Structure and arrangement method of secondary air pipe of garbage incinerator

Abstract

The invention discloses a structure and an arrangement method of a secondary air pipe of a garbage incinerator, the structure comprises an air spray pipe, a steam sleeve is nested in the air spray pipe to form a steam nested pipe, and the air pipe outlet direction of the air spray pipe is consistent with the steam outlet direction of the steam sleeve; through the structure and the arrangement method that the steam sleeve is nested in the air spraying pipe to form the steam nested pipe, the air can be accelerated after steam and air are mixed in the steam nested pipe, so that the speed of an outlet of a single air pipe is greatly increased; by means of the technical scheme, the speed of secondary air entering the hearth can be greatly increased, so that extremely high penetrating capacity can be brought by means of high air speed, the disturbance effect of the secondary air on a smoke flow field in the hearth can be enhanced, oxygen is evenly distributed, the more sufficient combustion effect can be achieved, and the CO standard exceeding frequency can be reduced conveniently.

Description

Technical Field

[0001] The present application relates to the technical field of secondary air ducts of waste incinerators, and in particular to a structure and arrangement method of secondary air ducts of waste incinerators. Background Art

[0002] At present, waste incinerators usually need to introduce secondary air to improve the combustion conditions in the furnace, improve combustion efficiency, ensure full combustion of waste, reduce unburned residues, and thus reduce environmental pollution. The main mechanism is to supplement the oxygen required for combustion, and at the same time strengthen the disturbance and mixing of the flue gas flow, so as to achieve enhanced combustion and reduce the CO content in the flue gas. For example, in a waste incinerator with a daily processing capacity of 750t / d, due to the large flow area of ​​the secondary air duct, the secondary air speed entering the furnace is low, and it cannot fully disturb the airflow, which leads to the weakening of the combustion-supporting and enhanced combustion effects, and the CO content in the flue gas exceeds the standard too many times.

[0003] In order to solve the problem that the secondary air speed of the incinerator is too low and the secondary air fails to achieve the ideal penetration effect after entering the furnace, it is necessary to structurally transform the secondary air duct in order to improve the penetration of the secondary air so that the secondary air can play a sufficient disturbing role, strengthen the secondary air's combustion-supporting and combustion-enhancing effects, and reduce some pollutant indicators in the flue gas.

[0004] There are various improvements to the secondary air inlets of waste incinerators, but they are mainly aimed at optimizing single air ducts and nozzles. For example, the diameter of the air duct is designed to shrink to increase the flow rate; or the nozzle is modified to produce a vortex (as shown in CN2141508Y). However, the essence of this type of design is to compress and speed up the flow of air, which requires a certain flow rate to produce an effect, and the secondary air injection sometimes needs to reduce the flow rate to cope with the situation of less waste incineration. This makes this type of method not flexible. If you want to have an adjustment function, you need an additional secondary air guide plate structure, which increases the complexity of the system (as shown in CN217423222U).

[0005] In view of the current situation that the kinetic energy of air is insufficient and the secondary air condition needs to be adjusted flexibly, there is also a design that uses steam to assist the secondary air. The reason is that the incinerator is generally used in conjunction with the boiler, and there is sufficient steam available; at the same time, the steam pressure is higher, and it can obtain greater kinetic energy than the air supplied by the fan. For example, air and steam are mixed in a box and then sprayed into the furnace (as shown in CN2330883Y). With the help of the high pressure of steam, the airflow in the furnace can be fully disturbed; or the high temperature of steam can be used to preheat the secondary air before sending it into the furnace (as shown in CN207568666U) to make the temperature field in the furnace uniform, thereby achieving the purpose of reducing the generation of pollutants.

