Biomass fluidized bed gasification-reburning integrated poly-generation device

Abstract

The utility model discloses a biomass fluidized bed gasification-reburning integrated poly-generation device, which relates to the field of biomass energy clean and efficient utilization equipment, and comprises a burning unit, a gas-solid separation unit, a reburning unit and a dust removal unit which are sequentially communicated through pipelines, the combustion unit is used for carrying out combustion operation on biomass raw materials; the gas-solid separation unit is used for carrying out gas-solid separation operation on the fuel gas and the biomass semi-coke particles generated by the combustion unit; the reburning unit is used for carrying out reburning and heat exchange operation on the fuel gas separated by the gas-solid separation unit; and the dust removal unit is used for carrying out dust removal and discharge operation on flue gas generated by combustion of the re-combustion unit. According to the device, the problem of coking at the bottom of the furnace is avoided in a biomass gasification reburning mode, meanwhile, fly ash fine powder obtained after gas-solid separation is rich in silicon, potassium and a small amount of fine-particle biochar, is a good inorganic fertilizer and bacterial fertilizer carrier and can be directly used as a fertilizer and a soil conditioner, the additional value of biomass resources is increased, and economic and environment-friendly benefits are remarkable.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of biomass energy clean and efficient utilization equipment, especially relates to a biomass fluidized bed gasification-reburning integrated polygeneration device. BACKGROUND

[0002] Biomass is a kind of renewable energy with wide distribution source, clean and low carbon, and has multiple resource utilization ways.Biomass gasification technology is one of the ways of large-scale, efficient and clean utilization of biomass energy, which can convert solid biomass resources into high-grade small molecule combustible gas, compared with direct biomass combustion, has the advantages of stable combustion, high thermal efficiency, small pollution, high utilization rate of raw materials, good environmental protection social benefits and more extensive application range.

[0003] At present, the relatively mature biomass gasification technology in China mainly includes fixed bed gasification technology and circulating fluidized bed gasification technology.The fixed bed gasification technology has simple equipment structure and low operation cost, but the single furnace processing capacity is small, the gasification rate is low, a large amount of difficult-to-treat tar and phenolic wastewater are produced, and secondary pollution is serious.The circulating fluidized bed gasification has large processing capacity and operation flexibility, continuous operation and wide raw material adaptability, and is suitable for large-scale processing of biomass resources, but due to the potassium ion in biomass, it is easy to cause the coking of fluidized bed, the gasification temperature is low, the conversion rate is reduced, and at the same time, the problem of entrained tar in the gas has not been effectively solved, which limits its application range.

[0004] At present, the biomass direct combustion boiler generally has the problems of superheating surface and flue ash sticking pollution, which leads to low heat exchange efficiency and flue blockage, and frequent regular cleaning is required, which causes great damage to the equipment. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a kind of biomass fluidized bed gasification-reburning integrated polygeneration device, solve the problem of any one of the low combustion efficiency caused by the high moisture content of biomass raw material, the low heat exchange efficiency caused by the serious flue ash sticking pollution, the coking problem of fluidized bed gasification furnace caused by the alkali metal such as potassium and sodium in biomass raw material and the secondary pollution caused by tar produced in the gasification process of biomass furnace.

[0006] To solve the above technical problems, the utility model adopts the following technical scheme:

[0007] The utility model provides a kind of biomass fluidized bed gasification-reburning integrated polygeneration device, including combustion unit, gas-solid separation unit, reburning unit and dust removal unit that are sequentially communicated by pipeline;

[0008] The combustion unit is used for the combustion operation of biomass raw material;

[0009] The gas-solid separation unit is used for gas-solid separation of the flue gas and the biomass semi-coke particles generated by the combustion unit.

[0010] The reburning unit is used for reburning and heat exchange of the flue gas separated by the gas-solid separation unit.

[0011] The dust removal unit is used for dust removal and discharge of the flue gas generated by the reburning unit.

[0012] Optionally, the combustion unit comprises a hopper, a screw feeder and a fluidized bed gasification furnace, the feeding port and the discharging port of the screw feeder are respectively installed at the bottom end of the hopper and the bottom end of the fluidized bed gasification furnace, the hopper stores the biomass raw material, and the bottom end of the fluidized bed gasification furnace is further provided with a gasification agent inlet.

[0013] Optionally, the gas-solid separation unit comprises a first gas-solid separator, a biochar cooler, a second gas-solid separator and a return feeder.

[0014] The feeding end of the first gas-solid separator is installed at the top end of the fluidized bed gasification furnace, the solid discharging end of the first gas-solid separator is connected with the top feeding end of the biochar cooler, and the bottom of the biochar cooler is provided with a biochar product discharging port.

