A pulverized coal burner with stable ignition and ignition method

Abstract

The present invention provides a pulverized coal burner for ignition and stability and an ignition method, belonging to the technical field of thermal power generation, the pulverized coal burner for ignition and stability comprises an ignition gun, an inlet section, a pre-combustion chamber and a flame transmission tube; a combustion zone and a secondary air channel for sending secondary air into the combustion zone are arranged in the pre-combustion chamber; the front end of the inlet section extends into the pre-combustion chamber and is aligned with the combustion zone, and the rear end is located outside the pre-combustion chamber as a primary air inlet; the ignition gun is installed at the center of the front end of the inlet section, and the front end extends into the pre-combustion chamber and is aligned with the combustion zone; the rear end of the flame transmission tube is connected to the front end of the pre-combustion chamber, and is used to send the pulverized coal flame burning in the combustion zone to a preset position in the main burner, and meet with the pulverized coal airflow of the main burner. The present invention uses pulverized coal as fuel, which is consistent with the existing fuel of the power plant, can completely replace the oil burner and the plasma ignition device, can realize the ultra-low load stable combustion and flexibility adjustment function of the power plant boiler, and the thermal power plant does not need to use oil as fuel.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal power generation, and specifically discloses a pulverized coal burner with stable ignition and an ignition method. Background Art

[0002] At present, the burners or auxiliary systems used for ignition and stable combustion in the thermal power generation industry generally use fuel oil and pulverized coal as fuel. For example, CN201822194419.1 discloses an oil burner device and a boiler, and the oil burner device has: a burner body having a first flow path and a second flow path for supplying liquid fuel, and a third flow path for supplying atomized fluid formed inside; and a burner nozzle, which is connected to the burner body, and the burner nozzle includes at least one first mixing nozzle for mixing and spraying the liquid fuel supplied by the first flow path with the atomized fluid supplied by the third flow path; and at least one second mixing nozzle for mixing and spraying the liquid fuel supplied by the second flow path with the atomized fluid supplied by the third flow path, and the at least one second mixing nozzle has a spray hole smaller than the spray hole of the first mixing nozzle. The above patent can expand the adjustment range of the fuel injection amount.

[0003] However, the use of oil burners leads to incomplete combustion during the startup phase, the flue gas treatment and environmental protection equipment cannot be put into use, and there is a problem of excessive exhaust emissions; during the ignition and stable combustion stages, the fuel consumption is huge, which is not in line with national industrial policies, and the fuel price is expensive and the operating costs are high.

[0004] The plasma ignition and stable combustion technology of pulverized coal boiler can directly ignite pulverized coal instead of fuel oil, and it is safe, economical and reliable to use. At present, plasma ignition and stable combustion technology has been successfully applied to hundreds of boilers of various units, with unit capacity levels ranging from 50MW to 1000MW; the coal quality used includes lean coal, inferior bituminous coal, bituminous coal and lignite; the combustion mode includes tangential combustion of direct current burner and wall combustion of swirl burner; the types of pulverizing system include direct blowing pulverizing system using medium speed mill, fan mill and double inlet and double outlet steel ball mill, and medium storage pulverizing system using single inlet and single outlet steel ball mill.

[0005] However, there are certain restrictions on the types of coal used for ignition when plasma technology is used, especially for low-volatile coal, where the ignition ability is not ideal; when used for stable combustion, it requires continuous consumption of electricity during operation, which has poor economy; in addition, the cathode material of the plasma ignition device has a short service life and needs to be replaced frequently, which seriously affects operation. Summary of the invention

[0006] The present invention provides a pulverized coal burner with ignition and stable combustion, which uses pulverized coal as fuel, which is consistent with the existing fuel of power plants and can completely replace oil burners and plasma ignition devices. It can realize ultra-low load stable combustion and flexibility adjustment functions of power plant boilers, and thermal power plants no longer need to use oil as fuel. Based on the above-mentioned pulverized coal burner with ignition and stable combustion, an ignition method is also provided.

[0007] The present invention provides a pulverized coal burner for ignition and stable combustion, comprising an ignition gun, an inlet section, a pre-combustion chamber and a flame transmission tube; the pre-combustion chamber is provided with a combustion zone and a secondary air channel for delivering secondary air into the combustion zone; the front end of the inlet section extends into the pre-combustion chamber and is aimed at the combustion zone, and the rear end is located outside the pre-combustion chamber as a primary air inlet; the ignition gun is installed at the center of the front end of the inlet section, and the front end extends into the pre-combustion chamber and is aimed at the combustion zone; the rear end of the flame transmission tube is connected to the front end of the pre-combustion chamber, and is used for delivering the pulverized coal flame burning in the combustion zone to a preset position in a main burner to meet with the pulverized coal airflow of the main burner.

