Combined airflow distribution plate suitable for ultrahigh electric dust remover

Abstract

The invention discloses a combined airflow distribution plate suitable for an ultrahigh electric precipitator. The combined airflow distribution plate comprises a first distribution plate, a second distribution plate and a third distribution plate, the first distribution plate is of a convex bottom inclined plane structure, the convex bottom is a plane A1, and vent holes are formed in the plane A1 and the inclined plane; the second distribution plate is of a convex bottom inclined plane structure, the convex bottom is a plane A2, vent holes are formed in the plane A2 and the inclined plane, and a first flue gas speed reduction pipe is arranged at the outlet position of the vent hole in the plane A2; the third distribution plate is of a concave bottom inclined plane structure, the concave bottom is a plane A3, vent holes are formed in the plane A3, and no vent hole is formed in the inclined plane. The combined distribution plate combining convex and concave surface structures has lower airflow resistance, and the flow velocity of flue gas is adjusted through the flue gas speed reducing pipe and the flue gas speed increasing pipe, so that airflow in an electric field is distributed according to a uniform airflow flow velocity standard, and the dust removal efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of electrostatic dust removal, and in particular to a combined airflow distribution plate suitable for an ultra-high type electrostatic precipitator. Background Art

[0002] At present, the structural design of the airflow distribution plate of the domestic ultra-high type electrostatic precipitator is mostly flat, installed in the air intake box, and the number of layouts is mostly 3 layers. After the flue gas enters the electric field through the airflow distribution plate, the airflow velocity generally presents a distribution of low in the middle and high around, and the airflow distribution is uneven. High and low velocity areas are formed in the local area of ​​the electric field, and eddies exist, which reduces the dust collection effect; on the other hand, the uneven airflow distribution will cause regional dust particles to accumulate inside the electrostatic precipitator, block the aperture of the airflow distribution plate, further destroy the uniformity of airflow distribution, and cause a vicious cycle. Therefore, a combined airflow distribution plate suitable for ultra-high type electrostatic precipitator is developed. The combined airflow distribution plate adopts a convex and concave surface combined structure and is supplemented by a flue gas speed increasing tube and a flue gas speed reducing tube. It has a low airflow resistance, and the airflow distribution tends to be uniform overall, which is conducive to realizing the distribution of flue gas in the entire electric field section according to the uniform airflow velocity standard, which has a positive significance for further exerting the role of efficient dust removal of electrostatic precipitator. Summary of the invention

[0003] The purpose of the present application is to provide a combined airflow distribution plate suitable for an ultra-high type electrostatic precipitator, which is installed in the air inlet box of the electrostatic precipitator. The combined distribution plate adopts a combination of convex and concave structures, has a lower airflow resistance and can adjust the flow rate of the flue gas entering the electric field, so as to achieve the distribution of the airflow in the electric field according to the uniform airflow velocity standard, thereby further exerting the efficient dust removal function of the electrostatic precipitator.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a combined airflow distribution plate suitable for an ultra-high type electrostatic precipitator, comprising a first distribution plate, a second distribution plate and a third distribution plate installed in an air inlet box of the electrostatic precipitator and arranged in sequence from left to right, wherein the first distribution plate is arranged close to the air inlet of the air inlet box of the electrostatic precipitator; The first distribution plate is a convex bottom inclined surface structure, the convex bottom is a plane A1, and both the plane A1 and the inclined surface are provided with ventilation holes; The second distribution plate is a convex bottom inclined surface structure, the convex bottom is a plane A2, both the plane A2 and the inclined surface are provided with ventilation holes, and a first flue gas velocity reduction pipe is provided at the outlet position of the ventilation hole on the plane A2; The third distribution plate is a concave bottom inclined surface structure, the concave bottom is a plane A3, a vent is provided on the plane A3, and there is no vent, the plane A3 is divided into an upper smoke velocity reduction zone A31, a middle smoke velocity increase zone A32, and a lower smoke velocity reduction zone A33 from top to bottom, and a second smoke velocity reduction pipe is arranged at the outlet position of the vents on the upper smoke velocity reduction zone A31 and the lower smoke velocity reduction zone A33, and a smoke velocity increase tube is arranged at the outlet position of the vent on the middle smoke velocity increase zone A32.

