Flow-increased jet centrifugal volute and centrifugal fan using the same

Abstract

The present application relates to centrifugal fan technical field, especially to a jet flow centrifugal volute of flow increasing and centrifugal fan using the same, the jet flow centrifugal volute includes the baffle and two side plates;Two side plates are installed on both sides of the baffle and form a volute cavity with a single air outlet, two side plates are parallel and symmetrically arranged about the center plane of the jet flow centrifugal volute, two side plates are respectively provided with air inlet, the structural size of two air inlets is consistent and symmetrically arranged about the center plane of the jet flow centrifugal volute;The baffle is provided with two convex structures near the air outlet, two convex structures are protruded from the inside to the outside of the volute cavity, and symmetrically arranged about the center plane of the jet flow centrifugal volute.The present application sets up symmetric convex structure near the air outlet of the volute baffle, optimizes the air flow state near the air outlet, to solve the technical problems of traditional centrifugal volute, such as airflow turbulence near the volute tongue, serious backflow, limited fan flow, high noise.

Description

Technical Field

[0001] This invention relates to the field of centrifugal volute technology, and more particularly to a jet centrifugal volute for increasing flow and a centrifugal fan using the same. Background Technology

[0002] The centrifugal volute is the core flow channel component of a centrifugal fan. Working in conjunction with the impeller, it completes the processes of airflow collection, guidance, and pressurization. Its structural design directly determines the fan's airflow efficiency, actual air volume output, and noise level. It is widely used in civil and industrial fields such as ventilation, refrigeration, HVAC, and industrial power transmission. Traditional jet centrifugal volutes are composed of a surrounding plate and two side plates. The side plates have air inlets, and the surrounding plates are smooth arc-shaped with a single air outlet. However, its flow channel structure is not optimized for the airflow characteristics near the air outlet. When the fan is operating, the airflow thrown out by the impeller is prone to turbulence and local backflow in the area of ​​the volute near the air outlet. This causes strong impacts between the airflow and the volute wall and volute tongue, increasing airflow impact losses, limiting the actual air volume output, and generating significant noise due to the high-frequency pressure pulsation caused by the impact. Furthermore, existing volute improvements mostly focus on simple adjustments to the volute tongue shape and flow channel curvature, without designing a dedicated airflow guiding structure. This fails to fundamentally optimize the airflow state near the air outlet, making it difficult to meet the modern demands for high efficiency and low noise in centrifugal fan applications. Summary of the Invention

[0003] One objective of this invention is to propose a jet centrifugal volute with enhanced flow. By setting symmetrical protrusions near the air outlet on the volute casing plate, the airflow state near the air outlet is optimized, thereby solving the technical problem of turbulent airflow and severe backflow near the outlet in traditional centrifugal volutes, which leads to limited air volume and high noise of the fan.

[0004] Another object of the present invention is to provide a flow-enhancing jet centrifugal fan, which uses a flow-enhancing jet centrifugal volute as described above.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A flow-enhancing centrifugal volute includes a perimeter plate and two side plates;

[0007] The two side plates surround and install the two sides of the enclosure, and together form a volute cavity with a single air outlet. The two side plates are parallel and symmetrically arranged about the center plane of the jet centrifugal volute. Each of the two side plates has an air inlet. The two air inlets have the same structural dimensions and are symmetrically arranged about the center plane of the jet centrifugal volute.

[0008] The enclosure has two protruding structures near the air outlet. Both protruding structures protrude from the inside of the volute cavity to the outside, and the two protruding structures are symmetrically arranged about the center plane of the jet centrifugal volute.

[0009] Preferably, the most prominent point of the protruding structure is defined as the center point X, and the outer edge of the protruding structure gradually converges towards the center point X and connects smoothly to form a smooth transition structure without sharp edges.

[0010] Preferably, the line connecting the centers of the two air inlets is defined as the rotation axis of the jet centrifugal volute, and the intersection of the rotation axis of the jet centrifugal volute and the center plane of the jet centrifugal volute is the axis O of the jet centrifugal volute.

[0011] A first section is made along a plane parallel to the center plane of the jet centrifugal volute and passing through the center point X of the protrusion structure. The profile of the surrounding plate includes a volute tongue segment, a spiral segment, a connecting segment and a protrusion segment connected in sequence, or a volute tongue segment, a spiral segment and a protrusion segment connected in sequence.

