Air inlet guide and centrifugal fan

Abstract

The present application relates to the field of kitchen equipment, and in particular to a guide air inlet ring and a centrifugal fan. The guide air inlet ring is formed with a plurality of guide structures to guide the airflow from the outside of the guide air inlet ring to the air inlet of the centrifugal fan on the inside of the guide air inlet ring; the plurality of guide structures are rotationally symmetrical along the center of the guide air inlet ring, and the guide structures form an arc-shaped guide path to deflect the airflow, so that the airflow passing through the plurality of guide paths moves in a preset direction of motion, and the preset direction of motion has a tangential motion component consistent with the rotation direction of the impeller of the centrifugal fan. The guide air inlet ring provided by the present application can generate an inlet airflow that rotates toward the inside of the fan, and the airflow has a movement tendency close to the rotation direction of the impeller when entering the blade flow channel, and has a small tangential speed difference relative to the blade, thereby reducing the separation of the airflow in the blade flow channel, optimizing the flow of the flow channel airflow, and solving the problems of uneven airflow at the fan inlet causing poor smoking effect and significant vortex impact noise.

Description

Technical Field

[0001] The present application relates to the field of kitchen equipment, and in particular to an air guide inlet ring and a centrifugal fan. Background Art

[0002] As the core component of the range hood, the multi-blade centrifugal fan plays a decisive role in the smoke extraction effect. Affected by the range hood structure and the air intake method of the centrifugal fan, the flow uniformity of the airflow at the fan inlet is poor. The uneven airflow causes serious airflow separation in the blade flow channel, reduces the effective flow area of ​​the airflow, reduces the fan efficiency, and produces significant vortex impact noise in the air duct. The problem of uneven airflow at the air inlet seriously affects the smoke extraction effect and user experience of the range hood, and easily pollutes the kitchen air environment. Summary of the invention

[0003] The purpose of the present application is to provide a guide air inlet ring and a centrifugal fan to guide the airflow at the air inlet of the centrifugal fan.

[0004] The present application provides a guide air inlet ring for a centrifugal fan, wherein the guide air inlet ring is formed with a plurality of guide structures to guide the airflow from the outer side of the guide air inlet ring to the air inlet of the centrifugal fan on the inner side of the guide air inlet ring;

[0005] Multiple guide structures are rotationally symmetrical along the center of the guide air inlet circle, and the guide structures form an arc-shaped guide path to deflect the airflow so that the airflow passing through the multiple guide paths moves in a preset movement direction, and the preset movement direction has a tangential movement component consistent with the rotation direction of the impeller of the centrifugal fan.

[0006] In the above technical solution, further, it includes a guide part;

[0007] The air guide portion is annular, and the inner ring opening of the air guide portion is arranged corresponding to the air inlet of the centrifugal fan; a wind guide surface is formed on the side of the air guide portion away from the centrifugal fan, and a cross section of the air guide portion is cut along the radial direction of the air guide portion. The contour line of the wind guide surface in the cross section is an arc segment convex from the middle to the side away from the centrifugal fan;

[0008] The guide structure is a guide groove formed in the guide portion. Along the length direction of the guide groove, the guide groove extends from the outer circle of the guide portion to the inner circle of the guide portion.

[0009] In the above technical solution, further, the center line of the guide groove in the length direction is a preset arc line;

[0010] The endpoint of the preset arc line close to the inner circle of the guide portion is the first endpoint, and the endpoint of the other end of the preset arc line is the second endpoint; the angle between the tangent of a circle whose center is the center of the guide portion and passes through the first endpoint and the connecting line connecting the first endpoint and the second endpoint is between 15° and 20°.

[0011] In the above technical solution, further, the center angle of the preset arc line is between 30° and 90°.

[0012] In the above technical solution, further, along the width direction of the guide groove, the groove bottom profile of the guide groove is arc-shaped;

[0013] At the apex of the protrusion of the air guide surface of the air guide portion, the depth of the air guide groove is half of the height of the protrusion of the air guide surface.

[0014] In the above technical solution, further, in the direction from the outer circle to the inner circle of the guide portion, the width of the slot profile of the guide groove has a tendency to first expand gradually and then contract gradually, and the degree of contraction of the slot profile of the guide groove at one end close to the outer circle of the guide portion is smaller than the degree of contraction of the slot profile of the guide groove at one end close to the inner circle of the guide portion.

