A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades

Abstract

This invention discloses a composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades. The impeller employs a composite structure combining double-layer and single-layer blades. The first blade is a backward-curved twisted blade, the second blade is a forward-curved twisted blade, and the third blade is a radial blade. This design effectively improves the flow pattern of the fluid within the flow channel, reducing noise. The third blade has a bent portion protruding inwards from the first and second outlet blades near the outlet side. The flow area is minimized at the bent portion, and maximized at the radially outer outlet of the third blade. This structural design more effectively boosts pressure and improves the efficiency of the fan operation.

Description

Technical Field

[0001] This invention relates to the field of fluid machinery technology, specifically to a three-dimensional impeller, and more specifically to a composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades. Background Technology

[0002] The impeller is the "heart" of a wind turbine. Its design (such as blade shape and angle) and materials directly affect the turbine's efficiency, energy consumption, and reliability. Its core function is to convert energy through mechanical motion and drive gas flow to meet the needs of different scenarios. Existing wind turbine impellers on the market generally suffer from problems such as high noise and low efficiency. As demands for wind turbines increase, the need for efficiency improvements in wind turbine impellers is growing stronger. Therefore, optimizing the design of wind turbine impellers is essential.

[0003] Existing technology CN104500445A discloses a novel axial flow fan, comprising: a main cylinder 1, an impeller assembly 2 disposed inside the main cylinder 1, a guide vane assembly 3 disposed inside the main cylinder 1, and a motor 4 disposed inside the main cylinder 1. The motor 4 is fixed inside the main cylinder 1 by a bracket. The impeller assembly 2 includes multiple impellers 5, and the outer surface of each impeller 5 has a polytetrafluoroethylene coating, making the surface of the impeller 5 relatively smooth and less prone to dust adhesion. The outer wall of the main cylinder 1 has a sound-absorbing panel, which has the function of sound absorption and noise reduction. The structure is simple and reasonable, and the blade surface is relatively smooth, making it less prone to dust adhesion.

[0004] However, the above structure has design limitations, and in the actual application of the wind turbine, there are still problems of high noise and low efficiency. Therefore, in order to address these problems, the applicant proposes a composite high-efficiency and low-noise three-dimensional impeller with backward-curved blades. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades, employing a double-suction structure, includes an upper impeller cover, a middle impeller cover, a disc, a first blade, a second blade, a third blade, and a hub. The first blade is installed between the upper and middle impeller covers, the second blade is installed between the middle impeller cover and the disc, and the third blade is installed between the upper impeller cover and the disc. The disc is fitted and fixed to the hub. The impeller is characterized in that: the first blade is a backward-curved twisted blade, the second blade is a forward-curved twisted blade, and the third blade is a radial blade; at the same radial position, the axial flow section of the first blade... The length W1 is greater than the axial length W2 of the flow section of the second blade; the flow sections of the first blade and the second blade are arranged side by side to form the inlet flow channel, and the third blade is located in the outlet flow channel; the leading edge of the first blade is farther from the central axis than the leading edge of the second blade, and the trailing edge of the second blade is farther from the central axis than the trailing edge of the first blade; an outlet premixing trough is provided at the position where the trailing edge of the first blade overlaps with the middle wheel cover, and the outlet premixing trough includes a first premixing trough located on the first blade and a second premixing trough located on the second blade, and the first premixing trough and the second premixing trough are arranged in communication.

[0008] Furthermore, the backward tilt angle of the first blade is A, and the forward tilt angle of the second blade is B, where A < B.

[0009] Furthermore, the first premixing tank is a fan-shaped tank, and the second premixing tank is a semi-circular tank, with the radii of the fan-shaped tank and the semi-circular tank being equal.

