CN112814943A - Integrally formed curved and swept combined blade, impeller and axial flow fan - Google Patents
Integrally formed curved and swept combined blade, impeller and axial flow fan Download PDFInfo
- Publication number
- CN112814943A CN112814943A CN202110151756.6A CN202110151756A CN112814943A CN 112814943 A CN112814943 A CN 112814943A CN 202110151756 A CN202110151756 A CN 202110151756A CN 112814943 A CN112814943 A CN 112814943A
- Authority
- CN
- China
- Prior art keywords
- blade
- impeller
- swept
- combined
- motor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000005484 gravity Effects 0.000 claims abstract description 33
- 238000005452 bending Methods 0.000 claims description 32
- 238000009434 installation Methods 0.000 claims description 10
- 239000002131 composite material Substances 0.000 claims description 8
- 230000007704 transition Effects 0.000 claims description 6
- 150000001875 compounds Chemical class 0.000 claims description 4
- 229910000838 Al alloy Inorganic materials 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 238000005065 mining Methods 0.000 abstract description 22
- 238000009826 distribution Methods 0.000 abstract description 8
- 230000037237 body shape Effects 0.000 abstract description 5
- 238000002474 experimental method Methods 0.000 abstract description 2
- 230000003068 static effect Effects 0.000 description 9
- 239000003245 coal Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 239000012530 fluid Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 238000010408 sweeping Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 239000000306 component Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000003584 silencer Effects 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000009423 ventilation Methods 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005206 flow analysis Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
Images
Classifications
-
- 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
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/38—Blades
- F04D29/388—Blades characterised by construction
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D19/00—Axial-flow pumps
- F04D19/002—Axial flow fans
-
- 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
-
- 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
- F04D25/16—Combinations of two or more pumps ; Producing two or more separate gas flows
- F04D25/166—Combinations of two or more pumps ; Producing two or more separate gas flows using fans
-
- 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
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/325—Rotors specially for elastic fluids for axial flow pumps for axial flow fans
-
- 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
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/325—Rotors specially for elastic fluids for axial flow pumps for axial flow fans
- F04D29/329—Details of the hub
-
- 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
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/34—Blade mountings
-
- 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
- F04D29/26—Rotors specially for elastic fluids
- F04D29/32—Rotors specially for elastic fluids for axial flow pumps
- F04D29/38—Blades
- F04D29/384—Blades characterised by form
- F04D29/386—Skewed blades
-
- 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
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/663—Sound attenuation
-
- 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
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/666—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by means of rotor construction or layout, e.g. unequal distribution of blades or vanes
-
- 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
- F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
- F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
- F04D29/667—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by influencing the flow pattern, e.g. suppression of turbulence
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
The invention provides an integrally formed curved combined blade and a mining axial-flow fan, wherein a plurality of curved combined blades are uniformly installed along the circumferential direction of a hub to form an impeller, a gravity center stacking line for controlling the shape of a blade body of the curved combined blade is a secondary Bezier curve, and a primary impeller and a secondary impeller of the mining axial-flow fan are oppositely arranged and rotate in opposite directions. The gravity center stacking line for controlling the blade body shape of the curved and swept combined blade is the curved and swept combined blade with the secondary Bezier curve, so that the radial force gradient and the secondary flow distribution along the blade height of the blade are effectively controlled, the stacking of boundary layers is eliminated, the vortex is prevented from converging, the vortex noise is reduced, the pneumatic performance of the mining axial flow fan is improved, and the working efficiency of the mining axial flow fan is improved. Experiments prove that the full-pressure efficiency of the mining axial-flow fan provided by the invention is 87%, and is improved by more than 5% compared with the full-pressure efficiency of the traditional mining axial-flow fan.
Description
Technical Field
The invention belongs to the field of ventilation of coal mines, and relates to an axial flow fan for a mine, in particular to an integrally formed curved and swept combined blade, an impeller and an axial flow fan.
Background
The mining fan is used as main technical equipment for mine safety production, is an important component of a mine ventilation system, and is the basis for mine safety production and disaster prevention and control. The problems of high and low operating efficiency and reliability of the mining fan are the focus of concern in coal mines. As the local old mine fan is aged and has low operating efficiency and is gradually replaced by the high-efficiency energy-saving fan, various fans are produced at the same time, and the counter-rotating fan is an updated product of the mine fan which is developed and produced by introducing a new technology of 80 years abroad after digestion and absorption. The coal mine air-conditioning system is deeply favored by coal mines due to the characteristics of high pressure, large flow, high efficiency, compact structure and easy air reversing. However, temporary practices prove that the counter-rotating axial flow mining fan has the defects of large noise and the like.
The energy consumption and noise of the ventilator are directly related to the core component of the ventilator, namely the fan blades, and the blade technology determines the final performance of the ventilator. Besides the torsion along the spanwise direction, the swept blade has the inclination (bending) along the circumferential rotation direction and the inclination (sweeping) along the incoming flow direction between the blade body top and the blade shank, and is a blade with a complex three-dimensional space structure. At present, the sweepback blades are widely applied to impeller machinery, and a large number of experimental researches and numerical calculations show that reasonable blade sweepback can change the radial component force of the acting force of the blades and airflow, control the pressure gradient distribution on the surfaces of the blades, reduce the flow loss and achieve the aim of improving the aerodynamic performance of the impeller machinery. The study on the sweep blade mainly focuses on sweep in the top and stem regions of the blade body, while the study on sweep in the whole blade height range, namely the specific shape of the gravity center stacking line, is not discussed much, and no consensus is obtained on what type of gravity center stacking line is selected and how to control the gravity center stacking line.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide an integrally formed curved and swept combined blade, an impeller and an axial flow fan, and solve the technical problem that the working efficiency of the axial flow fan for the mine is improved while the aerodynamic performance of the axial flow fan for the mine is reduced in the prior art.
