Ammonia-doped coal ignition structure, ammonia-doped coal burner and ammonia-doped coal ignition method

Abstract

The invention discloses an ammonia-doped coal ignition structure, an ammonia-doped coal burner and an ammonia-doped coal ignition method. The ammonia-doped coal ignition structure comprises an ignition channel, a first-stage fuel channel, a first-stage combustion-supporting channel, a second-stage fuel channel, a second-stage combustion-supporting channel and a main combustion chamber. Fuel in the ignition channel can be ignited through the ignition electrode, primary combustion of ammonia fuel is ignited through ignition flames from the ignition nozzle, then multi-stage ignition combustion of coal doped with ammonia is achieved, ignition is easier, control is easy, the flames are more stable, and meanwhile emission of nitric oxide is greatly reduced. The coal-doped ammonia ignition structure is adopted in the coal-doped ammonia burner, and the coal-doped ammonia ignition method is suitable for the coal-doped ammonia ignition structure and the coal-doped ammonia burner.

Description

Technical Field

[0001] The invention relates to the technical field of coal powder mixed with ammonia combustion thermal equipment, in particular to a coal mixed with ammonia ignition structure. Background Art

[0002] Coal, as a solid fuel, is less likely to ignite and burn than liquid and gaseous fuels. When the load and temperature of a boiler or industrial furnace are low, liquid or gaseous fuels are often needed to help ignite and stabilize the flame. For example, when igniting a thermal power boiler or when there is a peak load requirement, diesel or plasma igniters are used for ignition or combustion support. Ammonia is a carbon-free fuel that only emits water and nitrogen after complete combustion. It also has the advantages of high calorific value and easy storage.

[0003] In the prior art, coal-ammonia mixed combustion burners are of great significance in the field of thermal engineering. Since ammonia is difficult to ignite, and the difficulty of ignition is relatively higher than that of coal powder, the existing coal-ammonia burners generally ignite coal powder first and then use it as the ignition source for ammonia combustion. In the swirl burner disclosed in the invention patent application CN115585449A, an ammonia premixer is provided to allow ammonia, coal powder and air to be fully mixed in the primary air channel and then sent into the furnace, thereby reducing the difficulty of ammonia ignition. In its technical solution, coal powder is carried into the precombustion chamber by the primary air, and is preheated and decomposed at 800-1200°C to release volatile matter.

[0004] However, the preheating and decomposition conditions of pulverized coal are difficult to meet at the initial stage of ignition and under load fluctuations. Since pulverized coal ignition and burnout are also difficult, igniting pulverized coal as an ignition source for ammonia combustion requires a stable furnace temperature or consumes additional high-quality energy, such as diesel or natural gas, which is not conducive to the flexibility of current coal-fired boiler units and is not economical. In addition, pulverized coal flame, as a prerequisite for ammonia ignition and combustion, has great uncertainty, which will have an adverse effect on the stable combustion of ammonia and the control of nitrogen oxides. Summary of the invention

[0005] The purpose of the present invention is to provide a coal-ammonia ignition structure to solve one or more technical problems existing in the prior art and at least provide a beneficial choice or create conditions.

[0006] The technical solutions adopted to solve the above technical problems are:

[0007] A coal-ammonia ignition structure comprises: an ignition channel, a primary fuel channel, a primary combustion-supporting channel, a secondary fuel channel, a secondary combustion-supporting channel and a main combustion chamber;

[0008] The ignition channel extends forward and backward, and an ignition electrode and an ignition nozzle are provided at the front end of the ignition channel; the primary fuel channel has a primary fuel nozzle arranged beside the ignition nozzle; the primary combustion-supporting channel has a primary combustion nozzle connected to the ignition nozzle and the primary fuel nozzle; the secondary fuel channel has a secondary fuel nozzle arranged beside the primary combustion nozzle; the secondary combustion-supporting channel has a secondary combustion-supporting nozzle arranged beside the secondary fuel nozzle; the main combustion chamber is connected to the primary combustion nozzle, the secondary fuel nozzle and the secondary combustion-supporting nozzle.

[0009] The coal-ammonia ignition structure provided by the present invention has at least the following beneficial effects: primary combustion of ammonia fuel can be achieved through the primary fuel channel and the primary combustion-supporting channel, and secondary combustion of coal powder can be achieved through the secondary fuel channel and the secondary combustion-supporting channel. The ignition electrode can ignite the fuel in the ignition channel, and ignite the primary combustion of ammonia fuel from the ignition nozzle with the ignition flame, thereby achieving multi-stage ignition combustion of coal-ammonia, making ignition easier, simpler to control, more stable flames, and significantly reducing nitrogen oxide emissions.

