A circulating fluidized bed boiler with flexibility improving structure

Abstract

The utility model discloses a circulating fluidized bed boiler with flexible lifting structure, including coal bunker, feed pipe, second valve, air outlet, first support, cyclone separator, back material pipe, air outlet pipe, third valve, second support, flue, superheater, reheater, coal economizer, primary air inlet pipe and fourth valve, the coal bunker is fixedly connected with the feed pipe on, and the one end of feed pipe is connected with the hearth of conduction, and the inner wall of hearth is fixedly connected with the fixed plate, and the fixed plate is opened with the airflow ascending hole, and the fixed plate is fixedly connected with the venturi tube, the utility model discloses adjustable air duct structure, through setting adjustable venturi tube of opening cross section area size, can flexible adjustment primary air speed, thereby adapt to the fluidization demand under different load, reduce the wind speed when low load, improve the wind speed when high load, prevent the bed material deposition or the particle excessive inclusion caused by the wind speed of not enough too high wind speed.

Description

Technical Field

[0001] This utility model relates to the field of circulating fluidized bed boiler technology, and in particular to a circulating fluidized bed boiler with a flexible lifting structure. Background Technology

[0002] Circulating fluidized bed boilers are a type of high-efficiency and clean combustion technology equipment with significant advantages such as wide fuel adaptability, high combustion efficiency, and low pollutant emissions. They use high-speed airflow to keep the bed material in a fluidized state, forming a combustion environment with strong gas-solid two-phase mixing, which significantly enhances the heat and mass transfer process. The unique material circulation system enables multiple return of unburned particles to ensure complete combustion. It can efficiently burn a variety of fuels such as low-quality coal, coal gangue, and biomass. It has strong tolerance for fuel calorific value, volatile matter, and ash content, and is particularly suitable for handling fuels with high ash and high sulfur content that are difficult to utilize in traditional boilers.

[0003] Existing circulating fluidized bed boilers have the following defects: First, they cannot accurately control the particle concentration entering the cyclone separator. Sudden changes in circulating ash lead to bed temperature fluctuations, reduced combustion efficiency, and low flexibility. Second, the fixed air duct structure results in poor load regulation capability. The primary air velocity cannot be dynamically adjusted. At low loads, the air velocity is too high, leading to excessive particle entrainment and uncontrolled circulating ash. At high loads, the air velocity is insufficient, causing bed material deposition. Utility Model Content

[0004] The purpose of this invention is to provide a circulating fluidized bed boiler with a flexible lifting structure to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, this utility model provides the following technical solution: a circulating fluidized bed boiler with a flexible lifting structure, including a coal bunker, a feed pipe fixedly connected to the coal bunker, one end of the feed pipe being connected to a furnace, a fixed plate fixedly connected to the inner wall of the furnace, an airflow rising hole opened on the fixed plate, a venturi tube fixedly connected to the fixed plate, a cross-section adjustment plate provided inside the venturi tube, a rotating shaft fixedly connected to the cross-section adjustment plate and rotatably connected to the fixed plate, an adjusting motor fixedly connected to one side of the outer wall of the furnace, and one end of the rotating shaft fixedly connected to the output end of the adjusting motor.

[0006] As a further technical solution of this utility model, an air outlet is fixedly connected to the outer wall of the furnace, a cyclone separator is conductively connected to the air outlet, a return pipe is conductively connected to the bottom end of the cyclone separator, and the other end of the return pipe is conductively connected to the inside of the furnace.

[0007] As a further technical solution of this utility model, the top end of the cyclone separator is connected to an air outlet pipe, the other end of the air outlet pipe is connected to a flue, a superheater, a reheater and an economizer are fixedly connected to the flue, a primary air inlet pipe is fixedly connected to the outer wall of the flue, and the other end of the primary air inlet pipe is connected to the furnace.

[0008] As a further technical solution of this utility model, a first valve is fixedly connected to the feed pipe.

[0009] As a further technical solution of this utility model, a secondary air inlet pipe is fixedly connected to one side of the outer wall of the furnace, and a second valve is fixedly connected to the secondary air inlet pipe.

[0010] As a further technical solution of this utility model, a first support is fixedly connected to the cyclone separator, and a third valve is fixedly connected to the return pipe.

[0011] As a further technical solution of this utility model, a second bracket is fixedly connected to the flue, and a fourth valve is fixedly connected to the primary air inlet pipe.