In order to solve the technical problems, the invention adopts the following technical scheme:
an integrally formed swept combined blade comprises an integrally formed blade body and a blade handle; the blade body comprises a blade body root, a blade body middle part and a blade body top; a petiole clamping groove is formed in the petiole, and a gravity center stacking line for controlling the shape of the blade body of the sweeping combined blade is a secondary Bezier curve; wherein the content of the first and second substances,
the gravity center stacking line for controlling the shape of the blade body of the swept combined blade is projected in a circumferential plane to form a blade forward-bending control line, an x-y plane rectangular coordinate system is established in the circumferential plane, and x and y are respectively a horizontal coordinate and a vertical coordinate in the x-y plane rectangular coordinate system; in an x-y plane rectangular coordinate system, taking the intersection point of the gravity center of the root of the blade body and the blade shank as a coordinate origin, taking the tangential direction of an impeller where the blade is located as a horizontal coordinate x, and taking the radial direction of the blade as a vertical coordinate y;
in an x-y plane rectangular coordinate system, a blade forward-bending control line control equation is as follows:
Pxcontrolling the x-direction coordinate of the curve for the forward bending of the blade;
Pythe y-direction coordinate of the blade forward curve control curve is obtained;
r is the radial length of the blade;
alpha is a bending angle with the value range of 5-20 degrees;
t1is a Bezier function independent variable in a forward control line;
kxthe control parameter of the forward curve of the blade in the x direction is a value range of 0<kx<1.5；
kyThe value range of the y-direction control parameter of the blade forward bending control curve is 0<ky<1；
The gravity center stacking line for controlling the shape of the blade body of the swept combined blade is projected in an axial plane to form a blade forward-bending control line, a z-r plane rectangular coordinate system is established in the axial plane, and z and r are respectively a horizontal coordinate and a vertical coordinate in the z-r plane rectangular coordinate system; in a rectangular coordinate system of a z-r plane, taking the intersection point of the gravity center of the root of the blade body and the blade handle as a coordinate origin, taking the axial direction of the rotation center of the impeller in which the blade is parallel to as a horizontal coordinate z, and taking the radial direction of the blade as a vertical coordinate r;
in a rectangular coordinate system of a z-r plane, namely an axial plane, a control equation of a forward-swept control line of the blade is as follows:
in the formula (I), the compound is shown in the specification,
Pza Z-direction coordinate of a forward-swept control curve of the blade;
Prfor blade sweep-forward controlCoordinates in the direction of the curve r;
r is the radial length of the blade;
beta is a sweep angle, and the value range is 5-15 degrees;
t2is a Bezier function independent variable in a forward sweep control line;
kzthe value range of the Z-direction control parameter of the forward-swept control curve of the blade is-1<kz<1；
krThe forward sweep control curve r direction control parameter of the blade is a value range of 0<kr<1。
The invention also has the following technical characteristics:
for a swept combined blade with a blade length of 532mm,
the three parameters of the control equation of the forward bending control line of the blade are as follows:
α＝10°；
kx＝1.4；
ky＝0.6；
the three parameters of the control equation of the forward-swept control line of the blade are as follows:
β＝15°；
kz＝-0.6；
kr＝0.8。
the middle part of the blade body of the sweep-curved combined blade is positioned at 0.4 part of the blade body.
The sweep-bending combined blade is specifically an integrally formed aluminum alloy sweep-bending combined blade.
The thickness of the blade body of the curved and swept combined blade is gradually reduced from the front edge of the blade body to the rear edge of the blade body.
An impeller is formed by uniformly installing a plurality of curved and swept combined blades along the circumferential direction of a hub, a hub rotating shaft installation disc protruding forwards and backwards is arranged in the center of the hub, a hub rotating shaft installation hole is formed in the center of the hub rotating shaft installation disc, an annular web plate is arranged on the end face of the hub rotating shaft installation disc, and blade installation grooves are uniformly distributed in the annular web plate; the blade mounting disc is provided with a blade mounting hole which runs through the blade mounting disc and corresponds to the blade mounting groove towards the center of the hub, and a pin-shaped notch is formed in the blade mounting hole.
The sweep-bending combined blade is fixedly installed in the blade mounting hole through a hoop, the hoop comprises a first sub-hoop and a second sub-hoop, the first sub-hoop and the second sub-hoop are connected through a bolt, and a pin-shaped boss is arranged on the end face of the first sub-hoop.
