A CFB boiler with a full-circuit metal grid anti-wear structure

Abstract

The present invention discloses a CFB boiler with a full-loop metal grid anti-wear structure, comprising a boiler body, a water-cooled wall arranged on the heating surface of the heat circulation loop in the boiler body, the water-cooled wall as an evaporation heating surface can be divided into a straight-wall evaporation heating surface, an inclined-wall evaporation heating surface and an eddy-current evaporation heating surface, the three evaporation heating surfaces are respectively provided with a first grid anti-wear structure, a second grid anti-wear structure and a third grid anti-wear structure, and a pipeline anti-wear protective tube is also provided on the pipeline heating surface in the boiler body, the grid anti-wear structure and the pipeline anti-wear protective tube are used to protect the wear surface in the boiler body from the whole and all-round perspective, thereby extending the service life of the boiler, and at the same time increasing the heating area, effectively improving the heat exchange capacity of each evaporation heating surface, and greatly improving the operating stability and efficiency of the boiler; according to the temperature control requirements, the welding angle of the grid anti-wear structure is automatically adjusted to increase or decrease the heat exchange area of ​​effective radiation heat exchange, so as to meet the deep peak regulation requirements of the boiler unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of wear-resistant protection of CFB boilers, and more specifically, relates to a CFB boiler with a full-circuit metal grid wear-resistant structure. Background Art

[0002] Circulating fluidized bed boiler (CFB boiler) is currently recognized as the most industrialized boiler in the world. Compared with pulverized coal boiler, it has the characteristics of environmental protection, energy saving and high efficiency, so it occupies an important position in the field of power generation. Due to the working characteristics of CFB boiler, a large amount of high-temperature and high-speed flue gas is generated in the furnace during operation. This flue gas contains many tiny material particles. Under the scouring of the material particles, the heating surface of the CFB boiler is seriously worn. Many boilers have heating surface wear and leakage after a short operation time. According to statistics, abnormal shutdowns caused by heating surface wear and leakage account for more than 50% of the total number of CFB boiler accident shutdowns, which seriously affects the use efficiency of CFB boilers.

[0003] In the actual operation of CFB boilers, the following problems still exist: (1) Under low load conditions, the boiler water circulation is poor, the steam-water fluidity is poor, and some water-cooled wall areas are prone to overheating; (2) During the peak load regulation of the boiler unit, the boiler operating conditions deviate greatly from the design conditions, and the boiler system operating efficiency is far lower than the design efficiency; (3) During the deep peak load regulation, as the load decreases, the amount of fuel decreases, the temperature will also decrease accordingly, and the temperature fluctuates greatly; 4) During the deep peak load regulation, the boiler unit load is maintained at 20%~40%, which is far lower than the existing operating load. Therefore, the wall flow field in the furnace will change, the wear area will shift, and new wear areas will be generated; (5) The boiler unit needs to have the ability to quickly regulate the peak, and the heat exchange capacity of each heating surface must be strengthened. However, the anti-wear method used in most of the wear-prone areas of the existing CFB boilers is still spraying or casting covering, which has poor heat transfer performance and insufficient heat exchange capacity.

[0004] Patent CN203927990U discloses a novel membrane-type advection wall grid structure for a CFB boiler, comprising a plurality of horizontal plate groups vertically spaced apart on the membrane wall, a plurality of vertical plate groups horizontally spaced apart between the two horizontal plate groups, the horizontal plate groups being composed of a plurality of wear-resistant alloy plates horizontally placed and welded on the membrane wall and overlapping each other, the vertical plate groups being composed of a plurality of vertically overlapped rectangular plates, one side of the rectangular plates being welded to the fins between the two membrane wall tubes, the grid structure of the patent preventing the airflow with particulate matter from directly scouring the tube wall, making the airflow in contact with the tube wall smooth and not affecting the heating of the tube wall, thereby extending the service life of the membrane wall tube, but the grid structure in the patent is only applicable to straight wall heating surfaces, and cannot cover other heating surfaces or heating pipes in the CFB boiler, such as inclined wall heating surfaces or heating pipes, and cannot reduce the wear of other areas, and the grid structure of the patent cannot be temperature-controlled, and local overheating will still occur. Summary of the invention

