A preheater staged combustion precise air distribution and coal injection collaborative control method and system

Abstract

The application relates to the technical field of staged combustion control, in particular to a preheater staged combustion precise air distribution and coal injection collaborative control method and system, which comprises the following steps: obtaining a preheater cross-zone pressure difference, a denitration zone oxygen content, a mother pipe absolute pressure, a mother pipe absolute temperature and a coal powder charge pulse; calculating a denitration zone oxygen content reduction rate; calculating a burnout air valve opening degree increment; calculating a main air valve compensation increment; calculating a gas phase delay; calculating a difference value of a solid phase delay and the gas phase delay as a dormant waiting time length; determining a coal feeding target speed based on a coal feeding basic speed and issuing the coal feeding target speed, synchronously issuing the burnout air valve opening degree increment and the main air valve compensation increment, and starting a dormant period with a time length of the dormant waiting time length; maintaining a main air valve basic opening degree and a burnout air valve basic opening degree in the dormant period; and synchronously triggering the burnout air valve opening degree increment and the main air valve compensation increment after the dormant period ends. The application can solve the problem of phase dislocation of the injection port air and coal, and realize synchronous arrival.

Description

Technical Field

[0001] This application relates to the technical field of staged combustion control, and in particular to a method and system for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater. Background Technology

[0002] Industrial preheater staged combustion systems rely on the physical coordination of the air supply network and the pulverized coal pneumatic conveying pipeline during operation. Under dynamic peak shaving or load fluctuation conditions, the system needs to adjust the main air, burnout air, and coal feed rate in real time for the main combustion zone and burnout zone to maintain a predetermined air-fuel ratio. In this type of system structure, gaseous air is controlled by a servo-electric regulating valve and enters the furnace through the air supply network, while solid pulverized coal is conveyed to the nozzle section by a variable frequency coal feeder through an independent pneumatic conveying pipeline.

[0003] Chinese invention patent application CN115962480A discloses a combustion control method and system for a coal-fired boiler. This technical solution physically divides the combustion zone into a main combustion zone and a burnout zone. Within the main combustion zone, the pulverized coal flow rate in each pulverized coal pipeline is adjusted to be essentially the same, and the opening of the secondary air damper for each burner is adjusted synchronously to ensure that the air-coal ratio for each burner is essentially the same. While keeping the operating parameters of the main combustion zone constant, the system independently adjusts the opening of the burnout air nozzle damper at the corresponding location based on the gridded concentration data obtained from the CO / O2 sensor array located at the economizer outlet, thus maintaining the local CO / O2 content at a set value.

[0004] When the aforementioned system architecture operates under variable load conditions and performs synchronous parameter adjustments, due to the objective differences in the physical transport mechanisms of the gas-solid two-phase materials, the synchronously issued electrical control commands are translated into material flows with inconsistent arrival times in the physical pipeline. Driven by thermodynamic parameters, the gaseous fluid's pressure changes propagate through the pipeline network at transient sound speeds and rapidly reach the nozzle cross-section. Solid pulverized coal, carried by airflow in long-distance pipelines, is subject to physical constraints from pipeline friction resistance and back pressure, making it prone to slippage, resulting in a nonlinear time lag in its physical transport. The inherent asymmetric dynamic time difference in the two-phase pipeline causes a phase misalignment between the airflow and coal arrival at the nozzle cross-section during the system's adjustment transition period. During this transitional transient, the local combustion space falls into a state of physical runaway, either oxygen-rich or fuel-rich, leading to an unplanned surge in nitrogen oxide emissions or coking corrosion of the heated surfaces. Summary of the Invention

[0005] To address the issue of misaligned air and coal phases at the nozzle and achieve synchronous arrival, this application provides a method and system for coordinated control of precise air distribution and coal injection in staged combustion of the preheater.

[0006] In a first aspect, this application provides a method and system for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater, employing the following technical solution: A method for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater, comprising:

[0007] Obtain the pressure difference between the preheater zones, the oxygen content in the denitrification zone, the absolute pressure of the main pipe, the absolute temperature of the main pipe, and the charge pulse of the pulverized coal;

[0008] Based on the oxygen content in the denitrification zone, the rate of decrease in oxygen content in the denitrification zone was calculated.

[0009] When the pressure difference between the preheater zones is lower than the preset lower limit of the pressure difference and the rate of decrease of oxygen in the denitrification zone changes from negative to positive, the current steady-state parameters are extracted, and the current steady-state parameters are assigned to the main air valve basic opening, the burnout air valve basic opening and the coal feeding basic speed respectively, and locked.

[0010] Based on the deviation between the preheater inter-zone pressure difference and the preset target pressure difference, the burnout air valve opening increment is calculated;

[0011] Based on the absolute pressure and absolute temperature of the main pipe, the compensation increment of the main air valve is calculated according to the oxygen mass flow conservation rule.

[0012] The fluid sound velocity is calculated based on the absolute temperature of the main pipe, and the gas phase delay is calculated in combination with the preset main duct length.

[0013] The initial velocity of the pulverized coal is obtained by performing cross-correlation calculation on the charge pulse of the pulverized coal, and the solid phase delay is calculated by combining the preset coal conveying pipe length.

[0014] The difference between the solid-phase delay and the gas-phase delay is calculated and used as the dormancy waiting time.

[0015] The target coal feeding speed is determined and issued based on the basic coal feeding speed. Simultaneously, the burnout air valve opening increment and the main air valve compensation increment are issued, and a dormancy period with a duration equal to the dormancy waiting time is started.

[0016] During the dormancy period, control update commands are blocked to maintain the basic opening of the main air valve and the basic opening of the burnout air valve.

[0017] After the dormancy period ends, the burnout air valve opening increment and the main air valve compensation increment are triggered synchronously.

[0018] Optionally, calculating the rate of decrease in oxygen content in the denitrification zone based on the oxygen content in the denitrification zone includes:

[0019] The pressure difference across the preheater and the oxygen content in the denitrification zone are extracted synchronously at a preset sampling period and stored in a preset data window to construct a time series.

[0020] The oxygen content in the denitrification zone in the time series is differentially calculated to obtain the rate of decrease of oxygen content in the denitrification zone.

[0021] When the inter-zone pressure difference of the preheater is lower than the preset lower limit of pressure difference and the rate of decrease of oxygen in the denitrification zone changes from negative to positive, the current steady-state parameters are extracted, and the current steady-state parameters are respectively assigned to the basic opening degree of the main air valve, the basic opening degree of the burnout air valve, and the basic rotational speed of the coal feeder, and locked, including:

[0022] When the pressure difference across the preheater zones is lower than the preset lower limit of pressure difference for a consecutive preset number of cycles, and the rate of decrease in oxygen content in the denitrification zone changes from negative to positive, the current steady-state parameter is extracted.

[0023] The current steady-state parameters are assigned the corresponding values ​​to the main air valve base opening, the burnout air valve base opening, and the coal feed base rotation speed, and then locked.

[0024] Optionally, the step of calculating the main air valve compensation increment based on the oxygen mass flow conservation rule, combining the absolute pressure and absolute temperature of the main pipe, includes:

[0025] Calculate the gas density in the main pipe based on the absolute pressure and absolute temperature of the main pipe.

[0026] By combining the gas density in the main pipe with the increase in the opening degree of the burnout air valve, the oxygen diversion variable is calculated;

[0027] Based on the preset oxygen value and the oxygen diversion variable, the main wind compensation amount is deduced.

[0028] Based on a preset mapping relationship, the main air compensation amount is converted into the main air valve compensation increment.

[0029] Optionally, after calculating the difference between the solid-phase delay and the gas-phase delay as the dormancy waiting time, and before determining and issuing the target coal feeding speed based on the base coal feeding speed, the method further includes:

[0030] The expected opening is obtained by summing the compensation increment of the main air valve with the basic opening of the main air valve.

