阅读说明：本技术 一种高压力小流量风机 (High-pressure small-flow fan ) 是由 黄顺巧 周红 孙皓 满超 王小荣 侯海臣 于 2020-08-25 设计创作，主要内容包括：本发明属于风机技术领域,具体公开了一种高压力小流量风机,包括叶轮,所述叶轮包括前盘和后盘,所述前盘设为锥形,所述前盘和后盘之间设有若干叶片；所述叶片为后向型叶片且为直板型,所述叶轮的外缘轴向设有环形扩压盘；所述前盘设为锥形；所述叶片出口处的延长线与圆周切线之间的角度为55°-70°。上述风机,能够解决现有的高压力小流量风机存在的喘振和噪声、叶片加工困难、容易积灰及磨损问题。(The invention belongs to the technical field of fans, and particularly discloses a high-pressure small-flow fan which comprises an impeller, wherein the impeller comprises a front disc and a rear disc, the front disc is conical, and a plurality of blades are arranged between the front disc and the rear disc; the blades are backward-shaped blades and are straight-plate-shaped, and annular pressure-expanding discs are axially arranged at the outer edges of the impellers; the front disc is conical; the angle between the extension line at the blade outlet and the circumferential tangent is 55-70 degrees. The fan can solve the problems of surge and noise, difficult blade processing, easy dust accumulation and abrasion existing in the existing high-pressure small-flow fan.)

1. A high-pressure small-flow fan comprises an impeller, wherein the impeller comprises a front disc and a rear disc, and a plurality of blades are arranged between the front disc and the rear disc; the method is characterized in that: the blades are backward-shaped blades and are straight-plate-shaped, and annular pressure-expanding discs are axially arranged at the outer edges of the impellers; the front disc is conical; the angle between the extension line at the blade outlet and the circumferential tangent is 55-70 degrees.

2. The high-pressure small-flow fan according to claim 1, wherein: the outlet width of the impeller is 0.02-0.03 times of the diameter of the impeller, and the inlet width of the impeller is 0.07-0.08 times of the diameter of the impeller.

3. The high-pressure small-flow fan according to claim 1, wherein: the number of the blades is 8-12.

4. The high-pressure small-flow fan according to claim 1, wherein: the impeller and the volute matched with the impeller are subjected to matching design, the size of the volute matched with the impeller is parameterized, a Latin hypercube algorithm is adopted to select and calculate sample points, a response surface model is constructed according to the calculation result, and then a multi-island genetic algorithm is adopted to obtain the design parameters of the final volute.

5. The high-pressure small-flow fan according to claim 1, wherein: and the surface of the blade is subjected to polishing treatment in advance.

6. The high-pressure small-flow fan according to claim 1, wherein: the front disc and the annular diffusion disc are integrally formed.

7. The high-pressure small-flow fan according to claim 1, wherein: the head of the blade is inclined, and the width of the head of the blade is narrower than that of the tail of the blade.

8. The high-pressure small-flow fan according to claim 1, wherein: the blade is connected with the rear disc through full welding, and the blade is connected with the front disc through plug welding.

Technical Field

The invention belongs to the technical field of fans, and particularly relates to a high-pressure small-flow fan.