[0005] In view of the problems that the heating surface in the existing boiler is easy to wear, the heat exchange capacity is poor, and some areas are prone to overheating and abnormal noise, and the deep peak regulation of the boiler unit, the present invention provides a CFB boiler with a full-circuit metal grid anti-wear structure, which provides all-round protection for the heating surface of the boiler, increases the heat exchange capacity, and can also adjust the temperature to meet the needs of deep peak regulation of the boiler unit.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a CFB boiler with a full-circuit metal grid anti-wear structure, comprising a boiler body, a heat circulation circuit arranged in the boiler body, and a water-cooled wall arranged on the heating surface of the heat circulation circuit, wherein the water-cooled wall comprises a plurality of water-cooled wall tubes and fins connecting two adjacent water-cooled wall tubes, and the water-cooled wall as an evaporation heating surface can be divided into a straight-wall evaporation heating surface, an inclined-wall evaporation heating surface, and a vortex-type evaporation heating surface, and the CFB boiler also comprises: a first grid anti-wear structure arranged on the straight-wall evaporation heating surface for slowing down the wear of the water-cooled wall by flue gas, comprising a plurality of grid anti-wear horizontal plates and a first grid anti-wear vertical plate, and the angle between the first grid anti-wear structure and the straight-wall evaporation heating surface is adjusted to reduce The heat radiation area of ​​the water-cooled wall is reduced, and dust accumulation is prevented at the same time; the second grid anti-wear structure provided on the inclined wall evaporation heating surface reduces the impact force of the axial flue gas by adjusting the depression angle with the horizontal line, and prevents dust accumulation at the same time; the third grid anti-wear structure provided on the vortex type evaporation heating surface blocks the radial airflow to avoid the generation of vortices on the vortex type evaporation heating surface; and the pipeline anti-wear protective tube provided on the pipeline heating surface in the boiler body adjusts its bending angle according to the pipeline turning radius to fully cover the pipeline heating surface; the first grid anti-wear structure, the second grid anti-wear structure, the third grid anti-wear structure and the pipeline anti-wear protective tube are provided to perform full-circuit protection on the heating surface in the boiler body to prevent the heating surface from being worn.

[0007] Furthermore, the grille anti-wear horizontal plate is vertically arranged on the water-cooled wall, and its layout direction is perpendicular to the axial direction of the water-cooled wall tube, and multiple adjacent grille anti-wear horizontal plates are overlapped to form a grille anti-wear horizontal plate group; the first grille anti-wear vertical plate is vertically arranged on the fins of the water-cooled wall, and its layout direction is parallel to the axial direction of the water-cooled wall tube, and multiple adjacent first grille anti-wear vertical plates are overlapped to form a grille anti-wear vertical plate group; the grille anti-wear horizontal plate group and the grille anti-wear vertical plate group are interlaced to form a first grille anti-wear structure.

[0008] Preferably, the first grille anti-wear structure is tilted on the water-cooled wall, wherein: the angle between the windward surface of the grille anti-wear horizontal plate and the axial airflow direction is greater than 90°, and the angle between the windward surface of the first grille anti-wear vertical plate and the radial airflow direction is greater than 90°.

[0009] Furthermore, the grille anti-wear horizontal plate is a plate-like structure, which includes a flow stabilizing groove, an air hole, a left air hole, a right air hole and a horizontal plate welding groove, wherein: the air hole is arranged at the middle end of the bottom of the grille anti-wear horizontal plate, and its diameter is larger than the diameter of the water-cooled wall tube; the horizontal plate welding groove is arranged on both sides of the air hole; the left air hole and the right air hole are symmetrically arranged at both ends of the bottom of the grille anti-wear horizontal plate; the flow stabilizing groove is arranged at the top of the grille anti-wear horizontal plate.

[0010] Furthermore, the first grille anti-wear vertical plate is a plate-like structure, including a first vertical plate guide groove, an upper guide groove, a lower guide groove, an air-passing protrusion and a first vertical plate welding groove, wherein: the air-passing protrusion is arranged at the bottom of the first grille anti-wear vertical plate; the first vertical plate welding groove is arranged on the air-passing protrusion; the first vertical plate guide groove is arranged at the middle end of the top of the first grille anti-wear vertical plate; the upper guide groove is arranged at the upper end of the top of the first grille anti-wear vertical plate; the lower guide groove is arranged at the lower end of the top of the first grille anti-wear vertical plate.

[0011] Furthermore, the second grille anti-wear structure includes a plurality of grille anti-wear transverse plates and a second grille anti-wear vertical plate, wherein the depression angle range between the grille anti-wear transverse plate and the horizontal line is 10°-45°, the angle between the upper end and the bottom of the grille anti-wear transverse plate and the second grille anti-wear vertical plate is consistent with the angle between the grille anti-wear transverse plate and the inclined wall type evaporation heating surface, and the lower end of the second grille anti-wear vertical plate is parallel to the upper end.