[0008] Furthermore, the inlet section is a right-angle elbow, the front end is the end of the horizontal part, the rear end is the end of the vertical part, and the horizontal part and the vertical part are connected by an elbow; a central sleeve is arranged at the center of the inner edge of the horizontal part for installing the ignition gun; a guide vane is arranged in the elbow, the guide vane is made of ceramic material, is bent in the same direction as the elbow, and is located below the central sleeve.

[0009] Furthermore, multiple groups of spoiler assemblies are arranged axially in the horizontal part of the inlet section, each group of spoiler assemblies includes multiple spoiler blocks evenly distributed along the circumferential direction of the inner wall of the horizontal part, and two adjacent groups of spoiler assemblies are staggered; the spoiler blocks are wedge-shaped or hemispherical and are made of ceramic material.

[0010] Furthermore, a diverter cone is provided at the front end of the central sleeve, the diameter of which gradually increases from back to front, and the diverter cone is made of ceramic or silicon carbide; a fixing ring is vertically provided on the large end face of the diverter cone, and the fixing ring is fixed on the inner wall of the inlet section.

[0011] Furthermore, the pre-combustion chamber includes an outer plate, an inner plate, an annular baffle I, an annular baffle II, an annular baffle III and a secondary air inlet; the front end of the inner plate and the front end of the outer plate are connected by annular baffle I, the rear end of the inner plate is located inside the outer plate, the rear end of the inner plate and the inner wall of the outer plate are connected by annular baffle III, the outer plate, the inner plate, annular baffle I and annular baffle III enclose an annular cavity, the annular baffle III and the rear end of the outer plate are an air collecting cavity, and the inner plate is provided with a combustion zone; annular baffle II is located between annular baffle I and annular baffle III, dividing the annular cavity from front to back into an air separation cavity and a preheating interlayer; the secondary air inlet is arranged outside the outer plate corresponding to the air separation cavity, and is connected to the air separation cavity; an air separation hole is provided on the annular baffle II, and an air collecting hole is provided on the annular baffle III; the secondary air inlet, the air separation cavity, the air separation hole, the preheating interlayer, the air collecting hole, and the air collecting cavity constitute a secondary air channel.

[0012] Furthermore, a refractory material layer is provided on the inner wall of the inner plate, a sealing groove is provided at the rear end of the refractory material layer, the rear end of the refractory material layer is connected to the front end of the pre-combustion chamber, and a sealing filler is filled in the sealing groove.

[0013] Furthermore, the space within the refractory material layer is, from back to front, an inlet conical section, a straight cylinder section and an outlet conical section; the diameters of the inlet conical section and the outlet conical section gradually decrease from back to front; the front end of the inlet section is located inside the straight cylinder section, and secondary air swirl blades are installed on the outside; the straight cylinder section and the outlet conical section after the secondary air swirl blades constitute the combustion zone.

[0014] Furthermore, the ignition gun uses oil or gas as fuel, and includes a flame detector, an ignition electrode, an ignition fuel inlet and an ignition gun barrel; the flame detector and the ignition electrode are installed at the rear end of the ignition gun barrel, and the ignition fuel inlet is set on the side wall of the ignition gun barrel.

[0015] Furthermore, a mounting flange I is provided on the outer sleeve of the ignition gun barrel, the ignition gun barrel is inserted into the center sleeve, and the mounting flange I is connected to the connecting flange I at the rear end of the center sleeve; a mounting flange II is provided on the outer sleeve of the horizontal part of the inlet section, and the mounting flange II is connected to the connecting flange II at the rear end of the outer plate; the rear end of the flame transfer tube and the front end of the pre-combustion chamber are fixed to the back plate of the main burner through the mounting flange III.