[0005] As a preferred implementation manner in this embodiment, the angle a1 between the plane A1 of the first distribution plate and the inclined surface is ≤8°, the area of ​​the plane A1 accounts for 18-20% of the total area of ​​the first distribution plate 1, and the opening rate is ≥50%, the area of ​​the inclined surface accounts for 80-82% of the total area of ​​the first distribution plate 1, and the opening rate is ≥40%, and the central axis of the vent on the plane A1 is perpendicular to the plane A1, and the central axis of the vent on the inclined surface is perpendicular to the inclined surface.

[0006] As a preferred implementation manner in this embodiment, the angle a2 between the plane A2 and the inclined surface on the second distribution plate is ≤8°, the area of ​​the plane A2 accounts for 32~35% of the total area of ​​the second distribution plate, and the opening rate is ≥50%, the area of ​​the inclined surface accounts for 65~68% of the total area of ​​the second distribution plate, and the opening rate is ≥40%, and the central axis of the vent on the plane A2 is perpendicular to the plane A2, and the central axis of the vent on the inclined surface is perpendicular to the inclined surface.

[0007] As a preferred implementation manner in this embodiment, the angle a3 between the plane A3 of the third distribution plate and the inclined plane is ≥30°, the central axis of the vent on the plane A3 is perpendicular to the plane A3, the area of ​​the plane A3 accounts for 94~96% of the total area of ​​the air flow distribution plate 3, the area of ​​the upper smoke velocity reduction zone A31 accounts for 18~20% of the area of ​​the entire plane A3, and the opening rate is ≥30%, the area of ​​the middle smoke velocity increase zone A32 accounts for 60~64% of the area of ​​the entire plane A3, and the opening rate is ≥40%, and the area of ​​the lower smoke velocity reduction zone A33 accounts for 18~20% of the area of ​​the entire plane A3, and the opening rate is ≥30%.

[0008] As a preferred implementation in this embodiment, the central axis of the first flue gas velocity reduction pipe is consistent with the central axis of the corresponding vent hole, the inlet diameter of the first flue gas velocity reduction pipe is the same as the vent hole diameter, the outlet diameter is 1.10 to 1.15 times the inlet diameter, and the length is ≤60 mm; The central axis of the second flue gas velocity reduction pipe is consistent with the central axis of the corresponding vent hole, the inlet diameter of the second flue gas velocity reduction pipe is the same as the vent hole diameter, the outlet diameter is 1.05 to 1.10 times the inlet diameter, and the length is ≤60 mm; The central axis of the smoke accelerating tube is consistent with the central axis of the corresponding vent hole, the inlet diameter of the smoke accelerating tube is the same as the diameter of the vent hole, the outlet diameter is 0.90~0.95 times the inlet diameter, and the length is ≤60mm.

[0009] As a preferred implementation in this embodiment, the installation distance between the first distribution plate and the second distribution plate is L1, the installation distance between the second distribution plate and the third distribution plate is L2, and L2>(2-2.5)L1.

[0010] As a preferred implementation in this embodiment, the first distribution plate, the second distribution plate, and the third distribution plate are made of plates, and the thickness of the plates is 4-6 mm, and the material is carbon steel or low alloy steel; The first flue gas velocity reduction pipe, the second flue gas velocity reduction pipe and the flue gas velocity increase pipe are made of carbon steel or low alloy steel, and the wall thickness of the pipe is 3.5-4 mm.

[0011] In summary, the technical effects and advantages of the present invention are as follows: The present invention has a reasonable structure. The first distribution plate and the second distribution plate adopt a convex bottom inclined surface structure, the airflow distribution area is increased, the smoke velocity distribution trend is changed, the flow velocity of the surrounding smoke is reduced, the smoke kinetic energy in the middle area is enhanced, and the influence of the turbulence generated by the smoke in the acute angle area formed by the edges of the first distribution plate and the second distribution plate and the air inlet box on the airflow distribution is suppressed and weakened. The volume of the air chamber between the second distribution plate and the third distribution plate is increased and the smoke velocity in the middle area of ​​the second distribution plate is reduced by the first smoke gas speed reduction pipe, which is conducive to the uniform flow of smoke in the air chamber. The inclined surface of the third distribution plate does not have air holes, so as to prevent part of the smoke from deviating to the electric field area and above the ash hopper where no dust removal effect can be produced. The gas velocity of the smoke at the outlet of the combined airflow distribution plate is adjusted by the second smoke gas speed reduction pipe and the smoke gas speed increaser pipe. The overall airflow distribution tends to be uniform, which is conducive to realizing the distribution of smoke in the entire electric field section according to the uniform airflow velocity standard, thereby improving the dust removal efficiency of the ultra-high type electrostatic precipitator. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1This is a schematic diagram of the structure of the combined air flow distribution plate of the present invention; Figure 2 for Figure 1 The schematic diagram of the structure of the first distribution plate in the front view and the right view; Figure 3 for Figure 1 The structural intention of the second distribution plate in the middle from the front and right; Figure 4 for Figure 1 Schematic diagram of the front and right view of the third distribution plate.