[0012] Preferably, the depression angle between the grille anti-wear transverse plate and the horizontal line is 30°.

[0013] Furthermore, the third grille anti-wear structure includes multiple grille anti-wear horizontal plates and third grille anti-wear vertical plates, the third grille anti-wear vertical plates include anti-wear vertical plates and bending portions, the bending portions are fixedly arranged on the tops of the anti-wear vertical plates, and the angle between the windward surface and the radial airflow is greater than 90°.

[0014] Furthermore, the anti-wear protective tube is a tubular structure, and its diameter is adapted to the diameter of the pipeline in the boiler, and includes a protective tube body, a protective tube joint and a protective tube fixing bolt hole. The protective tube body adjusts the bending angle according to the turning radius of the pipeline and is sleeved on the pipeline. The diameter of the protective tube joint is larger than the diameter of the protective tube body. The protective tube joints of adjacent pipeline anti-wear protective tubes are sleeved on the protective tube body for tight connection. A protective tube fixing bolt hole is also provided on the top of the protective tube body.

[0015] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0016] (1) The CFB boiler with a full-circuit metal grid anti-wear structure of the present invention optimizes the full-circuit heat exchange of the boiler unit by providing a first grid anti-wear structure, a second grid anti-wear structure, a third grid anti-wear structure and a pipeline anti-wear protective pipe, thereby protecting the wear surface in the boiler body from the overall and all-round perspective, thereby extending the service life of the boiler.

[0017] (2) The CFB boiler with a full-circuit metal grid anti-wear structure of the present invention is provided with a first grid anti-wear structure, a second grid anti-wear structure, a third grid anti-wear structure and a pipeline anti-wear protective tube. These four types of structures are all cast from alloys with good thermal conductivity, and can transfer the received heat to the evaporating heating surface, thereby effectively improving the heat exchange capacity of each evaporating heating surface. The water-cooled wall serving as the evaporating heating surface does not need to be sprayed or covered with castables on its surface, so that its heat exchange capacity is no longer affected, the operation stability is higher, and its efficiency is greatly improved. The adjustment restrictions during the normal operation of the boiler are smaller, so that the time operation condition of the boiler reaches the design condition value.

[0018] (3) The CFB boiler with a full-circuit metal grid anti-wear structure of the present invention is provided with a grid structure and a water-cooled wall. When the boiler is operated at a low load, the heat exchange capacity of the overall evaporation heating surface is improved, and the overall temperature in the boiler is stabilized and the temperature fluctuation is small.

[0019] (4) The CFB boiler with a full-circuit metal grid anti-wear structure of the present invention effectively reduces the heat radiation area of ​​the parts prone to overheating through the grid anti-wear structure on each evaporating heating surface, and adjusts the temperature of each evaporating heating surface, so that the boiler unit as a whole can respond to the national call for deep peak regulation and adapt to the needs of rapid peak regulation and deep peak regulation without the occurrence of local overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a CFB boiler with a full-circuit metal grid anti-wear structure according to an embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the structure of the water-cooled wall in an embodiment of the present invention;

[0022] Figure 3 is a top view of the first grid anti-wear structure in an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the structure of the grille anti-wear horizontal plate in an embodiment of the present invention;

[0024] Figure 5 Schematic diagram of the structure of the first grille anti-wear vertical plate in an embodiment of the present invention;

[0025] Figure 6 is a side view of the second grid anti-wear structure in an embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of the layout of the third grid anti-wear vertical plate in an embodiment of the present invention;

[0027] Figure 8 It is a front view of the third grid anti-wear vertical plate in the embodiment of the present invention;

[0028] Fig. 9 A side view of a third grille anti-wear vertical plate in an embodiment of the present invention;

[0029] Fig.10 This is a schematic diagram of the layout of the pipeline anti-wear protection pipe in an embodiment of the present invention;

[0030] Fig.11 It is a schematic diagram of the structure of the pipeline anti-wear protective pipe in an embodiment of the present invention;

[0031] Fig.12 It is a cross-sectional view of the pipeline anti-wear protective pipe in an embodiment of the present invention.

