CN212297032U - Volute tongue body, fan volute tongue and fan volute - Google Patents

Abstract

The utility model provides a snail tongue body, fan snail tongue and fan spiral case, snail tongue body includes: a space curved surface which is synthesized by a volute tongue body two-dimensional curve cluster, a tangent point straight line connecting the volute tongue body and a volute casing enclosing plate and a volute tongue body outlet curve; the two-dimensional curve cluster of the volute tongue body comprises a plurality of two-dimensional curves of the volute tongue body; the cross sections of the two-dimensional curves of the plurality of volute tongue bodies are gradually increased along the extending direction from the center of the volute tongue body to the two ends; the curvature of the volute tongue body and the volute casing enclosing plate is continuous at the tangent point straight line where the volute tongue body and the volute casing enclosing plate are connected; the outlet curve of the volute tongue body is an inward concave curve; fitting the two-dimensional curve cluster of the volute tongue body and the outlet curve of the volute tongue body into a first concave curved surface of the volute tongue body; the volute tongue body is designed into a structural form of the concave arc curved surface with the variable cross section, so that airflow can be better separated, impact loss of outlet airflow is reduced, and pneumatic noise of a volute tongue area of the fan is reduced.

Description

Volute tongue body, fan volute tongue and fan volute

Technical Field

The utility model belongs to the technical field of the fan technique and specifically relates to a snail tongue body, fan snail tongue and fan spiral case are related to.

Background

In the noise component of the range hood, the aerodynamic noise has the greatest influence. The method is characterized in that pressure pulsation, a jet flow-wake flow structure, boundary layer separation and vortex shedding in the multi-wing centrifugal fan have great influence on the aerodynamic characteristics and noise characteristics of an air duct system, wherein a volute tongue area is continuously strongly impacted by airflow at the outlet of the multi-wing centrifugal fan and becomes one of main aerodynamic noise sources of the multi-wing centrifugal fan, the structure and the position of the volute tongue have great influence on an internal flow field of the fan, and an effective solution is not provided for the problem of great aerodynamic noise in the volute tongue area of the multi-wing centrifugal fan in the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a snail tongue body, fan snail tongue and fan spiral case to reduce the regional pneumatic noise of snail tongue of fan.

In a first aspect, the utility model provides a pair of snail tongue body, snail tongue body includes: a space curved surface which is synthesized by a volute tongue body two-dimensional curve cluster, a tangent point straight line connecting the volute tongue body and a volute casing enclosing plate and a volute tongue body outlet curve; the two-dimensional curve cluster of the volute tongue body comprises a plurality of two-dimensional curves of the volute tongue body; the cross sections of the two-dimensional curves of the plurality of volute tongue bodies are gradually increased along the extending direction from the center of the volute tongue body to the two ends of the volute tongue body; the curvature of the volute tongue body is continuous with that of the volute casing surrounding plate at the tangent point straight line where the volute tongue body is connected with the volute casing surrounding plate; the outlet curve of the volute tongue body is an inwards concave curve; and fitting the two-dimensional curve cluster of the volute tongue body and the outlet curve of the volute tongue body into a first concave curved surface of the volute tongue body.

Furthermore, the sectional area of the volute tongue body is gradually increased along the extending direction from the center of the volute tongue body to the two ends of the volute tongue body.

Further, the volute tongue body also comprises a first mounting surface; the first mounting surface is arranged at the first end of the volute tongue body; the first mounting surface is provided with a first mounting hole to be connected to the volute front plate through a screw.

Further, the volute tongue body also comprises a second mounting surface; the second mounting surface is arranged at the second end of the volute tongue body; the second mounting surface is provided with a second mounting hole to be connected to the volute back plate through a screw.

Furthermore, the volute tongue body also comprises a third mounting surface, and the fillet radius of the third mounting surface is the same as that of the mounting position of the volute tongue body on the volute casing plate.

In a second aspect, the present invention provides a blower volute tongue, which comprises an airflow guide and a volute tongue body according to any one of the first aspect; the airflow guide includes: the second concave curved surface is fit by the airflow guiding curve, the upper curve, the lower curve and the volute tongue body outlet curve; the second concave curved surface is connected with the first concave curved surface of the volute tongue body through the outlet curve of the volute tongue body.

Further, the airflow guiding curve, the upper curve and the lower curve are all concave curves.

