Internal circulation low-nitrogen burner

Abstract

The utility model relates to the technical field of combustors, in particular to an internal circulation low-nitrogen combustor. The internal circulation low-nitrogen combustor comprises a combustion-supporting air channel, an air injection necking, a gas main pipe, an annular cavity gas branch pipe, a central gas branch pipe, a central gas spray hole, a gas annular cavity, a gas injection branch pipe, a gas injection elbow, a gas injection spray hole, a gas injection mixing channel, a middle gas branch pipe, a middle gas spray hole, an air injection mixing channel and a fire gathering cover. An air injection necking opening is formed in the tail end of the combustion-supporting air channel, the gas main pipe is arranged on the inner side of the combustion-supporting air channel and is coaxially arranged with the combustion-supporting air channel, a plurality of annular cavity gas branch pipes are arranged on the periphery of the rear end of the gas main pipe, and the annular cavity gas branch pipes are connected with the gas main pipe in a penetrating mode. Generation of nitric oxide is reduced through fuel gas injection, flames are more stable through a center rotational flow structure, and generation of the nitric oxide is reduced through air injection.

Description

Technical Field

[0001] The utility model relates to the technical field of burners, in particular to an internal circulation low-nitrogen burner. Background Art

[0002] As an important component of industrial boilers, burners have the function of releasing fuel energy into heat energy.

[0003] At the same time, flue gas pollutants will also be produced. With the improvement of environmental protection requirements, low-nitrogen gas burners are also widely used.

[0004] The nozzle structure of the gas burner plays a decisive role in the emission of pollutants generated during the combustion process. The design and processing level of the burner nozzle structure determines the combustion load required in production and the safe and stable operation of the boiler.

[0005] Most of the current burners use staged combustion, rich-lean combustion, and diffusion combustion, which can only achieve a certain nitrogen reduction effect. In order to ensure sufficient combustion of the fuel, the burner generally adopts a design method that has a better mixture of fuel and air. However, with this method, the combustion temperature is still relatively high and the nitrogen hydride emission value is also relatively high.

[0006] The induced injection method reduces nitrogen hydrides but also causes a longer flame length and poorer adaptability. In order to further reduce nitrogen hydrides, control the flame length and ensure the stable and safe operation of the burner, these are issues that designers need to solve. Utility Model Content

[0007] The utility model aims to solve the above-mentioned shortcomings in the prior art and proposes an internal circulation low-nitrogen burner.

[0008] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0009] An internal circulation low nitrogen burner is designed, and the internal circulation low nitrogen burner includes a combustion-supporting air channel, an air injection constriction, a gas main pipe, an annular gas branch pipe, a central gas branch pipe, a central gas spray hole, a gas annular cavity, a gas injection branch pipe, a gas injection elbow, a gas injection spray hole, a gas injection mixing channel, an intermediate gas branch pipe, an intermediate gas spray hole, an air injection mixing channel, a flame hood, a flame hood notch, an intermediate combustion-supporting air channel, a flame stabilizing disk, and an air hole of the flame stabilizing disk;

[0010] The end of the combustion-supporting air channel is provided with an air injection constriction, the gas main pipe is arranged inside the combustion-supporting air channel and coaxially therewith, a plurality of annular cavity gas branch pipes are arranged on the periphery of the rear end of the gas main pipe, the two are connected through, a gas annular cavity is penetrated through the end of the annular cavity gas branch pipe, a plurality of gas injection branch pipes are arranged at the end of the gas annular cavity, and a gas injection elbow and a gas injection air jet are penetrated through the end of each gas injection branch pipe in sequence;

[0011] A plurality of intermediate gas branch pipes are arranged through the inner side of the gas ring cavity, a plurality of intermediate gas spray holes are arranged at the periphery of the end of the intermediate gas branch pipe, an air injection mixing channel is arranged at the rear end of the gas ring cavity, a plurality of gas injection mixing channels are arranged at the periphery of the middle of the air injection mixing channel, and the two are connected through, a fire hood is arranged at the end of the air injection mixing channel, and a plurality of fire hood notches are arranged at the periphery of the fire hood;

[0012] A central gas branch pipe is provided at the end of the gas main pipe, a plurality of central gas spray holes are provided on the periphery of the end of the central gas branch pipe, an intermediate combustion-supporting air channel is provided on the inner side of the air injection constriction, a flame stabilizing disk is provided at the end of the intermediate combustion-supporting air channel, and a plurality of flame stabilizing disk air holes are provided on the flame stabilizing disk.

