CN110805568B - Plate-shaped rear guide vane of diagonal flow fan and design method thereof - Google Patents
Plate-shaped rear guide vane of diagonal flow fan and design method thereof Download PDFInfo
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- CN110805568B CN110805568B CN201910994383.1A CN201910994383A CN110805568B CN 110805568 B CN110805568 B CN 110805568B CN 201910994383 A CN201910994383 A CN 201910994383A CN 110805568 B CN110805568 B CN 110805568B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D25/00—Pumping installations or systems
- F04D25/02—Units comprising pumps and their driving means
- F04D25/08—Units comprising pumps and their driving means the working fluid being air, e.g. for ventilation
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/52—Casings; Connections of working fluid for axial pumps
- F04D29/54—Fluid-guiding means, e.g. diffusers
- F04D29/541—Specially adapted for elastic fluid pumps
- F04D29/542—Bladed diffusers
- F04D29/544—Blade shapes
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- General Engineering & Computer Science (AREA)
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- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention discloses a plate-shaped rear guide vane of an oblique flow fan and a design method thereof, and relates to the technical field of fans. Providing main geometric parameters of the design of the plate-shaped rear guide vane, wherein the main geometric parameters comprise guide vane radius R, axial distance L of moving and static vanes, number n of the guide vanes and an inlet angle alpha of the guide vane; recording the diameter of the movable vane impeller of the diagonal flow fan as D, and recording the number of the movable vane impellers of the diagonal flow fan as N; the guide vane radius R and the diameter D of the oblique flow fan movable vane impeller meet the condition that R/D is more than or equal to 0.6 and less than or equal to 0.7, the axial distance L between the movable vane and the fixed vane and the diameter D of the oblique flow fan movable vane impeller meet the condition that L/D is more than or equal to 0.16 and less than or equal to 0.20, the number N of the guide vanes and the number N of the oblique flow fan movable vane impeller meet the condition that N-1 is more than or equal to N and less than or equal to N +1, and the inlet angle alpha of the guide vane blades is the outlet airflow angle of 70-80% of the blade heights of the oblique. The design parameters selected in the limited range of the invention can effectively avoid the deterioration of the flow field and effectively improve the performance of the diagonal flow fan.
Description
Technical Field
The invention relates to the technical field of fans, in particular to a plate-shaped rear guide vane of an oblique flow fan and a design method thereof.
Background
The ventilator is a machine for converting mechanical energy into gas energy, is widely applied to the fields of electric power, metallurgy, traffic, fire fighting and the like, and plays an important role in national economic development.
The diagonal flow fan is named because the airflow is diagonally crossed with the axial line in the meridian plane of the impeller, and is a fan between an axial flow type and a centrifugal type, so that the diagonal flow fan has the advantages of axial flow type large flow coefficient, high efficiency, centrifugal type high pressure coefficient, wide working range and the like.
The rear guide vane diagonal flow fan based on axial flow extension design mainly comprises: the impeller comprises an impeller, an inclined hub, a rear guide vane (comprising a guide vane hub) and a casing, kinetic energy at an outlet of the impeller is large, and the guide vane is designed behind the impeller in order to rotate deflected airflow flowing out of the impeller to the axial direction and convert the rotating kinetic energy of partial deflected airflow into static pressure, so that the static pressure efficiency is obviously improved.
The design parameters of the rear guide vane have important influence on the overall performance of the diagonal flow fan, and the unmatched rear guide vane can not achieve the purpose of improving the static pressure efficiency, but can deteriorate a flow field and increase the flow loss. The design of the rear guide vane comprehensively considers a plurality of aspects such as static pressure conversion capacity, flow loss of a blade path, axial size and the like.
The main design parameters of the plate-shaped rear guide vane are a vane inlet angle, the number of the guide vanes, the radius of the guide vane and the axial distance of the movable vane and the static vane, and the plate-shaped rear guide vane which has strong adaptability to the given movable vane and can achieve better performance effect is designed on the basis of the four parameters.
Disclosure of Invention
The invention solves the technical problems of the deterioration of the flow field of the diagonal flow fan and the insufficient static pressure conversion capability of the guide vane in the prior art, and provides a design method of a high-performance plate-shaped rear guide vane.
