Fluidized bed boiler suitable for multiple types of fuels

Abstract

The invention discloses a fluidized bed boiler suitable for multiple types of fuels. The fluidized bed boiler comprises a multi-stage fluidized bed hearth and a cyclone separator, the multi-stage fluidized bed hearth is divided into an upper stage and a lower stage, and the lower-stage fluidized bed hearth comprises a lower-stage air chamber, a lower-stage feeding port and a lower-stage fluidized bed hearth outlet flue; the lower-stage fluidized bed hearth outlet flue is positioned at the upper end of the lower-stage fluidized bed hearth The upper fluidized bed hearth is arranged at the upper end of the lower fluidized bed hearth; the upper-stage fluidized bed hearth comprises an upper-stage air chamber, an upper-stage feeding port and an upper-stage fluidized bed hearth outlet flue; the lower fluidized bed hearth outlet flue is communicated with the upper fluidized bed hearth; and the outlet flue of the upper-stage fluidized bed hearth is communicated to the cyclone separator. The system can adapt to different types of fuels, the fuels are combusted and utilized in the same boiler system at the same time, good combustion adaptability and combustion effect are achieved, and the comprehensive utilization benefits of the different types of fuels can be promoted; due to the adoption of a fluidized bed technology, pollutant emission can be fully controlled while combustion is carried out, and environmental friendliness is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of clean combustion and efficient utilization of fuel, and in particular to a fluidized bed boiler suitable for mixed combustion of solid fuels including coal, biomass and the like. BACKGROUND

[0002] The energy structure in China is mainly fossil energy, with coal accounting for a high proportion in primary energy production and consumption, while oil and natural gas also occupy a certain proportion. In addition, clean energy such as hydropower, wind power and solar energy is developing rapidly, and the overall situation presents a multi-energy complementary trend. Under such an energy structure background, the development of multi-type fuel fluidized bed technology is highly consistent with the country's energy demand. On the one hand, energy resources in China are widely distributed and diverse, and this technology can make full use of various types of energy, achieving efficient combustion of coal, biomass, waste and other fuels, thereby improving the overall energy utilization efficiency, reducing dependence on single energy, and enhancing the stability and flexibility of energy supply. On the other hand, multi-type fuel fluidized bed technology has obvious advantages in reducing pollutant emissions. Compared with traditional single fuel combustion methods, it can effectively control the generation and emission of pollutants such as sulfur dioxide, nitrogen oxides and particulate matter, which is of great significance for improving environmental quality and addressing air pollution challenges in China.

[0003] However, the current multi-type fuel fluidized bed technology still has certain limitations. For example, some mixed combustion type fluidized beds, due to the large differences in combustion characteristics of different fuels such as ignition point, volatile content and combustion rate, it is difficult to achieve precise combustion control in actual combustion process, and problems such as incomplete combustion or local overburning are prone to occur. At the same time, in order to adapt to the combustion needs of various fuels, the system equipment often needs to have complex fuel handling, conveying, mixing and regulation functions, which greatly increases the overall system complexity, not only increases the equipment cost, but also brings certain difficulty to operation and maintenance, to some extent, limits the large-scale popularization and application of the technology. SUMMARY

[0004] In view of the shortcomings of the existing fluidized bed technology, such as single type of fuel and difficulty in combustion control of mixed combustion fluidized bed technology, the present application designs a fluidized bed boiler which is simple in structure, easy to control and can adapt to multiple types of fuel at the same time.

[0005] The present application adopts the following technical solutions: A fluidized bed boiler suitable for multiple types of fuel, comprising a multi-stage fluidized bed hearth and a cyclone separator; The multi-stage fluidized bed hearth is arranged in an upper and lower level, and the lower stage fluidized bed hearth comprises a lower stage air chamber, a lower stage feeding port and a lower stage fluidized bed hearth outlet flue; wherein the lower stage fluidized bed hearth outlet flue is located at the upper end of the lower stage fluidized bed hearth; The upper fluidized bed furnace is arranged on the upper end of the lower fluidized bed furnace. The upper fluidized bed furnace comprises an upper air chamber, an upper feeding port and an upper fluidized bed furnace outlet flue; the lower fluidized bed furnace outlet flue is communicated with the upper fluidized bed furnace; and the upper fluidized bed furnace outlet flue is communicated to a cyclone separator.

[0006] Preferably, the lower air chamber comprises a lower air distribution plate, a lower slag falling pipe and a lower air chamber guide plate.

[0007] Preferably, the upper air chamber comprises an upper air distribution plate; the upper air chamber and the upper air distribution plate are arranged around the lower fluidized bed furnace outlet flue, and the upper air distribution plate is arranged on the upper end of the upper air chamber.

[0008] Preferably, the cyclone separator is provided with a separator outlet flue on the upper end and a separator standpipe and a two-stage return device on the lower end.

[0009] Preferably, the separator standpipe is connected with an upper return device and a lower return device respectively; the upper return device is communicated with the upper fluidized bed furnace, and the lower return device is communicated with the lower fluidized bed furnace.

[0010] Preferably, the lower air chamber is arranged with lower fluidization air, and the lower feeding port is arranged with lower seeding air.

[0011] Preferably, the upper air chamber is arranged with upper fluidization air, and the upper feeding port is arranged with upper seeding air.

[0012] Preferably, the upper return device is arranged with upper return air, and the lower return device is arranged with lower return air.

[0013] Preferably, the upper air distribution plate is arranged obliquely.

[0014] The present application has the advantages that: the present application designs a fluidized bed boiler suitable for multiple types of fuel, which can adapt to different types of fuel, such as coal, biomass and the like, and simultaneously burn and utilize in the same set of boiler system, has good combustion adaptability and combustion effect, can promote the comprehensive utilization benefit of different types of fuel, and saves equipment investment cost; because the fluidized bed technology is adopted, the combustion can fully control the pollutant emission at the same time, and has environmental friendliness. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic view of the present application; 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

[0016] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings: 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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. 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. 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.

[0023] The above embodiments will be used for practical applications in the following sections.

[0024] 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.

[0025] 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.

[0026] 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.

2. A fluidized bed boiler adaptable to multiple types of fuels according to claim 1, characterized in that, 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.

3. A fluidized bed boiler adaptable to multiple types of fuels according to claim 1, characterized in that, The upper-level air chamber includes an upper-level air distribution plate; the upper-level air chamber and the upper-level air distribution plate are arranged around the flue gas outlet of the lower-level fluidized bed furnace, and the upper-level air distribution plate is arranged at the upper end of the upper-level air chamber.

4. A fluidized bed boiler adaptable to multiple types of fuels according to claim 1, characterized in that, The cyclone separator is equipped with a separator outlet flue at the upper end and a separator riser and a two-stage return feeder at the lower end.

5. A fluidized bed boiler adaptable to multiple types of fuels according to claim 4, characterized in that, 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.

6. 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.

7. 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.

8. 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.

9. A fluidized bed boiler adaptable to multiple types of fuels according to claim 3, characterized in that, The upper-level air distribution plate is arranged at an angle.

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