Pure ammonia burner based on ammonia pre-decomposition method

Abstract

The invention belongs to the technical field of industrial combustors, and particularly relates to decomposition efficiency and safety performance of a pure ammonia combustor. According to the pure ammonia burner based on the ammonia pre-decomposition method, safe, efficient and stable decomposition of ammonia gas is achieved. Emission of harmful gas is reduced, and clean energy for other production processes is generated; the pure ammonia combustor comprises a combustion chamber, a decomposition chamber and a liquid ammonia storage device; a flue gas backflow area arranged in the combustion chamber is arranged in the decomposition chamber in a sleeving manner; the combustion chamber is provided with a first-stage ammonia gas channel, an ignition device and an air conditioning system; a bluff body is arranged at the end part of the primary ammonia gas channel; the decomposition chamber is provided with a secondary ammonia gas inlet, a catalytic device and a pyrolysis gas outlet channel; the catalytic device is assembled on the inner wall of the decomposition chamber, and the position of the catalytic device corresponds to the flue gas backflow area; a heat exchange device is assembled on the outer wall of the pyrolysis gas outlet channel; the liquid ammonia storage device is connected with the heat exchange device and used for conveying ammonia gas to the first-stage ammonia gas channel and the second-stage ammonia gas inlet.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial burners, and specifically relates to the decomposition efficiency and safety performance of pure ammonia burners. Background Art

[0002] With the transformation of the global energy structure and the continuous improvement of environmental protection requirements, ammonia, as a highly potential clean energy source, is attracting increasing attention. Due to its high energy density and low carbon emissions, ammonia is regarded as an essential part of the future hydrogen economy.

[0003] Ammonia combustion technology mainly relies on high-temperature combustion to promote the decomposition of ammonia. However, this method usually leads to excessively high combustion temperatures and the emission of harmful gases such as NOx. To address these issues, ammonia pre-decomposition technology has been proposed as an effective solution. Ammonia pre-decomposition technology can decompose ammonia at a lower temperature through catalysts or other means, thereby reducing the combustion temperature and the generation of harmful gases.

[0004] However, some existing burner designs based on ammonia decomposition still have some deficiencies. A Chinese patent document with the publication number CN117267711A discloses an ammonia burner. This burner consists of a coaxially nested combustion chamber, an ammonia heating chamber, and a high-temperature ammonia decomposition chamber; it uses the high-temperature tail gas generated by the ammonia decomposition reaction for heating hot water, producing steam, etc. In the ammonia decomposition reaction, hydrogen burns in the combustion chamber, ammonia is input into the ammonia heating chamber, and the ammonia in the ammonia heating chamber reaches the decomposition temperature through the heat provided by the initial hydrogen combustion. The heated ammonia is input into the high-temperature ammonia decomposition chamber for catalytic decomposition reaction, decomposing ammonia into a mixed gas of nitrogen and hydrogen, and then the decomposed mixed gas is re-input into the combustion chamber for combustion to provide heat for the ammonia heating chamber.

[0005] However, the above device relies on the heat generated by hydrogen combustion to initiate the ammonia decomposition process, which not only increases the complexity of the system, requiring additional hydrogen supply and treatment facilities; but also increases safety risks because hydrogen is flammable and explosive. Moreover, all the hydrogen generated by ammonia decomposition in the above burner is transported to the combustion chamber for combustion to provide heat for ammonia catalytic decomposition, but it cannot provide clean energy for other production processes. In addition, in the prior art, when ammonia undergoes a decomposition reaction through a catalyst, it needs to react with the catalyst at a certain temperature, and the temperature fluctuation during decomposition will have a significant impact on the decomposition efficiency and decomposition products. Summary of the Invention

[0006] The object of the present invention is to provide a pure ammonia burner based on an ammonia pre-decomposition method, aiming to achieve the safe, efficient and stable decomposition of ammonia, without the participation of other types of fuels during the combustion process. At the same time, this process is committed to reducing the emission of harmful gases and generating clean energy that can be used in other production processes, thereby optimizing resource utilization and promoting environmentally friendly production.

[0007] The present invention is achieved through the following technical solutions: A pure ammonia burner based on an ammonia pre-decomposition method, comprising a combustion chamber, a decomposition chamber and a liquid ammonia storage device; the flue gas recirculation zone provided in the combustion chamber is sleeved inside the decomposition chamber; the combustion chamber is equipped with a primary ammonia channel, an ignition device and an air conditioning system; a bluff body is provided at the end of the primary ammonia channel; the decomposition chamber is equipped with a secondary ammonia inlet, a catalytic device and a pyrolysis gas outlet channel; the catalytic device is assembled on the inner wall of the decomposition chamber, and its position corresponds to the flue gas recirculation zone; a heat exchange device is assembled on the outer wall of the pyrolysis gas outlet channel; the liquid ammonia storage device is connected to the heat exchange device for delivering ammonia to the primary ammonia channel and the secondary ammonia inlet.