[0014] In the figure: 1. first distribution plate; 2. second distribution plate; 3. third distribution plate; 4. first flue gas velocity reduction pipe; 5. second flue gas velocity reduction pipe; 6. flue gas velocity increase pipe; 7. air vent; 8. electric precipitator air inlet box. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example: Reference Figure 1-4 A combined airflow distribution plate suitable for an ultra-high type electrostatic precipitator is shown, comprising a first distribution plate 1, a second distribution plate 2 and a third distribution plate 3 installed in an air inlet box of the electrostatic precipitator and arranged in sequence from left to right, wherein the first distribution plate 1 is arranged close to the air inlet of the air inlet box of the electrostatic precipitator; The first distribution plate 1 is a convex bottom inclined surface structure, the convex bottom is a plane A1, and both the plane A1 and the inclined surface are provided with ventilation holes 7; The second distribution plate 2 is a convex bottom inclined surface structure, the convex bottom is a plane A2, both the plane A2 and the inclined surface are provided with ventilation holes 7, and the first flue gas velocity reduction pipe 4 is provided at the outlet position of the ventilation hole 7 on the plane A2; The third distribution plate 3 is a concave bottom inclined surface structure, the concave bottom is a plane A3, a vent hole 7 is opened on the plane A3, and there is no vent hole 7 on the inclined surface. The plane A3 is divided into an upper smoke velocity reduction zone A31, a middle smoke velocity increase zone A32, and a lower smoke velocity reduction zone A33 from top to bottom. A second smoke velocity reduction pipe 6 is arranged at the outlet position of the vent holes 7 on the upper smoke velocity reduction zone A31 and the lower smoke velocity reduction zone A33, and a smoke velocity increase tube 6 is arranged at the outlet position of the vent holes on the middle smoke velocity increase zone A32.

[0017] The first distribution plate 1 and the second distribution plate 2 adopt a convex bottom inclined surface structure, the airflow distribution area is increased, the smoke velocity distribution trend is changed, the flow velocity of the surrounding smoke is reduced, the smoke kinetic energy in the middle area is enhanced, the turbulence generated by the smoke in the acute angle area formed by the edges of the first distribution plate 1 and the second distribution plate 2 and the air inlet box on the airflow distribution is suppressed and weakened, and the airflow resistance is reduced. The volume of the air chamber between the second distribution plate 2 and the third distribution plate 3 is increased, and the air velocity of the smoke at the outlet of the middle area of ​​the second distribution plate 2 is reduced by the first smoke gas speed reduction pipe 4, which is conducive to the uniform flow of smoke in the air chamber. The inclined surface of the third distribution plate 3 does not have air holes to prevent part of the smoke from deviating to the electric field area and above the ash hopper where the dust removal effect cannot be generated. The second smoke gas speed reduction pipe 5 is used to reduce the air velocity of the smoke at the outlet of the upper and lower areas of the third distribution plate 3, and the smoke speed increasing pipe 6 is used to increase the air velocity of the smoke at the outlet of the middle area of ​​the third distribution plate 3. When the smoke passes through the combined airflow distribution plate, the airflow distribution tends to be uniform overall, and the uneven airflow distribution state of low in the middle and high around is no longer generated. The combined distribution plate with convex and concave structures has lower airflow resistance and the overall airflow distribution tends to be uniform, which is conducive to achieving the distribution of flue gas in the entire electric field section according to the uniform airflow velocity standard, thereby improving the dust removal efficiency of the ultra-high type electrostatic precipitator.

