CN112128124A

CN112128124A - Air-cooled heat dissipation axial flow cooling fan for electronic equipment

Info

Publication number: CN112128124A
Application number: CN202011043022.8A
Authority: CN
Inventors: 周晓东; 熊长武; 何智航; 任建峰; 翁夏
Original assignee: Southwest Electronic Technology Institute No 10 Institute of Cetc
Current assignee: CETC 10 Research Institute; Southwest Electronic Technology Institute No 10 Institute of Cetc
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2020-12-25

Abstract

The invention discloses an air-cooling heat-dissipation axial flow cooling fan for electronic equipment, and aims to provide an axial flow fan which is high in efficiency, small in vibration, large in air quantity, high in back pressure and low in noise. The invention is realized by the following technical scheme: the casing is a backward air draft air duct, the front end is wide, the middle is narrow and the back is wide, the casing is a double-funnel-shaped inclined angle air duct casing with an inclined angle inner wall, the middle section of the casing is changed according to a linear rule, the blades are of a front bending edge type, an axial flow swept-shaped blade is formed by a suction curved surface with an upper inclined angle of at least-14 degrees and a pressure curved surface with a lower inclined angle of at least-11 degrees, and a spiral radian flow guide stationary blade matched with the airflow direction of the fan and the air duct is used for converting kinetic energy generated by the airflow after the impeller is wound into pressure.

Description

Air-cooled heat dissipation axial flow cooling fan for electronic equipment

Technical Field

The invention relates to a high-performance fan which is applied to various loading platforms such as an airborne fan, a shipborne fan and a vehicle-mounted fan, can provide a high-reliability large-air-volume air source for air cooling and heat dissipation of electronic equipment and has low noise, in particular to a large-air-volume low-noise axial flow cooling fan.

Background

The fan is used for conveying gas, and converting mechanical energy input by a prime motor into gas kinetic energy and pressure energy to output a fluid mechanical device. Axial flow fans have long been widely used in various industries due to their simple structure, convenient use, low noise, large flow rate, and significant exhaust and ventilation effects. The axial flow fan mainly comprises a fan impeller and a casing. Generally, a flange type mounting structure is adopted for a blade handle of the low-noise axial flow fan, and a counter bore for mounting the flange type blade handle is arranged on the periphery of the outer surface of a hub.

The fan noise is mainly aerodynamic noise, which is mainly noise generated by unsteady flow of gas, namely disturbance of gas flow, interaction of gas and object. The noise sources may be classified into eddy current noise and rotational noise. The rotational noise is generated by the periodic interaction of the blades with the surrounding air, is related to the geometric structures of the fan impeller and the blades, and has discrete characteristics; the vortex noise is generated by the pressure pulsation of the flow and the separation of the blade boundary layer, such as the instability of the incoming flow, the turbulent boundary layer, the shedding vortex, the blade tip vortex and the like, has a broadband characteristic, and is a main noise source of the fan. Studies have shown that the efficiency of the fan and the amount of noise are closely related to the aerodynamic characteristics of the impeller, while the geometry of the blades is the main factor determining the aerodynamic characteristics of the impeller. For example, the vortex generated by the flat blade is larger, so the vortex noise is also larger; while the impact noise of straight blades is greater. Therefore, the geometric shape of the fan blade is reasonably improved, and the method is an effective means for reducing noise and improving the cooling performance of the fan.

