A plasma-assisted, staged combustion ammonia-oxygen-enriched burner for rotary kilns

Abstract

This invention discloses a plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for rotary kilns, belonging to the field of combustion equipment and technology. It generates plasma by discharging and breaking down air between electrodes, which diffuses and combusts with incoming ammonia gas to produce an ammonia flame. This ammonia flame ignites the ammonia fuel in the fuel-rich zone of the ammonia staged combustion module, generating a stable second ammonia-oxygen-enriched fuel flame. The flue gas generated by this second ammonia-oxygen-enriched fuel flame mixes with oxygen-enriched air to produce an ammonia-oxygen-enriched lean fuel flame. This ammonia-oxygen-enriched lean fuel flame leads to the rotary kiln furnace. In the flue gas recirculation module located on the outermost side of the burner, the flue gas flows counter-currently towards the burner head. The flue gas enters the combustion chamber through film cooling holes, mixing with the high-temperature fuel gas from the fuel zone, reducing flame temperature and outlet temperature uniformity. This invention solves the problems of difficult ignition, unstable combustion, and low flame temperature inherent in pure ammonia combustion, and also effectively controls NO. x Emissions and ammonia escape issues.

Description

Technical Field

[0001] This invention relates to the field of combustion equipment and technology, specifically to a plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for rotary kilns. Background Technology

[0002] The cement industry is an indispensable basic raw material industry for national economic development, production and construction, and people's lives. During cement production, the decomposition of carbonates and the combustion of coal both generate large amounts of CO2.

[0003] Ammonia combustion is clean and produces zero carbon emissions, making it an ideal alternative to fossil fuels. Using ammonia as a coal substitute in rotary kilns offers significant potential for CO2 emission reduction. However, ammonia combustion faces two key challenges. First, ammonia is difficult to ignite stably under normal conditions, exhibiting a narrow combustion limit range, slow flame propagation speed, and a lower adiabatic flame temperature than traditional fuels like coal and natural gas, while rotary kilns require burner flame temperatures of 1800°C or higher. Second, due to its high nitrogen content, ammonia combustion is often accompanied by high NOx emissions.

[0004] Oxygen-enriched combustion technology can significantly enhance the combustion intensity of ammonia and accelerate flame propagation speed, particularly in increasing the temperature of rotary kilns, thus compensating for the low flame temperature of ammonia. However, oxygen-enriched combustion also leads to increased NOx emissions. Maintaining ammonia-rich fuel combustion under oxygen-enriched conditions is an effective means to control NOx emissions. However, this method may lead to NH3 escape, which is a problem that needs further investigation. It is worth noting that the increased flame temperature under oxygen-enriched conditions can enhance the self-driven cracking of NH3, promoting the overall cracking efficiency of the fuel and thus inhibiting the escape of residual NH3 at the fuel-rich end. Therefore, oxygen-enriched fuel combustion of ammonia helps maintain the stability of the ammonia flame, reduces NOx emissions, and can control ammonia escape to a certain extent. Burners designed based on ammonia oxygen-enriched combustion technology can effectively replace traditional pulverized coal burners in the cement industry, while simultaneously achieving CO2 emission reduction. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by disclosing a plasma-assisted combustion and staged combustion ammonia oxygen-enriched burner for rotary kilns. It proposes a pure ammonia combustion technology solution that combines plasma-assisted combustion, staged combustion technology, oxygen-enriched combustion technology, and flue gas recirculation technology, which can effectively solve the problems of low ammonia combustion temperature and high NOx emissions from ammonia combustion.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A plasma-assisted combustion and staged combustion ammonia-oxygen-enriched burner for rotary kilns, comprising a plasma ammonia pre-combustion stage module, an ammonia staged combustion module, and a flue gas recirculation module.

[0008] The plasma ammonia pre-combustion stage module, ammonia staged combustion module, and flue gas recirculation module are designed to be concentrically arranged, with the three modules arranged radially from the inside to the outside. The inlet ends of the plasma ammonia pre-combustion stage module, ammonia staged combustion module, and flue gas recirculation module are arranged sequentially from front to back. The outlet of the plasma ammonia pre-combustion stage module is located inside the ammonia staged combustion module near the inlet, while the outlet of the ammonia staged combustion module is located inside the rotary kiln furnace. The flue gas recirculation module adopts a counter-current air intake method.