[0016] The present invention also provides an ignition method, which is performed using the above-mentioned ignition and stable combustion pulverized coal burner, comprising the following steps:

[0017] S1, before starting, ignite the fuel or gas sprayed from the ignition gun, preheat the pre-combustion chamber to 750℃~800℃, then introduce primary air and coal powder. After the primary air and coal powder are ignited, turn off the fuel or gas of the ignition gun;

[0018] S2, the secondary air is introduced. The secondary air enters from the secondary air inlet, is evenly distributed in the air distribution cavity, enters the preheating interlayer through the air distribution holes, and evenly enters the air collection cavity 3.8 through the air collection holes 3.7. After passing through the secondary air swirl blades, a swirl is formed, and the secondary air and the pulverized coal are evenly mixed in the combustion zone, promoting the full combustion of the primary air and the pulverized coal, and forming a continuous and stable flame;

[0019] S3, the ignited pulverized coal flame and high-temperature flue gas are ejected from the pre-combustion chamber, pass through the flame transfer tube, reach the preset position and mix with the pulverized coal airflow of the main burner, forming a continuous and stable ignition heat source, and igniting the pulverized coal airflow of the main burner.

[0020] Compared with the prior art, the present invention has the following beneficial effects.

[0021] 1. The above-mentioned ignition and stable combustion pulverized coal burner can realize the ignition start-up and stable combustion of pulverized coal fuel under cold furnace conditions, and does not require the use of fuel oil, gas or electricity as auxiliary energy during operation;

[0022] 2. The design scheme of using secondary air to cool the pre-combustion chamber not only reduces the material requirements of the pre-combustion chamber, but also improves the stability of coal powder combustion after the secondary air is preheated;

[0023] 3. Using pulverized coal as the ignition heat source, its ignition energy is much greater than that of plasma ignition, micro-oil ignition and other ignition methods, with high ignition reliability and good stable combustion effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A cross-sectional view of a pulverized coal burner for ignition and stable combustion;

[0026] Figure 2 This is the outline diagram of the ignition gun;

[0027] Figure 3 is the cross-sectional view of the inlet section;

[0028] Figure 4 A cross-sectional view of the pre-combustion chamber.

[0029] In the figure: 1-ignition gun; 1.1-flame detector; 1.2-ignition electrode; 1.3-ignition fuel inlet; 1.4-mounting flange I; 1.5-ignition gun barrel; 2-inlet section; 2.1-primary air inlet; 2.2-center sleeve; 2.3-guide vane; 2.4-spoiler block; 2.5-mounting flange II; 2.6-diverter cone; 2.7-fixing ring; 2.8-secondary air swirl blade; 3-precombustion chamber; 3.1-secondary air inlet; 3.2-gas distribution cavity; 3.3-gas distribution hole; 3.4-outer plate; 3.5-inner plate; 3.6-preheating interlayer; 3.7-gas collecting hole; 3.8-gas collecting cavity; 3.9-refractory material layer; 3.10-sealing groove; 4-flame transfer tube; 5-sealing filler; 6-mounting flange III; 7-main burner back plate. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The present embodiment provides a pulverized coal burner for ignition and stable combustion, comprising an ignition gun 1, an inlet section 2, a pre-combustion chamber 3 and a flame transmission tube 4; a combustion zone and a secondary air channel for delivering secondary air into the combustion zone are arranged in the pre-combustion chamber 3; the front end of the inlet section 2 extends into the pre-combustion chamber 3 and is aimed at the combustion zone, and the rear end is located outside the pre-combustion chamber 3 as a primary air inlet 2.1; the ignition gun 1 is installed at the center of the front end of the inlet section 2, and the front end extends into the pre-combustion chamber 3 and is aimed at the combustion zone; the rear end of the flame transmission tube 4 is connected to the front end of the pre-combustion chamber 3, and is used to deliver the pulverized coal flame burning in the combustion zone to a preset position in the main burner to meet the pulverized coal airflow of the main burner.

[0032] Furthermore, the ignition gun 1 uses oil or gas as fuel, and comprises a flame detector 1.1, an ignition electrode 1.2, an ignition fuel inlet 1.3, a mounting flange I 1.4 and an ignition gun barrel 1.5; the flame detector 1.1 and the ignition electrode 1.2 are mounted at the rear end of the ignition gun barrel 1.5, and the ignition fuel inlet 1.3 is arranged on the side wall of the ignition gun barrel 1.5. The mounting flange I 1.4 is sleeved outside the ignition gun barrel 1.5.

