An integrated thermal fusion pulverized coal combustion system with ignition, stable combustion, and energy saving.

Abstract

This utility model proposes an integrated thermonuclear fusion pulverized coal composite combustion system with ignition, stable combustion, and energy saving, relating to the field of burners. It includes: a multi-stage pulverized coal burner comprising a staged ignition tube and a bent pipe connected to the rear end of the staged ignition tube; a coal air pipe connected to the other end of the bent pipe, with a coal intake port on one side; an inlet of a cyclone coal collector connected to the coal intake port, and its bottom outlet connected to a composite combustion torch; a grounding electrode fixedly connected to the front end of the outer casing of the composite combustion torch; a central coal air pipe sequentially passing through the outer casing and the grounding electrode, with its rear end connected to a high-pressure air supply pipe and a dense-phase pulverized coal inlet pipe; a multiphase electrode assembly equally spaced between the central coal air pipe and the outer casing and connected to a multiphase AC plasma power supply, with its multiple electrode heads equidistantly distributed inside the grounding electrode; and the front end of the grounding electrode connected to the staged ignition tube via a flame stabilizing pipe. This application enables efficient, stable, environmentally friendly, and energy-saving operation of power plant boilers under deep peak-shaving conditions.

Description

Technical Field

[0001] This utility model relates to the field of burners, and more specifically, to an integrated thermonuclear fusion coal powder composite combustion system with ignition, stable combustion, and energy saving. Background Technology

[0002] In accordance with the national policy of clean energy and carbon reduction, the utilization of solar, wind, and hydropower is gradually increasing, putting greater pressure on thermal power plants to achieve deep peak shaving and control the rate of load change. When the boiler load is operating at 30-50%, traditional power plant boiler ignition and stable combustion are basically achieved through staged ignition and gradual amplification, specifically using oil gun ignition and the newer alternative technology plasma arc ignition.

[0003] Oil gun ignition, currently popularly using micro-oil ignition at approximately 120 kg / h of diesel fuel, presents significant environmental challenges due to incomplete combustion of diesel. This leads to frequent issues such as filter bag sticking and even fires, and also poses considerable safety risks on-site. The declining quality of coal used also forces many power plants to maintain high-volume oil gun ignition.

[0004] Plasma arc ignition currently mostly uses DC plasma arc generators. However, due to the high temperature of the DC plasma arc column (3000-5000°C), and even higher temperatures at the arc root spot, directly vaporizing the electrode metal, high-pressure water cooling is necessary for both the anode and cathode. Even so, the cathode lifespan is only 80-100 hours, and the anode lifespan is less than 500 hours. Sometimes, electrode erosion and water leakage occur, leading to severe coking of the burner, and in severe cases, complete burner blockage. Furthermore, deep peak shaving causes plasma arc generators to start even more frequently; currently, power plants need to replace the electrode head almost every 3 days. This not only significantly reduces equipment reliability and increases worker workload, but also exacerbates the difficulties of plasma arc ignition technology. As a result, power plants are showing a trend of abandoning plasma ignition and reverting to the use of oil guns. Utility Model Content

[0005] The purpose of this utility model is to provide an integrated thermonuclear fusion coal powder composite combustion system that combines ignition, stable combustion and energy saving. It integrates the three functions of ignition, stable combustion and energy saving, and can realize the efficient, stable, environmentally friendly and energy-saving operation of power plant boilers under deep peak shaving conditions.

[0006] The embodiments of this utility model are implemented as follows: This application provides an integrated thermonuclear fusion pulverized coal combustion system with ignition, stable combustion, and energy saving, comprising a multi-stage pulverized coal burner, air-coal pipes, a composite combustion torch, and a cyclone coal collector. The multi-stage pulverized coal burner includes a staged ignition tube and a bend connected to the rear end of the staged ignition tube; the air-coal pipe is connected to the other end of the bend, and a coal intake port is provided on one side of it. The inlet of the cyclone coal collector is connected to the coal inlet through a coal powder airflow inlet pipe, and its bottom outlet is connected to the composite combustion torch through a dense phase coal powder inlet pipe. The composite combustion torch includes an outer casing, a central air-fuel pipe, a multiphase electrode assembly, a grounding electrode, and a high-pressure air supply pipe. The front end of the outer casing is fixedly connected to the grounding electrode. The central air-fuel pipe passes through the outer casing and the grounding electrode sequentially, and its rear end is connected to the high-pressure air supply pipe and the dense-phase pulverized coal inlet pipe. The multiphase electrode assembly is equally spaced between the central air-fuel pipe and the outer casing and connected to a multiphase AC plasma power supply, and its multiple electrode heads are equidistantly distributed inside the grounding electrode. The front end of the grounding electrode is connected to the staged ignition tube through a flame stabilizing pipe.

