Plasma ignition system of coal-fired boiler

Abstract

The utility model relates to the field of thermal power generation, in particular to a plasma ignition system of a coal-fired boiler. Comprising a coal-fired boiler, a plasma generator and the like. The hearth is communicated with a pulverized coal conveying pipeline, an air pipeline and a cooling air duct, the pulverized coal conveying pipeline and the air pipeline are arranged above the pulverized coal separation net, and the cooling air duct is arranged below the pulverized coal separation net. And the pulverized coal conveying pipeline is provided with a one-way valve and is communicated with the hearth at an angle of 45-70 degrees. And a high-temperature-resistant pulverized coal separation net is arranged above the positive and negative rotation coal blowing fan, and a vibration motor is arranged below the positive and negative rotation coal blowing fan. And the plasma generator is circularly distributed around the coal blowing fan and penetrates through the pulverized coal separation net. A second dustproof filter screen is arranged in the cooling air duct, an output port faces the coal blowing fan, and efficient ignition and stable operation are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thermal power generation, in particular to a coal-fired boiler plasma ignition system. BACKGROUND

[0002] In today's world with growing energy demand, coal as an important energy resource still occupies a key position in the field of power production and other fields. The traditional coal-fired boiler ignition method mainly relies on oil ignition. This ignition method gradually exposes a series of problems in the long-term application process. The price of fuel oil fluctuates greatly and is generally at a high level. Using fuel oil ignition will result in high ignition cost. For large coal-fired power plants or industrial boilers, the fuel consumption is large during each start-up and low-load stable combustion stage, which brings a heavy economic burden to enterprises and greatly affects the economic benefits and market competitiveness of enterprises. Fuel oil combustion produces harmful gases and particulate matter, such as sulfur dioxide, nitrogen oxides, and smoke. The emission of these pollutants damages the atmospheric environment.

[0003] The traditional oil ignition method is facing increasing pressure, and enterprises urgently need to find more environmentally friendly ignition solutions. Over-reliance on oil ignition affects the stability of energy supply. The supply of fuel oil is restricted by international markets and other factors, and there is a certain degree of uncertainty. CONTENT OF THE INVENTION

[0004] In order to solve the problems of high fuel oil price, large fluctuation, high cost, pollution caused by combustion, damage to the atmospheric environment, conflict with the concept of environmental protection, and poor stability of energy supply due to the restriction of international market and other factors, the present application proposes the following technical solutions:

[0005] A coal-fired boiler plasma ignition system, comprising a coal-fired boiler and a plasma generator, wherein the coal-fired boiler is provided with a hearth, characterized in that the hearth is respectively connected with a coal powder conveying pipeline, an air pipeline, and a cooling air duct, the coal-fired boiler is provided at the bottom with a coal blowing fan, the coal blowing fan is connected with the hearth through a blowing pipeline, the hearth is provided at the bottom with a plurality of plasma generators, the plasma generators are provided above with a coal powder isolation net, the coal powder conveying pipeline and the air pipeline are located above the coal powder isolation net, and the cooling air duct is located below the coal powder isolation net.

[0006] Preferably, the coal powder conveying pipeline is provided with a one-way valve, the input port of the coal powder conveying pipeline is connected with a pre-process, and the output port of the coal powder conveying pipeline is connected with the hearth.

[0007] Preferably, the coal powder conveying pipeline is directed towards the bottom of the hearth, and the included angle between the coal powder conveying pipeline and the bottom of the hearth is 45 degrees to 70 degrees.

[0008] Preferably, the two plasma generators are located on the left and right sides above the blowing pipe.

[0009] Preferably, the coal blowing fan is a forward-reverse fan.

[0010] Preferably, the coal dust isolation net is made of high-temperature-resistant material, which is selected from any one of ceramic, metal fiber and sintered metal.

[0011] Preferably, the coal-fired boiler is provided with a high-temperature-resistant vibration motor on one side, and the high-temperature-resistant vibration motor is in the same plane as the coal dust isolation net.

[0012] Preferably, the blowing pipe is directed towards the coal dust isolation net, and the plasma generator is closely attached to the coal dust isolation net.

[0013] Preferably, the cooling air duct is provided with a second dustproof filter screen, the input port of the cooling air duct is communicated with the external process, the output port of the cooling air duct is communicated with the bottom of the furnace, and the output port of the cooling air duct is directed towards the coal blowing fan.

[0014] Preferably, the blowing pipe is provided with a dust isolation net.

[0015] The utility model has the advantages that:

[0016] 1. The coal dust conveying pipe and the air pipe are located above the coal dust filter screen, and the fan and the plasma generators around the fan are located below the filter screen. This layout enables the coal dust falling from the coal dust conveying pipe to fully contact with the plasma generated by the plasma generators below during the process of passing through the coal dust filter screen, and the coal dust is mixed with air under the action of the fan, which helps to improve the ignition efficiency of the coal dust and the completeness of combustion.

