Axial flow fan and air conditioner

Abstract

The invention discloses an axial flow fan and an air conditioner, and belongs to the technical field of fans. The axial fan includes: a hub; the blades are connected with the hub, the blades comprise first blades and second blades which are arranged in series, the front edges of the first blades form the front edges of the blades, and the rear edges of the second blades form the rear edges of the blades; in the blade-shaped cross sections of the blades, in the direction perpendicular to the axis of the hub, the distance between the rear edge end of the first blade and the front edge end of the second blade is theta 1; assuming that the transverse axis of the theta1 linear graph is the radius of a circle with the axis of the hub as the center and the longitudinal axis is theta1, and representing the relationship between the size of theta1 and the radius as a theta1 linear line; the [theta] 1 linear line has a gradually increasing shape as the radius increases. The air conditioner comprises the axial flow fan. The fan performance is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fan, in particular to an axial fan and air conditioner. BACKGROUND

[0002] The axial fan generally has a cylindrical hub and a plurality of blades distributed on the outer periphery of the hub. When the hub is driven to rotate, the blades rotate with the hub to push the airflow to flow.

[0003] At present, the performance improvement of the axial fan mainly relies on the optimization of the twisted shape of the fan blade. The optimization requires a long time and a large amount of calculation, and even reaches the limit of performance improvement. SUMMARY

[0004] The present application provides an axial fan and air conditioner, which improves the fan performance.

[0005] In one aspect of the present application, an axial fan includes: a hub configured to be driven to rotate around a central axis; a plurality of blades connected to the hub, the blades including first blades and second blades in series, a leading edge of the first blade forming a leading edge of the blade, and a trailing edge of the second blade forming a trailing edge of the blade.

[0006] In the blade profile section, in a direction perpendicular to the hub axis, the distance from the trailing edge end of the first blade to the leading edge end of the second blade is θ1.

[0007] Assuming that the horizontal axis of the θ1 linear graph is the radius of the circle with the hub axis as the center, and the vertical axis is the size of θ1, the relationship between the size of θ1 and the radius is expressed as a θ1 linear line. The θ1 linear line gradually increases with the increase of the radius.

[0008] In some embodiments, the outer diameter of the axial fan is 260mm-410mm, the minimum value of θ1 is not less than 2mm, and the maximum value of θ1 is not greater than 12mm.

[0009] In some embodiments, in the blade profile section, in a direction parallel to the hub axis, the distance from the trailing edge end of the first blade to the leading edge end of the second blade is θ2; in any blade profile section, the value of θ2 is the same.

[0010] In some embodiments, the outer diameter of the axial fan is 260mm-410mm, and θ2=8-10mm.

[0011] In some embodiments, in a plane perpendicular to the axis of the hub, a circle with the hub axis as the center and passing through the blade, the arc length from the leading edge of the first blade to the trailing edge of the second blade is L1, the arc length of the first blade is L2, and L2 / L1=n, n=0.4-0.6.

[0012] In some embodiments, assuming that the horizontal axis of the n-linear diagram is the radius size of a circle with the hub's axis as the center and the vertical axis is the size of n, the relationship between the size of n and the radius is expressed as an n-linear line; the n-linear line has a first part and a second part, wherein the first part is at the smaller end of the radius and the horizontal axis interval of the second part is greater than that of the first part; as the radius increases, the second part of the n-linear line presents a gradually increasing shape.

[0013] In some embodiments, in the airfoil section of the blade, the angle between the imaginary line perpendicular to the axis of the hub and intersecting a point on the airfoil section and the imaginary line representing the tangent of the point is defined as the β angle; the β angle of the trailing edge end of the first blade is the same size as the β angle of the leading edge end of the second blade.

[0014] In some embodiments, in the airfoil section of the blade, the angle between the imaginary line perpendicular to the axis of the hub and intersecting a point on the airfoil section and the imaginary line representing the tangent of the point is defined as the β angle; in the plane perpendicular to the axis of the hub, the total arc length of the circular arc passing through the hub's axis as the center is L1, and the ratio of the arc length of any point on the circular arc to L1 is defined as z; the horizontal axis of the outer edge β angle linear diagram of the blade is z, and the vertical axis is the size of the β angle of the outer edge of the blade; the relationship between the size of the outer edge β angle and z is expressed as an outer edge β angle linear line; the outer edge β angle linear line includes a first line and a second line, and the first line is closer to the vertical axis than the second line; according to the trend of the first line, the highest point of the first line is connected to the second line by a dashed line DL, and the part of the second line close to the first line is below the dashed line DL.