[0007] Furthermore, based on the aforementioned scheme, the top of the cyclone coal collector is connected to the upper side wall of the bend via a waste gas conveying pipe, and the waste gas conveying pipe is equipped with a variable frequency induced draft fan.

[0008] Furthermore, based on the aforementioned scheme, a sealed coal unloading valve, a coal powder drop pipe, and a coal powder ejector are sequentially connected between the bottom outlet of the cyclone coal collector and the dense phase coal powder inlet pipe.

[0009] Furthermore, based on the aforementioned scheme, the grounding electrode has an outer cylindrical shape, and its interior gradually narrows from a cylindrical shape to a plum blossom shape along the wind direction; multiple electrode heads are located one-to-one in multiple plum blossom-shaped receiving cavities; and the end of the central air-coal pipe near the electrode head is outwardly flared; the electrode head has a shape that is thinner at the front and thicker at the back.

[0010] Furthermore, based on the aforementioned scheme, the distance between the electrode head and the inner wall of the grounding electrode, and between the electrode head and the central air-fuel pipe, are 3-15 mm respectively; the plasma carrier gas velocity is 15-35 m / s.

[0011] Furthermore, based on the aforementioned scheme, a blunt cone is connected to the front end of the central air-coal pipe, the outer diameter of the blunt cone being consistent with the outer diameter of the central air-coal pipe, and the tip being opposite to the axis of the central air-coal pipe.

[0012] Furthermore, based on the aforementioned scheme, the blunt cone is fixed to the end of the central ventilation pipe by a support bar.

[0013] Furthermore, based on the aforementioned scheme, the front end of the grounding electrode is connected to a flame stabilizing tube; the flame stabilizing tube is connected to the multi-stage pulverized coal burner, and multiple swirl blades are respectively arranged circumferentially on the inner wall of the flame stabilizing tube and the inner wall of the central air-coal pipe near the electrode head.

[0014] Furthermore, based on the aforementioned scheme, the outer wall of the grounding electrode is evenly divided into multiple support spokes along its circumference, and one end of the flame stabilizer tube is fixed to the support spokes.

[0015] Furthermore, based on the aforementioned scheme, a cable junction box is provided at the end of the outer sleeve away from the grounding electrode, and two glass viewing holes are provided on the outer end face of the cable junction box, and a cable outlet sealing sleeve is provided on the annular side of the cable junction box.

[0016] Compared with the prior art, the embodiments of this utility model have at least the following advantages or beneficial effects: This application concentrates dilute-phase pulverized coal fed into the air-coal duct by introducing it into a cyclone coal collector through a pulverized coal gas flow inlet pipe. The concentrated dense-phase pulverized coal is then sent into the central air-coal duct by high-pressure air from the high-pressure air supply pipe, where it is dispersed into the low-temperature sliding plasma arc region through a blunt cone diffusion ring spray. Simultaneously, the gradually decreasing distance between the grounding electrode and the electrode head ensures that the plasma carrier gas velocity is within a suitable range, achieving rapid ignition. After the pulverized coal is ignited, a small fire ignites a large fire, and the flame sequentially ignites the concentrated-dilute phase ignition tubes inside the multi-stage pulverized coal burner (stages 1-5), thus ensuring the ignition and stable combustion of all the pulverized coal entering the furnace. This application integrates ignition, stable combustion, and energy-saving functions, enabling efficient, stable, environmentally friendly, and energy-saving operation of power plant boilers under deep peak-shaving conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the integrated thermonuclear fusion coal powder combustion system for ignition, stable combustion, and energy saving, as described in this embodiment of the utility model. Figure 2 This is a cross-sectional view of the composite combustion system according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the external structure of the composite combustion torch according to an embodiment of the present invention; Figure 4 This is a cross-sectional view of the composite combustion torch according to an embodiment of the present invention; Figure 5 This is an embodiment of the present utility model. Figure 4 Enlarged view of a portion; Figure 6 This is an enlarged schematic diagram of the structure of the grounding electrode in an embodiment of this utility model; Figure 7 This is a rear view of the composite combustion torch according to an embodiment of the present invention; Figure 8 These are photographs of plasma discharge at different moments in the 12KW thermonuclear fusion coal powder composite combustion torch of this utility model embodiment; Figure 9 These are infrared imaging photographs taken at different moments of plasma discharge in the 12KW thermonuclear fusion coal powder composite combustion torch of this utility model embodiment; Figure 10 Photos of different ignition times of 4500kCal bituminous coal powder (60kg / kg) in this embodiment of the present invention; Figure 11 Photos of different ignition times of 60 kg / kg of 3500 kcal lignite powder in this embodiment of the present invention.

