Intelligent detection system for blockage of heat transfer element of air pre-heater

Abstract

The invention relates to the technical field of air pre-heaters, and discloses an air pre-heater heat transfer element blockage intelligent detection system which comprises a middle rotating shaft, a hot end middle beam, a cold end middle beam, a rotor and a control box, a heat transfer element is arranged on the rotor, and a light source generator facing the rotor is arranged on the cold end middle beam. A visible light camera device facing the rotor and corresponding to the light source generator is arranged on the hot end middle beam, power sources of the light source generator and the visible light camera device are both connected with the control box, and the visible light camera device is further connected with the control box through a digital-to-analog converter. According to the intelligent blockage detection system for the heat transfer element of the air pre-heater, the blockage condition of the element in a certain area of the air pre-heater is detected by adopting the penetration brightness of the light source, and the intelligent blockage detection system has the advantages of visual operation, simplicity in system control operation, rapidness and accuracy in positioning and high feasibility.

Description

Technical Field

[0001] The present invention relates to the technical field of air preheaters, and in particular to an intelligent detection system for blockage of heat transfer elements of air preheaters. Background Art

[0002] At present, the problem of air preheater blockage has always been a common chronic disease and a pain point in unit operation. The reasons for the blockage are also varied. With the widespread popularization and application of boiler denitrification equipment, the ammonium bisulfate produced by the reaction of residual ammonia and sulfur trioxide in the flue gas will have a serious negative impact on the rotary preheater. The heat transfer elements at the cold end of the preheater will be corroded and blocked, eventually leading to varying degrees of damage to the heat transfer elements, which will have a significant impact on the normal operation of the preheater and boiler.

[0003] At present, the main technical method for judging the blockage of air preheater heat transfer elements is to judge the blockage situation through the pressure difference signal at the inlet and outlet of the air preheater on site. When the resistance rises to a certain value, only high-pressure water flushing and other means can be used for large-scale cleaning.

[0004] As boiler coal quality declines and ammonia injection equipment becomes unstable, ammonium bisulfate gradually deposits in a certain area of the air preheater's cold-end components. As the accumulated ash continues to absorb, the entire component slowly begins to clog, causing the air preheater's operating resistance to gradually increase. The blockage becomes increasingly severe, and once serious blockage is detected, measures such as high-pressure soot blowing are ineffective. Furthermore, blindly increasing the flushing pressure during online flushing can damage the components, shortening the heat transfer element's service life and causing irreversible damage. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the existing heat transfer element blockage detection is not timely and the blockage position cannot be accurately flushed.

[0006] In order to solve the above technical problems, the technical solution of the present invention is to provide an intelligent detection system for blockage of heat transfer elements in an air preheater, comprising an intermediate rotating shaft, a hot-end intermediate beam, a cold-end intermediate beam, a rotor, and a control box. The hot-end intermediate beam and the cold-end intermediate beam are respectively arranged at both ends of the rotating shaft. The rotor is arranged outside the intermediate rotating shaft and located between the hot-end intermediate beam and the cold-end intermediate beam. The rotor is provided with a heat transfer element, the cold-end intermediate beam is provided with a light source generator facing the rotor, and the hot-end intermediate beam is provided with a visible light camera device facing the rotor and corresponding to the light source generator. The power supplies of the light source generator and the visible light camera device are both connected to the control box, and the visible light camera device is also connected to the control box via a digital-to-analog converter.

[0007] Optionally, the control box is connected to an input power supply, a display device and an alarm device, the input power supply provides power to the control box, the display device is used to display the detection screen of the visible light camera device, and the alarm device is used for fault alarm.

[0008] Optionally, a rotor grid is provided in the circumferential direction of the rotor, a circle of metal sheets is provided on the middle rotating shaft at the middle beam of the cold end, the number of metal sheets is the same as the number of rotor grids, a proximity switch is provided on the outside of the metal sheet, the proximity switch is provided on the middle beam of the cold end, and the signal end of the proximity switch is connected to the control box.

