Strong crushing and high-efficiency blade impeller, fan including the impeller and design method thereof

Abstract

The invention discloses a strong crushing and high-efficiency blade-type impeller, a fan including the impeller and a design method thereof, and belongs to the technical field of accessories of road cleaning equipment. The invention solves the problems that the fan has low efficiency, cannot crush flaky garbage well, and easily blocks the flow channel in the fan, causing equipment paralysis. The main points of the technical scheme are that the impeller body comprises an impeller rear disc, a main blade which is annularly arrayed on the impeller rear disc and is in a circular arc shape, and a sub-blade which is arranged on the top of the main blade and has the same streamline shape as the main blade. The main blade comprises a plurality of long blades and a plurality of short blades arranged alternately, the inlet angle β1 of the long blade and the short blade is the same as that of 60-70°, the outlet angle β2 of the long blade and the short blade is the same as that of 65-75°, a large inclination angle is arranged at the inlet of the long blade, the angle α of the large inclination angle is 28-35°, the ratio of the inlet diameter D1 of the impeller body to the outlet diameter D2 of the impeller body is 0.25:0.35, and the effects of high efficiency, good strength performance and strong crushing ability are achieved.

Description

Technical Field

[0001] The invention relates to the field of accessories for road sweeping equipment, and in particular to a strong-crushing and high-efficiency blade-type impeller, a fan including the impeller and a design method thereof. Background Art

[0002] As the main force of urban sanitation, street sweepers play a vital role in the cleanliness of cities. The suction power source and key equipment for garbage crushing and recycling in street sweepers are their built-in centrifugal fans, which require large suction, good crushing function, and high fan efficiency. Taking the SCL4.0 street sweeper developed by Taizhou Huanfeng Energy Saving Technology Co., Ltd. as an example, after combining market requirements, the required air volume and pressure of the fan are as follows: speed N (rpm) greater than 2850, flow rate Q (m³ / h) between 2360-2957, total pressure P (Pa) between 2617-2405, and when the street sweeper is running, it also has a strong crushing function for wet flaky garbage (such as large leaves). The current conventional design of the fan structure (reference Figure 1 and Figure 2 As shown in the figure), the fan efficiency is low, the air volume and air pressure of the fan cannot meet the above requirements, and the flaky garbage cannot be crushed well, which easily blocks the flow channel in the fan and causes equipment paralysis. Summary of the invention

[0003] The purpose of the present invention is to address the shortcomings of the prior art and at least to some extent solve the technical problems in the related technology, and provide a strong crushing and high-efficiency blade impeller to achieve the purposes of high efficiency, good strength performance, strong crushing ability, rapid crushing of garbage, and not easy to cause blockage.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a strong crushing and high-efficiency blade impeller, including an impeller body, the impeller body includes an impeller rear disk, a main blade in an annular array on the impeller rear disk and in a circular arc shape, and a sub-blade arranged on the top of the main blade and consistent with the streamline shape of the main blade, the main blade includes a plurality of long blades and a plurality of short blades arranged alternately, the inlet angle β1 of the long blade and the short blade are the same, both are 60-70°, the outlet angle β2 of the long blade and the short blade are the same, both are 65-75°, a large inclination angle is provided at the inlet of the long blade, the angle α of the large inclination angle is 28-35°, the ratio of the inlet diameter D1 of the impeller body to the outlet diameter D2 of the impeller body is 0.25:0.35, the outlet width b of the long blade and the short blade are the same, and the ratio of the outlet width b of the long blade to the outlet diameter D2 of the impeller body is 0.13:0.2.

[0005] As a specific solution of the present invention, it may be preferred that: a round chamfer is provided at the inlet bottom of the long blade.

[0006] As a specific solution of the present invention, it may be preferred that: the number of the long blades and the number of the short blades are both 8.

[0007] As a specific solution of the present invention, it may be preferred that the inlet angles β1 of the long blades and the short blades are the same, both being 66°.