[0012] The protruding structure is integrally formed on the protruding section, and the cross-sectional shape of the protruding structure on the first cross-section is a first circular arc segment.

[0013] Preferably, the connection point between the spiral segment and the connecting segment or the protruding segment is defined as design point V;

[0014] Define the straight line connecting the design point V and the axis O as the straight line VO, and draw a horizontal line perpendicular to the straight line VO through the axis O;

[0015] The point on the first arc segment with the longest vertical distance to the horizontal line is defined as design point P, the straight-line distance between design point V and axis O is defined as H, and the vertical distance from design point P to the horizontal line is defined as K.

[0016] Where K≤(0.8~1)H.

[0017] Preferably, the radius of the first arc segment is defined as the convex radius R1;

[0018] The air inlet is circular, and the radius of the air inlet is defined as the air inlet radius R0;

[0019] Where R1 = (0.5~2)R0.

[0020] Preferably, the two endpoints of the first arc segment are defined as design point A and design point B, respectively;

[0021] Define the total arc length of the first arc segment as LAB;

[0022] The arc length of the first circular arc segment between design point A and design point P is defined as LAP;

[0023] Wherein, LAP = (0.1~0.9)LAB.

[0024] Preferably, the angle formed by the line connecting the design point V, the axis O, and the design point A is defined as the included angle M;

[0025] Define the angle N as the angle formed by the lines connecting design point A, axis O, and design point B;

[0026] Among them, 0º≤M≤40º, 5º≤N≤25º.

[0027] Preferably, a projection is made along a direction perpendicular to the horizontal plane where the horizontal line is located, and the vertical distance between the center point X of the protruding structure and the center plane of the jet centrifugal volute is defined as L;

[0028] Define the vertical distance between the side plate and the center surface of the jet centrifugal volute as D;

[0029] Where 0.4≤L / D≤0.6.

[0030] Preferably, a second cross section is made along a plane parallel to the horizontal plane where the straight line VO is located and passing through the center point X of the protruding structure, and the cross section shape of the protruding structure on the second cross section is a second circular arc segment;

[0031] Define the radius corresponding to the second arc segment as R2;

[0032] The air inlet is circular, and the radius of the air inlet is defined as the air inlet radius R0;

[0033] Where R2 = (0.05~0.35)R0.

[0034] A centrifugal fan includes an impeller and a flow-enhancing centrifugal volute as described above;

[0035] The impeller is installed inside the volute cavity of the jet centrifugal volute, and the rotation axis of the impeller is coaxially overlapped with the rotation axis of the jet centrifugal volute.

[0036] One of the above technical solutions has the following beneficial effects: it optimizes the airflow trend near the air outlet as a whole, reduces the backflow phenomenon caused by airflow bias and turbulence, reduces the irregular impact of airflow on the volute wall, improves the airflow efficiency towards the air outlet, and lays a structural foundation for increasing air volume; the symmetrical structure makes the volute uniformly stressed, avoids volute vibration caused by airflow bias, and indirectly reduces the noise generated by vibration. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a jet centrifugal volute for flow enhancement according to the present invention;

[0038] Figure 2 This is a top view schematic diagram of a jet centrifugal volute for flow enhancement according to the present invention;

[0039] Figure 3 yes Figure 2 A cross-sectional schematic diagram of the ZZ section;

[0040] Figure 4 yes Figure 3 Simplified design drawings;

[0041] Figure 5 yes Figure 2 A cross-sectional view of YY;

[0042] Figure 6 yes Figure 5 Simplified design drawing at point C;

[0043] Figure 7 This is a schematic diagram of the structure of a centrifugal fan with a jet centrifugal volute that applies flow enhancement according to the present invention;

[0044] Figure 8 This is a test airflow distribution diagram of a centrifugal fan using a jet centrifugal volute with flow enhancement according to the present invention;

[0045] Figure 9 This is a test airflow distribution diagram based on existing technology;

[0046] In the attached diagram: 1. Enclosure panel; 2. Side panel; 3. Air outlet; 4. Air inlet; 5. Protruding structure; 6. Center surface; 7. Rotating shaft of the jet centrifugal volute; 8. Rotating shaft of the impeller; 11. Volute tongue section; 12. Spiral section; 13. Connecting section; 14. Protruding section; 100. Impeller; 200. Jet centrifugal volute. Detailed Implementation