[0009] Optionally, a DCS resistance measuring point is further included, and the signal of the DCS resistance measuring point is transmitted to the control box. The DCS resistance measuring point can be set on the intermediate rotating shaft, the hot end intermediate beam or the cold end intermediate beam.

[0010] Optionally, the heat fransfer element includes multiple circles of heat fransfer element packages of different specifications from the inside out, and each layer of the heat fransfer element package area is correspondingly provided with a light source generator and a visible light camera device.

[0011] Optionally, it also includes a soot blower and a soot blowing air source connected to the soot blower, the soot blower includes an upper soot blower and a lower soot blower, the upper soot blower is located above the rotor, the lower soot blower is located below the rotor, and both are facing the rotor, the motor of the upper soot blower is connected to the upper soot blower radial position converter and then connected to the control box, the motor of the lower soot blower is connected to the lower soot blower radial position converter and then connected to the control box, the position of each bin heat transfer element package and the required moving distance are pre-set in the upper soot blower radial position converter and the lower soot blower radial position converter.

[0012] Optionally, the light source generator and the visible light camera device are both connected to a cooling air source.

[0013] Optionally, the light source generator includes a light source generator housing, a constant light source and a mounting plate, the mounting plate is welded to the cold end middle beam, the cold end middle beam is provided with an opening, the light source generator housing is connected to the mounting plate and one end passes through the mounting plate and is inserted into the opening, the constant light source is arranged in the light source generator housing, a detachable flange seat is provided on the light source generator housing at the end of the constant light source, the flange seat is provided with a thermal insulation pad, one end of the light source generator housing located in the opening is provided with a light source generator terminal connected to the constant light source, the other end of the light source generator housing is provided with a light source generator optical fiber, and the light source generator housing at the constant light source is provided with an air source interface connected to the cooling air source.

[0014] Optionally, the visible light camera device includes a mounting plate, a camera light spot analysis recorder and a camera housing, the mounting plate is welded to the middle beam of the hot end, the middle beam of the hot end is provided with an opening, the camera housing is connected to the mounting plate and one end is provided in the opening, the camera light spot analysis recorder is provided in the other end of the camera housing located in the opening, a camera device terminal is connected to it, a camera light spot analysis recorder is connected to the camera device light guide tube, the camera housing is provided with an air source interface connected to the cooling air source, the middle section of the camera housing is provided with a flange seat, and the flange seat is provided with a thermal insulation pad.

[0015] In summary, the intelligent blockage detection system for heat transfer elements of air preheaters provided by the present invention detects blockage of elements in a certain area of the air preheater by using the penetrating brightness of the light source, and has visual operation, simple system control operation, fast and accurate positioning, and strong feasibility; the detection data directly enters the system display or automatically judges to the lower-level operation, and can realize online operation, detection and processing at the same time. When a blockage problem occurs in a certain area, it can guide the purge equipment to solve it quickly and effectively, which can avoid the subsequent aggravation of the blockage situation, save the use of the purge system medium, and avoid the damage of the heat transfer elements in other positions due to full coverage flushing. At the same time, the purge time is faster and the detection efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a system connection diagram of the intelligent blockage detection system for heat transfer elements of air preheaters;

[0017] Figure 2 This is a cross-sectional layout diagram of the intelligent blockage detection system for heat transfer elements in air preheaters;

[0018] Figure 3 This is a top view of the intelligent blockage detection system for heat transfer elements in air preheaters;

[0019] Figure 4 Schematic diagram of the structure of a visible light camera device;

[0020] Figure 5 Schematic diagram of the structure of the light source generator;

[0021] In the figure: 1. middle beam of the hot end; 2. middle beam of the cold end; 3. heat transfer element; 4. visible light camera; 5. light source generator; 6. input power supply; 7. control box; 8. soot blower; 9. soot blowing air source; 10. digital-to-analog converter; 11. cooling air source; 12. display; 13. alarm device; 14. proximity switch; 15. radial position converter of the upper soot blower; 16. radial position converter of the lower soot blower; 17. mounting plate; 18. air source interface; 19. flange seat thermal insulation pad; 20. flange seat; 21. camera light pipe; 22. camera light spot analysis recorder; 23. camera housing; 24. camera terminal; 25. light pipe of the light source generator; 26. light source generator housing; 27. constant light source; 28. light source generator terminal. DETAILED DESCRIPTION

[0022] The following combination Figure 1-5 The present invention is described in further detail.

