Centrifugal fan air outlet structure, fan and combined fan applying same

Abstract

The application discloses a centrifugal fan air outlet structure, a fan applying the same and a combined fan, and belongs to the technical field of centrifugal fans. The centrifugal fan air outlet structure comprises an outer shell plate, an air outlet and an air inlet. The air inlet is arranged on one side wall of the outer shell plate. The other side of the outer shell plate is open to form an opening. The air outlet is arranged on one end of the outer shell plate. The centrifugal fan air outlet structure further comprises a wind guide part. The wind guide part is arranged on the upper edge of the outer shell plate connected with the air outlet. When viewed along the air outlet direction of the air outlet, the included angle between the inner side of the wind guide part facing the inner cavity and the horizontal plane is B, and 0° < B ≤ 15°. The flow rate difference of the air inlet is adjusted through the inclination angle of the wind guide part, so that the airflow turbulence at the outlet is reduced, the noise of the fan is reduced, and low-pressure surge is eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal fans, and particularly relates to an air outlet structure of a centrifugal fan, a fan using the same, and a combined fan. Background Art

[0002] A centrifugal fan is a device that accelerates gas by a high-speed rotating impeller, then decelerates and changes the flow direction, converting kinetic energy into potential energy. In a centrifugal fan, gas enters the impeller axially, changes to radial when flowing through the impeller, and then enters a diffuser. In the diffuser, the gas changes the flow direction and the cross-sectional area of the pipeline increases to slow down the air flow. This deceleration action converts kinetic energy into pressure energy. The pressure increase mainly occurs in the impeller and secondly in the diffusion process, thereby outputting pressurized air outward.

[0003] A patent with the publication number CN217900019U discloses an air conditioner, including: a housing provided with a fresh air inlet and an air outlet; a fresh air device including a volute, a centrifugal fan, and an air inlet ring. The centrifugal fan is arranged inside the volute. The volute is provided with a volute air inlet and a volute air outlet. The volute air inlet is connected to the fresh air inlet, and the volute air outlet is connected to the air outlet. The air inlet ring is arranged at the volute air inlet. Among them, the diameter of the centrifugal fan is a, and the diameter of the air inlet ring is b, and a and b satisfy the relationship: b ≤ 0.95a. When fresh air passes through the air inlet ring and leads to the centrifugal fan, the air inlet ring will block part of the fresh air flowing into the centrifugal fan, playing a role in rectifying the fresh air. However, the housing of this air conditioner does not consider the uneven air outlet load of the impeller. Its air outlet is horizontally arranged and does not balance the air outlet pressure, resulting in the fan still experiencing surging phenomenon and reducing the air outlet efficiency of the fan. Summary of the Invention

[0004] One of the purposes of the present invention is to provide an air outlet structure of a centrifugal fan, which solves the problem that the existing centrifugal fan has unbalanced air outlet pressure, resulting in fan surging.

[0005] To achieve the above-mentioned invention purpose, the technical solution adopted by the present invention is as follows:

[0006] An air outlet structure of a centrifugal fan includes an outer shell plate, an air outlet, and an air inlet. The air inlet is arranged on one side wall of the outer shell plate. The other side of the outer shell plate is open to form an opening. The air outlet is arranged at one end of the outer shell plate. The outer shell plate has an inner cavity for accommodating the fan. It further includes a wind guiding part. The wind guiding part is arranged on the upper edge of the outer shell plate connected to the air outlet. Looking inward along the air outlet direction of the air outlet, the included angle between the surface of the wind guiding part facing the inner cavity and the horizontal plane is B, 0° < B ≤ 15°. By adjusting the inclination angle of the wind guiding part, the flow velocity difference of the incoming air is adjusted, thereby reducing the air flow turbulence at the outlet, reducing the noise of the fan, and eliminating low-pressure surging.

[0007] Furthermore, the air guide section includes an incoming air section, a transition section, and an outgoing air section connected in sequence. The outer shell plate includes an annular plate and a side plate. The incoming air section extends from the upper part of the annular plate toward the air outlet and gradually approaches the center of the air outlet. The two ends of the transition section are connected to the incoming air section and the outgoing air section respectively, and the transition is smooth. The end of the incoming air section near the air outlet is away from the center of the air outlet. The incoming air section can rectify the air and increase the air velocity.