[0047] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "left," "right," "vertical," "level," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0050] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0051] A flow-enhancing centrifugal volute includes a surrounding plate 1 and two side plates 2;

[0052] The two side plates 2 are installed around the two sides of the enclosure plate 1 and together form a volute cavity with a single air outlet 3. The two side plates 2 are parallel and symmetrically arranged about the center plane 6 of the jet centrifugal volute. The two side plates 2 are respectively provided with air inlets 4. The two air inlets 4 have the same structural dimensions and are symmetrically arranged about the center plane 6 of the jet centrifugal volute.

[0053] The enclosure 1 has two protruding structures 5 near the air outlet 3. Both protruding structures 5 protrude from the inside of the volute cavity to the outside, and the two protruding structures 5 are symmetrically arranged about the center surface 6 of the jet centrifugal volute.

[0054] like Figure 1-2 As shown, the present invention forms a volute cavity with a single air outlet 3 by enclosing a surrounding plate 1 and two side plates 2. The two side plates 2 and the two air inlets 4 on them are arranged parallel and symmetrically about the center plane 6 of the volute, ensuring that the airflow enters the jet centrifugal volute uniformly from both sides. Two protruding structures 5 are provided on the surrounding plate 1 near the air outlet 3, which protrude from the inside of the jet centrifugal volute outward, and the protruding structures 5 are symmetrical about the center plane 6 of the jet centrifugal volute. When the airflow thrown out by the impeller flows towards the air outlet 3, the symmetrical protruding structures 5 will form a synchronous and balanced guiding effect on the airflow on both sides of the jet centrifugal volute, change the cross-sectional shape of the flow channel near the air outlet 3, guide the turbulent airflow to converge orderly towards the air outlet 3 along the protruding contour, and at the same time cancel the bias pressure generated by the unilateral flow of the airflow, so that the airflow pressure field inside the volute is uniformly distributed.

[0055] To further explain, the most prominent point of the protruding structure 5 is defined as the center point X. The outer edges of the protruding structure 5 gradually converge towards the center point X and connect smoothly to form a smooth transition structure without sharp edges.

[0056] like Figure 1 , 3 As shown in Figure 5, the outer edge of the protruding structure 5 is smoothly connected to the most convex point, i.e., the center point X, to form a smooth transition structure without sharp corners. This avoids the protrusion itself having structural features such as sharp corners or right angles that are prone to causing airflow impact. When the airflow flows over the protruding surface, it can flow continuously along the smooth contour surface. This not only eliminates the secondary impact of the protruding structure 5 on the airflow and avoids the introduction of new airflow losses due to the protruding structure 5, but also ensures the pure guiding effect of the protrusion on the airflow. At the same time, the smooth structure reduces the pressure change of the airflow on the protruding surface, reduces local pressure pulsation, and further suppresses noise generation.

[0057] To further explain, the line connecting the centers of the two air inlets 4 is defined as the rotation axis 7 of the jet centrifugal volute, and the intersection of the rotation axis 7 of the jet centrifugal volute and the center plane 6 of the jet centrifugal volute is defined as the axis O of the jet centrifugal volute.

[0058] A first section is made along a plane parallel to the center plane 6 of the jet centrifugal volute and passing through the center point X of the protrusion structure 5. The profile of the enclosure plate 1 includes a volute tongue segment 11, a spiral segment 12, a connecting segment 13 and a protrusion segment 14 connected in sequence, or a volute tongue segment 11, a spiral segment 12 and a protrusion segment 14 connected in sequence.

[0059] The protruding structure 5 is integrally formed on the protruding section 14, and the cross-sectional shape of the protruding structure 5 on the first cross-section is a first circular arc segment.

