Impeller, mixed-flow fan and ducted fan

Abstract

The application discloses a kind of impeller, mixed flow fan and air duct machine, the impeller includes hub and be set on the blade of the hub, the intersection of the leading edge of the blade with the hub is a, the intersection of the trailing edge of the blade with the hub is b;The end point of the leading edge of the blade away from the hub is c, the end point of the trailing edge of the blade away from the hub is d;a, b, c, d are respectively projected to the projection plane perpendicular to the axis of rotation of the impeller, and the corresponding projection points A, B, C, D are obtained, the value range of ∠CAD is 35°~90°.The impeller of the application can ensure sufficient working area by adjusting the blade profile, and can also ensure that the resistance of the impeller will not have a greater impact on the flow, so that all indicators of the impeller will be improved, maintained in a stable interval, and the air supply effect of the impeller is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the air conditioning technical field, specifically relates to a kind of impeller, mixed flow fan and ducted air conditioner. BACKGROUND

[0002] Ducted air conditioner is a kind of air conditioner, in order to improve comfort, some ducted air conditioner adopts the mode of upper cold air and lower hot air, which can realize waterfall type refrigeration and carpet type warm air, in order to realize this air outlet mode, the air outlet of ducted air conditioner needs to be reversible, in the existing air outlet reversible ducted air conditioner, axial fan and centrifugal fan are usually used, but the air direction of such fan cannot be reversed due to the setting mode of fan blade, therefore, at least two fans are set, one is responsible for forward air outlet, and the other is responsible for reverse air outlet, which not only makes the structure of ducted air conditioner larger, but also increases the cost.

[0003] In order to reduce the cost, the fan needs to be reduced, and the mixed flow fan is a fan between axial fan and centrifugal fan, the impeller of mixed flow fan makes air do both centrifugal motion and axial motion, the airflow in the volute moves in a mixed manner of axial and centrifugal motion, so it is called "mixed flow". Moreover, mixed flow fan can not only be small in size, but also can ensure the flow direction and air pressure of airflow.

[0004] It can be seen that the impeller plays an important role in mixed flow fan as an element that does work on airflow, improving the work efficiency of impeller can effectively improve the air outlet efficiency of mixed flow fan. However, due to the limitation of mixed flow fan structure, the size of impeller is limited, and the work area of each blade is very limited, which leads to limited air supply effect of impeller, therefore, how to optimize the structure of impeller under the premise of existing volume limitation and improve the air supply efficiency is a problem to be solved in the field. SUMMARY

[0005] The present application discloses a kind of impeller, mixed flow fan and ducted air conditioner, solve the problem of limited air supply effect of existing impeller due to volume limitation.

[0006] According to the first aspect of the present application, an impeller is disclosed, comprising a hub and a blade arranged on the hub, the intersection of the leading edge of the blade and the hub is a, and the intersection of the trailing edge of the blade and the hub is b;The end point of the leading edge of the blade away from the hub is c, and the end point of the trailing edge of the blade away from the hub is d;a, b, c and d are respectively orthographically projected onto the projection plane perpendicular to the rotation axis of the impeller, and the corresponding projection points A, B, C and D are obtained, and the value range of ∠CAD is 35°-90°.

[0007] Further, the value range of ∠DAB is-20°-20°.

[0008] Further, the impeller further comprises: a wheel cover, the wheel cover and the wheel hub form an airflow channel, the blade is located in the airflow channel; the leading edge c point of the blade is connected to the wheel cover; the trailing edge d point of the blade is connected to the wheel cover.

[0009] Further, the blade is a plurality of, a plurality of the blade is arranged on the wheel hub.

[0010] Further, the blade comprises a long blade and a short blade, the long blade and the short blade are arranged at intervals.

[0011] Further, the blade is provided with a noise reduction structure.

[0012] Further, the noise reduction structure comprises a noise reduction sawtooth, the noise reduction sawtooth is arranged on the trailing edge of the blade.

[0013] According to the second aspect of the present application, a mixed flow fan is disclosed, comprising the above-mentioned impeller.