[0033] Furthermore, the inlet section 2 is a right-angle elbow, the front end is the end of the horizontal part, the rear end is the end of the vertical part, the horizontal part and the vertical part are connected by an elbow, and the outer sleeve of the horizontal part is provided with a mounting flange II 2.5; a central sleeve 2.2 is provided at the center of the inner edge of the horizontal part, the ignition gun barrel 1.5 is inserted into the central sleeve 2.2, and the mounting flange I 1.4 is connected to the connecting flange I at the rear end of the central sleeve 2.2, thereby realizing the installation of the ignition gun 1; a guide vane 2.3 is provided in the elbow, the guide vane 2.3 is made of ceramic material, bent in the same direction as the elbow, and located below the central sleeve 2.2, so as to prevent the air from generating vortices at the sharp turn, resulting in poor airflow, energy loss, noise and other disadvantages.

[0034] In order to enhance the turbulence of the primary air and coal powder airflow, destroy the laminar bottom layer, and achieve the effect of enhancing heat exchange, multiple groups of spoiler components are arranged along the axial direction in the horizontal part of the inlet section 2, each group of spoiler components includes multiple spoiler blocks 2.4 evenly distributed along the circumferential direction of the inner wall of the horizontal part, and two adjacent groups of spoiler components are staggered; the spoiler blocks 2.4 are wedge-shaped or hemispherical and made of ceramic. In this embodiment, a total of 3 groups of spoiler components are arranged, each group of spoiler components includes 4 spoiler blocks 2.4, and the installation angle of two adjacent groups of spoiler components is rotated 60° along the circumferential direction of the inner wall of the horizontal part.

[0035] Furthermore, the front end of the central sleeve 2.2 is sleeved with a diverter cone 2.6, and the diameter of the diverter cone 2.6 gradually increases from the back to the front; a fixing ring 2.7 is vertically arranged on the large end face of the diverter cone 2.6, and the fixing ring 2.7 is fixed on the inner wall of the inlet section 2, thereby fixing the diverter cone 2.6. The diverter cone 2.6 is used to break up the primary air and coal powder airflow from the inlet section 2, and evenly distribute them in the cavity of the pre-combustion chamber 3. At the same time, the rear part of the diverter cone 2.6 can form a reflow zone, so that the flames of the ignition gun 1 and the primary air coal powder are stable here. The diverter cone 2.6 is made of ceramic or silicon carbide, and is required to be wear-resistant and high-temperature resistant.

[0036] A secondary air swirl blade 2.8 is installed on the outer side of the front end of the inlet section 2 to swirl the secondary air.

[0037] Furthermore, the pre-combustion chamber 3 includes an outer plate 3.4, an inner plate 3.5, an annular baffle I, an annular baffle II, an annular baffle III and a secondary air inlet 3.1; the front end of the inner plate 3.5 and the front end of the outer plate 3.4 are connected through the annular baffle I, the rear end of the inner plate 3.5 is located inside the outer plate, the rear end of the inner plate 3.5 and the inner wall of the outer plate are connected through the annular baffle III, the outer plate 3.4, the inner plate 3.5, the annular baffle I and the annular baffle III enclose an annular cavity, the annular baffle III and the rear end of the outer plate 3.4 are between the gas collecting cavity 3.8, and the inner plate 3.5 is provided with a combustion zone ; Annular baffle II is located between annular baffle I and annular baffle III, dividing the annular cavity from front to back into a split air cavity 3.2 and a preheating interlayer 3.6; the secondary air inlet 3.1 is arranged outside the outer plate 3.4 corresponding to the split air cavity 3.2, and is connected to the split air cavity 3.2; annular baffle II is provided with a split air hole 3.3, and annular baffle III is provided with a collecting air hole 3.7; the secondary air inlet 3.1, split air cavity 3.2, split air hole 3.3, preheating interlayer 3.6, collecting air hole 3.7, and collecting air cavity 3.8 constitute a secondary air channel, which can ensure that the secondary air flows into and burns evenly and ensures the ignition and stable combustion effect. The outer plate 3.4 and the inner plate 3.5 are made of steel plates, and the secondary air cools the inner plate 3.5 in the preheating interlayer 3.6, and is preheated at the same time.