[0032] In all the drawings, the same reference numerals represent the same technical features, specifically: 1- boiler body, 12- furnace, 13- water-cooled screen, 14- cyclone separator, 15- U-type return feeder, 16- vertical pipe, 17- superheater, 18- reheater, 19- economizer, 2- water-cooled wall, 21- water-cooled wall tube, 22- fin, 3- first grid anti-wear structure, 31- first grid anti-wear vertical plate, 311- first vertical plate guide groove, 312- upper end guide groove, 313- lower end guide groove, 314- first vertical plate welding groove, 315- gas convex Outlet, 4-second grille anti-wear structure, 41-second grille anti-wear vertical plate, 411-second vertical plate guide groove, 412-second vertical plate welding groove, 5-third grille anti-wear structure, 51-third grille anti-wear vertical plate, 511-wear-proof vertical plate, 512-bending portion, 513-third vertical plate welding groove, 6-pipe anti-wear protective pipe, 61-protective pipe body, 62-protective pipe joint, 63-protective pipe fixing bolt hole, 7-grid anti-wear horizontal plate, 71-steady flow groove, 72-air hole, 73-left air hole, 74-right air hole, 75-horizontal plate welding groove. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] like Figure 1-12 As shown, the present invention provides a CFB boiler with a full-circuit metal grid anti-wear structure, comprising a boiler body 1, a water-cooled wall 2 arranged on the heating surface of the heat circulation loop in the boiler body 1, the water-cooled wall 2 serving as an evaporation heating surface, playing a role in cooling and preventing the boiler heating surface from being worn; according to the direction of flue gas on each evaporation heating surface in the boiler body 1, the evaporation heating surface can be divided into an axial flow evaporation heating surface (i.e., the flue gas flows in a vertical direction) and a vortex evaporation heating surface (a vortex formed by axial and radial winds), wherein the axial flow evaporation heating surface includes a straight wall evaporation heating surface and an inclined wall evaporation heating surface. On the basis of each evaporating heating surface, the CFB boiler with a full-circuit metal grid anti-wear structure of the present invention further increases the heat exchange capacity and anti-wear effect by providing a variety of metal grid anti-structures: wherein the straight-wall evaporating heating surface is provided with a first grid anti-wear structure 3, the inclined-wall evaporating heating surface is provided with a second grid anti-wear structure 4, and the vortex-type evaporating heating surface is provided with a third grid anti-wear structure 5. By providing a variety of metal grid anti-structures, the heat circulation circuit in the boiler body 1 is fully protected, and the wear of the evaporating heating surface by particulate matter in the flue gas is effectively reduced. At the same time, the area of ​​the evaporating heating surface is also increased, and the heat exchange capacity of the evaporating heating surface is enhanced; further, by providing a pipe anti-wear protective tube 6 on the pipe in the boiler body 1, the wear surface in the boiler body 1 is protected from the overall and all-round perspective, thereby extending the service life of the boiler in the embodiment of the present invention.

[0035] like Figure 1-2As shown, in the embodiment of the present invention, the water-cooled wall 2 is a membrane water-cooled wall, including a plurality of water-cooled wall tubes 21 and fins 22 connecting two adjacent water-cooled wall tubes 21. In the boiler body 1, the furnace 12, the cyclone separator 14, the U-shaped returner 15 and the riser 16 constitute a heat circulation loop, and the heating surface of the whole loop is replaced by the water-cooled wall 2 instead of the original heating wall surface, so that the heat storage capacity of the whole loop is reduced, and the boiler body 1 can be heated up and cooled quickly, and the startup and shutdown cooling time of the CFB boiler of the present invention can be shortened, and the rapid peak regulation capability of the boiler unit is improved. Among them, the heating surface of the upper chamber wall of the furnace 12, the hanging screen of the water-cooled screen 13 and other parts are perpendicular to the horizontal plane, and the flue gas in contact flows axially, and the water-cooled wall 2 laid on them forms a straight wall evaporation heating surface; the heating surface of the dense phase area at the lower end of the furnace 12, the lower cone section of the cyclone separator 14 and other parts are inclined at a certain angle to the horizontal plane, and the flue gas in contact also flows axially, and the water-cooled wall 2 laid parallel thereon forms an inclined wall evaporation heating surface; the heating surface of the cyclone separator 14, the U-shaped return feeder 15, the vertical pipe 16 and the air outlet and other parts are simultaneously subjected to axial and radial winds, and the flue gas forms a vortex and contacts the heating surface, and the water-cooled wall 2 laid thereon forms a vortex evaporation heating surface. The bottom of the hanging screen of the water-cooled screen 13, the superheater 17, the reheater 18 and the economizer 19 and other pipeline structures are easy to wear, and the pipeline anti-wear protective tube 6 in the embodiment of the present invention is used to protect these parts.

