Blade structure, impeller, fan system and range hood

Abstract

The present invention discloses a blade structure, an impeller, a fan system and a range hood, wherein the blade structure comprises a main blade, wherein the main blade has an inlet, an outlet, a suction surface and a pressure surface, wherein a notch is provided on the main blade, wherein the notch is located between the inlet and the outlet; wherein the blade structure further comprises an auxiliary blade, wherein the auxiliary blade is arranged at the notch and matches the notch, wherein the auxiliary blade is rotationally connected to the main blade and can rotate in the direction of the suction surface, wherein the rotation axis of the auxiliary blade is consistent with the length direction of the main blade. Compared with the prior art, the advantages of the present invention are as follows: through the above-mentioned composite blade scheme, the auxiliary blade suppresses the generation of a large vortex near the suction surface of the main blade; a gap flow is formed between the auxiliary blade and the main blade because of the pressure surface, thereby further dispersing the possibility of a vortex formed on the suction surface at the rear end, and the gap flow further dispersing the local discontinuity mutation vortex formed due to the expansion of the auxiliary blade, thereby improving efficiency and reducing noise.

Description

Technical Field

[0001] The invention relates to a power device, in particular to a blade structure, an impeller using the blade structure, a fan system using the impeller, and a range hood using the fan system. Background Art

[0002] Multi-blade centrifugal fans have the characteristics of high pressure and low noise. Therefore, the current society generally uses multi-blade centrifugal fan systems as power sources, using high-speed rotating impellers to complete the two functions of work and filtering in the volute. For example, it is often used in range hoods, and the multi-blade centrifugal fan installed inside the range hood absorbs and exhausts oil smoke. The multi-blade centrifugal fan includes a volute, an impeller installed in the volute, and a motor that drives the impeller to rotate. When the impeller rotates, negative pressure suction is generated in the center of the fan, sucking the oil smoke under the range hood into the fan, and after being accelerated by the fan, it is collected by the volute and guided to be discharged outdoors.

[0003] The existing range hoods generally use a multi-blade centrifugal fan as the power device, and the impeller blades 100' of the fan are mainly single arc blades, see Fig.10 This type of blade, on the one hand, has different intake states at different circumferential positions, and the intake state also changes greatly with the working conditions and speed changes. The suction surface of the blade near the inlet side (the back side of the work) is prone to large local reflux due to the negative pressure difference, see Fig.11 , is the blade path under low speed and smooth working conditions, Fig.12 The figure shows the blade path under high-speed congestion conditions, where the arrows indicate the airflow path. It can be seen that as the operating conditions worsen, the suction surface vortex (the space surrounded by the triangle in the figure) increases, which will reduce efficiency and increase noise. On the other hand, the uneven air intake along the axial direction can easily cause the vortex on the suction surface to flow further laterally, generating secondary flow along the axis, further reducing the overall aerodynamic efficiency and increasing noise. Summary of the invention

[0004] The first technical problem to be solved by the present invention is to provide a blade structure to reduce energy loss, improve work efficiency and reduce noise in view of the deficiencies in the above-mentioned prior art.

[0005] The second technical problem to be solved by the present invention is to provide an impeller having the above blade structure.

[0006] The third technical problem to be solved by the present invention is to provide a fan system using the above-mentioned impeller.

[0007] The fourth technical problem to be solved by the present invention is to provide a range hood using the above-mentioned fan system.

[0008] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a blade structure, comprising a main blade, the main blade having an inlet, an outlet, a suction surface and a pressure surface, characterized in that: a notch is opened on the main blade, and the notch is located between the inlet and the outlet;

[0009] The blade structure also includes an auxiliary blade, which is arranged at the notch and matches the notch. The auxiliary blade is rotatably connected to the main blade and can rotate in the direction of the suction surface. The rotation axis of the auxiliary blade is consistent with the length direction of the main blade. The connection position between the auxiliary blade and the main blade is located on the side of the auxiliary blade facing the inlet.

[0010] Through the above-mentioned composite blade scheme, ① the auxiliary blades suppress the generation of large vortices near the suction surface of the main blades; ② a gap flow is formed between the auxiliary blades and the main blades due to the pressure surface, which can further disperse the possibility of vortices forming on the rear suction surface. The gap flow further disperses the local discontinuity mutation vortex formed due to the expansion of the auxiliary blades, thereby improving efficiency and reducing noise.

[0011] Preferably, in order to facilitate the rotational connection between the auxiliary blade and the main blade, the auxiliary blade is rotationally connected to the main blade via a rotating shaft, and the rotating shaft is arranged on a side of the auxiliary blade away from the inlet.

