A guide vane and a design method and a box fan thereof

Abstract

The application discloses a guide plate, a design method thereof and a box type fan. The guide plate comprises a guide part with a guide surface, the guide part is an axis-symmetrical structure, the guide surface is a curved surface protruding to the outside of an air inlet, and the guide surface is symmetrically arranged relative to the central axis surface of the guide part. The guide plate, the design method thereof and the box type fan provided by the embodiment of the application can guide the gas in the air pipe at the air inlet side to the flow channels on the left and right sides of the box, so that more air can flow into the impeller from the main flow channels on the left and right sides of the box under the premise that the power of the motor is unchanged, the backflow generated by the air flowing into the clearance between the volute and the upper and lower cover plates of the box is eliminated, the influence of the backflow on the gas flowing into the main flow channels is further eliminated, the air volume flowing into the impeller is increased, and the efficiency of the fan is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the fan technical field, especially to a guide vane and a design method thereof, and a box-type fan. BACKGROUND

[0002] The commercial central purification system adopts a power distribution system to uniformly distribute air volume of each merchant, and extracts and filters oil fume in a flue through a box-type fan and a purifier, which can effectively purify air, and thus can be applied to each shopping mall, hotel, etc.

[0003] As a power device for extracting oil fume, the fan on the market is directly connected with a wind pipe at an inlet side and an outlet side. Since the volute of the fan is in a spiral type, there is a large space between the volute and the bottom of the box from the inlet side of the box-type fan, and thus a large amount of air flows into the space from the wind pipe after flowing into the inlet side of the box-type fan, instead of all entering the air inlets on the left and right sides of the volute, which can reduce the air volume entering the impeller of the fan, and the air flowing into the space can generate backflow, which can affect the flow of the main flow, and thus affect the efficiency of the fan. SUMMARY

[0004] The present application provides a guide vane and a design method thereof, and a box-type fan to increase air volume and improve the efficiency of the fan.

[0005] According to an aspect of the present application, a guide vane is provided, which is used to be installed at an air inlet side of a box-type fan.

[0006] The guide vane includes a guide portion with a guide surface, the guide portion is an axisymmetric structure, and the guide surface is a curved surface protruding outwardly from the air inlet.

[0007] The guide surface includes a first guide curved surface and a second guide curved surface, the first guide curved surface and the second guide curved surface are adjacent, and the first guide curved surface and the second guide curved surface are symmetrically arranged with respect to a central axis surface of the guide portion.

[0008] Optionally, on a horizontal cross section of the guide surface, a tangent line passing through an end point of the first guide curved surface away from the second guide curved surface and being tangent to the first guide curved surface is a first tangent line, a tangent line passing through an end point of the second guide curved surface away from the first guide curved surface and being tangent to the second guide curved surface is a second tangent line, and an included angle between the first tangent line and the second tangent line is α, where 110°≤α≤130°.

[0009] Optionally, the horizontal cross section of the guide surface is a Bezier curve.

[0010] The Bezier curve satisfies:

[0011]

[0012] wherein p(t) is a coordinate of an arbitrary point on the Bezier curve, n is an order of the Bezier curve, and n is a positive integer greater than 3; i is a current order, i = 0, 1, 2, …, n; p i is a position vector of a preset vertex on the Bezier curve; B i，n (t) is a Bernstein basis function, t is a parameter variable of the Bezier curve, 0≤t≤1.

[0013] Optionally, the box-type fan is provided with an inlet flange at the air inlet, and the inlet flange comprises an air inlet hole.

[0014] The height of the flow guide plate is the same as the height of the air inlet hole.

[0015] Optionally, the flow guide plate further comprises a first bending portion and a second bending portion located on two sides of the flow guide portion, respectively.

[0016] Mounting through holes are arranged on the first bending portion and the second bending portion, and the flow guide plate is fixedly connected with the support frame of the box-type fan through the mounting through holes.

[0017] Optionally, the first bending portion comprises a first bending sub-portion and a second bending sub-portion which are adjacent to each other.

[0018] The second bending portion comprises a third bending sub-portion and a fourth bending sub-portion which are adjacent to each other.

[0019] The first bending sub-portion and the third bending sub-portion are connected with two sides of the flow guide portion, respectively.

[0020] The first bending sub-portion and the third bending sub-portion are in contact with the surface of the support frame close to the flow guide portion.

[0021] The mounting through holes are arranged on the second bending sub-portion and the fourth bending sub-portion.

[0022] The second bending sub-portion and the fourth bending sub-portion are fixedly connected with the inner surface of the support frame at the air inlet through the mounting through holes.

[0023] According to another aspect of the present application, there is provided a box-type fan, comprising a box body, a support frame, a motor, a fan and any flow guide plate according to the first aspect.

[0024] The support frame and the fan are located inside the box body, and the support frame is located on opposite sides of the fan for supporting the fan.

[0025] The motor is located outside the box body, and the motor is connected with the fan.

[0026] The box includes an air inlet and an air outlet, and the guide plate is installed on the air inlet side of the box.

[0027] According to another aspect of the present application, a design method of a guide plate is provided for designing any guide plate of the first aspect, the design method comprising:

[0028] S1, determining a horizontal section of a guide surface of the guide plate according to a Bezier curve wherein p(t) is a coordinate of any point on the Bezier curve, and n is an order of the Bezier curve; i is a current order, i = 0, 1, 2,..., n; p i is a position vector of a preset vertex on the Bezier curve; B i，n (t) is a Bernstein basis function, t is a parameter variable of the Bezier curve, 0≤t≤1;

[0029] S2, determining a height of the guide plate according to a height of an air inlet hole of an inlet flange of the box fan;

[0030] S3, determining a structure of the guide plate according to the horizontal section of the guide surface of the guide plate and the height of the guide plate.

