Pure ammonia burner equipped with ammonia catalytic combustion decomposition compound and control method

Abstract

The present invention relates to the technical field of combustion equipment. The present invention discloses a pure ammonia burner equipped with ammonia catalytic combustion and decomposition compound and a control method. The pure ammonia burner includes a combustion sleeve, the combustion sleeve includes an inner sleeve and an outer sleeve, an outer chamber is formed between the inner sleeve and the outer sleeve, the inner sleeve is provided with an inner chamber, the inner chamber includes a combustion nozzle, a combustion chamber and a chamber to be burned, a first ignition device is provided between the combustion chamber and the chamber to be burned, the chamber to be burned is connected to a first air inlet, the outer chamber includes a preheating chamber, a combustion catalytic chamber and a catalytic decomposition chamber; the preheating chamber is located at the periphery of the combustion chamber; the combustion catalytic chamber is located at the periphery of the chamber to be burned, the combustion catalytic chamber is provided with an ammonia catalytic combustion catalyst and a second ignition device, the catalytic decomposition chamber is provided with an ammonia catalytic decomposition catalyst, and the catalytic decomposition chamber is connected to the chamber to be burned. The present invention solves the problems of difficult pure ammonia ignition, slow laminar combustion speed, difficult flame stability and high NOx emissions.

Description

Technical Field

[0001] The present invention relates to the technical field of combustion equipment, and in particular to a pure ammonia burner equipped with ammonia catalytic combustion decomposition and compounding and a control method. Background Art

[0002] Ammonia fuel, a carbon-free, clean fuel, has garnered widespread attention in recent years. However, several challenges remain during its combustion. Due to its low calorific value, ammonia is prone to combustion instability and ignition difficulties. Furthermore, since ammonia molecules contain nitrogen, they generate significant amounts of fuel-type NOx during combustion. These drawbacks make it difficult for ammonia to meet combustion requirements as a single fuel, limiting its development as a fuel source.

[0003] Hydrogen complements ammonia in terms of ignition and combustion performance, and as both are carbon-free fuels, no CO2 is generated during combustion. Therefore, mixing the two and then burning them is considered a feasible solution for ammonia energy utilization. Therefore, current ammonia burners all mix hydrogen for combustion to improve combustion stability. However, the flame temperature of ammonia combustion in current ammonia burners is high, so nozzles made of heat-resistant materials are required, which increases costs. The thermal energy utilization efficiency of ammonia-hydrogen combustion is low, and a large amount of heat is dissipated through the walls in the form of radiation. The flue gas carries less sensible heat, resulting in serious energy waste. In addition, at this stage, achieving self-heating hydrogen co-combustion with ammonia as the only fuel requires complex processes and large-module equipment, resulting in additional energy and space waste. Summary of the Invention

[0004] The purpose of the present invention is to provide a pure ammonia burner equipped with ammonia catalytic combustion decomposition compound and a control method to solve one or more technical problems existing in the prior art and at least provide a beneficial option or create conditions.

[0005] The technical solutions adopted to solve the above technical problems are:

[0006] The present invention provides a pure ammonia burner equipped with ammonia catalytic combustion decomposition and recombination, comprising:

[0007] The combustion sleeve comprises an inner sleeve and an outer sleeve sleeved on the outer circumference of the inner sleeve, an annular outer chamber is formed between the inner sleeve and the outer sleeve, the inner circumference of the inner sleeve is provided with an inner chamber, the inner chamber comprises a combustion nozzle, a combustion chamber and a chamber to be burned which are sequentially connected along the axial direction, a first ignition device for igniting the mixed combustion gas is provided between the combustion chamber and the chamber to be burned, the chamber to be burned is connected to a first air inlet for air to enter, the outer chamber comprises a preheating chamber, a combustion catalytic chamber and a catalytic decomposition chamber which are sequentially connected in the direction from the combustion nozzle to the chamber to be burned; the preheating chamber The cavity is located at the periphery of the combustion cavity and has a partition heat exchange relationship with the combustion cavity; the combustion catalytic cavity is located at the periphery of the cavity to be burned and has a partition heat exchange relationship with the cavity to be burned, the combustion catalytic cavity is provided with an ammonia catalytic combustion catalyst for catalytic combustion of ammonia and a second ignition device for igniting a mixture of ammonia and air, the catalytic decomposition cavity is provided with an ammonia catalytic decomposition catalyst for catalytic decomposition of ammonia, the preheating cavity is connected to a second air inlet for air and an ammonia inlet for ammonia, and the catalytic decomposition cavity is connected to the cavity to be burned.