[0018] It should be noted that, first, the ultra-high type electrostatic precipitator referred to in this application refers to an electrostatic precipitator with a plate height of ≥18m in the electric field; second, the first distribution plate 1 is a convex bottom inclined surface structure, the middle area is a convex bottom plane, and the peripheral area is an inclined surface; the second distribution plate 2 is a convex bottom inclined surface structure, the middle area is a convex bottom plane, and the peripheral area is an inclined surface; the third distribution plate 3 is a concave bottom inclined surface structure, the middle area is a concave bottom plane, and the peripheral area is an inclined surface; third, taking the technical upgrading and transformation of an electrostatic precipitator with a dust removal area of ​​168m2 in a certain unit as an example, the plate height is 18m, and the combined airflow distribution of the present invention is adopted The cloth plate replaces the original three-layer flat-plate structure airflow distribution plate, and is vertically installed in the air intake box of the electrostatic precipitator. The air intake box has a conical trumpet with an angle of 90°. The electrostatic precipitator flue gas volume is 540,000 m3 / h, the flue gas temperature is ≤160℃, and the flue gas dust content is 4~5g / m3. The results of the simulation test show that the inlet flue gas velocity is 12.5m / s. At the 0.5m section of the first electric field inlet, the relative root mean square value of the flat-plate structure airflow distribution plate is δ=0.263, and the airflow distribution is unqualified. After the combined airflow distribution plate of this embodiment is used, δ≤0.15, and the airflow distribution is better. After the electrostatic precipitator is put into operation, the actual test results are: the outlet flue gas dust content is <35mg / m3, and the dust removal efficiency is >99%.

[0019] As a preferred implementation in this embodiment, Figure 2As shown, the angle a1 between the plane A1 and the inclined surface of the first distribution plate 1 is ≤8°, the area of ​​the plane A1 accounts for 18-20% of the total area of ​​the first distribution plate 1, the opening rate is ≥50%, the area of ​​the inclined surface accounts for 80-82% of the total area of ​​the first distribution plate 1, the opening rate is ≥40%, and the central axis of the vent hole 7 on the plane A1 is perpendicular to the plane A1, and the central axis of the vent hole 7 on the inclined surface is perpendicular to the inclined surface.

[0020] The area of ​​plane A1 of the first distribution plate 1 is smaller than the area of ​​the inclined surface, and the opening rate is ≥50%, which can reduce the loss of kinetic energy of smoke in the middle area and reduce airflow resistance. The inclined surface area accounts for 80-82% of the total area of ​​the first distribution plate 1, and the opening rate is ≥40%, which increases the airflow distribution area. The angle a1 between plane A1 and the inclined surface is ≤8°, which changes the flow velocity distribution trend of the smoke. The smoke is guided to the middle area and the air flow distribution state is adjusted through the air chamber between the first distribution plate 1 and the second distribution plate 2, which suppresses and weakens the influence of the turbulence generated by the smoke in the acute angle area formed by the first distribution plate 1 and the air inlet box on the air flow distribution, thereby reducing the airflow resistance.

[0021] As a preferred implementation in this embodiment, Figure 3 As shown, the angle a2 between the plane A2 on the second distribution plate 2 and the inclined surface is ≤8°, the area of ​​the plane A2 accounts for 32-35% of the total area of ​​the second distribution plate 2, the opening rate is ≥50%, the area of ​​the inclined surface accounts for 65-68% of the total area of ​​the second distribution plate 2, the opening rate is ≥40%, and the central axis of the vent hole 7 on the plane A2 is perpendicular to the plane A2, and the central axis of the vent hole 7 on the inclined surface is perpendicular to the inclined surface.

[0022] The area of ​​plane A2 of the second distribution plate 2 accounts for 32-35% of the total area of ​​the second distribution plate 2, which is close to twice the area of ​​plane A1 of the first distribution plate 1, and the opening rate is ≥50%, which improves the airflow distribution in the air chamber and reduces the airflow resistance. The inclined surface area of ​​the second distribution plate 2 accounts for 65-68% of the total area of ​​the second distribution plate 2, the angle a2≤8°, and the inclined surface is parallel to the inclined surface of the first distribution plate 1, which increases the airflow distribution area, further suppresses and weakens the influence of the turbulence generated by the flue gas in the acute angle area formed by the second distribution plate 2 and the air inlet box on the airflow distribution, and reduces the airflow resistance.