[0015] The feeding end of the second gas-solid separator is installed at the top end of the first gas-solid separator, and the solid discharging end of the second gas-solid separator is connected with the feeding end of the return feeder.

[0016] The discharging end of the return feeder is connected with the bottom end of the fluidized bed gasification furnace through a pipeline, and the return feeder is connected with a return fan for sending the material particles back to the fluidized bed gasification furnace.

[0017] Optionally, the reburning unit comprises a staged combustion air pipe and a reburning chamber, one end of the staged combustion air pipe is connected with the gas discharging end of the second gas-solid separator, and the other end is connected with the gas inlet end of the reburning chamber.

[0018] The reburning chamber is sequentially provided with a high-temperature air preheater, an evaporator, a superheater, an economizer and a low-temperature air preheater, and the superheater and the economizer are both provided with a plurality of.

[0019] The reburning unit further comprises a gasification fan and a combustion fan, one end of the gasification fan is connected with the high-temperature air preheater through a pipeline, and the other end is connected with the gasification agent inlet through a pipeline; one end of the combustion fan is connected with the low-temperature air preheater through a pipeline, and the other end is connected with the side wall of the staged combustion air pipe through a pipeline.

[0020] Optionally, the dust removal unit comprises a bag filter, an induced draft fan and a chimney, the gas inlet end of the bag filter is connected with the gas outlet end of the reburning chamber through a pipeline, and a biological fine powder outlet is arranged on the bag filter; one end of the induced draft fan is connected with the gas outlet end of the bag filter through a pipeline, and the other end is connected with the chimney through a pipeline.

[0021] Optionally, the bottom end of the fluidized bed gasification furnace is further connected with a slag cooler.

[0022] Compared with the prior art, the beneficial technical effects of the utility model are:

[0023] 1) the fluidized bed gasification furnace, the gasification agent inlet, the reburning chamber, the high-temperature air preheater and the gasification fan are cooperated with each other, the problem of low combustion efficiency caused by high moisture content of the biological material is effectively solved, the moisture contained in the biological material is used as a gasification agent, the biological material is converted into CO and H2 combustible gas through reaction in the high-temperature gasification process, the influence of the moisture of the raw material on combustion and energy consumption is reduced, and the adaptability of the device to the biological material is improved.

[0024] 2) while carrying out the biomass gasification reburning, the device produces and prepares high-quality biochar through the gas-solid separation unit, the whole process fully utilizes the biomass resources, and no waste slag is discharged.

[0025] 3) the device avoids the problem of coke formation at the bottom of the furnace through the biomass gasification reburning mode, at the same time, the fly ash fine powder separated from the gas-solid separation is rich in silicon, potassium and a small amount of fine particle biochar, is a good inorganic fertilizer and microbial fertilizer carrier, can be directly used as a fertilizer and a soil conditioner, the added value of the biomass resources is improved, and economic and environmental protection benefits are remarkable.

[0026] 4) the device generates high-temperature fuel gas through the biomass gasification reburning mode, then burns the high-temperature fuel gas, can effectively reduce the initial concentration of nitrogen oxides in flue gas, and is beneficial to system emission standard reaching.

[0027] 5) through the biomass gasification reburning mode, the system operation load can be flexibly adjusted in a large range, and the system flexibility and adaptability are improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] The utility model will be further described in connection with the description of the drawings.

[0029] Figure 1 It is a biomass fluidized bed gasification-reburning integrated polygeneration device structure schematic view.

[0030] Explanation of reference numerals in the attached diagram: 1. Hopper; 2. Screw feeder; 3. Fluidized bed gasifier; 4. Gasifying agent inlet; 5. Slag cooler; 6. First gas-solid separator; 7. Biochar cooler; 8. Biochar product outlet; 9. Second gas-solid separator; 10. Return feeder; 11. Staged combustion duct; 12. Recombustion chamber; 13. Evaporator; 14. Superheater; 15. Economizer; 16. Low-temperature air preheater; 17. High-temperature air preheater; 18. Exhaust fan; 19. Chimney; 20. Gasification fan; 21. Combustion fan; 22. Return feeder; 23. Biochar fine powder outlet; 24. Baghouse dust collector. Detailed Implementation

[0031] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0032] like Figure 1 As shown, a biomass fluidized bed gasification-re-combustion integrated multi-generation device includes a combustion unit, a gas-solid separation unit, a re-combustion unit and a dust removal unit connected in sequence by pipelines;

[0033] The combustion unit is used for the combustion of biomass raw materials;

[0034] The gas-solid separation unit is used to perform gas-solid separation on the fuel gas and biomass semi-coke particles produced by the combustion unit.

[0035] The reburning unit is used to reburn and exchange the gas separated by the gas-solid separation unit.

