CFB (circulating fluid bed) boiler anti-abrasion device

Abstract

The utility model provides an anti-abrasion device for a CFB (circulating fluid bed) boiler. A plurality of water cooling wall pipes are vertically arranged on the inner wall of a hearth of the CFB boiler at intervals, a dense-phase area, a transition area and a dilute-phase area are sequentially arranged along the water cooling wall pipes from bottom to top, a plurality of anti-abrasion grid layers are arranged in the dense-phase area, the transition area and the dilute-phase area in the height direction of the water cooling wall pipes at intervals, and each anti-abrasion grid layer is defined by a plurality of Z-shaped anti-abrasion assemblies. Each Z-shaped anti-abrasion assembly is composed of two horizontal flow guide plates which are arranged in an up-down spaced mode and an inclined flow guide plate which is obliquely arranged between the two horizontal flow guide plates, and the arrangement density of the Z-shaped anti-abrasion assemblies of the dense-phase area, the transition area and the dilute-phase area is sequentially reduced. According to the CFB boiler anti-abrasion device, the surface flow field of the water cooling wall is optimized, local vortex, turbulent flow and various vector type airflow are eliminated, the adherence movement speed of gas-solid two-phase flow is reduced, the cutting force and chiseling force of material particles to the water cooling wall are reduced, and the abrasion problem of the water cooling wall is effectively controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler anti-wear, in particular to an anti-wear device for a CFB boiler. Background Art

[0002] Circulating fluidized bed combustion technology has unique advantages unparalleled by other combustion technologies in aspects such as alternative fuels, treatment of various wastes, and environmental protection. A circulating fluidized bed boiler is abbreviated as a CFB boiler. The water wall is the main heat-receiving part of the CFB boiler, which is mainly composed of a plurality of water wall tubes vertically and spacedly arranged on the inner wall of the furnace. The water wall enables the outside to receive the heat of the furnace flame through the flowing water or steam generated inside. However, the water wall will be worn by the particles in the furnace during use, thereby reducing its service life.

[0003] Currently, most CFB boilers adopt a multi-stage anti-wear device, which is mainly composed of pins and bosses made of refractory and wear-resistant materials. The bosses are fixed on the water wall through the pins, and the bosses are horizontally arranged in multiple stages at a certain interval along the height direction of the water wall. The above anti-wear device reduces the flow velocity of the materials near the wall of the furnace and reduces the wear of the heating surface to a certain extent. However, the above anti-wear device does not optimize the surface flow field of the water wall well, and cannot eliminate the adverse effects brought by local eddies, turbulences, and various vector-shaped airflows, resulting in limited anti-wear effect.

[0004] In view of this, the present utility model is specifically proposed. Summary of the Utility Model

[0005] The purpose of the present utility model is to provide an anti-wear device for a CFB boiler, which optimizes the surface flow field of the water wall, eliminates local eddies, turbulences, and various vector-shaped airflows, and realizes the long-term stable operation of the CFB boiler.

[0006] The present utility model provides an anti-wear device for a CFB boiler. A plurality of water wall tubes are vertically and spacedly arranged on the inner wall of the furnace of the CFB boiler. The plurality of water wall tubes are connected by fins. A dense phase region, a transition region, and a dilute phase region are sequentially arranged along the water wall tubes from bottom to top. Multiple layers of anti-wear grid layers are spacedly arranged along the height direction of the water wall tubes in the dense phase region, the transition region, and the dilute phase region respectively. Each layer of anti-wear grid layer is surrounded by a plurality of Z-shaped anti-wear components. Each Z-shaped anti-wear component is composed of two horizontally arranged guide plates spaced up and down and an inclined guide plate inclined between the two horizontally arranged guide plates. The setting density of the Z-shaped anti-wear components of the anti-wear grid layers in the dense phase region, the transition region, and the dilute phase region decreases in sequence.

[0007] Further, the dense phase region is the region from the cold ash hopper to 15 - 20 meters above it, the dilute phase region is the region from the separator outlet to 5 - 10 meters below it, and the transition region is the region between the dense phase region and the dilute phase region.