[0009] The plasma ammonia pre-combustion stage module generates plasma by discharging and breaking down air between electrodes. This plasma then diffuses and combusts with the incoming ammonia gas to produce an ammonia flame. The ammonia flame ignites the ammonia fuel in the fuel-rich zone of the ammonia staged combustion module, producing a stable ammonia-oxygen-rich fuel flame. The flue gas generated by the ammonia-oxygen-rich fuel flame mixes and reacts with oxygen-rich air to produce an ammonia-oxygen-lean fuel flame. This ammonia-oxygen-lean fuel flame leads to the rotary kiln furnace. In the flue gas recirculation module located on the outermost side of the burner, the flue gas flows in the opposite direction to the burner head. The flue gas enters the combustion chamber through the film cooling holes and mixes with the high-temperature fuel gas from the fuel zone, reducing the unevenness of the flame temperature and the outlet temperature.

[0010] Furthermore, the plasma ammonia pre-combustion stage module comprises a first air channel, a sliding arc discharge structure, a first cyclone, a first ammonia channel, a second cyclone, a blunt body cavity, a first nozzle, and an ammonia flame. The sliding arc discharge structure comprises a first electrode and a second electrode, which are respectively connected to a high-voltage and a low-voltage power supply. The discharge breaks down the air to form a first swirling sliding arc. Conventional air is introduced into the first air channel, forming a swirling flow through the first cyclone. Ammonia is introduced into the first ammonia channel, forming a swirling flow through the second cyclone. The first swirling sliding arc mixes with the ammonia introduced into the first ammonia channel. Under the action of the sliding arc combustion-supporting effect and the swirling flow recirculation zone, a stable ammonia flame is formed through the blunt body cavity and the first nozzle.

[0011] Furthermore, the ammonia staged combustion module comprises an ammonia-oxygen-rich and fuel-rich stage module, a rapid mixing module, and an ammonia-oxygen-rich and fuel-lean stage module. The ammonia-oxygen-rich and fuel-rich stage module consists of a second ammonia gas channel, a third cyclone separator, a third air channel, a second nozzle, and a second ammonia-oxygen-rich fuel flame. The second ammonia gas channel and the second air channel are designed to be concentrically arranged, with the second air channel located outside the second ammonia gas channel. Ammonia gas is introduced into the second ammonia gas channel, and oxygen-rich air is introduced into the second air channel. The ammonia gas and oxygen-rich air introduced into the second ammonia gas channel and the second air channel form a swirling current through the third cyclone separator and the blunt body cavity. Under the action of swirling flow and ammonia flame, the gas is ejected through the second nozzle to form a second ammonia-oxygen-rich fuel-rich flame. The rapid mixing module consists of a fourth air channel, a fifth air channel, multiple air outlet holes, and a first mixing chamber. Oxygen-rich air is introduced into the third and fourth air channels and flows out through the air outlet holes, mixing with the flue gas generated by the ammonia-oxygen-rich fuel-rich stage module in the first mixing chamber. The mixed gas flowing into the ammonia-oxygen-rich lean fuel stage module from the rapid mixing module is ejected through the third nozzle to generate a third ammonia-oxygen-rich lean fuel flame. The third ammonia-oxygen-rich lean fuel flame is an oxygen-rich and ammonia-lean flame, which is sprayed into the furnace.

[0012] Furthermore, the flue gas recirculation module consists of a flue gas channel and a film cooling hole; the flue gas introduced into the tail end of the rotary kiln through the flue gas channel enters the combustion chamber through the film cooling hole, isolating the high-temperature combustion gas and carrying away some of the radiant heat of the high-temperature combustion gas on the wall, thereby playing a good cooling and protection role for the wall, and at the same time playing a role in regulating the temperature.

[0013] Furthermore, the ammonia flame generated by the plasma ammonia pre-combustion stage module igniting the ammonia fuel serves as the standby flame for the second ammonia-oxygen-rich fuel-rich flame in the ammonia staged combustion module, providing a large heat source for the ignition of ammonia.