[0012] Compared with the prior art, the beneficial effects achieved by this utility model are as follows: This utility model is designed with an adjustable air duct structure. By setting a Venturi tube with an adjustable opening cross-sectional area, the primary air velocity can be flexibly adjusted to adapt to the fluidization requirements under different loads. The air velocity is reduced at low loads and increased at high loads to prevent bed material deposition due to insufficient air velocity or excessive particle entrainment due to excessive air velocity. At the same time, the contraction-expansion structure of the Venturi tube can enhance the airflow's ability to carry particles. Adjusting the opening size can accurately control the particle concentration entering the cyclone separator, maintain a stable circulating material quantity, and avoid bed temperature fluctuations or combustion efficiency reduction caused by sudden changes in circulating ash content, thus significantly improving the flexibility of the circulating fluidized bed boiler. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model;

[0015] Figure 2 This is a schematic diagram of the overall front view of the present invention;

[0016] Figure 3 This is a top view of the overall structure of this utility model;

[0017] Figure 4 This is a three-dimensional cross-sectional view of the furnace chamber of this utility model.

[0018] In the diagram: 1. Coal bunker; 2. Feed pipe; 3. First valve; 4. Furnace; 5. Fixed plate; 6. Airflow riser hole; 7. Venturi tube; 8. Cross-section adjustment plate; 9. Adjustment motor; 10. Rotating shaft; 11. Secondary air inlet pipe; 12. Second valve; 13. Air outlet; 14. First support; 15. Cyclone separator; 16. Return pipe; 17. Air outlet pipe; 18. Third valve; 19. Second support; 20. Flue; 21. Superheater; 22. Reheater; 23. Economizer; 24. Primary air inlet pipe; 25. Fourth valve. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] Please see the appendix Figure 1 -Appendix Figure 4This utility model provides an embodiment of a circulating fluidized bed boiler with a flexible lifting structure, comprising a coal bunker 1, a feed pipe 2 fixedly connected to the coal bunker 1, one end of the feed pipe 2 being conductively connected to a furnace 4, a fixed plate 5 fixedly connected to the inner wall of the furnace 4, an airflow rising hole 6 opened on the fixed plate 5, a venturi tube 7 fixedly connected to the fixed plate 5, a cross-section adjusting plate 8 disposed inside the venturi tube 7, a rotating shaft 10 fixedly connected to the cross-section adjusting plate 8, and the rotating shaft 10 being rotatably connected to the fixed plate 5, and an adjusting motor 9 fixedly connected to one side of the outer wall of the furnace 4. One end of the rotating shaft 10 is fixedly connected to the output end of the regulating motor 9; an air outlet 13 is fixedly connected to the outer wall of the furnace 4, and a cyclone separator 15 is connected to the air outlet 13. The bottom end of the cyclone separator 15 is connected to a return pipe 16, and the other end of the return pipe 16 is connected to the inside of the furnace 4. The flue gas carrying unburned particles enters the cyclone separator 15 tangentially through the air outlet 13, and gas-solid separation is achieved under the action of centrifugal force. The ash particles collected by the cyclone separator 15 are returned to the furnace 4 through the return pipe 16. The third valve 18 controls the circulation by adjusting the air volume. Ash content; the top of the cyclone separator 15 is connected to an air outlet pipe 17, and the other end of the air outlet pipe 17 is connected to a flue 20. A superheater 21, a reheater 22, and an economizer 23 are fixedly connected to the flue 20. A primary air inlet pipe 24 is fixedly connected to the outer wall of the flue 20, and the other end of the primary air inlet pipe 24 is connected to the furnace 4. Flue gas enters the flue 20 through the air outlet pipe 17, and the flue gas passes through the superheater 21, reheater 22, and economizer 23 in sequence for heat recovery. A first valve 3 is fixedly connected to the feed pipe 2. On one side of the outer wall of the furnace 4... A secondary air inlet pipe 11 is fixedly connected, and a second valve 12 is fixedly connected to the secondary air inlet pipe 11; a first support 14 is fixedly connected to the cyclone separator 15, and a third valve 18 is fixedly connected to the return material pipe 16; a second support 19 is fixedly connected to the flue 20, and a fourth valve 25 is fixedly connected to the primary air inlet pipe 24. The first support 14 and the second support 19 are used to fix the cyclone separator 15 and the flue 20, respectively. The ratio of primary air inlet to secondary air inlet is adjusted by the fourth valve 25 and the second valve 12 to maintain the bed temperature and balance desulfurization efficiency and NOx generation inhibition.