[0008] Through the primary ammonia channel, ammonia is transported into the combustion chamber. At the same time, the air conditioning system provides a certain amount of oxygen, which, in cooperation with the ignition device, enables ammonia to be ignited in the combustion chamber and burn stably under the regulation of the air conditioning system. In the combustion chamber, a bluff body is provided at the end of the primary ammonia channel, and the gas formed after ammonia combustion forms a flue gas recirculation zone in the combustion chamber behind the bluff body. Since when ammonia is not completely decomposed, some harmful gases may be generated, such as nitrogen oxides, etc., and the flue gas recirculation zone effectively concentrates the heat generated by ammonia combustion, providing sufficient heat source for the decomposition chamber, ensuring the continuity and stability of the ammonia decomposition process, making the ammonia decomposition more complete, and reducing the emission of undecomposed ammonia and harmful gases.

[0009] In the decomposition chamber, the catalytic device is assembled on the inner wall of the decomposition chamber corresponding to the flue gas recirculation zone, and can make full use of the heat transferred from the combustion chamber to catalyze the decomposition of ammonia. The ammonia decomposition products generated by the decomposition of ammonia are then discharged through the pyrolysis gas outlet channel. Among them, hydrogen can be used as clean energy in other production processes.

[0010] In addition, the heat exchange device is installed on the outer wall of the pyrolysis gas outlet channel. It reduces the temperature of the ammonia decomposition product hydrogen in the pyrolysis gas outlet channel to reduce the corrosion or fouling problems of the device caused by the ammonia decomposition product in a high-temperature environment. At the same time, the heat exchange device also absorbs the thermal energy of the ammonia decomposition product in the pyrolysis gas outlet channel and uses this part of the thermal energy as the heating heat source for the liquid ammonia storage device. Such a heat cycle design maximizes the energy efficiency of the entire device and significantly reduces energy waste.

[0011] When the decomposition temperature of ammonia is too high, it will cause the catalyst in the catalytic device to fail or sinter, thereby reducing the catalytic activity of the catalyst in the catalytic device. After the catalyst fails, the decomposition efficiency of ammonia will drop significantly, and even may cause the decomposition reaction to not proceed normally. When the decomposition temperature of ammonia is too low, the decomposition reaction of ammonia will be inhibited, resulting in incomplete decomposition, reducing the utilization rate of ammonia, and may also produce undecomposed ammonia and other harmful intermediate products, causing environmental pollution. Therefore, in the combustion chamber, different flow rates of oxygen are provided through the air conditioning system to adjust the combustion temperature in the combustion chamber, so as to maintain a stable and continuous heat source in the decomposition chamber, avoid accidents caused by too high combustion temperature, and ensure the safety of the combustion chamber. Moreover, the ammonia in the decomposition chamber is decomposed continuously and smoothly, avoiding the problems of reduced decomposition efficiency or reaction interruption caused by too high or too low temperature, and improving the utilization rate of ammonia.

[0012] In the decomposition chamber, through the stable heat source and catalytic device provided by the combustion chamber, ammonia can be completely decomposed, reducing harmful gases such as nitrogen oxides generated due to incomplete decomposition of ammonia. The assembly position of the catalytic device corresponds to the position of the flue gas recirculation zone, ensuring that ammonia is in full contact with the catalyst in the catalytic device for decomposition reaction under the stable heat source provided by the flue gas recirculation zone, and avoiding the generation of harmful gases due to incomplete decomposition of ammonia.

[0013] The heat exchange device realizes the effective recovery and utilization of heat. By heating the liquid ammonia in the liquid ammonia storage device, the ammonia gas after vaporization of the liquid ammonia is transported to the primary ammonia channel and the secondary ammonia inlet, reducing the additional energy consumption and improving the energy efficiency of the entire burner. At the same time, the clean energy such as nitrogen and hydrogen generated by decomposition is discharged through the pyrolysis gas outlet channel and can also be used as raw materials for other production processes, increasing the economic benefits.

[0014] Preferably, the air conditioning system includes an air inlet channel, a first air volume regulating valve, and a first temperature sensor. The first air volume regulating valve is assembled on the inner wall of the combustion chamber, behind the air inlet channel. The first temperature sensor is assembled on the inner wall of the combustion chamber behind the first air volume regulating valve.

[0015] The air conditioning system maintains the temperature stability in the chamber by precisely controlling the air flow rate entering the combustion chamber. The air inlet channel, as the only path for external air to enter the combustion chamber, ensures the singularity and controllability of the air source. The first air volume regulating valve is assembled behind the air inlet channel. By adjusting the opening degree of this valve, the air flow rate entering the combustion chamber can be precisely controlled, thereby realizing the regulation of the combustion process. The first temperature sensor is assembled on the inner wall of the combustion chamber behind the first air volume regulating valve, used to monitor the temperature in the chamber in real time. If the temperature is too high or too low, the opening degree of the first air volume regulating valve is adjusted to maintain the temperature stability in the combustion chamber.