[0014] Furthermore, the ammonia staged combustion module employs fuel-rich, rapid mixing, and lean combustion technologies. In the ammonia-oxygen-rich fuel-rich stage module, the relatively low temperature reduces the generation of oxygen-containing intermediate products, thereby maximally suppressing the production of nitrogen oxides. In the rapid mixing module, multiple air outlets are provided to increase the air jet flow rate and jet depth, promoting rapid mixing of air with the flue gas generated in the ammonia-oxygen-rich fuel-rich stage module. Finally, the second-stage ammonia flame is ignited and combusted in the ammonia-oxygen-lean combustion stage module.

[0015] Furthermore, the ammonia staged combustion module introduces an oxygen-rich atmosphere to increase the combustion intensity of ammonia, compensating for the low flame temperature of ammonia. At the same time, the increased flame temperature can promote the cracking of ammonia and inhibit the escape of residual ammonia from the oxygen-rich combustion stage module.

[0016] Furthermore, the gas film cooling holes in the flue gas recirculation module are controllable opening and closing cooling holes, which are coordinated with the combustion state in real time, thus avoiding the risk of overheating or excessive cooling.

[0017] The beneficial effects of this invention are:

[0018] This invention employs plasma-assisted combustion technology, generating a stable ammonia flame through a plasma ammonia pre-combustion module to provide heat for the oxygen-enriched fuel stage in the ammonia staged combustion module. Under the influence of the ammonia flame and the recirculation zone, a stable oxygen-enriched fuel flame is formed. The ammonia staged combustion module utilizes fuel-enriched, rapid mixing, and lean-fuel technology, effectively reducing NOx emissions. Introducing an oxygen-enriched atmosphere enhances the combustion intensity of ammonia, compensating for the low flame temperature of ammonia. Simultaneously, the increased flame temperature promotes ammonia decomposition and inhibits the escape of residual ammonia from the oxygen-enriched fuel stage. Furthermore, the film cooling holes in the flue gas recirculation module are controllably openable and closable, which can be used to cool the walls and regulate the combustion chamber temperature. This technology combines plasma-assisted combustion, staged combustion, oxygen-enriched combustion, and flue gas recirculation, not only solving the problems of ignition difficulties, unstable combustion, low flame temperature, and difficulty in meeting the temperature requirements of industrial kilns in pure ammonia combustion, but also effectively controlling NOx emissions and ammonia escape during ammonia combustion. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a plasma-assisted combustion and staged combustion ammonia-oxygen-enriched burner for a rotary kiln according to the present invention.

[0020] Figure 2 This is a schematic diagram of the structural principle of a plasma-assisted combustion and staged combustion ammonia oxygen-enriched burner for rotary kilns according to the present invention.

[0021] Figure 3 This is a side view of the structure of a plasma-assisted combustion, staged combustion ammonia oxygen-enriched burner for a rotary kiln according to the present invention;

[0022] Marked in the image:

[0023] 1 is the plasma ammonia pre-combustion stage module, 2 is the ammonia staged combustion module, and 3 is the flue gas recirculation module; 1-1 is the first air channel, 1-2 is the sliding arc discharge structure, 1-2-1 is the first electrode, 1-2-2 is the second electrode, 1-3 is the first cyclone separator, 1-4 is the first ammonia channel, 1-5 is the second cyclone separator, 1-6 is the blunt body cavity, 1-7 is the first nozzle, and 1-8 is the ammonia flame; 2-1 is the ammonia oxygen-rich and fuel-rich stage module, 2-2 is the rapid mixing module, 2-3 is the ammonia oxygen-rich and fuel-lean stage module, and 2-1-1 is... The second ammonia gas passage, 2-1-2 is the third cyclone separator, 2-1-3 is the second air passage, 2-1-4 is the second nozzle, 2-1-5 is the ammonia-oxygen-rich fuel-rich flame, 2-2-1 is the third air passage, 2-2-2 is the fourth air passage, 2-2-3 is the air outlet, 2-2-4 is the first mixing chamber, 2-3-1 is the third nozzle, 2-3-2 is the ammonia-oxygen-rich lean fuel flame; 3-1 is the flue gas passage, 3-2 is the gas film cooling hole; 4 is ammonia, 5 is conventional air, 6 is oxygen-rich air, and 7 is flue gas. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement all the contents of the claims of the present invention.