[0015] In the above technical solution, further, from the outer circle to the inner circle of the guide portion, the width of the notch profile of the guide groove is uniform;

[0016] The two ends of the groove profile of the guide groove are arc transitioned.

[0017] In the above technical solution, further, the air guide and air inlet ring also includes a connecting portion, the connecting portion is located in the circumference of the air guide portion, and the connecting portion is used to connect the centrifugal fan.

[0018] In the above technical solution, further, the air guide and air inlet ring is formed by bending a plate to form the air guide portion and the connecting portion, and the air guide portion is pressed to form the air guide groove.

[0019] The present application also provides a centrifugal fan, comprising the guide air inlet ring described in the above solution.

[0020] Compared with the prior art, the beneficial effects of this application are:

[0021] The guide air inlet ring provided in the present application is used for a centrifugal fan, especially a multi-blade centrifugal fan. The guide air inlet ring is formed with multiple guide structures to guide the airflow from the outside of the guide air inlet ring to the air inlet of the centrifugal fan on the inside of the guide air inlet ring. The overall structure does not occupy the air inlet area, does not hinder the air inlet flow, and reduces the dissipation of airflow energy.

[0022] The multiple guide structures are rotationally symmetrical along the center of the guide air inlet circle, and the guide structures form an arc-shaped guide path to deflect the airflow so that the airflow passing through the multiple guide paths moves in a preset movement direction, and the preset movement direction has a tangential movement component consistent with the rotation direction of the impeller of the centrifugal fan.

[0023] Specifically, the airflow at the air inlet circle converges from the circumference of the air inlet circle to the air inlet, and multiple guide structures are rotationally symmetrical along the center of the guide air inlet circle, so as to guide the airflow at various circumferences to ensure the uniformity of air intake at various air inlets.

[0024] Furthermore, the guide structure forms an arc-shaped guide path to deflect the airflow to generate a tangential motion in the same direction as the impeller linear velocity. Under the joint action of the traction force of the fan inlet, an inlet airflow rotating toward the inside of the fan is generated. This method of pre-rotating the airflow improves the uniformity of the airflow at the air inlet, increases the flow area of ​​the air inlet, and makes it easier for the airflow to enter the impeller; the airflow has a certain tangential velocity, so that when the airflow enters the blade flow channel, it has a movement trend close to the impeller rotation direction, and has a smaller tangential velocity difference relative to the blade, thereby weakening the airflow separation in the blade flow channel, optimizing the flow of the flow channel airflow, and solving the problems of poor smoking effect and significant vortex impact noise caused by uneven airflow at the fan inlet.

[0025] The present application also provides a centrifugal fan, including the guide air inlet ring described in the above solution. Based on the above analysis, it can be seen that the centrifugal fan also has the above beneficial effects, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A schematic diagram of the assembly structure of the air guide and air inlet ring provided in this application;

[0028] Figure 2 A schematic diagram of the structure of the air inlet guide ring provided in this application;

[0029] Figure 3 for Figure 2 The enlarged schematic diagram of point A in the middle;

[0030] Figure 4 A schematic cross-sectional view of the air inlet guide ring provided in this application;

[0031] Figure 5A first structural schematic diagram of the guide groove provided in this application;

[0032] Figure 6 A second structural schematic diagram of the guide trough provided in this application;

[0033] Figure 7 This is a third structural schematic diagram of the guide trough provided in this application.

[0034] In the figure: 101-centrifugal fan; 102-impeller; 103-air guide portion; 104-connecting portion; 105-air guide surface; 106-connecting hole; 107-air guide groove; 108-preset arc line; 109-first endpoint; 110-second endpoint. DETAILED DESCRIPTION

[0035] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0036] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] Embodiment 1

[0039] In view of the technical problems existing in the prior art, this application makes the following analysis:

[0040] 1. The fan air intake is uneven and the smoking effect is poor: Due to the limitations of the volute structure, the fan assembly inside the range hood has a main working area of ​​the impeller in the diffuser section below the air outlet, where the flow is unobstructed and the airflow is dense, while the diffuser section on the rear side of the vortex tongue is the main reflow area of ​​the impeller, where the airflow is turbulent. The above factors lead to uneven airflow at the fan inlet, which in turn leads to uneven smoke intake at the range hood smoke inlet.