[0006] The steam nested structure (as shown in CN111256152A) in the related art is also disclosed, but this structure is used in a rotary kiln, and its steam flow rate and steam volume account for the proportion of secondary air, which is not suitable for the grate furnace type of domestic waste. When the domestic waste incinerator in the related art is in operation, the speed of the secondary air entering the furnace is relatively small, which is not enough to form an ideal disturbance effect on the flow field in the furnace; this will cause the oxygen carried by the secondary air to be unevenly distributed in the furnace, directly rise along the furnace wall, and fail to participate in the combustion reaction; thus, it leads to an increase in the amount of oxygen in the flue gas and an increase in the number of CO exceeding the standard. Summary of the invention

[0007] The purpose of the present application is to provide a structure and arrangement method for the secondary air duct of a waste incinerator, so as to solve the problem that the speed of the secondary air entering the furnace during the operation of the domestic waste incinerator in the related technology is relatively low, which is insufficient to form an ideal disturbance effect on the flow field in the furnace; this will cause the oxygen carried by the secondary air to be unevenly distributed in the furnace, directly rise along the furnace wall, and fail to participate in the combustion reaction; thus leading to an increase in the amount of oxygen in the flue gas and an increase in the number of CO exceeding the standard.

[0008] On the one hand, the structure of the secondary air duct of a waste incinerator provided in the present application adopts the following technical solution: A secondary air duct structure of a garbage incinerator comprises an air nozzle, wherein a steam sleeve is nested inside the air nozzle to form a steam nested pipe, and the air duct outlet direction of the air nozzle is consistent with the steam outlet direction of the steam sleeve.

[0009] Furthermore, the distance between the steam outlet and the air duct outlet is 150-300 mm.

[0010] Furthermore, the inner diameter of the steam jacket is 4-14 mm.

[0011] Furthermore, the steam nested tubes are arranged at staggered intervals on both sides of the furnace.

[0012] Furthermore, a connecting piece is provided at one end of the air nozzle away from the air duct outlet. Furthermore, a steam delivery pipe connected to the steam sleeve is provided on the outer side of the air nozzle, and a plurality of pipeline compensators are provided on the steam delivery pipe.

[0013] On the other hand, the present application provides a method for arranging secondary air ducts of a waste incinerator using the following technical solution: A method for arranging secondary air ducts of a garbage incinerator includes the following arrangement schemes by changing the distance parameter between the steam outlet and the air duct outlet: Scheme 1: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 150 mm, the steam pressure is 0.5 MPa, the diffusion angle is 19°, and the outlet velocity is 564 m / s; Solution 2: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 200 mm, the steam pressure is 0.5 MPa, the diffusion angle is 22°, and the outlet velocity is 627 m / s; Scheme 3: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 250 mm, the steam pressure is 0.5 MPa, the diffusion angle is 19°, and the outlet velocity is 585 m / s; Scheme 4: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 300 mm, the steam pressure is 0.5 MPa, the diffusion angle is 18°, and the outlet velocity is 554 m / s.

[0014] Furthermore, under the condition that other boundary conditions remain unchanged, by changing the inner diameter parameter of the steam casing in the steam nested pipe, the following arrangement schemes are included: Scheme 1: The inner diameter of the steam jacket is 10 mm, and the furnace oxygen concentration uniformity coefficient is 0.558; Solution 2: The inner diameter of the steam jacket is 8 mm, and the furnace oxygen concentration uniformity coefficient is 0.534; Solution 3: The inner diameter of the steam jacket is 6 mm, and the furnace oxygen concentration uniformity coefficient is 0.530; Solution 4: The inner diameter of the steam jacket is 4 mm, and the furnace oxygen concentration uniformity coefficient is 0.649.

[0015] Furthermore, by changing the position parameters of the steam nested tubes and the conventional air ducts arranged on both sides of the furnace, the following arrangement schemes are included: Solution 1: Several conventional air ducts are symmetrically arranged on both sides of the furnace; Solution 2: Several steam nested tubes are symmetrically arranged on both sides of the furnace; Solution 3: Several conventional air ducts are arranged on one side of the furnace, and several steam nested tubes are arranged on the other side of the furnace; Solution 4: Several conventional air ducts and several steam nested tubes are arranged alternately on one side of the furnace, and several conventional air ducts and several steam nested tubes are arranged alternately on the other side of the furnace; Solution 5: A steam nested pipe is installed behind every two conventional air ducts on one side of the furnace, and a conventional air duct is installed behind every two steam nested pipes on the other side of the furnace; Solution 6: A steam nested tube is installed behind every two conventional air ducts on one side of the furnace, and two conventional air ducts are installed behind every steam nested tube on the other side of the furnace.