An axial flow fan comprises an air duct, a motor and an impeller, wherein the air duct comprises an air inlet duct and an air outlet duct, the motor comprises a primary motor and a secondary motor, and the impeller comprises a primary impeller and a secondary impeller; the primary impeller is connected with a primary motor, the primary motor is arranged in a primary motor barrel, and the primary motor barrel is arranged in an air inlet barrel; the secondary impeller is connected with a secondary motor, the secondary motor is arranged in a secondary motor barrel, and the secondary motor barrel is arranged in the air outlet barrel; the secondary motor cylinder is connected with the conical transition section motor cylinder, the primary impeller and the secondary impeller are impellers according to claim 7, and the primary impeller and the secondary impeller are oppositely arranged and rotate in opposite directions.
The number of the blades of the first-stage impeller is 10, and the number of the blades of the second-stage impeller is 9.
The hub rotating shaft mounting holes at the centers of the hubs of the first-stage impeller and the second-stage impeller are respectively and rotatably mounted on the first-stage motor and the second-stage motor; the primary motor and the secondary motor are both explosion-proof motors, and the primary motor barrel and the secondary motor barrel are connected with the air duct through rib plates.
Compared with the prior art, the invention has the following technical effects:
the gravity center stacking line for controlling the blade body shape of the curved and swept combined blade is the curved and swept combined blade with the secondary Bezier curve, so that the radial force gradient of the blade and the secondary flow distribution along the blade height are effectively controlled, the boundary layer stacking is eliminated, the vortex convergence is avoided, the vortex noise is reduced, the pneumatic performance of the mining axial flow fan is improved, and the working efficiency of the mining axial flow fan is improved. Experiments prove that the full-pressure efficiency of the mining axial-flow fan provided by the invention is 87%, and is improved by more than 5% compared with the full-pressure efficiency of the traditional mining axial-flow fan.
According to the invention, the blade adopts the integrally formed swept combined blade, the swept combined orthogonal three-dimensional optimization design theoretical design is applied, the cross section of the blade is of a wing type, and the front edge of the blade is designed with a fillet, so that the reduction of the fatigue resistance of the blade caused by the sharp top of the blade body is avoided, the strength and the rigidity of the blade are improved, and the service life of the blade is prolonged.
(III) the blades of the swept-curved combined blade can be swept forward by 15 degrees to adjust the static pressure distribution of the suction surface at the top of the movable blade body, so that the pressure difference between the pressure surface and the suction surface is reduced, and the loss caused by the leakage vortex at the top of the blade body is reduced; by changing the static pressure distribution of the suction surface, the static pressure gradient from the middle part of the blade body to the top of the blade body is reduced, the radial secondary flow on the surface of the blade is weakened, the low-energy fluid at the top of the blade body is prevented from being accumulated, and the pneumatic performance and efficiency of the blade are improved.
(IV) the forward bending of the blades of the swept-curved combined blade changes the static pressure distribution at the lower end wall of the blade, reduces the suction surface adverse pressure gradient of the root part of the blade body, weakens the loss caused by circumferential secondary flow at the end wall of the root part of the blade body, enables the low-energy fluid at the root part of the blade body to migrate to the middle part of the blade body in advance, reduces the loss and airflow blockage caused by the accumulation of the low-energy fluid at the tail edge of the root part of the blade body, and improves the pneumatic performance and efficiency of the blade.
Drawings
Fig. 1 is a schematic structural view of an impeller.
Fig. 2 is a schematic view of a blade structure.
FIG. 3 is a schematic top view of a blade.
Fig. 4 is a schematic view of a clip structure.
FIG. 5 is a grid division diagram of stress concentration sites of the hub and key positions of the blade.
Fig. 6 is a cloud of radial deformations of the impeller.
FIG. 7 is a curve diagram of the x-y plane forward curvature of a swept combined blade.
FIG. 8 is a z-r plane forward sweep graph of a swept combined blade.
Fig. 9 is a schematic structural diagram of a mining axial-flow fan.
FIG. 10 is a full streamline distribution diagram of a mining axial-flow fan under a working condition of 2500Pa static pressure rise.
FIG. 11 is a full streamline distribution diagram of a mining axial-flow fan under a static pressure rise working condition of 3000 Pa.
The meaning of the individual reference symbols in the figures is: 1-blade body, 2-blade handle, 3-blade handle clamping groove, 4-sweep combined blade, 5-hub, 6-impeller, 7-hub rotating shaft mounting disc, 8-hub rotating shaft mounting hole, 9-annular web, 10-blade mounting groove, 11-blade mounting disc, 12-blade mounting hole, 13-pin-shaped notch, 14-hoop, 15-wind cone, 16-motor, 17-primary motor barrel, 18-secondary motor barrel, 19-conical transition section motor barrel and 20-ribbed plate.
101-blade root, 102-blade middle, 103-blade top, 104-blade leading edge, and 105-blade trailing edge.
601-first-stage impeller, 602-second-stage impeller.
1401-first sub-band, 1402-second sub-band, 1403-bolt, 1404-pin boss.
1501-air inlet cylinder, 1502-air outlet cylinder.
1601-primary motor, 1602-secondary motor.
The present invention will be explained in further detail with reference to examples.
