A secondary air system and control method for a circulating fluidized bed boiler co-firing solid waste

Abstract

The present invention discloses a secondary air system and a control method for a circulating fluidized bed boiler burning solid waste mixedly, belonging to the technical field of circulating fluidized bed boilers. A first detection component is fixedly installed on both the secondary air fan and the air preheater of the present invention, and the secondary air pipeline is arranged in the inner circle of the first detection component. A secondary air box is fixedly arranged on the fluidized bed boiler. A second detection component is fixedly installed on both the air preheater and the secondary air box, and the secondary air pipeline is arranged in the inner circle of the second detection component. A plurality of secondary air nozzles are communicatedly arranged on the fluidized bed boiler. An opening and closing component is rotatably arranged on the secondary air nozzles, and a cleaning component is also fixedly arranged on the secondary air nozzles. The present invention can not only detect whether the secondary air pipeline leaks air. In addition, the cleaning component adopted by the invention has a relatively high degree of automation, and the secondary air nozzles can be cleaned by using wind power, saving electric energy.

Description

Technical Field

[0001] The present invention belongs to the technical field of circulating fluidized bed boilers, and specifically relates to a secondary air system and control method for a circulating fluidized bed boiler co-firing solid waste. Background Art

[0002] A circulating fluidized bed boiler is a boiler that uses fluidized combustion technology and is widely used in the power generation field and industrial field. In order to practice the environmental protection concept, during the use of a circulating fluidized bed boiler, in addition to burning pure fuel, it can also mix and burn fuel with biomass fuels such as sludge, which not only recycles solid waste but also reduces the fuel consumption.

[0003] Chinese Patent CN217329769U discloses a secondary air grading arrangement system for a circulating fluidized bed boiler, including a circulating fluidized bed boiler body and a secondary air blower. The secondary air blower is arranged on one side of the circulating fluidized bed boiler body. A dual-channel air inlet structure is arranged on the side wall of the circulating fluidized bed boiler body. The dual-channel air inlet structure adopts a layered structure design and is connected to the secondary air blower. This utility model adopts a dual-channel layered structure design, and the air outlets are arranged in an annular array. The air volume on each branch can be adjusted, which can effectively improve the stability of secondary air injection. At the same time, in cooperation with the air direction adjustment structure, the injected secondary air can be effectively adjusted. The structure is reasonable, the operation is simple, and the practicability is strong.

[0004] The above-mentioned disclosed prior art proposes a secondary air grading arrangement system for a circulating fluidized bed boiler. Although this secondary air grading arrangement system can adjust the intake volume and intake direction of secondary air, it does not have the function of detecting the secondary air pipeline. Therefore, when the secondary air pipeline leaks, it will cause the intake air volume of secondary air to be unstable, which will affect the combustion effect of the circulating fluidized bed boiler. In addition, after the secondary air nozzles in the secondary air system have been used for a long time, dust will accumulate inside the secondary air nozzles, which will change the inner diameter of the secondary air nozzles. As a result, when secondary air passes through the inside of the secondary air nozzles, the passing path changes, and finally the secondary air entering the furnace is unstable, which will also affect the combustion effect.

[0005] Therefore, we propose a secondary air system and control method for a circulating fluidized bed boiler co-firing solid waste to solve the above-mentioned problems. Summary of the Invention

[0006] Aiming at the problems existing in the prior art that it does not have the function of detecting the secondary air duct, and after the secondary air nozzles in the secondary air system have been used for a long time, dust will accumulate inside the secondary air nozzles, affecting the combustion effect, the purpose of the present invention is to provide a secondary air system and control method for a waste-incinerating circulating fluidized bed boiler.

[0007] To solve the above problems, the technical solutions adopted by the present invention are as follows: A secondary air system for a waste-incinerating circulating fluidized bed boiler includes a fluidized bed boiler. A secondary air blower and an air preheater are respectively arranged on the side of the fluidized bed boiler. The secondary air blower and the air preheater are connected through a secondary air duct. A detection component one is fixedly installed on both the secondary air blower and the air preheater, and the secondary air duct is arranged in the inner circle of the detection component one. A secondary air box is fixedly arranged on the fluidized bed boiler. The air preheater and the secondary air box are connected through a secondary air duct. A detection component two is fixedly installed on both the air preheater and the secondary air box, and the secondary air duct is arranged in the inner circle of the detection component two. A number of secondary air nozzles are connected to the fluidized bed boiler. The air inlet end of the secondary air nozzle is connected to the air outlet end of the secondary air box through a secondary air duct. An opening and closing component is rotatably arranged on the secondary air nozzle, and a cleaning component is also fixedly arranged on the secondary air nozzle;

[0008] The detection component two includes a transparent outer shell two. A square tube is arranged in the inner cavity of the transparent outer shell two. The outer side wall of the square tube is fixedly connected to the inner side wall of the transparent outer shell two through a number of fixing blocks. Four mounting plates are fixedly installed on the inner side wall of the transparent outer shell two. The four mounting plates are respectively parallel to the four side walls of the square tube. A number of through holes are opened on each mounting plate. A thin film is arranged on the side wall of the inner cavity of the through hole. A white coating is applied to the side wall of the thin film facing the transparent outer shell two, and a brightly colored coating is applied to the side wall of the thin film facing the square tube. A number of jacking components are fixedly installed on the outer side wall of the square tube. The jacking components are concentric with the through holes and the thin film;

