Large-load-range coal water slurry gasification process burner device

Abstract

The invention discloses a large-load-range coal water slurry gasification process burner device, relates to the technical field of coal gasification, and aims to solve the problem that large-range flexible adjustment of load cannot be realized under the same burner structure in the prior art. The coal slurry channel is arranged on the inner side of the outer oxygen channel and is used for introducing coal water slurry; the inner side oxygen channel is arranged on the inner side of the coal slurry channel and is used for introducing oxygen; the ignition assembly is arranged in the center of the inner side oxygen channel; the carbon dioxide pipeline is communicated with the outer side oxygen channel and / or the coal slurry channel and is used for introducing carbon dioxide into the outer side oxygen channel and / or the coal slurry channel during low-load operation; by means of the arrangement, seamless switching between high-load efficient operation and low-load safe operation is achieved through the same burner structure, and the operation efficiency of the device is improved.

Description

Technical Field

[0001] This invention relates to the field of coal gasification technology, and more specifically, to a burner device for a coal-water slurry gasification process with a large load range. Background Technology

[0002] Coal gasification technology is one of the core technologies for the clean and efficient utilization of coal. As a key piece of equipment in the gasifier, the operational stability of the gasification burner directly affects the safety and economy of the gasification unit. During coal gasification production, the load adjustment of the process burner is subject to strict hydrodynamic constraints; the flow velocity of the medium in each channel must be controlled within a specific range. Taking the oxygen channel as an example, its flow velocity typically needs to be maintained between 105-130 m / s: excessively high flow velocities lead to accelerated wear on the burner head, while the high-speed airflow impacts the gasifier wall, causing refractory material erosion and furnace wall damage; excessively low flow velocities easily trigger flame flashback, causing high-temperature flue gas to flow back to the burner head, resulting in burner body erosion and damage, and in severe cases, even safety accidents. Therefore, traditional gasification burners must strictly adhere to the flow velocity control boundaries of each channel when adjusting the load.

[0003] Currently, significant load adjustments in industrial plants often require shutdown and replacement of burners of different specifications. This not only leads to substantial energy and material waste during start-up and shutdown but also significantly reduces the plant's operating hours and economic efficiency. Existing technologies include Texaco coal-water slurry gasification burners with a three-channel coaxial structure, multi-nozzle gasification burners with a pre-film atomization design, and Shell, GSP, and aerospace pulverized coal gasification burners with a multi-channel common-ring structure and swirl fins to enhance atomization. However, these technologies all rely on fixed geometric flow channel designs for material transport and mixing, failing to achieve flexible load adjustments over a wide range within the same burner structure. This makes it difficult to meet the urgent needs of modern coal chemical plants for wide-load operation, rapid peak shaving, and long-term stable operation of gasifiers.

[0004] Therefore, how to solve the problem of the inability to achieve a wide range of flexible load adjustment under the same burner structure in the existing technology is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a burner device for a coal-water slurry gasification process with a large load range, which achieves seamless switching between high-load and high-efficiency operation and low-load and safe operation through the same burner structure, thereby improving the operating efficiency of the device.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A burner device for a high-load-range coal-water slurry gasification process includes:

[0008] At least two external oxygen channels are provided for oxygen supply.

[0009] The coal slurry channel is located inside the outer oxygen channel and is used to introduce coal-water slurry.

[0010] An inner oxygen channel is located inside the coal slurry channel and is used to introduce oxygen.

[0011] The ignition assembly is located in the center of the inner oxygen passage.

[0012] A carbon dioxide pipeline, connected to an outer oxygen channel and / or a coal slurry channel, is used to introduce carbon dioxide into the outer oxygen channel and / or the coal slurry channel during low-load operation.

[0013] In some embodiments, at least two external oxygen channels include a first oxygen channel and a second oxygen channel. The second oxygen channel is disposed inside the first oxygen channel. The first oxygen channel is connected to a first oxygen supply pipe, and the second oxygen channel is connected to a second oxygen supply pipe. The first oxygen supply pipe and the second oxygen supply pipe are respectively provided with valves for controlling the opening and closing of the pipes.

[0014] In some embodiments, the coal slurry channel is connected to a coal-water slurry supply pipeline, and the coal-water slurry supply pipeline is equipped with a valve to control the opening and closing of the pipeline.

[0015] In some embodiments, a flushing water pipe connected to the coal-water slurry supply pipe is also included for introducing flushing water into the coal slurry channel when the burner is shut down. The flushing water pipe is equipped with a valve to control the opening and closing of the pipe.

[0016] In some embodiments, the carbon dioxide pipeline includes a first carbon dioxide pipeline and a second carbon dioxide pipeline. The first carbon dioxide pipeline is connected to a first oxygen supply pipeline, and the second carbon dioxide pipeline is connected to a coal-water slurry supply pipeline. The first carbon dioxide pipeline and the second carbon dioxide pipeline are respectively provided with valves for controlling the on / off state of the pipeline.