[0010] The present invention also provides a coal-ammonia burner adopting the above-mentioned coal-ammonia ignition structure, comprising: an ignition gun, a primary combustion device and a secondary combustion device;

[0011] The ignition channel is arranged in the ignition gun;

[0012] The primary combustion device comprises a primary inner sleeve and a primary outer sleeve, and the primary inner sleeve and the primary outer sleeve are sequentially sleeved on the ignition gun from the inside to the outside in radial direction to form the primary fuel channel and the primary combustion-supporting channel;

[0013] The secondary combustion device comprises a secondary inner sleeve and a secondary outer sleeve, and the secondary inner sleeve and the secondary outer sleeve are sequentially sleeved on the primary combustion device from the inside to the outside in radial direction to form the secondary fuel channel and the secondary combustion-supporting channel.

[0014] The coal-ammonia burner provided by the present invention has at least the following beneficial effects: the ignition gun can realize ignition processing, the primary combustion device and the secondary combustion device can respectively realize the combustion of ammonia fuel and pulverized coal fuel, thereby realizing the staged combustion of coal-ammonia, and the ammonia combustion flame ignited by the ignition gun can realize rapid ignition of pulverized coal fuel, has a very strong stable combustion ability and the generation of nitrogen oxides is very low. The primary combustion-supporting air and the secondary combustion-supporting air respectively introduced into the primary outer sleeve and the secondary outer sleeve can be mixed and burned with the two fuels respectively, thereby realizing the oxygen content control of staged combustion. The coal-ammonia burner of the present invention integrates the electronic ignition gun, the main ammonia burner, the pulverized coal burner and the multi-stage air supply device in one burner, realizing direct ignition of ammonia fuel and pulverized coal fuel, low-load stable combustion and ultra-low nitrogen combustion.

[0015] As a further improvement of the above technical solution, an ignition mixing chamber connected to the ignition channel is provided at the end of the ignition gun, and the ignition mixing chamber has an ignition fuel inlet and an ignition air inlet.

[0016] As a further improvement of the above technical solution, an electrode rod extending forward and backward is provided in the ignition channel, and the ignition electrode is provided at the front end of the electrode rod.

[0017] As a further improvement of the above technical solution, the front end of the first-stage outer sleeve has a first-stage combustion chamber, the first-stage combustion chamber is arranged on the front side of the ignition gun, the first-stage combustion chamber is connected to the ignition nozzle and the first-stage fuel nozzle and has the first-stage combustion nozzle.

[0018] As a further improvement of the above technical solution, the front part of the primary combustion chamber is in a conical shape which is narrow at the front and wide at the rear, and the primary combustion nozzle is arranged at the front end of the primary combustion chamber and is coaxially arranged with the ignition gun.

[0019] As a further improvement of the above technical solution, a cyclone is provided inside the first-stage outer sleeve, and the cyclone is sleeved on the outside of the first-stage inner sleeve.

[0020] As a further improvement of the above technical solution, the plurality of first-stage fuel nozzles are arranged on the outer periphery of the front end of the first-stage inner sleeve and are connected to the front space of the swirler.

[0021] As a further improvement of the above technical solution, the front end of the first-stage inner sleeve is flush with the front end of the ignition gun, and the front end of the second-stage inner sleeve is flush with the front end of the second-stage outer sleeve.

[0022] The present invention also provides a coal-ammonia ignition method applicable to the above-mentioned coal-ammonia ignition structure and the above-mentioned coal-ammonia burner:

[0023] First, a small amount of fuel and combustion-supporting gas is introduced into the ignition channel and ignited at the ignition nozzle through the ignition electrode;

[0024] Then, ammonia fuel is continuously introduced into the primary fuel channel, combustion-supporting gas is continuously introduced into the primary combustion-supporting channel, and the flame is ignited by the flame of the ignition nozzle, so that the flame is continuously ejected from the primary combustion nozzle;

[0025] Then, pulverized coal fuel is continuously introduced into the secondary fuel channel, combustion-supporting gas is continuously introduced into the secondary combustion-supporting channel, and the flame of the primary combustion nozzle is ignited to achieve multi-stage ignition of coal-ammonia combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments;

[0027] Figure 1 This is a side cross-sectional view of an embodiment of the coal-ammonia ignition structure provided by the present invention;

[0028] Figure 2 This is a side cross-sectional view of an embodiment of the coal-ammonia blending burner provided by the present invention;

[0029] Figure 3 yes Figure 2 A partial enlarged view of area A.

