Multi-step anti-abrasion furnace lining structure of fluidized bed boiler

Abstract

The utility model belongs to the technical field of abrasion prevention in a circulating fluidized bed boiler, and particularly relates to a multi-step anti-abrasion furnace lining structure of a fluidized bed boiler. According to the technical scheme, the multistage step anti-abrasion furnace lining structure of the fluidized bed boiler comprises a circulating fluidized bed boiler furnace, a water cooling wall surface is arranged on a shell of the circulating fluidized bed boiler furnace, a plurality of openings are formed in the water cooling wall surface, and step furnace linings are arranged around the area, where the openings are formed, of the water cooling wall surface; and the stepped furnace lining is circumferentially pulled through on the wall surface of the water cooling wall. The utility model provides a multi-step anti-abrasion furnace lining structure of a fluidized bed boiler.

Description

Technical Field

[0001] The utility model belongs to the technical field of in-furnace anti-wear of circulating fluidized bed boilers, and particularly relates to a multi-stage stepped anti-wear furnace lining structure for a fluidized bed boiler. Background Technique

[0002] As an efficient and clean technology, the circulating fluidized bed combustion method is widely used in coal-fired power plants. However, the reliability of circulating fluidized bed boilers has always been questioned by people. This is because the circulating fluidized bed coal combustion technology causes a large amount of material circulation in the boiler. The material circulation of the circulating fluidized bed boiler includes an internal circulation and an external circulation. The amount of material participating in the internal circulation is very large. The internal circulation material flows down along the wall surface, and the rate also increases. This causes wear or impact on different positions such as the furnace water-cooled wall, secondary air nozzles, coal feeding ports, return ports, air distribution plates, and air caps.

[0003] Although the anti-wear technology for circulating fluidized bed boilers is also constantly developing, and the reliability of circulating fluidized bed boilers has been greatly improved, wear still occurs from time to time at some positions in the dense phase zone of the circulating fluidized bed, such as key parts like secondary air nozzles, coal feeding ports, return ports, and air distribution plate air caps. The wear at these places greatly affects the reliability of boiler operation.

[0004] Application No. CN201310113791 proposed to arrange multiple horizontal baffle beams along the upper edge of the furnace outlet on the wear-resistant plastic in the dense phase zone of the furnace to prevent the upper water-cooled wall of the furnace from being worn; Application No. CN202311291150 proposed to set multiple groups of horizontal and vertical anti-wear plates on the water-cooled wall tubes in the circulating fluidized bed furnace to reduce the erosion of the water-cooled wall by the materials flowing from top to bottom in the furnace; Application No. CN202122738255 proposed an anti-wear and diversion device for a circulating fluidized bed boiler, which has replaceable anti-wear plates for anti-wear of the boiler water-cooled wall tubes; Application No. CN201510245992 proposed a tube anti-wear device for the dense phase zone of the water-cooled wall of a circulating fluidized bed boiler to solve the wear of the dense phase zone of the water-cooled wall.

[0005] The above-mentioned patents are all to solve the wear of the tubes in the area where the castable is not laid on the fire-facing side of the furnace water-cooled wall, and do not consider the wear of the secondary air nozzles, coal feeding ports, return ports, and the air caps at the bottom of the furnace in the lower castable area of the furnace caused by the internal circulation materials flowing from top to bottom.

[0006] In the prior art, for the anti-wear of some furnace secondary air nozzles, coal feeding ports, and return ports, wear-resistant furnace linings are thickened and laid around each opening. Although this protects these openings, due to the formation of gaps between the furnace linings, the flow rate of the downflow along the wall in the gap area increases instead, and the flow velocity increases (see Figure 6 ), making the air distribution plate and air caps below the area corresponding to the gap face a more serious wear risk. Content of the Utility Model

[0007] In order to solve the above problems existing in the prior art, the purpose of the present utility model is to provide a multi-stage stepped wear-resistant furnace lining structure for a fluidized bed boiler.