[0019] Icons: 1-Multi-stage pulverized coal burner, 11-Stage ignition tube, 12-Bend, 2-Air / coal pipe, 21-Coal intake port, 3-Composite combustion torch, 31-Outer jacket, 311-Wear-resistant protective layer, 32-Central air / coal pipe, 321-Insulation layer, 33-Multiphase electrode assembly, 331-Electrode head, 332-Electrode rod, 333-First insulator, 334-Second insulator, 335-Pipe body, 34-Grounding electrode, 341-Support spokes, 35-High-pressure air supply pipe, 36-Flame stabilizer pipe 37-Blunt cone, 371-Support bar, 38-Swirl vane, 39-Cable junction box, 391-Glass observation hole, 392-Cable outlet sealing sleeve, 4-Cyclone coal collector, 41-Pulverized coal airflow inlet pipe, 42-Dense phase pulverized coal inlet pipe, 43-Exhaust gas inlet pipe, 44-Exhaust gas outlet pipe, 45-Variable frequency induced draft fan, 46-Sealed coal unloading valve, 47-Pulverized coal drop pipe, 48-Pulverized coal ejector, 5-Slide rail, 6-Support frame, 7-Reducer, 8-Electrical controller, 9-High pressure fan. Detailed Implementation

[0020] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0021] Please refer to Figures 1-11 The diagram shows the overall structure of the integrated thermonuclear fusion pulverized coal combustion system, which combines ignition, stable combustion, and energy saving. This embodiment provides an integrated thermonuclear fusion pulverized coal combustion system with ignition, stable combustion, and energy saving, comprising a multi-stage pulverized coal burner 1, an air-coal pipe 2, a composite combustion torch 3, and a cyclone coal collector 4. The multi-stage pulverized coal burner 1 includes a staged ignition tube 11 and a bend 12 connected to the rear end of the staged ignition tube 11; the air-coal pipe 2 is connected to the other end of the bend 12, and a coal intake port 21 is provided on one side of it. The composite combustion torch 3 includes an outer casing 31, a central air-fuel pipe 32, a multiphase electrode assembly 33, a grounding electrode 34, and a high-pressure air supply pipe 35. The front end of the outer casing 31 is fixedly connected to the grounding electrode 34. The central air-fuel pipe 32 passes through the outer casing 31 and the grounding electrode 34 in sequence, and its front end is connected to a blunt cone 37, while its rear end is connected to the high-pressure air supply pipe 35. The tip of the blunt cone 37 is opposite to the axis of the central air-fuel pipe 32. The multiphase electrode assembly 33 is evenly distributed between the central air-fuel pipe 32 and the outer casing 31, and its multiple electrode heads 331 are equidistantly distributed inside the grounding electrode 34. The distance between the electrode heads 331 and the grounding electrode 34 gradually decreases along the wind direction. The inlet of the cyclone coal collector 4 is connected to the coal outlet 21 through the coal powder airflow inlet pipe 41, and its bottom outlet is connected to the central air-coal pipe 32 through the dense phase coal powder inlet pipe 42.

[0022] The exemplary embodiment of this paper will now be further described, providing an integrated thermonuclear fusion coal powder combustion system for ignition, stable combustion, and energy saving.

[0023] In some embodiments, the multi-stage pulverized coal burner 1 is responsible for the main combustion task, including a rich-lean phase staged ignition tube 11 and a bend 12 connected to the rear end of the staged ignition tube 11. The staged ignition tube 11 and the bend 12 are connected by a flange. The multi-stage pulverized coal burner 1 achieves rich-lean phase staged combustion, and in conjunction with the low-temperature plasma region formed by the composite combustion torch 3, a smooth transition from ignition to main combustion is achieved. The air-coal pipe 2 is connected to the other end of the bend 12 by a flange, and a coal intake port 21 is provided on one side of it. The air-coal pipe 2 provides the main combustion-supporting air and pulverized coal for the combustion reaction, and is generally fed from the bottom upwards.

