High static pressure centrifugal axial flow fan
By designing a high-static pressure centrifugal axial flow fan, using a structure of centrifugal impeller and a specific taper ratio, the existing axial flow fan stalls and surges at high pressure and small flow rates, achieving lower noise and higher efficiency fan performance.
Patent Information
- Application Number
- CN202421642456.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-12
- Publication Date
- 2025-04-11
- Estimated Expiration
- 2034-07-12
AI Technical Summary
Existing axial flow fans are noise high when designed with high pressure, and are prone to stall or surge when flow is small, resulting in low static pressure and reduced efficiency.
A high-static pressure centrifugal axial flow fan is designed, adopting a centrifugal impeller structure. The taper of the front conical disc of the impeller is greater than the taper of the rear conical disc of the impeller. The ratio of the inner diameter of the air cylinder to the outer diameter of the centrifugal impeller is between 1.5 and 1.85 to ensure that the air flow does not stall in the small flow area.
It realizes that the fan can still work normally when the flow rate in the high-pressure zone, avoid stalling and surge, reduce noise and improve efficiency.
Smart Images
Figure CN222746282U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of axial flow fans, in particular to a high static pressure centrifugal axial flow fan. Background Art
[0002] Axial flow fans are widely used in civil, industrial, subway, nuclear power and other industries due to their simple structure and high flow rate. The application of fan equipment in nuclear power plants has its own unique requirements. Due to site restrictions and the complexity of the HVAC system, there is often a demand for axial flow fans with small flow and high pressure.
[0003] At present, axial flow fans are also accompanied by high noise when designed at high pressure, and will also stall at low flow rates. They are sensitive to the resistance characteristics of the pipe network and generally have low static pressure, which causes axial flow fans to surge at low flow rates in high pressure areas, increasing the internal pressure loss of the fan and reducing the fan efficiency. Utility Model Content The purpose of the utility model is to provide a high static pressure centrifugal axial flow fan that can continue to work at low flow rates in high pressure areas without stalling or surging, so as to solve the problems existing in the above-mentioned prior art. Utility Model Content
[0004] The utility model aims to provide a high static pressure centrifugal axial flow fan, which can continue to work without stalling or surging when the flow rate is small in the high pressure area, so as to solve the problems existing in the above-mentioned prior art.
[0005] To achieve the above purpose, the utility model provides the following solutions:
[0006] The utility model provides a high static pressure centrifugal axial flow fan, comprising:
[0007] Hair dryer;
[0008] A centrifugal impeller is coaxially arranged in the air duct, the centrifugal impeller comprises a shaft disk, an impeller front cone disk, an impeller rear cone disk and blades, the impeller rear cone disk is coaxially connected to the shaft disk, and the small end to the large end of the impeller rear cone disk are arranged along the airflow direction, the impeller front cone disk is spaced in front of the impeller rear cone disk and is coaxial with the impeller rear cone disk, and the small end to the large end of the impeller front cone disk are arranged along the airflow direction, and the edges of the impeller front cone disk and the impeller rear cone disk are connected by a plurality of the blades;
[0009] A collector is arranged at the air inlet of the wind tube, and the collector can introduce the airflow into the small head end of the front cone of the impeller;
[0010] The motor is arranged in the wind tube, the output shaft of the motor is coaxially connected with the shaft disc, and the motor is used to drive the centrifugal impeller to rotate.
[0011] Preferably, the outer edge of the impeller front cone disk and the outer edge of the impeller rear cone disk are located on the same cylindrical surface, and the cylindrical surface is coaxial with the shaft disk; the blades are located in the centrifugal impeller and are arranged close to the outer edge of the impeller front cone disk and the outer edge of the impeller rear cone disk.
[0012] Preferably, the taper of the impeller front cone disk is greater than the taper of the impeller rear cone disk.
[0013] Preferably, the wind cylinder is a cylindrical wind cylinder, and the ratio of the inner diameter d1 of the wind cylinder to the outer contour diameter D1 of the centrifugal impeller is ξ=d1 / D1, and the value of ξ is 1.5-1.85.
[0014] Preferably, it further comprises a guide vane disposed in the wind tube, wherein the guide vane is located at an end of the centrifugal impeller away from the collector.
