 , Figure 4 and Figure 6 As shown, optionally, the radius of the first guide plate 101 is r1. The radius of the second guide plate 102 is r2. The radius of the third guide plate 103 is r3. The radius of the first guide plate 101 is r1, the radius of the second guide plate 102 is r2, and the radius of the third guide plate 103 is r3 satisfy the following formula:

[0058] r3>r1>r2.

[0059] Combination Figure 3 As shown, illustratively, the radius r1 of the first guide plate 101, the radius r2 of the second guide plate 102, and the radius r3 of the third guide plate 103 also satisfy the following formula:

[0060]

[0061] Optionally, the structure of the first guide plate 101 , the structure of the second guide plate 102 , and the structure of the third guide plate 103 all include but are not limited to arc plate structures.

[0062] In this embodiment, when the first guide plate 101, the second guide plate 102 and the third guide plate 103 with an arc structure are applied to the range hood 200, they can reduce noise and guide the discharge of oil smoke, making the flow field smoother.

[0063] Combination Figure 3 As shown, optionally, the central angle corresponding to the first guide plate 101, the central angle corresponding to the second guide plate 102 and the central angle corresponding to the third guide plate 103 are the same and are all α.

[0064] Optionally, the radians a of the first guide plate 101 , the second guide plate 102 , and the third guide plate 103 and the central angles α corresponding to the first guide plate 101 , the second guide plate 102 , and the third guide plate 103 satisfy the following formula:

[0065] a=3.14·α / 180.

[0066] Optionally, the central angle α corresponding to the first guide plate 101, the second guide plate 102 and the third guide plate 103 satisfies the following range:

[0067] 30°≤α≤90°.

[0068] Combination Figure 1 , Figure 3 , Figure 4 and Figure 6 As shown, in some embodiments, Ld = a·(r1+r2) / 2. Lc = a·(r1+r3) / 2. Wherein, a is the radian of the first guide plate 101, the second guide plate 102 and the third guide plate 103, in rad. r1 is the radius of the first guide plate 101, in m. r2 is the radius of the second guide plate 102, in m. r3 is the radius of the third guide plate 103, in m.

[0069] In this embodiment, the length of the arc-shaped first flow channel 104 can be obtained by the radius r1 of the first flow guide plate 101, the radius r2 of the second flow guide plate 102, and the curvature a of the first flow guide plate 101 and the second flow guide plate 102. The length of the arc-shaped second flow channel 105 can be obtained by the radius r1 of the first flow guide plate 101, the radius r3 of the third flow guide plate 103, and the curvature a of the first flow guide plate 101 and the third flow guide plate 103.

[0070] In this embodiment, the length of the first flow channel 104 and the length of the second flow channel 105 can be set to an odd multiple of λ / 2, thereby achieving noise reduction of noise sound waves propagating through the first flow channel 104 and the second flow channel 105.

[0071] In some embodiments, λ=v / f; wherein λ is the wavelength of the sound wave of the noise, in m, v is the speed of sound, in m / s, and f is the frequency of the noise, in Hz.

[0072] Exemplarily, the speed of sound v=340 m / s.

[0073] Combination Figure 3 As shown, in this embodiment, when the noise reduction air duct 100 is applied to the range hood 200, the noise generated by the fan 201 of the range hood 200 when working enters the first flow channel 104 and the second flow channel 105 from the upper end of the first flow channel 104 and the upper end of the second flow channel 105. The difference between the length of the second flow channel 105 and the length of the first flow channel 104 is an odd multiple of λ / 2, so that the waveform of the noise sound wave after passing through the lower end of the first flow channel 104 is L1, and the waveform of the noise sound wave after passing through the lower end of the second flow channel 105 is L2. The sound wave propagation distance of the noise sound wave in the second flow channel 105 is longer than the sound wave propagation distance in the first flow channel 104 by an odd multiple of λ2. That is, the phase difference of the noise sound wave at the lower end outlet of the first flow channel 104 and the lower end outlet of the second flow channel 105 at the same time is π. The noise sound waves are transmitted from the lower end of the first flow channel 104 and the lower end of the second flow channel 105 and then merged, and the energy of the sound waves at the confluence cancels each other out, thereby reducing the noise transmitted into the room when the fan 201 is working.