In a third aspect, the present invention provides a blower volute, comprising a check valve and a blower volute tongue according to any one of the above second aspects.

Further, the fan volute tongue is arranged on the check valve.

Furthermore, the first concave curved surface and the second concave curved surface of the fan volute tongue are arranged on the outlet side of the fan volute.

The utility model provides a pair of snail tongue body, fan snail tongue and fan spiral case, the snail tongue body includes: a space curved surface which is synthesized by a volute tongue body two-dimensional curve cluster, a tangent point straight line connecting the volute tongue body and a volute casing enclosing plate and a volute tongue body outlet curve; the two-dimensional curve cluster of the volute tongue body comprises a plurality of two-dimensional curves of the volute tongue body; the cross sections of the two-dimensional curves of the plurality of volute tongue bodies are gradually increased along the extending direction from the center of the volute tongue body to the two ends; the curvature of the volute tongue body and the volute casing enclosing plate is continuous at the tangent point straight line where the volute tongue body and the volute casing enclosing plate are connected; the outlet curve of the volute tongue body is an inward concave curve; fitting the two-dimensional curve cluster of the volute tongue body and the outlet curve of the volute tongue body into a first concave curved surface of the volute tongue body; the volute tongue body is designed into a structural form of the concave arc curved surface with the variable cross section, so that airflow can be better separated, impact loss of outlet airflow is reduced, and pneumatic noise of a volute tongue area of the fan is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural view of a volute tongue body according to an embodiment of the present invention;

fig. 2 is a schematic diagram illustrating a comparison between a volute tongue body and a conventional volute tongue body according to an embodiment of the present invention;

fig. 3 is a schematic view of a position relationship between a volute tongue body and a volute casing surrounding plate according to an embodiment of the present invention;

fig. 4 is a schematic view of a two-dimensional curve of a volute tongue body according to an embodiment of the present invention;

fig. 5 is a schematic view of a volute structure of a blower provided with a traditional volute tongue body according to an embodiment of the present invention;

fig. 6 is a schematic view of a volute structure of a blower on which a volute tongue body is mounted according to an embodiment of the present invention;

fig. 7 is a schematic structural view of an airflow guide according to an embodiment of the present invention;

fig. 8 is a schematic view illustrating a connection between a volute tongue body and an airflow guide according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of an outlet side of a blower volute according to an embodiment of the present invention;

fig. 10 is an airflow diagram after installation of an airflow guide according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a blower volute provided by an embodiment of the present invention;

fig. 12 is a speed field cloud diagram of an outlet region of a volute where a conventional volute tongue body is installed according to an embodiment of the present invention;

fig. 13 is a speed field cloud diagram of an outlet region of a volute on which a volute tongue of a fan is mounted according to an embodiment of the present invention;

fig. 14 is a velocity vector diagram of a vortex region for installing a conventional volute tongue body according to an embodiment of the present invention;

fig. 15 is a velocity vector diagram of a vortex region for mounting a volute tongue of a fan according to an embodiment of the present invention;

fig. 16 is a total pressure cloud diagram of the outlet of the middle section of the impeller provided with the traditional volute tongue body according to the embodiment of the present invention;

fig. 17 is a total pressure cloud diagram of the outlet of the middle section of the impeller provided with the volute tongue of the fan according to the embodiment of the present invention;

fig. 18 is a schematic view of a broadband noise simulation cloud chart of a conventional volute tongue body according to an embodiment of the present invention;

fig. 19 is a schematic view of a fan volute tongue broadband noise simulation cloud chart provided by an embodiment of the present invention;

fig. 20 is a schematic view illustrating an installation of a fan volute tongue according to an embodiment of the present invention;

fig. 21 is a schematic structural diagram of another blower volute provided by the embodiment of the present invention.

