GB2545767A - Improved Axial Fan - Google Patents
Improved Axial Fan Download PDFInfo
- Publication number
- GB2545767A GB2545767A GB1614080.8A GB201614080A GB2545767A GB 2545767 A GB2545767 A GB 2545767A GB 201614080 A GB201614080 A GB 201614080A GB 2545767 A GB2545767 A GB 2545767A
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- GB
- United Kingdom
- Prior art keywords
- blade
- wind
- tail
- head
- wing type
- 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.)
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Classifications
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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
- F04D19/00—Axial-flow pumps
- F04D19/02—Multi-stage pumps
- F04D19/024—Multi-stage pumps with contrarotating parts
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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
- F04D29/26—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
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2240/00—Components
- F05D2240/20—Rotors
- F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
- F05D2240/303—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor related to the leading edge of a rotor blade
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2240/00—Components
- F05D2240/20—Rotors
- F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
- F05D2240/304—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor related to the trailing edge of a rotor blade
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2240/00—Components
- F05D2240/20—Rotors
- F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
- F05D2240/305—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor related to the pressure side of a rotor blade
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2250/00—Geometry
- F05D2250/30—Arrangement of components
- F05D2250/31—Arrangement of components according to the direction of their main axis or their axis of rotation
- F05D2250/311—Arrangement of components according to the direction of their main axis or their axis of rotation the axes being in line
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
Abstract
A contra-rotating axial-flow fan comprises a wind inlet-side blade and a wind outlet-side blade, the wind inlet-side blade 4 and the wind outlet-side blade 5 are respectively driven by independent electric motors 6, 7 arranged opposite each other, the blade tail of the wind inlet-side blade and the blade head of the wind outlet-side blade are arranged opposite each other, and the blade tail of the wind inlet-side blade and the blade head of the wind outlet-side blade are straight edges parallel to a central axis. The blade shape of the present invention shortens the distance between two groups of impellers, and when an air inlet-side impeller operates, the air density in a contra-rotating area between an air outlet-side impeller and the air inlet-side impeller is substantially uniform, significantly improving the airflow interference caused by non-uniform spacings between end faces of interacting ends.
Description
IMPROVED HIGH-PRESSURE AXIAL-FLOW FAN BLADE AND CONTRAROTATING AXIAL-FLOW FAN HAVING THE SAME.
The present invention relates to a bird wing type high-pressure axial-flow fan blade and a contra-rotating axial-flow fan having the same. A known bird wing type high-pressure axial-flow fan blade having, in practical applications, the advantage of high flow capacity as well as higher full pressure, and achieving an ultra-far blowing distance, is disclosed in Chinese patent no. ZL 2010 1 05724711 (ZL’711). The technical solution therein improves the shape of the blade, significantly increases fan efficiency, reduces radial flow of a compressed airflow, and reduces losses, which has the advantage of high flow capacity as well as higher full pressure, and achieves the ultra-far blowing distance; however, the original blade shape does not achieve an ideal effect when applied to an axial-flow fan with a contra-rotating structure.
In an axial-flow fan of a contra-rotating structure, a tail part of an air inlet-side impeller and a blade head of an air outlet-side impeller are combined at unequal distances, which renders the two groups of impellers during operation less reasonable to some extent, and produces some airflow interferences, and when the wing of ZL’711 is adopted, the inventors have realised that the performance can be imporved if the protrusion in the blade acceleration area runs along an axis of the blade body from a blade top to a blade root.
To this end, an object of the present invention is to propose a technical solution of a contra-rotating axial-flow fan with bird wing type high-pressure axial-flow fan blades, which is suitable for an axial-flow fan of a contra-rotating structure, wherein two straight edges of the blade tail of the air inlet-side impeller (a blade rotating in a first, or left direction) and the blade head of the air outlet-side impeller (a blade rotating in a second, or right direction) are substantially parallel, which reduces the distance between the two groups of impellers, and when the air inlet-side impeller (rotating in the first, or left direction) operates, the air density of a contra-rotating area between the air outlet-side impeller (rotating in the second, or right direction) and the air inlet-side impeller is substantially uniform. The invention can significantly improve airflow interference caused by non-uniform spacings between end faces of interacting ends. The invention can be achieved by configuring or improving the tail part of the air inlet-side impeller and an inwardly recessed part close to a blade root of the air outlet-side impeller.