Detailed Description
The gravity center stacking line for controlling the shape of the blade body of the curved and swept combined blade is a secondary Bezier curve;
the gravity center stacking line for controlling the blade body shape of the sweep combined blade is projected in a circumferential plane to form a blade forward-bending control line, the gravity center stacking line for controlling the blade body shape of the sweep combined blade is projected in an axial plane to form a blade forward-sweeping control line, an x-y plane rectangular coordinate system is established in the circumferential plane, and x and y are respectively a horizontal coordinate and a vertical coordinate in the x-y plane rectangular coordinate system; in an x-y plane rectangular coordinate system, taking the intersection point of the gravity center of the root of the blade body and the blade shank as a coordinate origin, taking the tangential direction of an impeller where the blade is located as a horizontal coordinate x, and taking the radial direction of the blade as a vertical coordinate y; establishing a z-r plane rectangular coordinate system in an axial plane, wherein z and r are respectively an abscissa and an ordinate in the z-r plane rectangular coordinate system; in a rectangular coordinate system of a z-r plane, taking the intersection point of the gravity center of the root of the blade body and the blade handle as a coordinate origin, taking the axial direction of the rotation center of the impeller in which the blade is parallel to as a horizontal coordinate z, and taking the radial direction of the blade as a vertical coordinate r;
the center of gravity stacking line, the circumferential plane and the axial plane are common knowledge in the art.
The line of the center of gravity is defined as a curve formed by the root of the blade body to the center of gravity of each section of the blade body top.
The circumferential plane is defined as a circumferential plane formed by the circumferential tangent of the impeller and the radial direction of the impeller, namely a plane which is perpendicular to the rotating central axis of the impeller and divides the thickness of the impeller.
The axial plane is defined as the axial plane formed by the axial direction of the impeller and the radial direction of the impeller, namely the plane which is parallel to the rotation central axis of the impeller and bisects the impeller.
As shown in fig. 7 and 8, the gravity center stacking line for controlling the blade body shape of the swept-curved composite blade is a quadratic Bezier curve, the starting point P1 of the gravity center stacking line is the intersection point of the blade body root gravity center and the blade shank, i.e. the starting point P1 is located at the coordinate origin on the x-y plane rectangular coordinate system, the point a is the middle part of the blade body, P2 is the gravity center at the top part of the blade body, P3 is the blade forward-curved control point, k is the blade forward-curved control pointxControl parameter, k, for the blade camber control point P3 in the x-directionyThe control parameter of the blade forward bending control point P3 in the y direction; p4 is the blade sweep forward control point, kzControl parameter, k, for the blade sweep forward control point P4 in the z-directionrIs the control parameter of the blade forward-swept control point P4 in the direction r. Introducing specific parameters of the blade: blade length R, bend angle alpha, sweep angle beta.
Under an x-y plane rectangular coordinate system, the coordinates of each point P1, P2 and P3 of the forward-curved blade are respectively as follows: p1(0, 0), P2(R sin alpha, Rcos alpha), P3 (k)x Rsinα、kyRcos α); under the rz-r plane rectangular coordinate system, the coordinates of each point P1, P2 and P4 of the forward-swept blade are respectively as follows: p1(0, 0), P2(R sin beta, R cos beta), P4 (k)z R sinβ、kz R cosβ)。
In an x-y plane rectangular coordinate system, a blade forward-bending control line control equation is as follows:
in a rectangular coordinate system of a z-r plane, the control equation of the forward-swept control line of the blade is as follows:
in the formula (I), the compound is shown in the specification,
Pxcontrolling the x-direction coordinate of the curve for the forward bending of the blade;
Pythe y-direction coordinate of the blade forward curve control curve is obtained;
Pza Z-direction coordinate of a forward-swept control curve of the blade;
Prthe direction coordinate of the forward-swept control curve r of the blade is shown;
r is the radial length of the blade;
alpha is a bending angle with the value range of 5-20 degrees;
beta is a sweep angle, and the value range is 5-15 degrees;
t1is a Bezier function independent variable in a forward control line;
t2is a Bezier function independent variable in a forward sweep control line;
kxthe control parameter of the forward curve of the blade in the x direction is a value range of 0<kx<1.5；
kyThe value range of the y-direction control parameter of the blade forward bending control curve is 0<ky<1；
kzThe value range of the Z-direction control parameter of the forward-swept control curve of the blade is-1<kz<1；
krThe forward sweep control curve r direction control parameter of the blade is a value range of 0<kr<1。
All parts in the present invention are those known in the art, unless otherwise specified.
The following embodiments of the present invention are provided, and it should be noted that the present invention is not limited to the following embodiments, and all equivalent changes based on the technical solutions of the present invention are within the protection scope of the present invention.
