A kind of air supply system for power plant boiler high temperature corrosion prevention and control equipment

Abstract

The application provides a kind of air supply system for power station boiler high temperature corrosion prevention and control equipment, including secondary air main pipe, main pipe connecting pipe, prevention and control air main pipe, main pipe adjusting assembly, at least two shunt branch pipes and at least two groups of branch pipe adjusting assembly;Main pipe connecting pipe connects secondary air main pipe and prevention and control air main pipe, main pipe adjusting assembly includes the main pipe adjusting valve and pressure interlock controller of main pipe connecting pipe, pressure interlock controller is used for controlling the opening of main pipe adjusting valve according to the pressure in secondary air main pipe;Shunt branch pipe is connected with prevention and control air main pipe respectively, and a group of branch pipe adjusting assembly is correspondingly provided in each shunt branch pipe, and branch pipe adjusting assembly includes branch pipe adjusting valve and differential pressure interlock controller, and branch pipe adjusting valve is arranged in corresponding shunt branch pipe, and differential pressure interlock controller is used for controlling the opening of shunt branch pipe according to the pressure difference between inside and outside of corresponding shunt branch pipe.The system of the application supplies air continuously and stably, improves corrosion prevention and control effect, reduces operation and maintenance cost, prolongs the service life of pipeline.

Description

Technical Field

[0001] This invention belongs to the technical field of boiler air supply system, specifically relating to an air supply system for high-temperature corrosion prevention and control equipment in power plant boilers. Background Technology

[0002] Coal-fired power plant boilers are core equipment in power generation, and their safe and stable operation directly affects the reliability of power supply. Currently, coal-fired power plant boilers generally adopt low-NOx... x Combustion technology controls nitrogen oxide emissions by creating a reducing atmosphere in the main combustion zone, effectively suppressing NOx emissions. x In addition, under the reducing atmosphere of the main combustion zone, high concentrations of corrosive substances such as H2S, S, and CO are easily generated near the water-cooled walls. These substances react chemically with the metal material of the water-cooled walls, leading to high-temperature corrosion, thinning, leakage, and even tube rupture, seriously affecting boiler operation safety and increasing maintenance costs and downtime losses. Furthermore, to save on coal costs, most power plants currently widely blend high-sulfur coal, which releases a large amount of sulfur during combustion, further increasing the concentration of corrosive substances near the water-cooled walls. This makes the high-temperature corrosion problem more prominent, significantly accelerating the corrosion rate and drastically shortening the service life of the water-cooled walls. This severely restricts the flexibility of peak shaving and long-term safe operation of the unit. High-temperature corrosion prevention and control has become a core pain point in the operation and maintenance of power plant boilers under deep peak shaving conditions. Currently, among the methods for preventing and controlling high-temperature corrosion in boilers, specialized auxiliary air supply is a relatively efficient technical approach. By delivering customized air volume and pressure protective air to the corrosion area of ​​the wall, an air film is formed to block harmful flue gas erosion, thereby achieving high-temperature corrosion prevention and control.

[0003] However, existing supporting air supply equipment has many technical shortcomings: First, most use independent fans to supply protective air, resulting in high equipment investment costs, large energy consumption, and the need for separate air supply pipelines, leading to low system integration and cumbersome layout. Alternatively, air is directly drawn from the boiler's secondary air branch pipe, which can easily cause mutual interference between the main secondary air and the protective air pressure, resulting in poor air supply stability. Second, the air supply parameter adjustment is lagging. The main pipe often uses manual valves or fixed-opening air supply, which cannot be dynamically adjusted according to the boiler load. During deep peak shaving, there is excessive air supply at low loads and insufficient air supply at high loads, significantly reducing the corrosion control effect. Third, the air supply pipelines are often rigidly connected to the boiler body's rigid beams. Under high-temperature operation, thermal expansion stress cannot be released, easily leading to problems such as pipeline deformation, weld cracking, and air leakage. Fourth, there is a lack of graded pressure control and monitoring methods, making it impossible to accurately adapt the air supply parameters to the corrosion control needs of the area, significantly reducing the control effect. Therefore, there is an urgent need for an air supply device that solves the above problems. Summary of the Invention

[0004] The embodiments of the present invention aim to at least solve one of the technical problems existing in the prior art, and provide an air supply system for high-temperature corrosion prevention and control equipment for power plant boilers.

