Combined ammonia-doped combustor and ammonia-doped combustion direct-current combustor suitable for corner tangential boiler
By designing a combined ammonia-blended burner, the angle and velocity differences between ammonia and combustion air are utilized to pyrolyze ammonia into hydrogen and nitrogen in the boiler, solving the problems of rapid combustion of ammonia fuel and generation of nitrogen oxides, and achieving high-efficiency combustion and low-pollution emissions in the boiler.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-03
- Publication Date
- 2026-04-07
AI Technical Summary
In the existing technology, there is a lack of research on combustion equipment and structures for traditional fossil fuel boilers that co-fire ammonia fuel, which makes it difficult to control the rapid combustion of ammonia fuel and the generation of nitrogen oxides, and thus difficult to meet the requirements for carbon reduction and low NOx emissions.
A combined ammonia-blended burner is designed, with an angle and velocity difference between the ammonia nozzle and the combustion air nozzle. Ammonia is injected into the high-temperature zone of the furnace under an oxygen-deficient environment and pyrolyzed into hydrogen and nitrogen. The rapid combustion of hydrogen solves the problem of rapid combustion of ammonia. The ammonia injection is controlled by cooling air ducts and valve groups to avoid the generation of nitrogen oxides.
It achieves efficient combustion of ammonia fuel and low NOx emissions, meeting the carbon reduction requirements of traditional fossil fuel boilers, controlling the generation of nitrogen oxides, and realizing efficient combustion and low pollution emissions of boilers.
Smart Images
Figure CN224094469U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a combined ammonia-blending burner and its suitable DC burner for ammonia blending in a four-corner tangential boiler. Background Technology
[0002] Ammonia serves as both a hydrogen storage medium and a direct combustion fuel for boilers, releasing heat. Furthermore, ammonia molecules contain no carbon, making it a carbon-free fuel. With my country's goals of achieving carbon peaking and carbon neutrality, and the increasing pressure on the energy sector to reduce carbon emissions, the technical routes and solutions for co-firing ammonia fuel in traditional fossil fuel boilers to achieve carbon reduction have received increasing attention and research. However, current research primarily focuses on the feasibility of overall boiler co-firing schemes and technical routes, with less research on specific combustion equipment and structures for co-firing. This invention mainly designs a combined ammonia-blending burner and a direct-current burner suitable for co-firing ammonia in tangential-circular boilers, based on the combustion characteristics of ammonia, to meet the needs of co-firing ammonia fuel in traditional fossil fuel boilers. Utility Model Content
[0003] This utility model provides a combined ammonia-blended burner, including an ammonia inlet, an ammonia channel, an ammonia nozzle, a combustion air inlet, a combustion air channel, a combustion air nozzle, a cooling air duct and its valve assembly; the combustion air channel is located above the ammonia channel; the ammonia channel is connected to the ammonia nozzle; the combustion air channel is connected to the combustion air nozzle.
[0004] Preferably, a cooling air duct is provided between the combustion air inlet and the ammonia inlet, and a valve group is arranged in the cooling air duct.
[0005] This utility model also provides a direct-flow burner for ammonia co-firing in a four-corner tangential boiler, comprising fossil fuel nozzles arranged at the four corners of the boiler and a combined ammonia co-firing burner arranged adjacent to the fossil fuel nozzles.
[0006] Preferably, the combined ammonia-blended burner is arranged above the nozzle of a conventional fossil fuel burner in a four-corner tangential boiler, and its combustion air passage is located above the ammonia passage. The combustion air nozzle has a tapered structure, and the combined combustion air passage and the ammonia passage are separated by a partition and injected into the furnace respectively.
[0007] Preferably, the ammonia gas channel is arranged below the combustion air channel along the height direction of the furnace. The ammonia gas channel is located inside the furnace and is connected to multiple ammonia gas pipes to form an ammonia gas nozzle. The ammonia gas nozzle adopts a tapered nozzle structure, and its outlet jet direction forms an angle α with the inlet jet direction. The inlet jet direction is consistent with the combustion air direction, and the outlet jet direction is towards the center of the cross section of the boiler furnace with a tangent circle at the four corners, that is, the center position of the imaginary tangent circle.
[0008] Preferably, the ammonia nozzles are evenly distributed horizontally inside the furnace, and the number of nozzles is 2 to 6 depending on the power of the ammonia-blended burner.
[0009] Preferably, the ammonia nozzle is located inside the furnace and consists of 2 to 6 evenly distributed tapered nozzles in the horizontal direction. The ammonia jet velocity at the outlet is 100 to 200 m / s, and the ammonia jet direction at the outlet is along the center of the furnace.
