Sound wave soot blowing system for secondary air bellow

Abstract

The sound wave soot blowing system comprises a sound wave soot blowing assembly and a sound wave device, the sound wave soot blowing assembly comprises an air guide pipe and a sound wave device, the air guide pipe is arranged below the secondary air box and used for guiding in compressed air, a plurality of branch pipes are arranged on the air guide pipe, the first ends of the branch pipes extend into the secondary air box, and the second ends of the branch pipes extend into the secondary air box; the number of the sound wave devices is multiple, the multiple sound wave devices are installed at the first ends of the branch pipes respectively, and each branch pipe is provided with a control valve. The dust monitoring assembly is arranged at the bottom of the secondary air bellow and used for monitoring the thickness of dust in the secondary air bellow; and the controller is in signal connection with the control valve and the dust monitoring assembly, and the controller is used for controlling on-off of the control valve according to data of the dust monitoring assembly. Therefore, compared with an ash removal mode in the related technology, the ash removal effect in the secondary air box is improved, and ash removal is more thorough.

Description

Technical Field

[0001] The present disclosure relates to the technical field of cleaning dust accumulation in secondary air boxes, and in particular to a sonic soot blowing system for secondary air boxes. Background Art

[0002] The secondary air box is an important part of the boiler system, responsible for providing the airflow required for combustion. When the secondary air is heated by the rotary air preheater, the fly ash particles in the flue gas often enter the secondary air along with the heat exchange elements. When the hot secondary air flows to the annular air box through the air duct, the wind speed decreases. After a long period of operation, a large amount of dust may accumulate at the bottom, which may seriously affect the safety of the boiler fire detection system.

[0003] In the related art, in order to clean the dust in the secondary air box, pulse jet cleaning systems, vibration soot blowing systems and rotary mechanical soot cleaners are usually used. Due to the complex internal structure of the boiler, variable geometric shapes, curved pipes and other factors, the existing cleaning methods have the problems of poor cleaning effect and incomplete cleaning. Summary of the invention

[0004] The purpose of the present disclosure is to provide a sonic soot blowing system for a secondary air box, which can improve the soot cleaning effect of the secondary air box to at least partially solve the problems in the related art.

[0005] In order to achieve the above-mentioned purpose, the present disclosure provides a sonic soot blowing system for a secondary air box, comprising: a sonic soot blowing assembly, comprising an air duct and a sonicator, the air duct being arranged below the secondary air box and used for introducing compressed air, the air duct being provided with a plurality of branch pipes, the first ends of the branch pipes extending into the secondary air box, the sonicators being provided in a plurality of numbers, the plurality of sonicators being respectively mounted at the first ends of the branch pipes, each of the branch pipes being provided with a control valve; and a dust monitoring assembly being arranged at the bottom of the secondary air box and used for monitoring the thickness of dust in the secondary air box; and a controller, the controller being connected to the control valve and the dust monitoring assembly by signal, the controller being used for controlling the on and off of the control valve according to data of the dust monitoring assembly.

[0006] Optionally, the sonicator includes a main body, which is in a frustum shape and has a connecting pipe in the middle of the large end of the main body, the connecting pipe is connected to the first end of the branch pipe, a guide channel is provided in the main body, and an annular air outlet connected to the guide channel is provided on the outer periphery of the connecting pipe.

[0007] Optionally, the width of the annular air outlet is 2 mm to 4 mm.

[0008] Optionally, the annular air outlet is arranged in one-to-one correspondence with the guide channel.

[0009] Optionally, a reduced diameter section is provided at one end of the guide channel close to the annular air outlet.

[0010] Optionally, there are multiple annular air outlets, and the multiple annular air outlets are concentrically arranged.

[0011] Optionally, at least part of the sonicator is disposed at a corner of the secondary air box, and the sonicator is inclined from the corner toward the middle of the secondary air box, and the inclination angle is 35°~45°.

[0012] Optionally, the dust monitoring component includes a plurality of level meters, the plurality of level meters are arranged at intervals along the extension direction of the secondary air box, and the plurality of level meters are connected to the controller signal.

[0013] Optionally, the material level meter is a passive nuclear material level meter, and a plurality of the passive nuclear material level meters are arranged at equal intervals along the extension direction of the secondary wind box.