Icon: 10-volute tongue body; 11-two-dimensional curve cluster of the volute tongue body; 12-a tangent point straight line connecting the volute tongue body and the volute casing coaming; 13-volute tongue body outlet curve; 20-traditional volute tongue body; 21-a check valve; 22-volute back plate; 23-a motor; 24-a volute enclosure; 25-volute front plate; 30-an airflow guide; 31-air flow guide curve; 32-upper curve; 33-lower curve; 34-impeller middle disc; 35-an impeller; 36-volute mounting flange; 37-a wind-guiding ring; 40-blower volute tongue.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

With the improvement of the social living standard, the requirements of people on the noise of the range hood are higher and higher. In the noise component of the range hood, aerodynamic noise has the greatest influence. The volute tongue area of the range hood is continuously strongly impacted by airflow at the outlet of the multi-wing centrifugal fan, so that the volute tongue area becomes one of main pneumatic noise sources of the multi-wing centrifugal fan, and the structure and the position of the volute tongue have great influence on the internal flow field of the fan. Aiming at the technical problems of reducing the impact of airflow on the volute tongue and the vortex intensity of the volute tongue area and reducing the aerodynamic noise of the fan, a great deal of research is carried out by many scholars, but an effective solution is not provided at present. Based on this, the embodiment of the utility model provides a snail tongue body, fan snail tongue and fan spiral case, this technique can be applied to in the pneumatic noise that reduces the snail tongue region of fan is used.

In order to facilitate understanding of the embodiment, a volute tongue body disclosed by the embodiment of the invention is first described in detail; referring to fig. 1, a schematic structural diagram of a volute tongue body is shown, wherein the volute tongue body 10 includes: a space curved surface which is synthesized by a volute tongue body two-dimensional curve cluster 11, a tangent point straight line 12 connecting the volute tongue body and a volute casing enclosing plate and a volute tongue body outlet curve 13; wherein, the two-dimensional curve cluster 11 of the volute tongue body comprises a plurality of two-dimensional curves of the volute tongue body; the cross sections of the two-dimensional curves of the plurality of volute tongue bodies are gradually increased along the extending direction from the center of the volute tongue body to the two ends; the curvature of the volute tongue body and the volute casing enclosing plate is continuous at the tangent point straight line where the volute tongue body and the volute casing enclosing plate are connected; the outlet curve of the volute tongue body is an inward concave curve; and fitting the two-dimensional curve cluster of the volute tongue body and the outlet curve of the volute tongue body into a first concave curved surface of the volute tongue body.

The volute tongue body can be understood as a tongue-shaped structure which is formed by the shell wall and is like a tongue and is arranged at the connecting position of the volute enclosing plate and the air outlet of the fan; the plurality of volute tongue body two-dimensional curves contained in the volute tongue body two-dimensional curve cluster can be obtained by adopting a Non-Uniform Rational B-spline (NURBS) method through a simulation experiment; in practical implementation, multiple factors such as impact of airflow on the volute tongue body, vortex intensity of the volute tongue area or aerodynamic noise of a fan and the like are generally considered comprehensively, the shape of the two-dimensional curves of the plurality of volute tongue bodies is adjusted and optimized, so that the matching of the factors is optimal, and the optimized two-dimensional curves of the plurality of volute tongue bodies are obtained finally; the cross sections of the obtained two-dimensional curves of the plurality of volute tongue bodies are usually different in size, and the cross sections of the two-dimensional curves of the plurality of volute tongue bodies generally tend to be gradually increased along the extending direction from the center to the two ends of the volute tongue bodies to form an inwards concave shape.

Referring to a comparison schematic diagram of a volute tongue body and a traditional volute tongue body shown in fig. 2, in actual implementation, the molded line of the volute casing plate is generally in the form of a volute spiral line, in the scheme, the curvature of the joint of the volute spiral line and the volute tongue body is continuous through design, and a tangent point straight line connecting the volute tongue body and the volute casing plate is formed, so that smooth transition between the volute spiral line and the volute tongue body can be realized; the volute tongue body outlet curve is usually an inward concave curve and can also be understood as a curved shape, and is usually a B-spline curve obtained by adopting a non-uniform rational B-spline method; the two-dimensional curve cluster of the volute tongue body and the outlet curve of the volute tongue body can be fitted into a first concave curved surface of the volute tongue body, and the first concave curved surface is a smooth concave curved surface generally; as can be seen from fig. 2, the conventional volute tongue body 20 is only a single circular arc and does not include a concave curved surface.

The non-uniform rational B-spline method can unify a B-spline method for describing a free curve surface and a mathematical method for accurately representing a quadratic curve and a quadratic surface; the non-uniform rational B-spline surface modeling is widely applied to the engineering research fields of CAD (Computer Aided Design), CAM (Computer Aided Manufacturing) or Computer graphics, and the like, can accurately describe a free curve surface and accurately express a quadratic curve, and has great superiority in the aspect of complex curve surface modeling, high modeling efficiency and easy control of the curve surface. The B-spline curve surface has many excellent properties of geometric invariance, convex hull property, convexity protection, variation reduction, local support property and the like, and is a common geometric representation method of the CAD system at present, so that parameterization based on measurement data and B-spline surface reconstruction are one of research hotspots and key technologies of reverse engineering.