[0074] Combination Figures 1 to 6 As shown, an embodiment of the present disclosure provides a range hood 200, comprising: a noise reduction air duct 100 as in any of the previous embodiments.

[0075] The range hood 200 provided in the embodiment of the present disclosure can reduce noise and facilitate user use and installation without increasing the impeller size of the fan 201 and the overall width of the range hood 200 by providing the noise reduction air duct 100.

[0076] In this embodiment, the noise reduction air duct 100 includes an arc-shaped first flow channel 104 and an arc-shaped second flow channel 105. The arc-shaped first flow channel 104 and the arc-shaped second flow channel 105 are arranged side by side. The difference between the length of the second flow channel 105 and the length of the first flow channel 104 is an odd multiple of λ2. The noise sound waves generated by the operation of the range hood 200 enter from the end of the first flow channel 104 and the second flow channel 105 on the same side, and the difference between the length of the second flow channel 105 and the length of the first flow channel 104 is an odd multiple of λ2, so that the phase difference of the noise sound waves after they are transmitted from the ends on the other side of the first flow channel 104 and the second flow channel 105 is π, and the noise sound waves are transmitted from the ends on the other side of the first flow channel 104 and the second flow channel 105. After being transmitted, the noise sound waves converge, and part of the energy of the sound waves at the confluence cancels each other, thereby achieving noise reduction.

[0077] Combination Figures 3 to 6 As shown, in some embodiments, the range hood 200 further includes a fan 201. The fan 201 is located above the noise reduction air duct 100. The parameters of the fan 201 and the size of the noise reduction air duct 100 satisfy the following formula:

[0078]

[0079] Wherein, a is the radian of the first guide plate 101, the second guide plate 102 and the third guide plate 103, in rad. r2 is the radius of the second guide plate 102, in m. r3 is the radius of the third guide plate 103, in m. n is the rated speed of the fan 201, in rpm. N is the number of blades of the fan 201, in pieces. k is a positive odd number.

[0080] In this embodiment, the main source of noise of the range hood 200 is the noise generated when the fan 201 is working. The noise generated when the fan 201 is working enters the first flow channel 104 and the second flow channel 105 from the upper end of the first flow channel 104 and the upper end of the second flow channel 105. The difference between the length of the second flow channel 105 and the length of the first flow channel 104 is an odd multiple of λ / 2, so that the phase difference of the noise sound wave after it is transmitted from the lower end of the first flow channel 104 and the lower end of the second flow channel 105 is π. The noise sound waves converge after being transmitted from the lower end of the first flow channel 104 and the lower end of the second flow channel 105, and part of the energy of the noise sound waves at the confluence cancels each other to achieve noise reduction.

[0081] In this embodiment, through the relationship formula between the parameters of the fan 201 and the size of the noise reduction air duct 100, it is possible to select and design the parameters of the fan 201 and the size of the noise reduction air duct 100 according to actual needs, so as to reduce noise and facilitate user use and installation without increasing the impeller size of the fan 201 and the overall width of the range hood 200, thereby further meeting the user's usage needs.

[0082] Optionally, the parameters of the fan 201 include a rated rotation speed n of the fan 201 and a number N of blades of the fan 201 .

[0083] Exemplarily, the number N of blades of the fan 201 satisfies the following range:

[0084] 50≤N≤70.

[0085] Optionally, the fan 201 includes a multi-blade centrifugal fan 201 .

[0086] In some embodiments, the relationship between the frequency of the noise generated by the fan 201 and the parameters of the fan 201 satisfies the following formula: f=n·N / 60. In the formula, f is the frequency of the noise, in Hz.