[0010] Furthermore, the third blade is a plate-shaped blade group structure, which includes a first outlet blade and a second outlet blade arranged at intervals. The inlet ends of the first outlet blade and the second outlet blade are close to each other, and the outlet ends are far apart from each other. The first outlet blade and the second outlet blade are provided with a bent part protruding into the flow channel at the outlet side. The flow area of ​​the flow channel is the smallest at the bent part, and the flow area of ​​the flow channel is the largest at the radially outer outlet of the third blade.

[0011] Furthermore, the flow area from the radially inner inlet of the third blade to the bend in the flow channel shows a trend of first increasing and then decreasing, while the flow area from the bend in the flow channel to the radially outer outlet of the third blade shows a trend of gradually expanding.

[0012] Furthermore, the outlet end of the upper wheel cover is further away from the central axis than the outlet end of the wheel disc, and the radially outer outlet end of the third blade is aligned with the outlet end of the wheel disc.

[0013] Furthermore, the main body of the hub has a hollow cylindrical structure, and the end of the hub is provided with an umbrella-shaped flow guide surface. The inlet end of the umbrella-shaped flow guide surface is in the same position as the inlet end of the middle wheel cover in the axial direction, and the outlet end of the umbrella-shaped flow guide surface points in the axial direction towards the side of the second blade flow channel near the wheel disk.

[0014] Furthermore, the mid-arc of the umbrella-shaped guide surface is part of a hyperbola.

[0015] Furthermore, the top of the umbrella-shaped guide surface has a spherical structure.

[0016] Furthermore, A = (0.2 ~ 0.6)B.

[0017] Furthermore, W1 = (1.1 ~ 1.5)W2.

[0018] Furthermore, the thickness δ1 of the first blade is greater than the thickness δ2 of the second blade, and 1.2mm≤δ2≤3mm.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. In existing technologies, most impellers use single-layer blades, resulting in low conveying efficiency. This invention employs a composite impeller structure combining double-layer and single-layer blades, which more effectively improves the flow pattern of the fluid within the flow channel. Specifically, because the upper layer of turbulence at the impeller inlet is relatively larger, this invention uses backward-curved twisted blades for the upper layer. Conversely, the lower layer of turbulence at the impeller inlet is relatively stable, so this invention uses forward-curved twisted blades for the lower layer. To further enhance pressurization and conveying, this invention incorporates a third blade with a plate-like blade assembly at the outlet. The first and second outlet blades have bends protruding inwards from the outlet side, minimizing the flow area at these bends. The third blade's radially outer outlet has the largest flow area. This structure provides more effective pressurization, and the design of the third blade also effectively reduces noise and improves the fan's operating efficiency.

[0021] 2. Due to the structural differences between the first and second blades, mutual interference may occur at the overlapping position of the two blades at the outlet. Based on this, an outlet premixing groove is provided at the overlapping position of the trailing edge of the first blade and the middle wheel cover in this invention. The outlet premixing groove includes a first premixing groove located on the first blade and a second premixing groove located on the second blade. The first premixing groove and the second premixing groove are connected and arranged. The above structure enables premixing before interference, effectively reducing the vibration and noise of the fan.

[0022] 3. The flow area from the radial inner inlet of the third blade to the bend in the flow channel shows a trend of first increasing and then decreasing, while the flow area from the bend in the flow channel to the radial outer outlet of the third blade shows a trend of gradually expanding. The above structure can improve airflow, reduce flow loss, and improve air outlet efficiency.

[0023] 4. The main body of the hub is a hollow cylindrical structure. The end of the hub is provided with an umbrella-shaped flow guide surface. The inlet end of the umbrella-shaped flow guide surface is in the same position as the inlet end of the middle wheel cover in the axial direction. The outlet end of the umbrella-shaped flow guide surface points in the axial direction towards the side of the second blade flow channel near the wheel disk. The design of the flow guide structure effectively changes the inlet flow state of the lower blade and has the effect of suppressing the generation of noise and vibration.