[0014] Optionally, the sonic soot blowing system for the secondary air box further comprises an air supply pipe, the air supply pipe is connected to the air guide pipe, and a check valve, a filter, a pneumatic butterfly valve and a pressure switch are sequentially provided on the air supply pipe along the gas delivery direction.

[0015] Through the above technical scheme, the controller controls the on and off of the control valves corresponding to each sonicator in the sonic sootblowing assembly according to the data of the dust monitoring assembly to blow and dust the secondary air box of the boiler. Among them, through the setting of multiple sonicators, the sound waves can cover the corners, dead corners and other positions in the secondary air box, thereby improving the cleaning effect in the secondary air box relative to the cleaning methods in the related art, and the cleaning is more thorough. At the same time, the setting of multiple sonicators can also selectively open the corresponding sonicators according to the degree of dust accumulation at different positions in the secondary air box obtained by the dust monitoring assembly, thereby being able to clean the secondary air box more accurately and reduce costs.

[0016] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 is a schematic structural diagram of a sonic soot blowing system for a secondary air box provided in an exemplary embodiment of the present disclosure; Figure 2 is a partial schematic diagram of an assembly of an acoustic sootblowing assembly and a secondary sealing box provided in an exemplary embodiment of the present disclosure; Figure 3 1 is a partially enlarged schematic diagram of an acoustic wave device provided in an exemplary embodiment of the present disclosure.

[0018] Description of Reference Numerals 1-air guide pipe; 11-branch pipe; 12-control valve; 2-sonic wave generator; 21-main body; 22-connecting pipe; 23-flow guide channel; 24-annular air outlet; 25-reduced diameter section; 3-secondary air box; 31-burner; 4-dust monitoring component; 41-level meter; 5-air supply pipe; 6-check valve; 7-filter; 8-pneumatic butterfly valve; 9-pressure switch. DETAILED DESCRIPTION

[0019] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0020] In the present disclosure, unless otherwise stated, the terms used, such as "first", "second", etc., are intended to distinguish one element from another element and do not have order or importance. In addition, in the description with reference to the drawings, the same reference numerals in different drawings represent the same elements.

[0021] In the related technology, the secondary air box is an important component of the boiler system, responsible for providing the airflow required for combustion. When the secondary air is heated by the rotary air preheater, the fly ash particles in the flue gas often enter the secondary air along with the heat exchange elements. When the hot secondary air flows to the annular air box through the air duct, the wind speed decreases. After a long period of operation, a large amount of dust may accumulate at the bottom, which may seriously affect the safety of the boiler fire detection system. In order to clean the dust in the secondary air box, pulse jet cleaning systems, vibrating soot blowing systems, and rotary mechanical soot cleaners are usually used. Due to the complex internal structure of the boiler, variable geometric shapes, and curved pipes, the existing cleaning methods have the problems of poor cleaning effect and incomplete cleaning.

[0022] In order to solve the above technical problems, Figure 1-Figure 3As shown, the present disclosure provides a sonic soot blowing system for a secondary air box, comprising: a sonic soot blowing component, a dust monitoring component 4 and a controller, the sonic soot blowing component comprising an air duct 1 and a sonicator 2, the air duct 1 being arranged below the secondary air box 3 and being used for introducing compressed air, the air duct 1 being provided with a plurality of branch pipes 11, the first ends of the branch pipes 11 extending into the secondary air box 3, the number of sonicators 2 being multiple, the plurality of sonicators 2 being respectively mounted at the first ends of the branch pipes 11, and a control valve 12 being provided on each branch pipe 11; the dust monitoring component 4 being arranged at the bottom of the secondary air box 3, being used for monitoring the thickness of dust in the secondary air box 3; the controller being connected to the control valve 12 and the dust monitoring component 4 by signal, the controller being used for controlling the on and off of the corresponding control valve 12 according to the data of the dust monitoring component 4.

[0023] Through the above technical scheme, the controller controls the opening and closing of the control valve 12 corresponding to each sonicator 2 in the sonic sootblowing assembly according to the data of the dust monitoring assembly 4 to blow and dust the secondary air box 3 of the boiler. Among them, through the setting of multiple sonicators 2, the sound waves can cover the corners, dead corners and other positions in the secondary air box 3, thereby improving the cleaning effect in the secondary air box relative to the cleaning method in the related art, and the cleaning is more thorough. At the same time, the setting of multiple sonicators 2 can also selectively open the corresponding sonicators 2 according to the dust accumulation degree at different positions in the secondary air box 3 obtained by the dust monitoring assembly 4, so that the secondary air box 3 can be cleaned more accurately and the cost can be reduced.