[0015] In some embodiments, with the axis direction of the hub as the reference, the leading edge is located in front of the trailing edge, and the trailing edge end of the first blade is located behind the leading edge end of the second blade.

[0016] Another aspect of the present application is an air conditioner, comprising: a housing; a refrigerant circuit having a condenser and an evaporator; an axial fan as above provided in the housing for blowing air to at least one of the condenser and the evaporator. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A perspective view of an air conditioner according to some embodiments is shown from a front view angle;

[0018] Figure 2 A perspective view of an air conditioner according to some embodiments is shown from a rear view angle;

[0019] Figure 3 A perspective view of an air conditioner according to some embodiments is shown from a rear view angle; Figure 1

[0020] Figure 4 ​Internal configuration of an air conditioner is shown according to some embodiments Figure 2 ;

[0021] Figure 5 Front view of an axial fan is shown according to some embodiments

[0022] Figure 6 Side view of an axial fan is shown according to some embodiments

[0023] Figure 7 Blade profile cross-section of an axial fan is shown according to some embodiments

[0024] Figure 8 Linear plot of radius versus spacing of tandem blades of an axial fan is shown according to some embodiments

[0025] Figure 9 Front view of a blade of an axial fan is shown according to some embodiments

[0026] Figure 10 Linear plot of n of an axial fan is shown according to some embodiments

[0027] Figure 11 Blade profile cross-section of an axial fan is shown according to some embodiments

[0028] Figure 12 Linear plot of outer rim beta angle of an axial fan is shown according to some embodiments

[0029] Figure 13 Static pressure contour plots of prior art and an axial fan according to some embodiments are shown

[0030] Figure 14 Whole machine wind field contour plots of prior art and an air conditioner according to some embodiments are shown

[0031] Figure 15 Perspective view of an axial fan is shown according to further embodiments

[0032] Figure 16 Front view of an axial fan is shown according to further embodiments

[0033] Figure 17 Static pressure contour plots of prior art and an axial fan according to further embodiments are shown

[0034] Figure 18 Whole machine wind field contour plots of prior art and an air conditioner according to further embodiments are shown

[0035] Figure 19 Exploded view of an axial fan is shown according to further embodiments

[0036] In the above figures, 10 is a housing; 11 is a front plate; 12 is a rear plate; 13 is a top plate; 14 is a bottom plate; 15 is a left side plate; 16 is a right side plate; 17 is a lattice plate; 20 is a motor; 21 is a motor support; 30 is a heat exchanger;

[0037] 100 is an axial flow fan; 110 is a hub; 111 is a first hub portion; 112 is a second hub portion; 113 is a first positioning portion; 114 is a second positioning portion; 115 is a hook groove; 116 is a hook portion; 117 is a first mounting portion; 118 is a second mounting portion; 120 is a blade; 121 is a first blade; 122 is a second blade; 123 is a leading edge; 124 is a trailing edge; 125 is an outer edge; 126 is an inner edge; 127 is a pressure surface; 128 is a suction surface; 130 is a splitter blade. DETAILED DESCRIPTION

[0038] In order to make the purpose and implementation of the present application more clear, the following will combine the drawings in the exemplary embodiments of the present application to clearly and completely describe the exemplary embodiments of the present application. Obviously, the described exemplary embodiments are only a part of the embodiments of the present application, but not all the embodiments.

[0039] In the description of the present application, it needs to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] The terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0041] In the description of the present application, it needs to be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] [Air conditioner]

[0043] The air conditioner in this application performs a refrigeration cycle of the air conditioner by using a compressor, a condenser, an expansion valve, and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation, and supplies refrigerant to the air that has been adjusted and heat-exchanged.

[0044] The compressor compresses refrigerant gas in a low-temperature and low-pressure state and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0045] The expansion valve expands the liquid-phase refrigerant in a high-temperature and high-pressure state condensed in the condenser into a low-pressure liquid-phase refrigerant. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a refrigeration effect by heat-exchanging with a material to be cooled using latent heat of evaporation of the refrigerant. Throughout the cycle, the air conditioner can adjust the temperature of the indoor space.

[0046] The outdoor unit of the air conditioner refers to the part of the refrigeration cycle including the compressor and the outdoor heat exchanger, the indoor unit of the air conditioner includes the indoor heat exchanger, and the expansion valve can be provided in the indoor unit or the outdoor unit.

[0047] The indoor heat exchanger and the outdoor heat exchanger serve as a condenser or an evaporator. When the indoor heat exchanger serves as a condenser, the air conditioner serves as a heater in a heating mode, and when the indoor heat exchanger serves as an evaporator, the air conditioner serves as a cooler in a cooling mode.