[0016] Furthermore, in Scheme 4 and Scheme 5, the corresponding pipe types on both sides of the furnace are different.

[0017] Compared with the prior art, the beneficial effects of this application are: By nesting a steam sleeve inside the air nozzle to form a steam nested tube structure and arrangement method, the steam and air can be mixed in the steam nested tube to accelerate the air, so that the speed at the outlet of a single air duct is greatly enhanced, and the speed of the secondary air entering the furnace can be greatly enhanced. The high wind speed can bring a strong penetration ability, and then the disturbance effect of the secondary air on the flue gas flow field in the furnace can be strengthened, and the oxygen can be evenly distributed, so that a more sufficient combustion effect can be achieved, so as to reduce the number of CO exceeding the standard.

[0018] In addition, by changing the distance between the steam outlet and the air duct outlet, the injection effect of the mixture of steam and air can be affected, which not only maximizes the diffusion angle but also the outlet wind speed, so that the secondary air can cover a larger area during flight after entering the furnace, and the probability of direct contact with the flue gas is increased, and the mixing of oxygen and flue gas in the secondary air is more complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the secondary air duct of the garbage incinerator in the embodiment of the present application.

[0020] Figure 2 This is a data graph showing the effect of nested tube design parameters on the secondary air entering the furnace from a single duct.

[0021] Figure 3 It is a schematic diagram of the installation of the staggered arrangement of steam nested tubes and conventional air ducts in the embodiment of the present application.

[0022] Figure 4 It is a schematic diagram of the installation of the steam nested tubes in the embodiment of the present application and other arrangements of conventional air ducts.

[0023] Figure 5 yes Figure 4 Data graph showing the effect of different layout schemes on oxygen concentration.

[0024] Figure 6 This is a data diagram of the implementation effect of different steam casing inner diameters in the embodiments of the present application. DETAILED DESCRIPTION

[0025] The following is combined with Figure 1-6This application is described in further detail.

[0026] On the one hand, the present application embodiment discloses a structure of a secondary air duct of a garbage incinerator, referring to Figure 1 In this embodiment, the structure includes an air nozzle and a steam sleeve. The air nozzle adopts a DN125 steel pipe with a length of 450 mm, an outer diameter of 133 mm, and an inner diameter of 121 mm. A connector is installed at one end of the air nozzle away from the air duct outlet. The connector is a flange. The flange on the air nozzle is firmly installed on the flange on the air delivery pipe through a structure in which bolts and nuts cooperate with each other. The air delivery pipe is connected to an external air supply device to discharge air into the air nozzle along the air delivery pipe.

[0027] One end of the steam sleeve is nested and installed on the inner wall of the air nozzle to form a steam nested pipe. Specifically, the steam sleeve is composed of a long pipe with a length of 100 mm and a short pipe with a length of 58 mm, and one end of the short pipe is vertically installed on the inner wall of the air nozzle and extends out of the air nozzle. One end of the long pipe and the other end of the short pipe are vertically installed to each other to form an L-shaped pipe.

[0028] The end of the long pipe away from the short pipe extends along the air duct outlet direction of the air nozzle, so that the air duct outlet direction of the air nozzle is consistent with the steam outlet direction of the steam sleeve, so that it is convenient to use the steam and air to mix in the air nozzle to achieve the effect of accelerating the air.

