Carbon-based fuel partial gasification coupled boiler system and carbon-based fuel combustion method

Abstract

The application relates to the technical field of boilers, in particular to a carbon-based fuel partial gasification coupled boiler system and a carbon-based fuel combustion method. A high-temperature gas-solid mixture is generated in a gasification chamber of a gasifier, and the high-temperature gas-solid mixture is sprayed into a boiler from a gasification chamber outlet for combustion. The carbon-based fuel is partially gasified through the gasifier, the fuel can be preheated to above 1000 DEG C, the combustion stability problem of (ultra) low-volatile carbon-based fuel can be solved, flue gas discharged from the boiler is recirculated to a feeding assembly, the gasifier and the boiler through a pipeline, the flue gas is mixed into a gasification agent and a combustion-supporting agent, the CO2 content in the flue gas can be increased to above 90%, CO2 collection is facilitated, and high-efficiency, low-nitrogen and low-carbon combustion and utilization of the carbon-based fuel are realized.

Description

Technical Field

[0001] This application relates to the field of boiler technology, and in particular to a boiler system with partial gasification coupling of carbon-based fuel and a method for combustion of carbon-based fuel. Background Technology

[0002] Currently, in the boiler industry, traditional suspension combustion and circulating fluidized combustion technologies are insufficient to solve the problems of stable and efficient combustion of ultra-low volatile carbon-based fuels and low nitrogen emissions. Summary of the Invention

[0003] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0004] To address the technical problems of poor combustion stability, low efficiency, and high carbon emissions of carbon-based fuels, this application provides a boiler system with partial gasification coupling of carbon-based fuels and a method for carbon-based fuel combustion.

[0005] To achieve the above-mentioned objectives, this application adopts the following technical solution:

[0006] A boiler system with partial gasification coupling of carbon-based fuel, comprising:

[0007] Feeding assembly for conveying carbon-based fuel;

[0008] A gasifier, connected to the feeding assembly via a delivery pipe, is used to cause a partial gasification reaction of the carbon-based fuel to form a gas-solid mixture;

[0009] The boiler has a flue gas outlet and a nozzle assembly; and

[0010] A purification device, connected to the flue gas outlet, is used to remove sulfur oxides and / or particulate matter and / or nitrogen oxides from the flue gas;

[0011] The gasifier is connected to the furnace of the boiler, the flue gas outlet is also connected to the gasifier and / or the nozzle group of the boiler, and the outlet of the purification device is connected to the feeding assembly.

[0012] The gasifier generates a high-temperature gas-solid mixture in the gasification chamber and injects it into the boiler for combustion from the gasification chamber outlet. The flue gas discharged from the boiler is recirculated through pipelines to the feeding assembly, gasifier and boiler, and the flue gas is mixed with gasifying agent and combustion aid to solve the problem of CO2 greenhouse gas emissions from carbon-based fuels and achieve efficient, low-nitrogen and low-carbon combustion utilization of carbon-based fuels.

[0013] Furthermore, in some embodiments of the present application, a gas preheater is also included;

[0014] The gas preheater has a first heat exchange channel and a second heat exchange channel. One end of the first heat exchange channel is connected to the flue gas outlet, and the other end is connected to the purification device.

[0015] The inlet of the second heat exchange channel is connected to the combustion-supporting agent storage device, and the outlet of the second heat exchange channel is connected to the boiler.

[0016] Furthermore, in some embodiments of the present application, the nozzle assembly includes a first air nozzle and a second air nozzle located below the first air nozzle;

[0017] The second heat exchange channel is connected to the first air nozzle and / or the second air nozzle to introduce combustion aid into the furnace.

[0018] The flue gas outlet is connected to the first air nozzle and / or the second air nozzle.

[0019] Specifically, a high-temperature gas-solid mixture is generated in the gasification chamber and first injected into the main combustion zone of the boiler from the gasification chamber outlet. In the main combustion zone, it is strongly mixed with the combustion aid injected into the first air nozzle. After completing the main combustion process, it enters the burnout zone. The unburned solid combustible material continues to be strongly mixed with the burnout air injected into the second air nozzle to complete the burnout process.