[0024] It should be noted that the above-mentioned secondary wind box 3 is a non-partitioned and non-independent secondary wind box, and the projection of the secondary wind box in the vertical direction is U-shaped. The ventilation flow path in the secondary wind box flows from one side of the U-shape to the other side, and a burner 31 is also provided in the middle part of the secondary wind box 3. The fly ash agitated by the sonicator 2 can enter the furnace through the secondary air nozzle of the burner 31. In addition, in some feasible methods, in order to make the sound waves generated by the sonicator 2 agitate and take away the bottom of the secondary wind box 3, the vertical distance between the sonicator 2 and the burner 31 is 1.4~2m, and the horizontal distance is 0.4m~0.7m. In this way, by setting the relative position of the sonicator 2 and the burner 31, when the sonicator 2 emits sound wave vibrations, the dust at the bottom of the secondary wind box 3 can be agitated and enter the furnace through the secondary air nozzle of the burner 31 to remove the accumulated ash. In addition, the sonicator 2 is arranged in the secondary air box 3 so that when sound waves are generated, they can help disturb the airflow in the secondary air box 3, accelerate the flow of smoke in the secondary air box 3, and promote the speed at which the secondary air box 3 provides secondary air, thereby improving the working efficiency of the secondary air box 3.

[0025] In order to facilitate the formation of sound waves by the sonicator to remove dust in the secondary wind box 3, in some specific embodiments, the sonicator 2 includes a body 21, which can be a metal part, and is in the shape of a truncated cone and provided with a connecting pipe 22 in the middle of the large end of the body 21, the connecting pipe 22 is connected to the first end of the branch pipe 11, a guide channel 23 is provided in the body 21, and an annular air outlet 24 connected to the guide channel 23 is provided on the outer periphery of the connecting pipe 22, and the annular air outlet 24 is arranged toward the bottom of the secondary wind box 3. In this way, the gas enters the connecting pipe 22 through the branch pipe 11 and is guided from the guide channel 23 to blow from the annular air outlet 24 toward the bottom of the secondary wind box 3, thereby stirring up the dust at the bottom of the secondary wind box 3 and entering the furnace through the secondary air nozzle of the burner 31 to remove the accumulated dust.

[0026] In some practicable embodiments, in order to further agitate the dust at the bottom of the secondary air box 3 through the sonicator 2, the sonicator 2 is set as a point sound source, the sound frequency is 25Hz to 250Hz, the sound intensity is 140dB to 150dB on average, the compressed air pressure of the annular air outlet 24 of the sonicator 2 is 0.4MPa to 0.6MPa, and the amount is 1m 3 / min~2.5m 3 / min, so that after the compressed air enters the sonicator 2, it can agitate the dust at the bottom of the secondary air box 3 and enter the furnace through the secondary air nozzle of the burner 31 to remove the accumulated dust.

[0027] In order to facilitate the compressed air to be sent out from the annular air outlet 24 and to agitate the dust at the bottom of the secondary air box 3, in some practicable ways, the annular air outlet 24 is arranged in a one-to-one correspondence with the guide channel 23, the number of the annular air outlet 24 is multiple and the multiple annular air outlets 24 are concentrically arranged, specifically, as Figure 3 As shown, the number of the annular air outlet 24 and the guide channel 23 are both two, the centers of the two annular air outlets 24 are both located on the central axis of the connecting pipe 22 in the vertical direction and the centers of the two annular air outlets 24 coincide, so that the two annular air outlets 24 are concentrically arranged, the outer diameter of the annular air outlet 24 is 30mm~35mm, the width of the annular air outlet 24 is 2mm~4mm, and the height of the main body 21 in the vertical direction is 60mm~80mm.