[0029] At the same time, refer to Figure 1 In this embodiment, a steam delivery pipe is also installed on the outside of the air nozzle, one end of the steam delivery pipe is interconnected with one end of the short pipe of the steam jacket, and the other end of the steam delivery pipe is interconnected with an external steam supply device, so that the steam is discharged into the steam jacket along the steam delivery pipe, and then the steam is ejected from the steam jacket, so that the steam and air are mixed with each other inside the steam jacket.

[0030] Preferably, a plurality of pipeline compensators are installed on the steam delivery pipe, which can absorb the displacement of the steam delivery pipe caused by thermal expansion and contraction, reduce the impact of vibration and impact on the steam delivery pipe, reduce stress concentration, and facilitate the installation and removal of valve pipelines.

[0031] Therefore, by setting up the steam nested tubes, the steam and air can be mixed in the steam nested tubes to accelerate the air, so that the speed at the outlet of the single air duct is greatly enhanced, and the speed of the secondary air entering the furnace can be greatly enhanced. The high wind speed can bring a strong penetration ability, and then the disturbance effect of the secondary air on the flue gas flow field in the furnace can be enhanced, and the oxygen can be evenly distributed, so as to achieve a more sufficient combustion effect, so as to reduce the number of CO exceeding the standard.

[0032] To explain in detail: in a certain existing domestic waste incinerator, the size of the secondary air duct is 133mm in outer diameter and 6mm in wall thickness. A row of secondary air inlet pipes is installed on the upper and lower front walls of the incinerator furnace, each row has 14 pipes, and the total number of secondary air inlet pipes on the front wall is 28 pipes; the rear wall of the incinerator furnace is only installed with a row of secondary air inlet pipes, which has 14 pipes; that is, there are a total of 42 secondary air inlet pipes on the incinerator furnace.

[0033] The steam nested pipe structure provided by the present application mainly targets the 14 pipes on the front wall and the 14 pipes on the rear wall of the furnace, and does not modify the air ducts on the lower row of the front wall. Even if there are secondary air ducts that may need to be modified, not all of them need to be modified, but some air ducts are selected for opening according to the specific implementation effect.

[0034] In addition, the wind speed of a single secondary air duct in normal stable operation is 20m / s, the pressure is 2000pa, and the composition is air; the flue gas enters from the bottom of the incinerator and reaches a temperature of 1100℃ near the height of the secondary air duct; the horizontal cross-sectional size of the furnace is 3940×14000mm, and the flue gas upward flow velocity is 3.191m / s. This part of data is the known basic furnace operation data, which is used as the boundary condition of the simulation.

[0035] Therefore, on the other hand, the present application also provides a method for arranging secondary air ducts of a waste incinerator, which adopts the following technical solution: 1) Optimization of the distance between the steam outlet and the air duct outlet; The influence of the secondary air entering the furnace through a single air duct is affected by changing the distance parameter between the steam outlet and the air duct outlet. Specifically, in this embodiment, the distance between the steam outlet and the air duct outlet is 150-300 mm.

[0036] More specifically, refer to Figure 2 In this embodiment, the arrangement method includes the following arrangement schemes: Scheme 1: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 150 mm, the steam pressure is 0.5 MPa, the diffusion angle is 19°, and the outlet velocity is 564 m / s; Solution 2: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 200 mm, the steam pressure is 0.5 MPa, the diffusion angle is 22°, and the outlet velocity is 627 m / s; Scheme 3: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 250 mm, the steam pressure is 0.5 MPa, the diffusion angle is 19°, and the outlet velocity is 585 m / s; Scheme 4: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 300 mm, the steam pressure is 0.5 MPa, the diffusion angle is 18°, and the outlet velocity is 554 m / s.

[0037] Depend on Figure 2 It can be seen that when the distance between the steam outlet and the air duct outlet is changed, the injection effect of the steam and air after mixing will be affected, that is, the optimal design value of the steam duct outlet distance from the secondary air duct outlet is 250mm. The gas velocity and diffusion angle of a single air duct are optimized in Scheme 2: its diffusion angle is the largest, and the outlet velocity is also the largest, which means that after the secondary air enters the furnace, it can cover a larger area during flight, and the probability of direct contact with the flue gas increases. At the same time, the mixing of oxygen and flue gas in the secondary air will be more complete.

