An air preheater flue gas pipeline blockage online monitoring and unblocking system

Abstract

The present application relates to a kind of air preheater flue gas pipeline blockage on-line monitoring and clearing system, belong to air preheater technical field, including infrared detection system and heat source system, further including along the equal interval arrangement of flue gas pipeline body length direction and install in the inside of flue gas pipeline body constant opening baffle, the constant opening baffle is controlled unfolding by opening and closing device;The infrared detection system includes the infrared acquisition device for shooting flue gas pipeline body infrared image and the monitoring control module for identifying flue gas pipeline body blockage area, the flue gas pipeline body between any two adjacent constant opening baffle is connected with heat source system by jet pipe, infrared acquisition device and each the heat source system is electrically connected with monitoring control module.The present application realizes the timely early warning to air preheater flue gas pipeline blockage, and can respond quickly and clear, guarantee air preheater normal operation.

Description

Technical Field

[0001] This invention relates to an online monitoring and unblocking system for air preheater flue gas duct blockage, belonging to the field of air preheater technology. Background Technology

[0002] With increasingly stringent environmental emission standards, coal-fired boilers are generally equipped with SCR denitrification devices. During the denitrification process, unreacted escaped ammonia (NH3) reacts with sulfur trioxide (SO3) in the flue gas at a suitable temperature to generate ammonium bisulfate (NH4HSO4). Ammonium bisulfate is in a molten and viscous state between 147℃ and 230℃, which easily adheres to the heat exchange surface of the air preheater and captures fly ash, leading to blockage of the air preheater flue gas duct.

[0003] Once the flue gas duct of the air preheater becomes blocked, the pressure difference between the air preheater inlet and outlet will rise sharply, the power consumption of the induced draft fan will increase, and in severe cases, the boiler may even be forced to shut down for manual cleaning. At present, there is a lack of accurate means of monitoring the location of the blockage, and it is often only discovered after the blockage has become severe and the pressure difference has risen significantly, which makes it impossible to deal with it in time. Therefore, it is urgent to improve it. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention designs an online monitoring and unblocking system for air preheater flue gas duct blockage, which enables timely early warning of air preheater flue gas duct blockage and can quickly respond to unblocking, ensuring the normal operation of the air preheater.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: Technical Solution 1 An online monitoring and unblocking system for air preheater flue gas duct blockage includes an infrared detection system and a heat source system. It also includes normally open baffles that are arranged at equal intervals along the length of the flue gas duct body and installed inside the flue gas duct body. The normally open baffles are controlled to unfold by an opening and closing device. The infrared detection system includes an infrared acquisition device for capturing infrared images of the flue gas duct body and a monitoring and control module for identifying blocked areas in the flue gas duct body. A heat source system is connected to the flue gas duct body between any two adjacent normally open baffles via jet pipes. The infrared acquisition device and each of the heat source systems are electrically connected to the monitoring and control module.

[0006] Furthermore, the monitoring and control module includes: Temperature field reference module: used to store healthy temperature field data of the flue gas duct body under clean conditions; Temperature difference analysis module: used to compare the real-time temperature field with the healthy temperature field to identify abnormal temperature areas; Blockage Detection Module: When the temperature of a certain area is continuously higher than the healthy temperature field of the corresponding area and the temperature difference exceeds the set threshold, it is determined that there is a blockage in that area; Heating control module: Based on the blockage determination result, activate the heat source system of the corresponding area to release high-temperature hot gas into the flue gas duct body; Effect verification module: After heating is completed, the temperature field of the area is analyzed again. If the temperature returns to the normal range, the blockage is considered to have been cleared successfully.

[0007] Furthermore, the normally open baffle includes two symmetrically arranged baffle bodies, with a plurality of first rotating rods and second rotating rods arranged alternately between the two baffle bodies, and the first rotating rods and second rotating rods are arranged coaxially. One baffle body is fixedly connected to each of the first rotating rods, and the other baffle body is fixedly connected to each of the second rotating rods. The opening and closing device is used to drive the first rotating rods and second rotating rods to rotate in opposite directions.