[0031] When the expected opening is not less than the preset opening threshold, the instruction is truncated according to the preset opening threshold, and the opening difference between the expected opening and the preset opening threshold is extracted.

[0032] Based on the gas density in the main pipe, the opening difference is converted into oxygen-deficient mass;

[0033] Based on the preset carbon-oxygen ratio, the oxygen-deficient mass is converted into an equivalent carbon content, and the speed reduction is calculated.

[0034] The step of determining and issuing the target coal feeding speed based on the basic coal feeding speed includes: subtracting the speed deduction amount from the basic coal feeding speed to obtain the target coal feeding speed and issuing it.

[0035] Optionally, the step of calculating the fluid sound velocity based on the absolute temperature of the main pipe and calculating the gas phase delay in combination with the preset main duct length includes:

[0036] Obtain the preset adiabatic index and preset gas constant;

[0037] The fluid velocity is obtained by taking the square root of the product of the preset adiabatic index, the preset gas constant, and the absolute temperature of the main pipe.

[0038] The gas phase delay is obtained by dividing the preset main duct length by the fluid sound velocity.

[0039] Optionally, obtaining the coal powder charge pulse includes: extracting the charge sequences output by two electrostatic nodes with a preset spacing, and using them as the coal powder charge pulse;

[0040] The step of performing cross-correlation calculations on the pulverized coal charge pulses to obtain the initial velocity of the pulverized coal, and calculating the solid-phase delay in conjunction with the preset coal conveying pipe length, includes:

[0041] Perform cross-correlation calculations on the pulverized coal charge pulses to extract the extreme value time difference;

[0042] Divide the preset spacing by the extreme time difference to calculate the initial velocity of the pulverized coal;

[0043] The solid phase delay is calculated by dividing the preset coal conveying pipe length by the initial velocity of the pulverized coal.

[0044] Optionally, during the dormancy period, it also includes:

[0045] Obtain the preset actual air pressure of the coal conveying pipe;

[0046] When the actual wind pressure drop value is greater than the preset drop threshold and the actual wind pressure is greater than the preset critical threshold, the pressure drop rate of the actual wind pressure is mapped to the velocity reduction based on the preset slip model.

[0047] The remaining duration is calculated based on the flow rate reduction, and the sleep waiting duration is updated to the remaining duration.

[0048] When the actual wind pressure is not greater than the preset critical threshold, the method of precise air distribution and pulverized coal injection coordinated control of staged combustion in the preheater is interrupted, the dormancy period is terminated, and a preset cleaning command is issued.

[0049] Optionally, the step of simultaneously issuing the burnout air valve opening increment and the main air valve compensation increment, and initiating the dormancy period with a duration equal to the dormancy waiting time, includes:

[0050] Invoke the preset synchronization protocol;

[0051] Based on the synchronization protocol, the burnout valve opening increment and the main air valve compensation increment are simultaneously sent within the same preset scanning cycle.

[0052] Write the sleep waiting time into a preset timer to start the sleep period;

[0053] The simultaneous triggering of the burnout damper opening increment and the main damper compensation increment after the dormancy period ends includes:

[0054] When the count value of the preset timer reaches zero, the dormancy period is determined to have ended, and the burnout air valve opening increment and the main air valve compensation increment are triggered synchronously.

[0055] Optionally, the step of synchronously sending the burnout valve opening increment and the main air valve compensation increment within the same preset scanning cycle based on the synchronization protocol includes:

[0056] Based on the synchronization protocol, a preset clock mapping between the master control terminal and the preset slave node is established;

[0057] The burnout air valve opening increment and the main air valve compensation increment are combined and encapsulated into a synchronization frame;

[0058] The synchronization frame is broadcast to the preset slave node in advance, and execution is triggered synchronously when the clock mapping reaches the preset time.

[0059] Secondly, the present application provides a method and system for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater, which adopts the following technical solution: a preheater staged combustion precise air distribution and pulverized coal injection coordinated control system, comprising:

[0060] The data acquisition module is used to acquire the pressure difference between the preheater zones, the oxygen content in the denitrification zone, the absolute pressure of the main pipe, the absolute temperature of the main pipe, and the charge pulse of the pulverized coal.

[0061] The state locking module is used to calculate the rate of decrease of oxygen in the denitrification zone based on the oxygen content in the denitrification zone; when the pressure difference between the preheater zones is lower than the preset pressure difference lower limit and the rate of decrease of oxygen in the denitrification zone changes from negative to positive, the current steady-state parameters are extracted, and the current steady-state parameters are assigned to the main air valve basic opening degree, the burnout air valve basic opening degree and the coal feed basic speed respectively, and the locking is performed.

[0062] The incremental calculation module is used to calculate the burnout air valve opening increment based on the deviation between the preheater inter-zone pressure difference and the preset target pressure difference; and to calculate the main air valve compensation increment based on the oxygen mass flow conservation rule by combining the absolute pressure and absolute temperature of the main pipe.

[0063] The delay calculation module is used to calculate the fluid sound velocity based on the absolute temperature of the main pipe, and calculate the gas phase delay in combination with the preset main duct length; perform cross-correlation calculation on the coal powder charge pulse to obtain the initial velocity of the coal powder, and calculate the solid phase delay in combination with the preset coal conveying pipe length; and calculate the difference between the solid phase delay and the gas phase delay as the sleep waiting time.

[0064] The collaborative execution module is used to determine and issue the target coal feeding speed based on the basic coal feeding speed, simultaneously issue the burnout air valve opening increment and the main air valve compensation increment, and initiate a dormancy period with a duration equal to the dormancy waiting time; during the dormancy period, control update commands are blocked, and the basic opening of the main air valve and the basic opening of the burnout air valve are maintained; after the dormancy period ends, the burnout air valve opening increment and the main air valve compensation increment are synchronously triggered for execution.

[0065] In summary, this application includes the following beneficial technical effects:

[0066] 1. By locking the current steady-state parameters as the basic operands when triggering coordinated control, and constructing a dormancy waiting period based on the difference between solid-phase delay and gas-phase delay, the dormancy period is initiated after simultaneously issuing the burnout air valve opening increment, main air valve compensation increment, and coal feeding target speed. During the dormancy period, the basic opening of the main air valve and the basic opening of the burnout air valve are maintained. After the dormancy period ends, the gas phase adjustment command is triggered synchronously to delay the gas phase pressure wave that quickly arrives at the nozzle section to be at the same time reference as the slowly arriving solid coal powder. This allows the air and coal phase materials to arrive at the nozzle section synchronously, thereby effectively eliminating the nozzle air and coal phase misalignment caused by the difference in the physical transport mechanism of the gas and solid phases, and avoiding the local combustion space from falling into an oxygen-rich or fuel-rich runaway state during the transition transient.

[0067] 2. After calculating the difference between the solid-phase delay and the gas-phase delay as the dormancy waiting time, the expected opening is obtained by summing the main air valve compensation increment with the main air valve base opening. When the expected opening is not less than the preset opening threshold, the command is truncated according to the opening threshold and the opening difference is extracted. Combined with the gas density of the main pipe, the opening difference is converted into oxygen-deficient mass. Then, based on the preset carbon-oxygen ratio, it is converted into equivalent carbon content and the speed reduction is calculated. The coal feeding base speed minus the speed reduction is used as the coal feeding target speed. When the main air valve opening is limited by the physical stroke boundary, the coal feed is reduced synchronously to match the actual available oxygen content. This avoids carbon-oxygen imbalance caused by insufficient actual oxygen supply after the main air valve command is truncated, so that the system can still maintain the balance of the combustion air-fuel ratio under the valve saturation boundary.