[0038] When the distance is too long, it is easy to cause a large pressure difference between the two gases and cause backflow; when the distance is too short, it is easy to cause the air to not be accelerated by the steam, and the degree of mixing between the air and steam is insufficient, which cannot play the role of optimizing the secondary air combustion.

[0039] 2) Optimization of the layout of the air ducts in the furnace; By changing the position parameters of the steam nested tubes and the conventional air ducts arranged on both sides of the furnace, the physical parameters of the secondary air entering the furnace through the upper row of the front wall and the single row of the rear wall air ducts and the influence of the secondary air on the oxygen concentration distribution in the furnace are controlled. Specifically, refer to Figure 3 In this embodiment, the steam nested tubes are arranged in a staggered manner on the front wall and the rear wall of the furnace.

[0040] Since the steam nested pipe structure adds a steam casing to the original structure, there will be additional steam consumption in actual operation. In order to save steam and achieve the design purpose, it is not necessary to use the steam nested pipe structure. The optimized solution is to arrange traditional air ducts and steam nested pipes of this design at intervals in the existing two rows of air nozzles, and keep the opposite side of the steam nested pipe always arranged with traditional air ducts.

[0041] Therefore, in this embodiment, under basic operating conditions, simulation can be used to obtain the physical parameters of the secondary air entering the furnace through the upper row of air ducts on the front wall and the single row of air ducts on the rear wall, as well as the influence of the secondary air on the oxygen concentration distribution in the furnace.

[0042] The following table shows the effect of nested nozzle implementation: Among them, the coefficient reflecting the uniformity of oxygen concentration is simply defined in this application as (maximum oxygen concentration Max-minimum oxygen concentration Min) / (maximum oxygen concentration Max+minimum oxygen concentration Min) on the horizontal cross section of the secondary air duct installation position in the furnace, and the value is between 0 and 1. The smaller the value, the more uniform the gas distribution in the furnace.

[0043] Therefore, it can be seen from the table that by using steam nested tubes, the velocity at the outlet of a single air duct is greatly enhanced, and the high wind speed will bring extremely strong penetration ability, sending the combustion air to the middle of the furnace. The wind speed in the middle of the furnace can reach 21.6m / s, which has a strong disturbing effect on the flue gas. The oxygen concentration is reduced to 13wt% in the center of the furnace, which is much lower than the traditional arrangement, indicating that the oxygen has been spread to other locations in the furnace, rather than concentrated locally. The oxygen concentration uniformity coefficient can also support the above description. 0.521 is significantly lower than 0.612, indicating that using the solution of the present application, oxygen can be evenly distributed, which can make the combustion more complete.

[0044] In addition, Figure 3 Based on Figure 4 In this embodiment, other arrangements of conventional air ducts and steam nested tubes are also listed; the following are explained in detail: Figure 4 A is a conventional air duct and B is a steam nested duct.

[0045] Specifically, in this embodiment, the following arrangement scheme is also included: Scheme 1: Several conventional air ducts are symmetrically arranged on both sides of the furnace. This scheme 1 is a conventional arrangement scheme. Figure 4 and Figure 5 ,From the table, it can be concluded that due to the lack of the ,steam nested tube, the mixing effect of air and flue gas is not good, ,and the oxygen concentration distribution is not uniform.

[0046] Solution 2: Several steam nested tubes are symmetrically arranged on both sides of the furnace. Figure 4 and Figure 5 ,It can be concluded from the table that using all steam nested tubes has the best mixing effect, but consumes a lot of steam.

[0047] Solution 3: Several conventional air ducts are arranged on one side of the furnace, and several steam nested tubes are arranged on the other side of the furnace. Figure 4 and Figure 5 ,It can be concluded from the table that, since all steam nested tubes are arranged in a single row, the area with high oxygen concentration value will be compressed to the side where steam nested tubes are not arranged, resulting in uneven oxygen distribution in the entire furnace and a large coefficient.

