A magnetic levitation fan system for fly ash gasification delivery

Abstract

A magnetic levitation fan system for fly ash gasification conveying includes a raw ash silo, a coarse ash silo, and a fine ash silo. Each silo is equipped with a corresponding magnetic levitation centrifugal fan. The outlet of each fan is connected to the corresponding atomizing pipe in the raw, coarse, and fine ash silos via a gasification air pipeline to provide fluidized gasification air. Each fan's outlet pipeline is equipped with a pressure transmitter and a temperature sensor. Each fan, pressure transmitter, and temperature sensor is signal-connected to a control unit. Parallel pipelines of multiple fans are connected to interconnecting valves, enabling interconnection and interoperability between the fans. This achieves integrated self-consistent control of gasification air power and heat supply, resulting in precise and stable control of the outlet air temperature without the need for an external heater, fundamentally eliminating the high energy consumption of independent heating stages.

Description

Technical Field

[0001] This invention relates to a magnetic levitation fan system for the gasification and conveying of fly ash, belonging to the field of auxiliary equipment and energy-saving technology for thermal power plants. Background Technology

[0002] In the field of pneumatic conveying of fly ash in coal-fired power plants, traditional technologies typically employ Roots blowers to provide gasification air and use independent electric or steam heaters to heat the gasification air to meet drying and anti-caking requirements in order to achieve fluidization of fly ash. This existing technology constitutes a separate system of blower supply and independent heating. However, this approach has significant drawbacks: First, the Roots blower itself has low efficiency, and its use with an independent heater leads to high overall system energy consumption and expensive operating costs. Second, the control loops for air volume, pressure, and temperature are independent and subject to coupling interference. For example, adjusting the blower to meet flow requirements can cause fluctuations in pressure and temperature, while the lag in heater response exacerbates the instability of temperature control, resulting in low overall control accuracy and slow response. This makes it difficult to accurately match the gasification air parameters with the real-time process requirements of fly ash, leading not only to energy waste but also affecting the reliability and economy of the conveying system. Summary of the Invention

[0003] To address the aforementioned problems in existing technologies, this invention provides a magnetic levitation fan system for fly ash gasification and conveying, which achieves integrated self-consistent regulation of gasification air power supply and heat supply, enabling precise and stable control of outlet air temperature without the need for an external heater, thus fundamentally eliminating the high energy consumption of independent heating links.

[0004] The technical solution of the present invention is as follows: A magnetic levitation fan system for fly ash gasification and conveying includes a raw ash silo, a coarse ash silo, and a fine ash silo. Each of the raw ash silo, coarse ash silo, and fine ash silo is equipped with a corresponding magnetic levitation centrifugal fan. The outlet of each magnetic levitation centrifugal fan is connected to the corresponding atomizing pipe of the raw ash silo, coarse ash silo, and fine ash silo via a gasification air pipeline to provide fluidized gasification air. Each magnetic levitation centrifugal fan's outlet pipeline is equipped with a pressure transmitter and a temperature sensor. Each magnetic levitation centrifugal fan, each pressure transmitter, and each temperature sensor is signal-connected to a control unit. A connecting valve is connected to the parallel pipelines of multiple magnetic levitation centrifugal fans to achieve interconnection and interoperability between the fans.

[0005] A method for controlling the gasification and conveying of fly ash, comprising the aforementioned magnetic levitation fan system for fly ash gasification and conveying, characterized by the following steps: S1: Determine the target air pressure, target air volume, and target air temperature based on the operating requirements of the original ash silo, coarse ash silo, and fine ash silo; S2: Start the magnetic levitation centrifugal fan and adjust its speed to make the pressure and flow rate of the output gasified air reach the target air pressure and target air volume; S3: Real-time monitoring of the outlet air temperature of the magnetic levitation centrifugal fan; S4: Compare the monitored outlet air temperature with the target air temperature; S5: Based on the comparison results, dynamically adjust the rotation speed of the magnetic levitation centrifugal fan to utilize the compression heat of the magnetic levitation centrifugal fan to control the outlet air temperature within the allowable fluctuation range of the target air temperature.

[0006] In step S5, the dynamic adjustment of the speed of the magnetic levitation centrifugal fan is achieved through a dual-loop collaborative control architecture. This architecture includes a primary temperature control loop and an embedded secondary control loop, specifically comprising: S5.1: For each raw ash silo, coarse ash silo, and fine ash silo, establish an independent temperature main control loop with the outlet air temperature as the controlled variable. The speed adjustment amount in the previous loop cycle is used as the feedforward compensation benchmark for the control decision of this loop. S5.2: In the main feedback control loop, a secondary control loop with pressure and flow rate as the rapid adjustment targets is embedded; when the control unit receives a change in the valve opening of the gasification pipeline corresponding to the original ash silo, coarse ash silo and fine ash silo, the secondary control loop first dynamically adjusts the speed of the corresponding magnetic levitation centrifugal fan according to the preset valve opening-airflow mapping relationship to quickly stabilize the pressure and meet the increased flow rate demand; then, the main temperature control loop finely adjusts the speed based on the new outlet air temperature measurement value to suppress the compression heat fluctuation caused by the dynamic response of the magnetic levitation centrifugal fan, thereby minimizing the disturbance of the outlet air temperature.

