Roasting circulating fluidized bed combustion system

Abstract

The utility model relates to the technical field of circulating fluidized beds, in particular to a roasting circulating fluidized bed combustion system. According to the technical scheme, the device comprises a hearth, a separator connected with the hearth, a flue communicated with the top of the separator and a post-treatment module connected with the flue, and further comprises a primary air inlet component and a secondary air inlet component which are installed in the hearth, and the primary air inlet component is located below the secondary air inlet component; the primary air inlet component and the secondary air inlet component each comprise a flow dividing ring fixedly installed in the hearth, a plurality of exhaust holes are formed in each flow dividing ring, and an airflow balance assembly for balancing the air output of the exhaust holes is installed in each flow dividing ring. The gas flow balancing assembly can reduce the gas flow passing through the exhaust holes close to the connector and can increase the gas flow passing through the exhaust holes far away from the connector, so that the difference of the gas flow passing through the exhaust holes can be effectively reduced, and the uniformity of gas in a hearth can be improved.

Description

Technical Field

[0001] This utility model relates to the field of circulating fluidized bed technology, and in particular to a roasting circulating fluidized bed combustion system. Background Technology

[0002] Circulating fluidized bed combustion (CFBCC) technology is a clean coal combustion technology that has been developed over the past two decades. It boasts advantages such as wide fuel adaptability, high combustion efficiency, low nitrogen oxide emissions, low-cost limestone in-furnace desulfurization, large load adjustment ratio, and rapid load adjustment. The key to CFBCC technology is its main circulation loop, which separates a large amount of high-temperature solid material from the gas flow and returns it to the combustion chamber. This maintains a stable fluidized state within the combustion chamber, ensuring multiple cycles of combustion and reaction of fuel and desulfurizing agent, thereby improving both combustion and desulfurization efficiency.

[0003] In a calcining circulating fluidized bed combustion system, the air intake inside the furnace is crucial, as it directly affects combustion efficiency and stability. In the air intake system, gas is typically delivered into the furnace via a fan. However, to improve the uniformity of gas flow into the furnace, multiple vents are usually installed. But in actual use, it's impossible to guarantee that the gas flow rate in each vent is equal. This is because gas preferentially flows through vents closer to the gas source, resulting in reduced flow rates to vents further away from the gas source, which is detrimental to improving the uniformity of gas distribution within the furnace. Utility Model Content

[0004] The purpose of this invention is to address the problems existing in the background technology by proposing a roasting circulating fluidized bed combustion system.

[0005] The technical solution of this utility model: a roasting circulating fluidized bed combustion system, including a furnace, a separator connected to the furnace, a flue connected to the top of the separator, and a post-processing module connected to the flue. The furnace is connected to a feeding module, and further includes:

[0006] A primary air intake component and a secondary air intake component are installed inside the furnace. The primary air intake component is located below the secondary air intake component. Both the primary and secondary air intake components include a flow divider ring fixedly installed inside the furnace. The flow divider ring is provided with multiple exhaust holes. An airflow balancing component that balances the air output of the multiple exhaust holes is installed inside the flow divider ring.

[0007] Optionally, the feeding module includes a lime conveyor and a coal feeder fixedly connected to the furnace, and a slag discharge pipe is provided at the bottom of the furnace.

[0008] Optionally, a J valve is fixedly installed at the bottom of the separator, the other end of the J valve is connected to the furnace, and a return fan is fixedly connected to the J valve.

[0009] Optionally, the post-treatment module includes an exhaust pipe fixedly installed on the flue, a dust collector fixedly connected to the exhaust pipe, an induced draft fan connected to the dust collector, and the output end of the induced draft fan connected to the chimney.

[0010] Optionally, an ammonia tank is connected to the top of the separator.

[0011] Optionally, a steam drum is connected to the furnace and the flue, a first heat exchange tube is fixedly installed in the flue, and a second heat exchange tube is fixedly installed in the furnace. Both the first heat exchange tube and the second heat exchange tube are connected to the steam drum.

[0012] Optionally, the primary air intake component includes a primary air intake pipe communicating with the bottom of the furnace, and a primary air fan is fixedly installed on the primary air intake pipe. The secondary air intake component includes connectors fixedly installed on both sides of the furnace, with diversion pipes fixedly installed on the connectors. Secondary air intake pipes are fixedly installed on the two diversion pipes, and secondary air fans are fixedly installed on the secondary air intake pipes.

