Anti-blocking hood of circulating fluidized bed boiler and circulating fluidized bed boiler

Abstract

The utility model discloses an anti-blocking air cap of a circulating fluidized bed boiler and the circulating fluidized bed boiler, and belongs to the technical field of fluidized bed boilers. The anti-blocking air cap of the circulating fluidized bed boiler comprises an air cap hood head and an air cap core tube, and a plurality of first air outlet holes are formed in the air cap hood head at intervals in the circumferential direction; the ends, facing the interior of the hood head, of every two adjacent first air outlet holes are arranged in an attached mode, and the attached distance is smaller than the hole diameter of the first air outlet holes. According to the anti-blocking air cap of the circulating fluidized bed boiler, the contact area of the inner side wall of the air cap hood head and smoke is reduced, then the area where dust in the smoke can be attached and stayed is reduced, the smoke carrying the dust can be directly blown out of the air cap hood head and cannot be deposited in the air cap hood head, the air cap is effectively prevented from being blocked, and the service life of the air cap is prolonged. The anti-blocking air cap of the circulating fluidized bed boiler is simple in structure, uniform in air distribution and good in durability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fluidized bed boilers, in particular to a circulating fluidized bed boiler air blocking prevention cap and a circulating fluidized bed boiler. BACKGROUND

[0002] The circulating fluidized bed boiler is a high-efficiency and low-pollution combustion technology, which is based on the principle of fluidization, so that solid particles are suspended in the gas flow to form a fluidized bed, thereby realizing the combustion of fuel.

[0003] The amount of the gasification agent of the circulating fluidized bed boiler must be kept relatively stable and uniform to ensure the fluidization state in the furnace. The amount of the gasification agent is generally adjusted according to the material layer differential pressure, bed temperature and load condition. However, according to statistics, about 4000-6000 m 3 of flue gas is generated per ton of sinter produced, which carries a large amount of dust, generally containing 0.5-15 g / m 3 of dust, and contains some corrosive gases such as SOx (sulfur oxide), NOx (nitrogen oxide) and other acidic gaseous pollutants, resulting in relatively poor flowability of the bottom slag of the fluidized bed gasification furnace, uneven temperature field distribution of the bottom slag, easy blocking of the air cap, and low stability of the entire gasification system. When the coal type is changed or the ash melting point changes, it is easy to cause the gasification furnace to be slagged or shut down.

[0004] The air cap is a key component in the circulating fluidized bed boiler, and its main function is to provide appropriate air volume to the furnace to make the materials in the furnace in a fluidized state, thereby ensuring the stable combustion of the boiler. The structure and working state of the air cap directly affect the air distribution of the furnace bed, the dynamic characteristics of the gas-solid two-phase flow in the furnace, and further affect the safe and economic operation of the boiler. Common air caps include bell-shaped, cylindrical, spherical and umbrella-shaped forms. In actual application, the arrangement and number of the air cap need to be selected and configured according to the specifications and design requirements of the boiler to ensure the best fluidization effect and combustion efficiency.

[0005] When the air cap is working normally, the flow path of the gas flow is from the air chamber into the air cap core pipe, out of the air cap core pipe into the air cap cover head, flows inside the air cap cover head, and finally flows out from the air outlet hole of the air cap cover head. The current air cap structure has the problem of easy blocking. Specifically, when the flue gas contains dust, the dust particles are easily attached to the inner wall of the air cap cover head, and then continuously deposited inside the air cap cover head, eventually causing the air cap to be blocked, so that the air in the air chamber cannot flow into the air cap core pipe and then flow out from the air cap cover head, affecting the generation of fluidization. CONTENT OF THE UTILITY MODEL

[0006] The present application provides a circulating fluidized bed boiler air blocking prevention cap and a circulating fluidized bed boiler, aiming to solve the problem of easy blocking of the air cap by dust in the flue gas in the prior art, which affects the normal operation of the air cap.

