Large-scale biomass gasification system and method of use

Abstract

The invention discloses a large-scale biomass gasification system, which comprises a biomass gasification furnace, a combustion chamber, a gas inlet pipe, a gas outlet pipe, a gas inlet pipe and a gas outlet pipe, the burner is arranged at the top of the combustion chamber, and the burner comprises a fuel gas pipe, an oxygen feeding pipe and a plurality of feeding pipes; the conveying system comprises a normal-pressure powder storage bin and a plurality of powder supply modules corresponding to the feeding pipes in number, each powder supply module comprises a feeding tank and at least one variable-pressure lock hopper, and a feeding port and a discharging port of each variable-pressure lock hopper communicate with the normal-pressure powder storage bin and the feeding tank correspondingly; according to the large-scale biomass gasification system, materials are alternately conveyed and stored through the multiple sets of independent powder supply modules, large-scale continuous production is achieved, the invention further discloses a using method of the large-scale biomass gasification system, and continuous production of a biomass gasification furnace can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass gasifiers, and more particularly to a large-scale biomass gasification system and a method for using the same. Background Art

[0002] Biomass fuel, a renewable, carbon-neutral resource, can be converted into synthesis gas primarily composed of carbon monoxide and hydrogen through gasification technology, offering significant environmental value and promising resource utilization. Synthesis gas produced by biomass gasifiers can serve as a key raw material for the production of clean energy sources such as methanol and aviation fuel, providing an important path to replace traditional fossil fuels. With the continuous improvement of the biomass energy industry chain, similar to coal chemical and petrochemical industries, the large-scale development of biomass gasification plants has become an inevitable trend to reduce unit production costs and improve economies of scale. However, this process faces unique technical challenges posed by the characteristics of biomass raw materials.

[0003] Existing technologies for large-scale biomass gasification primarily employ two approaches: one is to deploy multiple independent, small-scale gasification units, each processing a single type of biomass feedstock, operating them in parallel to meet overall throughput requirements; the other is to directly scale up a single unit, increasing its size to increase processing capacity. The former requires duplication of gasifiers, frames, and auxiliary systems, significantly increasing investment costs; the latter is limited by the low bulk density of biomass—to meet continuous feedstock requirements, the equipment diameter often exceeds road transport limits. Furthermore, given the diverse biomass feedstocks in a region, operational flexibility is limited.

[0004] Current technology has three key flaws. First, there is a fundamental contradiction between large-scale equipment and transportation restrictions. The capacity of a single feed tank cannot take into account both large processing capacity and size constraints. Adding additional gasifiers will significantly increase investment. Second, when using a variety of different biomass raw materials, some raw materials are difficult to mix after crushing due to factors such as moisture content and particle size. Switching between different biomass types requires emptying the system, which greatly extends maintenance time.

[0005] Therefore, it is necessary to propose a new type of system with a parallel architecture of multiple storage modules. Under the premise of strictly controlling the transportation size limitations of the equipment, it can break through the processing capacity bottleneck of a single feeding system, realize online seamless switching and zero-interruption continuous production of multiple varieties of biomass raw materials, and ensure the flexibility of system operation and maintenance through redundant design. Summary of the Invention

[0006] One objective of the present invention is to propose a large-scale biomass gasification system and method of use, which can break through the processing capacity bottleneck of a single feeding system while controlling the transportation size limitations of the equipment, and can achieve online seamless switching and zero-interruption continuous production of the same or multiple varieties of biomass raw materials.

[0007] An object of the present invention is to provide a large-scale biomass gasification system comprising: The biomass gasifier has a combustion chamber disposed in the upper portion of its shell, wherein oxygen in the combustion chamber reacts with biomass powder to generate high-temperature synthesis gas, wherein the high-temperature synthesis gas is discharged from the biomass gasifier after cooling; A burner is provided at the top of the combustion chamber, and includes a fuel gas pipe, an oxygen supply pipe and a plurality of material supply pipes; The conveying system includes a normal pressure powder storage bin and several groups of powder supply modules corresponding to the number of the feeding pipes. The powder supply modules include a feeding tank and at least one variable pressure lock hopper. The feed port and the discharge port of the variable pressure lock hopper are respectively connected to the normal pressure powder storage bin and the feeding tank. The feeding tank is connected to the feeding pipe in a one-to-one matching manner.

[0008] Preferably, a central oxygen supply pipe is provided outside the fuel gas pipe in the burner, and the annular space between the central oxygen supply pipe and the fuel gas pipe forms a central oxygen supply channel, a first feeding pipe is provided outside the central oxygen supply pipe, and a first feeding channel is formed between the first feeding pipe and the central oxygen supply pipe, an outer ring oxygen supply pipe is provided outside the first feeding pipe, and an outer ring oxygen supply channel is formed between the first feeding pipe and the outer ring oxygen supply pipe, a second feeding pipe is provided outside the outer ring oxygen supply pipe, and a second feeding channel is formed between the second feeding pipe and the outer ring oxygen supply pipe; the conveying system includes two groups of powder supply modules, and the feeding tanks in each powder supply module are respectively connected to the first feeding channel and the second feeding channel.

[0009] Preferably, the biomass gasifier is a plug flow reactor, the material and high-temperature synthesis gas flow in one direction along the axis of the biomass gasifier, and the diameter of the combustion chamber outlet is equal to the diameter of the combustion chamber middle end.

[0010] Preferably, the biomass gasifier is further provided with a waste boiler chamber and a quenching chamber, the waste boiler chamber is arranged at the lower part of the combustion chamber, the inlet of the waste boiler chamber is connected to the outlet of the combustion chamber, and the outlet of the waste boiler chamber is connected to the inlet of the quenching chamber.

[0011] Preferably, a water-cooled wall with a built-in circulating water pipe is provided in the combustion chamber.

[0012] Preferably, the shell of the biomass gasifier located in the quenching chamber is detachably connected to the remaining shells via a flange.