[0008] As a specific solution of the present invention, it may be preferred that the outlet angles β2 of the long blade and the short blade are the same, both being 70°.

[0009] As a specific solution of the present invention, it may be preferred that: the angle α of the large inclination angle is 31°.

[0010] The present application also proposes a fan, including a volute, on which a fan air inlet, a fan air outlet, a cleaning door and a pulley transmission device are provided, and also includes the above-mentioned strong crushing and high-efficiency blade impeller.

[0011] The present application also proposes a design method for the above-mentioned fan, comprising the following steps:

[0012] A. Carry out CFD numerical simulation analysis on the prototype fan, compare the numerical simulation performance curve calculated by CFD with the design input requirements, and determine whether it meets the design requirements and propose optimization directions;

[0013] a1. Model preprocessing and establishment of aerodynamic 3D model.

[0014] In the 3D modeling software, the aerodynamic 3D model of the prototype fan is established, and the fragmented parts that have no effect on the aerodynamics are removed. The establishment of the model meets the requirements of fan calculation preprocessing and physical model calculation. The fan is divided into a rotating domain and a stationary domain, and the relative coordinate system is used for calculation to improve the calculation robustness and efficiency.

[0015] a2. Aerodynamic mesh division,

[0016] Import the processed 3D aerodynamic model into the meshing software, establish the parts of the fan, locally encrypt the parts that have a significant impact on the calculation performance, such as the interface between the impeller and the domain, and the matching position between the air inlet and the impeller, and reasonably control the number of meshes and the quality of the meshes;

[0017] a3. Establishment of calculation model,

[0018] Import the divided grid into the CFD calculation software, set the model boundary conditions, select the turbulence model and calculation algorithm;

[0019] a4. Post-processing, extracting aerodynamic results,

[0020] In the post-processing software, the aerodynamic parameters of the fan are extracted to analyze the flow field, air volume, air pressure, and aerodynamic efficiency;

[0021] a5. Comparison of aerodynamic performance and design input requirements,

[0022] Extract the performance curve of the prototype fan, analyze the problems of the prototype fan, and propose optimization directions;

[0023] B. Optimization design research

[0024] b1. Aiming at the problems existing in analysis A, optimize the fan pneumatic model and select the best solution through gradual optimization and iteration;

[0025] b2. Conduct strength analysis on the optimized aerodynamic design scheme, control and eliminate the parts with excessive stress, so that the stress of the fan during operation is controlled within the allowable range; when all performances meet the design requirements, output the calculation scheme;

[0026] C. Experimental research

[0027] Output the design plan for the calculation and optimization results of B; build a test bench, test the manufactured fan in the test bench, and collect measured data; on this basis, compare and analyze the measured results with the calculated results to verify the accuracy of the calculated data and whether the test results meet the design requirements; if they cannot meet the requirements, perform iterative analysis on the calculated data; if they meet the requirements, the R&D project can be closed.

[0028] As a specific solution of the present invention, it may be preferred that: in step a3, the model inlet boundary condition is set to velocity, and the model outlet boundary condition is set to static pressure.

[0029] As a specific solution of the present invention, it may be preferred that: in step a3, the SST turbulence model is selected.

[0030] The technical effects of the present invention are mainly reflected in the following aspects: 1. A sub-blade consistent with the streamline shape of the main blade is provided at the top of the main blade to improve the crushing capacity; 2. A long and short blade scheme is adopted to reduce the blockage of the airflow at the inlet of the impeller body; 3. A large inclination angle is provided at the inlet of the long blade to effectively increase the crushing edge length of the long blade, thereby effectively increasing the crushing capacity of the long blade; 4. A rounded chamfer is provided at the bottom of the inlet of the long blade, which can be used to eliminate the local stress of the long blade and effectively avoid the deformation of the long blade from affecting the accuracy of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the overall structure of the prototype fan;

[0032] Figure 2 This is a schematic diagram of the structure of the prototype fan impeller;