[0025] Example

[0026] A plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for a rotary kiln includes a shell and a combustion chamber. The combustion chamber is disposed inside the shell, and a flue gas passage with an outlet end is formed between the shell and the combustion chamber. An air inlet port is provided on one side of the combustion chamber. The air inlet port includes a first air passage 1-1, a first ammonia passage 1-4, a blunt body cavity 1-6, a second ammonia passage 2-1-1, and a second air passage 2-1-3 arranged concentrically from the inside to the outside. A sliding arc discharge structure is provided in the first air passage. A first mixing chamber 2-2-4 is formed in the middle of the combustion chamber. The first mixing chamber 2-2-4 is connected to the third air passage 2-2-1 and the fourth air passage 2-2-2. An air outlet hole 2-2-3 is provided on the cavity wall of the first mixing chamber 2-2-4. The combustion chamber is divided into a first cavity and a second cavity by the first mixing chamber 2-2-4 in the middle. A film cooling hole 3-2 is provided on the cavity wall of the first cavity and the second cavity.

[0027] The sliding arc discharge structure includes a first electrode and a second electrode, which are respectively connected to a high-voltage power supply and a low-voltage power supply. A first cyclone separator 1-3 is installed in the first air channel 1-1, a second cyclone separator 1-5 is installed in the first ammonia channel 1-4, and a third cyclone separator 2-1-2 is installed in the second ammonia channel 2-1-1. A first nozzle 1-7 is installed at the outlet of the first air channel 1-1 and the first ammonia channel, and a second nozzle 1-7 is installed at the outlet of the second air channel 2-1-3 and the second ammonia channel. The combustion chamber is provided with a third nozzle 2-3-1 at its outlet end; the diameter of the first mixing chamber 2-2-4 is smaller than the diameter of the first chamber and the second chamber; the first air channel 1-1, the second air channel 2-1-3, the third air channel 2-2-1 and the fourth air channel 2-2-2 are used to introduce conventional air 5; the first ammonia channel 1-4 and the second ammonia channel 2-1-1 are used to introduce ammonia 4; the flue gas channel is used to introduce flue gas 7; and the gas film cooling hole 3-2 is a controllable opening and closing cooling hole.

[0028] like Figure 1 and 2 As shown, according to one embodiment of the present invention, a plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for rotary kilns is mainly aimed at the industrial furnace field, and is particularly suitable for cement kilns with high-temperature requirements. The plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for rotary kilns includes a plasma ammonia pre-combustion stage module 1, an ammonia staged combustion module 2, and a flue gas recirculation module 3.

[0029] like Figure 1 and 3 As shown, the plasma ammonia pre-combustion stage module 1, the ammonia staged combustion module 2, and the flue gas recirculation module 3 are designed to be concentrically arranged, with the plasma ammonia pre-combustion stage module 1, the ammonia staged combustion module 2, and the flue gas recirculation module 3 arranged radially from the inside to the outside; the inlet ends of the plasma ammonia pre-combustion stage module 1, the ammonia staged combustion module 2, and the flue gas recirculation module 3 are arranged sequentially from front to back; the outlet of the plasma ammonia pre-combustion stage module 1 is located inside the ammonia staged combustion module 2 near the inlet, and the outlet of the ammonia staged combustion module 2 is located inside the rotary kiln furnace; the flue gas recirculation module 3 adopts a counter-current air intake method.

[0030] like Figure 2As shown, the plasma ammonia pre-combustion stage module 1 generates plasma by discharging and breaking down air between electrodes. This plasma then diffuses and combusts with the incoming ammonia gas to produce an ammonia flame 1-8. The ammonia flame 1-8 ignites the ammonia fuel in the fuel-rich zone of the ammonia staged combustion module 2, producing a stable ammonia-oxygen-rich fuel flame 2-1-5. The flue gas 7 generated by the ammonia-oxygen-rich fuel flame 2-1-5 mixes and reacts with oxygen-rich air 6 to produce an ammonia-oxygen-lean fuel flame 2-3-2. This ammonia-oxygen-rich lean fuel flame 2-3-2 flows into the rotary kiln furnace. In the flue gas recirculation module 3, located on the outermost side of the burner, the flue gas flows counter-currently towards the burner head. The flue gas 7 enters the combustion chamber through the film cooling hole 3-2, mixing with the high-temperature fuel gas from the fuel zone, reducing flame temperature and outlet temperature uniformity. In a preferred embodiment, the nozzle of a plasma-assisted, staged combustion ammonia-oxygen-rich burner for a rotary kiln is arranged in the firing zone of the cement kiln. The pure ammonia flame temperature can reach above 1800℃, ensuring efficient combustion and heat transfer.