The embodiment of the utility model provides a snail tongue body, this snail tongue body includes: a space curved surface which is synthesized by a volute tongue body two-dimensional curve cluster, a tangent point straight line connecting the volute tongue body and a volute casing enclosing plate and a volute tongue body outlet curve; the two-dimensional curve cluster of the volute tongue body comprises a plurality of two-dimensional curves of the volute tongue body; the cross sections of the two-dimensional curves of the plurality of volute tongue bodies are gradually increased along the extending direction from the center of the volute tongue body to the two ends; the curvature of the volute tongue body and the volute casing enclosing plate is continuous at the tangent point straight line where the volute tongue body and the volute casing enclosing plate are connected; the outlet curve of the volute tongue body is an inward concave curve; fitting the two-dimensional curve cluster of the volute tongue body and the outlet curve of the volute tongue body into a first concave curved surface of the volute tongue body; the volute tongue body is designed into a structural form of the concave arc curved surface with the variable cross section, so that airflow can be better separated, impact loss of outlet airflow is reduced, and pneumatic noise of a volute tongue area of the fan is reduced.

Further, each two-dimensional curve in the two-dimensional curve cluster of the volute tongue body can be obtained through the following steps from one step to the seventh step:

acquiring a preset two-dimensional curve type line equation, wherein the two-dimensional curve type line equation corresponds to a B spline curve; the B-spline curve is usually a polynomial parameter curve, and in practical implementation, the preset two-dimensional curve type line equation includes:

wherein n represents the number of times of a B-spline curve, and the two-dimensional curve type line equation can also be understood as representing a B-spline curve for n times; pi represents a control point i of the B spline curve; the number of the control points is n +1, each control point comprises a corresponding position coordinate, the shape of the B-spline curve can be changed by changing the position coordinates of the control points, the curve generation mode is visual and flexible, and any curve shape can be generated; the two-dimensional curve of the prior volute tongue body is generally in a single arc shape.

And step two, receiving an adjusting instruction sent by a user aiming at each B spline curve.

The adjusting instruction can be understood as an instruction sent by a user to adjust or modify the shape of the B-spline curve and the like; for example, the shape of the B-spline curve is adjusted to increase or decrease the section of the B-spline curve, or the like; in practical implementation, each two-dimensional curve in the two-dimensional curve cluster of the volute tongue body usually needs to be adjusted, and an adjustment instruction sent by a user can be received through analysis software, wherein the analysis software can be fluid calculation software or CAD software.

And step three, adjusting the number of control points and the position coordinate corresponding to each control point in the two-dimensional curve type line equation corresponding to the B-spline curve according to the adjustment instruction to obtain the adjusted B-spline curve.

In actual implementation, the adjustment instruction sent by the user usually includes the number of the set control points and the position coordinates corresponding to each control point; the number of the control points can be set by setting the n value in the two-dimensional curve type line equation, for example, if n is set to be 4, since the number of the control points is n +1, the number of the control points adopted by the B-spline curve for 4 times is 5, and the position coordinates corresponding to the 5 control points can be adjusted to adjust the B-spline curve, so as to obtain the adjusted B-spline curve.

And step four, analyzing the adjusted B-spline curve to obtain an analysis result.

The analysis result usually includes analysis data such as the vortex intensity of the volute tongue area, the aerodynamic noise of the fan and the like; in actual implementation, after the adjusted B-spline curve is obtained, the adjusted B-spline curve is analyzed to obtain analysis results of the eddy intensity of the corresponding volute tongue area, the pneumatic noise of the fan and the like.

Judging whether the analysis result meets a preset result or not; if yes, executing step six; if not, go to step seven.

The preset result is usually a parameter value corresponding to each factor when the impact of the gas on the volute tongue body, the vortex intensity of the volute tongue area, the aerodynamic noise of the fan and other factors are optimally matched; under an ideal condition, the smaller the impact of the gas on the volute tongue body, the better the impact, the smaller the eddy strength of the volute tongue area and the better the aerodynamic noise of the fan, but considering the mutual influence among a plurality of factors, all the factors need to be comprehensively considered, so that the plurality of factors reach the state of optimal matching; of course, the preset result can also be set according to the requirement of the user. In practical implementation, after an analysis result corresponding to the adjusted B-spline curve is obtained, it is necessary to determine whether the analysis result meets a preset result.

