Temperature coordinated control system for a group of roasters

Abstract

The present application relates to the technical field of roaster control, in particular to a temperature cooperative control system for roaster group, comprising: a thermal field reconstruction module, used for collecting the fireway temperature and oxygen content of each furnace chamber and obtaining the current temperature deviation of each furnace chamber; a channeling flow feedforward module, used for calculating the volatile release indication based on the fireway temperature and oxygen content of the upstream furnace chamber, and weighting and accumulating to deduce the channeling flow heat disturbance feedforward quantity acting on the downstream furnace chamber; a cooperative control module, used for constructing a feedforward compensation type cascade cooperative control law to calculate the gas valve opening degree; and a parameter updating module, used for rolling shifting the volatile release indication and the conversion coefficient to update the cooperative parameters when the fire changing action is triggered. The present application avoids the temperature spike of the downstream material box caused by the channeling flow heat disturbance from the control structure.

Description

Technical Field

[0001] This invention relates to the field of roasting furnace control technology, and more specifically, to a temperature coordination control system for roasting furnace groups. Background Technology

[0002] The quality of carbon products is highly dependent on the temperature history curve of pitch volatilization, polymerization and carbonization in the roasting process. Modern carbon enterprises usually use ring roasting furnace groups for continuous production. A group of furnaces consists of dozens of furnace chambers connected in series according to the flame system. The combustion of gas in the fire channel gradually heats the green blanks filled in the material box, forming a moving flame section for preheating, heating, heat preservation and cooling. The entire process cycle can last for hundreds of hours.

[0003] The temperature control of existing roasting furnace groups usually adopts a distributed PID loop, that is, each furnace chamber or each fire channel independently deploys temperature acquisition points and gas valve actuators. The controller adjusts the gas flow and negative pressure according to the deviation between the current temperature of the measuring point and the set value of the process curve, so that the temperature of each fire channel steadily rises along the process curve. The host computer collects the real-time temperature of each furnace chamber through the SCADA system and advances the flame system as a whole according to the preset flame switching cycle, realizing the sequential movement of the flame segment in the furnace group.

[0004] However, adjacent furnace chambers share the same flue wall and duct. Volatile matter released from the upstream furnace chamber can directly enter the downstream furnace chamber along the flue gas flow and undergo secondary combustion and heat release, resulting in a significant heat cross-flow effect between the furnace chambers. When the upstream preheating section furnace chamber experiences explosive volatile matter release within a certain temperature window due to a high asphalt content in the green billet, this volatile matter will enter the downstream heating section furnace chamber with the flue gas flow and undergo secondary combustion and heat release. This causes the downstream furnace chamber's flue temperature to experience a positive temperature rise pulse far exceeding the PID adjustable rate in a very short time. The independent PID loop of the downstream furnace chamber can only passively close the gas valve of its own furnace chamber after sensing the over-temperature, and cannot suppress the actual heat source in the reverse direction. Ultimately, this leads to a local temperature peak in the downstream material box that exceeds the process limit, causing defects such as surface cracks and uneven bulk density in the anode blocks. This cross-furnace thermal disturbance caused by volatile matter cross-flow cannot be identified and suppressed in advance under the traditional single-furnace independent PID architecture. Summary of the Invention

[0005] To address the existing technical problem that the distributed PID control architecture cannot identify and collaboratively suppress downstream furnace temperature pulses caused by upstream volatile matter crossflows in advance, this invention provides a temperature collaborative control system for calcining furnace groups.

[0006] This invention provides a temperature collaborative control system for a group of roasting furnaces, comprising: a thermal field reconstruction module, used to collect the flue temperature and oxygen content of each furnace chamber in the roasting furnace group, arrange them along the flame propagation direction in the furnace chamber dimension, reconstruct a thermal field profile that unfolds along the flue gas flow direction, and identify the flame front on the thermal field profile to obtain the current temperature deviation of each furnace chamber; and a crossflow feedforward module, used to calculate the volatile matter release indication of the upstream furnace chamber based on the flue temperature and oxygen content of the upstream furnace chamber, and forward the volatile matter release indication of each upstream furnace chamber along the gas flow direction. The flow direction is weighted and accumulated according to the furnace chamber spacing to deduce the feedforward amount of crossflow thermal disturbance acting on the downstream furnace chamber; the cooperative control module is used to inject the feedforward amount of crossflow thermal disturbance into the deviation calculation of the proportional and integral terms through the conversion coefficient, and maintain the dependence of the differential term on the temperature deviation to construct a feedforward compensated cascade cooperative control law to calculate the gas valve opening of the downstream furnace chamber; the parameter update module is used to roll-shift the volatile matter release indication and the conversion coefficient along the furnace chamber number when each fire switching action is triggered, so as to update the cooperative parameters rollingly with the fire switching cycle.

[0007] By incorporating the measured temperatures of each furnace chamber within the same flame system into the thermal field profile framework, the scale of the incoming crossflow heat can be quantitatively estimated before the downstream furnace chamber temperature measurement points respond. This allows for the early suppression of crossflow thermal disturbances at the control structure level, effectively preventing downstream material box temperature spikes from exceeding the process limit.

[0008] Preferably, the thermal field reconstruction module includes: a matrix construction unit, used to read the flue temperature and oxygen content of each furnace chamber at a fixed sampling period to form a two-dimensional temperature matrix with the furnace chamber number as the row and the flue depth as the column; and a profile generation unit, used to regard at least two adjacent furnace chambers currently in the same flame system as a whole, arrange the two-dimensional temperature matrix along the flame propagation direction in the furnace chamber dimension, and finally obtain a thermal field profile that unfolds along the flue airflow direction.