Example 1:
the embodiment provides an integrally formed swept combined blade, as shown in fig. 1 to 4, which comprises an integrally formed blade body 1 and a blade handle 2; the blade body 1 comprises a blade body root 101, a blade body middle part 102 and a blade body top part 103; a petiole clamping groove 3 is formed in the petiole 2, and a gravity center stacking line of the shape of the blade body 1 of the sweep-controlling combined blade 4 is a quadratic Bezier curve; wherein the content of the first and second substances,
the gravity center stacking line for controlling the shape of the blade body 1 of the sweep combined blade 4 is projected in a circumferential plane to form a blade forward-bending control line, an x-y plane rectangular coordinate system is established in the circumferential plane, and x and y are respectively a horizontal coordinate and a vertical coordinate in the x-y plane rectangular coordinate system; in an x-y plane rectangular coordinate system, taking the intersection point of the gravity center of the root of the blade body and the blade shank as a coordinate origin, taking the tangential direction of an impeller where the blade is located as a horizontal coordinate x, and taking the radial direction of the blade as a vertical coordinate y;
in an x-y plane rectangular coordinate system, a blade forward-bending control line control equation is as follows:
Pxcontrolling the x-direction coordinate of the curve for the forward bending of the blade;
Pythe y-direction coordinate of the blade forward curve control curve is obtained;
r is the radial length of the blade;
alpha is a bending angle with the value range of 5-20 degrees;
t1is a Bezier function independent variable in a forward control line;
kxthe control parameter of the forward curve of the blade in the x direction is a value range of 0<kx<1.5；
kyThe value range of the y-direction control parameter of the blade forward bending control curve is 0<ky<1；
The gravity center integral line for controlling the shape of the blade body 1 of the sweep combined blade 4 is projected in an axial plane to form a blade forward-bending control line, a z-r plane rectangular coordinate system is established in the axial plane, and z and r are respectively an abscissa and an ordinate in the z-r plane rectangular coordinate system; in a rectangular coordinate system of a z-r plane, taking the intersection point of the gravity center of the root of the blade body and the blade handle as a coordinate origin, taking the axial direction of the rotation center of the impeller in which the blade is parallel to as a horizontal coordinate z, and taking the radial direction of the blade as a vertical coordinate r;
in a rectangular coordinate system of a z-r plane, namely an axial plane, a control equation of a forward-swept control line of the blade is as follows:
in the formula (I), the compound is shown in the specification,
Pza Z-direction coordinate of a forward-swept control curve of the blade;
Prthe direction coordinate of the forward-swept control curve r of the blade is shown;
r is the radial length of the blade;
beta is a sweep angle, and the value range is 5-15 degrees;
t2is a Bezier function independent variable in a forward sweep control line;
kzthe value range of the Z-direction control parameter of the forward-swept control curve of the blade is-1<kz<1；
krThe forward sweep control curve r direction control parameter of the blade is a value range of 0<kr<1。
As a preferable mode of the present embodiment, for the sweep-down combination vane 4 having a vane length of 532mm,
the three parameters of the control equation of the forward bending control line of the blade are as follows:
α＝10°；
kx＝1.4；
ky＝0.6；
the three parameters of the control equation of the forward-swept control line of the blade are as follows:
β＝15°；
kz＝-0.6；
kr＝0.8。
as a preferable solution of this embodiment, the midship 102 of the swept-curved combined blade 4 is at 0.4 of the blade body.
As a preferable solution of this embodiment, the swept-curved composite blade 4 is specifically an integrally formed aluminum alloy swept-curved composite blade.
As a preferable solution of this embodiment, the thickness of the blade body 1 of the swept-curved combined blade 4 gradually decreases from the blade body leading edge 104 to the blade body trailing edge 105.
An impeller is characterized in that a plurality of curved and swept combined blades 4 are uniformly arranged along the circumferential direction of a hub 5 to form an impeller 6, a hub rotating shaft mounting disc 7 protruding forwards and backwards is arranged at the center of the hub 5, a hub rotating shaft mounting hole 8 is arranged at the center of the hub rotating shaft mounting disc 7, an annular web plate 9 is arranged on the end face of the hub rotating shaft mounting disc 7, and blade mounting grooves 10 are uniformly distributed on the annular web plate 9; the outer circle of the annular web plate 9 is provided with a blade mounting disc 11 protruding from the front and the back, the blade mounting disc 11 is provided with a blade mounting hole 12 which runs through the blade mounting disc 11 and corresponds to the blade mounting groove 10 towards the center of the hub 5, and the blade mounting hole 12 is provided with a pin-shaped notch 13.
As a preferable scheme of this embodiment, the swept-curved combined blade 4 is fixedly installed in the blade mounting hole 12 through a hoop 14, the hoop 14 includes a first sub-hoop 1401 and a second sub-hoop 1402, the first sub-hoop 1401 and the second sub-hoop 1402 are connected through a bolt 1403, and an end face of the first sub-hoop 1401 is provided with a pin-shaped boss 1404.
An axial flow fan comprises an air duct 15, a motor 16 and an impeller 6, wherein the air duct 15 comprises an air inlet duct 1501 and an air outlet duct 1502, the motor 16 comprises a primary motor 1601 and a secondary motor 1602, and the impeller 6 comprises a primary impeller 601 and a secondary impeller 602; the primary impeller 601 is connected with a primary motor 1601, the primary motor 1601 is installed in a primary motor barrel 17, and the primary motor barrel 17 is installed in an air inlet barrel 1501; the secondary impeller 602 is connected with a secondary motor 1602, the secondary motor 1602 is installed in the secondary motor barrel 18, and the secondary motor barrel 18 is installed in the air outlet barrel 1502; the secondary motor barrel 18 is arranged to be connected to the conical transition section motor barrel 19, the primary impeller 601 and the secondary impeller 602 are impellers as claimed in claim 7, and the primary impeller 601 and the secondary impeller 602 are oppositely arranged to rotate in opposite directions.
As a preferable mode of the present embodiment, the number of the blades of the primary impeller 601 is 10, and the number of the blades of the secondary impeller 602 is 9.