[0023] As a preferred implementation in this embodiment, Figure 3As shown, the angle a3 between the plane A3 of the third distribution plate 3 and the inclined plane is ≥30°, the central axis of the vent hole 7 on the plane A3 is perpendicular to the plane A3, the area of ​​the plane A3 accounts for 94-96% of the total area of ​​the third distribution plate 3, the area of ​​the upper smoke velocity reduction zone A31 accounts for 18-20% of the area of ​​the entire plane A3, and the opening rate is ≥30%, the area of ​​the middle smoke velocity increase zone A32 accounts for 60-64% of the area of ​​the entire plane A3, and the opening rate is ≥40%, and the area of ​​the lower smoke velocity reduction zone A33 accounts for 18-20% of the area of ​​the entire plane A3, and the opening rate is ≥30%.

[0024] The third distribution plate 3 adopts a concave bottom inclined surface structure, and the inclined surface has no ventilation holes to prevent part of the flue gas from deviating to the electric field area and above the ash hopper where no dust removal effect can be produced. The angle a3 between the inclined surface and the plane A3 is ≥30°, forming an obtuse angle area at the edge of the air inlet box, so that the flue gas will not form excessive turbulence, and the inclined surface has no airflow distribution effect. Therefore, the area of ​​the plane A3 accounts for 94~96% of the total area of ​​the third distribution plate 3. In order to further change the phenomenon that after the flue gas enters the electric field, the airflow velocity is generally low in the middle and high around, and the velocity contour lines on the cross section are "annual ring"-like, the plane A3 is divided into an upper flue gas velocity reduction zone A31, a middle flue gas velocity increase zone A32 and a lower flue gas velocity reduction zone A33 from top to bottom. In the present invention, combined with the numerical simulation test of the airflow distribution plate of the ultra-high electrostatic precipitator, the flue gas velocity reduction zones A31 and A33 adopt the same area, which are both 18-20% of the area of ​​the plane A3, and the opening rate is ≥30%. The flue gas velocity increase zone A32 is 60-64% of the area of ​​the plane A3, and the opening rate is ≥40%. The second flue gas velocity reduction tube 5 and the flue gas velocity increase tube 6 are used to adjust the outlet flue gas velocity of the entire plane A3, and the airflow velocity tends to be uniform overall.

[0025] As a preferred implementation in this embodiment, the central axis of the first flue gas deceleration pipe 4 is consistent with the central axis of the corresponding vent hole 7, the inlet diameter of the first flue gas deceleration pipe 4 is the same as the diameter of the vent hole 7, the outlet diameter is 1.10-1.15 times the inlet diameter, and the length is ≤60mm; The first smoke reduction tube 4 is set at the outlet position of the vent hole of the entire plane A2 of the second distribution plate 2. The outlet smoke velocity of each first smoke reduction tube 4 is reduced by 15-20%. Therefore, the gas velocity of the outlet smoke of the entire plane A2 area generally shows a downward trend. Since the second distribution plate 2 is a convex bottom inclined structure, the smoke in the surrounding area is biased to the middle. By reducing the gas velocity at the outlet position of the vent hole of the entire plane A2 area, it is avoided that the smoke velocity in some areas in the air chamber is too high and the smoke velocity in some areas is too low. The first smoke reduction tube 4 adopts a concentric short tube with different diameters, with a total length of ≤60mm. The short tube has small flow resistance, small change in smoke velocity and small loss of kinetic energy.

[0026] The central axis of the second flue gas deceleration pipe 5 is consistent with the central axis of the corresponding vent hole 7. The inlet diameter of the second flue gas deceleration pipe 5 is the same as the diameter of the vent hole 7, the outlet diameter is 1.05-1.10 times the inlet diameter, and the length is ≤60mm; The central axis of the smoke accelerating tube 6 is consistent with the central axis of the corresponding vent hole, the inlet diameter of the smoke accelerating tube 6 is the same as the diameter of the vent hole 7, the outlet diameter is 0.90-0.95 times the inlet diameter, and the length is ≤60mm.