[0031] Optionally, determining a horizontal section of a guide surface of the guide plate according to a Bezier curve comprises:

[0032] determining a position vector of the preset vertex P0and a position vector of the preset vertex P n according to a spacing of a support frame of the box fan at the air inlet;

[0033] determining at least three preset vertices P1-P n-1 according to the position vector of the preset vertex P0and the position vector of the preset vertex P n ; and

[0034] determining the horizontal section of the guide surface of the guide plate according to the preset vertices P0-P n and the Bezier curve .

[0035] Optionally, after determining the structure of the guide plate, the method further comprises:

[0036] S4, obtaining a difference ΔF1 between an air inlet pressure and an air outlet pressure of the box fan after the guide plate is installed;

[0037] S5, when (ΔF1-ΔF2) / ΔF2 does not meet the preset standard, repeating steps S1-S4 until (ΔF1-ΔF2) / ΔF2 meets the preset standard, wherein ΔF2 is the difference between the inlet air pressure and the outlet air pressure of the box fan when the guide plate is not installed.

[0038] The guide plate, the design method thereof and the box fan provided by the embodiment of the present application are provided with a guide plate including a guide part with a guide surface, the guide surface is a curved surface protruding outwardly from the inlet, the guide part is an axis-symmetrical structure, and the guide surface is symmetrically arranged with respect to the central axis surface of the guide part. The guide plate is installed at the inlet side of the box fan, and the gas in the air pipe at the inlet side can be guided to the flow channels at the left and right sides of the box body, so that more air can flow into the impeller from the main flow channels at the left and right sides of the box body under the premise of unchanged motor power, the backflow generated by the air flowing into the clearance between the volute and the upper and lower cover plates of the box body is eliminated, and the influence of the backflow on the air flowing into the main flow channels is further eliminated, the air volume flowing into the impeller is increased, and the efficiency of the fan is improved.

[0039] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0041] Figure 1 A structural schematic diagram of a guide plate provided by the embodiment of the present application;

[0042] Figure 2 A horizontal cross-sectional structural schematic diagram of a guide plate provided by the embodiment of the present application;

[0043] Figure 3 An installation structural schematic diagram of a guide plate provided by the embodiment of the present application;

[0044] Figure 4 An installation structural schematic diagram of another guide plate provided by the embodiment of the present application;

[0045] Figure 5 A fluid flow schematic diagram of a box fan provided by the embodiment of the present application;

[0046] Figure 6 A fluid flow schematic diagram of another box fan provided by the embodiment of the present application;

[0047] Figure 7 Another fluid flow schematic diagram of a box fan is provided for an embodiment of the present application;

[0048] Figure 8 A flow diagram of a design method of a deflector is provided for an embodiment of the present application;

[0049] Figure 9 A flow diagram of another design method of a deflector is provided for an embodiment of the present application;

[0050] Figure 10 A flow diagram of still another design method of a deflector is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to make the personnel in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person of ordinary skill in the art without creative labor should belong to the protection scope of the present application.

[0052] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0053] Figure 1 A structural schematic diagram of a deflector is provided for an embodiment of the present application, Figure 2 A horizontal cross-sectional structural schematic diagram of a deflector is provided for an embodiment of the present application, Figure 3 An installation structural schematic diagram of a deflector is provided for an embodiment of the present application, Figure 4 Another installation structural schematic diagram of a deflector is provided for an embodiment of the present application, such as Figures 1-4As shown, the guide plate 10 provided by the embodiment of the present application is used to be installed at the air inlet 20 side of the box fan 11, the guide plate 10 comprises a guide part 13 with a guide surface 12, the guide part 13 is an axisymmetric structure, and the guide surface 12 is a curved surface protruding outwardly from the air inlet 20. The guide surface 12 comprises a first guide curved surface 121 and a second guide curved surface 122, the first guide curved surface 121 and the second guide curved surface 122 are adjacent, and the first guide curved surface 121 and the second guide curved surface 122 are symmetrically arranged relative to the central axial surface 130 of the guide part 13.

[0054] Specifically, as shown in the figures, Figure 3 and Figure 4 The box fan 11 can specifically comprise a box body 30, a support frame 31, a motor 32 and a fan 33, etc., wherein the fan 33 is installed in the box body 30, the fan 33 comprises a volute 331 and an impeller 332 located in the volute 331, the support frame 31 is arranged in the box body 30 and located at both sides of the volute 331, the support frame 31 is vertically placed and fixedly connected with the volute 331 to support the volute 331.

[0055] The support frame 31 is installed with a belt pulley 34, the belt pulley 34 is located outside the box body 30, and the impeller 332 is connected with the belt pulley 34 through a rotating shaft 35. The motor 32 is installed at the top of the box body 30, and the motor 32 can be specifically installed at the top of the box body 30 through a motor support 36, and the belt pulley 35 is connected with the motor 32 through a belt 37, so that the impeller 332 can be driven to rotate by the motor 32.

[0056] The end surface of the impeller 332 corresponds to the air inlets at both sides of the volute 331 respectively, and the fan 33 can be a multi-wing centrifugal fan, which can take in air from both sides of the volute 331, but is not limited thereto.

[0057] In this embodiment, the fan 33 is installed in the box body 30, and the motor 32 is installed outside the box body 30. Compared with the traditional integral structure, the power can be designed to be larger, the rotating speed of the fan 33 can be faster, the disassembly and maintenance in the later stage are more convenient, and the air inlets 20 and air outlets 21 on the box body 30 can be better connected with the air pipe through the external box body 30.

