Volute tongue structure and centrifugal fan

Abstract

The utility model belongs to the technical field of centrifugal fans, and discloses a volute tongue structure and a centrifugal fan, a contour line of the volute tongue structure comprises a first arc section, a second arc section and a third arc section which are sequentially connected from an air outlet to the starting end of a volute molded line, and the intersection point of the first arc section and the second arc section forms a protruding point of the contour line. The intersection point of the second arc section and the third arc section forms a concave point of the contour line; the second arc section is internally tangent to the first arc section, the third circle center of the third arc section, the first circle center of the first arc section and the second circle center of the second arc section are collinear, and the third circle center is located between the first circle center and the second circle center. The contour line of the volute tongue structure is subjected to bionic reconstruction design on the basis of the outer contour molded line of the dolphin kiss part, so that left and right shunting is gentle, turbulent flow formed by reverse airflow impact is avoided, aerodynamic efficiency is improved, and working noise of the centrifugal fan is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal fans, in particular to a volute tongue structure and a centrifugal fan. Background Art

[0002] The function of the volute of a centrifugal fan is to collect and guide the medium gas conveyed by the impeller of the centrifugal fan, so that the gas converges to the outlet of the volute. A shell wall structure is usually arranged at the connection between the volute and the air outlet, which is in the shape of a tongue, and is called a volute tongue. The volute tongue is located at the demarcation point between the volute drainage and the output air flow. The function of the volute tongue is to prevent some air flow from circulating in the volute: when the blades of the impeller rotate, the air flow near the air outlet passes over the volute tongue, and the volute tongue divides the air flow into two parts. Most of the air flow flows along the flow channel to the air outlet, and a small part of the air flow flows back into the volute through the gap between the volute tongue and the impeller, and returns to the volute tongue to participate in the new diversion after rotating one week with the impeller in the volute; Therefore, the shape of the volute tongue directly affects the noise level and aerodynamic efficiency of the fan. The air flow near the volute tongue is complex. The volute tongue is periodically impacted by the air flow at the air outlet. Part of the air flow impacts the volute tongue to form a counter-flow air flow, which forms a convective interference with the air flow in the direction of the air outlet and the circulating air flow flowing into the volute, resulting in turbulent flow, affecting the aerodynamic efficiency and increasing the fan noise.

[0003] Therefore, there is an urgent need for a volute tongue structure and a centrifugal fan to solve the above problems. Summary of the Utility Model

[0004] An object of the utility model is to provide a volute tongue structure, which can solve the problem that the existing volute tongue is periodically impacted by the air flow to form a counter-flow air flow, which forms a convective interference with the air flow in the direction of the air outlet and the circulating air flow flowing into the volute, thereby affecting the aerodynamic efficiency and increasing the fan noise.

[0005] To achieve this purpose, the utility model adopts the following technical solutions in one aspect:

[0006] Provide a volute tongue structure, which is arranged in the volute. The volute is provided with an air outlet, and the volute has a volute profile. The volute tongue structure is connected to the starting end of the volute profile. The volute tongue structure has a contour line, and the contour line includes a first arc segment, a second arc segment and a third arc segment. From the air outlet to the starting end of the volute profile, the first arc segment, the second arc segment and the third arc segment are connected in sequence. The intersection of the first arc segment and the second arc segment forms a convex point of the contour line, and the intersection of the second arc segment and the third arc segment forms an inner concave point of the contour line;

[0007] Wherein, the second arc segment is inscribed in the first arc segment, the third center of the third arc segment is collinear with the first center of the first arc segment and the second center of the second arc segment, and the third center is located between the first center and the second center.

[0008] In one embodiment, the third arc segment is tangentially connected to the volute profile.

[0009] In one embodiment, the second arc segment and the third arc segment are connected by a transitional chamfer.

[0010] In one embodiment, an impeller is disposed in the volute, the radius of the first arc segment is R, the radius of the impeller is R, and 0.005*R ≤ R1 ≤ 0.25*R; and / or,

[0011] The central angle of the first arc segment is α, and 30° ≤ α ≤ 85°.

[0012] In one embodiment, an impeller is disposed in the volute, the radius of the second arc segment is R2, the radius of the impeller is R, and 0.005*R ≤ R2 ≤ 0.05*R; and / or,

[0013] The central angle of the second arc segment is β, and 20° ≤ β ≤ 80°.