[0036] like Figure 3-5 As shown, in the embodiment of the present invention, the first grille anti-wear structure 3 includes a grille anti-wear horizontal plate 7 and a first grille anti-wear vertical plate 31, wherein the grille anti-wear horizontal plate 7 is vertically arranged on the water-cooled wall 2, and its arrangement direction is perpendicular to the axial direction of the water-cooled wall tube 21, and a plurality of adjacent grille anti-wear horizontal plates 7 are overlapped to form a grille anti-wear horizontal plate group; the first grille anti-wear vertical plate 31 is vertically arranged on the fin 22 of the water-cooled wall 2, and its arrangement direction is parallel to the axial direction of the water-cooled wall tube 4, and a plurality of adjacent first grille anti-wear vertical plates 31 are overlapped to form a grille anti-wear vertical plate group, and the grille anti-wear horizontal plate group and the grille anti-wear vertical plate group are interlaced to form the first grille anti-wear structure 3. In the embodiment of the present invention, by providing the first grille anti-wear structure 3, the flue gas flowing in the vertical direction on the straight wall evaporation heating surface can be blocked from scouring the surface of the water-cooled wall 2, thereby preventing it from being worn and extending the service life of the boiler.

[0037] like Figure 4As shown, the grille anti-wear cross plate 7 is a plate-like structure, which includes a flow stabilizing groove 71, an air hole 72, a left air hole 73, a right air hole 74 and a cross plate welding groove 75 on the plate body, wherein the air hole 72 is arranged at the middle end of the bottom of the plate body, which is a semicircular irregular groove with a diameter slightly larger than the water-cooled wall tube 21 and can pass through the water-cooled wall tube 21; cross plate welding grooves 75 are provided on both sides of the air hole 72, and welding reinforcement is performed through the cross plate welding grooves 75 to achieve a fixed connection between the grille anti-wear cross plate 7 and the water-cooled wall 2; the grille anti-wear cross plate 77 is also symmetrically provided with a left air hole 73 and a right air hole 74 at both ends of the plate body bottom, and the two are respectively overlapped with the left air hole 73 and the right air hole 74 of the adjacent grille anti-wear cross plate 7 to form a semicircular irregular groove, whose diameter is consistent with the air hole 72 and can pass through the water-cooled wall tube 21. During installation, the air holes 72 are clamped on the top of the water-cooled wall tube 21, and the grid anti-wear horizontal plate 7 is vertically welded to the fin 22 through the horizontal plate welding groove 75. The left air holes 73 overlap with the right air holes 74 on the left adjacent grid anti-wear horizontal plate 7 above the water-cooled wall tube 21, and the right air holes 74 overlap with the left air holes 73 on the right adjacent grid anti-wear horizontal plate 7 above the water-cooled wall tube 21. In the embodiment of the present invention, the diameter of the air holes 72 is slightly larger than the water-cooled wall tube 21, so that there is a gap between the two, so that the hot air flow flows with the air holes 72, thereby increasing the heat exchange capacity of the water-cooled wall 2; by designing the air holes 72 as semicircular irregular grooves to reduce the angle between the air holes 72 and the relative air flow, the air flow can flow smoothly along the surface of the water-cooled wall 2 to prevent the generation of eddy currents. A flow stabilizing groove 71 is provided on the top of the grille anti-wear cross plate 7 to guide the high-speed airflow to pass smoothly, so that the solid particles in the airflow can flow downward through it, effectively avoiding the accumulation of solid particles on the grille anti-wear cross plate 7, and at the same time reducing the erosion of the grille anti-wear cross plate 7 itself, thereby protecting the transverse alloy plate 1 and extending its service life. Preferably, two groups of flow stabilizing grooves 71 can be symmetrically provided on the top of the plate body.

[0038] like Figure 5As shown, the first grid anti-wear vertical plate 31 is a plate-like structure, including a first vertical plate guide groove 311, an upper guide groove 312, a lower guide groove 313, a gas protrusion 315 and a first vertical plate welding groove 314 arranged on the plate body; wherein, a gas protrusion 315 is arranged at the bottom of the plate body, and the first vertical plate welding groove 314 arranged on the gas protrusion 315 is used for welding reinforcement to realize the fixed connection between the first grid anti-wear vertical plate 31 and the water-cooled wall 2, and a gap is left between the two sides of the gas protrusion 315 and the fins 22 to form an air flow channel, so that the hot air flow can flow along the air flow channel, thereby increasing the heating area of ​​the water-cooled wall 2 and enhancing the heat exchange capacity of the water-cooled wall. The first vertical plate guide groove 311 is arranged at the middle end of the top of the first grid anti-wear vertical plate 31, which is a semicircular groove, used to guide the radial air flow to pass smoothly and avoid the accumulation of solid particles in the air flow. Preferably, the first vertical plate guide groove 311 is provided with two groups. An upper guide groove 312 and a lower guide groove 313 are symmetrically provided at the upper and lower ends of the top of the first grille anti-wear vertical plate 31, respectively. The upper guide groove 312 and the lower guide groove 313 of adjacent first grille anti-wear vertical plates 31 overlap to form a semicircular groove, the diameter of which is the same as that of the first vertical plate guide groove 311.