[0013] The combustion-supporting air channel, air injection constriction, gas main pipe, central gas branch pipe, gas ring cavity, air injection mixing channel, and fire hood are all coaxially arranged, and each gas injection elbow is coaxially arranged with the corresponding gas injection air spray and gas injection mixing channel.

[0014] In detail, the number of the annular cavity gas branch pipes is 2-1.

[0015] Specifically speaking, the number of the gas injection branch pipes is 4 to 8.

[0016] In detail, the number of the gas injection mixing channels is 4-8.

[0017] In detail, the number of the intermediate gas branch pipes is 4 to 8.

[0018] Specifically, the number of the intermediate gas injection holes is 1 to 3.

[0019] Specifically, the fire hood has 4-5 openings.

[0020] Specifically, the flame stabilizing disk has 8 to 24 air holes.

[0021] The design scheme proposed by the utility model has the following beneficial effects during application:

[0022] 1. Gas injection reduces the generation of nitrogen oxides. The central swirl structure makes the flame more stable, and air injection reduces the generation of nitrogen oxides. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional structural diagram of the utility model;

[0024] Figure 2 It is the front view of the utility model;

[0025] Figure 3 for Figure 2 A cross-sectional view of

[0026] Figure 4 for Figure 2 Right view of;

[0027] Figure 5 for Figure 2 Left view of .

[0028] In the figure: 1 combustion-supporting air channel, 1-1 air injection constriction, 2 gas main pipe, 3 annular gas branch pipe, 4 center gas branch pipe, 4-1 center gas spray hole, 5 gas annular cavity, 6 gas injection branch pipe, 6-1 gas injection elbow, 6-2 gas injection air, 7 gas injection mixing channel, 8 middle gas branch pipe, 8-1 middle gas spray hole, 9 air injection mixing channel, 10 fire hood, 10-1 fire hood notch, 11 middle combustion-supporting air channel, 11-1 flame stabilizing disk, 11-2 flame stabilizing disk air hole. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] Reference Figure 1-Figure 5 , an internal circulation low nitrogen burner, the internal circulation low nitrogen burner comprises a combustion-supporting air channel 1, an air injection constriction 1-1, a gas main pipe 2, an annular cavity gas branch pipe 3, a central gas branch pipe 4, a central gas spray hole 4-1, a gas annular cavity 5, a gas injection branch pipe 6, a gas injection elbow 6-1, a gas injection spray hole 6-2, a gas injection mixing channel 7, an intermediate gas branch pipe 8, an intermediate gas spray hole 8-1, an air injection mixing channel 9, a flame hood 10, a flame hood notch 10-1, an intermediate combustion-supporting air channel 11, a flame stabilizing disk 11-1, and a flame stabilizing disk air hole 11-2;

[0031] An air injection constriction 1-1 is provided at the end of the combustion-supporting air channel 1, a gas main pipe 2 is arranged inside the combustion-supporting air channel 1 and coaxially therewith, a plurality of annular cavity gas branch pipes 3 are provided on the periphery of the rear end of the gas main pipe 2, and the two are connected through, a gas annular cavity 5 is provided through the end of the annular cavity gas branch pipe 3, a plurality of gas injection branch pipes 6 are provided at the end of the gas annular cavity 5, and a gas injection elbow 6-1 and a gas injection air jet 6-2 are provided at the end of each gas injection branch pipe 6 in sequence;

[0032] A plurality of intermediate gas branch pipes 8 are provided through the inner side of the gas ring cavity 5, and a plurality of intermediate gas spray holes 8-1 are provided at the periphery of the end of the intermediate gas branch pipe 8. An air injection mixing channel 9 is provided at the rear end of the gas ring cavity 5, and a plurality of gas injection mixing channels 7 are provided at the periphery of the middle of the air injection mixing channel 9. The two are connected through, and a fire cover 10 is provided at the end of the air injection mixing channel 9, and a plurality of fire cover notches 10-1 are provided at the periphery of the fire cover 10.