[0013] The present invention further claims a method for using the large-scale biomass gasification system, comprising the following steps: S1. Several powder supply modules can deliver powder to the biomass gasifier sequentially or simultaneously. In the simultaneous delivery mode, when one variable-pressure lock hopper in a group of powder supply modules is in a feeding operation, the other variable-pressure lock hopper is in a storage operation, and the two feeding tanks jointly deliver materials to the gasifier. In the sequential delivery mode, one group of powder supply modules is in a feeding operation, and the other group is in a storage operation or undergoing maintenance. The powder supply modules deliver a single type of biomass powder in one feeding operation. S2: After the biomass powder is mixed with oxygen, a gasification reaction occurs in the combustion chamber, generating high-temperature synthesis gas mainly composed of carbon monoxide and hydrogen, and molten slag, which flows downward and leaves the combustion chamber together; S3: The high-temperature synthesis gas and molten slag enter the waste boiler room, where heat is recovered and steam is generated. The high-temperature synthesis gas and slag after heat recovery enter the quenching chamber for secondary cooling before leaving the biomass gasifier.

[0014] Preferably, in the sequential conveying operation, when the first feeding tank in one group of powder supply modules has finished conveying the first type of powder and needs to switch to the second feeding tank storing the second type of powder in another group of powder supply modules, a mixing transition step is performed, which includes the following steps: A1. While the first feeding tank is still feeding, open the outlet valve of the second feeding tank to allow the second type of powder to enter the second feeding channel at the initial mass flow rate. Simultaneously, reduce the opening of the outlet valve of the first feeding tank to reduce the mass flow rate of the first type of powder from the rated mass flow rate; and simultaneously increase the opening of the outlet valve of the second feeding tank to increase the mass flow rate of the second biomass material. A2. Dynamically adjust the central oxygen flow rate and the outer ring oxygen flow rate of the biomass gasifier based on the real-time ratio of the mass flow rate of the first type of powder to the mass flow rate of the second type of powder; A3. When the mass flow rate of the first type of powder drops to zero, close the outlet valve of the first feeding tank. When the mass flow rate of the second type of powder reaches its rated mass flow rate, lock the opening of the outlet valve of the second feeding tank.

[0015] Preferably, the remaining first type powder mass in the first feeding tank 31 is monitored. M s ,when , where is the rated mass flow rate of the first type of powder, T For transition time, η is the response regulator, ,in V 1 、V 2 are the volatile matter contents of the first and second type of powders, respectively. Ea1 、 E a2 are the activation energies of the first and second types of powders, respectively; The mass flow rate of the first type of powder in the mixing transition step varies according to the following nonlinear function: ; The mass flow rate of the second type of powder in the mixing transition step varies according to the following nonlinear function: ; in, Rated mass flow rate for the second type of powder.

[0016] Preferably, the calculation formula of the transition time T is: ; in, R 1 、R 2 is the reaction factor coefficient of the first type of powder and the second type of powder, 、 , FC 1 、 FC 2 is the fixed carbon content of the first and second type powders, ρ 1 、 ρ 2 is the bulk density of the first and second type powders, β 1 、 β 2 are the fluidity indexes of the first type of powder and the second type of powder, respectively; a, b, and c are all weight coefficients, which are determined by regression based on the operating data of the biomass gasifier 5.

[0017] The present invention has at least the following beneficial effects: First, the present invention significantly improves the overall processing capacity of the system by providing a biomass gasifier and at least two independent powder supply modules, while ensuring that the equipment size meets transportation specifications. The biomass gasifier is used to ensure that it can adapt to biomass raw materials with different reactivity, while the two feeding modules can greatly improve the feeding capacity of a single furnace.

[0018] Secondly, the layered structure of the burner of the present invention enables the matching connection between the two groups of powder supply modules and the dual biomass channels, forming a physically isolated powder conveying path. This architecture enables different types of biomass powders to be accurately injected into the biomass gasifier through independent channels, avoiding premature mixing of materials with different physical properties during the conveying process. At the same time, the dual-channel design ensures that when a single-channel powder supply module is overhauled, the remaining channel can still maintain the rated atomization speed of the burner, preventing uneven material dispersion due to reduced flow rate.

[0019] Third, when the powder supply module of the present invention needs maintenance or switching of raw material types, another powder supply module can seamlessly take over the feeding task to maintain the continuous operation of the biomass gasifier.

[0020] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the overall system in a technical solution of the present invention; Figure 2 A schematic diagram of a nozzle in a technical solution of the present invention; Figure 3 This is a schematic diagram of the interior of the nozzle in a technical solution of the present invention.

[0022] Figure markings: 1-normal pressure powder storage bin, 2-pressure lock hopper, 3-feeding tank, 31-first feeding tank, 32-second feeding tank, 4-burner, 41-fuel gas pipe, 42-oxygen supply pipe, 421-central oxygen supply pipe, 4211-central oxygen supply channel, 422-outer ring oxygen supply pipe, 4221-outer ring oxygen supply channel, 43-feeding pipe, 431-first feeding pipe, 4311-first feeding channel, 432-second feeding pipe, 4321-second feeding channel, 44-cooling water pipe, 45-burner cooling water pipe, 5-biomass gasification furnace, 51-combustion chamber, 52-waste boiler chamber, 53-quenching chamber, 54-synthesis gas outlet, 55-slag water outlet. DETAILED DESCRIPTION

[0023] The present invention is described in further detail below so that those skilled in the art can implement the invention with reference to the description.

[0024] It should be understood that terms such as "having," "comprising," and "including" used in the embodiments of this application do not exclude the presence or addition of one or more other elements or combinations thereof. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are intended only to explain the relative positional relationships and movement of components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. When an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element through an intervening element. References to "first," "second," etc. in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features designated as "first" or "second" may explicitly or implicitly include at least one of such features.