[0008] Furthermore, the opening and closing device includes a first rotating block, a second rotating block, and a reciprocating pushing mechanism. The free end of the second rotating rod, which is located at the end, rotates and seals through the flue gas duct body and is fixedly connected to the second rotating block. The first rotating block is spaced apart at the free end of the second rotating block. A sleeve rod is fixedly connected to the first rotating block. The free end of the sleeve rod is rotatably sleeved inside the second rotating rod, and the sleeve rod is fixedly sleeved with at least one first rotating rod. The reciprocating pushing mechanism is located outside the flue gas duct body and is used to drive the first rotating block and the second rotating block to rotate in opposite directions.

[0009] Furthermore, the reciprocating pushing mechanism includes an outer U-shaped frame, an inner U-shaped frame is slidably installed in the U-shaped groove of the outer U-shaped frame, the opening direction of the inner U-shaped frame is the same as the opening direction of the outer U-shaped frame, and a telescopic cylinder is provided between the inner U-shaped frame and the outer U-shaped frame. An inner extension plate is integrally provided on both side walls of the inner U-shaped frame, and a toggle slot is provided on both inner extension plates. The first rotating block has an integrally formed first extension protrusion on its side, and a first actuating rod is vertically fixedly connected to the first extension protrusion. The free end of the first actuating rod is movably locked in one of the actuating slots. The second rotating block has an integrally formed second extension protrusion on its side. A second actuating rod is vertically fixedly connected to the second extension protrusion. The free end of the second actuating rod is movably engaged in another actuating slot.

[0010] Furthermore, an infrared acquisition device is installed on the outside of the flue gas duct body between any two adjacent normally open baffles, and each of the infrared acquisition devices is connected to the cooling device.

[0011] Furthermore, the cooling device includes a cold source system and a fan system connected to the cold source system. The infrared acquisition device is connected to the fan system through a main cooling pipe, and an auxiliary cooling pipe is also connected between the main cooling pipe and the fan system.

[0012] Furthermore, a swirling nozzle is provided at the nozzle where the jet pipe connects to the flue gas duct body, and the swirling nozzle is located upstream between any two adjacent normally open baffles.

[0013] Furthermore, the heat source system outputs hot air at 300°C to 340°C.

[0014] Technical Solution Two A method for unblocking a blockage-free system based on the online monitoring and unblocking system for air preheater flue gas duct blockage in technical solution one includes the following steps: Step 1: Establish a health baseline by collecting the temperature field of the flue gas duct body under clean conditions as the health temperature field. Step 2: Real-time monitoring, continuously collecting the temperature field of the flue gas duct body during the operation of the air preheater; Step 3: Temperature difference analysis and blockage location. The real-time temperature field is compared with the healthy temperature field to identify abnormal temperature areas and determine their corresponding heating zones. Step 4: Targeted heating to clear blockages. Start the heat source system of the corresponding heating zone and introduce hot air at 300°C to 340°C into the flue gas duct body of the corresponding heating zone. At the same time, control the normally open baffle at the downstream position of the corresponding heating zone to open, thereby decomposing the ammonium bisulfate adhering to the inner wall of the flue gas duct body. Step 5: Effect verification. After the targeted heating and blockage removal is completed, the temperature field of the area is collected again to verify the blockage removal effect. Step 6: Loop through the monitoring process and return to Step 2 to continue monitoring.

[0015] Compared with the prior art, the present invention has the following features and beneficial effects: 1. This invention breaks through the limitations of traditional overall unblocking or manual locating of blockage points. By independently setting infrared acquisition devices in each heating pipe unit, combined with the temperature field reference module, temperature difference analysis module and blockage determination module of the monitoring and control module, it achieves precise positioning of the blockage area. When clearing the blockage, only the heat source system at the corresponding location is activated for targeted heating, avoiding ineffective heating of the entire pipeline system and significantly reducing energy consumption.

