Grille and air conditioner

Abstract

The present invention provides a mesh cover and an air conditioner. The mesh cover is arranged behind an axial flow fan blade, and comprises: an inner frame (1); a middle frame (2) arranged outside the inner frame (1); an outer frame (3) arranged outside the middle frame (2); a first radial rib (4) arranged between the inner frame (1) and the middle frame (2); a second radial rib (5) arranged between the middle frame (2) and the outer frame (3), and the first radial rib (4) and the second radial rib (5) have opposite rotation directions. The mesh cover is divided into two inner and outer regions, and radial ribs with opposite rotation directions are arranged in the inner and outer regions, so that the reverse winds flowing out of the two regions are mixed and dissipated with each other, thereby reducing aerodynamic noise, expanding the wind outlet area, and increasing the wind outlet volume.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to a mesh cover and an air conditioner. Background Art

[0002] The coupled flow field distribution of the air duct system of the outdoor unit of the air conditioner directly affects the aerodynamic noise and air volume, and thus affects the overall performance of the air conditioner. In the air duct system of the outdoor unit of the air conditioner, the geometric structure of the mesh is a key component that affects the air velocity distribution of the outdoor unit outlet. Large-scale low-speed air flow vortices are easily formed near the center of the mesh, causing the air flow at the outlet to deteriorate. A large amount of gas backflow increases the turbulent noise of the system and increases the resistance of the system's air outlet, which reduces the circulating air volume of the entire system. Summary of the invention

[0003] The main purpose of the present invention is to provide a mesh cover and an air conditioner, by arranging radial ribs with opposite rotation directions in the two areas inside and outside the mesh cover, so that the reverse winds flowing out of the two areas are mixed and dissipated with each other, thereby reducing aerodynamic noise, expanding the air outlet area, and increasing the air outlet volume.

[0004] On one hand, the present invention provides a mesh cover, which is arranged behind an axial flow fan blade, and is characterized in that the mesh cover includes: an inner frame 1; a middle frame 2, which is arranged outside the inner frame 1; an outer frame 3, which is arranged outside the middle frame 2; a first radial rib 4, which is arranged between the inner frame 1 and the middle frame 2; a second radial rib 5, which is arranged between the middle frame 2 and the outer frame 3, and the first radial rib 4 and the second radial rib 5 have opposite rotation directions.

[0005] Therefore, radial ribs with opposite rotation directions are arranged in the two areas inside and outside the mesh cover, so that the reverse winds flowing out of the two areas are mixed and dissipated with each other, reducing aerodynamic noise, expanding the wind outlet area, and increasing the air outlet volume.

[0006] Optionally, the first radial ribs 4 have a rotation direction opposite to that of the axial flow blades, and the second radial ribs 5 have a rotation direction identical to that of the axial flow blades.

[0007] As a result, the gas backflow in the central region is further reduced.

[0008] Optionally, the orthographic projection of the second radial rib 5 in a plane perpendicular to the axis is an arc, and the area between the middle frame 2 and the outer frame 3 is evenly divided into M areas 6 , and each area 6 is provided with N second radial ribs 5 .

[0009] Optionally, each of the second radial ribs 5 forms a connection point with the outer frame 3, and along the rotation direction of the second radial ribs 5, the central angle formed by the connection point corresponding to two adjacent second radial ribs 5 in the region 6 and the center of the mesh is α 1 , α2 ,……,α N , α 1 <α 2 <……<α N .

[0010] Optionally, the difference between two adjacent central angles is (1 / N)°.

[0011] As a result, the spacing between the radial ribs in the central area is increased, the air outlet area is increased, the air outlet resistance is reduced, and the grille in the outer area of ​​the mesh cover is reinforced.

[0012] Optionally, the central angle α N ≤8mm / R3, wherein R3 is the radius of the outer frame 3.

[0013] Therefore, it is ensured that the gaps between the second radial ribs of the mesh cover meet the safety regulations.

[0014] Optionally, the orthographic projections of the N second radial ribs 5 in the region 6 in a plane perpendicular to the axis are concentric circular arcs.

[0015] Optionally, the middle frame 2 and the outer frame 3 are equally divided into M areas 6 by M second radial ribs 5, or the middle frame 2 and the outer frame 3 are equally divided into M areas 6 by M third radial ribs 8, and the orthographic projection of the third radial rib 8 in a plane perpendicular to the axis is a line segment.