[0048] [Outdoor unit]

[0049] Referring to Figures 1 to 4 , the outdoor unit includes a housing 10 constituting the overall appearance of the outdoor unit. The housing 10 can be in the shape of a rectangular box.

[0050] The housing 10 includes a front plate 11 constituting the front surface of the housing 10, a rear plate 12 constituting the back surface of the housing 10, a top plate 13 constituting the upper surface of the housing 10, a bottom plate 14 constituting the lower surface of the housing 10, and a pair of side plates 15 and 16 constituting the pair of side surfaces of the housing 10.

[0051] An air inlet is formed on the left side plate 15 and the rear plate 12 of the housing 10 to suck in air from the outside. An opening is provided on the front plate 11 of the housing 10, and a grating plate 17 can be installed at the opening. Holes formed on the grating plate 17 form an air outlet to blow out air from the inside of the housing 10 to the outside. The grating plate 17 can prevent external objects from contacting the axial flow fan 100 inside the housing 10.

[0052] The outdoor unit includes a motor 20 for rotating the axial fan 100. The motor 20 is mounted on a motor bracket 21. The motor bracket 21 is disposed between the motor 20 and the heat exchanger 30.

[0053] The outdoor unit includes the axial fan 100 which rotates about a rotational axis RA, thereby causing air to enter the casing 10 from an air inlet of the casing 10 and to be blown out of the casing 10 from an air outlet.

[0054] The outdoor unit includes the heat exchanger 30 which is connected in the casing 10 corresponding to the air inlet. The heat exchanger 30 is located at a suction side of the axial fan 100 and has a plurality of fins which are arranged in parallel in a stacking direction, and heat transfer tubes which pass through the respective fins in the stacking direction. The heat transfer tubes are connected in a refrigerant circuit so that refrigerant circulates in the heat transfer tubes. The heat exchanger 30 functions as an evaporator when the air conditioner is operated in a heating mode, and functions as a condenser when the air conditioner is operated in a cooling mode.

[0055] [axial fan 100]

[0056] The axial fan 100 of the present application can be used in an outdoor unit of an air conditioner. The axial fan 100 rotates to form an air flow at the outdoor unit.

[0057] With reference to Figure 5 and Figure 6 , the axial fan 100 includes a hub 110 for connection with a rotational axis of the motor 20. The hub 110 can be cylindrical.

[0058] The axial fan 100 includes a plurality of blades 120 which are connected to a circumferential surface of the hub 110. The blades 120 extend radially outward from the circumferential surface of the hub 110, and the plurality of blades 120 are arranged in a radial pattern with respect to the hub 110.

[0059] The plurality of blades 120 are arranged in a circumferentially spaced apart manner. Exemplarily, three blades 120 are shown in the drawings, but the number of blades 120 is not limited to three.

[0060] The blade 120 has a leading edge 123, a trailing edge 124, an outer edge 125, and an inner edge 126.

[0061] In any blade 120, with reference to a rotational direction RD, the leading edge 123 is an edge of a front side of the blade 120, and the trailing edge 124 is an edge of a rear side of the blade 120. The leading edge 123 is located forward of the trailing edge 124 in the rotational direction RD, and the trailing edge 124 is located rearward of the leading edge 124 in the rotational direction RD. The leading edge 123 is located on an upstream side with respect to the trailing edge 124 in a direction in which the air flow is generated, and the trailing edge 124 is located on a downstream side with respect to the leading edge 123 in the direction in which the air flow is generated.

[0062] The outer edge 125 is an edge of the outer circumferential side of the blade 120. The outer edge 125 connects the outermost end of the leading edge 123 and the outermost end of the trailing edge 124.

[0063] The inner edge 126 is an edge of the blade 120 connected to the hub 110. The inner edge 126 connects the innermost end of the leading edge 123 and the innermost end of the trailing edge 124. The inner edge 126 of the blade 120 can be integrally formed with the hub 110.

[0064] In the circumferential direction, the length of the outer edge 125 is greater than the length of the inner edge 126.

[0065] The blade 120 is formed obliquely with respect to a plane perpendicular to the axis of the hub 110. The blade 120 pushes the air present between the blades 120 with the blade face, accompanying the rotation of the axial flow fan 100, thereby delivering the air.

[0066] The face in which the air is pushed and the pressure rises in the blade face is referred to as the pressure face 127, and the face opposite to the pressure face 127 is referred to as the suction face 128. In the blade 120, with the flow direction of the air as a reference, the face on the upstream side of the blade 120 becomes the suction face 128, and the face on the downstream side of the blade 120 becomes the pressure face 127.