[0008] Further, the Z-shaped anti-wear components in the dense phase region, the transition region, and the dilute phase region have the same shape. The size of the Z-shaped anti-wear component in the transition region is 1.4 - 1.6 times that of the Z-shaped anti-wear component in the dense phase region, and the size of the Z-shaped anti-wear component in the dilute phase region is 1.9 - 2.1 times that of the Z-shaped anti-wear component in the dense phase region.

[0009] Further, a plurality of arc-shaped grooves matching the water-cooled wall tubes are arranged at intervals on the side of the horizontal deflector facing the water-cooled wall tubes. Arc transitions matching the water-cooled wall tubes are respectively arranged on both sides of the horizontal deflector, and the horizontal deflector is fixedly connected to the fin.

[0010] Further, more than one connecting plate is arranged at intervals on the side of the inclined deflector facing the water-cooled wall tubes. The two ends of the inclined deflector are respectively fixedly connected to the ends of two horizontal deflectors, and the connecting plate of the inclined deflector is fixedly connected to the fin.

[0011] Further, at least one row of air distribution holes is respectively arranged on the horizontal deflector and the inclined deflector. Each row of air distribution holes includes a plurality of air distribution holes arranged at intervals along the length direction.

[0012] Further, the shapes of the air distribution holes on the horizontal deflector and the inclined deflector are both circular. The diameters of the air distribution holes on the horizontal deflector and the inclined deflector are respectively 1 / 3 to 1 / 4 of the widths of the horizontal deflector and the inclined deflector, and the distance between adjacent air distribution holes is 3 - 5 times the diameter of the air distribution hole.

[0013] Further, more than two rows of air distribution holes are respectively arranged on the horizontal deflector and the inclined deflector, and the adjacent two rows of air distribution holes are arranged staggeredly.

[0014] Further, the multiple Z-shaped anti-wear components in each anti-wear grid layer are arranged mirror-symmetrically along the furnace center line.

[0015] Further, the horizontal deflector is arranged horizontally, and the inclination angle of the inclined deflector is 30 - 60 degrees.

[0016] In the utility model, a dense phase region, a transition region, and a dilute phase region are sequentially arranged from bottom to top along the water-cooled wall tubes of the CFB boiler. The setting density of the Z-shaped anti-wear components in the anti-wear grid layers in the dense phase region, the transition region, and the dilute phase region decreases in sequence, which can not only well meet the anti-wear requirements of each region, but also does not affect the heat exchange effect of the furnace. By setting the Z-shaped anti-wear components in a specific manner, the flow field on the surface of the water-cooled wall is optimized, local eddy currents, turbulences, and various vector-shaped airflows are eliminated, the wall attachment movement speed of the gas-solid two-phase flow is reduced, the cutting force and chiseling force of the material particles on the water-cooled wall are reduced, the wear problem of the water-cooled wall is effectively controlled, and the long-term stable operation of the CFB boiler is realized. Description of the Drawings

[0017] In order to more clearly illustrate the specific embodiments of the present utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of a CFB boiler;

[0019] Figure 2 It is a schematic structural diagram of a Z-shaped anti-wear component;

[0020] Figure 3 It is a schematic structural diagram of a horizontal deflector;

[0021] Figure 4 It is a schematic structural diagram of an inclined deflector.

[0022] Explanation of reference numerals:

[0023] 1: CFB boiler; 11: Dense phase zone; 12: Transition zone; 13: Lean phase zone; 14: Cold ash hopper; 15: Separator; 2: Water wall tube; 21: Fins; 22: Welding points; 3: Horizontal deflector; 31: Arc-shaped groove; 32: Arc transition; 33: Air distribution holes; 4: Inclined deflector; 41: Connecting plate; 42: Air distribution holes. Specific embodiments

[0024] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0025] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] The technical solutions of the present utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0027] Embodiment 1

[0028] Combined Figures 1 to 4 As shown, this embodiment provides an anti-abrasion device for a CFB boiler. The anti-abrasion device for the CFB boiler is arranged inside the CFB boiler 1, and the CFB boiler 1 is a conventional structure in the art. Specifically, the CFB boiler 1 includes a furnace, the cross-sectional shape of the furnace is rectangular, a plurality of water-cooled wall tubes 2 are vertically arranged at intervals around the inner wall of the furnace, the plurality of water-cooled wall tubes 2 are connected by fins 21, a cold ash hopper 14 is arranged at the bottom of the furnace, and a separator outlet is arranged at the upper part of the furnace. The separator outlet is connected to the separator 15.