[0024] The inlet of the aforementioned cyclone coal collector 4 is directly and sealed to the coal inlet 21 on the air-coal pipe 2 via a pulverized coal airflow inlet pipe 41, and its bottom outlet is connected to the composite combustion torch 3 via a dense-phase pulverized coal inlet pipe 42. Generally, at the start-up and ignition of a power plant boiler, pulverized coal with a relatively low phase coal-air ratio of 0.2 kg / kg (0.2 kg of pulverized coal per kg of air) and a velocity of 18 m / s, supplied by equipment such as a coal mill, is sent into the air-coal pipe 2, making ignition particularly difficult. This application addresses this by installing a cyclone coal collector 4 near the side of the air-coal pipe 2, which concentrates the relatively low phase pulverized coal into dense-phase pulverized coal before sending it into the composite combustion torch 3, thereby improving ignition efficiency and achieving rapid ignition. It should be noted that the principle of the aforementioned cyclone coal collector 4 is similar to that of existing cyclone dust collectors, achieving pulverized coal concentration by increasing the pulverized coal concentration in the central air-coal pipe 32 by 2-5 times, significantly improving ignition efficiency and flame stability, and enabling the direct ignition of low-quality coal.

[0025] The aforementioned composite combustion torch 3 includes an outer casing 31, a central air-fuel pipe 32, a multiphase electrode assembly 33, a grounding electrode 34, and a high-pressure air supply pipe 35. The front end of the outer casing 31 is fixedly connected to the grounding electrode 34. The central air-fuel pipe 32 passes sequentially through the outer casing 31 and the grounding electrode 34, and its rear end is connected to the high-pressure air supply pipe 35 and the dense-phase pulverized coal inlet pipe 42. The multiphase electrode assembly 33 is evenly distributed between the central air-fuel pipe 32 and the outer casing 31 and is connected to a multiphase AC plasma power supply. Its multiple electrode heads 331 are equidistantly distributed inside the grounding electrode 34. The electrode head 331 is made of a rare high-melting-point metal material. The front end of the grounding electrode 34 is connected to the staged ignition tube 11 through a flame stabilizing pipe 36. The multiphase electrode assembly 33 preferably has 6 phase electrodes, with two layers of insulating tubes fitted on the electrode rods 332; and through the first insulator 333 and the tube body 335 with the second insulator 334 attached, the multiphase electrode rods 332 are accurately parallel and equally divided and fixed and distributed in the annular space outside the central air-coal pipe 32 and inside the casing.

[0026] The aforementioned high-pressure air supply pipe 35 is connected to the high-pressure blower 9. High-pressure air of 0.3-0.8 MPa generated by the blower 9 is injected into the dense-phase pulverized coal inlet pipe 42. At this time, dense-phase pulverized coal with a coal-air ratio of 0.4-0.8 kg / kg, 15-20 m / s, and 40-100 kg / h is sent along with the high-pressure air into the central air-coal pipe 32 of the thermonuclear fusion pulverized coal composite combustion torch 3 and ejected. It is then sent into the sliding plasma arc region at a low temperature of 150-300°C at the front end. After the pulverized coal is ignited, a small fire ignites a large fire, and the flame sequentially ignites the dense-dilute phase grading ignition tubes 11 inside the multi-stage pulverized coal burner 1 (stages 1-5), thereby ensuring the ignition and stable combustion of all the pulverized coal entering the furnace.

[0027] It should be noted that the above-mentioned coal powder composite combustion in a multiphase high-frequency alternating sliding plasma arc is essentially a process in which the deuterium-tritium fusion energy and chemical energy in the coal powder are simultaneously combusted and released. Under the same energy output conditions, more than 2% of the coal powder can be saved. The principle is a publicly disclosed existing technology, which has been described in several series of patents of the inventor. Moreover, it has been explained in detail in the inventor's academic monographs "Theory and Application of Warm Nuclear Fusion Accompanied by Fossil Fuel Burning" (Xuzhou, China University of Mining and Technology Press, June 2022, First Edition) and "Theory and Application of Warm Nuclear Fusion Accompanied by Fossil Fuel Burning" (USA, China Culture Press, July 2025, Second Edition). It will not be repeated here.

