Fluidized bed boiler adapted to multiple types of fuel

Abstract

This invention discloses a fluidized bed boiler adaptable to multiple fuel types, comprising a multi-stage fluidized bed furnace and a cyclone separator. The multi-stage fluidized bed furnace is arranged in upper and lower stages. The lower-stage fluidized bed furnace includes a lower-stage air chamber, a lower-stage feed inlet, and a lower-stage fluidized bed furnace outlet flue. The lower-stage fluidized bed furnace outlet flue is located at the upper end of the lower-stage fluidized bed furnace. The upper-stage fluidized bed furnace is positioned above the lower-stage fluidized bed furnace. The upper-stage fluidized bed furnace includes an upper-stage air chamber, an upper-stage feed inlet, and an upper-stage fluidized bed furnace outlet flue. The lower-stage fluidized bed furnace outlet flue connects to the upper-stage fluidized bed furnace. The upper-stage fluidized bed furnace outlet flue connects to the cyclone separator. This invention can adapt to different types of fuels and simultaneously burn them in the same boiler system, exhibiting good combustion adaptability and combustion effect, and promoting the comprehensive utilization benefits of different types of fuels. Due to the use of fluidized bed technology, pollutant emissions can be effectively controlled during combustion, making it environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of clean combustion and efficient utilization of fuels, and in particular to a fluidized bed boiler adaptable to multiple types of fuels, suitable for mixed combustion applications of solid fuels including coal, biomass and the like. Background Technology

[0002] my country's energy structure is dominated by fossil fuels, with coal accounting for a significant portion of primary energy production and consumption. Oil and natural gas also constitute a certain proportion, while clean energy sources such as hydropower, wind power, and solar energy are developing rapidly, exhibiting an overall multi-energy complementary pattern. Against this backdrop, the development of fluidized bed technology for multiple fuel types aligns perfectly with the country's energy needs. Firstly, my country's energy resources are widely distributed and diverse. This technology can fully utilize various energy sources, achieving efficient combustion of multiple fuels such as coal, biomass, and waste, thereby improving overall energy utilization efficiency, reducing dependence on a single energy source, and enhancing the stability and flexibility of energy supply. Secondly, multi-fuel fluidized bed technology offers significant advantages in reducing pollutant emissions. Compared to traditional single-fuel combustion methods, it can effectively control the generation and emission of pollutants such as sulfur dioxide, nitrogen oxides, and particulate matter. This is of great significance for my country to improve environmental quality and address the challenges of air pollution.

[0003] However, current multi-fuel fluidized bed technology still has certain limitations. For example, in some co-firing fluidized beds, due to the significant differences in the combustion characteristics of different fuels, such as ignition point, volatile matter content, and combustion rate, precise combustion control is difficult to achieve in actual combustion, easily leading to problems such as incomplete combustion or localized overburning. Furthermore, to adapt to the combustion requirements of multiple fuels, the system equipment often needs to possess complex fuel handling, transportation, mixing, and control functions, resulting in a significant increase in overall system complexity. This not only increases equipment costs but also poses challenges to operation and maintenance, thus limiting the large-scale application of this technology to some extent. Summary of the Invention

[0004] In view of the shortcomings of existing fluidized bed technology, such as the limited variety of fuels and the difficulty in combustion control of co-firing fluidized bed technology, this invention designs a fluidized bed boiler with a simple structure, convenient control, and the ability to adapt to multiple types of fuels.

[0005] The present invention adopts the following technical solution:

[0006] A fluidized bed boiler adaptable to multiple types of fuels, comprising a multi-stage fluidized bed furnace and a cyclone separator;

[0007] The multi-stage fluidized bed furnace is arranged in upper and lower stages. The lower-stage fluidized bed furnace includes a lower-stage air chamber, a lower-stage feed port, and a lower-stage fluidized bed furnace outlet flue; the lower-stage fluidized bed furnace outlet flue is located at the upper end of the lower-stage fluidized bed furnace.

[0008] The upper-level fluidized bed furnace is located above the lower-level fluidized bed furnace;

[0009] The upper fluidized bed furnace includes an upper air chamber, an upper feed port, and an upper fluidized bed furnace outlet flue; the lower fluidized bed furnace outlet flue is connected to the upper fluidized bed furnace; the upper fluidized bed furnace outlet flue is connected to the cyclone separator.

[0010] Preferably, the lower-level air chamber includes a lower-level air distribution plate, a lower-level slag discharge pipe, and a lower-level air chamber guide plate.

[0011] Preferably, the upper air chamber includes an upper air distribution plate; the upper air chamber and the upper air distribution plate are arranged around the flue gas outlet of the lower fluidized bed furnace, and the upper air distribution plate is arranged at the upper end of the upper air chamber.

[0012] Preferably, the cyclone separator is provided with a separator outlet flue at the upper end and a separator riser and a two-stage return feeder at the lower end.