[0033] Figure 3 It is a schematic diagram of the three-dimensional structure of the strong crushing and high-efficiency blade-type impeller of the present invention;

[0034] Figure 4 This is a schematic diagram of the main structure of the strong crushing and high-efficiency blade-type impeller of the present invention;

[0035] Figure 5 It is a schematic cross-sectional structure diagram of the strong crushing and high-efficiency blade-type impeller of the present invention;

[0036] Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure in the AA direction;

[0037] Figure 7 It is a schematic diagram of the three-dimensional structure of the fan of the present invention;

[0038] Figure 8 A schematic diagram of the three-dimensional structure of the fan of the present invention from another perspective;

[0039] Fig. 9 A pre-processed 3D model of the prototype wind turbine as a whole;

[0040] Fig.10 A pre-processed 3D model of the prototype fan impeller;

[0041] Fig.11 This is the mesh division diagram of the prototype wind turbine as a whole;

[0042] Fig.12 This is the mesh division diagram of the prototype fan impeller;

[0043] Fig.13 This is the CFD performance curve of the prototype fan;

[0044] Fig.14 This is a schematic diagram of the three-dimensional structure of the impeller of the OPT2 model fan;

[0045] Fig.15 This is a schematic diagram of the three-dimensional structure of the impeller of the OPT3 model fan;

[0046] Fig.16 The CFD performance comparison chart of the prototype fan, OPT2 model fan and OPT3 model fan;

[0047] Fig.17 This is a stress test diagram of the OPT3 model fan impeller when the bottom of the long blade inlet has no round chamfer;

[0048] Fig.18 This is a stress test diagram of the OPT3 model fan impeller with a rounded chamfer at the bottom of the long blade inlet;

[0049] Fig.19 This is a flow chart of the research path of the fan design method of the present invention.

[0050] Figure numerals: 1. impeller rear disc; 2. main blade; 21. long blade; 22. short blade; 3. sub-blade; 4. large inclination angle; 5. round chamfer; 6. volute; 7. fan air inlet; 8. fan air outlet; 9. cleaning door; 10. pulley transmission device. DETAILED DESCRIPTION

[0051] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention so that the technical solution of the present invention is easier to understand and grasp, but should not be understood as a limitation to the present invention. Example

[0052] Strong crushing and high efficiency blade impeller, reference Figure 3-6 As shown, the strong crushing and high-efficiency blade impeller of the present invention includes an impeller body, the impeller body includes an impeller rear disk, a main blade in an annular array on the impeller rear disk and in a circular arc shape, and a sub-blade arranged on the top of the main blade and consistent with the streamline shape of the main blade. The streamline shape of the main blade is in a circular arc shape, and it forms an arc along the streamline shape. The streamline shape of the sub-blade is consistent with the main blade and is also in a circular arc shape, and it also forms an arc along the streamline shape. The center of the arc presented by the main blade along the streamline shape is at the same point as the center of the arc presented by the sub-blade along the streamline shape. The blade of the sub-blade faces forward, and the cutting direction is consistent with the rotation direction of the impeller body. The main blade includes alternately arranged A plurality of long blades and a plurality of short blades are arranged, the inlet angle β1 of the long blades and the short blades are the same, both being 60-70°, the outlet angle β2 of the long blades and the short blades are the same, both being 65-75°, a large inclination angle is arranged at the inlet of the long blade, and the angle α of the large inclination angle is 28-35°. The design of the large inclination angle can effectively increase the crushing edge length of the long blade, and effectively increase the crushing capacity of the long blade, the ratio of the inlet diameter D1 of the impeller body to the outlet diameter D2 of the impeller body is 0.25:0.35, the outlet width b of the long blades and the short blades is the same, and the ratio of the outlet width b of the long blade to the outlet diameter D2 of the impeller body is 0.13:0.2.

[0053] The inlet bottom of the long blade is provided with a round chamfer, which can be used to eliminate the local stress of the long blade and effectively prevent the deformation of the long blade from affecting the accuracy of use.