[0031] like Figure 1 and 2 As shown, the plasma ammonia pre-combustion stage module 1 consists of a first air channel 1-1, a sliding arc discharge structure 1-2, a first cyclone separator 1-3, a first ammonia gas channel 1-4, a second cyclone separator 1-5, a blunt body cavity 1-6, a first nozzle 1-7, and an ammonia flame 1-8. The sliding arc discharge structure consists of a first electrode 1-2-1 and a second electrode 1-2-2. The first electrode 1-2-1 and the second electrode 1-2-2 are respectively connected to a high-voltage and a low-voltage power supply. The discharge breaks down the air to form a first swirling sliding arc. Conventional air 5 is introduced into the first air channel 1-1 and forms a swirling flow through the first cyclone separator 1-3. Ammonia gas 4 is introduced into the first ammonia gas channel 1-4 and forms a swirling flow through the second cyclone separator 1-5. The first swirling sliding arc mixes with the ammonia gas 4 introduced into the first ammonia gas channel 1-4. Under the action of the sliding arc combustion and the swirling flow recirculation zone, a stable burning ammonia flame 1-8 is formed through the blunt body cavity 1-6 and the first nozzle 1-7. In a preferred embodiment, the air introduced into the first air passage 1-1 comes from the air drawn in from the atmosphere by the primary fan. The air introduced into the first air passage 1-1 is the standby air, and the flow rate of the standby air can be adjusted independently, which is beneficial to the stable combustion of the standby flame.

[0032] like Figure 1 and 2As shown, the ammonia staged combustion module 2 consists of an ammonia-oxygen-rich fuel-rich stage module 2-1, a rapid mixing module 2-2, and an ammonia-oxygen-rich lean fuel-rich stage module 2-3. The ammonia-oxygen-rich fuel-rich stage module 2-1 consists of a second ammonia channel 2-1-1, a third cyclone separator 2-1-2, a second air channel 2-1-3, a second nozzle 2-1-4, and an ammonia-oxygen-rich fuel-rich flame 2-1-5. The second ammonia channel 2-1-1 and the second air channel 2-1-3 are designed to be concentrically arranged, with the second air channel 2-1-3 located outside the second ammonia channel 2-1-1. Ammonia gas 4 is introduced into the second ammonia channel 2-1-1, and oxygen-rich air 6 is introduced into the second air channel 2-1-3. The ammonia gas 4 and oxygen-rich air 6 introduced into the second ammonia channel 2-1-1 and the second air channel 2-1-3 are shaped by the third cyclone separator 2-1-2 and the blunt cavity 1-6 to form... The swirling flow, under the action of the swirling flow and the ammonia flame 1-8, is ejected through the second nozzle 2-1-4 to form an ammonia-oxygen-rich fuel-rich flame 2-1-5; the rapid mixing module 2-2 consists of a third air channel 2-2-1, a fourth air channel 2-2-2, multiple air outlet holes 2-2-3, and a first mixing chamber 2-2-4. Oxygen-rich air 6 is introduced into the third air channel 2-2-1 and the fourth air channel 2-2-2 and flows out through the air outlet holes 2-2-3, where it is mixed with the flue gas 7 generated by the ammonia-oxygen-rich fuel-rich stage module 2-1 in the first mixing chamber 2-2-4; the mixed gas flowing into the ammonia-oxygen-rich lean fuel stage module 2-3 from the rapid mixing module 2-2 is ejected through the third nozzle 2-3-1 to generate an ammonia-oxygen-rich lean fuel flame 2-3-2, which is an oxygen-rich and ammonia-lean flame, and is sprayed into the furnace. In a preferred embodiment, the ammonia-oxygen-enriched combustion stage module 2-1 is supplied with oxygen-enriched air 6 through the second air channel 2-1-3, the third air channel 2-2-1, and the fourth air channel 2-2-2. This oxygen-enriched air 6 contains oxygen at a concentration higher than that of air (20.947%). The oxygen required by the ammonia-oxygen-enriched burner comes from hydrogen produced by water electrolysis. This process involves electrolyzing water molecules using an external current to generate hydrogen and oxygen. The generated oxygen is then supplied to the oxygen supply system to prepare the oxygen-enriched air 6 required by the burner.