[0068] 3. By continuously acquiring the preset actual air pressure of the coal conveying pipe during the dormancy period, when the drop value of the actual air pressure is greater than the preset drop threshold and the actual air pressure is greater than the preset critical threshold, the pressure drop rate of the actual air pressure is mapped to the velocity reduction based on the preset slip model, and the remaining time is calculated based on the velocity reduction to dynamically update the dormancy waiting time. When the actual air pressure is not greater than the preset critical threshold, the coordinated control is interrupted and a cleaning command is issued. When slippage occurs during the coal powder conveying process, resulting in an extension of solid phase delay, the dormancy waiting time is adaptively corrected. When the air pressure is too low, the dormancy period is terminated in time and cleaning is triggered. This maintains the matching between the dormancy waiting time and the dynamically changing solid phase transmission state, and prevents the risk of pipe blockage caused by coal powder deposition in the coal conveying pipe, thereby improving the adaptability and safety of the control method under variable load conditions. Attached Figure Description

[0069] Figure 1 A flowchart of the preheater staged combustion precise air distribution and pulverized coal injection coordinated control method provided in the embodiments of this application;

[0070] Figure 2 This is a schematic diagram of the physical hardware architecture provided in the embodiments of this application;

[0071] Figure 3 This is a system virtual functional module architecture diagram provided in the embodiments of this application. Detailed Implementation

[0072] The following combination Figures 1-3 This application will be described in further detail.

[0073] This application discloses a method for precise air distribution and pulverized coal injection coordinated control in a preheater staged combustion system. The preheater staged combustion system includes a main air supply pipe, a main air branch and a burnout air branch connected in parallel to the main air supply pipe, servo-electric regulating valves with absolute position encoders installed in the main air branch and burnout air branch, a pulverized coal pneumatic conveying pipeline independent of the gas phase fluid pipeline network, a variable frequency coal feeder installed at the starting end of the pulverized coal pneumatic conveying pipeline, and an edge coordination controller. The edge coordination controller is equipped with a hardware clock that supports the IEEE 1588 PTP precise time protocol. The edge coordination controller and the servo-electric regulating valves communicate via EtherCAT real-time industrial Ethernet to ensure that the burnout air valve control commands and the main air valve control commands are within the same preset scan cycle.

[0074] A differential pressure transmitter and an oxygen sensor are installed at the preheater elevation. A sheathed thermocouple temperature transmitter and an absolute pressure transmitter are installed inside the main air supply pipe. A primary air pressure transmitter is installed on the pre-installed coal conveying pipe. Two electrostatic nodes are spaced axially at intervals at the beginning of the pulverized coal pneumatic conveying pipeline. Both electrostatic nodes adopt a ring electrode structure, with the ring electrode insulated from the pulverized coal pneumatic conveying pipeline. Pulverized coal particles generate induced charges as they pass through the cross-section of the ring electrode. The electrostatic nodes output one-dimensional time-domain voltage pulses via charge amplifiers. The pre-installed spacing between the two electrostatic nodes can be set from 0.5m to 1m, ensuring that the related pulses formed by the same pulverized coal agglomerate remain identifiable in two charge sequences. The differential pressure transmitter outputs the differential pressure between the preheater zones, the oxygen sensor outputs the oxygen content in the denitrification zone, the absolute pressure transmitter outputs the absolute pressure of the main pipe, the sheathed thermocouple temperature transmitter outputs the absolute temperature of the main pipe, the two electrostatic nodes output pulverized coal charge pulses, and the primary air pressure transmitter outputs the actual air pressure of the pre-installed coal conveying pipe. The physical outputs of each sensor are converted from analog to digital to form sampled values ​​with hardware clock timestamps. The edge collaborative controller is the only physical execution entity for subsequent calculation and control commands. The variable frequency coal feeder and the servo electric regulating valve are the underlying physical controlled entities for the target coal feeding speed and valve opening control, respectively.

[0075] The cross-zone differential pressure transmitter, oxygen sensor, absolute pressure transmitter, armored thermocouple temperature transmitter, and two electrostatic nodes output sampled values ​​under a unified hardware clock reference. The edge collaborative controller acquires the cross-zone differential pressure of the preheater, the oxygen content in the denitrification zone, the absolute pressure of the main pipe, the absolute temperature of the main pipe, and the pulverized coal charge pulses, forming a current-round input dataset containing sampled values, sampling times, data validity flags, and sensor channel identifiers. For example... Figure 1 As shown, the control system relies on this input dataset to enter the cyclic verification network. When specific parameters trigger threshold conditions, it sequentially performs state locking, delay calculation, and incremental synchronization. During the initial sleep period, it selects to maintain shielding or trigger cleaning based on the actual wind pressure. The current input dataset is the only input for state locking; no subsequent control commands are generated if a valid current input dataset is not obtained.

[0076] The edge collaborative controller calculates the rate of decrease in oxygen content in the denitrification zone based on the oxygen content therein. Specifically, the edge collaborative controller synchronously extracts the inter-zone pressure difference of the preheater and the oxygen content in the denitrification zone at a preset sampling period, and stores them in a preset data window to construct a time series. The preset sampling period can be set to 20ms to 50ms, and the preset data window must cover at least a preset number of consecutive periods, which can be set to 3 to 5. The oxygen content in the denitrification zone in the time series is differentially calculated to obtain the rate of decrease in oxygen content. The rate of decrease at the k-th sampling time can be expressed as... ,in, Let k be the oxygen content in the denitrification zone at the k-th sampling time. The preset sampling period is used. To suppress random noise from the oxygen sensor, a three-point moving average can be performed on the preset data window before differential calculation. The moving average only changes the noise component of the input sequence and does not change the joint triggering relationship between the preheater cross-zone pressure difference continuously falling below the preset lower limit and the oxygen decrease rate in the denitrification zone turning from negative to positive.

[0077] When the inter-zone pressure difference of the preheater is lower than the preset lower limit and the rate of decrease in oxygen in the denitrification zone changes from negative to positive, the edge collaborative controller extracts the current steady-state parameters and assigns them to the basic opening of the main air valve, the basic opening of the burnout air valve, and the basic speed of the coal feeder, respectively, and locks them. Specifically, when the inter-zone pressure difference of the preheater is lower than the preset lower limit for a continuous preset number of cycles, and the rate of decrease in oxygen in the denitrification zone changes from negative to positive, the edge collaborative controller confirms that the inter-zone pressure difference of the preheater is lower than the preset lower limit and the rate of decrease in oxygen in the denitrification zone changes from negative to positive, and extracts the current steady-state parameters. The preset lower limit of pressure difference can be calibrated within the range of 50Pa to 150Pa based on the number of preheater stages, flue gas load, and anti-back-mixing boundary. The continuous preset number of cycles is used to eliminate single-point pressure pulsations, and the rate of decrease in oxygen in the denitrification zone changing from negative to positive is used to rigorously characterize the physical transient state where the oxygen condition stops smoothly recovering and transitions to severe consumption. Both together limit the trigger boundary of collaborative control.

[0078] The current steady-state parameters include the current absolute position encoded values ​​of the main air branch servo electric regulating valves, the current absolute position encoded values ​​of the burnout air branch servo electric regulating valves, and the current speed feedback value of the variable frequency coal feeder. The edge collaborative controller assigns the current steady-state parameters to the basic opening degree of the main air valve, the basic opening degree of the burnout air valve, and the basic speed of the coal feeder, respectively, and locks them. The basic opening degree of the main air valve is denoted as... The basic opening degree of the burnout air valve is recorded as The basic rotational speed of the coal feeder is denoted as The locking result constitutes the basic operand of this round of control transactions, and until the end of this round of control transactions, the valve opening or coal feeding speed of other preset scan cycles will not be used to overwrite this basic operand.