[0033] A central gas branch pipe 4 is provided at the end of the gas main pipe 2, and a plurality of central gas spray holes 4-1 are provided on the periphery of the end of the central gas branch pipe 4. An intermediate combustion-supporting air channel 11 is provided on the inner side of the air injection constriction 1-1. A flame stabilizing disk 11-1 is provided at the end of the intermediate combustion-supporting air channel 11, and a plurality of flame stabilizing disk air holes 11-2 are provided on the flame stabilizing disk 11-1.

[0034] The combustion-supporting air channel 1, the air injection constriction 1-1, the gas main pipe 2, the central gas branch pipe 4, the gas ring cavity 5, the air injection mixing channel 9, and the fire hood 10 are all coaxially arranged, and each gas injection elbow 6-1 is coaxially arranged with the corresponding gas injection nozzle 6-2 and the gas injection mixing channel 7.

[0035] It should be further explained that the number of annular cavity gas branch pipes 3 is 2-1.

[0036] It should be further explained that the number of the gas injection branch pipes 6 is 4 to 8.

[0037] It should be further explained that the number of the gas injection mixing channels 7 is 4 to 8.

[0038] It should be further explained that the number of intermediate gas branch pipes 8 is 4 to 8.

[0039] It should be further explained that the number of the intermediate gas injection holes 8-1 is 1 to 3.

[0040] It should be further explained that the number of the fire hood notches 10-1 is 4-5.

[0041] It should be further explained that the number of the flame stabilizing disk air holes 11-2 is 8 to 24.

[0042] Working mode: The combustion-supporting air channel 1 is used as a channel for the combustion-supporting air to flow through, and guides the air to the boiler furnace. The gas main pipe 2 is used as a channel for the gas to enter the burner, and guides the gas to the boiler furnace.

[0043] Air enters the burner from the combustion-supporting air channel 1, flows backwards, and is divided into two parts in front of the intermediate combustion-supporting air channel 11. The first part flows from the inside of the intermediate combustion-supporting air channel 11, and then flows out from the flame-stabilizing disk air hole 11-2 on the flame-stabilizing disk 11-1 to form central combustion-supporting air; the second part flows between the outer periphery of the intermediate combustion-supporting air channel 11 and the inner side of the air introduction constriction 1-1. At the outlet of the air introduction constriction 1-1, the flow area is reduced and the flow velocity is increased, forming a negative pressure area. Under the action of the pressure difference, the flue gas is sucked into the burner through the annular gap between the gas ring cavity 5 and the air introduction constriction 1-1. After that, the combustion-supporting air and the sucked-in flue gas are fully mixed in the air introduction mixing channel 9, and develop backwards to be ejected from the outlet of the fire hood 10 to form a peripheral mixed gas.

[0044] The gas enters the burner from the gas main pipe 2, flows backward, and is divided into two parts at the end of the gas main pipe 2. The first part flows from the central gas branch pipe 4, and then is sprayed out from the central gas spray hole 4-1 at the end of the central gas branch pipe 4, fully mixed with the central combustion-supporting air and burned to form a central flame. Under the action of the flame stabilizing disk 11-1, the combustion is more stable; the second part flows through a plurality of annular cavity gas branch pipes 3, enters the gas annular cavity 5, and is divided into two parts again in the gas annular cavity 5. One part flows through a plurality of intermediate gas branch pipes 8, and is sprayed out from the intermediate gas spray hole 8-1 at the end to form an outer flame. The surrounding gas; the other part flows out from a plurality of gas injection branch pipes 6 at the end of the gas ring cavity 5, passes through the gas injection elbow 6-1 and is ejected from the gas injection nozzle 6-2. Under the action of the gas injection nozzle 6-2, the gas flow rate is increased to form a negative pressure area, and the smoke in the furnace is sucked into the burner. After the gas and the smoke are mixed in the gas injection mixing channel 7, they flow into the air injection mixing channel 9, continue to mix with the mixture of the injection combustion-supporting air and the smoke, and form a gas, combustion-supporting air, and smoke mixer, and finally are ejected from the fire hood 10, continue to mix and burn with the peripheral flame, and develop backward to form a peripheral premixed flame.