[0009] The secondary air nozzle includes a nozzle body. A through groove is opened on the side wall of the nozzle body, and a baffle is fixedly installed on the inner side wall of the through groove;

[0010] The cleaning component includes a first load-bearing plate fixedly installed on the side wall of the nozzle body and a second load-bearing plate fixedly installed on the first load-bearing plate. A pair of electric telescopic columns are fixedly installed on the side wall of the second load-bearing plate. The output ends of the two electric telescopic columns are jointly fixedly installed with a connecting plate. A pair of mounting brackets are fixedly installed on the outer side wall of the connecting plate. A connecting shaft is rotatably installed through the mounting brackets. A fan blade is fixedly installed on the side wall of one end of the connecting shaft. A first cleaning part, a second cleaning part, and a third cleaning part are respectively fixedly connected to the outer side wall of the connecting shaft.

[0011] Further, the first detection component includes a transparent outer shell I. An electronic air valve is communicated and arranged on the top surface of the transparent outer shell I. A color film is closely adhered to the circumferential outer wall of the secondary air duct. An air cavity is formed between the circumferential outer wall of the color film and the side wall of the inner cavity of the transparent outer shell I.

[0012] Further, the secondary air box includes an annular box body. The inner side wall of the annular box body and the outer side wall of the fluidized bed boiler are fixedly connected through a plurality of connecting blocks.

[0013] Further, the square pipe includes a pipe body. Guide plates are fixedly installed at the four corners inside the pipe body.

[0014] Further, the jacking component includes an installation cylinder fixedly installed on the outer side wall of the pipe body and a push block slidably installed inside the installation cylinder. The push block and the installation cylinder are elastically connected through a first spring. An air chamber is also formed between the push block and the installation cylinder. Inert gas is contained inside the air chamber. A plurality of installation grooves are formed at the edge of the outer side wall of the push block. A limiting post is fixedly installed in the inner cavity of the installation groove. A top rod is rotatably sleeved on the limiting post. The side wall of the top rod and the side wall of the inner cavity of the installation groove are elastically connected through a second spring.

[0015] Further, the opening and closing component includes an F-shaped bracket fixedly installed on the side wall of the nozzle body and a motor fixedly installed on the F-shaped bracket. The output end of the motor is fixedly connected with a rotating shaft. The rotating shaft penetrates through a through groove. A turning plate is rotatably arranged in the through groove. The turning plate is fixedly sleeved on the rotating shaft. An embedded part is formed on the inner side wall of the turning plate. The shape of the embedded part is mutually fitted with that of the baffle. A high-temperature resistant sealing pad is arranged at the contact part between the embedded part and the baffle. A plugging plate is embedded and slidably installed on the side wall of the inner cavity of the through groove.

[0016] Further, the first cleaning part includes a first connecting rod fixedly connected to the outer side wall of the connecting shaft. A first sliding groove is formed inside the first connecting rod. Inert gas is contained inside the first sliding groove. A first scraping plate is slidably installed inside the first sliding groove. The first scraping plate and the side wall of the inner cavity of the first sliding groove are elastically connected through a third spring;

[0017] The second cleaning part includes a second connecting rod fixedly connected to the outer side wall of the connecting shaft. Second sliding grooves are respectively formed at both ends of the second connecting rod. Inert gas is contained inside the second sliding grooves. A second scraping plate is slidably installed inside the second sliding grooves. The second scraping plate and the side wall of the inner cavity of the second sliding grooves are elastically connected through a fourth spring;

[0018] The third cleaning member includes a third connecting rod fixedly connected to the outer side wall of the connecting shaft. A third sliding groove is formed inside the third connecting rod. An inert gas is contained inside the third sliding groove. A third scraping plate is slidably installed inside the third sliding groove. The third scraping plate is elastically connected to the side wall of the inner cavity of the third sliding groove through a fifth spring.

[0019] The present invention also provides another technical solution: a control method for a secondary air system of a waste-incinerating circulating fluidized bed boiler, including the following steps:

[0020] S1: When the inspection staff observes through the first transparent housing whether there are bubbles in the color film, it is used to judge whether there is a leakage in the secondary air pipeline;

[0021] S2: The inspection personnel observes through the second transparent housing whether the film has a distinct color, which is used to judge whether there is a breakage in the secondary air pipeline;

[0022] S3: After operating for a period of time, the fluidized bed boiler stops running, and the cleaning assembly is started to clean the dust inside the secondary air nozzle;

[0023] S4: After the dust cleaning is completed, the cleaning assembly is reset, and the fluidized bed boiler starts to run.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. When the inspection staff observes through the first transparent housing that there are bubbles in the color film, it indicates that there is a relatively large leakage in the secondary air pipeline, and corresponding countermeasures can be taken to stop the loss in time. Moreover, due to the setting of the first transparent housing, the leaked high-pressure gas will not directly blow to the outside, reducing the probability of causing other accidents.