[0015] Preferably, the guide vanes are arranged on the outer periphery of the motor, and a plurality of the guide vanes are evenly distributed in a circle with the axis of the wind cylinder as the center.
[0016] Preferably, the inner end of any one of the guide vanes is connected to the motor, and the outer end of any one of the guide vanes is spaced apart from the inner wall of the wind tube.
[0017] Preferably, the small head end of the impeller front cone is rotatably connected to the air outlet of the collector, so that the interior of the collector is connected to the interior of the centrifugal impeller to form an air flow channel.
[0018] Preferably, the collector is a conical collector, which is arranged inside the wind tube, and the large end to the small end of the conical collector are arranged along the airflow direction, and the small end of the conical collector is rotatably connected to the small end of the impeller front cone disk.
[0019] Compared with the prior art, the utility model has achieved the following technical effects:
[0020] The high static pressure centrifugal axial flow fan proposed by the utility model has a novel and reasonable structure. The centrifugal impeller is directly connected to the motor. The motor is installed inside the wind tube. The centrifugal impeller rotates to do work on the gas, which can generate higher potential energy to transport the gas out. This fan has the following characteristics:
[0021] (1) The structure is simple and has no volute. Compared with the counter-cyclone fan and the fan-in-series fan, which both require at least two impellers and two motors, it is more economical and has lower requirements for installation space, and has a wider range of applications.
[0022] (2) The air flow direction entering the air duct is coaxial with the centrifugal impeller, which occupies less space and is more flexible and convenient to install and use.
[0023] (III) The taper of the front cone disk of the centrifugal impeller is greater than the taper of the rear cone disk of the impeller, forming a backward inclined impeller. The centrifugal impeller is coaxially installed with the wind cylinder, and the ratio ξ of the inner diameter d1 of the wind cylinder to the outer contour diameter D1 of the centrifugal impeller is set to 1.5-1.85, which can ensure that the gap between the centrifugal impeller and the wind cylinder is sufficient for the air flow to flow through, and at the same time can control the gap between the centrifugal impeller and the wind cylinder within a smaller range. Combined with the structural characteristics of the centrifugal impeller's oblique rear exhaust (which is based on the design that the taper of the front cone disk of the impeller is greater than the taper of the rear cone disk of the impeller), it can avoid the axial flow fan in the small flow area from stalling due to boundary layer separation and surging.
[0024] (IV) Due to the centrifugal impeller structure with flat performance curve, extremely wide effective working area, no stall in small flow area, high pressure and other characteristics, the noise is lower than that of general axial flow fans and the efficiency is higher than that of multi-blade fans. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0026] Figure 1 It is a schematic structural diagram of a high static pressure centrifugal axial flow fan without guide vanes disclosed in the utility model;
[0027] Figure 2 It is a structural schematic diagram of a high static pressure centrifugal axial flow fan with guide vanes disclosed in the utility model;
[0028] Figure 3 It is a schematic diagram of the structure of the centrifugal impeller disclosed in the embodiment of the utility model;
[0029] Figure 4 It is a schematic diagram of the airflow direction of the high static pressure centrifugal axial flow fan (with guide vanes) disclosed in the utility model;
[0030] Figure 5 It is the performance curve diagram of the existing centrifugal fan;
[0031] Figure 6 It is the performance curve diagram of the existing axial flow fan;
[0032] Figure 7 This is the performance curve of the high static pressure centrifugal axial flow fan disclosed in the utility model;
[0033] Figure 8The utility model discloses a noise comparison diagram of the high static pressure centrifugal axial flow fan, the existing multi-blade fan, and the existing axial flow fan.
[0034] In the figure, the reference numerals are:
[0035] 100. High static pressure centrifugal axial flow fan;
[0036] 1. Hair dryer;
[0037] 2. Centrifugal impeller; 21. Shaft disk; 22. Impeller front cone disk; 23. Impeller rear cone disk; 24. Blades;
[0038] 3. Current collector;
[0039] 4. Motor;
[0040] 5. Guide vane. DETAILED DESCRIPTION
[0041] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0042] The utility model aims to provide a high static pressure centrifugal axial flow fan, which can continue to work without stalling or surging when the flow rate is small in the high pressure area, so as to solve the problems existing in the existing axial flow fans.