[0067] [Series of blades]

[0068] The blade 120 includes at least two blades arranged in series, the two series of blades being a first blade 121 and a second blade 122, respectively. The first blade 121 and the second blade 122 have a gap in the rotation direction RD. The first blade 121 and the second blade 122 have a gap in the direction along the axis of the hub 110.

[0069] The leading edge 123 of the blade 120 is the leading edge 123 of the first blade 121, and the trailing edge 124 of the blade 120 is the trailing edge 122 of the second blade 122.

[0070] In any blade 120, the first blade 121 is located on the front side with respect to the second blade 122 in the rotation direction, and the second blade 122 is located on the rear side with respect to the first blade 121 in the rotation direction.

[0071] In the embodiments provided in the present application, the blade is divided into two: the first blade 121 and the second blade 122, the first blade 121 and the second blade 122 are arranged in series, the air passes through the suction face 128 of the first blade 121 to generate a certain thickness of boundary layer, and the boundary layer is redistributed when passing through the second blade 122, which is conducive to reducing the aerodynamic loss of the axial flow fan 100.

[0072] A plane of the cylindrical surface of the hub 110 that is coaxial with the axis of the hub 110 and that intersects the blade 120 is referred to as a blade profile section.

[0073] In some embodiments, with reference to Figure 7 In any blade profile section of the blade 120, in a direction perpendicular to the axis of the hub 110, the distance from the trailing edge end of the first blade 121 to the leading edge end of the second blade 122 is denoted as θ1.

[0074] With reference to Figure 8 Assuming that the horizontal axis of the θ1 linear graph is the radius of a circle with the axis of the hub 110 as the center and the vertical axis is the size of θ1, the relationship between the size of θ1 and the radius is represented as a θ1 linear line. The θ1 linear line presents a gradually increasing shape as the radius increases. That is, in a direction from the inner edge 126 side to the outer edge 125 side, the distance θ1 of the first blade 121 and the second blade 122 gradually increases.

[0075] Since the part of the blade close to the inner edge 126 does less work, the corresponding θ1 can be set to be relatively small.

[0076] Since the working area of the blade is roughly concentrated in the area close to the trailing edge and close to the outer edge of the second blade 122, the θ1 of the first blade 121 and the second blade 122 close to the outer edge 125 is large, which is conducive to the redistribution of the boundary layer of the air flow close to the outer edge 125, thereby reducing the aerodynamic loss of the fan.

[0077] According to the embodiments of the present application, for an axial flow fan with an outer diameter of 260mm-410mm, the value of θ1 at the inner edge 126 end is not less than 2mm, and the value of θ1 at the outer edge 125 end is not greater than 12mm. It can be avoided that θ1 is too small or too large to affect the redistribution of the boundary layer on the second blade 122.

[0078] Exemplarily, in the direction of increasing radius, the value of θ1 can gradually increase from 2mm to 12mm.

[0079] In some embodiments, with reference to Figure 7 and Figure 8 In any blade profile section of the blade 120, in a direction parallel to the axis of the hub 110, the distance from the trailing edge end of the first blade 121 to the leading edge end of the second blade 122 is denoted as θ2.

[0080] The value of θ2 at any radius is constant. That is, the axial distance θ2 between the first blade 121 and the second blade 122 is a constant value.

[0081] According to the embodiments of the present application, for the axial flow fan with the maximum outer diameter of 260mm-410mm, θ2=8-10mm. Exemplarily, θ2=9.3mm. Within this range, the tandem blade can greatly improve the fan performance.

[0082] In some embodiments, referring to Figure 9 In the plane perpendicular to the axis of the hub 110, the arc length from the leading edge 123 of the first blade 121 to the trailing edge 124 of the second blade 122 on the circle passing through the blade 120 with the hub 110 as the center is L1, and the arc length of the first blade 122 is L2, and L2 / L1=n, n=0.4-0.6. That is, the position of the tandem of the first blade 121 and the second blade 122 is approximately at the midpoint of the total arc length. In any blade profile section, the arc length of the first blade 121 is approximately equal to the arc length of the second blade 122.

[0083] Exemplarily, n gradually increases from the inner edge 126 side to the outer edge 125 side, for example, n can gradually increase from 0.4 to 0.6.

[0084] Exemplarily, referring to Figure 10 Assuming that the horizontal axis of the n linear graph is the radius of the circle with the hub 100 as the center, and the vertical axis is the size of n, the relationship between the size of n and the radius is expressed as an n linear line.