[0012] Furthermore, in order to make the state of the auxiliary blade automatically adapt to different working conditions, a torsion spring is arranged on the rotating shaft, and the torsion spring makes the auxiliary blade maintain a tendency to be placed in the notch.

[0013] Further, according to one aspect of the present invention, there are at least two auxiliary blades arranged at intervals along the length direction of the main blade, and the elastic forces of the torsion springs of the auxiliary blades are not completely the same, thereby avoiding the generation of secondary flow along the axial direction, further improving the overall aerodynamic efficiency, and reducing the noise problem.

[0014] Preferably, a middle plate buckle is formed on the main blade, and the auxiliary blades have at least two and are distributed on both sides of the middle plate buckle along the length direction of the main blade.

[0015] In order to avoid affecting the work done by the middle disk area corresponding to the middle disk buckle, the length of the main blade is L, the distance between the auxiliary blade closest to the middle disk buckle and the middle disk buckle is L1, and the range of L1 / L is [0.1-0.35].

[0016] Preferably, the wrap angle position of the auxiliary blade close to the inlet of the main blade is ∠A∈[5°, 40°]. If it is too far forward, the suppression of the rear vortex will be weakened, and if it is too far back, the elimination effect of the front side where the main vortex occurs will be reduced.

[0017] Preferably, the auxiliary blade and the main blade are arc-shaped, and the center angle of the auxiliary blade is ∠B∈[10°,40°]. If this angle is too small, the effective size of the auxiliary blade is too short and the large vortex on the suction surface cannot be effectively suppressed. If the angle is too large, the working ability of the main blade will be weakened.

[0018] Preferably, the rotation angle of the auxiliary blade is ∠C:∈[0,30], so as to avoid the angle being too large to hinder the main flow from passing through the blade channel.

[0019] Preferably, the length ratio of the auxiliary blade to the main blade is k, and satisfies k∈[0.25,0.8]. If this value is too small, the auxiliary blade is too narrow and has little effect, and if this value is too large, the installation and structural strength of the blade structure cannot be guaranteed.

[0020] The technical solution adopted by the present invention to solve the second technical problem is: an impeller, characterized in that: the blade structure as described above is applied, and the length direction of the main blade is the axial direction of the impeller. .

[0021] The technical solution adopted by the present invention to solve the third technical problem is: a fan system, which is a multi-blade centrifugal fan, characterized in that: an impeller as described above is applied.

[0022] The technical solution adopted by the present invention to solve the fourth technical problem is: a range hood, characterized in that: the fan system as described above is applied.

[0023] Compared with the prior art, the advantages of the present invention are: by adopting the composite blade solution, ① the auxiliary blades suppress the generation of large vortices near the suction surface of the main blades; ② a gap flow is formed between the auxiliary blades and the main blades due to the pressure surface, which can further disperse the possibility of vortices forming on the rear end suction surface, and the gap flow further disperses the local discontinuity mutation vortex formed due to the expansion of the auxiliary blades, thereby improving efficiency and reducing noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of an impeller according to a first embodiment of the present invention;

[0025] Figure 2 is a cross-sectional view of an impeller according to a first embodiment of the present invention;

[0026] Figure 3 for Figure 2 A schematic diagram of the partial enlargement of Ⅰ;

[0027] Figure 4 It is a schematic diagram of the blade structure of the first embodiment of the present invention (closed state);

[0028] Figure 5 for Figure 4 A partial II enlarged schematic diagram of

[0029] Figure 6 It is a schematic diagram of the blade structure of the first embodiment of the present invention (open state);

[0030] Figure 7 Schematic diagram of the impeller blade path of the first embodiment of the present invention (low speed normal working condition);

[0031] Figure 8 Schematic diagram of the impeller blade path of the first embodiment of the present invention (high speed congestion condition);

[0032] Fig. 9 is a schematic diagram of the blade structure of an impeller according to a second embodiment of the present invention;

[0033] Fig.10 is a schematic diagram of an impeller of the prior art;

[0034] Fig.11 A schematic diagram of the impeller blade path of the prior art (low speed normal working condition);

[0035] Fig.12 It is a schematic diagram of the blade path of the impeller of the prior art (high speed congestion condition). DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Since the embodiments disclosed in the present invention can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0038] Embodiment 1

[0039] See also Figure 1 to Figure 3The invention discloses an impeller for a fan system, wherein the fan system is a multi-blade centrifugal fan, which can be mainly used for a range hood, and can also be used for other occasions requiring a similar power device.