[0013] Preferably, the separator riser is connected to an upper-level return feeder and a lower-level return feeder, with the upper-level return feeder connected to the upper-level fluidized bed furnace and the lower-level return feeder connected to the lower-level fluidized bed furnace.

[0014] Preferably, the lower-level air chamber is equipped with lower-level fluidizing air, and the lower-level feed port is equipped with lower-level feeding air.

[0015] Preferably, the upper-level air chamber is equipped with upper-level fluidizing air, and the upper-level feed port is equipped with upper-level feeding air.

[0016] Preferably, the upper-level return feeder is equipped with upper-level return air, and the lower-level return feeder is equipped with lower-level return air.

[0017] Preferably, the upper air distribution plate is arranged at an angle.

[0018] The beneficial effects of this invention are as follows: This invention designs a fluidized bed boiler that is adaptable to multiple types of fuels, such as coal and biomass, and can simultaneously burn and utilize them in the same boiler system. It has good combustion adaptability and combustion effect, which can promote the comprehensive utilization benefits of different types of fuels and save equipment investment costs. Because it adopts fluidized bed technology, pollutant emissions can be fully controlled during combustion, which is environmentally friendly. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention;

[0020] In the diagram: 1. Lower fluidized bed furnace, 2. Lower air chamber, 3. Lower slag discharge pipe, 4. Lower air distribution plate, 5. Lower fluidizing air, 6. Lower air chamber guide plate, 7. Lower feeding air, 8. Lower feed port, 9. Upper fluidized bed furnace, 10. Upper air chamber, 11. Upper fluidizing air, 12. Upper feeding air, 13. Upper air distribution plate, 14. Lower fluidized bed furnace outlet flue, 15. Upper feed port, 16. Upper fluidized bed furnace outlet flue, 17. Cyclone separator, 18. Separator outlet flue, 19. Upper return feeder, 20. Upper return air, 21. Lower return feeder, 22. Lower return air, 23. Separator riser. Detailed Implementation

[0021] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0022] Example: Figure 1 As shown, a multi-stage fluidized bed boiler device adaptable to multiple types of fuels includes a lower-stage fluidized bed furnace 1, an upper-stage fluidized bed furnace 9, and a cyclone separator 17.

[0023] The lower fluidized bed furnace 1 is provided with a lower air chamber 2 for introducing lower fluidizing air 5, a lower feed port 8 for feeding, and a lower fluidized bed furnace outlet flue 14 for discharging the mixture after combustion in the lower fluidized bed furnace 1; wherein the lower fluidized bed furnace outlet flue 14 is connected to the upper fluidized bed furnace 9.

[0024] The lower-level air chamber 2 is equipped with a lower-level air distribution plate 4 for uniformly delivering the lower-level fluidizing air 5, a lower-level slag discharge pipe 3 for discharging the slag in the lower-level fluidized bed furnace 1, and a lower-level air chamber guide plate 6 for guiding the lower-level fluidizing air 5.

[0025] The upper fluidized bed furnace 9 is provided with an upper air chamber 10 for introducing upper fluidizing air 11, an upper feed port 15 for feeding, and an upper fluidized bed furnace outlet flue 16 for discharging the mixture after combustion in the upper fluidized bed furnace 9 to a cyclone separator 17.

[0026] The upper air chamber 10 is equipped with an upper air distribution plate 13. The slag produced by combustion in the upper fluidized bed furnace 9 is discharged into the lower fluidized bed furnace 1 through the lower fluidized bed furnace outlet flue 14, and finally discharged through the lower slag discharge pipe 3.

[0027] The cyclone separator 17 has a separator outlet flue 18 at the upper end to discharge high-temperature flue gas, and a separator riser 23 at the lower end for returning the separated solid materials.

[0028] The separator riser 23 is connected to an upper return feeder 19 and a lower return feeder 21 respectively. The upper return feeder 19 is used to return the material separated by the cyclone separator 17 to the upper fluidized bed furnace 9, and the lower return feeder 21 is used to return the material to the lower fluidized bed furnace 1.

[0029] The lower-level air chamber 2 is equipped with lower-level fluidizing air 5 for fuel fluidization within the lower-level fluidized bed furnace 1; the lower-level feed port 8 is equipped with lower-level feeding air 7 for feeding material into the lower-level fluidized bed furnace 1; the upper-level air chamber 10 is equipped with upper-level fluidizing air 11 for fuel fluidization within the upper-level fluidized bed furnace 9; the upper-level feed port 15 is equipped with upper-level feeding air 12 for feeding material into the upper-level fluidized bed furnace 9; the upper-level return feeder 19 is equipped with upper-level return air 20 for returning material to the upper-level fluidized bed furnace 9; and the lower-level return feeder 21 is equipped with lower-level return air 22 for returning material into the lower-level fluidized bed furnace 1.