[0087] In this embodiment, the frequency f of the noise generated by the fan 201 can be determined according to the rated speed n of the fan 201 and the number N of blades of the fan 201. The sound wave wavelength λ of the noise can be obtained by the frequency f of the noise and the sound speed v. The length of the second flow channel 105 and the length of the first flow channel 104 are set to meet the difference between the length of the second flow channel 105 and the length of the first flow channel 104 being an odd multiple of λ / 2. The length of the second flow channel 105 and the length of the first flow channel 104 are adjusted according to the selected fan 201. It can not only reduce the noise generated by the fan 201 when it is working, but also meet the user's usage needs and improve user satisfaction.

[0088] For example, taking the fan 201 as a multi-blade centrifugal fan, the noise of the range hood 200 is mainly generated by the rotation of the blades of the multi-blade centrifugal fan, and therefore, the frequency of the noise generated by the rotation of the blades of the multi-blade centrifugal fan is used as the frequency of the noise when the range hood 200 is working. The relationship between the parameters of the fan 201 and the size of the noise reduction air duct 100 is specifically described as follows.

[0089] The rated speed of the fan 201 is n rpm. The number of blades of the fan 201 is N.

[0090] The frequency f (in Hz) of the noise when the range hood 200 is working is obtained according to the following formula:

[0091] f=n·N / 60 (1)

[0092] According to the frequency f of the noise when the range hood 200 is working, the sound wave wavelength λ (in m) of the noise is obtained according to the following formula:

[0093] λ=v / f (2)

[0094] Where v is the speed of sound in m / s.

[0095] Since the second guide plate 102 and the first guide plate 101 define the first flow channel 104, the length Ld (in m) of the first flow channel 104 is obtained according to the following formula:

[0096] Ld=a·(r1+r2) / 2 (3)

[0097] Wherein, a is the radian of the first guide plate 101, the second guide plate 102 and the third guide plate 103, and the unit is rad. r1 is the radius of the first guide plate 101, and the unit is m. r2 is the radius of the second guide plate 102, and the unit is m.

[0098] Since the third guide plate 103 and the first guide plate 101 define the second flow channel 105, the length Lc (in m) of the second flow channel 105 is obtained according to the following formula:

[0099] Lc=a·(r1+r3) / 2 (4)

[0100] Wherein, a is the radian of the first guide plate 101, the second guide plate 102 and the third guide plate 103, and the unit is rad. r2 is the radius of the second guide plate 102, and the unit is m. r3 is the radius of the third guide plate 103, and the unit is m.

[0101] According to the length Ld of the first flow channel 104, the length Lc of the second flow channel 105 and the acoustic wavelength λ of the noise, the length of the first flow channel 104 and the length of the second flow channel 105 satisfy the following formula:

[0102]

[0103] Wherein, k is a positive odd number.

[0104] In this example, k=1; speed of sound v=340 m / s.

[0105] Substituting formula (1) to formula (4) and k = 1 and sound speed v = 340 m / s into formula (5), we obtain:

[0106]

[0107] Simplifying, we get:

[0108]

[0109] Therefore, in this example, the parameters of the fan 201 and the size of the noise reduction duct 100 satisfy:

[0110]

[0111] Exemplarily, when the size of the noise reduction air duct 100 is determined, the specific process of selecting the parameters of the fan 201 is as follows:

[0112] Since the size of the noise reduction air duct 100 has been determined, the radius of the first guide plate 101 is r1, the radius of the second guide plate 102 is r2, the radius of the third guide plate 103 is r3, and the curvature a of the first guide plate 101, the second guide plate 102 and the third guide plate 103 can be obtained.

[0113] According to the formula:

[0114]

[0115] The product of the rated rotation speed n of the fan 201 and the number N of blades of the fan 201 can be obtained.

[0116] Since the number N of blades of the fan 201 is selected in the range of 50 to 70, that is, 50≤N≤70, the number N of blades of the fan 201 is selected according to actual conditions.

[0117] The rated speed n of the fan 201 is selected based on the product of the obtained rated speed n of the fan 201 and the number N of blades of the fan 201 and the selected number N of blades of the fan 201 .

[0118] It can be understood that the rated speed n of the fan 201 and the number N of blades of the fan 201 can be adaptively selected according to actual needs.