And step six, if the analysis result accords with the preset result, determining the adjusted B spline curve as a two-dimensional curve in the snail tongue body two-dimensional curve cluster.

If the analysis result meets the preset result, the adjusted B-spline curve meets the design requirement, and the adjusted B-spline curve can be determined as a two-dimensional curve in the snail tongue body two-dimensional curve cluster.

And step seven, if the analysis result does not accord with the preset result, continuing to execute the step of receiving the adjustment instruction sent by the user until the analysis result accords with the preset result.

If the analysis result shows that a plurality of factors such as the impact of gas on the volute tongue body, the vortex intensity of the volute tongue area, the aerodynamic noise of the fan and the like do not reach the optimal matching state, the step of receiving an adjustment instruction sent by a user is continuously executed to continuously adjust the adjusted B-spline curve until the analysis result meets the preset result, and finally each two-dimensional curve in the two-dimensional curve cluster of the volute tongue body meets the preset result.

A specific example is provided below to further understand the process of acquiring each two-dimensional curve in the above-mentioned two-dimensional curve cluster of the volute tongue body. Assuming that n is 4 in the two-dimensional curve type equation, the 4-degree B-spline curve adopts n +1 control points, i.e. 5 control points, and since { Pi } is a control vertex, i is 0, 1, 2, 3, 4; referring to a schematic diagram of a position relationship between a volute tongue body and a volute casing enclosing plate shown in fig. 3, in combination with an actual volute casing enclosing plate structure, it can be determined that a starting point of a curve of the volute tongue body is a control point P0(32.7, 155.8), the curve of the volute tongue body and a logarithmic spiral of the volute casing are in tangential transition at the point, and an included angle between a connecting line of the point and a base circle center point of the volute casing and a Y axis is 22 degrees; it is also possible to determine the volute tongue body curve end point as the P4(47, 172.1) control point at which the volute tongue body curve transitions tangentially to the volute exit section.

Referring to a schematic diagram of a two-dimensional curve of a volute tongue body shown in fig. 4, in addition to a P0(32.7, 155.8) control point and a P4(47, 172.1) control point, the diagram further includes three other control points, namely P1, P2 and P3, the shape of the two-dimensional curve of the volute tongue body can be controlled by adjusting position coordinates of the three control points, the positions of the control points can be finally determined through simulation and experiment, and through simulation analysis, the determined optimal position coordinates of the three control points are respectively: p1(47.6,150.2), P2(51.8,148.9), P3(55.9,158.6); the head of the volute tongue body is generally streamline, and the impact effect of airflow on the volute tongue body can be relieved by the aid of the structure, so that rotating noise can be reduced.

Based on the n value and the position coordinates of each control point, the following first column number and second column number can be obtained as follows:

from the above n values and the coordinates of the X-axis vector corresponding to each of the 5 control points P0, P1, P2, P3, and P4, the following first row numbers can be obtained from n being 4, P0 being 32.7, P1 being 47.6, P2 being 51.8, P3 being 55.9, and P4 being 47:

from the above n values and the coordinates of the Y axis vector corresponding to each of the 5 control points P0, P1, P2, P3, and P4, the following second columns can be obtained, where the second columns are obtained from n 4, P0 155.8, P1 150.2, P2 148.9, P3 158.6, and P4 172.1:

the first column number B1(t) may represent coordinates of X-axis vectors of all corresponding points on the two-dimensional curve of the volute tongue body; the second column number B2(t) may represent the coordinates of the Y-axis vectors of all points corresponding to the two-dimensional curve of the tongue body, where t is any number within the range of 0 to 1. The different values of t in B1(t) and B2(t) can be adjusted to correspond to B1(t) and B2 (t); the positions of all points on the two-dimensional curve of the volute tongue body can be represented by B1(t) and B2(t), and the shape and size parameters of the two-dimensional curve of the volute tongue body are determined.