The power of the electronic equipment applied in the fields of aviation, aerospace and the like is higher and higher, the heat productivity is higher and higher, and the auxiliary heat dissipation is carried out by the aid of an axial flow fan with high reliability and large air volume. Electronic equipment is cooled in many ways, mainly including air cooling, liquid cooling, and phase change cooling. The air cooling has the characteristics of convenience, simple equipment, low cost and the like, and is quite wide in application, wherein the fan impact jet flow has absolute advantages in the aspects of local cooling, quick heat dissipation and the like, and the heat sink is matched for cooling the electronic element, so that the heat sink type air cooling device is an effective way for solving the heat dissipation problem of the avionic equipment. The heat of the heating source is conducted outwards through the heat sink in direct contact with the surface of the heating source, and then most of the heat is taken away by the fan rotating at high speed in a convection mode. The large air volume axial flow fan on the market at present is usually quite noisy, for example, for an axial flow fan with the blade diameter of 70mm, when the air volume is more than 105CFM @28V, the noise measured according to GB/T10069.1-2006 standard is usually more than 80 dB. The noise of the fan is very harmful to human bodies, influences the hearing of people, can cause pathological changes of a central nervous system to cause mental syndromes such as memory deterioration and the like, and is also very unfavorable for the use, debugging, maintenance and maintenance of electronic equipment. The factors influencing the performance of the axial flow fan are many, and how to make the aerodynamic performance of the axial flow fan under a certain working condition is the problem which needs to be solved urgently in the design of the axial flow fan. The difference of the fan blade installation angle can cause the pressure distribution, the speed distribution and the like on the surface of the blade to be correspondingly changed, thereby having important influence on the flow, the efficiency, the noise and the like of the fan. In a certain range, the installation angle is reduced, the aerodynamic noise of the blade is reduced along with the reduction of pressure pulsation and load on the surface of the blade, but the flow and the efficiency of the fan are reduced due to the excessively small installation angle, and the static characteristic requirement of the fan cannot be met; conversely, the stagger angle increases, the pressure pulsation and the load on the blade surface increase, and an excessively large stagger angle even causes the fan to be in a stall condition, but the increase of the stagger angle also causes a large increase in the fan flow rate. In terms of maximum efficiency, a larger mounting angle means that the more upright the blade is, the more wind resistance and loss are experienced, the efficiency is reduced, and the power required by the motor must be increased to operate the fan normally. When the number of the blades is increased to 8, although the gas can be increased to obtain the energy from the impeller, the number of the blades is too large to generate more disturbance on the gas, the turbulent energy loss is increased, the efficiency of the fan is reduced, and the flow and the static pressure are not increased too much. If the height of the blade is increased, the contact area between the impeller and the gas is increased, the energy obtained by the gas is increased, and the static pressure value is further increased; the blade height is reduced, the clearance between the blade and the outer frame is enlarged, the gas backflow and counter-flow phenomena are serious, the energy loss of the gas flow is increased, and the pressure energy and the kinetic energy of the gas are reduced due to the reduction of the contact surface, so that the overall performance of the fan is reduced. A high-performance fan which can meet the requirements of large air quantity and high back pressure of heat dissipation of electronic equipment and has lower noise is urgently needed.

Disclosure of Invention

The invention aims to overcome the defect of high noise of the existing large-air-volume axial flow fan and provide the air-cooled heat-dissipation axial flow fan for the electronic equipment, which has the advantages of high efficiency, small vibration, large air volume, high back pressure and low noise.

In order to achieve the purpose, the invention adopts the following technical scheme: an air-cooled heat dissipation axial flow cooling fan for electronic equipment, comprising: lie in the motor of connecting through cable channel 4 in casing 2, fix impeller and blade 1, its characterized in that with motor hub connection in the 2 pipelines of casing: the casing is a double-funnel-shaped inclined angle air channel casing which is wide at the front end, narrow in the middle and wide in the back direction of the backward air draft air channel, has an inclined angle inner wall, and has sections in the middle which change according to a linear rule, an axial flow swept blade is formed by a suction curved surface with an installation angle of at least 27.4 degrees, a forward bending angle of at least 30.6 degrees, an upper inclined angle of at least-14 degrees and a pressure curved surface with a lower inclined angle of at least-11 degrees at the blade root of the blade 1, and a spiral flow guide stationary blade 3 with an installation angle of at least 65 degrees at the blade root matched with the airflow direction of the; the inner wall of the inclination angle of the shell 2 prevents the blade tops of the fan blades 1 from being leaked, the pressure of the inner wall of the shell is cut, after the pressure gradient on the shell is reduced, the guide stationary blade 3 converts partial kinetic energy generated by the airflow after the impeller is wound into pressure, and the pressure and the axial flow swept-shaped blade form forced airflow to prevent the boundary layer of the fan blades 1 from being separated and send the airflow out.