[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0044] like Figure 1 to Figure 4As shown, this embodiment provides a high static pressure centrifugal axial flow fan 100, including a wind tube 1, a centrifugal impeller 2, a collector 3 and a motor 4, the centrifugal impeller 2 is arranged in the wind tube 1 and coaxially arranged with the wind tube 1, the centrifugal impeller 2 includes a shaft disk 21, an impeller front cone disk 22, an impeller rear cone disk 23 and blades 24, the impeller rear cone disk 23 is coaxially connected with the shaft disk 21, and the small end to the large end of the impeller rear cone disk 23 are arranged along the air flow direction (that is, the large end of the impeller rear cone disk 23 is away from the air inlet of the wind tube 1), and the blades The front cone disk 22 is arranged in front of the rear cone disk 23 of the impeller at intervals and is coaxial with the rear cone disk 23 of the impeller. The small end to the large end of the front cone disk 22 of the impeller are arranged along the airflow direction (that is, the large end of the front cone disk 22 of the impeller is away from the air inlet of the wind tube 1). An airflow cavity is formed between the front cone disk 22 of the impeller and the rear cone disk 23 of the impeller. The edges of the front cone disk 22 of the impeller and the rear cone disk 23 of the impeller are connected by a plurality of blades 24, and the blades 24 are evenly spaced along the circumferential direction of the front cone disk 22 of the impeller and the rear cone disk 23 of the impeller. The collector 3 is arranged at the air inlet of the wind tube 1, such as Figure 1 As shown, the collector 3 can introduce the airflow into the small end of the impeller front cone disk 22, the motor 4 can be fixed in the wind tube 1 through the motor support and other mounting structures, the output shaft of the motor 4 is directly connected to the shaft disk 21 of the centrifugal impeller 2, and the output shaft of the motor 4 is coaxially connected to the shaft disk 21 of the centrifugal impeller 2, and the motor 4 is used to drive the centrifugal impeller 2 to rotate, so that the gas entering the airflow cavity between the impeller front cone disk 22 and the impeller rear cone disk 23 through the small end of the impeller front cone disk 22 is subjected to centrifugal force and flows out through the edge of the airflow cavity. Figure 1 As shown in , the arrows indicate the flow direction of the airflow in the high static pressure centrifugal axial flow fan 100 .
[0045] In this embodiment, Figure 1 to Figure 4 As shown, the outer edge of the impeller front cone disk 22 and the outer edge of the impeller rear cone disk 23 are located on the same cylindrical surface, and the cylindrical surface is coaxial with the shaft disk 21; the blade 24 is located in the centrifugal impeller 2 and is arranged close to the outer edge of the impeller front cone disk 22 and the outer edge of the impeller rear cone disk 23, as shown in FIG. Figure 3 As shown, the blades 24 do not extend beyond the outer edges of the impeller front cone 22 and the impeller rear cone 23 .
[0046] In this embodiment, it is preferred that the taper of the impeller front cone disk 22 is greater than the taper of the impeller rear cone disk 23. The larger the taper, the sharper the cone disk, and the smaller the angle between the corresponding cone disk generatrix and the cone disk axis; compared with the impeller rear cone disk 23, the impeller front cone disk 22 has a larger taper, a sharper cone disk, and a smaller angle between the cone disk generatrix and the cone disk axis. Correspondingly, the impeller rear cone disk 23 has a smaller taper, a gentler cone disk, and a larger angle between the cone disk generatrix and the cone disk axis. Figure 3As shown, by setting the taper of the impeller front cone disk 22 to be greater than the taper of the impeller rear cone disk 23, the gas entering the airflow cavity of the centrifugal impeller 2 can have a tendency to flow backward. By the structural design that the taper of the impeller front cone disk is greater than the taper of the impeller rear cone disk, the edge of the inner airflow cavity of the centrifugal impeller 2 is tilted backward, thereby forming a backward inclined impeller, which can make the airflow discharged obliquely backward.
[0047] In this embodiment, the wind tube 1 is preferably a cylindrical tube-type wind tube, which is a component for collecting and conveying gas. The ratio of the inner diameter d1 of the wind tube 1 to the outer contour diameter D1 of the centrifugal impeller 2 (i.e., the diameter of the aforementioned cylindrical surface) is ξ=d1 / D1, and the value of ξ is preferably 1.5 to 1.85. The outside of the wind tube 1 is generally provided with mounting feet, reinforcing ribs, brackets and other components for equipment structure reinforcement and installation.