[0016] Therefore, when the second radial ribs are used for equal distribution, the cost is reduced.

[0017] Optionally, the second radial rib 5 or the third radial rib 8 that equally divides the middle frame 2 and the outer frame 3 is the boundary of the region 6 , and one end of the second radial rib 5 in the region 6 is connected to the boundary or the middle frame 2 .

[0018] Optionally, the number M of the regions 6 ranges from K to 2K, wherein K is the number of blades in the axial flow fan blade.

[0019] Thus, the grilles in the outer area of ​​the mesh cover are divided into zones by corresponding blades, thereby improving the air outlet effect of the grilles in the outer area of ​​the mesh cover.

[0020] Optionally, the orthographic projection of the first radial rib 4 in a plane perpendicular to the axis is an arc, and two ends of the arc are tangent to the inner frame 1 and the middle frame 2 respectively.

[0021] This facilitates air flow and avoids increasing air flow resistance.

[0022] Optionally, the inclination angle of the air guide surface of the first radial rib 4 relative to the axis changes with the radial distance between the air guide surface of the first radial rib 4 and the axis, and / or the inclination angle of the air guide surface of the second radial rib 5 relative to the axis changes with the radial distance between the air guide surface of the second radial rib 5 and the axis.

[0023] Optionally, the inclination angle of the air guiding surface of the first radial rib 4 relative to the axis ranges from 10° to 25°.

[0024] Optionally, the inclination angle of the air guiding surface of the second radial rib 5 relative to the axis ranges from 10° to 20°.

[0025] Therefore, the inclination angle of the ribs matches the wind outlet angle of the fan blades, thereby improving the rectification effect.

[0026] Optionally, the number of the first radial ribs 4 is 9 to 15.

[0027] In this way, it can be ensured that the spacing between the first radial ribs meets the safety requirements, and it can also be avoided that the air volume is reduced and the air noise is increased due to the increase of the air resistance.

[0028] Optionally, the radius R2 of the middle frame 2 ranges from 0.1R3 ​​to 0.2R3, wherein R3 is the radius of the outer frame 3 .

[0029] As a result, the circumferential component velocity loss of the rectified airflow outlet velocity is reduced.

[0030] Optionally, the mesh cover further includes: one or more annular ribs 7, which are arranged in the outer frame 3 and have a radial distance from the outer frame 3 that is less than a preset value.

[0031] Therefore, the grille on the outer frame is encrypted to enhance the strength of the mesh cover.

[0032] Another aspect of the present invention provides an air conditioner, comprising the mesh cover as described above.

[0033] The air conditioner has the same advantages as the above-mentioned mesh cover, which will not be described here. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A The structure diagram of the mesh cover provided by one embodiment of the present invention is schematically shown;

[0035] Figure 1B The structure diagram of the mesh cover provided by another embodiment of the present invention is schematically shown;

[0036] Figure 2A The schematic diagram shows the structure of the area 6 in the mesh cover provided by one embodiment of the present invention;

[0037] Figure 2B The schematic diagram shows the structure of the area 6 in the mesh cover provided by another embodiment of the present invention;

[0038] Figure 3A A schematic diagram showing the inclination angle direction of the first radial ribs in the mesh cover provided by an embodiment of the present invention is shown;

[0039] Figure 3B A schematic diagram showing the inclination angle direction of the second radial ribs in the mesh cover provided by an embodiment of the present invention is shown;

[0040] Figure 3C The schematic diagram of the velocity triangle of the airflow in the mesh cover provided by an embodiment of the present invention is schematically shown.

[0041] Description of reference numerals:

[0042] 1-inner frame; 2-middle frame; 3-outer frame; 4-first radial rib; 5-second radial rib; 6-region; 7-annular rib; 8-third radial rib. DETAILED DESCRIPTION

[0043] In order to make the application purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0044] Figure 1A The schematic diagram of the structure of the mesh cover provided by an embodiment of the present invention is shown schematically. In this embodiment, the air conditioner outdoor unit is used as the application scenario. Figure 1A , while combining Figure 1B-Figure 3C , the mesh cover in this embodiment is described in detail.