[0023] The present invention discloses an intelligent detection system for blockage of heat transfer elements of air preheater, referring to Figure 1 , including an intermediate rotating shaft, a hot-end intermediate beam 1, a cold-end intermediate beam 2, a rotor and a control box 7. The hot-end intermediate beam 1 and the cold-end intermediate beam 2 are respectively arranged at the two ends of the rotating shaft. The rotor is arranged outside the intermediate rotating shaft and located between the hot-end intermediate beam 1 and the cold-end intermediate beam 2. A heat transfer element 3 is provided on the rotor. A light source generator 5 facing the rotor is provided on the cold-end intermediate beam 2. The light source generator 5 can emit a visible constant light source. A visible light camera device 4 facing the rotor and corresponding to the light source generator 5 is provided on the hot-end intermediate beam 1. When the light source penetrates the heat transfer element 3, the visible light camera device 4 can receive the light source and output an image. The power supplies of the light source generator 5 and the visible light camera device 4 are both connected to the control box 7. The visible light camera device 4 is also connected to the control box 7 through a digital-to-analog converter 10.

[0024] In a further embodiment, the control box 7 is connected to an input power supply 6, a display device 12 and an alarm device 13;

[0025] Specifically, the input power supply 6 provides power for the control box 7, and the control box 7 controls the switch of the light source generator 5 and the start and stop of the visible light camera 4. The display device 12 is used to display the detection screen of the visible light camera 4. The light brightness signal and the screen of the visible light camera 4 are connected to the digital-to-analog converter 10 and then connected to the control box 7. The control box 7 outputs the light spot signal of the light source intensity in the entire detection area to the display device 12, and the real-time screen of the blockage situation can be observed online. The control box 7 can also send the relevant data screen to the on-site control room, and realize local and remote synchronous observation. The alarm device 13 is used for fault alarm. When the control box 7 detects that there is a fault in the equipment in the entire system, it will output an alarm signal to the alarm device 13 for an alarm prompt.

[0026] In a further embodiment, referring to Figure 3 A rotor grid is provided in the circumferential direction of the rotor, and a circle of metal sheets is provided on the intermediate rotating shaft at the cold end intermediate beam 2. The number of metal sheets is the same as the number of rotor grids. A proximity switch 14 is provided on the outside of the metal sheet. The proximity switch 14 is provided on the cold end intermediate beam 2. The signal end of the proximity switch 14 is connected to the control box 7; it also includes a DCS resistance measuring point, and the signal of the DCS resistance measuring point is transmitted to the control box 7. The DCS resistance measuring point can be provided on the intermediate rotating shaft, the hot end intermediate beam 1 or the cold end intermediate beam 2.

[0027] Specifically, when the rotor rotates, driving the circular metal sheet to rotate together, the proximity switch 14 starts to measure the counting signal and outputs it to the control box 7. When the count value is the same as the number of rotor compartments, it means that all compartments have been detected, and the entire blockage detection system stops the detection this time; the entire blockage detection system controls the start of the blockage detection system through the numerical value of the DCS resistance measurement point collected by the control box 7. When the prompt resistance rises to a certain set value, the blockage detection system automatically starts, and the counting signal sent by the proximity switch 14 is output to the control box 7, controlling the blockage detection system to end the detection this time.

[0028] In a further embodiment, referring to Figure 2 and Figure 3 The heat transfer element 3 includes multiple circles of heat transfer element packages of different specifications from the inside out. Each compartment heat transfer element package area is correspondingly equipped with a light source generator 5 and a visible light camera 4. The heat transfer element 3 also includes a soot blower 8 and a soot blowing air source 9 connected to the soot blower 8. The soot blower 8 includes an upper soot blower and a lower soot blower. The upper soot blower is located above the rotor, and the lower soot blower is located below the rotor. Both soot blowers face the rotor. The motor of the upper soot blower is connected to the upper soot blower radial position converter 15 and then connected to the control box 7. The motor of the lower soot blower is connected to the lower soot blower radial position converter 16 and then connected to the control box 7. The position of each compartment heat transfer element package and the required moving distance are pre-set in the upper soot blower radial position converter 15 and the lower soot blower radial position converter 16.

