Novel air distribution device of double-air-inlet circulating fluidized bed boiler

Abstract

The novel double-air-inlet circulating fluidized bed boiler air distribution device comprises split air caps and graded air distribution plates, the air caps are evenly distributed on the air distribution plate on each layer, each air cap comprises an air pipe and a bell jar, the bottom end of each air pipe is welded to the corresponding air distribution plate, first through holes are formed in the top of each air pipe in a layered mode, and the top of each air pipe is provided with a second through hole. First through holes are formed in the top of the air pipe and evenly distributed in the top of the air pipe, the top of the air pipe is sleeved with the bell jar, the top of the bell jar is welded to the air pipe in the circumferential direction, air outlets are evenly formed in the bottom of the bell jar in the circumferential direction, and the end face, located below the air outlets, of the bell jar is installed on the air pipe in a sealed mode. And the worn air cap is more convenient to replace. The bell jars with different numbers of holes are arranged on different layers of air caps, so that the overall air volume distribution is more uniform, the material fluidization is more balanced, the local high temperature is reduced, the generation of nitrogen oxides is reduced, the design structure is simpler, the overhaul and maintenance are simpler and more convenient, and the overhaul cost is lower.

Description

Technical Field

[0001] The invention relates to the technical field of circulating fluidized bed boiler air distribution, and in particular to a novel double-air-inlet circulating fluidized bed boiler air distribution device. Background Art

[0002] The air distribution device is a circulating fluidized bed boiler that evenly distributes air over the entire furnace cross section and provides sufficient wind pressure to evenly fluidize the bed material, avoiding undesirable phenomena such as channeling, choking, excessive bubble size, and fluidization dead zones. The air distribution plate provides a certain resistance to the airflow passing through, so that the airflow velocity distribution on the air distribution plate is uniform; the guide plate inside the hood can accurately control the direction and speed of the airflow, achieve fine control of the bed gasification and combustion process, improve the thermal efficiency and combustion efficiency of the boiler, and prevent large particles from settling and entering the primary air duct in reverse to damage the boiler.

[0003] The existing air distribution device has the following technical problems: 1. There are primary hot air ducts on both sides of the water-cooled air chamber at the bottom of the furnace. The air inlet type is from both sides of the air chamber. Since the hot primary air is blown from both sides to the middle, the air volume in the middle area is large, the wind pressure is large, and the temperature in the middle is significantly higher than that on both sides.

[0004] 2. The fluidization of materials on the hood can easily cause wear of the hood, because the bell cover and air duct of the original hood are fixed together, and the hood is welded to the air distribution plate. At the same time, when replacing the hood, the castable needs to be removed, and the weld at the bottom needs to be cut open for replacement, which makes it difficult to repair and replace the hood.

[0005] 3. Due to the air intake method on both sides, the air intake volume in different parts is different. The closer to the middle, the greater the air volume. The aperture and number of holes on the hood are the same. The air intake volume in different parts cannot be adjusted, resulting in uneven combustion and producing more atmospheric pollutants.

[0006] Therefore, it is necessary to provide a novel double-inlet circulating fluidized bed boiler air distribution device. Summary of the invention

[0007] In view of the problems existing in the above-mentioned prior art, the present invention provides a novel double-inlet circulating fluidized bed boiler air distribution device, which can make the overall air volume distribution more uniform, make the material fluidization more balanced, reduce local high temperature and thus reduce the generation of nitrogen oxides, and realize a simpler design structure, easier inspection and maintenance, and lower inspection and maintenance costs.

[0008] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical scheme: a novel double-inlet circulating fluidized bed boiler air distribution device, including a split wind hood and a graded air distribution plate, the air distribution plate on each level is evenly distributed with wind hoods, the wind hood includes an air duct and a bell cover, the bottom end of the air duct is welded to the air distribution plate, the top of the air duct is layered with through holes, and the through holes are evenly distributed on the top of the air duct, the bell cover is sleeved on the top of the air duct, and the top of the bell cover is circumferentially welded to the air duct, the bottom of the bell cover is circumferentially evenly provided with air outlets, and the end face of the bell cover located below the air outlet is sealed and installed with the air duct.