[0005] An embodiment of the present invention provides an air supply system for high-temperature corrosion prevention and control equipment for power plant boilers, including a secondary air main pipe, a main pipe connecting pipe, a prevention and control air main pipe, a main pipe regulating assembly, at least two branch pipes and at least two sets of branch pipe regulating assemblies; The main pipe connecting pipe connects the secondary air main pipe and the control air main pipe. The main pipe regulating component includes a main pipe regulating valve and a pressure interlock controller. The main pipe regulating valve is located on the main pipe connecting pipe. The pressure interlock controller is electrically connected to the main pipe regulating valve. The pressure interlock controller is used to control the opening degree of the main pipe regulating valve according to the pressure in the secondary air main pipe. At least two of the branch pipes are respectively connected to the main duct for ventilation control. Each branch pipe is provided with a set of branch pipe adjustment components. The branch pipe adjustment components include a branch pipe adjustment valve and a differential pressure interlock controller. The branch pipe adjustment valve is located on the corresponding branch pipe. The differential pressure interlock controller is electrically connected to the branch pipe adjustment valve. The differential pressure interlock controller is used to control the opening degree of the branch pipe according to the pressure difference between the inside and outside of the corresponding branch pipe.

[0006] In some embodiments of the present invention, the system further includes at least two air supply distributors, with each branch pipe having a corresponding air supply distributor at its outlet. The differential pressure interlock controller is used to control the opening of the branch pipe regulating valve based on the pressure difference between the pressure output by the air supply distributor and the pressure inside the branch pipe.

[0007] In some embodiments of the present invention, the air distributor is provided with a plurality of spaced and evenly distributed air outlets.

[0008] In some embodiments of the present invention, the air supply distributor is a cuboid structure, and the length direction of the cuboid structure is the same as the extension direction of the membrane water-cooled wall of the boiler.

[0009] In some embodiments of the present invention, the system further includes an expansion joint, one end of which is fixedly connected to the main air control pipe, and the other end of which is fixedly connected to the rigid beam of the boiler furnace body.

[0010] In some embodiments of the present invention, the system further includes at least two expansion joints, which are spaced apart along the length of the main duct for controlling airflow.

[0011] In some embodiments of the present invention, the system further includes two expansion joints, which are respectively located near both ends of the main air control pipe.

[0012] In some embodiments of the present invention, the system includes four branch pipes, which are connected to the main control pipe at intervals along the length of the main control pipe.

[0013] In some embodiments of the present invention, the system further includes a main pipe anemometer and multiple branch pipe anemometers. The main pipe anemometer is disposed inside the secondary air main pipe and is electrically connected to the pressure interlock controller. Each branch pipe has an anemometer inside and at its outlet. Each differential pressure interlock controller is electrically connected to two branch pipe anemometers corresponding to the inside and outlet of the branch pipe.

[0014] In some embodiments of the present invention, both the main pipe anemometer and the branch pipe anemometer are wind speed sensors or pitot tubes.

[0015] In the air supply system for high-temperature corrosion prevention and control equipment of power plant boilers according to embodiments of the present invention, the pressure interlock controller adjusts the opening of the main pipe regulating valve set on the main pipe connecting pipe according to the air pressure in the secondary air main pipe, so as to control the air volume delivered to the prevention and control air main pipe; the differential pressure interlock controller adjusts the opening of the branch pipe regulating valve set on the branch pipe according to the pressure difference between the pressure in the corresponding branch pipe and the pressure at the outlet of the branch pipe, so as to control the air volume output by the branch pipe. By installing an adjustable-opening control air main pipe between the secondary air main pipe and the branch pipes, mutual interference between secondary air and control air can be avoided, improving the stability of air supply. The airflow entering the control air main pipe is regulated by a pressure interlock controller, and the airflow output from the control air main pipe through the branch pipes is regulated by a differential pressure interlock controller. This allows for real-time dynamic adjustment of the air supply according to the boiler load, ensuring adequate air supply during low loads and sufficient air supply during high loads, thus improving corrosion prevention and control. Furthermore, by using two interlock controllers to regulate the opening of the control air main pipe and the branch pipes respectively, precise control of the airflow output can be achieved, further enhancing corrosion prevention and control. The air supply system of this invention can ensure a continuous and stable air supply to high-temperature corrosion prevention and control equipment, improving corrosion prevention and control effects, while simplifying the system structure, reducing operation and maintenance costs, and extending pipeline service life. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the air supply system for a high-temperature corrosion prevention and control device for a power plant boiler, according to an embodiment of the present invention.