[0016] 2. This invention constructs a complete closed loop from anomaly identification, blockage determination, fixed-point blockage clearing to effect feedback by using the temperature difference analysis module, blockage determination module, heating control module and effect verification module built into the monitoring and control module. The system can automatically complete the entire process of monitoring, blockage clearing and verification without manual intervention, which greatly improves the efficiency of operation and maintenance and the level of intelligence. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a system connection block diagram of the monitoring and control module of the present invention; Figure 3 This is a schematic diagram of the structure of the normally open baffle of the present invention after it has been unfolded; Figure 4 This is a schematic diagram of the cooperation between the opening and closing device of the present invention and the normally open baffle; Figure 5 This is a schematic diagram of the opening and closing device of the present invention.

[0018] The attached diagrams are labeled as follows: 1. Flue gas duct body; 11. Heating duct unit; 2. Cooling device; 21. Cold source system; 22. Fan system; 23. Infrared acquisition device; 24. Main cooling pipe; 25. Auxiliary cooling pipe; 3. Heat source system; 31. Jet pipe; 4. Opening and closing device; 41. Outer U-shaped frame; 42. Baffle body; 43. Telescopic cylinder; 44. Inner U-shaped frame; 441. Inner extension plate; 442. Actuating slot; 45. First rotating block; 451, First extended protrusion; 4511, First actuating rod; 452, First rotating rod; 453, Sleeve rod; 46, Second rotating block; 461, Second extended protrusion; 4611, Second actuating rod; 462, Second rotating rod; 100, Monitoring and control module; 101, Temperature field reference module; 102, Temperature difference analysis module; 103, Blockage determination module; 104, Heating control module; 105, Effect verification module. Detailed Implementation

[0019] The present invention will now be described in more detail with reference to the embodiments.

[0020] Example 1 Please see Figures 1 to 5 The air preheater flue gas duct blockage online monitoring and unblocking system of this embodiment includes an infrared detection system and a heat source system 3. In this embodiment, the heat source system 3 can output hot air at 300°C to 340°C.

[0021] This embodiment also includes normally open baffles that are evenly spaced along the length of the flue gas duct body 1 and installed inside the flue gas duct body 1. It should be emphasized that the normally open baffles are in the normally open state when the air preheater is working normally to avoid affecting the delivery of flue gas. The normally open baffles are controlled to open by the opening and closing device 4. Moreover, when the normally open baffles are fully opened by the opening and closing device 4, they will not completely close the flue gas duct body 1. The normally open baffles are only used to change the airflow path of the incoming hot air. This disturbance can cause the hot air to impact the ammonium bisulfate adhering to the inner wall of the flue gas duct body 1, and the high temperature of over 300°C will cause the ammonium bisulfate to vaporize and decompose, thereby achieving unblocking.

[0022] Specifically, the infrared detection system includes an infrared acquisition device 23 for capturing infrared images of the flue gas duct body 1 and a monitoring and control module 100 for identifying blocked areas of the flue gas duct body 1. A heat source system 3 is connected to the flue gas duct body 1 between any two adjacent normally open baffles via a jet pipe 31. The infrared acquisition device 23, the opening and closing device 4, and each heat source system 3 are electrically connected to the monitoring and control module 100.

[0023] In this embodiment, the normally open baffle divides the flue gas duct body 1 into multiple heating duct units 11. Each heating duct unit 11 corresponds to a heat source system 3 and an infrared acquisition device 23, which can improve the accuracy of detection and respond to blockages at the corresponding locations in a timely manner, thereby improving the blockage clearing efficiency.

[0024] As can be seen from the above description, the beneficial effect of the present invention is that the infrared acquisition device 23 can capture infrared images of the flue gas duct body 1 in real time, and the monitoring and control module 100 can identify and analyze them, thereby accurately locating the blockage area and realizing non-contact, online continuous monitoring of the blockage status of the air preheater flue gas duct.

[0025] When the monitoring and control module 100 detects a blockage in a section of the heating pipe unit 11, it can quickly respond and start the corresponding heat source system 3 to introduce high-temperature hot air above 300°C into the heating pipe unit 11. At the same time, it controls the opening and closing device 4 to adjust the deployment state of the normally open baffle. The normally open baffle changes the path of the high-temperature airflow, creating a local disturbance, so that the high-temperature hot air can directly impact and act on the ammonium bisulfate attached to the pipe wall, causing it to quickly vaporize and decompose. This achieves closed-loop control from precise blockage location to directional removal.