[0020] Furthermore, in some embodiments of the present application, the first air nozzle is provided in multiple locations and distributed on the walls on opposite sides of the boiler.

[0021] Furthermore, in some embodiments of the scheme in this application,

[0022] The second air nozzle is provided in one or two layers, with multiple second air nozzles in each layer, and the multiple second air nozzles in each layer are distributed on the walls on opposite sides of the boiler.

[0023] Furthermore, in some embodiments of the present application, the feeding assembly includes a storage component and an air-powder mixer, the feeding assembly is connected to the air-powder mixer, and the air-powder mixer is connected to the gasification chamber of the gasifier through a powder feeding pipe.

[0024] Furthermore, in some embodiments of this application, the outlet of the purification device is connected to the inlet of the air-powder mixer.

[0025] Furthermore, in some embodiments of this application, the outlet of the purification device is also connected to a carbon dioxide enrichment device.

[0026] Furthermore, in some embodiments of this application, the vaporizer contains a vaporizing agent, which includes water vapor and / or an O2 / CO2 combustion aid, and the excess air coefficient in the vaporizer is between 0.2 and 0.4.

[0027] The carbon-based fuel can be a mixture of various carbon-based fuels such as pulverized coal, semi-coke powder, biomass powder, or coke powder, gasification waste residue, etc.

[0028] A method for burning carbon-based fuels, comprising:

[0029] Carbon-based fuel is partially gasified inside the gasifier to form a gas-solid mixture, which is then introduced into the boiler.

[0030] The gas-solid mixture is then subjected to primary combustion in the main combustion zone of the boiler.

[0031] This allows unburned solid combustible material to enter the burnout zone and reignite;

[0032] Part of the flue gas discharged from the boiler is introduced into the main combustion zone and / or the burnout zone and / or the gasifier.

[0033] As can be seen from the above technical solutions, the advantages and positive effects of the carbon-based fuel partial gasification coupled boiler system and carbon-based fuel combustion method of this application are as follows:

[0034] This application provides a boiler system with partial gasification coupling of carbon-based fuel, including a feeding assembly, a gasifier, a boiler, and a purification device. The feeding assembly is used to transport carbon-based fuel. The gasifier is connected to the feeding assembly through a conveying pipe and is used to partially gasify the carbon-based fuel to form a gas-solid mixture. The boiler has a flue gas outlet and a nozzle assembly. The purification device is connected to the flue gas outlet and is used to remove sulfur oxides and / or particulate matter and / or nitrogen oxides from the flue gas. The gasifier is connected to the furnace of the boiler. The flue gas outlet is also connected to the gasifier and / or the nozzle assembly of the boiler. The purification device is connected to the feeding assembly.

[0035] The gasifier generates a high-temperature gas-solid mixture in the gasification chamber and injects it into the boiler for combustion through the gasification chamber outlet. The gasifier achieves partial gasification of carbon-based fuels and can preheat the fuel to over 1000°C, which can solve the problem of combustion stability of (ultra) low volatile carbon-based fuels. The flue gas discharged from the boiler is recirculated through pipelines to the feeding assembly, gasifier and boiler, and mixed with gasifying agent and combustion aid, which can increase the CO2 content in the flue gas to over 90%, which facilitates CO2 collection and achieves efficient, low-nitrogen and low-carbon combustion utilization of carbon-based fuels. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of a boiler system with partial gasification coupling of carbon-based fuel, according to an exemplary embodiment.

[0039] Figure 2 This is another structural schematic diagram of a boiler system with partial gasification coupling of carbon-based fuel, according to an exemplary embodiment.

