Air distribution method for gasification furnace

Abstract

The invention relates to the technical field of gasification furnaces, in particular to a gasification furnace air distribution method which comprises the following steps that primary air is supplied to a gasification furnace hearth through a primary air main pipeline, and the primary air main pipeline is attached to the outer wall of a gasification furnace to conduct preheating through waste heat of a furnace body; secondary air is supplied to a hearth of the gasification furnace through a secondary air main pipeline, the secondary air main pipeline is communicated with the primary air main pipeline and clings to the outer wall of the gasification furnace for preheating, a secondary air outlet is located below a primary air outlet, and the secondary air outlet and the primary air outlet are arranged in a radial staggered mode; primary air is sprayed into the hearth through an inverted air cap arranged at the tail end of the primary air main pipeline, and a plurality of air outlet holes are formed in the inverted air cap. By changing the airflow outlet path, optimizing the air distribution injection direction and enhancing the turbulence degree in the furnace, the gasification efficiency is improved, and the coking risk is reduced.

Description

Technical Field

[0001] This application relates to the technical field of gasifiers, and in particular to a gasifier air distribution method. Background Technology

[0002] Gasifiers, as important coal gasification equipment, are widely used in alumina roasting, chemical syngas production, and other fields. Circulating fluidized bed gasifiers, due to their high gas-solid contact efficiency and uniform reaction, have become one of the mainstream gasifier types in current coal gasification technology. In actual operation, the gasifier's air distribution system has a decisive influence on the flow field distribution within the furnace, gas-solid mixing efficiency, and reaction conversion rate.

[0003] Currently, common gasifier air distribution systems typically employ a fixed air cap structure, with the air caps evenly distributed at the bottom of the furnace, delivering airflow into the furnace through the core tube. In existing technologies, the air caps are mostly vertical or have a simple flared structure, resulting in a relatively unidirectional airflow, primarily vertically upward. While this type of air distribution can achieve basic fluidization, it suffers from uneven airflow distribution, localized low flow velocities, and insufficient turbulence intensity, leading to insufficient gas-solid contact in the furnace bottom area, which easily results in dead zones or coking.

[0004] The main shortcomings of existing air distribution systems are uneven air distribution, a single airflow path, and insufficient turbulence intensity, which leads to problems such as high carbon content in the bottom ash, low carbon conversion rate, and easy formation of small coke lumps. To improve these problems, the air distribution structure and airflow organization need to be optimized. This can be achieved by changing the airflow outlet path, optimizing the airflow injection direction, and enhancing the degree of turbulence inside the furnace, thereby improving gasification efficiency and reducing the risk of coking. Summary of the Invention

[0005] To partially improve the above-mentioned problems, this application provides a gasifier air distribution method.

[0006] This application provides a gasifier air distribution method, which adopts the following technical solution: A method for air distribution in a gasifier includes the following steps: Primary air is supplied to the gasifier furnace through a primary air main duct, which is attached to the outer wall of the gasifier to utilize the waste heat of the furnace body for preheating. Secondary air is supplied to the gasifier furnace through the secondary air main duct. The secondary air main duct is connected to the primary air main duct and is attached to the outer wall of the gasifier for preheating. The secondary air outlet is located below the primary air outlet and is radially offset from the primary air outlet. The primary air is injected into the furnace through an inverted air cap located at the end of the primary air main duct, and the inverted air cap has multiple air outlet holes.

[0007] By adopting the above technical solution, the raw material enters the upper part of the furnace from the feed port and settles under gravity. The gasifying agent is supplied with preheated primary air through the primary air main pipe attached to the outer wall of the gasifier, and preheated secondary air is supplied through the connected secondary air main pipe. The primary air is injected into the bottom of the furnace through the inverted air cap, pushing the material upward. The secondary air is injected above the dense phase zone and is radially staggered from the primary air outlet. The gasifying agent is supplied through primary air, secondary air, and pulse air, forming turbulence and increasing reaction efficiency. The preheated primary air increases the inlet air temperature, allowing the bottom dense phase zone to quickly reach the reaction temperature. The staggered arrangement of the secondary air creates a concentration gradient in the transition zone, optimizing gas-solid mixing. The inverted air cap changes the traditional vertical air distribution method, causing the material to rise in a spiral trajectory, extending the residence time. Throughout the flow path, the gas-solid contact area increases, improving reaction efficiency.