[0079] The edge-coordinated controller takes the preheater inter-zone pressure difference, the preset target pressure difference, and the locking result as inputs. Based on the deviation between the preheater inter-zone pressure difference and the preset target pressure difference, it calculates the increment of the burnout damper opening. The preset target pressure difference has a clear engineering calibration basis in actual industrial implementation: to ensure the penetration kinetic energy of the main combustion zone airflow and prevent back mixing of two-phase flow, the system uses a preset lower limit of pressure difference as a safety baseline, setting the range of the preset target pressure difference to be 1.2 to 1.5 times the preset lower limit. The establishment of this engineering calibration boundary avoids the risk of system divergence caused by unbounded and isolated parameter values. The pressure difference deviation can be expressed as... ,in, The preset target pressure difference, Let be the preheater cross-zone pressure difference at the k-th sampling time. The edge collaborative controller inputs the pressure difference deviation into the preset PID controller, according to... Calculate the increment of the burnout damper opening, where, , and These are the proportional coefficient, integral coefficient, and derivative coefficient, respectively. These coefficients inherently possess engineering dimension conversion properties to achieve dimensional mapping from pressure difference deviation to valve opening increment. The integral term is set with a limit value matching the physical stroke of the burnout air valve to prevent integral saturation when the burnout air valve reaches its stroke boundary. The burnout air valve opening increment serves as the sole valve increment input for calculating the oxygen diversion variable. As an optional implementation, the PID controller can be replaced with a piecewise linear mapping table established based on the preheater inter-zone pressure difference and the effective flow area of ​​the burnout air valve, performing linear interpolation between adjacent calibration points to output the burnout air valve opening increment.

[0080] After the burnout damper opening increment is established, the edge co-controller, combining the absolute pressure and absolute temperature of the main pipe, calculates the main damper compensation increment based on the oxygen mass flow conservation rule. The absolute temperature of the main pipe is calculated using the Kelvin scale; when the sheathed thermocouple temperature transmitter outputs Celsius temperature, the edge co-controller... Complete the temperature scale conversion. Based on the absolute pressure and absolute temperature of the main pipe, apply the ideal gas law. Calculate the gas density in the main pipe, where, The density of the main pipe gas. The absolute pressure of the main pipe, The absolute temperature of the mother tube. This is a preset gas constant for the mixed gas.

[0081] The edge-coordinated controller combines the main gas density and the burnout valve opening increment to calculate the oxygen splitting variable. The mass flow rate of the burnout valve can be calculated based on the valve calibration curve; within the incompressible approximate applicable pressure ratio range, the mass flow rate is expressed as... ,in, The flow coefficient of the burnout damper. The effective flow area corresponding to the opening degree of the burnout damper. The pressure difference across the burnout air valve.

[0082] Since the system lacks physical sensors to measure the back pressure of the valves and furnace, the edge collaborative controller utilizes existing parameters to construct a parameterized back pressure extrapolation logic to calculate the pressure difference: the pressure difference across the preheater zones is converted into the downstream equivalent relative back pressure according to a preset correlation weight. This preset correlation weight is not a fixed constant; the edge collaborative controller extracts the ratio of the basic opening of the burnout air valve to the basic opening of the main air valve. When this ratio increases, it indicates a shift in the downstream system's flow field resistance distribution. The edge collaborative controller adjusts the preset correlation weight in real-time according to the magnitude of this ratio change using a positive correlation dynamic mapping rule. By constructing this adaptive mapping based on existing parameters of the control closed loop, the back pressure extrapolation process under conditions without physical measurement points is completed.

[0083] Furthermore, the edge collaborative controller is equipped with a preset atmospheric environmental pressure constant. By subtracting the preset atmospheric environmental pressure constant from the absolute pressure of the main pipe to convert it into the gauge pressure of the main pipe, and then subtracting the downstream equivalent relative back pressure from this gauge pressure of the main pipe, the pressure difference across the burnout air valve can be dynamically calculated under a unified relative pressure benchmark. This thermodynamic benchmark alignment mechanism ensures the validity of the input to the orifice flow equation for incompressible fluids, avoiding flow estimation errors caused by cross-benchmark subtraction. The burnout damper opening is determined by... Change to The resulting change in mass flow rate is denoted as The oxygen splitting variable is expressed as ,in, This represents the oxygen mass fraction in the air supply medium.

[0084] The edge-coordinated controller extrapolates the main wind compensation amount based on preset oxygen values ​​and oxygen diversion variables. The preset oxygen value is the oxygen mass flow rate corresponding to the main combustion zone at the moment of lockout. To maintain the oxygen mass balance in the main combustion zone before and after the change in burnout wind, the main wind compensation amount must meet the following requirements. According to the valve flow direction definition, when the increase in burnout air corresponds to a decrease in the available oxygen in the main combustion zone, the main air compensation amount is taken as follows: .

[0085] The edge-coordinated controller converts the main air compensation amount into the main air valve compensation increment based on a preset mapping relationship. This preset mapping relationship is determined by the effective flow area curve of the main air valve, the main air valve flow coefficient, the main pipe air density, and the pressure difference across the main air valve, and can be expressed as follows: ,in, This is the calibration function relating the main air valve opening to the effective flow area. It is an inverse function. The flow coefficient of the main air valve The pressure difference across the main air valve. Similarly, This is also derived through the aforementioned logical deduction of the downstream equivalent relative back pressure using the pressure gauge of the main pipe. The resulting main air valve compensation increment and the burnout air valve opening increment share the same thermodynamic state reference of the main pipe.

[0086] When the pressure ratio between the main air supply pipe and the valve reaches the critical condition for compressible flow, the compressible flow parameters of the pneumatic components specified in ISO 6358 can be used to calculate the valve mass flow rate using the sonic conductance and critical back pressure ratio, replacing the incompressible orifice equation. As an optional implementation, a Coriolis mass flow meter capable of directly outputting mass flow rate can be installed on the main air supply pipe. The mass flow meter output is used to verify the gas density in the main pipe and the valve calibration curve; the oxygen split variable is still obtained by multiplying the change in burnout air mass flow rate by the oxygen mass fraction according to the oxygen mass flow rate conservation rule.

[0087] After the main air valve compensation increment calculation is completed, the edge collaborative controller uses the absolute temperature of the main duct and the preset main air duct length as inputs. Based on the absolute temperature of the main duct, it calculates the fluid sound velocity, and combines this with the preset main air duct length to calculate the gas phase delay. The edge collaborative controller obtains the preset adiabatic index and the preset gas constant, and takes the square root of the product of the preset adiabatic index, the preset gas constant, and the absolute temperature of the main duct to obtain the fluid sound velocity, i.e. Regarding the preset adiabatic index, those skilled in the art, during the system design phase, according to the International Association for the Properties of Steam (IAPWS-95) formula and the standard composition of dry air (containing 20.95% oxygen and 79.05% nitrogen), calibrated the preset adiabatic index to a fixed value of 1.365 and assigned this fixed value to the adiabatic index. By employing this engineering constraint mechanism based on international standard physical properties, the deviation in sound velocity calculation introduced within the typical inlet air temperature range of the preheater (150℃ to 350℃) does not exceed 0.5%, ensuring the reliability of fluid sound velocity prediction and avoiding time prediction distortion caused by subjective empirical values ​​of constants. The edge collaborative controller divides the preset main duct length by the fluid sound velocity to obtain the gas phase delay, i.e. .

[0088] Two electrostatic nodes output charge sequences at a sampling frequency more than twice the effective bandwidth of the pulverized coal charge pulse to satisfy the Nyquist sampling condition. The electrostatic sampling frequency can be set from 5kHz to 20kHz. The edge co-controller extracts the charge sequences output by the two electrostatic nodes at a preset interval as the pulverized coal charge pulse. The charge sequence output by the front-end electrostatic node is denoted as... The charge sequence output by the back-end electrostatic node is denoted as The two sequences are window-aligned using the same hardware clock timestamp and the DC component is removed.

