A burner tail gas cooling and nitrogen reduction device based on flue gas external circulation technology

Abstract

The present invention discloses a burner tail gas temperature reduction and nitrogen reduction device based on flue gas external circulation technology, which relates to the technical field of flue gas external circulation, and specifically includes a burner body, a flue gas collecting ring, a mounting flange, a flue gas injection pipe and a flue gas inlet flange. The front of the burner body is externally sleeved with a flue gas collecting ring, and the front of the flue gas collecting ring is provided with a mounting flange, the front of the mounting flange is provided with a flue gas injection pipe, and one side of the flue gas collecting ring is provided with a flue gas inlet flange. The burner tail gas temperature reduction and nitrogen reduction device based on flue gas external circulation technology has the flue gas injection intensity of twelve flue gas injection pipes being equal, and the flue gas injection intensity of the twelve flue gas injection pipes being greater than the injection intensity of the outer flame of the burner body combustion, so that the flue gas ejected from the flue gas injection pipes evenly cuts the flame ejected from the burner body, so that the flue gas ejected from the flue gas injection pipes can be more fully burned, and effectively reduces the pollution of harmful substances in the flue gas to the environment.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas external circulation, and in particular to a burner tail gas temperature and nitrogen reduction device based on the flue gas external circulation technology. Background Art

[0002] Driven by national environmental protection policies, low-nitrogen burners have developed very rapidly in recent years, and corresponding low-nitrogen combustion technologies have become increasingly abundant, but the current mainstream technologies are fully premixed surface combustion and flue gas external circulation.

[0003] The flue gas external circulation technology is to recycle the flue gas after the fuel combustion into the burner, mix the flue gas with combustion air and then mix it with fuel for combustion. This obviously increases the total volume of combustion air and reduces the oxygen percentage content of the combustion mixed air while ensuring that the total amount of combustion oxygen remains unchanged.

[0004] This method of flue gas external circulation can indeed reduce the NO generated by combustion. X However, it also brings some negative effects, such as the generation of condensed water during the flue gas mixing process and the unstable combustion caused by the reduction of oxygen content in the combustion air, which significantly increase the failure rate of the burner during operation.

[0005] The existing low-nitrogen burner technology has solved some problems, but it has also brought some negative effects. The failure rate of the burner during operation has increased significantly. How to design a burner that can reduce NO X On the basis of ensuring the long-term stable operation of combustion is an urgent problem facing scientific and technological personnel. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a burner tail gas temperature and nitrogen reduction device based on flue gas external circulation technology, which solves the problems raised in the above background technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a burner tail gas cooling and nitrogen reduction device based on flue gas external circulation technology, comprising a burner body, a flue gas collecting ring, a mounting flange, a flue gas injection pipe and a flue gas inlet flange, the front of the burner body is externally sleeved with a flue gas collecting ring, and the front of the flue gas collecting ring is provided with a mounting flange, the front of the mounting flange is provided with a flue gas injection pipe, one side of the flue gas collecting ring is provided with a flue gas inlet flange, there are twelve flue gas injection pipes in total, the twelve flue gas injection pipes are distributed in a ring shape on the front of the mounting flange, the flue gas nozzles of the twelve flue gas injection pipes all point to the center line of the outlet end face of the burner body, the flue gas injection intensities of the twelve flue gas injection pipes are equal, and the flue gas injection intensities of the twelve flue gas injection pipes are greater than the injection intensity of the outer flame of the burner body combustion.

[0008] Optionally, one end of the smoke injection pipe passes through the inner cavity of the smoke collecting ring, and the bending angles of the smoke injection ports of the twelve smoke injection pipes are 120° to 135°.

[0009] The present invention provides a burner tail gas temperature and nitrogen reduction device based on flue gas external circulation technology, which has the following beneficial effects:

[0010] 1. The burner tail gas cooling and nitrogen reduction device based on the flue gas external circulation technology uses a flue gas collecting ring and a flue gas injection pipe to make the flue gas directly spray the outer flame of the combustion flame, divide the combustion flame, disrupt the flame shape, and cool the flame in the combustion area, especially the outer flame. At the same time, the high-speed flue gas injection can cause more flue gas to reflux inside the boiler to form a flue gas internal circulation, and the unburned flue gas refluxed from the shrinkage of the burner body flame tube and the forced injection flue gas return to the center of the flame tube. Under the turbulence effect of the blunt body of the burner body combustion head, it is mixed with the central axial flow wind again, so that the flue gas flows back to the flame, further reducing NO X At the same time, since the flue gas enters the flame from the outer area of ​​the flame, the flame root of the burner is still normal air-assisted combustion, which avoids the intersection of cold and hot air inside the burner and the generation of condensed water, thereby improving the combustion stability of the burner.

[0011] 2. The burner tail gas cooling and nitrogen reduction device based on the flue gas external circulation technology has the flue gas injection intensity of the twelve flue gas injection pipes equal, and the flue gas injection intensity of the twelve flue gas injection pipes is greater than the injection intensity of the outer flame of the burner body combustion, so that the flue gas ejected from the flue gas injection pipes can evenly cut the flame ejected from the burner body, so that the flue gas ejected from the flue gas injection pipes can be burned more fully, effectively reducing the pollution of harmful substances in the flue gas to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is the front view of the present invention;

[0013] Figure 2 A top view of the present invention;

[0014] Figure 3 It is a left side cross-sectional view of the present invention;

[0015] Figure 4 It is a front view of the present invention.