[0036] The dust removal unit is used to remove dust from the flue gas generated by the combustion in the reburning unit and discharge it externally.

[0037] Specifically, the combustion unit includes a hopper 1, a screw feeder 2, and a fluidized bed gasifier 3. The feed inlet and discharge outlet of the screw feeder 2 are respectively installed at the bottom of the hopper 1 and the bottom of the fluidized bed gasifier 3. The hopper 1 stores biomass raw materials, and the bottom of the fluidized bed gasifier 3 is also equipped with a gasifying agent inlet 4.

[0038] Specifically, the gas-solid separation unit includes a first gas-solid separator 6, a biochar cooler 7, a second gas-solid separator 9, and a return feeder 10;

[0039] The feed end of the first gas-solid separator 6 is installed at the top of the fluidized bed gasifier 3, the solid discharge end of the first gas-solid separator 6 is connected to the top feed end of the biochar cooler 7, and the bottom of the biochar cooler 7 is provided with a biochar product discharge port 8.

[0040] The feeding end of the second gas-solid separator 9 is installed at the top end of the first gas-solid separator 6, and the solid discharging end of the second gas-solid separator 9 is connected with the feeding end of the return feeder 10;

[0041] The discharging end of the return feeder 10 is connected with the bottom end of the fluidized bed gasification furnace 3 through a pipeline, and the return feeder 10 is connected with a return fan 22 for sending material particles back to the fluidized bed gasification furnace 3.

[0042] Specifically, the re-burning unit comprises a staged combustion air pipe 11 and a re-burning chamber 12, one end of the staged combustion air pipe 11 is connected with the gas discharging end of the second gas-solid separator 9, and the other end is connected with the gas inlet end of the re-burning chamber 12.

[0043] The re-burning chamber 12 is sequentially installed with a high-temperature air preheater 17, an evaporator 13, a superheater 14, an economizer 15 and a low-temperature air preheater 16, and the superheater 14 and the economizer 15 are both provided with a plurality of.

[0044] The re-burning unit further comprises a gasification fan 20 and a combustion fan 21, one end of the gasification fan 20 is connected with the high-temperature air preheater 17 through a pipeline, and the other end is connected with the gasification agent inlet 4 through a pipeline; one end of the combustion fan 21 is connected with the low-temperature air preheater 16 through a pipeline, and the other end is connected with the side wall of the staged combustion air pipe 11 through a pipeline.

[0045] Specifically, the dust removal unit comprises a bag-type dust collector 24, an induced draft fan 18 and a chimney 19, the gas inlet end of the bag-type dust collector 24 is connected with the gas outlet end of the re-burning chamber 12 through a pipeline, and the bag-type dust collector 24 is provided with a biological fine powder outlet 23; one end of the induced draft fan 18 is connected with the gas outlet end of the bag-type dust collector 24 through a pipeline, and the other end is connected with the chimney 19 through a pipeline.

[0046] Specifically, the bottom end of the fluidized bed gasification furnace 3 is further connected with a slag cooler 5.

[0047] The working principle of the utility model is as follows:

[0048] Biomass feedstock of 0-20mm is added to hopper 1, and then fed into the bottom of fluidized bed gasifier 3 by screw feeder 2. It reacts violently with high-temperature air (600℃) and low-pressure steam preheated by high-temperature air preheater 17. The biomass feedstock mixes and rapidly undergoes combustion and pyrolysis gasification at 750-850℃ to generate high-temperature combustible gas and biomass semi-coke particles. The high-temperature gas carries the biomass semi-coke particles upwards to the outlet of fluidized bed gasifier 3, where they pass through two stages of gas-solid separators. Biomass semi-coke particles larger than a preset threshold separated by the first gas-solid separator 6 enter the biochar cooler 7 for cooling and passivation treatment. The treated biomass semi-coke particles are then sent out as biochar products. Biomass semi-coke particles smaller than a preset threshold separated by the second gas-solid separator 9 are directly recycled back to the bottom of fluidized bed gasifier 3 via return feeder 10 for combustion and gasification treatment, achieving the recycling of biomass semi-coke particles. The return air for the return feeder is provided by return fan 22. The high-temperature gas from the second gas-solid separator 9 directly enters the recombustion chamber 12 and undergoes full combustion and heat release with the preheated air supplied by the staged combustion duct 11. Simultaneously, the gas passes through the water-cooled wall cavity of the recombustion chamber 12, sequentially passing through the high-temperature air preheater 17, evaporator 13, superheater 14, economizer 15, and low-temperature air preheater 16 for heat exchange to recover flue gas heat. The high-temperature air preheater 17 exchanges heat between the gasified air and the high-temperature flue gas; the resulting high-temperature air (around 600°C) is used as a gasifying agent and is sent back to the gasifying agent inlet 4 by the gasification fan 20. The low-temperature air preheater 16 exchanges heat between the flue gas and the combustion air; the preheated air (around 150°C) is used as combustion air for the high-temperature gas and is sent back to the staged combustion duct 11 by the combustion fan 21. After heat exchange, the flue gas enters the bag filter 24, where it is purified and then sent to the chimney 19 by the induced draft fan 18 for emission standards. The fine fly ash separated by the bag filter 24 is rich in silicon, potassium, and a small amount of micro-particle biochar, making it an excellent carrier for inorganic fertilizers and microbial fertilizers. It can be directly used as a raw material for fertilizers or soil conditioners and sold externally. Large particles of slag are periodically discharged from the bottom of the fluidized bed gasifier 3 according to the bed pressure difference. After being cooled by the slag cooler 5, they are sent externally.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0050] The above-described embodiments are merely preferred modes of the present application, and are not intended to limit the scope of the present application, and various modifications and improvements to the technical solutions of the present application made by those of ordinary skill in the art without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A biomass fluidized bed gasification-reburning integrated multi-product unit, characterized in that: It includes a combustion unit, a gas-solid separation unit, a re-combustion unit, and a dust removal unit, which are connected in sequence through pipelines; The combustion unit is used for the combustion of biomass raw materials; The gas-solid separation unit is used to perform gas-solid separation on the fuel gas and biomass semi-coke particles produced by the combustion unit. The reburning unit is used to reburn and exchange the gas separated by the gas-solid separation unit. The dust removal unit is used to remove dust from the flue gas generated by the combustion in the reburning unit and discharge it externally.