[0089] The edge co-controller performs cross-correlation calculations on the pulverized coal charge pulses. The cross-correlation function can be expressed as follows: The edge collaborative controller extracts the extreme value location of the maximum absolute value of the cross-correlation function. ,Will With electrostatic sampling period Multiply to obtain the extreme time difference The edge collaborative controller divides the preset spacing by the extreme time difference to calculate the initial velocity of the pulverized coal, i.e. ,in, For the initial velocity of pulverized coal, The preset spacing between the two electrostatic nodes. This represents the extreme value time difference. When the ratio of the relevant peak value to the root mean square of the sequence is lower than a preset confidence threshold, the initial velocity of the current round of pulverized coal is marked as invalid and will not enter the dormant waiting time calculation. The preset confidence threshold is not a fixed constant.

[0090] During pneumatic conveying, changes in pulverized coal concentration significantly affect the background electrostatic noise level. The edge-cooperative controller extracts the base rotational speed of the coal feed and uses it as a parameter representing the solid mass flow rate. As the base rotational speed increases, it indicates that particle collisions and friction within the pipeline intensify, leading to a rise in background random charge noise. The edge-cooperative controller dynamically adjusts a preset confidence threshold based on a positive correlation mapping rule according to the increase in the base rotational speed; its empirical range is set between 2.5 and 4.0. By constructing this adaptive calibration mechanism based on existing parameters of the control closed loop, the identification threshold of the effective signal is always matched with the background noise of the current pipeline concentration, effectively preventing high-frequency disturbances from being misjudged as effective extreme time differences, thus ensuring the high-confidence physical authenticity of the extreme time difference and its derived initial pulverized coal velocity.

[0091] The edge coordinating controller divides the preset coal conveying pipe length by the initial velocity of the pulverized coal to calculate the solid phase delay, i.e. The preset length of the coal conveying pipe The calibration is based on the total length of the pipeline centerline from the operating section of the variable frequency coal feeder to the pulverized coal nozzle section, for example, 45m. Solid phase delay is the solid phase input for calculating the sleep waiting time.

[0092] The edge collaborative controller uses solid-phase delay and gas-phase delay as its sole inputs, and calculates the difference between the solid-phase delay and gas-phase delay as the sleep waiting time. When the preset main duct length is 15m, the preset coal conveying pipe length is 45m, and the initial velocity of pulverized coal is within the range of conventional pneumatic conveying speed, the solid phase delay is greater than the gas phase delay, and the dormancy waiting time is a positive value. When the dormancy waiting time is less than one preset scan cycle, the edge collaborative controller writes the dormancy waiting time to zero, so that the gas phase control command and the target coal feeding speed are in the same preset scan cycle; when the solid phase delay is not greater than the gas phase delay and the difference exceeds the measurement uncertainty, the data for this round is marked as abnormal pipeline parameters, and the negative duration is not used to start the dormancy period.

[0093] After calculating the difference between the solid-phase delay and the gas-phase delay as the dormancy waiting time, the edge collaborative controller sums the main air valve compensation increment with the main air valve's base opening to obtain the expected opening. When the expected opening is not less than a preset opening threshold, the edge collaborative controller truncates the command according to the preset opening threshold and extracts the opening difference between the expected opening and the preset opening threshold. The preset opening threshold can be taken as 95% of the main air valve's full stroke. The edge collaborative controller, combined with the main pipe air density, converts the opening difference into anoxic mass through the main air valve's effective flow area curve. The control holding time H is used as the conversion time window. Control holding time The value determination mechanism is as follows: the edge collaborative controller directly extracts the sleep waiting time obtained from the previous calculation in this step, and dynamically assigns its value to the control hold time. Because this dormancy waiting time objectively corresponds to the time misalignment period of the gas phase command waiting for solid-phase coal powder under the current transient state, it is used as the integral time window for the anoxic quality, restoring the objective compensation requirement, realizing the time-series closed loop of equivalent carbon quantity calculation, and eliminating the risk of logical deadlock caused by premature invocation before the time parameters are generated. The anoxic quality can be expressed as... ,in, For the expected opening size, This is the preset opening threshold.

[0094] The edge-coordinated controller converts the oxygen-deficient mass into equivalent carbon content based on a preset carbon-oxygen ratio and calculates the speed reduction. This preset carbon-oxygen ratio is not a fixed constant in engineering practice, but is obtained through an adaptive dynamic calibration mechanism: In the offline phase, industrial analysis of the current coal type is performed according to the "Industrial Analysis Methods for Coal" to obtain the received-basis fixed carbon mass fraction and received-basis hydrogen mass fraction of pulverized coal, and then the theoretical oxygen demand mass is calculated according to the molar combustion stoichiometric equation; In the online operation phase, the edge-coordinated controller extracts the previously obtained oxygen reduction rate in the denitrification zone as a parameter characterizing the intensity of combustion. When the oxygen reduction rate in the denitrification zone increases, the actual combustion efficiency is adjusted upwards in real time according to a positive correlation mapping rule; the theoretical oxygen demand mass is then multiplied by the actual combustion efficiency for dynamic correction, thus obtaining the preset carbon-oxygen ratio for engineering practice. This white-box calibration mechanism, combining coal quality standard analysis and existing dynamic parameters of the system, ensures that the process of converting oxygen-deficient mass into equivalent carbon content accurately adapts to real furnace conditions, effectively preventing gas-solid compensation distortion caused by static constants that deviate from the combustion physics framework.

[0095] The equivalent carbon content is characterized by the equivalent pulverized coal mass. The edge co-controller divides the oxygen-deficient mass by the preset carbon-oxygen ratio to obtain the equivalent pulverized coal mass. Converting the equivalent pulverized coal mass into a speed reduction, the speed reduction can be expressed as follows: ,in For equivalent pulverized coal quality, The aforementioned control holding time. When the main air valve does not reach the preset opening threshold, the speed reduction is set to zero. The main air valve compensation increment, the command truncation result, and the speed reduction together constitute the constraint output for the gas phase increment calculation.

[0096] Subsequently, the edge collaborative controller uses the base coal feeding speed and speed reduction as inputs to determine and issue the target coal feeding speed based on the base coal feeding speed. Specifically, when no main air valve command interruption occurs, the speed reduction is zero, and the target coal feeding speed equals the base coal feeding speed; when a main air valve command interruption occurs, the base coal feeding speed is subtracted from the speed reduction to obtain the target coal feeding speed, which is then issued. The target coal feeding speed command frame includes at least the control transaction sequence number, target coal feeding speed, target effective time, data validity flag, and cyclic redundancy check field. The variable frequency coal feeder adjusts its output frequency according to the target coal feeding speed, ensuring that solid coal powder preferentially enters the coal powder pneumatic conveying pipeline.

[0097] After receiving a valid response from the communication interface to the coal feeding target speed command, the edge co-controller invokes a preset synchronization protocol. Based on this protocol, a preset clock mapping is established between the master control terminal and the preset slave nodes. The IEEE 1588 PTP precise time protocol transmits the master clock time through Sync and Follow_Up messages, and estimates the link propagation delay through Delay_Req and Delay_Resp messages. The preset slave nodes then form a clock mapping corresponding to the preset master control terminal. The EtherCAT distributed clock is used to constrain the local execution time of each preset slave node, ensuring that the clock deviation is less than a preset electrical scan cycle.

[0098] The edge collaborative controller merges the burnout damper opening increment and the main damper compensation increment into a synchronization frame. Within the same preset scan cycle, it broadcasts this synchronization frame to preset slave nodes in advance, so that the underlying layer can synchronously trigger execution when the clock mapping reaches a preset time. Upon receiving the frame, the preset slave nodes enter a suspended waiting state. Subsequently, the edge collaborative controller writes the sleep waiting duration into a preset timer to initiate a sleep period with a duration equal to the sleep waiting duration.

[0099] During the dormancy period, the edge coordinating controller blocks control update commands, maintaining the basic opening of the main air valve and the basic opening of the burnout air valve. Blocking control update commands means prohibiting the current round of PID output, general adjustment quantities of the upper-level DCS, or other non-safety level control quantities from overriding the lockout results; overpressure, underpressure, actuator failure, and emergency stop signals maintain the highest priority and are not restricted by the blocking status.