[0007] The air blocking prevention cap of the circulating fluidized bed boiler comprises a cap cover and a cap core pipe, a plurality of first air outlets are arranged on the cap cover in a circumferential direction, and two adjacent first air outlets are arranged close to one end of the cap cover, and the close distance is less than the diameter of the first air outlet.

[0008] Through the above technical means, the contact area between the inner wall of the cap cover and the flue gas can be reduced, and the area where the dust in the flue gas can adhere and stay can be reduced, so that the flue gas carrying dust can be directly blown out of the cap cover, preventing dust from depositing in the cap cover. On the other hand, it is helpful to set the diameter of the second air outlet larger, further increasing the air supply area, and effectively preventing the cap from being blocked.

[0009] Optionally, a spacing region is formed between the two adjacent first air outlets, and the length of each spacing region on one side of the cross section of the spacing region towards the inside of the cap cover accounts for less than or equal to 3% of the circumference of the cap cover.

[0010] Through the above technical means, the inner length of the spacing region in the cross section is limited within a smaller range, so that the inner side area of the spacing region is as small as possible, and the actual inner wall area of the cap cover in contact with the dust at the air outlet position is reduced, which can effectively reduce the adhesion of dust.

[0011] Optionally, the cross-sectional shape of the spacing region is fan-shaped.

[0012] Optionally, the cap cover is arranged outside the cap core pipe, and the distance between the inner wall of the cap cover and the outer wall of the cap core pipe is greater than or equal to one-third of the diameter of the first air outlet.

[0013] Through the above technical means, the flow area of the flue gas in the cap cover can be ensured, the dust can be discharged, the dust can be prevented from depositing in the cap cover to cause blockage, and the uniformity of air distribution can be maintained to ensure the fluidization effect in the fluidized bed.

[0014] Optionally, the number of the plurality of first air outlets is 8, and the diameter of the first air outlet is greater than or equal to 19mm.

[0015] Optionally, the axis of the first air outlet is perpendicular to the axis of the cap cover.

[0016] Optionally, the top end of the cap core pipe is provided with an air outlet structure, the cap cover is arranged outside the cap core pipe, and the first air outlet is arranged on the cap cover away from the air outlet structure.

[0017] Through the technical means, the air flow microcirculation of up and down can be formed inside the hood cover head, the air flow is more uniform, the fluidization effect of the bed material is improved, the direct blowing between the hoods is reduced, and the problem of air chamber leakage caused by ash backflow is avoided.

[0018] Optionally, the air outlet structure is provided with at least two layers, and each layer of the air outlet structure comprises a plurality of second air outlet holes distributed along the circumference of the hood core pipe.

[0019] Through the technical means, the uniformity of the air flow can be further improved, and the ash backflow is prevented.

[0020] Optionally, the second air outlet holes in the adjacent two layers of the air outlet structure are staggered.

[0021] Through the technical means, the second air outlet holes in the adjacent two layers of the air outlet structure are staggered, which helps to improve the uniformity of the air distribution, reduce the ash particle blockage and wear, and further optimize the air supply effect.

[0022] Optionally, the material of the hood cover head comprises an alloy.

[0023] Through the technical means, ZGA297HK or GH3030, GH3039, GH3044, GH3128 and the like are used as the material of the hood cover head, which is resistant to high temperature and corrosion, and can ensure the reliability and long service life of the hood in a high-temperature and corrosive environment.

[0024] Beneficial effects:

[0025] The anti-blocking hood for a circulating fluidized bed boiler provided in the application comprises a hood cover head and a hood core pipe, a plurality of first air outlet holes are arranged on the hood cover head in a circumferential direction, and the two adjacent first air outlet holes are arranged close to one end of the hood cover head in the interior of the hood cover head, and the close distance is smaller than the hole diameter of the first air outlet hole. The anti-blocking hood for a circulating fluidized bed boiler provided in the application has a smaller inner wall area of the interval region formed between the two adjacent first air outlet holes, reduces the contact area between the inner wall of the hood cover head and the flue gas, and further reduces the area where the dust in the flue gas can adhere and stay, so that the flue gas carrying the dust can be directly blown out of the hood cover head and cannot be deposited in the hood cover head, thereby effectively preventing the hood from being blocked and ensuring the normal work of the hood. On the other hand, the closer the distance between the two adjacent first air outlet holes is, the smaller the interval between the two first air outlet holes is, and under the condition that the size of the hood cover head and the number of the first air outlet holes remain unchanged, the hole diameter of the first air outlet hole can be set larger, which helps to increase the air supply area and promote the discharge of the dust, further reduces the deposition of the dust, and prevents the hood from being blocked.