[0007] In step S5.2, the "preset valve opening-airflow mapping relationship" is dynamically generated through a multivariate collaborative feedforward model. This multivariate collaborative feedforward model introduces instantaneous air temperature control deviation as the core feedback into the feedforward loop to achieve self-correction of the valve disturbance advance compensation amount. Specifically, the multivariate collaborative feedforward model uses the real-time valve opening value... Current fan speed and ambient temperature As an input variable; and a dynamic airflow feedforward compensation coefficient is introduced. The formula: ,in, It is a basic mapping coefficient based on the rated characteristics calibration of the magnetic levitation centrifugal fan (11) and the gasification air duct. The real-time air temperature control deviation calculated for the main temperature control loop. This serves as the reference value for setting the air temperature control deviation. This is the coupling gain coefficient; When the secondary control loop receives a valve opening change signal, it performs the following steps: S5.2a: Call the multivariate collaborative feedforward model to input the real-time valve opening value. Current speed of magnetic levitation centrifugal fan and ambient temperature and real-time wind temperature deviation Substitute into the formula to calculate the current dynamic airflow feedforward compensation coefficient. ; S5.2b: Based on the dynamic airflow feedforward compensation coefficient k, the pair is mapped from the basic... Calculated baseline air volume change estimate Make corrections to obtain the final airflow feedforward command. ; S5.2c: Based on airflow feedforward command Generate speed feedforward adjustment command; when real-time air temperature control deviation... When the volume increases, the multivariate collaborative feedforward model compensates for the increase through dynamic airflow feedforward coefficients. Automatically amplify the feedforward compensation for valve disturbances, making the rotational speed response of the magnetic levitation centrifugal fan (11) more aggressive, thereby using a larger change in compression heat to offset the air temperature disturbance more quickly, and vice versa.

[0008] The multivariate collaborative feedforward model also includes an online self-learning function, specifically including: the control unit (14) continuously records the actual air volume response value after the action of the secondary control loop. With time for wind temperature to stabilize ; By optimizing the algorithm to make Minimize and With the goal of minimizing the time required, the basic mapping function in the multivariate collaborative feedforward model is iteratively updated online. and coupling gain coefficient This enables the multivariate collaborative feedforward model to adapt to changes in system characteristics.

[0009] The control unit (14) is further configured to execute a collaborative temperature control strategy based on the physical properties of fly ash, specifically including the following steps: S5.3: Online moisture monitors and ash temperature sensors are installed near the bottom unloading valves of the original ash silo, coarse ash silo and fine ash silo respectively, so as to obtain the moisture content signal and the current ash temperature signal of the fly ash in each silo in real time. S5.4: The control unit dynamically calculates and updates the personalized target air temperature corresponding to each ash silo based on the real-time moisture content of each ash silo and the pre-stored correspondence between the moisture content of fly ash of different particle sizes and the ideal gasification air temperature; wherein, for fly ash with higher moisture content, a higher personalized target air temperature is set. S5.5: When the operating conditions of any of the original ash silos, coarse ash silos, and fine ash silos change, causing an imbalance between their gasification demand and the personalized target air temperature, the control unit performs coordinated temperature control optimization: First, it dynamically adjusts the speed of the corresponding magnetic levitation centrifugal fan according to the secondary control loop to meet the real-time flow and pressure requirements; simultaneously, it calculates the excess or deficiency of compressive heat generated by the speed adjustment of the magnetic levitation centrifugal fan relative to its personalized target air temperature, and by adjusting the connecting valve and coordinating the speed fine-tuning of the magnetic levitation centrifugal fans in other ash silos, it directs the excess heat to the ash silo that currently needs the most heat or transfers the heat from other ash silos to the ash silo with insufficient heat; this process is constrained by meeting the updated personalized target air temperature of each ash silo, and is solved and controlled in real time with the optimization objective of minimizing the total power consumption of all operating magnetic levitation centrifugal fans.

[0010] The control unit is further configured to execute a preventative vaporization strategy, specifically including the following steps: S5.6: The control unit continuously records and stores historical fly ash temperature data and historical ambient temperature data obtained by the fly ash temperature sensors of each silo; based on the historical fly ash temperature data and historical ambient temperature data, it analyzes the cooling conditions experienced by the fly ash in each silo within a set historical period. The cooling conditions are characterized by calculating the difference between the average fly ash temperature and the average ambient temperature, and by statistically analyzing the cumulative duration of the fly ash temperature being lower than a set threshold. S5.7: The control unit calculates and generates the real-time caking risk coefficient of fly ash in each silo based on the real-time moisture content, particle size characteristics, and cooling condition data obtained from the analysis of each silo's fly ash, using a pre-trained caking risk prediction model. S5.8: When the caking risk coefficient of any ash silo exceeds a preset threshold, regardless of its current gasification demand, the control unit initiates a preventative gasification operation for that ash silo: First, the personalized target air temperature of the ash silo is temporarily increased, and within a set time period, a short-term high-temperature, high-pressure turbulent airflow is output by increasing the speed of its corresponding magnetic levitation centrifugal fan to purge and loosen potentially caking materials at the bottom of the ash silo; during this process, the system calculates the excess heat generated in real time and, based on the coordinated temperature control strategy, dispatches this heat to other ash silos that need heat the most at this time through the connecting valve; after the preventative operation is completed, the system restores the normal personalized target air temperature and speed control of the ash silo and reassesses its caking risk coefficient.