[0026] Because the normally open baffle divides the flue gas duct body 1 into multiple independent heating duct units 11, and each unit is equipped with its own corresponding heat source system 3 and infrared acquisition device 23, the system can perform independent operation on one or more blocked units. This not only avoids the energy waste caused by traditional whole-unit heating for clearing blockages, but also significantly improves the response speed and targeting of the clearing process.

[0027] In addition, the normally open damper remains open when not in operation, ensuring that the normal delivery of flue gas is not affected, and the pipeline is not completely closed during unblocking operations, thus ensuring the safety and stability of the system and effectively solving the problem of easy blockage and difficult unblocking of the flue gas pipeline of the air preheater.

[0028] Furthermore, the monitoring and control module 100 includes: Temperature field reference module 101: used to store healthy temperature field data of flue gas duct body 1 under clean conditions; Temperature difference analysis module 102: used to compare the real-time temperature field with the healthy temperature field to identify abnormal temperature areas; Blockage determination module 103: When the temperature of a certain area is continuously higher than the healthy temperature field of the corresponding area and the temperature difference exceeds the set threshold, it is determined that there is a blockage in the area; Heating control module 104: Based on the blockage determination result, activate the heat source system 3 of the corresponding area to release high-temperature hot gas into the flue gas duct body 1; Effect verification module 105: After heating is completed, the temperature field of the area is analyzed again. If the temperature returns to the normal range, the blockage is considered to have been cleared successfully.

[0029] As can be seen from the above description, by setting up the temperature field reference module 101, temperature difference analysis module 102, blockage judgment module 103, heating control module 104 and effect verification module 105, the entire process of automated closed-loop control from temperature data comparison, anomaly identification, blockage judgment, fixed-point heating to effect feedback is realized, which significantly improves response speed and operation efficiency.

[0030] Furthermore, the normally open baffle includes two symmetrically arranged baffle bodies 42, and a plurality of first rotating rods 452 and second rotating rods 462 are arranged alternately between the two baffle bodies 42. In this embodiment, there are two first rotating rods 452 and three second rotating rods 462, and the specific arrangement is second rotating rod 462-first rotating rod 452-second rotating rod 462-first rotating rod 452-second rotating rod 462.

[0031] The first rotating rod 452 and the second rotating rod 462 are arranged coaxially. One baffle body 42 is fixedly connected to each of the first rotating rods 452, and the other baffle body 42 is fixedly connected to each of the second rotating rods 462. The opening and closing device 4 is used to drive the first rotating rod 452 and the second rotating rod 462 to rotate in opposite directions.

[0032] As can be seen from the above description, when the opening and closing device 4 receives the instruction from the monitoring and control module 100, it will drive the first rotating rod 452 and the second rotating rod 462 to rotate in opposite directions around the same axis. Since the two baffle bodies 42 follow different rotating rod groups, this reverse rotation will drive the two baffle bodies 42 to open or close relative to each other, thereby realizing the adjustment of the cross-sectional area of ​​the airflow channel inside the flue gas duct body 1.

[0033] Specifically, the opening and closing device 4 includes a first rotating block 45, a second rotating block 46, and a reciprocating pushing mechanism. The first rotating block 45 and the second rotating block 46 are circular blocks of the same size, and the first rotating block 45 and the second rotating block 46 are concentrically arranged.

[0034] Please see Figures 3 to 5The free end of the second rotating rod 462, which is located at the end, rotates and seals through the flue gas pipe body 1 and is then concentrically and fixedly connected to the second rotating block 46. The first rotating block 45 is spaced apart at the free end of the second rotating block 46. A sleeve rod 453 is concentrically and fixedly connected to the first rotating block 45. The free end of the sleeve rod 453 is rotatably sleeved inside the second rotating rod 462, and the sleeve rod 453 is fixedly sleeved with both first rotating rods 452.

[0035] The reciprocating drive mechanism is located outside the flue gas duct body 1 and is used to drive the first rotating block 45 and the second rotating block 46 to rotate in opposite directions.

