Combined ammonia-doped burner
By designing a combined ammonia-doped burner in a traditional fossil fuel boiler, the injection technology of speed difference and angle difference is used to delay the mixing of ammonia and combustion-supporting air, so that the ammonia is rapidly pyrolyzed at high temperatures, solving the problem of rapid combustion of ammonia and excessive nitrogen oxide generation, and achieving the effect of efficient combustion and low NOx emissions.
Patent Information
- Application Number
- CN202510239030.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-03
- Publication Date
- 2025-04-22
AI Technical Summary
When the prior art is mixed with ammonia fuel in traditional fossil fuel boilers, it is difficult to effectively control the rapid combustion and burnout of ammonia, resulting in excessive nitrogen oxide generation and difficult to meet the requirements of low NOx emissions and carbon reduction.
A combined ammonia-doped burner is designed. By arranging immediately above a traditional fossil fuel burner, the speed difference is set by using the ammonia injection speed and the combustion-supporting air injection speed, and the angle difference is set in the injection direction, the mixing of ammonia and combustion-supporting air is delayed, so that the ammonia gas can be rapidly pyrolyzed into hydrogen and nitrogen under a high-temperature and hypoxia environment, and avoiding direct combustion to produce nitrogen oxides.
It effectively delays the mixing of ammonia and combustion-supporting air, achieves rapid pyrolysis of ammonia at high temperatures, reduces the generation of nitrogen oxides, meets the requirements of efficient combustion and low NOx emissions of ammonia-dried DC burners in traditional fossil fuel boilers, and achieves the carbon reduction target of the boiler.
Smart Images
Figure CN119860531A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a combined ammonia-blending burner and an ammonia-blending direct-flow burner suitable for a four-corner tangential boiler. Background Art
[0002] Ammonia is not only a hydrogen storage medium, but also can be directly used as boiler fuel to burn and release heat. Ammonia molecules do not contain carbon elements, so it is a carbon-free fuel. However, most of the research is on the feasibility of the overall boiler blending scheme and technical route, and there is less research on the combustion equipment and structure of specific blending. The present invention mainly designs a combined ammonia blending burner and ammonia blending direct current burner suitable for four-corner tangential boilers based on the combustion characteristics of ammonia, so as to meet the demand for blending ammonia fuel in traditional fossil fuel boilers. Summary of the invention
[0003] The present invention provides a combined ammonia-blending burner, comprising an ammonia inlet, an ammonia channel, an ammonia nozzle, a combustion-supporting air inlet, a combustion-supporting air channel, a combustion-supporting air nozzle, a cooling air duct and a valve group thereof; the combustion-supporting air channel is located above the ammonia channel; the ammonia channel is connected to the ammonia nozzle; the combustion-supporting air channel is connected to the combustion-supporting air nozzle.
[0004] Preferably, a cooling air duct is provided at the combustion-supporting air inlet and the ammonia inlet channel, and a valve group is arranged in the cooling air duct.
[0005] The present invention also provides a direct-flow burner suitable for ammonia-combined combustion in a four-corner tangential boiler, comprising fossil fuel nozzles arranged at the four corners of the boiler and a combined ammonia-combined burner arranged immediately above the fossil fuel nozzles.
[0006] Preferably, the combined ammonia-blending burner is arranged above the nozzle of the conventional fossil fuel burner in the four-corner tangential boiler, and its combustion-supporting air channel is located above the ammonia channel, the combustion-supporting air nozzle is a tapered structure, and the combined combustion-supporting air channel and the ammonia channel are separated by a partition and sprayed into the furnace respectively; Preferably, the ammonia channel is located below the combustion-supporting air channel, and the inner side of the ammonia channel furnace is connected to multiple ammonia pipelines to form an ammonia nozzle, and the ammonia nozzle is a tapered nozzle, and there is an angle α between the nozzle outlet jet and the inlet jet, and the inlet jet direction is consistent with the combustion-supporting air direction, and the outlet jet direction is toward the center of the cross section of the four-corner tangential circle boiler furnace, that is, the center position of the imaginary tangential circle; Preferably, the ammonia nozzles are evenly distributed in the horizontal direction inside the furnace, and the number of nozzles is 2 to 6 according to the power of the ammonia burner; Preferably, a connecting channel 9 is designed between the combustion-supporting air channel inlet 6 and the ammonia channel inlet 3 , and the connection and isolation of the connecting channel are controlled by a valve group 10 .