[0008] The technical solution adopted by the present utility model is as follows:

[0009] A multi-stage stepped wear-resistant furnace lining structure for a fluidized bed boiler, including the furnace chamber of a circulating fluidized bed boiler. A water-cooled wall surface is arranged on the shell of the furnace chamber of the circulating fluidized bed boiler. A plurality of openings are arranged on the water-cooled wall surface, and stepped furnace linings are arranged around the area where the openings are arranged on the water-cooled wall surface; the stepped furnace linings are circumferentially continuous on the water-cooled wall surface.

[0010] Most of the secondary air inlets, coal feeding inlets, and return material inlets of a circulating fluidized bed boiler are arranged in the dense phase zone of the furnace chamber. In some boilers, the secondary air inlets are arranged in the dilute phase zone, and problems such as wear and deformation often occur. For example, the secondary air duct deforms and tears the water-cooled wall, and the coal feeding inlet deforms and tears, seriously affecting the reliability of the boiler. In the prior art, wear-resistant furnace linings are thickly laid around each opening. Although this protects the local opening position, it will increase the flow velocity of the opening gap, thereby causing regional wear problems. The present utility model combines the characteristics that most of the secondary air inlets, coal feeding inlets, and return material inlets are respectively arranged at the same elevation or the elevation difference is very small, and designs a circumferentially continuous stepped furnace lining, which can not only protect the opening position but also avoid the problems caused by the prior art.

[0011] The materials in the circulating fluidized bed flow downward along the wall, and the flow velocity becomes higher and higher. If not blocked and directly rushes into the air distributor plate area, it will cause wear problems such as cutting and scouring of the air caps on the air distributor plate. Some existing technologies use the surrounding boss technology to slow down the impact of the wall-attached flow, but its change to the wall-attached flow is one-time and has limitations. The present utility model uses a multi-stage stepped furnace lining to effectively reduce the flow velocity of the wall-attached flow, effectively reduce the flow rate of the wall-attached flow, and effectively change the flow direction of the wall-attached flow.

[0012] As a preferred solution of the present utility model, the types of the openings include secondary air inlets, coal feeding inlets, and return material inlets.

[0013] As a preferred solution of the present utility model, the edge of the stepped furnace lining is smoothly transitioned with the water-cooled wall surface. That is, the longitudinal cross-sectional shape of the stepped furnace lining is trapezoidal.

[0014] As a preferred solution of the present utility model, when there is an overlapping area in the height direction for different openings, only one stepped furnace lining is correspondingly arranged for the different openings with the overlapping area in height.

[0015] As a preferred embodiment of the present utility model, when the secondary air inlet is not at the same elevation as the feeding port or the return material port, and if a two-layer stepped furnace lining is made, there will be overlap, or when a unified stepped furnace lining is made, the height of the stepped furnace lining is relatively large, a special-shaped stepped furnace lining is installed on the water wall surface.

[0016] As a preferred embodiment of the present utility model, the upper part of the special-shaped stepped furnace lining is circumferentially connected, and a part of the gap is left according to the distance between the feeding port or the return material port at the lower part of the special-shaped stepped furnace lining.

[0017] As a preferred embodiment of the present utility model, the included angle a between the upper side of the stepped furnace lining and the water wall surface is 90° - 165°.

[0018] As a preferred embodiment of the present utility model, the included angle b between the lower side of the stepped furnace lining and the water wall surface is 90° - 165°.

[0019] As a preferred embodiment of the present utility model, the thickness d of the stepped furnace lining is 10 - 300 mm.

[0020] As a preferred embodiment of the present utility model, the height of the upper side of the stepped furnace lining is the same at each circumferential position.