[0029] In a further embodiment, referring to Figure 5 , the light source generator 5 and the visible light camera device 4 are both connected to a cooling air source 11;

[0030] The light source generator 5 includes a light source generator housing 26, a constant light source 27 and a mounting plate 17. The mounting plate 17 is welded to the cold end middle beam 2. The cold end middle beam 2 is provided with an opening. The light source generator housing 26 is connected to the mounting plate 17 and one end passes through the mounting plate 17 and is inserted into the opening. The constant light source 27 is arranged in the light source generator housing 26. A detachable flange seat 20 is provided on the light source generator housing 26 at the end of the constant light source 27. The flange seat 20 is provided with a thermal insulation pad 19. One end of the light source generator housing 26 located in the opening is provided with a light source generator terminal 28 connected to the constant light source 27. The other end of the light source generator housing 26 is provided with a light source generator light pipe 25. , an air source interface 18 connected to the cooling air source 11 is provided on the light source generator housing 26 at the constant light source 27; during installation, first overlap and weld the mounting plate 17 and the housing at the opening of the cold end middle beam 2, connect the cooling air source 11 pipeline to the air source interface 18, and connect the power cord to the light source generator terminal 28 to complete the installation; when in use, open the cooling air source 11 pipeline valve, and the cooling air enters the light source generator 5 through the air source interface 18 to prevent dust accumulation on the light source generator optical fiber 25 and the constant light source 27, and play a cooling role. If the constant light source 27 fails and needs to be replaced, the flange seat 20 can be opened online and the constant light source 27 can be pulled out and replaced. The disassembly and assembly are quick and convenient.

[0031] In a further embodiment, referring to Figure 4 The visible light camera device 4 includes a mounting plate 17, a camera spot analysis recorder 22 and a camera housing 23. The mounting plate 17 is welded to the hot end middle beam 1. The hot end middle beam 1 is provided with an opening. The camera housing 23 is connected to the mounting plate 17 and one end is provided in the opening. The camera spot analysis recorder 22 is provided in the other end of the camera housing 23 located in the opening. The camera device terminal 24 is connected to the camera spot analysis recorder 22. The camera device light guide 21 is connected to the camera spot analysis recorder 22. The camera housing 23 is provided with an air source interface 18 connected to the cooling air source 11. The middle section of the camera housing 23 is provided with a flange seat 20. The flange seat 20 is provided with a There is a thermal insulation pad 19. During installation, the mounting plate 17 can be overlapped and welded to the outer shell plate at the opening of the hot end middle beam 1, the cooling air source 11 pipeline can be connected to the air source interface 18, and the power line and signal line can be connected to the camera device terminal 24 to complete the installation; when in use, open the cooling air source 11 pipeline valve, and the cooling air enters the camera device through the air source interface 18, which can cool the camera light spot analysis recorder 22 and prevent the camera device light guide 21 from being blocked by dust. When the camera light spot analysis recorder 22 needs to be inspected or replaced, the flange seat 20 can be directly opened online, and the entire camera light spot analysis recorder 22 can be pulled out and replaced. Assembly and disassembly are also very convenient.

[0032] In this embodiment, the rotation of the air preheater causes the heat transfer element 3 to rotate slowly. The heat transfer element 3 is arranged with four circles of heat transfer element packages of different specifications, A, B, C, and D, from the inside to the outside. Figure 2 and Figure 3 As shown, a light source generator 5 is provided in each heat transfer element package area at the cold end, emitting light that penetrates each heat transfer element 3. The position and number of visible light cameras 4 arranged at the hot end are the same as those at the cold end. Each visible light camera 4 at a corresponding position can display brightness, indicating that the element at that position is not blocked. If the visible light camera 4 at position B of a heat transfer element 3 displays dimly, it indicates that the entire element package B of the heat transfer element 3 is blocked. The location of the blockage and a screenshot can be displayed on the display unit 12 in the on-site control box 7 or on the display screen in the centralized control room.