[0008] Optionally, the following steps are also included: Pulsed air is supplied to the gasifier furnace through a pulsed air duct. The pulsed air outlet is located below the primary air outlet and is inclined toward the primary air outlet. The pulsed wind is controlled to be ejected in a pulsed manner, and its tilt direction and kinetic energy drive the primary wind to rotate.

[0009] By adopting the above technical solution, during the material flow process, pulsed air is supplied through a pulsed air duct. The pulsed air outlet is located below the primary air outlet and tilted towards it. The pulsed air is controlled to be injected in a pulsed manner, and the tilting direction and kinetic energy drive the primary air to rotate. The pulsed air periodically disturbs the bottom of the dense phase zone, reducing particle deposition and coking. The tilted injection provides power for the rotation of the primary air, enhancing the bottom turbulence effect. The pulsed manner avoids interference from continuous high-speed airflow on the stable flow field, stabilizing the bed pressure drop at 3-5 kPa with reduced fluctuations.

[0010] Optionally, the multiple air outlets on the hood are angled and rotated to form a multi-directional rotating airflow.

[0011] By adopting the above technical solution, the multiple inclined air outlets on the wind cap rotate to form a multi-directional rotating airflow, which affects the movement trajectory of particles in the entire flow path. The multi-directional rotating airflow enhances the turbulence intensity in various regions of the furnace, increases the particle diffusion coefficient to 2-3 times that of traditional air distribution, promotes more uniform gas-solid mixing in the dilute phase region, shortens the mixing time, achieves a fully mixed state, improves reaction efficiency, reduces the carbon content at the bottom of the furnace, reduces the possibility of coking, and increases the gasification rate of coal gas.

[0012] Optionally, the wind cap is rotatable, and the wind cap rotates due to pulsed air blowing.

[0013] By adopting the above technical solution, the wind cap is rotated, and the rotation of the wind cap is driven by pulsed air, which continuously affects the flow state of the bottom dense phase zone. The rotating wind cap makes the airflow distribution uniform, avoids local high temperature zones, enhances the scouring effect of the airflow on the bottom sediments, reduces the amount of small coke at the bottom, reduces the frequency of wind cap clogging, and reduces the number of maintenance times.

[0014] Optionally, the air outlet on the wind cap includes multiple sets of oblique holes, which are distributed unequally in the circumferential direction, so that the ejected airflow forms an asymmetric rotating flow field.

[0015] By adopting the above technical solution, the multiple sets of oblique holes on the wind cap are distributed circumferentially at unequal intervals, forming an asymmetric rotating flow field. Different flow effects are generated as the material rises from the dense phase region to the dilute phase region. The asymmetric flow field breaks the limitations of the traditional symmetric flow field, enhances the lateral migration of particles in the flow field, and improves the fluidization quality. The distribution state of particles in the circulation loop is optimized, and the bubble size is uniformly controlled between 5-15cm, reducing dead zones and channeling phenomena.

[0016] Optionally, it also includes dynamically adjusting the ratio of primary air to secondary air based on feedback from the temperature sensor at the bottom of the furnace, with the ratio range being 60%-80% : 20%-40%.

[0017] By adopting the above technical solution, the ratio of primary air to secondary air (60%-80% : 20%-40%) is dynamically adjusted based on feedback from the temperature sensor at the bottom of the furnace, optimizing the combustion state of each zone in real time. This achieves real-time optimization of air volume ratio to adapt to different operating conditions. Temperature feedback ensures a balanced temperature distribution between the dense and dilute phase zones, resulting in uniform temperature distribution and reducing the temperature difference from 200℃ to below 50℃, thus improving carbon conversion rate and reducing the carbon content of the bottom slag. Intelligent adjustment is added to the basic air distribution structure, enabling the asymmetric rotating flow field to automatically adjust according to actual temperature conditions, achieving precise control throughout the material flow path, and further enhancing the system's adaptability and stability.

