Volute, centrifugal fan and range hood

Abstract

The utility model provides a volute, centrifugal fan and range hood, the molded line of volute comprises tangent line and spiral line, the adjacent part of tangent line and spiral line is provided with transition curve, the transition curve is the motion trail line determined according to the formula # imgabs0 # that the point C moves from point S4 to point S1, S1 is the midpoint of tangent line, S2 is one end point of tangent line, O is the center of volute, and S is the center of volute. S3 is a point determined according to an included angle S3OS2 = an included angle S2OS1, S4 is an intersection point of an angular bisector of the included angle S3OS2 and the spiral line, and S5 is another end point of the tangent line; and the points A, B and C are respectively points on the straight lines S4S2, S2S1 and AB. According to the volute, the centrifugal fan and the range hood, under the condition that the installation size is limited, the size requirement is met through the cutting area, the transition curve is arranged at the adjacent position of the tangent line and the spiral line, flow separation of airflow at the corner of the cutting area is reduced, energy loss caused by the fact that fluid impacts the wall face of the volute is reduced, flow resistance is reduced, and the service life of the volute is prolonged. And the working efficiency of the fan is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of range hoods, in particular to a volute, a centrifugal fan and a range hood. Background Art

[0002] In some scenarios, due to the influence of the structural design of the range hood product, the installation size of the fan system is limited. Therefore, the purpose of compactness of the system is usually achieved at the expense of the performance of the fan system. At present, the design ideas for the fan system under the condition of limited installation size are usually: first, reduce the overall volute size to ensure that it meets the installation size requirements. In this case, the complete logarithmic spiral can be preserved; second, cut the volute in the area that exceeds the installation space while keeping the contour lines of other areas unchanged. Because the size of the fan system is often positively correlated with the performance of the fan, in actual projects, the size of the volute and impeller is often made as large as possible to achieve better fan performance. Therefore, when the installation size is limited, the second cutting method is often used to meet the requirements of insufficient installation size.

[0003] The current method of cutting the volute will sacrifice the performance of the fan system to a certain extent. The main reasons are: first, the reduced flow channel space increases the resistance of the fluid when flowing through the cut area; second, the originally smooth spiral line is transformed from a curve to a straight line due to cutting. The large turning angle in the transition area usually causes local flow separation, and the impact of the fluid on the volute wall will also be aggravated, causing energy loss, thereby reducing the efficiency of the fan system. Utility Model Content

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art in that the fan volute of the range hood has a flow separation caused by an excessively large turning angle in the cutting area, resulting in large flow resistance and low fan efficiency, and to provide a volute, a centrifugal fan and a range hood.

[0005] The utility model solves the above technical problems through the following technical solutions:

[0006] A volute for a centrifugal fan of a range hood, the volute comprising a cutting area cut out in an axial direction, the profile of the volute comprising a tangent corresponding to the cutting area and a spiral connected to the tangent, a transition curve being provided at the junction of the tangent and the spiral, the transition curve being a point C moving from point S4 to point S1, and according to the formula Determine the motion trajectory,

[0007] Among them, S1 is the midpoint of the tangent, S2 is one endpoint of the tangent and the adjacent spiral line, O is the center of the cross section of the volute perpendicular to the axial direction, S3 is a point on the spiral line and determined according to the angle ∠S3OS2=angle ∠S2OS1, S4 is the intersection of the angle bisector of the angle ∠S3OS2 and the spiral line, and S5 is the other endpoint of the tangent; A is a point on the straight line S4S2, B is a point on the straight line S2S1, and C is a point on the straight line AB.

[0008] In this solution, when the installation size of the volute is limited, the external dimensions of the volute are not reduced to avoid affecting the overall performance of the fan. Instead, the installation size requirements are met through the cutting area, and the transition curve formed by the above setting, on the one hand, makes the tangent and the adjacent spiral line form a sufficiently smooth transition, and the airflow flows smoothly in this transition area, reducing the resistance; on the other hand, the flow channel area in the volute is not excessively occupied, and the airflow does not reduce the flow rate due to the setting of the transition curve, thereby avoiding increasing the flow resistance; thereby reducing the flow separation of the airflow at the turning corner of the cutting area, reducing the energy loss caused by the fluid impacting the volute wall, reducing the flow resistance, and improving the working efficiency of the fan.

[0009] Preferably, the transition curve is tangent to the straight line S4S2 at point S4.

[0010] In this solution, the transition curve is set to be tangent to the straight line S4S2 to ensure a smooth transition of the volute profile near the point S4.

[0011] Preferably, the transition curve is tangent to the straight line S2S1 at point S1.

[0012] In this solution, the transition curve is set to be tangent to the straight line S2S1 to ensure a smooth transition of the volute profile near the point S1.

[0013] Preferably, the transition curve is provided at both ends of the tangent line.

[0014] In this solution, the above-mentioned transition curves are provided at both ends of the tangent to ensure that the volute can smoothly transition at the turning corners connected by the tangent, thereby reducing flow resistance and further improving the working efficiency of the fan.