[0011] The present invention has the following beneficial effects: This invention utilizes a magnetic levitation centrifugal fan in conjunction with a temperature sensor, pressure transmitter, and control unit. By using rotational speed as the sole adjustment method and leveraging the inherent compression heat of the magnetic levitation centrifugal fan as a heat source, it achieves integrated self-consistent regulation of gasification air power supply and heat supply. This results in precise and stable control of the outlet air temperature without the need for an external heater, fundamentally eliminating the high energy consumption of independent heating stages.

[0012] This invention employs a dual-loop collaborative control architecture consisting of a primary temperature control loop and a secondary control loop. The secondary loop rapidly responds to flow disturbances caused by changes in valve opening, while the primary loop performs speed fine-tuning based on the measured fresh air temperature. This achieves synergy between feedforward compensation and feedback fine-tuning of the main valve actions, minimizing the impact of sudden valve opening changes on the outlet air temperature and significantly improving the accuracy and stability of air temperature control.

[0013] This invention integrates online moisture monitoring, ash temperature sensing, and personalized target air temperature calculation functions in the control unit. It dynamically sets the target air temperature of each silo based on the real-time moisture content of fly ash, and combines the cross-silo scheduling of excess heat achieved by the connecting valve. This realizes the matching of gasification air temperature supply with the physical properties of fly ash materials and the dynamic optimization of system-level heat energy distribution, achieving the effect of on-demand heating and optimal overall operating energy efficiency.

[0014] This invention analyzes historical fly ash temperature and environmental data through a control unit to assess the cooling status and predicts caking risk by combining real-time data. When the risk exceeds the standard, it automatically triggers a preventive high-temperature and high-pressure gasification operation and recovers and utilizes the excess heat generated in this process. This achieves proactive prediction, intervention and maintenance of fly ash caking hazards, and intensive utilization of energy consumption, thus achieving the effects of preventing problems before they occur, improving the long-term operational reliability of the system and reducing maintenance costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the magnetic levitation fan system of the present invention.

[0016] The reference numerals in the figure are as follows: 1. Raw ash silo; 2. Coarse ash silo; 3. Fine ash silo; 11. Magnetic levitation centrifugal fan; 6. Raw ash silo atomizing pipe; 7. Coarse ash silo atomizing pipe; 8. Fine ash silo atomizing pipe; 12. Pressure transmitter; 13. Temperature sensor; 14. Control unit; 15. Connecting valve. Detailed Implementation

[0017] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0018] Please see Figure 1The invention provides a technical solution: A magnetic levitation fan system for fly ash gasification and conveying is provided. The system consists of a pneumatic conveying execution unit, a sensing and detection unit, an intelligent control unit, and a pipeline interconnection unit. It is designed for the storage and pneumatic conveying of fly ash of different particle sizes (raw ash, coarse ash, and fine ash) in coal-fired power plants, aiming to achieve efficient, energy-saving, precise and controllable gasification air supply.

[0019] The system includes a raw ash silo 1, a coarse ash silo 2, and a fine ash silo 3 arranged in parallel, which are used to store fly ash with different particle size ranges, respectively. Each ash silo is independently equipped with a complete gasification air supply subsystem. The core of each subsystem includes a magnetic levitation centrifugal fan 11, which features high efficiency, low vibration, and a wide speed range.

[0020] Each magnetic levitation centrifugal fan 11 has its outlet connected to the corresponding aeration device at the bottom of the ash silo via an independent aeration air duct. Specifically, the fan outlet serving the original ash silo 1 is connected to the original ash silo atomizing pipe 6, the fan serving the coarse ash silo 2 is connected to the coarse ash silo atomizing pipe 7, and the fan serving the fine ash silo 3 is connected to the fine ash silo atomizing pipe 8. These atomizing pipes are evenly arranged at the bottom of the ash silo, and their function is to uniformly introduce dry aeration air into the fly ash, fluidizing the fly ash and facilitating subsequent pipeline transportation. To achieve accurate monitoring and closed-loop control of the gasification air status, each magnetic levitation centrifugal fan 11 is equipped with a pressure transmitter 12 and a temperature sensor 13 on its outlet pipe. The pressure transmitter 12 is used to monitor the gasification air pressure at the fan outlet in real time, and the temperature sensor 13 is used to monitor the gasification air temperature in real time. These key parameters form the basis for the control system's decision-making.

[0021] Each of the magnetic levitation centrifugal fans 11, each of the pressure transmitters 12, and each of the temperature sensors 13 are connected to a control unit 14 via signal cables. The intelligent core of the system is the control unit 14, which can typically be implemented using a programmable logic controller (PLC) or an industrial control computer. The control unit 14 is responsible for receiving real-time data from all sensors, running the built-in control algorithm, and sending speed adjustment commands to the frequency converters of each magnetic levitation centrifugal fan 11, thereby forming a complete monitoring-control closed loop.

[0022] Furthermore, to enhance the system's flexibility, reliability, and energy efficiency optimization potential, connecting valves 15 are connected to the parallel pipelines of multiple magnetic levitation centrifugal fans 11 to achieve interconnection between them. Connecting valves 15 are typically electric or pneumatic regulating valves. When the connecting valve 15 is open, the outlet pipelines of different magnetic levitation centrifugal fans 11 can be connected, enabling interconnection and mutual backup of the gasification air sources. This design allows for coordinated air supply from adjacent fans to ensure continuous system operation in the event of a single fan failure or under specific operating conditions. It also provides a physical channel for dynamically adjusting air volume and temperature between different ash storage areas, serving as a key hardware foundation for implementing advanced collaborative control strategies.