[0048] In this embodiment, a guide vane 5 is also provided in the wind tube 1, and the guide vane 5 is located at the end of the centrifugal impeller 2 away from the collector 3. Figure 1 As shown in FIG. 1 , when the guide vane 5 is not provided, the airflow is discharged along the original arc route after being guided out through the edge of the centrifugal impeller 2; and as shown in FIG. Figure 4 As shown, after the guide vane 5 is arranged behind the centrifugal impeller 2, the guide vane 5 can guide the airflow so that the airflow is discharged parallel to the axial direction of the air cylinder 1.
[0049] In this embodiment, the guide vanes 5 are preferably arranged on the outer periphery of the motor 4, and a plurality of guide vanes 5 are evenly distributed in a circle with the axis of the wind tube 1 as the center. The inner end of any guide vane 5 is connected to the motor 4, and the outer end of any guide vane 5 is arranged at intervals from the inner wall of the wind tube 1. The guide vanes 5 are axial guide vanes, which can arrange the airflow discharged by the centrifugal impeller 2 into a horizontal airflow parallel to the axial direction of the wind tube 1. The axial guide vanes are a conventional design in axial flow fans, and the specific structure and functional principle will not be repeated here.
[0050] In this embodiment, the small end of the impeller front cone 22 is preferably rotatably connected to the air outlet of the collector 3, so that the interior of the collector 3 is connected to the interior of the centrifugal impeller 2 to form an air flow channel, and the collector 3 will not hinder the rotation of the centrifugal impeller 2.
[0051] In this embodiment, the collector 3 is preferably a conical collector. The conical collector is arranged inside the air duct 1, and the large end to the small end of the conical collector are arranged along the airflow direction, the small end of the conical collector is rotatably connected to the small end of the impeller front cone 22, the large end of the conical collector is generally arranged flush with the front air inlet of the air duct 1, and the diameter of the large end of the conical collector is equal to or slightly smaller than the inner diameter of the air duct 1, so as to ensure that all the airflow entering the air duct 1 enters the conical collector, and then the airflow is sent to the centrifugal impeller 2 through the gathering effect of the small end of the conical collector.
[0052] When in use, the airflow follows Figure 4 The "airflow direction" shown in the figure enters the collector 3, is collected by the collector 3 and sent to the airflow cavity in the centrifugal impeller 2, and then the motor 4 drives the centrifugal impeller 2 to rotate, so that the airflow flows to the edge of the centrifugal impeller 2 under the action of the centrifugal force, and is discharged from the centrifugal impeller 2 obliquely backward under the action of the backward inclined structure of the edge of the centrifugal impeller 2. The discharged airflow is arranged by the guide vane 5 to form a parallel wind and be discharged from the wind tube 1. For specific airflow direction, see Figure 4 Arrow in the.
[0053] The high static pressure centrifugal axial flow fan 100 has a novel and reasonable structure. The centrifugal impeller is directly connected to the motor. The motor is installed inside the wind tube. The centrifugal impeller rotates to work on the gas, which can generate higher potential energy to transport the gas. This fan has the following characteristics:
[0054] A. The structure is simple and has no volute. Compared with the counter-cyclone fan and fan-in-series fan, which both require at least 2 impellers and 2 motors, it is more economical and has lower requirements for installation space, and has a wider range of applications.
[0055] B. The airflow direction entering the air duct is coaxial with the centrifugal impeller, which occupies less space and is more flexible and convenient to install and use.
[0056] C. The taper of the front cone disk of the centrifugal impeller is greater than the taper of the rear cone disk of the impeller, forming a backward inclined impeller. The centrifugal impeller is coaxially installed with the wind cylinder, and the ratio ξ of the inner diameter d1 of the wind cylinder to the outer contour diameter D1 of the centrifugal impeller is set to 1.5-1.85, which can ensure that the gap between the centrifugal impeller and the wind cylinder is sufficient for the air flow to flow through, and at the same time can control the gap between the centrifugal impeller and the wind cylinder within a smaller range. Combined with the structural characteristics of the centrifugal impeller's oblique rear exhaust (which is based on the design that the taper of the front cone disk of the impeller is greater than the taper of the rear cone disk of the impeller), it can avoid the axial flow fan in the small flow area from stalling due to boundary layer separation and surging.
