Abrasion-proof circulating fluidized bed boiler hearth

Abstract

The utility model discloses an anti-abrasion type circulating fluidized bed boiler furnace which comprises a primary air inlet pipeline, a primary air chamber, an air distribution plate, a bed layer area, a dense phase area, a transition area, a dilute phase area, a cyclone separator, a material returning mechanism, a water cooling wall, a downcomer, a steam pocket, a purified flue gas outlet, a coal feeder and an anti-abrasion grating. The hearth structure not only can thoroughly solve the problem of abrasion of the water cooling walls in the layer area and the dense-phase area, but also ensures that the circulating fluidized bed boiler can stably operate for a long time, and the availability of the circulating fluidized bed boiler is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of anti-wear of circulating fluidized beds, in particular to an anti-wear type circulating fluidized bed boiler furnace. Background Art

[0002] The circulating fluidized bed boiler is a high-efficiency, low-pollution furnace type developed after the chain furnace and pulverized coal furnace. It has the advantages of high combustion efficiency, wide adaptability to coal types, large load adjustment range, low nitrogen oxide emissions, and easy desulfurization. Because the concentration and particle size of solid materials used in the circulating fluidized bed boiler are much larger than those in the pulverized coal furnace, the wear of the circulating fluidized bed boiler is much more serious than that of the pulverized coal furnace. The problem of water-cooled wall wear is more prominent, which seriously restricts the long-term economic operation of this furnace type and directly affects the availability of the circulating fluidized bed boiler unit. Utility Model Content

[0003] In order to solve the above technical problems, the purpose of the utility model is to provide a wear-resistant circulating fluidized bed boiler furnace.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] The utility model discloses a wear-resistant circulating fluidized bed boiler furnace, comprising a primary air inlet duct, a primary air chamber, an air distribution plate, a bed zone, a dense phase zone, a transition zone, a dilute phase zone, a cyclone separator, a material return mechanism, a water-cooled wall, a downcomer, a steam drum, a clean flue gas outlet, and a coal feeder;

[0006] The fuel is fed into the bed layer area of ​​the furnace of the circulating fluidized bed boiler through the coal feeder, the primary air is fed into the primary air chamber at the bottom of the air distribution plate through the primary air inlet pipe, and the primary air is fed into the furnace through the air distribution plate;

[0007] The fuel boils and burns under the action of the primary air, and the large coal particles and the fuel continuously wash the heat-insulating bricks and the wear-resistant castable layer in the bed area and the dense phase area of ​​the furnace;

[0008] The fuel and hot flue gas flow into the transition zone and the dilute phase zone in sequence, the water-cooled walls are arranged in these two zones, and the fuel and hot flue gas flush these two zones in sequence;

[0009] The fuel and hot flue gas enter the cyclone separator, and the clean flue gas is sent to the rear heating surface of the circulating fluidized bed boiler through the clean flue gas outlet; the large particles of fuel are sent back to the bed area of ​​the circulating fluidized bed boiler through the return mechanism under the action of the cyclone separator to participate in combustion again;

[0010] Three anti-wear beams are arranged horizontally in the transition zone, and anti-wear grilles are installed in the horizontal and vertical directions of the water-cooled wall of the transition zone; anti-wear grilles are installed in the horizontal and vertical directions of the water-cooled wall of the dilute phase zone;

[0011] The water-cooled wall, downcomer and steam drum constitute the evaporation system of the circulating fluidized bed boiler.

[0012] Furthermore, the air distribution plate includes a hood.

[0013] Furthermore, the inner circumference of the furnace is sequentially laid with heat-insulating bricks, a wear-resistant castable layer, and a heat-insulating layer.

[0014] Furthermore, the vertical spacing between each of the anti-wear beams is 2m, the grid spacing in the transition zone is 400mm, and the grid spacing in the freeboard zone is 800mm.

[0015] Furthermore, although water-cooled walls are installed in the transition zone and the dilute phase zone, the anti-wear beams and anti-wear grids arranged in these areas can effectively prevent the fuel and hot flue gas from scouring the water-cooled walls in these two areas.

[0016] Furthermore, the anti-wear beam leaves an expansion gap.

[0017] Furthermore, secondary air nozzles are installed around the dense phase zone.

[0018] Furthermore, a furnace expansion joint is installed between the dense phase zone and the transition zone.

[0019] Furthermore, the water-cooled wall lower header is arranged above the furnace expansion joint.