[0023] A method for controlling the gasification and conveying of fly ash, comprising a magnetic levitation fan system for the gasification and conveying of fly ash, characterized by the following steps: S1: The control unit 14 determines and sets independent target air pressure, target air volume and target air temperature for each ash silo's gasification subsystem according to the real-time operating requirements of the original ash silo 1, coarse ash silo 2 and fine ash silo 3. This step is fundamental to control. The required operating conditions can be derived from instructions from the upstream conveying system, level signals from each ash silo, or empirical values ​​based on different particle sizes and moisture content of fly ash. Target air pressure and air volume primarily ensure that the fly ash receives sufficient fluidization power; target air temperature aims to provide the necessary drying heat to prevent ash particles from clumping or sticking to the pipe walls. S2: Control unit 14 starts magnetic levitation centrifugal fan 11 and precisely controls the fan speed by adjusting its built-in frequency converter so that the pressure and flow rate of the output gasified air reach the target air pressure and target air volume. Since the output air pressure and air volume of the magnetic levitation centrifugal fan 11 are functions of its rotation speed, the control unit 14 receives the real-time pressure signal fed back by the pressure transmitter 12 and compares it with the set target air pressure and target air volume. It then uses proportional-integral control algorithms to dynamically adjust the rotation speed so that the gasification air pressure and flow rate at the outlet of the magnetic levitation centrifugal fan 11 can quickly and stably reach the preset target values, thereby establishing stable pneumatic conveying conditions. S3: While adjusting the air pressure and air volume, the control unit 14 monitors the outlet air temperature of the magnetic levitation centrifugal fan 11 in real time through the temperature sensor 13. S4: The control unit 14 compares the monitored outlet air temperature with the target air temperature and calculates the deviation between the current air temperature and the target value. The magnitude and direction of this deviation value are the basis for the drive control system to perform correction actions; S5: Based on the comparison results, dynamically adjust the rotation speed of the magnetic levitation centrifugal fan 11 so as to use the compression heat of the magnetic levitation centrifugal fan 11 to control the outlet air temperature within the allowable fluctuation range of the target air temperature.

[0024] The control logic is as follows: When the magnetic levitation centrifugal fan 11 performs work on the air (compressing it to increase pressure), the air temperature inevitably rises, which is known as "compression heat." When the outlet air temperature is lower than the target, the control unit 14 will further increase the speed of the magnetic levitation centrifugal fan 11 appropriately, while still meeting the air pressure and air volume requirements. This increase in speed directly increases compression heat, raising the outlet air temperature. Furthermore, through sophisticated algorithm design, the system ensures that the resulting increase in air pressure and flow does not exceed the allowable range, or is balanced through other means (such as fine-tuning downstream valves). Conversely, when the air temperature is too high, the speed is appropriately reduced. Through this dynamic closed-loop system, with air temperature as the ultimate control target and speed as the sole adjustment method, the system can automatically and accurately stabilize the outlet air temperature within the allowable fluctuation range of the target air temperature. This achieves a synergistic self-consistency between the power supply and heat supply of the vaporized air, fundamentally eliminating the energy consumption of traditional independent heating methods.

[0025] In step S5, the dynamic adjustment of the rotational speed of the magnetic levitation centrifugal fan 11 is achieved through a dual-loop collaborative control architecture. This architecture includes a primary temperature control loop and an embedded secondary control loop, which can fundamentally suppress the impact of compression heat fluctuations caused by sudden changes in process requirements (such as valve actuation) on the outlet air temperature. Specifically, it includes: S5.1: For each of the raw ash silos 1, coarse ash silos 2 and fine ash silos 3, the control unit 14 establishes an independent temperature main control loop with the outlet air temperature as the controlled variable. The loop uses the real-time air temperature at the outlet of the corresponding magnetic levitation centrifugal fan 11 as the controlled variable and the target air temperature set in step S1 as the set value. Specifically, in the calculation of each control cycle, the control unit 14 not only considers the current wind temperature deviation, but also incorporates the adjustment of the fan speed made in the previous control cycle to correct the deviation as an important feedforward compensation benchmark into the control decision of the current cycle. This allows the control system to predict the adjustment trend required to maintain or approach the target wind temperature, thereby significantly reducing overshoot and making the wind temperature adjustment process smoother and more responsive.

[0026] S5.2: In the main feedback control loop, a secondary control loop is embedded with pressure and flow as the rapid adjustment targets. The trigger signal of this secondary control loop is the change in the opening degree of the valves in the gasification pipelines of each ash silo. When the control unit 14 receives a change (increase or decrease) in the opening degree of the gasification pipeline valves corresponding to the original ash silo 1, coarse ash silo 2 and fine ash silo 3, the secondary control loop takes the lead. First, the secondary control loop dynamically adjusts the speed of the corresponding magnetic levitation centrifugal fan 11 according to the preset valve opening-airflow mapping relationship to quickly stabilize the pressure and meet the increased flow demand. Then, the temperature main control loop fine-tunes the speed based on the new outlet air temperature measurement value to suppress the compression heat fluctuation caused by the dynamic response of the magnetic levitation centrifugal fan 11, thereby minimizing the disturbance of the outlet air temperature.