[0017] In some embodiments, the inner oxygen channel is connected to a third oxygen supply pipeline, and the third oxygen supply pipeline is equipped with a valve to control the opening and closing of the pipeline.

[0018] In some embodiments, the ignition assembly includes an ignition gun and an inner channel regulator, the inner channel regulator being movably disposed within the inner oxygen channel for blocking a portion of the flow area of ​​the inner oxygen channel when the burner is operating at low load.

[0019] In some embodiments, the outlet end of the outer oxygen channel is provided with swirl fins.

[0020] In some embodiments, the outlet ends of the inner oxygen channel and the coal slurry channel are narrowed, while the outlet end of the outer oxygen channel is widened.

[0021] In some embodiments, a cooling water jacket is also included, which is disposed on the outermost side of the outer oxygen channel, and is externally connected to a cooling water supply pipe and a cooling water return pipe.

[0022] The burner device for a high-load-range coal-water slurry gasification process provided by the present invention includes an outer oxygen channel, a coal slurry channel, an inner oxygen channel, an ignition assembly, and a carbon dioxide pipeline. Specifically, the outer oxygen channel is used to introduce oxygen, the coal slurry channel is located inside the outer oxygen channel and is used to introduce coal-water slurry, the inner oxygen channel is located inside the coal slurry channel and is used to introduce oxygen, the ignition assembly is located at the center of the inner oxygen channel, and the carbon dioxide pipeline is connected to the outer oxygen channel and / or the coal slurry channel for introducing carbon dioxide into the outer oxygen channel and / or the coal slurry channel during low-load operation.

[0023] By incorporating at least two outer oxygen channels, a coal slurry channel, and an inner oxygen channel, a multi-channel coaxial burner structure is formed. This structure features a compact layout and clearly defined flow channels, facilitating the orderly transport and staged mixing of various media. Furthermore, the design of multiple outer oxygen channels enables staged oxygen supply, optimizing the radial distribution of the gasification reaction. By adding carbon dioxide pipelines to the outer oxygen channels and / or coal slurry channels, a wide range of flexible load adjustments are achieved within the same burner unit. This allows the burner to adapt to different load conditions without replacement, improving the equipment's versatility and adaptability.

[0024] During high-load operation, multiple outer oxygen channels can simultaneously supply oxygen, increasing the total oxygen flow area and reducing the oxygen flow velocity in individual channels. This reduces the scouring and wear of the high-speed oxygen flow on the burner head and gasifier wall. Simultaneously, the staged oxygen supply enhances the atomization effect of the coal-water slurry, making the gasification reaction more uniform and complete, thus improving carbon conversion rate and syngas quality. During low-load operation, carbon dioxide is introduced into the outer oxygen channels and / or coal slurry channels through carbon dioxide pipelines. This effectively maintains the medium flow velocity in each channel of the burner head, keeping it within a safe operating range. This ensures that the oxygen channel flow velocity does not fall below the tempering critical value, while preventing sedimentation or atomization deterioration in the coal slurry channel due to reduced flow, guaranteeing stable burner operation under low load. Furthermore, the injection of carbon dioxide forms a stable airflow barrier at the burner head. This inert gas barrier physically isolates the high-temperature reaction zone from the burner end face, preventing high-temperature gas back-mixing, optimizing the burner outlet flow field distribution, extending burner lifespan, reducing equipment maintenance frequency and replacement costs, and improving the reliability and economy of the unit.

[0025] The large-load range coal-water slurry gasification process burner unit set up in the above manner achieves seamless switching between high-load and high-efficiency operation and low-load and safe operation through the same set of burner structure. This eliminates the need to stop and replace burners when the industrial unit makes significant load adjustments, significantly reducing energy and material losses during start-up and shutdown, increasing the number of hours the unit operates and its economic benefits, enhancing the operational flexibility and peak-shaving capability of the gasification unit, and is simple in structure and easy to implement. Attached Figure Description

[0026] 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, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 A schematic diagram of the burner device for the large-load-range water-coal slurry gasification process provided by the present invention.

[0028] Figure 2 for Figure 1 A schematic diagram of the piping connected to the first oxygen channel in the middle.

[0029] Figure 3 for Figure 1 Schematic diagram of the external pipeline connecting to the coal slurry channel;

[0030] Figure 4 for Figure 3 A partial sectional view.

[0031] The annotations in the attached figures are explained as follows:

[0032] 1-External oxygen channel, 11-First oxygen channel, 12-Second oxygen channel;

[0033] 2-Coal slurry channel;

[0034] 3-Inner oxygen channel;

[0035] 4-Ignition assembly;

[0036] 5-Carbon dioxide pipeline;

[0037] 6-First oxygen supply pipeline;

[0038] 7- Coal-water slurry supply pipeline;

[0039] 8- Flushing water pipe. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] The core of this invention is to provide a burner device for a coal-water slurry gasification process with a large load range. Through the same burner structure, it achieves seamless switching between high-load and high-efficiency operation and low-load and safe operation, thereby improving the operating efficiency of the device.