According to one aspect, the invention resides in a high-pressure axial-flow fan blade, comprising a blade body and a blade shank, said blade body being constituted by a blade head, a blade top, a blade tail and a blade root, the blade root being fixed onto the blade shank, an axis of the blade body being a vertical line, or substantially perpendicular straight line, extending from a blade shank central line, or a central portion of the shank, to the blade top, a windward side of the blade being a blade basin, a leeward side of the blade being a blade bow, and the cross section of the blade from the blade root to the blade top having a curve, or being in a twisted shape, wherein the blade basin of said blade has an arc-shaped protrusion running along the axis of the blade body from the blade top to the blade root, and either the blade tail or blade head of said blade is a straight edge parallel to said axis of the blade body. The fan blade can be a bird wing type.
The blade tail of said blade can be the straight edge parallel to said axis of the blade body. The blade head of the blade can have a bird wing-shaped smooth transitional curve with a lower part thereof being a wing type blade socket area, a middle part thereof being a blade raised area, and an upper part thereof being a wing type blade recessed area; and configured such that when the blade head of said blade is the straight edge parallel to said axis of the blade body, the blade tail of the blade is an arc-shaped curve.
The arc-shaped protrusion can be an arc-shaped protrusion formed by smoothly connecting an arc surface gradually raised from the blade tail side toward a central axis with an arc surface gradually raised from the blade head side toward the central axis.
According to another aspect, the invention resides in a contra-rotating axial-flow fan with bird wing type high-pressure axial-flow fan blades having a wind inlet-side blade and a wind outlet-side blade, the wind inlet-side blade and the wind outlet-side blade being respectively driven by independent electric motors arranged opposite each other, said wind inlet-side blade and the wind outlet-side blade being respectively provided with a blade body and a blade shank, said blade body being constituted by a blade head, a blade top, a blade tail and a blade root, the blade root being fixed onto the blade shank, a central axis of the blade body being a vertical line, or substantially perpendicular straight line, extending from a blade shank central line, or a central portion of the shank, to the blade top, a windward side of the blade being a blade basin, a leeward side of the blade being a blade bow, and the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade being arranged opposite each other, wherein the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade are straight edges respectively substantially parallel to said axis of the blade body.
The blade head of said wind inlet-side blade can have a bird wing-shaped smooth transitional curve with a lower part thereof being a wing type blade socket area, a middle part thereof being a blade raised area, and an upper part thereof being a wing type blade recessed area. The blade tail of said wind outlet-side blade is an arc-shaped edge.
The straight edge of the blade head of said wind outlet-side blade, which originally has a blade shape having the wing type blade socket area at the lower part, the blade raised area in the middle part and the wing type blade recessed area at the upper part, can be configured having a straight edge formed by extending forward the wing type blade socket area at the lower part and connecting the same to the blade raised area in the middle part and the wing type blade recessed area at the upper part after they are flattened.
The blade basins of said wind inlet-side blade and wind outlet-side blade can be respectively provided with an acceleration area with arc-shaped protrusion. The acceleration area can run along the axis of the blade body from the blade top to the blade root. Said arc-shaped protrusion can be an arc-shaped protrusion formed by smoothly connecting an arc surface gradually raised from the blade tail toward a central axis with an arc surface gradually raised from the blade head toward the central axis.
The distance between the two straight edges of the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade perpendicular to the axis can be between 10 to 30 mm.
The number of wind outlet-side blades can be at least two more than the number of wind inlet-side blades.
The ratio of the number of wind outlet-side blades to the number of wind inlet-side blades can be 6 : 7, or 9 : 11, or 11 : 13.
The power of the electric motor driving said wind outlet-side blade can be greater than the power of the electric motor driving the wind inlet-side blade.
The beneficial effects of the present invention lie in that it can be clearly seen from the structure of the improved blade shape that the two straight edges of the blade tail of the blade rotating in a first or left direction and the blade head of the blade rotating in a second or right direction keep parallel, reduces the distance between the two groups of impellers. When the air inlet-side impeller (rotating in left direction) operates, the air density in a contra-rotating area between the air outlet-side impeller (rotating in right direction) and the air inlet-side impeller is substantially uniform, significantly improves airflow interference caused by non-uniform spacings between end faces of interacting ends.
The invention facilitates a full secondary compression of the airflow, and facilitates the fast passing of the airflow, thereby further increasing the fan pressure and efficiency. A contour line (curve) of the blade body air-inlet edge of the wind inlet-side blade in the present invention is significantly longer than the central axis of the blade body, and can capture more airflow for compression.