[0026] This application also provides a circulating fluidized bed boiler, including the circulating fluidized bed boiler anti-clogging vent cap as described above.

[0027] The circulating fluidized bed boiler, equipped with the aforementioned anti-clogging hood, allows dust-laden flue gas to be directly blown out of the hood, preventing it from accumulating inside. This effectively avoids hood blockage, ensuring stable and continuous operation of the hood and maintaining the fluidized state of the material in the furnace, thereby guaranteeing stable combustion of the boiler. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of an anti-clogging air cap for a circulating fluidized bed boiler according to an embodiment of this application;

[0030] Figure 2 This is a schematic diagram of the structure of the wind cap cover in the anti-clogging wind cap of a circulating fluidized bed boiler according to an embodiment of this application;

[0031] Figure 3 This application Figure 2 Cross-sectional view at point AA;

[0032] Figure 4 This is a schematic diagram of the structure of the core tube of the anti-clogging wind cap in a circulating fluidized bed boiler according to an embodiment of this application;

[0033] Figure 5 This application Figure 4 Sectional view at point BB;

[0034] Figure 6 This application Figure 4 Sectional view at point CC.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Wind cap cover; 11. First air outlet; 12. Interval area; 2. Wind cap core tube; 21. Second air outlet. Detailed Implementation

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0038] The circulating fluidized bed boiler is a high-efficiency and low-pollution combustion technology, which is based on the principle of fluidization, making solid particles suspended in the gas flow to form a fluidized bed, thereby realizing the combustion of fuel. As a key component in the circulating fluidized bed boiler, the wind cap is mainly used to provide appropriate air volume to the furnace to keep the materials in the furnace in a fluidized state, thereby ensuring the stable combustion of the boiler. In the circulating fluidized bed boiler, the structure and working state of the wind cap directly affect the air distribution of the furnace bed and the dynamic characteristics of the gas-solid two-phase flow in the furnace, and further affect the safe and economic operation of the boiler. Common wind caps include bell-shaped, cylindrical, spherical, and umbrella-shaped forms. In actual application, the arrangement and number of wind caps need to be selected and configured according to the specifications and design requirements of the boiler to ensure the best fluidization effect and combustion efficiency. The wind cap generates an upward airflow to make the solid materials in the furnace form a circulating flow, thereby realizing the full mixing and uniform distribution of the materials.

[0039] When the wind cap is working normally, the flow path of the airflow is from the wind chamber into the wind cap core pipe, out of the wind cap core pipe into the wind cap cover head, flows inside the wind cap cover head, and finally flows out from the air outlet holes on the wind cap cover head.

[0040] The current wind cap structure has the problem of easy clogging, which is different from the problem of slag leakage. The slag leakage of the wind cap is due to gas backflow, i.e., the reverse flow from the wind cap cover head to the wind cap core pipe, which causes large particles of ash and slag carried in the gas to fall back into the wind chamber from the wind cap core pipe, causing wear to the wind chamber. The clogging of the wind cap is due to the contact between the airflow and the inner wall of the wind cap cover head when the airflow normally flows inside the wind cap cover head. The dust in the airflow adheres and stays on the inner wall of the wind cap cover head and continuously deposits inside the wind cap cover head, eventually causing the wind cap to be clogged, so that the air in the wind chamber cannot flow into the wind cap core pipe and then flow out from the wind cap cover head, affecting the generation of fluidization.

[0041] Therefore, the embodiments of the present application propose a circulating fluidized bed boiler anti-clogging wind cap to solve the problem of easy clogging of the wind cap structure in the prior art.