[0016] The air conditioning system effectively improves the stability and efficiency of the combustion process by precisely controlling the air flow into the combustion chamber. It avoids the phenomena of incomplete combustion or overheating caused by too large or too small air flow, thereby extending the service life of the combustion chamber and related equipment. Secondly, the real-time monitoring and feedback mechanism of the first temperature sensor enables the device to quickly respond to changes in the temperature inside the chamber, and thus ensure the stability of the temperature inside the combustion chamber by adjusting the air volume.

[0017] Preferably, the inner wall of the secondary ammonia inlet is provided with a second air volume regulating valve for regulating the ammonia flow rate.

[0018] The second air volume regulating valve controls the opening degree of the valve mechanically or electronically, thereby regulating the ammonia flow rate into the decomposition chamber. When it is necessary to increase the ammonia input amount, the opening degree of the second air volume regulating valve will increase accordingly, allowing more ammonia to enter the decomposition chamber; conversely, when it is necessary to reduce the ammonia input amount, the opening degree of the valve will decrease, restricting the ammonia flow rate. It ensures the precise adjustability of the ammonia flow rate and provides a stable raw material supply for the ammonia decomposition reaction in the decomposition chamber.

[0019] By precisely controlling the ammonia flow rate, the second air volume regulating valve ensures the stability and efficiency of the ammonia decomposition reaction in the decomposition chamber. It avoids the problems of incomplete decomposition or decreased reaction rate caused by too large or too small ammonia flow rate, thereby improving the utilization rate of ammonia and the quality of decomposition products. Secondly, the second air volume regulating valve also enhances the flexibility and adaptability of the device. According to different production requirements and process conditions, the operator can conveniently adjust the ammonia flow rate to meet different decomposition reaction requirements.

[0020] Preferably, the inner wall of the secondary ammonia inlet is provided with a second temperature sensor, which is arranged between the second air volume regulating valve and the catalytic device.

[0021] The second temperature sensor can monitor the ammonia temperature in this area in real time. By precisely measuring the temperature, the second temperature sensor can feedback the temperature data to the control system, and the control system then makes fine adjustments to the opening degree of the second air volume regulating valve according to these data to ensure that the ammonia reaches the optimal reaction temperature before entering the catalytic device.

[0022] By monitoring the ammonia temperature in real time, the second temperature sensor provides accurate data support for the control system, enabling the system to precisely adjust the ammonia flow rate according to the actual situation, so as to ensure that the ammonia is within the optimal reaction temperature range before entering the catalytic device. This not only improves the decomposition efficiency of ammonia, but also reduces the energy consumption and emissions caused by improper temperature.

[0023] Preferably, the heat exchange device includes a cold water pipe and a heat exchange pipe connected to each other. The cold water pipe is wound around the outer wall of the pyrolysis gas outlet channel; the heat exchange pipe is assembled inside the liquid ammonia storage device.

[0024] The cold water pipe is wound around the outer wall of the pyrolysis gas outlet channel, and the heat carried by the high-temperature pyrolysis gas in the pyrolysis gas outlet channel is used to heat the cold water in the cold water pipe. The cold water pipe and the heat exchange pipe are connected to each other. The heated water in the cold water pipe is sent into the heat exchange pipe, and the heat exchange pipe is assembled inside the liquid ammonia storage device. The hot water in the heat exchange pipe is used to heat the liquid ammonia in the liquid ammonia storage device to turn it into gas.

[0025] The heat exchange device effectively utilizes the high-temperature heat in the pyrolysis gas outlet channel, transfers this part of heat to the cold water in the cold water pipe, and finally transfers it to the liquid ammonia in the liquid ammonia storage device through the heat exchange pipe, thus realizing the recovery and reuse of heat. The recovery and reuse of heat are realized, and the energy efficiency of the whole system is also improved.

[0026] Preferably, a plurality of ammonia spray holes are provided on the side wall of the primary ammonia channel close to the bluff body.

[0027] Ammonia is evenly sprayed outwards through the ammonia spray holes via the primary ammonia channel. The bluff body guides or changes the flow path of the fluid. The ammonia spray holes are opened on the side wall of the primary ammonia channel close to the bluff body, so that ammonia can be sprayed out within a certain area, and ammonia is concentrated around the bluff body to ensure that the ignited ammonia can be concentrated in the flue gas recirculation zone.

[0028] Due to the ammonia spray holes, ammonia is evenly sprayed within a certain range, reducing the waste and emission of ammonia, and enabling the heat generated after the combustion of ammonia to be concentrated in the flue gas recirculation zone. Moreover, by optimizing the spraying mode and distribution of ammonia, the pressure fluctuation inside the equipment can be reduced, and the operation stability and safety of the equipment can be improved.