[0007] Preferably, the ammonia-doped direct current burners are arranged in a four-corner tangential circle in the boiler, and four combined ammonia-doped burners are arranged at the corresponding four corners of the boiler in each layer.
[0008] The present invention arranges a combined ammonia blending burner above and adjacent to a traditional fossil fuel burner, and sets an angle difference between the injection direction of the ammonia nozzle of the combined ammonia blending burner and the injection direction of the combustion-supporting air. The speed difference between the ammonia injection speed and the combustion-supporting air injection speed is used to set the speed difference, thereby effectively delaying the mixing of the injected ammonia and the combustion-supporting air, so that the ammonia is quickly sprayed into the high-temperature oxygen-deficient atmosphere in the center of the furnace, and quickly pyrolyzed to form hydrogen and nitrogen. The hydrogen combustion solves the problem of rapid combustion and burnout of ammonia, and the pyrolysis of ammonia is used to generate nitrogen, so that the generation of nitrogen oxides by ammonia combustion is effectively controlled.
[0009] The present invention has a simple structure and is easy to control. It can effectively control nitrogen oxides while achieving carbon reduction. It can meet the requirements of efficient combustion and low NOx emission of ammonia-blended direct current burners in conventional fossil fuel four-corner tangential boilers and achieve the goal of boiler carbon reduction. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 The diagram is a longitudinal section diagram of a direct-flow burner arrangement suitable for ammonia-co-firing in a four-corner tangential boiler.
[0011] Figure 2 The cross-sectional diagram of the arrangement of a direct-flow burner suitable for ammonia-co-firing in a four-corner tangential boiler is shown.
[0012] Figure 3 and Figure 4 It is a structural schematic diagram of a combined ammonia-blending burner 1.
[0013] Figure 3 The diagram is a top view of a combined ammonia-blending burner, showing the horizontal distribution of the ammonia gas nozzle (5) and the combustion-supporting air nozzle (8).
[0014] Figure 4 This is a main view showing the vertical position relationship between the ammonia channel (4) and the combustion-supporting air channel (7).
[0015] Figure numerals: combined ammonia-blending burner 1, fossil fuel nozzle 2, ammonia inlet 3, ammonia channel 4, ammonia nozzle 5, combustion-supporting air inlet 6, combustion-supporting air channel 7, combustion-supporting air nozzle 8, cooling air duct 9, valve group 10. DETAILED DESCRIPTION
[0016] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods, but the present invention is not limited to the following embodiments.
[0017] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings.
[0018] like Figure 1 As shown, the present invention provides a direct-flow burner for ammonia-blended combustion in a four-corner tangential boiler, which includes conventional fossil fuel nozzles 2 and a combined ammonia-blended burner 1 arranged at the four corners of the boiler.
[0019] like Figure 3 and Figure 4 As shown, the combined ammonia-blending burner 1 of the present invention comprises an ammonia inlet 3, an ammonia channel 4, an ammonia nozzle 5, a combustion-supporting air inlet 6, a combustion-supporting air channel 7, a combustion-supporting air nozzle 8, a cooling air duct 9 and a valve group 10 thereof.
[0020] The combined ammonia burners 1 arranged at each layer at the four corners of the boiler are placed immediately above the traditional fossil fuel nozzles 2, and no other combustion air nozzles are arranged in the middle to avoid rapid contact and combustion between ammonia gas and the rising combustion air flow after it is sprayed into the furnace. For the ammonia modification of traditional fossil fuel boilers, the combined ammonia burners can be arranged by modifying the secondary air nozzles above the original fossil fuel nozzles 2.
[0021] like Figure 4 As shown, the ammonia nozzle 5 of the combined ammonia burner 1 is arranged at the bottom along the furnace height direction, the combustion air nozzle 8 is arranged at the top along the furnace height direction, the combustion air nozzle injection angle is set according to the requirements of the conventional boiler imaginary tangent circle, and is consistent with the original boiler swirl secondary air injection angle, the ammonia nozzle injection angle is toward the center of the furnace, and the angle between the combustion air injection angle and the ammonia nozzle injection angle is α. The injection speed of the combustion air nozzle of the combined ammonia burner of the present invention is the same as the injection speed of the conventional combustion air nozzle of the four-corner tangent circle, which is usually about 40~60m / s, while the ammonia injection speed of the combined ammonia burner of the present invention is set at 100~200 m / s. The present invention sets an angle difference and a speed difference between ammonia injection and combustion-supporting air injection, so that the ammonia jet is separated from the combustion-supporting air within a certain distance from the nozzle, delays the mixing and combustion of ammonia and combustion-supporting air, and sprays ammonia into a high-temperature area along the center direction of the furnace in an oxygen-deficient environment, so that most of the ammonia is pyrolyzed into hydrogen and nitrogen at high temperature, avoiding direct combustion of ammonia to generate a large amount of nitrogen oxides. The maximum laminar flame speed of hydrogen is more than 40 times that of ammonia, so it is very easy to mix, burn and burn out with the combustion-supporting air.