[0039] In the boiler, heat is transferred from the boiler cavity to the water-cooled wall 2 in the form of radiation heat exchange (mostly) and convection heat exchange (a small part), and is absorbed and carried away by the water or steam-water mixture in the water-cooled wall tube 21. Therefore, by reducing the heat radiation area of ​​the water-cooled wall 2, its heat exchange capacity can be effectively weakened, the amount of heat absorbed by it can be reduced, and the temperature can be lowered, and vice versa. In the new preferred example of the present experiment, the first grid anti-wear structure 3 is welded and fixed as a whole to the surface of the water-cooled wall 2 perpendicularly at the part where heat exchange is required according to the needs of different parts in the boiler, thereby increasing the radiation heat exchange area of ​​the water-cooled wall 2 so that it absorbs more heat, and then the heat is taken away by the water and steam-water mixture in the water-cooled wall tube 21, avoiding the occurrence of overheating, so that the boiler unit needs to have the ability of rapid peak regulation, and at the same time, the operating efficiency of the boiler system is also increased; further, in the area of ​​the water-cooled wall 2 where the temperature is lower, the first grid anti-wear structure 3 is tilted as a whole at a certain angle to the water-cooled wall 2 for welding and fixing, wherein the angle between the windward surface of the grid anti-wear horizontal plate 7 and the axial airflow direction is greater than 90°, and the angle between the windward surface of the first grid anti-wear vertical plate 31 and the radial airflow direction is greater than 90°, and the actual angle can be adjusted according to the actual temperature of different parts, reducing the radiation heat exchange area of ​​the water-cooled wall 2 so that it absorbs less heat, thereby avoiding a decrease in the combustion efficiency of the boiler.

[0040] In the embodiment of the present invention, the second grid anti-wear structure 4 provided on the inclined wall type evaporation heating surface is as follows: Figure 6As shown, it includes a plurality of grid anti-wear horizontal plates 7 and a second grid anti-wear vertical plate 41. In order to avoid the accumulation of solid particles in the high-speed airflow on the grid anti-wear horizontal plate 7, the depression angle between the grid anti-wear horizontal plate 7 and the horizontal line is set in the range of 10°-45°, preferably 30°, which can effectively prevent the solid particles from vertically impacting the surface of the grid anti-wear horizontal plate 7 and causing wear on it; further, the angle between the upper end and the bottom of the second grid anti-wear vertical plate 41 is consistent with the angle between the grid anti-wear horizontal plate 7 and the inclined wall type evaporation heating surface, and the lower end of the second grid anti-wear vertical plate 41 is parallel to the upper end. By arranging the second grid anti-wear structure 4 in the dense phase area at the bottom of the furnace 12, the lower cone section of the cyclone separator 14 and other parts, the strong impact force caused by the dense flue gas and the large solid particle density in such parts is alleviated, and its inclined structure can guide the axial airflow to pass smoothly, while avoiding the influence of the accumulation of solid particles on the heat exchange capacity of the water-cooled wall 2.

[0041] In the embodiment of the present invention, the third grid anti-wear structure 5 provided on the eddy current evaporation heating surface is as follows: Figure 7-9 As shown, it includes a plurality of grid anti-wear horizontal plates 7 and a third grid anti-wear vertical plate 51. In order to prevent the strong radial airflow from merging with the axial airflow in the cyclone separator 14, the U-shaped return material 15, the vertical pipe 16 and the air outlet to form a vortex, the third grid anti-wear vertical plate 51 is provided with a bending portion 512 on the top to slow down the radial airflow, which can effectively avoid the generation of vortex and prevent the solid particles carried by it from sinking and causing wear on the water-cooled wall 2. The third grid anti-wear vertical plate 51 includes an anti-wear vertical plate 511 and a bending portion 512, wherein the bending portion 512 is fixedly arranged on the top of the anti-wear vertical plate 511, and the angle between its windward surface and the radial airflow is greater than 90°. By providing the third grid anti-wear vertical plate 5, while reducing wear, it avoids the sinking and accumulation of materials, which leads to a reduction in the radiation heat exchange area of ​​the water-cooled wall 2, thereby reducing the over-temperature phenomenon in the cyclone separator 14, the U-shaped return material 15, the vertical pipe 16 and the air outlet, etc., which is conducive to deep peak regulation of the boiler.