[0058] Figure 5 A fluid flow schematic diagram of a box fan provided by the embodiment of the present application, Figure 6 Another fluid flow schematic diagram of a box fan provided by the embodiment of the present application, as shown in the figures, Figure 5 and Figure 6As shown, when the box fan 11 is not installed with the flow guide plate, at the air inlet 20 side of the box fan 11, due to the spiral type of the volute 331, part of the fluid will flow into the angle between the volute 331 and the upper and lower cover plates of the box 30 from the front air pipe, instead of all flowing into the flow channels on the left and right sides to enter the air inlets 333 on the left and right sides of the volute 331. The fluid flowing into the angle will also generate a separation vortex, which will affect the fluid flowing into the air inlets 333 on the left and right sides of the volute 331.

[0059] With reference to the foregoing Figure 6 Due to the blocking of the volute 331 wall surface, a large amount of air will collide with the volute 331 wall surface after flowing into the air inlet 20 of the box fan 11, and then adjust the flow direction to the main flow direction on the left and right sides. This not only causes a large amount of energy loss, but also generates a separation vortex and a secondary flow due to the sudden change of the flow channel, which affects the air flow.

[0060] Therefore, the above two aspects will cause the air volume flowing into the air inlets 333 on the left and right sides of the volute 331 to decrease under the condition that the motor power is the same.

[0061] With reference to the foregoing Figures 1-4 The embodiment provides a flow guide plate 10, which is used for being installed at the air inlet 20 side of the box fan 11. The flow guide part 13 of the flow guide plate 10 has a flow guide surface 12 on the side away from the fan 33. The flow guide surface 12 is a curved surface protruding outward of the air inlet 20. Specifically, as shown in Figure 3 and Figure 4 As shown, the flow guide plate 10 is arranged at the air inlet 20 of the box fan 11. The side of the flow guide plate 10 away from the fan 33 is the air inlet 20 side, that is, the flow guide surface 12 is arranged outward of the box 30 along the direction X in which the fan 33 points to the flow guide plate 10. The gas in the air inlet side air pipe will flow into the air inlet 20 along the protruding flow guide surface 12, and then enter the volute 331 inside the box 30. The flow guide part 13 is an axisymmetric structure, the central axis surface 130 of the flow guide part 13 is located in the vertical direction, the flow guide surface 12 includes the first flow guide curved surface 121 and the second flow guide curved surface 122 arranged adjacent in the horizontal direction, and the first flow guide curved surface 121 and the second flow guide curved surface 122 are connected to make the cross section of the flow guide surface 12 in the horizontal direction present a herringbone shape.

[0062] Figure 7 Another fluid flow diagram of the box fan is provided for the embodiment of the application, as shown in Figure 7As shown, after the box fan 11 is installed with the flow guide plate 10 provided by the embodiment of the present application, the flow guide plate 10 can play a role of guiding flow, and the gas in the air pipe on the side of the air inlet 20 can be guided by the flow guide surface 12 of the flow guide part 13 to the flow channels on the left and right sides of the box body 30, so that more air can flow into the impeller 332 from the volute 331 (main flow channel) on the left and right sides of the box body 30 under the premise of unchanged motor power, the backflow generated by the air flowing into the gap between the volute 331 and the upper and lower cover plates of the box body 30 is eliminated, and then the influence of the backflow on the gas flowing into the main flow channel is eliminated, the air volume flowing into the impeller 332 can be increased under the condition of unchanged motor power, and thus the fan efficiency is improved.

[0063] With reference to the drawings still, Figures 1-4 the first flow guide curved surface 121 and the second flow guide curved surface 122 are symmetrically arranged relative to the central axis surface 130 of the flow guide part 13, so that the flow guide surface 12 has a left-right symmetry structure, and then the flow guide surface 12 is left-right symmetric relative to the vertical central axis surface of the air inlet 20, so as to uniformly guide the gas in the air pipe on the side of the air inlet 20 to the flow channels on the left and right sides of the box body 30, which helps to increase the air volume flowing into the impeller 332 and improve the fan efficiency.

[0064] In summary, the flow guide plate provided by the embodiment of the present application is provided with a flow guide part having a flow guide surface, the flow guide surface is a curved surface protruding outward from the air inlet, the flow guide part has an axis symmetry structure, and the flow guide surface is symmetrically arranged relative to the central axis surface of the flow guide part. The flow guide plate is installed on the air inlet side of the box fan, the gas in the air pipe on the side of the air inlet can be guided to the flow channels on the left and right sides of the box body, so that more air can flow into the impeller from the main flow channel on the left and right sides of the box body under the premise of unchanged motor power, the backflow generated by the air flowing into the gap between the volute and the upper and lower cover plates of the box body is eliminated, and then the influence of the backflow on the gas flowing into the main flow channel is eliminated, the air volume flowing into the impeller is increased, and the fan efficiency is improved.

[0065] With reference to the drawings still, Figure 2 Optionally, on the horizontal cross section of the flow guide surface 12, the tangent line passing through the end point of the first flow guide curved surface 121 away from the second flow guide curved surface 122 and being tangent to the first flow guide curved surface 121 is the first tangent line 41, the tangent line passing through the end point of the second flow guide curved surface 122 away from the first flow guide curved surface 121 and being tangent to the second flow guide curved surface 122 is the second tangent line 42, and the included angle between the first tangent line 41 and the second tangent line 42 is α, wherein 110°≤α≤130°.