[0043] Please refer to Figure 1 , Figure 2 , Figure 3 A burner device for a high-load-range coal-water slurry gasification process includes an outer oxygen channel 1, a coal slurry channel 2, an inner oxygen channel 3, an ignition assembly 4, and a carbon dioxide pipeline 5.

[0044] Specifically, the outer oxygen channel 1 is used to introduce oxygen, the coal slurry channel 2 is located inside the outer oxygen channel 1 and is used to introduce coal-water slurry, the inner oxygen channel 3 is located inside the coal slurry channel 2 and is used to introduce oxygen, the ignition assembly 4 is located at the center of the inner oxygen channel 3, and the carbon dioxide pipeline 5 is connected to the outer oxygen channel 1 and / or the coal slurry channel 2 and is used to introduce carbon dioxide into the outer oxygen channel 1 and / or the coal slurry channel 2 during low-load operation.

[0045] By setting at least two outer oxygen channels 1, a coal slurry channel 2, and an inner oxygen channel 3, a multi-channel coaxial burner structure is formed. This structure has a compact layout and clear flow channels, which is conducive to the orderly transportation and staged mixing of various media. At the same time, the design of multiple outer oxygen channels 1 enables staged oxygen supply and optimizes the radial distribution of the gasification reaction. By adding carbon dioxide pipelines 5 to the outer oxygen channels 1 and / or coal slurry channels 2, a wide range of flexible load adjustments can be achieved under the same burner unit. This allows the burner to adapt to different load conditions without replacement, improving the versatility and adaptability of the equipment.

[0046] During high-load operation, multiple outer oxygen channels 1 can simultaneously supply oxygen, increasing the total oxygen flow area and reducing the oxygen flow velocity in individual channels. This reduces the scouring and wear of the high-speed oxygen flow on the burner head and gasifier wall. Simultaneously, the staged oxygen supply enhances the atomization effect of the coal-water slurry, making the gasification reaction more uniform and complete, thus improving carbon conversion rate and syngas quality. During low-load operation, carbon dioxide is introduced into the outer oxygen channels 1 and / or the coal slurry channel 2 through the carbon dioxide pipeline 5. This effectively maintains the medium flow velocity in each channel of the burner head, keeping it within a safe operating range. This ensures that the oxygen channel flow velocity does not fall below the tempering critical value, while preventing sedimentation or atomization deterioration in the coal slurry channel 2 due to reduced flow, thus guaranteeing stable burner operation under low load. Furthermore, the injection of carbon dioxide forms a stable airflow barrier at the burner head. This inert gas barrier physically isolates the high-temperature reaction zone from the burner end face, preventing high-temperature gas back-mixing, optimizing the burner outlet flow field distribution, extending burner lifespan, reducing equipment maintenance frequency and replacement costs, and improving the reliability and economy of the unit.

[0047] The large-load range coal-water slurry gasification process burner unit set up in the above manner achieves seamless switching between high-load and high-efficiency operation and low-load and safe operation through the same set of burner structure. This eliminates the need to stop and replace burners when the industrial unit makes significant load adjustments, significantly reducing energy and material losses during start-up and shutdown, increasing the number of hours the unit operates and its economic benefits, enhancing the operational flexibility and peak-shaving capability of the gasification unit, and is simple in structure and easy to implement.

[0048] In the above embodiment, at least two outer oxygen channels 1 include a first oxygen channel 11 and a second oxygen channel 12. The second oxygen channel 12 is disposed inside the first oxygen channel 11. The first oxygen channel 11 is connected to a first oxygen supply pipe 6, and the second oxygen channel 12 is connected to a second oxygen supply pipe. The first oxygen supply pipe 6 and the second oxygen supply pipe are respectively provided with valves to control the opening and closing of the pipes.

[0049] It should be noted that a four-channel coaxial burner structure is formed by setting up a first oxygen channel 11, a second oxygen channel 12, a coal slurry channel 2, and an inner oxygen channel 3. The design of a double-layered outer oxygen channel 1, with the second oxygen channel 12 positioned inside the first oxygen channel 11, constitutes a two-stage oxygen supply structure. This structural layout creates a gradient distribution of oxygen supply from the outside to the inside, which is beneficial for achieving staged atomization of the coal-water slurry and radial optimization of the gasification reaction.