[0027] The secondary control loop immediately calculates the estimated airflow change required to match the valve opening change based on a pre-established and stored "valve opening-airflow mapping relationship" model, and generates a speed feedforward adjustment command accordingly to quickly adjust the speed of the corresponding magnetic levitation centrifugal fan 11. The purpose of this is to quickly stabilize the pipeline pressure and meet the instantaneous flow demand caused by valve action, absorbing the most significant flow disturbance before it affects the air temperature. Subsequently, the main temperature control loop begins to operate: based on the new outlet air temperature value measured by temperature sensor 13 after the secondary loop's operation, it finely adjusts the speed, specifically to compensate for and suppress compression heat fluctuations caused by rapid changes in fan speed (caused by the secondary loop). Through this collaborative mechanism, the system can minimize the impact of valve opening changes, the main disturbance, on the outlet air temperature, achieving high-precision stable air temperature control.

[0028] The "preset valve opening-airflow mapping relationship" mentioned in step S5.2 is dynamically generated through a multivariate collaborative feedforward model. This multivariate collaborative feedforward model introduces the instantaneous air temperature control deviation as the core feedback into the feedforward loop to achieve self-correction of the valve disturbance advance compensation amount. Specifically, the multivariate collaborative feedforward model uses the real-time valve opening value... Current fan speed and ambient temperature As an input variable; and a dynamic airflow feedforward compensation coefficient is introduced. The formula: ,in, These are the basic mapping coefficients based on the rated characteristics calibration of the magnetic levitation centrifugal fan 11 and the gasification air duct. The real-time air temperature control deviation calculated for the main temperature control loop. This serves as the reference value for setting the air temperature control deviation. This is the coupling gain coefficient; When the secondary control loop receives a valve opening change signal, it performs the following steps: S5.2a: Call the multivariate collaborative feedforward model to input the real-time valve opening value. Magnetic levitation centrifugal fan 11 current speed and ambient temperature and real-time wind temperature deviation Substitute into the formula to calculate the current dynamic airflow feedforward compensation coefficient. ; S5.2b: Based on the dynamic airflow feedforward compensation coefficient k, the pair is mapped from the basic... Calculated baseline air volume change estimate Make corrections to obtain the final airflow feedforward command. ; S5.2c: Based on airflow feedforward command Generate speed feedforward adjustment command; when real-time air temperature control deviation... When the volume increases, the multivariate collaborative feedforward model compensates for the increase through dynamic airflow feedforward coefficients. The automatic amplification of the feedforward compensation for valve disturbances makes the speed response of the magnetic levitation centrifugal fan 11 more aggressive, thereby using a larger change in compression heat to offset the air temperature disturbance more quickly, and vice versa.

[0029] The multivariate collaborative feedforward model also includes an online self-learning function, specifically: the control unit 14 continuously records the actual airflow response value after the secondary control loop is activated. With time for wind temperature to stabilize ; By optimizing the algorithm to make Minimize and With the goal of minimizing the time required, the basic mapping function in the multivariate collaborative feedforward model is iteratively updated online. and coupling gain coefficient This enables the multivariate collaborative feedforward model to adapt to changes in system characteristics.

[0030] The control unit 14 is also configured to execute a collaborative temperature control strategy based on the physical properties of fly ash. This strategy achieves the dual objectives of on-demand heating and optimal system energy efficiency by sensing the properties of fly ash itself. Specifically, it includes the following steps: S5.3: Online moisture monitors and ash temperature sensors are installed near the bottom unloading valves of the original ash silo 1, coarse ash silo 2 and fine ash silo 3 respectively, so as to obtain the moisture content signal and the current ash temperature signal of the fly ash in each silo in real time. Specifically, to achieve precise control of fly ash, this system has added online moisture monitors and ash temperature sensors at key locations such as the bottom discharge valves of the raw ash silo 1, coarse ash silo 2, and fine ash silo 3. The online moisture monitors can non-contactly measure the moisture content of the fly ash about to enter the conveying pipeline in real time; this parameter is the most critical variable determining the heat required for drying. The ash temperature sensor directly measures the temperature of the ash itself, reflecting the current thermal state of the fly ash within the silo. These two types of sensors transmit the captured moisture content and ash temperature signals to the control unit 14 in real time, providing first-hand process data directly from the material itself for dynamic control decisions, replacing the traditional extensive control mode that relies on fixed experience values.

[0031] S5.4: The control unit 14 dynamically calculates and updates the personalized target air temperature corresponding to each ash silo based on the real-time moisture content of each ash silo and the pre-stored correspondence between the moisture content of fly ash of different particle sizes and the ideal gasification air temperature; wherein, for fly ash with higher moisture content, a higher personalized target air temperature is set. In detail, after acquiring the real-time moisture content of fly ash in each silo, the control unit 14 does not use a uniform temperature setpoint. Instead, it calls upon a pre-stored graph showing the correlation between moisture content and ideal gasification air temperature for fly ash of different particle sizes. This graph, obtained through numerous process experiments, clarifies the optimal gasification air temperature required for efficient fluidization and non-caking of fly ash of different particle sizes (raw ash, coarse ash, fine ash, etc.) at specific moisture contents. Based on this graph and real-time moisture content data, the control unit 14 dynamically calculates and updates the personalized target air temperature for each ash silo.