[0100] During its dormancy period, the edge collaborative controller acquires the preset actual air pressure of the coal conveying pipe and uses the actual air pressure corresponding to the moment the target coal feeding speed is issued as the reference air pressure. The drop value of the actual air pressure is the difference between the reference air pressure and the current actual air pressure. The pressure drop rate of the actual air pressure is obtained by dividing the actual air pressure difference between adjacent sampling times by the preset sampling period. When the drop value of the actual air pressure is greater than the preset drop threshold, and the actual air pressure is greater than the preset critical threshold, the edge collaborative controller maps the pressure drop rate of the actual air pressure to a flow velocity reduction based on the preset slip model. The preset drop threshold is used to accurately identify local wind resistance changes caused by coal powder slippage in the pipeline network, and it is not a fixed constant.

[0101] Considering the tolerance of solid particle slip fluctuations to different supply air pressures in the main air system, the edge collaborative controller extracts the absolute pressure of the main pipe. When the absolute pressure of the main pipe increases, leading to a larger back pressure fluctuation benchmark in the overall pipeline network, the normal system turbulent pulsation difference will also amplify. Therefore, the edge collaborative controller dynamically adjusts the preset drop threshold based on the positive linear mapping model according to the increase ratio of the absolute pressure of the main pipe. Its empirical range is set to 5% to 10% of the actual steady-state wind pressure benchmark value. This mechanism, which adaptively calibrates the preset drop threshold based on the gas phase dynamics source parameters, satisfies the engineering rigor of parameter calibration, ensuring that the control system can accurately filter normal turbulent pressure difference pulsations under different gas-solid loads. The velocity reduction calculation is only triggered when a sudden drop in pressure difference occurs due to actual coal powder slip, effectively avoiding frequent false triggering of the slip correction model and control oscillations during the dormant period.

[0102] Furthermore, the edge collaborative controller constructs a physical equivalent transformation logic: extracting the pressure drop rate of the actual wind pressure, multiplying its absolute value by the solid-phase delay calculated in the previous step, thereby converting this time difference variable into the preset additional pipe section pressure drop along the coal conveying pipe in the spatial domain. Solid-phase delay is used as a multiplier because it objectively characterizes the entire residence period of solid-phase pulverized coal in the local coal conveying network. The product of this characteristic time and the pressure drop rate truly reflects the accumulated spatial resistance during the slippage.

[0103] The pre-defined slip model can be constructed from the Darcy-Weisbach equation and the particle slip relation. For an inner diameter of... Effective conveying length is The pre-designed coal conveying pipe allows the apparent gas velocity to be determined by... Estimate, among which, The additional pipe section pressure drop calculated above, Darcy's friction factor. The density of the transported gas. The velocity of the pulverized coal can be expressed as... ,in, The carry-over coefficient is used. The edge coordinating controller acquires the current coal feed base speed and the absolute pressure of the main pipeline, and uses the ratio of these two values ​​to equivalently characterize the solid-to-gas ratio state within the pipeline network. Based on the physical law that a higher solid-to-gas ratio leads to more severe particle group slippage interference, resulting in a decrease in gas flow carrying efficiency, the edge coordinating controller dynamically adjusts the carry-over coefficient according to a preset negative exponential decay function when this ratio increases. The value of is determined. By constructing a logical link based on existing parameters, the slip mechanism of gas-solid two-phase coupling is restored, improving the adaptive accuracy of velocity estimation. This represents the slip velocity resulting from particle settling, wall collisions, and turbulent diffusion. The velocity reduction caused by the actual decrease in wind pressure can be expressed as... .

[0104] The edge collaborative controller calculates the remaining duration based on the flow rate reduction and updates the sleep waiting time to the remaining duration. Specifically, the edge collaborative controller dynamically updates the real-time pulverized coal speed using the flow rate reduction, according to... The cumulative distance traveled by pulverized coal is based on the preset coal conveying pipe length. The remaining distance is obtained by subtracting the distance already flown, and the remaining time required to complete the entire journey is calculated by discretely summing the spatial distance elements divided by the real-time speed. The edge collaborative controller then replaces and refreshes the currently preset timer count value with this calculated remaining time.

[0105] To address the physical causal conflict between the master controller's unilateral extension of the preset timer and the preset absolute time already locked at the slave node's underlying layer, the edge collaborative controller constructs a timestamp dynamic overwrite service link: During the sleep period, the edge collaborative controller adheres to the system constraint of shielding control update instructions, namely, freezing the issuance and updating of service-level valve opening values, maintaining the basic opening of the main air valve and the basic opening of the burnout air valve, as well as the calculated burnout air valve opening increment and the main air valve compensation increment, unchanged. Under this architectural constraint, when the sleep waiting time is updated to the remaining time, the edge collaborative controller extracts this remaining time and, in conjunction with the clock mapping, recalculates the delayed preset time in the clock domain.

[0106] Subsequently, the edge collaborative controller invokes a preset synchronization protocol to re-encapsulate the unchanged burnout air valve opening increment and the main air valve compensation increment, along with the updated preset time, into a synchronization frame, and rebroadcasts this synchronization frame to the preset slave nodes in advance. Upon receiving the rebroadcast synchronization frame, the preset slave nodes identify the delayed change in the preset time within the frame and directly overwrite the previously locked old timestamp in their underlying distributed hardware clock. By constructing this dynamic overwrite mechanism based on the reuse of existing communication frames, the business instruction shielding state during the dormant period is penetrated, eliminating the timing mutual exclusion phenomenon caused by unilateral modification of the master-side timer, which prevents dynamic adjustment of the slave's historical timestamp. This mechanism ensures that the preset slave nodes can accurately follow delayed actions under pulverized coal sliding conditions, effectively preventing the local combustion space from falling into an oxygen-rich or fuel-rich runaway state due to gas-solid timing phase misalignment during transitional transients, maintaining the precise balance of the system's air-fuel ratio and stable combustion.

[0107] The preset critical threshold corresponds to the minimum primary air pressure required to maintain the suspension of pulverized coal during transport. This pressure can be calibrated using preset parameters such as the empty pipe resistance, solid-to-gas ratio, and particle terminal settling velocity of the coal conveying pipe. When the actual air pressure is not greater than the preset critical threshold, there is a risk that the pulverized coal will detach from its suspended state and accumulate at the bottom of the pipe. In this case, the edge coordination controller will interrupt the coordinated control, terminate the dormancy period, and issue a preset cleaning command.

[0108] This allows the underlying layer to synchronously trigger the execution of the burnout valve opening increment and the main air valve compensation increment after the sleep period ends. Specifically, when the preset timer count reaches zero, the edge co-controller determines that the sleep period has ended, allowing the underlying layer to synchronously trigger the execution of the burnout valve opening increment and the main air valve compensation increment. At the physical timing alignment level, this determination point strictly corresponds to the preset time when the local distributed hardware clock related to the clock mapping within the preset slave node arrives at the preset time encapsulated in the synchronization frame (or after dynamic overwriting and updating). At this time, without the master control end issuing an active trigger command, the issued command can automatically trigger the servo controlled entity to execute the burnout valve opening increment and the main air valve compensation increment when the preset time is reached. This architecture of macro-determination and hardware clock linkage triggering resolves the timing mutual exclusion phenomenon between the master control timer soft clock and the slave hardware clock, avoids the time lag caused by the instruction parsing time, and ensures high-precision synchronization of control commands. The two servo electric regulating valves update the target position according to the same preset time in the synchronization frame. By inserting the sleep waiting time between the time node corresponding to the coal feeding target speed and the time node corresponding to the triggering gas phase command, the starting point of the gas-solid two-phase control signal is forcibly staggered, so that the time when the gas phase pressure wave reaches the nozzle section after the gas phase delay matches the time when the coal powder reaches the nozzle section after the solid phase delay.