The blade socket area of the blade body air-inlet edge of the wind inlet-side blade in the present invention can effectively further compress the compressed airflow passing through an impeller fairing, which reduces the radial flow of the compressed airflow, and reduces losses.
The blade raised area of the blade body air-inlet edge of the wind inlet-side blade of the present invention can effectively collect the radial airflow passing over the blade socket area for compression, and can prevent an airflow barrier caused by high-speed mnning of the blade, and increases the volumetric flow. A fluidic channel can be formed between an acceleration area with a protrusion, which runs along the blade axis from the blade top to the blade root, in the blade basin of the blade of the present invention and an adjacent blade, having the function of significant airflow acceleration, and since the curve of the blade basin is longer than the curve of the blade bow, when the airflow passes, an upward lift force caused by the passage of the airflow is effectively eliminated, thereby increasing the fan efficiency.
The blade recessed area of the blade body air-inlet edge of the wind inlet-side blade in the present invention can facilitate the movement of airflow towards the centre of the blade and backward compression thereof.
The contour line (curve) of the blade tail at the rear end of the blade body of the wind outlet-side blade in the present invention is significantly longer than the central axis of the blade, which not only prevents a high load on the blade caused by excessively long retention of the high-pressure airflow, but also increases the backward movement of the airflow.
The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.
Fig. 1 is a structural schematic diagram of a bird wing type high-pressure axial-flow fan blade of the present invention;
Fig. 2 is an intermediate cross-sectional schematic diagram of the bird wing type high-pressure axial-flow fan blade of the present invention;
Fig. 3 is a schematic diagram of the bird wing type high-pressure axial-flow fan blade of the present invention in a twisted state;
Fig. 4 is a schematic diagram of a high-pressure axial-flow fan blade with a blade tail thereof being a straight edge;
Fig. 5 is a schematic diagram of the high-pressure axial-flow fan blade with a blade head thereof being a straight edge;
Fig. 6 is a structural schematic diagram of a contra-rotating axial-flow fan of the present invention;
Fig. 7 is a structural schematic diagram of a wind inlet-side blade of the present invention;
Fig. 8 is a structural schematic diagram of a wind outlet-side blade of the present invention;
Fig. 9 is a structural schematic diagram of the wind inlet-side blade and the wind outlet-side blade of the present invention arranged opposite each other;
Fig. 10 is a schematic diagram of the wind inlet-side blade and the wind outlet-side blade of the present invention in the contra-rotating direction; and
Fig. 11 is a schematic diagram of the formation of a straight edge of a blade head of the wind outlet-side blade in the present invention.
Embodiment 1: A bird wing type high-pressure axial-flow fan blade, as shown in figure 1, comprises a blade body 1 and a blade shank 2, wherein said blade body is constituted by a blade head 101, a blade top 102, a blade tail 103 and a blade root 104, the blade root is fixed onto the blade shank, an axis of the blade body 105 is a vertical line extending from a blade shank central line to the blade top; as shown in figure 2, a windward side of the blade is a blade basin 106, a leeward side of the blade is a blade bow 107; as shown in figure 3, the cross section of the blade from the blade root to the blade top is in a twisted shape, wherein as shown in figure 2, the blade basin of said blade is provided with an acceleration area with arc-shaped protrusion 108 which runs along the axis of the blade body from the blade top to the blade root; the blade tail of said blade as shown in figure 4 or the blade head as shown in figure 5 is a straight edge parallel to said axis of the blade body; said straight edge is a straight edge viewed from a direction parallel to said axis of the blade body, and if viewed from a direction perpendicular to said axis of the blade body, the straight edge thereof is a line formed by the blade basin and the blade bow of the blade; and wherein the central axis deviates away from the blade tail of the blade body and is close to the blade head.
In an embodiment, when the blade tail of said blade is the straight edge parallel to said axis of the blade body, as shown in figure 4, the blade head of the blade has a bird wing-shaped smooth transitional curve with a lower part thereof being a wing type blade socket area 1011, a middle part thereof being a blade raised area 1012, and an upper part thereof being a wing type blade recessed area 1013; and when the blade head of said blade is the straight edge parallel to said axis of the blade body, as shown in figure 5, the blade tail of the blade is an arc-shaped curve 1031.
In an embodiment: said arc-shaped protrusion is an arc-shaped protrusion formed by smoothly connecting an arc surface gradually raised (in a parabolic form) from the blade tail toward a central axis with an arc surface gradually raised (in a parabolic form) from the blade head toward the central axis.