[0018] Optionally, the jet velocity of the secondary air is less than that of the primary air, and the asymmetric rotating flow field and the secondary air are staggered to form a differential fluidization zone.

[0019] By adopting the above technical solution, the injection velocity of the secondary air is lower than that of the primary air. The asymmetric rotating flow field and the secondary air are staggered to form a differential fluidization zone, which affects the material distribution from the dense phase zone to the transition zone. The differential fluidization zone creates different fluidization states to accommodate fuel particles of different sizes. The velocity difference enhances the relative motion between particles and promotes the mixing effect. An ideal concentration gradient distribution is formed in the transition zone, and the bed expansion ratio is stabilized in the ideal range of 1.8-2.2. The differential fluidization effect is superimposed on the asymmetric rotating flow field, and with the help of temperature feedback regulation, a multi-level and multi-scale flow field structure is formed in the material flow path, which significantly improves the fluidization quality and reaction efficiency.

[0020] Optionally, the pulse air dynamic pressure can be indirectly determined and adjusted based on the running time, bed pressure drop, or temperature uniformity index, with the ratio of pulse air dynamic pressure to primary air dynamic pressure being 1.5-3.0.

[0021] By adopting the above technical solution, the pulse wind dynamic pressure is indirectly judged and adjusted based on running time, bed pressure drop, or temperature uniformity indicators. The ratio of pulse wind dynamic pressure to primary air dynamic pressure is 1.5-3.0, maintaining stable energy transfer during material flow. The system can indirectly diagnose the flow field state and adjust the pulse wind dynamic pressure accordingly based on measurable parameters such as running time, bed pressure drop, or temperature uniformity. This method avoids the technical difficulties of directly measuring rotational speed and achieves closed-loop intelligent control of pulse wind kinetic energy. By stabilizing the dynamic pressure ratio of pulse wind to primary air within the optimized range of 1.5-3.0, continuous and stable power is provided for the rotation of the wind cap and the asymmetric flow field, while avoiding energy waste. This effectively maintains the strong turbulence and stability of the bottom flow field, ultimately significantly reducing the overall system energy consumption and resistance while ensuring efficient gas-solid mixing and reaction.

[0022] Optionally, the ratio of the total cross-sectional area of ​​the air outlet of the inverted vent cap to the cross-sectional area of ​​the primary air main duct is 0.6-0.9, and an enlarged portion is provided at the end of the air outlet near the primary air main duct.

[0023] By adopting the above technical solution, the ratio of the total cross-sectional area of ​​the air outlet of the inverted air cap to the cross-sectional area of ​​the primary air main duct is 0.6-0.9. The design of the enlarged part of the air outlet optimizes the airflow distribution in the bottom dense phase zone. The optimized cross-sectional area ratio ensures appropriate airflow velocity and air cap rotation, reducing wear caused by excessive flow velocity while ensuring sufficient fluidization capacity. The enlarged part of the air outlet reduces airflow resistance, allowing airflow to converge at the air cap, facilitating air cap rotation, reducing energy consumption, and improving the uniformity of airflow distribution in the bottom dense phase zone. Based on the rotating air cap and asymmetric air distribution structure, the optimized geometric parameters further improve airflow quality, significantly improving the fluidization state of the material in the initial stage of flow.

[0024] Optionally, an airflow compensation mechanism can be established during the pulse wind interval to adjust the pressure of the primary air main duct during the pulse wind cessation period.