Compared with the prior art, the method has the beneficial effects that:

the efficiency is high. The casing is a double-funnel shape with the inclined inner wall, the front end of the backward air draft air duct is wide, the middle of the backward air draft air duct is narrow, and the backward air draft air duct is wide. Compared with the common cylindrical shell, the shell with the inner wall with a certain inclination angle can better prevent the leakage of the fan blade top, overcome the defects of gas backflow and countercurrent phenomena and increased airflow energy loss, and simultaneously avoid the increase of friction loss due to the increase of the contact surface, the pressure energy and the kinetic energy of the gas are increased, the overall performance is improved, and the efficiency is improved.

The vibration is small. The invention adopts the structure that the blade 1 adopts the suction curved surface with the installation angle of at least 27.4 degrees at the blade root, the forward bending angle of at least 30.6 degrees at the blade root and the upper inclination angle of at least-14 degrees and the pressure curved surface with the lower inclination angle of at least-11 degrees to form the axial flow swept blade, the spiral guide static blade 3 with the installation angle of at least 65 degrees at the blade root matched with the airflow direction and the airflow channel of the fan is arranged at the rear end of the airflow channel, partial kinetic energy generated by the airflow circumnutation behind the impeller can be converted into rising pressure, and the wind loss of the fan can be reduced.

The air volume is large. The invention adopts the axial flow swept blade formed by the suction curved surface and the pressure curved surface in the blade 1, the axial flow swept blade forms forced airflow to prevent the separation of the boundary layer of the fan blade 1 and send the airflow out, the energy obtained by the air from the impeller is increased under the condition of the same rotating speed, and the overall efficiency, static pressure and power of the fan show the trend of increasing. The axial flow swept blade is used for forming forced airflow, the airflow is made to generate a convolution in front of the impeller, and an inlet airflow angle of the airflow entering the blade can be changed, so that the aerodynamic performance of the impeller is changed. The axial flow swept-shaped blades form forced airflow to prevent the separation of the boundary layer of the fan blade 1 and send the airflow out. Under the condition of keeping the size of the whole structure and the size of the blades not increased, the high-power electronic equipment cooling high-air-volume fan can meet the requirement of high-power electronic equipment cooling high air volume, and has low noise, thereby providing a good noise environment for use, debugging, maintenance and maintenance of the electronic equipment.

High back pressure and low noise. The inner wall of the casing 2 with the inclination angle prevents the blade tops of the fan blades 1 from leaking, the pressure of the inner wall of the casing is cut, the pressure gradient on the casing is reduced, the back pressure is high, the noise is low, and the defect that the static pressure at the outlet is slightly reduced due to the severe change of the pressure gradient at the tail end of each blade is overcome. The fan can have 7 quiet leaf, except that a quiet leaf plays cable channel's effect, all the other quiet leaves all play the water conservancy diversion effect, the disturbance of having avoided gas formation, gas is more relaxed at the disturbance of impeller, gaseous flow loss is less, make the air current instability in the runner weaken, multiplicable gas obtains the energy from the impeller, reduce torrent energy loss, make fan efficiency descend, can be better, send away the air current more relevantly, make the air current of fan export more steady, thereby realize the demand that fan noise reduces.

The power consumption is reduced, and the efficiency is improved. The invention uses single thinner silicon steel sheets to be overlapped into a stator 7 with a certain thickness, and the stator is fixed outside the middle pipe 5, thereby greatly improving the torque of the motor, simultaneously correspondingly reducing the temperature rise of the motor, reducing the power consumption, improving the efficiency and leading the highest rotating speed of the fan to be more than 30000 RPM.