[0010] Preferably, the combustion air nozzle is located inside the furnace and has an integral tapered nozzle structure. The combustion air jet velocity at the outlet is 40~60m / s, and the jet direction of the combustion air at the outlet is the same as the direction of the secondary air at the start of the four-corner tangential boiler.
[0011] Preferably, a connecting channel is designed between the combustion air inlet 6 and the ammonia inlet 3, and the opening and closing of the connecting channel is controlled by the valve group 10.
[0012] Preferably, the ammonia-blended DC burners are arranged in a tangential pattern at the four corners of the boiler, with four combined ammonia-blended burners arranged at the corresponding four corners of the boiler on each floor.
[0013] This invention places a combined ammonia co-firing burner above and adjacent to a traditional fossil fuel burner. An angle difference is established between the ammonia injection direction and the combustion air injection direction in the combined ammonia co-firing burner. This speed difference between the ammonia injection velocity and the combustion air injection velocity effectively delays the mixing of the injected ammonia and combustion air, allowing ammonia to be rapidly injected into the high-temperature, oxygen-deficient atmosphere at the center of the furnace. The ammonia then rapidly pyrolyzes to form hydrogen and nitrogen. The use of hydrogen combustion solves the problem of rapid combustion and burnout of ammonia. Simultaneously, the generation of nitrogen from the pyrolysis of ammonia effectively controls the formation of nitrogen oxides during ammonia combustion.
[0014] This invention features a simple structure and convenient control. It effectively controls nitrogen oxides while reducing carbon emissions. It can meet the requirements of high-efficiency combustion and low NOx emissions of ammonia-blended once-through burners in conventional fossil fuel tangential boilers, and achieve the boiler carbon reduction target. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the longitudinal section of a DC burner arrangement suitable for ammonia co-firing in a four-corner tangential boiler.
[0016] Figure 2 This is a schematic diagram of the cross-sectional arrangement of a direct-current burner for ammonia co-firing in a four-corner tangential boiler.
[0017] Figure 3 This is a top view schematic diagram of a combined ammonia-blended burner.
[0018] Figure 4This is a front view of a combined ammonia-blended burner.
[0019] Figure reference numerals: 1. Combined ammonia-blended burner; 2. Fossil fuel nozzle; 3. Ammonia inlet; 4. Ammonia passage; 5. Combustion air inlet; 6. Combustion air passage; 7. Combustion air nozzle; 8. Cooling air duct; 9. Valve assembly; 10. Detailed Implementation
[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the following embodiments.
[0021] To make this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings.
[0022] like Figure 1 As shown, the present invention provides a direct-current burner for ammonia co-firing in a four-corner tangential boiler, which includes conventional fossil fuel nozzles 2 and combined ammonia co-firing burners 1 arranged at the four corners of the boiler.
[0023] Figure 3 This is a top view of a combined ammonia-blended burner, showing the horizontal distribution of the ammonia nozzle (5) and the combustion air nozzle (8). Figure 4 The main view of the combined ammonia-blended burner shows the vertical positional relationship between the ammonia gas passage (4) and the combustion air passage (7).
[0024] like Figure 3 and Figure 4 As shown, the combined ammonia-blended burner 1 of this utility model includes an ammonia inlet 3, an ammonia channel 4, an ammonia nozzle 5, a combustion air inlet 6, a combustion air channel 7, a combustion air nozzle 8, a cooling air duct 9, and a valve group 10.
[0025] The combined ammonia-blended burners 1 arranged at each of the four corners of the boiler are placed immediately above the traditional fossil fuel nozzles 2, with no other combustion air nozzles in between, to avoid rapid contact and combustion of ammonia gas with the rising combustion air flow after it is injected into the furnace. For the ammonia-blended retrofit of traditional fossil fuel boilers, the combined ammonia-blended burners can be arranged by modifying the secondary air nozzles above the original fossil fuel nozzles 2.
[0026] like Figure 4As shown, in the combined ammonia-blended burner 1, the ammonia nozzle 5 is arranged below along the height of the furnace, and the combustion air nozzle 8 is arranged above along the height of the furnace. The injection angle of the combustion air nozzle is set according to the requirements of the imaginary tangent circle of a conventional boiler, consistent with the injection angle of the secondary air during the start-up of the original boiler. The injection angle of the ammonia nozzle faces the center of the furnace, and the angle between the injection angle of the combustion air nozzle and the injection angle of the ammonia nozzle is α. The injection speed of the combustion air nozzle in this combined ammonia-blended burner is the same as that of the conventional four-corner tangent circle combustion air nozzle, usually around 40~60 m / s, while the ammonia injection speed of this combined ammonia-blended burner is set at 100~200 m / s. This invention sets an angle and velocity difference between the ammonia injection and the combustion air injection, causing the ammonia jet to separate from the combustion air within a certain distance of the nozzle. This delays the mixing and combustion of ammonia and combustion air, allowing ammonia to be injected into the high-temperature zone along the center of the furnace in an oxygen-deficient environment. As a result, most of the ammonia is pyrolyzed into hydrogen and nitrogen at high temperatures, avoiding the direct combustion of ammonia that generates a large amount of nitrogen oxides. The maximum laminar flame velocity of hydrogen is more than forty times that of ammonia, making it easy to mix, burn, and burn out with the combustion air.