[0038] Furthermore, a refractory material layer 3.9 is provided on the inner wall of the inner plate 3.5 to reduce heat loss in the pre-combustion chamber 3; the refractory material layer 3.9 is made of heavy low-cement castable material, which is required to have high density, good volume stability, high strength, thermal shock resistance, and erosion resistance, and no significant decrease in strength at 800-1200°C. A sealing groove 3.10 is provided at the rear end of the refractory material layer 3.9, and the rear end of the refractory material layer 3.9 is connected to the front end of the pre-combustion chamber 4, and a sealing filler 5 is filled in the sealing groove 3.10. Furthermore, the space within the refractory material layer 3.9 is composed of an inlet conical section, a straight cylindrical section and an outlet conical section from back to front; the diameters of the inlet conical section and the outlet conical section gradually decrease from back to front; the secondary air swirl blade 2.8 of the inlet section 2 is inserted into the straight cylindrical section, and the mounting flange II 2.5 is connected to the connecting flange II at the rear end of the outer plate 3.4; the straight cylindrical section and the outlet conical section after the secondary air swirl blade 2.8 constitute the combustion zone.

[0039] The length L1 of the pre-combustion chamber 3 is related to the type of coal used, and the value range is 0.9m to 1.1m. The inner diameter D1 of the pre-combustion chamber 3 is related to the flow rate of the pulverized coal, and the value range of D1 is 0.3m to 0.5m.

[0040] The flame transmission tube 4 has a combustion stabilizing effect. The length L2 is determined by the main burner structure, and the value of L2 cannot exceed 3m. The inner diameter D2 of the flame transmission tube 4 is related to the coal powder flow rate, and the value range of D2 is 0.6D1 to 0.8D1. The flame transmission tube 4 is made of silicon carbide or silicon nitride, which requires stable chemical properties, high thermal conductivity, small thermal expansion coefficient, good wear resistance, and can operate for a long time at a high temperature of 2000℃.

[0041] The rear end of the flame transfer tube 4 and the front end of the pre-combustion chamber 3 are fixed to the main burner back plate 7 through the mounting flange III 6 and bolts.

[0042] The specific process of the ignition method using the above-mentioned ignition and stable combustion pulverized coal burner is described below in conjunction with the accompanying drawings.

[0043] Before starting, the fuel or gas sprayed from the ignition gun 1 is ignited first to preheat the pre-combustion chamber 3 to 750°C to 800°C, and then the primary air and coal powder are introduced; after the primary air and coal powder are ignited, the fuel or gas of the ignition gun 1 is turned off.

[0044] Secondary air is introduced, and the secondary air enters from the secondary air inlet 3.1, is evenly distributed in the air distribution cavity 3.2, and enters the preheating interlayer 3.6 through the air distribution hole 3.3; the secondary air cools the inner plate 3.5, and the secondary air is preheated at the same time; the secondary air passes through the air collecting hole 3.7 and evenly enters the air collecting cavity 3.8; the secondary air forms a vortex after passing through the secondary air vortex blade 2.8, and is evenly mixed with the primary air and coal powder in the combustion zone, promoting the full combustion of the primary air and coal powder to form a continuous and stable flame.

[0045] The ignited pulverized coal flame and high-temperature flue gas are ejected from the pre-combustion chamber 3, pass through the flame transfer tube 4, and mix with the pulverized coal airflow of the main burner at an appropriate position to form a continuous and stable ignition heat source and ignite the pulverized coal airflow of the main burner.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coal powder burner with stable ignition, characterized in that: It includes an ignition gun, an inlet section, a pre-combustion chamber and a flame transmission tube; The pre-combustion chamber is provided with a combustion zone and a secondary air passage for delivering secondary air into the combustion zone; The front end of the inlet section extends into the pre-combustion chamber and is aligned with the combustion zone, and the rear end is located outside the pre-combustion chamber and is the primary air inlet; The ignition gun is installed at the center of the front end of the inlet section, and the front end extends into the pre-combustion chamber and is aligned with the combustion zone; The rear end of the flame transmission tube is connected to the front end of the pre-combustion chamber, and is used to send the pulverized coal flame burning in the combustion zone to a preset position in the main burner to meet with the pulverized coal airflow of the main burner; The pre-combustion chamber includes an outer plate, an inner plate, annular baffle I, annular baffle II, annular baffle III and a secondary air inlet; The front end of the inner plate and the front end of the outer plate are connected by an annular baffle plate I, the rear end of the inner plate is located inside the outer plate, the rear end of the inner plate and the inner wall of the outer plate are connected by an annular baffle plate III, the outer plate, the inner plate, the annular baffle plate I and the annular baffle plate III enclose an annular cavity, the annular baffle plate III and the rear end of the outer plate are a gas collecting cavity, and a combustion zone is arranged in the inner plate; The annular partition II is located between the annular partition I and the annular partition III, and divides the annular cavity into a gas separation cavity and a preheating interlayer from front to back; The secondary air inlet is arranged outside the outer plate corresponding to the air distribution cavity and is connected to the air distribution cavity; The annular partition plate II is provided with air distribution holes, and the annular partition plate III is provided with air collection holes; The secondary air inlet, the air distribution cavity, the air distribution hole, the preheating interlayer, the air collection hole, and the air collection cavity constitute a secondary air channel; A refractory material layer is arranged on the inner wall of the inner plate, a sealing groove is arranged at the rear end of the refractory material layer, the rear end of the refractory material layer is connected to the front end of the pre-combustion chamber, and a sealing filler is filled in the sealing groove; The space in the refractory material layer is composed of an inlet frustum section, a straight cylinder section and an outlet frustum section from back to front; The diameters of the inlet frustum section and the outlet frustum section gradually decrease from the back to the front; The front end of the inlet section is located inside the straight tube section, and secondary air swirl blades are installed on the outside; The straight cylinder section after the secondary air swirl blades and the outlet cone section constitute the combustion zone.