[0033] If a blockage is detected at the position of package B of the heat transfer element 3, the spot recorder at position B of the visible light camera 4 transmits a dark spot signal to the control box 7 via the digital-to-analog converter 10. The control box 7 transmits the position signal to the display 12 and also to the upper sootblower radial position converter 15 and the lower sootblower radial position converter 16 of the upper and lower sootblower. The radial position converters 15 and 16 have been set with the radial movement distances corresponding to packages A, B, C, and D, respectively. When receiving the dark spot signal of package B, the radial position converters 15 and 16 activate the drive motor of the sootblower 8, directly extending and retracting the purge barrel to the position of package B according to the corresponding movement distance. The sootblowing air source 9 is then turned on to start purge of the package B area. Simultaneously, the proximity switch 14 starts counting. When the count reaches the last bin, the purge is complete, the sootblowing air source 9 is turned off, and the sootblower 8 returns to its initial position to await the next instruction.

[0034] If both packages B and C of the heat transfer element 3 are detected to be clogged, the spot recorder of the visible light camera 4 simultaneously transmits spot signals from both locations to the control box 7 via the digital-to-analog converter 10. The control box 7 transmits these location signals to the display 12 and to the radial position transducers 15 and 16 of the upper and lower sootblowers. The radial position transducers drive the sootblowers 8 to begin purge inwards, then outwards. That is, the sootblowers 8 first move to package B based on the corresponding movement distance to purge it. The proximity switch 14 simultaneously begins counting. When the count is complete, the purge of package B is complete. The sootblowers 8 are then controlled to retreat by the difference in the movement distance "BC" to purge the area of package C again. The proximity switch 14 simultaneously begins counting again. When the count is complete, the purge of package C is complete, and the sootblowers 8 return to their initial position to await instructions. If three or more locations are detected as clogged, such as locations A, B, and C, the full-range purge process can be initiated directly, without purging individual locations of the heat transfer element 3.

[0035] When a purge is completed, the heat transfer element blockage detection system control box 7 will re-collect the current resistance data. If the resistance data indicates normal and there is no dark spot signal, the control box 7 will turn off the light source generator 5 and the visible light camera device 4 will also be in the standby detection state. When the resistance data rises again, the blockage detection system will start again, and the control box 7 will turn on the light source generator 5 and the visible light camera device 4 to start the detection program again.

[0036] The intelligent blockage detection device for heat transfer elements of air preheaters of the present invention is adaptable to various operating conditions, has high processing efficiency, fast timeliness, and convenient on-site maintenance. When local blockage is detected in a certain part, it can be dealt with in a timely manner, thus avoiding the accumulation and deterioration of the blockage. At the same time, it also reduces the amount of post-stage purge medium used, avoids large-scale ineffective purge, reduces the energy consumption of the entire soot blowing system, improves the purge efficiency, and extends the service life of the heat transfer elements.

[0037] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An intelligent detection system for blockage of heat transfer elements in air preheaters, characterized by: The invention comprises an intermediate rotating shaft, a hot-end intermediate beam (1), a cold-end intermediate beam (2), a rotor and a control box (7); the hot-end intermediate beam (1) and the cold-end intermediate beam (2) are respectively arranged at two ends of the rotating shaft; the rotor is arranged outside the intermediate rotating shaft and between the hot-end intermediate beam (1) and the cold-end intermediate beam (2); a heat transfer element (3) is provided on the rotor; a light source generator (5) facing the rotor is provided on the cold-end intermediate beam (2); a visible light camera device (4) facing the rotor and corresponding to the light source generator (5) is provided on the hot-end intermediate beam (1); power supplies of the light source generator (5) and the visible light camera device (4) are both connected to the control box (7); and the visible light camera device (4) is further connected to the control box (7) via a digital-to-analog converter (10).