[0015] Preferably, the helix is ​​a helix determined according to a logarithmic equation.

[0016] Preferably, the tangent line is located at one or more of the 90°, 180°, and 270° regions of the volute profile.

[0017] The 0° position of the volute profile is the position where the radial line of the volute is vertically upward when the outlet of the volute is vertically upward, and the volute profile is divided into areas of different angles from the 0° position along the airflow outflow direction.

[0018] In this solution, one or more cutouts are created in different areas of the volute to accommodate installation requirements at various locations with limited dimensions. The 90°, 180°, and 270° areas of the volute provide larger flow paths. Placing the tangent lines in these areas minimizes flow changes within the path and avoids increasing flow resistance.

[0019] Preferably, the tangent line is provided in a region where the profile of the volute is located at a 180° position along the outflow direction of the airflow.

[0020] In this solution, the area where the volute's profile is located at 180° along the airflow outflow direction is an area with a larger flow channel space. The tangent is set in the area at this position, and the above-mentioned transition curve is set. While reducing flow separation and improving the working efficiency of the fan, it does not affect the installation of the volute on both sides of the area, and the layout is reasonable.

[0021] A centrifugal fan comprises the volute as described above.

[0022] In this solution, the centrifugal fan passes through the above-mentioned volute. When the installation size of the volute is limited, the installation size requirements are met through the cutting area, and the transition curve formed by the above-mentioned setting reduces the flow separation of the airflow at the turning corner of the cutting area, reduces the energy loss caused by the fluid impacting the volute wall, reduces the flow resistance, and improves the working efficiency of the fan.

[0023] A range hood comprises the centrifugal fan as described above.

[0024] In this solution, the range hood uses the above-mentioned centrifugal fan to meet the installation size requirements through the cutting area when the installation size of the volute is limited. The transition curve formed by the above-mentioned setting reduces the flow separation of the airflow at the turning corner of the cutting area, reduces the energy loss caused by the fluid impacting the volute wall, reduces the flow resistance, and improves the working efficiency of the fan.

[0025] The positive progressive effect of the present invention is that when the installation size of the volute is limited, the volute, centrifugal fan and range hood meet the installation size requirements through the cutting area, and by arranging the above-mentioned transition curve at the junction of the tangent and the spiral line, the flow separation of the airflow at the turning corner of the cutting area is reduced, the energy loss caused by the fluid impacting the volute wall is reduced, the flow resistance is reduced, and the working efficiency of the fan is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the volute profile of an embodiment of the present utility model.

[0027] Figure 2 This is a structural schematic diagram of a volute in an embodiment of the utility model forming a transition curve at the turning corner of the cutting area.

[0028] Figure 3 This is a structural schematic diagram of a volute according to an embodiment of the utility model having transition curves at both ends of the tangent line of the cutting area.

[0029] Description of reference numerals:

[0030] Cutting area 1

[0031] Helix 2

[0032] Tangent 3

[0033] Transition curve 5

[0034] Volute outlet 6

[0035] Radial line of volute 7

[0036] Airflow outflow direction D DETAILED DESCRIPTION

[0037] A preferred embodiment is given below, and the present invention is described more clearly and completely in conjunction with the accompanying drawings.

[0038] This embodiment provides a volute for a centrifugal fan in a range hood. Due to the range hood's structural design and installation environment, the volute's installation dimensions are affected, making it impossible to retain the volute's complete logarithmic spiral shape. Consequently, one or more areas must be cut out of the volute's spiral profile to meet the required installation dimensions.

[0039] like Figure 1-3 As shown, the spiral profile of the volute includes a cut area 1, and the profile of the volute includes a tangent line 3 corresponding to the cut area and a spiral line 2 connected to the tangent line. A transition curve 5 is provided at the junction of the tangent line 3 and the spiral line 2. The transition curve 5 is the movement from point C from point S4 to point S1, and according to the formula Determine the motion trajectory.

[0040] Here, S1 is the midpoint of tangent line 3, S2 is one endpoint of tangent line 3 and the adjacent helix line 2, O is the center of the volute's cross section perpendicular to the axial direction, S3 is a point on helix line 2 determined by the angle ∠S3OS2 = ∠S2OS1, S4 is the intersection of the angle bisector of angle ∠S3OS2 and helix line 2, and S5 is the other endpoint of tangent line 3. A is a point on line S4S2, B is a point on line S2S1, and C is a point on line AB. As point A moves from S4 to S2 (i.e., points A at different positions on line S4S2 form the trajectory of point A), point C on line AB also moves from S4 to S1, thus forming transition curve 5.

[0041] When the installation size of the volute is limited, the external dimensions of the volute are not reduced to avoid affecting the overall performance of the fan. Instead, the installation size requirements are met through the cutting area. The transition curve 5 formed by the above-mentioned setting, on the one hand, makes the tangent 3 and the adjacent spiral line 2 form a sufficiently smooth transition, and the airflow flows smoothly in this transition area, reducing the resistance; on the other hand, the flow channel area in the volute is not excessively occupied, and the airflow does not reduce the flow rate due to the setting of the transition curve 5, thereby avoiding increasing the flow resistance; thereby reducing the flow separation of the airflow at the turning corner of the cutting area 1, reducing the energy loss caused by the fluid impacting the volute wall, reducing the flow resistance, and improving the working efficiency of the fan.