[0032] For fly ash with higher real-time moisture content, the system automatically sets a higher personalized target air temperature to ensure sufficient latent heat of vaporization; conversely, for drier fly ash, the target air temperature is appropriately lowered to avoid energy waste. This enables a precise match between the air temperature supply and the actual needs of the material.

[0033] S5.5: When the operating conditions of any of the original ash silos 1, coarse ash silos 2, and fine ash silos 3 change, causing an imbalance between its gasification demand and the personalized target air temperature, the control unit 14 performs coordinated temperature control optimization: First, it dynamically adjusts the speed of the corresponding magnetic levitation centrifugal fan 11 according to the secondary control loop to meet the real-time flow and pressure requirements; at the same time, it calculates the excess or deficiency of compressive heat generated by the speed adjustment of the magnetic levitation centrifugal fan 11 relative to its personalized target air temperature, and adjusts the connecting valve 15 and performs coordinated speed fine-tuning of the magnetic levitation centrifugal fans 11 in other ash silos to guide the excess heat to the ash silo that currently needs the most heat or to transfer heat from other ash silos to ash silos with insufficient heat; this process is constrained by meeting the updated personalized target air temperature of each ash silo, and is solved and controlled in real time with the optimization objective of minimizing the total power consumption of all operating magnetic levitation centrifugal fans 11.

[0034] Specifically, when any ash silo experiences an imbalance between its gasification demand (manifested as a change in valve opening) and the current personalized target air temperature due to process operations (such as starting or stopping large-scale unloading), potentially resulting in excess or insufficient compression heat, this invention initiates collaborative temperature control optimization. The control unit 14 first rapidly adjusts the rotational speed of the corresponding magnetic levitation centrifugal fan 11 based on the secondary control loop to meet real-time flow and pressure requirements.

[0035] Simultaneously, the system calculates in real time the deviation of the compressible heat generated by the speed adjustment of the magnetic levitation centrifugal fan 11 relative to its personalized target air temperature, i.e., excess or insufficient heat. Subsequently, the control unit 14 adjusts the opening of the connecting valve 15 and performs coordinated speed fine-tuning of other operating fans to intelligently and directionally guide the excess heat of a certain ash silo to the ash silo that currently needs heat the most (such as the one with the highest personalized target air temperature) in the form of controllable hot air, or transfers heat from other silos to make up for the shortage in the ash silo. The entire dynamic scheduling process takes meeting the updated personalized target air temperature of all ash silos as a rigid constraint and minimizing the total power consumption of all operating magnetic levitation centrifugal fans 11 as the ultimate optimization goal, and performs real-time solution and closed-loop control.

[0036] The control unit 14 is also configured to execute a preventative vaporization strategy, specifically including the following steps: S5.6: The control unit 14 continuously records and stores historical fly ash temperature data and historical ambient temperature data obtained by the fly ash temperature sensors of each silo; based on the historical fly ash temperature data and historical ambient temperature data, it analyzes the cooling conditions experienced by the fly ash in each silo within a set historical period. The cooling conditions are characterized by calculating the difference between the average fly ash temperature and the average ambient temperature, and by statistically analyzing the cumulative duration of the fly ash temperature being lower than a set threshold. Specifically, the control unit 14 not only monitors the real-time status of fly ash, but also continuously records and stores historical data sequences of fly ash body temperature obtained by the ash temperature sensors of each ash silo, as well as the corresponding historical ambient temperature data. Based on this time-series data, the control unit 14 uses data analysis algorithms to quantitatively evaluate the cooling conditions experienced by the fly ash in each ash silo within a set historical period (such as the past 24 hours or a storage period).

[0037] This assessment is not a simple comparison of temperature points, but a comprehensive indicator: it reflects the overall temperature drop of the fly ash by calculating the difference between the average temperature of the fly ash and the average temperature of the environment within the specified period; simultaneously, it quantifies the duration of the fly ash being in a dangerous state prone to condensation and caking by statistically analyzing the cumulative duration for which the fly ash temperature is below a certain set safety threshold (this threshold is related to the critical condition for fly ash condensation). The combination of these two dimensions characterizes the severity of the low-temperature, high-humidity environment experienced by the fly ash, and is a key precursor signal for predicting changes in its physical stability.

[0038] S5.7: The control unit 14 calculates and generates the real-time caking risk coefficient of each silo fly ash based on the real-time moisture content, particle size characteristics (inherent properties of raw ash, coarse ash, and fine ash) of each silo fly ash and the analyzed cooling condition data, through a pre-trained caking risk prediction model. After obtaining real-time moisture content, particle size characteristics (inherent properties of raw fly ash, coarse fly ash, and fine fly ash), and the quantitative data on cooling conditions obtained from step S5.6, the control unit 14 inputs this multi-source heterogeneous data into a pre-trained caking risk prediction model. This model is trained using machine learning algorithms based on a large amount of historical operating data and samples of whether caking ultimately occurred, and can capture the complex nonlinear relationship between various factors and caking tendency. After the model runs, it will output a real-time, dynamically updated caking risk coefficient for each ash silo. This coefficient is a value between 0 and 1 (or a percentage), objectively and quantitatively reflecting the probability of bottom caking of the fly ash in the silo under current and recent historical conditions.