[0017] The labels in the attached diagram are as follows: 1. Secondary air main pipe; 2. Pressure interlock controller; 3. Main pipe regulating valve; 4. Control air main pipe; 5. Expansion joint; 6. Furnace body rigid beam; 7. Diversion branch pipe; 8. Branch pipe regulating valve; 9. Air supply distributor; 10. Differential pressure interlock controller; 11. Main pipe connecting pipe. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit disclosure. The described embodiments are some, but not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0019] like Figure 1 As shown, an embodiment of the present invention provides an air supply system for high-temperature corrosion prevention and control equipment for power plant boilers, including a secondary air main pipe 1, a main pipe connecting pipe 11, a prevention and control air main pipe 4, a main pipe regulating assembly, at least two branch pipes 7, and at least two sets of branch pipe regulating assemblies. The main pipe connecting pipe 11 connects the secondary air main pipe 1 and the control air main pipe 4. The main pipe regulating component includes a main pipe regulating valve 3 and a pressure interlock controller 2. The main pipe regulating valve 3 is located on the main pipe connecting pipe 11. The pressure interlock controller 2 is electrically connected to the main pipe regulating valve 3. The pressure interlock controller 2 is used to control the opening degree of the main pipe regulating valve 3 according to the pressure in the secondary air main pipe 1. At least two branch pipes 7 are connected to the main duct 4 for ventilation. Each branch pipe 7 is provided with a set of branch pipe adjustment components. The branch pipe adjustment components include a branch pipe adjustment valve 8 and a differential pressure interlock controller 10. The branch pipe adjustment valve 8 is located on the corresponding branch pipe 7. The differential pressure interlock controller 10 is electrically connected to the branch pipe adjustment valve 8. The differential pressure interlock controller 10 is used to control the opening degree of the branch pipe 7 according to the pressure difference between the inside and outside of the corresponding branch pipe 7.

[0020] In the air supply system for high-temperature corrosion prevention and control equipment of power plant boilers according to the embodiment of the present invention, the pressure interlock controller 2 adjusts the opening of the main pipe regulating valve 3 set on the main pipe connecting pipe 11 according to the air pressure in the secondary air main pipe 1, so as to control the air volume delivered to the prevention and control air main pipe 4; the differential pressure interlock controller 10 adjusts the opening of the branch pipe regulating valve 8 set on the branch pipe 7 according to the pressure difference between the pressure in the corresponding branch pipe 7 and the pressure at the outlet of the branch pipe 7, so as to control the air volume output by the branch pipe 7. By installing an adjustable-opening control air main pipe 4 between the secondary air main pipe 1 and the branch pipe 7, mutual interference between the secondary air and the control air can be avoided, improving the stability of the air supply. The airflow entering the control air main pipe 4 is regulated by the pressure interlock controller 2, and the airflow output from the control air main pipe 4 through the branch pipe 7 is regulated by the differential pressure interlock controller 10. This allows for real-time dynamic adjustment of the air supply according to the boiler load, ensuring adequate air supply during low load periods and sufficient air supply during high load periods, thus improving corrosion prevention and control. Furthermore, by controlling the opening of the control air main pipe 4 and the branch pipe 7 respectively through two interlock controllers, precise control of the airflow output can be achieved, further enhancing the corrosion prevention and control effect. The air supply system of this embodiment can ensure a continuous and stable air supply to high-temperature corrosion prevention and control equipment, improve corrosion prevention and control effects, while simplifying the system structure, reducing operation and maintenance costs, and extending the service life of the pipelines.