[0036] As can be seen from the above description, after the free end of the second rotating rod 462 located at the end rotates and seals through the flue gas pipe body 1, it is concentrically fixedly connected with the second rotating block 46, ensuring that the rotation of the second rotating block 46 can directly drive the baffle body 42 connected to the second rotating rod 462. The other baffle body 42 is driven by the first rotating block 45 and the sleeve rod 453. When the reciprocating pushing mechanism acts on the first rotating block 45 and the second rotating block 46, it can drive the two to rotate in opposite directions, thereby causing the two baffle bodies 42 to open and close.

[0037] Furthermore, the reciprocating drive mechanism includes an outer U-shaped frame 41, an inner U-shaped frame 44 is slidably installed in the U-shaped groove of the outer U-shaped frame 41, the opening direction of the inner U-shaped frame 44 is the same as the opening direction of the outer U-shaped frame 41, and a telescopic cylinder 43 is provided between the inner U-shaped frame 44 and the outer U-shaped frame 41. The telescopic cylinder 43 can be an electric cylinder. An inner extension plate 441 is integrally provided on both sides of the inner U-shaped frame 44, and a toggle slot 442 is provided on both inner extension plates 441. The first rotating block 45 has an integrally formed first extension protrusion 451 on its side. A first actuating rod 4511 is vertically fixedly connected to the first extension protrusion 451. The free end of the first actuating rod 4511 is movably locked in one of the actuating slots 442. The second rotating block 46 has a second extended protrusion 461 integrally provided on its side. A second toggle rod 4611 is vertically fixedly connected to the second extended protrusion 461. The free end of the second toggle rod 4611 is movably locked in another toggle slot 442.

[0038] As can be seen from the above description, when the telescopic cylinder 43 extends or retracts, it drives the inner U-shaped frame 44 to slide smoothly along the U-shaped groove of the outer U-shaped frame 41. When the inner U-shaped frame 44 moves back and forth, the two actuating slots 442 will push the corresponding actuating rods in sync. Since the two actuating rods are located on the side of the first rotating block 45 and the second rotating block 46 respectively, the two rotating blocks can rotate in opposite directions around the axis, thereby driving the two baffle bodies 42 to open and close.

[0039] The double-layer U-shaped frame guide structure ensures the smooth movement of the inner U-shaped frame 44, enabling the two baffle bodies 42 to open and close synchronously and symmetrically, achieving efficient guidance of high-temperature hot airflow. Through local disturbance, the hot air is concentrated to impact the ammonium bisulfate adhering to the pipe wall of the flue gas duct body 1, significantly improving the targeting and efficiency of the unblocking operation.

[0040] Furthermore, an infrared acquisition device 23 is installed on the outside of the flue gas duct body 1 between any two adjacent normally open baffles (i.e., each section of heating duct unit 11), and each infrared acquisition device 23 is connected to the cooling device 2.

[0041] As can be seen from the above description, each section of the heating pipe unit 11 is independently equipped with an infrared acquisition device 23 for real-time acquisition of temperature distribution. By connecting each infrared acquisition device 23 to the cooling device 2, the cooling device 2 can continuously provide cooling protection for the infrared acquisition device 23, ensuring that it works stably under suitable temperature conditions.

[0042] Furthermore, the cooling device 2 includes a cold source system 21 and a fan system 22 connected to the cold source system 21. The infrared acquisition device 23 is connected to the fan system 22 through the main cooling pipe 24, and an auxiliary cooling pipe 25 is also connected between the main cooling pipe 24 and the fan system 22.

[0043] As described above, the cooling capacity generated by the cold source system 21 is driven by the fan system 22 and transported to each infrared acquisition device 23 via the main cooling pipe 24 to continuously cool and lower the internal precision components. At the same time, when the main cooling pipe 24 requires maintenance or experiences flow fluctuations, the auxiliary cooling pipe 25 can participate in the cooling cycle as a backup or auxiliary channel to ensure the continuity of cooling medium delivery.

[0044] Furthermore, a swirling nozzle is provided at the nozzle where the jet pipe 31 connects to the flue gas duct body 1, and the swirling nozzle is located upstream between any two adjacent normally open baffles.