[0029] Preferably, rotating blades are assembled in the flue gas recirculation zone.

[0030] The rotating blades enhance the turbulence of the air flow through rotation, can guide the flue gas after combustion to form a recirculation, and enhance the flue gas recirculation effect in combination with the bluff body. Moreover, the rotating blades promote the mixing and exchange between air and ammonia through rotation, improving the combustion efficiency. Stable combustion in the central area of the burner is achieved, providing heat for the outer decomposition chamber.

[0031] Preferably, the liquid ammonia storage device is provided with a liquid ammonia inlet pipe and a plurality of ammonia outlet pipes.

[0032] Liquid ammonia is safely and efficiently injected into the interior of the storage device through the liquid ammonia inlet pipe. During storage, the liquid ammonia maintains its liquid form to save storage space and reduce transportation costs. When ammonia gas is needed, the liquid ammonia in the storage device is converted into gaseous ammonia by heating or other means and output through multiple ammonia gas outlet pipes.

[0033] The volume of liquid ammonia is much smaller than that of gaseous ammonia. Therefore, the liquid ammonia storage device can efficiently store liquid ammonia gas, saving storage space and reducing transportation costs. The multiple ammonia gas outlet pipes make the output of ammonia gas more flexible and controllable. Ammonia gas can be transported to different devices according to actual needs.

[0034] Preferably, the end of the combustion chamber is a tapered trapezoidal structure.

[0035] A flue gas recirculation zone is formed in the combustion chamber by the bluff body and the tapered trapezoidal structure. During combustion, when the flue gas flows in the chamber, due to the existence of the tapered trapezoidal structure, the flow path of the flue gas gradually becomes narrower. This narrowing path causes the flow velocity of the flue gas to increase. According to Bernoulli's principle, when the flow velocity increases, the static pressure in this area will decrease. Therefore, at the rear of the tapered trapezoidal structure, that is, the wider part of the combustion chamber, a relatively high-pressure zone will be formed relative to the narrow front part. This pressure difference prompts the flue gas to form a recirculation zone in the combustion chamber, that is, the flue gas flows back from the high-pressure zone to the low-pressure zone, enabling the flue gas to recirculate in the flue gas recirculation zone and ensuring that the combustion chamber can effectively provide a concentrated and high-temperature heating environment for the decomposition chamber.

[0036] Preferably, a flange is provided on the outer wall of the decomposition chamber near the pyrolysis gas outlet channel.

[0037] A flange is a mechanical component, usually made of high-strength materials, with a flat contact surface and bolt holes, used for reliable connection between two pipes, equipment or components. It is assembled on the outer wall of the decomposition chamber near the pyrolysis gas outlet channel. As a pipe connector, it is used to fix and seal the pipe interfaces of different parts. Ensure that the pyrolysis gas outlet channel can be tightly and firmly connected to the subsequent processing equipment or pipes, prevent the leakage of pyrolysis gas during transmission, and at the same time facilitate installation, disassembly and maintenance.

[0038] It ensures high tightness between the pyrolysis gas outlet channel and the subsequent equipment or pipes. Makes the connection between the pyrolysis gas outlet channel and the subsequent equipment simple and fast, greatly shortening the installation time. At the same time, when maintenance or component replacement is required, it can be easily disassembled by simply loosening the bolts on the flange, improving the convenience and efficiency of maintenance.

[0039] Compared with the prior art, the present invention has the following beneficial effects: A pure ammonia burner based on an ammonia pre-decomposition method controls the temperature in the combustion chamber through an air conditioning system, avoiding the problems of catalyst device failure and incomplete ammonia decomposition caused by too high or too low temperature, improving the utilization rate and decomposition efficiency of ammonia, and reducing the emission of harmful gases at the same time. The assembly position of the catalyst device corresponds to the position of the flue gas recirculation zone, ensuring that ammonia is fully decomposed under a stable heat source and avoiding the generation of harmful gases. The heat exchange device recovers the high-temperature heat in the pyrolysis gas outlet channel and uses it to heat the liquid ammonia in the liquid ammonia storage device, thereby reducing the additional energy consumption for heating liquid ammonia. The clean energy generated by decomposition can be used as raw materials, increasing economic benefits.

[0040] Furthermore, the air conditioning system improves the stability and efficiency of the combustion process by precisely controlling the air flow, extends the service life of the combustion chamber and related equipment, and reduces failures caused by incomplete combustion or overheating.

[0041] Furthermore, the second air volume regulating valve ensures the stability and efficiency of the ammonia decomposition reaction in the decomposition chamber by controlling the ammonia flow, improves the utilization rate of ammonia and the quality of decomposition products, and enhances the flexibility and adaptability of the device.