[0025] It should be noted that the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0026] like Figures 1 - 3 As shown, the present invention provides a large-scale biomass gasification system, characterized by comprising: A biomass gasifier 5 is provided with a combustion chamber 51 at the upper part of its shell, in which oxygen reacts with biomass powder to generate high-temperature synthesis gas, wherein the high-temperature synthesis gas is discharged from the biomass gasifier 5 after cooling; a burner 4 is provided at the top of the combustion chamber 51, and the burner 4 includes a fuel gas pipe 41, an oxygen supply pipe 42 and several feed pipes 43; a conveying system includes a normal pressure powder storage bin 1 and several groups of powder supply modules corresponding to the number of the feed pipes 43, the powder supply module includes a feeding tank 3 and at least one variable pressure lock hopper 2, the feed port and the discharge port of the variable pressure lock hopper 2 are respectively connected to the normal pressure powder storage bin 1 and the feeding tank 3, and the feeding tank 3 is connected to the feed pipe 43 in a one-to-one matching manner.

[0027] In this technical solution, a diversion interface is set at the bottom of the atmospheric pressure powder storage bin 1, and powder is distributed to each pressure-changing lock hopper 2 synchronously through multiple pipelines. The pressure-changing lock hopper 2 realizes pressure isolation between the atmospheric pressure powder storage bin 1 and the feeding tank 3, and maintains continuous transportation of powder by periodic pressurization and pressure relief. For a group of powder supply modules, the biomass powder falls from the atmospheric pressure powder storage bin 1 to the pressure-changing lock hopper 2 by gravity. After the pressure-changing lock hopper 2 is filled to a certain amount, the feed valve is closed, and then the pressure-changing lock hopper 2 is filled with high-pressure gas and the pressure is increased to the same level as the feeding tank 3. The pressure is maintained constant, and then the discharge valve of the variable pressure lock hopper 2 is opened to allow the powder to enter the feeding tank 3. When the powder supply module performs the feeding operation, the powder in the feeding tank 3 is transported by the carrier gas after being pressurized, and is continuously injected into the feeding pipe 43 of the burner 4 through the pipeline. Each powder supply module operates independently. When a variable pressure lock hopper 2 of a group of powder supply modules performs pressure relief or loading, the other lock hopper can continue to feed the feeding pipe, ensuring that the two feeding tanks can feed the burner simultaneously or alternately, ensuring the uninterrupted operation of the biomass gasifier 5.

[0028] In the present technical solution, each feeding tank 3 is provided with at least two material outlets, and each material outlet is separately connected to the corresponding feed pipe 43 through a pipeline, so as to solve the blockage risk that may be caused by a single material outlet. The feeding tank 3 of each group of powder supply modules is only connected to a single feed pipe 43, forming a physically isolated conveying path to avoid cross-mixing of materials from different powder supply modules. A feed pipeline can be provided between the feeding tank 3 and the corresponding feed pipe 43 to prevent local blockage.

[0029] The working principle of the biomass gasifier 5 is based on the thermochemical reaction occurring in its combustion chamber 51. Fuel gas, oxygen and biomass powder are input into the combustion chamber 51 through the fuel gas pipe 41, oxygen supply pipe 42 and feed pipe 43 of the burner 4, and a gasification reaction occurs in a high-temperature environment. The fuel gas is first burned to provide a basic heat source, so that the furnace temperature rises to the threshold required for biomass pyrolysis. Then the fuel gas is withdrawn, and only biomass and oxygen are used as reaction raw materials. After being heated, the biomass powder is cracked to release volatile matter, and its solid carbon undergoes a partial oxidation reaction with the oxygen introduced to generate a high-temperature synthesis gas mainly composed of carbon monoxide and hydrogen. The high-temperature synthesis gas generated by the reaction completes the conversion of basic components in the combustion chamber 51, and is discharged from the biomass gasifier 5 after step-by-step cooling treatment. The entire process achieves preliminary control of the reaction temperature and synthesis gas composition through the staged input of fuel and biomass.

[0030] In this technical solution, multiple groups of powder supply modules are set up to match the number of feeding pipes 43. The two groups of feeding modules can feed materials simultaneously or alternately, so that each powder supply module can independently perform the charging-pressurizing-delivering cycle. When the feeding tank 3 of one group of powder supply modules continuously delivers powder to the burner 4, the lock bucket 2 of other modules can perform pressure relief, feeding from the normal pressure powder storage bin 1 or pressurizing operation at the same time. This design breaks through the inherent limitations of the traditional single feeding chain, that is, the traditional biomass gasification system needs to interrupt production when the biomass powder is switched or the feeding tank needs to be repaired. This technical solution can It realizes the online seamless alternating supply of the same or different types of biomass powder. At the same time, the modular architecture can control the size of a single set of equipment in the entire system within the width and height limits of road transportation, reducing the overall construction cost. The parallel connection of multiple powder supply modules significantly improves the total processing capacity of the system to meet the needs of large-scale biomass gasification. Each powder supply module conveys a unique type of biomass powder in a single feeding operation, which can effectively avoid the premature mixing of different types of biomass powder during the transportation process, thereby realizing the effective separation of different types of biomass materials.

[0031] In another technical solution, the fuel gas pipe 41 in the burner 4 is provided with a central oxygen supply pipe 421 on the outer sleeve, and the annular space between the central oxygen supply pipe 421 and the fuel gas pipe 41 forms a central oxygen supply channel 4211. The central oxygen supply pipe 421 is provided with a first feeding pipe 431 on the outer sleeve, and a first feeding channel 4311 is formed between the first feeding pipe 431 and the central oxygen supply pipe 421. The first feeding pipe 431 is provided with an outer ring oxygen supply pipe 422 on the outer sleeve, and an outer ring oxygen supply channel 4221 is formed between the first feeding pipe 431 and the outer ring oxygen supply pipe 422. The outer ring oxygen supply pipe 422 is provided with a second feeding pipe 432 on the outer sleeve, and a second feeding channel 4321 is formed between the second feeding pipe 432 and the outer ring oxygen supply pipe 422. The conveying system It includes two groups of powder supply modules, and the feeding tank 3 in each powder supply module is respectively connected to the first feeding channel 4311 and the second feeding channel 4321. Specifically, a cooling water pipe 44 is further provided between the fuel gas pipe 41 and the central oxygen supply pipe 421. Ignition cooling water circulates in the annular space between the cooling water pipe 44 and the fuel gas pipe 41. The annular space between the cooling water pipe 44 and the central oxygen supply pipe 421 forms a central oxygen supply channel 4211. The burner 4 realizes the physical isolation and transportation of biomass powder and oxidant through a multi-layer concentric sleeve structure. The fuel gas pipe 41 provides a basic fire core, and the central oxygen supply channel 4211 continuously transports central oxygen to maintain flame stability. After the gasifier temperature meets the requirements, the biomass enters the gasifier, and then the fuel gas exits. The first feeding channel 4311 and the second feeding channel 4321 are independently connected to the two groups of powder supply modules, so that the biomass powder delivered in batches is not cross-mixed before the outlet of the burner 4. The outer ring oxygen supply channel 4221 continuously delivers outer ring oxygen that wraps around the biomass powder. A burner cooling water pipe 45 is also provided outside the outer ring oxygen supply pipe 422, and burner cooling water circulates inside the pipe to cool the burner 4 as a whole.