As a preferable solution of this embodiment, the hub rotating shaft mounting holes 8 at the centers of the hubs 5 of the primary impeller 601 and the secondary impeller 602 are rotatably mounted on the primary motor 1601 and the secondary motor 1602 respectively; the primary motor 1601 and the secondary motor 1602 are explosion-proof motors, and the primary motor barrel 17 and the secondary motor barrel 18 are connected with the air duct 15 through a rib plate 20.
As shown in fig. 5, finite element meshing is performed on the impeller, and in order to obtain a good calculation result, the mesh is subjected to encryption division at a key part of stress and a stress concentration part. Finite element strength analysis of the impeller as shown in figure 6, the maximum radial displacement occurred at the leading edge of the tip of the blade body, which was 0.38999 mm. The value of the top clearance is far smaller than the top clearance standard of the blade body of the ventilator, which is specified by the national coal safety regulations and is larger than 3 mm.
According to the technical scheme, as shown in fig. 9, the distance between the first-stage impeller and the second-stage impeller is 30mm, and the clearance between the swept-curved combined blades mounted on the first-stage impeller and the second-stage impeller and the air duct is 3 mm.
The flow analysis is carried out on the mining axial-flow fan, the numerical simulation of the mining axial-flow fan is carried out in a standard atmospheric state, the flowing medium is air, the atmospheric pressure PA is 101325Pa, the ambient temperature TA is 25 ℃, the gas density rho is 1.185kg/m3, the altitude A is 0m, and the rotating speed n of the simulated fan is 590 rpm.
As shown in fig. 10 and 11, in the steady-state flow numerical simulation of the ventilator, each blade channel is periodically symmetrical, so that the flow of only one periodic channel needs to be calculated. Along with the increase of back pressure, the forward rotating speed of the airflow at the outlet of the second-stage impeller is increased, obvious airflow separation phenomena do not occur in the blade straight channel and the motor cylinder of the conical transition section, but an airflow three-dimensional separation backflow area occurs in the motor cylinder of the conical transition section of the mining axial-flow fan. This is because the fan tail cone has an insufficient model length, but there is no sign of separation, stall, in the vane passages and the spar ring section passages.
CFD analysis is a technique commonly used in the art. The static pressure refers to the pressure of the air on the surface of an object parallel to the airflow, the static pressure of the ventilator is used for overcoming the resistance of an air supply pipeline, and the air supply quantity of the ventilator is determined by the size of the static pressure.
Compared with the existing mining axial-flow fan, the pneumatic noise caused by the blades is measured and tested under the condition that the silencer is not additionally arranged. Table 1 and table 2 show the sound pressure level test results of the integrally formed curved and swept combined blade axial flow fan for mine and the conventional axial flow fan for mine respectively:
TABLE 1 integrally formed axial-flow ventilator with curved and swept combined blades for mine (dB)
TABLE 2 Sound pressure level data (dB) of traditional mine axial-flow fan
The above tests can be compared, and under the condition that no silencer is additionally arranged, the noise of the traditional mining axial-flow fan with the integrally formed curved and swept combined blades is obviously reduced by about 10 decibels compared with the noise of the traditional mining axial-flow fan with the traditional blades.
Claims (10)
1. An integrally formed swept combined blade comprises an integrally formed blade body (1) and a blade handle (2); the blade body (1) comprises a blade body root part (101), a blade body middle part (102) and a blade body top part (103); the combined blade is characterized in that a gravity center stacking line for controlling the shape of the blade body (1) of the swept combined blade (4) is a quadratic Bezier curve; wherein the content of the first and second substances,
the gravity center stacking line for controlling the shape of the blade body (1) of the swept combined blade (4) is projected in a circumferential plane to form a blade forward-bending control line, an x-y plane rectangular coordinate system is established in the circumferential plane, and x and y are respectively a horizontal coordinate and a vertical coordinate in the x-y plane rectangular coordinate system; in an x-y plane rectangular coordinate system, taking the intersection point of the gravity center of the root of the blade body and the blade shank as a coordinate origin, taking the tangential direction of an impeller where the blade is located as a horizontal coordinate x, and taking the radial direction of the blade as a vertical coordinate y;
in an x-y plane rectangular coordinate system, a blade forward-bending control line control equation is as follows:
Pxcontrolling the x-direction coordinate of the curve for the forward bending of the blade;
Pythe y-direction coordinate of the blade forward curve control curve is obtained;
r is the radial length of the blade;
alpha is a bending angle with the value range of 5-20 degrees;
t1is a Bezier function independent variable in a forward control line;
kxthe control parameter of the forward curve of the blade in the x direction is a value range of 0<kx<1.5；
kyThe value range of the y-direction control parameter of the blade forward bending control curve is 0<ky<1；
The gravity center stacking line for controlling the shape of the blade body (1) of the sweep combined blade (4) is projected in an axial plane to form a blade forward-bending control line, a z-r plane rectangular coordinate system is established in the axial plane, and z and r are respectively an abscissa and an ordinate in the z-r plane rectangular coordinate system; in a rectangular coordinate system of a z-r plane, taking the intersection point of the gravity center of the root of the blade body and the blade handle as a coordinate origin, taking the axial direction of the rotation center of the impeller in which the blade is parallel to as a horizontal coordinate z, and taking the radial direction of the blade as a vertical coordinate r;
in a rectangular coordinate system of a z-r plane, namely an axial plane, a control equation of a forward-swept control line of the blade is as follows:
in the formula (I), the compound is shown in the specification,
Pza Z-direction coordinate of a forward-swept control curve of the blade;
Prthe direction coordinate of the forward-swept control curve r of the blade is shown;
r is the radial length of the blade;
beta is a sweep angle, and the value range is 5-15 degrees;
t2is a Bezier function independent variable in a forward sweep control line;
kzthe value range of the Z-direction control parameter of the forward-swept control curve of the blade is-1<kz<1；
krThe forward sweep control curve r direction control parameter of the blade is a value range of 0<kr<1。
2. The integrally formed swept composite blade according to claim 1, wherein for a swept composite blade (4) having a radial blade length of 532mm,
the three parameters of the control equation of the forward bending control line of the blade are as follows:
α＝10°；
kx＝1.4；
ky＝0.6；
the three parameters of the control equation of the forward-swept control line of the blade are as follows:
β＝15°；
kz＝-0.6；
kr＝0.8。
3. the integrally formed swept combined blade according to claim 2, characterized in that the midship (102) of the swept combined blade (4) is at 0.4 of the blade body (1).
