High-reliability coal feeding pipe for large circulating fluidized bed boiler

Abstract

The utility model relates to the technical field of boiler combustion, in particular to a high-reliability coal feeding pipe for a large circulating fluidized bed boiler. Comprising an inclined main pipe section and a bent section at the tail end, an inner cavity of the main pipe section is of an eccentric structure, the lower portion of the inner cavity at the junction of the main pipe section and the bent section is in a gentle slope shape, and a thickening structure is arranged at the tongue plate position of the bent section. The conveying path of the pulverized coal is changed through the eccentric structure, the flowing track of the pulverized coal is optimized, impact of the pulverized coal on the pipe wall is reduced, and therefore friction and resistance of the pulverized coal in the conveying process are reduced, and the conveying efficiency is improved. And the gentle slope structure can ensure that the pulverized coal passes more smoothly, so that the accumulation and blockage risks of the coal are effectively reduced, and the coal feeding efficiency is further improved. And a thickening structure is arranged at the position of the tongue plate, so that the impact resistance and the wear resistance of the position are enhanced, the tongue plate can be effectively protected from being damaged, and the service life of the coal feeding pipe is further prolonged.

Description

Technical Field

[0001] This utility model relates to the field of boiler combustion technology, specifically a highly reliable coal feed pipe for a large circulating fluidized bed boiler. Background Technology

[0002] In the coal feeding system of a fluidized bed boiler, the design of the coal feed pipe directly affects the coal conveying efficiency and the stable operation of the boiler. Traditional coal feed pipe designs often overlook certain key details, leading to a series of problems during actual operation.

[0003] First, the coal feeding pipe is a straight pipe with its end facing the furnace wall. In actual use, this structure causes a lot of friction between the coal powder and the end tongue plate during transportation, which will lead to significant wear on the tongue plate and affect the coal feeding efficiency.

[0004] Secondly, the tongue plate at the end of the coal feed pipe inlet is in direct contact with the high-temperature circulating material inside the furnace, making it the area with the most severe boiler operating conditions. The fluidized state of the circulating material inside the furnace will cause a certain impact on this location, which is also one of the main reasons for tongue plate damage.

[0005] Furthermore, during the fluidized bed coal feeding process, coal particles and debris fall freely from a high position in the coal feeding pipe to the coal inlet at the end, and then slide into the furnace. During this process, the tongue plate at the end of the coal inlet is the end of the acceleration section of the falling coal particles, and it is also the position with the fastest speed and strongest impact force, making it prone to damage.

[0006] Finally, the traditional coal feeder structure is not conducive to the uniform distribution of pulverized coal, resulting in incomplete combustion. Utility Model Content

[0007] The present invention aims to solve the above problems, thereby providing a more stable and longer-lasting high-reliability coal feed pipe for large circulating fluidized bed boilers.

[0008] The technical solution adopted by this utility model to solve the aforementioned problem is:

[0009] A highly reliable coal feed pipe for a large circulating fluidized bed boiler includes an inclined main section and a bent section at the end. The inner cavity of the main section has an eccentric structure, and the lower part of the inner cavity at the junction of the main section and the bent section is gently sloping. The tongue plate of the bent section is provided with a thickened structure.

[0010] Compared with the prior art, the outstanding features of this utility model, which adopts the above technical solution, are:

[0011] The eccentric structure alters the pulverized coal conveying path, helping to optimize the flow trajectory of the pulverized coal, reducing the impact of the pulverized coal on the pipe wall, thereby reducing friction and resistance during the conveying process and improving conveying efficiency. The gentle slope structure ensures smoother passage of pulverized coal, effectively reducing the risk of coal accumulation and blockage, further improving coal feeding efficiency. The thickened structure at the tongue plate location enhances the impact and wear resistance of this area, effectively protecting the tongue plate from damage and further extending the service life of the coal feeding pipe. The eccentric and gentle slope structures not only reduce wear and impact but also help to evenly distribute pulverized coal during the coal feeding process, which can improve the boiler's combustion efficiency, reduce incomplete combustion, and thus reduce energy consumption and emissions.

[0012] As a preferred embodiment, a further technical solution of this utility model is:

[0013] Furthermore, the coal feed pipe includes an outer stainless steel sleeve and an inner silicon carbide ceramic layer, with an asphalt layer laid between the stainless steel sleeve and the silicon carbide ceramic layer.