[0008] The beneficial effects of the pure ammonia burner of the present invention are:

[0009] During the startup phase of the pure ammonia burner, a mixture of ammonia and air in a preset ratio is introduced into the preheating chamber through the ammonia inlet and the second air inlet respectively, and then enters the combustion catalytic chamber through the preheating chamber. The ammonia is ignited by the second ignition device. Under the catalytic action of the ammonia catalytic combustion catalyst, part of the ammonia undergoes a catalytic combustion reaction on the surface of the ammonia catalytic combustion catalyst, and generates heat of catalytic combustion to form a high-temperature mixed gas. The high-temperature mixed gas is then introduced into the catalytic decomposition chamber. Under the catalytic action of the ammonia catalytic decomposition catalyst, part of the ammonia in the high-temperature mixed gas undergoes a catalytic combustion reaction, and generates heat of catalytic combustion to form a high-temperature mixed gas. The decomposition reaction is carried out to produce hydrogen, which is mixed into the high-temperature mixed gas to form a mixed gas to be burned. The mixing of hydrogen in ammonia can effectively increase the combustion characteristics of ammonia. Then the mixed gas to be burned and the air added from the first air inlet are introduced into the combustion chamber to be burned for mixing to form a mixed combustion gas. At this time, the heat generated by the catalytic combustion inside the combustion catalytic chamber is preheated to preheat the mixed combustion gas in the combustion chamber to make up for the heat consumed by the catalytic decomposition of ammonia and to heat the newly added air. Then the first ignition device is controlled to ignite the mixed combustion gas, and it burns in the combustion chamber to generate a flame.

[0010] During the stable operation stage of the pure ammonia burner, a stable flame is formed in the combustion chamber. At this time, both the second ignition device and the first ignition device can be closed. Since the preheating chamber and the combustion chamber are in a wall heat exchange relationship, the mixed gas of ammonia and air can effectively absorb heat from the combustion chamber when in the preheating chamber. This can protect the combustion sleeve from overheating while preheating the mixed gas. The temperature of the preheated mixed gas reaches the starting requirement of catalytic combustion, preheats the ammonia catalytic combustion catalyst, and provides the starting energy of the catalytic combustion reaction, so that the catalytic combustion reaction can continue to be carried out efficiently and stably in the combustion catalytic chamber. The high-temperature mixed gas formed then passes through the catalytic decomposition chamber to further form a mixture to be burned mixed with hydrogen. After mixing with the newly introduced air, it is introduced into the combustion chamber to form a stable ammonia-hydrogen mixed combustion flame, realizing ammonia-hydrogen mixed combustion under the condition that ammonia is the only fuel.

[0011] The present invention utilizes the self-heating hydrogen production of ammonia catalytic combustion and ammonia catalytic decomposition, and utilizes heat recycling to preheat the mixed gas in the preheating chamber and the mixed combustion gas in the combustion chamber, thereby ensuring the activation energy of catalytic combustion, avoiding the low-temperature combustion mixed temperature after the ammonia catalytic decomposition reaction being too low, thereby hindering the local flame propagation of ammonia and generating excessive residual ammonia, improving the thermal energy utilization efficiency of ammonia-hydrogen combustion, and protecting the wall surface of the combustion chamber. Therefore, no temperature-resistant material is required, reducing manufacturing costs. As a result, the present invention solves the problems of difficult ignition of pure ammonia, slow laminar combustion speed, difficult flame stability, and high NOx emissions.

[0012] As a further improvement of the above technical solution, an annular first air-distributing baffle is provided between the preheating chamber and the combustion catalytic chamber, and a plurality of first air vents are distributed on the first air-distributing baffle.

[0013] As a further improvement of the above technical solution, an annular second gas distribution baffle is provided between the combustion catalytic chamber and the catalytic decomposition chamber, and a plurality of second vent holes are distributed on the second gas distribution baffle.

[0014] As a further improvement of the above technical solution, a plurality of third vent holes are distributed on the periphery of one end of the chamber to be burned away from the combustion chamber, and the plurality of third vent holes are used to connect the catalytic decomposition chamber with the chamber to be burned.

[0015] As a further improvement of the above technical solution, the first air inlet is connected to the inner circumferential wall of the chamber to be burned, and the first air inlet is arranged along the tangential direction of the inner circumference of the chamber to be burned.