The noise reduction effect is obvious. In order to meet the requirement of static characteristics of the fan, the blade adopts a larger installation angle, the installation angle of the blade root of the axial flow swept blade is 27.4 degrees, the forward bending angle of the blade is 30.6 degrees, the borne wind resistance and loss are small, and the efficiency is reduced. The contact area of the impeller and the gas is increased, the provided guide stationary blade matched with the whole fan air channel increases the energy obtained by the gas, so that the static pressure value is improved, and the friction loss of the gas and a solid boundary is reduced. On the premise of ensuring the original aerodynamic performance parameters of the fan, compared with the noise measured according to the GB/T10069.1-2006 standard, the noise measured by the fan model in the prior art is more than 80dB, the noise is reduced to 71dB, the reduction value is 9dB, the noise reduction effect is obvious, and therefore the working environment of operators is greatly improved. Meanwhile, the impeller rotating speed of 5000r/min can obtain higher efficiency, the efficiency can be obtained under the condition of larger air quantity, the system resistance can be better overcome, the air pressure is greatly improved,

has high working reliability. The casing can be designed by adopting a light aluminum alloy material, the shape and the size of the fan can be ensured to be unchanged, the phenomena of fracture, shaft breakage, cracks and the like of the fan blade can be avoided in working environments such as high rotating speed, high acceleration and the like, and the strength and the stability of the casing are improved. Can be adapted to various complicated and severe working environment conditions and has high working reliability.

Drawings

FIG. 1 is a front view of an axial flow cooling fan for air cooling and heat dissipation of an electronic device according to the present invention;

FIG. 2 is a side view of FIG. 1;

in the figure: 1 blade, 2 casings, 3 guide stationary blades, 4 cable channels, 5 middle pipes, 6 rear bearings, 7 stators, 8 front bearings, 9 rotating shafts, 10 rotors and 11 impellers.

The technical scheme of the invention is clearly and completely described below by combining the attached drawings.

Detailed Description

Refer to fig. 1 and 2. In the preferred embodiment described below: an air-cooled heat dissipation axial flow cooling fan for electronic equipment, comprising: lie in the motor of connecting through cable channel 4 in casing 2, fix impeller and blade 1, its characterized in that with motor hub connection in the 2 pipelines of casing: the casing is a double-funnel-shaped inclined angle air channel casing which is wide at the front end, narrow in the middle and wide in the back direction of the backward air draft air channel, has an inclined angle inner wall, and has sections in the middle which change according to a linear rule, an axial flow swept blade is formed by a suction curved surface with an installation angle of at least 27.4 degrees, a forward bending angle of at least 30.6 degrees, an upper inclined angle of at least-14 degrees and a pressure curved surface with a lower inclined angle of at least-11 degrees at the blade root of the blade 1, and a spiral flow guide stationary blade 3 with an installation angle of at least 65 degrees at the blade root matched with the airflow direction of the; the inner wall of the inclination angle of the shell 2 prevents the blade tops of the fan blades 1 from being leaked, the pressure of the inner wall of the shell is cut, after the pressure gradient on the shell is reduced, the guide stationary blade 3 converts partial kinetic energy generated by the airflow after the impeller is wound into pressure, and the pressure and the axial flow swept-shaped blade form forced airflow to prevent the boundary layer of the fan blades 1 from being separated and send the airflow out.

The casing 2 is designed by adopting a light aluminum alloy material, the overall dimension of the fan can be ensured to be unchanged, the phenomena of fracture, broken shaft, cracks and the like of the fan blades in working environments such as high rotating speed, high acceleration and the like can be avoided, and the strength and the stability of the casing are improved.

In this embodiment, the fan can have 7 guide stationary blades 3 in total, one of them guide stationary blade 3 system has cable channel 4, and other stationary blades 3 all make the guide way, make the air current instability in the runner weaken, can send out the air current better, more releivedly, make the air current of fan export more steady to realize the demand of fan noise reduction.

See fig. 2. The fan comprises 5-7 guide stationary blades 3, wherein one guide stationary blade 3 is provided with a cable channel 4, and the other stationary blades 3 are provided with guide channels.

The motor includes: an impeller 11 fixed in the pipe of the casing 2 and connected with a motor rotor 10 and a rotating shaft 9 with one end connected with the blade 1.