[0008] Preferably, the tangent at the end of the transition section connected to the incoming air section is parallel to the horizontal line, and the size of the cross-section is changed when the air is discharged to enhance the ability to guide the airflow.

[0009] Preferably, the ratio of the airflow deflection section to the airflow inflection section is 1:5, which improves the ability to balance airflow.

[0010] Preferably, when viewed inward along the air outlet direction, the portion of the air guide near the side plate of the outer casing is lower in height than the portion of the air guide near the opening, so as to balance the airflow based on the air intake difference of the impeller.

[0011] Furthermore, it also includes a volute tongue, which is disposed on the lower edge of the outer casing plate connected to the air outlet, for rectifying the airflow, and can also be combined with the air guide to adjust the airflow pressure.

[0012] Preferably, the volute tongue protrudes towards the air guide section, and the cross-sectional edge of the volute tongue has a smooth transition to rectify the airflow and eliminate the adverse effects of fresh air.

[0013] More preferably, the combination of the volute tongue and the air guide forms the air guide in a wide-mouth shape along the air outlet direction, which can reduce noise after air outlet.

[0014] The second objective of this invention is to provide a fan that solves the problems of unbalanced outlet pressure, large vibration, and high noise in existing centrifugal fans.

[0015] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0016] A fan includes an air outlet structure, a mounting plate, a fan wheel, and a drive motor. The mounting plate is disposed on the opening of the air outlet structure and together with the outer casing plate forms a volute. The fan wheel is rotatably connected inside the volute, and the drive motor is connected to the fan wheel, thereby reducing the vibration of the fan.

[0017] The third objective of this invention is to provide a combined fan that solves the problems of large airflow vibration in existing centrifugal fans and the complexity of producing fans with different power specifications.

[0018] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0019] A combined fan includes a first air outlet structure and a second air outlet structure arranged opposite to each other. The first air outlet structure is the air outlet structure, and the second air outlet structure is a mirror image of the first air outlet structure. The openings of the first air outlet structure and the second air outlet structure are detachably connected. The first air outlet structure and the second air outlet structure are combined to form a fan volute. When the air volume is increased, the anti-surge vibration function of the air outlet structure is retained, and the manufacturing cost is reduced.

[0020] The beneficial effects of this invention are as follows:

[0021] (1) The air outlet structure is provided with an air guide section, which is located on the upper edge connected to the air outlet and extends inward along the air outlet direction. The edge of the air guide section forms an angle with the horizontal line. The air guide section adjusts the degree of cross-sectional change of the outlet to balance the wind pressure from the impeller. Due to the different positions of the impeller when it is inlet, there is a certain deviation in the inlet volume and inlet speed. After the hollow part is sucked in by the impeller, it is expanded in the outer shell plate. When it is discharged outward through the air guide section, the cross-sectional area of ​​each part of the air guide section is different, which compresses the air into the equal parts, thereby eliminating the fan surge and noise caused by the different wind pressure and improving the air outlet efficiency.

[0022] (2) The air guide section on the air outlet structure consists of an incoming air section, a transition section and an outgoing air section connected in sequence. The incoming air section extends towards the center of the air outlet, making the entire air outlet cross section smaller and increasing the air outlet pressure. At the same time, it blocks the fresh air on the edge of the outer shell plate and plays a rectification role. The transition section connects the incoming air section and the outgoing air section, so that the airflow transitions smoothly at the outlet plate and reduces the impact of the airflow on the outer shell plate. The outgoing air section extends away from the air outlet, so that the noise at the edge of the air outlet is reduced.

[0023] (3) The air outlet structure is also provided with a volute tongue, which is set on the lower edge of the outer shell plate connected to the air outlet. The volute tongue protrudes in the direction of the air guide and is opposite to the air guide, which reduces the area of ​​the air outlet and plays the role of rectifying and improving the air outlet speed.