[0033] like Figure 1 and 2As shown, the flue gas recirculation module 3 consists of a flue gas channel 3-1 and a film cooling hole 3-2. Flue gas 7 from the tail end of the rotary kiln is introduced through the flue gas channel 3-1 and enters the combustion chamber through the film cooling hole 3-2, isolating the high-temperature combustion gas and carrying away some of the radiant heat from the high-temperature combustion gas on the wall surface, thus providing good cooling and protection for the wall surface and simultaneously regulating the temperature. In a preferred embodiment, using the plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for a rotary kiln, the temperature can be adjusted by regulating the oxygen concentration and the flue gas inflow rate into the combustion chamber during the start-up and calcination stages.

[0034] like Figure 2 As shown, the ammonia flame 1-8 generated by the plasma ammonia pre-combustion stage module 1 ignites the ammonia fuel and serves as the standby flame for the ammonia oxygen-rich fuel-rich flame 2-1-5 in the ammonia staged combustion module 2, providing a large amount of heat source for the ignition of ammonia.

[0035] like Figure 2 As shown, the ammonia staged combustion module 2 employs fuel-rich, rapid mixing, and lean combustion technologies. In the ammonia-oxygen-rich fuel-rich stage module 2-1, the relatively low temperature reduces the generation of oxygen-containing intermediate products, thereby maximally suppressing the production of nitrogen oxides. In the rapid mixing module 2-2, multiple air outlet holes are provided to increase the air jet flow rate and jet depth, promoting rapid mixing of air with the flue gas 7 generated in the ammonia-oxygen-rich fuel-rich stage module 2-1. Finally, the second-stage ammonia flame is ignited and combusted in the ammonia-oxygen-lean combustion stage module 2-3.

[0036] like Figure 2 As shown, the ammonia staged combustion module 2 introduces an oxygen-rich atmosphere to increase the combustion intensity of ammonia, which compensates for the disadvantage of low flame temperature of ammonia. At the same time, the increased flame temperature can promote the cracking of ammonia and inhibit the escape of residual ammonia from the oxygen-rich combustion stage module 2-1.

[0037] Furthermore, the gas film cooling holes 3-2 in the flue gas recirculation module 3 are controllable opening and closing cooling holes, which are coordinated with the combustion state in real time, thus avoiding the risk of overheating or excessive cooling.

[0038] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for rotary kilns, characterized in that, It includes: plasma ammonia pre-combustion stage module (1), ammonia staged combustion module (2), and flue gas recirculation module (3); The plasma ammonia pre-combustion stage module (1), the ammonia staged combustion module (2), and the flue gas recirculation module (3) are designed to be concentrically arranged, and are arranged radially from the inside to the outside; the inlet ends of the plasma ammonia pre-combustion stage module (1), the ammonia staged combustion module (2), and the flue gas recirculation module (3) are arranged sequentially from front to back; The outlet of the plasma ammonia pre-combustion stage module (1) is located inside the ammonia staged combustion module (2) near the inlet, and the outlet of the ammonia staged combustion module (2) is located inside the rotary kiln furnace; the flue gas recirculation module (3) adopts a counter-current air intake method; The plasma ammonia pre-combustion stage module (1) generates plasma by discharging and breaking down air between electrodes. It diffuses and burns with the incoming ammonia gas to produce an ammonia flame (1-8). The ammonia flame (1-8) ignites the ammonia fuel in the fuel-rich zone of the ammonia stage combustion module (2) to produce a stable second ammonia-oxygen-rich fuel flame (2-1-5). The flue gas generated by the second ammonia-oxygen-rich fuel flame (2-1-5) mixes with the oxygen-rich air to produce a third ammonia-oxygen-rich lean fuel flame (2-3-2). The third ammonia-oxygen-rich lean fuel flame (2-3-2) is directed to the rotary kiln furnace. In the flue gas recirculation module (3) located on the outermost side of the burner, the flue gas flows in the opposite direction to the burner head. The flue gas enters the combustion chamber through the gas film cooling hole (3-2) and mixes with the high-temperature gas from the fuel zone to reduce the flame temperature and the unevenness of the outlet temperature.