[0021] The beneficial effects of the present utility model are as follows:

[0022] 1. In a circulating fluidized bed boiler, most of the secondary air inlets, coal feeding ports, and return material ports are arranged in the dense phase zone of the furnace. In some boilers, the secondary air inlets are arranged in the dilute phase zone, and there are often problems such as wear and deformation. For example, the secondary air duct is deformed and tears the water wall, and the coal feeding port is deformed and torn, which seriously affects the reliability of the boiler. In the prior art, wear-resistant furnace linings are thickly laid around each opening. Although this protects the local opening position, it will increase the flow velocity of the opening gap, thereby causing regional wear problems. The present utility model combines the characteristics that most of the secondary air inlets, coal feeding ports, and return material ports are respectively arranged at the same elevation or the elevation difference is very small, and designs a circumferentially connected stepped furnace lining, which can not only protect the opening position but also avoid the problems caused by the prior art.

[0023] 2. In the circulating fluidized bed, the wall-attached flow of materials flows downward, and the flow velocity becomes higher and higher. If there is no obstruction and it directly rushes into the air distributor area, it will cause wear problems such as cutting and scouring of the air caps on the air distributor. Some existing technologies use the surrounding boss technology to slow down the impact of the wall-attached flow, but its change to the wall-attached flow is one-time and has limitations. The present utility model uses a multi-stage stepped furnace lining to effectively reduce the flow velocity of the wall-attached flow, effectively reduce the flow rate of the wall-attached flow, and effectively change the flow direction of the wall-attached flow. Description of the Drawings

[0024] Figure 1 is a cross-sectional view of the present utility model;

[0025] Figure 2 It is a schematic structural diagram of a stepped furnace lining arranged at the secondary air inlet and the feeding port;

[0026] Figure 3 It is a schematic structural diagram of a stepped furnace lining arranged at the secondary air inlet and the return material port;

[0027] Figure 4 It is a schematic structural diagram of a stepped furnace lining with overlapping areas in the height direction for different openings;

[0028] Figure 5 It is a schematic structural diagram of a special-shaped stepped furnace lining;

[0029] Figure 6 It is a schematic structural diagram of an existing furnace lining with thickened periphery around the opening.

[0030] In the figure: 1 - the furnace chamber of a circulating fluidized bed boiler; 2 - the water-cooled wall surface; 3 - the secondary air inlet; 4 - the stepped furnace lining; 5 - the feeding port; 6 - the return material port. Specific implementation manners

[0031] To make the objectives, 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 accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0032] 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 claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention. It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0033] As Figures 1 to 5 shown, the multi-stage stepped anti-wear furnace lining structure of the fluidized bed boiler in this embodiment includes a furnace chamber 1 of a circulating fluidized bed boiler. A water-cooled wall surface 2 is arranged on the shell of the furnace chamber 1 of the circulating fluidized bed boiler. A plurality of openings are arranged on the water-cooled wall surface 2, and a stepped furnace lining 4 is arranged around the area where the openings are arranged on the water-cooled wall surface 2; the stepped furnace lining 4 is circumferentially continuous on the water-cooled wall surface 2.

[0034] The secondary air inlets 3, coal feeding inlets, and return material inlets 6 of a circulating fluidized bed boiler are mostly arranged in the dense phase zone of the furnace. In some boilers, the secondary air inlets 3 are arranged in the dilute phase zone, and problems such as wear and deformation often occur. For example, the deformation of the secondary air duct pulls and cracks the water wall, and the deformation of the coal feeding inlet pulls and cracks, etc., seriously affecting the reliability of the boiler. In the prior art, wear-resistant furnace linings are thickly laid around each opening. Although this protects the local opening position, it will increase the flow velocity of the opening gap, thereby causing regional wear problems. The utility model combines the characteristics that the secondary air inlets 3, coal feeding inlets, and return material inlets 6 are mostly arranged at the same elevation or have a very small elevation difference, and designs a circumferentially continuous stepped furnace lining 4, which can not only protect the opening position but also avoid the problems caused by the prior art.