[0066] As shown in the drawings, Figure 2 by setting the included angle between the tangent lines on the left and right sides of the flow guide surface 12 to 110°-130°, the surface type of the flow guide surface 12 can better conform to the direction of air flow, the sudden change of the flow channel is avoided, the air utilization rate is improved, the air volume is increased, and the fan operation efficiency is improved.

[0067] With reference to the accompanying drawings Figure 1 and Figure 2 Optionally, the horizontal section of the flow guide surface 12 is a Bezier curve.

[0068] The Bezier curve satisfies:

[0069] wherein p(t) is the coordinate of any point on the Bezier curve, n is the order of the Bezier curve, and n is a positive integer greater than 3; i is the current order, i = 0, 1, 2,..., n; p i is the position vector of a preset vertex on the Bezier curve; B i，n (t) is a Bernstein basis function, t is a parameter variable of the Bezier curve, and 0≤t≤1.

[0070] wherein the horizontal section of the flow guide surface 12 is set to satisfy the Bezier curve The surface shape of the flow guide surface 12 can better conform to the direction of air flow, avoid sudden changes in the flow channel, improve the utilization rate of air, increase the air volume, and improve the operating efficiency of the fan.

[0071] At the same time, by adjusting the position vector of the preset vertex on the Bezier curve, the corresponding flow guide plate 10 with the optimal profile can be obtained according to different fan performance parameters, that is, the Bezier curve can be used to optimize the flow guide plate 10 of different shapes based on different performance parameters of the fan, the method is simple, and the application range of the flow guide plate 10 is more extensive.

[0072] With reference to the accompanying drawings Figure 3 and Figure 7 Optionally, the box-type fan 11 is provided with an inlet flange 38 at the air inlet 20, the inlet flange 38 comprises an air inlet hole 381, and the height of the flow guide plate 10 is the same as the height of the air inlet hole 381.

[0073] wherein, as Figure 3 shown, the inlet flange 38 is installed at the air inlet 20 of the box body 30, and the inlet flange 38 is used to connect the air inlet 20 of the box body 30 with the air pipe, that is, the air inlet 20 of the box body 30 is connected with the air pipe through the inlet flange 38, which makes the later disassembly and maintenance more convenient.

[0074] In the embodiment, the height of the upper and lower sides of the flow guide plate 10 is consistent with the height of the upper and lower sides of the air inlet hole 381 of the inlet flange 38, so that the upper and lower sides of the flow guide plate 10 are just clamped in the air inlet hole 381 of the inlet flange 38. The fluid in the air pipe can be prevented from flowing into the angle between the volute 331 and the upper and lower cover plates of the box body 30, so as to eliminate the separation vortex of the fluid flowing into the angle, and affect the fluid flowing into the air inlet hole 333 of the left and right sides of the volute 331. It is helpful to increase the air volume flowing into the impeller 332 and improve the efficiency of the fan.

[0075] With reference to Figure 1 , Figure 2 and Figure 4 optionally, the flow guide plate 10 further comprises a first bending portion 51 and a second bending portion 52 located on the two sides of the flow guide portion 13 respectively, and the first bending portion 51 and the second bending portion 52 are provided with mounting through holes 40. The flow guide plate 10 is fixedly connected with the support frame 31 of the box fan 11 through the mounting through holes 40.

[0076] Specifically, as shown in Figure 1 , Figure 2 and Figure 4 , one side of the flow guide portion 13 of the flow guide plate 10 is connected with the first bending portion 51, and the other side of the flow guide portion 13 is connected with the second bending portion 52. The first bending portion 51 and the second bending portion 52 are located on the opposite sides of the flow guide portion 13 and can be symmetrically arranged relative to the central axial surface 130 of the flow guide portion 13. The first bending portion 51 and the second bending portion 52 are provided with mounting through holes 40. The self-tapping screws can pass through the mounting through holes 40 and be screwed into the holes in the support frame 31, so as to symmetrically mount and fix the flow guide plate 10 on the support frames 31 on the left and right sides of the fan 33. At the same time, it is also convenient for later disassembly and maintenance.

[0077] It should be noted that the flow guide portion 13, the first bending portion 51 and the second bending portion 52 can be an integral structure, so that the connection between the flow guide portion 13, the first bending portion 51 and the second bending portion 52 is more firm.

[0078] In addition, the flow guide plate 10 can be made of galvanized sheet to have good corrosion resistance.

[0079] In some embodiments, the galvanized sheet can be bent to form the flow guide plate 10 with the flow guide portion 13, the first bending portion 51 and the second bending portion 52. The process is simple and easy to implement.

[0080] With reference to Figure 1 , Figure 2 and Figure 4Optionally, the first bending part 51 comprises a first bending subpart 511 and a second bending subpart 512 which are adjacent to each other, and the second bending part 52 comprises a third bending subpart 521 and a fourth bending subpart 522 which are adjacent to each other. The first bending subpart 511 and the third bending subpart 521 are connected to the two sides of the flow guide part 13 respectively, and the first bending subpart 511 and the third bending subpart 521 are in contact with the surface of the support frame 31 which is close to the flow guide part 13. The mounting through hole 40 is arranged on the second bending subpart 512 and the fourth bending subpart 522, and the second bending subpart 512 and the fourth bending subpart 522 are fixedly connected to the inner side surface of the support frame 31 at the air inlet 20 through the mounting through hole 40.

[0081] Specifically, as shown in Figure 1 、 Figure 2 and Figure 4 , the first bending part 51 comprises a first bending subpart 511 which is adjacent to one side of the flow guide part 13 and a second bending subpart 512 which is adjacent to the first bending subpart 511, and the second bending subpart 512 is perpendicular to the first bending subpart 511. The second bending part 52 comprises a third bending subpart 521 which is adjacent to the other side of the flow guide part 13 and a fourth bending subpart 522 which is adjacent to the third bending subpart 521, and the fourth bending subpart 522 is perpendicular to the third bending subpart 521.