[0085] The n linear line has a first part and a second part, wherein the first part is at the smaller end of the radius, and the horizontal axis spacing of the second part is greater than that of the first part. The first part presents a shape of first increasing and then decreasing with the increase of the radius, and the second part presents a shape of gradually increasing with the increase of the radius.

[0086] In some embodiments, continuing to refer to Figure 9 In the plane perpendicular to the axis of the hub, the total arc length of the circular arc passing through the blade 120 with the hub as the center is L1, and the ratio of the arc length of any point on the circular arc to L1 is defined as z.

[0087] Referring to Figure 11 In the blade profile section of the blade 120, the angle between the imaginary line perpendicular to the axis of the hub 110 and intersecting the point on the midline of the blade profile section and the imaginary line representing the tangent of the point is defined as the β angle.

[0088] The β angle of the trailing edge end of the first blade 121 is the same size as the β angle of the leading edge end of the second blade 122.

[0089] Referring to Figure 12 The horizontal axis of the outer edge β angle linear graph is the size of z, and the vertical axis is the size of the β angle. The relationship between the size of the β angle and the size of z is expressed as an outer edge β angle linear line.

[0090] The β angle of the first blade 121 and the second blade 122 close to each other is the same.

[0091] The outer edge β angle linear line has two lines, which are the first line LP1 and the second line LP2. The highest point of the first line LP1 is connected to the second line LP2 by a dashed line DL according to the trend of the first line LP1. The intersection point of the dashed line DL and the second line LP2 is marked as W, and W divides the second line LP2 into a front part of the second blade and a rear part of the second blade, wherein the z value of the front part of the second blade is smaller than the z value of the rear part of the second blade.

[0092] The first line LP1, the dashed line DL, and the rear part of the second blade form the outer edge β angle linear line of the existing whole blade. That is to say, only the front part of the second blade in the tandem blade of the present application is different from the outer edge β angle linear line of the existing whole blade.

[0093] In the present application, the angle parameters of other parts are unchanged except that the β angle at the leading edge of the second blade changes slightly.

[0094] According to the embodiment of the present application, the first line LP1 presents a shape of gradually increasing first and then gradually decreasing as the transverse axis increases. The lowest point of the first line LP1 is close to the leading edge side, at which time the part close to the leading edge and close to the outer edge on the first blade will usually turn outward to the suction surface, thereby reducing the β angle.

[0095] The second line LP2 presents a gradually increasing shape as the transverse axis increases.

[0096] Referring to Figure 13 By simulating the existing technology axial flow fan and the axial flow fan 100 of the present application, the fan surface static pressure cloud chart can be obtained, and the red color is the area with high work function. By comparing the work area of the existing technology (before optimization) and the axial flow fan 100 (after optimization), it can be seen that after the axial flow fan 100 of the present application adopts the tandem blade, the work function of the blade 120 close to the hub 110 side is improved, and the overall work area is widened. It can be seen that the axial flow fan 100 of the present application can effectively improve the performance of the fan.

[0097] Referring to Figure 14 By simulating the existing technology air conditioner and the air conditioner of the present application, the whole machine wind field cloud chart can be obtained, and the red color is the high wind speed area. By comparing the wind field trend of the existing technology (before optimization) and the air conditioner of the present application (after optimization), it can be found that in the air conditioner of the present application, the divergence angle (the angle between the two straight lines in the figure) of the outlet air is smaller after the axial flow fan 100 adopts the tandem blade; and in the air conditioner of the present application, the wind speed is improved and the air supply distance is improved at a position far from the whole machine (the position surrounded in the figure).

[0098] The following table is a comparison of the measured results of the prior art axial fan and the axial fan 100 of the present application:

[0099] Comparative item Rotation speed rpm Air volume CMH Fan efficiency % Noise dB(A) Prior art 720 4390 44.9％ 56 The present application 720 4432 49.4％ 54 Improvement rate 42 4.5％ 2

[0100] As can be seen from the measured results, after the axial fan 100 of the present application adopts the tandem blade, the air volume is increased by 42 CMH, the fan efficiency is increased by 4.5%, and the noise is reduced by 2 dB(A) at the same speed.

[0101] Therefore, after the axial fan 100 of the present application adopts the tandem blade, the fan efficiency can be significantly improved, and the aerodynamic noise of the fan can be reduced without modifying the three-dimensional torque shape of the blade.