As shown in figure 2, said blade bow 107 is arc-shaped, the acceleration area with protrusion of said blade basin is formed in such a way that said blade basin corresponds to the blade tail side which has a blade chord f in the shape of an arc surface gradually raised from the blade tail toward the central axis in a parabolic form, and the other side of the blade basin corresponds to the blade head side which has an inward arc-shaped protrusion g; the highest point of the inward arc-shaped protrusion is on the side of the blade head passing over the central axis; the arc-shaped protrusion is smoothly connected to the blade chord and has a downwardly recessed arc shape toward the blade head, i.e. a connecting face gradually raised from the blade head toward the central axis in a parabolic shape, and the above-mentioned shape forms an acceleration area with protrusion which runs along the axis of the blade body from the blade top to the blade root, wherein the thickness at the highest point of the protrusion is 1.8 to 2.3 times the thickness at the starting point (the blade head side) of the protrusion.
The twisted angle of the blade in the present embodiment is designed according to non-uniform axial linear velocities of the impeller in rotational motion so as to ensure that the entire blade is exerted by a uniform force. In the embodiment, the twisted angle of the blade is appropriately increased; the purpose thereof firstly is to reduce the airflow frictional resistance between the blade top end and an air duct, and secondly to reduce blade movement and vibration caused by excessively large motion resistance at the upper end of the blade; and this design effectively improves the service life of the fan and reduces the working noise. When the fan of the present invention operates and a blade group rotates, a bowl-shaped curved surface shape is formed, a compressed airflow output by the blade group substantially moves along the axis of a cylindrical air-rectifying channel, which reduces the friction between the airflow and the wall face of the cylindrical air-rectifying channel, thereby not only reducing the noise but also increasing the wind speed.
The blade rotates with a wheel hub at high speed, the linear velocity from a blade root portion to a blade top portion is different, the air inlet angle of each cross section is also different, and in order to increase the compression efficiency and reduce losses as much as possible, the present invention adopts a twisted blade. Provided are the shape and twisted angle of four cross sections of the blade from top to bottom, i.e. the cross-section shape of the blade top portion, the cross-section shape of the wing type blade raised area, the cross-section shape of the wing type blade socket area, and the cross-section shape of the blade root portion. The cross section of the blade top portion is twisted by 18° with respect to the central line of the cross section of the blade root, the cross section of the wing type blade raised area is twisted by 12° with respect to the central line of the cross section of the blade root portion, and the cross section of the wing type blade socket area is twisted by 6° with respect to the central line of the cross section of the blade root portion.
In the present embodiment, the ratio of the height at the central point of said wing type blade raised area to the height of the blade body is 36 : 93; when the height of the blade is 133 mm, the central point of the wing type blade raised area is located at a distance of 51.48 mm from the blade root, and the central point of the wing type blade socket area is located at a distance of 11 mm from the blade root. The distance from a leading edge (an air inlet edge) of the cross section of the blade top portion to the axis of the blade body is 21.8 mm, the distance from a leading edge (an air inlet edge) of the cross section of the wing type blade raised area to the axis of the blade body is 25.1 mm, and the distance from a leading edge (an air inlet edge) of the cross section of the wing type blade socket area to the axis of the blade body is 14.2 mm. Since an inwardly protruded acceleration area is arranged on a blade basin face of the blade body, the width of the cross section of a fluid-dynamical flow channel corresponding to the inwardly protruded acceleration area is reduced by 2.7 mm in comparison with the width of the cross section of a fluid-dynamical flow channel of the air inlet edge.
Embodiment 2: A contra-rotating axial-flow fan with bird wing type high-pressure axial-flow fan blades of the present embodiment uses the bird wing type high-pressure axial-flow fan blade as stated in embodiment 1, and the contents of the fan blade to which the present embodiment relates shall contain the contents of embodiment 1. As shown in figure 6, a fan housing 3 is comprised, the inner side of the fan housing is cylindrical, one end of the cylinder is used for wind inlet and is provided with a wind inlet-side blade 4, the other end of the cylinder is used for wind outlet and is provided with a wind outlet-side blade 5, the wind inlet-side blade and the wind outlet-side blade are respectively driven by independent electric motors 6 and 7 arranged opposite each other; as shown in figures 7 and 8, said wind inlet-side blade and wind outlet-side blade are respectively provided with a blade body 401, 501 and a blade shank 402, 502, said blade bodies are respectively formed in such a way that the wind inlet-side blade is constituted by a blade head 4011, a blade top 4012, a blade tail 4013 and a blade root 4014 of the wind inlet-side blade, and the wind outlet-side blade is constituted by a blade head 5011, a blade top 5012, a blade tail 5013 and a blade root 5014 of the wind outlet-side blade; the blade roots 4014, 5014 are fixed onto the blade shanks 402, 502; central axes 4015, 5015 of the blade bodies are vertical lines extending from blade shank central lines to the blade tops, and the blade shank central line is necessarily perpendicular to the axis of the electric motor; as shown in figures 9 and 10, the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade are arranged opposite each other; a windward side of the blade is a blade basin, a leeward side of the blade is a blade bow, and the cross section of the blade from the blade root to the blade top is in a twisted shape; wherein the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade are straight edges respectively parallel to said axis of the blade body, said straight edge is a straight edge viewed from a direction perpendicular to a motor shaft, and if viewed from the longitudinal direction of the motor shaft, the straight edge thereof is a line formed by the blade basin and the blade bow of the blade; and wherein the central axis deviates away from the blade tail of the blade body and is close to the blade head.