[0119] Exemplary, combined Figure 3 As shown, when the parameters of the fan 201 are determined, the specific process of designing the size of the noise reduction air duct 100 is as follows:

[0120] The rated speed n of the fan 201 is obtained to be 1300 rpm, and the number N of blades of the fan 201 is 60.

[0121] The range hood 200 is modeled in solidworks software. Design control points A, B, C and control line G are extracted according to the height H of the first shell 202, the width b of the first shell 202, the upper edge point B of the noise outlet of the fan 201, the lower edge point C of the noise outlet of the fan 201 and the lower edge point A of the oil fume outlet of the external oil net 204.

[0122] In this example, the height H of the first shell 202 is 0.52 m, and the width b is 0.309 m.

[0123] Create an arbitrary arc passing through point A and point B, select the arc and control line G and set the arc to be tangent to the control line G. In the solidworks software, determine that the radius of the arc is r3 = 0.35m, and the center of the arc is point O. The radius r3 of the arc is the radius r3 of the third guide plate 103. The center O of the arc is the center O of the concentric circles where the first guide plate 101, the second guide plate 102 and the third guide plate 103 are located.

[0124] With point O as the center and the distance OC from point O to the lower edge point C of the noise outlet of the fan 201 as the radius, draw an arc with a radius of r2, and the intersection of the arc and the straight line OA is point D. At this time, r2 = 0.17m. The radius r2 of the arc is the radius r2 of the second guide plate 102.

[0125] According to the formula Substitute the radius r3 = 0.35 m of the third guide plate 103, the radius r2 = 0.17 m of the second guide plate 102, the rated speed n of the fan 201 of 1300 rpm and the number N of blades of the fan 201 of 60 into the formula to obtain the radians a of the first guide plate 101, the second guide plate 102 and the third guide plate 103.

[0126] According to the formula a=3.14·α / 180, α=83° is calculated. That is, the central angle α corresponding to the first guide plate 101 , the second guide plate 102 and the third guide plate 103 is 83°.

[0127] With point O as the center and line segment OA as the reference, an arc with an angle α=83° is drawn through point A to obtain arc AB′. Arc AB′ is an arc with a radius of r3. Arc AB′ is the third guide plate 103.

[0128] With point O as the center and line segment OA as the reference, an arc with an angle α=83° is drawn through point D to obtain an arc DC′. Arc DC′ is an arc with a radius of r2. Arc DC′ is the second guide plate 102.

[0129] according to r3=0.35m and r2=0.17m, we get That is, the radius r1 of the first guide plate 101 is obtained to be 0.26 m.

[0130] With O as the center and r1=0.26m as the radius, draw an arc. The intersection of the arc and the line OA is point E, and the intersection of the arc and the line OB' is point E, so arc EF is obtained. Arc EF is an arc with a radius of r1. Arc EF is the first guide plate 101.

[0131] In this example, based on the determined parameters of the fan 201, the radius of the first guide plate 101, the radius of the second guide plate 102, the radius of the third guide plate 103 and the central angle α corresponding to the first guide plate 101, the second guide plate 102 and the third guide plate 103 are obtained, thereby realizing the dimensional design of the noise reduction air duct 100.

[0132] In actual application, the fan 201 is selected and the noise reduction air duct 100 is designed according to actual needs, so as to reduce noise and facilitate user use and installation without increasing the impeller size of the fan 201 and the overall width of the range hood 200, thereby meeting the user's needs.

[0133] Combination Figures 3 to 6As shown, in some embodiments, the range hood 200 further includes a first shell 202 and a second shell 203. The fan 201 is disposed in the first shell 202. The second shell 203 is communicated with the lower part of the first shell 202. The noise reduction air duct 100 is disposed in the space defined by the first shell 202 and the second shell 203.

[0134] In this embodiment, the first housing 202 is used as the main housing of the range hood 200, and the fan 201 can be installed in the first housing 202. The second housing 203 is used as the smoke collecting chamber housing of the range hood 200, and is used to collect smoke. The smoke can enter the first housing 202 through the second housing 203.