[0102] [Splitter blade]

[0103] Referring to Figure 15 and Figure 16 , the axial fan 100 can include a plurality of splitter blades 130. The plurality of splitter blades 130 are connected with the hub 110 and are arranged one-to-one corresponding to the blades 120.

[0104] The corresponding splitter blade 130 and blade 120 form a group. In each group of splitter blades 130 and blades 120, the splitter blades 130 and the blades 120 are arranged in parallel to the axis direction of the hub 110; the splitter blades 130 are located on the side of the pressure surface 127 of the first blade 121.

[0105] The embodiments provided by the present application add the splitter blades 130 on the basis of the tandem blade, and the splitter blades 130 correspond to the pressure surface side of the first blade 121, which can further enhance the fan's power, improve the flow condition between the tandem blades, and improve the efficiency.

[0106] According to the embodiments of the present application, in the plane perpendicular to the axis of the hub 110, most of the area of the splitter blade 130 coincides with the first blade 121, and the splitter blade 130 does not coincide with the second blade 122. Thus, it can be ensured that the splitter blade 130 is close to the leading edge of the blade 120, and the air flow entering the leading edge of the blade 120 is split, thereby improving the fan's power.

[0107] In some embodiments, the shape of the splitter blade 130 can be the same as that of the second blade 122. The β angle of the splitter blade 130 is consistent with the β angle parameter of the second blade 122. That is, the inclination angle of the splitter blade 130 relative to the hub 110 is the same as that of the second blade 122, which can simplify the structure design of the splitter blade 130.

[0108] Referring to Figure 17By simulating the axial flow fan of the prior art and the axial flow fan 100 of the present application, the fan surface static pressure nephogram can be obtained. By comparing the working area of the axial flow fan of the prior art (before optimization) and the axial flow fan 100 of the present application (after optimization), it can be seen that, after the axial flow fan 100 of the present application adopts the tandem blade and the splitter blade, the blade working area is dispersed: from a single blade area to be evenly distributed on the splitter blade 130 and the second blade 122, and the overall working area is widened. It can be seen that, after the axial flow fan 100 of the present application is provided with the splitter blade 130, the performance of the fan can be improved.

[0109] With reference to Figure 18 By simulating the air conditioner of the prior art and the air conditioner of the present application, the whole machine wind field nephogram can be obtained. The red color is the high wind speed area. By comparing the wind field trend of the air conditioner of the prior art (before optimization) and the air conditioner of the present application (after optimization), it can be found that, in the air conditioner of the present application, after the axial flow fan 100 adopts the tandem blade and the splitter blade, the divergence angle of the outlet air (the angle between the two straight lines in the figure) is smaller; and in the air conditioner of the present application, the outlet air (the position enclosed in the figure) wind speed is improved, and the air supply distance is improved.

[0110] The following table is the comparison of the measured results of the axial flow fan of the prior art and the axial flow fan 100 of the present application:

[0111]

[0112]

[0113] It can be seen from the measured results that, after the axial flow fan 100 of the present application adopts the tandem blade and the splitter blade, the air volume of the whole machine is increased by 608 CMH under the same speed, and the fan efficiency is improved by 2.4%, which significantly improves the working capacity and efficiency of the fan. Under the same air volume, the fan speed of the present application can be reduced by about 70 rpm, and the fan noise under the same air volume is reduced by 3d B.

[0114] Therefore, after the axial flow fan 100 of the present application adopts the tandem blade and the splitter blade, the working capacity of the fan can be improved without modifying the three-dimensional torque shape of the blade, and the aerodynamic noise of the fan is reduced.

[0115] For the axial flow fan without the splitter blade, the blades 120 do not overlap in the axial direction, and the mold is respectively molded in the upward and downward directions. However, for the axial flow fan with the splitter blade 130, the blades 120 and the splitter blade 130 are stacked in the axial direction, and cannot be normally molded.

[0116] Therefore, in the embodiment of the present application, with reference to Figure 19The hub 110 comprises a first hub part 111 and a second hub part 112. The first hub part 111 and the second hub part 112 are two-piece structures, and are assembled into the hub 110 in a split connection manner.

[0117] The vane 120 is connected to the first hub part 111, and the splitter vane 130 is connected to the second hub part 112. Since the vane 120 and the splitter vane 130 are respectively located on two parts, the first hub part 111 and the vane 120 can be molded out of one mold, and the second hub part 112 and the splitter vane 130 can be molded out of another mold.

[0118] In the embodiments provided in the present application, by splitting the axial fan 100 into two parts connected in a split connection manner, the vane 120 and the first hub part 111 are one part, and the splitter vane 130 and the second hub part 112 are one part, so that normal molding of the two parts can be ensured, and the molding of the axial fan 100 can be realized.