It can be clearly seen from figures 6, 9 and 10 that the two straight edges of the blade tail of the wind inlet-side blade (a blade rotating in left direction) and the blade head of the wind outlet-side blade (a blade rotating in left direction) are substantially parallel, which can reduce the distance between the two groups of impellers as much as possible, and when the air inlet-side impeller (rotating in left direction) operates, the air density in a contra-rotating area between the air outlet-side impeller (rotating in right direction) and the air inlet-side impeller is substantially uniform, which significantly improves airflow interference caused by non-uniform spacings between end faces of interacting ends.
In the embodiment: as shown in figure 7, the blade head of said wind inlet-side blade has a bird wing-shaped smooth transitional curve with a lower part thereof being a wing type blade socket area a, a middle part thereof being a blade raised area b, and an upper part thereof being a wing type blade recessed area c; and as shown in figure 8, the blade tail of said wind outlet-side blade is an arc-shaped edge d; and an acceleration area of said wind inlet-side blade and wind outlet-side blade protrudes in an arc shape and is as stated in embodiment 1: as shown in figure 2, said blade bow 107 is arc-shaped, the acceleration area with protrusion of said blade basin is formed in such a way that said blade basin corresponds to the blade tail side which has a blade chord f in the shape of an arc surface gradually raised from the blade tail toward the central axis in a parabolic form, the other side of the blade basin corresponds to the blade head side which has an inward arc-shaped protrusion g; the highest point of the inward arc-shaped protrusion is on the side of the blade head passing over the central axis; the arc-shaped protrusion is smoothly connected to the blade chord and has a downwardly recessed arc shape toward the blade head, i.e. a connecting face gradually raised from the blade head side toward the central axis in a parabolic shape; and the above-mentioned shape forms a acceleration area with protrusion which runs along the axis of the blade body from the blade top to the blade root, wherein the thickness at the highest point of the protrusion is 1.8 to 2.3 times the thickness at the starting point (the blade head side) of the protrusion.
In the embodiment: as shown in figure 11, the straight edge 5011 of the blade head of said wind outlet-side blade, which originally has a blade shape having the wing type blade socket area at the lower part, the blade raised area in the middle part and the wing type blade recessed area at the upper part, is a straight edge formed by extending forward the wing type blade socket area a at the lower part and connecting the same to the blade raised area in the middle part and the wing type blade recessed area at the upper part after they are flattened, and the rest remains the same as the basic structure of the original bird wing type blade.
In the embodiment: the distance between the two straight edges of the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade perpendicular to the axis is 10 to 30 mm.
In the embodiment: the number of wind outlet-side blades is at least two more than the number of wind inlet-side blades. When the number is two, the ratio of the number of wind outlet-side blades to the number of wind inlet-side blades is 6 : 7, or 9 : 11, or 11 : 13.
Both the blade rotating in left direction and the blade rotating in right direction in the embodiment can be independently applied to an axial-flow fan, and by means of the design thereof matching front and rear fixed guide blades, the blade can be adapted to various special needs, and the efficiency thereof in independent use is still superior over the traditional wing type blade.