Background

The full pressure of the high-pressure small-flow fan is in direct proportion to the density of the medium, the rotating speed of the impeller and the outlet angle of the blades, and when the gas medium is determined and higher pressure is required to be obtained, the rotating speed of the impeller is limited by materials, so that the aim of increasing the pressure is achieved only by increasing the outlet angle of the blades. When the outlet angle exceeds 90 degrees along with the increase of the outlet angle of the blades, the impeller is changed from a backward impeller to a forward impeller, and meanwhile, the inlet attack angle of the blades is also considered, so that the blades become arc-shaped blades under the condition that the inlet and outlet angles of the blades are restrained. The forward impeller is theoretically stronger in power-applying capability than the backward impeller, but strong separation flow, secondary flow and jet flow are always inevitable in the flow channel due to the arc-shaped flow channel, the separation flow is easy to generate quadrupole noise, and the jet flow impacts the wall surface of the shell and is easy to generate dipole noise; meanwhile, the impeller flow channel of the high-pressure small-flow fan is wide in width, sufficient development space is provided for separated flow and secondary flow, the circumferential area of the whole impeller is increased due to the large flow channel width, so that the relative speed of a medium in the flow channel is small, the small relative speed is not beneficial to overcoming large pressure gradient, backflow is easy to generate at the tail of the blade, the generation of various flow losses causes the low efficiency and high noise of the fan in the prior art, the complex flow channel and the complex flow are easy to accumulate dust, and the arc-shaped blade also has the defects of complex manufacturing process and high cost.

Disclosure of Invention

The invention aims to provide a high-pressure small-flow fan, which aims to solve the problems of surge and noise, difficult blade processing, easy dust accumulation and easy abrasion of the existing high-pressure small-flow fan.

In order to achieve the purpose, the technical scheme of the invention is as follows: a high-pressure small-flow fan comprises an impeller, wherein the impeller comprises a front disc and a rear disc, and a plurality of blades are arranged between the front disc and the rear disc; the blades are backward-shaped blades and are straight-plate-shaped, and annular pressure-expanding discs are axially arranged at the outer edges of the impellers; the front disc is conical; the angle between the extension line at the blade outlet and the circumferential tangent is 55-70 degrees.

Further, the outlet width of the impeller is 0.02-0.03 times of the diameter of the impeller, and the inlet width of the impeller is 0.07-0.08 times of the diameter of the impeller.

Further, the number of the blades is 8-12.

Further, the impeller and a volute matched with the impeller are subjected to matching design, the size of the volute matched with the impeller is parameterized, a Latin hypercube algorithm is adopted to select and calculate sample points, a response surface model is constructed according to the calculation result, and then a multi-island genetic algorithm is adopted to obtain the design parameters of the final volute.

Further, the surface of the blade is subjected to polishing treatment in advance.

Further, the front disc and the annular diffusion disc are integrally formed.

Further, the head of the blade is inclined, and the width of the blade head is narrower than that of the blade tail.

Further, the blade and the rear disc are connected by full welding, and the blade and the front disc are connected by plug welding.

The beneficial effects of this technical scheme lie in:

1. the blade adopts backward type and be the straight plate type, and this structure has following advantage: the manufacturing process is simple and the cost is low; secondly, the flow channel formed by the blade is simple, and the flow separation, secondary flow and jet flow of gas in the distorted complex flow channel are avoided; the outlet angle of the air flow is reduced, so that the absolute speed of the air is reduced, the impact of the air flowing out of the impeller outlet on the wall surface of the volute near the volute tongue is weakened, the impact loss between the air and the shell is reduced, and the noise reduction is facilitated; and fourthly, although the backward type blade adopts a smaller blade outlet angle, the backward type blade still has stronger working capacity due to lower loss, the pressure coefficient of the backward type blade reaches 0.7-0.8, and the specific rotating speed of the backward type blade is 15-18.

2. The outer edge of the impeller is axially provided with an annular pressure expansion disc, after gas leaves the tail edge of the blade, if the annular pressure expansion disc is not arranged, when the dynamic pressure of fluid in the impeller flow channel is insufficient, high-pressure gas in the volute inhibits the gas in the impeller from flowing out, backflow is generated at the tail edge of the blade, after the annular pressure expansion disc is added, a buffer zone is equivalently arranged between the volute and the impeller, and after the gas leaves the tail edge of the blade, enough pressure expansion space is formed, and the influence of the high-pressure gas in the volute on the flow of the blade outlet is weakened.