[0028] Understandably, to facilitate the installation and maintenance of the aforementioned composite combustion torch 3, the composite combustion torch 3 is mounted on a slide rail 5, and the torch is driven to slide on it by a reducer 7. An electrical controller 8 is installed on the slide rail 5 to control the forward and backward movement of the thermonuclear fusion coal powder composite combustion torch 3. The slide rail 5 is mounted on a support frame 6, which is fixed to the bend 12 via a connecting flange.

[0029] In a preferred embodiment, the top of the aforementioned cyclone dust collector 4 is connected to the upper side wall of the bend 12 via a waste gas conveying pipe, and a variable frequency induced draft fan 45 is installed on the waste gas conveying pipe. Specifically, the waste gas conveying pipe includes a waste gas outlet pipe 44 and a waste gas inlet pipe 43. The waste gas outlet pipe 44 is directly connected to the top outlet of the cyclone dust collector, and the waste gas inlet pipe 43 is connected to the bend 12. The variable frequency induced draft fan 45 is connected between the waste gas outlet pipe 44 and the waste gas inlet pipe 43. When the cyclone dust collector concentrates pulverized coal, it generates waste gas. This waste gas is conveyed through the waste gas outlet pipe 44 and the waste gas inlet pipe 43, and after being pressurized by the variable frequency induced draft fan 45, it is transported to the bend 12 for recycling. The recycling design allows the low-concentration pulverized coal gas flow after cyclone separation to return to the main combustion system, improving the utilization rate of pulverized coal and reducing the carbon content of fly ash. Furthermore, the variable frequency induced draft fan 45 can dynamically adjust the amount of exhaust gas returned according to the system load, maintaining the optimal combustion state within the 30-100% load range. This also avoids energy waste and environmental pollution caused by direct exhaust gas emissions, thereby improving the overall energy efficiency of the system.

[0030] In a preferred embodiment, a sealed unloading valve 46, a pulverized coal drop pipe 47, and a pulverized coal ejector 48 are sequentially connected between the bottom outlet of the cyclone coal collector 4 and the dense-phase pulverized coal inlet pipe 42. The sealed unloading valve 46 effectively prevents high-pressure air from entering the cyclone coal collector 4 and controls the amount of dense-phase pulverized coal falling, ensuring stable pulverized coal separation efficiency. The pulverized coal ejector 48 utilizes the Venturi effect to achieve unpowered conveying of dense-phase pulverized coal, reducing system energy consumption. The multi-stage sealing design keeps the air leakage rate during pulverized coal conveying below 0.5%, ensuring combustion stability. Furthermore, the modular design facilitates maintenance and replacement, shortening the replacement time for individual components.

[0031] In a preferred embodiment, the grounding electrode 34 has an external cylindrical shape, which gradually narrows towards the wind direction to a quincunx shape inside. Multiple electrode heads 331 are located one-to-one within the multiple quincunx-shaped accommodating cavities. The quincunx-shaped inner wall design matches the shape of the electrode heads 331, creating a multi-regional electric field enhancement effect, improving plasma generation efficiency. Furthermore, the gradually narrowing transition structure guides the plasma arc towards the center, increasing energy density while avoiding localized high temperatures. The central air duct 32 has an outward-expanding end near the electrode heads 331, reducing the resistance to coal dust airflow. The electrode heads 331 are tapered at the front and thickened at the back, reducing energy concentration at the arc root and extending electrode lifespan.

[0032] Specifically, the distance between the electrode head 331 and the inner wall of the grounding electrode 34 is 15-3 mm, gradually narrowing towards the front. The distance between the electrode head 331 and the central air-fuel pipe 32 is 3-15 mm, gradually widening towards the front. The electrode head 331 is pagoda-shaped, thinner at the front and thicker at the back, to facilitate the formation of a sliding plasma arc, significantly extending the electrode life to 3000-8500 hours; simultaneously ensuring a plasma carrier gas velocity within the range of 15-35 m / s, achieving rapid and stable ignition.

[0033] In a preferred embodiment, a blunt cone 37 is connected to the front end of the central air-coal pipe 32. The outer diameter of the blunt cone 37 is the same as the outer diameter of the central air-coal pipe 32, and its tip is opposite to the central air-coal pipe 32. The blunt cone 37, located at the front end of the central air-coal pipe 32, can disperse the dense-phase coal powder delivered by the central air-coal pipe 32, causing it to diffuse in a ring-shaped circumferential direction, thereby driving the coal powder into the electric arc region and achieving rapid ignition.