[0026] 2. The inspection personnel can easily see the broken film with distinct colors through the second transparent housing, and then immediately judge that there is a breakage in this section of the secondary air pipeline. The operator can immediately take remedial measures to reduce the loss, and take corresponding measures to ensure the full combustion of the fuel. The setting of the second transparent housing can prevent the high-temperature gas from directly spraying to the outside, reducing the risk of harm to the surrounding equipment and personnel.

[0027] 3. The cleaning assembly adopted by the present invention has a high degree of automation, and can clean the secondary air nozzle by using wind power, saving electric energy. Moreover, it can be operated without waiting for the fluidized bed boiler to drop to a very low temperature, saving time cost. And it does not require personnel to use tools for cleaning, which is not only efficient but also does not cause physical harm to the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 For Figure 1 Enlarged view of part A of

[0030] Figure 3 Schematic cross-sectional view of detection component 1 of the present invention;

[0031] Figure 4 For Figure 3 Enlarged view of part B of

[0032] Figure 5 Schematic disassembled view of detection component 1 of the present invention;

[0033] Figure 6 Schematic cross-sectional view of the secondary air box and detection component 2 of the present invention;

[0034] Figure 7 For Figure 6 Enlarged view of part C of

[0035] Figure 8 Schematic view of the installation position of detection component 2 of the present invention;

[0036] Figure 9 For Figure 8 Enlarged view of part D of

[0037] Figure 10 Schematic three-dimensional structure view of the jacking component of the present invention;

[0038] Figure 11 Schematic cross-sectional view of the jacking component of the present invention;

[0039] Figure 12 Schematic view of the installation position of the secondary air nozzle of the present invention;

[0040] Figure 13 For Figure 12 Enlarged view of part E of

[0041] Figure 14 Schematic view of the open state of the opening and closing component of the present invention;

[0042] Figure 15 Schematic disassembled view of the opening and closing component of the present invention;

[0043] Figure 16 Schematic view of the installation position of the baffle of the present invention;

[0044] Figure 17 Schematic cross-sectional view of the secondary air nozzle of the present invention;

[0045] Figure 18 For Figure 17 Enlarged view of part F of

[0046] Figure 19 Schematic cross-sectional view of the first cleaning member, the second cleaning member and the third cleaning member of the present invention;

[0047] Figure 20 is Figure 19 Enlarged view of part G of

[0048] Figure 21 is Figure 19 Enlarged view of part H of

[0049] Figure 22 Schematic three-dimensional structure view of the cleaning assembly of the present invention;

[0050] Figure 23 is Figure 22 Enlarged view of part I of

[0051] In the figure: 1, fluidized bed boiler; 2, secondary air fan; 3, air preheater; 4, detection component one; 41, transparent outer shell one; 42, color film; 43, electronic air valve; 44, air cavity; 5, secondary air box; 51, annular box body; 52, connecting block; 6, detection component two; 61, transparent outer shell two; 62, square pipe; 621, pipe body; 622, guiding plate; 63, fixed block; 64, mounting plate; 65, through hole; 66, jacking component; 661, mounting cylinder; 662, pushing block; 663, air chamber; 664, first spring; 665, mounting groove; 666, limiting column; 667, ejector rod; 668, second spring; 67, thin film; 7, secondary air nozzle; 71, nozzle body; 72, through groove; 73, baffle; 74, high-temperature gasket; 8, cleaning assembly; 81, first bearing plate; 82, second bearing plate; 83, electric telescopic column; 84, connecting plate; 85, mounting frame; 86, connecting shaft; 87, fan blade; 88, first cleaning member; 881, first connecting rod; 882, first chute; 883, first scraping plate; 884, third spring; 89, second cleaning member; 891, second connecting rod; 892, second chute; 893, second scraping plate; 894, fourth spring; 820, third cleaning member; 8201, third connecting rod; 8202, third chute; 8203, third scraping plate; 8204, fifth spring; 9, secondary air duct; 10, opening and closing component; 101, F-shaped bracket; 102, motor; 103, rotating shaft; 104, turning plate; 105, embedded part; 106, blocking plate. Detailed implementation manners

[0052] The present invention will be further described below in conjunction with specific embodiments.

[0053] To solve the problem that the existing secondary air system cannot detect air leakage in the secondary air duct 9 in the middle section between the secondary air fan 2 and the air preheater 3, as shown in Figure 1 - Figure 6As shown in the figure:

[0054] A secondary air system for a circulating fluidized bed boiler co-firing solid waste includes a fluidized bed boiler 1. After mixing pure fuel and biomass fuel, the mixed fuel is transported into the furnace of the fluidized bed boiler 1 through the feed port for combustion. A secondary air blower 2 and an air preheater 3 are respectively arranged on the side of the fluidized bed boiler 1. The secondary air blower 2 and the air preheater 3 are connected through a secondary air pipeline 9. The secondary air blower 2 is used to generate secondary air, and the air preheater 3 is used to heat the secondary air to prevent the oxygen supply from being affected due to frosting of the secondary air pipeline 9. And the heated secondary air enters the furnace, which is beneficial to the full combustion of the fuel. A detection component 4 is fixedly installed on both the secondary air blower 2 and the air preheater 3, and the secondary air pipeline 9 is arranged in the inner circle of the detection component 4. The detection component 4 is used to detect whether there is leakage in the secondary air pipeline 9 between the secondary air blower 2 and the air preheater 3 to keep the secondary air system always in a stable operating state. A secondary air box 5 is fixedly arranged on the fluidized bed boiler 1. The air preheater 3 and the secondary air box 5 are connected through the secondary air pipeline 9. The gas heated by the air preheater 3 will enter the secondary air box 5 through the secondary air pipeline 9. A detection component 6 is fixedly installed on both the air preheater 3 and the secondary air box 5, and the secondary air pipeline 9 is arranged in the inner circle of the detection component 6. The detection component 6 is used to detect whether there is leakage in the secondary air pipeline 9 between the air preheater 3 and the secondary air box 5, which is also to keep the secondary air system always in a stable operating state.