[0050] The system comprises a first oxygen channel 11 connected to a first oxygen supply pipe 6, and a second oxygen channel 12 connected to a second oxygen supply pipe, each equipped with valves to control the on / off states of the pipes. This configuration forms an independent and controllable dual-path external oxygen supply system, allowing for independent adjustment of the on / off states and flow distribution of the two external oxygen channels 1. Under high-load conditions, both valves are open simultaneously, and the two external oxygen channels 1 work together, increasing the total oxygen flow area, effectively dispersing the oxygen flow velocity, and reducing the scouring and wear of the high-speed airflow on the burner head and gasifier wall. Under low-load conditions, one valve can be closed to achieve operation of a single external oxygen channel 1. While reducing the total oxygen supply, a suitable flow velocity is maintained within the operating channel, avoiding the problem of excessively low flow velocity caused by a sharp reduction in flow rate, thereby effectively preventing flame backfire and burner erosion.

[0051] During long-term operation, the wear of the two outer oxygen channels 1 can be balanced by periodically switching their operating status, preventing premature failure caused by excessive wear in a single channel. This extends the overall lifespan of the burner and reduces maintenance costs and replacement frequency. Simultaneously, this structure facilitates the protective introduction of carbon dioxide. When one of the outer oxygen channels 1 is shut down, carbon dioxide can be introduced into that channel through its corresponding carbon dioxide pipe 5. This maintains the flow rate while forming an inert gas protective layer, further optimizing the flow field distribution and thermal protection effect at the burner head. This significantly broadens the load adjustment range and enhances the operational flexibility and reliability of the device.

[0052] In the above situation, the coal slurry channel 2 is connected to the coal-water slurry supply pipeline 7. The coal-water slurry supply pipeline 7 is equipped with valves to control the opening and closing of the pipeline, forming an independent and controllable coal-water slurry supply system. This allows the opening and closing status and flow rate of the coal-water slurry to be independently adjusted according to the load requirements of the gasifier, realizing flexible control of the coal slurry feed amount and providing a direct control means for switching between high and low load conditions.

[0053] During high-load operation, the valve is fully open to ensure a stable supply of coal-water slurry at the designed flow rate, meeting the material requirements of the gasifier's full-load production. During low-load operation, the flow rate of the coal-water slurry can be precisely reduced by decreasing the valve opening, achieving a smooth decrease in feed rate and avoiding system fluctuations caused by sudden changes in flow. More importantly, the coordinated operation of this valve with the carbon dioxide pipeline 5 provides technical assurance for safe operation under low load conditions. When the coal slurry flow rate decreases, carbon dioxide can be introduced into the coal slurry channel 2 through the carbon dioxide pipeline 5. While the valve adjusts to reduce the coal slurry flow rate, carbon dioxide is used to maintain the overall flow velocity within the coal slurry channel 2, preventing sedimentation, blockage, and atomization deterioration caused by excessively low coal slurry flow rate, ensuring stable delivery and good atomization effect under low-load conditions.

[0054] Furthermore, a flushing water pipe 8 connected to the coal-water slurry supply pipe 7 is included. This pipe is used to introduce flushing water into the coal slurry channel 2 when the burner is shut down. The flushing water pipe 8 is equipped with a valve to control the flow of the pipe. During normal burner operation, the valve of the flushing water pipe 8 is closed, and the coal-water slurry supply pipe 7 independently supplies coal-water slurry, with the two pipes not interfering with each other. When the burner is shut down, the valve of the coal-water slurry supply pipe 7 is closed, and the valve of the flushing water pipe 8 is opened, allowing flushing water to be introduced into the coal slurry channel 2. The flushing action of the water flow removes residual coal slurry particles and deposits from the inner wall of the channel, preventing the coal slurry from drying and clogging the channel, keeping the coal slurry channel 2 clean and unobstructed, and creating favorable conditions for the next startup. This cleaning and protection function significantly reduces the workload and frequency of burner maintenance, extends the service life of the coal slurry channel 2, and improves the reliability and availability of the burner unit. Meanwhile, the flushing water pipe 8 can also be used in conjunction with the carbon dioxide pipe 5 to introduce carbon dioxide for drying and protection after cleaning, preventing corrosion of the inner wall of the channel, further optimizing the shutdown protection effect of the burner, and ensuring the long-term stable operation of the device.

[0055] In the above embodiment, the carbon dioxide pipeline 5 includes a first carbon dioxide pipeline and a second carbon dioxide pipeline. The first carbon dioxide pipeline is connected to the first oxygen supply pipeline 6, and the second carbon dioxide pipeline is connected to the coal-water slurry supply pipeline 7. The first carbon dioxide pipeline and the second carbon dioxide pipeline are respectively equipped with valves for controlling the on / off state of the pipeline.