[0016] As a further improvement of the above technical solution, a guide body with a conical outer shape is provided between the combustion chamber and the chamber to be burned, and the outer diameter of the guide body is gradually reduced from the combustion nozzle to the chamber to be burned.

[0017] As a further improvement of the above technical solution, a plurality of swirl fins are distributed circumferentially on the outer periphery of the guide body, and a conical funnel-shaped guide annular surface is provided on the inner periphery of the combustion chamber close to one end of the chamber to be burned, and the guide annular surface is located on the outer periphery of the guide body.

[0018] As a further improvement to the above technical solution, the first ignition device includes a plurality of first ignition power generation parts, which are radially arranged in an annular pattern and located at one end of the plurality of swirl fins close to the combustion chamber, and the distance between the first ignition power generation part and the inner wall of the inner chamber is 3 to 5 mm;

[0019] The second ignition device includes a second ignition power generation portion suspended in the combustion catalytic chamber, and the distance between the second ignition power generation portion and the inner wall of the combustion catalytic chamber is 3-5 mm.

[0020] As a further improvement of the above technical solution, the preheating chamber is connected to a gas mixing chamber, one axial end of the gas mixing chamber is connected to the ammonia inlet, and the other end is connected to the preheating chamber, and the second air inlet is arranged on the peripheral wall of the gas mixing chamber and is arranged along the tangential direction of the inner circumference of the gas mixing chamber.

[0021] In addition, the present invention also proposes a control method applicable to the pure ammonia burner, the control method comprising:

[0022] Controlling a mixed gas of ammonia and air in a preset ratio to flow into the preheating chamber and then into the combustion catalytic chamber;

[0023] controlling the second ignition device to ignite the ammonia, so that part of the ammonia in the mixed gas undergoes a catalytic combustion reaction to generate a high-temperature mixed gas;

[0024] Controlling the high-temperature mixed gas to flow into the catalytic decomposition chamber, so that part of the ammonia in the high-temperature mixed gas undergoes a catalytic decomposition reaction to generate hydrogen, which is then mixed with the high-temperature mixed gas to form a mixed gas to be combusted;

[0025] Controlling the mixed gas to be combusted and a preset amount of air to be introduced into the combusted chamber for mixing to form a mixed combustion gas, wherein the mixed combustion gas is preheated by the heat of the combustion catalytic chamber;

[0026] controlling the first ignition device to ignite the mixed combustion gas and burn it in the combustion chamber;

[0027] After the pure ammonia burner operates stably, the second ignition device and the first ignition device are controlled to stop operating, and the mixed gas in the preheating chamber is preheated to a preset catalytic combustion temperature by the heat generated by the combustion in the combustion chamber, so that the mixed gas continues to undergo a catalytic combustion reaction in the combustion catalytic chamber, and the mixed combustion gas is controlled to flow into the combustion chamber for continuous combustion.

[0028] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0030] Figure 1 This is a structural schematic diagram of an embodiment of the pure ammonia burner provided by the present invention;

[0031] Figure 2 This is a gas flow diagram of an embodiment of the pure ammonia burner provided by the present invention;

[0032] Figure 3 This is a flow chart of an embodiment of the control method provided by the present invention;

[0033] Figure Number:

[0034] Combustion sleeve 100; inner sleeve 110; outer sleeve 120;

[0035] Outer chamber 200; preheating chamber 210; combustion catalytic chamber 220; ammonia catalytic combustion catalyst 221; catalytic decomposition chamber 230; ammonia catalytic decomposition catalyst 231; second air inlet 240; ammonia inlet 250; second ignition device 260; second ignition power generation unit 261; gas mixing chamber 270; first gas equalizing baffle 280; second gas equalizing baffle 290;

[0036] Inner chamber 300; combustion nozzle 310; combustion chamber 320; waiting chamber 330; first air inlet 331; third vent 332;

[0037] First ignition device 400; first ignition power generation unit 410;

[0038] The guide body 500 ; the swirl fins 510 ; and the connecting column 520 . DETAILED DESCRIPTION

[0039] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0040] In the description of the present invention, it should be understood that descriptions involving orientation, such as the orientation or positional relationship indicated by up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 cannot be understood as a limitation on the present invention.

[0041] In the description of the present invention, "a plurality" refers to more than two. The use of "first" or "second" is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of the indicated technical features, or implicitly indicating the order of the indicated technical features.