[0029] Based on mathematical modeling and dynamic simulation technology, the operating state of the CFB boiler is simulated. Along the water-cooled wall tube 2, the dense phase zone 11, the transition zone 12, and the dilute phase zone 13 are sequentially arranged from bottom to top; specifically, the dense phase zone 11 is the area from the cold ash hopper 14 to 15 - 20 meters above it, the dilute phase zone 13 is the area from the separator outlet to 5 - 10 meters below it, and the transition zone 12 is the area between the dense phase zone 11 and the dilute phase zone 13.

[0030] In the dense phase zone 11, the transition zone 12, and the dilute phase zone 13, multiple layers of anti-abrasion grid layers are arranged at intervals along the height direction of the water-cooled wall tube 2. Each layer of anti-abrasion grid layer is surrounded by a plurality of Z-shaped anti-abrasion components. Specifically, each Z-shaped anti-abrasion component is composed of two horizontally deflector plates 3 (respectively called the upper horizontal deflector plate and the lower horizontal deflector plate) arranged at intervals up and down and an inclined deflector plate 4 arranged obliquely between the two horizontally deflector plates 3. The two horizontally deflector plates 3 and the inclined deflector plate 4 form a Z shape. The two horizontally deflector plates 3 of the Z-shaped anti-abrasion component are horizontally arranged, and the inclination angle of the inclined deflector plate 4 is 30 - 60 degrees, for example, 45 degrees.

[0031] A plurality of arc-shaped grooves 31 matching the water-cooled wall tube 2 are arranged at intervals on the side of the horizontally deflector plate 3 facing the water-cooled wall tube 2. Arc transitions 32 matching the water-cooled wall tube 2 are respectively arranged on both sides of the horizontally deflector plate 3. The arc-shaped grooves 31 and the arc transitions 32 of the horizontally deflector plate 3 are respectively arranged corresponding to the water-cooled wall tube 2 and do not fit with each other, avoiding the adverse effects such as the reduction of the heat transfer effect at the covered position and the increase of the furnace temperature caused by the horizontally deflector plate 3 covering the water-cooled wall tube 2. The arc transitions 32 of adjacent Z-shaped anti-abrasion components can be combined into 180 degrees, and the part between the arc-shaped grooves 31 and the arc transitions 32 of the horizontally deflector plate 3 is welded to the water-cooled wall tube 2 to form a welding point 22.

[0032] One or more connecting plates 41 are arranged at intervals on the side of the inclined deflector plate 4 facing the water-cooled wall tube 2. The two ends of the inclined deflector plate 4 are respectively fixedly connected to the two ends of the upper horizontal deflector plate and the lower horizontal deflector plate. The connecting plate 41 of the inclined deflector plate 4 is welded to the fin 21 to form a welding point 22. At the same time, the inclined deflector plate 4 does not fit closely with the water-cooled wall tube 2, avoiding the adverse effects such as the reduction of the heat transfer effect at the covered position and the increase of the furnace temperature caused by the inclined deflector plate 4 covering the water-cooled wall tube 2.

[0033] Further, at least one row of air distribution holes is arranged on the horizontal deflector plate 3 and the inclined deflector plate 4 respectively. Each row of air distribution holes on the horizontal deflector plate 3 and the inclined deflector plate 4 respectively includes a plurality of air distribution holes 33 and air distribution holes 42 arranged at intervals along the length direction. The shapes of the air distribution holes 33 and air distribution holes 42 on the horizontal deflector plate 3 and the inclined deflector plate 4 are both circular. The diameters of the air distribution holes 33 and air distribution holes 42 on the horizontal deflector plate 3 and the inclined deflector plate 4 are respectively 1 / 3 to 1 / 4 of the widths of the horizontal deflector plate 3 and the inclined deflector plate 4. The distances between adjacent air distribution holes 33 and air distribution holes 42 are respectively 3-5 times the diameters of the air distribution holes 33 and air distribution holes 42. In addition, when two or more rows of air distribution holes are arranged on the horizontal deflector plate 3 and the inclined deflector plate 4 respectively, the adjacent two rows of air distribution holes can be arranged staggeredly.