[0056] It is understandable that the structural layout connecting the first carbon dioxide pipeline to the first oxygen supply pipeline 6 allows carbon dioxide to enter the first oxygen channel 11 through the first oxygen supply pipeline 6, or to be directly connected to the first oxygen channel 11. The carbon dioxide supply and the valve of the first oxygen supply pipeline 6 form a coordinated control relationship. During high-load operation, the valve of the first carbon dioxide pipeline is closed, and the first oxygen supply pipeline 6 normally supplies oxygen. During low-load operation or when the first oxygen channel 11 needs protection, the valve of the first oxygen supply pipeline 6 is closed, and the valve of the first carbon dioxide pipeline is opened, thus switching the flow of carbon dioxide into the first oxygen channel 11. While maintaining the flow rate in this channel, an inert gas protective barrier is formed to prevent back-mixing of high-temperature gases, achieving protective operation or low-load flow rate maintenance of this channel. The structural layout connecting the second carbon dioxide pipeline to the coal-water slurry supply pipeline 7 allows carbon dioxide to enter the coal slurry channel 2 through the coal-water slurry supply pipeline 7, or to be directly connected to the coal slurry channel 2. The carbon dioxide supply and the valve of the coal-water slurry supply pipeline 7 form a linkage regulation mechanism. When the valve of the coal-water slurry supply pipeline 7 is reduced to decrease the coal slurry flow rate during low-load operation, the valve of the second carbon dioxide pipeline can be opened to supplement carbon dioxide into the coal slurry channel 2. The introduction of carbon dioxide maintains the overall flow rate in the coal slurry channel 2, preventing the flow rate from being too low and the problem of sedimentation and blockage caused by the reduction of coal slurry flow, and ensuring the stable transportation and atomization effect of coal slurry.

[0057] It should be noted that the two carbon dioxide pipelines 5 are equipped with independent valve control structures, enabling flexible combination and precise control of carbon dioxide supply. Depending on load adjustment requirements, multiple operating modes can be selected, such as supplying carbon dioxide only to the first oxygen channel 11, only to the coal slurry channel 2, or simultaneously to both channels, adapting to different low-load conditions and channel protection needs. This dual-path independent valve design, together with the valves of the first oxygen supply pipeline 6, the second oxygen supply pipeline, and the coal-water slurry supply pipeline 7, forms a complete media switching system. Through the coordinated operation of each valve, rapid switching between various operating conditions, such as high-load oxygen operation, low-load carbon dioxide protection, single-channel operation, and dual-channel coordination, can be achieved without shutdown. This significantly enhances the operational flexibility, adjustment accuracy, and operational reliability of the burner unit, providing structural assurance for continuous adjustment of the gasifier across a wide load range.

[0058] The first and second carbon dioxide pipes extend into the corresponding first oxygen supply pipe 6 and coal-water slurry supply pipe 7, respectively, forming an embedded injection structure. The first carbon dioxide pipe extends vertically into the internal flow channel of the first oxygen supply pipe 6 from its side wall or end, and the second carbon dioxide pipe extends into the coal-water slurry supply pipe 7 in the same manner. The insertion depth of the two pipes is determined according to the mixing uniformity requirements and the pipe diameter to ensure sufficient mixing of carbon dioxide with the mainstream medium. In addition, the insertion ends of the first and second carbon dioxide pipes are provided with vent holes, which provide multiple dispersed outlet channels for carbon dioxide, avoiding local concentration unevenness and flow field disturbance caused by single-point injection. Multiple vent holes are provided and distributed along the circumference and axial direction of the pipes, forming a three-dimensional porous gas distribution structure. The circumferentially distributed vent holes allow carbon dioxide to be released uniformly across the pipe cross-section, forming radial mixing with the surrounding mainstream medium; the axially distributed vent holes allow carbon dioxide to be injected gradually along the length of the pipe, achieving axial gradient mixing. This porous gas distribution structure significantly increases the contact area between carbon dioxide and oxygen or coal-water slurry, promoting rapid and uniform mixing of the gas-gas or gas-liquid two phases and avoiding local velocity fluctuations and flow field distortions caused by uneven mixing. Furthermore, the specific aperture, number of pores, and distribution density of the gas outlets are determined based on the carbon dioxide injection rate and the velocity and pressure of the mainstream medium within the pipeline.

[0059] Based on the above embodiment, the inner oxygen channel 3 is connected to a third oxygen supply pipeline, which is equipped with a valve to control the on / off state of the pipeline. This direct connection between the third oxygen supply pipeline and the inner oxygen channel 3 allows for independent adjustment of the central oxygen supply status, unaffected by the operating status of the outer oxygen channel 1. This valve structure opens during high-load operation, allowing central oxygen to flow in at the designed flow rate, working in conjunction with the two outer oxygen channels to form a three-stage oxygen distribution from the outside in, enhancing the radial uniformity of the multi-stage atomization and gasification reaction of the coal-water slurry. During low-load operation, the valve opening can be flexibly adjusted according to operating conditions to achieve precise control of the central oxygen flow rate, or it can be used in conjunction with the carbon dioxide switching operation of the outer oxygen channel 1 to maintain a suitable oxygen-to-coal ratio and flame structure.