[0035] The materials in the circulating fluidized bed flow downward along the wall in a wall-attached flow, and the flow velocity becomes higher and higher. If not blocked and directly rushes into the air distributor area, it will cause wear problems such as cutting and scouring of the air caps on the air distributor. Some existing technologies use the four-sided boss technology to slow down the impact of the wall-attached flow, but its change to the wall-attached flow is one-time and has limitations. The utility model uses a multi-stage stepped furnace lining 4 to effectively reduce the flow velocity of the wall-attached flow, effectively reduce the flow rate of the wall-attached flow, and effectively change the flow direction of the wall-attached flow.

[0036] Among them, the types of the openings include secondary air inlets 3, coal feeding inlets 5, and return material inlets 6.

[0037] The edge of the stepped furnace lining 4 is smoothly transitioned with the water wall surface 2. That is, the longitudinal cross-sectional shape of the stepped furnace lining 4 is trapezoidal.

[0038] Such as Figure 4 As shown, when there is an overlapping area in the height direction for different openings, only one stepped furnace lining 4 is correspondingly arranged for the different openings with the overlapping area in height.

[0039] Such as Figure 5 As shown, when the secondary air inlet 3 and the coal feeding inlet 5 or the return material inlet 6 are not at the same elevation, and if making a two-layer stepped furnace lining 4 will cause overlap, or when the height of the stepped furnace lining 4 is relatively large if making a unified stepped furnace lining 4, a special-shaped stepped furnace lining 4 is installed on the water wall surface 2.

[0040] It should be noted that the upper part of the special-shaped stepped furnace lining 4 is circumferentially continuous, and a part of the gap is left at the lower part of the special-shaped stepped furnace lining 4 according to the distance between the coal feeding inlet 5 or the return material inlet 6.

[0041] Among them, the included angle a between the upper side of the stepped furnace lining 4 and the water wall surface 2 is 90° to 165°.

[0042] The included angle b between the lower side of the stepped furnace lining 4 and the water wall surface 2 is 90° to 165°.

[0043] The thickness d of the stepped furnace lining 4 is 10 to 300 mm.

[0044] The height of the upper side of the stepped furnace lining 4 is the same at all circumferential positions.

[0045] The stepped furnace lining 4 uses conventional materials and construction techniques in the industry.

[0046] The stepped furnace lining 4 can be arranged in the dense phase zone, the dilute phase zone, the dense phase zone and the dilute phase zone of the furnace.

[0047] The stepped furnace lining 4 can be arranged on the front wall, the rear wall, and the left and right side walls of the furnace water wall.

[0048] The number of the stepped furnace linings 4 can be 1 to 10.

[0049] The stepped furnace lining 4 can be arranged in the opening area of the furnace of the circulating fluidized bed boiler 1, or can be added in the non-opening area of the furnace of the circulating fluidized bed boiler 1.

[0050] The upper surface and the lower surface of the stepped furnace lining 4 can be flat surfaces, can also be arc surfaces, or even stepped surfaces.

[0051] The outer surface of the stepped furnace lining 4 can be parallel to the surface of the basic furnace lining of the water wall, or can have a certain included angle.

[0052] The multi-stage stepped furnace lining 4 effectively reduces the flow velocity of the material adhering to the wall, effectively reduces the flow rate of the wall-adhering flow, and effectively changes the flow direction of the wall-adhering flow; enhances the anti-abrasion of the opening area of the fluidized bed; effectively avoids the wear of the air caps on the air distribution plate, especially the wear of the air caps around the air distribution plate; avoids the problem of increased gap flow velocity and more serious local wear caused by conventional technologies; the stepped furnace lining 4 can be constructed uniformly, and the overall dimensions can be better guaranteed, and the large deviations that may be brought by individual construction in the prior art can be avoided.