[0041] 2. Severe flow channel separation and significant noise: When the airflow at the air inlet of the above-mentioned range hood is not interfered with, the airflow in the blade flow channel has a large attack angle relative to the blade, resulting in strong separation, enhanced vortex impact noise in the flow channel, and a small effective flow area of ​​the flow channel, reducing the fan efficiency and smoking effect.

[0042] Based on the above analysis, the present application improves the air inlet ring provided at the air inlet of the centrifugal fan to pre-swirl the airflow entering the air inlet.

[0043] The air inlet guide ring provided in the present application is used for a centrifugal fan, especially a multi-blade centrifugal fan. Figures 1 to 7 As shown, the guide air inlet ring is formed with multiple guide structures to guide the airflow from the outside of the guide air inlet ring to the air inlet of the centrifugal fan 101 inside the guide air inlet ring. The overall structure does not occupy the air inlet area, will not hinder the air inlet flow, and reduce the dissipation of air flow energy.

[0044] The plurality of guide structures are rotationally symmetrical along the center of the guide air inlet circle, and the guide structures form an arc-shaped guide path to deflect the airflow, so that the airflow passing through the plurality of guide paths moves in a preset direction of movement, and the preset direction of movement has the same rotation direction as the impeller 102 of the centrifugal fan 101 ( Figure 2 The component of tangential motion consistent with the B direction (clockwise) shown in FIG. Figure 1 The arrows in FIG. 1 show the flow direction of the guided airflow.

[0045] Specifically, the airflow at the guide air inlet circle converges from the circumference to the air inlet, and multiple guide structures are rotationally symmetrical along the center of the guide air inlet circle, so as to guide the airflow at various circumferences to ensure the uniformity of air intake at various air inlets.

[0046] Furthermore, the guide structure forms an arc-shaped guide path to deflect the airflow to generate a tangential motion in the same direction as the linear velocity of the impeller 102. Under the joint action of the traction force of the fan inlet, an inlet airflow rotating toward the inside of the fan is generated. This method of pre-rotating the airflow improves the uniformity of the airflow at the air inlet, increases the flow area of ​​the air inlet, and makes it easier for the airflow to enter the impeller 102; the airflow has a certain tangential velocity, so that when the airflow enters the blade flow channel, it has a movement trend close to the rotation direction of the impeller 102, and has a smaller tangential velocity difference relative to the blade, thereby reducing the separation of the blade flow channel airflow, optimizing the flow of the flow channel airflow, and solving the problems of uneven airflow at the fan inlet resulting in poor smoking effect and significant vortex impact noise.

[0047] See Figures 2 to 4 As shown, in an optional solution of this embodiment, the air guide and air inlet ring includes an air guide portion 103 and a connecting portion 104 .

[0048] The guide part 103 is annular, and the inner opening of the guide part 103 is arranged corresponding to the air inlet of the centrifugal fan 101; a guide surface 105 is formed on the side of the guide part 103 away from the centrifugal fan 101, and the cross section of the guide part 103 is intercepted along the radial direction of the guide part 103. The contour line of the guide surface 105 in the cross section is a circular arc segment protruding from the middle to the side away from the centrifugal fan 101. The connecting part 104 is located in the circumference of the guide part 103, and the connecting part 104 is used to connect the centrifugal fan 101. The arc-shaped guide surface 105 can smoothly guide the airflow to the impeller 102, which can effectively improve the performance of the fan, and when the fan flow is large, the noise value is relatively low.

[0049] The connection part 104 is located in the circumference of the air guide part 103, and the connection part 104 is used to connect the centrifugal fan 101. The connection part 104 shown in the figure is also arranged in an annular shape, and the connection part 104 is provided with a plurality of evenly distributed connection holes 106, so that the air guide air inlet ring can be installed at the air inlet of the centrifugal fan 101 by bolts. Optionally, the connection part 104 can also be a plurality of connection points arranged at intervals, and a connection hole 106 is provided at each connection point to connect the centrifugal fan 101. Of course, compared with the structure in which the air guide air inlet ring is provided with a plurality of connection points, the air guide air inlet ring is provided with an annular connection part 104, and the overall structural strength is higher.