The rotor 10 is fixed in the impeller 11, and the casing 2 and the middle pipe 5 are connected together through the guide stationary blade 3 and the cable channel 4.

The impeller 11 is assembled on the rotary drum at a larger interval through the middle pipe 5 step cylinder, and the rotating shaft 9 is fixed at the bottom end of the annular cavity of the impeller 11 along the airflow direction of the fan through the front bearing 8 and the rear bearing 6 which are assembled on the rotary drum in sequence, so as to support the running stability of the fan.

The rotor 10 is fixed in the annular cavity of the impeller 11 and wraps the stator 7; the stator 7 is formed by overlapping single thinner silicon steel sheets in a certain thickness and is fixed on the outer side of the middle pipe 5, so that the motor torque is greatly improved, the temperature rise of the motor is correspondingly reduced, the power consumption is reduced, the efficiency is improved, and the maximum rotating speed of the fan can reach above 30000 RPM.

The impeller 11 is assembled on the rotary drum through the step cylinder body of the middle pipe 5 at a larger interval, and the rotary shaft 9, the two ends of which are provided with the front bearing 8 and the rear bearing 6, is fixed at the bottom end of the annular cavity of the impeller 11 through the rotary drum to support the running stability of the fan.

All features disclosed in this specification may be combined in any combination, except features and/or steps that are mutually exclusive. It will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and are intended to be within the scope of the invention. Those not described in detail in this specification are within the skill of the art.

Claims

1. An air-cooled heat dissipation axial flow cooling fan for electronic equipment, comprising: lie in motor that connects through cable channel (4) in casing (2), fix impeller (11) and blade (1) that are connected with motor hub in casing (2) pipeline, its characterized in that: the casing is a double-funnel-shaped inclined angle air channel casing which is wide at the front end of a backward air draft air channel, narrow in the middle and wide backward, has an inclined angle inner wall, and has sections in the middle which change according to a linear rule, an axial flow swept blade is formed by a suction curved surface with an installation angle of at least 27.4 degrees, a blade forward bending angle of at least 30.6 degrees, an upper inclination angle of at least-14 degrees and a pressure curved surface with a lower inclination angle of at least-11 degrees at the blade root of the blade (1), a spiral guide stationary blade (3) with an installation angle of at least 65 degrees at the blade root and matched with the air flow direction of a fan and an air channel is arranged at the rear end of the air channel, the inclined angle inner wall of the casing (2) prevents the blade top of the fan blade (1) from leaking, the pressure of the inner wall of the casing is cut, after the pressure gradient on the casing is relieved, the guide stationary blade (3), the air flow is sent out.

2. The electronic device air-cooled heat-dissipating axial flow cooling fan of claim 1, wherein: the fan comprises 5-7 guide stationary blades (3), wherein one guide stationary blade (3) is provided with a cable channel (4), and the other stationary blades (3) are provided with guide channels.

3. The electronic device air-cooled heat-dissipating axial flow cooling fan of claim 1, wherein: the motor includes: an impeller (11) fixed in the pipeline of the casing (2) and connected with the motor rotor (10) and a rotating shaft (9) with one end connected with the blade (1).

4. The electronic device air-cooled heat-dissipating axial flow cooling fan of claim 1, wherein: the rotor (10) is fixedly connected inside the impeller (11), and the casing (2) and the middle pipe (5) are connected together through the guide stationary blade (3) and the cable channel (4).

5. The electronic device air-cooled heat-dissipating axial flow cooling fan of claim 1, wherein: impeller (11) pass through well (5) step barrel to the assembly of great interval on the rotary drum, pivot (9) along fan air current direction loop through with front bearing (8) and rear bearing (6) of rotary drum assembly, fix the bottom in impeller (11) annular chamber, support fan operating stability.

6. The electronic device air-cooled heat-dissipating axial flow cooling fan of claim 1, wherein: the rotor (10) is fixed in the annular cavity of the impeller (11) and wraps the stator (7).