Circulating bed boiler

Abstract

The utility model discloses a circulating bed boiler, which belongs to the technical field of circulating bed boilers and comprises a boiler body, and an air distribution plate is arranged in the boiler body. A slag falling pipe penetrates through the air distribution plate; the outer wall of the slag falling pipe is sleeved with a water cooling sleeve; the slag falling pipe extends out of the upper surface of the air distribution plate; a protective layer is arranged on the outer wall of the slag falling pipe on the upper surface of the air distribution plate; the protective layer is formed by castable, and the thickness of the protective layer is 150 mm. The circulating bed boiler can effectively solve the problems that in the prior art, a slag falling pipe in a circulating fluidized bed boiler is continuously scoured by high-concentration bed materials for a long time, so that the slag falling pipe and a water cooling sleeve on the outer wall are abraded or exploded, and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of circulating bed boilers, and specifically relates to a circulating bed boiler. Background Art

[0002] In recent years, circulating fluidized bed boilers have mostly adopted water-cooled jackets for their slag drop pipes. Cooling the high-temperature ash through the medium in the water-cooled jacket can reduce boiler heat loss. When using water-cooled jackets, the material requirements for the slag drop pipe can be appropriately lowered, saving costs. However, some boilers using water-cooled jackets have experienced varying degrees of pipe bursting after operation. Analysis shows that due to the severe material disturbance in the furnace slag drop area, the water-cooled jacket is exposed to the outside and is continuously eroded by the high-concentration bed material, causing wear or bursting of the slag drop pipe and the water-cooled jacket on the outer wall. Conventional designs install anti-wear end covers on the upper end of the core tube to protect the water-cooled jacket, but as the operating time increases, the jacket will still wear out. Once a pipe bursts, the boiler must be shut down, seriously affecting the continuous, safe and stable operation of the boiler. Utility Model Content

[0003] The purpose of this utility model is to provide a circulating fluidized bed boiler to address the above-mentioned shortcomings and solve the problems of the slag drop pipe in the existing circulating fluidized bed boiler being continuously eroded by high-concentration bed material for a long time, causing the slag drop pipe and the water-cooling jacket on the outer wall to wear or burst. In order to achieve the above-mentioned purpose, the utility model provides the following technical solutions:

[0004] A circulating bed boiler comprises a furnace body, wherein an air distribution plate is arranged on the upper surface of the furnace body; a slag dropping pipe is penetrated by the air distribution plate; a water-cooling sleeve is sleeved on the outer wall of the slag dropping pipe; the slag dropping pipe extends beyond the upper surface of the air distribution plate; a protective layer is provided on the outer wall of the slag dropping pipe on the upper surface of the air distribution plate; the protective layer is formed by castable, and the thickness of the protective layer is 150 mm.

[0005] Furthermore, the upper surface of the protective layer is flush with the upper surface of the slag dropping pipe.

[0006] Furthermore, the upper end portion of the slag dropping pipe is provided with a reinforcement sleeve.

[0007] Furthermore, a plurality of water-cooled wall tubes are arranged in the air distribution plate; some of the water-cooled wall tubes are bent to avoid the slag falling pipes; and cooling medium flows through the water-cooled wall tubes.

[0008] Furthermore, a cooling water pipe is provided in the air distribution plate; the cooling water pipe is connected to the water cooling jacket.

[0009] Furthermore, it also includes a water circulation system; the water circulation system includes an upper header, water-cooled wall tubes, water-cooled jackets and a lower header; the cooling medium in the lower header absorbs heat through the water-cooled wall tubes and water-cooled jackets and then flows into the upper header, and the cooling medium in the upper header flows back to the lower header, forming a circulating utilization of the cooling medium.

[0010] Furthermore, the air distribution plate is provided with a plurality of ventilation holes, and the plurality of ventilation holes are interlaced with the slag dropping pipes, water-cooled wall pipes and cooling water pipes without interfering with each other.

[0011] Furthermore, a hood is connected to the ventilation hole; and air outlets are provided on both sides of the hood.

[0012] Furthermore, the material of the reinforcement sleeve is 06Cr19Ni10.

[0013] Furthermore, a pin is welded on the outer wall of the slag dropping pipe above the air distribution plate.