[0050] The specific form of the guide structure is a guide groove 107 formed in the guide part 103. Along the length direction of the guide groove 107, the guide groove 107 extends from the outer circle of the guide part 103, passes through the highest point of the guide part 103, and finally extends to the inner circle of the guide part 103. By utilizing the fluid attachment flow effect, when the airflow flows to the arc-shaped protruding guide part 103, at least a part of the airflow can flow into the guide groove 107. Under the guidance of the guide groove 107, the airflow can be deflected in the same direction as the rotation direction of the impeller 102. The airflow will produce a reverse thrust effect on the inlet airflow of the centrifugal fan 101, weakening the reverse relative movement trend of the inlet airflow and the impeller 102, which can effectively reduce the separation of the airflow in the impeller 102 flow channel, increase the effective work area, improve the performance of the centrifugal fan 101, and further improve the smoke extraction effect of the range hood.

[0051] Furthermore, the air guide and air inlet ring is formed by bending a plate to form an air guide portion 103 and a connecting portion 104, and the air guide portion 103 is pressed to form an air guide groove 107, so that the air guide and air inlet ring is lighter.

[0052] In the optional solution of this embodiment, see Figure 2 and Figure 3 As shown, the center line of the guide groove 107 in the length direction is a preset arc line 108; the endpoint of the preset arc line 108 close to the inner circle of the guide portion 103 is a first endpoint 109, and the endpoint of the other end of the preset arc line 108 is a second endpoint 110; the angle ( Figure 2 and Figure 3 The angle C) shown in FIG. 1 is between 15° and 20°.

[0053] This angle determines the degree of deflection of the guide groove 107 relative to the impeller 102, and also determines the length of the guide groove 107 when the width of the guide portion 103 is constant. It has been verified that the guide groove 107 deflected within the above angle range has a better guiding effect. If the angle is too large, the component of the tangential motion consistent with the rotation direction of the impeller 102 of the centrifugal fan 101 is small, and the deflection effect on the airflow is poor; if the angle is too small, the flow path of the airflow in the guide groove 107 is too long, which is easy to cause the dissipation of airflow energy.

[0054] In an optional solution of this embodiment, the center angle of the arc line 108 is preset ( Figure 2 and Figure 3 The angle D) shown in the figure is between 30° and 90°. Preferably, the central angle of the preset arc line 108 is 45°. This angle is used to control the curvature of the guide path formed by the guide groove 107 so that the airflow can smoothly flow into the impeller 102 in the air inlet while forming a vortex.

[0055] In the optional solution of this embodiment, along the width direction of the guide groove 107, the groove bottom profile of the guide groove 107 is arc-shaped, and the groove bottom structure is streamlined, which generates relatively less resistance. At the apex of the protrusion of the wind guide surface 105 of the guide portion 103, the maximum depth of the guide groove 107 is specifically set to half the height of the protrusion of the wind guide surface 105; from the apex of the protrusion of the wind guide surface 105 to the direction of the inner circle and the direction of the outer circle of the guide portion 103, the depth of the guide groove 107 gradually decreases.

[0056] Embodiment 2

[0057] The air inlet guide ring in the second embodiment is an improvement on the above embodiment, and the technical contents disclosed in the above embodiment will not be described repeatedly, and the contents disclosed in the above embodiment also belong to the contents disclosed in the second embodiment.

[0058] See also Figures 1 to 6 As shown, in an optional scheme of this embodiment, from the outer circle to the inner circle of the guide portion 103, the width of the slot profile of the guide groove 107 has a tendency to first expand gradually and then contract gradually, and the degree of contraction of the slot profile of the guide groove 107 at one end close to the outer circle of the guide portion 103 is smaller than the degree of contraction of the slot profile of the guide groove 107 at one end close to the inner circle of the guide portion 103, that is, from the widest point of the slot profile of the guide groove 107 towards the outer circle of the guide portion 103, the slope of the profile contraction is relatively small; from the widest point of the slot profile of the guide groove 107 towards the inner circle of the guide portion 103, the slope of the profile contraction is relatively large.