[0040] The reference numerals in the attached figures are explained as follows:

[0041] 1-Storage unit; 2-Air-powder mixer; 3-Gasifier; 31-Gasification chamber; 4-Boiler; 5-Gas preheater; 6-Purification device;

[0042] 41-Furnace chamber; 42-First air nozzle; 43-Second air nozzle; 44-Convection heat exchange surface; 45-Tail flue; 46-Flue gas outlet. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] In the boiler industry, traditional suspension combustion and circulating fluidized combustion technologies are insufficient to solve the problems of stable and efficient combustion of ultra-low volatile carbon-based fuels and low nitrogen emissions.

[0045] To address the technical problems of poor combustion stability, low efficiency, and high nitrogen and carbon emissions of carbon-based fuels, this application provides a boiler system and method for partial gasification coupling of carbon-based fuels, including a feeding assembly, a gasifier 3, a boiler 4, and a purification device 6. The feeding assembly is used to transport carbon-based fuels. The gasifier 3 is connected to the feeding assembly through a conveying pipe and is used to partially gasify the carbon-based fuels to form a gas-solid mixture. The boiler 4 has a flue gas outlet 46 and a nozzle assembly. The purification device 6 is connected to the flue gas outlet 46 and is used to remove sulfur oxides and / or particulate matter and / or nitrogen oxides from the flue gas. The gasifier 3 is connected to the furnace 41 of the boiler 4. The flue gas outlet 46 is also connected to the gasifier 3 and / or the nozzle assembly of the boiler 4. The purification device 6 is connected to the feeding assembly.

[0046] When boiler 4 is working, a high-temperature gas-solid mixture is generated in the gasification chamber 31 of gasifier 3 and injected into boiler 4 through the outlet of gasification chamber 31 for combustion. The gasifier 3 achieves partial gasification of carbon-based fuel, which can preheat the fuel to above 1000℃. This can solve the problem of combustion stability of (ultra) low volatile carbon-based fuel. The flue gas discharged from boiler 4 is recirculated through pipelines to the feeding assembly, gasifier 3 and boiler 4. The flue gas is mixed with gasifying agent and combustion aid, which can increase the CO2 content in the flue gas to more than 90%, which facilitates CO2 collection in the flue gas, solves the problem of CO2 greenhouse gas emissions from carbon-based fuel, and achieves efficient, low-nitrogen and low-carbon combustion utilization of carbon-based fuel.

[0047] Figure 1 This is a schematic diagram of a boiler system with partial gasification coupling of carbon-based fuel, according to an exemplary embodiment. Figure 2 This is another structural schematic diagram of a boiler system with partial gasification coupling of carbon-based fuel, according to an exemplary embodiment.

[0048] refer to Figure 1 As shown, the carbon-based fuel partial gasification coupled boiler system provided by the present invention includes a feeding assembly, a gasifier 3, a boiler 4, a gas preheater 5, and a purification device 6.

[0049] The feeding assembly includes a storage unit 1 and a powder mixer 2.

[0050] Boiler 4 includes furnace 41, nozzle group, convective heat exchange surface 44, flue 45, and flue gas outlet 46.

[0051] The nozzle assembly includes a first air nozzle 42 and a second air nozzle 43.

[0052] The gas preheater 5 includes a first heat exchange channel and a second heat exchange channel.

[0053] The storage unit 1 is connected to the ventilation powder mixer 2. The ventilation powder mixer 2 is connected to the gasification chamber 31 of the gasifier 3 through the powder feeding pipe. The outlet of the gasifier 3 is sealed and connected to the furnace 41 of the boiler 4. One end of the first heat exchange channel is connected to the flue gas outlet 46, and the other end of the first heat exchange channel is connected to the purification device 6. One end of the second heat exchange channel is used to connect to the combustion aid storage unit. The other end of the second heat exchange channel is connected to the gasifier 3 and / or the first air nozzle 42 and / or the second air nozzle 43. The outlet of the purification device 6 is connected to the ventilation powder mixer 2 and the carbon dioxide enrichment device to solve the carbon dioxide emission problem.