[0042] Referring to Figure 1 A circulating fluidized bed boiler anti-clogging wind cap includes a wind cap cover head 1 and a wind cap core pipe 2. A plurality of first air outlet holes 11 are circumferentially spaced apart on the wind cap cover head 1. Adjacent two first air outlet holes 11 are closely arranged towards one end of the inside of the wind cap cover head 1, and the close distance is less than the hole diameter of the first air outlet hole 11.

[0043] Referring to Figure 1 , in particular, the circulating fluidized bed boiler anti-blocking air cap comprises an air cap cover head 1 and an air cap core pipe 2, the air cap core pipe 2 is provided in a tubular structure and has an air inlet end and an air outlet end, the air cap cover head 1 is in a bell-shaped structure and has a cylindrical cavity inside, the air cap cover head 1 covers the air outlet end of the air cap core pipe 2, and a plurality of first air outlet holes 11 are arranged on the air cap cover head 1, gas can enter from the air inlet end of the air cap core pipe 2, flow out from the air outlet end of the air cap core pipe 2, then flow into the inside of the air cap cover head 1, and flow out from the first air outlet holes 11.

[0044] Referring to Figure 2 and Figure 3 , the plurality of first air outlet holes 11 are uniformly and spacedly distributed along the circumference of the air cap cover head 1, and the inner ends of the adjacent two first air outlet holes 11 are close to each other, and the close distance is less than the diameter of the first air outlet hole 11. For convenience of description, in the embodiment, the inner end of the first air outlet hole 11 towards the inside of the air cap cover head 1 is defined as the inner end of the first air outlet hole 11, and the outer end of the first air outlet hole 11 towards the outside of the air cap cover head 1 is defined as the outer end of the first air outlet hole 11. In particular, for the case that the first air outlet hole 11 is a variable-diameter hole, such as a tapered hole or a horn hole, and the diameter of the first air outlet hole 11 gradually increases from the inner end to the outer end, the close distance of the inner ends of the adjacent two first air outlet holes 11 should be less than the diameter of the inner end of the first air outlet hole 11.

[0045] When the flue gas with dust flows in the inside of the air cap cover head 1, the flue gas will contact the inner wall of the air cap cover head 1, and the dust particles will adhere to the inner wall surface of the air cap cover head 1, and at the air outlet position of the air cap cover head 1, the inner wall surface of the interval area 12 formed between the adjacent two first air outlet holes 11 is the dust adhesion surface, therefore, the closer the inner ends of the adjacent two first air outlet holes 11, the smaller the inner wall surface of the interval area 12 formed, and the smaller the dust adhesion surface. Since the close distance of the inner ends of the adjacent two first air outlet holes 11 is less than the diameter of the first air outlet hole 11, therefore, at the air outlet position of the air cap cover head 1, the dust adhesion area is less than the air outlet area, that is, the dust adhesion area is less than the dust dischargeable area, which can effectively reduce the adhesion and residence of dust in the inside of the air cap cover head 1, so that the dust can be directly blown out of the air cap cover head 1 along with the airflow, and will not deposit in the air cap cover head 1, thereby effectively preventing the air cap from being blocked and ensuring the normal work of the air cap.

[0046] On the other hand, the closer the distance between the inner ends of the two adjacent first air outlets 11, the smaller the spacing between the two adjacent first air outlets 11, and thus, the larger the diameter of the first air outlet 11 can be set when the size of the hood cover head 1 and the number of first air outlets 11 remain unchanged, which can increase the air supply area and promote the discharge of dust, further reducing the deposition of dust in the hood cover head 1 and ensuring the normal operation of the hood.

[0047] In this embodiment, by optimizing the arrangement spacing of the first air outlets 11, the inner ends of the two adjacent first air outlets 11 are arranged close to each other, and the distance between them is less than the diameter of the first air outlet 11. The attachable area and dischargeable area of dust in the hood cover head 1 are redistributed, which can reduce the attachment of dust and actively increase the dust discharge capacity, ultimately solving the problem of clogging of the hood cover head 1.