[0055] A number of secondary air nozzles 7 are connected to the fluidized bed boiler 1. The air inlet end of the secondary air nozzle 7 and the air outlet end of the secondary air box 5 are connected through the secondary air pipeline 9. The secondary air in the secondary air box 5 enters the secondary air nozzle 7 through the secondary air pipeline 9 and is then sprayed into the furnace of the fluidized bed boiler 1 by the secondary air nozzle 7 to promote the full combustion of the fuel. An opening and closing component 10 is rotatably arranged on the secondary air nozzle 7, and a cleaning component 8 is also fixedly arranged on the secondary air nozzle 7. When there is dust deposited inside the secondary air nozzle 7, the opening and closing component 10 is started to make the inside of the secondary air nozzle 7 communicate with the outside, and then the dust deposited inside the secondary air nozzle 7 is cleaned by the cleaning component 8. After the dust is cleaned, the opening and closing component 10 is started again to make the inside of the secondary air nozzle 7 not communicate with the outside, and then the secondary air nozzle 7 can be used normally.

[0056] The detection component 4 includes a transparent outer shell 41. An electronic air valve 43 is connected to the top surface of the transparent outer shell 41. A color film 42 is tightly adhered to the circumferential outer wall of the secondary air pipeline 9. An air cavity 44 is formed between the circumferential outer wall of the color film 42 and the side wall of the inner cavity of the transparent outer shell 41.

[0057] Specifically, since the secondary air has not passed through the air preheater 3 for heating, the temperature of the secondary air duct 9 in this section is relatively low. In the initial state, the operator uses an external air pump to inflate the air chamber 44 through the electronic air valve 43, so that an appropriate air pressure is generated inside the air chamber 44. The high-pressure gas in the air chamber 44 will exert pressure on the color film 42, making the color film 42 firmly adhere to the circumferential outer wall of the secondary air duct 9, preventing the color film 42 from falling off. When there is a small leak in the secondary air duct 9 and the secondary air velocity is small, under the sealing effect of the color film 42 and the pressure of the high-pressure gas in the air chamber 44, the effect of initially plugging the leak can be achieved, so that the air volume of the secondary air is in a stable state, reducing the impact on the internal combustion effect of the fluidized bed boiler 1. When there is a large leak in the secondary air duct 9 and the secondary air velocity is large, the air flow pressure blown out from the damaged part of the secondary air duct 9 is greater than the pressure of the high-pressure gas in the air chamber 44, resulting in the formation of bubbles on the circumferential outer wall of the secondary air duct 9 by the color film 42. When the inspection staff observes the bubbles on the color film 42 through the transparent outer shell 41, it indicates that there is a large leak in the secondary air duct 9, and corresponding countermeasures can be taken to stop losses in time. Moreover, due to the setting of the transparent outer shell 41, the leaked high-pressure gas will not directly blow to the outside, reducing the probability of causing other accidents.

[0058] To solve the problem that the existing secondary air system cannot detect air leakage in the secondary air duct 9 in the middle section between the air preheater 3 and the secondary air box 5, as Figure 1 - Figure 2 and Figure 6 - Figure 11 shown:

[0059] The secondary air box 5 includes an annular box body 51, and the inner side wall of the annular box body 51 is fixedly connected to the outer side wall of the fluidized bed boiler 1 through a plurality of connecting blocks 52.

[0060] The detection component two 6 includes a transparent outer shell two 61. The setting of the transparent outer shell two 61 facilitates the inspection personnel to observe the internal conditions through the transparent outer shell two 61. A square tube 62 is arranged in the inner cavity of the transparent outer shell two 61. The square tube 62 is made of a heat-conducting material. The outer side wall of the square tube 62 and the inner side wall of the transparent outer shell two 61 are fixedly connected by a plurality of fixing blocks 63. Four mounting plates 64 are fixedly installed on the inner side wall of the transparent outer shell two 61. The four mounting plates 64 are respectively arranged parallel to the four side walls of the square tube 62. A plurality of through holes 65 are formed in each mounting plate 64. A thin film 67 is arranged on the side wall of the inner cavity of the through hole 65. A white coating is applied on the side wall of the thin film 67 facing the transparent outer shell two 61. A brightly colored coating is applied on the side wall of the thin film 67 facing the square tube 62. A plurality of jacking components 66 are fixedly installed on the outer side wall of the square tube 62. The jacking components 66 are concentric with the through holes 65 and the thin film 67.