[0021] Specifically, the two ends of the main pipe connecting pipe 11 are respectively connected to the center position of the secondary air main pipe 1 in the length direction and the center position of the control air main pipe 4 in the length direction, so as to ensure that the secondary air in the secondary air main pipe 1 diffuses more evenly to both ends of the control air main pipe 4 in the control air main pipe 4, so that the air in the control air main pipe 4 enters each branch pipe 7 more evenly.

[0022] In some embodiments of the present invention, the system further includes an expansion joint 5, one end of which is fixedly connected to the control air main pipe 4, and the other end of which is fixedly connected to the rigid beam 6 of the boiler furnace body. The control air main pipe 4 is fixed to the rigid beam 6 of the boiler furnace body via a flange connection with the expansion joint 5, which is used to compensate for the thermal expansion displacement of the control air main pipe 4 during high-temperature operation, release the thermal stress of the pipeline, and prevent the pipeline from deforming and cracking.

[0023] In some embodiments of the present invention, the system further includes at least two expansion joints 5, which are spaced apart along the length of the main air control pipe 4. Connecting the main air control pipe 4 and the rigid beam 6 of the furnace body with at least two expansion joints 5 improves the robustness of the connection between the main air control pipe 4 and the rigid beam 6 of the furnace body. Specifically, the number of expansion joints 5 can be two, three, four, five, six, or more than six.

[0024] In some embodiments of the present invention, the system further includes two expansion joints 5, which are respectively close to both ends of the main duct for controlling the airflow 4. By setting the two expansion joints 5 close to both ends of the main duct for controlling the airflow 4, sufficient installation space can be provided for the installation of the branch pipe 7.

[0025] In some embodiments of the present invention, the number of branch pipes 7 can be two, three, four, five, six, or more. In this embodiment, based on the air supply requirements and the size of the main air control pipe 4, the number of branch pipes 7 is set to four, that is, the system includes four branch pipes 7. The four branch pipes are connected to the main air control pipe 4 at intervals along the length of the main air control pipe 4, so that the air in the main air control pipe 4 enters the four branch pipes 7 more evenly. Specifically, the four branch pipes 7 are located between two expansion joints 5.

[0026] In some embodiments of the present invention, the system further includes at least two air supply distributors 9. Each branch pipe 7 has a corresponding air supply distributor 9 at its outlet, meaning the air supply distributor 9 is connected to the outlet of the corresponding branch pipe 7 to diffuse the air output from the outlet of the branch pipe 7. Each differential pressure interlock controller 10 controls the opening of the branch pipe regulating valve 8 based on the pressure difference between the pressure output by the air supply distributor 9 and the pressure inside the branch pipe 7, thereby achieving dynamic regulation of the air output from the branch pipe 7 and ensuring the stability of the air supply volume of each air supply distributor 9. To achieve dynamic regulation of the air supply volume of the air supply branch based on information such as the boiler's operating conditions, the differential pressure interlock controller 10 can be electrically connected to the boiler's control processor to control the air supply volume of each branch based on information such as the boiler's operating conditions and temperature. In order to dynamically adjust the air supply volume of the air supply branch based on information such as the boiler's operating conditions, the pressure interlock controller 2 can be electrically connected to the boiler's control processor to control the air supply volume of each control air main pipe 4 according to information such as the boiler's operating conditions and temperature.

[0027] In some embodiments of the present invention, the air distributor 9 is provided with a plurality of spaced and evenly distributed air outlets. By providing a plurality of air outlets facing the interior of the boiler furnace, the air supplied to the furnace can be more evenly distributed, thereby making combustion more complete.

[0028] In some embodiments of the present invention, the air distributor 9 has a cuboid structure, the length of which is the same as the extension direction of the boiler's membrane water-cooled wall. The cuboid air distributor 9 fits perfectly with the planar structure of the water-cooled wall, saving space and making the connection between the air distributor 9 and the water-cooled wall more stable. This ensures that the air supply can be delivered evenly and stably into the furnace, thereby making the boiler burn more vigorously, more safely, and more durable.