[0042] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0043] The technical solutions of the present invention will be described clearly and completely below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present invention, not all embodiments.

[0044] The following problems exist in the actual production and use of current ammonia burners: ammonia is difficult to burn directly as a single fuel. Direct combustion of ammonia will produce a large amount of nitrogen oxides, which needs to be solved by adding hydrogen. The flame temperature of ammonia combustion is high, so heat-resistant materials are required, which increases costs. The thermal energy utilization efficiency of ammonia-hydrogen combustion is low. A large amount of heat is lost through the wall in the form of radiation, and the flue gas carries less sensible heat, resulting in serious energy waste. At this stage, the realization of self-heating hydrogen production and mixed combustion with ammonia as the only fuel requires complex processes and large-module equipment, resulting in additional energy waste and space waste.

[0045] Therefore, the present invention proposes a pure ammonia burner equipped with ammonia catalytic combustion decomposition compound, which solves the problems of pure ammonia ignition difficulty, slow laminar combustion speed, difficult flame stability, and high NOx emissions.

[0046] like Figure 1 As shown, the pure ammonia burner of the present invention includes a combustion sleeve 100 .

[0047] The combustion sleeve 100 includes an inner sleeve 110 and an outer sleeve 120 sleeved on the outer periphery of the inner sleeve 110. In order to improve the smoothness of gas flow and the uniformity of heating, the inner sleeve 110 and the outer sleeve 120 of this embodiment both adopt a circular cylinder structure, wherein the outer sleeve 120 and the inner sleeve 110 are closed at both ends along the axial direction, and an annular outer chamber 200 is formed between the inner sleeve 110 and the outer sleeve 120. The inner periphery of the inner sleeve 110 is provided with an inner chamber 300, and the inner chamber 300 includes a combustion nozzle 310, a combustion chamber 320 and a chamber to be burned 330 connected in sequence along the axial direction. One end of the inner sleeve 110 of this embodiment is closed, and the combustion nozzle 310 is provided at the other end of the inner sleeve 110, and the exhaust gas is discharged through the combustion nozzle 310.

[0048] A first ignition device 400 is provided between the combustion chamber 320 and the chamber to be burned 330. The first ignition device 400 is used to ignite the mixed combustion gas entering the combustion chamber 320 from the chamber to be burned 330. The chamber to be burned 330 is connected to a first air inlet 331 for air to enter. When in use, the first air inlet 331 can be connected to an external air supply device.

[0049] The outer chamber 200 of this embodiment includes a preheating chamber 210, a combustion catalytic chamber 220 and a catalytic decomposition chamber 230, which are connected in sequence from the combustion nozzle 310 to the chamber to be burned 330, wherein the preheating chamber 210 is located at the periphery of the combustion chamber 320, and the preheating chamber 210 and the combustion chamber 320 have a wall heat exchange relationship, the combustion catalytic chamber 220 is located at the periphery of the chamber to be burned 330, and the combustion catalytic chamber 220 and the chamber to be burned 330 have a wall heat exchange relationship, the preheating chamber 210 is connected to a second air inlet 240 for air and an ammonia inlet 250 for ammonia, the second air inlet 240 can be connected to an external air supply device, the ammonia inlet 250 can be connected to an external ammonia supply device, and the catalytic decomposition chamber 230 is connected to the chamber to be burned 330.

[0050] The combustion catalytic chamber 220 of this embodiment is provided with an ammonia catalytic combustion catalyst 221 and a second ignition device 260. The ammonia catalytic combustion catalyst 221 is used to promote catalytic combustion of ammonia and generate the heat required for catalytic decomposition of ammonia to form a high-temperature mixed gas. The second ignition device 260 is used to ignite the mixed gas of ammonia and air. The second ignition device 260 starts and ignites during the startup phase or the variable operating phase of the pure ammonia burner. During operation, only a small portion of the ammonia in the mixed gas is catalytically combusted and ignited in the combustion catalytic chamber 220. As for the amount of catalytic combustion of ammonia, since ammonia requires air for combustion assistance during catalytic combustion, the amount of air introduced into the preheating chamber 210 can be controlled.

[0051] The catalytic decomposition chamber 230 of this embodiment is provided with an ammonia catalytic decomposition catalyst 231, which is used to catalytically decompose ammonia. During operation, only a small portion of the ammonia in the high-temperature mixed gas is catalytically decomposed in the catalytic decomposition chamber 230. After the high-temperature mixed gas enters the catalytic decomposition chamber 230, under the action of the ammonia catalytic decomposition catalyst 231, the heat of the high-temperature mixed gas is absorbed and utilized to decompose the small portion of the ammonia in the high-temperature mixed gas into hydrogen, which is then mixed into the high-temperature mixed gas to form a mixed gas to be burned. The mixing of hydrogen into ammonia can effectively improve the combustion characteristics of ammonia.