[0014] In one embodiment, an impeller is disposed in the volute, the radius of the third arc segment is R3, the radius of the impeller is R, and 0.03*R ≤ R3 ≤ 0.15*R; and / or,

[0015] The central angle of the third arc segment is γ, and 30° ≤ γ ≤ 85°.

[0016] In one embodiment, an impeller is disposed in the volute, and the clearance between the connection point of the third arc segment and the volute profile and the impeller is the minimum volute tongue clearance.

[0017] In one embodiment, the sum of the central angles of the first arc segment, the second arc segment, and the third arc segment is not greater than 180°.

[0018] Another object of the present invention is to provide a centrifugal fan, the volute tongue structure of which can prevent the existing volute tongue from being periodically impacted by air flow to form a counter-flow air flow, causing convective interference to the air flow in the outlet direction and the circulating air flow flowing into the volute, thereby affecting the aerodynamic efficiency and increasing the fan noise.

[0019] To achieve this object, the present invention adopts the following technical solutions on the other hand:

[0020] Provided is a centrifugal fan, including the volute tongue structure as described above. The centrifugal fan further includes a volute and an impeller rotatably disposed in the volute, and the volute tongue structure is connected to the volute.

[0021] In one embodiment, the volute type of the volute adopts an Archimedean spiral or a logarithmic spiral.

[0022] Advantages of the present utility model:

[0023] The volute tongue structure provided by the present utility model has a contour line, which includes a first arc segment, a second arc segment, and a third arc segment. From the air outlet to the starting end of the volute profile line, the first arc segment, the second arc segment, and the third arc segment are sequentially connected. The intersection of the first arc segment and the second arc segment forms a convex point of the contour line, and the intersection of the second arc segment and the third arc segment forms a concave point of the contour line. Among them, the first arc segment and the second arc segment are internally tangent, the third center of the third arc segment is collinear with the first center of the first arc segment and the second center of the second arc segment, and the third center is located between the first center and the second center. The volute tongue structure is bionically reconstructed on the basis of the outer contour line of the dolphin's snout. The first arc segment, the second arc segment, and the third arc segment resemble the dolphin's snout. The convex point, as the arch point of the contour line, simulates the forefront of the dolphin's snout and diverts the oncoming flow. The concave point simulates the transition part of the snout to the abdomen of the body and guides the diverted gas. After the convex point encounters the airflow impact, the airflow direction is split, making the left and right divergences relatively gentle. The diverted airflow respectively flows along the first arc segment to the air outlet and along the second arc segment and the third arc segment back to the volute profile line, without forming a reverse impact, and without interfering with other airflows on the air outlet side and the circulating airflow flowing into the volute, thus avoiding the turbulence formed by the reverse airflow impact.

[0024] The centrifugal fan provided by the present utility model includes the above-mentioned volute tongue structure. The volute tongue structure is bionically reconstructed on the basis of the outer contour line of the dolphin's snout. The first arc segment, the second arc segment, and the third arc segment resemble the dolphin's snout. The convex point, as the arch point of the contour line, simulates the forefront of the dolphin's snout and diverts the oncoming flow. The concave point simulates the transition part of the snout to the abdomen of the body and guides the diverted gas. After the convex point encounters the airflow impact, the airflow direction is split, making the left and right divergences smoother, without forming a reverse impact. Part of the diverted airflow flows along the first arc segment to the air outlet, and part of it flows back to the volute profile line along the second arc segment and the third arc segment, without interfering with other airflows on the air outlet side and the circulating airflow flowing into the volute, avoiding turbulence, improving the aerodynamic efficiency, and reducing the working noise of the centrifugal fan. Description of the Drawings

[0025] Figure 1 is the main structural view of the volute tongue structure provided by the embodiment of the present utility model;

[0026] Figure 2 It is a schematic diagram of the airflow guided by the volute tongue structure provided by the embodiment of the present utility model;

[0027] Figure 3 It is a schematic structural diagram of the volute tongue structure provided by the embodiment of the present utility model;

[0028] Figure 4 It is a schematic structural diagram of the centrifugal fan provided by the embodiment of the present utility model.