[0054] Preferably, the number of the long blades and the number of the short blades are both 8.

[0055] Preferably, the inlet angles β1 of the long blades and the short blades are the same, both being 66°.

[0056] Preferably, the outlet angles β2 of the long blades and the short blades are the same, both being 70°.

[0057] Preferably, the angle α of the large inclination is 31°.

[0058] This application also proposes a fan, reference Figure 7 and Figure 8 , including a volute, on which a fan air inlet, a fan air outlet, a cleaning door and a pulley transmission device are arranged, and also includes the above-mentioned strong crushing and high-efficiency blade impeller.

[0059] refer to Fig.19 As shown, the present application also proposes a design method for the above-mentioned fan, comprising the following steps:

[0060] A. Carry out CFD numerical simulation analysis on the prototype fan, compare the numerical simulation performance curve calculated by CFD with the design input requirements, and determine whether it meets the design requirements and propose optimization directions;

[0061] a1. Model preprocessing and establishment of aerodynamic 3D model.

[0062] refer to Figure 1 As shown in the figure, in Solidworks, UG and other 3D modeling software, the aerodynamic 3D model of the prototype fan is established, and the fragmented parts that have no effect on the aerodynamics are removed. The establishment of the model meets the requirements of fan calculation preprocessing and physical model calculation. The fan is divided into a rotating domain (such as an impeller) and a stationary domain (such as a volute). The relative coordinate system is used for calculation to improve the calculation robustness and efficiency. The preprocessing 3D model reference Fig. 9 and Fig.10 As shown;

[0063] a2. Aerodynamic mesh division,

[0064] Import the processed 3D aerodynamic model into ICEM and other meshing software, establish the parts of the fan, locally encrypt the parts that have a significant impact on the calculation performance, such as the interface between the impeller and the domain, and the matching position between the air inlet and the impeller, and reasonably control the number of meshes and the quality of the mesh. The meshing diagram is referenced Fig.11 and Fig.12 As shown;

[0065] a3. Establishment of calculation model,

[0066] Import the divided grid into CFD calculation software such as CFX or Fluent, set the model boundary conditions, select the turbulence model, and the calculation algorithm. Preferably, set the model inlet boundary condition to velocity and the model outlet boundary condition to static pressure. Since this type of fan has large swirl and shear flow, preferably, select the SST turbulence model;

[0067] a4. Post-processing, extracting aerodynamic results,

[0068] In the post-processing software, the aerodynamic parameters of the fan are extracted to analyze the flow field, air volume, air pressure, and aerodynamic efficiency;

[0069] a5. Comparison of aerodynamic performance and design input requirements,

[0070] Extract the performance curve of the prototype fan, analyze the problems of the prototype fan, and propose optimization directions;

[0071] refer to Fig.13 As shown, through the analysis of the aerodynamic performance curve, it can be seen that the highest efficiency is about 51%, the corresponding operating flow is 1283m³ / h, and the total pressure is 2188Pa. When the efficiency is in the high-efficiency zone above 46%, the corresponding air volume is 933~1633m³ / h, and the air pressure is 2305~1866Pa. The air volume and air pressure are both smaller than the air volume of 2360~2957m³ / h and the air pressure of 2617~2405Pa given in the background technology, especially the air volume is much smaller than the given data. By comparison, it can be seen that the air volume and pressure of the original model cannot meet the design requirements;

[0072] B. Optimization design research

[0073] b1. Aiming at the problems existing in analysis A, optimize the fan pneumatic model and select the best solution through gradual optimization and iteration.

[0074] Through A's analysis of the prototype fan, it can be seen that the prototype fan has a blockage phenomenon. There are two reasons for this: 1. The main blade inlet is blocked. The structure that blocks the airflow at the inlet is removed, and the long and short blade scheme is adopted at the same time; 2. The air volume and pressure of the prototype fan do not meet the design requirements, that is, the suction is not enough. Therefore, this optimization plan starts with the optimization of the blockage.

