Steam soot blowing system of power station boiler

Abstract

A steam soot blowing system of a power station boiler belongs to the technical field of boiler soot blowing and comprises a rack and a soot blowing pipe, the soot blowing pipe is movably arranged on the rack through a linear driving mechanism, one end of the soot blowing pipe is detachably provided with a spray head, the other end of the soot blowing pipe is connected with an air source, and a spray hole is formed in the side wall of the spray head and is of a flaring structure. The cross section of each spraying hole is in a kidney shape or an oval shape, the coverage area of sprayed steam can be enlarged as much as possible, the soot blowing range can be enlarged, the number or the arrangement density of the spraying holes is reduced, the device is suitable for different working conditions, blowing damage of the steam to the pipe wall of the heating surface can be reduced, the needed air supply pressure and flow are low, and therefore energy consumption is reduced.

Description

Technical Field

[0001] This utility model relates to the field of boiler soot blowing technology, and in particular to a steam soot blowing system for power plant boilers. Background Technology

[0002] Power plant boilers have complex structures, generally consisting of several major heating surfaces such as water-cooled walls, superheaters, reheaters, and economizers. Due to heat exchange and flue gas circulation, a large amount of ash accumulates in the flue or cokes on the heating surface tubes. The accumulation and adhesion of large amounts of ash reduces heat exchange efficiency and increases energy consumption; ash blockage affects flue gas passages, increasing induced draft fan power and increasing power loss; ash adhesion on tubes can lead to uneven heating and tube rupture accidents; and increased flue gas emissions aggravate air pollution. Therefore, soot blowing is necessary.

[0003] Currently, steam blowing is the most common method. A nozzle (such as CN214094548U) is installed at the end of the blowing pipe. The nozzle has several cylindrical nozzle holes. Steam is sprayed through the nozzle to a designated location on the heated surface, and the steam blows off the dust on the surface of the heated pipe, thus achieving a cleaning effect.

[0004] The nozzles installed at the ends of existing soot blowing pipes are cylindrical nozzles. Although this can concentrate the jet, it will generate a large impact force. It is suitable for working scenarios that require high impact force. However, the removal of dust from heated surfaces does not require excessive impact force. Using cylindrical nozzles will easily lead to waste of resources, and the heated surface pipes will be blown away faster due to the impact of the large airflow. In addition, when the airflow enters the nozzle, it directly contacts the inner opening of the nozzle. The impact of the airflow will accelerate the blown away of the nozzle, resulting in a short service life of the nozzle. Utility Model Content

[0005] To address the technical problem in the background art where the existing soot blowing pipe end nozzles are cylindrical nozzles with high airflow impact force, which accelerates the damage to the heated surface, this utility model provides a steam soot blowing system for power plant boilers.

[0006] The technical solution of this utility model is as follows:

[0007] This utility model provides a steam soot blowing system for a power plant boiler, including a frame and a soot blowing pipe. The soot blowing pipe is movably mounted on the frame via a linear drive mechanism. One end of the soot blowing pipe is detachably equipped with a nozzle, and the other end is connected to a gas source. The nozzle has a spray hole on its side wall. The spray hole has a flared structure, and the cross-section of the spray hole is waist-shaped or elliptical, which can maximize the coverage area of ​​the ejected steam. This not only helps to expand the soot blowing range and reduce the number or arrangement density of spray holes, and is suitable for different operating conditions, but also reduces the damage of the steam itself to the heating surface tube wall. Furthermore, it requires lower gas supply pressure and flow rate, thereby saving energy.

[0008] Preferably, a protective plate is fixedly installed on the inner wall of the nozzle. The protective plate is fixedly installed at the inner opening of the nozzle and is arranged along the inner opening contour of the corresponding nozzle to prevent the inner opening of the nozzle from directly contacting the steam, thereby effectively improving the service life of the nozzle.