[0060] like Figure 3-4 As shown, the rotation axis 7 and the axis O of the jet centrifugal volute are first defined as the reference positioning of the jet centrifugal volute. Since the surrounding plate 1 has thickness, the first section is made along the plane parallel to the center plane 6 of the jet centrifugal volute and passing through the center point X of the protrusion structure 5. The profile of the surrounding plate 1 is defined with the outer wall of the surrounding plate 1 as the reference. The profile of the surrounding plate 1 includes the volute tongue section 11, the spiral section 12, the connecting section 13 and the protrusion section 14 connected in sequence, or the volute tongue section 11, the spiral section 12 and the protrusion section 14 connected in sequence. Among them, the protrusion structure 5 is integrally formed on the protrusion section 14 and the cross section is the first arc section, so that the protrusion structure 5 is seamlessly connected with the profile of the surrounding plate 1. When the airflow can enter from the connecting section 13 or directly enter the protrusion section 14, it is gradually guided to the outlet 3 along the arc contour of the first arc section, realizing the gradual flow of airflow and further improving the orderliness of airflow. At the same time, the integrally formed structure improves the structural strength of the volute and reduces the processing and assembly difficulty.

[0061] To further explain, the connection point between the spiral segment 12 and the connecting segment 13 or the protruding segment 14 is defined as design point V;

[0062] Define the straight line connecting the design point V and the axis O as the straight line VO, and draw a horizontal line perpendicular to the straight line VO through the axis O;

[0063] The point on the first arc segment with the longest vertical distance to the horizontal line is defined as design point P, the straight-line distance between design point V and axis O is defined as H, and the vertical distance from design point P to the horizontal line is defined as K.

[0064] Where K≤(0.8~1)H.

[0065] like Figure 3-4 As shown, the design point P is the point with the longest vertical distance between the first arc segment and the horizontal line, representing the highest point of the protrusion of the protrusion structure 5. H is the straight-line distance between the design point V and the axis O, which is the reference height of the jet centrifugal volute channel. K is limited to (0.8~1)H to ensure that the protrusion height of the protrusion structure 5 matches the reference height of the jet centrifugal volute channel. This ensures that the protrusion structure 5 can effectively guide the airflow, while avoiding the situation where the protrusion of the protrusion structure 5 is too high, resulting in an excessively small cross-section of the jet centrifugal volute channel and causing airflow obstruction, or the protrusion is too low, failing to play an effective guiding role.

[0066] The above-mentioned precise control of the protrusion height of the protrusion structure 5 ensures the flow area of ​​the jet centrifugal volute channel while achieving effective airflow guidance, thus avoiding airflow loss and pressure surge caused by airflow blockage. At the same time, the reasonable protrusion height makes the airflow velocity change at the protrusion more gradual, reducing turbulence noise caused by sudden velocity changes.

[0067] It should be noted that the center point X of the protruding structure 5 is the most convex point on the protruding structure 5 with the longest vertical distance between the straight line connecting the design point A and the design point B, and the design point P of the protruding structure 5 is the highest convex point on the protruding structure 5 with the longest vertical distance between the straight line and the horizontal line perpendicular to the straight line VO.

[0068] To further explain, the radius of the first arc segment is defined as the convex radius R1;

[0069] The air inlet 4 is circular, and the radius of the air inlet 4 is defined as the air inlet radius R0;

[0070] Where R1 = (0.5~2)R0.

[0071] like Figure 3-4As shown, the inlet radius R0 determines the initial flow rate and velocity of the airflow entering the jet centrifugal volute. By limiting R1 to (0.5~2)R0, the arc curvature of the protruding structure 5 is matched with the initial flow characteristics of the airflow. If the curvature is too large (i.e., R1 is too small), the airflow will bend excessively on the surface of the protruding structure 5, increasing the flow resistance; while if the curvature is too small (i.e., R1 is too large), the guiding effect of the protruding structure 5 will be insufficient, and it will be unable to effectively sort out the turbulent airflow.

[0072] The above-mentioned constraints ensure that the arc-shaped profile of the protruding structure 5 in the first section is highly compatible with the initial flow characteristics of the airflow, which not only ensures the effective sorting and guidance of turbulent airflow, but also avoids the generation of additional flow resistance due to excessive bending of the airflow, thereby achieving the optimal balance between flow resistance and guidance effect and further improving the airflow efficiency.

[0073] To further explain, the two endpoints of the first arc segment are defined as design point A and design point B, respectively;

[0074] Define the total arc length of the first arc segment as LAB;

[0075] The arc length of the first circular arc segment between design point A and design point P is defined as LAP;

[0076] Wherein, LAP = (0.1~0.9)LAB.