[0027] A cooling air connection pipe 9 is arranged between the combustion air inlet 6 and the ammonia inlet 3 of the combined ammonia-blended burner. A valve group 10 is installed on the connection pipe 9. The cooling air connection pipe is opened and closed by adjusting the valve group 10. The valve group 10 has unidirectional flow capability. The airflow can only be introduced into the ammonia channel 4 from the combustion air inlet 6 and flow out from the ammonia nozzle 5. It is used to cool the ammonia nozzle when the combined ammonia-blended burner stops ammonia blending.
[0028] The above description is a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model. These improvements and modifications are also considered to be within the protection scope of the present utility model, and the protection scope of the present utility model shall be defined by the claims.
Claims
1. A combined ammonia-blended burner, characterized in that, It includes an ammonia inlet (3), an ammonia channel (4), an ammonia nozzle (5), a combustion air inlet (6), a combustion air channel (7), a combustion air nozzle (8), a cooling air duct (9), and a valve group (10); the combustion air channel (7) is located above the ammonia channel (4); the ammonia channel (4) is connected to the ammonia nozzle (5); the combustion air channel (7) is connected to the combustion air nozzle (8).
2. The combined ammonia-blended burner as described in claim 1, characterized in that, A cooling air duct (9) is provided between the combustion air inlet (6) and the ammonia inlet (3), and a valve group (10) is arranged in the cooling air duct (9).
3. A once-through burner for ammonia co-firing in a tangentially shaped boiler, characterized in that, It includes fossil fuel nozzles (2) arranged at the four corners of the boiler and a combined ammonia-blended burner (1) as described in claim 1 or 2 arranged immediately above the fossil fuel nozzles (2).
4. The once-through burner for ammonia co-firing in a tangentially circular boiler as described in claim 3, characterized in that, The combined ammonia-blended burner is arranged above the nozzle of a conventional fossil fuel burner in a four-corner tangential boiler, while its combustion air passage is located above the ammonia passage. The combustion air nozzle has a tapered structure, and the combined combustion air passage and the ammonia passage are separated by a partition and injected into the furnace respectively.
5. The once-through burner for ammonia co-firing in a tangentially circular boiler as described in claim 3, characterized in that, The ammonia gas channel (4) is arranged below the combustion air channel (7) along the height direction of the furnace. The ammonia gas channel (4) is located inside the furnace and is connected to multiple ammonia gas pipes to form an ammonia gas nozzle (5). The ammonia gas nozzle adopts a tapered nozzle structure. Its outlet jet direction forms an angle α with the inlet jet direction. The inlet jet direction is consistent with the combustion air direction, and the outlet jet direction is towards the center of the cross section of the boiler furnace with four corners tangent, that is, the center of the imaginary tangent circle.
6. The once-through burner for ammonia co-firing in a tangentially circular boiler as described in claim 5, characterized in that, The ammonia nozzle (5) is located inside the furnace. The ammonia nozzle consists of 2 to 6 evenly distributed tapered nozzles in the horizontal direction. The ammonia jet velocity at the outlet position is 100~200m / s, and the ammonia jet direction at the outlet position is along the center of the furnace.
7. The once-through burner for ammonia co-firing in a tangentially circular boiler as described in claim 6, characterized in that, The combustion air nozzle (8) is located inside the furnace. The combustion air nozzle is an integral tapered nozzle structure. The velocity of the combustion air jet at the outlet is 40~60m / s. The direction of the combustion air jet at the outlet is the same as the direction of the secondary air of the four-corner tangential boiler.
8. The once-through burner for ammonia co-firing in a tangentially circular boiler as described in claim 3, characterized in that, A connection channel is designed between the combustion air inlet (6) and the ammonia inlet (3), and the opening and closing of the connection channel is controlled by a valve group (10).
9. The once-through burner for ammonia co-firing in a tangentially circular boiler as described in claim 3, characterized in that, The ammonia-blended DC burners are arranged in a tangential circle at the four corners of the boiler, with four combined ammonia-blended burners (1) arranged at the corresponding four corners of the boiler on each floor.