When contra-rotating is used in the present embodiment, the number of blades of the air outlet-side impeller (rotating in right direction ) is greater than the number of blades of the air inlet-side impeller, such as 6 : 7, 9 : 11 or 11 : 13, the principle thereof is the same as the cooperation of a movable vane and a fixed vane; it can be construed that the air outlet-side impeller is a “fixed vane” rotating in the opposite direction of the air inlet-side impeller, and the theory of this relative motion is also true for the air inlet-side impeller. Since the air outlet-side impeller mainly plays the role of pressurization while increasing the flow rate, and since the number of blades of the air outlet-side impeller is greater than the number of blades of the air inlet-side impeller, the wind shear rate thereof is significantly higher than the air inlet-side impeller, thus the load of the air outlet-side impeller is higher than the air inlet-side impeller, and under normal conditions, a wind shear angle of the blade of the air outlet-side impeller is smaller than that of the air inlet-side impeller; or in the case that the wind shear angles of the blades are the same, the electric motor power of the air outlet-side impeller is increased. In the embodiment: the power of the electric motor driving said wind outlet-side blade is greater than the power of the electric motor driving the wind inlet-side blade.
The twisted angle of the blade in the present embodiment is designed according to non-uniform axial linear velocities of the impeller in rotational motion so as to ensure that the entire blade is exerted by an uniform force. In the embodiment, the twisted angle of the blade is appropriately increased; the purpose thereof firstly is to reduce the airflow frictional resistance between the blade top end and an air duct, and secondly to reduce blade movement and vibration caused by excessively large motion resistance at the upper end of the blade; and this design effectively improves the service life of the fan and reduces the working noise.
The blade shapes of the left and right contra-rotating blades in the embodiment are separated improvements for the bird wing type blade, which retain the basic characteristics and profile of the bird wing type blade, while only the wind inlet and outlet-side blade edges are different, and since the rotational directions of the impellers are different, the bending directions of the blade bows are on the contrary.
In the embodiment, the axial-flow fan has cone-shaped fairings 601 and 701, and the cylindrical faired air channel at the inner side of the fan housing is a cylindrical thin-shell structure. In practical applications, the blade of the present invention is mounted on a wheel hub, a cone-shaped fairing 601 is mounted at the front end of a wind inlet wheel hub so as to reduce the air inlet losses; the inlet airflow flows along the fairing towards the blades, having a relatively large radial flow component; and the blade socket area of the blade body air-inlet edge of the present invention can effectively further compress the airflow passing through the impeller fairing, which reduces the radial flow of the compressed airflow, and reduces the losses.
In the present embodiment, the blade raised area of said blade body air-inlet edge adopts a configuration imitating a bird wing, and the blade raised area can prevent an airflow barrier caused by the high-speed running of the blades, thereby increasing the air flow rate. The radial airflow passing through the blade socket area can be effectively collected for compression. The air-inlet edge of a conventional axial-flow fan blade is a straight edge, and when the rotational speed reaches a certain critical value, the gas flow of the fan will be significantly reduced, which is usually considered as due to the generation of an airflow barrier.
In the present embodiment, the blade recessed area at the upper part of the blade body air-inlet edge adopts a configuration imitating a bird wing, and the blade recessed area facilitates the airflow moving towards the centre and compressing backwards, and increases the air flow rate.
When the fan of the present invention operates and the air inlet-side blade group rotates, a bowl-shaped curved surface shape is formed, a compressed airflow output by the blade group substantially moves along the axis of a cylindrical rectifying air channel, which reduces the friction between the airflow and the wall face of the cylindrical rectifying air channel, thereby not only reducing the noise but also increasing the wind speed.
The blade rotates with a wheel hub at high speed, the linear velocity from a blade root portion to a blade top portion is different, the air inlet angle of each cross section is also different, and in order to increase the compression efficiency and reduce losses as much as possible, the present invention adopts a twisted blade. Provided are the shape and twisted angle of four cross sections of the blade from top to bottom, i.e. the cross-section shape of the blade top portion, the cross-section shape of the wing type blade raised area, the cross-section shape of the wing type blade socket area, and the cross-section shape of the blade root portion. The cross section of the blade top portion is twisted by 18° with respect to the central line of the cross section of the blade root, the cross section of the wing type blade raised area is twisted by 12° with respect to the central line of the cross section of the blade root portion, and the cross section of the wing type blade socket area is twisted by 6° with respect to the central line of the cross section of the blade root portion.