[0082] When the flow guide plate 10 is connected to the support frame 31, the first bending subpart 511 and the third bending subpart 521 are connected in contact with the surface of the two support frames 31 which are located on both sides of the fan 33 and are close to the flow guide part 13, and the second bending subpart 512 and the fourth bending subpart 522 are fixedly connected to the two surfaces which are opposite to each other between the two support frames 31 which are located on both sides of the fan 33 through the mounting through hole 40 by using self-tapping screws, so as to more firmly install and fix the flow guide plate 10 on the support frames 31 which are located on both sides of the fan 33, and also facilitate the later disassembly and maintenance.

[0083] The length of the flow guide plate 10 in the horizontal direction can be calculated according to the distance between the two support frames 31 which are located on both sides of the fan 33, and the first bending subpart 511, the second bending subpart 512, the third bending subpart 521 and the fourth bending subpart 522 on the left and right sides of the flow guide plate 10 can be determined according to the width of the support frame 31, which is not limited in the embodiments of the present application.

[0084] Based on the same inventive concept, the embodiments of the present application also provide a box type fan, which continues to refer to Figure 3 、 Figure 4 and Figure 7The box type fan 11 comprises a box body 30, a support frame 31, a motor 32, a fan 33 and the flow guide plate 10 provided in any of the embodiments of the present application, and thus the box type fan 11 provided in the embodiments of the present application has the technical effects of the technical solutions in any of the above embodiments. The same or corresponding structures and the explanations of the terms are not repeated here.

[0085] Specifically, as shown in Figure 3 , Figure 4 and Figure 7 , the support frame 31 and the fan 33 are located inside the box body 30, the support frame 31 is located on the opposite sides of the fan 33 and is used for supporting the fan 33, the motor 32 is located outside the box body 30, and the motor 32 is connected with the fan 33 to drive the impeller 332 of the fan 33 to rotate. Compared with the traditional integral structure, the power can be designed to be larger, the rotating speed of the fan 33 can be faster, the disassembly and maintenance in the later period are more convenient, and the air inlet 20 and the air outlet 21 on the box body 30 can be better connected with the air pipe through the external box body 30.

[0086] Further, by installing the flow guide plate 10 on the air inlet 20 side of the box body 30, the flow guide plate 10 can play a role of guiding flow. The gas in the air pipe on the air inlet 20 side can be guided to the flow passages on the left and right sides of the box body 30 by the guide surface 12 of the guide part 13 of the flow guide plate 10. Thus, under the premise of unchanged motor power, more air can flow into the impeller 332 from the air inlet ring (main flow passage) of the volute 331 on the left and right sides of the box body 30, the backflow generated by the air flowing into the gap between the volute 331 and the upper and lower cover plates of the box body 30 is eliminated, and then the influence of the backflow on the gas flowing into the main flow passage is eliminated. Under the condition of unchanged motor power, the air volume flowing into the impeller 332 can be increased, and thus the fan efficiency is improved.

[0087] Based on the same inventive concept, the embodiments of the present application also provide a design method of a flow guide plate for preparing any of the flow guide plates provided in the above embodiments. The same or corresponding structures and the explanations of the terms are not repeated here, Figure 8 a flow chart of the design method of the flow guide plate provided in the embodiments of the present application, as shown in Figure 8 , the design method comprises the following steps:

[0088] S1, determining the horizontal section of the guide surface of the flow guide plate according to the Bezier curve ; wherein p(t) is the coordinate of any point on the Bezier curve, n is the order of the Bezier curve, i is the current order, i=0, 1, 2,..., n, p i is the position vector of a preset vertex on the Bezier curve, B i，n (t) is the Bernstein basis function, t is the parameter variable of the Bezier curve, 0≤t≤1.

[0089] wherein the horizontal section of the guide surface is determined according to the Bezier curve The horizontal section of the guide surface can be better matched with the air flow direction, the sudden change of the flow channel can be avoided, the air usage rate can be improved, the air volume can be increased, and the fan operation efficiency can be improved.

[0090] Meanwhile, by adjusting the position vector of the preset vertex on the Bezier curve, the guide plate with the optimal profile corresponding to different fan performance parameters can be obtained, that is, the Bezier curve can be used to construct the guide plate with different shapes based on different performance parameters of the fan, the method is simple, and the application range of the guide plate is wider.

[0091] S2, the height of the guide plate is determined according to the height of the air inlet hole of the inlet flange of the box type fan.

[0092] The inlet flange is arranged at the air inlet of the box body, and the inlet flange is used to connect the air inlet of the box body with the air pipe, that is, the air inlet of the box body is connected with the air pipe through the inlet flange, which makes the disassembly and maintenance more convenient.

[0093] In this embodiment, the height of the guide plate is determined according to the height of the air inlet hole of the inlet flange, wherein the height of the guide plate is less than or equal to the height of the air inlet hole of the inlet flange, so that the guide plate can be installed in the air inlet hole of the inlet flange, thereby playing a role of guiding flow at the air inlet hole.

[0094] Further, the height of the upper and lower sides of the guide plate can be consistent with the height of the upper and lower sides of the air inlet hole of the inlet flange, so that the upper and lower sides of the guide plate are just clamped in the air inlet hole of the inlet flange, which can avoid the flow in the air pipe flowing into the included angle between the volute and the upper and lower cover plates of the box body, thereby eliminating the influence of the flow into the included angle on the flow into the inlet side of the volute on the left and right sides, which helps to increase the air volume flowing into the impeller and improve the efficiency of the fan.