4. The integrally formed swept composite blade according to claim 3, wherein the swept composite blade (4) is an integrally formed aluminum alloy swept composite blade.
5. The integrally formed swept combined blade according to claim 4, wherein the thickness of the blade body (1) of the swept combined blade (4) is gradually reduced from the blade body leading edge (104) to the blade body trailing edge (105).
6. An impeller, characterized in that a plurality of curved and swept combined blades (4) according to claim 5 are uniformly installed along the circumferential direction of a hub (5) to form an impeller (6), the center of the hub (5) is provided with a hub rotating shaft installation disc (7) protruding forwards and backwards, the center of the hub rotating shaft installation disc (7) is provided with a hub rotating shaft installation hole (8), the end surface of the hub rotating shaft installation disc (7) is provided with an annular web plate (9), and the annular web plate (9) is provided with uniformly distributed blade installation grooves (10); annular web (9) excircle convex blade mounting disc (11) around being provided with, blade mounting disc (11) go up to wheel hub (5) center seted up and link up blade mounting disc (11) and with corresponding blade mounting groove (10) blade mounting hole (12), be provided with round pin shape breach (13) on blade mounting hole (12).
7. The impeller as claimed in claim 6, wherein the swept and curved combined blade (4) is fixedly installed in the blade mounting hole (12) through a clamping hoop (14), the clamping hoop (14) comprises a first sub-hoop (1401) and a second sub-hoop (1402), the first sub-hoop (1401) and the second sub-hoop (1402) are connected through a bolt (1403), and a pin-shaped boss (1404) is arranged on the end face of the first sub-hoop (1401).
8. An axial-flow fan comprises an air duct (15), a motor (16) and an impeller (6), wherein the air duct (15) comprises an air inlet duct (1501) and an air outlet duct (1502), the motor (16) comprises a primary motor (1601) and a secondary motor (1602), and the impeller (6) comprises a primary impeller (601) and a secondary impeller (602); the primary impeller (601) is connected with a primary motor (1601), the primary motor (1601) is installed in a primary motor barrel (17), and the primary motor barrel (17) is installed in an air inlet barrel (1501); the secondary impeller (602) is connected with a secondary motor (1602), the secondary motor (1602) is arranged in a secondary motor barrel (18), and the secondary motor barrel (18) is arranged in the air outlet barrel (1502); characterized in that the secondary motor barrel (18) is connected to a conical transition section motor barrel (19), the primary impeller (601) and the secondary impeller (602) are impellers (6) according to claim 7, and the primary impeller (601) and the secondary impeller (602) are arranged opposite to each other and rotate in opposite directions.
9. An axial-flow fan according to claim 8, characterized in that the number of blades of said primary impeller (601) is 10 and the number of blades of said secondary impeller (602) is 9.