Furthermore, the sectional area of the volute tongue body is gradually increased along the extending direction from the center of the volute tongue body to the two ends of the volute tongue body. For example, the volute tongue body can be in a shape of a concave arc curved surface with a variable cross section along the axial direction by taking a two-dimensional curve of the volute tongue body determined by 5 control points, namely P0, P1, P2, P3 and P4 in the above example, and the cross section area of the volute tongue body is gradually increased from the center of the volute tongue body to two ends.

Further, the volute tongue body also comprises a first mounting surface and a second mounting surface; the first mounting surface is arranged at the first end of the volute tongue body, and the second mounting surface is arranged at the second end of the volute tongue body; the first mounting surface is provided with a first mounting hole so as to be connected to the front plate of the volute through a screw; the second mounting surface is provided with second mounting holes to be connected to the volute back plate by screws.

Referring to fig. 5, a schematic diagram of a blower volute with a conventional volute tongue body mounted thereon is shown, in which the blower volute includes a check valve 21, a conventional volute tongue body 20, a volute back plate 22, a motor 23 and a volute enclosure plate 24; a traditional volute tongue body 20 is arranged at the volute tongue mounting position of the volute casing plate 24 close to the airflow outlet side, and the traditional volute tongue body 20 does not comprise an inwards concave curved surface; referring to fig. 6, a schematic diagram of a volute structure of a blower with a volute tongue body mounted thereon is shown, in which the volute of the blower includes a check valve 21, a volute tongue body 10, a volute back plate 22, a motor 23 and a volute enclosure plate 24; the volute tongue body 10 in the scheme is arranged at the volute tongue mounting position of the volute casing enclosing plate 24 close to the airflow outlet side, and the volute tongue body 10 is in a variable cross-section concave arc curved surface shape; the height of the volute tongue body 10 is equal to the thickness of the corresponding volute casing enclosing plate 24, and mounting holes are formed in the front end and the rear end of the volute tongue body 10 and are fixedly connected with the volute casing front plate and the volute casing rear plate through screws respectively.

Furthermore, the volute tongue body also comprises a third mounting surface, and the fillet radius of the third mounting surface is the same as that of the mounting position of the volute tongue body on the volute casing boarding. Specifically, the radius of the fillet at the mounting position of the volute tongue body on the volute casing enclosing plate is consistent with that of the fillet at the mounting position of the volute tongue body on the volute casing enclosing plate, so that the mounting surface of the volute tongue body can be tightly attached to the mounting position of the volute tongue body on the volute casing enclosing plate.

A non-uniform rational B spline (NURBS) curved surface modeling tool based on CAD software can carry out parametric geometric modeling design on a volute tongue body in a volute of an oil smoke exhauster by adjusting a two-dimensional curve cluster of the volute tongue body and an outlet curve of the volute tongue body, and can carry out pneumatic and flow field optimization design on an air duct system of the oil smoke exhauster by combining fluid calculation software, so that the structure of the volute tongue body with the variable cross-section concave curved surface is determined, and the pneumatic performance of the oil smoke exhauster is improved.

The embodiment of the utility model also provides a fan volute tongue, the fan volute tongue 40 comprises an airflow guide 30 and the volute tongue body 10; the airflow guide includes: a second concave curved surface which is fit by the airflow guiding curve 31, the upper curve 32, the lower curve 33 and the volute tongue body outlet curve 13; the second concave curved surface is connected with the first concave curved surface of the volute tongue body through the outlet curve of the volute tongue body; the airflow guiding curve, the upper curve and the lower curve are all concave curves.

In practical implementation, the airflow guiding curve and the volute tongue outlet curve may be B-spline curves obtained by a non-uniform rational B-spline method; the airflow guide curve 31, the upper curve 32 and the lower curve 33 are all generally concave curves; referring to fig. 7, a schematic diagram of an airflow guide may be formed by a curved airflow guide line 31, a curved volute outlet line 13, an upper curved line 32 and a lower curved line 33 through NURBS surface modeling technology to form a corresponding second concave curved surface, which may also be referred to as a concave airflow guide surface. Referring to fig. 8, a schematic connection diagram of the volute tongue body and the airflow guide part is shown, wherein the volute tongue body and the airflow guide part comprise an airflow guide part 30, a volute tongue body 10, an impeller center disk 34, an impeller 35 and a volute mounting flange 36; the airflow guide piece 30 is connected with the volute tongue body 10; referring to fig. 9, a schematic structural diagram of an outlet side of a blower volute is shown, which includes a volute enclosing plate 24, a volute mounting flange 36, an airflow guide 30 and a volute tongue body 10, where the airflow guide 30 is connected with the volute tongue body 10; as can be seen from fig. 8 and 9, the second concave curved surface corresponding to the airflow guide 30 is connected with the first concave curved surface of the volute tongue body 10 through the volute tongue body outlet curve 13, in practical implementation, the volute tongue body 10 and the airflow guide 30 may be an integral structure, and the airflow guide 30 is usually disposed on the airflow outlet side of the volute tongue body 10.