[0095] S3, the structure of the guide plate is determined according to the horizontal section of the guide surface of the guide plate and the height of the guide plate.

[0096] The shape structure of the guide plate can be obtained by three-dimensional modeling of the guide plate based on the horizontal section of the guide surface of the guide plate and the vertical height of the guide plate.

[0097] The horizontal section of the guide surface of the guide plate is determined according to the Bezier curve The horizontal section of the guide surface of the guide plate is determined according to the Bezier curve

[0098] The position vectors of the preset vertex P0 and the preset vertex P1 are determined according to the spacing of the support frame of the box type fan at the air inlet. n The position vectors of the preset vertex P0 and the preset vertex P1 are determined according to the spacing of the support frame of the box type fan at the air inlet.

[0099] According to the position vectors of the preset vertex P0 and the preset vertex P n , at least three preset vertices P1-P n-1 are determined.

[0100] According to the preset vertex P0-P n and the Bezier curve , the horizontal section of the guide surface of the guide vane is determined.

[0101] The position vectors of the preset vertex P0 and the preset vertex P n may be determined according to the distance between the support frames on the left and right sides of the fan, and the preset vertex P0 and the preset vertex P n are the fixed points at the two ends of the horizontal section of the guide surface. It can be understood that the distance between the preset vertex P0 and the preset vertex P n is the length of the guide surface in the horizontal direction.

[0102] In this embodiment, the position vectors of the preset vertex P0 and the preset vertex P n are determined according to the distance between the support frames on the left and right sides of the fan, so that the finally constructed guide vane can be fixedly installed on the support frames on the left and right sides of the fan.

[0103] After the preset vertex P0 and the preset vertex P n are determined, at least three preset vertices P1-P n-1 may be selected between the preset vertex P0 and the preset vertex P n , and then the guide vane profile, i.e., the horizontal section of the guide surface of the guide vane, is drawn according to the Bezier curve , wherein the preset vertex P0 and P n are the fixed points on the left and right sides, and the preset vertex P1-P n-1 are adjustable control points. The guide vane with the optimal profile corresponding to different fan performance parameters can be obtained by adjusting the position vectors of P1-P n-1 , so that the surface type of the guide surface can better conform to the direction of air flow, avoid the sudden change of the flow channel, improve the utilization rate of air, increase the air volume, and improve the operating efficiency of the fan.

[0104] For example, n=4 is taken as an example for illustration. The guide vane profile can be determined by the preset vertex P0 and P4 on the left and right sides, and the preset vertex P1, P2 and P3 in the middle. At this time, a fourth-order Bezier curve is used to draw the line shape of the horizontal section of the guide surface. The five preset vertices P0, P1, P2, P3 and P4 define the fourth-order Bezier curve, wherein the preset vertex P0 and P4 are the fixed points on the left and right sides, and the preset vertex P1, P2 and P3 are adjustable control points. The guide vane with the optimal profile corresponding to different fan performance parameters can be obtained by adjusting the position vectors of P1, P2 and P3.

[0105] Figure 9 Another flowchart of the method for designing the guide vane is provided for the embodiments of the present application, as shown in Figure 9 Optionally, after determining the structure of the guide vane, the method further comprises:

[0106] S4, obtaining the difference ΔF1 between the inlet air pressure and the outlet air pressure of the box-type fan after the guide vane is installed.

[0107] S5, when (ΔF1-ΔF2) / ΔF2 does not meet the preset standard, repeating steps S1-S4 until (ΔF1-ΔF2) / ΔF2 meets the preset standard, wherein ΔF2 is the difference between the inlet air pressure and the outlet air pressure of the box-type fan when the guide vane is not installed.

[0108] The geometric size of the box body can be determined according to the performance parameters and geometric size of the fan, so that the fan can be installed inside the box body.

[0109] Further, the fan and the box body can be three-dimensionally modeled, a box-type fan model is constructed, and full three-dimensional flow field simulation calculation is performed to obtain the inlet and outlet pressure distribution data and the flow line distribution in the flow field of the box-type fan model when the guide vane is not installed, and obtain the difference ΔF2 between the inlet air pressure and the outlet air pressure of the box-type fan when the guide vane is not installed.

[0110] After the horizontal cross section of the guide surface of the guide vane and the height of the guide vane are determined, the guide vane can be three-dimensionally modeled according to the horizontal cross section of the guide surface of the guide vane and the height of the guide vane, and the guide vane is assembled on the box-type fan model.

[0111] Further, numerical simulation software can be used to perform three-dimensional simulation calculation on the fluid domain of the box-type fan model with the assembled guide vane to obtain the inlet and outlet pressure distribution data of the box-type fan model with the assembled guide vane and the flow line distribution in the flow field, and obtain the difference ΔF1 between the inlet air pressure and the outlet air pressure of the box-type fan after the guide vane is installed.

[0112] Under the rated operating condition of the box-type fan, if (ΔF1-ΔF2) / ΔF2 meets the preset standard, that is, the difference ΔF1 between the inlet air pressure and the outlet air pressure of the box-type fan after the guide vane is installed is much higher than the difference ΔF2 between the inlet air pressure and the outlet air pressure of the box-type fan when the guide vane is not installed, it indicates that the assembled guide vane can play a good flow guiding role, and under the condition that the motor power remains unchanged, the air flow into the impeller can be greatly increased, thereby improving the efficiency of the fan, and therefore, the structure of the guide vane assembled at this time is taken as the final guide vane structure and is assembled on the box-type fan.