[0034] Specifically, the blunt cone 37 is fixed to the end of the central air-coal pipe 32 by support bars 371. Preferably, there are two support bars 371, which are symmetrically fixed on both sides of the blunt cone 37, with one end fixed to the end of the central air-coal pipe 32, so as to ensure structural strength while minimizing airflow disturbance.

[0035] In a preferred embodiment, the inner wall of the flame stabilizer 36 and the inner wall of the central air-fuel pipe 32 near the electrode head 331 are respectively provided with multiple swirl blades 38 along their circumference. All swirl blades 38 are made of wear-resistant material. This causes the airflow to form a spiral direction with a long flow path, increasing the mixing intensity of pulverized coal and air, thereby improving combustion efficiency and achieving stable combustion.

[0036] In a preferred embodiment, the outer wall of the grounding electrode 34 is evenly divided into multiple support spokes 341 along its circumference. One end of the flame stabilizer tube 36 is fixed to the support spokes 341 to support and fix the flame stabilizer tube 36, so that it is subjected to uniform force and has a stable structure.

[0037] In a preferred embodiment, a cable junction box 39 is installed at the end of the outer sleeve 31 furthest from the grounding electrode 34. The outer end face of the cable junction box 39 has two glass observation holes 391 made of high-temperature resistant borosilicate glass, capable of withstanding temperatures above 200℃, ensuring long-term stable observation and enabling comprehensive observation of the electrode's operating status and pulverized coal conveying conditions, facilitating fault diagnosis. A cable outlet sealing sleeve 392 is provided on the annular side of the cable junction box 39. The cable outlet sealing sleeve 392 facilitates cable connection and its sealing design is waterproof and dustproof, adapting to the humid and dusty environment of a power plant.

[0038] In a preferred embodiment, the outer wall of the outer casing 31 is covered with a wear-resistant protective layer 311, preferably a ceramic composite coating, to improve wear resistance and extend its service life. The central air / coal duct 32 is covered with an insulation layer 321 to reduce temperature loss and facilitate ignition. The central air / coal duct 32 is a ceramic-lined composite steel pipe with good wear resistance.

[0039] In one specific embodiment, coal powder with a coal-air ratio of 0.2 kg / kg and a speed of 18 m / s is fed into the coal-air pipe 2. The cyclone coal collector 4 concentrates the coal powder and sends it through the sealed coal unloading valve 46 into the coal powder drop pipe and then into the coal powder ejector 48. High-pressure air of 0.3-0.8 MPa generated by the high-pressure blower 9 is ejected into the dense phase coal powder inlet pipe 42. At this time, dense phase coal powder with a coal-air ratio of 0.4-0.8 kg / kg, a speed of 15-20 m / s and a speed of 40-100 kg / h is sent into the central coal-air pipe 32 of the thermonuclear fusion coal powder composite combustion torch 3 and ejected. The pulverized coal is dispersed into the low-temperature sliding plasma arc region of 150-300°C through the blunt cone 37. After the pulverized coal is ignited, the small fire ignites the large fire, and the flame sequentially ignites the rich and poor phase classification ignition tube 11 inside the multi-stage pulverized coal burner 11 of stages 1-5, thereby ensuring the ignition and stable combustion of all the pulverized coal entering the furnace.

[0040] like Figure 8 These are photos of plasma discharge at different moments in a 12KW thermonuclear fusion coal powder composite combustion torch; Figure 9 These are infrared images taken at different moments during plasma discharge in a 12kW thermonuclear fusion coal-fired composite combustion torch. The images show that the temperature in the plasma sliding arc region is generally between 30-200°C.

[0041] Figure 10 These are photos of 4500kCal bituminous coal powder at 60kg / kg ignition at different times; Figure 11 These are photos taken at different times during the ignition of 3500kCal lignite powder at 60kg / kg. Figure 10 and 11 It can be seen intuitively that low-temperature sliding plasma arc ignition and stable combustion of pulverized coal have been achieved at temperatures ranging from 30 to 200°C.

