Pulverized coal boiler structure capable of preventing coke hanging

Abstract

The utility model relates to a pulverized coal boiler structure capable of preventing coke hanging, which comprises a boiler body and a burner, a combustion-supporting cavity is arranged in the upper section of the boiler body, a combustion cavity is arranged in the middle section of the boiler body, a dry bottom hopper is arranged in the lower section of the boiler body, and the combustion cavity, the combustion-supporting cavity and the dry bottom hopper are communicated up and down; an arch wall protruding downwards and outwards is arranged on the front side of the combustion cavity, the inclination angle of the inclined wall of the upper section of the arch wall ranges from 30 degrees to 40 degrees, and the combustor is installed on the straight wall of the lower section of the arch wall. The combustion area of the internal combustion chamber is increased by increasing the arch wall on the front side of the furnace body, and the problem of coking on the inner wall of the combustion chamber is solved by reasonably arranging the depth and width of the hearth in the flame area of the combustor through the inclination angle of the inclined wall; combustion-supporting air is blown into the combustion-supporting cavity through the inclined blowing pipe and then intersects at the center, an air layer air cushion is formed, the secondary afterburning effect of pulverized coal is effectively improved, the mechanical incomplete loss of the boiler and the generation amount of CO can be effectively reduced, and therefore the heat efficiency of the boiler is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of boiler equipment and relates to a pulverized coal boiler structure capable of preventing coking. Background Art

[0002] At present, most of the high-tonnage and high-parameter pulverized coal boilers in the country are in the form of direct current burners, and the burners of small-scale low-parameter and low-tonnage pulverized coal boilers are mostly swirl pulverized coal burners. In order to meet the national environmental protection requirements, the slenderness ratio of the combustion flame of the domestic swirl pulverized coal burner is getting larger and larger, which requires the depth and width of the furnace of the pulverized coal boiler to be larger and larger. In order to meet the combustion characteristics of the boiler, the furnace height cannot be reduced, which will inevitably increase the weight of the boiler and increase the production cost; and the furnace combustion area of ​​the small-scale low-parameter and low-tonnage pulverized coal boiler is prone to coking, and it is also inconvenient to clean the coal slag in the ash hopper of some boilers. Summary of the invention

[0003] The utility model aims to overcome the deficiencies in the prior art, solve the problem that the furnace combustion area of ​​a small-tonnage pulverized coal boiler is prone to coking and the ash hopper is inconvenient to clean, and provide a pulverized coal boiler structure that prevents coking.

[0004] In order to achieve the above purpose, the following technical solutions are adopted:

[0005] The anti-coking pulverized coal boiler structure comprises a furnace body and a burner, wherein a combustion-supporting chamber is arranged inside the upper section of the furnace body, and air ducts are arranged in parallel at the lower ends of the two side walls of the combustion-supporting chamber; a combustion chamber is arranged inside the middle section of the furnace body, and a cold ash hopper is arranged inside the lower section of the furnace body, and the combustion chamber, the combustion-supporting chamber and the cold ash hopper are connected up and down; an arch wall protruding downward and outward is arranged on the front side of the combustion chamber, and the inclined wall of the upper section of the arch wall has an inclination angle of 30-40°, and the burner is installed on the straight wall of the lower section of the arch wall.

[0006] Preferably, ash collecting walls contracting downward and inward are respectively provided on both sides of the cold ash hopper, and the inclination angle of the ash collecting walls is 50-60°.

[0007] Preferably, an inclined blowpipe is provided at the end of the air duct extending into the combustion-supporting chamber, the pipe openings of the two diagonal inclined blowpipes are arranged opposite to each other, and the diagonal lines of the four inclined blowpipes intersect at the center of the combustion-supporting chamber.

[0008] Preferably, the furnace walls of the furnace body are all membrane wall structures.

[0009] Preferably, the center of the lower end of the cold ash hopper is located below the center of the combustion chamber.