[0024] (4) The combined fan is formed by combining the exhaust fan structure and the solid body of the fan structure mirrored along one side wall to form the fan volute. Looking inward along the direction of air outlet, the air guide part of the air outlet is the highest at the center, and then tilts downward to both sides, changing the cross-sectional shape of the air outlet. This can adjust the pressure of the airflow after it passes through the volute and make the airflow pressure at the outlet balanced. The fan volute is formed by combining two similar exhaust structures, which increases the air volume while reducing the vibration of the entire fan. It is easy to manufacture and generates little noise. Attached Figure Description

[0025] Figure 1 The isometric view of the fan provided by the present invention Figure 1 ;

[0026] Figure 2 The isometric view of the fan provided by the present invention Figure 2 ;

[0027] Figure 3 A cross-sectional view of the fan provided by the present invention;

[0028] Figure 4 A front view of the fan provided by the present invention;

[0029] Figure 5 A side view of the fan provided by the present invention;

[0030] Figure 6 for Figure 5 Cross-sectional view along the upper AA line;

[0031] Figure 7 A front view of the wind turbine provided by the present invention;

[0032] Figure 8 Axonometric view of the combined fan provided in Embodiment 2 of the present invention Figure 1 ;

[0033] Figure 9 Axonometric view of the combined fan provided in Embodiment 2 of the present invention Figure 2 ;

[0034] Figure 10 A front view of a combined fan is provided for Embodiment 2 of the present invention.

[0035] Figure label:

[0036] 1. Air outlet structure; 11. Air outlet; 12. Air inlet; 13. Mounting plate; 14. Outer shell plate; 141. Annular plate; 142. Side plate; 15. Air guide section; 151. Air outflow section; 152. Transition section; 153. Air inflow section; 16. Volute; 17. Opening; 2. Fan wheel; 3. Drive motor; 4. Second air outlet structure. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] like Figures 1-7As shown in the figure, this embodiment discloses an air outlet structure 1 of a centrifugal fan, which includes a housing plate 14, an air outlet 11 and an air inlet 12. The air inlet 12 is arranged on one side wall of the housing plate 14. The other side of the housing plate 14 is open to form an opening 17. The air outlet 11 is arranged at one end of the housing plate 14. The housing plate 14 has an inner cavity for accommodating the fan. It further includes a wind guiding part 15, which is arranged on the upper edge of the housing plate 14 connected to the air outlet 11. Looking inwards along the air outlet direction of the air outlet 11, the included angle between the surface of the wind guiding part 15 facing the inner cavity and the horizontal plane is B, where 0° < B ≤ 15°. Since the shapes of the front and rear parts of the blades of the impeller 2 are different, the effects of the pressure surface and the suction surface of the incoming air on the air are different, and the speeds of the air after being inhaled into the housing plate 14 are different, resulting in turbulence when the air is discharged outwards and the fan surging. The wind guiding part 15 is arranged obliquely, which can adjust the cross-sectional size of the air outlet 11, thereby balancing the air pressure of the outgoing air and preventing the fan from surging.

[0040] Furthermore, the wind guiding part 15 includes an incoming wind section 153, a transition section 152 and an outgoing wind section 151 connected in sequence. The housing plate 14 includes an annular plate 141 and a side plate 142. The incoming wind section 153 extends from the upper part of the annular plate 141 towards the air outlet 11 and gradually approaches the center of the air outlet 11. The two ends of the transition section 152 are respectively connected to the incoming wind section 153 and the outgoing wind section 151, and are in smooth transition. The end of the incoming wind section 153 close to the air outlet 11 is far from the center of the air outlet 11. The incoming wind section 153 adjusts the outgoing air pressure by changing the cross-section before the air outlet. The outgoing wind section 151 is in direct contact with the outside air, and reduces the impact intensity of the air flow by expanding the contact area at the edge, thereby reducing the outgoing air noise.

[0041] Preferably, the tangent line of the end of the transition section 152 connected to the incoming wind section 153 is parallel to the horizontal line, and this end point is the lowest point of the wind guiding part 15. The transition section 152 changes the guiding side line to surface guiding, improving the rectifying ability of the air flow and having little hindrance to the air flow.