[0119] In some embodiments, the circumferential side wall of the first hub part 111 is provided with a hook groove 115. The circumferential side wall of the second hub part 112 is provided with a hook portion 116, which can be fitted into the hook groove 115.

[0120] When assembling, the hook portion 116 of the second hub part 112 is screwed into the hook groove 115 of the first hub part 111, and through the cooperation of the hook portion 116 and the hook groove 115, the installation and positioning of the first hub part 111 and the second hub part 112 can be realized.

[0121] In other embodiments, the positions of the hook portion 116 and the hook groove 115 can be interchanged, that is, the hook portion 116 is arranged on the first hub part 111, and the hook groove 115 is arranged on the second hub part 112, and the positioning of the first hub part 111 and the second hub part 112 can still be realized through the cooperation of the hook portion 116 and the hook groove 115.

[0122] For convenience of description, it is defined that along the axial direction of the hub 110, the first hub part 111 is located on the front side of the second hub part 112, and the second hub part 112 is located on the rear side of the first hub part 111.

[0123] The rear end surface of the first hub part 111 is provided with an opening, and the hook groove 115 is formed by the opening extending obliquely along the circumferential side wall.

[0124] In some embodiments, the outer circumferential part of the first hub part 111 is provided with a plurality of first positioning portions 113 arranged at intervals, and the first positioning portion 113 is formed by the circumferential part of the first hub part 111 protruding outward. The first positioning portion 113 is provided with a first positioning hole.

[0125] The outer circumferential portion of the second hub portion 112 is provided with a plurality of second positioning portions 114 which are formed by the circumferential portion of the second hub portion 112 being outwardly protruded. The second positioning portions 114 are provided with second positioning holes.

[0126] The fasteners such as screws or bolts are sequentially arranged in the first positioning holes and the second positioning holes to fasten and connect the first hub portion 111 and the second hub portion 112.

[0127] For example, the first hub portion 111 is provided with three first positioning portions 113 which are evenly distributed along the circumference. The second hub portion 112 is provided with three second positioning portions 114 which are evenly distributed along the circumference. The three first positioning portions 113 and the three second positioning portions 114 are one-to-one corresponding and are connected by the fasteners.

[0128] In some embodiments, the first hub portion 111 is provided with a first mounting portion 117 which is located at the center of the hub 110 and is connected with the circumferential side wall of the first hub portion 111 by a radial wall. The first mounting portion 117 is provided with a plurality of third positioning holes.

[0129] The second hub portion 112 is provided with a second mounting portion 118 which is located at the center of the hub 110 and is connected with the circumferential side wall of the second hub portion 112 by a radial wall. The second mounting portion 118 is provided with a plurality of fourth positioning holes.

[0130] The third positioning holes and the fourth positioning holes are one-to-one corresponding. During assembly, the fasteners such as screws or bolts are sequentially arranged in the third positioning holes and the fourth positioning holes to fasten and connect the first hub portion 111 and the second hub portion 112.

[0131] In the present application, the existing entire blade is split into two: a first blade 121 and a second blade 122, and the first blade 121 and the second blade 122 are arranged in series. When air passes through the suction surface 128 of the first blade 121, a boundary layer with a certain thickness is generated. When the air continues to pass through the second blade 122, the boundary layer is redistributed, which is beneficial to reduce the aerodynamic loss of the axial flow fan 100.

[0132] In the present application, after the axial flow fan 100 adopts the tandem blade, the working capacity of the blade 120 near the hub 110 side is improved, and the overall working area is widened. The axial flow fan 100 of the present application can effectively improve the performance of the fan.

[0133] In the present application, after the axial flow fan 100 adopts the tandem blade, compared with the prior art, the air volume is increased by 42 CMH at the same speed, the fan efficiency is increased by 4.5%, and the noise is reduced by 2dB(A).

[0134] In the application, the splitter blade 130 is additionally arranged on the basis of the tandem blade, and the splitter blade 130 corresponds to the pressure surface side of the first blade 121, so that the fan work capacity can be further enhanced, the flow condition of the blade passage between the tandem blades can be improved, and the efficiency can be improved.

[0135] In the application, after the axial fan 100 adopts the tandem blade and the splitter blade, the blade work area is dispersed: from a single blade area to be uniformly distributed on the splitter blade 130 and the second blade 122, and the overall work area is widened, so that the performance of the fan is improved.