[0053] Example 1:

[0054] As Figures 1 to 3 shown, when there are two layers of secondary air inlets 3 arranged in the dense phase zone of the furnace of the circulating fluidized bed boiler 1, a feed inlet 5 is arranged on the front wall, and a return material inlet 6 is arranged on the rear wall. Install a layer of stepped furnace lining 4 on the upper-layer secondary air inlets 3 on the front and rear walls; uniformly install a layer of stepped furnace lining 4 on the lower-layer secondary air inlets 3 and the feed inlet 5 on the front wall; uniformly install a layer of stepped furnace lining 4 on the lower-layer secondary air inlets 3 and the return material inlet 6 on the rear wall.

[0055] Example 2:

[0056] As Figure 4 shown, when all the secondary air inlets 3 of the furnace of the circulating fluidized bed boiler 1 are not at the same elevation, but can be divided within a certain appropriate range, a layer of stepped furnace lining 4 can be uniformly installed.

[0057] Example 3:

[0058] As Figure 4As shown, when the secondary air inlet 3 is not at the same elevation as the feed inlet 5 or the return material inlet 6, but making a two-layer stepped furnace lining 4 will result in overlap, and the distance between the feed inlet 5 or the return material inlet 6 is very large. If a unified stepped furnace lining 4 is made for all, more materials will be used. In this case, a special-shaped stepped furnace lining 4 can be installed, that is, the upper part of the furnace lining is made continuous, and part of the gap is left according to the distance between the feed inlet 5 or the return material inlet 6 at the lower part. Figure 4 The special-shaped stepped furnace lining 4 is arranged in the area of the secondary air inlet 3 and the feed inlet 5. When the special-shaped stepped furnace lining 4 is arranged in the area of the secondary air inlet 3 and the return material inlet 6, Figure 4 the feed inlet 5 in it can be replaced with the return material inlet 6.

[0059] The present utility model is not limited to the above optional embodiments. Any person can obtain other various forms of products under the inspiration of the present utility model. However, no matter what changes are made in its shape or structure, as long as the technical solutions fall within the scope defined by the claims of the present utility model, they all fall within the protection scope of the present utility model.

Claims

1. A multi-stage stepped anti-wear furnace lining structure for a fluidized bed boiler, characterized in that: It includes the furnace (1) of a circulating fluidized bed boiler. A water wall surface (2) is provided on the shell of the furnace (1) of the circulating fluidized bed boiler. A number of openings are provided on the water wall surface (2), and a stepped furnace lining (4) is arranged around the area where the openings are provided on the water wall surface (2); the stepped furnace lining (4) is circumferentially continuous on the water wall surface (2).

2. The multi-stage cascade anti-wear furnace lining structure of a fluidized bed boiler according to claim 1, characterized in that: The types of the openings include secondary air inlets (3), feeding ports (5), and return material ports (6).

3. A multi-stage stepped wear-resistant furnace lining structure for a fluidized bed boiler according to claim 1, characterized in that: The edge of the stepped furnace lining (4) is in smooth transition with the water wall surface (2).

4. A multi-stage stepped wear-resistant furnace lining structure for a fluidized bed boiler according to claim 1, characterized in that: When there is an overlapping area in the height direction for different openings, only one stepped furnace lining (4) is correspondingly provided for the different openings with the overlapping area in height.

5. A multi-stage stepped anti-wear furnace lining structure for a fluidized bed boiler according to claim 1, characterized in that: The included angle a between the upper side of the stepped furnace lining (4) and the water wall surface (2) is 90° to 165°.

6. A multi-stage stepped anti-wear furnace lining structure for a fluidized bed boiler according to claim 1, characterized in that: The included angle b between the lower side of the stepped furnace lining (4) and the water wall surface (2) is 90° to 165°.

7. A multi-stage stepped anti-wear furnace lining structure for a fluidized bed boiler according to claim 1, characterized in that: The thickness d of the stepped furnace lining (4) is 10 to 300 mm.

8. A multi-stage stepped anti-wear furnace lining structure for a fluidized bed boiler according to any one of claims 1 to 7, characterized in that: The height of the upper side of the stepped furnace lining (4) is consistent at each point in the circumferential direction.

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