[0048] Optionally, a spacing area 12 is formed between the two adjacent first air outlets 11, and the length of the spacing area 12 towards the inside of the hood cover head 1 accounts for less than or equal to 3% of the circumference of the inner circumference of the hood cover head 1 in cross section.

[0049] Specifically, for convenience of description, the inner side of the spacing area 12 towards the hood cover head 1 is defined as the inner side of the spacing area 12 in this embodiment. Referring to Figure 3 , Figure 3 The cross-sectional view of the hood cover head 1 at the air outlet position A-A is also a schematic view of the cross section of the spacing area 12. The length of the inner side of the spacing area 12 is the distance between the inner ends of the two adjacent first air outlets 11 in cross section. Since the inner ends of the two adjacent first air outlets 11 are arranged close to each other, the length of the inner side of the spacing area 12 in cross section is also relatively short. Specifically, the length of the inner side of each spacing area 12 accounts for less than or equal to 3% of the total circumference of the inner circumference of the hood cover head 1. When the flue gas flows out of the first air outlet 11 from the inside of the hood cover head 1, the dust in the flue gas will contact the inner side of the spacing area 12. The inner side of the spacing area 12 is the inner wall surface of the hood cover head 1 that actually contacts the dust at the air outlet position. By limiting the length of the inner side of the spacing area 12 in cross section to a relatively small range, the area of the inner side of the spacing area 12 is minimized, and thus the area of the inner wall surface of the hood cover head 1 that actually contacts the dust at the air outlet position is reduced, effectively reducing the attachment of dust and preventing the hood from being clogged.

[0050] Optionally, the cross-sectional shape of the spacing area 12 is fan-shaped.

[0051] Referring to Figure 3In a preferred embodiment, the shape of the hood 1 is cylindrical, with an outer diameter of 85mm and an inner diameter of 65mm. The first air outlet 11 is arranged radially along the hood 1, and the cross-sectional shape of the interval region 12 formed between two adjacent first air outlets 11 is fan-shaped. The arc length of the fan-shaped interval region 12 facing the inside of the hood 1 is less than or equal to 6.12mm.

[0052] Optionally, the number of the plurality of first air outlets 11 is set to 8, and the diameter of the first air outlets 11 is greater than or equal to 19 mm.

[0053] Specifically, in this embodiment, for a hood 1 with an outer diameter of 85mm and an inner diameter of 65mm, the number of first air outlet holes 11 can be set to 8, which are evenly distributed along the circumference of the hood 1. The diameter of the first air outlet hole 11 is greater than or equal to 19mm. Compared with the air outlet hole with a diameter of 15mm in the conventional hood structure, its hole diameter is larger and has a larger air delivery area, which can promote the discharge of dust and reduce the deposition of dust in the hood 1.

[0054] Specifically, as an example, the diameter of the first air outlet 11 is set to 19mm, and the inner arc length of the corresponding interval area 12 is about 6.12mm, accounting for about 3% of the inner circumference of the hood 1; as an example, the diameter of the first air outlet 11 is set to 22mm, and the inner arc length of the corresponding interval area 12 is about 3.08mm, accounting for about 1.5% of the inner circumference of the hood 1.

[0055] Optionally, the axis of the first air outlet 11 is perpendicular to the axis of the hood 1.

[0056] like Figure 1 As shown, in this embodiment, the hood 1 is arranged vertically with its axis set in the vertical direction, and the first air outlet 11 is arranged horizontally with its axis perpendicular to the axis of the hood 1.

[0057] Optionally, the hood 1 covers the outside of the hood core tube 2, and the distance between the inner wall of the hood 1 and the outer wall of the hood core tube 2 is greater than or equal to one-third of the diameter of the first air outlet 11.

