Flue gas denitration efficiency improvement control device for full-combustion gas boiler

Abstract

The invention relates to a full-combustion gas boiler flue gas denitration efficiency improvement control device which comprises a boiler hearth, a driving device shell, a spray gun, a servo motor, a universal flexible connector, a compression spring, a piston, a gas cavity, a quick exhaust pipeline, a denitration agent pipeline, a quick return electromagnetic valve and the like. Wherein the adjustable denitration spray gun overall device is fixedly installed on the right side of a hearth, the spray gun penetrates through the driving device shell and the air cavity, the driving device shell and the air cavity are connected through the universal flexible connector, and the servo motor is fixedly installed at the bottom of the driving device shell and connected with the spray gun through a ball head. A piston is installed in the air cavity and fixedly installed with the spray gun, and the air source output end on the left side of the pneumatic positioning and control device is connected with the air cavity through a quick exhaust pipeline. The flue gas temperature field is positioned and analyzed, and the position of the spray gun is automatically controlled, so that a denitration agent and high-temperature flue gas are fully blended and reacted, and the denitration effect is improved.

Description

Technical Field

[0001] This invention relates to a control device, specifically a control device for improving the denitrification efficiency of flue gas in a coal-fired boiler, belonging to the field of flue gas denitrification control technology for coal-fired boilers. Background Technology

[0002] Currently, ultra-low emission requirements for thermal power plants and steel enterprises are becoming increasingly stringent, especially after 2014, when strict emission standards were established, requiring all thermal power units nationwide to achieve ultra-low emissions by 2020. The NOx content in boiler flue gas is related to the nitrogen content in blast furnace gas and coke oven gas, as well as the combustion center temperature. Therefore, the application of flue gas denitrification devices is extremely common in thermal power plants. The BSNCR biomass denitrification process is a novel flue gas denitrification technology. Its principle is as follows: the biomass denitrification agent is injected into the furnace within the flue gas temperature range of 700-950℃ using a spray gun. Under the catalytic action of calcium ions and high temperature, it rapidly decomposes to produce highly active free reducing groups, which react with NOx to reduce NOx to N2, CO2, and H2O.

[0003] After extensive use of denitrification agent, it was found that the agent produced large amounts of scale on each stage of the superheater in the furnace, affecting the boiler's heat exchange efficiency and causing the flue gas to fail to exchange heat effectively, resulting in excessively high exhaust gas temperature. The cause was found to be that the denitrification spray gun was fixed in the same position and sprayed the denitrification agent in the same direction for an extended period of time.

[0004] Because the denitrification spray gun is fixed in a high-temperature zone for a long time, it becomes clogged and there is no effective cooling medium, resulting in large-scale damage to the denitrification spray gun and further affecting the denitrification effect.

[0005] There is an urgent need to invent a device for denitrification of high-temperature flue gas in boilers that can automatically target and track concentrated areas of flue gas to adjust the direction of denitrification agent injection, improve denitrification efficiency, avoid the drawback of heat pipe scaling caused by long-term injection in the same area, and design a device that can cool the spray gun head online and automatically retract the spray gun to protect the safe operation of the spray gun. Summary of the Invention

[0006] This invention addresses the technical problems existing in the prior art by providing a control device for improving the efficiency of flue gas denitrification in all-gas-fired boilers. This ingenious and compact design achieves automatic, efficient, and precise denitrification, overcoming the problems of short lifespan of denitrification spray guns and easy scaling of denitrification agents in conventional biomass calcium denitrification technology. Through automatic adjustment and withdrawal of the spray guns, the aim is to ensure a better denitrification agent injection flow field, resulting in more thorough and effective denitrification of the high-temperature flue gas. Simultaneously, it prevents scaling of the flue gas on downstream heating surfaces and air preheaters when the denitrification agent reaction is incomplete.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: a control device for improving the denitrification efficiency of flue gas in a coal-fired boiler. The control device includes a boiler furnace, a drive unit housing, a spray gun, a servo motor, a universal flexible connector, a compression spring, a piston, a gas chamber, a quick-exhaust pipeline, a denitrification agent pipeline, a quick-return solenoid valve, a compressed air source, a pneumatic positioning and control device, a temperature probe cable, and a servo motor control cable. The adjustable denitrification spray gun is fixedly installed on the right side of the furnace. The spray gun is installed through the drive unit housing and the gas chamber. The drive unit housing and the gas chamber are connected by a universal flexible connector, facilitating free adjustment of the spray gun head direction. The movement and drive unit has a servo motor fixedly mounted on its bottom housing. The servo motor is connected to the spray gun via a ball joint. A piston is installed inside the air chamber and is fixedly mounted to the spray gun. The piston is connected to one side of the air gun via a compression spring. A denitrification agent pipeline runs through the piston. A compressed air source is installed at the top of the pneumatic positioning and control device. One end of the air source output on the left side of the pneumatic positioning and control device is connected to the air chamber via a quick-release pipeline, with a quick-return solenoid valve installed in the middle for control. One end of the input on the left side of the pneumatic positioning and control device is connected to a temperature probe via a temperature probe cable, and one end of the output on the left side of the pneumatic positioning and control device is connected to the servo motor via a servo motor control cable.