[0042] Furthermore, the second temperature sensor monitors the ammonia temperature in real time, ensuring that ammonia is within the optimal reaction temperature range and decomposing under the action of the catalyst device, improving the decomposition efficiency and reducing energy consumption and emissions.

[0043] Furthermore, the heat exchange device effectively recovers and utilizes the high-temperature heat in the pyrolysis gas outlet channel, transfers it to the liquid ammonia in the liquid ammonia storage device, realizes the recovery and reuse of heat, and improves the energy efficiency of the entire system.

[0044] Furthermore, the ammonia injection holes uniformly inject ammonia within a certain range, reducing the waste and emission of ammonia, and at the same time concentrating the heat after ammonia combustion in the flue gas recirculation zone, improving the operating stability and safety of the equipment.

[0045] Furthermore, the rotating blades enhance the turbulence of the air flow through rotation to strengthen the mixing of air and ammonia, improve the combustion efficiency, and provide a stable heat source for the outer decomposition chamber.

[0046] Furthermore, the liquid ammonia storage device can efficiently store liquid ammonia, saving storage space and reducing transportation costs. Multiple ammonia outlet pipes make the output of ammonia more flexible and controllable, meeting the needs of different devices.

[0047] Furthermore, the flange ensures the high tightness of the device, facilitates the connection of the burner to other devices, simplifies the installation process, is easy to disassemble quickly, and improves the maintenance efficiency.

[0048] Furthermore, the flange ensures high tightness between the pyrolysis gas outlet channel and subsequent equipment or pipelines, preventing leakage of pyrolysis gas during transmission, and also facilitating installation, disassembly, and maintenance.

[0049] Other features and advantages of the present invention will be disclosed in detail in the following specific embodiments and the accompanying drawings. Description of the Drawings

[0050] The present invention will be further described below with reference to the accompanying drawings: Figure 1 is a schematic structural diagram of a pure ammonia burner based on an ammonia pre-decomposition method of the present invention; Figure 2 is a schematic structural diagram of the flue gas recirculation zone of the present invention; Figure 3 is a schematic structural diagram of the pyrolysis gas outlet channel of the present invention; Figure 4 is a schematic structural diagram of the liquid ammonia storage device of the present invention; The description of the reference numerals in the drawings is as follows: Combustion chamber 1, decomposition chamber 2, liquid ammonia storage device 3, heat exchange device 4, flue gas recirculation zone 10, primary ammonia channel 11, ignition device 12, air conditioning system 13, bluff body 14, ammonia injection hole 15, tapered trapezoidal structure 16, combustion gas outlet 17, secondary ammonia inlet 21, catalytic device 22, pyrolysis gas outlet channel 23, flange 24, liquid ammonia inlet pipe 31, ammonia outlet pipe 32, primary ammonia delivery pipe 321, secondary ammonia delivery pipe 322, heat preservation housing 33, rotating blade 101, air inlet channel 131, first air volume regulating valve 132, first temperature sensor 133, second air volume regulating valve 211, second temperature sensor 212, cold water pipe 41, cold water pipe inlet 411, cold water pipe outlet 412, heat exchange pipe 42, heat exchange pipe inlet 421, heat exchange pipe outlet 422. Specific Embodiments

[0051] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings of the embodiments of the present invention. However, the following embodiments are only the preferred embodiments of the present invention and not all of them. Based on the embodiments in the embodiments, other embodiments obtained by those skilled in the art without creative efforts all fall within the protection scope of the present invention.

[0052] In the following description, terms such as "inner", "outer", "upper", "lower", "left", "right", etc. indicating orientation or position relationship are only for convenience of describing the embodiments and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0053] As Figures 1 to 4 shown, a pure ammonia burner based on an ammonia pre-decomposition method includes a combustion chamber 1, a decomposition chamber 2, and a liquid ammonia storage device 3; the 10 flue gas recirculation zones provided in the combustion chamber 1 are sleeved inside the decomposition chamber 2; the combustion chamber 1 is equipped with a primary ammonia channel 11, an ignition device 12, and an air conditioning system 13; a blunt body 14 is provided at the end of the primary ammonia channel 11; the decomposition chamber 2 is equipped with a secondary ammonia inlet 21, a catalytic device 22, and a pyrolysis gas outlet channel 23; the catalytic device 22 is assembled on the inner wall of the decomposition chamber 2, and its position corresponds to the flue gas recirculation zone 10; a heat exchange device 4 is assembled on the outer wall of the pyrolysis gas outlet channel 23; the liquid ammonia storage device 3 is connected to the heat exchange device 4 for delivering ammonia to the primary ammonia channel 11 and the secondary ammonia inlet 21.