[0025] By adopting the above technical solution, an airflow compensation mechanism is established during the pulse wind interval. The pressure of the primary air main pipeline is increased during the pulse wind stoppage to ensure the continuity of material flow. This compensates for the power loss during the pulse wind interval and maintains the continuity of the rotating flow field. It avoids flow field fluctuations caused by the cessation of pulse wind, maintains a stable flow state during material circulation, extends the operating cycle, and improves the stability of material flow under various operating conditions.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The preheated primary air increases the furnace inlet air temperature, allowing the bottom dense phase zone to quickly reach the reaction temperature; the staggered arrangement of secondary air creates a concentration gradient in the transition zone, optimizing gas-solid mixing; the inverted air cap changes the traditional vertical air distribution method, causing the material to rise in a spiral trajectory, extending the residence time; throughout the flow path, the gas-solid contact area increases, improving reaction efficiency. 2. The ratio of the total cross-sectional area of ​​the outlet of the inverted air cap to the cross-sectional area of ​​the primary air main duct is 0.6-0.9. The design of the expanded outlet section optimizes the airflow distribution in the bottom dense phase zone. The optimized cross-sectional area ratio ensures appropriate airflow velocity and air cap rotation, reducing wear caused by excessive flow velocity while ensuring sufficient fluidization capacity. The expanded outlet section reduces airflow resistance, allowing airflow to converge at the air cap, facilitating air cap rotation, reducing energy consumption, and improving the uniformity of airflow distribution in the bottom dense phase zone. Based on the rotating air cap and asymmetric air distribution structure, the optimized geometric parameters further improve airflow quality, significantly improving the fluidization state of the material in the initial stage of flow. 3. Establish an airflow compensation mechanism during the pulse air interval, increase the pressure of the primary air main pipeline during the pulse air stoppage to ensure the continuity of material flow; compensate for the power loss during the pulse air interval, maintain the continuity of the rotating flow field; avoid flow field fluctuations caused by the cessation of pulse air, maintain a stable flow state during material circulation, extend the operating cycle, and improve the stability of material flow under various operating conditions. Detailed Implementation

[0027] The following provides a further detailed description of this application.

[0028] This embodiment discloses a method for air distribution in a gasifier.

[0029] Example 1: Gasification furnace air distribution method, including the following steps: Primary air is supplied to the gasifier furnace through a primary air main duct, which is attached to the outer wall of the gasifier to utilize the waste heat of the furnace body for preheating. Secondary air is supplied to the gasifier furnace through the secondary air main duct. The secondary air main duct is connected to the primary air main duct and is attached to the outer wall of the gasifier for preheating. The secondary air outlet is located below the primary air outlet and is radially offset from the primary air outlet. The primary air is injected into the furnace through an inverted air cap located at the end of the primary air main duct, and the inverted air cap has multiple air outlet holes.

[0030] Specifically, firstly, the system is initially configured by spiraling the primary air main duct around the outer wall of the gasifier, with high-temperature resistant insulation material applied to the outer wall. Similarly, the secondary air main duct is connected in parallel with the primary air main duct, using the same spiral arrangement. An inverted air cap is installed at the end of the primary air main duct. This air cap has a conical structure with multiple evenly spaced 5mm diameter air outlets on its sidewall. The axis of the air outlets forms a 30° angle with the vertical direction and is inclined circumferentially along the air cap, designed to create a rotating airflow.

[0031] When the system starts up, the raw coal powder is fed into the feed port at the top of the furnace and settles naturally under gravity. At the same time, the gasifying agent is transported through the primary air main pipe and the secondary air main pipe to deliver primary air and secondary air respectively. The air is preheated by the residual heat of the furnace surface at 300-500℃ through the main pipe path attached to the outer wall of the furnace, so that the temperature of the air entering the furnace is raised to 200-350℃.

[0032] The preheated primary air is injected into the bottom of the furnace through the inclined air outlet of the inverted air cap, forming an inclined airflow with a certain horizontal component, which pushes the settled material upward. The secondary air is injected above the dense phase zone, and its air outlet is arranged at a 60° angle offset from the primary air outlet in the circumferential direction, and is located inside the primary air outlet. That is, the secondary air and the primary air are arranged radially, forming a staggered impact effect.