In the present embodiment, the ratio of the height at the central point of said wing type blade raised area to the height of the blade body is 36 : 93; when the height of the blade is 133 mm, the central point of the wing type blade raised area is located at a distance of 51.48 mm from the blade root, and the central point of the wing type blade socket area is located at a distance of 11 mm from the blade root. The distance from a leading edge (an air inlet edge) of the cross section of the blade top portion to the axis of the blade body is 21.8 mm, the distance from a leading edge (an air inlet edge) of the cross section of the wing type blade raised area to the axis of the blade body is 25.1 mm, and the distance from a leading edge (an air inlet edge) of the cross section of the wing type blade socket area to the axis of the blade body is 14.2 mm. Since an inwardly protruded acceleration area is arranged on a blade basin face of the blade body, the width of the cross section of a fluid-dynamical flow channel corresponding to the inwardly protruded acceleration area is reduced by 2.7 mm in comparison with the width of the cross section of a fluid-dynamical flow channel of the air inlet edge.
Claims (11)
1. A contra-rotating axial-flow fan with bird wing type high-pressure axial-flow fan blades, comprising a wind inlet-side blade and a wind outlet-side blade, the wind inlet-side blade and the wind outlet-side blade being respectively driven by independent electric motors arranged opposite each other, said wind inlet-side blade and wind outlet-side blade being respectively provided with a blade body and a blade shank, said blade body being constituted by a blade head, a blade top, a blade tail and a blade root, the blade root being fixed onto the blade shank, an axis of the blade body being a vertical line extending from a blade shank central line to the blade top, a windward side of the blade being a blade basin, a leeward side of the blade being a blade bow, and the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade being arranged opposite each other, characterized in that the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade are straight edges respectively parallel to said axis of the blade body.
2. A contra-rotating axial-flow fan according to Claim 1, wherein the blade head of said wind inlet-side blade has a bird wing-shaped smooth transitional curve with a lower part thereof being a wing type blade socket area, a middle part thereof being a blade raised area, and an upper part thereof being a wing type blade recessed area; and the blade tail of said wind outlet-side blade is an arc-shaped edge.
3. A contra-rotating axial-flow fan according to Claim 1, wherein the straight edge of the blade head of said wind outlet-side blade, which originally has a blade shape having the wing type blade socket area at the lower part, the blade raised area in the middle part and the wing type blade recessed area at the upper part, is a straight edge formed by extending forward the wing type blade socket area at the lower part and connecting the same to the blade raised area in the middle part and the wing type blade recessed area at the upper part after they are flattened.
4. A contra-rotating axial-flow fan according to any of Claims 1, 2 and 3, wherein the blade basins of said wind inlet-side blade and wind outlet-side blade are respectively provided with an acceleration area with arc-shaped protrusion which runs along the axis of the blade body from the blade top to the blade root, and said arc-shaped protrusion is an arc-shaped protrusion formed by smoothly connecting an arc surface gradually raised from the blade tail toward a central axis with an arc surface gradually raised from the blade head toward the central axis.
5. A contra-rotating axial-flow fan according to Claim 1, wherein the distance between the two straight edges of the blade tail of said wind inlet-side blade and the blade head of said wind outlet-side blade perpendicular to the axis is 10 to 30 mm.
6. A contra-rotating axial-flow fan according to Claim 1, 4 or 5, wherein the number of wind outlet-side blades is at least two more than the number of wind inlet-side blades.
7. A contra-rotating axial-flow fan according to Claim 6, wherein the ratio of the number of wind outlet-side blades to the number of wind inlet-side blades is 6 : 7, or 9 : 11, or 11 : 13.
8. Bird wing type high-pressure axial-flow fan blade, comprising a blade body and a blade shank, said blade body being constituted by a blade head, a blade top, a blade tail and a blade root, the blade root being fixed onto the blade shank, an axis of the blade body being a vertical line extending from a blade shank central line to the blade top, a windward side of the blade being a blade basin, a leeward side of the blade being a blade bow, and the cross section of the blade from the blade root to the blade top being in a twisted shape, wherein the blade basin of said blade has an arc-shaped protrusion running along the axis of the blade body from the blade top to the blade root, and either the blade tail or blade head of said blade is a straight edge parallel to said axis of the blade body.
9. A blade according to Claim 1, wherein when the blade tail of said blade is the straight edge parallel to said axis of the blade body, the blade head of the blade has a bird wing-shaped smooth transitional curve with a lower part thereof being a wing type blade socket area, a middle part thereof being a blade raised area, and an upper part thereof being a wing type blade recessed area; and when the blade head of said blade is the straight edge parallel to said axis of the blade body, the blade tail of the blade is an arcshaped curve.
10. A blade according to Claim 8 or 9, wherein said arc-shaped protrusion is an arc-shaped protrusion formed by smoothly connecting an arc surface gradually raised from the blade tail side toward a central axis with an arc surface gradually raised from the blade head side toward the central axis.