[0054] In the combustion stage, the liquid ammonia absorbs heat in the liquid ammonia storage device 3 and turns into ammonia, which enters the combustion chamber 1, where the combustion process is completed. Ammonia nozzles 15 are evenly distributed on the side wall of the primary ammonia channel 11 to achieve uniform ammonia injection, fully mix with air, and enhance combustion stability. The rotating blades 101 enhance the turbulence of the air flow to ensure efficient combustion. The generated high-temperature flue gas forms a recirculation zone through the blunt body 14, and after fully exchanging heat with the external ammonia pyrolysis, it flows through the combustion gas outlet 17 at the end of the combustion chamber 1 to the pyrolysis gas outlet channel 23. This device optimizes the pyrolysis and combustion processes of ammonia, not only improving the pyrolysis efficiency, but also maximizing the energy recovery and utilization, and reducing the NOx generated by combustion.

[0055] Among them, the ammonia nozzles 15 are evenly distributed on the side wall of the ammonia combustion chamber, so that ammonia is evenly ejected in the combustion chamber, ensuring full mixing of ammonia and air. Through the design of the nozzles, ammonia can form a uniform combustion air flow throughout the combustion chamber, improving the combustion stability. The rotating blades 101 enhance the turbulence of the air flow, further promoting the thoroughness of the combustion process. In actual operation, this design effectively improves the combustion efficiency and reduces the phenomenon of incomplete combustion. The blunt body 14 forms a recirculation zone, effectively recovering the generated heat and ensuring full pyrolysis of the outer layer of ammonia. A tapered trapezoidal structure 16 is formed at the end of the flue gas recirculation zone 10. Cooperating with the blunt body 14, the flue gas generated by combustion can be refluxed more effectively, improving the flue gas reflux effect.

[0056] Among them, the air conditioning system 13 includes an air inlet passage 131, a first air volume regulating valve 132, and a first temperature sensor 133; the first air volume regulating valve 132 is assembled on the inner wall of the combustion chamber 1, behind the air inlet passage 131; the first temperature sensor 133 is assembled on the inner wall of the combustion chamber 1 behind the first air volume regulating valve 132. The first air volume regulating valve 132 is used to regulate the air flow entering the air inlet passage 131; the air temperature is monitored by the first temperature sensor 133; a rotating blade 101 is assembled in the flue gas recirculation zone 10 to strengthen the mixing of air and ammonia and enhance the combustion efficiency. The inner wall of the secondary ammonia inlet 21 is provided with a second air volume regulating valve 211 for regulating the ammonia flow; the inner wall of the secondary ammonia inlet 21 is provided with a second temperature sensor 212, which is arranged between the second air volume regulating valve 211 and the catalytic device 22.

[0057] This device precisely controls the flow rate, temperature of air and ammonia, and the catalytic process to achieve an efficient pyrolysis and combustion process. First, air enters through the air inlet passage 131, and the flow rate is precisely controlled by the first air volume regulating valve 132. The first temperature sensor 133 monitors the air temperature to ensure suitable combustion conditions. By igniting a part of the ammonia in the center, the heat generated by the combustion of ammonia is used to pyrolyze the outer layer of ammonia. The ammonia used for pyrolysis enters the decomposition chamber 2 through the secondary ammonia inlet 21, and the flow rate is controlled by the second air volume regulating valve 211. The second temperature sensor 212 monitors the ammonia temperature to ensure the stability of the pyrolysis process. The catalytic device 22 promotes the ammonia decomposition reaction, decomposing ammonia into hydrogen and nitrogen at high temperature, thereby reducing NOx emissions. The pyrolysis gas after decomposition recovers the heat generated through the heat exchange device 4 to improve energy efficiency, and at the same time transfers the heat to the liquid ammonia storage device 3. The liquid ammonia storage device 3 is independent of the combustion chamber 1 and the decomposition chamber 2 and is connected to the heat exchange device 4 to provide raw materials for the ammonia to be pyrolyzed and the ammonia to be combusted, and fully recover the waste heat of pyrolysis.

[0058] Furthermore, the heat exchange device 4 is assembled on the outer wall of the pyrolysis gas outlet passage 23 to recover the heat of the pyrolysis gas. The heat exchange device 4 includes a cold water pipe 41 and a heat exchange pipe 42 connected to each other. The cold water pipe 41 is wound around the outer wall of the pyrolysis gas outlet passage 23; the heat exchange pipe 42 is assembled in the liquid ammonia storage device 3. One end of the cold water pipe 41 is the cold water pipe inlet 411, and the other end is the cold water pipe outlet 412; cooling water is introduced into the cold water pipe inlet 411 to absorb the heat of the pyrolysis gas in the pyrolysis gas outlet passage 23, and the processed gas is discharged through the pyrolysis gas outlet passage 23. The cooling water in the cold water pipe 41 becomes hot water after absorbing heat from the outer wall of the pyrolysis gas outlet passage 23 and is discharged from the cold water pipe outlet 412.