[0045] Due to the effect of partial premixing, the flame is more stable, and under the action of double smoke entrainment, the combustion temperature is further reduced, thereby further reducing the generation of nitrogen oxides. Under the action of the flame hood notch 10-1, part of the mixed gas develops radially, so that the flame diameter is expanded to solve the problem of slender flame caused by entrainment, so that the burner can burn stably while having low nitrogen oxide emissions.

[0046] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An internal circulation low nitrogen burner, characterized in that: The internal circulation low nitrogen burner comprises a combustion-supporting air channel (1), an air injection constriction (1-1), a gas main pipe (2), an annular gas branch pipe (3), a central gas branch pipe (4), a central gas spray hole (4-1), a gas annular cavity (5), a gas injection branch pipe (6), a gas injection elbow (6-1), a gas injection spray hole (6-2), a gas injection mixing channel (7), an intermediate gas branch pipe (8), an intermediate gas spray hole (8-1), an air injection mixing channel (9), a flame hood (10), a flame hood notch (10-1), an intermediate combustion-supporting air channel (11), a flame stabilizing disk (11-1), and an air hole (11-2) of the flame stabilizing disk; The end of the combustion-supporting air channel (1) is provided with an air injection constriction (1-1); the gas main pipe (2) is arranged inside the combustion-supporting air channel (1) and coaxially therewith; a plurality of annular cavity gas branch pipes (3) are arranged on the periphery of the rear end of the gas main pipe (2); the two are connected through-connected; a gas annular cavity (5) is penetrated at the end of the annular cavity gas branch pipe (3); a plurality of gas injection branch pipes (6) are disposed at the end of the gas annular cavity (5); and a gas injection elbow (6-1) and a gas injection air jet (6-2) are sequentially penetrated at the end of each gas injection branch pipe (6); A plurality of intermediate gas branch pipes (8) are provided through the inner side of the gas ring cavity (5), and a plurality of intermediate gas spray holes (8-1) are provided on the periphery of the end of the intermediate gas branch pipe (8). An air injection mixing channel (9) is provided at the rear end of the gas ring cavity (5), and a plurality of gas injection mixing channels (7) are provided on the periphery of the middle of the air injection mixing channel (9), and the two are connected through each other. A fire hood (10) is provided at the end of the air injection mixing channel (9), and a plurality of fire hood notches (10-1) are provided on the periphery of the fire hood (10); The end of the gas main pipe (2) is provided with a central gas branch pipe (4), the outer periphery of the end of the central gas branch pipe (4) is provided with a plurality of central gas spray holes (4-1), the inner side of the air injection constriction (1-1) is provided with an intermediate combustion-supporting air channel (11), the end of the intermediate combustion-supporting air channel (11) is provided with a flame stabilizing disk (11-1), and the flame stabilizing disk (11-1) is provided with a plurality of flame stabilizing disk air holes (11-2); The combustion-supporting air channel (1), the air injection constriction (1-1), the gas main pipe (2), the central gas branch pipe (4), the gas ring cavity (5), the air injection mixing channel (9), and the fire hood (10) are all coaxially arranged, and each gas injection elbow (6-1) is coaxially arranged with the corresponding gas injection nozzle (6-2) and the gas injection mixing channel (7).

2. An internal circulation low nitrogen burner according to claim 1, characterized in that: The number of the annular cavity gas branch pipes (3) is 2-1.

3. The internal circulation low nitrogen burner according to claim 1 is characterized in that: The number of the gas injection branch pipes (6) is 4 to 8.

4. The internal circulation low nitrogen burner according to claim 1 is characterized in that: The number of the gas injection mixing channels (7) is 4 to 8.

5. The internal circulation low nitrogen burner according to claim 1, characterized in that: The number of the intermediate gas branch pipes (8) is 4 to 8.

6. The internal circulation low nitrogen burner according to claim 1, characterized in that: The number of the intermediate gas injection holes (8-1) is 1 to 3.

7. The internal circulation low nitrogen burner according to claim 1 is characterized in that: The number of the fire hood notches (10-1) is 4-5.

8. The internal circulation low nitrogen burner according to claim 1, characterized in that: The flame stabilizing disk has 8 to 24 air holes (11-2).

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