11. A bird wing type high-pressure axial-flow fan blade, or contra-rotating axial-flow fan with bird wing type high-pressure axial-flow fan blades as hereinbefore described and shown in the Figures.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510623901.0A CN105257596B (en) | 2015-09-28 | 2015-09-28 | Wing shaped blade of high-pressure axial fan and Counter rotating axial flow Fan thereof |
| GB1517638.1A GB2543062B (en) | 2015-09-28 | 2015-10-06 | Improved high-pressure axial-flow fan blade and contra-rotating axial-flow fan having the same |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201614080D0 GB201614080D0 (en) | 2016-09-28 |
| GB2545767A true GB2545767A (en) | 2017-06-28 |
| GB2545767B GB2545767B (en) | 2018-01-10 |
Family
ID=55097462
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1614080.8A Expired - Fee Related GB2545767B (en) | 2015-09-28 | 2015-10-06 | Contra-rotating axial-flow fan |
| GB1517638.1A Expired - Fee Related GB2543062B (en) | 2015-09-28 | 2015-10-06 | Improved high-pressure axial-flow fan blade and contra-rotating axial-flow fan having the same |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1517638.1A Expired - Fee Related GB2543062B (en) | 2015-09-28 | 2015-10-06 | Improved high-pressure axial-flow fan blade and contra-rotating axial-flow fan having the same |
Country Status (4)
| Country | Link |
|---|---|
| CN (1) | CN105257596B (en) |
| GB (2) | GB2545767B (en) |
| TW (1) | TWI638101B (en) |
| WO (1) | WO2017054387A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105257596B (en) * | 2015-09-28 | 2016-06-15 | 北京图正实验室科技有限公司 | Wing shaped blade of high-pressure axial fan and Counter rotating axial flow Fan thereof |
| CN107701508A (en) * | 2017-10-31 | 2018-02-16 | 广东飞鹿电器有限公司 | A kind of flabellum of industrial electric fan |
| JP7155807B2 (en) | 2018-09-25 | 2022-10-19 | 日本電産株式会社 | blower |
| CN114526253B (en) * | 2022-04-24 | 2022-07-05 | 佛山市南海九洲普惠风机有限公司 | Small boiler draught fan |
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| FR1368753A (en) * | 1963-02-06 | 1964-08-07 | Process for making wings and propellers, in particular for air and sea vehicles, as well as wings, propellers and profiled surfaces obtained by implementing this process or a similar process | |
| JPH0821398A (en) * | 1994-07-08 | 1996-01-23 | Ishikawajima Harima Heavy Ind Co Ltd | Rotor blade of compressor |
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-
2015
- 2015-09-28 CN CN201510623901.0A patent/CN105257596B/en not_active Expired - Fee Related
- 2015-10-06 GB GB1614080.8A patent/GB2545767B/en not_active Expired - Fee Related
- 2015-10-06 GB GB1517638.1A patent/GB2543062B/en not_active Expired - Fee Related
-
2016
- 2016-02-04 WO PCT/CN2016/073410 patent/WO2017054387A1/en active Application Filing
- 2016-08-04 TW TW105124817A patent/TWI638101B/en not_active IP Right Cessation
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| DE2443754A1 (en) * | 1974-09-13 | 1976-03-25 | Korfmann Gmbh Maschf | Axial flow fan with pneumatic drive - by standard air motor co-axially secured in fan casing |
| CA1199170A (en) * | 1982-12-08 | 1986-01-14 | Sheldon Affleck | Grain aeration fan |
| JPH0363440A (en) * | 1989-08-02 | 1991-03-19 | Mitsubishi Electric Corp | Counter rotating fan type ventilator |
| CN201013646Y (en) * | 2006-11-13 | 2008-01-30 | 湖北赛福机械有限公司 | Impeller shaft coupling device of disrotatory axial-flow ventilating fan |
| CN102367805A (en) * | 2011-09-14 | 2012-03-07 | 大连汇通科技发展有限公司 | Counter-rotating fan |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI638101B (en) | 2018-10-11 |
| WO2017054387A1 (en) | 2017-04-06 |
| GB2543062B (en) | 2017-10-04 |
| GB2543062A (en) | 2017-04-12 |
| TW201712233A (en) | 2017-04-01 |
| CN105257596A (en) | 2016-01-20 |
| GB201517638D0 (en) | 2015-11-18 |
| CN105257596B (en) | 2016-06-15 |
| GB2545767B (en) | 2018-01-10 |
| GB201614080D0 (en) | 2016-09-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20191006 |