[0014] Furthermore, the thickness of the asphalt layer is greater than or equal to 2 mm. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the main cross-sectional structure of an embodiment of the present utility model;

[0016] Figure 2 This is an embodiment of the present utility model. Figure 1 Schematic diagram of the main view structure in the P direction;

[0017] Figure 3 This is an embodiment of the present utility model. Figure 1 A schematic diagram of the cross-sectional structure of the eccentric structure in the AA direction;

[0018] Figure 4 This is a schematic diagram showing the relative positions of the sleeve and the silicon carbide ceramic layer in the coal feed pipe body according to an embodiment of this utility model;

[0019] The markings in the diagram are: coal feed pipe 1, stainless steel sleeve 11, silicon carbide ceramic layer 12, Y-shaped grab stud 13, steel mesh 14, main pipe section 15, bending section 16, tongue plate 2, asphalt layer 3. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments, the purpose of which is only to better understand the content of the present invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0021] A highly reliable coal feed pipe for a large circulating fluidized bed boiler includes an inclined main pipe section 15 and a bent section 16 at the end. The inner cavity of the main pipe section 15 has an eccentric structure. The upper part of the pipe wall of the main pipe section 15 is thin and the lower part is thick. The lower part of the inner cavity at the junction of the main pipe section 15 and the bent section 16 is gently sloping. The tongue plate of the bent section 16 is provided with a thickened structure. The bottom thickness of the main pipe section 15 of the coal feed pipe 1 is not less than 50 mm, and the thickness of the thickened structure at the tongue plate 2 is not less than 100 mm.

[0022] Furthermore, the coal feed pipe 1 includes an outer stainless steel sleeve 11 and an inner silicon carbide ceramic layer 12. Y-shaped catches 13 are welded on the stainless steel sleeve 11, and steel mesh 14 is arranged between the Y-shaped catches 13. The silicon carbide ceramic layer 12 is laid on the Y-shaped catches 13 and steel mesh 14. The Y-shaped catches 13 and steel mesh 14 are used to ensure the strength of the silicon carbide ceramic layer 12. The spacing between adjacent Y-shaped catches 13 along the length of the pipe is less than 80mm. An asphalt layer 3 is laid between the stainless steel sleeve 11 and the silicon carbide ceramic layer 12. Under hot conditions, there is a difference in expansion between the stainless steel sleeve 11 and the silicon carbide ceramic layer 12 during the expansion process, and the metal is more prone to deformation, which may have a certain impact on the silicon carbide ceramic layer 12. Asphalt paint is applied inside the stainless steel sleeve 11 as an asphalt layer 3 to absorb the difference in expansion and deformation between the two.

[0023] Furthermore, the thickness of the asphalt layer 3 is greater than or equal to 2 mm.

[0024] The eccentric structure alters the coal powder's conveying path, helping to optimize its flow trajectory and reduce its impact on the pipe wall. This reduces friction and resistance during conveying, improving conveying efficiency. The gentle slope structure ensures smoother coal flow, effectively reducing coal accumulation and blockage risks, further enhancing feeding efficiency. A thickened structure at the location of the tongue plate 2 enhances its impact and wear resistance, effectively protecting it from damage and extending the service life of the coal feeding pipe 1. The eccentric and gentle slope designs not only reduce wear and impact but also facilitate uniform coal powder distribution during feeding, improving boiler combustion efficiency, reducing incomplete combustion, and thus lowering energy consumption and emissions.

[0025] The above description is only a preferred embodiment of the present utility model and does not limit the scope of the present utility model. All equivalent changes made based on the content of the present utility model specification and its drawings are included within the scope of the present utility model.

Claims

1. A highly reliable coal feeding pipe for a large circulating fluidized bed boiler, characterized by: The main pipe section and the bending section of the end are included, the inner cavity of the main pipe section is eccentric structure, the lower part of the inner cavity of the junction of the main pipe section and the bending section is gentle slope, and the tongue plate position of the bending section is provided with thickening structure.

2. The high-reliability coal feeding pipe for a large circulating fluidized bed boiler according to claim 1, characterized by: The pipe body of the coal feeding pipe includes a stainless steel sleeve on the outside and a silicon carbide ceramic layer on the inside, and an asphalt layer is laid between the stainless steel sleeve and the silicon carbide ceramic layer.

3. The high-reliability coal feeding pipe for a large circulating fluidized bed boiler according to claim 1, characterized by: The thickness of the asphalt layer is greater than or equal to 2 mm.

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