[0008] As an improvement of the present invention, the control device further includes a temperature probe, which is mounted on the head of the spray gun.

[0009] As an improvement of the present invention, the control device further includes a cooling pipeline, and a cooling pipeline is added to one end of the pneumatic positioning and control device bottom output.

[0010] The control process is as follows: an infrared temperature probe positioned at the spray gun head detects the concentrated distribution area of ​​the high-temperature flue gas temperature field within the flue in real time. The infrared temperature detection and control instrument calculates and analyzes the temperature signal, and uses thermal imaging analysis to locate and determine the concentrated distribution direction of the high-temperature flue gas within the flue. The pneumatic positioning and control device compares the set positions (up, down, left, right) inside the flue reaction zone with the temperature detection positioning signals and outputs the following: one control output sends a servo motor to adjust the up, down, left, and right displacement of the spray gun head; the other control output sends compressed air to cool the spray gun head online. When the denitrification process stops, to prevent the spray gun head from being damaged by the high-temperature flue gas, the pneumatic positioning and control device outputs a control signal to de-energize the quick-exhaust solenoid valve, venting the air chamber and causing the spray gun to automatically retract.

[0011] Compared with existing technologies, this invention has the following advantages: 1. This scheme detects and automatically determines the temperature and flow fields of the high-temperature flue gas distribution area within the reaction zone, locates the thermal NOx concentration area, and outputs control signals to drive the spray gun to adjust the spray position. This maximizes the mixing and fusion of the denitrification agent and the high-temperature flue gas, improves reaction efficiency, enhances denitrification effect, and prevents incomplete reaction from causing large-area scaling of reaction residues on the heating surface, affecting the heat exchange efficiency of the boiler heating surface; 2. This scheme utilizes a servo motor and electric gear to drive the spray rod to rotate up, down, left, and right. It provides all-around three-dimensional control of the spray direction of the spray device; 3. The infrared temperature detection and control device in this scheme, by adding a temperature detector to the spray gun head, detects the concentration of the flue gas temperature field using an infrared temperature detector. A concentrated flue gas temperature distribution area is considered the area with the highest flue gas density. The high-temperature flue gas flows unevenly in the horizontal flue at a certain velocity. The corresponding infrared detector, through temperature measurement and flow field analysis, analyzes the location of the flue gas concentration area. Theoretically, the temperature acquisition of the high-temperature concentration area should correspond to the flue gas distribution concentration area. The control system collects, analyzes, judges, and outputs control signals to drive the denitrification agent spray gun to adjust its direction; 4. The solution provides an online compressed air automatic cooling spray gun head and an automatic spray gun retraction device. This ensures the spray gun's working safety to the greatest extent and improves its service life; 5. The solution designs a desulfurization agent spray gun that can automatically adjust its spray direction, precisely controlling the spray position and angle, so that the denitrification agent tracks the concentrated distribution area of ​​flue gas to carry out the denitrification reaction, improving the denitrification effect; 6. The solution designs an infrared temperature detection and control system, which analyzes the flue gas temperature field and automatically controls the spray gun to adjust its position, achieving full mixing and reaction between the denitrification agent and the high-temperature flue gas, improving the denitrification effect. Attached Figure Description

[0012] Figure 1 This is a site layout diagram for an adjustable pin-removing spray gun.