[0052] In order to achieve rapid mixing of ammonia and air, the preheating chamber 210 is connected to the gas mixing chamber 270. One axial end of the gas mixing chamber 270 is connected to the ammonia inlet 250, and the other end is connected to the preheating chamber 210. The second air inlet 240 is arranged on the peripheral wall of the gas mixing chamber 270 and is arranged along the tangential direction of the inner circumference of the gas mixing chamber 270. The air enters the gas mixing chamber 270 tangentially along the second air inlet 240 to generate a swirl, and then mixes with the ammonia in the gas mixing chamber 270. The mixed gas is then passed into the preheating chamber 210.

[0053] The present invention uses ammonia as the only fuel source. Ammonia is introduced into the ammonia inlet 250, and air is introduced into the first air inlet 331 and the second air inlet 240 respectively in some way. First, a small amount of air is introduced into the second air inlet 240, mixed with ammonia in the gas mixing chamber 270, and then enters the preheating chamber 210, the combustion catalytic chamber 220, the catalytic decomposition chamber 230 and the chamber to be burned 330 in succession. Secondly, most of the air is introduced into the first air inlet 331, mixed with the mixed gas to be burned in the chamber to be burned 330, and then enters the combustion chamber 320 for combustion.

[0054] In this embodiment, an annular first gas equalizing baffle 280 is provided between the preheating chamber 210 and the combustion catalytic chamber 220. The first gas equalizing baffle 280 is distributed with multiple first air holes. The mixed gas passing from the preheating chamber 210 into the combustion catalytic chamber 220 is diverted through the first gas equalizing baffle 280 so that the mixed gas can pass into the combustion catalytic chamber 220 evenly.

[0055] In addition, an annular second gas equalizing baffle 290 is provided between the combustion catalytic chamber 220 and the catalytic decomposition chamber 230. The second gas equalizing baffle 290 is distributed with a plurality of second air vents. The high-temperature mixed gas entering the catalytic decomposition chamber 230 from the combustion catalytic chamber 220 is diverted through the second gas equalizing baffle 290 so that the high-temperature mixed gas can be evenly passed into the catalytic decomposition chamber 230.

[0056] At the same time, the first air-distributing baffle 280 and the second air-distributing baffle 290 can block the ammonia catalytic combustion catalyst 221 , so that the ammonia catalytic combustion catalyst 221 cannot pass through the second vent hole and the first vent hole.

[0057] A plurality of third air holes 332 are distributed on the periphery of one end of the chamber to be burned 330 away from the combustion chamber 320. The plurality of third air holes 332 are used to connect the catalytic decomposition chamber 230 with the chamber to be burned 330, so that the ammonia catalytic decomposition catalyst 231 cannot pass through the second air holes and the third air holes 332 on the second air equalizing baffle 290, thereby blocking the ammonia catalytic decomposition catalyst 231.

[0058] Furthermore, a guide body 500 with a conical outer shape is provided between the combustion chamber 320 and the chamber to be burned 330. The outer diameter of the guide body 500 is gradually reduced from the combustion nozzle 310 to the chamber to be burned 330. The airflow can be diffused and sprayed around along the outer peripheral wall of the guide body 500 to improve the combustion efficiency.

[0059] In order to further improve the combustion effect, a plurality of swirl fins 510 are distributed circumferentially at intervals on the outer periphery of the guide body 500, and a conical funnel-shaped guide annulus is provided on the inner periphery of the combustion chamber 320 close to one end of the combustion chamber 330. The guide annulus is located on the outer periphery of the guide body 500. The combustion airflow can flow along the plurality of swirl fins 510 to form a stable swirl flow field flame. The swirl flow field can form a recirculation zone, forming local super-enthalpy combustion, which helps to stabilize the combustion flame.

[0060] In this embodiment, the guide body 500 is connected to a connecting column 520 at one end close to the chamber to be burned 330, wherein the connecting column 520 is fixedly connected to the closed end of the chamber to be burned 330, so that the guide body 500 is mounted between the combustion chamber 320 and the chamber to be burned 330.