[0045] As can be seen from the above description, the rotating airflow generated by the swirl nozzle has stronger turbulence intensity and a longer wall-attached flow path, which can more fully contact the ammonium bisulfate adhering to the inner wall of the flue gas duct body 1, significantly improving the flushing efficiency and heat transfer effect of the high-temperature hot air on the deposits on the inner wall of the flue gas duct body 1, so that the ammonium bisulfate can be heated and decomposed more quickly and evenly.

[0046] Furthermore, the heat source system 3 outputs hot air at 300°C to 340°C.

[0047] As can be seen from the above description, setting the hot air temperature to 300℃ to 340℃ can ensure that after the heat is transferred to the deposits on the pipe wall, it can still be stably maintained above its vaporization temperature, so that ammonium bisulfate can quickly absorb heat and directly transform from a viscous liquid or solid state into a gaseous state, and be discharged with the flue gas flow, thereby achieving efficient blockage removal.

[0048] Example 2 A method for unblocking an online monitoring and unblocking system for air preheater flue gas duct blockage, based on the above-described embodiment one, includes the following steps: Step 1: Establish a health baseline by collecting the temperature field of flue gas duct body 1 under clean conditions as the health temperature field.

[0049] Specifically, after the air preheater is put into operation for the first time or the pipeline is thoroughly cleaned, the infrared acquisition device 23 is activated to perform a comprehensive scan of the flue gas pipeline body 1, collect its temperature field distribution data under clean conditions, and store the data as a healthy temperature field reference in the temperature field reference module 101.

[0050] Step 2: Real-time monitoring, continuously collecting the temperature field of flue gas duct body 1 during the operation of the air preheater.

[0051] Specifically, during the normal operation of the air preheater, the infrared acquisition device 23 arranged outside each heating pipe unit 11 continuously performs infrared thermal imaging scanning on the corresponding heating pipe unit 11 and uploads the collected real-time temperature field data to the monitoring and control module 100.

[0052] Step 3: Temperature difference analysis and blockage location. The real-time temperature field is compared with the healthy temperature field to identify abnormal temperature areas and determine their corresponding heating zones.

[0053] Specifically, the temperature difference analysis module 102 compares the received real-time temperature field data with the healthy temperature field data stored in the temperature field reference module 101 point by point. When the real-time temperature of a certain area is continuously higher than the temperature of the corresponding area of ​​the healthy temperature field, and the temperature difference value reaches the preset threshold in the blockage determination module 103, the blockage determination module 103 determines that there is ammonium bisulfate deposition blockage in the area, and determines the corresponding heating pipe unit 11 number according to the location of the area.

[0054] Step 4: Targeted heating to clear blockages. Start the heat source system 3 of the corresponding heating zone and introduce hot air at 300°C to 340°C into the flue gas duct body 1 of the corresponding heating zone. At the same time, control the normally open baffle at the downstream position of the corresponding heating zone to open, thereby decomposing the ammonium bisulfate attached to the inner wall of the flue gas duct body 1.

[0055] Specifically, the heating control module 104 sends a start command to the heat source system 3 of the corresponding numbered heating pipe unit 11 based on the blockage location result, and introduces high-temperature hot air of 300°C to 340°C into its interior.

[0056] Simultaneously, the heating control module 104 sends a command to the opening and closing device 4 corresponding to the normally open baffle located downstream of the heating pipe unit 11, driving the first rotating rod 452 and the second rotating rod 462 to rotate in opposite directions, causing the two baffle bodies 42 to unfold to a preset angle. The unfolded baffle bodies 42 create airflow disturbance to the incoming high-temperature hot air, changing its flow path, so that the rotating airflow fully impacts the inner wall of the flue gas pipe body 1, and uses the high temperature of over 300°C to rapidly absorb heat, vaporize and decompose the ammonium bisulfate attached to this area, and discharge it with the flue gas.

[0057] Step 5: Effect verification. After the targeted heating and blockage removal is completed, the temperature field of the area is collected again to verify the blockage removal effect.

[0058] Specifically, after the targeted heating and unblocking operation is completed, the heating control module 104 shuts down the heat source system 3 and instructs the opening and closing device 4 to reset the normally open baffle to the normally open state. Subsequently, the effect verification module 105 collects temperature field data again through the infrared acquisition device 23 corresponding to the area and compares it with the healthy temperature field. If the temperature has returned to the normal range, the unblocking is determined to be successful; if the temperature is still abnormally high, the unblocking is determined to be unsuccessful, and the monitoring and control module 100 issues an early warning signal or re-executes step four.