[0030] The upper-level return air 20 and the lower-level return air 22 can control the return amount of the upper-level return feeder 19 and the lower-level return feeder 21 by adjusting the air volume ratio.

[0031] The above embodiments will be used for practical applications in the following sections.

[0032] Check all boiler components to ensure they are in good condition. Fill the lower air distribution plate 4 and upper air distribution plate 13 with bed material, start the blower, start the ignition device of the lower fluidized bed furnace 1 and ensure good combustion. Preheat the combustion air, add fuel through the lower feed port 8 and ensure good fuel combustion, then add fuel through the upper feed port 15 and ensure stable combustion in the upper and lower fluidized bed furnaces.

[0033] The mixture after combustion in the lower fluidized bed furnace 1 enters the upper fluidized bed furnace 9 through the lower fluidized bed furnace outlet flue 14 and mixes with the materials therein. The mixture after fuel combustion in the upper fluidized bed furnace 9 enters the cyclone separator 17 through the upper fluidized bed furnace outlet flue 16. In the cyclone separator 17, coarse particles are separated from the flue gas flow and discharged from the separator riser 23. The gas flow enters the subsequent flue through the separator outlet flue 18 at the upper end of the cyclone separator 17. In the separator riser 23, coarse particles enter the upper fluidized bed furnace 9 and the lower fluidized bed furnace 1 respectively from the upper return feeder 19 and the lower return feeder 21.

[0034] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A fluidized bed boiler adaptable to multiple types of fuels, characterized in that, It includes a multi-stage fluidized bed furnace and a cyclone separator; The multi-stage fluidized bed furnace is arranged in upper and lower stages. The lower-stage fluidized bed furnace includes a lower-stage air chamber, a lower-stage feed port, and a lower-stage fluidized bed furnace outlet flue. The outlet flue of the lower-level fluidized bed furnace is located at the upper end of the lower-level fluidized bed furnace; The upper-level fluidized bed furnace is located above the lower-level fluidized bed furnace; The upper fluidized bed furnace includes an upper air chamber, an upper feed inlet, and an upper fluidized bed furnace outlet flue; the lower fluidized bed furnace outlet flue is connected to the upper fluidized bed furnace. The flue gas outlet of the upper fluidized bed furnace is connected to the cyclone separator; The lower-level air chamber includes a lower-level air distribution plate, a lower-level slag discharge pipe, and a lower-level air chamber guide plate; The upper air chamber includes an upper air distribution plate; the upper air chamber and the upper air distribution plate are arranged around the outlet flue of the lower fluidized bed furnace, and the upper air distribution plate is arranged at the upper end of the upper air chamber; The cyclone separator is provided with a separator outlet flue at the upper end and a separator riser and a two-stage return feeder at the lower end; The separator riser is connected to an upper-level return feeder and a lower-level return feeder, respectively. The upper-level return feeder is connected to the upper-level fluidized bed furnace, and the lower-level return feeder is connected to the lower-level fluidized bed furnace. Check all boiler components to ensure they are in good condition. Fill the lower and upper air distribution plates with bed material, start the blower, start the ignition device in the lower fluidized bed furnace and ensure good combustion. Preheat the combustion air, add fuel through the lower feed port and ensure good fuel combustion, then add fuel through the upper feed port and ensure stable combustion in the upper and lower fluidized bed furnaces. The mixture after combustion in the lower-level fluidized bed furnace enters the upper-level fluidized bed furnace through the lower-level fluidized bed furnace outlet flue and mixes with the materials therein. The mixture after fuel combustion in the upper-level fluidized bed furnace enters the cyclone separator through the upper-level fluidized bed furnace outlet flue. In the cyclone separator, coarse particles are separated from the flue gas flow and discharged from the separator riser. The gas flow enters the subsequent flue through the separator outlet flue at the upper end of the cyclone separator. In the separator riser, coarse particles enter the upper-level fluidized bed furnace and the lower-level fluidized bed furnace respectively from the upper-level return feeder and the lower-level return feeder.

2. A fluidized bed boiler adaptable to multiple types of fuels according to claim 1, characterized in that, The lower-level air chamber is equipped with lower-level fluidizing air, and the lower-level feed port is equipped with lower-level feeding air.

3. A fluidized bed boiler adaptable to multiple types of fuels according to claim 1, characterized in that, The upper-level air chamber is equipped with upper-level fluidizing air, and the upper-level feed port is equipped with upper-level feeding air.

4. A fluidized bed boiler adaptable to multiple types of fuels according to claim 1, characterized in that, The upper-level return feeder is equipped with upper-level return air, and the lower-level return feeder is equipped with lower-level return air.

5. A fluidized bed boiler adaptable to multiple types of fuels according to claim 1, characterized in that, The upper-level air distribution plate is arranged at an angle.

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