[0013] Figure 2 This is a block diagram illustrating the principle of a pneumatic positioning and control device.

[0014] In the diagram: 1. Boiler furnace, 2. Temperature probe, 3. Drive unit housing, 4. Spray gun, 5. Servo motor, 6. Universal flexible connector, 7. Compression spring, 8. Piston, 9. Air chamber, 10. Quick exhaust pipeline, 11. Denitrification agent pipeline, 12. Quick return solenoid valve, 13. Compressed air source, 14. Pneumatic positioning and control device, 15. Cooling pipeline, 16. Temperature probe cable, 17. Servo motor control cable. Detailed Implementation

[0015] To enhance understanding of the present invention, the embodiments will be described in detail below with reference to the accompanying drawings.

[0016] Example 1: See Figure 1 , Figure 2 A control device for improving the denitrification efficiency of flue gas in a coal-fired boiler is disclosed. The control device includes a boiler furnace 1, a drive unit housing 3, a spray gun 4, a servo motor 5, a universal flexible connector 6, a compression spring 7, a piston 8, a gas chamber 9, a quick-exhaust pipeline 10, a denitrification agent pipeline 11, a quick-return solenoid valve 12, a compressed air source 13, a pneumatic positioning and control device 14, a temperature probe cable 16, and a servo motor control cable 17. The adjustable denitrification spray gun is fixedly installed on the right side of the furnace 1. The spray gun 4 is installed through the drive unit housing 3 and the gas chamber 9. The drive unit housing 3 and the gas chamber 9 are connected by the universal flexible connector 6, facilitating free movement of the spray gun head. The servo motor 5 is fixedly installed at the bottom of the drive unit housing 3 and connected to the spray gun via a ball joint. A piston spring 7 is installed inside the gas chamber 9. The piston 8 and spray gun 4 are fixedly installed. The piston 8 is connected to the air gun 9 on one side by a compression spring 7. The denitrification agent pipeline 11 is installed through the piston 8. The upper end of the pneumatic positioning and control device 14 is equipped with a compressed air source 13. The left end of the pneumatic positioning and control device 14 is connected to the air chamber 9 through a quick exhaust pipeline 10. A quick return solenoid valve 12 is installed in the middle for control. The left end of the pneumatic positioning and control device 14 is connected to the temperature probe 2 through a temperature probe cable 16. The left end of the pneumatic positioning and control device 14 is connected to the servo motor 5 through a servo motor control cable 17. The control device also includes a temperature probe 2, which is installed at the head of the spray gun 4. The control device also includes a cooling pipeline 15, which is installed at the bottom end of the pneumatic positioning and control device 14.

[0017] The control process is as follows: an infrared temperature probe positioned at the spray gun head detects the concentrated distribution area of ​​the high-temperature flue gas temperature field within the flue in real time. The infrared temperature detection and control instrument calculates and analyzes the temperature signal, and uses thermal imaging analysis to locate and determine the concentrated distribution direction of the high-temperature flue gas within the flue. The pneumatic positioning and control device compares the set positions (up, down, left, right) inside the flue reaction zone with the temperature detection positioning signals and outputs the following: one control output sends a servo motor to adjust the up, down, left, and right displacement of the spray gun head; the other control output sends compressed air to cool the spray gun head online. When the denitrification process stops, to prevent the spray gun head from being damaged by the high-temperature flue gas, the pneumatic positioning and control device outputs a control signal to de-energize the quick-exhaust solenoid valve, venting the air chamber and causing the spray gun to automatically retract.