[0059] Step 6: Loop through the monitoring process and return to Step 2 to continue monitoring.

[0060] Specifically, after completing one unblocking and effect verification, the system automatically returns to step two to continue real-time monitoring of each area of ​​the flue gas duct body 1, realizing fully automated cyclical operation.

[0061] The working principle of this invention is as follows: the infrared acquisition device 23 arranged on the outside of each heating pipe unit 11 collects the temperature field information of the flue gas pipe body 1 in real time and uploads it to the monitoring and control module 100.

[0062] The monitoring and control module 100 compares and analyzes the real-time temperature field with the pre-stored healthy temperature field. When the temperature in a certain area is abnormally high and exceeds the set threshold, it automatically determines that ammonium bisulfate blockage has occurred in that area and accurately locates the corresponding heating pipe unit 11.

[0063] Subsequently, the monitoring and control module 100 starts the heat source system 3 corresponding to the unit, and introduces high-temperature hot air of 300°C to 340°C into it. At the same time, it instructs the opening and closing device 4 to drive the normally open baffle downstream of the unit to open, creating airflow disturbance to the high-temperature hot air, so that the rotating airflow fully impacts the pipe wall, and uses the high temperature to quickly vaporize and decompose ammonium bisulfate, thereby achieving targeted clearing of blockages.

[0064] After the blockage is cleared, the system collects the temperature field of the area again to verify the effect. Once it is confirmed to be normal, it continues to monitor in a loop, thereby realizing intelligent closed-loop control of the entire process from automatic blockage identification, precise location, point-to-point clearing to effect feedback.

[0065] In the description of this invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0066] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. An online monitoring and unblocking system for air preheater flue gas duct blockage, characterized in that: It includes an infrared detection system and a heat source system (3), and also includes normally open baffles arranged at equal intervals along the length of the flue gas duct body (1) and installed inside the flue gas duct body (1), the normally open baffles being controlled to unfold by an opening and closing device (4); The infrared detection system includes an infrared acquisition device (23) for capturing infrared images of the flue gas duct body (1) and a monitoring and control module (100) for identifying the blockage area of ​​the flue gas duct body (1). A heat source system (3) is connected to the flue gas duct body (1) between any two adjacent normally open baffles through a jet pipe (31). The infrared acquisition device (23) and each of the heat source systems (3) are electrically connected to the monitoring and control module (100).

2. The online monitoring and unblocking system for air preheater flue gas duct blockage according to claim 1, characterized in that: The monitoring and control module (100) includes: Temperature field reference module (101): used to store healthy temperature field data of flue gas duct body (1) under clean conditions; Temperature difference analysis module (102): used to compare the real-time temperature field with the healthy temperature field and identify abnormal temperature areas; Blockage determination module (103): When the temperature of a certain area is continuously higher than the healthy temperature field of the corresponding area and the temperature difference exceeds the set threshold, it is determined that there is a blockage in the area; Heating control module (104): Based on the blockage determination result, start the heat source system (3) of the corresponding area to release high-temperature hot gas into the flue gas duct body (1); Effect verification module (105): After heating is completed, the temperature field of the area is analyzed again. If the temperature returns to the normal range, the blockage is determined to be cleared successfully.

3. The online monitoring and unblocking system for air preheater flue gas duct blockage according to claim 1, characterized in that: The normally open baffle includes two symmetrically arranged baffle bodies (42). Between the two baffle bodies (42) are several first rotating rods (452) and second rotating rods (462) arranged alternately in sequence. The first rotating rods (452) and second rotating rods (462) are arranged coaxially. One baffle body (42) is fixedly connected to each of the first rotating rods (452), and the other baffle body (42) is fixedly connected to each of the second rotating rods (462). The opening and closing device (4) is used to drive the first rotating rods (452) and the second rotating rods (462) to rotate in opposite directions.