[0039] S5.8: When the caking risk coefficient of any ash silo exceeds a preset threshold, regardless of its current gasification demand, the control unit 14 initiates a preventative gasification operation for that ash silo: First, the personalized target air temperature of the ash silo is temporarily increased, and within a set time period, a short-term high-temperature, high-pressure turbulent airflow is output by increasing the rotation speed of its corresponding magnetic levitation centrifugal fan 11 to purge and loosen the potentially caking material at the bottom of the ash silo; during this process, the system calculates the excess heat generated in real time and, based on the coordinated temperature control strategy, dispatches this heat to other ash silos that need heat the most at this time through the connecting valve 15; after the preventative operation is completed, the system restores the normal personalized target air temperature and rotation speed control of the ash silo and reassesses its caking risk coefficient.

[0040] When the caking risk factor of any ash silo exceeds the preset safety threshold, the control unit 14 will proactively trigger a targeted preventative vaporization operation, regardless of whether the silo currently has a conveying task (the valve opening may be zero), to prevent problems before they occur. The operation process is as follows: First, the system temporarily and purposefully increases the personalized target air temperature setpoint for the silo. In the following short, pre-set period, the control unit 14 significantly increases the speed of the corresponding magnetic levitation centrifugal fan 11, causing it to output a turbulent airflow with higher temperature and pressure. This airflow is not used for normal conveying; its purpose is to use its thermal shock force and dynamic pressure to blow away and loosen the potential, nascent caking material layer at the bottom of the silo, destroying its bonding structure and thus dissolving it before it hardens.

[0041] The embodiments described above are merely illustrative of specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A magnetic levitation fan system for conveying fly ash gasification, characterized in that: The system includes a raw ash silo (1), a coarse ash silo (2), and a fine ash silo (3). Each of the raw ash silos (1), coarse ash silos (2), and fine ash silos (3) is equipped with a magnetic levitation centrifugal fan (11). The outlet of each magnetic levitation centrifugal fan (11) is connected to the corresponding atomizing pipe (6) of the raw ash silo, the atomizing pipe (7) of the coarse ash silo, and the atomizing pipe (8) of the fine ash silo via a gasification air pipeline to provide fluidized gasification air. Each magnetic levitation centrifugal fan (11) is equipped with a pressure transmitter (12) and a temperature sensor (13) on its outlet pipeline. Each magnetic levitation centrifugal fan (11), each pressure transmitter (12), and each temperature sensor (13) is connected to a control unit (14). A connecting valve (15) is connected to the parallel pipeline of multiple magnetic levitation centrifugal fans (11) to realize the interconnection between each magnetic levitation centrifugal fan (11).

2. A method for controlling the gasification and conveying of fly ash, comprising the magnetic levitation fan system for fly ash gasification and conveying as described in claim 1, characterized in that, Includes the following steps: S1: Determine the target air pressure, target air volume and target air temperature based on the working conditions of the original ash silo (1), coarse ash silo (2) and fine ash silo (3); S2: Start the magnetic levitation centrifugal fan (11) and adjust its speed to make the pressure and flow rate of the output gasified air reach the target air pressure and target air volume; S3: Real-time monitoring of the outlet air temperature of the magnetic levitation centrifugal fan (11); S4: Compare the monitored outlet air temperature with the target air temperature; S5: Based on the comparison results, dynamically adjust the rotation speed of the magnetic levitation centrifugal fan (11) so as to use the compression heat of the magnetic levitation centrifugal fan (11) to control the outlet air temperature within the allowable fluctuation range of the target air temperature.

3. The fly ash gasification conveying control method as described in claim 2, characterized in that, In step S5, the dynamic adjustment of the rotational speed of the magnetic levitation centrifugal fan (11) is achieved through a dual-loop collaborative control architecture. The dual-loop collaborative control architecture includes a main temperature control loop and a secondary control loop embedded therein, specifically including: S5.1: For each raw ash silo (1), coarse ash silo (2) and fine ash silo (3), establish an independent temperature main control loop with outlet air temperature as the controlled variable. The speed adjustment amount in the previous loop cycle is used as the feedforward compensation benchmark for the control decision of this loop. S5.2: In the main feedback control loop, a secondary control loop with pressure and flow as the rapid adjustment target is embedded; when the control unit (14) receives a change in the valve opening of the gasification pipeline corresponding to the original ash silo (1), coarse ash silo (2) and fine ash silo (3), the secondary control loop first dynamically adjusts the speed of the corresponding magnetic levitation centrifugal fan (11) according to the preset valve opening-airflow mapping relationship to quickly stabilize the pressure and meet the new flow demand; then, the temperature main control loop finely adjusts the speed based on the new outlet air temperature measurement value to suppress the compression heat fluctuation caused by the dynamic response of the magnetic levitation centrifugal fan (11), thereby minimizing the disturbance of the outlet air temperature.