[0077] like Figure 3-4 As shown, LAB is the total arc length of the first arc segment, and LAP is the arc length from design point A to design point P. By limiting LAP to (0.1~0.9)LAB, the position of the highest protrusion point P of the protrusion can be precisely controlled in the first arc segment, so that the guiding effect of the protrusion can be exerted at the optimal position when the airflow enters the protrusion segment 14. This avoids the situation where point P is too close to design point A, causing the airflow to be sharply lifted as soon as it enters the protrusion segment 14, or too close to design point B, resulting in insufficient airflow guidance and failure to form an orderly flow in front of the air outlet 3.

[0078] The above-mentioned optimized protrusion structure 5 is positioned at the highest point of the first cross section, so that the protrusion structure 5 plays a guiding role in the optimal stage of airflow, ensuring that the airflow is fully sorted into an orderly flow in front of the air outlet 3, minimizing backflow and turbulence near the air outlet 3, and improving the outflow efficiency of the airflow; at the same time, the reasonable arc length ratio makes the pressure change of the airflow in the protrusion section 14 more uniform and reduces the pressure pulsation gradient.

[0079] To further clarify, the angle formed by the line connecting the design point V, the axis O, and the design point A is defined as angle M.

[0080] Define the angle N as the angle formed by the lines connecting design point A, axis O, and design point B;

[0081] Among them, 0º≤M≤40º, 5º≤N≤25º.

[0082] like Figure 3-4 As shown, the included angle M is the angle between design point V, axis O and design point A, which determines the starting position of the protruding structure 5 in the jet centrifugal volute flow channel. It is limited to 0º≤M≤40º, so that the protruding structure 5 starts in a reasonable area from the volute tongue to the air outlet 3, avoiding the protruding structure 5 being too close to the volute tongue, causing the airflow to be disturbed as soon as it leaves the impeller, or too close to the air outlet 3, resulting in a short guiding distance and insufficient effect. The included angle N is the angle between design point A, axis O and design point B, which determines the axial coverage range of the protruding structure 5. It is limited to 5º≤N≤25º, so that the coverage range of the protruding structure 5 matches the turbulent airflow area near the air outlet 3, ensuring full coverage of the turbulent area, while avoiding excessive coverage that would increase the flow channel resistance.

[0083] The aforementioned precise positioning of the protruding structure 5 within the jet centrifugal volute flow channel, including its initial position and axial coverage, ensures that the guiding effect of the protruding structure 5 is highly matched with the turbulent airflow area near the outlet 3. This achieves precise and comprehensive management of the turbulent airflow while avoiding the introduction of additional flow channel resistance due to unreasonable protrusion position or range, thus balancing guiding effect and flow efficiency. Furthermore, reasonable angle parameters can reduce the direct impact between the airflow and the volute tongue, thereby reducing the impact pressure pulsation at the volute tongue.

[0084] To further explain, by projecting along a direction perpendicular to the horizontal plane where the horizontal line is located, the vertical distance between the center point X of the protruding structure 5 and the center plane 6 of the jet centrifugal volute is defined as L.

[0085] Define the vertical distance between the side plate 2 and the center surface 6 of the jet centrifugal volute as D;

[0086] Where 0.4≤L / D≤0.6.

[0087] like Figure 2 As shown, L is the vertical distance between the center point X of the protrusion and the center surface 6 of the jet centrifugal volute, and D is the vertical distance between the side plate 2 and the center surface 6. The limit is 0.4≤L / D≤0.6, so that the two symmetrical protrusions 5 are in a reasonable position in the radial direction of the jet centrifugal volute. This ensures that the protrusions 5 can effectively guide the airflow in the mainstream radial region of the jet centrifugal volute, while avoiding the protrusions 5 being too close to the side plate 2, which would cause the airflow to form a local stagnation zone between the side plate 2 and the protrusions 5, or being too close to the center surface 6, which would result in insufficient guiding effect on the airflow in the mainstream region.

[0088] The above-mentioned optimized arrangement of the protruding structure 5 in the radial direction of the volute allows the protruding structure 5 to act on the mainstream airflow in the jet centrifugal volute, maximizing the guiding effect, while avoiding the formation of airflow stagnation areas near the side plate 2 and reducing local airflow loss; the symmetrical radial arrangement further ensures the uniform distribution of the airflow pressure field and velocity field in the jet centrifugal volute, reducing the noise caused by uneven airflow distribution.