[0059] The heat exchange tube 42 is assembled in the liquid ammonia storage device 3 and is used to preheat the liquid ammonia to increase the heat recovery efficiency. One end of the heat exchange tube 42 is the heat exchange tube inlet 421, and the other end is the heat exchange tube outlet 422; the heat exchange tube inlet 421 is connected to the cold water pipe outlet 412, and hot water is introduced into the heat exchange tube 42, flows through the liquid ammonia storage device 3, and is discharged from the heat exchange tube outlet 422.

[0060] The primary ammonia channel 11 and the secondary ammonia inlet 21 receive the ammonia gas vaporized from the liquid ammonia storage device 3. A liquid ammonia inlet pipe 31 is provided on one side of the liquid ammonia storage device 3, and an ammonia gas outlet pipe 32 is provided on the other side; the ammonia gas outlet pipe 32 is divided into two pipes. One is the primary ammonia delivery pipe 321, which delivers ammonia gas to the combustion chamber 1; the other is the secondary ammonia delivery pipe 322, which delivers ammonia gas to the decomposition chamber 2. Among them, the ammonia gas in the primary ammonia delivery pipe 321 is ejected through the ammonia gas spray holes 15, is fully mixed with air, and is ignited by the ignition device 12 assembled in the center of the primary ammonia delivery pipe 321. A flue gas recirculation zone 10 is formed by the blunt body 14 structure at the end of the primary ammonia delivery pipe 321, and the heat is transferred to the ammonia gas introduced into the secondary ammonia inlet 21. The decomposed ammonia gas finally discharges from the pyrolysis gas outlet channel 23. A flange 24 is provided on the outer wall of the decomposition chamber 2 close to the pyrolysis gas outlet channel 23. The flange 24 plays a role in fixing the entire device and facilitates the connection of this device with other production devices, so that the decomposed ammonia gas product hydrogen can be applied to other production processes.

[0061] The above process can effectively recover the waste heat of the exhaust gas and use it for the energy supplement of the entire device, greatly improving the energy utilization efficiency. The treated pyrolysis gas is transported to other devices, such as the furnace, through the pyrolysis gas outlet channel 23 for further combustion, further improving the overall energy efficiency of the system.

[0062] Furthermore, the liquid ammonia enters the liquid ammonia storage device 3 through the liquid ammonia inlet pipe 31. When the liquid nitrogen level is lower than the liquid ammonia inlet pipe 31, the liquid ammonia will be automatically filled. During the storage process, the liquid ammonia exchanges heat with the hot water entering the heat exchange tube 42. The liquid ammonia is heated and converted into gaseous ammonia during this process. The vaporized ammonia gas flows through the pipeline and is ready to participate in the subsequent chemical reactions. The hot water after the heat exchange process is discharged from the heat exchange tube outlet 422, and the temperature decreases. Then the water with the decreased temperature is circulated to the cold water pipe 41 in the heat exchange device 4 for heating to realize the circulation of the cooling water. At the same time, the liquid ammonia storage device 3 is wrapped by a thermal insulation shell 33 to maintain the stable temperature inside the system and improve the energy efficiency, preventing the influence of the external environment. This thermal insulation shell can effectively prevent the influence of the external low temperature on the liquid ammonia storage device 3 and ensure that the ammonia gas in the liquid ammonia storage device 3 is always within an appropriate temperature range. The thermal insulation design ensures the thermal efficiency of the system, reduces the influence brought by the external temperature change, and improves the stability and energy utilization rate of the system.

[0063] Furthermore, the heat exchange tube 42 in the liquid ammonia storage device 3 can increase the initial temperature of ammonia gas during the ammonia pyrolysis process, enhance the reaction rate of ammonia decomposition, and further improve the energy efficiency of the overall device.

[0064] In practical applications, liquid ammonia is usually stored in a low-temperature and low-pressure environment. Through the liquid ammonia inlet pipe 31, liquid ammonia is introduced into the liquid ammonia storage device 3, and this area is maintained in a stable state of liquid ammonia by a temperature control device. When the burner requires ammonia gas, the liquid ammonia can be released as needed. The liquid ammonia exchanges heat with the hot water entering through the heat exchange tube inlet 421. During the heat exchange process, the temperature of the liquid ammonia gradually rises and is converted into gaseous ammonia. The heated ammonia gas flows out through the ammonia gas outlet pipe 32 and enters the primary ammonia gas channel 11 and the secondary ammonia gas inlet 21 through the primary ammonia gas delivery pipe 321 and the secondary ammonia gas delivery pipe 322 respectively, preparing to further participate in the combustion and pyrolysis reactions. This process can ensure that the ammonia gas is always in an appropriate temperature and pressure state, ensuring the efficient operation of the system.