[0027] The cross-sectional area of ​​the air inlet box of the ultra-high electrostatic precipitator is very large, and the overall airflow velocity entering the electric field area tends to be uniform. It is necessary to adjust the flow velocity of the flue gas in the outlet section of the combined airflow distribution plate again. Therefore, the plane A3 of the third distribution plate 3 is divided from top to bottom into an upper flue gas velocity reduction zone A31, a middle flue gas velocity increase zone A32 and a lower flue gas velocity reduction zone A33. A second smoke deceleration tube 5 is provided at the outlet of the vents in the entire deceleration zone A31 and A33. The outlet smoke velocity of each second smoke deceleration tube 5 is reduced by 10-15%. Therefore, the outlet smoke velocity of the entire deceleration zone A31 and A33 region generally presents a downward trend. A smoke speed-increasing tube 6 is provided at the outlet of the vents in the entire smoke speed-increasing zone A32. The outlet smoke velocity of each smoke speed-increasing tube 6 is increased by 10-20%. Therefore, the outlet smoke velocity of the entire smoke speed-increasing zone A32 generally presents an upward trend. After the smoke enters the electric field after the deceleration and acceleration of the third distribution plate 3, the airflow velocity of the entire electric field section generally tends to be uniform. The second smoke deceleration tube 5 and the smoke speed-increasing tube 6 both use concentric short tubes of different diameters with a total length of ≤60mm. The short tube has a small flow resistance, a small change in the smoke velocity, and a small loss of kinetic energy. As a preferred implementation in this embodiment, Figure 1 As shown, the installation distance between the first distribution plate 1 and the second distribution plate 2 is L1, and the installation distance between the second distribution plate 2 and the third distribution plate 3 is L2, and L2>(2-2.5)L1.

[0028] Since the diameter of the ventilation holes of the distribution plate is small, after the smoke passes through the distribution plate, the smoke flow velocity facing the small holes is large, and the smoke flow velocity between the holes is small, resulting in uneven air flow in a small range centered on the hole. This turbulent state of smoke flow needs to gradually stabilize after a certain distance. The installation spacing L1 between the first distribution plate 1 and the second distribution plate 2 and the installation spacing L2 between the second distribution plate 2 and the third distribution plate 3 need to meet this condition. In the present invention, L2> (2~2.5) L1. On the one hand, the first smoke deceleration tube 4 is arranged behind the ventilation hole of the plane A2 of the second distribution plate 2, which increases the stable area of ​​the smoke flow. On the other hand, the increase of L2 also expands the volume of the air chamber, and the smoke flows relatively stably in the air chamber.

[0029] As a preferred implementation in this embodiment, the first distribution plate 1, the second distribution plate 2, and the third distribution plate 3 are made of plates with a thickness of 4-6 mm and made of carbon steel or low alloy steel; The first flue gas velocity reduction pipe 4, the second flue gas velocity reduction pipe 5 and the flue gas velocity increasing pipe 6 are made of carbon steel or low alloy steel, and the wall thickness of the pipe is 3.5-4 mm.

[0030] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A combined air flow distribution plate suitable for an ultra-high type electrostatic precipitator, characterized in that: The invention comprises a first distribution plate (1), a second distribution plate (2) and a third distribution plate (3) which are installed in an air inlet box (8) of an electrostatic precipitator and are arranged in sequence from left to right, wherein the first distribution plate (1) is arranged close to the air inlet of the air inlet box of the electrostatic precipitator; The first distribution plate (1) is a convex bottom inclined surface structure, the convex bottom is a plane A1, and both the plane A1 and the inclined surface are provided with ventilation holes (7); The second distribution plate (2) is a convex bottom inclined surface structure, the convex bottom is a plane A2, both the plane A2 and the inclined surface are provided with ventilation holes (7), and a first smoke reduction pipe (4) is provided at the outlet position of the ventilation hole (7) on the plane A2; The third distribution plate (3) is a concave bottom inclined surface structure, the concave bottom is a plane A3, a ventilation hole (7) is provided on the plane A3, and there is no ventilation hole (7) on the inclined surface, the plane A3 is divided from top to bottom into an upper smoke speed reduction zone A31, a middle smoke speed increase zone A32, and a lower smoke speed reduction zone A33, a second smoke speed reduction pipe (5) is provided at the outlet position of the ventilation hole (7) on the upper smoke speed reduction zone A31 and the lower smoke speed reduction zone A33, and a smoke speed increase pipe (6) is provided at the outlet position of the ventilation hole on the middle smoke speed increase zone A32.