[0009] Preferably, a plugging head is provided on the inner wall of the air duct above the through hole 1, and a sealing plate at the bottom of the plugging head seals the air duct. A raised column on the upper part of the plugging head penetrates the top of the air duct, and the circumferential surface of the raised column and the raised opening at the top of the bell cover are sealed by circumferential welding, and the raised column and the sealing plate are integrally arranged.

[0010] Preferably, the air distribution plates are divided into three levels, and by analyzing the air intake of the air distribution plates at each level, wind hoods that match the air intake are installed on the air distribution plates at the corresponding level.

[0011] Preferably, the hot primary air enters the dense phase area at the bottom of the furnace through three-level air distribution plates, and the wind pressure is made to be steadily and evenly distributed in the entire furnace through the adjustment of different wind hoods.

[0012] In summary, the present invention provides a novel double-inlet circulating fluidized bed boiler air distribution device. The beneficial effects achieved by the present invention patent are as follows: the present invention patent adopts a novel split hood, and the bell cover is welded separately on the air duct, which is more convenient for replacing the worn hood. Bell covers with different numbers of holes are arranged on hoods at different levels to make the overall air volume distribution more uniform, the material fluidization more balanced, reduce local high temperature and thus reduce the generation of nitrogen oxides, and achieve a simpler design structure, simpler maintenance and lower maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a novel double-inlet circulating fluidized bed boiler air distribution device of the present invention; Figure 2 It is a schematic diagram of the cross-sectional analysis of the structure of the novel double-inlet circulating fluidized bed boiler air distribution device of the present invention; In the figure: hood 1, air duct 2, bell cover 3, through hole 1 4, air outlet 5, sealing plate 6, raised column 7, raised opening 11. DETAILED DESCRIPTION

[0014] The present invention will be further described below in conjunction with the accompanying drawings.

[0015] like Figure 1 to Figure 2 As shown: To solve the technical problems existing in the existing air distribution device: 1. Since the air intake is from both sides of the air chamber, and the hot primary air is blown from both sides to the middle, the air intake volume and wind pressure in the middle area are large, and the temperature in the middle is significantly higher than that on both sides; 2. The bell cover and air duct of the original hood are fixed together. When replacing the hood, the casting material needs to be removed and the weld at the bottom needs to be cut open for replacement, which makes it difficult to repair and replace the hood. 3. Since the aperture and number of the air outlets of the original hood are consistent, the air intake at different locations cannot be adjusted, resulting in uneven combustion and the generation of more air pollutants.

[0016] The present invention proposes a novel double-inlet circulating fluidized bed boiler air distribution device, which adopts a technical method including a split wind hood 1 and a graded air distribution plate. The wind hood 1 is evenly distributed on the air distribution plate on each level. The wind hood 1 includes an air duct 2 and a bell jar 3. The bottom end of the air duct 2 is welded to the air distribution plate. The top of the air duct 2 is provided with through holes 4 in layers, and the through holes 4 are evenly distributed on the top of the air duct 2. The bell jar 3 is sleeved on the top of the air duct 2, and the top of the bell jar 3 is circumferentially welded to the air duct 2. The circumferential welding method is more secure and more convenient to replace than the original bell jar installation method; the bottom of the bell jar 3 is evenly provided with air outlets 5 in a circumferential direction, and the end face of the bell jar 3 located below the air outlet 5 is sealed and installed with the air duct 2.

[0017] In at least one embodiment, a plugging head is provided on the inner wall of the air duct 2 above the through hole 14, and a sealing plate 6 at the bottom of the plugging head seals the air duct 2. A raised column 7 at the top of the plugging head penetrates the top of the air duct 2, and the circumferential surface of the raised column 7 and the raised opening 11 at the top of the bell cover 3 are sealed by circumferential welding, and the raised column 7 and the sealing plate 6 are integrally arranged.