[0061] The square tube 62 includes a tube body 621. Guide plates 622 are fixedly installed at the four corners inside the tube body 621. When the damaged part of the secondary air duct 9 faces the guide plates 622, the high-temperature air flow ejected from the inside of the secondary air duct 9 will diverge to both sides through the guide plates 622.

[0062] The jacking component 66 includes a mounting cylinder 661 fixedly installed on the outer side wall of the tube body 621 and a push block 662 slidably installed inside the mounting cylinder 661. The push block 662 and the mounting cylinder 661 are elastically connected by a first spring 664. An air chamber 663 is also formed between the push block 662 and the mounting cylinder 661. An inert gas is contained inside the air chamber 663. A plurality of mounting grooves 665 are formed at the edge of the outer side wall of the push block 662. A limiting post 666 is fixedly installed in the inner cavity of the mounting groove 665. A top rod 667 is rotatably sleeved on the limiting post 666. The side wall of the top rod 667 and the side wall of the inner cavity of the mounting groove 665 are elastically connected by a second spring 668.

[0063] Specifically, since the secondary air at this time has been heated by the air preheater 3, the secondary air in the secondary air duct 9 of this section has a relatively high temperature. When the circumferential outer wall of the secondary air duct 9 is damaged, the high-temperature gas inside the secondary air duct 9 will quickly spray onto the square pipe 62. Since the square pipe 62 is made of a heat-conducting material, the square pipe 62 will quickly conduct the temperature to the inside of the air chamber 663 and heat the inert gas inside the air chamber 663. The heated inert gas expands and generates a thrust. When the thrust is greater than the elastic force of the first spring 664, it pushes the push block 662, the limit post 666, and the ejector rod 667 to move together towards the outside of the mounting cylinder 661. During the movement, the ejector rod 667 will pierce the film 67 in the through hole 65 outwards. When the end of the ejector rod 667 close to the mounting cylinder 661 crosses the edge of the opening of the mounting cylinder 661, under the elastic force of the second spring 668, the ejector rod 667 will flip outwards, expand the damaged part of the film 67, and flip the side of the film 67 coated with the colored paint towards the side of the transparent outer shell two 61, so that the inspection personnel can easily see the broken and brightly colored film 67 through the transparent outer shell two 61, and then immediately judge that the secondary air duct 9 of this section is damaged. The operator can immediately take remedial measures to reduce the loss and take corresponding measures to ensure the full combustion of the fuel.

[0064] When the damaged part of the secondary air duct 9 faces the guide plate 622, the high-temperature air flow ejected from the inside of the secondary air duct 9 will diverge to both sides through the guide plate 622, and the square pipe 62 will continue to conduct the heat to the nearby lifting assembly 66, so that the lifting assembly 66 will pierce the film 67, and then the inspection personnel can find that the secondary air duct 9 of this section is damaged, preventing dead angles from occurring, resulting in the lifting assembly 66 being unable to pierce the film 67, and then the inspection personnel being unable to detect the damage of the secondary air duct 9 in time. Eventually, it will not only affect the combustion effect of the fuel, but may also cause other accidents. The setting of the transparent outer shell two 61 can prevent the high-temperature gas from directly spraying to the outside, reducing the risk of harm to the surrounding equipment and personnel.

[0065] Since the temperature of the secondary air in this section is relatively high, when the secondary air duct 9 is not damaged, the secondary air duct 9 will also conduct a small part of the heat to the inside of the air chamber 663 through the square pipe 62. At this time, the air pressure generated by the inert gas in the air chamber 663 cannot overcome the elastic force of the first spring 664. Therefore, the lifting assembly 66 will not pierce the film 67, and thus will not cause misjudgment problems for the inspection personnel.

[0066] After the repair of the damaged part of the secondary air duct 9 is completed, at this time, the temperature in the air chamber 663 decreases, making the air pressure of the inert gas less than the elastic force of the first spring 664. At this time, the jacking assembly 66 gradually retracts into the interior of the mounting cylinder 661. During this process, the outer sidewall of the ejector rod 667 will come into contact with the inner sidewall of the mounting cylinder 661, and cause the ejector rod 667 to flip into the interior of the mounting groove 665 and compress the second spring 668. Through this setting, a plurality of ejector rods 667 are restored to the gathered state for the next use. Then, the maintenance personnel can replace the broken film 67 with a new film 67 for the next detection. With this setting method, the maintenance is simple and convenient, and it is easy to observe.

[0067] In order to solve the problem that after the secondary air nozzle 7 has been used for a long time, dust will accumulate inside the secondary air nozzle 7, affecting the combustion effect, as Figure 12 - Figure 23 shown:

[0068] The secondary air nozzle 7 includes a nozzle body 71. A through groove 72 is formed in the side wall of the nozzle body 71, and a baffle 73 is fixedly installed on the inner side wall of the through groove 72.