[0075] like Fig.14 and Fig.15 As shown in the figure, two sets of optimization schemes were adopted: the impeller of the OPT2 model fan is a straight blade type main blade, there is no inclination at the entrance of the long blade, the sub-blade is backward, and the cutting direction is opposite to the impeller rotation direction; the impeller of the OPT3 model fan includes an impeller body, the impeller body includes an impeller rear disk, an annular array of arc-shaped main blades on the impeller rear disk, and a sub-blade arranged on the top of the main blade with the same streamline shape as the main blade, the sub-blade is forward, and the cutting direction is consistent with the impeller body rotation direction, and the main blade includes a plurality of alternately arranged Long blades and several short blades, the inlet angle β1 of long blades and short blades is the same, both are 60-70°, the outlet angle β2 of long blades and short blades is the same, both are 65-75°, a large inclination angle is set at the inlet of the long blade, the angle α of the large inclination angle is 28-35°, the ratio of the inlet diameter D1 of the impeller body to the outlet diameter D2 of the impeller body is 0.25:0.35, the outlet width b of the long blades and short blades is the same, the ratio of the outlet width b of the long blade to the outlet diameter D2 of the impeller body is 0.13:0.2. The same CFD calculation method is used to analyze the performance comparison of each scheme. Reference Fig.16As shown, it can be seen that the efficiency and pressure of the OPT3 model fan are improved to a certain extent compared with the OPT2 model fan, and the impeller scheme of the OPT3 model fan adopts 8 long blades and 8 short blades, the inlet angle β1 of the long blades and the short blades are the same, both are 66°, the outlet angle β2 of the long blades and the short blades are the same, both are 70°, and the large inclination angle α is 31°. It has better fan efficiency and crushing function. Therefore, the final aerodynamic optimization scheme selects the OPT3 model fan.

[0076] b2. Since the long blades of the OPT3 model fan have a large inclination angle at the inlet, and the connection between the long blades and the rear disc of the impeller is a sharp angle, there is a large stress concentration during operation, which is not conducive to safe and reliable operation. Fig.17 and 18 As shown, the bottom of the inlet of the long blade is provided with a round chamfer. After testing, the stress in this part is greatly reduced and the stress is controlled within the allowable range. When all performances meet the design requirements, the calculation plan is output;

[0077] C. Experimental research

[0078] Output the design plan for the calculation and optimization results of B. Build a test bench, test the manufactured fan in the test bench, and collect measured data. On this basis, compare and analyze the measured results with the calculated results to verify the accuracy of the calculated data and whether the test results meet the design requirements. If the requirements cannot be met, iteratively analyze the calculated data; if the requirements are met, the R&D project can be closed.

[0079] Of course, the above are only typical examples of the present invention. In addition, the present invention may also have many other specific implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. Strong crushing and high efficiency blade impeller, including an impeller body, characterized by: The impeller body includes an impeller rear disk, a main blade in an annular array on the impeller rear disk and in an arc shape, and a sub-blade arranged on the top of the main blade and consistent with the streamline shape of the main blade. The streamline shape of the main blade is in an arc shape, and it forms an arc along the streamline shape. The streamline shape of the sub-blade is consistent with the main blade and is also in an arc shape, and it also forms an arc along the streamline shape. The center of the arc presented by the main blade along the streamline shape and the center of the arc presented by the sub-blade along the streamline shape are at the same point. The blade of the sub-blade faces forward, and the cutting direction is consistent with the rotation direction of the impeller body. The main blade includes a plurality of long blades and a plurality of short blades arranged alternately. The long blade The inlet angle β1 of the long blade is the same as that of the short blade, which is 60-70°. The outlet angle β2 of the long blade and the short blade is the same as that of the long blade, which is 65-75°. A large inclination angle is provided at the inlet of the long blade, and the angle α of the large inclination angle is 28-35°. The design of the large inclination angle can effectively increase the crushing edge length of the long blade, and effectively increase the crushing capacity of the long blade. The ratio of the inlet diameter D1 of the impeller body to the outlet diameter D2 of the impeller body is 0.25:0.35, the outlet width b of the long blade and the short blade is the same, and the ratio of the outlet width b of the long blade to the outlet diameter D2 of the impeller body is 0.13:0.2; the sub-blade is perpendicular to the main blade.