[0029] In the figure:

[0030] 1. Outline; 11. First arc segment; 111. First center; 12. Second arc segment; 121. Second center; 13. Third arc segment; 131. Third center; 132. Connection point; 14. Protruding point; 15. Concave point;

[0031] 100. Volute; 101. Air outlet; 102. Volute profile; 1021. Starting end;

[0032] 200. Impeller. Specific embodiments

[0033] The present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. In addition, it should be noted that for the convenience of description, only the parts related to the present utility model rather than all the structures are shown in the drawings.

[0034] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0035] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0036] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "left" and "right" are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0037] The function of the volute of a centrifugal fan is to collect and guide the medium gas conveyed by the impeller of the centrifugal fan, so that the gas converges to the volute outlet. There is usually a shell wall structure at the connection between the volute and the air outlet, which is tongue-shaped like a tongue and is called the volute tongue. The volute tongue is at the demarcation point of the volute's air flow diversion and output. The function of the volute tongue is to prevent some air flow from circulating in the volute: when the blades of the impeller rotate, the air flow near the air outlet passes over the volute tongue, and the volute tongue divides this air flow into two parts. Most of the air flow flows along the flow channel to the air outlet, and a small part of the air flow flows back into the volute through the gap between the volute tongue and the impeller, and after rotating one week with the impeller in the volute, it returns to the volute tongue to participate in a new flow division; therefore, the shape of the volute tongue directly affects the noise level and aerodynamic efficiency of the fan. The air flow near the volute tongue is complex. The volute tongue is periodically impacted by the air flow at the air outlet. Some of the air flow impacts the volute tongue to form a counter-flow air flow, which forms a convective interference with the air flow in the air outlet direction and the circulating air flow flowing into the volute, resulting in turbulent flow, affecting the aerodynamic efficiency and increasing the fan noise.

[0038] In view of the above problems, the inventor found through research that the head of a bottlenose dolphin has remarkable features, and its front snout is in a flat elliptical arc shape. When it swims, the front snout acts as a forward cruise device to break through the water flow in front. Due to the smooth lines of the front snout shape, the water flow is divided into two side deflections, and there will be no reverse flow to form an impact with the water flow in front, which affects the swimming speed of the dolphin. This flow field form is relatively similar to the movement trend of the air flow field where the volute tongue of the fan is located. On this basis, the inventor applied the shape characteristics of the front snout of the bottlenose dolphin to the structural design of the volute tongue, forming the volute tongue structure in Embodiment 1, and solved the above problems through the bionic volute tongue.

[0039] Embodiment 1

[0040] As Figures 1 to 3 shown, in this embodiment, a volute tongue structure is first provided. The volute tongue structure is disposed within a volute casing 100. The volute casing 100 is provided with an air outlet 101 and has a volute profile 102. The volute tongue structure is connected to the starting end 1021 of the volute profile 102. The volute tongue structure has a contour line 1, which includes a first arc segment 11, a second arc segment 12, and a third arc segment 13. From the air outlet 101 to the starting end 1021 of the volute profile 102, the first arc segment 11, the second arc segment 12, and the third arc segment 13 are sequentially connected. The intersection of the first arc segment 11 and the second arc segment 12 forms a convex point 14 of the contour line 1, and the intersection of the second arc segment 12 and the third arc segment 13 forms a concave point 15 of the contour line 1. Among them, the second arc segment 12 is inscribed in the first arc segment 11, and the third center 131 of the third arc segment 13 is collinear with the first center 111 of the first arc segment 11 and the second center 121 of the second arc segment 12, and the third center 131 is located between the first center 111 and the second center 121.

[0041] The volute tongue structure proposed in the first new embodiment of this embodiment is a bionic reconstruction design based on the outer contour line of a dolphin's snout. The first arc segment 11, the second arc segment 12, and the third arc segment 13 resemble the snout of a dolphin. The convex point 14 simulates the forefront of the dolphin's snout and becomes the arch point of the contour line 1, which diverts the oncoming flow. The concave point 15 simulates the transition part of the snout to the abdomen of the body and guides the diverted gas. After the convex point 14 encounters the airflow impact, it splits the airflow direction, making the left and right divergences smoother. As Figure 3 shown, no reverse impact will be formed. The diverted airflow respectively flows along the first arc segment 11 towards the air outlet 101, and along the second arc segment 12 and the third arc segment 13 back to the volute profile 102, without interfering with other airflows on the side of the air outlet 101 and the circulating airflow flowing into the volute casing 100, avoiding turbulence, improving the aerodynamic efficiency, and reducing noise.