[0028] In order to discharge the compressed air from the annular air outlet 24 at a preset pressure, in some feasible embodiments, a reduced diameter section 25 is provided at one end of the guide channel 23 close to the annular air outlet 24. For example, there are two guide channels 23, and the two guide channels 23 are provided with a reduced diameter section 25 at one end close to the annular air outlet 24. The reduced diameter section 25 can be located at one of the two oppositely arranged inner side walls of the guide channel 23. The setting of the reduced diameter section 25 can reduce the flow area of ​​the outlet of the guide channel 23, so that the compressed air can be discharged from the annular air outlet 24 at a higher pressure, agitate the dust at the bottom of the secondary air box 3, and enter the furnace through the secondary air nozzle of the burner 31 to remove the accumulated dust.

[0029] In some practicable embodiments, in order to accurately remove dust from the secondary air box 3, the dust monitoring assembly 4 includes a plurality of level meters 41, which are arranged at intervals along the extension direction of the secondary air box 3, and the plurality of level meters 41 are connected to the controller signal. Figure 1 As shown, the number of the level meter 41 can be three, and the level meter 41 can be a passive nuclear level meter. The passive nuclear level meter can be arranged at intervals along the extension direction of the secondary wind box 3. Preferably, the three passive nuclear level meters can be arranged at equal intervals along the extension direction of the secondary wind box. For example, the passive nuclear level meters are respectively installed at one-quarter, two-quarters and three-quarters of the length of the air duct of the secondary wind box 3. The thickness of the ash accumulation in the secondary wind box 3 is judged according to the measured values ​​of the three passive nuclear level meters, and the controller turns on the corresponding sonicator 2 according to the measured data of the three passive nuclear level meters. It can be understood that the above-mentioned controller can be a control platform of a single-chip microcomputer, a PLC controller or a boiler control system, and the present disclosure does not make specific limitations.

[0030] For example, passive nuclear level meters can be installed at one quarter, two quarters and three quarters of the length of the air duct of the secondary wind box 3, respectively. The number of sonicators 2 can be eight and they are arranged at intervals along the air duct of the secondary wind box 3, respectively. The secondary wind box 3 is U-shaped, and at least part of the sonicators 2 are arranged at the corners of the secondary wind box 3. Preferably, a sonicator 2 is arranged at each of the two corners of the secondary wind box 3, and the sonicator 2 is inclined from the corner toward the middle of the secondary wind box 3, and preferably, the inclination angle is 35°~45°. Thus, the dust accumulation thickness in the secondary wind box 3 is collected by three passive nuclear level meters, and the controller judges to open the sonicator 2 to remove the dust accumulation in the secondary wind box 3 according to the dust accumulation thickness data in the secondary wind box 3.

[0031] In addition, since the dust accumulation conditions at different parts of the bottom of the secondary wind box 3 are different, in order to adapt to the above working conditions, each sonicator 2 can be provided with a separate control valve 12, and the number of passive nuclear level meters is three, and the three passive nuclear level meters are arranged at equal intervals along the air duct of the secondary wind box 3, and the number of sonicators 2 is eight, and the eight sonicators 2 are arranged at equal intervals along the air duct of the secondary wind box 3 and avoid the arrangement of the passive box level meter, among which the passive nuclear level meter near the inlet of the secondary wind box 3 is linked with the four adjacent sonicators 2, the passive nuclear level meter in the middle of the secondary wind box 3 is linked with the two adjacent sonicators 2, and the passive nuclear level meter at the outlet of the secondary wind box 3 is linked with the two adjacent sonicators 2. In this way, the sonicators 2 at different positions in the secondary wind box 3 can be selectively opened according to the different passive nuclear level meters located in the secondary wind box 3, so as to accurately clean the dust accumulated in the secondary wind box 3.

[0032] It can be understood that the above-mentioned level meter is a passive nuclear level meter, which can specifically be any one of an ultrasonic level meter, a guided wave radar level meter, and a radio frequency admittance level meter.

[0033] In order to accurately control the soot blowing and cleaning frequency of the sonicator 2, in some practicable ways, the controller controls the soot blowing frequency of the sonicator 2 to be two to six times a day, so that the sonicator 2 is put into operation when the boiler is under high load and shut down when the boiler is under low load, thereby reducing costs. Of course, it can be understood that the above soot blowing frequency of two to six times a day is also schematic, and the specific soot blowing frequency can be selectively set according to the specific working conditions, which is not limited in the present disclosure.