[0024] 5. The middle arc of the umbrella-shaped guide surface is part of a hyperbola, and the top of the umbrella-shaped guide surface is a spherical structure. This is a further optimization of the guide structure. The design of the middle arc is more in line with the fluid flow pattern inside the impeller, and the spherical structure also effectively reduces noise, reduces airflow turbulence, and reduces pressure loss, thereby ensuring the stability and uniformity of the fan flow and improving the fan efficiency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the impeller structure of the present invention;

[0026] Figure 2 for Figure 1 Enlarged view of the outlet premix tank in the middle;

[0027] Figure 3 This is a schematic diagram of the third blade structure of the present invention;

[0028] Figure 4 for Figure 3 Enlarged view of the flow channel structure of the third blade in the middle.

[0029] In the figure: upper wheel cover 1, middle wheel cover 2, wheel disk 3, first blade 4, second blade 5, third blade 6, hub 7, outlet premix tank 8, first premix tank 81, second premix tank 82, first outlet blade 61, second outlet blade 62, bent part 63, hollow cylindrical structure 71, umbrella-shaped guide surface 72, axial length W1 of the flow section of the first blade 4, axial length W2 of the flow section of the second blade 5, backward tilt angle A of the first blade 4, forward tilt angle B of the second blade 5, thickness δ1 of the first blade 4, and thickness δ2 of the second blade 5. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings.

[0032] like Figure 1-4 As shown, a composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades is disclosed. The impeller adopts a double-suction structure and includes an upper impeller cover 1, a middle impeller cover 2, a disc 3, a first blade 4, a second blade 5, a third blade 6, and a hub 7. The first blade 4 is installed between the upper impeller cover 1 and the middle impeller cover 2, the second blade 5 is installed between the middle impeller cover 2 and the disc 3, and the third blade 6 is installed between the upper impeller cover 1 and the disc 3. The disc 3 is sleeved and fixed on the hub 7. The impeller is characterized in that: the first blade 4 is a backward-curved twisted blade, the second blade 5 is a forward-curved twisted blade, and the third blade 6 is a radial blade; at the same radial position, the flow cross section of the first blade 4 is... The axial length W1 is greater than the axial length W2 of the flow section of the second blade 5; the flow section of the first blade 4 and the flow section of the second blade 5 are arranged side by side to form the inlet flow channel, and the third blade 6 is located in the outlet flow channel; the leading edge of the first blade 4 is farther from the central axis than the leading edge of the second blade 5, and the trailing edge of the second blade 5 is farther from the central axis than the trailing edge of the first blade 4; an outlet premixing trough 8 is provided at the position where the trailing edge of the first blade 4 overlaps with the middle wheel cover 2, the outlet premixing trough 8 includes a first premixing trough 81 located on the first blade 4 and a second premixing trough 82 located on the second blade 5, and the first premixing trough 81 and the second premixing trough 82 are arranged in communication.

[0033] Furthermore, the backward tilt angle of the first blade 4 is A, and the forward tilt angle of the second blade 5 is B, where A < B.

[0034] Furthermore, the first premixing tank 81 is a fan-shaped tank, and the second premixing tank 82 is a semi-circular tank, with the radii of the fan-shaped tank and the semi-circular tank being equal.

[0035] Furthermore, the third blade 6 is a plate-shaped blade group structure, which includes a first outlet blade 61 and a second outlet blade 62 arranged at intervals. The inlet ends of the first outlet blade 61 and the second outlet blade 62 are close to each other, and the outlet ends are far apart from each other. The first outlet blade 61 and the second outlet blade 62 are provided with a bent portion 63 protruding towards the inside of the flow channel near the outlet side. The flow area of ​​the flow channel is the smallest at the bent portion 63, and the flow area of ​​the flow channel is the largest at the radially outer outlet of the third blade 6.

[0036] Furthermore, the flow area from the radially inner inlet of the third blade 6 to the bend 63 shows a trend of first increasing and then decreasing, while the flow area from the bend 63 to the radially outer outlet of the third blade 6 shows a trend of gradually expanding.