[0109] This application also discloses a preheater staged combustion precision air distribution and pulverized coal injection coordinated control system, which adopts a virtual functional module architecture and a physical hardware architecture. For example... Figure 3 As shown, the virtual functional module architecture cascades data acquisition module, state locking module, incremental calculation module, delay calculation module, and collaborative execution module in sequence along the data flow direction.

[0110] The data acquisition module's input is connected to various sensors, and its output carries the preheater inter-zone pressure difference, denitrification zone oxygen content, main pipe absolute pressure, main pipe absolute temperature, and pulverized coal charge pulses. The state locking module calculates the rate of decrease in denitrification zone oxygen content based on the denitrification zone oxygen content. When the preheater inter-zone pressure difference is lower than a preset lower limit and the rate of decrease in denitrification zone oxygen content changes from negative to positive, the current steady-state parameters are extracted and assigned to the corresponding values ​​of the main air valve basic opening, burnout air valve basic opening, and coal feed basic speed, and then locked. The state locking module internally has preset sampling period parameters, preset data windows, preset number of periods, and preset lower pressure difference limits. Its output carries the main air valve basic opening, burnout air valve basic opening, and coal feed basic speed.

[0111] The incremental calculation module is used to calculate the increment of the burnout air valve opening based on the deviation between the preheater inter-zone pressure difference and the preset target pressure difference; and to calculate the main air valve compensation increment based on the oxygen mass flow conservation rule by combining the absolute pressure and absolute temperature of the main pipe.

[0112] In the delay calculation module, the square root of the product of the preset adiabatic index, the preset gas constant, and the absolute temperature of the main pipe corresponds to the fluid sound velocity, and the preset ratio of the main duct length to the fluid sound velocity corresponds to the gas phase delay. The extreme value positions of the cross-correlation function of the two charge sequences correspond to the extreme value time difference, the preset interval to the extreme value time difference corresponds to the initial velocity of the pulverized coal, the preset ratio of the coal conveying pipe length to the initial velocity of the pulverized coal corresponds to the solid phase delay, and the difference between the solid phase delay and the gas phase delay corresponds to the dormancy waiting time.

[0113] After generating the sleep waiting time, the incremental calculation module obtains this time and activates the servo limit saturation constraint structure. The sum of the main air valve compensation increment and the main air valve base opening corresponds to the expected opening. The state where the expected opening is not less than the preset opening threshold corresponds to the command truncation state. The difference between the expected opening and the preset opening threshold is combined with the main pipe gas density, and the sleep waiting time is used as the integral conversion time window to output the anoxic mass. The anoxic mass is combined with the preset carbon-oxygen ratio to correspond to the equivalent carbon content. The equivalent carbon content is combined with the variable frequency coal feeder mass flow rate-speed calibration coefficient and the speed deduction corresponding to the sleep waiting time. The constraint output of the incremental calculation module includes the preset opening threshold, anoxic mass, equivalent carbon content, and speed deduction.

[0114] The collaborative execution module determines and issues the target coal feeding speed based on the base coal feeding speed, simultaneously issues the burnout air valve opening increment and the main air valve compensation increment, and initiates a dormancy period with a duration equal to the dormancy waiting time. During the dormancy period, control update commands are blocked, and the base openings of the main air valve and burnout air valve are maintained. This allows the underlying layer to synchronously trigger the execution of the burnout air valve opening increment and the main air valve compensation increment after the dormancy period ends. The preset timer count value returning to zero corresponds to the state where the dormancy period is determined to have ended and the underlying layer is ready to synchronously trigger execution. The collaborative execution module also has a dynamic extrapolation and correction data structure for the dormancy period. The actual air pressure drop rate is substituted into the preset slip model using the aforementioned constructed physical equivalent transformation logic to correspond to the flow rate reduction. The result of the flow rate reduction calculation corresponds to the remaining time.

[0115] The physical hardware architecture includes an edge co-controller, processor, memory, hardware clock, analog-to-digital converter interface, digital input / output interface, industrial Ethernet communication interface, fieldbus communication interface, various sensors, a variable frequency coal feeder, and servo-electric regulating valves installed in the main air branch and the burnout air branch respectively. For example... Figure 2 As shown, the edge co-controller, which integrates a processor, memory, hardware clock, and programmable logic array hard core, acts as the master control node and establishes a high-speed interactive link with the servo electric regulating valve at the controlled end via the EtherCAT communication bus. Among the aforementioned virtual functional modules, the data acquisition module, state locking module, incremental calculation module, and co-execution module are implemented by the processor reading and executing the computer program in memory.

[0116] In the physical architecture, this delay calculation module is specifically manifested as a programmable logic array (PLA) hard core within the edge co-controller. This PLA hard core is equipped with an independent multiply-accumulator pipeline for hardware-level acceleration of cross-correlation operations and the square root of the fluid sound velocity. After the processor parses the arithmetic logic of the solid-phase delay and the gas-phase delay, it writes the difference between them in two's complement form into a dedicated timer register within the PLA, which serves as the physical time base for the delay calculation module. Simultaneously, the PLA uses its internal phase-locked loop to multiply the hardware clock, decrementing the dedicated timer register with nanosecond-level precision to provide a precise physical time base for the sleep period. By configuring the aforementioned underlying hardware physical links, the execution latency and clock jitter caused by operating system soft interrupt scheduling in conventional systems are effectively eliminated, ensuring high-precision physical synchronization performance during control flow sleep and wake-up.

[0117] In summary, by pre-calculating and extracting the logic for the parameter decay rate and basic state parameters in the main step, a rigorous self-consistency between the control timing and data generation dependency is achieved, eliminating the logical causal gap caused by variables being invoked before they are generated. At the same time, by clearly defining the underlying physical actions as the accompanying execution result of the single downward instruction issued by the main control end, the instruction issuing entity and the physical execution entity are decoupled, the legal risks of multi-entity mixed execution are resolved, and the independence and overall robustness of the system control execution are improved.

[0118] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for coordinated control of precise air distribution and pulverized coal injection in staged combustion of a preheater, characterized in that, include: Obtain the pressure difference between the preheater zones, the oxygen content in the denitrification zone, the absolute pressure of the main pipe, the absolute temperature of the main pipe, and the charge pulse of the pulverized coal; Based on the oxygen content in the denitrification zone, the rate of decrease in oxygen content in the denitrification zone was calculated. When the pressure difference between the preheater zones is lower than the preset lower limit of the pressure difference and the rate of decrease of oxygen in the denitrification zone changes from negative to positive, the current steady-state parameters are extracted, and the current steady-state parameters are assigned to the main air valve basic opening, the burnout air valve basic opening and the coal feeding basic speed respectively, and locked. Based on the deviation between the preheater inter-zone pressure difference and the preset target pressure difference, the burnout air valve opening increment is calculated; Based on the absolute pressure and absolute temperature of the main pipe, the compensation increment of the main air valve is calculated according to the oxygen mass flow conservation rule. The fluid sound velocity is calculated based on the absolute temperature of the main pipe, and the gas phase delay is calculated in combination with the preset main duct length. The initial velocity of the pulverized coal is obtained by performing cross-correlation calculation on the charge pulse of the pulverized coal, and the solid phase delay is calculated by combining the preset coal conveying pipe length. The difference between the solid-phase delay and the gas-phase delay is calculated and used as the dormancy waiting time. The target coal feeding speed is determined and issued based on the basic coal feeding speed. Simultaneously, the burnout air valve opening increment and the main air valve compensation increment are issued, and a dormancy period with a duration equal to the dormancy waiting time is started. During the dormancy period, control update commands are blocked to maintain the basic opening of the main air valve and the basic opening of the burnout air valve. After the dormancy period ends, the burnout air valve opening increment and the main air valve compensation increment are triggered synchronously.