2. The ignition and stable combustion pulverized coal burner according to claim 1, characterized in that: The inlet section is a right-angle elbow, the front end is the end of the horizontal part, the rear end is the end of the vertical part, and the horizontal part and the vertical part are connected by an elbow; A central sleeve is provided at the center of the inner edge of the horizontal portion for mounting an ignition gun; A guide vane is arranged in the elbow. The guide vane is made of ceramic material, is bent in the same direction as the elbow, and is located below the central sleeve.

3. The ignition and stable combustion pulverized coal burner according to claim 2 is characterized in that: A plurality of groups of spoiler components are arranged in the horizontal part of the inlet section along the axial direction, each group of spoiler components includes a plurality of spoiler blocks evenly distributed along the circumferential direction of the inner wall of the horizontal part, and two adjacent groups of spoiler components are staggered; The spoiler is wedge-shaped or hemispherical and is made of ceramic.

4. The ignition and stable combustion pulverized coal burner according to claim 3 is characterized in that: The front end of the central sleeve is provided with a diverter cone, the diameter of which gradually increases from the back to the front, and the diverter cone is made of ceramic or silicon carbide; A fixing ring is vertically arranged on the large end surface of the splitter cone, and the fixing ring is fixed on the inner wall of the inlet section.

5. The ignition and stable combustion pulverized coal burner according to claim 1, characterized in that: The ignition gun uses oil or gas as fuel, and includes a flame detector, an ignition electrode, an ignition fuel inlet and an ignition gun barrel; The flame detector and the ignition electrode are installed at the rear end of the ignition gun barrel, and the ignition fuel inlet is arranged on the side wall of the ignition gun barrel.

6. The ignition and stable combustion pulverized coal burner according to claim 5, characterized in that: The outer sleeve of the ignition gun barrel is provided with a mounting flange I, the ignition gun barrel is inserted into the central sleeve, and the mounting flange I is connected to the connecting flange I at the rear end of the central sleeve; The horizontal outer shell of the inlet section is provided with a mounting flange II, which is connected to the connecting flange II at the rear end of the outer plate; The rear end of the flame transfer tube and the front end of the pre-combustion chamber are fixed to the back plate of the main burner through the mounting flange III.

7. An ignition method, characterized in that: The method is carried out using the ignition stable combustion pulverized coal burner according to any one of claims 1 to 6, comprising the following steps: S1, before starting, ignite the fuel or gas sprayed from the ignition gun, preheat the pre-combustion chamber to 750℃~800℃, then introduce primary air and coal powder. After the primary air and coal powder are ignited, turn off the fuel or gas of the ignition gun; S2, the secondary air is introduced. The secondary air enters from the secondary air inlet, is evenly distributed in the air distribution cavity, enters the preheating interlayer through the air distribution holes, and evenly enters the air collection cavity through the air collection holes. After passing through the secondary air swirl blades, a swirl is formed. The secondary air is evenly mixed with the primary air and coal powder in the combustion zone, promoting the full combustion of the primary air and coal powder to form a continuous and stable flame. S3, the ignited pulverized coal flame and high-temperature flue gas are ejected from the pre-combustion chamber, pass through the flame transfer tube, reach the preset position and mix with the pulverized coal airflow of the main burner, forming a continuous and stable ignition heat source, and igniting the pulverized coal airflow of the main burner.

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