[0045] like Figure 1A As shown, the mesh cover includes an inner frame 1, a middle frame 2 and an outer frame 3, wherein the inner frame 1, the middle frame 2 and the outer frame 3 are concentric rings, and the middle frame 2 is arranged between the inner frame 1 and the outer frame 3. The inner frame 1 and the middle frame 2 divide the mesh cover into three parts, namely, the part surrounded by the inner frame 1, the part between the inner frame 1 and the middle frame 2, and the part between the middle frame 2 and the outer frame 3. The mesh cover also includes a first radial rib 4 arranged between the inner frame 1 and the middle frame 2, and a second radial rib 5 arranged between the middle frame 2 and the outer frame 3, and the first radial rib 4 and the second radial rib 5 have opposite rotation directions. The first radial rib 4 connects the inner frame 1 and the middle frame 2, and the second radial rib 5 connects the middle frame 2 and the outer frame 3.

[0046] In the embodiment of the present invention, the mesh cover is arranged behind the axial flow fan blade, that is, arranged on the air outlet side of the axial flow fan blade. The axial flow fan blade is, for example, an electric fan, an air conditioner outdoor unit fan, etc. The first radial rib 4 rotates in the opposite direction to the axial flow fan blade, and the second radial rib 5 rotates in the same direction as the axial flow fan blade.

[0047] Taking the clockwise rotation direction of the axial flow fan blade as an example, the first radial rib 4 rotates in the counterclockwise direction, and the second radial rib 5 rotates in the clockwise direction. Figure 1A The mesh disturbs the flow field of the axial fan outlet, and the central area (i.e., the area between the middle frame 2 and the inner frame 1) generates a counterclockwise vortex airflow, and the peripheral area (i.e., the area between the middle frame 2 and the outer frame 3) generates a clockwise vortex airflow. These two reverse vortex airflows are combined and dissipated, reducing the air backflow in the central area and the vortex intensity in the peripheral area, reducing aerodynamic resistance, reducing aerodynamic noise, expanding the blowing area, and increasing the air output.

[0048] The orthographic projection of the first radial rib 4 in a plane perpendicular to the axis of the mesh cover is an arc, and the two ends of the arc are tangent to the inner frame 1 and the middle frame 2 respectively, so that when the area between the middle frame 2 and the inner frame 1 is much smaller than the area between the middle frame 2 and the outer frame 3, the first radial rib 4 can still ensure that the counterclockwise vortex airflow formed is sufficient to be mixed and dissipated with the clockwise vortex airflow. The number of the first radial ribs 4 between the inner frame 1 and the middle frame 2 is set to 9 to 15, which can not only ensure that the spacing of the first radial ribs meets the safety requirements, but also avoid the increase of wind resistance, reduction of wind volume and increase of wind noise due to too small spacing.

[0049] The orthographic projection of the second radial rib 5 in a plane perpendicular to the axis is an arc. The area between the middle frame 2 and the outer frame 3 is evenly divided into M regions 6. Each region 6 is provided with N second radial ribs 5, where N is an integer greater than 1. Each second radial rib 5 forms a connection point with the outer frame 3. Along the rotation direction of the second radial rib 5, the connection points of the N second radial ribs 5 in the region 6 with the outer frame 3 are A 1 , A 2 ,……,A N , the connection point A corresponding to two adjacent second radial ribs 5 in region 6 n-1 , A n The line connecting the center of the mesh screen forms a central angle α n , n = 1, 2, ..., N, where α 1 It is the connection point between the boundary of area 6 and its adjacent area and the outer frame 3, and the connection point A 1 The line connecting the center of the mesh screen forms a central angle. n ≤8mm / R3, that is, the length of the outer frame 3 between any two adjacent connection points is R3*α nNot greater than 8 mm, n=1, 2, ..., N, wherein R3 is the radius of the outer frame 3.

[0050] According to an embodiment of the present disclosure, the N second radial ribs 5 in the region 6 are concentric arcs, that is, the region 6 is composed of N concentric second radial ribs 5. It can be understood that the N second radial ribs 5 in the region 6 can also be non-concentric arcs, that is, the region 6 is composed of N non-concentric second radial ribs 5.