[0032] During actual operation, the two groups of powder supply modules can be responsible for conveying different types of biomass powder to the first feeding channel 4311 and the second feeding channel 4321 respectively. When the first group of powder supply modules is working, the biomass powder enters its variable pressure lock hopper 2 from the normal pressure powder storage bin 1. After the variable pressure lock hopper 2 is pressurized to the same pressure as the feeding tank 3, the powder is fed into the feeding tank 3. The feeding tank 3 then uses the carrier gas to transport the powder along the pipeline to the first feeding channel 4311. When the two feeding modules discharge materials at the same time, the second group of feeding modules repeats the same action as the first group. When the second group completes maintenance and needs to be started, its variable pressure lock hopper 2 receives the same or another type of biomass powder from the normal pressure powder storage bin 1. After the variable pressure lock hopper 2 completes pressurization, it is sent to the corresponding feeding tank 3, waiting for the feeding instruction, and the fuel gas pipe 41 transports the fuel gas to the combustion chamber 51.

[0033] The use of a multi-layer nested burner 4 structure in conjunction with multiple groups of independent powder supply modules realizes the physical isolation and transportation of two batches of biomass powder, avoiding premature mixing of different types of powder during transportation, thereby reducing reaction fluctuations caused by differences in material properties. The oxygen in the central oxygen supply pipe 421 and the outer ring oxygen supply pipe 422 are independently adjusted, which can accurately control the reaction conditions according to the gasification requirements of different powders, thereby ensuring the uniformity and stability of the reaction in the combustion chamber 51.

[0034] In another technical solution, the biomass gasifier 5 is a plug flow reactor, and the material and high-temperature synthesis gas flow unidirectionally along the axial direction of the biomass gasifier 5. The outlet diameter of the combustion chamber 51 is equal to the diameter of the middle end of the combustion chamber 51. In this technical solution, the outlet diameter of the combustion chamber 51 is equal to the diameter of the middle end, and an equal-diameter channel is formed inside the entire combustion chamber 51. The flow velocity of the biomass powder is stable during the flow process, avoiding local turbulence or retention caused by changes in cross-sectional area. When the high-temperature synthesis gas and molten slag move from the middle section of the combustion chamber 51 to the outlet, the equal-diameter structure ensures that their flow path is uniform, and there will be no sudden drop or increase in flow velocity due to sudden expansion or contraction of the space, thereby reducing the local friction between the synthesis gas and the furnace wall, and avoiding the accumulation of molten slag in local areas. This flow state makes the residence time of each part of the material in the combustion chamber 51 basically consistent, and the reaction conditions are gradiently distributed along the axial direction, ensuring that the gasification reaction proceeds in an orderly manner according to the preset process.

[0035] In another technical solution, the biomass gasifier 5 is further provided with a waste boiler chamber 52 and a quenching chamber 53. The waste boiler chamber 52 is provided at the lower part of the combustion chamber 51. The inlet of the waste boiler chamber 52 is connected to the outlet of the combustion chamber 51, and the outlet of the waste boiler chamber 52 is connected to the inlet of the quenching chamber 53. In this technical solution, the waste boiler chamber 52 is a heat exchange device provided at the lower part of the combustion chamber 51 for recovering high-temperature synthesis gas. A coil or tube structure is arranged inside the waste boiler chamber 52. Boiler water flows in the tube to exchange heat with the high-temperature synthesis gas outside the tube. The quenching chamber 53 is a device that uses water quenching to quickly cool the high-temperature synthesis gas and separate the slag. The quenching chamber 53 A certain liquid level is maintained inside the boiler. High-temperature synthesis gas and slag enter the water through the downcomer. The slag solidifies and settles to the bottom. The synthesis gas is washed with water and discharged from the top outlet. The cooled synthesis gas leaves the gasifier through the synthesis gas outlet 54, while the ash water is discharged from the slag water outlet 55. Boiler water in the waste boiler chamber 52 enters from the waste boiler inlet, leaves from the waste boiler outlet after heat exchange and produces saturated steam. The combination of the waste boiler chamber 52 and the quenching chamber 53 realizes the efficient synergy of sensible heat recovery of high-temperature synthesis gas and ash separation. By recovering heat in the waste boiler chamber 52 to produce saturated steam, the energy utilization rate of the system is significantly improved. About 40% to 50% of the sensible heat of the synthesis gas can be converted into usable steam, reducing overall energy consumption. The water quenching cooling method in the quenching chamber 53 not only quickly solidifies the slag, facilitating subsequent processing, but also preliminarily purifies the synthesis gas through water washing, reducing the dust content, and providing cleaner raw gas for downstream processes. In addition, this two-stage cooling structure avoids the energy waste caused by direct quenching of high-temperature synthesis gas.

[0036] In another technical solution, a water-cooled wall with a built-in circulating water pipe is provided in the combustion chamber 51. The circulating water pipe of the water-cooled wall is evenly arranged along the circumference of the inner wall of the combustion chamber 51, and is in a vertical or spiral ascending structure. The lower end is connected to the lower header, and the upper end is connected to the upper header, forming a closed water circulation system. The boiler water enters the circulating water pipe from the lower header. After absorbing the high-temperature flame radiation heat in the pipe, part of the water is vaporized into steam, forming a steam-water mixture that flows upward to the upper header. After separation in the steam-water separator, the steam is discharged from the system, and the separated water returns to the lower header to continue circulation, isolating the high temperature in the combustion chamber 51 from the refractory material of the furnace wall, effectively reducing the surface temperature of the refractory material to below 1000°C.