[0034] In each layer of the anti-wear grid layer, the upper horizontal deflector plates and the lower horizontal deflector plates of adjacent Z-shaped anti-wear components are respectively located on the same horizontal plane. The upper horizontal deflector plates and the lower horizontal deflector plates of adjacent Z-shaped anti-wear components are arranged adjacent to each other in sequence and are not welded to each other. In addition, the inclined deflector plates 4 of adjacent Z-shaped anti-wear components are arranged parallel to each other.

[0035] There is no strict limit on the number of layers of the anti-wear grid layer in the dense phase region 11, the transition region 12, and the dilute phase region 13, and it can be reasonably set according to the actual situation. Specifically, the number of layers of the anti-wear grid layer in the dense phase region 11 can be 2-3 layers, such as 2 layers; the number of layers of the anti-wear grid layer in the transition region 12 can be 8-10 layers, such as 9 layers; the number of layers of the anti-wear grid layer in the dilute phase region 13 can be 2-3 layers, such as 2 layers. In addition, the distance between adjacent two layers of the anti-wear grid layer can be about 1 / 2 of the height of the Z-shaped anti-wear component.

[0036] In particular, the setting densities of the Z-shaped anti-wear components in the dense phase region 11, the transition region 12, and the dilute phase region 13 decrease in sequence, that is, they are arranged in the way of being dense at the bottom and sparse at the top. Since the material concentrations in the dense phase region 11, the transition region 12, and the dilute phase region 13 decrease in sequence, and the overall wear degree of the heating surface also decreases in sequence, the setting method of being dense at the bottom and sparse at the top can not only well meet the anti-wear requirements of each region, but also does not affect the heat transfer effect of the furnace.

[0037] There is no strict restriction on setting the Z-shaped anti-wear components in the dense phase region 11, the transition region 12, and the dilute phase region 13 in a manner where the density decreases successively. For example, the setting density of the Z-shaped anti-wear components can be controlled by controlling the size of the Z-shaped anti-wear components. It can be understood that the larger the size of the Z-shaped anti-wear components, the fewer the number of Z-shaped anti-wear components set in each anti-wear grid layer, and the sparser the setting density of the Z-shaped anti-wear components; conversely, the smaller the size of the Z-shaped anti-wear components, the more the number of Z-shaped anti-wear components set in each anti-wear grid layer, and the denser the setting density of the Z-shaped anti-wear components.

[0038] The Z-shaped anti-wear components in the dense phase region 11, the transition region 12, and the dilute phase region 13 have the same shape. The size of the Z-shaped anti-wear components in the transition region 12 is 1.4 - 1.6 times, such as 1.5 times, the size of the Z-shaped anti-wear components in the dense phase region 11, and the size of the Z-shaped anti-wear components in the dilute phase region 13 is 1.9 - 2.1 times, such as 2 times, the size of the Z-shaped anti-wear components in the dense phase region 11. In addition, multiple Z-shaped anti-wear components in each anti-wear grid layer can be arranged mirror-symmetrically along the furnace centerline.

[0039] In this embodiment, the dense phase region 11, the transition region 12, and the dilute phase region 13 are sequentially arranged along the water-cooled wall tube 2 of the CFB boiler 1 from bottom to top. The setting density of the Z-shaped anti-wear components in the anti-wear grid layers of the dense phase region 11, the transition region 12, and the dilute phase region 13 decreases successively, which can not only well meet the anti-wear requirements of each region but also does not affect the heat exchange effect of the furnace. By setting the Z-shaped anti-wear components in a specific manner, the flow field on the water-cooled wall surface is optimized, local eddies, turbulences, and various vector-shaped airflows are eliminated, the wall-attached movement speed of the gas-solid two-phase flow is reduced, the wear of the water-cooled wall by flue gas, ash, and particles is minimized to the greatest extent, the wear problem of the water-cooled wall is effectively controlled, and the long-term stable operation of the CFB boiler is realized.