[0020] Compared with the prior art, the beneficial technical effects of the utility model are:

[0021] 1. The utility model provides a method for manufacturing a wear-resistant circulating fluidized bed boiler furnace. The wear area of ​​the circulating fluidized bed water-cooled wall mainly occurs in the bed area and the dense phase area. The utility model does not arrange the water-cooled wall heating surface in the bed area and the dense phase area. Although a small amount of thermal efficiency of the boiler will be lost, it can completely solve the water-cooled wall wear problem in these two areas;

[0022] 2. The utility model provides a method for manufacturing a wear-resistant circulating fluidized bed boiler furnace. The wear problem in the transition zone and the dilute phase zone is not as serious as that in the bed zone and the dense phase zone. The use of anti-wear grid technology and anti-wear beam technology in these two areas ensures that the circulating fluidized bed boiler can operate stably for a long time, greatly improving the availability of the circulating fluidized bed boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The utility model will be further described below in conjunction with the accompanying drawings.

[0024] Figure 1 Schematic diagram of the structure of the wear-resistant circulating fluidized bed boiler furnace

[0025] Figure 2A partial enlarged view of the furnace of a wear-resistant circulating fluidized bed boiler

[0026] Figure 3 A top view of the furnace bed area of ​​a wear-resistant circulating fluidized bed boiler

[0027] Figure 4 A top view of the transition zone of the furnace of a wear-resistant circulating fluidized bed boiler

[0028] Figure 5 This is a schematic diagram of the installation of the wear-resistant circulating fluidized bed boiler furnace wear-resistant grid;

[0029] Explanation of the reference numerals: 1. primary air inlet duct; 2. primary air chamber; 3. air distribution plate; 31. wind hood; 4. bed zone; 5. dense phase zone; 51. secondary air nozzle; 52. thermal insulation bricks, wear-resistant casting layer; 53. insulation layer; 6. transition zone; 61. water-cooled wall lower header; 62. anti-wear beam; 63. expansion gap; 64. furnace expansion joint; 7. dilute phase zone; 8. cyclone separator; 9. return mechanism; 10. water-cooled wall; 11. downcomer; 12. steam drum; 13. clean flue gas outlet; 14. coal feeder; 15. anti-wear grille. DETAILED DESCRIPTION

[0030] like Figures 1 to 5 As shown, a wear-resistant circulating fluidized bed boiler furnace includes a primary air inlet duct 1, a primary air chamber 2, an air distribution plate 3, a hood 31, a bed area 4, a dense phase area 5, a secondary air nozzle 51, thermal insulation bricks, a wear-resistant castable layer 52, an insulation layer 53, a transition area 6, a water-cooled wall lower header 61, an anti-wear beam 62, an expansion gap 63, a furnace expansion joint 64, a dilute phase area 7, a cyclone separator 8, a return mechanism 9, a water-cooled wall 10, a downcomer 11, a steam drum 12, a clean flue gas outlet 13, a coal feeder 14, and an anti-wear grid 15.

[0031] The circulating fluidized bed furnace structure is divided into a bed zone 4, a dense phase zone 5, a transition zone 6, and a dilute phase zone 7;

[0032] The bed area 4 and the air distribution plate 3 are not equipped with water-cooled walls, and only the heat-insulating bricks, the wear-resistant casting material layer 52 and the heat-insulating layer 53 are sequentially laid on the furnace side;

[0033] The dense phase area is not equipped with a water-cooled wall, and only thermal insulation bricks, a wear-resistant castable layer 52, and a thermal insulation layer 53 are sequentially laid on the furnace side;

[0034] Secondary air nozzles are installed around the dense phase zone 5, and a furnace expansion joint is installed between the dense phase zone and the transition zone;

[0035] The transition zone 6 and the dilute phase zone 7 are provided with a water-cooled wall 10, and the water-cooled wall lower header 61 is arranged above the furnace expansion joint 64;

[0036] The water-cooled wall 10, the downcomer 11, and the steam drum 12 constitute the evaporation system of the circulating fluidized bed boiler;

[0037] The water-cooled walls 10 of the transition zone 6 and the freeboard zone 7 are provided with anti-wear grilles 15 in the transverse and longitudinal directions. The spacing of the anti-wear grilles in the transition zone 6 is 400 mm, and the spacing of the anti-wear grilles in the freeboard zone 7 is 800 mm;

[0038] Three anti-wear beams 62 are arranged around the furnace of the transition zone 6, and the vertical spacing between the anti-wear beams is 2m;

[0039] The anti-wear beam 62 leaves an expansion gap 63 .

[0040] The working principle and use process of this utility model:

[0041] The fuel is fed into the bed area 4 of the furnace of the circulating fluidized bed boiler through the coal feeder 14, and the primary air is fed into the primary air chamber 2 at the bottom of the air distribution plate 3 through the primary air inlet pipe 1; the primary air is fed into the furnace through the air distribution plate 3 and the air cap 31;

[0042] The fuel boils and burns under the action of the primary air, and the large coal particles and the fuel continuously wash the heat-insulating bricks and the wear-resistant castable layer 52 in the furnace bed area 4 and the dense phase area 5;

[0043] The water-cooled wall 10 is not installed in the bed zone 4 and the dense phase zone 5, so there will be no wear problem of the water-cooled wall in these two areas;

[0044] The fuel and hot flue gas flow into the transition zone 6 and the dilute phase zone 7 in sequence. The water-cooled wall 10 is arranged in this zone. The fuel and hot flue gas flush the two zones in sequence.