[0042] In the embodiment of the present invention, the pipeline anti-wear protective tube 6 provided on the pipeline is as follows Figure 10-12As shown, it is a tubular structure, and its diameter is compatible with the diameter of the pipeline in the boiler, and can be sleeved on the pipeline to protect the heating surface of the pipeline. The pipeline anti-wear protective tube 6 includes a protective tube body 61, a protective tube joint 62 and a protective tube fixing bolt hole 63, wherein the protective tube body 61 can adjust its bending angle according to the turning radius of the pipeline and be sleeved on the pipeline to fully cover the heating surface of the pipeline; the diameter of the protective tube joint 62 is larger than the diameter of the protective tube body 61, and the protective tube joints 62 of adjacent pipeline anti-wear protective tubes 6 can be sleeved on the protective tube body 61 for tight connection, and the heating surface of the pipeline is fully protected, which can avoid wear of the pipeline and extend the service life of the pipeline. The top of the protective tube body 61 is also provided with a protective tube fixing bolt hole 63, and the fixed connection between the pipeline anti-wear protective tube 6 and the pipeline can be achieved by bolts.

[0043] In the embodiment of the present invention, the whole-circuit heat exchange optimization transformation of the boiler unit is carried out by providing a first grid anti-wear structure 3, a second grid anti-wear structure 4, a third grid anti-wear structure 5 and a pipeline anti-wear protective tube 6. These four types of structures are all cast by alloys with good thermal conductivity, and the received heat can be transferred to the evaporation heating surface, effectively improving the heat exchange capacity of each evaporation heating surface; at the same time, the water-cooled wall 2 as the evaporation heating surface is protected by the first grid anti-wear structure 3, the second grid anti-wear structure 4, the third grid anti-wear structure 5 and the pipeline anti-wear protective tube 6, avoiding the wear of the flue gas on it, and there is no need to spray or cover the surface with castables, so that its heat exchange capacity It is no longer affected, its operation stability is higher, its efficiency is greatly improved, and the adjustment restrictions during normal operation of the boiler are smaller, so that the boiler's time operating conditions reach the design operating conditions; further, when the boiler is running at low load, due to the improvement of the heat exchange capacity of the overall evaporating heating surface, the overall temperature in the boiler increases accordingly and the temperature fluctuation is small; further, through the anti-wear structure of the grille on each evaporating heating surface, the radiation heat exchange area of ​​the parts prone to overheating is effectively increased, and the temperature of each evaporating heating surface is adjusted, so that the boiler unit as a whole can respond to the country's call for deep peak regulation and adapt to the needs of rapid peak regulation and deep peak regulation, and there will be no local overheating.