[0040] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A CFB boiler anti-abrasion device. A plurality of water-cooled wall tubes are vertically and spacedly arranged on the inner wall of the furnace of the CFB boiler, and the plurality of water-cooled wall tubes are connected by fins. It is characterized in that, A dense phase zone, a transition zone, and a dilute phase zone are sequentially arranged from bottom to top along the water-cooled wall tubes. Multiple layers of anti-wear grid layers are arranged at intervals along the height direction of the water-cooled wall tubes in the dense phase zone, the transition zone, and the dilute phase zone. Each layer of anti-wear grid layer is surrounded by a plurality of Z-shaped anti-wear components. Each Z-shaped anti-wear component is composed of two horizontally arranged guide plates spaced up and down and an inclined guide plate inclined between the two horizontally arranged guide plates. The setting density of the Z-shaped anti-wear components of the anti-wear grid layers in the dense phase zone, the transition zone, and the dilute phase zone decreases in sequence.

2. The CFB boiler anti-wear device according to claim 1, wherein The dense phase zone is the area from the cold ash hopper to 15 - 20 meters above it. The dilute phase zone is the area from the separator outlet to 5 - 10 meters below it. The transition zone is the area between the dense phase zone and the dilute phase zone.

3. The CFB boiler anti-wear device according to claim 1, characterized in that, The shapes of the Z-shaped anti-wear components in the dense phase zone, the transition zone, and the dilute phase zone are the same. The size of the Z-shaped anti-wear components in the transition zone is 1.4 - 1.6 times the size of the Z-shaped anti-wear components in the dense phase zone. The size of the Z-shaped anti-wear components in the dilute phase zone is 1.9 - 2.1 times the size of the Z-shaped anti-wear components in the dense phase zone.

4. The CFB boiler anti-wear device according to claim 1, characterized in that, A plurality of arc-shaped grooves matching the water-cooled wall tubes are arranged at intervals on the side of the horizontal guide plate facing the water-cooled wall tubes. Arc transitions matching the water-cooled wall tubes are respectively arranged on both sides of the horizontal guide plate. The horizontal guide plate is fixedly connected to the fin.

5. The CFB boiler anti-wear device according to claim 1, characterized in that, More than one connecting plate is arranged at intervals on the side of the inclined guide plate facing the water-cooled wall tubes. The two ends of the inclined guide plate are respectively fixedly connected to the ends of the two horizontal guide plates. The connecting plate of the inclined guide plate is fixedly connected to the fin.

6. The CFB boiler anti-wear device according to claim 1, characterized in that, At least one row of air distribution holes is respectively arranged on the horizontal guide plate and the inclined guide plate. Each row of air distribution holes includes a plurality of air distribution holes arranged at intervals along the length direction.

7. The CFB boiler anti-wear device according to claim 6, wherein, The shapes of the air distribution holes on the horizontal guide plate and the inclined guide plate are both circular. The diameters of the air distribution holes on the horizontal guide plate and the inclined guide plate are respectively 1 / 3 to 1 / 4 of the widths of the horizontal guide plate and the inclined guide plate. The distance between adjacent air distribution holes is 3 - 5 times the diameter of the air distribution holes.

8. The CFB boiler anti-wear device according to claim 6, characterized in that, More than two rows of air distribution holes are respectively arranged on the horizontal guide plate and the inclined guide plate. The adjacent two rows of air distribution holes are arranged staggeredly.

9. The CFB boiler abrasion prevention device according to claim 1, characterized in that, The plurality of Z-shaped anti-wear components in each layer of anti-wear grid layer are arranged mirror-symmetrically along the furnace center line.

10. The CFB boiler anti-wear device according to claim 1, characterized in that, The horizontal guide plate is horizontally arranged. The inclination angle of the inclined guide plate is 30 - 60 degrees.

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