[0033] During operation, the ratio of primary air to secondary air is dynamically adjusted by monitoring the temperature distribution at the bottom of the furnace. When a local temperature is detected to be too high, the proportion of secondary air in that area is appropriately increased to 40% to enhance the cooling effect; when the temperature is too low, the proportion of primary air is increased to 80% to enhance the bottom reaction intensity.

[0034] This embodiment achieves the following significant effects through simple structural improvements: preheating air using waste heat from the furnace body saves external heating energy consumption; the staggered arrangement of secondary air effectively improves the uneven airflow distribution problem of traditional symmetrical air distribution; the inclined air outlet design of the inverted air cap makes the material present a spiral upward trajectory, extending the average residence time; the gas-solid contact area is increased, the carbon conversion rate is improved, and the carbon content of the bottom ash is reduced.

[0035] Example 2: This example differs from Example 1 in that it further includes the following steps: Pulsed air is supplied to the gasifier furnace through a pulsed air duct. The pulsed air outlet is located below the primary air outlet and is inclined toward the primary air outlet. The pulsed air is controlled to be injected in a pulsed manner, and the primary air is rotated by its tilt direction and kinetic energy; the dynamic pressure of the pulsed air is indirectly judged and adjusted according to the running time, bed pressure drop or temperature uniformity index, and the ratio of the dynamic pressure of the pulsed air to the dynamic pressure of the primary air is 1.5-3.0; an airflow compensation mechanism is established during the pulsed air intermittent period, and the pressure of the primary air main pipeline is adjusted during the pulsed air stop.

[0036] Furthermore, the multiple air outlets on the wind cap are inclined and rotate to form a multi-directional rotating airflow; the wind cap is rotated and the pulse wind blows the wind cap to rotate; the air outlets on the wind cap include multiple sets of inclined holes, which are distributed circumferentially at unequal intervals, so that the ejected airflow forms an asymmetric rotating flow field; the ratio of the total cross-sectional area of ​​the air outlets of the inverted wind cap to the cross-sectional area of ​​the primary air main duct is 0.6-0.9, and an enlarged part is provided at the end of the air outlets near the primary air main duct.

[0037] The jet velocity of the secondary air is less than that of the primary air, and the asymmetric rotating flow field and the secondary air are staggered to form a differential fluidization zone.

[0038] It also includes dynamically adjusting the ratio of primary air to secondary air based on feedback from the temperature sensor at the bottom of the furnace, with the ratio range being 60%-80%:20%-40%.

[0039] Specifically, the primary air main duct is spirally arranged along the outer wall of the gasifier, and the outside of the duct is covered with high-temperature resistant insulation material. The residual heat of the furnace surface at 300-500°C is used to preheat the primary air, so that the temperature of the air entering the furnace reaches 200-350°C. The secondary air main duct is connected in parallel with the primary air main duct and is also spirally arranged around the outer wall of the furnace for preheating. The secondary air outlet is located below the primary air outlet and is staggered by 60° in the circumferential direction from the primary air outlet, forming a radially staggered impact effect. An inverted air cap is installed at the end of the primary air main duct. The air cap is rotatably connected by a high-temperature ceramic bearing and can rotate freely. The air cap has a conical structure and 12 radially distributed guide vanes on its outer surface. Multiple sets of air outlet holes are opened on the side wall of the air cap, including three sets of oblique holes. The circumferential holes of each set are not evenly distributed (the included angles between adjacent sets are 80°, 120° and 160°, respectively), forming an asymmetrical air distribution pattern. The axis of the air outlet is at a 30° angle to the vertical direction and is inclined along the circumferential direction of the air cap. The ratio of the total cross-sectional area of ​​the air outlet to the cross-sectional area of ​​the primary air main duct is 0.75. Each air outlet has a tapered enlargement (enlargement angle of 15°) at one end near the primary air main duct to reduce airflow resistance.

