PLC-based denitration control system applied to cement industry

Abstract

The utility model relates to the field of gas treatment, in particular to a denitration control system based on a PLC (Programmable Logic Controller), which is applied to the cement industry and comprises the PLC, an ammonia water distribution module, a compressed air module, a heating module and an SCR (Selective Catalytic Reduction) reactor, the input end of the ammonia water distribution module is connected with the ammonia water storage tank, and the output end of the ammonia water distribution module is connected to the flue gas input end of the SCR reactor; the output end of the compressed air module is connected with the SCR reactor, and the compressed air module is used for inputting compressed air into the SCR reactor so as to provide the compressed air to the sound wave soot blower; the output end of the air compression module is further connected with the heating module, and the heating module is used for heating compression control and providing the compression control to the rake type soot blower. An outlet of the SCR reactor is provided with ammonia gas detection equipment for detecting the ammonia gas escape amount; according to the system, the ammonia water distribution module, the compressed air module and the heating module in the denitration process are controlled by the PLC, so that the efficiency is higher.

Description

Technical Field

[0001] This utility model relates to the field of gas treatment, specifically a PLC-based denitrification control system applied in the cement industry. Background Technology

[0002] Denitrification technology, as a key means of controlling nitrogen oxide emissions in flue gas, has been widely used in energy-intensive industries such as power, steel, and cement. However, existing denitrification systems mainly rely on manual control, and still have shortcomings in terms of operating efficiency, energy consumption, and control system stability. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a PLC-based denitrification control system for the cement industry, so as to solve the problem that the existing denitrification system relies on manual labor.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This utility model discloses a PLC-based denitrification control system for the cement industry, comprising a PLC controller, an ammonia water distribution module, a compressed air module, a heating module, and an SCR reactor.

[0006] The input end of the ammonia water distribution module is connected to the ammonia water storage tank, and the output end of the ammonia water distribution module is connected to the flue gas input end of the SCR reactor.

[0007] The output of the compressed air module is connected to the SCR reactor to input compressed air into the SCR reactor for supply to the acoustic soot blower; the output of the compressed air module is also connected to the heating module, which controls the heating of the compressed air and supplies it to the rake soot blower.

[0008] The outlet of the SCR reactor is equipped with an ammonia detection device for detecting the amount of ammonia escaping. The ammonia detection device, the ammonia water distribution module, the compressed air module, and the heating module are all connected to the PLC controller.

[0009] In one embodiment of this application, the flue gas inlet of the SCR reactor is provided with a plurality of gate valves for adjusting the flue gas flow rate.

[0010] In one embodiment of this application, the ammonia storage tank is connected to the ammonia distribution module via an ammonia supply pump, and the ammonia supply pump is used to pump ammonia into the ammonia distribution module.

[0011] In one embodiment of this application, the compressed air module includes a plurality of air compressors and a compressed air tank. The output ends of the plurality of air compressors are connected to the input ends of the compressed air tank, the output ends of the compressed air tank are connected to the SCR reactor, and the output ends of the compressed air tank are also connected to the heating module.

[0012] In one embodiment of this application, the heating module includes a heater and a heat exchanger. The output end of the compressed air tank is connected to the input end of the heater, the output end of the heater is connected to the input end of the heat exchanger, and the output end of the heat exchanger is respectively connected to the first-layer rake soot blower, the second-layer rake soot blower and the third-layer rake soot blower of the SCR reactor.

[0013] In one embodiment of this application, the gas discharge end of the SCR reactor is connected to a waste heat boiler to send heated air to the waste heat boiler.

[0014] In one embodiment of this application, a first zipper machine, an intermediate silo, a second zipper machine, a third zipper machine, and a cooling water circulation system are provided below the solid discharge end of the SCR reactor;

[0015] The input end of the first zipper is connected to the solid discharge end of the SCR reactor, the output end of the first zipper is connected to the inlet of the intermediate silo, the outlet of the intermediate silo is connected to the input end of the second zipper, the output end of the second zipper is connected to the input end of the third zipper, the output end of the third zipper is connected to the dust collector return ash conveying device, and the cooling water circulation system is connected to the third zipper to cool it.

[0016] The beneficial effects of this utility model are as follows: This utility model provides a PLC-based denitrification control system for the cement industry, including a PLC controller, an ammonia water distribution module, a compressed air module, a heating module, and an SCR reactor; the input end of the ammonia water distribution module is connected to an ammonia water storage tank, and the output end of the ammonia water distribution module is connected to the flue gas input end of the SCR reactor; the output end of the compressed air module is connected to the SCR reactor to input compressed air into the SCR reactor for supplying it to the sonic soot blower; the output end of the compressed air module is also connected to the heating module, which is used to heat the compressed air and supply it to the rake soot blower; the outlet of the SCR reactor is equipped with an ammonia detection device for detecting the amount of ammonia gas escaping; this application utilizes a PLC controller to control the ammonia water distribution module, compressed air module, and heating module in the denitrification process, resulting in higher efficiency. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0018] Figure 1 This is a schematic diagram of a PLC-based denitrification control system for the cement industry according to this utility model.