[0069] The opening and closing assembly 10 includes an F-shaped bracket 101 fixedly installed on the side wall of the nozzle body 71 and a motor 102 fixedly installed on the F-shaped bracket 101. The output end of the motor 102 is fixedly connected to a rotating shaft 103. The rotating shaft 103 is disposed through the through groove 72. A turning plate 104 is rotatably disposed in the through groove 72. The turning plate 104 is fixedly sleeved on the rotating shaft 103. An embedded portion 105 is formed on the inner side wall of the turning plate 104. The shape of the embedded portion 105 is mutually fitted with that of the baffle 73. A high-temperature resistant gasket 74 is arranged at the contact portion between the embedded portion 105 and the baffle 73. A plugging plate 106 is embedded and slidably installed on the side wall of the inner cavity of the through groove 72.

[0070] The cleaning assembly 8 includes a first load-bearing plate 81 fixedly installed on the side wall of the nozzle body 71 and a second load-bearing plate 82 fixedly installed on the first load-bearing plate 81. A pair of electric telescopic columns 83 are fixedly installed on the side wall of the second load-bearing plate 82. The output ends of the two electric telescopic columns 83 are jointly fixedly installed with a connecting plate 84. A pair of mounting brackets 85 are fixedly installed on the outer side wall of the connecting plate 84. A connecting shaft 86 is rotatably installed through the mounting brackets 85. A fan blade 87 is fixedly installed on the side wall of one end of the connecting shaft 86. The outer side wall of the connecting shaft 86 is fixedly connected with a first cleaning member 88, a second cleaning member 89 and a third cleaning member 820 respectively.

[0071] The first cleaning member 88 includes a first connecting rod 881 fixedly connected to the outer sidewall of the connecting shaft 86. A first sliding groove 882 is formed inside the first connecting rod 881. An inert gas is contained inside the first sliding groove 882. A first scraping plate 883 is slidably installed inside the first sliding groove 882. An elastic connection is made between the first scraping plate 883 and the sidewall of the inner cavity of the first sliding groove 882 through a third spring 884.

[0072] The second cleaning member 89 includes a second connecting rod 891 fixedly connected to the outer sidewall of the connecting shaft 86. Second sliding grooves 892 are respectively formed at both ends of the second connecting rod 891. An inert gas is contained inside the second sliding grooves 892. A second scraping plate 893 is slidably installed inside the second sliding grooves 892. An elastic connection is made between the second scraping plate 893 and the sidewall of the inner cavity of the second sliding grooves 892 through a fourth spring 894.

[0073] The third cleaning member 820 includes a third connecting rod 8201 fixedly connected to the outer sidewall of the connecting shaft 86. A third sliding groove 8202 is formed inside the third connecting rod 8201. An inert gas is contained inside the third sliding groove 8202. A third scraping plate 8203 is slidably installed inside the third sliding groove 8202. An elastic connection is made between the third scraping plate 8203 and the sidewall of the inner cavity of the third sliding groove 8202 through a fifth spring 8204.

[0074] Specifically, when the secondary air nozzle 7 is used for a long time, a lot of dust will accumulate inside the secondary air nozzle 7. When cleaning the dust inside the secondary air nozzle 7, usually, first the fluidized bed boiler 1 is stopped, and when the fluidized bed boiler 1 cools down to a suitable temperature, the operator will wear protective gear and use professional cleaning tools to clean the dust inside the secondary air nozzle 7. Using this cleaning method, not only is the efficiency low, but also it is necessary to wait for the fluidized bed boiler 1 to cool down to a suitable temperature before starting the operation, resulting in a large time cost and also causing a certain degree of harm to the health of the operator.

[0075] The specific operation of the present invention is as follows: First, after the fluidized bed boiler 1 stops running, the operation can be carried out without waiting for the fluidized bed boiler 1 to drop to a very low temperature, saving time cost. Then, start the motor 102, and the motor 102 drives the flip plate 104 to turn outwards through the rotating shaft 103, so that the inside of the secondary air nozzle 7 is in communication with the outside world. Then, start the two electric telescopic columns 83 to extend, driving the connecting plate 84, the mounting frame 85, the connecting shaft 86, the fan blade 87, the first cleaning member 88, the second cleaning member 89 and the third cleaning member 820 to move towards the inside of the secondary air nozzle 7. When the movement is in place, the two electric telescopic columns 83 stop extending. Since the secondary air in this section has a relatively high temperature, the inert gas inside the first chute 882, the second chute 892 and the third chute 8202 expands due to heat, pushing the first scraper 883 out of the inside of the first chute 882, pushing the second scraper 893 out of the inside of the second chute 892, and pushing the third scraper 8203 out of the inside of the third chute 8202. As a result, the first cleaning member 88, the second cleaning member 89 and the third cleaning member 820 can fit the shape of the inside of the secondary air nozzle 7, achieving a better cleaning effect. When cleaning the dust inside the secondary air nozzle 7, increase the wind speed of the secondary air to blow the fan blade 87 to rotate at a high speed. During the high-speed rotation of the fan blade 87, the connecting shaft 86 will be driven to rotate synchronously. The connecting shaft 86 will then drive the first cleaning member 88, the second cleaning member 89 and the third cleaning member 820 to rotate, thereby achieving the effect of cleaning the dust inside the secondary air nozzle 7. After the cleaning is completed, reset each component.