[0057] D. Due to the centrifugal impeller structure, it has a flat performance curve, a very wide effective working area, no stall in the small flow area, and high pressure. Figures 5 to 8 The performance curve of the high static pressure centrifugal axial flow fan 100 has no hump, the noise is lower than that of the general axial flow fan, and the efficiency is higher than that of the multi-blade fan. Figure 5 to Figure 7 In the table, P represents pressure (pa), Q represents flow rate (m 3 / h), N represents power (kW); Figure 8 In the figure, the SPL on the ordinate represents the sound pressure level, and the Q on the abscissa represents the flow rate.
[0058] It can be seen that the high static pressure centrifugal axial flow fan 100 of the utility model achieves the purpose of reducing the internal pressure loss of the fan and improving the efficiency of the fan by modifying the design form of the axial flow fan and the reshaping design of the impeller, and can continue to work without stalling or surging at a small flow rate in the high-pressure area, thereby solving the problem of the existing small air volume and high static pressure axial flow fans, the difficulty in manufacturing and the problem of surging in the small flow area.
[0059] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of the present invention. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. A high static pressure centrifugal axial flow fan, characterized in that: include: Hair dryer; A centrifugal impeller is coaxially arranged in the air duct, the centrifugal impeller comprises a shaft disk, an impeller front cone disk, an impeller rear cone disk and blades, the impeller rear cone disk is coaxially connected to the shaft disk, and the small end to the large end of the impeller rear cone disk are arranged along the airflow direction, the impeller front cone disk is spaced in front of the impeller rear cone disk and is coaxial with the impeller rear cone disk, and the small end to the large end of the impeller front cone disk are arranged along the airflow direction, and the edges of the impeller front cone disk and the impeller rear cone disk are connected by a plurality of the blades; A collector is arranged at the air inlet of the wind tube, and the collector can introduce the airflow into the small head end of the front cone of the impeller; The motor is arranged in the wind tube, the output shaft of the motor is coaxially connected with the shaft disc, and the motor is used to drive the centrifugal impeller to rotate.
2. The high static pressure centrifugal axial flow fan according to claim 1, characterized in that: The outer edge of the impeller front cone disk and the outer edge of the impeller rear cone disk are located on the same cylindrical surface, and the cylindrical surface is coaxial with the shaft disk; the blades are located in the centrifugal impeller and are arranged close to the outer edge of the impeller front cone disk and the outer edge of the impeller rear cone disk.
3. The high static pressure centrifugal axial flow fan according to claim 2, characterized in that: The taper of the impeller front cone disk is greater than the taper of the impeller rear cone disk.
4. The high static pressure centrifugal axial flow fan according to claim 2 or 3, characterized in that: The wind cylinder is a cylindrical wind cylinder, and the ratio of the inner diameter d1 of the wind cylinder to the outer contour diameter D1 of the centrifugal impeller is ξ=d1 / D1, and the value of ξ is 1.5-1.
85.
5. The high static pressure centrifugal axial flow fan according to claim 4, characterized in that: It also includes a guide vane arranged in the wind tube, and the guide vane is located at an end of the centrifugal impeller away from the collector.
6. The high static pressure centrifugal axial flow fan according to claim 5, characterized in that: The guide vanes are arranged on the outer periphery of the motor, and a plurality of the guide vanes are evenly distributed in a circle with the axis of the wind tube as the center.
7. The high static pressure centrifugal axial flow fan according to claim 6, characterized in that: The inner end of any one of the guide vanes is connected to the motor, and the outer end of any one of the guide vanes is spaced apart from the inner wall of the wind tube.
8. The high static pressure centrifugal axial flow fan according to any one of claims 1 to 3, characterized in that: The small head end of the impeller front cone is rotatably connected to the air outlet of the collector, so that the interior of the collector is connected to the interior of the centrifugal impeller to form an air flow channel.
9. The high static pressure centrifugal axial flow fan according to claim 8, characterized in that: The collector is a conical collector, which is arranged inside the wind tube, and the large end to the small end of the conical collector are arranged along the airflow direction, and the small end of the conical collector is rotatably connected to the small end of the impeller front cone disk.