[0060] By coordinating and adjusting the opening and closing states and opening ratios of the four valves in the first oxygen supply pipeline 6, the second oxygen supply pipeline, the third oxygen supply pipeline, and the coal-water slurry supply pipeline 7, precise multi-dimensional matching of total oxygen quantity, oxygen distribution, and oxygen-to-coal ratio can be achieved, optimizing gasification reaction conditions under different loads. Simultaneously, this structure provides independent protection for the inner oxygen channel 3. Under special operating conditions, protective gases such as nitrogen can be introduced into the inner oxygen channel 3, or the central oxygen can be cut off to achieve specific flow field control, significantly enhancing the burner unit's control flexibility, reaction adaptability, and operational stability.

[0061] In the above embodiment, the ignition assembly 4 includes an ignition gun and an inner channel regulator. The inner channel regulator is movably disposed in the inner oxygen channel 3 and is used to block part of the flow area of ​​the inner oxygen channel 3 when the burner is running at low load.

[0062] Understandably, the internal channel regulator, movably positioned within the inner oxygen channel 3, achieves mechanical stepless adjustment of the flow area. During high-load operation, it moves to the retracted position, completely opening up the flow cross-section of the inner oxygen channel 3, without affecting the normal intake and flow field distribution of central oxygen. During low-load operation, it moves to the adjustment position, physically blocking part of the flow area through the fit between its outer contour and the inner wall of the inner oxygen channel 3, reducing the effective ventilation cross-section. This allows for maintaining a high outlet flow rate even with reduced central oxygen flow, avoiding flame instability and the risk of backfire due to excessively low flow rate.

[0063] In a preferred embodiment, the outlet end of the outer oxygen channel 1 is equipped with swirl fins, which force the high-speed oxygen flow to rotate before leaving the channel, forming a rotating jet with a certain swirl intensity. After leaving the burner, this rotating jet generates a centrifugal diffusion effect in the radial direction, expanding the contact area and mixing zone between oxygen and coal-water slurry, enhancing momentum exchange and mass transfer between the gas and liquid phases, resulting in smaller and more uniform atomized particle size of the coal-water slurry, and improving the rate and completeness of the gasification reaction. Simultaneously, the central negative pressure zone generated by the swirl is beneficial for entraining high-temperature flue gas, stabilizing the flame root, and enhancing combustion stability.

[0064] During high-load operation, oxygen is introduced into the outer oxygen channel 1, and the swirl fins enhance the atomization and mixing effect of the oxygen. During low-load operation, carbon dioxide is introduced into the outer oxygen channel 1, and the swirl fins also make the carbon dioxide form a rotating protective airflow, forming a uniform inert gas barrier around the burner head, which enhances the effect of isolating high-temperature gas back-mixing and optimizes the head flow field distribution and thermal protection performance under low-load conditions.

[0065] When both outer oxygen channels 1 are equipped with swirl fins, a double-layer rotating airflow can be formed. The swirl direction of the two layers can be designed to be in the same direction or opposite direction. By adjusting the matching relationship between the swirl angle and the swirl intensity, the atomization effect and flow field structure can be further optimized to adapt to different coal slurry characteristics and gasification load requirements, which significantly improves the atomization efficiency, combustion stability and operating condition adaptability of the burner device.

[0066] In the above case, the outlet ends of the inner oxygen channel 3 and the coal slurry channel 2 are narrowed, while the outlet end of the outer oxygen channel 1 is widened.

[0067] Understandably, the inner oxygen channel 3 employs a narrowing structure at its outlet, causing the central oxygen to gradually decrease in cross-section before exiting the channel, further increasing its velocity and forming a high-speed central jet. This high-speed jet creates a strong entrainment effect in the burner axis region, entraining surrounding media to form a stable central recirculation zone, which is beneficial for stable combustion of the flame and preheating of high-temperature flue gas. Simultaneously, the shearing effect between the high-speed central oxygen and the inner coal slurry is enhanced, strengthening the atomization effect in the central region. The coal slurry channel 2 also employs a narrowing structure at its outlet, accelerating the coal-water slurry before ejection to form a coal slurry jet with a certain initial velocity. This velocity matching design makes the velocity difference between the coal slurry and the oxygen on both the inner and outer sides more reasonable, optimizing the relative gas-liquid velocity and atomization quality.

[0068] Furthermore, the outer oxygen channel 1 adopts an expanded diameter structure at its outlet, causing the outer oxygen to gradually expand its flow cross-section as it leaves the channel, resulting in a slight decrease in velocity and a recovery in pressure, forming a relatively low-speed peripheral airflow. This low-speed peripheral airflow effectively envelops and constrains the high-speed inner jet, preventing it from directly impacting the gasifier wall and reducing wall erosion and refractory material loss. Simultaneously, the expanded diameter structure increases the outlet area of ​​the outer oxygen, shifting the contact interface with the inner medium outward and extending the gas-liquid mixing distance, thus creating the necessary space for the staged gasification reaction.