[0061] The first ignition device 400 of this embodiment includes a plurality of first ignition power generation parts 410, and the plurality of first ignition power generation parts 410 are arranged in a radial annular pattern at intervals. The plurality of first ignition power generation parts 410 are located one by one at one end of the plurality of swirl fins 510 close to the combustion chamber 330. This embodiment uses the plurality of first ignition power generation parts 410 for ignition to improve the efficiency of ignition and make the flame spray more evenly.

[0062] The distance between the first ignition power generation part 410 and the inner wall of the inner chamber 300 is 3-5 mm.

[0063] The second ignition device 260 of this embodiment includes a second ignition power generation portion 261 suspended in the combustion catalytic chamber 220 , wherein the distance between the second ignition power generation portion 261 and the inner wall of the combustion catalytic chamber 220 is 3-5 mm.

[0064] The pure ammonia burner of the present invention has different control modes in the startup phase and the stable operation phase, which can improve the startup speed in the startup phase and maintain flame stability and reduce energy consumption in the stable operation phase.

[0065] During the startup phase of the pure ammonia burner:

[0066] like Figure 2 As shown, ammonia and a small amount of air are introduced into the gas mixing chamber 270 through the ammonia inlet 250 and the second air inlet 240 respectively for mixing to obtain a mixed gas. The mixed gas is then introduced into the preheating chamber 210 and enters the combustion catalytic chamber 220 through the preheating chamber 210. The ammonia is ignited by the second ignition power generation unit 261. Under the catalytic action of the ammonia catalytic combustion catalyst 221, part of the ammonia and air undergo a catalytic combustion reaction on the surface of the ammonia catalytic combustion catalyst 221, generating heat from the catalytic combustion to form a high-temperature mixed gas. Catalytic combustion has the advantages of reducing reaction activation energy, achieving low-temperature and high-efficiency combustion, and adapting to complex flow fields and low-concentration reactions.

[0067] The high-temperature mixed gas is passed into the catalytic decomposition chamber 230. Under the catalytic action of the ammonia catalytic decomposition catalyst 231 and by absorbing and utilizing the heat in the high-temperature mixed gas, a portion of the ammonia in the high-temperature mixed gas undergoes a catalytic decomposition reaction to produce hydrogen, which is then mixed with the high-temperature mixed gas to form a mixture to be combusted. The mixing of hydrogen with ammonia can effectively improve the combustion characteristics of ammonia. Specifically, the rate of the active free radical chain reaction is effectively increased, the laminar combustion velocity is increased, and the formation of nitrogen oxides is suppressed, achieving a double breakthrough in combustion rate and environmental protection.

[0068] The mixture to be burned and the air added from the first air inlet 331 are introduced into the combustion chamber 330 to be mixed to form a mixed combustion gas. At this time, the heat generated by the internal catalytic combustion of the combustion catalytic chamber 220 is preheated to the mixed combustion gas in the combustion chamber 330 to make up for the heat consumed by the catalytic decomposition of ammonia and to heat the newly added air. Then, multiple first ignition power generation units 410 are controlled to ignite the mixed combustion gas to form a stable vortex flow field flame. The vortex flow field can form a recirculation zone and form local super-enthalpy combustion, which is conducive to the stability of the combustion flame.

[0069] During the stable operation stage of the pure ammonia burner:

[0070] like Figure 2As shown, the supply of ammonia and air is maintained to form a stable flame in the combustion chamber 320. At this time, the second ignition device 260 and the first ignition device 400 can both be closed. Since the preheating chamber 210 and the combustion chamber 320 are in a partition heat exchange relationship, the mixed gas of ammonia and air can effectively absorb the heat from the combustion chamber 320 when flowing through the preheating chamber 210. This can protect the combustion sleeve 100 from overheating while preheating the mixed gas. The temperature of the preheated mixed gas reaches the starting requirement of catalytic combustion, preheats the ammonia catalytic combustion catalyst 221, and provides the starting energy for the catalytic combustion reaction, so that the catalytic combustion reaction is continuously, efficiently and stably carried out in the combustion catalytic chamber 220. The high-temperature mixed gas formed then passes through the catalytic decomposition chamber 230 to further form a mixed gas to be burned that is doped with hydrogen. After being mixed with the newly introduced air, it is introduced into the combustion chamber 320 to form a stable ammonia-hydrogen mixed combustion flame, thereby realizing ammonia-hydrogen mixed combustion under the condition that ammonia is the only fuel.