[0059] In this embodiment, specifically, Figure 5 and Figure 6 Two notch profile structures of the guide groove 107 are shown respectively: Figure 5 The fish-shaped structure outline and Figure 6 The middle is the wing-shaped structure profile. The fish-shaped structure profile is a bionic fish profile to reduce the resistance to airflow. The wing-shaped structure includes wing-shaped structures of various curved forms, and the leading edge of the wing-shaped structure is located in the inner side of the guide portion 103. Similarly, the wing-shaped structure also has a small wind resistance.

[0060] In addition, see Figure 7 As shown, in the optional solution of this embodiment, the width of the notch profile of the guide groove 107 is uniform from the outer circle to the inner circle of the guide portion 103; the two ends of the notch profile of the guide groove 107 are arc transitions. That is, the width of the guide groove 107 at the beginning and end is unchanged, and the profiles at the beginning and end of the guide groove 107 are both arc-shaped.

[0061] For the above two structural forms, the groove profiles of the guide groove 107 are smooth curves, which have the technical effect of facilitating the passage of airflow and reducing airflow resistance and impact.

[0062] Embodiment 3

[0063] Embodiment 3 of the present application provides a centrifugal fan, including an air guide inlet ring of any of the above embodiments, and thus has all the beneficial technical effects of the air guide inlet ring of any of the above embodiments, which will not be elaborated here.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. In addition, a person skilled in the art can understand that although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments means being within the scope of the present application and forming different embodiments.

Claims

1. A guide air inlet ring for a centrifugal fan, characterized in that: The guide air inlet ring is formed with a plurality of guide structures to guide the airflow from the outer side of the guide air inlet ring to the air inlet of the centrifugal fan on the inner side of the guide air inlet ring; A plurality of guide structures are rotationally symmetrical about the center of the guide air inlet circle, and the guide structures form an arc-shaped guide path to deflect the airflow, so that the airflow passing through the plurality of guide paths moves in a preset movement direction, and the preset movement direction has a tangential movement component consistent with the rotation direction of the impeller of the centrifugal fan; including a guide portion; The air guide portion is annular, and the inner ring opening of the air guide portion is arranged corresponding to the air inlet of the centrifugal fan; a wind guide surface is formed on the side of the air guide portion away from the centrifugal fan, and a cross section of the air guide portion is cut along the radial direction of the air guide portion. The contour line of the wind guide surface in the cross section is an arc segment convex from the middle to the side away from the centrifugal fan; The guide structure is a guide groove formed on the guide portion, and along the length direction of the guide groove, the guide groove extends from the outer circle of the guide portion to the inner circle of the guide portion; Along the width direction of the guide groove, the groove bottom profile of the guide groove is arc-shaped; At the apex of the protrusion of the air guide surface of the air guide portion, the depth of the air guide groove is half of the height of the protrusion of the air guide surface.

2. The air inlet guide ring according to claim 1, characterized in that: The center line of the guide groove in the length direction is a preset arc line; The endpoint of the preset arc line close to the inner circle of the guide portion is the first endpoint, and the endpoint of the other end of the preset arc line is the second endpoint; the angle between the tangent of a circle whose center is the center of the guide portion and passes through the first endpoint and the connecting line connecting the first endpoint and the second endpoint is between 15° and 20°.

3. The air inlet guide ring according to claim 2, characterized in that: The center angle of the preset arc line is between 30° and 90°.

4. The air inlet guide ring according to claim 1, characterized in that: From the outer circle to the inner circle of the guide part, the width of the slot profile of the guide groove has a tendency to expand first and then shrink gradually, and the contraction degree of the slot profile of the guide groove at one end close to the outer circle of the guide part is smaller than the contraction degree of the slot profile of the guide groove at one end close to the inner circle of the guide part.

5. The air inlet guide ring according to claim 1, characterized in that: From the outer circle to the inner circle of the guide portion, the width of the notch profile of the guide groove is uniform; The two ends of the groove profile of the guide groove are arc transitioned.

6. The air inlet guide ring according to claim 1, characterized in that: The air guide and air inlet ring further includes a connecting portion, which is located in the circumference of the air guide portion and is used to connect to the centrifugal fan.

7. The air inlet guide ring according to claim 6, characterized in that: The air guide and air inlet ring is formed by bending a plate to form the air guide portion and the connecting portion, and the air guide portion is pressed to form the air guide groove.

8. A centrifugal fan, characterized in that: It comprises the air inlet guide ring as claimed in any one of claims 1 to 7.

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