[0042] This application embodiment integrates ignition, stable combustion, and energy-saving functions, enabling boilers to achieve peak-shaving, stable combustion, and ignition with accompanying combustion at any time and in any weather condition, with loads ranging from 100% to 15%. The differences between this and existing burners are shown in Table 1 below: Table 1:

[0043] Furthermore, unless otherwise explicitly specified or limited, the terms "installation" and "connection" in this application embodiment should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. The terms "upper," "lower," "left," "right," "inner," "outer," and "side," etc., are merely for reference to the direction in the accompanying drawings or the usual placement of the product during use. They are only for clearly describing this application and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limitations on this application. The terms "first," "second," etc., are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance; "multiple" refers to at least two. In this application embodiment, the limitations on relative positional relationships such as parallel, perpendicular, and aligned are all relative to the current technological level and are not absolutely strict limitations. Slight deviations are allowed; approximations of parallel, perpendicular, and aligned are all acceptable. For example, "A and B are parallel" means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 degrees and 10 degrees.

[0044] The above are only some embodiments and implementation methods of this application. The protection scope of this application is not limited thereto. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. Any combination of features in different embodiments is also within the protection scope of this application. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. A combined ignition, stable combustion, and energy-saving thermonuclear fusion pulverized coal combustion system, characterized in that, Includes multi-stage pulverized coal burners, air and coal pipes, composite combustion torches, and cyclone coal collectors. The multi-stage pulverized coal burner includes a staged ignition tube and a bend connected to the rear end of the staged ignition tube; the air-coal pipe is connected to the other end of the bend, and a coal intake port is provided on one side of it. The inlet of the cyclone coal collector is connected to the coal inlet through a coal powder airflow inlet pipe, and its bottom outlet is connected to the composite combustion torch through a dense phase coal powder inlet pipe. The composite combustion torch includes an outer casing, a central air-fuel pipe, a multiphase electrode assembly, a grounding electrode, and a high-pressure air supply pipe. The front end of the outer casing is fixedly connected to the grounding electrode. The central air-fuel pipe passes through the outer casing and the grounding electrode sequentially, and its rear end is connected to the high-pressure air supply pipe and the dense-phase pulverized coal inlet pipe. The multiphase electrode assembly is equally spaced between the central air-fuel pipe and the outer casing and connected to a multiphase AC plasma power supply, and its multiple electrode heads are equidistantly distributed inside the grounding electrode. The front end of the grounding electrode is connected to the staged ignition tube through a flame stabilizing pipe.

2. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving as described in claim 1, characterized in that, The top of the cyclone coal collector is connected to the upper side wall of the bend through a waste gas conveying pipe, and the waste gas conveying pipe is equipped with a variable frequency induced draft fan.

3. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving as described in claim 1, characterized in that, A sealed coal unloading valve, a coal powder drop pipe, and a coal powder ejector are sequentially connected between the bottom outlet of the cyclone coal collector and the dense phase coal powder inlet pipe.

4. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving as described in claim 1, characterized in that, The grounding electrode is cylindrical on the outside, and gradually narrows to a plum blossom shape on the inside along the wind direction; multiple electrode heads are located one-to-one in multiple plum blossom-shaped receiving cavities; and the end of the central air-coal pipe near the electrode head is outwardly flared; the electrode head is thinner at the front and thicker at the back.

5. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving as described in claim 4, characterized in that, The distance between the electrode head and the inner wall of the grounding electrode, and between the electrode head and the central air-fuel pipe, are 3-15 mm; the plasma carrier gas velocity is 15-35 m / s.

6. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving according to claim 1 or 5, characterized in that, The front end of the central ventilation pipe is connected to a blunt cone, the outer diameter of which is the same as the outer diameter of the central ventilation pipe, and the tip of which is opposite to the axis of the central ventilation pipe.

7. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving as described in claim 1, characterized in that, The blunt cone is fixed to the end of the central ventilation pipe by a support bar.

8. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving as described in claim 1, characterized in that, The inner wall of the flame stabilizer tube and the inner wall of the central air-fuel pipe near the electrode head are respectively provided with multiple swirl blades along their circumference.

9. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving as described in claim 8, is characterized in that, The outer wall of the grounding electrode is evenly divided into multiple support spokes along its circumference, and one end of the flame stabilizer tube is fixed to the support spokes.

10. The integrated thermonuclear fusion pulverized coal combustion system for ignition, stable combustion, and energy saving according to claim 1, characterized in that, A cable junction box is provided at the end of the outer sleeve away from the grounding electrode. Two glass viewing holes are provided on the outer end face of the cable junction box. A cable outlet sealing sleeve is provided on the annular side of the cable junction box.

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