2. The integrated biomass fluidized bed gasification-reburning multi-product unit according to claim 1, characterized in that: The combustion unit includes a hopper (1), a screw feeder (2), and a fluidized bed gasifier (3). The feed inlet and discharge outlet of the screw feeder (2) are respectively installed at the bottom of the hopper (1) and the bottom of the fluidized bed gasifier (3). The hopper (1) stores biomass raw materials, and the bottom of the fluidized bed gasifier (3) is also equipped with a gasifying agent inlet (4).

3. The integrated biomass fluidized bed gasification-reburning multi-product unit according to claim 2, characterized in that: The gas-solid separation unit includes a first gas-solid separator (6), a biochar cooler (7), a second gas-solid separator (9), and a return feeder (10). The feed end of the first gas-solid separator (6) is installed at the top of the fluidized bed gasifier (3), the solid discharge end of the first gas-solid separator (6) is connected to the top feed end of the biochar cooler (7), and the bottom of the biochar cooler (7) is provided with a biochar product discharge port (8). The feed end of the second gas-solid separator (9) is installed at the top of the first gas-solid separator (6), and the solid discharge end of the second gas-solid separator (9) is connected to the feed end of the return feeder (10). The discharge end of the return feeder (10) is connected to the bottom end of the fluidized bed gasifier (3) via a pipe. The return feeder (10) is connected to a return fan (22) for sending material particles back to the fluidized bed gasifier (3).

4. The integrated biomass fluidized bed gasification-reburning multi-product unit according to claim 3, characterized in that: The reburning unit includes a staged combustion duct (11) and a reburning chamber (12). One end of the staged combustion duct (11) is connected to the gas outlet of the second gas-solid separator (9), and the other end is connected to the air inlet of the reburning chamber (12). The reburning chamber (12) is sequentially equipped with a high-temperature air preheater (17), an evaporator (13), a superheater (14), an economizer (15), and a low-temperature air preheater (16), and multiple superheaters (14) and economizers (15) are provided. The reburning unit also includes a gasification fan (20) and a combustion fan (21). One end of the gasification fan (20) is connected to the high-temperature air preheater (17) through a pipe, and the other end is connected to the gasification agent inlet (4) through a pipe. One end of the combustion fan (21) is connected to the low-temperature air preheater (16) through a pipe, and the other end is connected to the side wall of the staged combustion air duct (11) through a pipe.

5. The integrated biomass fluidized bed gasification-reburning multi-product unit according to claim 4, characterized in that: The dust removal unit includes a bag filter (24), an induced draft fan (18), and a chimney (19). The inlet of the bag filter (24) is connected to the outlet of the recombustion chamber (12) through a pipe. The bag filter (24) is provided with a biological fine powder outlet (23). One end of the induced draft fan (18) is connected to the outlet of the bag filter (24) through a pipe, and the other end is connected to the chimney (19) through a pipe.

6. The integrated biomass fluidized bed gasification-reburning multi-product unit according to claim 2, characterized in that: The bottom end of the fluidized bed gasifier (3) is also connected to a slag cooler (5).

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