4. The fly ash gasification conveying control method as described in claim 3, characterized in that, The "preset valve opening-airflow mapping relationship" mentioned in step S5.2 is dynamically generated through a multivariate collaborative feedforward model. This multivariate collaborative feedforward model introduces the instantaneous air temperature control deviation as the core feedback into the feedforward loop to achieve self-correction of the valve disturbance advance compensation amount. Specifically, the multivariate collaborative feedforward model uses the real-time valve opening value... Current fan speed and ambient temperature As an input variable; and a dynamic airflow feedforward compensation coefficient is introduced. The formula: ,in, It is a basic mapping coefficient based on the rated characteristics calibration of the magnetic levitation centrifugal fan (11) and the gasification air duct. The real-time air temperature control deviation calculated for the main temperature control loop. This serves as the reference value for setting the air temperature control deviation. This is the coupling gain coefficient; When the secondary control loop receives a valve opening change signal, it performs the following steps: S5.2a: Call the multivariate collaborative feedforward model to input the real-time valve opening value. Magnetic levitation centrifugal fan (11) current speed and ambient temperature and real-time wind temperature deviation Substitute into the formula to calculate the current dynamic airflow feedforward compensation coefficient. ; S5.2b: Based on the dynamic airflow feedforward compensation coefficient k, the pair is mapped from the basic... Calculated baseline air volume change estimate Make corrections to obtain the final airflow feedforward command. ; S5.2c: Based on airflow feedforward command Generate speed feedforward adjustment command; when real-time air temperature control deviation... When the volume increases, the multivariate collaborative feedforward model compensates for the increase through dynamic airflow feedforward coefficients. Automatically amplify the feedforward compensation for valve disturbances, making the rotational speed response of the magnetic levitation centrifugal fan (11) more aggressive, thereby using a larger change in compression heat to offset the air temperature disturbance more quickly, and vice versa.

5. The fly ash gasification conveying control method as described in claim 4, characterized in that, The multivariate collaborative feedforward model also includes an online self-learning function, specifically including: the control unit (14) continuously records the actual air volume response value after the action of the secondary control loop. With time for wind temperature to stabilize ; By optimizing the algorithm to make Minimize and With the goal of minimizing the time required, the basic mapping function in the multivariate collaborative feedforward model is iteratively updated online. and coupling gain coefficient This enables the multivariate collaborative feedforward model to adapt to changes in system characteristics.

6. The fly ash gasification conveying control method according to claim 5, characterized in that, The control unit (14) is also configured to execute a collaborative temperature control strategy based on the physical properties of fly ash, specifically including the following steps: S5.3: Online moisture monitors and ash temperature sensors are installed near the bottom unloading valves of the original ash silo (1), coarse ash silo (2) and fine ash silo (3) respectively, so as to obtain the moisture content signal and the current ash temperature signal of each silo fly ash in real time. S5.4: The control unit (14) dynamically calculates and updates the personalized target air temperature corresponding to each ash silo based on the real-time moisture content of each ash silo and the pre-stored correspondence between the moisture content of fly ash of different particle sizes and the ideal gasification air temperature; wherein, for fly ash with higher moisture content, a higher personalized target air temperature is set. S5.5: When the operating conditions of any of the original ash silos (1), coarse ash silos (2), and fine ash silos (3) change, causing an imbalance between their gasification demand and the personalized target air temperature, the control unit (14) performs coordinated temperature control optimization: First, it dynamically adjusts the speed of the corresponding magnetic levitation centrifugal fan (11) according to the secondary control loop to meet the real-time flow and pressure requirements; at the same time, it calculates the excess or deficiency of the compressed heat generated by the speed adjustment of the magnetic levitation centrifugal fan (11) relative to its personalized target air temperature, and by adjusting the connecting valve (15) and coordinating the speed fine-tuning of the magnetic levitation centrifugal fans (11) of other ash silos, it directs the excess heat to the ash silos that currently need the most heat or transfers the heat from other ash silos to ash silos that lack heat; this process is constrained by meeting the updated personalized target air temperature of each ash silo, and is solved and controlled in real time with the optimization objective of minimizing the total power consumption of all operating magnetic levitation centrifugal fans (11).

7. The fly ash gasification conveying control method according to claim 6, characterized in that, The control unit (14) is also configured to execute a preventative vaporization strategy, specifically including the following steps: S5.6: The control unit (14) continuously records and stores the historical data of fly ash temperature and the historical data of ambient temperature obtained by the fly ash temperature sensors of each silo; based on the historical data of fly ash temperature and the historical data of ambient temperature, it analyzes the cooling status experienced by each silo fly ash within a set historical period. The cooling status is characterized by calculating the difference between the average fly ash temperature and the average ambient temperature, and by statistically analyzing the cumulative duration of the fly ash temperature being lower than a set threshold. S5.7: The control unit (14) calculates and generates the real-time caking risk coefficient of each silo fly ash based on the real-time moisture content, particle size characteristics and cooling status data of each silo fly ash through a pre-trained caking risk prediction model. S5.8: When the caking risk coefficient of any ash silo exceeds the preset threshold, regardless of its current gasification demand, the control unit (14) initiates a preventive gasification operation for that ash silo: First, the personalized target air temperature of the ash silo is temporarily increased, and within a set time period, a short-term high-temperature, high-pressure turbulent airflow is output by increasing the speed of its corresponding magnetic levitation centrifugal fan (11) to purge and loosen the potential caking material at the bottom of the ash silo; During this process, the system calculates the excess heat generated in real time, and according to the collaborative temperature control strategy, dispatches this part of the heat to other ash silos that need the most heat at this time through the connecting valve (15); After the preventive operation is completed, the system restores the normal personalized target air temperature and speed control of the ash silo, and reassesses its caking risk coefficient.

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