[0009] Preferably, the width of the protective plate is smaller than the radius of the nozzle, so that there is space between the relatively arranged nozzles to allow steam to pass through, thus avoiding affecting the discharge of steam.

[0010] Preferably, the soot blowing pipe includes an inner pipe and an outer pipe. One end of the inner pipe is inserted into the outer pipe, and the other end of the inner pipe is connected to the air source. The inner pipe is fixedly installed on the frame, and the outer pipe is slidably installed on the frame. The nozzle is detachably installed on the end of the outer pipe away from the inner pipe, so that the position of the nozzle can be changed according to the needs to meet different working requirements.

[0011] Preferably, a condensate draining unit is fixed on the frame, and the inner tube is connected to the air source through the condensate draining unit to reduce water droplets carried by the steam and prevent the steam from carrying water and increasing the degree of damage to the soot blowing tube and the heated surface tube.

[0012] Preferably, the end of the outer tube furthest from the nozzle is rotatably mounted inside the mounting box. The mounting box is connected to a linear drive mechanism via a hanger. The mounting box is equipped with a rotary drive mechanism, which is connected to the outer tube, enabling the outer tube to rotate around an axis.

[0013] Preferably, the frame is equipped with a control unit, which is connected to a flue gas temperature detection unit and a heated surface tube wall temperature detection unit. The control unit is also connected to a linear drive mechanism, a rotary drive mechanism, and an air source. The control unit can control the soot blowing operation through online temperature detection, thereby improving the accuracy and automation of soot blowing.

[0014] As can be seen from the above technical solutions, the advantages of this utility model are:

[0015] 1. The nozzles on the soot blowing pipe are designed with an flared structure, and the cross-section of the nozzles is waist-shaped or elliptical. This can maximize the coverage area of ​​the ejected steam, which not only helps to expand the soot blowing range, reduce the number or density of nozzles, and make it suitable for different working conditions, but also reduces the damage of the steam itself to the heated pipe wall. Furthermore, it requires lower gas supply pressure and flow rate, thus saving energy.

[0016] 2. A protective plate is fixedly installed on the inner wall of the nozzle. The protective plate is fixedly installed at the inner opening of the nozzle. The protective plate is arranged along the inner opening contour of the corresponding nozzle to prevent the inner opening of the nozzle from directly contacting the steam, thus effectively improving the service life of the nozzle.

[0017] 3. The control unit is connected to a flue gas temperature detection unit and a heated surface tube wall temperature detection unit. The control unit is also connected to a linear drive mechanism, a rotary drive mechanism, and an air source. The control unit can control the soot blowing operation through online detection of temperature changes and changes in the outer surface wall temperature of the heated surface tube, thereby improving the accuracy and automation of soot blowing and realizing the intelligentization of soot blowing operation.

[0018] 4. The setting of the condensate drain unit can achieve the function of condensate draining of steam, avoiding water carryover in steam and fatigue damage to the soot blower. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the steam soot blowing system according to one or more embodiments of the present invention;

[0021] Figure 2 This is a cross-sectional structural diagram of the nozzle according to one or more embodiments of the present invention;

[0022] The components represented by the various reference numerals in the diagram are:

[0023] 1. Frame; 2. Wiring unit; 3. Control unit; 4. Drive motor; 5. Hanger; 6. Mounting box; 7. Inner tube; 8. Outer tube; 9. Nozzle; 10. Spray hole; 11. Protective plate; 12. Drainage unit. Detailed Implementation

[0024] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0025] In a typical embodiment of this utility model, such as Figures 1-2 As shown, a steam soot blowing system for a power plant boiler is proposed, including: a frame 1 and a soot blowing pipe. The soot blowing pipe is movably mounted on the frame 1 through a linear drive mechanism, which can drive the soot blowing pipe to move axially under the action of the linear drive mechanism. One end of the soot blowing pipe is detachably equipped with a nozzle 9, and the other end is connected to an air source.