[0037] In another technical solution, the shell of the biomass gasifier 5 located in the quenching chamber 53 is detachably connected to the rest of the shell through a flange. The high-temperature synthesis gas contains a high amount of chlorine, so the shell of the quenching chamber 53 is exposed to much greater corrosion than other parts of the gasifier. Therefore, the fragile quenching chamber 53 is designed as an independent module. When the quenching chamber 53 reaches the end of its service life due to corrosion, the module can be quickly replaced by removing the flange, avoiding the overall shutdown of the biomass gasifier 5 for maintenance, greatly shortening the inspection time and reducing maintenance costs. Optionally, corrosion-resistant materials such as high-nickel alloys can be used to make the shell of the quenching chamber 53.

[0038] A method for using a large-scale biomass gasification system is applied to the above-mentioned large-scale biomass gasification system, and is characterized by comprising the following steps: S1. Several powder supply modules can convey powder into the biomass gasifier 5 in sequence or simultaneously. In the simultaneous conveying condition, when one pressure-variable lock hopper 2 in a group of powder supply modules is in feeding operation, the other pressure-variable lock hopper 2 performs storage operation, and the two feeding tanks 3 jointly convey materials to the gasifier. In the sequential conveying condition, one group of powder supply modules performs feeding operation, and the other group performs storage operation or maintenance. The type of biomass powder conveyed by the powder supply module in one feeding operation is unique. Specifically, in the system startup phase, multiple groups of powder supply modules enter the working state simultaneously or in sequence according to a preset order. The pressure-variable lock hopper 2 of the first group of powder supply modules receives a specific type of biomass powder from the atmospheric pressure powder storage bin 1. After the pressure-variable lock hopper 2 increases the pressure to the same as the feeding tank 3 by filling it with inert gas, it opens the bottom valve to convey the biomass powder to the feeding tank 3; In a group of powder supply modules, when one of the variable pressure lock hoppers 2 is feeding materials to the corresponding feeding tank 3, the pressure of other variable pressure lock hoppers 2 is at normal pressure and collects materials from the normal pressure storage tank. The feeding tank 3 uses carrier gas to transport the powder along the pipeline to the corresponding feeding channel of the nozzle 4, such as the first feeding channel 4311. Each group of powder supply modules can be configured with an independent control system, and the material status is monitored in real time through pressure sensors and level meters to ensure the stability of the feeding operation.

[0039] When the biomass powder level in the feeding tank 3 in a group of powder supply modules is low, the system enters the feeding program, and the valve below the full-level transformer lock hopper 2 opens to supply material to the feeding tank 3. After the transformer lock hopper 2 completes the feeding of the feeding tank 3, the valve between the transformer lock hopper 2 and the feeding tank 3 is cut off, and then the transformer lock hopper 2 is depressurized and enters the collection program to achieve seamless connection. Optionally, when the types of powder in the two powder supply modules are different, the control system can also control the two powder supply modules to gradually open or close the valves, so that the system can adapt to the supply fluctuations of different biomass powders. For example, when switching from conveying sawdust powder to straw powder, the carrier gas flow of the feed tank 3 in the powder supply module storing straw powder is gradually increased from zero to the rated value, and at the same time, the carrier gas flow of the feed tank 3 in the powder supply module that is supplying sawdust powder is synchronously reduced. The entire switching process lasts about 5 to 15 minutes, during which the reaction stability in the combustion chamber 51 is maintained by adjusting the oxygen flow. This modular switching mechanism enables the system to adapt to the supply fluctuations of different biomass powders, ensures the continuous operation of the biomass gasifier 5, and significantly improves production efficiency.

[0040] S2: After the biomass powder is mixed with oxygen, a gasification reaction occurs in the combustion chamber 51 to generate high-temperature synthesis gas mainly composed of carbon monoxide and hydrogen, and molten slag, which flow downward together and leave the combustion chamber 51. Specifically, after the biomass powder enters the combustion chamber 51 with the carrier gas, it quickly undergoes drying, pyrolysis and gasification processes. The water evaporates within a few milliseconds, the volatile matter is quickly precipitated and reacts with oxygen to release heat, and the remaining fixed carbon undergoes a reduction reaction with carbon dioxide and water vapor to generate carbon monoxide and hydrogen.

[0041] S3: The high-temperature synthesis gas and molten slag enter the waste boiler chamber 52, which recovers heat and generates steam. The high-temperature synthesis gas and slag after heat recovery enter the quenching chamber 53 for secondary cooling before leaving the biomass gasifier 5.

[0042] This technical solution has significant advantages over the existing technology. In the feeding link, steps S1 and S2 can realize the continuous delivery of the same or different types of biomass powders through the independent control and storage of multiple groups of powder supply modules when the materials need to be replaced in the middle, which greatly improves the continuity and stability of the system operation. At the same time, it can flexibly adapt to the supply needs of diversified biomass raw materials. In the reaction stage S3, relying on the reasonable design of the combustion chamber, the biomass powder and oxygen are fully mixed and reacted efficiently, ensuring the stable output of synthesis gas and the smooth flow of molten slag. The subsequent S4 realizes the cascade utilization of energy through heat recovery in the waste boiler chamber 52 and secondary cooling in the quenching chamber 53. The effective separation and treatment of synthesis gas and slag are ensured through graded cooling, avoiding damage to subsequent equipment due to high temperature, and improving the energy utilization rate and operation economy of the system as a whole.