[0113] If (ΔF1-ΔF2) / ΔF2 does not meet the preset standard, repeat steps S1 to S4. This can be achieved by adjusting P1 to P2. n-1 The position vector controls the shape of the guide vane profile, that is, adjusts the horizontal cross-section of the guide surface to produce a smooth curve. A new guide vane model is constructed and assembled on the box-type fan model for three-dimensional simulation calculation. The difference ΔF1 between the inlet air pressure and the outlet air pressure of the box-type fan after the new guide vane is installed is obtained. It is then determined whether (ΔF1-ΔF2) / ΔF2 meets the preset standard. If (ΔF1-ΔF2) / ΔF2 meets the preset standard, the assembled guide vane is determined to be the final guide vane structure. If (ΔF1-ΔF2) / ΔF2 does not meet the preset standard, steps S1 to S4 are repeated until (ΔF1-ΔF2) / ΔF2 meets the preset standard.

[0114] It should be noted that the preset standard can be set according to actual needs. For example, if (ΔF1-ΔF2) / ΔF2≥10%, then (ΔF1-ΔF2) / ΔF2 meets the preset standard; if (ΔF1-ΔF2) / ΔF2<10%, then (ΔF1-ΔF2) / ΔF2 does not meet the preset standard; the value of 10% can be replaced by other values, and the embodiments of the present invention do not specifically limit this.

[0115] In addition, numerical simulation software can be used, such as ANSYS CFX and Fluent, but it is not limited to these.

[0116] To more clearly describe the technical solutions provided by the embodiments of the present invention, the design method of the guide plate provided by the present invention will be described in detail below with a feasible implementation method. The explanations of the same or corresponding terms as those in the above embodiments will not be repeated here.

[0117] Figure 10 A flowchart illustrating another design method for a baffle provided in an embodiment of the present invention is shown below. Figure 10 As shown, the design method of the deflector includes:

[0118] Obtain the performance parameters and geometric dimensions of the wind turbine.

[0119] The geometric dimensions of the enclosure are determined based on the fan's performance parameters and geometric dimensions, so that the fan can be installed inside the enclosure.

[0120] A three-dimensional model of the fan and housing was constructed to create a box-type fan model. The full three-dimensional flow field was simulated and calculated to obtain the inlet and outlet pressure distribution data and streamline distribution in the flow field of the box-type fan model without the guide vane installed. The difference ΔF2 between the inlet air pressure and the outlet air pressure of the box-type fan without the guide vane installed was also obtained.

[0121] Based on Bézier curves Constructing the guide vane profile, i.e. the horizontal cross-sectional curve of the guide surface of the guide vane, and determining the height of the guide vane according to the size of the inlet of the box body, so that the guide vane can be installed on the side of the inlet of the box body.

[0122] Wherein, P(t) is the coordinate of any point on the parametric Bezier curve, n is the order of the Bezier curve; i is the current order, i = 0, 1, 2, …, n; p i is the position vector of the preset vertex on the Bezier curve; B i，n (t) is the Bernstein basis function, t is the parameter variable of the Bezier curve, 0≤t≤1.

[0123] Taking n = 4 as an example, the guide vane profile is determined by the left and right fixed points and the middle three points, so a 4th order Bezier curve is selected to draw the guide vane profile, and the preset vertices P0, P1, P2, P3, P4 define the 4th order Bezier curve. The preset vertices P0 and P4 are the fixed points on the left and right sides, and the preset vertices P1, P2, P3 are the adjustable control points in the middle. By adjusting the position vectors of the preset vertices P1, P2, P3, the guide vane of the optimal profile corresponding to different fan performance parameters is obtained.

[0124] According to the guide vane profile (i.e. the horizontal cross-sectional curve of the guide surface of the guide vane) and the height of the guide vane, a three-dimensional model of the guide vane is established, and the guide vane model is assembled on the box fan model. The fluid domain of the box fan is re-adjusted.

[0125] The fluid domain of the box fan after assembling the guide vane is simulated and calculated by using numerical simulation software, and the inlet and outlet pressure distribution data of the box fan after assembling the guide vane and the stream line distribution in the flow field are obtained. The difference ΔF1 between the inlet air pressure and the outlet air pressure of the box fan after installing the guide vane is obtained.

[0126] The ΔF1 is compared with the initial calculation result (i.e. ΔF2). If the obtained ΔF1 is higher than ΔF2 by 10% or more under the rated operating condition, the guide vane of the optimal profile is obtained.

[0127] If the obtained ΔF1 does not meet the preset standard that it is higher than ΔF2 by 10% under the rated operating condition, the process of constructing the guide vane profile based on the Bezier curve is repeated. The guide vane profile and the subsequent steps are constructed. By adjusting the position vectors of the preset vertices P1, P2, P3, the shape of the guide vane profile is controlled to change, and a smooth curve is generated, until the obtained ΔF1 is higher than ΔF2 by 10% or more under the rated operating condition, and the guide vane profile equation of the optimal solution is obtained.

[0128] The design method of the guide plate provided by the embodiment of the application proposes a design method of an optimized guide plate of a box type fan air duct. First, the geometric size of the box is determined according to the performance parameters of the box type fan, and three-dimensional modeling simulation is performed. Then, the air duct optimized guide plate is constructed by using the Bezier curve. The box type fan with the added guide plate is simulated to obtain the optimized performance parameters. The optimized performance parameters are compared with the original model performance parameters. If the expected requirements are met, the optimal structure of the guide plate is obtained. If not, the guide plate profile is designed again by using the Bezier curve. By adding the guide plate with the optimal profile to the air inlet side of the box type fan, the air volume can be maximized, the backflow can be reduced, and the fan efficiency can be improved while the motor power remains unchanged.