[0017] 2. The cooling air duct is located below the coal dust filter screen and has an output port directed towards the fan, which can directly cool the fan, ensures the stable operation of the fan in a high-temperature environment, prolongs the service life of the fan, and is also conducive to maintaining the stability of the overall temperature field in the furnace and avoiding local overheating to damage the equipment.

[0018] 3. The one-way valve provided on the coal dust conveying pipe can prevent the flame and hot gas in the furnace from flowing into the coal dust conveying pipe in the reverse direction, avoid causing safety accidents, and ensure the safety of the coal dust conveying process.

[0019] 4. The coal dust conveying pipe is directed towards the bottom of the furnace at an angle of 45 degrees to 70 degrees with the bottom of the furnace, which is conducive to the coal dust falling into the furnace at a suitable angle and speed, making the coal dust more evenly distributed in the furnace, further promoting the combustion effect and improving the energy utilization efficiency.

[0020] 5. Two plasma generators are distributed on the left and right sides above the air blowing duct, which can form a relatively uniform high-temperature plasma area at the bottom of the furnace, ensuring the reliability and stability of ignition and improving the overall ignition success rate.

[0021] 6. The use of forward and reverse rotating fans allows for flexible adjustment of the airflow direction and speed within the furnace. This facilitates the mixing of pulverized coal and air, and in certain operating conditions, such as when it is necessary to quickly discharge exhaust gas from the furnace or adjust the combustion atmosphere, the direction of the fan rotation can be changed, thereby enhancing the system's operational flexibility and adaptability.

[0022] 7. This utility model uses high-temperature resistant materials such as ceramics, metal fibers or sintered metals to make the filter screen, ensuring that the filter screen maintains good mechanical and filtration performance in the high-temperature environment of the furnace, effectively blocking coal powder from passing through, and at the same time has a long service life, reducing system failures and maintenance costs caused by filter screen damage.

[0023] 8. The vibration motor installed below the filter screen of this utility model can make the filter screen vibrate, prevent coal powder from being excessively accumulated and compacted on the filter screen, ensure the air permeability of the filter screen, maintain smooth air passage, and thus ensure the stable progress of the ignition and combustion process. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a plasma ignition system for a coal-fired boiler.

[0025] In the diagram: 1. Coal-fired boiler; 11. Furnace; 2. Plasma generator; 3. Pulverized coal conveying pipeline; 31. One-way valve; 4. Air duct; 41. First dust filter; 5. Coal blowing fan; 51. Air blowing duct; 52. Dust filter; 6. Pulverized coal isolation net; 61. High-temperature resistant vibration motor; 7. Cooling air duct; 71. Second dust filter. Detailed Implementation

[0026] A plasma ignition system for a coal-fired boiler includes a coal-fired boiler 1 and a plasma generator 2. The coal-fired boiler 1 is provided with a furnace 11. The furnace 11 is characterized in that it is connected to a pulverized coal conveying pipe 3, an air pipe 4, and a cooling air duct 7. The pulverized coal conveying pipe 3 and the air pipe 4 are located above the pulverized coal isolation net 6, and the cooling air duct 7 is located below the pulverized coal isolation net 6.

[0027] A plasma ignition system for a coal-fired boiler includes a coal-fired boiler 1 and plasma generators 2. The coal-fired boiler 1 has a furnace 11, and several plasma generators 2 are arranged at the bottom of the furnace 11. There are two plasma generators 2, which are located on the left and right sides above the air blowing duct 51, respectively, and the plasma generators 2 are in close contact with the pulverized coal isolation mesh 6.

[0028] A coal blowing fan 5 is arranged at the bottom of the furnace 11, the coal blowing fan 5 is communicated with the furnace 11 through a blowing pipeline 51, the blowing pipeline 51 faces the coal powder isolation net 6, and a dust isolation net 52 is arranged in the blowing pipeline 51, and the coal blowing fan 5 is a forward-reverse fan.

[0029] The furnace 11 is communicated with a coal powder conveying pipeline 3, an air pipeline 4 and a cooling air duct 7 respectively. The coal powder conveying pipeline 3 and the air pipeline 4 are located above the coal powder isolation net 6, and the cooling air duct 7 is located below the coal powder isolation net 6.

[0030] The coal powder isolation net 6 is arranged above the plasma generator 2 and is made of high-temperature-resistant material, and the high-temperature-resistant material is selected from any one of medium ceramic, metal fiber and sintered metal.

[0031] The cooling air duct 7 is provided with a second dust prevention filter screen 71, the input end of the second dust prevention filter screen 71 is communicated with an external process, the output end is communicated with the bottom of the furnace 11, and the output end faces the coal blowing fan 5.