[0042] Preferably, the ratio of the outgoing wind section 151 to the incoming wind section 153 is 1:5, controlling the streamline of the entire wind guiding part 15 to minimize noise and surging.

[0043] More preferably, looking inwards along the air outlet direction of the air outlet 11, the horizontal height of the part of the wind guiding part 15 close to one side wall is higher than the part of the wind guiding part 15 close to the opening 17, so that the wind guiding part 15 is in Figure 5The fan is arranged with a lower left and higher right side, and the air intake is from the opposite direction of the included angle B. The air pressure is greater on the side of the air outlet 11 that is closer to the air inlet 12. Affected by the air pressure angle C and the air suction angle D of the impeller 2, the fan will experience surging vibration when the air volume is less than a certain amount. The air guide part 15 is needed to compensate for the airflow to make the air volume at the air outlet 11 balanced, thereby reducing vibration while ensuring air pressure and air volume.

[0044] The air outlet structure 1 is also provided with a volute tongue 16. The volute tongue 16 is located on the lower edge of the outer shell plate 14 connected to the air outlet 11. The volute tongue 16 can eliminate the fresh air entering along the annular plate 141. The fresh air here is less affected by the diffusion effect, and the fresh air discharged from the air outlet 11 will slow down the overall air outlet speed.

[0045] Preferably, the volute tongue 16 protrudes towards the air guide 15, and the cross-sectional edge of the volute tongue 16 is smoothly transitioned. The combination of the volute tongue 16 and the air guide 15 reduces the area of ​​the cross-section at the air outlet 11, thereby increasing the wind pressure.

[0046] More preferably, the volute tongue 16 and the air guide 15 are combined to form a flared air outlet section 151 along the air outlet direction. When the pressurized airflow discharged by the fan at the outermost end of the air outlet 11 comes into contact with the outside air, it will cause an impact and cause the fan to vibrate. The flared air outlet section 151 buffers the pressurized airflow, reduces the airflow impact at the outermost edge of the air outlet 11, and thus reduces the vibration and noise generated by the fan.

[0047] A fan includes an air outlet structure 1, a mounting plate 13, a fan wheel 2, and a drive motor 3. The mounting plate 13 is disposed on the opening 17 of the air outlet structure 1 to form a volute. The mounting plate 13 is used for wall mounting. The fan wheel 2 is rotatably connected inside the volute. The drive motor 3 is connected to the fan wheel 2. The drive motor 3 drives the fan wheel 2 to rotate clockwise, drawing air into the volute along the axial direction of the outer shell plate 14 for diffusion. The diffused air is discharged outward from the air outlet 11. During discharge, the air is subjected to the pressure equalization effect of the air guide 15, reducing the generation of turbulence after the air is discharged.

[0048] See Figure 7 Preferably, the impeller 2 is a forward-curved multi-blade centrifugal impeller with an inlet pressure angle of C, an outlet pressure angle of D, an inlet suction angle of E, and an outlet suction angle of F. The inlet pressure angle C of the blades is between 70° and 80°, and the corresponding outlet pressure angle D is between 15° and 20°. The inlet suction angle E is 2° to 5° larger than the inlet pressure angle C, and the outlet suction angle F is 2° to 4° larger than the outlet pressure angle D. The air guide section 15 is set with a tilt angle B ranging from 2° to 8° to balance the air intake difference of the impeller, which can greatly reduce the surge of the fan while ensuring the air volume.

[0049] The working process of this fan is as follows:

[0050] Air enters the volute through the axial air inlet 12. The impeller 2 compresses and draws in the air. Under the centrifugal force of the impeller 2, the air is compressed and diffused by the volute, giving it sufficient kinetic energy and flow rate. The compressed air then reaches the air outlet 11, where it is rectified by the volute tongue 16 and the air guide 15. The air is pressure-equalized by the air guide 15, ensuring that the axial airflow and flow rate are consistent. Finally, the air is discharged outward through the air outlet 11. During discharge, the air is discharged to the outside along the expansion of the exhaust section 151, weakening the impact of the airflow mixing with the outside air at the edge, thereby reducing the vibration and noise of the exhaust.