[0034] In some practicable embodiments, the sonic soot blowing system for the secondary air box also includes an air supply pipe 5, which is connected to the air guide pipe 1. A check valve 6, a filter 7, a pneumatic butterfly valve 8 and a pressure switch 9 are sequentially arranged on the air supply pipe 5 along the gas delivery direction. The air supply pipe 5 can be connected to the compressed air for power plant instruments, and the compressed air for power plant instruments is used as the gas source. The compressed air for power plant instruments enters the air supply pipe 5 and passes through the check valve 6, the filter 7, the pneumatic butterfly valve 8 and the pressure switch 9. The setting of the check valve 6 can control the flow direction of the air supply pipe 5 to prevent the compressed gas from flowing back, and the compressed air is filtered by the setting of the filter 7 so that the quality of the compressed air meets the soot blowing requirements, wherein the filter 7 can select the F series medium-efficiency filter, the pneumatic butterfly valve 8 and the pressure switch 9 can be connected to the controller signal, and the pneumatic butterfly valve 8 and the pressure switch 9 can be connected through an external device, and the external device can include a flow meter to monitor the flow rate of the compressed air, and the pneumatic butterfly valve 8 drives the cylinder and the pressure switch 9 drives the cylinder to control the disconnection of the air supply pipe 5. In this way, the controller can also control the pneumatic butterfly valve 8 and the pressure switch 9 to control the flow rate and opening and closing of the compressed air in the air supply pipe 5, so as to more intelligently regulate the dust accumulation in the secondary air box 3.

[0035] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0036] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0037] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A sonic soot blowing system for a secondary air box, characterized in that: include: A sonic sootblowing assembly, comprising an air guide pipe and a sonicator, wherein the air guide pipe is arranged below the secondary air box and is used to introduce compressed air, the air guide pipe is provided with a plurality of branch pipes, the first ends of the branch pipes extend into the secondary air box, the sonicators are in plurality, the plurality of sonicators are respectively installed at the first ends of the branch pipes, and each of the branch pipes is provided with a control valve; and A dust monitoring component, disposed at the bottom of the secondary air box, for monitoring the thickness of dust in the secondary air box; and A controller is connected to the control valve and the dust monitoring component by signals, and is used to control the on-off of the control valve according to data of the dust monitoring component.

2. The sonic soot blowing system for a secondary air box according to claim 1, characterized in that: The sonicator includes a main body, which is in a truncated cone shape and has a connecting pipe in the middle of the large end of the main body, the connecting pipe is connected to the first end of the branch pipe, a guide channel is provided in the main body, and an annular air outlet connected to the guide channel is provided on the outer periphery of the connecting pipe.

3. The sonic soot blowing system for a secondary air box according to claim 2, characterized in that: The width of the annular air outlet is 2 mm to 4 mm.

4. The sonic soot blowing system for a secondary air box according to claim 2, characterized in that: The annular air outlets are arranged in one-to-one correspondence with the flow guide channels.

5. The sonic soot blowing system for secondary air boxes according to claim 2, characterized in that: The guide channel has a reduced diameter section at one end close to the annular air outlet.

6. The sonic soot blowing system for a secondary air box according to claim 2, characterized in that: There are multiple annular air outlets, and the multiple annular air outlets are concentrically arranged.

7. The sonic soot blowing system for a secondary air box according to claim 1, characterized in that: At least part of the sonicator is disposed at a corner of the secondary air box, and the sonicator is inclined from the corner toward the middle of the secondary air box, and the inclination angle is 35° to 45°.

8. The sonic soot blowing system for a secondary air box according to claim 1, characterized in that: The dust monitoring component comprises a plurality of level meters, the plurality of level meters are arranged at intervals along the extension direction of the secondary air box, and the plurality of level meters are connected to the controller signal.

9. The sonic soot blowing system for a secondary air box according to claim 8, characterized in that: The material level meter is a passive nuclear material level meter, and a plurality of the passive nuclear material level meters are arranged at equal intervals along the extension direction of the secondary wind box.

10. The sonic soot blowing system for a secondary air box according to any one of claims 1 to 9, characterized in that: The sonic soot blowing system for the secondary air box also includes an air supply pipeline, which is connected to the air guide pipe. A check valve, a filter, a pneumatic butterfly valve and a pressure switch are sequentially arranged on the air supply pipeline along the gas delivery direction.

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