[0135] In this embodiment, the installation space defined by the first shell 202 and the second shell 203 can be used to install the noise reduction air duct 100. For example, the first guide plate 101, the second guide plate 102 and the third guide plate 103 of the noise reduction air duct 100 are all located in the installation space and are fixedly connected to the first shell 202.

[0136] When the range hood 200 is working, under the action of the fan 201, the oil smoke enters the first housing 202 through the second housing 203 and the noise reduction air duct 100 and is discharged by the fan 201. Specifically, the flow direction of the oil smoke in the noise reduction air duct 100 is: the oil smoke enters the first flow channel 104 and the second flow channel 105 through the lower end of the first flow channel 104 and the lower end of the second flow channel 105, and then flows out from the upper end of the first flow channel 104 and the upper end of the second flow channel 105. In the process of the oil smoke flowing, the second housing 203 plays a role in gathering the smoke, and the noise reduction air duct 100 plays a role in guiding the oil smoke, making the flow field smoother.

[0137] Meanwhile, the noise generated when the fan 201 is working is the main source of noise of the range hood 200. The noise generated when the fan 201 is working enters the first flow channel 104 and the second flow channel 105 from the upper end of the first flow channel 104 and the upper end of the second flow channel 105. The difference between the length of the second flow channel 105 and the length of the first flow channel 104 is an odd multiple of λ2, so that the phase difference of the noise sound wave after it is transmitted from the lower end of the first flow channel 104 and the lower end of the second flow channel 105 is π. The noise sound waves are transmitted from the lower end of the first flow channel 104 and the lower end of the second flow channel 105 and then merged, and part of the energy of the noise sound waves at the confluence cancels each other to achieve noise reduction.

[0138] In this embodiment, the noise reduction air duct 100 is installed in the space defined by the first shell 202 and the second shell 203, so as to not only guide the oil smoke but also reduce the noise generated by the fan 201 when it is working.

[0139] Combination Figure 3As shown, optionally, the third guide plate 103 is arranged tangentially to the inner wall of the first shell 202 .

[0140] Combination Figure 3 , Figure 4 and Figure 6 As shown, in some embodiments, the range hood 200 further includes an external oil net 204. The external oil net 204 is disposed at the smoke inlet of the second housing 203.

[0141] Combination Figure 3 and Figure 4 As shown, in some embodiments, the range hood 200 further includes an inner oil net 205. The inner oil net 205 is disposed at the smoke outlet of the second housing 203. The inner oil net 205 is provided with strip-shaped slits corresponding to the first guide plate 101, the second guide plate 102 and / or the third guide plate 103, respectively, so that the first guide plate 101, the second guide plate 102 and / or the third guide plate 103 pass through the inner oil net 205.

[0142] In this embodiment, an outer oil net 204 is installed at the smoke inlet of the second housing 203 for filtering the oil smoke for the first time, and an inner oil net 205 is installed at the smoke outlet of the second housing 203 for filtering the oil smoke for the second time.

[0143] In actual use, with the fan 201 providing power, the oil smoke is filtered first through the outer oil net 204 of the second shell 203 and then filtered a second time through the inner oil net 205, and enters the first shell 202 along the noise reduction air duct 100, and is finally discharged through the fan 201.

[0144] In actual application, for a range hood 200 without an inner oil net 205 , the first guide plate 101 , the second guide plate 102 and the third guide plate 103 are all arranged in a space defined by the first shell 202 and the second shell 203 .

[0145] In actual application, for the range hood 200 provided with the inner oil net 205, the first guide plate 101, the second guide plate 102 and / or the third guide plate 103 can pass through the strip slits of the inner oil net 205. For example, the inner oil net 205 is provided with strip slits corresponding to the first guide plate 101, the second guide plate 102 and the third guide plate 103, respectively, and the first guide plate 101, the second guide plate 102 and the third guide plate 103 pass through the strip slits of the inner oil net 205 accordingly. For another example, the inner oil net 205 is provided with strip slits corresponding to the first guide plate 101 and the third guide plate 103, respectively, and the first guide plate 101 and the third guide plate 103 pass through the strip slits of the inner oil net 205 accordingly, and at this time, the second guide plate 102 is located above the inner oil net 205.