[0076] Adopting this cleaning method, the degree of automation is relatively high, and the cleaning of the secondary air nozzle 7 can be achieved by using wind power, saving electric energy. Moreover, the operation can be carried out without waiting for the fluidized bed boiler 1 to drop to a very low temperature, saving time cost. And it does not require personnel to use tools for cleaning, which is not only highly efficient but also does not cause physical harm to the operators.

[0077] Since the flip plate 104 is rotatably arranged inside the through groove 72, in order not to interfere with the flipping action of the flip plate 104, the length of the through groove 72 is greater than the length of the flip plate 104. This makes the side wall of the flip plate 104 not in close contact with the side wall of the inner cavity of the through groove 72, and air leakage will occur during the transportation of the secondary air, which will affect the combustion efficiency of the fuel. To alleviate this problem, the present invention provides a baffle 73 on the side wall of the inner cavity of the through groove 72, and an embedded part 105 is provided on the inner side wall of the flip plate 104. The baffle 73 and the embedded part 105 are mutually embedded, and a high-temperature resistant gasket 74 is provided at the contact part between the embedded part 105 and the baffle 73 to completely seal the gap between the embedded part 105 and the baffle 73, achieving the effect of preventing air leakage and maintaining the stable output of the secondary air.

[0078] A sealing plate 106 is slidably installed in an embedded manner on another side wall of the through groove 72. When the turning plate 104 rotates, a pressure will be applied to the sealing plate 106, causing the sealing plate 106 to retract. When the turning plate 104 passes over the sealing plate 106, the pressure applied to the sealing plate 106 is withdrawn, and the sealing plate 106 will pop out again and closely fit against the side wall of the turning plate 104. A sealing gasket can be provided on the side wall of the sealing plate 106. When the sealing plate 106 closely fits against the side wall of the turning plate 104, a sealing effect is achieved through the sealing gasket, which is also used to maintain the stable output of the secondary air to ensure a good combustion effect of the fuel.

[0079] To better illustrate the above embodiments, the present invention also provides another implementation: a control method for a secondary air system of a waste-incinerating circulating fluidized bed boiler, including the following steps:

[0080] Step 1: When the inspection staff observes through the transparent outer shell 41 whether bubbles appear in the color film 42, it is used to judge whether the secondary air duct 9 leaks.

[0081] Step 2: The inspection personnel observe through the transparent outer shell 61 whether the film 67 shows distinct colors, which is used to judge whether the secondary air duct 9 is damaged.

[0082] Step 3: After running for a period of time, the fluidized bed boiler 1 stops running, and the cleaning component 8 is started to clean the dust inside the secondary air nozzle 7.

[0083] Step 4: After the dust cleaning is completed, the cleaning component 8 is reset, and the fluidized bed boiler 1 starts to run.

[0084] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0085] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A secondary air system for a circulating fluidized bed boiler co-firing solid waste, comprising a fluidized bed boiler (1), a secondary air blower (2) and an air preheater (3) are respectively arranged on the side of the fluidized bed boiler (1), and the secondary air blower (2) and the air preheater (3) are connected through a secondary air pipeline (9), and it is characterized in that: A first detection component (4) is fixedly installed on both the secondary air blower (2) and the air preheater (3), and the secondary air duct (9) is arranged in the inner circle of the first detection component (4). A secondary air box (5) is fixedly arranged on the fluidized bed boiler (1). The air preheater (3) and the secondary air box (5) are connected through the secondary air duct (9). A second detection component (6) is fixedly installed on both the air preheater (3) and the secondary air box (5), and the secondary air duct (9) is arranged in the inner circle of the second detection component (6). A plurality of secondary air nozzles (7) are connected to the fluidized bed boiler (1). The air inlet end of the secondary air nozzle (7) is connected to the air outlet end of the secondary air box (5) through the secondary air duct (9). An opening and closing component (10) is rotatably arranged on the secondary air nozzle (7), and a cleaning component (8) is fixedly arranged on the secondary air nozzle (7). The second detection component (6) includes a transparent outer shell two (61). A square tube (62) is arranged in the inner cavity of the transparent outer shell two (61). The outer side wall of the square tube (62) is fixedly connected to the inner side wall of the transparent outer shell two (61) through a plurality of fixing blocks (63). Four mounting plates (64) are fixedly installed on the inner side wall of the transparent outer shell two (61). The four mounting plates (64) are respectively parallel to the four side walls of the square tube (62). A plurality of through holes (65) are formed in each mounting plate (64). A thin film (67) is arranged on the side wall of the inner cavity of the through hole (65). A white coating is applied to the side wall of the thin film (67) facing the transparent outer shell two (61). A brightly colored coating is applied to the side wall of the thin film (67) facing the square tube (62). A plurality of jacking components (66) are fixedly installed on the outer side wall of the square tube (62). The jacking components (66) are concentric with the through holes (65) and the thin film (67). The square tube (62) includes a tube body (621). Guide plates (622) are fixedly installed at the four corners inside the tube body (621). The jacking component (66) includes an installation cylinder (661) fixedly installed on the outer side wall of the tube body (621) and a push block (662) slidably installed inside the installation cylinder (661). The push block (662) is elastically connected to the installation cylinder (661) through a first spring (664). An air chamber (663) is also formed between the push block (662) and the installation cylinder (661). An inert gas is contained inside the air chamber (663). A plurality of installation grooves (665) are formed at the edge of the outer side wall of the push block (662). A limiting column (666) is fixedly installed in the inner cavity of the installation groove (665). A top rod (667) is rotatably sleeved on the limiting column (666). The side wall of the top rod (667) is elastically connected to the side wall of the inner cavity of the installation groove (665) through a second spring (668).