[0043] In another technical solution, in step 2, when the first feeding tank 31 in one group of powder supply modules has completed delivering the first type of powder and needs to switch to the second feeding tank 32 storing the second type of powder in another group of powder supply modules, a mixing transition step is performed, which includes the following steps: A1. When the first feeding tank 31 is still in the feeding operation, the outlet valve of the second feeding tank 32 is opened to allow the second type of powder to enter the second feeding channel 4321 at the initial mass flow rate, and the outlet valve opening of the first feeding tank 31 is simultaneously reduced to reduce the mass flow rate of the first type of powder from the rated mass flow rate; the outlet valve opening of the second feeding tank is simultaneously increased to match the increase in the mass flow rate of the second biomass material. Specifically, when the first feeding tank 31 and the second feeding tank 32 contain the same type of biomass powder, the two groups of powder supply modules can be directly switched. However, when the types of stored biomass powder are different, If the direct switching method is continued, the temperature and pressure entering the combustion chamber 51 may fluctuate violently due to the large differences in the characteristics of different biomass materials. At the same time, since the rated flow rates of different types of biomass powders are different, direct switching will cause the powder flow rate to change instantly. If these fluctuations exceed the system safety threshold, the control system will trigger an emergency shutdown procedure to protect the equipment, significantly increasing the risk of shutdown. Even if the system is not shut down, the quality of the synthesis gas will be seriously deteriorated and the equipment loss will be increased, which violates the requirement of continuous and stable operation of large-scale biomass gasification systems. Therefore, a mixed transition step is required.

[0044] For example, when the material level of the first feed tank 31 drops to a preset switching threshold, the control system triggers the mixing transition program. First, the pneumatic control valve at the outlet of the second feed tank 32 is opened and its initial opening is set to 10% to 15% of the rated value, corresponding to an initial mass flow rate of the second type of powder of approximately 15% to 20% of the rated value. At the same time, the opening of the valve at the outlet of the first feed tank 31 is synchronously adjusted at a rate of 1% / s, so that its mass flow rate decreases linearly from the rated value. During the flow adjustment process, the flow data of the two biomass powders is monitored in real time by a mass flow meter, and the signal is fed back to the PLC control system. When the mass flow rate of the first type of powder drops to 80% of the rated value, the mass flow rate of the second feed tank 32 is synchronously increased to 20% of the rated value, and so on, to maintain the total mass flow rate fluctuation of the two types of powder within ±5%. The entire flow adjustment process lasts for approximately 5-8 minutes. During this period, the valve opening is accurately adjusted by the PID controller to ensure a smooth transition of the flow change and avoid pressure fluctuations in the combustion chamber 51 caused by sudden flow changes.

[0045] A2. Dynamically adjust the central oxygen flow rate and the outer ring oxygen flow rate of the biomass gasifier 5 based on the real-time ratio of the mass flow rates of the first and second types of powders. Dynamically adjust the oxygen flow rates of the central oxygen supply channel 4211 and the outer ring oxygen supply channel 4221 based on the real-time monitored mass flow rate ratio of the two types of powders. For example, when the mass ratio of the first type of powder of high volatile wood to the second type of powder of high fixed carbon herbaceous raw material is 7:3, the central oxygen flow rate accounts for 35% to 40% of the total oxygen, and the outer ring oxygen flow rate accounts for 60% to 65%. As the ratio changes to 3:7, the central oxygen flow rate is gradually adjusted to 30% to 35%, and the outer ring flow rate increases to 65% to 70%. The specific adjustment strategy is that in the mixing transition stage, the control system obtains the mass flow rate data of the first type of powder and the second type of powder every 200 milliseconds, and calculates the total oxygen demand in real time based on the unit oxygen demand parameters of the two types of powders determined in advance by elemental analysis and stored in the raw material characteristic database. At the same time, the PLC system stores a total of 1 including the two types of biomass powders from 0% to 100%. A lookup table of central oxygen distribution coefficients corresponding to different mixing ratio points is used. The actual central oxygen distribution coefficient is calculated by linear interpolation based on the current real-time mixing ratio of the two types of powder. For example, when the second type of powder accounts for 45%, the distribution coefficients corresponding to the two ratio points of 40% and 50% are used as the basis to calculate the coefficient at 45%. Then, the total oxygen amount is determined according to the preset oxygen-carbon ratio, and the total oxygen amount is distributed to the central oxygen supply channel 4211 and the outer ring oxygen supply channel 4221 according to the calculated distribution coefficients. The oxygen flow rates of the two channels are then converted into control signals to control the corresponding oxygen regulating valves respectively.

[0046] A3. When the mass flow rate of the first type of powder drops to zero, the outlet valve of the first feeding tank 31 is closed. When the mass flow rate of the second type of powder reaches its rated mass flow rate, the outlet valve opening of the second feeding tank 32 is locked.

[0047] In this technical solution, the mixed transition step gradually adjusts the mass flow of the first type of powder and the second type of powder, and dynamically matches the center and outer ring oxygen flow rates according to the real-time ratio, ultimately achieving seamless switching between the two types of powders. This avoids fluctuations in the internal working conditions of the combustion chamber 1 or even shutdowns caused by sudden replacement of biomass raw materials, ensures the stability of the synthesis gas composition, reduces local high-temperature slagging and pollutant generation, and extends the service life of equipment such as refractory materials, reduces maintenance costs, and at the same time, the process does not require production interruption, significantly improves the system's continuous operation capability, and enhances its adaptability to diverse biomass raw materials. This technical solution realizes seamless switching of different types of biomass powders under sequential conveying conditions, avoiding drastic fluctuations in the reaction conditions of the combustion chamber caused by sudden changes in the types of powders. By opening the second feeding tank 32 while the first feeding tank 31 is still feeding and synchronously adjusting the flow rates of the two, and coordinating the dynamic adjustment of the central and outer ring oxygen flow rates, the stability of the total material flow and reaction conditions during the switching process is ensured. The powder type switching can be completed without interrupting production, which not only ensures the consistency of the synthesis gas quality, but also extends the service life of the equipment and improves the system's continuous operation capability and adaptability to diversified raw materials.

[0048] In another technical solution, the quality of the remaining first type of powder in the first feeding tank 31 is monitored. M s ,when , where is the rated mass flow rate of the first type of powder, T For transition time, η is the response regulator, ,in V 1 、V 2 are the volatile matter contents of the first and second type of powders, respectively. E a1 、E a2 are the activation energies of the first and second type powders, respectively. The mass flow rate of the first type powder in the mixing transition step varies according to the following nonlinear function: , the mass flow rate of the second type of powder in the mixing transition step varies according to the following nonlinear function: ,in, Rated mass flow rate for the second type of powder.