[0037] Furthermore, the outlet end of the upper wheel cover 1 is further away from the central axis than the outlet end of the wheel disc 3, and the radially outer outlet end of the third blade 6 is aligned with the outlet end of the wheel disc 3.

[0038] Furthermore, the main body of the hub 7 is a hollow cylindrical structure 71, and the end of the hub 7 is provided with an umbrella-shaped flow guide surface 72. The inlet end of the umbrella-shaped flow guide surface 72 is in the same position as the inlet end of the middle wheel cover 2 in the axial direction, and the outlet end of the umbrella-shaped flow guide surface 72 points in the axial direction to the side of the flow channel of the second blade 5 near the wheel disk 3.

[0039] Furthermore, the mid-arc of the umbrella-shaped guide surface 72 is part of a hyperbola.

[0040] Furthermore, the top of the umbrella-shaped guide surface 72 has a spherical structure.

[0041] Furthermore, A = (0.2 ~ 0.6)B.

[0042] Furthermore, W1 = (1.1 ~ 1.5)W2.

[0043] Furthermore, the thickness δ1 of the first blade 4 is greater than the thickness δ2 of the second blade 5, and 1.2mm≤δ2≤3mm.

[0044] In existing technologies, most impellers use single-layer blades, resulting in low conveying efficiency. This invention employs a composite impeller structure combining double-layer and single-layer blades, which more effectively improves the flow pattern of the fluid within the flow channel. Specifically, because the upper layer of turbulence at the impeller inlet is relatively larger, this invention uses backward-curved twisted blades for the upper layer, while the lower layer of turbulence at the impeller inlet is relatively stable, so this invention uses forward-curved twisted blades for the lower layer. To further enhance pressurization and conveying, this invention incorporates a third blade with a plate-like blade assembly at the outlet. The first and second outlet blades have bends protruding inwards from the flow channel near the outlet side. The flow area is minimized at the bends, and maximized at the radially outer outlet of the third blade. This structure provides more effective pressurization, and the design of the third blade also effectively reduces noise and improves the efficiency of the fan operation.

[0045] Due to the structural differences between the first and second blades, they may interfere with each other at the overlapping position at the outlet. Therefore, in this invention, an outlet premixing groove is provided at the overlapping position of the trailing edge of the first blade and the middle wheel cover. The outlet premixing groove includes a first premixing groove on the first blade and a second premixing groove on the second blade. The first premixing groove and the second premixing groove are connected and arranged. The above structure allows for premixing before interference, effectively reducing the vibration and noise of the fan.

[0046] The flow area from the radially inner inlet of the third blade to the bend shows a trend of first increasing and then decreasing, while the flow area from the bend to the radially outer outlet of the third blade shows a trend of gradually expanding. The above structure can improve airflow, reduce flow loss, and improve air outlet efficiency.

[0047] The main body of the hub has a hollow cylindrical structure. The end of the hub is provided with an umbrella-shaped flow guide surface. The inlet end of the umbrella-shaped flow guide surface is in the same position as the inlet end of the middle wheel cover in the axial direction. The outlet end of the umbrella-shaped flow guide surface points in the axial direction towards the side of the flow channel of the second blade near the wheel disk. The design of the flow guide structure effectively changes the inlet flow state of the lower blade and has the effect of suppressing the generation of noise and vibration.

[0048] The mid-arc of the umbrella-shaped guide surface is part of a hyperbola, and the top of the umbrella-shaped guide surface is a spherical structure. This is a further optimization of the guide structure. The design of the mid-arc is more in line with the fluid flow pattern inside the impeller, and the spherical structure also effectively reduces noise, reduces airflow turbulence, and reduces pressure loss, thereby ensuring the stability and uniformity of the fan flow and improving the fan efficiency.