[0014] Further, the mixed flow fan further comprises: a volute, the impeller is arranged on the volute, the impeller and the volute form a fitting sphere.

[0015] According to the third aspect of the present application, a ducted air conditioner is disclosed, comprising the above-mentioned mixed flow fan.

[0016] The impeller of the present application can ensure sufficient working area and ensure that the resistance of the impeller will not have a great influence on the flow by adjusting the blade profile, so that the indicators of the impeller will be improved, maintained in the stable interval, and the air supply effect of the impeller is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of the impeller of the embodiment one of the present application;

[0018] Figure 2 is a front projection schematic diagram of the impeller of the embodiment one of the present application;

[0019] Figure 3 is a structural schematic diagram of the wheel cover of the impeller of the embodiment one of the present application;

[0020] Figure 4 is a structural schematic diagram of the long blade and the short blade of the impeller of the embodiment one of the present application;

[0021] Figure 5 is a structural schematic diagram of the mixed flow fan of the embodiment two of the present application;

[0022] Legend: 10, hub; 20, blade; 21, leading edge; 22, trailing edge; 23, long blade; 24, short blade; 30, wheel cover; 31, expansion section; 40, noise reduction structure; 50, volute. DETAILED DESCRIPTION

[0023] The application will be further described in connection with the following examples, but is not limited to the contents of the specification.

[0024] As Figure 1 and Figure 2 The first embodiment of the disclosed application discloses a kind of impeller, including hub 10 and the blade 20 of being arranged on hub 10, the intersection of the leading edge 21 of blade 20 and hub 10 is a, the intersection of the trailing edge of blade 20 and hub 10 is b;The end point of the leading edge 21 of blade 20 away from hub 10 is c, the end point of the trailing edge of blade 20 away from hub 10 is d;a, b, c, d are respectively projected to the projection plane vertical to the projection of impeller shaft, corresponding projection point A, B, C, D are obtained, the value range of ∠CAD is 35 °-90 °.The impeller of the application can ensure sufficient work area by adjusting the formation of blade 20, also can ensure that impeller resistance will not have greater influence on flow, so that the maximum of impeller air volume and pressure head, efficiency will be improved, keep in stable interval, improve the air supply effect of impeller.

[0025] As Figure 2 As shown, A point and C point are connected into segment AC, A point and D point are connected into segment AD, AD and AC form angle ∠CAD, ∠CAD basically determines the work area of blade 20, carry out simulation test to the impeller of the first embodiment, change the value of ∠CAD, simulation results are as follows:

[0026]

[0027] According to the simulation data, when ∠CAD is 65°, the fan work can ensure sufficient work area and can ensure that the fan resistance will not have a greater impact on the flow, at this time, the fan indicators will be improved and remain in the stable interval; when ∠CAD is reduced to 35°, the blade 20 work area is reduced, the pressure capacity is reduced, the air volume, the calculated pressure head and the efficiency are reduced; when ∠CAD continues to decrease to 20°, the blade 20 work area is small, the overall blade shape is biased towards the axial fan blade, and cannot be pressurized, so the air volume is seriously attenuated, the calculated pressure head is seriously attenuated, and the efficiency of the impeller is seriously reduced, reaching a state that cannot be used; when ∠CAD increases to 90°, the blade 20 work area is increased, which leads to the increase of the flow resistance of the airflow, resulting in the decrease of the air volume, the pressure head and the efficiency; when ∠CAD continues to increase to 100°, the blade 20 work area is too large, the overall blade shape is biased towards the centrifugal fan blade, which leads to the excessive flow resistance of the airflow, the air volume is seriously attenuated, the pressure head is seriously reduced, and the efficiency is excessively reduced, reaching a state that cannot be used. Therefore, it can be seen that under the same speed, when ∠CAD is 65°, the air volume and the pressure head are the largest, and the overall efficiency is the highest.