[0069] It should be noted that the high-speed oxygen jet in the center, the medium-speed coal slurry jet in the middle, and the low-speed oxygen jet in the periphery work together to form a reasonable velocity distribution and shear layer structure at the burner head. This ensures the stability of the central flame and the full atomization of the coal slurry, while also achieving wall protection and flow field shaping of the peripheral airflow. During low-load operation, when carbon dioxide is introduced into the outer oxygen channel 1, the expansion structure allows the carbon dioxide to flow out smoothly at a lower velocity, forming a stable outer protective gas curtain. Meanwhile, the inner narrowing structure ensures that the coal slurry and central oxygen maintain a relatively high velocity even when the flow rate decreases, preventing backfire and deposition. This significantly enhances the operational stability and safety of the burner unit across the entire load range.

[0070] In the above embodiments, a cooling water jacket is also included. The cooling water jacket is located on the outermost side of the outer oxygen channel 1, and the cooling water jacket is connected to a cooling water supply pipe and a cooling water return pipe.

[0071] It should be noted that the cooling water jacket is located at the outermost edge of the outer oxygen channel 1, so that the high-temperature zone of the burner head is separated from the cooling medium by only one layer of metal wall, resulting in low thermal resistance and high heat transfer efficiency. This jacket structure wraps around the outer periphery of the burner end and directly bears the radiative and convective heat load from the high-temperature flame and incandescent environment inside the gasifier. Through the continuous circulation of cooling water, the heat transferred to the burner head is carried away in a timely manner, effectively controlling the metal temperature of the burner end face, preventing material overheating deformation, ablation, or failure, and ensuring the structural integrity and long-term operational reliability of the burner.

[0072] The cooling water supply and return pipes are externally connected to the cooling water jacket, forming an independent closed-loop cooling circuit. The cooling water supply pipe introduces low-temperature cooling water into the jacket. The water absorbs heat within the jacket's flow channels, increasing its temperature, and then is discharged through the cooling water return pipe to the external cooling system for cooling, repeating the cycle continuously. This independent piping configuration allows the flow rate, pressure, and temperature of the cooling water to be adjusted according to the burner's thermal load conditions. During high-load operation, the cooling water flow rate is increased to enhance cooling, while during low-load operation, the flow rate is appropriately reduced to save energy, achieving optimized allocation and precise control of cooling resources.

[0073] The burner unit for the high-load range coal-water slurry gasification process operates under two conditions: high-load and low-load. During high-load operation, oxygen is supplied to the first oxygen channel 11, the second oxygen channel 12, and the inner oxygen channel 3, while coal-water slurry is supplied to the coal slurry channel 2. The flow rate of each channel is at its designed maximum load. At this time, the burner operates in a conventional, high-efficiency atomization combustion state. The three-stage oxygen supply enhances the atomization effect of the coal-water slurry, ensuring a complete gasification reaction and maximizing the unit's capacity. During low-load operation, carbon dioxide is introduced into specific channels to achieve the dual objectives of load reduction and flow rate maintenance. Specifically, carbon dioxide is switched to be supplied to the first oxygen channel 11 as a protective gas, while oxygen is maintained in the second oxygen channel 12 and the inner oxygen channel 3. Coal-water slurry is supplied to the coal slurry channel 2, but the flow rate is adjusted to a low-load value; alternatively, carbon dioxide is supplemented into the coal slurry channel 2 while coal-water slurry is supplied, and the coal slurry flow rate is adjusted to a low-load value, with all oxygen channels operating normally. These two operating modes can be implemented individually or in combination.

[0074] It should be noted that the oxygen channel needs to maintain a flow rate range of 103-130 m / s. Excessive flow rate will exacerbate burner wear, while insufficient flow rate will create a vacuum zone at the furnace head, causing high-temperature gas backflow that impacts the burner. When the unit operates at reduced load, resulting in a decrease in oxygen flow, switching to carbon dioxide in the first oxygen channel 11 can maintain the airflow velocity in this channel even with a reduced total oxygen volume, ensuring it remains within a safe flow rate range. Simultaneously, the carbon dioxide forms an inert gas barrier around the burner head, isolating high-temperature gas, preventing backmixing, and regulating the flow field at the burner head. The coal slurry channel 2 needs to maintain a flow rate range of 3-8 m / s. Excessive flow rate will cause channel wear, while insufficient flow rate will create a vacuum zone at the furnace head, triggering high-temperature gas backflow that impacts the burner. When the coal slurry flow rate decreases, carbon dioxide can be introduced into the coal slurry channel 2 to maintain the flow rate of the mixture in the channel even when the total amount of coal-water slurry decreases, so as to meet the minimum flow rate requirement. At the same time, the mixture of carbon dioxide and coal slurry forms a stable gas-liquid two-phase flow at the burner head, which plays a role in protecting the burner end face, preventing high-temperature back mixing, and optimizing the flow field at the head.