[0065] Among them, if the tail gas transported to the pyrolysis gas outlet channel 23 is directly introduced into the liquid ammonia storage device 3 for heating the liquid ammonia, due to the high temperature of the flue gas, it may cause corrosion or fouling of the heating equipment, especially in a high-temperature and chemically active environment. However, by using the cooling water in the cold water pipe 41 in this solution to isolate the flue gas from the liquid ammonia, these adverse effects are reduced. By using the cooling water as an intermediate medium, it is easier for the system to adjust the heat. The heat of the system no longer completely depends on the temperature fluctuation of the tail gas, but is adjusted by controlling the flow rate and temperature of the cooling water. It can more precisely adjust the heating process of the liquid ammonia. Moreover, liquid ammonia itself is a very volatile substance. Direct contact with the high-temperature tail gas may cause uneven evaporation and excessive gasification of the liquid ammonia, and even pose potential safety hazards. The cooling water as a heat exchange medium can effectively absorb the heat of the tail gas and transfer it to the liquid ammonia, avoiding waste of heat.

[0066] In addition, the use of cooling water enables the heat exchange device 4 to be managed and controlled more intelligently. For example, according to real-time data such as the temperature change, flow rate, and pressure of the cooling water, the heat input during the liquid ammonia heating process can be automatically adjusted, thereby achieving the adaptive adjustment of the system.

[0067] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the content described in the drawings and the above specific embodiments. Any modification that does not deviate from the functional and structural principles of the present invention will be included in the scope of the claims.

Claims

1. A pure ammonia burner based on an ammonia pre-decomposition method, characterized in that: It comprises a combustion chamber (1), a decomposition chamber (2) and a liquid ammonia storage device (3); the combustion chamber (1) is provided with a smoke reflow zone (10) which is sleeved inside the decomposition chamber (2); The combustion chamber (1) is equipped with a primary ammonia channel (11), an ignition device (12) and an air conditioning system (13); a blunt body (14) is provided at the end of the primary ammonia channel (11); the decomposition chamber (2) is equipped with a secondary ammonia inlet (21), a catalytic device (22) and a pyrolysis gas outlet channel (23); The catalytic device (22) is mounted on the inner wall of the decomposition chamber (2), and its position corresponds to the flue gas recirculation zone (10); The outer wall of the pyrolysis gas outlet channel (23) is equipped with a heat exchange device (4); the liquid ammonia storage device (3) is connected to the heat exchange device (4) and is used to transport ammonia to the primary ammonia channel (11) and the secondary ammonia inlet (21).

2. A pure ammonia burner based on the ammonia pre-decomposition method according to claim 1, characterized in that: The air conditioning system (13) comprises an air inlet passage (131), a first air volume regulating valve (132) and a first temperature sensor (133); the first air volume regulating valve (132) is mounted on the inner wall of the combustion chamber (1) and is located behind the air inlet passage (131); and the first temperature sensor (133) is mounted on the inner wall of the combustion chamber (1) behind the first air volume regulating valve (132).

3. A pure ammonia burner based on the ammonia pre-decomposition method according to claim 1, characterized in that: The inner wall of the secondary ammonia inlet (21) is provided with a second air volume regulating valve (211) for regulating the flow rate of ammonia.

4. A pure ammonia burner based on the ammonia pre-decomposition method according to claim 3, characterized in that: A second temperature sensor (212) is provided on the inner wall of the secondary ammonia inlet (21), and is arranged between the second air volume regulating valve (211) and the catalytic device (22).

5. A pure ammonia burner based on the ammonia pre-decomposition method according to claim 1, characterized in that: The heat exchange device (4) comprises a cold water pipe (41) and a heat exchange pipe (42) connected to each other, wherein the cold water pipe (41) is wound around the outer wall of the pyrolysis gas outlet channel (23); and the heat exchange pipe (42) is installed in the liquid ammonia storage device (3).

6. A pure ammonia burner based on the ammonia pre-decomposition method according to claim 1, characterized in that: The first-level ammonia passage (11) is provided with a plurality of ammonia spray holes (15) on a side wall close to the bluff body (14).

7. A pure ammonia burner based on the ammonia pre-decomposition method according to claim 1, characterized in that: Rotating blades (101) are installed in the smoke recirculation zone (10).

8. The pure ammonia burner based on the ammonia pre-decomposition method according to claim 1, characterized in that: The liquid ammonia storage device (3) is provided with a liquid ammonia inlet pipeline (31) and a plurality of ammonia gas outlet pipelines (32).

9. A pure ammonia burner based on the ammonia pre-decomposition method according to claim 1, characterized in that: The end of the smoke recirculation zone (10) is a tapered trapezoidal structure (16).

10. The pure ammonia burner based on the ammonia pre-decomposition method according to claim 1, characterized in that: The outer wall of the decomposition chamber (2) close to the pyrolysis gas outlet channel (23) is provided with a flange (24).

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