[0051] In one embodiment of the present disclosure, the middle frame 2 and the outer frame 3 are evenly divided into M areas 6 by M second radial ribs 5, and the two ends of the M second radial ribs 5 are respectively connected to the middle frame 2 and the outer frame 3. Figure 1A As shown, the region 6 formed is as Figure 2A In another embodiment of the present disclosure, the middle frame 2 and the outer frame 3 are equally divided into M areas 6 by M third radial ribs 8. The orthographic projection of the third radial rib 8 in a plane perpendicular to the axis is a line segment. The extension line of the third radial rib 8 passes through the center of the gate. Figure 1B As shown, the region 6 formed is as Figure 2B As shown. The second radial ribs 5 or the third radial ribs 8 that equally divide the middle frame 2 and the outer frame 3 are the boundaries of the region 6, and one end of the N second radial ribs 5 in the region 6 is connected to its boundary or to the middle frame 2. Specifically, along the rotation direction of the second radial ribs 5, one end of the 1st to kth second radial ribs 5 is connected to the boundary of the region 6, and one end of the k+1th to Nth second radial ribs 5 is connected to the inner frame 2, k is an integer greater than 1 and less than N, and the other ends of these N second radial ribs 5 are all connected to the outer frame 3. The number M of regions 6 ranges from K to 2K, where K is the number of blades in the axial flow fan blade.

[0052] In one embodiment of the present disclosure, the N central angles formed in the region 6 are equal, that is, α 1 =α 2 =……=α N The arc length of the outer frame 3 between two adjacent connection points is R3*α n ≤8mm. In addition, since the area between the middle frame 2 and the outer frame 3 is divided into M areas 6, α 1 +α 2 +……+α N =2π / M,α 1 =α 2 =……=α N =2π / MN, and R3*α n ≤8mm.

[0053] In another embodiment of the present disclosure, the N central angles formed in the region 6 are not equal, and α 1 <α 2 <……<αN The difference between two adjacent center angles is α n -α n-1 = (1 / N)°, the arc length R3*α of the outer frame 3 between the N-1th second radial rib 5 and the Nth second radial rib 5 N In addition, since the area between the middle frame 2 and the outer frame 3 is divided into M areas 6, α 1 +α 2 +……+α N =2π / M. The closer to the middle frame 2, the greater the outlet pressure and wind speed. Reducing the spacing of the second radial ribs 5 can reinforce the mesh cover. However, reducing the spacing will reduce the outlet area, increase the outlet resistance, and reduce the air volume. Therefore, in this embodiment, setting α 1 <α 2 <……<α N , R3*α N ≤8mm, which can not only ensure that the rib spacing at the middle frame 2 is large to increase the air output, but also make the maximum rib spacing meet the safety regulations.

[0054] Take the case where the number of blades K in the axial flow fan blade is 3, the number of regions 6 M is 2K (i.e. 6), the number of second radial ribs 5 N in each region 6 is 11, and the rotation direction of the second radial ribs 5 is clockwise as an example to explain region 6. Figure 1A The middle frame 2 and the outer frame 3 are divided into six regions 6 by six second radial ribs 5. Each region 6 is as follows. Figure 2A See Figure 2A , the region 6 is composed of eleven concentric second radial ribs 5. Along the clockwise direction, the intersections between the eleven second radial ribs 5 and the outer frame 3 are A1, A2, ..., A11, respectively. The first second radial rib 5 is close to the outer frame 3. Relative to the first second radial rib 5, the other second radial ribs 5 extend in a direction close to the middle frame 2. At this time, the region 6 satisfies the following conditions: α 1 <α 2 <……<α 11 , R3*α 11 ≤8mm, α 1 +α 2 +……+α 11 =π / 3,α n =(4.9+n / 11)°, n=1, 2, ..., 11, α n -α n-1 =(1 / 11)°.