[0075] In summary, the large-load-range coal-water slurry gasification burner device provided by this invention introduces carbon dioxide as a supplementary medium under low-load conditions. This effectively maintains the airflow velocity in each channel, keeping it within a safe operating range even with reduced oxygen and coal slurry flow rates. This avoids problems such as flame flashback, high-temperature gas backmixing, and burner erosion caused by excessively low flow velocities, while also preventing burner wear and furnace wall impact damage caused by excessively high flow velocities. The flexible injection of carbon dioxide allows for a smooth switch between high-load, high-efficiency operation and low-load, safe protection without requiring shutdown for burner replacement. This significantly reduces energy and material losses during start-up and shutdown, increases the device's operating hours and economic efficiency, enhances the gasification unit's operational flexibility and peak-shaving capabilities, and provides effective technical support for flexible production and energy conservation in modern coal chemical plants.

[0076] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0077] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0078] The above provides a detailed description of the burner device for a high-load-range coal-water slurry gasification process provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A burner device for a coal-water slurry gasification process with a large load range, characterized in that, include: At least two external oxygen channels (1) are provided for the introduction of oxygen; The coal slurry channel (2) is located inside the outer oxygen channel (1) and is used to introduce coal-water slurry. An inner oxygen channel (3) is provided inside the coal slurry channel (2) for introducing oxygen; The ignition assembly (4) is located at the center of the inner oxygen channel (3); A carbon dioxide pipeline (5) is connected to the outer oxygen channel (1) and / or the coal slurry channel (2) for introducing carbon dioxide into the outer oxygen channel (1) and / or the coal slurry channel (2) during low-load operation.

2. The burner device for the large-load range water-coal slurry gasification process according to claim 1, characterized in that, The at least two external oxygen channels (1) include a first oxygen channel (11) and a second oxygen channel (12). The second oxygen channel (12) is located inside the first oxygen channel (11). The first oxygen channel (11) is connected to a first oxygen supply pipe (6), and the second oxygen channel (12) is connected to a second oxygen supply pipe. The first oxygen supply pipe (6) and the second oxygen supply pipe are respectively provided with valves for controlling the opening and closing of the pipes.

3. The burner device for the large-load-range water-coal slurry gasification process according to claim 2, characterized in that, The coal slurry channel (2) is connected to a coal-water slurry supply pipeline (7), and the coal-water slurry supply pipeline (7) is equipped with a valve to control the opening and closing of the pipeline.

4. The burner device for the large-load-range water-coal slurry gasification process according to claim 3, characterized in that, It also includes a flushing water pipe (8) connected to the coal-water slurry supply pipe (7), used to introduce flushing water into the coal slurry channel (2) when the burner is shut down, and the flushing water pipe (8) is equipped with a valve to control the opening and closing of the pipe.

5. The burner device for the large-load-range water-coal slurry gasification process according to claim 3, characterized in that, The carbon dioxide pipeline (5) includes a first carbon dioxide pipeline and a second carbon dioxide pipeline. The first carbon dioxide pipeline is connected to the first oxygen supply pipeline (6), and the second carbon dioxide pipeline is connected to the coal-water slurry supply pipeline (7). The first carbon dioxide pipeline and the second carbon dioxide pipeline are respectively equipped with valves for controlling the opening and closing of the pipelines.

6. The burner device for the large-load-range water-coal slurry gasification process according to claim 1, characterized in that, The inner oxygen channel (3) is connected to a third oxygen supply pipeline, which is equipped with a valve to control the opening and closing of the pipeline.

7. The burner apparatus for a large-load-range coal-water slurry gasification process according to any one of claims 1-6, characterized in that, The ignition assembly (4) includes an ignition gun and an inner channel regulator. The inner channel regulator is movably disposed within the inner oxygen channel (3) and is used to block part of the flow area of ​​the inner oxygen channel (3) when the burner is running at low load.

8. The burner apparatus for a large-load-range coal-water slurry gasification process according to any one of claims 1-6, characterized in that, The outlet end of the outer oxygen channel (1) is provided with swirl fins.

9. The burner apparatus for a large-load-range coal-water slurry gasification process according to any one of claims 1-6, characterized in that, The outlet ends of the inner oxygen channel (3) and the coal slurry channel (2) are narrowed, while the outlet end of the outer oxygen channel (1) is widened.

10. The burner apparatus for a large-load-range coal-water slurry gasification process according to any one of claims 1-6, characterized in that, It also includes a cooling water jacket, which is located on the outermost side of the outer oxygen channel (1), and the cooling water jacket is connected to a cooling water supply pipe and a cooling water return pipe.

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