2. The plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for rotary kilns as described in claim 1, characterized in that, The plasma ammonia pre-combustion stage module (1) consists of a first air channel (1-1), a sliding arc discharge structure (1-2), a first cyclone (1-3), a first ammonia channel (1-4), a second cyclone (1-5), a blunt body cavity (1-6), a first nozzle (1-7), and an ammonia flame (1-8). The sliding arc discharge structure consists of a first electrode (1-2-1) and a second electrode (1-2-2). The first electrode (1-2-1) and the second electrode (1-2-2) are respectively connected to a high-voltage power supply. High pressure and low pressure, discharge breakdown air to form a first swirling sliding arc, the first air channel (1-1) is introduced with conventional air, which forms a swirling flow through the first swirler (1-3), the first ammonia channel (1-4) is introduced with ammonia, which forms a swirling flow through the second swirler (1-5), the first swirling sliding arc mixes with the ammonia introduced with the first ammonia channel (1-4), and under the action of the sliding arc combustion and the swirling flow backflow zone, a stable burning ammonia flame (1-8) is formed through the blunt body cavity (1-6) and the first nozzle (1-7).

3. The plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for rotary kilns as described in claim 1, characterized in that, The ammonia staged combustion module (2) consists of an ammonia-oxygen-rich and fuel-rich stage module (2-1), a rapid mixing module (2-2), and an ammonia-oxygen-rich and fuel-lean stage module (2-3). The ammonia-oxygen-rich and fuel-rich stage module (2-1) consists of a second ammonia channel (2-1-1), a third cyclone separator (2-1-2), a second air channel (2-1-3), a second nozzle (2-1-4), and a second ammonia-oxygen-rich fuel-rich flame (2-1-5). The second ammonia channel (2-1-1) and the second air channel (2-1-3) are... The two air channels (2-1-3) are designed in a concentric ring. The second air channel (2-1-3) is located outside the second ammonia channel (2-1-1). Ammonia is introduced into the second ammonia channel (2-1-1), and oxygen-enriched air is introduced into the second air channel (2-1-3). The ammonia and oxygen-enriched air introduced into the second ammonia channel (2-1-1) and the second air channel (2-1-3) form a swirling flow through the third cyclone separator (2-1-2) and the blunt cavity (1-6). Under the action of swirling flow and ammonia flame (1-8), the gas is ejected through the second nozzle (2-1-4) to form a second ammonia-oxygen-rich fuel flame (2-1-5); the rapid mixing module (2-2) consists of a third air channel (2-2-1), a fourth air channel (2-2-2), multiple air outlet holes (2-2-3), and a first mixing chamber (2-2-4). Oxygen-rich air is introduced into the third air channel (2-2-1) and the fourth air channel (2-2-2), and the gas flows out through the air outlet holes. (2-2-3) flows out and mixes with the flue gas generated by the ammonia-oxygen-rich and fuel-rich stage module (2-1) in the first mixing chamber (2-2-4); the mixed gas flowing into the ammonia-oxygen-rich and fuel-poor stage module (2-3) from the rapid mixing module (2-2) is ejected through the third nozzle (2-3-1) to generate the second ammonia-oxygen-rich and fuel-poor flame (2-3-2), the third ammonia-oxygen-rich and fuel-poor flame (2-3-2) is an oxygen-rich and ammonia-poor flame, and the third ammonia-oxygen-rich and fuel-poor flame (2-3-2) is sprayed into the furnace.

4. The plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for rotary kilns as described in claim 3, characterized in that, The plasma ammonia pre-combustion stage module (1) ignites the ammonia flame (1-8) generated by the ammonia fuel, which serves as the standby flame for the second ammonia-oxygen-rich fuel-rich flame (2-1-5) in the ammonia staged combustion module (2), providing a large amount of heat source for the ignition of ammonia.