[0018] In at least one embodiment, the air distribution plates are divided into three levels, and by analyzing the air intake of the air distribution plates at each level, hoods 1 that match the air intake are installed on the air distribution plates at the corresponding level.

[0019] In at least one embodiment, hot primary air enters the dense phase area at the bottom of the furnace through three-level air distribution plates. The wind pressure is adjusted to be stable and evenly distributed in the entire furnace through the adjustment of different wind hoods 1, so as to reduce local high-temperature areas and effectively reduce the original generation of nitrogen oxides.

[0020] The technical improvements of this patent are: 1. Design of split hood: The hood 1 uses a seamless steel tube core tube, and the bell cover 3 is the latest air distribution device structure welded and fixed on the top. It can not only increase the toughness of the core tube of the air distribution device to prevent breakage, but also only need to remove the upper worn bell cover every time it needs to be repaired and replaced, without removing the entire hood 1, making maintenance more convenient.

[0021] 2. Design a new bell cover: Through the analysis of the air intake of the air distribution plate, different bell covers 3 are used for the hoods 1 arranged at different levels. The amount of air passing through the hood 1 is controlled by changing the number of apertures on the bell cover 3, so that the entire air distribution is more uniform and local high temperature is reduced.

[0022] 3. The air distribution plates are graded according to the data of the air intake volume of each part. The patent of the present invention divides the air distribution plates into three levels, and installs three different types of wind caps 1 respectively to control the uniformity of the wind pressure above the air distribution plates.

[0023] 4. The patented design structure of the present invention is simpler, the maintenance is easier, and the maintenance cost is lower.

[0024] The embodiments of the present invention are only used to illustrate the present invention and do not constitute a limitation on the scope of the claims. Other substantially equivalent substitutes that can be thought of by those skilled in the art are all within the protection scope of the present invention.

Claims

1. A novel double-inlet circulating fluidized bed boiler air distribution device, characterized in that: The invention comprises a split-type hood (1) and a hierarchical air distribution plate, wherein the hood (1) is evenly distributed on the air distribution plate at each level, the hood (1) comprises an air duct (2) and a bell cover (3), the bottom end of the air duct (2) is welded to the air distribution plate, the top of the air duct (2) is provided with through holes (4) in layers, and the through holes (4) are evenly distributed on the top of the air duct (2), the bell cover (3) is sleeved on the top of the air duct (2), and the top of the bell cover (3) is circumferentially welded to the air duct (2), the bottom of the bell cover (3) is evenly provided with air outlets (5) in the circumferential direction, and the end face of the bell cover (3) located below the air outlet (5) is sealed and installed with the air duct (2).

2. The novel double-inlet circulating fluidized bed boiler air distribution device according to claim 1 is characterized in that: The air duct (2) is provided with a plugging head on the inner wall above the through hole 1 (4); a sealing plate (6) at the bottom of the plugging head seals the air duct (2); a raised column (7) at the top of the plugging head penetrates the top of the air duct (2); a circumferential surface of the raised column (7) and a raised opening (11) at the top of the bell cover (3) are sealed by circumferential welding; the raised column (7) and the sealing plate (6) are integrally arranged.

3. The novel double-inlet circulating fluidized bed boiler air distribution device according to claim 1 is characterized in that: The air distribution plates are divided into three levels. By analyzing the air intake of the air distribution plates at each level, hoods (1) that match the air intake are installed on the air distribution plates at the corresponding level.

4. The novel double-inlet circulating fluidized bed boiler air distribution device according to claim 3 is characterized in that: The hot primary air enters the dense phase area at the bottom of the furnace through three-level air distribution plates, and the wind pressure is adjusted by different air hoods (1) to be evenly distributed in the entire furnace.

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