[0026] The soot blowing tube includes an inner tube 7 and an outer tube 8. The inner tube 7 and the outer tube 8 are coaxially arranged and slidably connected to each other. Specifically, one end of the inner tube 7 is inserted into the outer tube 8, and the other end of the inner tube 7 is connected to the air source. The inner tube 7 is fixedly installed on the frame 1, and the outer tube 8 is slidably installed on the frame 1. The nozzle 9 is detachably installed on the end of the outer tube 8 away from the inner tube 7. Both the inner tube 7 and the outer tube 8 are made of more durable 0Cr19Ni9 material, which effectively increases the durability of the soot blowing tube itself.

[0027] In order to improve the service life of the soot blowing tube and the heating surface tube, a condensate drain unit 12 is also fixedly installed on the frame 1. In this embodiment, the condensate drain unit 12 is the existing condensate drain box structure. The inner tube 7 is connected to the air source through the condensate drain unit 12, thereby reducing the water droplets carried by the steam and avoiding the steam carrying water, which would increase the degree of damage to the soot blowing tube and the heating surface tube.

[0028] In this embodiment, the linear drive mechanism includes a drive motor 4, a screw, and a slider. The drive motor 4 is fixedly installed on the upper part of the frame 1. The output end of the drive motor 4 is fixedly connected to the screw. The frame 1 is provided with a slide rail. The screw is placed in the slide rail. The slider is slidably arranged in the slide rail and threadedly connected to the screw. The outer tube 8 is fixedly connected to the slider through a hanger 5, so that the outer tube 8 can be driven to move linearly along its axial direction by the slider.

[0029] It is understood that in other embodiments, the linear drive mechanism may also be a ball screw pair or other structures, and the specific design can be determined according to the actual design requirements. No further restrictions are imposed here.

[0030] The end of the outer tube 8 away from the nozzle 9 is rotatably mounted in the mounting box 6. The mounting box 6 is fixedly connected to the slider via the hanger 5. The mounting box 6 is equipped with a rotation drive mechanism, which cooperates with the end of the outer tube 8 to drive the outer tube 8 to rotate around the axis.

[0031] In this embodiment, a sprocket is fixedly provided at the end of the outer tube 8 away from the nozzle 9. A motor is provided inside the mounting box 6. The output end of the motor is fixedly provided with a sprocket. The sprocket at the output end of the motor is connected to the sprocket at the end of the outer tube 8 through a chain, thereby driving the outer tube 8 to rotate around the axis.

[0032] The frame 1 is equipped with a wiring unit 2 and a control unit 3. The control unit 3 is connected to components such as the drive motor 4 through the wiring unit 2.

[0033] like Figure 2As shown, nozzle 9 has nozzle holes 10 on its side wall. The nozzle holes 10 are flared structures with an inner opening size smaller than the outer opening size, and the cross-section of the nozzle holes 10 is waist-shaped or elliptical. Compared with the columnar circular hole structure, the nozzle holes 10 in this embodiment can maximize the coverage area of ​​the ejected steam. This not only helps to expand the soot blowing range, reduce the number or arrangement density of nozzle holes 10, and make it suitable for different working conditions, but also reduces the damage of the steam itself to the heated surface tube wall. Moreover, under the same soot blowing effect, the nozzle holes 10 in this embodiment require lower gas supply pressure and flow rate, thereby saving energy.

[0034] In this embodiment, there are two nozzles 10, and the two nozzles 10 are symmetrically arranged along the axis of the nozzle 9. In other embodiments, other numbers of nozzles 10 may be provided. The specific number and arrangement position are determined according to the actual design requirements, and no further restrictions are imposed here.