[0014] The beneficial effects of the utility model are:

[0015] The utility model discloses a circulating bed boiler, which is designed with an upper structure of a water-cooled slag drop pipe, a heightened core pipe of the slag drop pipe, and a castable material that is flush with the height of the raised core pipe of the slag drop pipe. Specifically, the thickness of the air distribution plate castable material is 150mm. The water-cooling sleeve is consistent with the original structural dimensions, and a castable material fixed with pins of a certain density is set around the core pipe and the water-cooling sleeve. The strongly disturbed material around the slag drop pipe only contacts the castable material and the upper surface of the core pipe when entering the slag drop pipe, effectively protecting the water-cooling sleeve port from scouring and maintaining the resistance of the air distribution plate unchanged. At this time, the primary air pressure can remain unchanged, the primary fan pressure does not increase, and the safety hazard caused by the burst of the water-cooling sleeve is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a cross-sectional view of the utility model's air distribution plate combined with the slag dropping pipe structure;

[0017] Figure 2 This is a top view of the air distribution plate structure of the utility model;

[0018] Figure 3 This is a schematic diagram of the wind cap structure on the wind distribution plate of the utility model;

[0019] In the attached figure: 1. Air distribution plate; 2. Slag drop pipe; 3. Water-cooling jacket; 4. Protective layer; 5. Reinforced jacket; 6. Water-cooling wall tube; 7. Cooling water pipe; 8. Ventilation hole; 9. Wind hood; 10. Air outlet. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] It should be noted that similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined in one figure, it does not require further definition or explanation in subsequent figures. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the figures, or the positions or relationships in which the utility model product is typically placed when in use. These terms are intended solely for ease of description and simplification of the description of the utility model, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the utility model. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance. Furthermore, terms such as "horizontal" and "vertical" do not imply that a component must be absolutely horizontal or overhanging, but rather may be slightly tilted. For example, "horizontal" simply refers to a direction that is more horizontal than "vertical," and does not imply that the structure must be completely horizontal, but rather may be slightly tilted. It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0022] Example 1:

[0023] See attached Figures 1 to 3. This embodiment provides a circulating bed boiler, including a furnace body and other necessary structures for completing the combustion of the circulating bed boiler. Specifically, the utility model improves the structure of the air distribution plate 1 and the slag drop pipe 2. The air distribution plate 1 is a carrier for carrying material combustion. The ventilation holes 8 on the air distribution plate 1 provide stable air combined with the material to fully burn above the air distribution plate 1. A slag drop pipe 2 is provided on the air distribution plate 1 and penetrates the air distribution plate 1. The residual material after combustion is discharged through the slag drop pipe 2. In order to recover the heat of the high-temperature residual waste and reduce the heat loss of the boiler, a heat recovery structure is provided inside the air distribution plate 1 and on the outer wall of the slag drop pipe 2 to fully recover the heat of the high-temperature residual waste. Several water-cooled wall tubes 6 are provided in the horizontal direction inside the air distribution plate 1. The air distribution plate 1 itself is cooled by circulating a cooling medium to complete the heat recovery of the air distribution plate 1. A water-cooling jacket 3 is sleeved on the outer wall of the slag drop pipe 2. Similarly, a cooling medium is circulated in the water-cooling jacket 3 to recover the heat of the high-temperature residual material. The high-temperature residual material is subjected to wind pressure from the air distribution plate 1, causing strong disturbances around the slag pipe 2, which can damage the slag pipe 2 itself. To increase the height of the slag pipe 2 above the air distribution plate 1, a castable is placed around the slag pipe 2 to form a protective layer 4. The castable thickness is preferably set to 150 mm, that is, the top plane of the slag pipe 2 is 150 mm higher than the air distribution plate. The protective layer 4 formed by the castable protects the slag pipe 2 and the water-cooling jacket 3 connected to the outside of the slag pipe 2 from being eroded by the residual material. A certain density of pins are welded around the slag pipe 2 and the water-cooling jacket 3 to improve the stability of the castable.

[0024] The cooling medium of the water-cooling jacket 3 is provided by the cooling water pipe 7. Part of the cooling water pipe 7 is connected to the water-cooling jacket 3 corresponding to the bottom of the slag dropping pipe 2, and the other part is arranged on the air distribution plate 1 and is connected to the water-cooling jacket 3 corresponding to the slag dropping pipe 2. The water-cooling jacket 3 cannot effectively cover the cooling of the flat part near the top of the slag dropping pipe 2, and the slag dropping pipe 2 cannot be cooled near the upper end. A reinforcing jacket 5 is set in this area without medium cooling, and the material of 06Cr19Ni10 is used to enhance the rigidity of this area to prevent the deformation of the slag dropping pipe 2, which may cause the weld between the water-cooling jacket 3 and the slag dropping pipe 2 to tear and cause the pipe to burst.