[0055] In this embodiment, the mesh cover is arranged on the air outlet side of the axial flow fan blade. Taking the outdoor unit of the air conditioner as an example, when the air conditioner model and the rotation angular velocity are determined, the angle θ between the air flow flowing out of the outlet side at the radius R of the axial flow fan blade and the blade axis is related to R. The larger R is (i.e., the farther away from the axis, the larger the radial distance from the axis), the smaller θ is. In order to ensure the air outlet effect of the mesh cover, it is necessary to set the inclination angle of the air guide surface of the first radial rib 4 and / or the second radial rib 5 relative to the axis. Specifically, the inclination angle of the air guide surface of the first radial rib 4 and / or the second radial rib 5 relative to the axis is matched with the air outlet angle of the axial flow fan blade (i.e., the angle between the air flow flowing out of the outlet side of the axial flow fan blade and the blade axis) to reduce the resistance of the air guide surface of the first radial rib 4 and / or the second radial rib 5 to the air flow, ensure the air outlet, and achieve a better air guide effect. When the axial flow fan blade operates at different speeds, the wind outlet angle will change. Therefore, the inclination angle of the wind guide surface of the first radial rib 4 and / or the second radial rib 5 relative to the axis cannot be consistent with the wind outlet angle at each speed. In this embodiment, the inclination angle of the wind guide surface of the first radial rib 4 and / or the second radial rib 5 relative to the axis is matched with the wind outlet angle of the axial flow fan blade, so that the difference between the inclination angle of the wind guide surface of the first radial rib 4 and / or the second radial rib 5 relative to the axis and the wind outlet angle of the axial flow fan blade at each speed is maintained between -3° and 3°. Since the wind outlet angle of the axial flow fan blade changes with the radial distance between the axial flow fan blade and the axis, the inclination angle of the wind guide surface of the first radial rib 4 relative to the axis changes with the radial distance between the wind guide surface of the first radial rib 4 and the axis, and / or the inclination angle of the wind guide surface of the second radial rib 5 relative to the axis changes with the radial distance between the wind guide surface of the second radial rib 5 and the axis.

[0056] Specifically, the value range of the inclination angle β1 of the air guide surface of the first radial rib 4 relative to the axis is 10° to 25°, and the inclination direction of the inclination angle of the air guide surface of the first radial rib 4 relative to the axis is as follows: Figure 3A The value range of the inclination angle β2 of the air guide surface of the second radial rib 5 relative to the axis is 10° to 20°, and the inclination direction of the inclination angle of the air guide surface of the second radial rib 5 relative to the axis is as shown in FIG. Figure 3B shown.

[0057] See also Figure 3C , the absolute velocity v of the airflow can be decomposed into the relative velocity w and the circumferential velocity u. The directions of the relative velocity w and the circumferential velocity u remain unchanged. Figure 3A, after the airflow is rectified by the first radial ribs 4 between the inner frame 1 and the middle frame 2, the direction of the absolute velocity v of the airflow changes, thereby forming a counterclockwise vortex airflow, the absolute velocity of the vortex airflow is v1, and the circumferential velocity obtained after the absolute velocity v1 is decomposed is less than the circumferential velocity u obtained after the absolute velocity v of the airflow is decomposed. It can be seen that there is a certain loss in the circumferential component velocity of the airflow outlet velocity after rectification. The larger the size of the middle frame 2, the greater the change in the direction of the airflow by the first radial ribs 4 between the middle frame 2 and the inner frame 1, and the greater the loss of the circumferential component velocity of the airflow outlet velocity after rectification. Therefore, the size of the middle frame 2 should not be too large. In this application, the range of the radius R2 of the middle frame 2 is set to 0.1R3 ​​to 0.2R3, where R3 is the radius of the outer frame 3, so as to reduce the loss of the circumferential component velocity after the airflow is rectified.

[0058] The mesh cover also includes one or more annular ribs 7, which are arranged in the outer frame 3 and have a radial distance from the outer frame 3 that is less than a preset value. In this embodiment, the grille is densified near the outer frame 3, that is, a plurality of annular ribs 7 having a smaller radial distance from the outer frame 3 are arranged in the mesh cover, so that the radius of the annular ribs 7 is slightly smaller than the radius R3 of the outer frame 3, thereby enhancing the strength of the mesh cover.

[0059] In this embodiment, the middle frame is used to divide the mesh cover into two inner and outer areas. The area between the inner frame and the middle frame is provided with radial ribs whose rotation direction is opposite to that of the axial flow fan blades. The area between the middle frame and the outer frame is provided with radial ribs whose rotation direction is the same as that of the axial flow fan blades. Spiral airflows in opposite directions are formed in the two areas, and the reverse winds flowing out of the two areas are mixed and dissipated with each other, thereby reducing aerodynamic noise, expanding the blowing area, and increasing the air output.