[0051] Example 2

[0052] like Figures 8-10 As shown, this embodiment also discloses a combined fan, including a first air outlet structure and a second air outlet structure 4. The first air outlet structure is the air outlet structure of the first fan, and the second air outlet structure 4 is a mirror image of the first air outlet structure. The openings 17 of the first air outlet structure and the second air outlet structure 4 are detachably connected. The first air outlet structure and the second air outlet structure 4 are combined to form a fan volute. Looking inward along the air outlet direction, the guide section 15 edge of the combined air outlet 11 is the highest at the center, and then tilts downward to both sides. By changing the cross-sectional shape of the air outlet 11, the air pressure difference formed by the impeller 2 is adjusted, so that the airflow pressure at the air outlet 11 is the same, which reduces the manufacturing difficulty of the fan. While increasing the air volume, the vibration of the entire fan is reduced, so that the large-volume fan can still meet the environmental noise requirements.

[0053] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and any modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A centrifugal fan outlet structure, comprising an outer shell plate (14), an outlet (11), and an inlet (12), wherein the inlet (12) is disposed on one side wall of the outer shell plate (14), the other side of the outer shell plate (14) is open to form an opening (17), the outlet (11) is disposed on one end of the outer shell plate (14), and the outer shell plate (14) has an inner cavity for accommodating the fan, characterized in that: It also includes an air guide (15), which is disposed on the upper edge of the outer shell plate (14) connected to the air outlet (11). When viewed inward along the air outlet (11), the angle between the side of the air guide (15) facing the inner cavity and the horizontal plane is B, 0°. <B≤15°; The air guide section (15) includes an incoming air section (153), a transition section (152) and an outgoing air section (151) connected in sequence. The outer shell plate (14) includes an annular plate (141) and a side plate (142). The incoming air section (153) extends from the upper part of the annular plate (141) toward the air outlet (11) and gradually approaches the center of the air outlet (11). The two ends of the transition section (152) are connected to the incoming air section (153) and the outgoing air section (151) respectively, and the transition is smooth. The end of the incoming air section (153) near the air outlet (11) is away from the center of the air outlet (11). The tangent at one end of the transition section (152) connected to the airflow section (153) is parallel to the horizontal line, and the endpoint is the lowest point of the airflow guide (15). Looking inward along the air outlet (11) direction, the height of a portion of the air guide (15) near the side plate (142) of the outer shell plate (14) is lower than that of a portion of the air guide (15) near the opening (17).

2. The centrifugal fan outlet structure according to claim 1, characterized in that: The ratio of the outflow section (151) to the inflow section (153) is 1:

5.

3. The centrifugal fan outlet structure according to claim 1, characterized in that: It also includes a volute (16), which is disposed on the lower edge of the outer shell plate (14) connected to the air outlet (11).

4. The centrifugal fan outlet structure according to claim 3, characterized in that: The volute tongue (16) protrudes toward the air guide (15), and the cross-sectional edge of the volute tongue (16) is smoothly transitioned.

5. The centrifugal fan outlet structure according to claim 4, characterized in that: The volute tongue (16) and the air guide (15) are combined to form the air guide (15) in a wide-mouth shape along the air outlet direction.

6. A fan, characterized in that: The device includes the air outlet structure, mounting plate (13), impeller (2) and drive motor (3) as described in any one of claims 1-5. The mounting plate (13) is disposed on the opening (17) of the air outlet structure and together with the outer shell plate (14) forms a volute. The impeller (2) is rotatably connected inside the volute. The drive motor (3) is connected to the impeller (2).

7. A combined volute fan, characterized in that: It includes a first air outlet structure and a second air outlet structure (4) arranged opposite to each other. The first air outlet structure is the air outlet structure according to any one of claims 1-6. The second air outlet structure (4) is a mirror image of the first air outlet structure. The openings (17) of the first air outlet structure and the second air outlet structure (4) are detachably connected. The first air outlet structure and the second air outlet structure (4) are combined to form a fan volute.

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