[0030] In the figure: 100-ignition gun, 110-ignition channel, 111-ignition nozzle, 120-electrode rod, 121-ignition electrode, 122-terminal, 130-ignition mixing chamber, 131-ignition fuel inlet, 132-ignition air inlet, 200-first-stage combustion device, 210-first-stage inner sleeve, 211-first-stage fuel channel, 212-first-stage fuel nozzle, 220-first-stage outer sleeve, 221-first-stage combustion-supporting channel, 222-first-stage combustion nozzle, 223-swirler, 224-first-stage combustion chamber, 300-secondary combustion device, 310-secondary inner sleeve, 311-secondary fuel channel, 312-secondary fuel nozzle, 320-secondary outer sleeve, 321-secondary combustion-supporting channel, 322-secondary combustion-supporting nozzle, 400-main combustion chamber. DETAILED DESCRIPTION

[0031] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0032] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 understood as a limitation on the present invention.

[0033] In the description of the present invention, if there are words such as "several", it means one or more, "more" means more than two, greater than, less than, exceed, etc. are understood as not including the number, and above, below, within, etc. are understood as including the number.

[0034] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. 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.

[0035] Reference Figures 1 to 3 The coal-ammonia ignition structure of the present invention is implemented as follows:

[0036] A coal-ammonia ignition structure includes: an ignition channel 110, a primary fuel channel 211, a primary combustion-supporting channel 221, a secondary fuel channel 311, a secondary combustion-supporting channel 321 and a main combustion chamber 400.

[0037] The ignition channel 110 extends forward and backward, and an ignition electrode 121 and an ignition nozzle 111 are provided at the front end of the ignition channel 110. The primary fuel channel 211 has a primary fuel nozzle 212 disposed beside the ignition nozzle 111. The primary combustion-supporting channel 221 has a primary combustion nozzle 222 connected to the ignition nozzle 111 and the primary fuel nozzle 212. The secondary fuel channel 311 has a secondary fuel nozzle 312 disposed beside the primary combustion nozzle 222. The secondary combustion-supporting channel 321 has a secondary combustion-supporting nozzle 322 disposed beside the secondary fuel nozzle 312. The main combustion chamber 400 is connected to the primary combustion nozzle 222, the secondary fuel nozzle 312 and the secondary combustion-supporting nozzle 322.

[0038] In actual use, the primary combustion of ammonia fuel can be achieved through the primary fuel channel 211 and the primary combustion-supporting channel 221, and the secondary combustion of coal powder can be achieved through the secondary fuel channel 311 and the secondary combustion-supporting channel 321. The ignition electrode 121 can ignite the fuel in the ignition channel 110, and ignite the primary combustion of ammonia fuel from the ignition nozzle 111, thereby achieving multi-stage ignition combustion of coal mixed with ammonia, making ignition easier, simpler to control, more stable flames, and significantly reducing nitrogen oxide emissions.

[0039] The coal-ammonia burner of the present invention adopts the above-mentioned coal-ammonia ignition structure. The coal-ammonia burner of the present invention comprises: an ignition gun 100, a primary combustion device 200 and a secondary combustion device 300.

[0040] The ignition gun 100 extends in the front-to-back direction, and the ignition channel 110 is arranged in the ignition gun 100. The primary combustion device 200 includes: a primary inner sleeve 210 and a primary outer sleeve 220. The primary inner sleeve 210 and the primary outer sleeve 220 are sequentially sleeved on the outer side of the ignition gun 100 from the inside to the outside in the radial direction to form the primary fuel channel 211 and the primary combustion-supporting channel 221.

[0041] The secondary combustion device 300 comprises: a secondary inner sleeve 310 and a secondary outer sleeve 320. The secondary inner sleeve 310 and the secondary outer sleeve 320 are sequentially sleeved on the outer side of the primary combustion device 200 from inside to outside in radial direction to form the secondary fuel channel 311 and the secondary combustion-supporting channel 321.