[0040] The pulse air duct is located inside the primary air main duct (i.e., closer to the furnace center axis), with its outlet positioned below the primary air outlet and angled towards the guide vanes of the air cap, forming a 30° angle with the axis of the primary air main duct. The pulse air is injected in a pulse manner through an independent control system.

[0041] The raw coal powder is fed into the upper feed port of the furnace and settles under gravity. Preheated primary air (gasifying agent) is first introduced and sprayed into the bottom of the furnace through the inclined air outlet of the inverted air cap, forming a multi-directional rotating airflow with a horizontal component, which pushes the material spiral upward. Secondary air is injected above the dense phase zone, and its injection speed is set to 65% of the primary air speed. It forms a differential fluidization zone with the asymmetric flow field of the primary air, which promotes the concentration gradient distribution of particles in the transition zone.

[0042] Primary air, secondary air, and pulsed air are all used to transport the vaporizing agent. In other embodiments, primary air transports the vaporizing agent, while secondary air and pulsed air transport other vaporizing agents.

[0043] After the bed is basically fluidized, the pulse air system is turned on; the pulse air is sprayed at a frequency of 10 times per hour, each lasting 20 seconds; the ratio of the dynamic pressure of the pulse air to the dynamic pressure of the primary air is controlled at 2.0 (which can be adjusted within the range of 1.5-3.0 according to the working conditions), and its kinetic energy impacts the guide vanes of the air cap, driving the air cap to rotate at a speed of about 10 revolutions per minute.

[0044] The rotating air cap creates an asymmetric rotating flow field in the airflow from the outlet, enhancing the turbulence intensity inside the furnace and increasing the particle diffusion coefficient to 2-3 times that of traditional air distribution. Dynamic airflow adjustment: Based on feedback from 8 temperature sensors at the bottom of the furnace, the ratio of primary air to secondary air is dynamically adjusted in real time; the primary air ratio is controlled at 60%-80%, and the secondary air ratio at 20%-40% (initially set at 70%:30%); when the local temperature is too high, the secondary air ratio is increased to 40% to enhance cooling; when the temperature is too low, the primary air ratio is increased to 80% to enhance the bottom reaction intensity.

[0045] Pulse wind correlation control: The kinetic energy of the pulse wind is correlated with the rotational speed of the primary wind. When the rotational speed of the primary wind decreases, the dynamic pressure ratio of the pulse wind is automatically increased to 2.5 to ensure the stability of the rotating flow field.

[0046] Airflow compensation mechanism: During the intermittent period of pulse wind (during the period of stopped jetting), the pressure of the primary air main duct is increased by 5%-8% to compensate for the lack of power, maintain the continuity of the flow field and the stability of the bed pressure drop (3-5 kPa).

[0047] Coal quality self-adaptation: When the thermal stability index of the coal fed into the furnace (TS+6≤60%) is low, the system automatically increases the pulse air frequency to 15 times per hour and adjusts the primary air ratio to 75% to ensure a full response to coals with low thermal stability.

[0048] This embodiment combines an asymmetric rotating flow field with a differential fluidization zone to uniformly control bubble size at 5-15cm and stabilize the bed expansion ratio at 1.8-2.2, reducing dead zones and channeling phenomena; increasing the gas-solid contact area, improving carbon conversion rate, and reducing the carbon content of bottom ash; achieving uniform furnace temperature distribution, with the temperature difference decreasing from 200℃ to within 50℃; and reducing blower energy consumption by 15-20% through pulsed air dynamic matching and airflow compensation mechanisms, reducing the frequency of air cap blockage, and extending the operating cycle. Through intelligent control, the system can adapt to different coal qualities and operating conditions, improving stability.