5. A plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for a rotary kiln as described in claim 3, characterized in that, The ammonia staged combustion module (2) adopts fuel-rich, rapid mixing, and lean combustion technology. In the ammonia-oxygen-rich fuel-rich stage module (2-1), due to the relatively low temperature, the amount of oxygen-containing intermediate products generated is reduced, thereby suppressing the generation of nitrogen oxides to the greatest extent. In the rapid mixing module (2-2), multiple air outlet holes (2-2-3) are set to increase the air jet flow rate and jet depth, and promote the rapid mixing of air with the flue gas generated in the ammonia-oxygen-rich fuel-rich stage module (2-1). Finally, the second-stage ammonia flame is ignited and burned in the ammonia-oxygen-lean combustion stage module (2-3).

6. A plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for a rotary kiln as described in claim 3, characterized in that, The ammonia staged combustion module (2) introduces an oxygen-rich atmosphere to improve the combustion intensity of ammonia, which makes up for the disadvantage of low flame temperature of ammonia. At the same time, the increased flame temperature can promote the cracking of ammonia and inhibit the escape of residual ammonia from the oxygen-rich combustion stage module (2-1).

7. A plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for a rotary kiln as described in claim 1, characterized in that, The flue gas recirculation module (3) consists of a flue gas channel (3-1) and a film cooling hole (3-2). The flue gas from the tail end of the rotary kiln is introduced through the flue gas channel (3-1) and enters the combustion chamber through the film cooling hole (3-2). This isolates the high-temperature combustion gas and carries away some of the radiant heat from the high-temperature combustion gas on the wall, thereby providing good cooling and protection for the wall and regulating the temperature.

8. A plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for a rotary kiln as described in claim 3, characterized in that, The gas film cooling holes (3-2) in the flue gas recirculation module (3) are controllable opening and closing cooling holes, which are coordinated with the combustion state in real time, thus avoiding the risk of overheating or excessive cooling.

9. A plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for a rotary kiln according to claim 1, characterized in that, The burner includes a shell and a combustion chamber, the combustion chamber being disposed within the shell, and a flue gas passage with an outlet opening between the shell and the combustion chamber; an air inlet port is provided on one side of the combustion chamber, the air inlet port including a first air passage (1-1), a first ammonia passage (1-4), a blunt body cavity (1-6), a second ammonia passage (2-1-1), and a second air passage (2-1-3) arranged concentrically from the inside to the outside, the first air passage being provided with a sliding arc discharge structure; a first mixing chamber (2-2-4) is formed in the middle of the combustion chamber, the first mixing chamber (2-2-4) connecting the third air passage (2-2-1) and the fourth air passage (2-2-2), and an air outlet hole (2-2-3) is provided on the cavity wall of the first mixing chamber (2-2-4); the combustion chamber is divided into a first cavity and a second cavity by the first mixing chamber (2-2-4) in the middle, and a film cooling hole (3-2) is provided on the cavity wall of the first cavity and the second cavity.

10. A plasma-assisted combustion, staged combustion ammonia-oxygen-enriched burner for a rotary kiln according to claim 9, characterized in that, The sliding arc discharge structure includes a first electrode and a second electrode, which are respectively connected to a high-voltage power supply and a low-voltage power supply. A first cyclone separator (1-3) is installed in the first air channel (1-1), a second cyclone separator (1-5) is installed in the first ammonia channel (1-4), and a third cyclone separator (2-1-2) is installed in the second ammonia channel (2-1-1). A first nozzle (1-7) is installed at the outlet of the first air channel (1-1) and the first ammonia channel, and a second nozzle is installed at the outlet of the second air channel (2-1-3) and the second ammonia channel. (2-1-4), the combustion chamber is provided with a third nozzle (2-3-1); the diameter of the first mixing chamber is smaller than the diameter of the first chamber and the second chamber; the first air channel (1-1), the second air channel (2-1-3), the third air channel (2-2-1) and the fourth air channel (2-2-2) are used to introduce conventional air (5); the first ammonia channel (1-4) and the second ammonia channel (2-1-1) are used to introduce ammonia (4); the flue gas channel is used to introduce flue gas (7); the gas film cooling hole (3-2) is a controllable opening and closing cooling hole.

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