According to the first aspect of the invention, the design method of the plate-shaped rear guide vane of the diagonal flow fan is provided, and main geometric parameters for designing the plate-shaped rear guide vane are provided, wherein the main geometric parameters comprise a guide vane radius R, a moving and static vane axial distance L, a guide vane number n and a guide vane inlet angle alpha;
recording the diameter of the movable vane impeller of the diagonal flow fan as D, and recording the number of the movable vane impellers of the diagonal flow fan as N; the guide vane radius R and the diameter D of the oblique flow fan movable vane impeller meet the condition that R/D is more than or equal to 0.6 and less than or equal to 0.7, the axial distance L between the movable vane and the fixed vane and the diameter D of the oblique flow fan movable vane impeller meet the condition that L/D is more than or equal to 0.16 and less than or equal to 0.20, the number N between the number N of the guide vanes and the number N of the oblique flow fan movable vane impeller meet the condition that N is more than or equal to 1 and less than or equal to N +1, and the inlet angle alpha of the guide vane blades is the outlet airflow angle at 70-80% of the height of.
Preferably, the relation between the guide vane radius R and the diameter D of the oblique flow fan movable vane impeller is that R/D is more than or equal to 0.61 and less than or equal to 0.7.
Preferably, the relation between the axial distance L of the movable and static blades and the diameter D of the movable blade wheel of the diagonal flow fan is 0.17 and L/D and 0.20.
Preferably, the number N of the guide vanes is equal to the number N of the oblique flow fan movable vane impellers.
Preferably, the inlet angle α of the guide vane blade is an outlet airflow angle of 75% of the blade height of the oblique flow fan blade.
According to another aspect of the invention, the plate-shaped rear guide vane of the diagonal flow fan obtained by any one of the design methods is provided.
Generally, compared with the prior art, the above technical solution conceived by the present invention mainly has the following technical advantages:
(1) the plate-shaped rear guide vane in the invention means that the guide vanes have the same curvature and the same thickness, and have better aerodynamic performance compared with an airfoil-shaped vane, and the design and the manufacture are simple and convenient. The method sets the selection of the four parameters of the plate-shaped rear guide vane of the diagonal flow fan by referring to a numerical simulation result and engineering practical experience, and the specific selection principle is determined according to the parameters of the impeller of the diagonal flow fan, so that the method has certain universality. The design parameters selected in the limited range of the invention can effectively avoid the deterioration of the flow field and effectively improve the performance of the diagonal flow fan.
(2) The invention can effectively improve the flow field of the fan, weaken the dynamic and static interference and improve the total pressure and efficiency of the whole machine by the mutual matching of the reasonable plate-shaped rear guide vane and the movable vane impeller. Under the working condition of small flow, the fan performance can be improved by increasing the number of the guide vanes, and under the working condition of large flow, the 5 guide vane diagonal flow fan with less number of the guide vanes has more excellent performance. According to the invention, the radius R of the guide vane and the diameter D of the inclined flow fan movable vane wheel meet the condition that R/D is more than or equal to 0.6 and less than or equal to 0.7, the axial distance L of the movable and static vanes and the diameter D of the inclined flow fan movable vane wheel meet the condition that L/D is more than or equal to 0.16 and less than or equal to 0.20, and a high performance value in a large range is shown.
(3) The invention provides an instructive method when a given movable blade requires to design or select and configure a rear guide vane.
Drawings
FIG. 1 is a schematic view of the working state of the plate-shaped rear guide vane of the present invention.
Fig. 2 is a view of the bucket wheel cooperating with the plate-shaped trailing vane of the invention in direction a.
FIG. 3 is a cross-sectional view along direction A of the plate-shaped trailing vane of the present invention at B-B'.
FIG. 4 is a perspective view of a single blade of the plate-shaped trailing vane of the present invention.
FIG. 5 is a view radially inward of a single blade of the plate-shaped trailing vane of the present invention.
FIG. 6 is a full pressure curve for an embodiment of the present invention for vane count.
FIG. 7 is a graph of full pressure efficiency for an embodiment of the present invention for vane count.
FIG. 8 is a graph of full pressure for a particular embodiment of vane radius for the present invention.