[0032] When the coal-fired boiler plasma ignition system ignites, the coal blowing fan 5 is started first, and the characteristics of the forward-reverse fan can flexibly adjust the blowing strength and direction. Through the blowing pipeline 51, the wind power is accurately directed to the coal powder isolation net 6, and a good air circulation environment is created for the subsequent ignition process. At the same time, the coal powder conveying pipeline 3 controls the coal powder conveyed from the pre-process to form an angle of 45-70 degrees with the bottom of the furnace 11, and the coal powder is high-speed injected into the furnace 11 under the action of wind pressure.

[0033] The plasma generator 2 starts to work and generates high-temperature plasma, which is closely attached to the coal powder isolation net 6. The high-speed injected coal powder is rapidly ignited when passing through the plasma area. The coal powder isolation net 6 is made of high-temperature-resistant medium ceramic, metal fiber or sintered metal, which not only effectively isolates the coal powder and prevents direct contact with the plasma generator 2, but also maintains stable performance in a high-temperature environment. The high-temperature-resistant vibration motor 61 is started synchronously, and the coal powder at the outlet of the coal powder conveying pipeline 3 always maintains good fluidity through vibration, so that the coal powder can be continuously and stably injected out to ensure sufficient contact with the plasma and improve the ignition efficiency.

[0034] The air duct 4 continuously delivers sufficient air into the furnace 11 to provide the necessary oxygen for the combustion of the pulverized coal. The cooling air duct 7 introduces external cooling air through the input port, filters it through the second dustproof filter screen 71, and then outputs it from the output port towards the coal blowing fan 5, which plays a cooling role on the coal blowing fan 5 to ensure its stable operation, and also helps to maintain the temperature balance at the bottom of the furnace 11 to avoid affecting the service life of the equipment due to excessive local temperature. Under the synergistic action of various components, efficient and stable ignition is achieved, which greatly reduces the ignition cost compared with the traditional ignition mode, and also reduces the pollution to the environment.

Claims

1. A coal-fired boiler plasma ignition system comprising a coal-fired boiler (1), a plasma generator (2), said coal-fired boiler (1) being provided with a furnace (11), characterized in that, The furnace (11) is respectively communicated with a pulverized coal conveying pipe (3), an air pipe (4) and a cooling air duct (7), the coal-fired boiler (1) is provided with a coal blowing fan (5) at the bottom, the coal blowing fan (5) is communicated with the furnace (11) through a blowing pipe (51), a plurality of plasma generators (2) are arranged at the bottom of the furnace (11), a pulverized coal isolation net (6) is arranged above the plasma generators (2), the pulverized coal conveying pipe (3) and the air pipe (4) are located above the pulverized coal isolation net (6), and the cooling air duct (7) is located below the pulverized coal isolation net (6).

2. A coal-fired boiler plasma ignition system according to claim 1, wherein The pulverized coal conveying pipe (3) is provided with a one-way valve (31), an input port of the pulverized coal conveying pipe (3) is communicated with a previous process, and an output port of the pulverized coal conveying pipe (3) is communicated with the furnace (11).

3. A coal-fired boiler plasma ignition system according to claim 2, wherein The pulverized coal conveying pipe (3) is directed towards the bottom of the furnace (11), and the included angle between the pulverized coal conveying pipe (3) and the bottom of the furnace (11) is 45-70 degrees.

4. A coal-fired boiler plasma ignition system according to claim 1, wherein The plasma generators (2) are two, and the two plasma generators (2) are respectively located on the left and right sides above the blowing pipe (51).

5. A coal-fired boiler plasma ignition system according to claim 1, wherein The coal blowing fan (5) is a forward-reverse fan.

6. A coal-fired boiler plasma ignition system according to claim 1, wherein The pulverized coal isolation net (6) is made of high-temperature-resistant material, and the high-temperature-resistant material is selected from any one of ceramic, metal fiber and sintered metal.

7. A coal-fired boiler plasma ignition system according to claim 1 wherein, The coal-fired boiler (1) is provided with a high-temperature-resistant vibration motor (61) on one side, and the high-temperature-resistant vibration motor (61) is in the same plane as the pulverized coal isolation net (6).

8. A coal-fired boiler plasma ignition system according to claim 1, wherein The blowing pipe (51) is directed towards the pulverized coal isolation net (6), and the plasma generators (2) are close to the pulverized coal isolation net (6).

9. A coal-fired boiler plasma ignition system according to claim 1 wherein, The cooling air duct (7) is provided with a second dustproof screen (71), an input port of the cooling air duct (7) is communicated with an external process, an output port of the cooling air duct (7) is communicated with the bottom of the furnace (11), and the output port of the cooling air duct (7) is directed towards the coal blowing fan (5).

10. A coal-fired boiler plasma ignition system according to claim 1, wherein The blowing pipe (51) is provided with a dust isolation net (52).

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