[0042] The third arc segment 13 is tangentially connected to the volute profile 102. The linear type of this tangential connection between the third arc segment 13 and the volute profile 102 is more in line with the curved shape of the dolphin's back arching during migration, and the connecting curve between the abdominal side profile and the snout is approximately tangentially connected; the tangential connection transition structure reduces the friction force on the airflow and reduces the aerodynamic loss.

[0043] Since an inner concave point 15 is formed between the second arc segment 12 and the third arc segment 13, in order to ensure a smooth transition at the inner concave point 15 and further reduce the friction force on the airflow, the second arc segment 12 and the third arc segment 13 are connected by a transition chamfer.

[0044] An impeller 200 is provided inside the volute 100 to drive the air flow. The radius of the first arc segment 11 is R1 (refer to Figure 2 ), the radius of the impeller 200 is R, and 0.005*R ≤ R1 ≤ 0.25*R. R1 can be selected as 0.005 times the radius R of the impeller 200, 0.01 times R, 0.1 times R, 0.2 times R, or other values between 0.005*R and 0.25*R, and can be selected according to the actual working conditions.

[0045] The central angle of the first arc segment 11 is α, and 30° ≤ α ≤ 85°. The central angle α can be selected as 30°, 35°, 40°, 80°, or other angles between 30° and 85°, and can be selected according to the actual working conditions.

[0046] The radius of the second arc segment 12 is R2, the radius of the impeller 200 is R, and 0.005*R ≤ R2 ≤ 0.05*R. R2 can be selected as 0.005 times the radius R of the impeller 200, 0.01 times R, 0.05 times R, or other values between 0.005*R and 0.05*R, and can be selected according to the actual working conditions. Since the second arc segment 12 is inscribed in the first arc segment 11, it is necessary to ensure that R2 is always less than R1.

[0047] The central angle of the second arc segment 12 is β, and 20° ≤ β ≤ 80°. The central angle β can be selected as 20°, 35°, 50°, 80°, or other angles between 20° and 80°, and can be selected according to the actual working conditions.

[0048] The radius of the third arc segment 13 is R3, the radius of the impeller 200 is R, and 0.03*R ≤ R3 ≤ 0.15*. R3 can be selected as 0.03 times the radius R of the impeller 200, 0.05 times R, 0.1 times R, 0.15 times R, or other values between 0.003*R and 0.15*R, and can be selected according to the actual working conditions.

[0049] The central angle of the third arc segment 13 is γ, and 30° ≤ γ ≤ 85°. The central angle γ can be selected as 30°, 45°, 50°, 85°, or other angles between 30° and 85°, and can be selected according to the actual working conditions.

[0050] In addition to the above respective central angle limitations of each arc segment, the sum of the central angles of the first arc segment 11, the second arc segment 12, and the third arc segment 13 needs to be no greater than 180°, ensuring that the air outlet 101 and the starting end 1021 of the volute profile 102 have an included angle less than 180°, and ensuring that the air flow can be effectively guided out.

[0051] The gap between the connection point 132 of the third arc segment 13 and the volute profile 102 and the impeller 200 is the minimum volute tongue gap, as Figure 4 shown. In the figure, L is the gap between the connection point 132 and the impeller 200, and this gap is the minimum value of the gap between the volute tongue structure and the impeller 200. By setting this position as the minimum value, the volute tongue gaps at other positions of the contour line 1 are all greater than this minimum value. The appropriately increased volute tongue gap can reduce the overall noise of the volute tongue structure.

[0052] Embodiment 2

[0053] Embodiment 2 of the present utility model provides a centrifugal fan. The centrifugal fan includes the volute tongue structure as in Embodiment 1 above. The centrifugal fan further includes a volute 100 and an impeller 200 rotatably arranged in the volute 100, and the volute tongue structure is connected to the volute 100. The volute tongue structure is bionically reconstructed and designed on the basis of the outer contour line of a dolphin's snout. The first arc segment 11, the second arc segment 12, and the third arc segment 13 resemble the snout of a dolphin. The convex point 14, which is the apex of the contour line 1, simulates the foremost end of the dolphin's snout to split the incoming flow. The concave point 15 simulates the transition part of the snout to the abdomen of the body to guide the gas after splitting. After the convex point 14 encounters the impact of the air flow, the air flow direction is split, making the left and right splits smoother and not forming a reverse impact. Part of the split air flow flows along the first arc segment 11 to the air outlet 101, and part of it flows back to the volute profile 102 along the second arc segment 12 and the third arc segment 13, without interfering with other air flows on the air outlet 101 side and the circulating air flow flowing into the volute 100, avoiding turbulence, improving the aerodynamic efficiency, and reducing the working noise of the centrifugal fan.