[0089] To further explain, a second cross section is made along a plane parallel to the horizontal plane where the straight line VO is located and passing through the center point X of the protruding structure 5, and the cross section shape of the protruding structure 5 on the second cross section is a second circular arc segment;

[0090] Define the radius corresponding to the second arc segment as R2;

[0091] The air inlet 4 is circular, and the radius of the air inlet 4 is defined as the air inlet radius R0;

[0092] Where R2 = (0.05~0.35)R0.

[0093] like Figure 5-6 As shown, R2 is the radius of the second arc segment of the protruding structure 5 on the second cross section, which is the cross section radius of the protruding structure 5 in the direction perpendicular to the horizontal plane of the connecting section 13. R2 is limited to (0.05~0.35)R0 so that the cross section arc of the protruding structure 5 in this direction matches the radial flow characteristics of the airflow, ensuring that the protruding structure 5 effectively constrains and guides the airflow in the radial direction.

[0094] The above-mentioned constraints optimize the structural form of the protrusion structure 5 in the radial dimension, so that the protrusion structure 5 can effectively guide the airflow in both the circumferential and radial directions, realize the three-dimensional spatial optimization of the airflow, and further improve the orderliness of the airflow. The reasonable cross-sectional radius makes the volume of the protrusion structure 5 match the flow channel, avoids the introduction of additional flow channel resistance, and at the same time reduces the impact of the protrusion structure 5 on the overall weight of the volute, ensuring the lightweight of the volute.

[0095] A centrifugal fan includes an impeller 100 and a flow-enhancing centrifugal volute 200 as described above;

[0096] The impeller 100 is installed in the volute cavity of the jet centrifugal volute 200, and the rotation shaft 8 of the impeller 100 and the rotation shaft 7 of the jet centrifugal volute 200 are coaxially overlapped.

[0097] like Figure 7As shown, the impeller 100 is rotatably mounted in the volute cavity of the jet centrifugal volute 200, and the rotation shaft 7 of the impeller 100 and the rotation shaft 7 of the jet centrifugal volute 200 are coaxially overlapped, ensuring that the air outlet direction of the impeller 100 is highly consistent with the flow channel direction of the jet centrifugal volute 200. The airflow thrown out by the impeller 100 can directly enter the area optimized by the protrusion structure 5 along the flow channel of the jet centrifugal volute. The guiding effect of the protrusion structure 5 on the airflow can directly act on the airflow thrown out by the impeller 100, avoiding airflow deflection caused by the misalignment of the impeller 100 and the jet centrifugal volute 200, and further improving the guiding effect of the protrusion structure 5.

[0098] To further demonstrate the improvements of this invention, a centrifugal fan using the jet centrifugal volute of this invention (hereinafter referred to as "modified") was compared with a centrifugal fan of the same model using a traditional smooth-walled volute (hereinafter referred to as "unmodified"). The test conditions were normal temperature and pressure, and the test airflow distribution was as follows. Figure 8-9 As shown in the table below:

[0099]

[0100] The test results show that, under the same air volume and static pressure, the centrifugal fan using the jet centrifugal volute of this invention has a slightly lower speed, a 0.5W reduction in power consumption, and a 0.9dBA reduction in noise. This achieves the technical effects of reduced noise and power loss. If the speed is kept consistent with that of the same model of centrifugal fan using a traditional smooth-walled volute, the actual air volume of the centrifugal fan using the jet centrifugal volute of this invention can be further increased.

[0101] Based on the test airflow distribution Figure 8 It can be seen that the centrifugal fan using the jet centrifugal volute of this invention, due to the altered pressure pulsation near the outlet 3 caused by the protruding structure 5, especially in the low-speed recirculation zone near the volute tongue section 11, not only has a smaller recirculation area but also an increased, more orderly airflow at the outlet, effectively improving the fan's flow rate. Compared to the test airflow distribution... Figure 9 The centrifugal fan of the same model using the traditional smooth-walled volute reduces ineffective work, thereby further improving the efficiency of the centrifugal fan using the jet centrifugal volute of this invention.

[0102] The values ​​of each parameter in this invention can be adjusted according to the actual size of the volute and the operating conditions of the fan. As long as the values ​​of each parameter are within the range, the technical effects of optimizing airflow and increasing flow and reducing noise can be achieved.