[0049] The above embodiments are illustrative of the present invention and not intended to limit the invention. It is understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades, the impeller adopting a double-suction structure, comprising an upper impeller cover (1), a middle impeller cover (2), a disc (3), a first blade (4), a second blade (5), a third blade (6), and a hub (7), wherein the first blade (4) is installed between the upper impeller cover (1) and the middle impeller cover (2), the second blade (5) is installed between the middle impeller cover (2) and the disc (3), the third blade (6) is installed between the upper impeller cover (1) and the disc (3), and the disc (3) is sleeved and fixed on the hub (7); characterized in that: The first blade (4) is a backward-curved twisted blade, the second blade (5) is a forward-curved twisted blade, and the third blade (6) is a radial blade. At the same radial position, the axial length W1 of the flow section of the first blade (4) is larger than the axial length W2 of the flow section of the second blade (5). The flow sections of the first blade (4) and the flow sections of the second blade (5) are arranged side by side to form the inlet flow channel, and the third blade (6) is located in the outlet flow channel. The leading edge of the first blade (4) is further away from the central axis than the leading edge of the second blade (5), and the trailing edge of the second blade (5) is further away from the central axis than the trailing edge of the first blade (4). An outlet premixing trough (8) is provided at the overlapping position of the trailing edge of the first blade (4) and the middle wheel cover (2). The outlet premixing trough (8) includes a first premixing trough (81) located on the first blade (4) and a second premixing trough (82) located on the second blade (5). The first premixing trough (81) and the second premixing trough (82) are arranged in communication.

2. The composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 1, characterized in that, The backward tilt angle of the first blade (4) is A, and the forward tilt angle of the second blade (5) is B, where A < B.

3. The composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 1, characterized in that, The first premixing tank (81) is a fan-shaped tank, and the second premixing tank (82) is a semi-circular tank, with the radii of the fan-shaped tank and the semi-circular tank being equal.

4. The composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 1, characterized in that, The third blade (6) is a plate-shaped blade group structure, which includes a first outlet blade (61) and a second outlet blade (62) arranged at intervals. The inlet ends of the first outlet blade (61) and the second outlet blade (62) are close to each other, and the outlet ends are far apart from each other. The first outlet blade (61) and the second outlet blade (62) are provided with a bent part (63) protruding towards the inside of the flow channel near the outlet side. The flow area of ​​the flow channel is the smallest at the bent part (63), and the flow area of ​​the flow channel is the largest at the radially outer outlet of the third blade (6).

5. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 4, characterized in that, The flow area from the radial inner inlet of the third blade (6) to the bend (63) shows a trend of first increasing and then decreasing, while the flow area from the bend (63) to the radial outer outlet of the third blade (6) shows a trend of gradually expanding.

6. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 1, characterized in that, The outlet end of the upper wheel cover (1) is further away from the central axis than the outlet end of the wheel disc (3), and the radially outer outlet end of the third blade (6) is aligned with the outlet end of the wheel disc (3).

7. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 1, characterized in that, The main body of the hub (7) is a hollow cylindrical structure (71). The end of the hub (7) is provided with an umbrella-shaped flow guide surface (72). The inlet end of the umbrella-shaped flow guide surface (72) is in the same position as the inlet end of the middle wheel cover (2) in the axial direction. The outlet end of the umbrella-shaped flow guide surface (72) points in the axial direction to the side of the flow channel of the second blade (5) near the wheel disk (3).

8. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 7, characterized in that, The mid-arc of the umbrella-shaped guide surface (72) is part of a hyperbola.

9. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 7, characterized in that, The top of the umbrella-shaped guide surface (72) is a spherical structure.

10. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 2, characterized in that, A = (0.2 ~ 0.6)B.

11. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 1, characterized in that, W1 = (1.1 ~ 1.5)W2.

12. A composite high-efficiency, low-noise three-dimensional impeller with backward-curved blades as described in claim 1, characterized in that, The thickness δ1 of the first blade (4) is greater than the thickness δ2 of the second blade (5), and 1.2mm≤δ2≤3mm.

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