[0071] The present invention utilizes the self-heating hydrogen production of ammonia catalytic combustion and ammonia catalytic decomposition, and utilizes heat recycling to preheat the mixed gas in the preheating chamber 210 and the mixed combustion gas in the combustion chamber 330, thereby ensuring the activation performance of the catalytic combustion, avoiding the low-temperature combustion mixed temperature after the ammonia catalytic decomposition reaction being too low, thereby hindering the local flame propagation of ammonia and generating excessive residual ammonia, improving the thermal energy utilization efficiency of ammonia-hydrogen combustion, and protecting the wall surface of the combustion chamber 320. Therefore, no temperature-resistant material is required, the manufacturing cost is reduced, and the structure is compact.

[0072] The pure ammonia burner of the present invention can be used for reforming hydrogen production equipment, online ammonia combustion equipment and industrial kiln equipment. Among them, reforming hydrogen production equipment: under zero-carbon industrial hydrogen production conditions, ammonia is used as the only fuel. Through this pure ammonia burner, stable combustion of ammonia and heat source supply can be achieved; online ammonia combustion equipment: under zero-carbon industrial conditions, this pure ammonia burner can overcome the direct combustion of pure ammonia under various conditions, such as online hydrogen production equipment, online power generation equipment, online steam engines, etc.; industrial kiln equipment: under zero-carbon industrial conditions, this pure ammonia burner can replace the traditional nozzle of the kiln to achieve zero-carbon kiln operation and industrial production.

[0073] like Figure 3 As shown, the present invention also proposes a control method applicable to the above-mentioned pure ammonia burner, the control method comprising:

[0074] Step S100: controlling a mixed gas of ammonia and air in a preset ratio to flow into the preheating chamber 210 and then into the combustion catalytic chamber 220;

[0075] Step S200: controlling the second ignition device 260 to ignite the ammonia gas, so that part of the ammonia gas in the mixed gas undergoes a catalytic combustion reaction to generate a high-temperature mixed gas;

[0076] Step S300: Controlling the high-temperature mixed gas to flow into the catalytic decomposition chamber 230, where a portion of the ammonia in the high-temperature mixed gas undergoes a catalytic decomposition reaction to generate hydrogen, which is then mixed with the high-temperature mixed gas to form a mixture to be combusted;

[0077] Step S400: Controlling the mixture to be combusted and a preset amount of air to be introduced into the combustion chamber 330 for mixing to form a mixed combustion gas, which is preheated by the heat of the combustion catalytic chamber 220;

[0078] Step S500: controlling the first ignition device 400 to ignite the mixed combustion gas and burn it in the combustion chamber 320;

[0079] Step S600: After the pure ammonia burner is operating stably, the second ignition device 260 and the first ignition device 400 are controlled to stop operating, and the heat generated by the combustion in the combustion chamber 320 is used to preheat the mixed gas in the preheating chamber 210 to a preset catalytic combustion temperature, so that the mixed gas continues to undergo a catalytic combustion reaction in the combustion catalytic chamber 220, and the mixed combustion gas is controlled to flow into the combustion chamber 320 for continuous combustion.

[0080] During the pure ammonia burner startup phase, the above steps S100 to S500 are executed. During the pure ammonia burner stable operation phase, when executing steps S200 and S500 , the second ignition device 260 and the first ignition device 400 do not need to be started.

[0081] In step S100 , ammonia gas is introduced into the ammonia gas inlet 250 , and a small amount of air is introduced into the second air inlet 240 and mixed with the ammonia gas in the gas mixing chamber 270 .

[0082] In step S400, most of the air enters the combustion chamber 330 through the first air inlet 331 and mixes with the mixed gas to be combusted in the combustion chamber 330. The heat inside the combustion catalytic chamber 220 preheats the mixed combustion gas.

[0083] Throughout this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" indicate that a particular feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of these terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