[0040] The impeller includes two end rings 200 arranged at intervals (the positional relationship of the two end rings 200 is the same as that in the prior art) and blade structures 100 mounted on the end rings 200 . The blade structures 100 are arranged at intervals between the two end rings 200 along the circumferential direction of the end rings 200 .

[0041] See also Figure 2 to Figure 5 The blade structure 100 includes a main blade 1 and a secondary blade 2, forming a composite blade, wherein the main blade 1 can be the same as an existing blade, such as a blade with a single arc profile, and the main blade 1 has an inlet 11 (leading edge) and an outlet 12 (trailing edge). The airflow enters from the inlet 11, flows along the blade channel Q formed between two adjacent blade structures 100, and then flows out from the outlet 12. The inlet 11 is closer to the radial inner side of the impeller relative to the outlet 12.

[0042] A notch 13 is provided on the main blade 1, and the notch 13 is located between the inlet 11 and the outlet 12. The auxiliary blade 2 is arranged at the notch 13, and the profile of the notch 13 is consistent with that of the main blade 1. Compared with the inlet 11 and the outlet 12, the auxiliary blade 2 is preferably closer to the inlet 11. The shape and size of the auxiliary blade 2 and the notch 13 are matched. In this embodiment, the auxiliary blade 2 is rectangular. The auxiliary blade 2 is rotatably connected to the main blade 1 through a rotating shaft 21. The extension direction of the rotating shaft 21 is consistent with the length direction of the main blade 1 (i.e., the axial direction of the impeller). The rotating shaft 21 is arranged on the side of the auxiliary blade 2 facing the inlet 11. A torsion spring 22 is arranged on the rotating shaft 21. One end of the torsion spring 22 can abut against the main blade 1, and the other end of the torsion spring 22 can abut against the auxiliary blade 2. The torsion spring 22 makes the auxiliary blade 2 tend to be placed in the notch 13.

[0043] The curvatures of the main blade 1 and the auxiliary blade 2 are consistent.

[0044] In this embodiment, taking the impeller used for double air inlet as an example, a middle disk 300 is further provided between the two end rings 200, and each blade structure 100 passes through the middle disk 300. A middle disk buckle 14 is formed on the main blade 1, and the position of the middle disk buckle 14 corresponds to the position of the middle disk 300 of the double air inlet impeller. The above-mentioned auxiliary blades 2 may have at least two, which are distributed on both sides of the middle disk buckle 14 along the length direction of the main blade 1. Since the vicinity of the middle disk 300 is the main working area, the auxiliary blades 2 are not provided in the middle disk 300 area. Let the length of the main blade 1 be L, and the distance between the auxiliary blade 2 closest to the middle disk buckle 14 and the middle disk buckle 14 be L1, and the preferred range satisfying L1 / L is [0.1-0.35].

[0045] According to the total axial length of the impeller and taking into account the installation and structural strength of the mechanism, the ratio of the length of the auxiliary blade 2 along the axial direction of the impeller (the length direction of the main blade 1) to the length of the main blade 1 is k, which can be taken as k∈[0.25,0.8]. If this value is too small, the auxiliary blade 2 is too narrow and has little effect. If this value is too large, the installation and structural strength of the blade structure cannot be guaranteed.

[0046] Alternatively, it can also be used for a single-inlet impeller, in which case the auxiliary blades 2 are not provided at the connection between the main blades 1 and the rear disc.

[0047] See also Figure 7 , a blade path Q is formed between two adjacent blade structures 100. Under the condition of low speed and large flow rate with good working conditions, the auxiliary blade 2 does not unfold under the action of the torsion spring 22 and centrifugal force, and works normally. Figure 6 and Figure 8 When the working condition deteriorates and the speed increases, the centrifugal effect is enhanced, and the auxiliary blade 2 overcomes the elastic force of the torsion spring 22 and rotates in the direction of the suction surface 15 to rebalance. At this time, the auxiliary blade 2 is unfolded like a flap. This can play the following two roles: ① The auxiliary blade 2 suppresses the generation of large vortices near the suction surface 15 of the main blade 1; ② On the other hand, a gap flow Q1 is formed between the auxiliary blade 2 and the main blade 1 because of the pressure surface 16, which can further disperse the possibility of vortices forming on the rear suction surface 15. The gap flow further disperses the local discontinuity mutation vortex formed by the expansion of the auxiliary blade 2, thereby improving efficiency and reducing noise. The above-mentioned gap flow Q1 is due to the fact that the suction surface 15 of the main blade 1 is a low-pressure area and the pressure surface 16 is a high-pressure area, causing the airflow to pass through the gap at the connection between the auxiliary blade 2 and the main blade 1, and flow from the pressure surface 16 side to the suction surface 15 side.