[0019] Figure 2 This is the control logic diagram of this utility model;

[0020] 1-Ammonia water distribution module, 2-SCR reactor, 3-Inlet gate, 4-Air compressor, 5-Compressed air tank, 6-Heater, 7-Heat exchanger, 8-Ammonia water supply pump, 9-First zipper machine, 10-Intermediate silo, 11-Second zipper machine, 12-Third zipper machine, 13-Ammonia water storage tank. Detailed Implementation

[0021] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0022] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the layers related to the present invention and are not drawn according to the actual number, shape and size of the layers in the actual implementation. In the actual implementation, the form, number and proportion of each layer can be arbitrarily changed, and the layer layout may also be more complex.

[0023] Numerous details are explored in the following description to provide a more thorough explanation of embodiments of the present invention; however, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details.

[0024] like Figures 1-2 As shown, a PLC-based denitrification control system for the cement industry in this application includes a PLC controller, an ammonia water distribution module 1, a compressed air module, a heating module, and an SCR reactor 2.

[0025] The input end of the ammonia water distribution module 1 is connected to the ammonia water storage tank 13, and the output end of the ammonia water distribution module 1 is connected to the flue gas input end of the SCR reactor 2.

[0026] The output of the compressed air module is connected to the SCR reactor 2 to input compressed air into the SCR reactor 2 for supply to the sonic soot blower; the output of the compressed air module is also connected to the heating module, which is used to control the heating of the compressed air and supply it to the rake soot blower.

[0027] The outlet of SCR reactor 2 is equipped with an ammonia detection device for detecting the amount of ammonia escaping. The ammonia detection device, ammonia water distribution module 1, compressed air module, and heating module are all connected to the PLC controller.

[0028] The ammonia detection equipment mainly includes an ammonia concentration sensor and a flow meter. The amount of ammonia escaping can be obtained by multiplying the measured flow rate by the ammonia concentration. The ammonia water distribution module 1 is controlled based on the amount of ammonia escaping.

[0029] Programmable Logic Controllers (PLCs) are widely used in industrial automation as an industrial automation control device due to their advantages such as high reliability, high flexibility, and ease of programming and maintenance.

[0030] The PLC-based denitrification control system in this application leverages the advantages of PLCs to optimize the control strategy for the denitrification process. By using a PLC in the denitrification system, real-time monitoring and precise control of the entire system can be achieved, reducing the complexity of human intervention, improving system stability and response speed, and simultaneously reducing energy consumption.

[0031] The PLC can automatically adjust key parameters such as ammonia injection rate, reactor temperature, and pressure according to preset algorithms to ensure optimal denitrification efficiency and compliance with environmental quality standards. Furthermore, the PLC-based denitrification control system boasts excellent compatibility and scalability, facilitating future technology upgrades and functional expansion. Through modular design, various sensors and actuators can be flexibly integrated to build a highly efficient, intelligent, and customizable denitrification system solution.

[0032] In one embodiment of this application, the flue gas inlet of the SCR reactor 2 is provided with a plurality of gate valves 3 for adjusting the flue gas flow rate. Specifically, it includes four gate valves 3, two of which are inlet gate valves 3 (one of which is a spare), and the other two are outlet gate valves 3 (one of which is a spare).

[0033] In one embodiment of this application, the ammonia storage tank 13 is connected to the ammonia distribution module 1 via an ammonia supply pump 8, which pumps ammonia into the ammonia distribution module 1.

[0034] In this application, ammonia water and flue gas are fed together into SCR reactor 2 for denitrification reaction. This application can collect the amount of ammonia gas escaping and adjust the amount of ammonia water added accordingly. The more ammonia gas escapes, the more ammonia water is added.

[0035] In one embodiment of this application, the compressed air module includes a plurality of air compressors 4 and a compressed air tank 5. The output ends of the plurality of air compressors 4 are connected to the input ends of the compressed air tank 5. The output ends of the compressed air tank 5 are connected to the SCR reactor 2. The output ends of the compressed air tank 5 are also connected to the heating module.

[0036] In one embodiment of this application, the heating module includes a heater 6 and a heat exchanger 7. The output end of the compressed air tank 5 is connected to the input end of the heater 6, the output end of the heater 6 is connected to the input end of the heat exchanger 7, and the output end of the heat exchanger 7 is connected to the first-layer rake soot blower, the second-layer rake soot blower and the third-layer rake soot blower of the SCR reactor 2, respectively.