[0044] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A CFB boiler with a full-circuit metal grid anti-wear structure, comprising a boiler body (1), a heat circulation circuit arranged in the boiler body (1), and a water-cooled wall (2) arranged on the heating surface of the heat circulation circuit, wherein the water-cooled wall (2) comprises a plurality of water-cooled wall tubes (21) and fins (22) connecting two adjacent water-cooled wall tubes (21), and the water-cooled wall (2) as an evaporation heating surface can be divided into a straight wall evaporation heating surface, an inclined wall evaporation heating surface, and a vortex type evaporation heating surface, characterized in that: The CFB boiler further comprises: A first grille anti-wear structure (3) is provided on the straight-wall evaporation heating surface for preventing flue gas from wearing the water-cooled wall (2), and comprises a plurality of grille anti-wear transverse plates (7) and a first grille anti-wear vertical plate (31). The angle between the first grille anti-wear structure (3) and the straight-wall evaporation heating surface is adjusted to reduce the heat radiation area of ​​the water-cooled wall (2) and prevent dust accumulation. The grille anti-wear transverse plate (7) is vertically provided on the water-cooled wall (2), and its layout direction is parallel to the water-cooled wall. The axial directions of the tubes (21) intersect vertically, and a plurality of adjacent grille anti-wear horizontal plates (7) are overlapped to form a grille anti-wear horizontal plate group; the first grille anti-wear vertical plates (31) are vertically arranged on the fins (22) of the water-cooled wall (2), and the arrangement direction thereof is parallel to the axial direction of the water-cooled wall tubes (21); a plurality of adjacent first grille anti-wear vertical plates (31) are overlapped to form a grille anti-wear vertical plate group; the grille anti-wear horizontal plate group and the grille anti-wear vertical plate group are interlaced to form a first grille anti-wear structure (3); A second grille anti-wear structure (4) provided on the inclined wall type evaporation heating surface reduces axial flue gas impact force and prevents dust accumulation by adjusting the depression angle with respect to the horizontal line; the second grille anti-wear structure (4) comprises a plurality of grille anti-wear transverse plates (7) and second grille anti-wear vertical plates (41), wherein the depression angle between the grille anti-wear transverse plates (7) and the horizontal line ranges from 10° to 45°, the angle between the upper end and the bottom of the grille anti-wear transverse plates (7) and the second grille anti-wear vertical plates (41) is consistent with the angle between the grille anti-wear transverse plates (7) and the inclined wall type evaporation heating surface, and the lower end of the second grille anti-wear vertical plates (41) is parallel to the upper end; A third grille anti-wear structure (5) provided on the vortex-type evaporation heating surface, which blocks radial airflow to prevent the generation of vortices on the vortex-type evaporation heating surface; the third grille anti-wear structure (5) comprises a plurality of grille anti-wear transverse plates (7) and third grille anti-wear vertical plates (51); the third grille anti-wear vertical plates (51) comprise anti-wear vertical plates (511) and a bent portion (512); the bent portion (512) is fixedly provided on the top of the anti-wear vertical plates (511); the angle between the windward surface of the third grille anti-wear structure and the radial airflow is greater than 90°; and a pipe anti-wear protective tube (6) arranged on the pipe heating surface in the boiler body (1), which adjusts its bending angle according to the pipe turning radius to fully cover the pipe heating surface; the pipe anti-wear protective tube (6) is a tubular structure, the diameter of which matches the diameter of the pipe in the boiler, and comprises a protective tube body (61), a protective tube joint (62) and a protective tube fixing bolt hole (63); the protective tube body (61) adjusts its bending angle according to the pipe turning radius and is sleeved on the pipe; the diameter of the protective tube joint (62) is larger than the diameter of the protective tube body (61); the protective tube joints (62) of adjacent pipe anti-wear protective tubes (6) are sleeved on the protective tube body (61) to be tightly connected; and the top of the protective tube body (61) is also provided with a protective tube fixing bolt hole (63); By providing a first grid anti-wear structure (3), a second grid anti-wear structure (4), a third grid anti-wear structure (5) and a pipeline anti-wear protective pipe (6), the entire circuit in the boiler body (1) is protected to prevent the heating surface from being worn.

2. The CFB boiler with full-circuit metal grid anti-wear structure according to claim 1 is characterized in that: The first grille anti-wear structure (3) is tiltedly arranged on the water-cooled wall (2), wherein: the angle between the windward surface of the grille anti-wear horizontal plate (7) and the axial airflow direction is greater than 90 degrees, and the angle between the windward surface of the first grille anti-wear vertical plate (31) and the radial airflow direction is greater than 90 degrees.

3. The CFB boiler with a full-circuit metal grid anti-wear structure according to any one of claims 1-2, characterized in that: The grille anti-wear horizontal plate (7) is a plate-shaped structure, comprising a flow stabilizing groove (71), an air hole (72), a left air hole (73), a right air hole (74) and a horizontal plate welding groove (75), wherein: The air hole (72) is arranged at the middle end of the bottom of the grid anti-wear horizontal plate (7), and its diameter is larger than the diameter of the water-cooled wall tube (21); The horizontal plate welding grooves (75) are arranged on both sides of the air holes (72); The left air hole (73) and the right air hole (74) are symmetrically arranged at two ends of the bottom of the grille anti-wear horizontal plate (7); The flow stabilizing groove (71) is arranged on the top of the grille anti-wear horizontal plate (7).

4. The CFB boiler with a full-circuit metal grid anti-wear structure according to any one of claims 1-2, characterized in that: The first grille anti-wear vertical plate (31) is a plate-shaped structure, comprising a first vertical plate guide groove (311), an upper guide groove (312), a lower guide groove (313), an air passing protrusion (315) and a first vertical plate welding groove (314), wherein: The air-passing protrusion (315) is arranged at the bottom of the first grille anti-wear vertical plate (31); The first vertical plate welding groove (314) is arranged on the gas-permeable protrusion (315); The first vertical plate guide groove (311) is arranged at the middle end of the top of the first grid anti-wear vertical plate (31); The upper guide groove (312) is arranged at the upper end of the top of the first grille anti-wear vertical plate (31); The lower end guide groove (313) is arranged at the lower end of the top of the first grille anti-wear vertical plate (31).

5. The CFB boiler with full-circuit metal grid anti-wear structure according to claim 1 is characterized in that: The depression angle between the grille anti-wear transverse plate (7) and the horizontal line is 30°.

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