[0054] In a specific example, carbon-based fuel is unloaded from storage unit 1 into air-coal mixer 2 and enters gasification chamber 31 of gasifier 3 through coal feeding pipe. Gasifying agent is introduced into gasifier 3, and the excess air coefficient in gasification chamber 31 is maintained at 0.2-0.4. In this application, since gasifier 3 is connected to the second heat exchange channel, the gasifying agent can be water vapor + O2 / CO2 combustion aid.

[0055] In this application, carbon-based fuel undergoes a partial high-temperature oxidation reaction in the gasification chamber 31 of the gasifier 3, thereby preheating the fuel to above 1000°C and solving the problem of combustion stability of (ultra)low volatile carbon-based fuel.

[0056] A high-temperature gas-solid mixture is generated in the gasification chamber 31 and is first injected into the main combustion zone of the boiler 4 from the outlet of the gasification chamber 31. It is strongly mixed with the combustion aid injected into the first air nozzle 42. After the main combustion process is completed, it enters the burnout zone. The unburned solid combustible material continues to be strongly mixed with the burnout air to complete the burnout process.

[0057] like Figure 1 In this application, the secondary air injection inlet is located above the second air injection port 43, that is, the first air injection port 42 is closer to the outlet of the gasification chamber 31. The secondary air injection inlet corresponds to the main combustion zone inside the boiler 4, and the second air injection port 43 corresponds to the burnout zone inside the boiler 4.

[0058] Based on this scheme, those skilled in the art can adjust the concentration of reducing gas in the gasification chamber 31 according to fuel changes to promote the reduction of volatile nitrogen in the gasification chamber 31; control the temperature in the gasification chamber 31 to suppress the generation of thermal NOx; and at the same time, adopt the in-furnace combustion aid staged combustion technology, namely the main combustion zone and the burnout zone, to suppress the generation of fuel NOx. The boiler system with partial gasification coupled combustion can realize NOx type and zone control.

[0059] The hot flue gas generated by combustion in the furnace 41 passes through the furnace 41 and the convective heat exchange surface 44, and is discharged from the flue gas outlet 46 of the boiler 4 through the flue duct 45. The discharged flue gas flows into the purification device 6 through the first heat exchange channel of the gas preheater 5. The purification device 6 can remove sulfur oxides and / or particulate matter and / or nitrogen oxides from the flue gas. The outlet of the flue gas purification device 6 is connected to the inlet of the air-coal mixer 2 and / or the carbon dioxide enrichment device. Combined with CO2 enrichment and storage technology, the problem of greenhouse gas CO2 emissions from carbon-based fuels is solved, and the efficient, low-nitrogen, and low-carbon combustion and utilization of carbon-based fuels is realized.

[0060] The combustion aid storage unit can introduce combustion aid into the second heat exchange channel. The outlet of the second heat exchange channel is connected to the first air nozzle 42 and the second air nozzle 43, thereby introducing combustion aid into the furnace 41. In this application, the carbon-based fuel can be one of pulverized coal, semi-coke powder, or biomass powder.

[0061] The gasifier 3 has a shell with an insulated wall surface to ensure that the gasification chamber 31 has a high temperature for pre-combustion of fuel. The shell is connected to the top of the furnace 41 by welding to seal the gasification chamber 31 and the furnace 41.

[0062] The gasifying agent introduced into the gasification chamber 31 can be water vapor and O2 / CO2 combustion aid. Preferably, the excess air coefficient in the gasification chamber 31 is maintained at 0.2-0.4 to ensure the combustion stability of carbon-based fuels.

[0063] Multiple first air nozzles 42 are provided, preferably 4-6. Multiple first air nozzles 42 are distributed on the walls on opposite sides of the boiler 4. In this example, 4 first air nozzles 42 can be provided, with 2 on each of the opposite side walls. The first air nozzles 42 on the opposite side walls are arranged one-to-one, so that the secondary air forms a tangential circle in the furnace, ensuring that the secondary air is well mixed in the furnace chamber 41.

