A direct current burner for simultaneously burning NH3 and pulverized coal

Abstract

The present invention discloses a direct current burner for simultaneously burning NH3 and pulverized coal, which includes an annular primary air passage (1), an NH3 combustion passage (3) arranged at the center of the primary air passage (1), and a perimeter air passage (2) arranged outside the primary air passage (1). When the direct current burner operates, NH3 and air burn in the porous medium combustion passage, releasing heat and heating the inner secondary air and the outer secondary air. The excessive NH3 can react with NO in the flue gas in the combustion zone, thereby removing part of the NOx. The present invention can reduce the usage amount of coal and can reduce the generation of NOx during the coal combustion process.

Description

Technical Field

[0001] The present invention belongs to the field of combustion technology, and particularly relates to a direct current burner for simultaneously burning NH3 and pulverized coal. Background Art

[0002] In recent years, the world's energy consumption has been increasing continuously. While the consumption of fossil fuels brings social and economic benefits, it will be accompanied by a series of environmental problems. The proposal of "carbon peak" and "carbon neutrality" requires finding other alternative fuels to reduce CO2 emissions. NH3 is regarded as a promising clean energy carrier and storage medium. NH3 can be obtained from biomass or other renewable resources, with a relatively low unit storage energy cost, a relatively high volume energy density, and good safety and reliability. Therefore, using NH3 to replace part of the coal combustion can reduce CO2 emissions. At the same time, NH3 can be synthesized by electric energy. By burning NH3, new energy electricity can be stored, and NH3 can be used as an energy storage material with low price and easy access. Summary of the Invention

[0003] The purpose of the present invention is to provide a direct current burner for simultaneously burning NH3 and pulverized coal, which can simultaneously burn NH3 and pulverized coal. During the combustion process of NH3, heat is released to heat the air required for the combustion of pulverized coal. After the excessive NH3 enters the combustion zone of the boiler furnace, it can reduce NOx in the flue gas, thereby reducing the generation of NOx during the boiler combustion process. Through the combustion of NH3, the coal consumption required for the boiler to carry load is reduced.

[0004] The present invention has the advantage of being able to simultaneously burn NH3 and pulverized coal. It can use the combustion of NH3 to replace part of the pulverized coal, thereby reducing coal consumption and reducing the generation of NOx during the combustion process.

[0005] The present invention is implemented by adopting the following technical solutions:

[0006] A direct current burner for simultaneously burning NH3 and pulverized coal includes an annular primary air passage, an NH3 combustion passage arranged at the center of the primary air passage, and a perimeter air passage arranged outside the primary air passage.

[0007] A further improvement of the present invention is that the primary air carries pulverized coal and enters the primary air passage through the primary air inlet, and the flow rate of the primary air and pulverized coal is controlled by a primary air valve.

[0008] A further improvement of the present invention is that the perimeter air enters the perimeter air passage through the perimeter air inlet, and the flow rate of the inner secondary air is controlled by a perimeter air valve.

[0009] A further improvement of the present invention is that gaseous NH3 enters the NH3 combustion passage through the NH3 inlet, and the flow rate of NH3 is controlled by an NH3 valve.

[0010] A further improvement of the present invention lies in that the combustion-supporting air enters the NH3 combustion channel through the air inlet, and the flow rate of the combustion-supporting air is controlled by the combustion-supporting air valve.

[0011] A further improvement of the present invention lies in that the NH3 combustion channel includes a premixing chamber at the front end and a porous medium combustion zone at the rear end.

[0012] A further improvement of the present invention lies in that the porous medium combustion zone adopts a metal porous medium with good heat transfer characteristics.

[0013] A further improvement of the present invention lies in that the flow rates of NH3 and the combustion-supporting air are controlled by the NH3 valve and the combustion-supporting air control valve. After entering the premixing chamber for sufficient premixing, premixed combustion occurs in the porous medium combustion zone. Heat is released during the combustion process, and the heat is used to heat the primary air in the primary air channel. When the primary air carrying pulverized coal flows in the primary air channel, the NH3 combustion channel located at the center of the channel is used as a bluff body.

[0014] A further improvement of the present invention lies in that the NH3 valve and the combustion-supporting air control valve control the ratio of NH3 to the combustion-supporting air to be 1:2.975 - 1:3.571.

[0015] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0016] (1) The burner of the present invention can burn part of NH3 and release heat to replace coal. Since no CO2 is generated after the combustion of NH3, the use of the burner of the present invention can help reduce the emission of CO2.

[0017] (2) Gaseous NH3 releases heat during the combustion process in the circular NH3 combustion channel distributed in the middle of the primary air channel, and transfers the heat to the primary air in the primary air channel through heat conduction, increasing the temperature of the inner primary air, improving the stability of pulverized coal ignition, and promoting the ignition and burnout of pulverized coal. Therefore, the burner of the present invention is particularly suitable for difficult-to-burn coal types with low volatile content and high ignition point.