[0021] Working Principle: In the fluidized combustion process using this invention, coal bunker 1 is fed into furnace 4 through feed pipe 2. The feed rate is controlled by the first valve 3. Air is introduced through the primary air inlet pipe 24 to fluidize the bed material, forming a dense phase combustion core zone and a dilute suspension combustion zone. The coal rises through the air riser hole 6 and Venturi tube 7 on the fixed plate 5. Secondary air is introduced through the secondary air inlet pipe 11 to supplement the oxygen required for combustion in the dense phase zone and enhance the material disturbance in the dilute phase zone. The oxygen content at the furnace 4 outlet is controlled at 3%-5%. The ratio of primary and secondary air is adjusted by the fourth valve 25 and the second valve 12 to maintain the bed temperature, balancing desulfurization efficiency and NOx generation inhibition. The flue gas carrying unburned particles enters the cyclone separator 15 tangentially through the air outlet 13, where centrifugal force... The cyclone separator 15 collects ash particles and returns them to the furnace 4 through the return pipe 16. The third valve 18 controls the amount of circulating ash by adjusting the air volume. The flue gas enters the flue 20 through the outlet pipe 17. The flue gas passes through the superheater 21, reheater 22 and economizer 23 in sequence for heat recovery. During the process, the regulating motor 9 controls the rotation of the cross-section regulating plate 8 through the rotating shaft 10 to adjust the opening area at the bottom of the venturi tube 7. The primary air velocity can be flexibly adjusted to adapt to the fluidization requirements under different loads. The air velocity is reduced at low loads and increased at high loads to prevent bed material deposition due to insufficient air velocity or excessive particle entrainment due to excessive air velocity. The first support 14 and the second support 19 are used to fix the cyclone separator 15 and the flue 20, respectively.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A circulating fluidized bed boiler with a flexible lifting structure, comprising a coal bunker (1), characterized in that: The coal bunker (1) is fixedly connected to a feed pipe (2), one end of which is connected to a furnace (4). A fixed plate (5) is fixedly connected to the inner wall of the furnace (4). An airflow rising hole (6) is opened on the fixed plate (5). A venturi tube (7) is fixedly connected to the fixed plate (5). A cross-section adjustment plate (8) is installed inside the venturi tube (7). A rotating shaft (10) is fixedly connected to the cross-section adjustment plate (8), and the rotating shaft (10) is rotatably connected to the fixed plate (5). An adjusting motor (9) is fixedly connected to one side of the outer wall of the furnace (4), and one end of the rotating shaft (10) is fixedly connected to the output end of the adjusting motor (9).

2. A circulating fluidized bed boiler with a flexible lifting structure according to claim 1, characterized in that: An air outlet (13) is fixedly connected to the outer wall of the furnace (4). A cyclone separator (15) is connected to the air outlet (13). A return pipe (16) is connected to the bottom end of the cyclone separator (15), and the other end of the return pipe (16) is connected to the inside of the furnace (4).

3. A circulating fluidized bed boiler with a flexible lifting structure according to claim 2, characterized in that: The top of the cyclone separator (15) is connected to an air outlet pipe (17), and the other end of the air outlet pipe (17) is connected to a flue (20). A superheater (21), a reheater (22) and an economizer (23) are fixedly connected to the flue (20). A primary air inlet pipe (24) is fixedly connected to the outer wall of the flue (20), and the other end of the primary air inlet pipe (24) is connected to the furnace (4).

4. A circulating fluidized bed boiler with a flexible lifting structure according to claim 1, characterized in that: The feed pipe (2) is fixedly connected to a first valve (3).

5. A circulating fluidized bed boiler with a flexible lifting structure according to claim 1, characterized in that: A secondary air inlet pipe (11) is fixedly connected to one side of the outer wall of the furnace (4), and a second valve (12) is fixedly connected to the secondary air inlet pipe (11).

6. A circulating fluidized bed boiler with a flexible lifting structure according to claim 2, characterized in that: The first support (14) is fixedly connected to the cyclone separator (15), and the third valve (18) is fixedly connected to the return pipe (16).

7. A circulating fluidized bed boiler with a flexible lifting structure according to claim 3, characterized in that: A second bracket (19) is fixedly connected to the flue (20), and a fourth valve (25) is fixedly connected to the primary air inlet pipe (24).

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