FIG. 9 is a graph of full pressure efficiency for a particular embodiment of the guide vane radius of the present invention.
Fig. 10 is a graph of full pressure for an embodiment of the present invention for a moving vane distance (L20, 40, 60, 80 mm).
Fig. 11 is a graph of full pressure for an embodiment of the present invention for a moving vane distance (L80, 100, 120, 140 mm).
In the figure: the method comprises the following steps of 1-front guide vane cone, 2-movable vane impeller, 3-plate-shaped rear guide vane, 4-guide vane hub, 5-casing, 6-plate-shaped rear guide vane low-pressure surface, 7-plate-shaped rear guide vane high-pressure surface, 8-plate-shaped rear guide vane upper curved surface and 9-plate-shaped rear guide vane lower curved surface.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The design parameters of the plate-shaped rear guide vane mainly comprise guide vane radius R, axial distance L of moving and static vanes, number n of guide vanes and an inlet angle alpha of the vanes.
The rear guide vane is arranged in an oblique flow fan shown in figure 1 to work, and the oblique flow fan mainly comprises a front guide vane cone 1, a movable vane impeller 2, a plate-shaped rear guide vane 3, a guide vane hub 4 and a casing 5.
The plate-shaped rear guide vane 3 is arranged on the guide vane wheel hub 4, and L is the distance between the movable vane wheel and the plate-shaped rear guide vane, namely the distance between the plate-shaped rear guide vane 3 and the movable vane wheel 2. A is the view direction along the axial direction to the right, and B-B' is the section of the rear guide vane which is transversely and radially intersected with the plate shape.
As shown in fig. 2, which is a view from a direction a, the shape of the bucket wheel 2 can be seen, and the diameter of the bucket wheel 2 is D.
As shown in fig. 3, a cross section of the plate-shaped rear guide vane 3 in the direction B-B' is taken along the direction a, the casing radius is R2, the guide vane hub radius is R1, and the gap between the plate-shaped rear guide vane 3 and the casing 5 is small (there may be no gap in actual manufacturing), so that the height R of the plate-shaped rear guide vane 3 is R2-R1. A certain gap exists between the movable blade impeller 2 and the casing 5, and the diameter D of the movable blade impeller 2 is less than 2R 2.
As shown in fig. 4 and 5, the plate-shaped trailing guide vane 3 profile is composed of a low-pressure curved surface 6, a high-pressure curved surface 7, an upper curved surface 8, and a lower curved surface 9. The plate-shaped rear vane 3 can be regarded as being obtained by cutting an elongated arc plate with a radius R by the vane hub 4 and the casing 5, so that the radius of the plate-shaped rear vane 3 is R, and the height of the plate-shaped rear vane 3 is R2-R1. The high-pressure curved surface is a concave surface of the blade, and when fluid flows through the guide vane, the pressure of the surface is higher; the low-pressure curved surface is a convex surface of the blade, and when fluid flows through the guide vane, the impact on the surface is small, and the pressure is low.
In fig. 5, line FO is the tangential direction of the plate-shaped rear guide vane 3 at the inlet, line CE is the frontal line, and α is the blade inlet angle α of the plate-shaped rear guide vane 3.
It can be seen from fig. 1, 2 and 3 that the number of blades of a given bucket wheel 2 is 6, and the number of blades of the plate-shaped trailing guide vane 3 is 5.
The plate-shaped rear guide vane 3 is determined according to parameters of a given movable vane, and the value taking method and the value taking range are as follows:
the optimal value of the guide vane number N of the plate-shaped rear guide vane 3 is influenced by the blade number of an impeller of an oblique flow fan, and the blade number of a given movable vane is N, the invention provides that: the number N of guide vanes is N or N +/-1. Selecting a scheme of reducing one blade (or the scheme of reducing the number of the blades as the movable blades) under the working condition of larger flow; and selecting a scheme of adding one sheet under the working condition of smaller flow.
The guide vane radius R of the plate-shaped rear guide vane 3 is controlled by the diameter of an oblique flow fan impeller, R is the plate-shaped rear guide vane radius, D is the diameter of a movable vane impeller, and the design meets the condition that R is more than or equal to 0.6 and R/D is less than or equal to 0.7.