[0084] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. A pure ammonia burner equipped with ammonia catalytic combustion decomposition compound, characterized in that: include: The combustion sleeve comprises an inner sleeve and an outer sleeve sleeved on the outer circumference of the inner sleeve, an annular outer chamber is formed between the inner sleeve and the outer sleeve, the inner circumference of the inner sleeve is provided with an inner chamber, the inner chamber comprises a combustion nozzle, a combustion chamber and a chamber to be burned which are sequentially connected along the axial direction, a first ignition device for igniting the mixed combustion gas is provided between the combustion chamber and the chamber to be burned, the chamber to be burned is connected to a first air inlet for air to enter, the outer chamber comprises a preheating chamber, a combustion catalytic chamber and a catalytic decomposition chamber which are sequentially connected in the direction from the combustion nozzle to the chamber to be burned; the preheating chamber The chamber is located at the periphery of the combustion chamber and has a partition wall heat exchange relationship with the combustion chamber; the combustion catalytic chamber is located at the periphery of the chamber to be burned and has a partition wall heat exchange relationship with the chamber to be burned, the combustion catalytic chamber is provided with an ammonia catalytic combustion catalyst for catalytic combustion of ammonia and a second ignition device for igniting a mixture of ammonia and air, the catalytic decomposition chamber is provided with an ammonia catalytic decomposition catalyst for catalytic decomposition of ammonia, the preheating chamber is connected to a second air inlet for air and an ammonia inlet for ammonia, and the catalytic decomposition chamber is connected to the chamber to be burned; A first annular air distribution baffle is provided between the preheating chamber and the combustion catalytic chamber, and a plurality of first air vents are distributed on the first air distribution baffle; A second annular air distribution baffle is provided between the combustion catalytic chamber and the catalytic decomposition chamber, and a plurality of second air vents are distributed on the second air distribution baffle; A plurality of third vent holes are distributed on the periphery of one end of the chamber to be burned away from the combustion chamber, and the plurality of third vent holes are used to connect the catalytic decomposition chamber with the chamber to be burned; The first air inlet is connected to the inner peripheral wall of the chamber to be burned, and the first air inlet is arranged along the tangential direction of the inner periphery of the chamber to be burned.

2. The pure ammonia burner according to claim 1, characterized in that: A guide body with a conical outer shape is provided between the combustion chamber and the chamber to be burned. The outer diameter of the guide body is gradually reduced in the direction from the combustion nozzle to the chamber to be burned.

3. The pure ammonia burner according to claim 2, characterized in that: The outer periphery of the guide body is provided with a plurality of swirl fins spaced circumferentially. The inner periphery of the combustion chamber close to one end of the chamber to be burned is provided with a conical funnel-shaped guide annular surface, and the guide annular surface is located on the outer periphery of the guide body.

4. The pure ammonia burner according to claim 3, characterized in that: The first ignition device includes a plurality of first ignition power generation parts, which are radially arranged in an annular pattern and located at one end of the plurality of swirl fins close to the combustion chamber, and the distance between the first ignition power generation part and the inner wall of the inner chamber is 3 to 5 mm; The second ignition device includes a second ignition power generation portion suspended in the combustion catalytic chamber, and the distance between the second ignition power generation portion and the inner wall of the combustion catalytic chamber is 3-5 mm.

5. The pure ammonia burner according to claim 1, characterized in that: The preheating chamber is connected to a gas mixing chamber, one axial end of the gas mixing chamber is connected to the ammonia inlet, and the other end is connected to the preheating chamber, and the second air inlet is provided on the peripheral wall of the gas mixing chamber and is arranged along the tangential direction of the inner circumference of the gas mixing chamber.

6. A control method, characterized in that: Applicable to the pure ammonia burner according to any one of claims 1 to 5, the control method comprises: Controlling a mixed gas of ammonia and air in a preset ratio to flow into the preheating chamber and then into the combustion catalytic chamber; controlling the second ignition device to ignite the ammonia, so that part of the ammonia in the mixed gas undergoes a catalytic combustion reaction to generate a high-temperature mixed gas; Controlling the high-temperature mixed gas to flow into the catalytic decomposition chamber, so that part of the ammonia in the high-temperature mixed gas undergoes a catalytic decomposition reaction to generate hydrogen, which is then mixed with the high-temperature mixed gas to form a mixed gas to be combusted; Controlling the mixed gas to be combusted and a preset amount of air to be introduced into the combusted chamber for mixing to form a mixed combustion gas, wherein the mixed combustion gas is preheated by the heat of the combustion catalytic chamber; controlling the first ignition device to ignite the mixed combustion gas and burn it in the combustion chamber; After the pure ammonia burner operates stably, the second ignition device and the first ignition device are controlled to stop operating, and the mixed gas in the preheating chamber is preheated to a preset catalytic combustion temperature by the heat generated by the combustion in the combustion chamber, so that the mixed gas continues to undergo a catalytic combustion reaction in the combustion catalytic chamber, and the mixed combustion gas is controlled to flow into the combustion chamber for continuous combustion.

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