[0037] One path of unheated compressed air supplies the sonic sootblower for vibration cleaning. The other path supplies the rake sootblower; since it needs to enter the reactor, it must be preheated. Temperature affects the effectiveness of the catalyst within the reactor. Heated compressed air exhibits better catalytic performance.

[0038] In one embodiment of this application, the gas outlet of the SCR reactor 2 is connected to a waste heat boiler to send heated air to the waste heat boiler, thereby utilizing the waste heat from the reaction to provide a heat source for the boiler.

[0039] In one embodiment of this application, a first zipper 9, an intermediate hopper 10, a second zipper 11, a third zipper 12, and a cooling water circulation system are provided below the solid discharge end of the SCR reactor 2.

[0040] The input end of the first zipper 9 is connected to the solid discharge end of the SCR reactor 2. The output end of the first zipper 9 is connected to the inlet of the intermediate silo 10. The outlet of the intermediate silo 10 is connected to the input end of the second zipper 11. The output end of the second zipper 11 is connected to the input end of the third zipper 12. The output end of the third zipper 12 is connected to the dust collector return ash conveying device. The cooling water circulation system is connected to the third zipper 12 to cool the third zipper 12.

[0041] The remaining ash material is discharged and fed into the intermediate silo 10 via the first zipper 9. The second zipper 11 and the third zipper 12 then transport it to the dust collector's ash return conveying device.

[0042] This application collects real-time ammonia slip data and automatically or manually adjusts the ammonia injection rate according to operating conditions, ensuring that the ammonia slip concentration is always maintained within the optimal range. The operation screen collects equipment control signals and operational feedback signals, enabling remote monitoring and control of key on-site equipment, and significantly reducing workload and risks when combined with on-site monitoring. The automatic soot blowing system allows operators to modify automatic operating parameters according to operating conditions, effectively adapting to various situations.

[0043] In the above embodiments, although the present invention has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. The embodiments of the present invention are intended to cover all such substitutions, modifications, and variations falling within the broad scope of the appended claims.

[0044] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A PLC-based denitrification control system for the cement industry, characterized in that, Includes a PLC controller, ammonia water distribution module, compressed air module, heating module, and SCR reactor; The input end of the ammonia water distribution module is connected to the ammonia water storage tank, and the output end of the ammonia water distribution module is connected to the flue gas input end of the SCR reactor. The output of the compressed air module is connected to the SCR reactor to input compressed air into the SCR reactor for supply to the acoustic soot blower; the output of the compressed air module is also connected to the heating module, which controls the heating of the compressed air and supplies it to the rake soot blower. The outlet of the SCR reactor is equipped with an ammonia detection device for detecting the amount of ammonia escaping. The ammonia detection device, the ammonia water distribution module, the compressed air module, and the heating module are all connected to the PLC controller.

2. The PLC-based denitrification control system for the cement industry according to claim 1, characterized in that, The SCR reactor is equipped with multiple gate valves at the flue gas inlet for adjusting the flue gas flow rate.

3. The PLC-based denitrification control system for the cement industry according to claim 1, characterized in that, The ammonia storage tank is connected to the ammonia distribution module via an ammonia supply pump, which pumps ammonia into the ammonia distribution module.

4. The PLC-based denitrification control system for the cement industry according to claim 1, characterized in that, The compressed air module includes multiple air compressors and a compressed air tank. The output ends of the multiple air compressors are connected to the input end of the compressed air tank. The output end of the compressed air tank is connected to the SCR reactor. The output end of the compressed air tank is also connected to the heating module.

5. A PLC-based denitrification control system for the cement industry according to claim 4, characterized in that, The heating module includes a heater and a heat exchanger. The output end of the compressed air tank is connected to the input end of the heater, the output end of the heater is connected to the input end of the heat exchanger, and the output end of the heat exchanger is connected to the first-layer rake soot blower, the second-layer rake soot blower, and the third-layer rake soot blower of the SCR reactor, respectively.

6. The PLC-based denitrification control system for the cement industry according to claim 1, characterized in that, The gas outlet of the SCR reactor is connected to a waste heat boiler to send heated air to the waste heat boiler.

7. A PLC-based denitrification control system for the cement industry according to claim 1, characterized in that, Below the solid discharge end of the SCR reactor are a first zipper machine, an intermediate hopper, a second zipper machine, a third zipper machine, and a cooling water circulation system. The input end of the first zipper is connected to the solid discharge end of the SCR reactor, the output end of the first zipper is connected to the inlet of the intermediate silo, the outlet of the intermediate silo is connected to the input end of the second zipper, the output end of the second zipper is connected to the input end of the third zipper, the output end of the third zipper is connected to the dust collector return ash conveying device, and the cooling water circulation system is connected to the third zipper to cool it.

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