2. The combined air flow distribution plate suitable for an ultra-high type electrostatic precipitator according to claim 1, characterized in that: The angle a1 between the plane A1 of the first distribution plate (1) and the inclined surface is ≤8°, the area of ​​the plane A1 accounts for 18-20% of the total area of ​​the first distribution plate (1), and the opening rate is ≥50%, the area of ​​the inclined surface accounts for 80-82% of the total area of ​​the first distribution plate (1), and the opening rate is ≥40%, the central axis of the vent hole (7) on the plane A1 is perpendicular to the plane A1, and the central axis of the vent hole (7) on the inclined surface is perpendicular to the inclined surface.

3. The combined air flow distribution plate suitable for an ultra-high type electrostatic precipitator according to claim 1, characterized in that: The angle a2 between the plane A2 and the inclined surface on the second distribution plate (2) is ≤8°, the area of ​​the plane A2 accounts for 32-35% of the total area of ​​the second distribution plate (2), and the opening rate is ≥50%, the area of ​​the inclined surface accounts for 65-68% of the total area of ​​the second distribution plate (2), and the opening rate is ≥40%, and the central axis of the vent hole (7) on the plane A2 is perpendicular to the plane A2, and the central axis of the vent hole (7) on the inclined surface is perpendicular to the inclined surface.

4. The combined air flow distribution plate suitable for an ultra-high type electrostatic precipitator according to claim 1, characterized in that: The included angle a3 between the plane A3 of the third distribution plate (3) and the inclined surface is ≥30°, the central axis of the ventilation hole (7) on the plane A3 is perpendicular to the plane A3, the area of ​​the plane A3 accounts for 94-96% of the total area of ​​the air flow distribution plate 3, the area of ​​the upper smoke velocity reduction zone A31 accounts for 18-20% of the entire area of ​​the plane A3, and the opening rate is ≥30%, the area of ​​the middle smoke velocity increase zone A32 accounts for 60-64% of the entire area of ​​the plane A3, and the opening rate is ≥40%, and the area of ​​the lower smoke velocity reduction zone A33 accounts for 18-20% of the entire area of ​​the plane A3, and the opening rate is ≥30%.

5. The combined air flow distribution plate suitable for an ultra-high type electrostatic precipitator according to claim 1, characterized in that: The central axis of the first flue gas velocity reduction pipe (4) is consistent with the central axis of the corresponding ventilation hole (7); the inlet diameter of the first flue gas velocity reduction pipe (4) is the same as the diameter of the ventilation hole (7); the outlet diameter is 1.10 to 1.15 times the inlet diameter; and the length is ≤60 mm; The central axis of the second smoke velocity reduction pipe (5) is consistent with the central axis of the corresponding ventilation hole (7); the inlet diameter of the second smoke velocity reduction pipe (5) is the same as the diameter of the ventilation hole (7); the outlet diameter is 1.05 to 1.10 times the inlet diameter; and the length is ≤60 mm; The central axis of the smoke accelerating tube (6) is consistent with the central axis of the corresponding ventilation hole (7), the inlet diameter of the smoke accelerating tube (6) is the same as the diameter of the ventilation hole (7), the outlet diameter is 0.90 to 0.95 times the inlet diameter, and the length is ≤60 mm.

6. The combined air flow distribution plate suitable for an ultra-high type electrostatic precipitator according to claim 1, characterized in that: The installation distance between the first distribution plate (1) and the second distribution plate (2) is L1, and the installation distance between the second distribution plate (2) and the third distribution plate (3) is L2, and L2>(2-2.5)L1.

7. The combined air flow distribution plate suitable for an ultra-high type electrostatic precipitator according to claim 1, characterized in that: The first distribution plate (1), the second distribution plate (2) and the third distribution plate (3) are made of plate materials with a thickness of 4 to 6 mm and made of carbon steel or low alloy steel; The first flue gas velocity reduction pipe (4), the second flue gas velocity reduction pipe (5) and the flue gas velocity increase pipe (6) are made of carbon steel or low alloy steel, and the wall thickness of the pipes is 3.5-4 mm.

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