[0028] Further, the value range of ∠DAB is -20°-20°. As shown in Figure 2 AB, AD and AB form an angle ∠DAB, which basically determines the tail blade shape of the blade 20. A suitable ∠DAB will make the tail blade shape of the blade 20 between centrifugal and axial, which can convert sufficient dynamic pressure into static pressure and reduce flow resistance to ensure unit air volume and improve unit efficiency. The simulation test is carried out on the impeller of the first embodiment, the value of ∠DAB is changed, and the simulation results are as follows:

[0029]

[0030] According to the simulation data, when ∠DAB is 1.5°, the tail profile of the blade 20 is between centrifugal and axial flow, which can convert sufficient dynamic pressure into static pressure and reduce flow resistance to ensure the air volume of the unit and improve the efficiency of the unit; when ∠DAB decreases to-20°, the pressure-carrying capacity of the blade 20 is improved, but the degree of distortion of the blade 20 increases, the flow resistance increases, and the air volume, calculated pressure head and efficiency all decrease; when ∠DAB continues to decrease to-30°, the blade 20 is more inclined to centrifugal fan blade, and the angle is too small to cause the blade 20 to be too distorted, the flow resistance greatly increases, the calculated pressure head seriously decreases, and the efficiency of the impeller is greatly reduced to reach a state that cannot be used; when ∠DAB increases to 20°, the expansion area of the blade 20 increases, which causes the solidity of the blade 20 to increase, and also causes the flow resistance to increase, resulting in a decrease in the air volume, pressure head and efficiency; when ∠DAB continues to increase to 30°, the blade 20 is more inclined to axial fan blade, and the expansion area of the blade 20 is too large to cause the solidity of the blade 20 to be too large, resulting in a great increase in the flow resistance of the airflow, a serious decrease in the air volume, a serious decrease in the pressure head, and a too much decrease in the efficiency to reach a state that cannot be used. Therefore, it can be seen that under the same speed, when ∠DAB is 1.5°, the air volume and pressure head are the largest, and the efficiency of the whole machine is the highest. It should be noted that, as shown in Figure 2 , when ∠DAB is 20°, it means that the included angle between the line segment AD and the line segment AB in the clockwise direction is 20°, and when ∠DAB is-20°, it means that the included angle between the line segment AD and the line segment AB in the counterclockwise direction is 20°.

[0031] As shown in Figure 3 , the impeller further comprises a cover 30, and the cover 30 and the hub 10 form an airflow passage, and the blade 20 is located in the airflow passage; the c point of the leading edge 21 of the blade 20 is connected to the cover 30; and the d point of the trailing edge 22 of the blade 20 is connected to the cover 30. The cover 30 forms an airflow passage inside, and the blade 20 is located in the airflow passage; the airflow passage has an expansion section 31, and the expansion section 31 is located between the inlet end of the airflow passage and the outlet end of the airflow passage, and the flow area of the expansion section 31 gradually increases in the direction from the inlet end of the airflow passage to the outlet end of the airflow passage. By arranging the expansion section 31, the static pressure of the airflow can be improved, thereby improving the working efficiency of the impeller.

[0032] In order to improve the air supply efficiency of the impeller, the blade 20 is a plurality of blades 20, and the plurality of blades 20 are arranged at intervals on the hub 10.

[0033] Generally, in order to improve the pressure-carrying capacity of the impeller, more blades 20 are often needed, and more number of blades 20 can help the fan to improve the work capacity, but at the same time, if more blades 20 are arranged at the air inlet position, a larger resistance will be formed in the limited air duct, which is also not conducive to the performance of the impeller. Therefore, in order to improve the performance of the impeller, the number of blades 20 is preferably 3-5, and the number of blades 20 is preferably 4. Figure 4As shown, the blade 20 includes a long blade 23 and a short blade 24, and the long blade 23 is spaced apart from the short blade 24. By spacing apart the long blade 23 and the short blade 24, the number of blades 20 doing work in the impeller is increased, thereby improving the pressure capacity. By arranging the short blade 24 at a position close to the air outlet end of the impeller, only the long blade 23 exists at a position close to the air inlet end of the impeller, and the flow resistance of the airflow is greatly reduced, and the short blade 24 can do work on the airflow at the air outlet position, so as to make the airflow carry pressure, thereby improving the pressure capacity of the fan without increasing the flow resistance of the fan.