[0042] Among them, the transition curve 5 is tangent to the straight lines S4S2 and S2S1 at points S4 and S1 respectively. This setting ensures a smooth transition of the volute profile near points S4 and S1, thereby ensuring a smooth transition at the turning corner.

[0043] Among them, such as Figure 3 As shown, transition curves 5 are provided at both ends of the tangent line 3 to ensure a smooth transition of the volute at the turning corners connected by the tangent lines, reducing flow resistance and further improving the operating efficiency of the fan. In other embodiments, depending on the layout of the cutting area and the required flow effect, the above-mentioned transition curve can be provided only at one end of the tangent line. However, it is not as good as providing the above-mentioned transition curves at both ends of the tangent line in this embodiment to ensure that flow resistance is reduced at all turning corners of the cutting area, achieving a better flow effect.

[0044] In this embodiment, before the volute is cut, the spiral line in the profile of the volute is a spiral line determined according to a logarithmic equation, which is beneficial to reducing flow separation and lowering flow resistance.

[0045] The tangent line 3 is located at one or more of the 90°, 180°, and 270° regions of the volute profile, wherein Figure 1As shown, the angle is defined as follows: the 0° position of the volute profile is the position where the volute radial line 7 is vertically upward when the volute outlet 6 is pointing vertically upward. The volute profile is divided into zones of varying angles along the airflow outflow direction D from the 0° position. One or more cutouts are created in different areas of the volute to accommodate installation requirements with limited dimensions at different locations. The 90°, 180°, and 270° areas of the volute have larger flow passages. Placing the tangent lines in these areas minimizes flow changes within the passage and avoids increasing flow resistance.

[0046] Furthermore, in this embodiment, if Figure 1 As shown, tangent line 3 is located in the area where the volute's profile is 180° along the airflow outflow direction D. This area has a large flow channel. Placing the tangent line there and providing the aforementioned transition curve reduces flow separation and improves fan efficiency while maintaining the volute's installation capabilities on both sides of the area, resulting in a reasonable layout.

[0047] This embodiment also provides a centrifugal fan including the aforementioned volute. The centrifugal fan utilizes the aforementioned volute to meet installation size requirements through the cutout area, even when the installation size of the volute is limited. Furthermore, the transition curve formed by the aforementioned arrangement reduces flow separation at the turning corners of the cutout area, reduces energy loss caused by fluid impacting the volute wall, lowers flow resistance, and improves fan efficiency.

[0048] This embodiment also provides a range hood including the centrifugal fan described above. The range hood utilizes the centrifugal fan to meet the installation size requirements of the volute, even when the installation size is limited. Furthermore, the transition curve formed by the above arrangement reduces flow separation at the turning corners of the cutout area, reduces energy loss caused by fluid impacting the volute wall, lowers flow resistance, and improves the fan's operating efficiency.

[0049] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of protection of the present invention.

Claims

1. A volute for a centrifugal fan of a range hood, the volute comprising a cutting area cut out in an axial direction, the profile of the volute comprising a tangent corresponding to the cutting area and a spiral line connected to the tangent, characterized in that: A transition curve is provided at the junction of the tangent line and the spiral line. The transition curve is the movement of point C from point S4 to point S1, and according to the formula Determine the motion trajectory, Wherein, S1 is the midpoint of the tangent line, S2 is one endpoint of the tangent line and the adjacent helical line, O is the center of the cross section of the volute perpendicular to the axial direction, S3 is a point on the helical line and determined according to the angle ∠S3OS2=angle ∠S2OS1, S4 is the intersection of the angle bisector of the angle ∠S3OS2 and the helical line, and S5 is the other endpoint of the tangent line; A is a point on the straight line S4S2, B is a point on the straight line S2S1, and C is a point on the straight line AB.

2. The volute according to claim 1, wherein: The transition curve is tangent to the straight line S4S2 at point S4.

3. The volute according to claim 1, wherein: The transition curve is tangent to the straight line S2S1 at point S1.

4. The volute according to claim 1, wherein: The transition curves are provided at both ends of the tangent line.

5. The volute according to claim 1, wherein: The helix is ​​a helix determined according to a logarithmic equation.

6. The volute according to claim 1, wherein: The tangent line is located at one or more of the 90°, 180°, and 270° regions of the volute profile. The 0° position of the volute profile is the position where the radial line of the volute is vertically upward when the outlet of the volute is vertically upward, and the volute profile is divided into areas of different angles from the 0° position along the airflow outflow direction.

7. The volute according to claim 6, wherein: The tangent line is arranged in an area where the profile line of the volute is located at a position of 180° along the outflow direction of the airflow.

8. A centrifugal fan, characterized in that: The centrifugal fan comprises a volute according to any one of claims 1 to 7.

9. A range hood, characterized in that: The range hood includes the centrifugal fan as claimed in claim 8.

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