[0042] See attached Figure 2 The ignition gun 100 is cylindrical. The primary inner sleeve 210, the primary outer sleeve 220, the secondary inner sleeve 310 and the secondary outer sleeve 320 are all cylindrically shaped and extend forward and backward. The primary inner sleeve 210, the primary outer sleeve 220, the secondary inner sleeve 310 and the secondary outer sleeve 320 are all coaxially arranged and are sequentially sleeved on the outer side of the ignition gun 100 in layers.

[0043] The ends of the first-stage inner sleeve 210, the first-stage outer sleeve 220, the second-stage inner sleeve 310 and the second-stage outer sleeve 320 are arranged in sequence from back to front so that the first-stage inner sleeve 210, the first-stage outer sleeve 220, the second-stage inner sleeve 310 and the second-stage outer sleeve 320 can all be exposed, thereby facilitating the introduction of fuel and corresponding combustion-supporting air.

[0044] An annular columnar primary fuel passage 211 is formed between the inner side wall of the primary inner sleeve 210 and the ignition gun 100. An annular columnar primary combustion-supporting passage 221 is formed between the inner side wall of the primary outer sleeve 220 and the primary inner sleeve 210. An annular columnar secondary fuel passage 311 is formed between the inner side wall of the secondary inner sleeve 310 and the primary outer sleeve 220. An annular columnar secondary combustion-supporting passage 321 is formed between the inner side wall of the secondary outer sleeve 320 and the secondary inner sleeve 310.

[0045] In actual use, the ignition gun 100 can realize ignition processing, and the primary combustion device 200 and the secondary combustion device 300 can respectively realize the combustion of ammonia fuel and coal powder fuel, thereby realizing the staged combustion of coal mixed with ammonia. The primary combustion-supporting air and the secondary combustion-supporting air respectively introduced into the primary outer sleeve 220 and the secondary outer sleeve 320 can be mixed and burned with the two fuels respectively, thereby realizing the oxygen content control of staged combustion. Specifically, the combustion of ammonia fuel is oxygen-deficient combustion, which can greatly reduce the amount of nitrogen oxides generated, and the hydrogen molecules, residual ammonia and carbon monoxide formed by incomplete combustion in the early combustion process will be brought into the main combustion chamber 400 by the combustion-supporting air of the secondary outer sleeve 320 and mixed with it, and finally completely burned at a suitable temperature. It relies on high-temperature ammonia flame to achieve rapid ignition of pulverized coal fuel, while achieving coordinated stable combustion of pulverized coal and ammonia and reducing nitrogen oxide emissions. It has very strong stable combustion ability and very low nitrogen oxide generation. It is used in coal-fired boilers or kilns to increase load regulation flexibility, reduce carbon dioxide emissions, and effectively reduce operating costs and equipment costs invested in other technical means to achieve the same ammonia fuel stable combustion, low carbon and low nitrogen goals.

[0046] The end of the ignition gun 100 is provided with an ignition mixing chamber 130 connected to the ignition channel 110, and the ignition mixing chamber 130 has an ignition fuel inlet 131 and an ignition air inlet 132. Before ignition, the ignition fuel and the combustion-supporting air are introduced into the ignition mixing chamber 130 through the ignition fuel inlet 131 and the ignition air inlet 132 respectively.

[0047] In this embodiment, an electrode rod 120 extending forward and backward is provided in the ignition channel 110, and the ignition electrode 121 is provided at the front end of the electrode rod 120. The end of the ignition electrode 121 is provided with a terminal 122 passing through and exposed at the rear end of the ignition gun 100. The electrode rod 120 is electrically connected through the terminal 122, so that the ignition timing can be flexibly controlled. The ignition gun 100 uses electronic ignition to directly ignite a small amount of ammonia, and then ignites the mainstream ammonia, relying on the high-temperature oxygen-deficient ammonia flame rich in active substances to ignite the pulverized coal to achieve the coordinated stable combustion of pulverized coal and ammonia and reduce nitrogen oxide emissions.

[0048] In this embodiment, the front end of the primary outer sleeve 220 has a primary combustion chamber 224, which is arranged at the front side of the ignition gun 100, and the primary combustion chamber 224 is connected to the ignition nozzle 111 and the primary fuel nozzle 212, and has the primary combustion nozzle 222. The front end of the primary inner sleeve 210 is flush with the front end of the ignition gun 100, and the front end of the secondary inner sleeve 310 is flush with the front end of the secondary outer sleeve 320.