[0049] In this technical solution, the weighing sensor configured in the feeding tank 3 is used to collect M s , and The transition time is determined based on the equipment's transport capacity and gasification reaction requirements. TThe selection of the gasification reaction should ensure a smooth transition when the mixing ratio of the two types of powders changes, avoiding drastic fluctuations in temperature and synthesis gas composition; V 1 、V 2 、E a1 、E a2 All were measured according to existing test methods. η The purpose is to quantify the degree of difference in reaction characteristics between the first type of powder and the second type of powder due to differences in volatile matter content and activation energy. is the difference in volatile matter between the two biomass powders, is the activation energy difference between the two biomass powders, where 2 and 0.3 are weight coefficients, and optionally, the reaction adjustment factor η The weight coefficients in the equation can be adjusted according to the dominant factors of the differences in feedstock characteristics, the limitations of system response capabilities, the balance between safety and economy, and data-driven optimization. For example, when the volatile matter of two types of feedstocks differs significantly, the weight of the volatile matter difference item can be increased to cope with changes in the pyrolysis gas production rate.

[0050] For example, in a biomass gasification system, the first feeding tank 31 is conveying sawdust powder, and the parameters corresponding to the sawdust powder are: V 1 =78%, E a1 =115kJ / mol, =167kg / min, the second feeding tank 32 stores straw powder, and the parameters corresponding to the straw powder are V 2 =65%, E a2 =140kJ / mol, =179kg / min, response adjustment factor η = 0.757, set the transition time T=600s, when the remaining sawdust mass in the first feeding tank is M S = 1120 kg The mixing transition step is performed at the same time. During the transition process, the mass flow rate of the sawdust powder is The mass flow rate of straw powder is nonlinearly reduced. Perform nonlinear increment.

[0051] In this technical solution, by monitoring the quality of the remaining biomass powder and combining the reaction regulating factor ηDetermining the switching start point ensures the rationality of the start timing of the transition step. At the same time, the nonlinear flow change design based on the hyperbolic tangent function enables a smooth transition of the two types of powder flows, avoiding the impact of sudden flow changes on the reaction, further ensuring the stability of the combustion chamber reaction, and reducing the fluctuation of the synthesis gas composition and the risk of equipment slagging.

[0052] In another technical solution, the calculation formula of the transition time T is: ; in, R 1 、R 2 is the reaction factor coefficient of the first type of powder and the second type of powder, 、 , FC 1 、 FC 2 is the fixed carbon content of the first and second type powders, ρ 1 、 ρ 2 is the bulk density of the first and second type powders, β 1 、 β 2 They are the fluidity indexes of the first and second types of powder respectively, a, b, c are weight coefficients, which are determined by regression based on the operating data of the biomass gasifier 5 and obtained through existing industrial analysis methods. β 1 、 β 2 、 FC 1 、 FC 2 、 ρ 1 、 ρ 2 .

[0053] In this technical solution, in order to determine the weight coefficients a, b, and c, it is necessary to conduct multiple switching tests on the entire system, including the following steps: B1. Select several typical biomass powder combinations, each containing two biomass powders to be switched, and determine the material information of each biomass powder in advance; B2. Perform multiple rounds of transition time gradient tests for each combination. After setting multiple sets of initial transition times T, perform switching operations between the first and second types of powders. Record the optimal transition time T at which key parameters such as temperature, pressure, and syngas composition in the biomass gasifier 5 stabilize at the transition time T. The optimal transition time T and the corresponding first and second type powder material information are used as sample pairs. B3. After collecting multiple groups of sample pairs with different combinations, a linear regression analysis method is used, with the actual transition time as the dependent variable and the various difference values ​​as the independent variables. The weight coefficients a, b, and c that best match the predicted transition time with the actual stable transition time are obtained through fitting calculation. Specifically, the dimensions of the weight coefficients are adapted to convert the characteristic parameter differences into time units.

[0054] For example, in a biomass gasification system, several groups of typical biomass powder combinations were selected in advance to conduct multiple rounds of transition time gradient tests, and regression calculations yielded a=0.15, b=0.08, and c=0.05. For this biomass gasification system, the corresponding transition time T is calculated as follows: The first type of powder is sawdust powder, and the second type of powder is straw powder. The parameters corresponding to sawdust powder are V 1 =78%, FC 1 =15%, E a1 =115kJ / mol, ρ 1 = 320kg / m³, β 1 = 82, the parameters corresponding to straw powder are V 2 =65%, FC 2 =18%, E a2 =140kJ / mol, ρ 2 = 280kg / m³, β 2 = 58 This corresponds to the transition time from sawdust powder to straw powder .

[0055] In this technical solution, the calculation formula for the transition time comprehensively considers the differences in powder fluidity index, bulk density and reaction factor coefficient. By determining the weight coefficients corresponding to different biomass powder combinations based on regression of system operation data, the influence of different characteristic differences of the same group of biomass powders on the transition time can be accurately quantified, ensuring that the transition time is sufficient to cope with the reaction changes caused by differences in raw material characteristics, and will not reduce production efficiency due to being too long. This effectively enhances the system's adaptability to biomass raw materials with different physical and chemical properties, and ensures the stability and efficiency of the switching process.

[0056] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. Large-scale biomass gasification system, characterized by: include: A biomass gasifier (5) is provided with a combustion chamber (51) at the upper portion of its shell, wherein oxygen reacts with biomass powder in the combustion chamber (51) to generate high-temperature synthesis gas, wherein the high-temperature synthesis gas is discharged from the biomass gasifier (5) after cooling; A burner (4) is arranged at the top of the combustion chamber (51), and the burner (4) includes a fuel gas pipe (41), an oxygen supply pipe (42) and a plurality of material supply pipes (43); A conveying system comprises a normal pressure powder storage bin (1) and a plurality of groups of powder supply modules corresponding to the number of the feeding pipes (43), wherein the powder supply modules comprise a feeding tank (3) and at least one variable pressure lock hopper (2), wherein the feed port and the discharge port of the variable pressure lock hopper (2) are respectively connected to the normal pressure powder storage bin (1) and the feeding tank (3), and the feeding tank (3) is connected to the feeding pipes (43) in a one-to-one matching manner.