[0049] Traditional symmetrical air distribution (such as three sets of 120° evenly distributed airflow) easily forms a stable, periodically repeating flow field structure, which may generate flow "dead zones" or weak fluidization zones on the axis of symmetry. The 80°-120°-160° layout completely breaks any form of symmetry, making it impossible for the airflow to form a stable periodic pattern, thus enabling it to reach every corner of the furnace bottom, greatly reducing the risk of particle deposition and coking. Due to the uneven distribution of the exhaust force in the circumferential direction, the airflow will generate strong lateral pulsations and shear forces in the furnace. A powerful jet (ejected from the narrow 80° interval) impacts the relatively static or weakly fluidized area (the wide 160° interval), entraining a large amount of material, generating intense momentum exchange and energy dissipation, significantly increasing the turbulence intensity (turbulent kinetic energy) of the bed. This makes the mixing of the gas and solid phases much more complete and intense than in a symmetrical or near-symmetrical flow field; the asymmetrical flow field generates a net lateral thrust, pushing solid particles along a non-circular, complex three-dimensional path. This not only prolongs the residence time of particles in the furnace but also promotes heat exchange between the particles and the bed wall, resulting in a more uniform temperature distribution. In a fluidized bed, the merging of small bubbles into large bubbles is one of the main reasons for reduced reaction efficiency. The unstable flow field generated by asymmetric air distribution can effectively break through and tear rising bubbles, inhibiting their merging and maintaining a smaller and more uniform bubble size within the bed, thereby increasing the gas-solid contact area.

[0050] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for air distribution in a gasifier, characterized in that: Includes the following steps: Primary air is supplied to the gasifier furnace through a primary air main duct, which is attached to the outer wall of the gasifier to utilize the waste heat of the furnace body for preheating. Secondary air is supplied to the gasifier furnace through the secondary air main duct. The secondary air main duct is connected to the primary air main duct and is attached to the outer wall of the gasifier for preheating. The secondary air outlet is located below the primary air outlet and is radially offset from the primary air outlet. The primary air is injected into the furnace through an inverted air cap located at the end of the primary air main duct, and the inverted air cap has multiple air outlet holes.

2. The gasifier air distribution method according to claim 1, characterized in that: It also includes the following steps: Pulsed air is supplied to the gasifier furnace through a pulsed air duct. The pulsed air outlet is located below the primary air outlet and is inclined toward the primary air outlet. The pulsed wind is controlled to be ejected in a pulsed manner, and its tilt direction and kinetic energy drive the primary wind to rotate.

3. The gasifier air distribution method according to claim 2, characterized in that: The multiple air outlets on the wind cap are angled and rotated to form a multi-directional rotating airflow.

4. The gasifier air distribution method according to claim 3, characterized in that: The wind cap is rotated, and the pulsed wind causes the wind cap to rotate.

5. The gasifier air distribution method according to claim 4, characterized in that: The air outlet on the wind cap includes multiple sets of oblique holes, which are distributed circumferentially at unequal intervals, so that the ejected airflow forms an asymmetric rotating flow field.

6. The gasifier air distribution method according to any one of claims 1-5, characterized in that: It also includes dynamically adjusting the ratio of primary air to secondary air based on feedback from the temperature sensor at the bottom of the furnace, with the ratio range being 60%-80% : 20%-40%.

7. The gasifier air distribution method according to claim 6, characterized in that: The jet velocity of the secondary air is less than that of the primary air, and the asymmetric rotating flow field and the secondary air are staggered to form a differential fluidization zone.

8. The gasifier air distribution method according to claim 7, characterized in that: Based on the operating time, bed pressure drop, or temperature uniformity indicators, the pulse air dynamic pressure is indirectly judged and adjusted. The ratio of pulse air dynamic pressure to primary air dynamic pressure is 1.5-3.

0.

9. The gasifier air distribution method according to claim 7, characterized in that: The ratio of the total cross-sectional area of ​​the air outlet of the inverted vent cap to the cross-sectional area of ​​the primary air main duct is 0.6-0.9, and an enlarged portion is provided at the end of the air outlet near the primary air main duct.

10. The gasifier air distribution method according to claim 6, characterized in that: Establish an airflow compensation mechanism during the intermittent period of pulsed wind, and adjust the pressure of the primary air main duct during the period when the pulsed wind stops.