3. In the technical scheme, the outlet width of the impeller is 0.02-0.03 times of the diameter of the impeller, and the inlet width of the impeller is 0.07-0.08 times of the diameter of the impeller. The width of an impeller in the prior art is wider, for example, in a 9-19 type fan, the width of an outlet of the impeller is 0.08-0.1 times of the diameter of the impeller, and the width of an inlet of the impeller is 0.15 times of the diameter of the impeller; the 8-9 type fan has impeller outlet width of 0.036 times impeller diameter and impeller inlet width of 0.08 times impeller diameter. The technical scheme reduces the width of the impeller, thereby reducing the circumferential area of the flow channel, improving the relative speed of the fluid medium in the flow channel (under the condition of certain volume flow, the smaller the circumferential area at the same radius, the larger the relative speed), improving the capacity of overcoming the adverse pressure gradient and weakening the backflow at the tail part of the blade.

4. The technical scheme adopts the straight-plate type blades and a small number of blades (the number of the blades adopted by the existing 9-19 type fan is 10-14, the number of the blades adopted by the 8-9 type fan is 20, wherein, 10 long blades and 10 short blades are adopted), thus realizing the purpose of high pressure; meanwhile, the surface of the blade is polished so as to reduce the surface roughness and achieve the effect of brightness and smoothness; the anti-adhesion capability of the fan can be improved through the means.

5. The outlet angle of the blade is 55-70 degrees, so that the blade can achieve the effect of high pressure.

6. The front disc is conical, and compared with an arc-shaped front disc adopted in the prior art, the manufacturing process is simple.

7. The front disc and the annular diffusion disc are integrally formed, so that a splicing welding seam between the front disc and the annular diffusion disc can be avoided, and the manufacturing procedures are reduced.

8. The blade head is inclined, which can reduce the fan noise significantly, and the noise level of the fan noise A is lower than 15dB (A) and far lower than 27dB (A) specified by the mechanical industry standard.

9. Because the impeller width among this technical scheme reduces, the runner width among this technical scheme is far less than the impeller width of relevant fan among the prior art, and the inside no welding space that has of runner, consequently adopts blade and back dish full weld to be connected, and the adoption plug welding of blade and front bezel is connected.

10. The surface of the blade is polished, so that the surface roughness is reduced, the effect of brightness and smoothness is achieved, the anti-adhesion capability of the fan can be improved, and the effect of difficult dust accumulation is achieved to a certain extent.

11. The impeller and the volute are designed in a matching mode, the volute is optimized under the condition that the overall size of the impeller is not changed, gas is compatible with and not destructive to flow in the volute after the gas comes out of an impeller outlet, and finally the overall efficiency is in a higher level and is higher than the national second-level energy efficiency.

12. The fan in the technical scheme is mainly applied to industrial scenes such as a converter gas fan in a steel plant, a grate cooling first-stage fan in a cement plant, a BT furnace fan in a tempering system in a glass plant and the like. Compared with the existing 9-19 type (forward type, bent blade) fan, the fan in the technical scheme has similar working capacity (pressure coefficient is close), has smaller specific speed, higher efficiency and better manufacturability.

13. The high-efficiency area efficiency of the fan in the technical scheme reaches 86% -89.6%, while the high-efficiency area efficiency of the existing 9-19 type fan is 76% -79.4%, and the high-efficiency area efficiency of the 8-9 type fan is 51% -56.2%. Therefore, the technical scheme has the characteristics of small flow and high pressure and high efficiency.

Drawings

FIG. 1 is a front view of a fan wheel of the prior art;

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

FIG. 3 is a front view of an impeller in a high pressure low flow fan of the present invention;

FIG. 4 is a side view of FIG. 3;

FIG. 5 is an assembly view of a high pressure low flow fan of the present invention;

figure 6 is a graph comparing the aerodynamic performance of the fan of the present invention with that of a 9-19 type fan.

Detailed Description

The following is further detailed by way of specific embodiments:

reference numerals in the drawings of the specification include: the front disc 1, the blades 2, the volute 3 and the annular pressure expansion disc 4.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.