[0054] The volute profile 102 of the volute 100 adopts an Archimedean spiral or a logarithmic spiral, and these two curve structures are more suitable for the actual flow state of the air flow.

[0055] Obviously, the above embodiments of the present utility model are merely examples for clearly illustrating the present utility model, rather than limiting the implementation manners of the present utility model. For those of ordinary skill in the art, various obvious changes, re-adjustments, and substitutions can be made without departing from the protection scope of the present utility model. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the claims of the present utility model.

Claims

1. The volute tongue structure is arranged inside the volute (100). The volute (100) is provided with an air outlet (101), and the volute (100) has a volute profile (102). The volute tongue structure is connected to the starting end (1021) of the volute profile (102), and is characterized in that, The volute tongue structure has a contour line (1), and the contour line (1) includes a first circular arc segment (11), a second circular arc segment (12), and a third circular arc segment (13). From the air outlet (101) to the starting end (1021) of the volute profile line (102), the first circular arc segment (11), the second circular arc segment (12), and the third circular arc segment (13) are connected in sequence. The intersection of the first circular arc segment (11) and the second circular arc segment (12) forms a convex point (14) of the contour line (1), and the intersection of the second circular arc segment (12) and the third circular arc segment (13) forms a concave point (15) of the contour line (1). Wherein, the second circular arc segment (12) is inscribed in the first circular arc segment (11), and the third center (131) of the third circular arc segment (13) is collinear with the first center (111) of the first circular arc segment (11) and the second center (121) of the second circular arc segment (12), and the third center (131) is located between the first center (111) and the second center (121).

2. The tongue structure according to claim 1, characterized in that, The third circular arc segment (13) is tangentially connected to the volute profile line (102).

3. The volute tongue structure according to claim 1, wherein, The second circular arc segment (12) and the third circular arc segment (13) are connected by a transition chamfer.

4. The scroll tongue structure according to claim 1, characterized in that, An impeller (200) is arranged in the volute (100). The radius of the first circular arc segment (11) is R1, and the radius of the impeller (200) is R, where 0.005*R ≤ R1 ≤ 0.25*R; and / or, The central angle of the first circular arc segment (11) is α, and 30° ≤ α ≤ 85°.

5. The volute tongue structure according to claim 1, characterized in that, An impeller (200) is arranged in the volute (100). The radius of the second circular arc segment (12) is R2, and the radius of the impeller (200) is R, where 0.005*R ≤ R2 ≤ 0.05*R; and / or, The central angle of the second circular arc segment (12) is β, and 20° ≤ β ≤ 80°.

6. The tongue structure according to claim 1, wherein An impeller (200) is arranged in the volute (100). The radius of the third circular arc segment (13) is R3, and the radius of the impeller (200) is R, where 0.03*R ≤ R3 ≤ 0.15*R; and / or, The central angle of the third circular arc segment (13) is γ, and 30° ≤ γ ≤ 85°.

7. The volute tongue structure according to any one of claims 1-6, characterized in that, An impeller (200) is arranged in the volute (100). The gap between the connection point (132) of the third circular arc segment (13) and the volute profile line (102) and the impeller (200) is the minimum volute tongue gap.

8. The scroll tongue structure according to any one of claims 1-6, characterized in that, The sum of the central angles of the first circular arc segment (11), the second circular arc segment (12), and the third circular arc segment (13) is not greater than 180°.

9. Centrifugal fan, characterized in that, Including the volute tongue structure according to any one of claims 1-8, the centrifugal fan further includes a volute (100) and an impeller (200) rotatably arranged in the volute (100), and the volute tongue structure is connected to the volute (100).

10. The centrifugal fan according to claim 9, wherein, The volute profile line (102) of the volute (100) adopts an Archimedean spiral or a logarithmic spiral.

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