The axial distance L of the moving and static blades of the plate-shaped rear guide blade 3 is controlled by the diameter of an oblique flow fan impeller, the axial distance L of the moving and static blades is designed to meet the condition that L/D is more than or equal to 0.16 and less than or equal to 0.20.
The optimal value of the blade inlet angle alpha of the plate-shaped rear guide blade 3 is influenced by the airflow angle at the outlet of the impeller of the oblique flow fan, and the invention provides the following steps: the inlet angle of the blade should be a value near the outlet airflow angle at the maximum flow rate at the position of 75% of the height of the moving blade of the diagonal flow fan.
Example 1
The diameter D of the impeller of the movable blade is 492mm, and the number N of the blades is 6. The numbers N of the plate-shaped rear guide vanes are respectively 5, 6, 7 and 11, and the fans provided with the corresponding plate-shaped rear guide vanes are respectively marked as N5, Y, N7 and N11. And performing simulation calculation on the four groups of fans to obtain a full-pressure curve chart in fig. 6 and a full-pressure efficiency curve in fig. 7.
From fig. 6 and 7, it can be seen that under the low flow rate condition (Q5500-6000 m)3And h), the full-pressure efficiency and the full-pressure efficiency of the four groups of fans are not greatly different, and the N7 and Y effects are better. Under the working condition of small flow, the performance of the fan can be improved by increasing the number of the guide vanes. Under the working condition of large flow (Q is 6500-7500 m)3H), it can be obtained from both graphs that the comparison of the full pressure and the full pressure efficiency is N5>Y>N7>N11, and the full pressure efficiency of N5 is increased more obviously than that of the prototype. Therefore, under the working condition of large flow, the 5 guide vane diagonal flow fan with less guide vanes has more excellent performance. According to the design method.
Example 2
The diameter D of the impeller of the movable blade is 492mm, and the number N of the blades is 6. The radiuses R of the plate-shaped rear guide vanes are respectively 250mm, 300mm, 350mm and 390mm, and fans provided with the corresponding plate-shaped rear guide vanes are respectively marked as R250, R300, R350 and R390.
And performing simulation calculation on the four groups of fans to obtain a full-pressure curve chart in fig. 8 and a full-pressure efficiency curve chart in fig. 9. In the full flow range, as can be seen in fig. 8 and 9, R300 does not dominate at low flow rates, but the pressure curve represented by R300 gradually rises and exhibits a high performance value in a wider range as the flow rate increases, and the full pressure and full pressure efficiency curves of R250 and R300 tend to coincide as the flow rate increases. But overall, the R300 scheme is more optimal. At this time, the value 295.2< R <344.4, which is consistent with R being more than or equal to 0.6D and less than or equal to 0.7D.
Example 3
The diameter D of the impeller of the movable blade is 492mm, and the number N of the blades is 6. Axial distances L of the moving and static vanes are respectively 20mm, 40mm, 60mm, 80mm, 100mm, 120mm and 140mm, and fans provided with corresponding plate-shaped rear guide vanes are respectively marked as L20, L40, L60, L80, L100, L120 and L140. The full pressure curves of the blower in fig. 10 and the blower in fig. 11 at L20, 40, 60 and 80mm are obtained by performing simulation calculation on seven groups of blowers.
Under the condition of small flow, the scheme is not very different from that shown in the combined observation of the figure 10 and the figure 11. Under the working condition of large flow, the L80 scheme is the best effect as can be seen from the comparison of the two graphs of FIG. 10 and FIG. 11; it can be seen from the observation of the full pressure that the performance gradually increases with increasing axial distance at axial distances less than 80mm, and the distribution of the seven schemes, where the performance starts to gradually decrease with increasing axial distance, shows a tendency to increase first and then decrease when the axial distance is greater than 80mm, and is highest at the L80 scheme. At this time, the value of L is more than 78.72 and less than 98.4, which is consistent with that L is more than or equal to 0.16D and less than or equal to 0.2D.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (6)
1. A design method of a plate-shaped rear guide vane of an oblique flow fan is characterized in that main geometric parameters for designing the plate-shaped rear guide vane are provided, wherein the main geometric parameters comprise a guide vane radius R, a moving and static vane axial distance L, a guide vane number n and a guide vane inlet angle alpha;
recording the diameter of the oblique flow fan movable vane impeller as D, and recording the number of the oblique flow fan movable vane impellers as N; the guide vane radius R and the diameter D of the movable vane impeller of the diagonal flow fan meet the condition that R/D is more than or equal to 0.6 and less than or equal to 0.7, the axial distance L of the movable vane and the fixed vane and the diameter D of the movable vane impeller of the diagonal flow fan meet the condition that L/D is more than or equal to 0.16 and less than or equal to 0.20, the number N of the guide vanes and the number N of the movable vane impeller of the diagonal flow fan meet the condition that N-1 and N are more than or equal to N +1, and the inlet angle alpha of the guide vane is the outlet airflow angle at the vane height of 70-80.