[0103] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A flow-enhancing jet centrifugal volute, characterized in that, It includes a perimeter panel (1) and two side panels (2); The two side plates (2) are installed around the two sides of the enclosure (1) and together form a volute cavity with a single air outlet (3). The two side plates (2) are parallel and symmetrically arranged about the center plane (6) of the jet centrifugal volute. The two side plates (2) are respectively provided with air inlets (4). The two air inlets (4) have the same structural dimensions and are symmetrically arranged about the center plane (6) of the jet centrifugal volute. The enclosure (1) has two protruding structures (5) near the air outlet (3). Both protruding structures (5) protrude from the inside of the volute cavity to the outside, and the two protruding structures (5) are symmetrically arranged about the center surface (6) of the jet centrifugal volute. The most prominent point of the protruding structure (5) is defined as the center point X. The outer edge of the protruding structure (5) gradually converges towards the center point X and connects smoothly to form a smooth transition structure without sharp edges. The center line connecting the two air inlets (4) is defined as the rotation axis of the jet centrifugal volute, and the intersection of the rotation axis of the jet centrifugal volute and the center plane (6) of the jet centrifugal volute is defined as the axis O of the jet centrifugal volute. A first section is made along a plane parallel to the center plane (6) of the jet centrifugal volute and passing through the center point X of the protrusion structure (5). The profile of the enclosure plate (1) includes a volute tongue segment (11), a spiral segment (12), a connecting segment (13) and a protrusion segment (14) connected in sequence, or a volute tongue segment (11), a spiral segment (12) and a protrusion segment (14) connected in sequence. The protruding structure (5) is integrally formed on the protruding section (14), and the cross-sectional shape of the protruding structure (5) on the first cross-section is a first circular arc segment; The connection point between the spiral segment (12) and the connecting segment (13) or the protruding segment (14) is defined as design point V; Define the straight line connecting the design point V and the axis O as the straight line VO, and draw a horizontal line perpendicular to the straight line VO through the axis O; The point on the first arc segment with the longest vertical distance to the horizontal line is defined as design point P, the straight-line distance between design point V and axis O is defined as H, and the vertical distance from design point P to the horizontal line is defined as K. Where K≤(0.8~1)H; Projecting along a direction perpendicular to the horizontal plane where the horizontal line is located, the vertical distance between the center point X of the protruding structure (5) and the center plane (6) of the jet centrifugal volute is defined as L; Define the vertical distance between the side plate (2) and the center surface (6) of the jet centrifugal volute as D; Where 0.4 ≤ L / D ≤ ​​0.6; A second section is made along a plane parallel to the horizontal plane where the straight line VO is located and passing through the center point X of the protruding structure (5), and the cross-sectional shape of the protruding structure (5) on the second section is a second circular arc segment; Define the radius corresponding to the second arc segment as R2; The air inlet (4) is circular, and the radius of the air inlet (4) is defined as the air inlet radius R0; Where R2 = (0.05~0.35)R0.

2. The flow-enhancing jet centrifugal volute according to claim 1, characterized in that, Define the radius of the first arc segment as the convex radius R1; The air inlet (4) is circular, and the radius of the air inlet (4) is defined as the air inlet radius R0; Where R1 = (0.5~2)R0.

3. The flow-enhancing jet centrifugal volute according to claim 1, characterized in that, Define the two endpoints of the first circular arc segment as design point A and design point B, respectively; Define the total arc length of the first arc segment as LAB; The arc length of the first circular arc segment between design point A and design point P is defined as LAP; Wherein, LAP = (0.1~0.9)LAB.

4. The flow-enhancing jet centrifugal volute according to claim 3, characterized in that, Define the angle M as the angle formed by the lines connecting the design point V, the axis O, and the design point A. Define the angle N as the angle formed by the lines connecting design point A, axis O, and design point B; Among them, 0º≤M≤40º, 5º≤N≤25º.

5. A centrifugal fan, characterized in that, It includes an impeller (100) and a flow-enhancing jet centrifugal volute (200) as described in any one of claims 1-4. The impeller (100) is installed in the volute cavity of the jet centrifugal volute (200), and the rotation axis of the impeller (100) is coaxially overlapped with the rotation axis of the jet centrifugal volute (200).

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