[0058] Specifically, the hood 1 is coaxially sleeved on the outside of the hood core tube 2. A gap exists between the inner wall of the hood 1 and the outer wall of the hood core tube 2, providing a flow channel for airflow. Figure 1As shown, after the gas flow out of the air outlet end of the air cap core pipe 2, the gas flow can flow along the gap in the air cap cover head 1 in the axial direction and finally flow to the first air outlet hole 11. The distance between the inner wall of the air cap cover head 1 and the outer wall of the air cap core pipe 2 is greater than or equal to one-third of the diameter of the first air outlet hole 11, which can ensure the flow area of the flue gas in the air cap cover head 1, making the whole flow process of the flue gas from entering the air cap cover head 1 to flowing out of the air cap cover head 1 more smooth. On the one hand, it can promote the discharge of dust, reduce the residence and adhesion of dust in the air cap cover head 1, and prevent the air cap cover head 1 from being blocked due to dust deposition. On the other hand, it helps to maintain the uniformity of the air distribution, thereby ensuring the fluidization effect in the fluidized bed.

[0059] Optionally, the top end of the air cap core pipe 2 is provided with an air outlet structure, the air cap cover head 1 is arranged outside the air cap core pipe 2, and the first air outlet hole 11 is arranged at one end of the air cap cover head 1 away from the air outlet structure.

[0060] Specifically, referring to Figure 1 and Figure 4 , the top end of the air cap core pipe 2 is an air outlet end and is provided with an air outlet structure, the air cap cover head 1 is arranged outside the top end of the air cap core pipe 2, and the first air outlet hole 11 is arranged at the bottom end of the air cap cover head 1, i.e. away from the air outlet structure. After the gas enters from the air inlet end at the bottom of the air cap core pipe 2, it flows along the air cap core pipe 2, flows out through the air outlet structure at the top end of the air cap core pipe 2, flows into the air cap cover head 1, and finally flows out from the first air outlet hole 11 at the bottom end of the air cap cover head 1. Therefore, by arranging the air outlet structure at the top end of the air cap core pipe 2 and the first air outlet hole 11 at the bottom end of the air cap cover head 1, a microcirculation of the air flow can be formed in the air cap cover head 1, which makes the air flow more uniform and helps to improve the fluidization effect of the bed material.

[0061] In addition, by arranging the first air outlet hole 11 at the bottom end of the air cap cover head 1, compared with arranging it at the top or middle of the air cap cover head 1, the gas flow can be more stable when flowing out, which can reduce the direct blowing between the air caps and prevent the ash in the gas from being blown back to the air cap core pipe 2 and then to the air chamber, thereby reducing the wear problem caused by the backflow of ash to the air chamber.

[0062] Optionally, the air outlet structure is provided with at least two layers, and each layer of the air outlet structure includes a plurality of second air outlet holes 21 distributed along the circumference of the air cap core pipe 2.

[0063] Specifically, referring to Figure 4In the embodiment, the air outlet structure at the top of the hood core pipe 2 is provided with two layers, and each layer of the air outlet structure includes a plurality of second air outlet holes 21. The second air outlet holes 21 in the same layer are uniformly and spacedly distributed along the circumference of the hood core pipe 2. Specifically, the hood core pipe 2 is arranged along the vertical direction, and the axis of the hood core pipe 2 is arranged in the vertical direction. The second air outlet holes 21 are arranged along the horizontal direction, and the axis of the second air outlet holes 21 is perpendicular to the axis of the hood core pipe 2. Compared with the way of opening the air outlet holes along the axis of the hood core pipe 2 at the top end of the hood core pipe 2, in the embodiment, the direction of the airflow is changed by arranging a plurality of second air outlet holes 21 distributed along the circumference of the hood core pipe 2, so that the gas flowing out of the hood core pipe 2 is more stable, and the arrangement of the air outlet structure in two layers can improve the uniformity of the airflow and prevent the problem of leakage of ash from the air chamber caused by backflow of ash.

[0064] In other embodiments, the air outlet structure can also be provided with more than two layers according to actual needs.

[0065] Optionally, the second air outlet holes 21 in the adjacent two layers of the air outlet structure are staggered.