2. The design method of the oblique flow fan plate-shaped rear guide vane as claimed in claim 1, wherein the relation between the guide vane radius R and the diameter D of the oblique flow fan moving blade impeller is 0.61-0.7.
3. The method for designing the plate-shaped rear guide vane of the diagonal flow fan as claimed in claim 1, wherein the relationship between the axial distance L of the moving and stationary vanes and the diameter D of the moving blade wheel of the diagonal flow fan is 0.17L/D0.20.
4. The method for designing the plate-shaped rear guide vane of the diagonal flow fan as claimed in claim 1, wherein the number N of the guide vanes is equal to the number N of the movable blade wheels of the diagonal flow fan.
5. The design method of the plate-shaped rear guide vane of the diagonal flow fan as claimed in claim 1, wherein the inlet angle α of the guide vane blade is an outlet airflow angle of the diagonal flow fan moving vane at 75% of the height of the vane.
6. The plate-shaped rear guide vane of the diagonal flow fan, which is obtained by the design method of any one of claims 1 to 5.
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| CN201910994383.1A CN110805568B (en) | 2019-10-18 | 2019-10-18 | Plate-shaped rear guide vane of diagonal flow fan and design method thereof |
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| CN201910994383.1A CN110805568B (en) | 2019-10-18 | 2019-10-18 | Plate-shaped rear guide vane of diagonal flow fan and design method thereof |
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| KR102333202B1 (en) * | 2020-05-07 | 2021-11-30 | 청호나이스 주식회사 | Air Blower and Air Purifier Including the Same |
| CN114909333A (en) * | 2022-05-27 | 2022-08-16 | 珠海格力电器股份有限公司 | Mixed flow fan and ducted air conditioner |
| CN115342068B (en) * | 2022-08-04 | 2023-06-27 | 中国农业大学 | Method for improving performance of agricultural ventilator |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN2217129Y (en) * | 1995-03-23 | 1996-01-10 | 北京当代复合材料有限公司 | Electric fan with inclined air flow |
| CN2259516Y (en) * | 1996-02-16 | 1997-08-13 | 武城华能玻璃钢制品有限公司 | Pipe type diagonal flow fan |
| US7168918B2 (en) * | 2004-09-30 | 2007-01-30 | General Electric Company | High performance cooling fan |
| CN100357612C (en) * | 2005-12-22 | 2007-12-26 | 上海交通大学 | Rotating rear guide vane of axial flow fan |
| CN203175980U (en) * | 2013-04-03 | 2013-09-04 | 宁波朗迪叶轮机械有限公司 | Oblique-flow centrifugal vane wheel |
| CN203189343U (en) * | 2013-04-23 | 2013-09-11 | 福建华大电机有限公司 | Diversion type diagonal flow fan |
| JP6990026B2 (en) * | 2017-02-16 | 2022-01-12 | シャープ株式会社 | How to manufacture electric blowers, vacuum cleaners, and impellers |
| CN106870459B (en) * | 2017-04-28 | 2019-08-16 | 广东威灵电机制造有限公司 | Guide vane wheel assembly and blower with it |
| CN108678994B (en) * | 2018-05-04 | 2019-08-09 | 华中科技大学 | A kind of efficient diagonal flow fan |
| CN109635496B (en) * | 2018-12-29 | 2023-05-09 | 沈阳鼓风机集团股份有限公司 | Method and device for designing guide vane and guide vane |
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