[0016] In the figure: 1. Burner body; 2. Flue gas collecting ring; 3. Mounting flange; 4. Flue gas injection pipe; 5. Flue gas inlet flange. DETAILED DESCRIPTION

[0017] 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 the embodiments.

[0018] See also Figures 1 to 4 A burner tail gas temperature reduction and nitrogen reduction device based on flue gas external circulation technology comprises a burner body 1, a flue gas collecting ring 2, a mounting flange 3, a flue gas injection pipe 4 and a flue gas inlet flange 5. The front of the burner body 1 is externally sleeved with a flue gas collecting ring 2, and the front of the flue gas collecting ring 2 is provided with a mounting flange 3, and the front of the mounting flange 3 is provided with a flue gas injection pipe 4, and one side of the flue gas collecting ring 2 is provided with a flue gas inlet flange 5, one end of the flue gas injection pipe 4 passes through the inner cavity of the flue gas collecting ring 2, and there are twelve flue gas injection pipes 4 in total, and the bending angles of the flue gas nozzles of the twelve flue gas injection pipes 4 are 120° to 135°, and the twelve flue gas injection pipes 4 are distributed in an annular manner in the installation flange 5. On the front side of the mounting flange 3, the flue gas nozzles of the twelve flue gas injection pipes 4 are all directed toward the center line of the outlet end face of the burner body 1. The twelve flue gas injection pipes 4 are directly spraying the outer flame of the burning flame to cool down the outer flame of the burning flame, so that the cooling effect of the flue gas on the burning flame is more obvious. The flue gas injection intensity of the twelve flue gas injection pipes 4 is equal, and the flue gas injection intensity of the twelve flue gas injection pipes 4 is greater than the injection intensity of the outer flame of the burner body 1. The flue gas ejected from the twelve flue gas injection pipes 4 can evenly cut the burning flame, increase the heat dissipation area of ​​the flame surface, and reduce the peak temperature of the flame. In this way, the high-temperature flue gas generated by the combustion will be further cooled, thereby playing a role in reducing NO. X The twelve flue gas injection pipes 4 inject the outer flame of the burning flame, so that the flue gas can be burned secondary, making the flue gas burn more fully, effectively improving the utilization rate of the flue gas. Since the low-temperature flue gas directly enters the furnace and directly injects the flame, it prevents the mixture of flue gas and air to form condensed water, avoiding the corrosion and damage of the equipment components by condensed water. The external flue gas injection cools the outer flame without affecting the root air distribution of the burning flame, ensuring sufficient stability of the flame and effectively improving the safety of the burner during use. The external high-speed injection of flue gas can induce sufficient reflux inside the furnace, further strengthening the internal recirculation of flue gas, so as to reduce NO X的 The effect is more significant.

[0019] When the burner tail gas cooling and nitrogen reduction device based on the flue gas external circulation technology is used, the flue gas inlet flange 5 is first installed at the flue gas outlet of the boiler, and then the natural gas is connected to the burner body 1, and then the burner body 1 is started, and the flue gas flows through the flue gas inlet flange 5, the flue gas collecting ring 2, and the flue gas injection pipe 4 and then ejected from each nozzle of the flue gas injection pipe 4. The flue gas injection adopts high-speed injection, and at the same time, the flue gas flow inside the furnace can be guided to enter the combustion area for the second time. The airflow entering the combustion area is fully mixed with the high-temperature flue gas after combustion. In this area, due to the intervention of the external circulating low-temperature flue gas, the low-temperature flue gas will fully exchange heat with the high-temperature hot flue gas of combustion, and at the same time, the combustion flame is cut and dispersed into multiple small flames.

[0020] 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 according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A burner tail gas temperature and nitrogen reduction device based on flue gas external circulation technology, comprising a burner body (1), a flue gas collecting ring (2), a mounting flange (3), a flue gas injection pipe (4) and a flue gas inlet flange (5), characterized in that: A flue gas collecting ring (2) is mounted on the outside of the front of the burner body (1), and a mounting flange (3) is provided on the front of the flue gas collecting ring (2). A flue gas injection pipe (4) is installed on the front of the mounting flange (3). A flue gas inlet flange (5) is provided on one side of the flue gas collecting ring (2). There are twelve flue gas injection pipes (4) in total. The twelve flue gas injection pipes (4) are distributed in a ring shape on the front of the mounting flange (3). The flue gas nozzles of the twelve flue gas injection pipes (4) all point to the center line of the outlet end face of the burner body (1). The flue gas injection intensities of the twelve flue gas injection pipes (4) are equal, and the flue gas injection intensities of the twelve flue gas injection pipes (4) are greater than the injection intensity of the outer flame of the burner body (1).

2. The burner tail gas temperature and nitrogen reduction device based on flue gas external circulation technology according to claim 1 is characterized by: One end of the smoke injection pipe (4) passes through the inner cavity of the smoke collecting ring (2), and the bending angles of the smoke injection ports of the twelve smoke injection pipes (4) are 120° to 135°.

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