[0013] Optionally, the airflow balancing assembly includes an air chamber disposed within a flow-dividing ring. A partition is fixedly installed within the air chamber, dividing the air chamber into an upper air chamber and an inner air chamber. The partition has multiple sets of connecting holes, and guide pipes are fixedly installed on the connecting holes. The guide pipes are connected to the exhaust port via an air pipe. Multiple sliding rods are slidably installed on the partition, each corresponding to a guide pipe and extending into the interior of the guide pipe. A conical block is fixedly installed on each sliding rod. A conical guide groove is provided at the top of the guide pipe, and the conical block is located inside the conical guide groove. A spring is fixedly installed on each sliding rod, and the other end of the spring is fixedly connected to the partition. The inner diameter of the exhaust port is larger than the inner diameter of the air pipe.

[0014] In summary, this application includes at least one of the following beneficial technical effects:

[0015] This invention uses an airflow balancing component to reduce the amount of gas passing through the exhaust port near the connector and increase the amount of gas passing through the exhaust port far away. This effectively reduces the difference in the amount of gas passing through multiple exhaust ports, thereby helping to improve the uniformity of the gas inside the furnace. Attached Figure Description

[0016] Figure 1 A system diagram of the circulating fluidized bed combustion system of this utility model is provided;

[0017] Figure 2 A schematic diagram of the flow divider ring in this utility model is provided;

[0018] Figure 3 for Figure 2 A magnified view of a portion of point A in the middle.

[0019] Reference numerals: 1. Furnace; 2. Separator; 3. Flue; 4. Lime conveyor; 5. Coal feeder; 6. Slag discharge pipe; 7. J valve; 8. Return fan; 9. Exhaust pipe; 10. Dust collector; 11. Induced draft fan; 12. Chimney; 13. Ammonia tank; 14. Steam drum; 15. First heat exchange tube; 16. Second heat exchange tube; 17. Primary air fan; 18. Secondary air fan; 19. Primary air inlet pipe; 20. Secondary air inlet pipe; 21. Diverter pipe; 22. Connector; 23. Diverter ring; 24. Gas chamber; 25. Baffle plate; 26. Connecting hole; 27. Guide pipe; 28. Exhaust port; 29. ​​Gas pipe; 30. Slide rod; 31. Conical block; 32. Conical guide groove; 33. Spring. Detailed Implementation

[0020] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1, as Figure 1 As shown, this utility model proposes a roasting circulating fluidized bed combustion system, including a furnace 1, a separator 2 connected to the furnace 1, and a flue 3 connected to the top of the separator 2. The furnace 1 is connected to a feeding module, which includes a lime conveyor 4 and a coal feeder 5 fixedly connected to the furnace 1. Fuel is transported into the furnace 1 via the lime conveyor 4 and the coal feeder 5, and ignited by an ignition device inside the furnace, allowing the fuel to burn within the furnace 1. The combustion gases enter the separator 2, where residues in the flue gas are separated from the gases. The residues are then transported back into the furnace 1, and the flue gas is transported into the flue 3. A slag discharge pipe 6 is located at the bottom of the furnace 1. The combustion waste is discharged through the slag discharge pipe 6.

[0022] A post-treatment module is connected to flue 3. The post-treatment module includes an exhaust pipe 9 fixedly installed on flue 3, a dust collector 10 fixedly connected to exhaust pipe 9, and an induced draft fan 11 connected to the dust collector 10. The output end of the induced draft fan 11 is connected to a chimney 12. The induced draft fan 11 removes dust from the flue gas entering flue 3 and discharges the dust-removed flue gas through chimney 12. Aluminum sulfate is added to the fuel. Aluminum sulfate may help improve the fluidization characteristics of the bed material during combustion. It can affect the particle size distribution and porosity of the bed material, thereby optimizing fluidization quality. Furthermore, aluminum sulfate is a commonly used desulfurizing agent that can react with sulfur dioxide during combustion to generate sulfate, thereby reducing SO2 emissions. This process typically occurs during the flue gas purification stage. Aluminum sulfate can react with SO2 and oxygen in the flue gas to generate solid aluminum sulfate, which is then removed by the dust collector 10.