[0022] A cooling air connecting pipe 9 is arranged between the combustion-supporting air inlet 6 and the ammonia inlet 3 of the combined ammonia-blending burner. A valve group 10 is installed on the connecting pipe 9. The cooling air connecting pipe is conducted and isolated by adjusting the valve group 10. The valve group 10 has a unidirectional conduction capability. The airflow can only be introduced into the ammonia channel 4 from the combustion-supporting air inlet 6 and flow out from the ammonia nozzle 5. It is used for cooling the ammonia nozzle when the combined ammonia-blending burner stops ammonia blending.
[0023] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and improvements can be made without departing from the principles of the present invention. These improvements and improvements are also regarded as the protection scope of the present invention. The protection scope of the present invention shall be based on the definition of the claims.
Claims
1. A combined ammonia-blending burner, characterized in that: The invention comprises an ammonia inlet (3), an ammonia channel (4), an ammonia nozzle (5), a combustion-supporting air inlet (6), a combustion-supporting air channel (7), a combustion-supporting air nozzle (8), a cooling air duct (9) and a valve group (10); the combustion-supporting air channel (7) is located above the ammonia channel (4); the ammonia channel (4) is connected to the ammonia nozzle (5); and the combustion-supporting air channel (7) is connected to the combustion-supporting air nozzle (8).
2. A combined ammonia-blending burner as claimed in claim 1, characterized in that: A cooling air duct (9) is provided between the combustion-supporting air inlet (6) and the ammonia gas inlet (3), and a valve group (10) is arranged in the cooling air duct (9).
3. A direct current burner suitable for ammonia-compounded combustion in a tangential boiler, characterized in that: The invention comprises fossil fuel nozzles (2) arranged at the four corners of the boiler and a combined ammonia-blending burner (1) as claimed in claim 1 or 2 arranged immediately above the fossil fuel nozzles (2).
4. The ammonia-blended direct current burner for a tangentially tangentially fired boiler as claimed in claim 3, characterized in that: The ammonia channel (4) is arranged below the combustion-supporting air channel (7) along the furnace height direction. The ammonia channel (4) is located inside the furnace and is connected to a plurality of ammonia pipelines to form an ammonia nozzle (5). The ammonia nozzle adopts a tapered nozzle structure. The outlet jet direction forms an angle α with the inlet jet direction. The inlet jet direction is consistent with the combustion-supporting air direction. The outlet jet direction is oriented toward the center of the furnace cross section of the four-corner tangent circle boiler, that is, the center position of the imaginary tangent circle.
5. The direct current burner suitable for ammonia-compounded combustion in a tangentially-shaped boiler as claimed in claim 4, characterized in that: The ammonia gas nozzle (5) is located inside the furnace. The ammonia gas nozzle is composed of 2 to 6 uniformly distributed tapered nozzles in the horizontal direction. The jet velocity of the ammonia gas at the outlet is 100 to 200 m / s. The jet direction of the ammonia gas at the outlet is along the center direction of the furnace.
6. The direct current burner suitable for ammonia-compounded combustion in a tangentially-circular boiler as claimed in claim 5, characterized in that: The combustion-supporting air nozzle (8) is located inside the furnace and is an integrally tapered nozzle structure. The jet velocity of the combustion-supporting air at the outlet is 40-60 m / s. The jet direction of the combustion-supporting air at the outlet is the same as the direction of the secondary air of the four-corner tangential boiler.
7. The direct current burner suitable for ammonia-compounded combustion in a tangentially-shaped boiler as claimed in claim 3, characterized in that: The ammonia-doped direct current burners are arranged in a four-corner tangential circle in the boiler, and four combined ammonia-doped burners (1) are arranged at the four corners of the boiler in each layer.