[0048] Scheme 4: Several conventional air ducts and several steam nested tubes are arranged alternately on one side of the furnace, and several conventional air ducts and several steam nested tubes are arranged alternately on the other side of the furnace. The corresponding pipe types on both sides of the furnace are different; and the layout of Scheme 4 should be Figure 3 Layout in. Figure 4 and Figure 5 ,It can be concluded from the table that the oxygen concentration uniformity coefficient is only 0.001 greater than that of Scheme 2, and the difference in the combustion-supporting effect in the furnace is not large, but reducing the steam consumption by half is more economically reasonable, so it is the optimal solution.

[0049] Solution 5: A steam nested pipe is installed behind every two conventional air ducts on one side of the furnace, and a conventional air duct is installed behind every two steam nested pipes on the other side of the furnace. The corresponding pipe types on both sides of the furnace are different.

[0050] Scheme 6: A steam nested tube is installed behind every two conventional air ducts on one side of the furnace, and two conventional air ducts are installed behind every steam nested tube on the other side of the furnace; that is, Scheme 6 reduces the number of steam nested tubes arranged on the basis of Scheme 5.

[0051] Reference Figure 4 and Figure 5 ,It can be concluded from the table that Schemes 5 and 6 have unreasonable ,arrangements and high oxygen concentration uniformity coefficients, and fail to achieve the optimal ,design effect of uniform mixing of oxygen and flue gas.

[0052] 3) Optimization of the inner diameter of the steam casing; After considering the above optimization indicators, the distance between the steam outlet and the air duct outlet is designed to be 250mm, and the arrangement between the air ducts is a scheme of staggered arrangement of steam nested tubes and conventional air ducts. In addition, under the condition that other boundary conditions remain unchanged, the inner diameter parameter of the steam jacket in the steam nested tube is modified to affect the uniformity of oxygen content distribution in the furnace. Specifically, the inner diameter of the steam jacket is 4-10mm.

[0053] More specifically, refer to Figure 6 In this embodiment, the arrangement method includes the following arrangement schemes: Scheme 1: The inner diameter of the steam jacket is 10 mm, and the furnace oxygen concentration uniformity coefficient is 0.558; Solution 2: The inner diameter of the steam jacket is 8 mm, and the furnace oxygen concentration uniformity coefficient is 0.534; Solution 3: The inner diameter of the steam jacket is 6 mm, and the furnace oxygen concentration uniformity coefficient is 0.530; Solution 4: The inner diameter of the steam jacket is 4 mm, and the furnace oxygen concentration uniformity coefficient is 0.649.

[0054] Therefore, by Figure 6 It can be seen that in Scheme 3, when the inner diameter of the steam jacket is 6 mm, the oxygen concentration distribution is most uniform.

[0055] In summary, the present application nests and installs a steam sleeve inside the air nozzle to form a steam nested tube structure and arrangement method, which can utilize the steam and air to mix in the steam nested tube to accelerate the air, so that the speed at the outlet of a single air duct is greatly enhanced, and the speed of the secondary air entering the furnace can be greatly enhanced, so that the high wind speed can bring extremely strong penetration ability, and then the disturbance effect of the secondary air on the flue gas flow field in the furnace can be enhanced, and the oxygen can be evenly distributed, so as to achieve a more sufficient combustion effect, so as to reduce the number of CO exceeding the standard.

[0056] In addition, by changing the distance between the steam outlet and the air duct outlet, the injection effect of the mixture of steam and air can be affected, which not only maximizes the diffusion angle but also the outlet wind speed, so that the secondary air can cover a larger area during flight after entering the furnace, and the probability of direct contact with the flue gas is increased, and the mixing of oxygen and flue gas in the secondary air is more complete.

[0057] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A structure of a secondary air duct of a garbage incinerator, characterized in that: It comprises an air nozzle, wherein a steam sleeve is nested inside the air nozzle to form a steam nested tube, and the air duct outlet direction of the air nozzle is consistent with the steam outlet direction of the steam sleeve.