10. The axial-flow fan of claim 9, wherein the hub rotating shaft mounting holes (8) at the centers of the hubs (5) of the primary impeller (601) and the secondary impeller (602) are rotatably mounted on the primary motor (1601) and the secondary motor (1602) respectively; the primary motor (1601) and the secondary motor (1602) are all explosion-proof motors, and the primary motor barrel (17) and the secondary motor barrel (18) are connected with the air duct (15) through rib plates (20).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110151756.6A CN112814943A (en) | 2021-02-03 | 2021-02-03 | Integrally formed curved and swept combined blade, impeller and axial flow fan |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110151756.6A CN112814943A (en) | 2021-02-03 | 2021-02-03 | Integrally formed curved and swept combined blade, impeller and axial flow fan |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112814943A true CN112814943A (en) | 2021-05-18 |
Family
ID=75861138
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110151756.6A Pending CN112814943A (en) | 2021-02-03 | 2021-02-03 | Integrally formed curved and swept combined blade, impeller and axial flow fan |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112814943A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114046263A (en) * | 2021-12-01 | 2022-02-15 | 江苏优格曼航空科技有限公司 | Sweepback combined orthogonal axial flow fan capable of automatically removing dust |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2797709Y (en) * | 2005-06-21 | 2006-07-19 | 张志杰 | Three contra rotation impeller axial-flow local-ventilation fan |
| US20080050240A1 (en) * | 2006-08-25 | 2008-02-28 | Sanyo Electric Co., Ltd. | Axial fan and blade design method for the same |
| CN103115021A (en) * | 2013-02-01 | 2013-05-22 | 华中科技大学 | Vane wheel device |
| CN107237777A (en) * | 2017-08-01 | 2017-10-10 | 中国农业大学 | A kind of agricultural ventilation blower flexural tensile elastic modulus and its design method |
| CN108443192A (en) * | 2018-05-29 | 2018-08-24 | 株洲联诚集团控股股份有限公司 | A kind of mining explosion-proof type counter-rotating axial fan |
| US20180363661A1 (en) * | 2015-12-02 | 2018-12-20 | Mahle International Gmbh | Fan wheel for an axial fan |
| CN210484188U (en) * | 2019-07-18 | 2020-05-08 | 江阴市精亚风机有限公司 | Forward-bending forward-sweeping offset-mounted blade, impeller and axial flow fan with forward-bending forward-sweeping offset-mounted blade |
| CN216044614U (en) * | 2021-02-03 | 2022-03-15 | 西安重装韩城煤矿机械有限公司 | Integrally formed curved and swept combined blade, impeller and axial flow fan |
-
2021
- 2021-02-03 CN CN202110151756.6A patent/CN112814943A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2797709Y (en) * | 2005-06-21 | 2006-07-19 | 张志杰 | Three contra rotation impeller axial-flow local-ventilation fan |
| US20080050240A1 (en) * | 2006-08-25 | 2008-02-28 | Sanyo Electric Co., Ltd. | Axial fan and blade design method for the same |
| CN103115021A (en) * | 2013-02-01 | 2013-05-22 | 华中科技大学 | Vane wheel device |
| US20180363661A1 (en) * | 2015-12-02 | 2018-12-20 | Mahle International Gmbh | Fan wheel for an axial fan |
| CN107237777A (en) * | 2017-08-01 | 2017-10-10 | 中国农业大学 | A kind of agricultural ventilation blower flexural tensile elastic modulus and its design method |
| CN108443192A (en) * | 2018-05-29 | 2018-08-24 | 株洲联诚集团控股股份有限公司 | A kind of mining explosion-proof type counter-rotating axial fan |
| CN210484188U (en) * | 2019-07-18 | 2020-05-08 | 江阴市精亚风机有限公司 | Forward-bending forward-sweeping offset-mounted blade, impeller and axial flow fan with forward-bending forward-sweeping offset-mounted blade |
| CN216044614U (en) * | 2021-02-03 | 2022-03-15 | 西安重装韩城煤矿机械有限公司 | Integrally formed curved and swept combined blade, impeller and axial flow fan |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114046263A (en) * | 2021-12-01 | 2022-02-15 | 江苏优格曼航空科技有限公司 | Sweepback combined orthogonal axial flow fan capable of automatically removing dust |
| CN114046263B (en) * | 2021-12-01 | 2023-06-23 | 江苏优格曼航空科技有限公司 | Bending and sweeping combined orthogonal axial fan capable of automatically removing dust |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112974734B (en) | Manufacturing method of integrally formed swept combined blade | |
| CN106438470A (en) | Axial-flow fan and refrigeration equipment | |
| CN110360150B (en) | Wind wheel, centrifugal fan and air conditioner indoor unit | |
| CN113719471B (en) | Noise reduction centrifugal impeller with bionic type tail edge blades for breathing machine | |
| CN107061329A (en) | A kind of axial flow blower | |
| CN104520536A (en) | Gas turbine | |
| CN110608196B (en) | Wedge-shaped diffuser with half-blade high and small blades | |
| CN216044614U (en) | Integrally formed curved and swept combined blade, impeller and axial flow fan | |
| CN112814943A (en) | Integrally formed curved and swept combined blade, impeller and axial flow fan | |
| CN111946664B (en) | Centrifugal fan blade with slotting structure | |
| CN109505790B (en) | High-load high-through-flow-capacity axial flow fan | |
| CN117709005A (en) | Straight blade grid type pre-rotation nozzle for turbine and design method thereof | |
| CN203584898U (en) | Low-noise high-efficiency central air conditioner outdoor machine cooling axial-flow fan | |
| WO2018196198A1 (en) | Impeller tube-type nozzle for gas turbine | |
| CN114607641B (en) | Guide vane structure of axial flow fan and axial flow fan | |
| CN210949272U (en) | Small blade independently designed wedge-shaped integral diffuser | |
| WO2023050693A1 (en) | Axial-flow compressor and method for improving full-circumference flow field | |
| CN110939601A (en) | Turbocharger compressor impeller with high-performance blades | |
| CN206738198U (en) | A kind of axial flow blower | |
| CN206972610U (en) | Centrifugal fan blade, centrifugal fan and air conditioner | |
| CN110552788A (en) | Cover plate disc with radial runway inclined hole type receiving hole for pre-rotation gas supply system | |
| CN113653672B (en) | Axial flow impeller with splitter blades | |
| CN207004919U (en) | Axial flow blower 3 d impeller with leaf vein texture and splitterr vanes | |
| CN208935017U (en) | A kind of airfoil type low noise axial fan blade | |
| CN206352585U (en) | A kind of efficiently big sweepforward type diagonal flow fan |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |