Coal activator, method of making and using same

Abstract

The application discloses a coal activating agent, a preparation and use method thereof, and belongs to the technical field of coal combustion. The activating agent is a core-shell type microcapsule powder, is suitable for a wind conveying powder gas-solid two-phase flow use state under 30%-60% rated load of a pulverized coal boiler, and has a powder particle size of 80-120 mu m. The microcapsule is composed of a core layer and a shell layer. According to total mass parts of the microcapsule, the core layer accounts for 60-70 parts, and the shell layer accounts for 30-40 parts. The high-efficiency anti-agglomeration effect of the shell layer effectively inhibits the agglomeration and wall deposition of the pulverized coal, greatly reduces the wind conveying agglomeration rate of the pulverized coal, and guarantees the uniform feeding of the pulverized coal into the furnace. Meanwhile, the core layer can significantly reduce the coal combustion activation energy, shorten the ignition delay time of the furnace, block the residual carbon adhesion and coke block generation from the source, greatly improve the burnout rate of the pulverized coal, and optimize the coal energy utilization efficiency.

Description

Technical Field

[0001] This invention relates to the field of coal combustion technology, and in particular to a coal activator, its preparation and application method. Background Technology

[0002] Coal is an important fossil energy source in industrial production. Pulverized coal boilers, due to their high combustion efficiency and strong adaptability, are widely used in power plants, industrial heating, and other fields. Low-load operation is a common condition in the actual production of pulverized coal boilers. As the core link in pulverized coal conveying in pulverized coal boilers, the stability of its operating conditions directly affects the combustion effect in the subsequent furnace. Coal activators, as an important type of coal combustion additive, can improve the combustion characteristics of coal, reduce the activation energy of coal combustion, increase the pulverized coal burnout rate, and reduce the occurrence of coking in the furnace. They play an important role in optimizing the combustion conditions of pulverized coal boilers and improving coal utilization efficiency, and therefore have become a key area of ​​research and application in the field of coal combustion.

[0003] Current research and design of coal activators primarily focus on the combustion stage within the furnace, designing components and performance solely based on core requirements such as combustion assistance, coking prevention, desulfurization, and denitrification of pulverized coal in the furnace. However, they neglect the critical operating condition of pneumatic conveying of pulverized coal during low-load operation of pulverized coal boilers, failing to consider the compatibility of the activator with the gas-solid two-phase flow conditions under low-load pneumatic conveying. Existing coal activators not only fail to solve the agglomeration problem that easily occurs in pulverized coal during low-load pneumatic conveying, but some activators, after mixing with pulverized coal, can also become agglomeration nuclei for coal particles, further exacerbating agglomeration. This leads to agglomerated pulverized coal adhering to the walls and depositing within the conveying pipes, resulting in uneven distribution of pulverized coal after entering the furnace and disrupting the normal combustion environment within the furnace.

[0004] Furthermore, existing coal activators, due to their neglect of the pneumatic conveying conditions, suffer from problems such as coal powder agglomeration and uneven conveying, which can trigger a chain reaction of problems during the furnace combustion stage. For example, when agglomerated coal powder enters the furnace, oxygen permeation between particles is hindered, leading to delayed ignition and oxygen-deficient combustion in the low-temperature combustion zone. Incompletely burned residual carbon easily adheres to each other and forms coke lumps, not only exacerbating coking within the furnace but also reducing the overall burnout rate of the coal powder and resulting in higher carbon content in fly ash. This reduces the energy utilization efficiency of coal and increases the maintenance costs of boiler equipment. In summary, existing coal activators struggle to simultaneously meet the coal powder dispersion requirements during the low-load pneumatic conveying stage of pulverized coal boilers and the combustion-supporting and coking-prevention requirements during the furnace combustion stage; the technical contradiction between these two aspects remains unresolved. Summary of the Invention

[0005] The main objective of this invention is to overcome the deficiencies of the existing technology and provide a coal activator that can be adapted to low-load pneumatic conveying of coal powder, suppress coal powder agglomeration, and take into account both low-temperature combustion and anti-coking. This invention also provides the preparation and usage methods of the above-mentioned coal activator.

[0006] To achieve the above objectives, the present invention provides a coal activator, wherein the coal activator is a core-shell type microcapsule powder, suitable for use in a pneumatic conveying gas-solid two-phase flow mode of pulverized coal boilers under 30%-60% rated load, and the powder particle size is 80μm-120μm; the microcapsule is composed of a core layer and a shell layer, wherein the core layer accounts for 60-70 parts and the shell layer accounts for 30-40 parts by weight of the total microcapsule.

[0007] The core layer is a low-temperature combustion-supporting and scorching-preventing active layer, which is composed of rare earth low-temperature combustion-supporting components, residual carbon depolymerization components, combustion-supporting carrier components and scorching-inhibiting components.

[0008] The shell layer is a coal powder anti-agglomeration and dispersion layer. It forms a solid lubricating isolation film on the surface of coal powder particles in the air conveying temperature range of 50℃-120℃. In the furnace high temperature zone of ≥300℃, it rapidly thermally decomposes. The core layer is released along with the shell layer and plays a role in low-temperature combustion and anti-coking.

[0009] When the coal activator of this invention is used, its shell layer plays a crucial role in the pneumatic conveying stage (temperature 50℃-120℃, corresponding to the conveying range from the pulverizer outlet to the furnace inlet during low-load operation of a pulverized coal boiler). During this stage, the shell layer acts as an anti-agglomeration and dispersing layer. After mixing with the pulverized coal from the pulverizer outlet in a set ratio, it rapidly forms a uniform solid lubricating isolation film on the surface of each pulverized coal particle due to its own properties. This isolation film effectively blocks the van der Waals forces between pulverized coal particles and isolates the moisture adsorbed on the surface of the pulverized coal, preventing moisture-mediated particle adhesion and inhibiting pulverized coal agglomeration at its source. Furthermore, because the coal activator of this invention is designed with a micron-sized particle size of 80μm-120μm, it is highly compatible with the pulverized coal particle size, thus preventing graded sedimentation during pneumatic conveying and ensuring uniform dispersion and conveying of the mixed pulverized coal in the low-load pneumatic gas-solid two-phase flow. Furthermore, by adjusting the mass ratio of the core and shell structure (60-70 parts core and 30-40 parts shell), the coal activator of this invention will not become an agglomeration nucleus. Instead, through the isolation and dispersion effect of the shell, it solves the problem of traditional activators aggravating coal powder deposition on the wall, providing a uniformly distributed coal powder base for subsequent furnace combustion.

[0010] When pulverized coal carrying the activator enters the furnace, as the furnace temperature rises above 300℃, it enters the combustion stage, achieving a seamless functional connection between the shell and core layers. At this point, the shell layer rapidly decomposes under the high-temperature environment inside the furnace, clearing obstacles for the release of the active components in the core layer without causing additional interference to the combustion process. The core layer, acting as a low-temperature combustion-supporting and coking-preventing active layer, is composed of rare-earth low-temperature combustion-supporting components, residual char deagglomeration components, combustion-supporting carrier components, and coking-inhibiting components. Its core functions are fully realized after the components are released: the rare-earth low-temperature combustion-supporting components reduce the activation energy of coal combustion, shorten the ignition delay time in the low-temperature stage, and solve the problem of difficult ignition of agglomerated pulverized coal; the residual char deagglomeration components prevent the adhesion between incompletely burned residual char particles, avoiding the formation of coke lumps; the combustion-supporting carrier components and the coking-inhibiting components work synergistically to improve the combustion efficiency of pulverized coal and fundamentally suppress the risk of coking in the furnace.

[0011] Preferably, the functional components in the core layer are as follows, based on the total mass of the core layer: 25-30 parts of rare earth low-temperature combustion-supporting component, 20-25 parts of residual char depolymerization component, 40-45 parts of combustion-supporting carrier component, and 5-10 parts of char-inhibiting component.

[0012] During the pneumatic conveying stage, the shell layer continues to function as an anti-agglomeration and dispersion layer, forming a solid lubricating isolation film within the 50℃-120℃ range to inhibit coal powder agglomeration and wall deposition, ensuring uniform coal powder delivery. During this stage, the functional components of the core layer remain stable under the protection of the shell layer. Its preset mass ratio ensures that each component is released in the optimal proportion during the subsequent combustion stage, avoiding functional imbalances caused by excessive or insufficient amounts of a single component, thus laying the foundation for synergistic effects during combustion. When the coal powder enters the furnace and the temperature rises to ≥300℃, the shell layer undergoes rapid thermal decomposition, and the core layer releases its functional components according to the set mass ratio. Based on their proportional advantages, each component forms a precise synergistic effect.

[0013] First, the combustion-supporting carrier component, at a maximum proportion of 40-45 parts, becomes the core carrier for the core layer function. Its sufficient proportion can fully support the rare earth low-temperature combustion-supporting component, the residual char deagglomeration component, and the coking-inhibiting component, expanding the contact area between the active components and the pulverized coal. This avoids uneven action caused by localized aggregation of the active components, solving the problem of low burnout rate in traditional activators due to unbalanced component distribution. Second, the rare earth low-temperature combustion-supporting component accounts for 25-30 parts. This proportion provides sufficient active oxygen ions to reduce the activation energy of coal combustion and shorten the ignition delay time in the low-temperature stage, without wasting resources or causing abnormally high combustion temperatures due to excessive component content. This precisely adapts to the difficulty of igniting agglomerated pulverized coal. In this scenario, the coal powder is rapidly and stably ignited. Next, the residual char deagglomeration component, at a ratio of 20-25 parts, complements the high proportion of the combustion-supporting carrier component. This effectively prevents the adhesion between incompletely burned residual char particles during coal powder combustion. The ratio is precisely matched to the amount of residual char generated, avoiding the formation of coke lumps due to insufficient components or the impact of excessive components on combustion efficiency. Finally, the coking inhibitor component, at a precise ratio of 5-10 parts, focuses on inhibiting the production of tar-like sticky substances. Therefore, it does not require a high proportion to function effectively, while avoiding interference with the combustion reaction due to excessive components. This fundamentally assists the residual char deagglomeration component in inhibiting coking in the furnace. It is evident that by optimizing the mass ratio of each functional component in the core layer, this invention enables the four major functions of rare earth low-temperature combustion assistance, residual carbon depolymerization, combustion support, and coking suppression to form a synergistic effect of sufficient carrier support, precise combustion assistance, targeted depolymerization blocking, and efficient coking suppression. This further improves the coal pulverization rate, strengthens the anti-coking effect, and makes the coal activator more adaptable to the entire process of low-load pneumatic conveying and furnace combustion.

[0014] Preferably, the rare earth low-temperature combustion-supporting component is a CeO2-ZrO2 composite oxide with a particle size of 5nm-10nm; the residual char depolymerization component is sodium lignosulfonate modified nano-SiO2 with a particle size of 10nm-50nm; the combustion-supporting carrier component is rice husk-based porous carbon with a pore size of 2nm-5nm; and the char-inhibiting component is ammonium aminosulfonate.

[0015] In the combustion stage at ≥300℃ in the furnace, after rapid thermal decomposition of the shell layer, the specific components of the core layer work synergistically according to their own characteristics: CeO2-ZrO2 composite oxides of 5nm-10nm serve as rare earth combustion aids, and the nanoparticle size significantly increases the contact area with coal powder, thereby efficiently generating active oxygen ions to rapidly reduce the activation energy of coal combustion, which helps to solve the problem of low-temperature ignition delay of agglomerated coal powder; at the same time, sodium lignosulfonate modified nano-SiO2 of 10nm-50nm serves as a residual char depolymerization component, and the nanoscale size makes it easier to adhere to the surface of residual char particles and accurately block the adhesion between residual char particles; in addition, rice husk-based porous carbon with a pore size of 2nm-5nm is selected as a combustion aid carrier component, and the suitable pore structure can stably support each nano-active component, ensuring its uniform dispersion, while optimizing the contact environment with coal powder; ammonium aminosulfonate serves as a coking inhibitor, which can specifically inhibit the formation of tar-like sticky substances during combustion, forming a synergistic anti-coking effect with the residual char depolymerization component. It is evident that by limiting the specific types and key particle size parameters of each functional component in the core layer, the problem of low efficiency and unstable effect of traditional activator components has been solved, and the effectiveness of low-temperature combustion and charring prevention has been greatly improved.

[0016] Preferably, the rice husk-based porous carbon is prepared by acid modification. The preparation process is as follows: the original rice husk-based porous carbon is immersed in a mixed acid solution of 5%-8% citric acid and 3%-5% phosphoric acid by mass, and modified at a constant temperature of 60℃-70℃ for 2-3 hours. After filtration, it is washed with deionized water until neutral, and dried at 105℃-110℃ to constant weight. The specific surface area of ​​the modified rice husk-based porous carbon is ≥300m² / g.

[0017] After isothermal modification with a mixture of citric acid and phosphoric acid, followed by washing and drying, rice husk-based porous carbon can form a richer pore structure, significantly increasing its specific surface area to ≥300 m² / g. As a combustion-supporting component, it can more fully and stably support active components such as CeO2-ZrO2 composite oxide and sodium lignosulfonate-modified nano-SiO2, ensuring that the active components are uniformly dispersed in the pores and on the surface, avoiding uneven action caused by the aggregation of active components, thereby greatly improving the contact efficiency between the active components and pulverized coal. Furthermore, the rich pore structure of modified rice husk-based porous carbon can efficiently adsorb free water on the surface of pulverized coal, reducing the adverse interference of moisture on low-temperature combustion. At the same time, it can work with rare earth low-temperature combustion-supporting components to further shorten the ignition delay time, and form a stronger functional synergy with residual carbon depolymerization components and coking-inhibiting components, making the residual carbon blocking, coking-inhibiting and anti-sticking effects more precise, further reducing the risk of coking in the furnace, improving the pulverized coal burnout rate, and making the overall low-temperature combustion-supporting and coking-inhibiting effect of the core layer more stable and efficient.

[0018] Preferably, the functional components in the shell are as follows, based on the total mass of the shell: 60-70 parts of film-forming isolation component, 20-25 parts of air-flow modification component, and 10-15 parts of pyrolysis promotion component.

[0019] During the 50℃-120℃ pneumatic conveying stage, the film-forming isolation component, which has the highest proportion, is the core component of the shell. Its sufficient proportion can ensure the formation of a uniform and dense solid lubricating isolation film on the surface of coal powder particles, thereby preventing the adhesion between coal powder particles from the source. The pneumatic flow modification component plays an auxiliary role with an appropriate proportion, effectively reducing the friction coefficient between coal powder particles and between particles and the conveying pipe wall, improving the flowability of gas-solid two-phase flow, and forming an anti-agglomeration and dispersion synergy with the film-forming component to avoid coal powder deposition on the wall. Moreover, at this proportion, the low proportion of the pyrolysis promoting component is reserved, which will not interfere with the structural stability of the shell during the conveying stage.

[0020] Furthermore, when pulverized coal enters the furnace and reaches ≥300℃, the precise proportion of the pyrolysis promoting component can meet the requirements for triggering rapid thermal pyrolysis of the shell layer. It forms a pyrolysis synergy with the film-forming isolation component and the air-flow modification component, ensuring the rate and integrity of the shell layer thermal pyrolysis, realizing rapid pyrolysis of the shell layer and timely release of the core layer. It also eliminates residual interference with the low-temperature combustion and anti-coking function of the core layer, solving the problem of delayed or insufficient shell layer pyrolysis caused by component ratio imbalance, and making the two-stage functional connection between the shell layer and the core layer more precise and efficient.

[0021] Preferably, the film-forming isolation component is water-soluble polyethylene wax with a melting point of 120℃-150℃; the air-assisted flow modification component is magnesium stearate with a particle size of 1μm-5μm; the pyrolysis promoting component is sodium bicarbonate; and the thermal pyrolysis rate of the shell in the furnace high-temperature zone of ≥300℃ is ≥98%.

[0022] During the pneumatic conveying stage at 50℃-120℃, water-soluble polyethylene wax is used as the film-forming isolation component. Its melting point, higher than the upper limit of the pneumatic conveying temperature, ensures the rapid formation and maintenance of a uniform and dense solid lubricating isolation film on the surface of coal particles. This effectively prevents film softening or adhesion under high-temperature pneumatic conveying, fundamentally preventing particle adhesion at a physical level. Simultaneously, its water solubility ensures its applicability to aqueous spray granulation processes, guaranteeing the uniformity and density of the shell coating. Magnesium stearate (1μm-5μm) is used as the pneumatic flow modifier. Its suitable particle size allows for better adhesion to coal particles, effectively reducing the friction coefficient between particles and between particles and the pipe wall, thus improving the dispersion and flowability of the gas-solid two-phase flow. Sodium bicarbonate, as a cracking promoter, maintains structural stability during this stage and does not interfere with the anti-agglomeration and dispersion effect of the shell. When pulverized coal enters the furnace and reaches ≥300℃, sodium bicarbonate triggers rapid thermal decomposition of the shell layer, ensuring a thermal decomposition rate of ≥98%. Its decomposition products are CO2, H2O, and Na2CO3, with no harmful gas residue. This avoids residual substances blocking the active components of the core layer and interfering with furnace combustion, while also allowing the shell layer to decompose rapidly and completely, ensuring the timely and full release of the active components of the core layer. This allows the core layer to efficiently perform its functions of low-temperature combustion assistance and coking prevention, achieving seamless integration of the functions of the shell and core layers.

[0023] This invention also provides a method for preparing a coal activator, comprising the following steps:

[0024] S101: Core layer powder preparation: The rare earth low-temperature combustion-supporting component, residual carbon depolymerization component, combustion-supporting carrier component and coke-inhibiting component of the core layer are added to a dry ball mill in proportion and ball milled at a speed of 200r / min-300r / min for 30min to obtain a core layer mixed powder with a particle size of 10μm-20μm.

[0025] S102: Preparation of shell coating solution: The shell film-forming isolation component, air-flow modification component and pyrolysis promoting component are added to deionized water in proportion, and stirred in a water bath at 70℃-80℃ until completely dissolved to obtain a shell coating solution with a solid content of 30-40 parts.

[0026] S103: Core-shell microcapsule granulation: The core-shell mixed powder obtained in step S101 is added to a spray granulator, and the shell coating solution obtained in step S102 is used as the atomizing medium. The inlet air temperature of the spray granulator is set to 80℃-90℃ and the outlet air temperature is set to 40℃-50℃. After spray granulation, core-shell microcapsule primary powder with a particle size of 80μm-120μm is obtained.

[0027] S104: Finished product packaging: The core-shell microcapsule powder obtained in step S103 is packaged under the protection of an inert gas at room temperature to obtain the finished coal activator.

[0028] In step S101, the core layer powder is prepared by dry ball milling at a speed of 200r / min-300r / min for 30min. The dry process can avoid the deactivation of the active components of the core layer when exposed to water. The specific speed and time allow the components such as rare earth low-temperature combustion and residual carbon depolymerization to be fully and uniformly mixed. At the same time, the core layer mixed powder with a diameter of 10μm-20μm is accurately prepared, which lays the foundation for the uniform coating of the shell layer and avoids uneven functional performance caused by local aggregation of components. In step S102, the shell coating solution is prepared by stirring in a water bath environment of 70℃-80℃ until the components are completely dissolved. By precisely controlling the solid content of 30-40 parts, the water bath temperature control ensures that the components of the shell layer do not undergo thermal decomposition and are fully dissolved. The appropriate solid content avoids the problem of the shell layer being too thick, too thin or not dense enough during coating, and ensures that the shell layer can form a uniform solid lubricating isolation film on the coal powder surface. In step S103, the core-shell microcapsule granulation uses the shell coating solution as the atomizing medium, combined with inlet air temperature parameters of 80℃-90℃ and outlet air temperature of 40℃-50℃. Through atomization, the shell solution uniformly coats the surface of the core powder, forming a dense core-shell structure. This precise temperature control prevents powder agglomeration and excessive particle size during granulation, ultimately producing microcapsule initial powder with a particle size of 80μm-120μm, matching the particle size requirements of low-load pneumatic conveying and preventing graded sedimentation during pneumatic conveying. In step S104, the finished product encapsulation is completed under ambient temperature inert gas protection, which effectively isolates the product from air and moisture, preventing moisture absorption and oxidation during storage and transportation. This ensures the integrity of the core-shell structure and the activity of each component, ensuring that the product can still stably perform its designed functions during use. This solves the problem of product performance degradation caused by the lack of protective encapsulation in traditional preparation processes. It is evident that the parameters of each step in the entire preparation process are precisely matched and seamlessly connected. From raw material mixing to finished product molding, the structure, particle size, and component activity of the product are controlled throughout the entire process to ensure that it can be accurately adapted to the application scenario.

[0029] Preferably, the inert gas mentioned in step S104 is nitrogen.

[0030] Nitrogen, as a highly stable inert gas, is non-oxidizing and does not react chemically with any components of the activator core or shell. It also forms a dense, inert atmosphere within the encapsulation system, effectively isolating external air (oxygen) and moisture from the environment. Furthermore, encapsulating the finished product under nitrogen protection at room temperature prevents oxidation of the rare-earth low-temperature combustion-supporting components and ammonium sulfamate in the core layer, thus preventing reduced efficiency or even failure due to oxidation. This ensures that during the subsequent furnace combustion stage, the core layer can efficiently release its designed components and perform its core functions of low-temperature combustion support, residual carbon deagglomeration, and slag suppression and anti-sticking. On the other hand, it completely blocks environmental moisture from entering the encapsulation system, preventing the shell components from absorbing moisture and agglomerating. Simultaneously, it prevents moisture penetration from damaging the dense structure of the core-shell microcapsules, ensuring that the shell layer can smoothly form a uniform and complete solid lubricating isolation film on the surface of the coal powder particles during the subsequent pneumatic conveying stage. This prevents damage to the anti-agglomeration and dispersion function due to structural breakage or component agglomeration.

[0031] In addition, nitrogen has the characteristics of being widely available in industry, low in production cost, non-corrosive and residue-free. Compared with other inert gases, it is more suitable for the industrial production and packaging needs of coal activators. While achieving high-efficiency protection, it will not impose additional cost burden on the subsequent storage and transportation of activators, nor will it generate any residual substances during packaging and subsequent use. It has no negative impact on the application effect of activators or boiler combustion environment.

[0032] This invention also provides a method for using a coal activator, comprising the following steps:

[0033] S201: Add the coal activator and pulverized coal with an outlet temperature of 50℃-120℃ to the mixer at a mass ratio of 0.5 parts to 0.8 parts, and dry mix for 10 min to 15 min until uniform. The mixed pulverized coal is directly fed into the original air conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow pulverization without adjusting the air velocity and pressure parameters of the air conveying pipeline.

[0034] S202: After pulverized coal is introduced into the furnace, the shell layer undergoes thermal pyrolysis and the core layer active components are released in the high-temperature zone of the furnace at ≥300℃. The core layer components play a role in low-temperature combustion assistance of pulverized coal and preventing coking in the furnace.

[0035] Since the outlet coal powder temperature of the coal mill in step S201 is 50℃-120℃, this temperature is exactly the same as the temperature range in which the activator shell layer exerts its anti-agglomeration effect. Mixing the activator with the coal powder at this temperature allows the shell layer to quickly adhere to the surface of the coal powder particles, laying the foundation for the subsequent formation of a solid lubricating isolation film and preventing temperature deviations from causing a decrease in the film-forming properties of the shell layer or premature thermal reactions. Simultaneously, mixing at a mass ratio of 0.5-0.8 parts ensures that each coal powder particle is coated with a sufficient amount of activator, guaranteeing the anti-agglomeration effect of the shell layer and the core... The combustion-supporting and anti-coking effects of the layer are fully utilized without wasting resources or increasing usage costs due to excessive activator. It also avoids functional failure caused by insufficient proportion. The dry mixing method is adopted and the mixing time is controlled at 10-15 minutes. The dry process can avoid moisture from damaging the core-shell structure of the activator. The specific mixing time allows the activator to be evenly dispersed and combined with the coal powder, ensuring that the surface of the coal powder particles is evenly covered with the activator. This solves the problems of local aggregation and uneven action of the activator caused by traditional mixing methods, and ensures the overall anti-agglomeration effect of the pneumatic conveying stage from the source.

[0036] In step S202, the mixed pulverized coal directly enters the existing pneumatic conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow conveying, without the need to adjust the pipeline's wind speed and pressure parameters. This design fully adapts to the actual usage requirements of industrial sites, avoiding the problem of traditional activators requiring boiler equipment modification and operating parameter adjustments due to poor adaptability to operating conditions, significantly reducing the threshold and cost of industrial applications. Simultaneously, under the existing pneumatic conveying parameters, the activator's micron-sized particles (80μm-120μm) can be conveyed synchronously with the pulverized coal, preventing graded sedimentation due to particle size mismatch. Combined with the solid lubricating isolation film formed by the shell layer, it effectively inhibits pulverized coal agglomeration and wall deposition, ensuring uniform pulverized coal entry into the furnace. When the uniformly mixed pulverized coal enters the furnace, the furnace temperature rises to ≥300℃, the shell layer rapidly thermally decomposes, and the active components of the core layer are released in a timely manner and fully contact the pulverized coal, precisely performing the core functions of low-temperature combustion assistance, residual carbon deagglomeration, and coking and anti-sticking, solving the problems of delayed ignition of agglomerated pulverized coal, low burnout rate, and intensified coking in the furnace.

[0037] Preferably, the optimal mass mixing ratio of the coal activator to pulverized coal is 0.6 parts.

[0038] Within the mass mixing ratio range of 0.5 to 0.8 parts, 0.6 parts is identified as the optimal mass mixing ratio of coal activator and pulverized coal. This ratio precisely matches the full operating conditions of pulverized coal boilers at 30%-60% of rated load, achieving the optimal balance between activator function, operating condition adaptability, and industrial application economy. It solves the problems of insufficient function due to a low mixing ratio and resource waste and slight interference with operating conditions due to a high mixing ratio, allowing the activator to achieve the best effect in both the pneumatic conveying and furnace combustion stages. Furthermore, during the pneumatic conveying stage at 50℃-120℃, a ratio of 0.6 parts allows the shell layer to form a complete, dense, and moderately thick solid lubricating isolation film on the coal powder surface. This avoids both insufficient ratio leading to discontinuous film layers that fail to effectively prevent coal powder agglomeration and wall deposition, and excessive ratio resulting in an overly thick film layer that increases particle adhesion or causes the formation of new agglomeration nuclei from free activators. Simultaneously, it does not alter the particle size distribution of the mixed system or interfere with the gas-solid two-phase flow state of the original pneumatic conveying pipeline. Combined with dry mixing technology, it achieves uniform bonding between the activator and coal powder. When the coal powder enters the furnace at ≥300℃, the core layer active components released by this ratio are highly matched to the actual requirements of low-load coal powder combustion. The rare earth low-temperature combustion-supporting components can sufficiently reduce the combustion activation energy, completely solving the ignition delay problem. The release of residual carbon deagglomeration and char-inhibiting components precisely covers the amount of residual carbon and tar-like substances generated throughout the combustion process, accurately achieving the anti-charging effect.

[0039] Beneficial effects:

[0040] 1. This invention designs the coal activator as a core-shell microcapsule powder with a particle size of 80μm-120μm. This particle size is highly compatible with pulverized coal and can directly match the gas-solid two-phase flow state of pneumatic conveying of pulverized coal under 30%-60% rated load of pulverized coal boiler. This avoids the problem of staged sedimentation during pneumatic conveying. From the perspective of product structure and physical parameters, this invention solves the technical defects of existing activators that ignore low-load pneumatic conveying conditions and have poor adaptability to actual conveying conditions, and achieves precise adaptation to this specific working condition.

[0041] 2. This invention designs the shell layer as a coal powder anti-agglomeration dispersion layer, which can form a solid lubricating isolation film on the surface of coal powder particles in the air conveying temperature range of 50℃-120℃. This film can block the adhesion between coal powder particles and isolate the surface moisture of the coal powder. Furthermore, the mass ratio design of 60-70 parts of the core layer and 30-40 parts of the shell layer ensures that the activator itself will not become a coal powder agglomeration nucleus. This completely solves the problem that existing activators cannot inhibit coal powder agglomeration and may even aggravate agglomeration and cause coal powder to adhere to the wall, thus ensuring the uniform dispersion and conveying of coal powder in the low-load air conveying process.

[0042] 3. This invention, through the functional zoning design of the core and shell layers, allows the shell layer to rapidly thermally decompose in the furnace at a high temperature of ≥300℃, clearing obstacles for the release of the core layer without secondary interference. The core layer, as a low-temperature combustion-supporting and coking-preventing active layer, can fully exert its low-temperature combustion-supporting and coking-preventing effects through its composite components. This reduces the activation energy of coal combustion, shortens the low-temperature ignition delay time, and also blocks residual carbon adhesion and inhibits furnace coking. From the product function level, this invention solves the core technical contradiction of existing activators being unable to simultaneously meet the requirements of low-load air-powder conveying and powder dispersion and the requirements of furnace combustion-supporting and coking-preventing, thus achieving both core functions simultaneously. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application 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 some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart of the coal activator preparation method of the present invention;

[0045] Figure 2 This is a TG-DSC combustion curve of a coal sample without the coal activator of this invention added;

[0046] Figure 3 This is a TG-DSC combustion curve of a coal sample with the coal activator of this invention added. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0049] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0050] In the description of this application, it should be noted that the use of terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These terms are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the use of terms such as "first" and "second" in the description of this application is only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0051] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this application does not imply that the component is required to be absolutely horizontal or suspended, but rather that it may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0052] In the description of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 application based on the specific circumstances. Furthermore, the term "part" in this invention, unless otherwise stated, refers to parts by weight.

[0053] Example 1:

[0054] This embodiment provides a coal activator, which is a core-shell microcapsule powder with a particle size of 100μm. It is suitable for use in a pneumatic conveying gas-solid two-phase flow mode of pulverized coal boilers at 45% rated load. By total mass of microcapsules, the core layer accounts for 65 parts and the shell layer accounts for 35 parts.

[0055] The core layer is a low-temperature combustion-supporting and scorching-preventing active layer. By total mass of the core layer, it consists of 28 parts of rare earth low-temperature combustion-supporting components (5nm-10nm CeO2-ZrO2 composite oxide), 22 parts of residual carbon depolymerization components (10nm-50nm sodium lignosulfonate modified nano-SiO2), 42 parts of combustion-supporting carrier components (acid-modified rice husk-based porous carbon with pore size of 2nm-5nm), and 8 parts of scorching-inhibiting components (ammonium aminosulfonate). The modification process of the rice husk-based porous carbon is as follows: the original rice husk-based porous carbon is immersed in a mixed acid solution of 6% citric acid and 4% phosphoric acid by mass, and modified at a constant temperature of 65℃ for 2.5h in a water bath. After filtration, it is washed with deionized water until neutral and dried at 108℃ to constant weight.

[0056] The shell is a powder conveying anti-agglomeration dispersion layer. By total mass of the shell, it consists of 65 parts of film-forming isolation component (water-soluble polyethylene wax, melting point 135℃), 23 parts of air-flow modification component (3μm magnesium stearate), and 12 parts of pyrolysis promoting component (sodium bicarbonate).

[0057] like Figure 1 As shown, the preparation method of the above-mentioned coal activator includes the following steps:

[0058] S101: Core layer powder preparation: Add each functional component of the core layer to a dry ball mill according to the above proportions, and ball mill and mix at a speed of 250 r / min for 30 min to obtain a core layer mixed powder with a D50 particle size of 15 μm;

[0059] S102: Preparation of shell coating solution: The shell film-forming isolation component, air-flow modification component and pyrolysis promoting component are added to deionized water in the above proportions and stirred in a 75°C water bath until completely dissolved to obtain a shell coating solution with a solid content of 35 parts.

[0060] S103: Core-shell microcapsule granulation: The core-shell mixed powder is added to a spray granulator, and the shell coating solution is used as the atomizing medium. The inlet air temperature is set to 85℃ and the outlet air temperature is set to 45℃. Spray granulation yields core-shell microcapsule primary powder with a particle size of 100μm.

[0061] S104: Finished product packaging: The microcapsule powder is packaged under nitrogen protection at room temperature to obtain the finished coal activator.

[0062] The above-mentioned coal activator usage method:

[0063] S201: Add coal activator and pulverized coal with an outlet temperature of 85℃ from the coal mill to the mixer at a mass ratio of 0.6 parts, dry mix for 12 minutes until uniform, and the mixed pulverized coal directly enters the original air conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow pulverization without adjusting the wind speed and pressure parameters.

[0064] S202: After pulverized coal is introduced into the furnace, the shell layer in the high-temperature zone of the furnace (≥300℃) undergoes rapid thermal decomposition, and the active components in the core layer are released, achieving low-temperature combustion assistance of pulverized coal and prevention of coking in the furnace.

[0065] Furthermore, in practical use, this invention, in conjunction with the appendix to the specification, Figure 2 and Figure 3It can be seen that the ignition temperature of the coal sample without the coal activator of the present invention is 557.1℃ and the burnout temperature is 852.8℃. However, after adding the coal activator of the present invention, the ignition temperature drops to 523.2℃ and the burnout temperature drops to 729.7℃. The maximum combustion rate increases from 5.15% / min to 7.48% / min. This proves that the coal activator of the present invention has the technical effect of significantly reducing the ignition temperature of pulverized coal, shortening the burnout time, and increasing the combustion rate, which fully meets the design expectations.

[0066] Example 2

[0067] This embodiment provides a coal activator, which is a core-shell microcapsule powder with a particle size of 80μm. It is suitable for use in a pneumatic conveying gas-solid two-phase flow mode of pulverized coal boilers under 30% rated load. By total mass of microcapsules, the core layer accounts for 60 parts and the shell layer accounts for 40 parts.

[0068] The core layer is a low-temperature combustion-supporting and scorching-preventing active layer. By total mass of the core layer, it consists of 25 parts of rare earth low-temperature combustion-supporting components (5nm-10nm CeO2-ZrO2 composite oxide), 20 parts of residual carbon depolymerization components (10nm-50nm sodium lignosulfonate modified nano-SiO2), 45 parts of combustion-supporting carrier components (acid-modified rice husk-based porous carbon with pore size of 2nm-5nm), and 10 parts of scorching-inhibiting components (ammonium aminosulfonate). The modification process of the rice husk-based porous carbon is as follows: the original rice husk-based porous carbon is immersed in a mixed acid solution of 5% citric acid and 3% phosphoric acid by mass, and modified at a constant temperature of 60℃ for 3 hours in a water bath. After filtration, it is washed with deionized water until neutral and dried at 105℃ to constant weight.

[0069] The shell is a powder conveying anti-agglomeration dispersion layer. By total mass of the shell, it consists of 60 parts of film-forming isolation component (water-soluble polyethylene wax, melting point 125℃), 25 parts of air-flow modification component (1μm magnesium stearate), and 15 parts of pyrolysis promoting component (sodium bicarbonate).

[0070] like Figure 1 As shown, the preparation method of the above-mentioned coal activator includes the following steps:

[0071] S101: Core layer powder preparation: Add each functional component of the core layer to a dry ball mill according to the above proportions, and mix them at a speed of 200 r / min for 30 min to obtain a core layer mixed powder with a D50 particle size of 10 μm;

[0072] S102: Preparation of shell coating solution: The shell film-forming isolation component, air-flow modification component and pyrolysis promoting component are added to deionized water in the above proportions and stirred in a 70°C water bath until completely dissolved to obtain a shell coating solution with a solid content of 30 parts.

[0073] S103: Core-shell microcapsule granulation: The core-shell mixed powder is added to a spray granulator, and the shell coating solution is used as the atomizing medium. The inlet air temperature is set to 80℃ and the outlet air temperature is set to 40℃. Spray granulation yields core-shell microcapsule primary powder with a particle size of 80μm.

[0074] S104: Finished product packaging: The microcapsule powder is packaged under nitrogen protection at room temperature to obtain the finished coal activator.

[0075] The above-mentioned coal activator usage method:

[0076] S201: Add coal activator and pulverized coal with an outlet temperature of 50℃ from the coal mill to the mixer at a mass ratio of 0.6 parts, dry mix for 10 minutes until uniform, and the mixed pulverized coal directly enters the original air conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow pulverization without adjusting the wind speed and pressure parameters.

[0077] S202: After pulverized coal is introduced into the furnace, the shell layer in the high-temperature zone of the furnace (≥300℃) undergoes rapid thermal decomposition, and the active components in the core layer are released, achieving low-temperature combustion assistance of pulverized coal and prevention of coking in the furnace.

[0078] Example 3

[0079] This embodiment provides a coal activator, which is a core-shell microcapsule powder with a particle size of 120μm. It is suitable for use in a pneumatic conveying gas-solid two-phase flow mode under 60% rated load of pulverized coal boiler. By total mass of microcapsules, the core layer accounts for 70 parts and the shell layer accounts for 30 parts.

[0080] The core layer is a low-temperature combustion-supporting and scorching-preventing active layer. By total mass of the core layer, it consists of 30 parts of rare earth low-temperature combustion-supporting components (5nm-10nm CeO2-ZrO2 composite oxide), 25 parts of residual carbon depolymerization components (10nm-50nm sodium lignosulfonate modified nano-SiO2), 40 parts of combustion-supporting carrier components (acid-modified rice husk-based porous carbon with pore size of 2nm-5nm), and 5 parts of scorching-inhibiting components (ammonium aminosulfonate). The modification process of the rice husk-based porous carbon is as follows: the original rice husk-based porous carbon is immersed in a mixed acid solution of 8% citric acid and 5% phosphoric acid by mass, and modified at a constant temperature of 70℃ for 2 hours in a water bath. After filtration, it is washed with deionized water until neutral and dried at 110℃ to constant weight.

[0081] The shell is a powder conveying anti-agglomeration dispersion layer. By total mass of the shell, it consists of 70 parts of film-forming isolation component (water-soluble polyethylene wax, melting point 145℃), 20 parts of air-flow modification component (5μm magnesium stearate), and 10 parts of pyrolysis promoting component (sodium bicarbonate).

[0082] like Figure 1 As shown, the preparation method of the above-mentioned coal activator includes the following steps:

[0083] S101: Core layer powder preparation: Add each functional component of the core layer to a dry ball mill according to the above proportions, and mix them at a speed of 300 r / min for 30 min to obtain a core layer mixed powder with a D50 particle size of 20 μm;

[0084] S102: Preparation of shell coating solution: The shell film-forming isolation component, air-flow modification component and pyrolysis promoting component are added to deionized water in the above proportions and stirred in an 80°C water bath until completely dissolved to obtain a shell coating solution with a solid content of 40 parts.

[0085] S103: Core-shell microcapsule granulation: The core-shell mixed powder is added to a spray granulator, and the shell coating solution is used as the atomizing medium. The inlet air temperature is set to 90℃ and the outlet air temperature is set to 50℃. Spray granulation yields core-shell microcapsule primary powder with a particle size of 120μm.

[0086] S104: Finished product packaging: The microcapsule powder is packaged under nitrogen protection at room temperature to obtain the finished coal activator.

[0087] The above-mentioned coal activator usage method:

[0088] S201: Add coal activator and pulverized coal with an outlet temperature of 120℃ from the coal mill to the mixer at a mass ratio of 0.6 parts, dry mix for 15 minutes until uniform, and the mixed pulverized coal directly enters the original air conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow pulverization without adjusting the wind speed and pressure parameters.

[0089] S202: After pulverized coal is introduced into the furnace, the shell layer in the high-temperature zone of the furnace (≥300℃) undergoes rapid thermal decomposition, and the active components in the core layer are released, achieving low-temperature combustion assistance of pulverized coal and prevention of coking in the furnace.

[0090] Example 4

[0091] This embodiment provides a coal activator, which is a core-shell type microcapsule powder with a particle size of 90μm. It is suitable for use in a pneumatic conveying gas-solid two-phase flow mode of pulverized coal boilers at 35% rated load. By total mass of microcapsules, the core layer accounts for 62 parts and the shell layer accounts for 38 parts.

[0092] The core layer is a low-temperature combustion-supporting and scorching-preventing active layer. By total mass of the core layer, it consists of 26 parts of rare earth low-temperature combustion-supporting components (5nm-10nm CeO2-ZrO2 composite oxide), 21 parts of residual carbon depolymerization components (10nm-50nm sodium lignosulfonate modified nano-SiO2), 44 parts of combustion-supporting carrier components (acid-modified rice husk-based porous carbon with pore size of 2nm-5nm), and 9 parts of scorching-inhibiting components (ammonium aminosulfonate). The modification process of the rice husk-based porous carbon is as follows: the original rice husk-based porous carbon is immersed in a mixed acid solution of 5.5% citric acid and 3.5% phosphoric acid by mass, and modified at a constant temperature of 62℃ for 2.8h. After filtration, it is washed with deionized water until neutral and dried at 106℃ to constant weight.

[0093] The shell is a powder conveying and anti-agglomeration dispersion layer. By total mass of the shell, it contains 62 parts of film-forming isolation component (water-soluble polyethylene wax, melting point 130℃), 24 parts of air-flow modification component (2μm magnesium stearate), and 14 parts of pyrolysis promoting component (sodium bicarbonate).

[0094] like Figure 1 As shown, the preparation method of the above-mentioned coal activator includes the following steps:

[0095] S101: Core layer powder preparation: Add each functional component of the core layer to a dry ball mill according to the above proportions, and ball mill and mix at a speed of 220 r / min for 30 min to obtain a core layer mixed powder with a D50 particle size of 12 μm;

[0096] S102: Preparation of shell coating solution: The shell film-forming isolation component, air-flow modification component and pyrolysis promoting component are added to deionized water in the above proportions, and stirred in a 72°C water bath until completely dissolved to obtain a shell coating solution with a solid content of 32 parts.

[0097] S103: Core-shell microcapsule granulation: The core-shell mixed powder is added to a spray granulator, and the shell coating solution is used as the atomizing medium. The inlet air temperature is set to 82℃ and the outlet air temperature is set to 42℃. Spray granulation yields core-shell microcapsule primary powder with a particle size of 90μm.

[0098] S104: Finished product packaging: The microcapsule powder is packaged under nitrogen protection at room temperature to obtain the finished coal activator.

[0099] The above-mentioned coal activator usage method:

[0100] S201: Add coal activator and pulverized coal with an outlet temperature of 65℃ from the coal mill to the mixer at a mass ratio of 0.6 parts, dry mix for 11 minutes until uniform, and the mixed pulverized coal directly enters the original air conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow pulverization without adjusting the wind speed and pressure parameters.

[0101] S202: After pulverized coal is introduced into the furnace, the shell layer in the high-temperature zone of the furnace (≥300℃) undergoes rapid thermal decomposition, and the active components in the core layer are released, achieving low-temperature combustion assistance of pulverized coal and prevention of coking in the furnace.

[0102] Example 5

[0103] This embodiment provides a coal activator, which is a core-shell type microcapsule powder with a particle size of 110μm. It is suitable for use in a gas-solid two-phase flow mode of air conveying pulverized coal under 55% rated load of pulverized coal boiler. By total mass of microcapsules, the core layer accounts for 68 parts and the shell layer accounts for 32 parts.

[0104] The core layer is a low-temperature combustion-supporting and scorching-preventing active layer. By total mass of the core layer, it consists of 29 parts of rare earth low-temperature combustion-supporting components (5nm-10nm CeO2-ZrO2 composite oxide), 24 parts of residual carbon depolymerization components (10nm-50nm sodium lignosulfonate modified nano-SiO2), 41 parts of combustion-supporting carrier components (acid-modified rice husk-based porous carbon with pore size of 2nm-5nm), and 6 parts of scorching-inhibiting components (ammonium aminosulfonate). The modification process of the rice husk-based porous carbon is as follows: the original rice husk-based porous carbon is immersed in a mixed acid solution of 7% citric acid and 4.5% phosphoric acid by mass, and modified at a constant temperature of 68℃ for 2.2h in a water bath. After filtration, it is washed with deionized water until neutral and dried at 109℃ to constant weight.

[0105] The shell is a powder conveying anti-agglomeration dispersion layer. By total mass of the shell, it contains 68 parts of film-forming isolation component (water-soluble polyethylene wax, melting point 140℃), 21 parts of air-flow modification component (4μm magnesium stearate), and 11 parts of pyrolysis promoting component (sodium bicarbonate).

[0106] like Figure 1 As shown, the preparation method of the above-mentioned coal activator includes the following steps:

[0107] S101: Core layer powder preparation: Add each functional component of the core layer to a dry ball mill according to the above proportions, and mix them at a speed of 280 r / min for 30 min to obtain a core layer mixed powder with a D50 particle size of 18 μm.

[0108] S102: Preparation of shell coating solution: The shell film-forming isolation component, air-flow modification component and pyrolysis promoting component are added to deionized water in the above proportions, and stirred in a 78°C water bath until completely dissolved to obtain a shell coating solution with a solid content of 38 parts.

[0109] S103: Core-shell microcapsule granulation: The core-shell mixed powder is added to a spray granulator, and the shell coating solution is used as the atomizing medium. The inlet air temperature is set to 88℃ and the outlet air temperature is set to 48℃. Spray granulation yields core-shell microcapsule primary powder with a particle size of 110μm.

[0110] S104: Finished product packaging: The microcapsule powder is packaged under nitrogen protection at room temperature to obtain the finished coal activator.

[0111] The above-mentioned coal activator usage method:

[0112] S201: Add coal activator and pulverized coal with an outlet temperature of 100℃ from the coal mill to the mixer at a mass ratio of 0.6 parts, dry mix for 14 minutes until uniform, and the mixed pulverized coal directly enters the original air conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow pulverization without adjusting the wind speed and pressure parameters.

[0113] S202: After pulverized coal is introduced into the furnace, the shell layer in the high-temperature zone of the furnace (≥300℃) undergoes rapid thermal decomposition, and the active components in the core layer are released, achieving low-temperature combustion assistance of pulverized coal and prevention of coking in the furnace.

[0114] Example 6

[0115] This embodiment provides a coal activator, which is a core-shell type microcapsule powder with a particle size of 95μm. It is suitable for use in a pneumatic conveying gas-solid two-phase flow mode of pulverized coal boilers at 50% rated load. By total mass of microcapsules, the core layer accounts for 66 parts and the shell layer accounts for 34 parts.

[0116] The core layer is a low-temperature combustion-supporting and scorching-preventing active layer. By total mass of the core layer, it consists of 27 parts of rare earth low-temperature combustion-supporting components (5nm-10nm CeO2-ZrO2 composite oxide), 23 parts of residual carbon depolymerization components (10nm-50nm sodium lignosulfonate modified nano-SiO2), 43 parts of combustion-supporting carrier components (acid-modified rice husk-based porous carbon with pore size of 2nm-5nm), and 7 parts of scorching-inhibiting components (ammonium aminosulfonate). The modification process of the rice husk-based porous carbon is as follows: the original rice husk-based porous carbon is immersed in a mixed acid solution of 6.5% citric acid and 3.8% phosphoric acid by mass, and modified at a constant temperature of 66℃ for 2.4h in a water bath. After filtration, it is washed with deionized water until neutral and dried at 107℃ to constant weight.

[0117] The shell layer is a powder conveying anti-agglomeration dispersion layer. By total mass of the shell layer, it contains 66 parts of film-forming isolation component (water-soluble polyethylene wax, melting point 138℃), 22 parts of air-flow modification component (2.5μm magnesium stearate), and 13 parts of pyrolysis promoting component (sodium bicarbonate).

[0118] like Figure 1 As shown, the preparation method of the above-mentioned coal activator includes the following steps:

[0119] S101: Core layer powder preparation: Add each functional component of the core layer to a dry ball mill according to the above proportions, and ball mill and mix at a speed of 260 r / min for 30 min to obtain a core layer mixed powder with a D50 particle size of 14 μm;

[0120] S102: Preparation of shell coating solution: The shell film-forming isolation component, air-flow modification component and pyrolysis promoting component are added to deionized water in the above proportions and stirred in a water bath at 76°C until completely dissolved to obtain a shell coating solution with a solid content of 36 parts.

[0121] S103: Core-shell microcapsule granulation: The core-shell mixed powder is added to a spray granulator, and the shell coating solution is used as the atomizing medium. The inlet air temperature is set to 86℃ and the outlet air temperature is set to 46℃. Spray granulation yields core-shell microcapsule primary powder with a particle size of 95μm.

[0122] S104: Finished product packaging: The microcapsule powder is packaged under nitrogen protection at room temperature to obtain the finished coal activator.

[0123] The above-mentioned coal activator usage method:

[0124] S201: Add coal activator and pulverized coal with an outlet temperature of 90℃ from the coal mill to the mixer at a mass ratio of 0.6 parts, dry mix for 13 minutes until uniform, and the mixed pulverized coal directly enters the original air conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow pulverization without adjusting the wind speed and pressure parameters.

[0125] S202: After pulverized coal is introduced into the furnace, the shell layer in the high-temperature zone of the furnace (≥300℃) undergoes rapid thermal decomposition, and the active components in the core layer are released, achieving low-temperature combustion assistance of pulverized coal and prevention of coking in the furnace.

[0126] Comparative Example 1:

[0127] This comparative example is based on Example 1, except that the mass ratio of the core and shell layers is changed, and all other conditions are the same as in Example 1.

[0128] The coal activator in this comparative example is a core-shell type microcapsule powder with a particle size of 100μm, suitable for use in a pneumatic conveying gas-solid two-phase flow mode under 45% rated load of pulverized coal boilers; by total mass of microcapsules, the core layer accounts for 50 parts and the shell layer accounts for 50 parts.

[0129] The component ratios, component types, and rice husk-based porous carbon modification processes of the core and shell layers are consistent with those of Example 1; the preparation method and usage method of the coal activator (0.6 parts by mass of coal powder, dry mixing for 12 min) are exactly the same as those of Example 1.

[0130] Conclusion: In this comparative example, the mass ratio of the core layer and the shell layer deviated from the specified range. The excessive amount of shell layer components led to an excessively thick isolation film on the surface of the pulverized coal, which increased the adhesion between pulverized coal particles. The insufficient amount of core layer components resulted in insufficient release of combustion-supporting and anti-coking active components in the subsequent furnace combustion stage.

[0131] Comparative Example 2:

[0132] This comparative example is based on Example 2, except that the type of rare earth low-temperature combustion-supporting component in the core layer is changed, and all other conditions are the same as in Example 2.

[0133] The coal activator in this comparative example is a core-shell microcapsule powder with a particle size of 80 μm. The core-shell ratio (60 parts core layer and 40 parts shell layer) and the ratio of each component in the core layer are the same as in Example 2. The rare earth low-temperature combustion-supporting component is replaced with a single CeO2 oxide (particle size 5 nm-10 nm).

[0134] The composition ratio and types of the shell, the rice husk-based porous carbon modification process, and the preparation and application methods of the coal activator are all exactly the same as in Example 2.

[0135] Conclusion: This comparative example uses a single rare earth oxide as the combustion aid component, without the synergistic effect of ZrO2, resulting in a significant reduction in the efficiency of generating active oxygen ions. Consequently, it cannot effectively reduce the activation energy of pulverized coal combustion, and the low-temperature combustion aid effect is significantly reduced.

[0136] Comparative Example 3:

[0137] This comparative example is based on Example 3, except that the modification process of rice husk-based porous carbon is changed, and all other conditions are the same as in Example 3.

[0138] The coal activator in this comparative example is a core-shell microcapsule powder with a particle size of 120 μm. The core-shell ratio, the composition ratio and type of the core and shell layers are the same as in Example 3. The rice husk-based porous carbon is modified with 8% citric acid (phosphoric acid is omitted) at a modification temperature of 70°C and a time of 2 hours. The drying conditions are the same as in Example 3.

[0139] The preparation and application methods of the coal activator are exactly the same as those in Example 3.

[0140] Conclusion: Due to the use of single acid modification, the pore structure of rice husk-based porous carbon in this comparative example was not fully developed, the specific surface area was insufficient, and the ability to support the active components of the core layer was greatly reduced, resulting in uneven distribution of active components and poorer adsorption of free water from coal powder.

[0141] Comparative Example 4:

[0142] This comparative example is based on Example 4, except that the mass ratio of each functional component in the shell is changed, and all other conditions are the same as in Example 4.

[0143] The coal activator in this comparative example is a core-shell microcapsule powder with a particle size of 90 μm. The core-shell ratio (62 parts core layer, 38 parts shell layer), the component ratio and type of the core layer, and the rice husk-based porous carbon modification process are all the same as in Example 4. The shell layer, by total mass, consists of: 50 parts film-forming isolation component, 20 parts air-assisted flow modification component, and 30 parts pyrolysis promoting component.

[0144] The preparation and application methods of the coal activator are exactly the same as those in Example 4.

[0145] Conclusion: In this comparative example, due to insufficient film-forming isolation components in the shell layer, a complete solid lubricating isolation film could not be formed on the surface of pulverized coal, resulting in poor anti-agglomeration effect; excessive pyrolysis promoting components caused partial thermal pyrolysis of the shell layer during the air conveying stage, which could not effectively protect the core layer components.

[0146] Comparative Example 5:

[0147] This comparative example is based on Example 5, except that the ball milling speed of the core layer powder is changed in the preparation method, and all other conditions are the same as in Example 5.

[0148] The core-shell ratio, composition ratio and type of the core and shell layers of the coal activator in this comparative example, as well as the rice husk-based porous carbon modification process, are all consistent with those in Example 5; the dry ball milling speed in preparation method S101 is adjusted to 150 r / min.

[0149] The preparation of the shell coating solution, the granulation of the core-shell microcapsules, the finished product packaging process, and the method of using the coal activator are all exactly the same as in Example 5.

[0150] Conclusion: In this comparative example, due to the excessively low ball mill speed, the functional components of the core layer could not be fully and evenly mixed, resulting in local component aggregation. Consequently, the combustion-supporting and anti-coking functions were unevenly utilized during the subsequent furnace combustion stage, and the active components in some areas became ineffective.

[0151] Comparative Example 6:

[0152] This comparative example is based on Example 6, except that the mass mixing ratio of coal activator and coal powder is changed, and all other conditions are the same as in Example 6.

[0153] The core-shell ratio, component ratio, and types of the coal activator in this comparative example, as well as the rice husk-based porous carbon modification process and preparation method, are all consistent with those in Example 6; however, the mass mixing ratio with pulverized coal in the usage method is adjusted to 0.4 parts.

[0154] Conclusion: In this comparative example, due to the low mixing ratio of activator, there was insufficient core-shell microcapsule powder adhering to the surface of pulverized coal, the shell layer could not form a complete isolation membrane, the anti-agglomeration effect was poor, and the release of active components in the core layer was far from meeting the combustion-supporting and anti-coking requirements of the furnace, and the core function could not be effectively performed.

[0155] In addition, to objectively verify the actual application effect of the coal activator of the present invention, six sets of experimental examples are set up below, corresponding to the above six sets of embodiments and corresponding comparative examples. By controlling the single variable method, the core performance indicators of each embodiment and the corresponding comparative examples are compared under the same experimental conditions.

[0156] The general instructions for the experiment are as follows:

[0157] Experimental objective: To compare the four core performance indicators of the coal activator in the embodiments of the present invention and the comparative examples under low-load operation of pulverized coal boilers: coal powder agglomeration rate, furnace ignition delay time, furnace coke formation amount, and coal powder burnout rate, to verify the anti-agglomeration, low-temperature combustion-promoting, anti-coking, and burnout rate improvement effects of the product of the present invention.

[0158] Testing Indicators and Methods: 1. Coal Powder Agglomeration Rate: The proportion of agglomerated particles in the coal powder at the outlet of the pneumatic conveying pipe is measured using a laser particle size analyzer, a standard industry testing method. 2. Furnace Ignition Delay Time: The time from coal powder entering the furnace to stable ignition is recorded using a furnace temperature monitor, a standard industry testing method. 3. Furnace Coke Formation: After the boiler has been running continuously for 8 hours, the coke in the furnace is manually cleaned and weighed, and the average value of three parallel experiments is taken. 4. Coal Powder Combustion Rate: Calculated by detecting the carbon content of fly ash, combustion rate = 1 - (carbon content of fly ash / carbon content of raw coal). The carbon content of fly ash is detected using the loss on ignition method, a standard industry testing method.

[0159] General experimental conditions: The same model SZL pulverized coal boiler was selected, which is suitable for operation at 30%-60% of the rated load; the experimental coal was all commonly used industrial bituminous coal (fixed carbon content 52%, volatile matter 28%); the basic operating parameters such as boiler air intake and raw coal conveying volume were kept consistent in each group of experiments; each experimental group and the control group were run continuously for 8 hours, and each index was tested in 3 parallel experiments. The average value of the results was taken to reduce experimental error.

[0160] Experimental principle: Each experimental group only changed the technical characteristics of the coal activator (corresponding to the example and comparative examples), while the other experimental conditions were completely consistent to ensure the comparability of the experimental results.

[0161] Experimental Example 1:

[0162] Experimental subjects: The experimental group was the coal activator prepared in Example 1 (65 parts core layer and 35 parts shell layer); the control group was the coal activator prepared in Comparative Example 1 (50 parts core layer and 50 parts shell layer).

[0163] Specific experimental conditions: The pulverized coal boiler was operated at 45% of its rated load, the pulverized coal temperature at the pulverizer outlet was 85℃, and the pulverized coal and activator were mixed in the corresponding proportion and then directly fed into the original air conveying pipeline. Other boiler operating parameters were consistent with the general experimental conditions.

[0164] Performance test results:

[0165] detection indicators experimental group control group Coal powder agglomeration rate (%) 3.2% 15.8% Furnace ignition delay time (s) 2.1s 6.8s Coke production rate in the furnace (kg / 8h) 0.8kg / 8h 5.6kg / 8h Pulverized coal combustion rate (%) 98.5% 89.2%

[0166] Conclusion: In the control group, the core-shell ratio deviated from the limits of this invention. Excessive shell layer led to an overly thick isolation film on the coal powder surface, causing secondary adhesion. Insufficient core layer resulted in a lack of release of combustion-supporting and anti-coking active components, thus significantly increasing the agglomeration rate, prolonging the ignition delay time, drastically increasing the amount of coke generated, and significantly decreasing the burnout rate. In contrast, the experimental group had a reasonable core-shell ratio, with the shell layer effectively preventing agglomeration and sufficient release of the active components in the core layer. All performance indicators were excellent, verifying the necessity and rationality of the core layer ratio limit of 60-70 parts and the shell layer ratio of 30-40 parts in this invention.

[0167] Experimental Example 2:

[0168] Experimental subjects: The experimental group was the coal activator prepared in Example 2; the control group was the coal activator prepared in Comparative Example 2.

[0169] Specific experimental conditions: The pulverized coal boiler was operated at 30% of its rated load, the pulverized coal temperature at the pulverizer outlet was 50℃, and the pulverized coal and activator were mixed in the corresponding proportion and then directly fed into the original air conveying pipeline. Other boiler operating parameters were consistent with the general experimental conditions.

[0170] Performance test results:

[0171] detection indicators experimental group control group Coal powder agglomeration rate (%) 2.8% 3.0% Furnace ignition delay time (s) 2.3s 7.5s Coke production rate in the furnace (kg / 8h) 0.7kg / 8h 6.2kg / 8h Pulverized coal combustion rate (%) 98.7% 88.5%

[0172] Conclusion: The control group only changed the type of rare earth combustion aid component, while the shell structure and ratio remained unchanged. Therefore, the coal powder agglomeration rate was not significantly different from that of the experimental group. However, the single CeO2 oxide lacked the synergistic effect of ZrO2, resulting in a significant reduction in the efficiency of active oxygen ion generation. This failed to effectively reduce the activation energy of coal powder combustion, leading to a significant increase in ignition delay time. The residual char formed a large amount of coke due to incomplete combustion, resulting in a significant decrease in burnout rate. The experimental group used CeO2-ZrO2 composite oxide as the combustion aid component, which showed significant low-temperature combustion aid effect and excellent performance in various combustion-related indicators. This verified the necessity and rationality of limiting the rare earth low-temperature combustion aid component to CeO2-ZrO2 composite oxide with a particle size of 5nm-10nm.

[0173] Experimental Example 3:

[0174] Experimental subjects: The experimental group was the coal activator prepared in Example 3; the control group was the coal activator prepared in Comparative Example 3.

[0175] Specific experimental conditions: The pulverized coal boiler was operated at 60% of its rated load, the pulverized coal temperature at the pulverizer outlet was 120℃, and the pulverized coal and activator were mixed in the corresponding proportion and then directly fed into the original air conveying pipeline. Other boiler operating parameters were consistent with the general experimental conditions.

[0176] Performance test results:

[0177] detection indicators experimental group control group Coal powder agglomeration rate (%) 3.5% 12.1% Furnace ignition delay time (s) 2.0s 5.9s Coke production rate in the furnace (kg / 8h) 0.9kg / 8h 4.8kg / 8h Pulverized coal combustion rate (%) 98.3% 90.1%

[0178] Conclusion: The control group, using rice husk-based porous carbon modified with citric acid alone, exhibited insufficient pore structure development, a specific surface area <300 m² / g, and a significantly reduced capacity to carry active components. This resulted in uneven distribution of active components and a poorer adsorption effect on free water in pulverized coal. Consequently, the coal powder agglomerated due to moisture, and the uneven action of combustion-supporting and coking-preventing components led to delayed ignition and coke formation. In contrast, the experimental group, modified with a mixture of citric acid and phosphoric acid, achieved the required specific surface area for the rice husk-based porous carbon. This allowed for both uniform carrying of active components and efficient adsorption of free water, resulting in a synergistic effect of anti-agglomeration and combustion-supporting and coking-preventing. This validates the necessity and rationality of the limitations imposed on the modification process and performance indicators of rice husk-based porous carbon in this invention.

[0179] Experiment Example 4:

[0180] Experimental subjects: The experimental group was the coal activator prepared in Example 4; the control group was the coal activator prepared in Comparative Example 4.

[0181] Specific experimental conditions: The pulverized coal boiler was operated at 35% of its rated load, the pulverized coal temperature at the pulverizer outlet was 65℃, and the pulverized coal and activator were mixed in the corresponding proportion and then directly fed into the original air conveying pipeline. Other boiler operating parameters were consistent with the general experimental conditions.

[0182] Performance test results:

[0183] detection indicators experimental group control group Coal powder agglomeration rate (%) 3.0% 18.5% Furnace ignition delay time (s) 2.2s 7.2s Coke production rate in the furnace (kg / 8h) 0.8kg / 8h 6.5kg / 8h Pulverized coal combustion rate (%) 98.6% 87.8%

[0184] Conclusion: The shell component ratio in the control group deviated from the specified range, resulting in insufficient film-forming isolation components and failure to form a complete isolation film. Excessive pyrolysis promoting components caused partial pyrolysis of the shell during the air conveying stage, which not only lost its anti-agglomeration effect but also caused premature loss of the core active components, thus leading to a sharp increase in the agglomeration rate. Insufficient active components during the combustion stage caused a series of problems. The shell component ratio in the experimental group was reasonable, and the film-forming isolation, flow modification, and pyrolysis promoting functions worked synergistically, achieving both efficient anti-agglomeration and ensuring the precise release of the core components in the furnace. This verified the necessity and rationality of the limitation of the ratio of each functional component in the shell in this invention.

[0185] Experimental Example 5:

[0186] Experimental subjects: The experimental group was the coal activator prepared in Example 5; the control group was the coal activator prepared in Comparative Example 5.

[0187] Specific experimental conditions: The pulverized coal boiler was operated at 55% of its rated load, the pulverized coal temperature at the pulverizer outlet was 100℃, and the pulverized coal and activator were mixed in the corresponding proportion and then directly fed into the original air conveying pipeline. Other boiler operating parameters were consistent with the general experimental conditions.

[0188] Performance test results:

[0189] detection indicators experimental group control group Coal powder agglomeration rate (%) 3.3% 4.1% Furnace ignition delay time (s) 2.1s 6.3s Coke production rate in the furnace (kg / 8h) 0.8kg / 8h 5.1kg / 8h Pulverized coal combustion rate (%) 98.4% 89.8%

[0190] Conclusion: In the control group, only the ball milling speed of the core layer powder was reduced, deviating from the specified range. This resulted in uneven mixing of the functional components of the core layer and local aggregation. The shell layer function was not affected, so the agglomeration rate difference was small. However, during the combustion stage, some areas had excessive active components and some areas were ineffective, resulting in a significant decrease in the overall combustion-supporting and coking-preventing effect, delayed ignition, and an increase in coke lumps. In the experimental group, the ball milling speed was within the specified range, the core layer components were mixed evenly, the active components were in full contact with the coal powder, and the combustion efficiency was high. This verifies the necessity and rationality of limiting the preparation process parameters in this invention.

[0191] Experimental Example 6:

[0192] Experimental subjects: The experimental group was the coal activator prepared in Example 6; the control group was the coal activator prepared in Comparative Example 6.

[0193] Specific experimental conditions: The pulverized coal boiler was operated at 50% of its rated load, the pulverized coal temperature at the pulverizer outlet was 90℃, and the pulverized coal and activator were mixed in the corresponding proportion and then directly fed into the original air conveying pipeline. Other boiler operating parameters were consistent with the general experimental conditions.

[0194] Performance test results:

[0195] detection indicators experimental group control group Coal powder agglomeration rate (%) 3.1% 16.2% Furnace ignition delay time (s) 2.2s 7.0s Coke production rate in the furnace (kg / 8h) 0.7kg / 8h 5.9kg / 8h Pulverized coal combustion rate (%) 98.6% 88.2%

[0196] Conclusion: In the control group, the mixing ratio of activator to pulverized coal was reduced to 0.4 parts, which deviated from the specified range. The amount of activator adhering to the surface of the pulverized coal was insufficient, the shell layer could not form a complete isolation film, and the release of active components in the core layer was far from meeting the combustion requirements. Therefore, the agglomeration rate increased, and the combustion-aiding and anti-coking effects decreased significantly. In contrast, the experimental group used the optimal mixing ratio of 0.6 parts, where the activator and pulverized coal were perfectly matched, and the functions of both the shell and core layers were maximized. All indicators were excellent, verifying the necessity and rationality of the present invention's limitation on the optimal mass mixing ratio of coal activator and pulverized coal.

[0197] The test results of the above 6 sets of experimental examples show that the coal activators prepared in Examples 1-6 of the present invention can achieve excellent effects such as low coal powder agglomeration rate, short ignition delay time, low coke production, and high coal powder burnout rate under 30%-60% rated load of pulverized coal boilers. However, due to deviations from the limits of key technical characteristics such as core-shell ratio, core component selection, carrier modification process, shell component ratio, preparation process parameters, and usage ratio, one or more performance indicators deteriorated significantly.

[0198] Furthermore, through comparative analysis of various comparative examples and experimental cases, this invention has significant advantages in the following aspects: First, it has excellent adaptability to pneumatic conveying of pulverized coal, accurately matching the gas-solid two-phase flow conditions of pulverized coal boilers under 30%-60% rated load. The shell layer's efficient anti-agglomeration effect effectively suppresses pulverized coal agglomeration and wall deposition, significantly reducing the agglomeration rate of pneumatically conveyed pulverized coal and ensuring uniform pulverized coal feeding into the furnace. Second, it exhibits outstanding low-temperature combustion aid and anti-coking effects. The core layer's functional components, after precise selection, modification, and proportioning design, work synergistically to significantly reduce the activation energy of pulverized coal combustion, shorten the furnace ignition delay time, and fundamentally prevent residual carbon adhesion and coke formation, while simultaneously greatly improving the pulverized coal burnout rate. First, it optimizes the efficiency of coal energy utilization; second, it has strong synergy among various technical features. The constraints of various technical features such as the core-shell mass ratio, component types and parameters, carrier modification process, preparation process parameters, and usage ratio form an organic whole, which works together to ensure the functional stability of the activator throughout the entire process from production to application, and none of them can be omitted; third, it has both convenience and economy in industrial application. The activator of this invention can be directly mixed with pulverized coal and then connected to the original air delivery pipeline of the boiler without the need to modify equipment or adjust operating parameters such as wind speed and pressure. Moreover, the optimal usage ratio achieves a balance between functional performance and raw material consumption, reducing the threshold and cost of industrial application, and making it more suitable for large-scale industrial application.

[0199] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A coal activator, characterized in that, The coal activator is a core-shell type microcapsule powder, suitable for use in pulverized coal boilers under 30%-60% rated load in a gas-solid two-phase flow mode of air conveying pulverized coal, with a particle size of 80μm-120μm; the microcapsule is composed of a core layer and a shell layer, with the core layer accounting for 60-70 parts and the shell layer accounting for 30-40 parts by total mass of the microcapsule. The core layer is a low-temperature combustion-supporting and scorching-preventing active layer, which is composed of rare earth low-temperature combustion-supporting components, residual carbon depolymerization components, combustion-supporting carrier components and scorching-inhibiting components. The shell layer is a coal powder anti-agglomeration and dispersion layer. It forms a solid lubricating isolation film on the surface of coal powder particles in the air conveying temperature range of 50℃-120℃. In the furnace high temperature zone of ≥300℃, it rapidly thermally decomposes. The core layer is released along with the shell layer and plays a role in low-temperature combustion and anti-coking.

2. The coal activator according to claim 1, characterized in that, The functional components in the core layer are as follows, based on the total mass of the core layer: 25-30 parts of rare earth low-temperature combustion-supporting component, 20-25 parts of residual char depolymerization component, 40-45 parts of combustion-supporting carrier component, and 5-10 parts of char-inhibiting component.

3. The coal activator according to claim 2, characterized in that, The rare earth low-temperature combustion-supporting component is a CeO2-ZrO2 composite oxide with a particle size of 5nm-10nm; the residual char depolymerization component is sodium lignosulfonate modified nano-SiO2 with a particle size of 10nm-50nm; the combustion-supporting carrier component is rice husk-based porous carbon with a pore size of 2nm-5nm; and the char-inhibiting component is ammonium aminosulfonate.

4. A coal activator according to claim 3, characterized in that, The rice husk-based porous carbon was prepared by acid modification. The preparation process is as follows: the original rice husk-based porous carbon was immersed in a mixed acid solution of 5%-8% citric acid and 3%-5% phosphoric acid by mass, and modified at a constant temperature of 60℃-70℃ for 2-3 hours. After filtration, it was washed with deionized water until neutral, and dried at 105℃-110℃ to constant weight. The specific surface area of ​​the modified rice husk-based porous carbon is ≥300m² / g.

5. A coal activator according to claim 1, characterized in that, The functional components in the shell are as follows, based on the total mass of the shell: 60-70 parts film-forming isolation component, 20-25 parts air-flow modification component, and 10-15 parts pyrolysis promoting component.

6. A coal activator according to claim 5, characterized in that, The film-forming isolation component is water-soluble polyethylene wax with a melting point of 120℃-150℃; the air-assisted flow modification component is magnesium stearate with a particle size of 1μm-5μm; the pyrolysis promoting component is sodium bicarbonate; and the thermal pyrolysis rate of the shell in the furnace high-temperature zone of ≥300℃ is ≥98%.

7. The method for preparing the coal activator according to any one of claims 1-6, characterized in that, Includes the following steps: S101: Core layer powder preparation: The rare earth low-temperature combustion-supporting component, residual carbon depolymerization component, combustion-supporting carrier component and coke-inhibiting component of the core layer are added to a dry ball mill in proportion and ball milled at a speed of 200r / min-300r / min for 30min to obtain a core layer mixed powder with a particle size of 10μm-20μm. S102: Preparation of shell coating solution: The shell film-forming isolation component, air-flow modification component and pyrolysis promoting component are added to deionized water in proportion, and stirred in a water bath at 70℃-80℃ until completely dissolved to obtain a shell coating solution with a solid content of 30-40 parts. S103: Core-shell microcapsule granulation: The core-shell mixed powder obtained in step S101 is added to a spray granulator, and the shell coating solution obtained in step S102 is used as the atomizing medium. The inlet air temperature of the spray granulator is set to 80℃-90℃ and the outlet air temperature is set to 40℃-50℃. After spray granulation, core-shell microcapsule primary powder with a particle size of 80μm-120μm is obtained. S104: Finished product packaging: The core-shell microcapsule powder obtained in step S103 is packaged under the protection of an inert gas at room temperature to obtain the finished coal activator.

8. The method for preparing the coal activator according to claim 7, characterized in that, The inert gas mentioned in step S104 is nitrogen.

9. The method of using the coal activator as described in any one of claims 1-6, characterized in that, Includes the following steps: S201: Add the coal activator and pulverized coal with an outlet temperature of 50℃-120℃ to the mixer at a mass ratio of 0.5 parts to 0.8 parts, and dry mix for 10 min to 15 min until uniform. The mixed pulverized coal is directly fed into the original air conveying pipeline of the pulverized coal boiler for gas-solid two-phase flow pulverization without adjusting the air velocity and pressure parameters of the air conveying pipeline. S202: After pulverized coal is introduced into the furnace, the shell layer undergoes thermal pyrolysis and the core layer active components are released in the high-temperature zone of the furnace at ≥300℃. The core layer components play a role in low-temperature combustion assistance of pulverized coal and preventing coking in the furnace.

10. The method of using the coal activator according to claim 9, characterized in that, The optimal mass mixing ratio of the coal activator to pulverized coal is 0.6 parts.

Images