2. The structure of the secondary air duct of a waste incinerator according to claim 1 is characterized in that: The distance between the steam outlet and the air duct outlet is 150-300 mm.

3. The structure of the secondary air duct of a waste incinerator according to claim 1 is characterized in that: The inner diameter of the steam jacket is 4-14 mm.

4. The structure of the secondary air duct of a garbage incinerator according to claim 1 is characterized in that: The steam nested tubes are arranged at staggered intervals on both sides of the furnace.

5. The structure of the secondary air duct of a garbage incinerator according to claim 1 is characterized in that: A connecting piece is arranged at one end of the air nozzle away from the air duct outlet.

6. The structure of the secondary air duct of a garbage incinerator according to claim 5 is characterized in that: A steam delivery pipe connected to the steam sleeve is also arranged on the outer side of the air nozzle, and a plurality of pipeline compensators are arranged on the steam delivery pipe.

7. A method for arranging secondary air ducts of a waste incinerator, according to the structure of the secondary air duct of a waste incinerator according to any one of claims 1 to 6, characterized in that: By changing the distance parameter between the steam outlet and the air duct outlet, the following layout schemes are included: Scheme 1: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 150 mm, the steam pressure is 0.5 MPa, the diffusion angle is 19°, and the outlet velocity is 564 m / s; Solution 2: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 200 mm, the steam pressure is 0.5 MPa, the diffusion angle is 22°, and the outlet velocity is 627 m / s; Scheme 3: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 250 mm, the steam pressure is 0.5 MPa, the diffusion angle is 19°, and the outlet velocity is 585 m / s; Scheme 4: The inner diameter of the steam jacket is 14 mm, the distance between the steam outlet and the air duct outlet is 300 mm, the steam pressure is 0.5 MPa, the diffusion angle is 18°, and the outlet velocity is 554 m / s.

8. The method for arranging secondary air ducts of a waste incinerator according to claim 7, characterized in that: When other boundary conditions remain unchanged, by changing the inner diameter parameter of the steam jacket in the steam nested pipe, the following arrangement schemes are included: Scheme 1: The inner diameter of the steam jacket is 10 mm, and the furnace oxygen concentration uniformity coefficient is 0.558; Solution 2: The inner diameter of the steam jacket is 8 mm, and the furnace oxygen concentration uniformity coefficient is 0.534; Solution 3: The inner diameter of the steam jacket is 6 mm, and the furnace oxygen concentration uniformity coefficient is 0.530; Solution 4: The inner diameter of the steam jacket is 4 mm, and the furnace oxygen concentration uniformity coefficient is 0.

649.

9. The method for arranging secondary air ducts of a waste incinerator according to claim 7, characterized in that: By changing the position parameters of the steam nested tubes and conventional air ducts arranged on both sides of the furnace, the following arrangement schemes are included: Solution 1: Several conventional air ducts are symmetrically arranged on both sides of the furnace; Solution 2: Several steam nested tubes are symmetrically arranged on both sides of the furnace; Solution 3: Several conventional air ducts are arranged on one side of the furnace, and several steam nested tubes are arranged on the other side of the furnace; Solution 4: Several conventional air ducts and several steam nested tubes are arranged alternately on one side of the furnace, and several conventional air ducts and several steam nested tubes are arranged alternately on the other side of the furnace; Solution 5: A steam nested pipe is installed behind every two conventional air ducts on one side of the furnace, and a conventional air duct is installed behind every two steam nested pipes on the other side of the furnace; Solution 6: A steam nested tube is installed behind every two conventional air ducts on one side of the furnace, and two conventional air ducts are installed behind every steam nested tube on the other side of the furnace.

10. The method for arranging secondary air ducts of a waste incinerator according to claim 9, characterized in that: In Scheme 4 and Scheme 5, the corresponding pipe types on both sides of the furnace are different.

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