[0066] Specifically, as shown in Figure 5 and Figure 6 , Figure 5 , the cross-sectional view of the hood core pipe 2 at B-B, that is, the cross-sectional view of the first layer of the air outlet structure, Figure 6 , the cross-sectional view of the hood core pipe 2 at C-C, that is, the cross-sectional view of the second layer of the air outlet structure, and the positions of the second air outlet holes 21 in the two layers of the air outlet structure are staggered, that is, the position of the second air outlet hole 21 in the first layer corresponds to the interval between two second air outlet holes 21 in the second layer. Through the above arrangement, the positions of the second air outlet holes 21 are more uniformly distributed, which helps to improve the uniformity of air distribution, enhance the air resistance, reduce the blockage and wear of ash particles, and further optimize the air supply effect.

[0067] In the embodiment, the air outlet structure is provided with two layers. In other embodiments, for the case where the air outlet structure is provided with more than two layers, the positions of the second air outlet holes 21 in the adjacent two layers of the air outlet structure are staggered, which can also improve the uniformity of air distribution and optimize the air supply effect.

[0068] In actual application, the specific number and aperture size of the second air outlet holes 21 can be reasonably arranged according to the size of the hood core pipe 2. As a preferred embodiment, in the embodiment, the outer diameter of the hood core pipe 2 is set to 51 mm, the inner diameter of the hood core pipe 2 is set to 41 mm, and both layers of the air outlet structure include 8 second air outlet holes 21. The diameter of each second air outlet hole 21 is set to 9 mm.

[0069] Optionally, the material of the hood cover 1 includes an alloy.

[0070] Specifically, in the embodiment, the material of the hood head 1 can adopt ZGA297HK.

[0071] ZGA297HK is a kind of heat-resistant cast steel material, which belongs to austenitic stainless steel, has good high-temperature performance and excellent corrosion resistance, and has high tensile strength and yield strength, and good durability. In addition, the material combines high-temperature performance with good ductility and weldability, which is beneficial to welding operations during manufacturing and maintenance processes, and is commonly used in high-temperature environments such as furnace parts, fuel burner parts, carburizing boxes, heat treatment baskets and clamps, heat exchangers, welding wires and electrodes. In the embodiment, ZGA297HK is used as the material of the hood head 1, which has high strength, is easy to process, and is resistant to high temperature and corrosion, and can ensure the reliability and long life of the hood in high-temperature and corrosive environments.

[0072] In other embodiments, the hood head 1 can also adopt high-temperature alloy materials such as GH3030, GH3039, GH3044, GH3128, which also have excellent corrosion resistance and high-temperature resistance.

[0073] Optionally, the hood head 1 is welded to the hood core pipe 2.

[0074] Specifically, in the embodiment, a connecting portion is provided on the hood core pipe 2 for easy installation and fixation with the hood head 1. The hood head 1 is invertedly arranged at the air outlet end of the hood core pipe 2, and the bottom of the hood head 1 is connected and fixed to the connecting portion on the hood core pipe 2 by welding.

[0075] In other embodiments, the hood head 1 and the hood core pipe 2 can also be installed and fixed by thread connection, clamping or other methods.

[0076] The air blocking prevention cap for the circulating fluidized bed boiler provided by the embodiment of the application is characterized in that: the two adjacent first air outlets 11 are arranged close to one end of the cap head 1, and the close distance is less than the diameter of the first air outlet 11, so that the inner wall area of the interval area 12 formed between the two adjacent first air outlets 11 is small, the contact area between the inner wall of the cap head 1 and the flue gas is reduced, and then the area where the dust in the flue gas can adhere and stay is reduced, so that the flue gas carrying the dust can be directly blown out of the cap head 1 and cannot be deposited in the cap head 1, thereby effectively preventing the cap from being blocked and ensuring the normal work of the cap. On the other hand, by arranging the two adjacent first air outlets 11 close to one end of the cap head 1, the diameter of the first air outlet 11 can be set larger under the condition that the size of the cap head 1 and the number of the first air outlets 11 remain unchanged, which is helpful to increase the air supply area and promote the discharge of the dust, and further reduce the deposition of the dust. The air blocking prevention cap for the circulating fluidized bed boiler provided by the embodiment of the application is simple in structure, uniform in air distribution, can effectively reduce the blocking problem, and has good durability.