[0064] The combustion accelerator introduced through the first air nozzle 42 is an O2 / CO2 combustion accelerator.

[0065] The second air nozzle 43 has 1-2 layers, such as Figure 1 As shown, the second air nozzle 43 is provided in one layer, and the number of nozzles in each layer is controlled between 4 and 6. In this example, four second air nozzles 43 are selected and symmetrically arranged on the walls on opposite sides, with two on each side wall, to ensure that the combustion air is well mixed in the furnace 41.

[0066] In this example, the second air nozzle 43 corresponds vertically to the combustible air nozzle, which is beneficial for complete fuel combustion. The combustion improver introduced into the second air nozzle 43 is an O2 / CO2 combustion improver.

[0067] It needs to be stated clearly that, Figure 1In the text, multiple letters B represent connected interfaces, and multiple letters A2 represent connected interfaces, namely, the outlet of the second heat exchange channel is connected to the vaporization chamber 31 and / or the first air nozzle 42 and / or the second air nozzle 43, and the outlet of the purification device 6 is connected to the ventilation powder mixer 2.

[0068] like Figure 2 As shown in the figure, the outlet of the second heat exchange channel is not connected to the gasifier 3. The flue gas outlet 46 of the boiler 4 is connected to the gasifier 3 and / or the first air nozzle 42 and / or the second air nozzle 43 through a pipeline. That is, flue gas is mixed into the combustion aid, which can increase the CO2 content of the flue gas discharged from the boiler 4. There are 6 first air nozzles 42 and two layers of second air nozzles 43, with 6 second air nozzles 43 in each layer.

[0069] Figure 2 In a specific example, the carbon-based fuel can be a blend of various carbon-based fuels such as pulverized coal, semi-coke, biomass powder, coke powder, and gasification waste residue. In this example, the carbon-based fuel is a blend of two or more types. The air-coal mixer 2 introduces carbon-based fuel into the gasification chamber 31 of the gasifier 3. A high-temperature gas-solid mixture is generated in the gasification chamber 31. The partial gasification technology can preheat the fuel to over 1000°C, which can solve the problem of combustion stability of (ultra) low volatile carbon-based fuel. The fuel is first injected into the main combustion zone of the boiler 4 from the outlet of the gasification chamber 31 and strongly mixed with the combustion aid injected into the first air nozzle 42. After completing the main combustion process, it enters the burnout zone. The unburned solid combustible material continues to be strongly mixed with the burnout air injected into the second air nozzle 43 to complete the burnout process. The hot flue gas generated by combustion passes through the furnace 41 and the convective heat exchange surface 44, and is discharged from the flue gas outlet 46 of the boiler 4 through the flue 45. Part of the discharged flue gas flows to the inlet of the gasification chamber 31, the connection between the first air nozzle 42 and the second air nozzle 43, and the other part flows to the inlet of the first heat exchange channel of the gas preheater 5.

[0070] The inlet of the second heat exchange channel of the gas preheater 5 is connected to an O2 / CO2 combustion-supporting agent, and the outlet of the second heat exchange channel is connected to the first air nozzle 42 and the second air nozzle 43. The gas preheater 5 can also preheat the combustion-supporting agent.

[0071] During the operation of boiler 4, the gasifying agent in gasification chamber 31 can be water vapor + recirculated flue gas, and the excess air coefficient in gasification chamber 31 is maintained at 0.2-0.4.

[0072] The combustion aid introduced through the first air nozzle 42 is O2 / CO2 combustion aid + recirculated flue gas.

[0073] The combustion aid introduced through the second air nozzle 43 is O2 / CO2 combustion aid + recirculated flue gas.

[0074] Purification device 6 removes sulfur oxides, particulate matter and nitrogen oxides from the flue gas. The outlet of purification device 6 is connected to the inlet of air-powder mixer 2 and carbon dioxide enrichment unit.