[0018] Working Principle: The denitrification agent is fed into the spray gun through the denitrification agent pipeline. When the high-temperature flue gas from the boiler furnace enters the reaction zone, the infrared temperature probe deployed in this patented technology detects the temperature distribution field of the flue gas in real time. The infrared temperature detection and control instrument calculates and analyzes the temperature signal, and uses thermal imaging analysis to locate and determine the concentrated distribution direction of the high-temperature flue gas in the flue. The pneumatic positioning and control device compares the set position (up, down, left, right) inside the flue reaction zone with the temperature detection positioning signal and outputs the result. When it detects that the high-temperature flue gas is distributed in different areas within the flue reaction zone, the system outputs a control signal to the servo motor to control the up, down, left, and right displacement adjustment of the spray gun position. At the same time, a compressed air source is output to cool the spray gun head online. By detecting the temperature field of the high-temperature flue gas distribution area in the flue reaction zone, automatically judging, locating, and outputting control signals to drive the spray gun to adjust the spray position, the mixing and fusion of the denitrification agent and the high-temperature flue gas is maximized, improving reaction efficiency and enhancing desulfurization effect. When the denitrification process stops, to prevent the spray gun head from being damaged by the high-temperature flue gas, the pneumatic positioning and control device outputs a control signal to de-energize the quick-exhaust solenoid valve, causing the air chamber to exhaust and the spray gun to automatically retract. This maximizes the safety of the spray gun during operation and extends its service life.

[0019] In summary, this patented technology, through a novel device for improving the denitrification efficiency of flue gas in coal-fired boilers, achieves a highly efficient reaction between the denitrification agent and high-temperature flue gas by automatically adjusting the spray position and angle of the denitrification spray gun, thereby increasing the reaction efficiency of the denitrification agent and enhancing the denitrification effect. Furthermore, the online cooling and automatic retraction of the spray gun ensures safe operation. This patented technology represents a significant breakthrough for environmentally friendly production and ultra-low emissions in the thermal power and steel industries.

[0020] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention. Equivalent transformations or substitutions made based on the above technical solutions all fall within the scope of protection of the claims of the present invention.

Claims

1. A control device for improving the denitrification efficiency of flue gas from a coal-fired boiler, characterized in that, The control device includes a boiler furnace, a drive unit housing, a spray gun, a servo motor, a universal flexible connector, a compression spring, a piston, a gas chamber, a quick exhaust pipeline, a denitrification agent pipeline, a quick return solenoid valve, a compressed air source, a pneumatic positioning and control device, a temperature probe cable, and a servo motor control cable. The adjustable denitrification spray gun is fixedly installed on the right side of the furnace. The spray gun is installed through the drive unit housing and inside the gas chamber. The drive unit housing and the gas chamber are connected by a universal flexible connector, allowing for free movement of the spray gun head. The servo motor is fixedly installed at the bottom of the drive unit housing. The servo motor and spray gun are connected via a ball joint. A piston is installed inside the air chamber and is fixedly installed with the spray gun. The piston is connected to one side of the air gun via a compression spring. A denitrification agent pipeline runs through the piston. A compressed air source is installed at the top of the pneumatic positioning and control device. One end of the air source output on the left side of the pneumatic positioning and control device is connected to the air chamber via a quick-release pipeline. A quick-return solenoid valve is installed in the middle for control. One end of the input on the left side of the pneumatic positioning and control device is connected to the temperature probe via a temperature probe cable. One end of the output on the left side of the pneumatic positioning and control device is connected to the servo motor via a servo motor control cable.

2. The control device for improving the denitrification efficiency of flue gas from a coal-fired boiler according to claim 1, characterized in that, The control device also includes a temperature probe, which is installed at the head of the spray gun.

3. The control device for improving the denitrification efficiency of flue gas from a coal-fired boiler according to claim 2, characterized in that, The control device also includes a cooling pipeline, and a cooling pipeline is installed at one end of the pneumatic positioning and control device bottom output.

4. The control device for improving the denitrification efficiency of a coal-fired boiler according to claim 3, characterized in that, The control process is as follows: an infrared temperature probe positioned at the spray gun head detects the concentrated distribution area of ​​the high-temperature flue gas temperature field within the flue in real time. The infrared temperature detection and control instrument calculates and analyzes the temperature signal, and uses thermal imaging analysis to locate and determine the concentrated distribution direction of the high-temperature flue gas within the flue. The pneumatic positioning and control device compares the set positions (up, down, left, right) inside the flue reaction zone with the temperature detection positioning signals and outputs the following: one control output sends a servo motor to adjust the up, down, left, and right displacement of the spray gun head; the other control output sends compressed air to cool the spray gun head online. When the denitrification process stops, to prevent the spray gun head from being damaged by the high-temperature flue gas, the pneumatic positioning and control device outputs a control signal to de-energize the quick-exhaust solenoid valve, venting the air chamber and causing the spray gun to automatically retract.

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