[0045] Three anti-wear beams 62 are arranged horizontally in the transition zone 6, and the vertical spacing of each anti-wear beam 62 is 2m. The water-cooled wall 10 in the transition zone 6 is installed with anti-wear grids 15 in the horizontal and vertical directions, and the grid spacing is 400mm. The water-cooled wall 10 in the dilute phase zone 7 is installed with anti-wear grids 15 in the horizontal and vertical directions, and the grid spacing is 800mm;

[0046] Although the transition zone 6 and the dilute phase zone 7 are equipped with water-cooled walls 10, the anti-wear beams 62 and anti-wear grids 15 arranged in these areas can effectively prevent the fuel and hot flue gas from scouring the water-cooled walls in these two areas;

[0047] The fuel and hot flue gas enter the cyclone separator 8, and the clean flue gas is sent to the rear heating surface of the circulating fluidized bed boiler through the clean flue gas outlet 13. The large particles of fuel are sent back to the bed area 4 of the circulating fluidized bed boiler through the return mechanism 9 under the action of the cyclone separator 8 to participate in combustion again.

[0048] The embodiments described above are only descriptions of the preferred methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A wear-resistant circulating fluidized bed boiler furnace, characterized in that: It comprises a primary air inlet duct (1), a primary air chamber (2), an air distribution plate (3), a bed zone (4), a dense phase zone (5), a transition zone (6), a dilute phase zone (7), a cyclone separator (8), a material return mechanism (9), a water-cooled wall (10), a downcomer (11), a steam drum (12), a clean flue gas outlet (13), a coal feeder (14), and an anti-wear grille (15); The fuel is fed into the bed area (4) of the furnace of the circulating fluidized bed boiler through a coal feeder (14), the primary air is fed into the primary air chamber (2) at the bottom of the air distribution plate (3) through the primary air inlet pipe (1), and the primary air is then fed into the furnace through the air distribution plate (3); The fuel boils and burns under the action of the primary air, and the large coal particles and the fuel continuously wash the heat-insulating bricks and the wear-resistant castable layer (52) in the bed area (4) and the dense phase area (5) of the furnace; The fuel and the hot flue gas flow into the transition zone (6) and the dilute phase zone (7) in sequence, the water-cooled wall (10) being arranged in these two zones, and the fuel and the hot flue gas flush these two zones in sequence; The fuel and hot flue gas enter the cyclone separator (8), and the clean flue gas is sent to the rear heating surface of the circulating fluidized bed boiler through the clean flue gas outlet (13); large particles of fuel are sent back to the bed area (4) of the circulating fluidized bed boiler through the return mechanism (9) under the action of the cyclone separator (8) to participate in combustion again; Three anti-wear beams (62) are arranged horizontally in the transition zone (6); the anti-wear grilles (15) are installed in the water-cooled wall (10) of the transition zone (6) in both the horizontal and vertical directions; the anti-wear grilles (15) are installed in the water-cooled wall (10) of the freeboard zone (7) in both the horizontal and vertical directions; The water-cooled wall (10), the downcomer (11), and the steam drum (12) constitute an evaporation system of a circulating fluidized bed boiler.

2. The wear-resistant circulating fluidized bed boiler furnace according to claim 1, characterized in that: The air distribution plate (3) comprises a wind cap (31).

3. The wear-resistant circulating fluidized bed boiler furnace according to claim 1, characterized in that: The heat insulating bricks, the wear-resistant castable material layer (52), and the heat insulating layer (53) are sequentially laid on the inner circumference of the furnace.

4. The wear-resistant circulating fluidized bed boiler furnace according to claim 1, characterized in that: The vertical spacing of each anti-wear beam (62) is 2m, the grid spacing of the transition zone (6) is 400mm, and the grid spacing of the freeboard zone (7) is 800mm.

5. The wear-resistant circulating fluidized bed boiler furnace according to claim 1, characterized in that: The anti-wear beam (62) leaves an expansion gap (63).

6. The wear-resistant circulating fluidized bed boiler furnace according to claim 1, characterized in that: Secondary air nozzles (51) are installed around the dense phase zone (5).

7. The wear-resistant circulating fluidized bed boiler furnace according to claim 1, characterized in that: A furnace expansion joint (64) is installed between the dense phase zone (5) and the transition zone (6).

8. The wear-resistant circulating fluidized bed boiler furnace according to claim 7, characterized in that: A water-cooled wall lower header (61) is arranged above the furnace expansion joint (64).

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