[0075] By using O2 / CO2 as an in-furnace combustion aid, some of the flue gas is mixed with the combustion aid to increase the CO2 content in the flue gas to over 90%. Combined with CO2 enrichment and storage technology, the problem of CO2 greenhouse gas emissions from carbon-based fuels can be solved, achieving efficient, low-nitrogen, and low-carbon combustion and utilization of carbon-based fuels.

[0076] In this application, the shell of the gasifier 3 is made of insulated wall to ensure that there is a high temperature for pre-combustion of fuel in the gasification chamber 31, and the connection between the shell and the top of the furnace 41 of the boiler 4 is made by welding.

[0077] Figure 2 In the example, there are 6 first air nozzles 42, which are symmetrically arranged on the walls on opposite sides of the furnace 41, with 3 nozzles on each side wall, so that the secondary air forms a tangential circle in the furnace and ensures that the secondary air is well mixed in the furnace 41.

[0078] The second air nozzle 43 has two layers, with the number of nozzles in each layer controlled to between six. They are symmetrically arranged on the walls on opposite sides of the furnace 41, with three nozzles on each side wall, to ensure that the burnout air is well mixed in the furnace 41.

[0079] It should be noted that, Figure 2 In the diagram, multiple A1s represent connected interfaces, multiple A2s represent connected interfaces, and multiple Bs represent connected interfaces.

[0080] This application also provides a method for burning carbon-based fuels.

[0081] Carbon-based fuel is partially gasified inside the gasifier to form a gas-solid mixture, which is then introduced into the boiler.

[0082] A combustion-supporting agent is introduced into the boiler;

[0083] The gas-solid mixture is then subjected to primary combustion in the main combustion zone of the boiler.

[0084] This allows unburned solid combustible material to enter the burnout zone and reignite;

[0085] Part of the flue gas discharged from the boiler is introduced into the main combustion zone and / or the burnout zone and / or the gasifier.

[0086] This method employs partial gasification technology for carbon-based fuels to preheat the fuel to over 1000℃, which can solve the combustion stability problem of (ultra)low volatile carbon-based fuels. It uses staged combustion technology with in-furnace combustion aids to suppress the formation of fuel-type NOx. The boiler system with partial gasification coupled combustion can achieve NOx classification and zone control. Using O2 / CO2 as in-furnace combustion aids increases the CO2 content in flue gas to over 90%. Combined with CO2 enrichment and storage technology, it solves the problem of CO2 greenhouse gas emissions from carbon-based fuels, achieving efficient, low-NOx, and low-carbon combustion and utilization of carbon-based fuels.

[0087] In summary, this application provides a boiler system and gas turbine fuel combustion method for partial gasification coupling of carbon-based fuel. The boiler system includes a fuel storage unit 1, an air-coal mixer 2, a gasifier 3, a boiler 4, a gas preheater 5, and a flue gas purification device 6. The boiler 4 includes a furnace 41, a first air nozzle 42, a second air nozzle 43, a convective heat exchange surface 44, a flue 45, and a flue gas outlet 46. Compared with the prior art, under safe and stable operating conditions, the carbon-based fuel undergoes a partial gasification reaction in the gasification chamber 31. Preheating combustibles enables stable combustion of ultra-low volatile carbon-based fuels and suppresses the formation of thermal NOx. Coupled with advanced low-NOx and oxygen-enriched combustion technologies, it achieves efficient, low-NOx and low-carbon combustion utilization of various types of carbon-based fuels. The application of partial gasification technology inside the gasifier 3 not only provides a preheating heat source but also realizes the classification and zoning control of NOx. The injection of combustion aids through the secondary air nozzle and the second air nozzle 43 enables the application of oxygen-enriched combustion technology, significantly increasing the CO2 concentration in the flue gas and reducing the cost and difficulty of CO2 recovery.