[0146] Combination Figures 4 to 6As shown, in some embodiments, the range hood 200 further includes a check valve 206. The check valve 206 is disposed in the first housing 202 and communicated with the exhaust port of the fan 201.

[0147] In this embodiment, a check valve 206 is installed on the first shell 202 and the check valve 206 is connected to the exhaust port of the fan 201 to prevent the exhausted oil smoke from returning to the fan 201, thereby improving the exhaust effect of the range hood 200 and enhancing the user experience.

[0148] In actual use, the fan 201 can provide power to allow the oil smoke to enter the first shell 202 after being filtered through the outer oil net 204 and the inner oil net 205 of the second shell 203, and enter the fan 201 from the air inlet of the fan 201, and be discharged through the exhaust port of the fan 201 and the check valve 206.

[0149] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A noise reduction air duct, characterized in that: include: a first guide plate; A second guide plate is disposed on one side of the first guide plate and defines a first flow channel with the first guide plate; a third guide plate, disposed on the other side of the first guide plate and defining a second flow channel with the first guide plate; The length of the first flow channel and the length of the second flow channel satisfy the following formula: Where, Ld is the length of the first flow channel; Lc is the length of the second flow channel; λ is the wavelength of the noise sound wave; k is a positive odd number; The noise sound wave is transmitted from the ends of the first flow channel and the second flow channel on the same side, and is transmitted from the ends of the first flow channel and the second flow channel on the other side and then merges.

2. The noise reduction air duct according to claim 1, characterized in that: The first guide plate, the second guide plate and the third guide plate are all arc-shaped structures and are concentrically arranged. The first guide plate, the second guide plate and the third guide plate have the same curvature and different radii.

3. The noise reduction air duct according to claim 2, characterized in that: Ld=a·(r1+r2) / 2; Lc=a·(r1+r3) / 2; Wherein, a is the radian of the first guide plate, the second guide plate and the third guide plate; r1 is the radius of the first guide plate; r2 is the radius of the second guide plate; and r3 is the radius of the third guide plate.

4. The noise reduction air duct according to any one of claims 1 to 3, characterized in that: λ = v / f; Where λ is the wavelength of the noise; v is the speed of sound; and f is the frequency of the noise.

5. A range hood, characterized in that: include: The noise reduction air duct according to any one of claims 1 to 4.

6. The range hood according to claim 5, characterized in that: Also includes: The fan is located above the noise reduction air duct; wherein the parameters of the fan and the size of the noise reduction air duct satisfy the following formula: Wherein, a is the radian of the first guide plate, the second guide plate and the third guide plate; r2 is the radius of the second guide plate; r3 is the radius of the third guide plate; n is the rated speed of the fan; N is the number of blades of the fan; and k is a positive odd number.

7. The range hood according to claim 6, characterized in that: The relationship between the frequency of the noise generated by the fan and the parameters of the fan satisfies the following formula: f = n·N / 60; Where f is the frequency of the noise.

8. The range hood according to any one of claims 5 to 7, characterized in that: Also includes: A first housing, in which the fan is disposed; A second shell is communicated with the lower part of the first shell; The noise reduction air duct is arranged in a space defined by the first shell and the second shell.

9. The range hood according to claim 8, characterized in that: Also includes: The outer oil net is arranged at the smoke inlet of the second shell.

10. The range hood according to claim 9, characterized in that: Also includes: The inner oil net is arranged at the smoke outlet of the second shell, and is provided with strip slits corresponding to the first guide plate, the second guide plate and / or the third guide plate respectively, so as to allow the first guide plate, the second guide plate and / or the third guide plate to pass through the inner oil net.

11. The range hood according to claim 8, characterized in that: Also includes: The check valve is arranged on the first housing and is communicated with the exhaust port of the fan.

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