2. The large-scale biomass gasification system according to claim 1, characterized in that: The fuel gas pipe (41) in the burner (4) is provided with a central oxygen supply pipe (421) on its outer sleeve, and the annular space between the central oxygen supply pipe (421) and the fuel gas pipe (41) forms a central oxygen supply channel (4211); the central oxygen supply pipe (421) is provided with a first feeding pipe (431) on its outer sleeve, and a first feeding channel (4311) is formed between the first feeding pipe (431) and the central oxygen supply pipe (421); the first feeding pipe (431) is provided with an outer ring oxygen supply pipe (422) on its outer sleeve, and an outer ring oxygen supply channel (4221) is formed between the first feeding pipe (431) and the outer ring oxygen supply pipe (422); the outer ring oxygen supply pipe (422) is provided with a second feeding pipe (432) on its outer sleeve, and a second feeding channel (4321) is formed between the second feeding pipe (432) and the outer ring oxygen supply pipe (422); The conveying system comprises two groups of powder material supply modules, and the feeding tank (3) in each powder material supply module is respectively connected to the first feeding channel (4311) and the second feeding channel (4321).

3. The large-scale biomass gasification system according to claim 1, characterized in that: The biomass gasifier (5) is a plug flow reactor, and the material and high-temperature synthesis gas flow in a single direction along the axial direction of the biomass gasifier (5). The outlet diameter of the combustion chamber (51) is equal to the diameter of the middle end of the combustion chamber (51).

4. The large-scale biomass gasification system according to claim 1, characterized in that: The biomass gasification furnace (5) is further provided with a waste boiler chamber (52) and a quenching chamber (53). The waste boiler chamber (52) is provided at the lower part of the combustion chamber (51). The inlet of the waste boiler chamber (52) is communicated with the outlet of the combustion chamber (51), and the outlet of the waste boiler chamber (52) is communicated with the inlet of the quenching chamber (53).

5. The large-scale biomass gasification system according to claim 1, characterized in that: A water-cooled wall with a built-in circulating water pipe is provided in the combustion chamber (51).

6. The large-scale biomass gasification system according to claim 4, characterized in that: The shell of the biomass gasifier (5) located in the quenching chamber (53) is detachably connected to the remaining shells via a flange.

7. A method for using a large-scale biomass gasification system, applied to the large-scale biomass gasification system according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Several powder supply modules can sequentially or simultaneously transport powder into the biomass gasifier (5). In the simultaneous transporting operation, when one variable pressure lock hopper (2) in a group of powder supply modules is in a feeding operation, the other variable pressure lock hopper (2) is in a storage operation, and the two feeding tanks (3) jointly transport materials to the gasifier. In the sequential transporting operation, one group of powder supply modules is in a feeding operation, and the other group is in a storage operation or undergoing maintenance. The powder supply modules transport a unique type of biomass powder in one transporting operation. S2: The biomass powder is mixed with oxygen and undergoes a gasification reaction in the combustion chamber (51), generating a high-temperature synthesis gas mainly composed of carbon monoxide and hydrogen and molten slag, which flows downward and leaves the combustion chamber (51); S3: The high-temperature synthesis gas and molten slag enter the waste boiler chamber (52), which recovers heat and generates steam. The high-temperature synthesis gas and slag after heat recovery enter the quenching chamber (53) for secondary cooling and then leave the biomass gasifier (5).

8. The method for using a large-scale biomass gasification system according to claim 7, wherein: In the sequential conveying mode, when the first feeding tank (31) in one group of powder supply modules has completed conveying the first type of powder and needs to switch to the second feeding tank (32) storing the second type of powder in another group of powder supply modules, a mixing transition step is performed, which includes the following steps: A1. When the first feeding tank (31) is still in the feeding operation, the outlet valve of the second feeding tank (32) is opened to allow the second type of powder to enter the second feeding channel (4321) at the initial mass flow rate, and the opening of the outlet valve of the first feeding tank (31) is simultaneously reduced to reduce the mass flow rate of the first type of powder from the rated mass flow rate; and the opening of the outlet valve of the second feeding tank is simultaneously increased to increase the mass flow rate of the second biomass material; A2. dynamically adjusting the central oxygen flow rate and the outer ring oxygen flow rate of the biomass gasifier (5) based on the real-time ratio of the mass flow rate of the first type of powder to the mass flow rate of the second type of powder; A3. When the mass flow rate of the first type of powder material drops to zero, the outlet valve of the first feeding tank (31) is closed. When the mass flow rate of the second type of powder material reaches its rated mass flow rate, the outlet valve opening of the second feeding tank (32) is locked.

9. The method for using a large-scale biomass gasification system according to claim 8, wherein: Monitor the quality of the remaining first type of powder in the first feeding tank (31) M s ,when , where is the rated mass flow rate of the first type of powder, T For transition time, η is the response regulator, ,in V 1 、V 2 are the volatile matter contents of the first and second type of powders, respectively. E a1 、E a2 are the activation energies of the first and second types of powders, respectively; The mass flow rate of the first type of powder in the mixing transition step varies according to the following nonlinear function: ； The mass flow rate of the second type of powder in the mixing transition step varies according to the following nonlinear function: ； in, Rated mass flow rate for the second type of powder.

10. The method for using a large-scale biomass gasification system according to claim 9, wherein: The calculation formula of the transition time T is: ； in, R 1 、R 2 is the reaction factor coefficient of the first type of powder and the second type of powder, 、 , FC 1 、 FC 2 is the fixed carbon content of the first and second type powders, ρ 1 、 ρ 2 is the bulk density of the first and second type powders, β 1 、 β 2 are the fluidity indexes of the first type of powder and the second type of powder, respectively; a, b, and c are all weight coefficients, which are determined by regression based on the operating data of the biomass gasifier (5).

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