[0088] It should be noted that, in this document, relational terms such as "first" and "second" are used merely 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 a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0089] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A boiler system with partial gasification coupling of carbon-based fuel, characterized in that: include; Feeding assembly for conveying carbon-based fuel; The gasifier (3) is connected to the feeding assembly via a conveying pipe and is used to cause the carbon-based fuel portion to undergo a gasification reaction to form a gas-solid mixture; The boiler (4) has a flue gas outlet (46) and a nozzle assembly; as well as Purification device (6) is connected to the flue gas outlet (46), and the purification device (6) is used to remove sulfur oxides and / or particulate matter and / or nitrogen oxides from the flue gas; The gasifier (3) is connected to the furnace (41) of the boiler (4), the flue gas outlet (46) is also connected to the gasifier (3) and / or the nozzle group of the boiler (4), and the outlet of the purification device (6) is connected to the feeding assembly. The gasifier (3) is used to directly couple the combustion organization and the gasification process. It includes a gasification chamber (31). A high-temperature gas-solid mixture is generated in the gasification chamber (31) of the gasifier (3) and injected into the boiler for combustion from the outlet of the gasification chamber (31). A tapered opening is formed at the bottom of the gasifier (3), which creates an acceleration effect, so that the high-temperature gas-solid mixture is injected directly into the boiler (4) at high speed. The vaporizer (3) contains a vaporizing agent, and the excess air coefficient in the vaporizer (3) is between 0.2 and 0.

4.

2. The boiler system with partial gasification coupling of carbon-based fuel according to claim 1, characterized in that: It also includes a gas preheater (5); The gas preheater (5) has a first heat exchange channel and a second heat exchange channel. One end of the first heat exchange channel is connected to the flue gas outlet (46), and the other end is connected to the purification device (6). The inlet of the second heat exchange channel is used to connect to the combustion aid storage device, and the outlet of the second heat exchange channel is connected to the boiler (4).

3. The boiler system with partial gasification coupling of carbon-based fuel according to claim 2, characterized in that: The nozzle assembly includes a first nozzle (42) and a second nozzle (43) located below the first nozzle (42); The second heat exchange channel is connected to the first air nozzle (42) and / or the second air nozzle (43) to introduce combustion aid into the furnace (41); The flue gas outlet (46) is connected to the first air nozzle (42) and / or the second air nozzle (43).

4. The boiler system with partial gasification coupling of carbon-based fuel according to claim 3, characterized in that: Multiple first air nozzles (42) are provided and distributed on the walls on opposite sides of the boiler (4).

5. The boiler system with partial gasification coupling of carbon-based fuel according to claim 3, characterized in that: The second air nozzle (43) is provided in one or two layers, and each layer is provided with multiple second air nozzles (43). In each layer, multiple second air nozzles (43) are distributed on the walls on opposite sides of the boiler (4).

6. The boiler system with partial gasification coupling of carbon-based fuel according to claim 1, characterized in that: The feeding assembly includes a storage unit (1) and a powder mixer (2). The feeding assembly is connected to the powder mixer (2). The powder mixer (2) is connected to the gasification chamber (31) of the gasifier (3) through a powder feeding pipe.

7. The boiler system with partial gasification coupling of carbon-based fuel according to claim 6, characterized in that: The outlet of the purification device (6) is connected to the inlet of the air-powder mixer (2).

8. The boiler system with partial gasification coupling of carbon-based fuel according to claim 1, characterized in that: The outlet of the purification device (6) is also connected to a carbon dioxide enrichment device.

9. A method for burning carbon-based fuel, using a boiler system with partial gasification coupling of carbon-based fuel as described in any one of claims 1 to 8, characterized in that, include: Carbon-based fuel is partially gasified inside the gasifier to form a gas-solid mixture, which is then introduced into the boiler. The gas-solid mixture is then subjected to primary combustion in the main combustion zone of the boiler. This allows unburned solid combustible material to enter the burnout zone and reignite; Part of the flue gas discharged from the boiler is introduced into the main combustion zone and / or the burnout zone and / or the gasifier.

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