[0060] Another embodiment of the present invention provides an air conditioner, which includes the mesh cover in the above embodiment, and the mesh cover is located on the air outlet side of the axial flow fan blades of the air conditioner.

[0061] The air conditioner has the same technical features as the mesh cover in the above embodiment, and has the same advantages as the mesh cover in the above embodiment, which will not be repeated here.

[0062] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A mesh cover, arranged behind an axial flow fan blade, characterized in that: The mesh cover comprises: Inner frame (1); A middle frame (2) is arranged outside the inner frame (1); An outer frame (3) is arranged outside the middle frame (2); A first radial rib (4) arranged between the inner frame (1) and the middle frame (2); A second radial rib (5) is arranged between the middle frame (2) and the outer frame (3), wherein the first radial rib (4) and the second radial rib (5) rotate in opposite directions; The first radial rib (4) rotates in the opposite direction to the axial flow fan blade, the second radial rib (5) rotates in the same direction as the axial flow fan blade, the orthographic projection of the second radial rib (5) in a plane perpendicular to the axis is an arc, the middle frame (2) and the outer frame (3) are equally divided into M regions (6), each of the regions (6) is provided with N second radial ribs (5), the number M of the regions (6) ranges from K to 2K, wherein K is the number of blades in the axial flow fan blade, the inclination angle of the air guide surface of the first radial rib (4) relative to the axis varies with the radial distance between the air guide surface of the first radial rib (4) and the axis, and / or the inclination angle of the air guide surface of the second radial rib (5) relative to the axis varies with the radial distance between the air guide surface of the second radial rib (5) and the axis, and the number of the first radial ribs (4) is 9 to 15.

2. The mesh cover according to claim 1, characterized in that: Each of the second radial ribs (5) forms a connection point with the outer frame (3), and along the rotation direction of the second radial ribs (5), the central angles formed by the connection points corresponding to two adjacent second radial ribs (5) in the region (6) and the center of the mesh cover are α1, α2, ..., α N , α1<α2<……<α N .

3. The mesh cover according to claim 2, characterized in that: The difference between two adjacent central angles is (1 / N)°.

4. The mesh cover according to claim 2, characterized in that: The central angle α N ≤8mm / R3, wherein R3 is the radius of the outer frame (3).

5. The mesh cover according to claim 1, characterized in that: The orthographic projections of the N second radial ribs (5) in the region (6) in a plane perpendicular to the axis are concentric circular arcs.

6. The mesh cover according to claim 1, characterized in that: The middle frame (2) and the outer frame (3) are equally divided into M areas (6) by M second radial ribs (5), or the middle frame (2) and the outer frame (3) are equally divided into M areas (6) by M third radial ribs (8), and the orthographic projection of the third radial rib (8) in a plane perpendicular to the axis is a line segment.

7. The mesh cover according to claim 6, characterized in that: The second radial rib (5) or the third radial rib (8) which equally divides the middle frame (2) and the outer frame (3) is the boundary of the area (6), and one end of the second radial rib (5) in the area (6) is connected to the boundary or to the middle frame (2).

8. The mesh cover according to claim 1, characterized in that: The orthographic projection of the first radial rib (4) in a plane perpendicular to the axis is an arc, and two ends of the arc are tangent to the inner frame (1) and the middle frame (2) respectively.

9. The mesh cover according to claim 1, characterized in that: The inclination angle of the air guide surface of the first radial rib (4) relative to the axis ranges from 10° to 25°.

10. The mesh cover according to claim 1, characterized in that: The inclination angle of the air guide surface of the second radial rib (5) relative to the axis ranges from 10° to 20°.

11. The mesh cover according to claim 1, characterized in that: The radius R2 of the middle frame (2) ranges from 0.1R3 ​​to 0.2R3, wherein R3 is the radius of the outer frame (3).

12. The mesh cover according to claim 1, characterized in that: The mesh cover also includes: One or more annular ribs (7) are arranged in the outer frame (3), and the radial distance between the annular ribs and the outer frame (3) is less than a preset value.

13. An air conditioner, characterized in that: The air conditioner comprises the mesh cover as described in any one of claims 1-12.

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