[0035] Because the steam ejection causes impact wear on the nozzle 10, the service life of the nozzle 10 is relatively short. Figure 2 As shown, in this embodiment, a protective plate 11 is welded and fixed on the inner wall of the nozzle 9. The protective plate 11 is fixedly installed at the inner opening of the nozzle 10, and the protective plate 11 is arranged along the inner opening contour of the corresponding nozzle 10 to avoid the inner opening of the nozzle 10 from directly contacting the steam, thereby effectively improving the service life of the nozzle 10.

[0036] It should be noted that the width of the protective plate 11 should be smaller than the radius of the nozzle 9 to ensure that there is space between the two protective plates 11 at the two oppositely set nozzles 10 to allow steam to pass through, so as to avoid affecting the steam discharge.

[0037] To improve the accuracy and automation of soot blowing, this embodiment also includes a flue gas temperature detection unit and a heated surface tube wall temperature detection unit. Both the flue gas temperature detection unit and the heated surface tube wall temperature detection unit are connected to the control unit 3. The control unit 3 can control the soot blowing operation through online temperature detection.

[0038] In this embodiment, the flue gas temperature detection unit includes two thermocouples. During soot blowing, the two thermocouples are distributed on both sides of the heated surface tube to detect the flue gas temperature on both sides of the heated surface tube online. The control unit 3 is preset with a flue gas temperature difference comparison module. When the flue gas temperature difference is between 20℃ and 40℃, it indicates that soot blowing is not required or that the soot blowing work is completed. The control unit 3 controls each functional component to stop working. The heated surface tube wall temperature detection unit is an infrared thermometer used to detect the temperature of the heated surface tube wall. When the temperature difference between the heated surface tube wall and the flue gas temperature is around 100℃, it indicates that soot blowing is not required or that the soot blowing work is completed. The control unit 3 controls each functional component to stop working.

[0039] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A steam soot blowing system for a power plant boiler, comprising: The frame (1) and the soot blowing pipe are characterized in that the soot blowing pipe is movably mounted on the frame (1) by a linear drive mechanism, one end of the soot blowing pipe is detachably mounted with a nozzle (9), and the other end is connected to an air source. The nozzle (9) has a spray hole (10) on its side wall. The spray hole (10) has a flared structure and the cross-section of the spray hole (10) is waist-shaped or elliptical.

2. The power plant boiler steam soot blowing system according to claim 1, characterized in that, A protective plate (11) is fixedly provided on the inner wall of the nozzle (9). The protective plate (11) is fixedly provided at the inner opening of the nozzle (10). The protective plate (11) is arranged along the inner opening contour of the corresponding nozzle (10).

3. The power plant boiler steam soot blowing system according to claim 1, characterized in that, The width of the protective plate (11) is smaller than the radius of the nozzle (9).

4. The power plant boiler steam soot blowing system according to claim 1, characterized in that, The soot blowing pipe includes an inner pipe (7) and an outer pipe (8). One end of the inner pipe (7) is inserted into the outer pipe (8), and the other end of the inner pipe (7) is connected to the air source. The inner pipe (7) is fixedly installed on the frame (1), and the outer pipe (8) is slidably installed on the frame (1). The nozzle (9) is detachably installed on the end of the outer pipe (8) away from the inner pipe (7).

5. The power plant boiler steam soot blowing system according to claim 4, characterized in that, A condensate drain unit (12) is fixedly installed on the frame (1), and the inner tube (7) is connected to the air source through the condensate drain unit (12).

6. The power plant boiler steam soot blowing system according to claim 4, characterized in that, The end of the outer tube (8) away from the nozzle (9) is rotatably installed in the mounting box (6). The mounting box (6) is connected to the linear drive mechanism through the hanger (5). The mounting box (6) is equipped with a rotary drive mechanism, which is connected to the outer tube (8).

7. The power plant boiler steam soot blowing system according to claim 6, characterized in that, The frame (1) is equipped with a control unit (3), which is connected to a flue gas temperature detection unit and a heated surface tube wall temperature detection unit. The control unit (3) is also connected to a linear drive mechanism, a rotary drive mechanism, and a gas source.

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