[0023] In this embodiment, a J valve 7 is fixedly installed at the bottom of the separator 2, and the other end of the J valve 7 is connected to the furnace 1. A return fan 8 is fixedly connected to the J valve 7. The residue separated by the separator 2 can be transported back into the furnace 1 through the J valve 7 via the return fan 8. An ammonia tank 13 is connected to the top of the separator 2. By supplying ammonia into the flue gas, the ammonia can react chemically with the nitrogen oxides in the flue gas, reducing them to nitrogen and water. This helps reduce air pollution and acid rain formation. A steam drum 14 is connected to the furnace 1 and the flue 3. A first heat exchange tube 15 is fixedly installed in the flue 3, and a second heat exchange tube 16 is fixedly installed in the furnace 1. Both the first heat exchange tube 15 and the second heat exchange tube 16 are connected to the steam drum 14. The liquid will first absorb the waste heat in the flue through the first heat exchange tube 15, and then enter the second heat exchange tube 16 through the steam drum 14, thereby heating the water inside the tube.

[0024] This embodiment also includes a primary air intake component and a secondary air intake component installed inside the furnace 1. The primary air intake component is located below the secondary air intake component. Both the primary and secondary air intake components include a distribution ring 23 fixedly installed inside the furnace 1. The distribution ring 23 is provided with multiple exhaust holes 28. The primary air intake component includes a primary air intake pipe 19 communicating with the bottom of the furnace 1. A primary air fan 17 is fixedly installed on the primary air intake pipe 19. The secondary air intake component includes connectors 22 fixedly installed on both sides of the furnace 1. Distribution pipes 21 are fixedly installed on the connectors 22. Secondary air intake pipes 20 are fixedly installed on the two distribution pipes 21. Secondary air fans 18 are fixedly installed on the secondary air intake pipes 20. Gas can be delivered to the corresponding distribution ring 23 by the primary air fan 17 and the secondary air fan 18 and ejected through the exhaust holes 28. The multiple exhaust holes 28 help to make the gas distribution inside the furnace 1 uniform.

[0025] The primary air intake components serve to provide sufficient oxygen to support fuel combustion and maintain the fluidization of the bed material. Primary air typically enters from the bottom of the furnace and is evenly distributed through air distributors to ensure good mixing of fuel and bed material, thus promoting the combustion process.

[0026] The function of secondary air intake components is to further supply oxygen to support combustion and help control the temperature distribution within the furnace. Secondary air typically enters from the middle or upper part of the furnace and can be used to regulate nitrogen oxide formation, optimize the combustion process, and reduce pollutant emissions.

[0027] Working principle: Fuel is transported to the furnace 1 via the lime conveyor 4 and the coal feeder 5, and ignited by the ignition device inside the furnace, allowing the fuel to burn inside the furnace 1. The combustion gas enters the separator 2, where the residue in the flue gas is separated from the gas. The residue is then transported back into the furnace 1, while the flue gas is transported into the flue duct 3. The induced draft fan 11 removes dust from the flue gas entering the flue duct 3, and the dust-removed flue gas is discharged through the chimney 12.

[0028] The primary air intake system's main function is to provide sufficient oxygen to support fuel combustion and maintain the fluidization of the bed material. Primary air typically enters from the bottom of the furnace and is evenly distributed through air distributors to ensure good mixing of fuel and bed material, promoting combustion. The secondary air intake system further supplies oxygen to support combustion and helps control the temperature distribution within the furnace. Secondary air typically enters from the middle or upper part of the furnace and can be used to regulate nitrogen oxide formation, optimize the combustion process, and reduce pollutant emissions.

[0029] Example 2, as Figures 2 to 3 As shown, based on Embodiment 1, an airflow balancing component is installed inside the flow divider ring 23 to balance the air volume of multiple exhaust holes 28. The airflow balancing assembly includes an air chamber 24 located within a flow divider ring 23. A baffle 25 is fixedly installed inside the air chamber 24, dividing the air chamber 24 into an upper air chamber and an air chamber. The baffle 25 has multiple sets of connecting holes 26, and a guide pipe 27 is fixedly installed on the connecting holes 26. The guide pipe 27 is connected to the exhaust port 28 via an air pipe 29. Multiple sliding rods 30 are slidably installed on the baffle 25. The sliding rods 30 correspond one-to-one with the guide pipes 27 and extend into the interior of the guide pipes 27. A conical block 31 is fixedly installed on the sliding rod 30. A conical guide groove 32 is provided at the top of the guide pipe 27. The conical block 31 is located inside the conical guide groove 32. A spring 33 is fixedly installed on the sliding rod 30. The other end of the spring 33 is fixedly connected to the baffle 25. The inner diameter of the exhaust port 28 is larger than the inner diameter of the air pipe 29.