[0034] As shown in the drawings, Figure 3 The blade 20 is provided with a noise reduction structure 40, and the noise reduction structure 40 is arranged on the blade 20, so as to reduce the noise generated by the rotation of the impeller. Preferably, the noise reduction structure 40 includes noise reduction sawteeth arranged on the trailing edge 22 of the blade 20. Not only can the noise be directly reduced, but also the scattering noise of the trailing edge 22 can be obviously reduced, and even the scattering noise can be eliminated. The noise reduction sawteeth can reduce the noise of the trailing edge 22 in a low frequency range, so as to further reduce the noise.

[0035] As shown in the drawings, Figure 5 Embodiment two of the present application discloses a mixed-flow fan, which comprises the above-mentioned impeller.

[0036] Further, the mixed-flow fan further comprises a volute 50, and the impeller is arranged on the volute 50, and the impeller and the volute 50 enclose a fitting sphere. The mixed-flow fan further comprises the volute 50, and the impeller is arranged on the volute 50, and the impeller and the volute 50 enclose a fitting sphere. By enclosing the fitting sphere, the size of the mixed-flow fan can be minimized, so as to ensure the air supply effect of the fan.

[0037] The mixed-flow fan is a fan between the axial-flow fan and the centrifugal fan, the impeller of the mixed-flow fan makes the air do both centrifugal motion and axial motion, and the airflow motion in the volute 50 mixes the axial flow and the centrifugal motion, so it is called “mixed flow”. Since the mixed-flow fan can not only be small in size, but also ensure the flow direction and the air pressure of the airflow, the mixed-flow fan is installed in the ducted fan, and the airflow direction is reversible, and the air outlet direction is changed.

[0038] According to embodiment three of the present application, a ducted fan is disclosed, which comprises the above-mentioned mixed-flow fan.

[0039] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above-mentioned description, other different forms of changes or variations can be made by those skilled in the art. It is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the present application still fall within the protection scope of the present application.

Claims

1. An impeller comprising a hub (10) and blades (20) disposed on the hub (10), characterized in that, The intersection point of the leading edge (21) of the blade (20) and the hub (10) is a, and the intersection point of the trailing edge (22) of the blade (20) and the hub (10) is b; The leading edge (21) of the blade (20) is c, which is away from the hub (10), and the trailing edge (22) of the blade (20) is d, which is away from the hub (10). Projecting a, b, c, and d onto the projection plane perpendicular to the impeller shaft, respectively, yields projection points A, B, C, and D. The value of ∠CAD ranges from 35° to 90°.

2. The impeller according to claim 1, characterized in that, The value of ∠DAB ranges from -20° to 20°.

3. The impeller according to claim 1, characterized in that, The impeller also includes: Wheel cover (30), an airflow channel is formed between the wheel cover (30) and the wheel hub (10), and the blade (20) is located in the airflow channel; The leading edge (21)c of the blade (20) is connected to the wheel cover (30); The trailing edge (22)d of the blade (20) is connected to the wheel cover (30).

4. The impeller according to claim 1, characterized in that, There are multiple blades (20), and the multiple blades (20) are spaced apart on the hub (10).

5. The impeller according to claim 4, characterized in that, The blade (20) includes a long blade (23) and a short blade (24), with the long blade (23) and the short blade (24) spaced apart.

6. The impeller according to claim 1, characterized in that, The blade (20) is provided with a noise reduction structure (40).

7. The impeller according to claim 6, characterized in that, The noise reduction structure (40) includes noise reduction serrations, which are disposed on the trailing edge (22) of the blade (20).

8. A mixed-flow fan, characterized in that, Includes the impeller according to any one of claims 1 to 7.

9. The mixed-flow fan according to claim 8, characterized in that, The mixed-flow fan also includes: The volute (50) has an impeller mounted on it, and the impeller and the volute (50) together form a fitted sphere.

10. A ducted air conditioner, characterized in that, Includes the mixed-flow fan as described in claim 8 or 9.

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