The traditional volute tongue body is not provided with an airflow guide connected with the volute tongue body, and because the outlet of the traditional volute is square or parallelogram and is transited to the round outlet through the check valve, the traditional structure is easy to form vortex at the outlet of the volute, and refer to an airflow diagram after the airflow guide is installed as shown in fig. 10; the air flow guide concave surface corresponding to the air flow guide piece can be used for realizing smooth air flow transition, so that outlet eddy current is eliminated, the energy dissipation of air flow is reduced, and the efficiency of the fan is improved.

Referring to fig. 11, a schematic diagram of a blower volute including a check valve 21 and the blower volute tongue 40; wherein, the check valve 21 belongs to an automatic valve which can prevent the air flow from flowing backwards; in fig. 11, the blower volute includes, in addition to the check valve 21 and the blower volute tongue 40, a volute shroud 24, a volute front plate 25, a volute back plate 22, an impeller 35, an impeller, and a wind guide ring 37, which may be implemented by using the prior art, and are not described herein again.

The shape, the distance and the radius of the volute tongue body in the volute tongue of the fan are closely related to the change of the flow field inside the fan and the generation of noise. Because of the structural characteristics of the fan volute tongue and the interaction between the fan volute tongue and the impeller, vortices with certain strength and separation backflow can appear in the area near the fan volute tongue, so the improvement and the optimization design of the shape of the fan volute tongue have very important significance for improving the performance of the multi-wing centrifugal fan.

Referring to a speed field cloud chart of an outlet area of a volute with a traditional volute tongue body shown in fig. 12 and a speed vector diagram of a vortex area with the traditional volute tongue body shown in fig. 14, it can be seen that the outlet section of the traditional volute tongue body has low wind speed and uneven speed distribution, and a large-scale vortex exists in an area close to the lower end of the volute tongue body, where energy dissipation exists in airflow, which affects fan efficiency and generates vortex noise; referring to a speed field cloud chart of an outlet area of a volute provided with a fan volute tongue shown in fig. 13 and a speed vector chart of a vortex area provided with the fan volute tongue shown in fig. 15, it can be seen that in the fan volute tongue of the scheme, a volute tongue body is in a shape of a concave arc curved surface with a variable cross section, an airflow guide piece is also in a shape of a concave curved surface, the air speed of the outlet cross section is improved, the air speed is uniformly distributed, and the vortex at the lower end of the volute tongue body is eliminated, so that pneumatic noise is favorably reduced.

Referring to the total pressure cloud diagram of the outlet of the middle section of the impeller provided with the traditional volute tongue body shown in fig. 16 and the total pressure cloud diagram of the outlet of the middle section of the impeller provided with the fan volute tongue shown in fig. 17, it can be seen that compared with the traditional volute tongue body, the total pressure of the airflow of the fan volute tongue impeller is high in the scheme, and the influence range on the surrounding airflow is large, so that the total pressure efficiency can be improved.

Referring to the schematic diagram of the broadband noise simulation cloud map of the conventional volute tongue body shown in fig. 18 and the schematic diagram of the broadband noise simulation cloud map of the blower volute tongue shown in fig. 19, it can be seen that the broadband noise of the conventional volute tongue body is 82.8dB, and compared with the conventional volute tongue body, the broadband noise of the blower volute tongue in the scheme is 80.3dB, so that the blower volute tongue adopting the scheme can obviously reduce the broadband noise of the air duct.