2. The intelligent detection system for air preheater heat transfer element blockage according to claim 1, characterized in that: The control box (7) is connected to an input power supply (6), a display device (12), and an alarm device (13). The input power supply (6) provides power to the control box (7), the display device (12) is used to display a detection image of the visible light camera device (4), and the alarm device (13) is used to alarm for faults.

3. The intelligent detection system for air preheater heat transfer element blockage according to claim 1, characterized in that: A rotor compartment is provided in the circumferential direction of the rotor, a circle of metal sheets is provided on the middle rotating shaft at the cold end middle beam (2), the number of the metal sheets being the same as the number of the rotor compartments, a proximity switch (14) is provided on the outer side of the metal sheet, the proximity switch (14) is provided on the cold end middle beam (2), and a signal end of the proximity switch (14) is connected to a control box (7).

4. The intelligent detection system for air preheater heat transfer element blockage according to claim 3 is characterized in that: It also includes a DCS resistance measuring point, the signal of which is transmitted to a control box (7). The DCS resistance measuring point can be arranged on the intermediate rotating shaft, the hot end intermediate beam (1) or the cold end intermediate beam (2).

5. The intelligent detection system for air preheater heat transfer element blockage according to claim 1, characterized in that: The heat transfer element (3) comprises multiple circles of heat transfer element packages of different specifications from the inside out, and each layer of the heat transfer element package area is correspondingly provided with a light source generator (5) and a visible light camera device (4).

6. The intelligent detection system for air preheater heat transfer element blockage according to claim 5, characterized in that: The invention also includes a soot blower (8) and a soot blowing air source (9) connected to the soot blower (8), wherein the soot blower (8) includes an upper soot blower and a lower soot blower, wherein the upper soot blower is located above the rotor and the lower soot blower is located below the rotor, and both of them face the rotor, and the motor of the upper soot blower is connected to the upper soot blower radial position converter (15) and then connected to the control box (7), and the motor of the lower soot blower is connected to the lower soot blower radial position converter (16) and then connected to the control box (7), and the position of each compartment heat transfer element package and the required moving distance are pre-set in the upper soot blower radial position converter (15) and the lower soot blower radial position converter (16).

7. The intelligent detection system for air preheater heat transfer element blockage according to claim 1, characterized in that: The light source generator (5) and the visible light camera device (4) are both connected to a cooling air source (11).

8. The intelligent detection system for air preheater heat transfer element blockage according to claim 7, characterized in that: The light source generator (5) comprises a light source generator housing (26), a constant light source (27) and a mounting plate (17), wherein the mounting plate (17) is welded to the cold end middle beam (2), and the cold end middle beam (2) is provided with an opening, the light source generator housing (26) is connected to the mounting plate (17), and one end thereof passes through the mounting plate (17) and is inserted into the opening, the constant light source (27) is arranged in the light source generator housing (26), a detachable flange seat (20) is provided on the light source generator housing (26) at the end of the constant light source (27), and a heat insulation pad (19) is provided on the flange seat (20), a light source generator terminal (28) connected to the constant light source (27) is provided at one end of the light source generator housing (26) located in the opening, and a light source generator light pipe (25) is provided at the other end of the light source generator housing (26), and an air source interface (18) connected to a cooling air source (11) is provided on the light source generator housing (26) at the constant light source (27).

9. The intelligent detection system for air preheater heat transfer element blockage according to claim 7, characterized in that: The visible light camera device (4) comprises a mounting plate (17), a camera spot analysis recorder (22) and a camera housing (23). The mounting plate (17) is welded to the hot end middle beam (1). The hot end middle beam (1) is provided with an opening. The camera housing (23) is connected to the mounting plate (17) and one end is provided in the opening. The camera spot analysis recorder (22) is provided in the other end of the camera housing (23) located in the opening and is connected to a camera device terminal (24). The camera spot analysis recorder (22) is connected to a camera device light guide (21). The camera housing (23) is provided with an air source interface (18) connected to a cooling air source (11). The middle section of the camera housing (23) is provided with a flange seat (20), and the flange seat (20) is provided with a heat insulation pad (19).

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