[0029] In some embodiments of the present invention, the system further includes a main pipe wind speed measuring device (not shown in the figure). The main pipe wind speed measuring device is located in the secondary air main pipe 1 and is electrically connected to the pressure interlock controller 2. The main pipe wind speed measuring device acquires information such as air volume and wind speed in the secondary air main pipe 1 and transmits the air volume and wind speed information to the pressure interlock controller 2. The pressure interlock controller 2 adjusts the air volume delivered to the control air main pipe 4 according to the air volume and wind speed information.

[0030] The system also includes multiple branch anemometers (not shown in the figure). Each branch branch 7 has one anemometer inside and one at its outlet. Each differential pressure interlock controller 10 is electrically connected to the two branch anemometers inside and at the outlet of the corresponding branch branch 7. The branch anemometers acquire information such as air volume and velocity inside the branch branch 7 and air volume and velocity at the outlet of the branch branch 7, and transmit the air volume and velocity information to the differential pressure interlock controller 10. The differential pressure interlock controller 10 adjusts the air volume delivered to the branch branch 7 based on the difference between the air pressure inside the branch branch 7 and the air pressure at the outlet of the branch branch 7.

[0031] In some embodiments of the present invention, both the main pipe anemometer and the branch pipe anemometer are wind speed sensors or pitot tubes. Wind speed sensors or pitot tubes can be used to measure information such as wind speed and wind pressure within the pipeline, enabling precise system-level control and stable, durable equipment.

[0032] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. An air supply system for high-temperature corrosion prevention and control equipment in power plant boilers, characterized in that, Includes a secondary air main duct, main duct connecting pipes, control air main duct, main duct regulating components, at least two branch ducts and at least two sets of branch duct regulating components; The main pipe connecting pipe connects the secondary air main pipe and the control air main pipe. The main pipe regulating component includes a main pipe regulating valve and a pressure interlock controller. The main pipe regulating valve is located on the main pipe connecting pipe. The pressure interlock controller is electrically connected to the main pipe regulating valve. The pressure interlock controller is used to control the opening degree of the main pipe regulating valve according to the pressure in the secondary air main pipe. At least two of the branch pipes are respectively connected to the main duct for ventilation control. Each branch pipe is provided with a set of branch pipe adjustment components. The branch pipe adjustment components include a branch pipe adjustment valve and a differential pressure interlock controller. The branch pipe adjustment valve is located on the corresponding branch pipe. The differential pressure interlock controller is electrically connected to the branch pipe adjustment valve. The differential pressure interlock controller is used to control the opening degree of the branch pipe according to the pressure difference between the inside and outside of the corresponding branch pipe.

2. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 1, characterized in that, The system also includes at least two air supply distributors, with each branch pipe having a corresponding air supply distributor at its outlet. The differential pressure interlock controller is used to control the opening of the branch pipe regulating valve based on the pressure difference between the pressure output by the air supply distributor and the pressure inside the branch pipe.

3. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 2, characterized in that, The air supply distributor is provided with multiple spaced and evenly distributed air outlets.

4. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 2, characterized in that, The air supply distributor has a cuboid structure, and the length direction of the cuboid structure is the same as the extension direction of the membrane water-cooled wall of the boiler.

5. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 1, characterized in that, The system also includes an expansion joint, one end of which is fixedly connected to the main air control pipe, and the other end of which is fixedly connected to the rigid beam of the boiler furnace body.

6. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 5, characterized in that, The system also includes at least two expansion joints, which are spaced apart along the length of the main duct for controlling airflow.

7. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 6, characterized in that, The system also includes two expansion joints, which are located near the two ends of the main air control pipe.

8. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 1, characterized in that, The system includes four branch pipes, which are connected to the main control pipe at intervals along the length of the main control pipe.

9. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 1, characterized in that, The system also includes a main pipe anemometer and multiple branch pipe anemometers. The main pipe anemometer is located inside the secondary air main pipe and is electrically connected to the pressure interlock controller. Each branch pipe has an anemometer located inside and at its outlet. Each differential pressure interlock controller is electrically connected to two branch pipe anemometers located inside and at their respective outlets of the branch pipe.

10. The air supply system for high-temperature corrosion prevention and control equipment in power plant boilers according to claim 9, characterized in that, Both the main pipe anemometer and the branch pipe anemometer are wind speed sensors or pitot tubes.

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