[0030] The gas entering the gas chamber 24 will enter the guide pipe 27 through multiple connecting holes 26. At this time, under the action of wind, an upward thrust will be applied to the conical block 31, causing the conical block 31 to move upward. This reduces the size of the gap between the conical block 31 and the conical guide groove 32, thereby reducing the effective flow area of ​​the gas and the amount of gas passing through that point. As the wind passes through multiple exhaust holes 28 sequentially from the end near the connector 22, the wind speed inside the gas chamber 24 will gradually decrease. Consequently, the thrust exerted by the wind on the conical block 31, which is gradually moving away from the connector 22, will gradually decrease, and the effective flow area of ​​the connecting holes, which are moving away from the connector 22, will gradually increase. In summary, the amount of gas passing through the exhaust holes 28 near the connector 22 can be reduced, while the amount of gas passing through the exhaust holes 28 can be increased. This effectively reduces the difference in the amount of gas passing through the multiple exhaust holes 28, thereby helping to improve the uniformity of the gas inside the furnace 1.

[0031] The above specific embodiments are merely several optional embodiments of this utility model. Based on the technical solution of this utility model and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A calcining circulating fluidized bed combustion system, comprising a furnace (1), a separator (2) connected to the furnace (1), a flue (3) communicating with the top of the separator (2), and a post-processing module connected to the flue (3), wherein the furnace (1) is connected to a feeding module, characterized in that, Also includes: A primary air intake component and a secondary air intake component are installed in the furnace (1). The primary air intake component is located below the secondary air intake component. Both the primary air intake component and the secondary air intake component include a flow divider ring (23) fixedly installed in the furnace (1). The flow divider ring (23) is provided with multiple exhaust holes (28). An airflow balancing component that balances the air output of the multiple exhaust holes (28) is installed in the flow divider ring (23).

2. The calcination circulating fluidized bed combustion system according to claim 1, characterized in that, The feeding module includes a lime conveyor (4) and a coal feeder (5) that are fixedly connected to the furnace (1), and a slag discharge pipe (6) is provided at the bottom of the furnace (1).

3. The calcination circulating fluidized bed combustion system according to claim 2, characterized in that, A J valve (7) is fixedly installed at the bottom of the separator (2), and the other end of the J valve (7) is connected to the furnace (1). A return fan (8) is fixedly connected to the J valve (7).

4. The calcination circulating fluidized bed combustion system according to claim 3, characterized in that, The post-processing module includes an exhaust pipe (9) fixedly installed on the flue (3), a dust collector (10) fixedly connected to the exhaust pipe (9), an induced draft fan (11) connected to the dust collector (10), and the output end of the induced draft fan (11) connected to the chimney (12).

5. A calcining circulating fluidized bed combustion system according to claim 4, characterized in that, The top of the separator (2) is connected to an ammonia tank (13).

6. A calcining circulating fluidized bed combustion system according to claim 5, characterized in that, A steam drum (14) is connected to the furnace (1) and the flue (3). A first heat exchange tube (15) is fixedly installed in the flue (3), and a second heat exchange tube (16) is fixedly installed in the furnace (1). Both the first heat exchange tube (15) and the second heat exchange tube (16) are connected to the steam drum (14).

7. A calcining circulating fluidized bed combustion system according to claim 6, characterized in that, The primary air intake component includes a primary air intake pipe (19) communicating with the bottom of the furnace (1), and a primary air fan (17) is fixedly installed on the primary air intake pipe (19). The secondary air intake component includes connectors (22) fixedly installed on both sides of the furnace (1), a diversion pipe (21) fixedly installed on the connector (22), a secondary air intake pipe (20) fixedly installed on the two diversion pipes (21), and a secondary air fan (18) fixedly installed on the secondary air intake pipe (20).

8. A calcining circulating fluidized bed combustion system according to claim 7, characterized in that, The airflow balancing assembly includes an air chamber (24) disposed within a flow divider ring (23). A partition (25) is fixedly installed inside the air chamber (24), dividing the air chamber (24) into an upper air chamber and an air chamber. The partition (25) has multiple sets of connecting holes (26), and a guide pipe (27) is fixedly installed on the connecting holes (26). The guide pipe (27) is connected to the exhaust port (28) through an air pipe (29). Multiple sliding rods (30) are slidably installed on the partition (25). (30) Corresponds one-to-one with the guide tube (27) and extends into the interior of the guide tube (27). A conical block (31) is fixedly installed on the slide rod (30). A conical guide groove (32) is provided at the top of the guide tube (27). The conical block (31) is located inside the conical guide groove (32). A spring (33) is fixedly installed on the slide rod (30). The other end of the spring (33) is fixedly connected to the partition plate (25). The inner diameter of the exhaust hole (28) is larger than the inner diameter of the air pipe (29).

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