[0129] It should be understood that the various forms of flow shown above can be used to reorder, add or delete steps. For example, each step described in the present application can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which is not limited herein.

[0130] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A deflector plate, characterized in that, For installation on the air inlet side of a box-type fan; The guide plate includes a guide portion with a guide surface, the guide portion having an axisymmetric structure, and the guide surface being a curved surface protruding outward from the air inlet; The guiding surface includes a first guiding surface and a second guiding surface, the first guiding surface and the second guiding surface are adjacent to each other, and the first guiding surface and the second guiding surface are symmetrically arranged with respect to the central axis of the guiding part; The box-type fan is equipped with an inlet flange at the air inlet, and the inlet flange includes an air inlet hole; the height of the guide plate is the same as the height of the air inlet hole. The box-type fan includes a box and a fan. The fan is installed in the box and includes a volute. Support frames are provided on both sides of the volute in the box. The support frames are placed vertically and fixedly connected to the volute. The length of the guide plate in the horizontal direction is the same as the distance between the two support frames on both sides of the fan. The guide plate also includes a first bend and a second bend located on both sides of the guide section; the first bend and the second bend are provided with mounting through holes, and the guide plate is fixedly connected to the support frame of the box-type fan through the mounting through holes; the horizontal cross section of the guide surface is a Bezier curve; The Bézier curve satisfies: ； in, Let be the coordinates of any point on the Bézier curve, n be the order of the Bézier curve, and n is a positive integer greater than 3; i is the current order, i = 0, 1, 2, ..., n; The position vector of a predefined vertex on the Bézier curve; These are Bernstein basis functions. ; t is the parameter variable of the Bézier curve, 0≤t≤1; The deflector is configured such that when it is installed on the box-type fan, (ΔF1-ΔF2) / ΔF2≥10%; where ΔF1 is the difference between the inlet air pressure and the outlet air pressure of the box-type fan after the deflector is installed, and ΔF2 is the difference between the inlet air pressure and the outlet air pressure of the box-type fan when the deflector is not installed.

2. The guide vane according to claim 1, characterized in that, On the horizontal cross-section of the guide surface, the tangent line passing through the endpoint of the first guide surface away from the second guide surface and tangent to the first guide surface is the first tangent line, and the tangent line passing through the endpoint of the second guide surface away from the first guide surface and tangent to the second guide surface is the second tangent line. The included angle between the first tangent line and the second tangent line is α, where 110°≤α≤130°.

3. The guide vane according to claim 1, characterized in that, The first bend includes an adjacent first bend portion and a second bend portion; The second bend includes a third bend and a fourth bend that are adjacent to each other; The first bending section and the third bending section are respectively connected to both sides of the guide section; The first bending portion and the third bending portion are in contact with the surface of the support frame near the flow guide portion; The mounting through hole is provided on the second bending section and the fourth bending section; The second bending section and the fourth bending section are fixedly connected to the inner surface of the support frame at the air inlet through the mounting through hole.

4. A box-type fan, characterized in that, Includes a housing, a support frame, a motor, a fan, and a guide plate as described in any one of claims 1-3; The support frame and the fan are located inside the housing, with the support frame located on opposite sides of the fan for supporting the fan; The motor is located outside the housing and is connected to the fan; The fan includes a volute and an impeller located inside the volute. A pulley is mounted on the support frame and is located outside the housing. The impeller is connected to the pulley via a shaft. The motor is mounted on the top of the housing, and the pulley and the motor are connected by a belt so that the motor drives the impeller to rotate. The enclosure includes an air inlet and an air outlet, and the baffle plate is installed on the air inlet side of the enclosure.

5. A method for designing a deflector, characterized in that, The method for designing the baffle according to any one of claims 1-3 includes: S1, According to Bézier curve Determine the horizontal cross-section of the guide surface of the guide plate; wherein, Let n be the coordinates of any point on the Bézier curve, n be the order of the Bézier curve, and i be the current order, i = 0, 1, 2, ..., n. The position vector of a predefined vertex on the Bézier curve; These are Bernstein basis functions. ; t is the parameter variable of the Bézier curve, 0≤t≤1; S2. Determine the height of the guide plate based on the height of the air inlet hole of the inlet flange of the box-type fan; wherein, the height of the guide plate is the same as the height of the air inlet hole; S3. Determine the structure of the guide plate based on the horizontal cross-section of the guide surface and the height of the guide plate; S4. Obtain the difference ΔF1 between the inlet air pressure and the outlet air pressure of the box-type fan after the guide plate is installed; S5. When (ΔF1-ΔF2) / ΔF2 < 10%, repeat steps S1 to S4 until (ΔF1-ΔF2) / ΔF2ΔF2 ≥ 10%, where ΔF2 is the difference between the inlet air pressure and the outlet air pressure of the box-type fan when the guide plate is not installed. According to Bézier curves Determining the horizontal cross-section of the guide surface of the guide plate includes: The preset vertex P0 and the preset vertex P are determined based on the spacing of the support frame of the box-type fan at the air inlet. n The position vector; wherein, the preset vertex P0 and the preset vertex P n The distance between them is the length of the guide surface in the horizontal direction, and the length of the guide surface in the horizontal direction is the same as the distance between the two support frames on both sides of the fan; According to the preset vertex P0 and the preset vertex P n The position vector determines at least three of the preset vertices P1~P n-1 ; According to the preset vertices P0~P n and the Bézier curve Determine the horizontal cross-section of the guide surface of the guide plate.

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