In addition, based on the existing fan volute structure, under the same air volume, the traditional volute tongue body and the volute tongue of the inwards concave curved surface fan in the scheme are subjected to test testing, and the maximum static pressure, total pressure efficiency and sound power noise parameters under two different structures are confirmed; through test tests: at the same 18.2m³At the air volume of/min, the maximum static pressure of the traditional volute tongue body is 870Pa, the full-pressure efficiency is 33.0 percent, and the sound power noise is 63.5dB (A); the maximum static pressure of the volute tongue of the concave curved surface fan in the scheme is 967Pa, the full-pressure efficiency is 35.5 percent, and the acoustic power noise is 62.0dB (A); compared with the traditional volute tongue body, the volute tongue of the inwards concave curved surface fan in the scheme has the maximum static pressure rise>90Pa, full pressure efficiency improvement>2%, the pneumatic performance is improved, meanwhile, the sound power noise is reduced by 1.5dB (A), the technical indexes of the range hood such as large air volume, large air pressure, high efficiency and low noise are improved, and the specific test data are shown in the following table 1.

TABLE 1

The fan volute tongue structure in the scheme of the application can better separate air flow, reduces the impact loss of outlet air flow, has smaller range and strength for generating pressure gradient, reduces the flow separation phenomenon, can enable the air flow to generate a certain phase difference when reaching the fan volute tongue, and can play a role in reducing fan rotation noise and vortex noise. On the premise of equal motor input power, the maximum static pressure and full pressure efficiency can be improved, the range hood has larger exhaust pressure, and the flue resistance of a low floor is overcome.

Further, the fan volute tongue is arranged on the check valve; the first concave curved surface and the second concave curved surface of the fan volute tongue are arranged on the outlet side of the fan volute. Referring to FIG. 20, a schematic view of a fan volute tongue is shown; in practical implementation, in order to improve convenience in manufacturing and installation, the fan volute tongue may be directly integrated on a check valve of the fan volute, and the first concave curved surface and the second concave curved surface of the fan volute tongue are generally disposed at an airflow outlet side of the fan volute, see another structural schematic diagram of the fan volute shown in fig. 21, in which the fan volute tongue is integrated on the check valve of the fan volute.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims (10)

1. A volute tongue body, comprising: a space curved surface which is synthesized by a volute tongue body two-dimensional curve cluster, a tangent point straight line connecting the volute tongue body and a volute casing enclosing plate and a volute tongue body outlet curve;

the two-dimensional curve cluster of the volute tongue body comprises a plurality of two-dimensional curves of the volute tongue body; the cross sections of the two-dimensional curves of the plurality of volute tongue bodies are gradually increased along the extending direction from the center of the volute tongue body to the two ends of the volute tongue body;

the curvature of the volute tongue body is continuous with that of the volute casing surrounding plate at the tangent point straight line where the volute tongue body is connected with the volute casing surrounding plate;

the outlet curve of the volute tongue body is an inwards concave curve; and fitting the two-dimensional curve cluster of the volute tongue body and the outlet curve of the volute tongue body into a first concave curved surface of the volute tongue body.

2. The volute tongue body of claim 1, wherein the cross-sectional area of the volute tongue body gradually increases along the extension direction from the center to both ends of the volute tongue body.

3. The volute tongue body of claim 1, wherein the volute tongue body further comprises a first mounting surface; the first mounting surface is arranged at the first end of the volute tongue body;

the first mounting surface is provided with a first mounting hole to be connected to the volute front plate through a screw.

4. The volute tongue body of claim 1, wherein the volute tongue body further comprises a second mounting surface; the second mounting surface is arranged at the second end of the volute tongue body;

the second mounting surface is provided with a second mounting hole to be connected to the volute back plate through a screw.

5. The volute tongue body of claim 1, further comprising a third mounting surface having a fillet radius that is the same as a fillet radius at which the volute tongue body is mounted on the volute shroud.

6. A fan volute tongue comprising an airflow guide and the volute tongue body of any one of claims 1-5;

the airflow guide includes: the second concave curved surface is fit by the airflow guiding curve, the upper curve, the lower curve and the volute tongue body outlet curve; the second concave curved surface is connected with the first concave curved surface of the volute tongue body through the outlet curve of the volute tongue body.

7. The fan volute tongue of claim 6, wherein the airflow directing curve, the upper curve, and the lower curve are each concave curves.

8. A fan volute comprising a check valve and a fan volute tongue according to any of claims 6 to 7.

9. The fan volute of claim 8, wherein the fan volute tongue is disposed on the check valve.

10. The blower volute of claim 8, wherein the first concave curved surface and the second concave curved surface of the blower volute tongue are disposed on an outlet side of the blower volute.

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