2. The strong crushing and high efficiency blade impeller according to claim 1, characterized in that: The inlet bottom of the long blade is provided with a round chamfer.

3. The strong crushing and high efficiency blade impeller according to claim 1, characterized in that: The number of the long blades and the number of the short blades are both 8.

4. The strong crushing and high efficiency blade impeller according to claim 1, characterized in that: The inlet angles β1 of the long blades and the short blades are the same, both being 66°.

5. The strong crushing and high efficiency blade impeller according to claim 1, characterized in that: The outlet angles β2 of the long blades and the short blades are the same, both being 70°.

6. The strong crushing and high efficiency blade impeller according to claim 1, characterized in that: The angle α of the large inclination is 31°.

7. A fan, comprising a volute, the volute being provided with a fan air inlet, a fan air outlet, a cleaning door and a pulley transmission device, characterized in that: It also comprises the strong crushing and high-efficiency blade impeller according to any one of claims 1-6.

8. A method for designing a fan, for completing the fan as claimed in claim 7, characterized in that: The following steps are involved: A. Carry out CFD numerical simulation analysis on the prototype fan, compare the numerical simulation performance curve calculated by CFD with the design input requirements, and determine whether it meets the design requirements and propose optimization directions; a1. Model preprocessing and establishment of aerodynamic 3D model. In the 3D modeling software, the aerodynamic 3D model of the prototype fan is established, and the fragmented parts that have no effect on the aerodynamics are removed. The establishment of the model meets the requirements of fan calculation preprocessing and physical model calculation. The fan is divided into a rotating domain and a stationary domain, and the relative coordinate system is used for calculation to improve the calculation robustness and efficiency. a2. Aerodynamic mesh division, Import the processed 3D aerodynamic model into the meshing software, establish the parts of the fan, locally encrypt the parts that have a significant impact on the calculation performance, such as the interface between the impeller and the domain, and the matching position between the air inlet and the impeller, and reasonably control the number of meshes and the quality of the meshes; a3. Establishment of calculation model, Import the divided grid into the CFD calculation software, set the model boundary conditions, select the turbulence model and calculation algorithm; a4. Post-processing, extracting aerodynamic results, In the post-processing software, the aerodynamic parameters of the fan are extracted to analyze the flow field, air volume, air pressure, and aerodynamic efficiency; a5. Comparison of aerodynamic performance and design input requirements, Extract the performance curve of the prototype fan, analyze the problems of the prototype fan, and propose optimization directions; B. Optimization design research b1. Aiming at the problems existing in analysis A, optimize the fan pneumatic model and select the best solution through gradual optimization and iteration; b2. Conduct strength analysis on the optimized aerodynamic design scheme, control and eliminate the parts with excessive stress, so that the stress of the fan during operation is controlled within the allowable range; when all performances meet the design requirements, output the calculation scheme; C. Experimental research Output the design plan based on the calculation and optimization results of B; Build a test bench, test the manufactured fan in the test bench, and collect measured data; On this basis, the measured results are compared and analyzed with the calculated results to verify the accuracy of the calculated data and whether the test results meet the design requirements; If the requirements cannot be met, iterative analysis of the calculated data is performed; If the requirements are met, the R&D project can be closed.

9. The design method of a fan according to claim 8, characterized in that: In step a3, the model inlet boundary condition is set to velocity, and the model outlet boundary condition is set to static pressure.

10. The design method of a fan according to claim 8, characterized in that: In step a3, the SST turbulence model is selected.

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