[0049] After the mixed gas at the outlet of the ignition gun 100 is ignited by electronic ignition, an ignition flame can be formed in the middle of the first-stage combustion chamber 224, thereby igniting the ammonia fuel and combustion-supporting air transported along the first-stage inner sleeve 210 and the first-stage outer sleeve 220, and continuously burning at the first-stage combustion nozzle 222. The stable high-energy ammonia flame provides sufficient energy and active components to the coal powder, thereby achieving ignition and stable combustion of the coal powder.

[0050] The front part of the primary combustion chamber 224 is in a conical shape with a narrow front and a wide rear, and the primary combustion nozzle 222 is arranged at the front end of the primary combustion chamber 224 and is coaxially arranged with the ignition gun 100. The primary combustion chamber 224 has a large enough space and a constricted outlet, which can increase the residence time of the mixed combustible gas of ammonia and combustion-supporting air in the primary combustion chamber 224, and the ignition and combustion of ammonia is not disturbed by the coal powder airflow, and the burning high-temperature flue gas can enter the central area of ​​the coal powder main flame in the main combustion chamber 400.

[0051] In this embodiment, a swirler 223 is provided inside the primary outer sleeve 220. The swirler 223 is sleeved outside the primary inner sleeve 210. When the combustion-supporting air is passed from the primary combustion-supporting channel 221 to the primary combustion chamber 224, a swirl can be formed under the action of the swirler 223, which accelerates the mixing of the ammonia fuel and the combustion-supporting air, and forms an internal recirculation zone in the primary combustion chamber 224 to maintain the relative independence and stability of the combustion of the ammonia fuel. On the one hand, it plays an ignition role in heating the pulverized coal fuel, and on the other hand, it realizes the flue gas recirculation effect, increases the combustion temperature of the ammonia fuel, and inhibits the generation of nitrogen oxides caused by the combustion of the ammonia fuel.

[0052] Furthermore, in this embodiment, there are a plurality of the primary fuel nozzles 212 . The plurality of primary fuel nozzles 212 are disposed at the front end periphery of the primary inner sleeve 210 and are connected to the front side space of the swirler 223 .

[0053] When ammonia is introduced into the primary combustion chamber 224 from the primary fuel channel 211, it can be radially ejected at the front end of the primary inner sleeve 210, and the cross jet of the combustion-supporting air swirl and the radial ejection of ammonia can accelerate the mixing of the ammonia fuel and the combustion-supporting air. Under the action of the combustion-supporting air swirl and the ammonia radial flow, a central reflux low-speed zone is formed in the primary combustion chamber 224, and after the mixed gas at the outlet of the ignition gun 100 is ignited by electronic ignition, a stable central flame is formed in the central reflux zone, thereby providing sufficient energy for the combustible mixed gas in the primary combustion chamber 224 to smoothly ignite the ammonia and keep the ammonia flame stable.

[0054] The present invention also provides a coal-ammonia ignition method applicable to the above-mentioned coal-ammonia ignition structure and coal-ammonia burner:

[0055] First, a small amount of fuel and combustion-supporting gas is introduced into the ignition channel 110 and ignited at the ignition nozzle 111 through the ignition electrode 121;

[0056] Then, ammonia fuel is continuously introduced into the primary fuel channel 211, and combustion-supporting gas is continuously introduced into the primary combustion-supporting channel 221, and the flame is ignited by the flame of the ignition nozzle 111, so that the flame is continuously ejected from the primary combustion nozzle 222;

[0057] Next, pulverized coal fuel is continuously introduced into the secondary fuel channel 311, and combustion-supporting gas is continuously introduced into the secondary combustion-supporting channel 321, and the flame is ignited through the primary combustion nozzle 222, thereby realizing multi-stage ignition of coal-ammonia combustion.

[0058] In this embodiment, a small amount of ammonia can be used as the ignition fuel, and an ignition flame is provided by igniting and burning the flammable gas formed by the mixture of ammonia and air, thereby igniting the primary combustion of the ammonia fuel. The stable high-energy ammonia flame provides sufficient energy and active components to the coal powder and the combustion-supporting air, thereby helping to achieve the ignition and stable combustion of the coal powder.