[0136] In the application, after the tandem blade and the splitter blade are adopted, the air volume of the whole machine is increased by 608 CMH at the same speed, the fan efficiency is increased by 2.4%, and the work capacity and efficiency of the fan are significantly improved. At the same air volume of the whole machine, the fan speed of the application can be reduced by about 70 rpm, and the noise of the fan with the same air volume is reduced by 3 dB.

[0137] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

[0138] In order to facilitate explanation, the above description has been made in combination with specific embodiments. However, the above exemplary discussion is not intended to exhaust or limit the embodiments to the specific forms disclosed above. According to the above teaching, various modifications and variations can be obtained. The selection and description of the above embodiments are to better explain the principles and practical applications, so that those skilled in the art can better use the embodiments and various different modified embodiments suitable for specific use considerations.

Claims

1. An axial flow fan, characterized in that, include: A hub is used to be driven to rotate about a central axis. Multiple blades are connected to the hub. The blades include a first blade and a second blade arranged in series. The leading edge of the first blade forms the leading edge of the blade, and the trailing edge of the second blade forms the trailing edge of the blade. In the airfoil section of the blade, in the direction perpendicular to the hub axis, the distance from the trailing edge of the first blade to the leading edge of the second blade is θ1; Assuming the horizontal axis of the θ1 linear graph is the radius of a circle centered at the hub's axis, and the vertical axis is the magnitude of θ1, the relationship between the magnitude of θ1 and the radius is represented by the θ1 linear line; The θ1 linear line gradually increases in size as the radius increases.

2. The axial flow fan according to claim 1, characterized in that, The outer diameter of the axial fan is 260mm to 410mm, the minimum value of θ1 is not less than 2mm, and the maximum value of θ1 is not greater than 12mm.

3. The axial flow fan according to claim 1, characterized in that, In the airfoil section of the blade, in a direction parallel to the hub axis, the distance from the trailing edge of the first blade to the leading edge of the second blade is θ2. The value of θ2 is the same in any airfoil section of the blade.

4. The axial flow fan according to claim 3, characterized in that, The outer diameter of the axial fan is 260mm to 410mm, and θ2 = 8 to 10mm.

5. The axial flow fan according to claim 1, characterized in that, In a plane perpendicular to the axis of the hub, on a circle centered on the hub's axis and passing through the blade, the arc length from the leading edge of the first blade to the trailing edge of the second blade is L1, and the arc length of the first blade is L2. L2 / L1 is defined as n, where n = 0.4 to 0.

6.

6. The axial flow fan according to claim 5, characterized in that, Assuming the horizontal axis of the n-linear graph is the radius of a circle centered at the hub's axis, and the vertical axis is the size of n, the relationship between the size of n and the radius is represented by the n-linear line; The n-linear line has a first part and a second part, wherein the first part is at the smaller radius end, and the horizontal axis spacing of the second part is greater than that of the first part; As the radius increases, the second part of the n-linear line takes on a gradually increasing shape.

7. The axial flow fan according to claim 1, characterized in that, In the blade's airfoil section, the angle between the imaginary line perpendicular to the hub's axis and intersecting a point on the airfoil section and the imaginary line representing the tangent at that point is defined as angle β. The β angle at the trailing edge of the first blade is the same as the β angle at the leading edge of the second blade.

8. The axial flow fan according to claim 1, characterized in that, In the blade's airfoil section, the angle between the imaginary line perpendicular to the hub's axis and intersecting a point on the airfoil section and the imaginary line representing the tangent at that point is defined as angle β. In a plane perpendicular to the axis of the hub, the total arc length of the arc passing through the blade with the hub's axis as the center is L1, and the ratio of the arc length from any point on the arc to the leading edge to L1 is defined as z. The horizontal axis of the linear graph of the outer edge β angle of the blade is z, and the vertical axis is the size of the β angle of the outer edge of the blade. The relationship between the size of the β angle of the outer edge and z is represented by the linear line of the outer edge β angle. The outer edge β-angle linear line includes a first line and a second line, with the first line closer to the vertical axis relative to the second line; the highest point of the first line is connected to the second line by a dashed line DL according to the trend of the first line, and the portion of the second line closer to the first line is located below the dashed line DL.

9. The axial flow fan according to claim 1, characterized in that, With reference to the axial direction of the hub, the leading edge is located in front of the trailing edge, and the trailing edge of the first blade is located behind the leading edge of the second blade.

10. An air conditioner, characterized in that, include: case; The refrigerant circuit includes a condenser and an evaporator. An axial fan as described in any one of claims 1-9, disposed within the housing, is used to blow air to at least one of the condenser and the evaporator.

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