[0010] Preferably, the burner is a swirl pulverized coal burner.

[0011] Compared with the prior art, the utility model has the following advantages:

[0012] The utility model increases the combustion area of ​​the internal combustion chamber by increasing the arch wall on the front side of the furnace body, and reasonably arranges the furnace depth and width of the burner flame area through the inclination angle of the inclined wall, thereby solving the problem of coke hanging on the wall in the combustion chamber; the inclined blowpipe at the end of the air duct allows the combustion-supporting air to converge at the center after entering the combustion-supporting chamber, which can form an air layer cushion, effectively improve the secondary combustion effect of the coal powder, and can effectively reduce the mechanical incomplete loss of the boiler and the generation of CO, thereby improving the thermal efficiency of the boiler, and greatly reducing the original NOx emission concentration of the pulverized coal boiler, thereby increasing the market share of small pulverized coal boilers. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0014] Figure 2 It is a left side schematic diagram of the utility model.

[0015] Figure 3 It is a schematic cross-sectional view of the combustion-supporting chamber of the present utility model.

[0016] In the figure: 1. furnace body; 2. burner; 3. cold ash hopper; 4. arch wall; 5. inclined wall; 6. straight wall; 7. ash collecting wall; 8. air duct; 9. inclined blowpipe; 10. combustion chamber; 11. combustion-supporting chamber. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0018] like Figure 1-Figure 3 As shown, a pulverized coal boiler structure for preventing coking includes a furnace body 1 and a burner 2. The burner 2 injects pulverized coal into the furnace body 1 and ignites it.

[0019] A combustion chamber 11 is provided inside the upper section of the furnace body 1, and air ducts 8 are provided in parallel at the lower ends of the two side walls of the combustion chamber 11, and the air ducts 8 can inject combustion air into the combustion chamber 11; a combustion chamber 10 is provided inside the middle section of the furnace body 1, and a cold ash hopper 3 is provided inside the lower section of the furnace body 1;

[0020] The combustion chamber 10 is connected with the combustion chamber 11 and the cold ash hopper 3. When the pulverized coal enters the furnace body 1, it is burned inside the combustion chamber 10. There is combustion-supporting air in the combustion chamber 11. The pulverized coal that is not fully burned is mixed with the combustion air above the combustion chamber 11 to achieve a supplementary combustion effect on the pulverized coal. The cold ash hopper 3 is used to collect the coal slag after combustion.

[0021] The front side of the combustion chamber 10 is provided with an arch wall 4 protruding downward and outward, and the inclination angle of the inclined wall 5 on the upper section of the arch wall 4 is 30-40 degrees. The width, depth, height of the burner flame area 7 and the arch angle of the inclined wall 5 are determined to be between 30 degrees and 40 degrees according to the flame length and diameter of the swirl pulverized coal burner 4. Reasonable arrangement of the cross-sectional heat load of the pulverized coal boiler can effectively ensure that the flame does not brush the wall when the boiler is running, the membrane wall is not coked around, and the pulverized coal particles are burned high;

[0022] The burner 2 is installed on the straight wall 6 of the lower section of the arch wall 4.

[0023] Preferably, ash collecting walls 7 contracting downward and inward are respectively provided on both sides of the cold ash hopper 3, and the ash collecting walls 7 have an inclination angle of 50-60 degrees. The coal powder falls after combustion, and the inclined ash collecting walls 7 facilitate the collection of coal ash.

[0024] Furthermore, an inclined blowpipe 9 is provided at the end of the air duct 8 extending into the combustion-supporting chamber 11, and the pipe openings of the two diagonally inclined blowpipes 9 are arranged opposite to each other, and the diagonals of the four inclined blowpipes 9 intersect at the center of the combustion-supporting chamber 11. The combustion-supporting wind is blown into the combustion-supporting chamber 11 through the inclined blowpipes 9 and then intersects at the center to form an air layer cushion, which effectively improves the secondary combustion effect of the coal powder, can effectively reduce the mechanical incomplete loss of the boiler and the generation of CO, thereby improving the thermal efficiency of the boiler.