[0025] There are several water-cooled wall tubes 6 arranged horizontally in the air distribution plate 1, some of which are bent to avoid the position of the slag falling pipe 2. The air distribution plate 1 is made of steel structure and carries materials to be burned above it. It needs to be fully cooled to increase its service life. Preferably, the cooling medium in the water-cooling jacket 3 and the cooling medium in the water-cooled wall tube 6 are both cooling water vapor mixtures. The inlet of the cooling water pipe 7 and the inlet of the water-cooled wall tube 6 are both located on one side of the air distribution plate 1 and connected to the cooling water vapor mixture in the lower header at the bottom of the circulating bed. The cooling water vapor mixture in the lower header begins to flow upward due to the pressure difference, and part of it flows into the water-cooled wall tube 6 on the air distribution plate through the pipe in the side wall of the air distribution plate 1; part of the cooling water vapor mixture enters the water-cooling jacket 3 in turn through the cooling water pipe 7 connected to the bottom of the slag dropping pipe 2, and finally flows out from the cooling water pipe 7 located in the air distribution plate 1 connected to the upper part of the slag dropping pipe 2. The water vapor mixture flowing from the cooling water pipe 7 and the water-cooled wall tube 6 flows upward through the pipe in the other side wall of the air distribution plate 1 and flows into the upper header after being collected at the top of the circulating bed. The cooling water vapor mixture in the upper header flows into the lower header and continues to circulate. The specific circulation structure can refer to the cooling water circulation system of the circulating bed in the prior art. In the technology of this field, the cooling water in the circulating bed flows from the bottom to the top due to the pressure difference to form a circulation.

[0026] A number of ventilation holes 8 are provided on the air distribution pipe in a parallel square with the slag dropping pipe 2, which are used for full contact and combustion between the wind and the material. A wind hood 9 is provided above the ventilation hole 8, and an air outlet 10 is provided on the wind hood 9 around it. The bottom of the air distribution plate 1 is provided with a wind pressure by the fan. The setting of the wind hood 9 changes the direction of the air outlet 10 and further increases the wind pressure of the air outlet 10, so that it has a strong wind pressure to drive the material to move above the air distribution plate 1, fully contact with the air, complete full combustion, and the residual material can be smoothly discharged from the slag dropping pipe 2.

[0027] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A circulating bed boiler, comprising a furnace body, characterized in that: An air distribution plate (1) is arranged in the furnace body; a slag dropping pipe (2) is passed through the air distribution plate (1); a water-cooling sleeve (3) is sleeved on the outer wall of the slag dropping pipe (2); the slag dropping pipe (2) extends out of the upper surface of the air distribution plate (1); a protective layer (4) is provided on the outer wall of the slag dropping pipe (2) on the upper surface of the air distribution plate (1); the protective layer (4) is formed by a castable, and the thickness of the protective layer (4) is 150 mm.

2. The circulating bed boiler according to claim 1, characterized in that: The upper surface of the protective layer (4) is flush with the upper surface of the slag dropping pipe (2).

3. The circulating bed boiler according to claim 1, characterized in that: The upper end portion of the slag dropping pipe (2) is provided with a reinforcement sleeve (5).

4. The circulating bed boiler according to claim 1, characterized in that: A plurality of water-cooled wall tubes (6) are arranged in the air distribution plate (1); some of the water-cooled wall tubes (6) are bent to avoid the slag falling tubes (2); and cooling medium flows through the water-cooled wall tubes (6).

5. The circulating bed boiler according to claim 4, characterized in that: A cooling water pipe (7) is provided in the air distribution plate (1); the cooling water pipe (7) is in communication with the water cooling jacket (3).

6. The circulating bed boiler according to claim 4, characterized in that: It also includes a water circulation system; the water circulation system includes an upper header, water-cooled wall tubes (6), a water-cooled jacket (3) and a lower header; the cooling medium in the lower header absorbs heat through the water-cooled wall tubes (6) and the water-cooled jacket (3) and then flows into the upper header, and the cooling medium in the upper header flows back to the lower header, thereby forming a circulating utilization of the cooling medium.

7. The circulating bed boiler according to claim 5, characterized in that: The air distribution plate (1) is provided with a plurality of ventilation holes (8), and the plurality of ventilation holes (8) are interlaced with the slag dropping pipe (2), the water-cooled wall pipe (6) and the cooling water pipe (7) without interfering with each other.

8. The circulating bed boiler according to claim 7, characterized in that: The ventilation hole (8) is connected to a hood (9); air outlets (10) are provided on both sides of the hood (9).

9. The circulating bed boiler according to claim 3, characterized in that: The material of the reinforcement sleeve (5) is 06Cr19Ni10.

10. The circulating bed boiler according to claim 1, characterized in that: The outer wall of the slag dropping pipe (2) located above the air distribution plate (1) is welded with pins.

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