[0018] (3) In the burner of the present invention, during the combustion process of NH3 and air, NH3 is in a slightly excessive state. After the unburned NH3 enters the pulverized coal combustion area, it will react with NO in the flue gas to generate N2 and H2O, thereby removing part of the NOx in the flue gas and achieving the purpose of reducing NOx emissions. Description of the Drawings

[0019] Figure 1 It is the front view of the direct current burner of the present invention.

[0020] Figure 2 It is the top view of the direct current burner of the present invention.

[0021] Description of reference numerals:

[0022] 1 - primary air duct; 2 - perimeter air duct; 3 - NH3 combustion duct; 4 - NH3 premixing chamber; 5 - NH3 valve; 6 - combustion air valve; 7 - primary air valve; 8 - primary air inlet; 9 - perimeter air inlet; 10 - perimeter air valve; 11 - NH3 inlet; 12 - combustion air inlet; 13 - porous medium. Detailed implementation manners

[0023] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0024] As Figure 1 and Figure 2 shown, a direct - flow burner for simultaneously burning NH3 and pulverized coal provided by the present invention includes an annular primary air duct 1, an NH3 combustion duct 3 disposed at the center of the primary air duct 1, and a perimeter air duct 2 disposed outside the primary air duct 1.

[0025] Preferably, the primary air carries pulverized coal and enters the primary air duct 1 through the primary air inlet 8, and the flow rate of the primary air and pulverized coal is controlled by the primary air valve 7.

[0026] Preferably, the perimeter air enters the perimeter air duct 2 through the perimeter air inlet 9, and the flow rate of the inner secondary air is controlled by the perimeter air valve 10.

[0027] Preferably, gaseous NH3 enters the NH3 combustion duct 3 through the NH3 inlet 11, and the flow rate of NH3 is controlled by the NH3 valve 5.

[0028] Preferably, the combustion air enters the NH3 combustion duct 3 through the air inlet 12, and the flow rate of the combustion air is controlled by the combustion air valve 6.

[0029] Preferably, the NH3 combustion duct 3 includes a premixing chamber 4 at the front end and a porous - medium combustion zone 13 at the rear end.

[0030] Preferably, the porous - medium combustion zone 13 uses a metal porous medium with good heat - transfer characteristics.

[0031] Preferably, the flow rates of NH3 and combustion-supporting air are controlled by the NH3 valve 5 and the combustion-supporting air control valve 6. After entering the premixing chamber 4 and being fully premixed, premixed combustion occurs in the porous medium combustion zone 13. Heat is released during the combustion process, and the heat is used to heat the primary air in the primary air passage 1. When the primary air carrying pulverized coal flows in the primary air passage 1, the NH3 combustion passage 3 located at the center of the passage is used as a bluff body.

[0032] Preferably, the ratio of NH3 to combustion-supporting air controlled by the NH3 valve 5 and the combustion-supporting air control valve 6 is 1:2.975 to 1:3.571.

[0033] Although the present invention has been described in detail with general descriptions and specific embodiments above, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of the present invention claimed.

Claims

1. A direct current burner for simultaneously burning NH3 and pulverized coal, characterized in that, It includes an annular primary air passage (1), an NH3 combustion passage (3) arranged at the center of the primary air passage (1), and a perimeter air passage (2) arranged outside the primary air passage (1); The NH3 combustion passage (3) includes a premixing chamber (4) at the front end and a porous medium combustion zone (13) at the rear end; the porous medium combustion zone (13) uses a metal porous medium with good heat transfer characteristics; The flow rates of NH3 and combustion-supporting air are controlled by an NH3 valve (5) and a combustion-supporting air control valve (6). After entering the premixing chamber (4) and being fully premixed, premixed combustion occurs in the porous medium combustion zone (13). Heat is released during the combustion process, and the heat is used to heat the primary air in the primary air passage (1). When the primary air carrying pulverized coal flows in the primary air passage (1), the NH3 combustion passage (3) located at the center of the passage is used as a bluff body; The NH3 valve (5) and the combustion-supporting air control valve (6) control the ratio of NH3 to combustion-supporting air to be 1:2.975 to 1:3.571; The primary air carrying pulverized coal enters the primary air passage (1) through the primary air inlet (8), and the flow rates of the primary air and the pulverized coal are controlled by the primary air valve (7); the perimeter air enters the perimeter air passage (2) through the perimeter air inlet (9), and the flow rate of the inner secondary air is controlled by the perimeter air valve (10); gaseous NH3 enters the NH3 combustion passage (3) through the NH3 inlet (11), and the flow rate of NH3 is controlled by the NH3 valve (5).

2. The direct current burner for simultaneously burning NH3 and pulverized coal according to claim 1, wherein The combustion-supporting air enters the NH3 combustion passage (3) through the air inlet (12), and the flow rate of the combustion-supporting air is controlled by the combustion-supporting air valve (6).

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