2. The method for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater according to claim 1, characterized in that, The calculation of the rate of decrease in oxygen content in the denitrification zone based on the oxygen content in the denitrification zone includes: The pressure difference across the preheater and the oxygen content in the denitrification zone are extracted synchronously at a preset sampling period and stored in a preset data window to construct a time series. The oxygen content in the denitrification zone in the time series is differentially calculated to obtain the rate of decrease of oxygen content in the denitrification zone. When the inter-zone pressure difference of the preheater is lower than the preset lower limit of pressure difference and the rate of decrease of oxygen in the denitrification zone changes from negative to positive, the current steady-state parameters are extracted, and the current steady-state parameters are respectively assigned to the basic opening degree of the main air valve, the basic opening degree of the burnout air valve, and the basic rotational speed of the coal feeder, and locked, including: When the pressure difference across the preheater zones is lower than the preset lower limit of pressure difference for a consecutive preset number of cycles, and the rate of decrease in oxygen content in the denitrification zone changes from negative to positive, the current steady-state parameter is extracted. The current steady-state parameters are assigned the corresponding values ​​to the main air valve base opening, the burnout air valve base opening, and the coal feed base rotation speed, and then locked.

3. The method for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater according to claim 1, characterized in that, The calculation of the main air valve compensation increment based on the oxygen mass flow conservation rule, combining the absolute pressure and absolute temperature of the main pipe, includes: Calculate the gas density in the main pipe based on the absolute pressure and absolute temperature of the main pipe. By combining the gas density in the main pipe with the increase in the opening degree of the burnout air valve, the oxygen diversion variable is calculated; Based on the preset oxygen value and the oxygen diversion variable, the main wind compensation amount is deduced. Based on a preset mapping relationship, the main air compensation amount is converted into the main air valve compensation increment.

4. The method for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater according to claim 3, characterized in that, After calculating the difference between the solid-phase delay and the gas-phase delay as the dormancy waiting time, and before determining and issuing the target coal feeding speed based on the base coal feeding speed, the process further includes: The expected opening is obtained by summing the compensation increment of the main air valve with the basic opening of the main air valve. When the expected opening is not less than the preset opening threshold, the instruction is truncated according to the preset opening threshold, and the opening difference between the expected opening and the preset opening threshold is extracted. Based on the gas density in the main pipe, the opening difference is converted into oxygen-deficient mass; Based on the preset carbon-oxygen ratio, the oxygen-deficient mass is converted into an equivalent carbon content, and the speed reduction is calculated. The step of determining and issuing the target coal feeding speed based on the basic coal feeding speed includes: subtracting the speed deduction amount from the basic coal feeding speed to obtain the target coal feeding speed and issuing it.

5. The method for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater according to claim 1, characterized in that, The step of calculating the fluid sound velocity based on the absolute temperature of the main pipe and calculating the gas phase delay in combination with the preset main duct length includes: Obtain the preset adiabatic index and preset gas constant; The fluid velocity is obtained by taking the square root of the product of the preset adiabatic index, the preset gas constant, and the absolute temperature of the main pipe. The gas phase delay is obtained by dividing the preset main duct length by the fluid sound velocity.

6. The method for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater according to claim 1, characterized in that, Obtaining the coal powder charge pulse includes: extracting the charge sequences output by two electrostatic nodes with a preset spacing, and using them as the coal powder charge pulse; The step of performing cross-correlation calculations on the pulverized coal charge pulses to obtain the initial velocity of the pulverized coal, and calculating the solid-phase delay in conjunction with the preset coal conveying pipe length, includes: Perform cross-correlation calculations on the pulverized coal charge pulses to extract the extreme value time difference; Divide the preset spacing by the extreme time difference to calculate the initial velocity of the pulverized coal; The solid phase delay is calculated by dividing the preset coal conveying pipe length by the initial velocity of the pulverized coal.

7. The method for coordinated control of precise air distribution and pulverized coal injection in staged combustion of a preheater according to claim 1, characterized in that, During the dormancy period, it also includes: Obtain the preset actual air pressure of the coal conveying pipe; When the actual wind pressure drop value is greater than the preset drop threshold and the actual wind pressure is greater than the preset critical threshold, the pressure drop rate of the actual wind pressure is mapped to the velocity reduction based on the preset slip model. The remaining duration is calculated based on the flow rate reduction, and the sleep waiting duration is updated to the remaining duration. When the actual wind pressure is not greater than the preset critical threshold, the method of precise air distribution and pulverized coal injection coordinated control of staged combustion in the preheater is interrupted, the dormancy period is terminated, and a preset cleaning command is issued.

8. The method for precise air distribution and pulverized coal injection coordinated control of staged combustion in a preheater according to claim 1, characterized in that, The simultaneous issuance of the burnout damper opening increment and the main damper compensation increment, and the initiation of the dormancy period with a duration equal to the dormancy waiting time, includes: Invoke the preset synchronization protocol; Based on the synchronization protocol, the burnout valve opening increment and the main air valve compensation increment are simultaneously sent within the same preset scanning cycle. Write the sleep waiting time into a preset timer to start the sleep period; The simultaneous triggering of the burnout damper opening increment and the main damper compensation increment after the dormancy period ends includes: When the count value of the preset timer reaches zero, the dormancy period is determined to have ended, and the burnout air valve opening increment and the main air valve compensation increment are triggered synchronously.

9. The method for coordinated control of precise air distribution and pulverized coal injection in staged combustion of a preheater according to claim 8, characterized in that, Based on the synchronization protocol, within the same preset scanning cycle, the synchronous transmission of the burnout valve opening increment and the main air valve compensation increment includes: Based on the synchronization protocol, a preset clock mapping between the master control terminal and the preset slave node is established; The burnout air valve opening increment and the main air valve compensation increment are combined and encapsulated into a synchronization frame; The synchronization frame is broadcast to the preset slave node in advance, and execution is triggered synchronously when the clock mapping reaches the preset time.

10. A preheater staged combustion precise air distribution and pulverized coal injection coordinated control system, used to execute the preheater staged combustion precise air distribution and pulverized coal injection coordinated control method as described in any one of claims 1-9, characterized in that, include: The data acquisition module is used to acquire the pressure difference between the preheater zones, the oxygen content in the denitrification zone, the absolute pressure of the main pipe, the absolute temperature of the main pipe, and the charge pulse of the pulverized coal. The state locking module is used to calculate the rate of decrease of oxygen in the denitrification zone based on the oxygen content in the denitrification zone; when the pressure difference between the preheater zones is lower than the preset pressure difference lower limit and the rate of decrease of oxygen in the denitrification zone changes from negative to positive, the current steady-state parameters are extracted, and the current steady-state parameters are assigned to the main air valve basic opening degree, the burnout air valve basic opening degree and the coal feed basic speed respectively, and the locking is performed. The incremental calculation module is used to calculate the increment of the burnout air valve opening based on the deviation between the cross-zone pressure difference of the preheater and the preset target pressure difference. Based on the absolute pressure and absolute temperature of the main pipe, the compensation increment of the main air valve is calculated according to the oxygen mass flow conservation rule. The delay calculation module is used to calculate the fluid sound velocity based on the absolute temperature of the main pipe and calculate the gas phase delay in combination with the preset main duct length. Perform cross-correlation calculation on the pulverized coal charge pulse to obtain the initial velocity of the pulverized coal, and calculate the solid phase delay in combination with the preset coal conveying pipe length; calculate the difference between the solid phase delay and the gas phase delay as the sleep waiting time; The collaborative execution module is used to determine and issue the target coal feeding speed based on the basic coal feeding speed, simultaneously issue the burnout air valve opening increment and the main air valve compensation increment, and initiate a dormancy period with a duration equal to the dormancy waiting time; during the dormancy period, control update commands are blocked, and the basic opening of the main air valve and the basic opening of the burnout air valve are maintained; after the dormancy period ends, the burnout air valve opening increment and the main air valve compensation increment are synchronously triggered for execution.

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