[0025] Furthermore, the furnace walls of the furnace body 1 are all membrane wall structures.

[0026] Furthermore, the center of the lower end of the cold ash hopper 3 is located below the center of the combustion chamber 10, and the center of the cold ash hopper 5 is at the highest point of the burner flame heat load, which can more smoothly discharge slag and ensure that there is no coke around the cold ash hopper.

[0027] Furthermore, the burner 2 is a swirl coal powder burner, which has stable combustion and small ignition pressure fluctuation.

[0028] Working Principle The utility model utilizes a combustion chamber 10 provided with an arch wall 4, and limits the arching angle of the inclined wall 5 to between 30° and 40°. Reasonable arrangement of the cross-sectional heat load of the pulverized coal boiler can effectively ensure that the flame does not brush the wall when the boiler is running, the membrane wall is not coked around, and the pulverized coal particles are burned high; a cold ash hopper 3 is arranged below the combustion chamber 10, and ash collecting walls 7 that shrink downward and inward are respectively arranged on both sides of the cold ash hopper 3, and the ash collecting wall 7 is inclined at an angle of 50-60°. The pulverized coal falls after combustion, and the inclined ash collecting wall 7 is convenient for collecting coal ash;

[0029] An inclined blowpipe 9 is provided at the end of the air duct 8 extending into the combustion-supporting chamber 11. The diagonals of the four inclined blowpipes 9 intersect at the center of the combustion-supporting chamber 11. The combustion-supporting air is blown into the combustion-supporting chamber 11 through the inclined blowpipes 9 and then intersects at the center to form an air layer cushion, which effectively improves the secondary combustion effect of the coal powder, can effectively reduce the mechanical incomplete loss of the boiler and the generation of CO, thereby improving the thermal efficiency of the boiler.

[0030] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A pulverized coal boiler structure for preventing coking, comprising a furnace body (1) and a burner (2), wherein: A combustion-supporting chamber (11) is arranged inside the upper section of the furnace body (1), and air ducts (8) are arranged in parallel at the lower ends of the two side walls of the combustion-supporting chamber (11); a combustion chamber (10) is arranged inside the middle section of the furnace body (1), and a cold ash hopper (3) is arranged inside the lower section of the furnace body (1); the combustion chamber (10) is connected to the combustion-supporting chamber (11) and the cold ash hopper (3) in upper and lower directions; an arch wall (4) protruding downward and outward is arranged on the front side of the combustion chamber (10), and the inclined wall (5) of the upper section of the arch wall (4) has an inclination angle of 30-40°, and the burner (2) is installed on the straight wall (6) of the lower section of the arch wall (4).

2. The anti-coking pulverized coal boiler structure according to claim 1 is characterized by: The cold ash hopper (3) is provided with ash collecting walls (7) that contract downward and inward respectively on both sides, and the ash collecting walls (7) have an inclination angle of 50-60°.

3. The anti-coking pulverized coal boiler structure according to claim 1 is characterized by: An inclined blowpipe (9) is arranged at the end of the air duct (8) extending into the combustion-supporting chamber (11), the pipe openings of the two diagonally inclined blowpipes (9) are arranged opposite to each other, and the diagonals of the four inclined blowpipes (9) intersect at the center of the combustion-supporting chamber (11).

4. The anti-coking pulverized coal boiler structure according to claim 1 is characterized by: The furnace walls of the furnace body (1) are all membrane wall structures.

5. The anti-coking pulverized coal boiler structure according to claim 1 is characterized by: The center of the lower end of the cold ash hopper (3) is located below the center of the combustion chamber (10).

6. The anti-coking pulverized coal boiler structure according to claim 1 is characterized by: The burner (2) is a swirl pulverized coal burner.

Images