2. The secondary air system of a circulating fluidized bed boiler for co-firing solid waste according to claim 1, characterized in that, The detection component 1 (4) includes a transparent housing 1 (41), an electronic air valve (43) is communicatively arranged on the top surface of the transparent housing 1 (41), a color film (42) is tightly adhered to the circumferential outer wall of the secondary air duct (9), and an air cavity (44) is formed between the circumferential outer wall of the color film (42) and the side wall of the inner cavity of the transparent housing 1 (41).

3. The secondary air system of a circulating fluidized bed boiler for co-firing solid waste according to claim 2, characterized in that, The secondary air box (5) includes an annular box body (51), and the inner side wall of the annular box body (51) and the outer side wall of the fluidized bed boiler (1) are fixedly connected by a plurality of connecting blocks (52).

4. The secondary air system of a circulating fluidized bed boiler for co-firing solid waste according to claim 3, characterized in that, The secondary air nozzle (7) includes a nozzle body (71), a through groove (72) is formed in the side wall of the nozzle body (71), and a baffle (73) is fixedly installed on the inner side wall of the through groove (72).

5. The secondary air system of a circulating fluidized bed boiler for co-firing solid waste according to claim 4, wherein The opening and closing component (10) includes an F-shaped bracket (101) fixedly installed on the side wall of the nozzle body (71) and a motor (102) fixedly installed on the F-shaped bracket (101). The output end of the motor (102) is fixedly connected to a rotating shaft (103). The rotating shaft (103) is arranged through the through groove (72). A turning plate (104) is rotatably arranged in the through groove (72). The turning plate (104) is fixedly sleeved on the rotating shaft (103). An embedded part (105) is formed in the inner side wall of the turning plate (104). The shape of the embedded part (105) is mutually fitted with that of the baffle (73). A high-temperature resistant sealing gasket (74) is arranged at the contact part between the embedded part (105) and the baffle (73). A plugging plate (106) is embedded and slidably installed on the side wall of the inner cavity of the through groove (72).

6. The secondary air system of a circulating fluidized bed boiler for co-firing solid waste according to claim 5, characterized in that The cleaning component (8) includes a first bearing plate (81) fixedly installed on the side wall of the nozzle body (71) and a second bearing plate (82) fixedly installed on the first bearing plate (81). A pair of electric telescopic columns (83) are fixedly installed on the side wall of the second bearing plate (82). The output ends of the two electric telescopic columns (83) are jointly fixedly installed with a connecting plate (84). A pair of mounting brackets (85) are fixedly installed on the outer side wall of the connecting plate (84). A connecting shaft (86) is rotatably arranged through the mounting brackets (85). A fan blade (87) is fixedly installed on the side wall of one end of the connecting shaft (86). A first cleaning member (88), a second cleaning member (89) and a third cleaning member (820) are respectively fixedly connected to the outer side wall of the connecting shaft (86). The first cleaning member (88) includes a first connecting rod (881) fixedly connected to the outer side wall of the connecting shaft (86). A first sliding groove (882) is formed inside the first connecting rod (881). An inert gas is contained inside the first sliding groove (882). A first scraping plate (883) is slidably installed inside the first sliding groove (882). The first scraping plate (883) and the side wall of the inner cavity of the first sliding groove (882) are elastically connected by a third spring (884). The second cleaning member (89) includes a second connecting rod (891) fixedly connected to the outer sidewall of the connecting shaft (86). Second chutes (892) are respectively formed at both ends of the second connecting rod (891). Inert gas is contained inside the second chutes (892). A second scraping plate (893) is slidably installed inside the second chutes (892). The second scraping plate (893) is elastically connected to the sidewall of the inner cavity of the second chutes (892) by a fourth spring (894). The third cleaning member (820) includes a third connecting rod (8201) fixedly connected to the outer sidewall of the connecting shaft (86). A third chute (8202) is formed inside the third connecting rod (8201). Inert gas is contained inside the third chute (8202). A third scraping plate (8203) is slidably installed inside the third chute (8202). The third scraping plate (8203) is elastically connected to the sidewall of the inner cavity of the third chute (8202) by a fifth spring (8204).

7. A control method applied to the secondary air system of a circulating fluidized bed boiler for co-firing solid waste as described in claim 6, characterized in that, It includes the following steps: S1: When the inspection staff observes whether there are bubbles in the color film (42) through the first transparent housing (41), it is used to judge whether there is a leak in the secondary air duct (9). S2: The inspection personnel observe whether the film (67) shows distinct colors through the second transparent housing (61) to judge whether there is a breakage in the secondary air duct (9). S3: After running for a period of time, the fluidized bed boiler (1) stops running, and the cleaning assembly (8) is started to clean the dust inside the secondary air nozzle (7). S4: After the dust cleaning is completed, the cleaning assembly (8) is reset, and the fluidized bed boiler (1) starts to run.

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