4. The online monitoring and unblocking system for air preheater flue gas duct blockage according to claim 3, characterized in that: The opening and closing device (4) includes a first rotating block (45), a second rotating block (46), and a reciprocating pushing mechanism. The free end of the second rotating rod (462) located at the end rotates and seals through the flue gas pipe body (1) and is fixedly connected to the second rotating block (46). The first rotating block (45) is spaced apart at the free end of the second rotating block (46). A sleeve rod (453) is fixedly connected to the first rotating block (45). The free end of the sleeve rod (453) is rotatably sleeved inside the second rotating rod (462), and the sleeve rod (453) is fixedly sleeved with at least one first rotating rod (452). The reciprocating pushing mechanism is located outside the flue gas pipe body (1) and is used to drive the first rotating block (45) and the second rotating block (46) to rotate in opposite directions.

5. The online monitoring and unblocking system for air preheater flue gas duct blockage according to claim 4, characterized in that: The reciprocating push mechanism includes an outer U-shaped frame (41), an inner U-shaped frame (44) is slidably installed in the U-shaped groove of the outer U-shaped frame (41), the opening direction of the inner U-shaped frame (44) is the same as the opening direction of the outer U-shaped frame (41), and a telescopic cylinder (43) is provided between the inner U-shaped frame (44) and the outer U-shaped frame (41). An inner extension plate (441) is integrally provided on both sides of the inner U-shaped frame (44), and a toggle slot (442) is provided on both inner extension plates (441). The first rotating block (45) has an integrally formed first extension protrusion (451) on its side. A first actuating rod (4511) is vertically fixedly connected to the first extension protrusion (451). The free end of the first actuating rod (4511) is movably locked in one of the actuating slots (442). The second rotating block (46) has an integrally formed second extension protrusion (461) on its side. The second extension protrusion (461) is vertically fixedly connected to a second toggle rod (4611). The free end of the second toggle rod (4611) is movably locked in another toggle slot (442).

6. The online monitoring and unblocking system for air preheater flue gas duct blockage according to claim 1, characterized in that: An infrared acquisition device (23) is installed on the outside of the flue gas duct body (1) between any two adjacent normally open baffles, and each of the infrared acquisition devices (23) is connected to the cooling device (2).

7. The online monitoring and unblocking system for air preheater flue gas duct blockage according to claim 6, characterized in that: The cooling device (2) includes a cold source system (21) and a fan system (22) connected to the cold source system (21). The infrared acquisition device (23) is connected to the fan system (22) through a main cooling pipe (24), and an auxiliary cooling pipe (25) is also connected between the main cooling pipe (24) and the fan system (22).

8. The online monitoring and unblocking system for air preheater flue gas duct blockage according to claim 1, characterized in that: A swirling nozzle is provided at the nozzle where the jet pipe (31) connects to the flue gas duct body (1), and the swirling nozzle is located upstream between any two adjacent normally open baffles.

9. The online monitoring and unblocking system for air preheater flue gas duct blockage according to claim 1, characterized in that: The heat source system (3) outputs hot air at 300°C to 340°C.

10. A method for unblocking a blockage-free system based on the online monitoring and unblocking system for air preheater flue gas duct blockage according to any one of claims 1-9, characterized in that: Includes the following steps: Step 1: Establish a health baseline by collecting the temperature field of the flue gas duct body (1) under clean conditions as the health temperature field; Step 2: Real-time monitoring, continuously collecting the temperature field of the flue gas duct body (1) during the operation of the air preheater; Step 3: Temperature difference analysis and blockage location. The real-time temperature field is compared with the healthy temperature field to identify abnormal temperature areas and determine their corresponding heating zones. Step 4: Targeted heating to clear blockages. Start the heat source system (3) of the corresponding heating zone and introduce hot air at 300°C to 340°C into the flue gas duct body (1) of the corresponding heating zone. At the same time, control the normally open baffle at the downstream position of the corresponding heating zone to open, thereby decomposing the ammonium bisulfate attached to the inner wall of the flue gas duct body (1). Step 5: Effect verification. After the targeted heating and blockage removal is completed, the temperature field of the area is collected again to verify the blockage removal effect. Step 6: Loop through the monitoring process and return to Step 2 to continue monitoring.

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