[0077] The embodiment of the application further provides a circulating fluidized bed boiler comprising the air blocking prevention cap for the circulating fluidized bed boiler.

[0078] Specifically, the air blocking prevention cap is usually arranged at the bottom of the furnace chamber and is used to provide appropriate air volume into the furnace chamber. The air blocking prevention cap generates an upward airflow to make the solid materials in the furnace chamber form a circulating flow, so as to realize the full mixing and uniform distribution of the materials. The circulating fluidized bed boiler is provided with the air blocking prevention cap for the circulating fluidized bed boiler, the flue gas carrying the dust can be directly blown out of the cap head 1 and cannot be deposited in the cap head 1, the problem of cap blocking can be effectively avoided, the cap can stably and continuously work, the materials in the furnace chamber can be kept in a fluidized state, and the stable combustion of the boiler is ensured.

[0079] It should be noted that each embodiment in the specification adopts a progressive description manner, and each embodiment focuses on the difference from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0080] It also needs to be explained that in this paper, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations, nor can it be understood as indicating or implying relative importance. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or terminal device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or terminal device including the element.

[0081] The above provides a detailed description of the technical solutions of the present application, and the principles and implementation modes of the present application are described by applying specific examples. The above example is only used to help understand the present application, and the content of the description should not be understood as limiting the present application. At the same time, for those skilled in the art, according to the present application, there will be different forms of changes in specific implementation modes and application ranges, which do not need and cannot be exhausted here, and the obvious changes or changes derived therefrom are still within the protection scope of the present application.

Claims

1.A wind blocking cap for a circulating fluidized bed boiler, comprising a cap cover and a cap core pipe, characterized in that: a plurality of first air outlets are arranged on the cap cover in a circumferential direction, and two adjacent first air outlets are arranged close to one end of the cap cover, and the close distance is less than the diameter of the first air outlet. 2.The wind blocking cap for a circulating fluidized bed boiler according to claim 1, characterized in that: a spacing region is formed between two adjacent first air outlets, and the length of each spacing region on one side of the cap cover is less than or equal to 3% of the inner circumference of the cap cover. 3.The wind blocking cap for a circulating fluidized bed boiler according to claim 2, characterized in that: the cross-sectional shape of the spacing region is a sector. 4.The wind blocking cap for a circulating fluidized bed boiler according to claim 1, characterized in that: the cap cover is arranged outside the cap core pipe, and the distance between the inner wall of the cap cover and the outer wall of the cap core pipe is greater than or equal to one third of the diameter of the first air outlet. 5.The wind blocking cap for a circulating fluidized bed boiler according to claim 1, characterized in that: the number of first air outlets is 8, and the diameter of the first air outlet is greater than or equal to 19 mm. 6.The wind blocking cap for a circulating fluidized bed boiler according to claim 1, characterized in that: the axis of the first air outlet is perpendicular to the axis of the cap cover. 7.The wind blocking cap for a circulating fluidized bed boiler according to claim 1, characterized in that: the top end of the cap core pipe is provided with an air outlet structure, and the first air outlet is arranged on the cap cover away from the air outlet structure. 8.The wind blocking cap for a circulating fluidized bed boiler according to claim 7, characterized in that: the air outlet structure is provided with at least two layers, and each layer of the air outlet structure comprises a plurality of second air outlets arranged in a circumferential direction on the cap core pipe. 9.The wind blocking cap for a circulating fluidized bed boiler according to claim 8, characterized in that: the second air outlets in two adjacent layers of the air outlet structure are staggered. A wind blocking cap for a circulating fluidized bed boiler according to any one of claims 1-9. ​ ​ ​ ​ ​ ​ ​ ​ 10. A circulating fluidized bed boiler, characterized in that ​

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