[0048] The wrap angle position ∠A∈[5°,40°] of the auxiliary blade 2 close to the inlet 11 of the main blade 1 is too far forward to weaken the vortex suppression on the rear side, and too far back to reduce the elimination effect on the front side where the main vortex occurs. The center angle ∠B∈[10°,40°] of the auxiliary blade 2 type line is too small and the effective size of the auxiliary blade 2 is too short to effectively suppress the large vortex on the suction surface. A too large angle will weaken the working ability of the main blade 1. The rotation angle ∠C of the auxiliary blade 2 is ∈[0,30]. When this angle is 0, the auxiliary blade 2 is tangentially fitted to the main blade 1. A too large angle may hinder the mainstream from passing through the blade channel Q.

[0049] Embodiment 2

[0050] See also Fig. 9In this embodiment, the difference from the above-mentioned embodiment 1 is that, considering the uneven air intake along the impeller axis, it is easy for the vortex on the suction surface 15 to further flow laterally, generating a secondary flow along the axial direction, further reducing the overall aerodynamic efficiency and increasing the noise. Therefore, the same impeller considers different axial air intake conditions and changes the inlet at different angles. Therefore, the elastic force of the torsion spring 22 of each auxiliary blade 2 can be set to be different, so that after the same speed is balanced, the unfolding angle of each auxiliary blade 2 is different, and even multiple groups can be set, changing along the axial direction. The opening angle close to the middle disk 300 is small (the middle disk 300 is the main flow area with few vortices), and the opening angle close to the impeller end ring 200 can be large (the vortex is more serious and requires a larger angle change).

Claims

1. A blade structure, comprising a main blade (1), wherein the main blade (1) has an inlet (11), an outlet (12), a suction surface (15) and a pressure surface (16), characterized in that: The main blade (1) is provided with a notch (13), and the notch (13) is located between the inlet (11) and the outlet (12); The blade structure further comprises an auxiliary blade (2), the auxiliary blade (2) being arranged at the notch (13) and matching the notch (13), the auxiliary blade (2) being rotatably connected to the main blade (1) and being able to rotate in the direction of the suction surface (15), the rotation axis of the auxiliary blade (2) being consistent with the length direction of the main blade (1), and the connection position of the auxiliary blade (2) and the main blade (1) being located on a side of the auxiliary blade (2) facing the inlet (11); The auxiliary blade (2) is rotatably connected to the main blade (1) via a rotating shaft (21); the rotating shaft (21) is arranged on a side of the auxiliary blade (2) facing the inlet (11); a torsion spring (22) is arranged on the rotating shaft (21); the torsion spring (22) enables the auxiliary blade (2) to maintain a tendency to be placed in the notch (13); the auxiliary blade (2) has at least two and is arranged at intervals along the length direction of the main blade (1); and the elastic forces of the torsion springs (22) of the auxiliary blades (2) are not completely the same.

2. The blade structure according to claim 1, characterized in that: A middle plate buckle (14) is formed on the main blade (1), and the auxiliary blades (2) have at least two and are distributed on both sides of the middle plate buckle (14) along the length direction of the main blade (1).

3. The blade structure according to claim 2, characterized in that: The length of the main blade (1) is L, the distance between the auxiliary blade (2) closest to the center plate buckle (14) and the center plate buckle (14) is L1, and the range of L1 / L is [0.1-0.35].

4. The blade structure according to claim 1, characterized in that: The auxiliary blade (2) is close to the inlet (11) of the main blade (1) at an angle of ∠A∈[5°, 40°].

5. The blade structure according to claim 1, characterized in that: The profiles of the auxiliary blade (2) and the main blade (1) are both circular arcs, and the center angle ∠B∈[10°, 40°] of the auxiliary blade (2).

6. The blade structure according to claim 1, characterized in that: The rotation angle ∠C of the auxiliary blade (2) is: ∈[0,30].

7. The blade structure according to claim 1, characterized in that: The length ratio of the auxiliary blade (2) to the main blade (1) is k, and satisfies k∈[0.25,0.8].

8. An impeller, characterized in that: A blade structure as claimed in any one of claims 1 to 7 is applied, wherein the length direction of the main blade (1) is the axial direction of the impeller.

9. A fan system, which is a multi-blade centrifugal fan, characterized in that: An impeller as claimed in claim 8 is used.

10. A range hood, characterized in that: A fan system as claimed in claim 9 is used.

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