[0059] Furthermore, under this staged combustion mode, a large amount of ammonia burns at high temperature under an air coefficient of 0.8 to 1, which can increase the probability of ammonia molecules breaking down into nitrogen molecules and hydrogen molecules, greatly reducing the possibility of generating nitrogen oxides.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0061] Although the embodiments of the present invention have been shown and described, a person skilled in the art may make various changes, modifications, substitutions and variations to these embodiments without departing from the principles and spirit of the present invention. These changes, modifications, equivalent variations or substitutions are all included in the scope defined by the claims of this application. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A coal-ammonia ignition structure, characterized in that: include: An ignition channel extends forward and backward and is provided with an ignition electrode and an ignition nozzle at the front end; A primary fuel channel having a primary fuel nozzle disposed beside the ignition nozzle; a primary combustion-supporting channel having a primary combustion nozzle connected to the ignition nozzle and the primary fuel nozzle; A secondary fuel passage having a secondary fuel nozzle disposed beside the primary combustion nozzle; A secondary combustion-supporting channel having a secondary combustion-supporting nozzle disposed beside the secondary fuel nozzle; The main combustion chamber is connected with the primary combustion nozzle, the secondary fuel nozzle and the secondary combustion-supporting nozzle.

2. A coal-ammonia burner, characterized in that: The coal-ammonia ignition structure according to claim 1 comprises: An ignition gun, wherein the ignition passage is arranged in the ignition gun; The primary combustion device comprises a primary inner sleeve and a primary outer sleeve, wherein the primary inner sleeve and the primary outer sleeve are sequentially sleeved on the ignition gun from the inside to the outside in radial direction to form the primary fuel channel and the primary combustion-supporting channel; The secondary combustion device comprises a secondary inner sleeve and a secondary outer sleeve, wherein the secondary inner sleeve and the secondary outer sleeve are sequentially sleeved on the primary combustion device from inside to outside in radial direction to form the secondary fuel channel and the secondary combustion-supporting channel.

3. The coal-ammonia burner according to claim 2 is characterized in that: An ignition mixing chamber communicated with the ignition passage is provided at the end of the ignition gun, and the ignition mixing chamber has an ignition fuel inlet and an ignition air inlet.

4. The coal-ammonia burner according to claim 3 is characterized in that: An electrode rod extending forward and backward is arranged in the ignition channel, and the ignition electrode is arranged at the front end of the electrode rod.

5. The coal-ammonia burner according to claim 2 is characterized in that: The front end of the primary outer sleeve is provided with a primary combustion chamber, the primary combustion chamber is arranged at the front side of the ignition gun, the primary combustion chamber is connected with the ignition nozzle and the primary fuel nozzle, and has the primary combustion nozzle.

6. The coal-ammonia burner according to claim 5, characterized in that: The front portion of the primary combustion chamber is in a conical shape that is narrow at the front and wide at the rear. The primary combustion nozzle is arranged at the front end of the primary combustion chamber and is coaxially arranged with the ignition gun.

7. The coal-ammonia burner according to claim 5 is characterized in that: A cyclone is arranged inside the first-stage outer sleeve, and the cyclone is sleeved on the outside of the first-stage inner sleeve.

8. The coal-ammonia burner according to claim 7 is characterized in that: The plurality of first-stage fuel nozzles are arranged on the outer periphery of the front end of the first-stage inner sleeve and are connected to the front space of the swirler.

9. The coal-ammonia burner according to claim 5, characterized in that: The front end of the primary inner sleeve is flush with the front end of the ignition gun, and the front end of the secondary inner sleeve is flush with the front end of the secondary outer sleeve.

10. A method for igniting coal with ammonia, characterized in that: Applicable to the coal-ammonia ignition structure as claimed in claim 1 and the coal-ammonia burner as claimed in any one of claims 2 to 9; First, a small amount of fuel and combustion-supporting gas is introduced into the ignition channel and ignited at the ignition nozzle through the ignition electrode; Then, ammonia fuel is continuously introduced into the primary fuel channel, combustion-supporting gas is continuously introduced into the primary combustion-supporting channel, and the flame of the ignition nozzle is ignited, so that the flame is continuously ejected from the primary combustion nozzle; Then, pulverized coal fuel is continuously introduced into the secondary fuel channel, combustion-supporting gas is continuously introduced into the secondary combustion-supporting channel, and the flame of the primary combustion nozzle is ignited to achieve multi-stage ignition of coal-ammonia combustion.

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