[0009] Preferably, the thermal field reconstruction module further includes: a front identification unit, used to identify the position with the largest temperature gradient on the thermal field profile as the flame front; and a deviation acquisition unit, used to compare the measured temperature of each furnace chamber upstream and downstream of the flame front with the set value of the process curve at the corresponding flame segment position point by point, and finally obtain the current temperature deviation of each furnace chamber.

[0010] Preferably, the crossflow feedforward module includes: a margin calculation unit, used to determine whether the flue temperature of the upstream furnace chamber is within the precipitation sensitive window, and to obtain the amount by which the flue temperature exceeds the lower edge of the precipitation sensitive window as the temperature margin; an oxygen consumption intensity unit, used to calculate the amount by which the oxygen content decreases relative to the no-fire calibration baseline as the flue oxygen consumption intensity; and an indicator generation unit, used to multiply the temperature margin by the flue oxygen consumption intensity to finally obtain the volatile matter release indicator of the upstream furnace chamber.

[0011] By constructing indicators of volatile matter release that rely solely on two objectively measurable parameters—flue temperature and flue oxygen content—the scale of the impending crossflow heat can be quantitatively estimated before the downstream furnace temperature measuring point responds, providing a physically verifiable input signal for the feedforward compensation of the subsequent control law.

[0012] Preferably, the crossflow feedforward module further includes: a distance acquisition unit for acquiring the physical distance from the upstream furnace chamber to the downstream furnace chamber along the fire channel; and a feedforward calculation unit for weighted summation of the volatile matter release indication of each upstream furnace chamber by the physical distance based on the current fire channel airflow direction of the flame system, so as to finally obtain the crossflow thermal disturbance feedforward amount acting on the downstream furnace chamber.

[0013] Preferably, the collaborative control module includes: a virtual deviation unit, used to subtract the product of the conversion factor and the feedforward amount of crossflow thermal disturbance from the temperature deviation to obtain a virtual positive temperature deviation; and a control law construction unit, used to take the virtual positive temperature deviation as the input of the proportional and integral terms, and the original temperature deviation as the input of the differential term, and finally construct a feedforward compensation type cascade collaborative control law.

[0014] By embedding the feedforward amount of crossflow thermal disturbance into the deviation calculation of the proportional and integral terms, it is equivalent to allowing the controller to sense a virtual positive temperature deviation in advance, thereby actively closing the gas valve of the furnace chamber before the actual temperature rise pulse arrives, reserving absorption space for the crossflow heat that is about to be injected.

[0015] Preferably, the collaborative control module further includes: a regression sample unit, used to retrieve the most recent consecutive samples up to the current fire switch action. The regression sample consists of paired records of the peak value of upstream volatile matter release indicator and the corresponding peak value of downstream temperature deviation for each completed fire-switching cycle. The preset positive integer is used as the coefficient update unit, which is used to calculate the current regression slope using the sliding window least squares method and assign it to the conversion coefficient.

[0016] Preferably, the collaborative control module further includes: a crossflow upper limit judgment unit, used to determine whether the crossflow thermal disturbance feedforward amount in the downstream furnace chamber exceeds the crossflow thermal disturbance feedforward upper limit set in advance according to the process curve of the flame section where the corresponding furnace chamber is currently located; and a collaborative constraint unit, used to reduce the gas increment in the upstream furnace chamber according to the recovery ratio by using the ratio of the crossflow thermal disturbance feedforward amount exceeding the crossflow thermal disturbance feedforward upper limit to the crossflow thermal disturbance feedforward upper limit as the recovery ratio, so as to apply collaborative constraint to the gas valve opening of the upstream furnace chamber.

[0017] Preferably, the parameter update module includes: a window correction unit, used for reading the green batch and asphalt content information to retrieve the initial value of the precipitation sensitive window for the preheating section furnace chamber newly added to the flame system, and correcting the lower edge of the precipitation sensitive window with the furnace chamber temperature corresponding to the start of continuous decrease in measured flue oxygen content, and correcting the upper edge of the precipitation sensitive window with the furnace chamber temperature corresponding to the rate of decrease in oxygen content falling back to the judgment threshold, thus completing the adaptive correction of the window boundary; a ledger archiving unit, used for pairing the recorded peak value of volatile matter release indication with the corresponding downstream temperature deviation peak value for the cooling section furnace chamber that has exited the flame system and storing it in the historical ledger; and a rolling shift unit, used for rolling shifting the maintained volatile matter release indication and conversion coefficient along the furnace chamber number, and finally rolling update of the collaborative parameters with the flame replacement cycle.

[0018] By synchronously performing the rolling shift of the collaborative parameters and the batch adaptive correction of the precipitation window of the new furnace chamber during each furnace change operation, the collaborative control law can be adaptively adjusted according to the current furnace chamber combination and the characteristics of the green batch, thereby improving the adaptability to changes in continuous production conditions and reducing the risk that the static parameter configuration will gradually fail due to the drift of operating conditions in multiple batches of continuous production.

[0019] Preferably, the temperature collaborative control system for the roasting furnace group also includes a collaborative control host, a fieldbus, multiple armored thermocouples, a negative pressure sensor and a flue gas oxygen content sensor.

[0020] Armored thermocouples are arranged along the depth of the flue in each furnace chamber. Negative pressure sensors and flue gas oxygen content sensors are set at the common flue inlet. The collaborative control host is connected to the armored thermocouples, negative pressure sensors and flue gas oxygen content sensors via fieldbus, and reads the flue temperature, flue negative pressure and oxygen content of each furnace chamber according to a fixed sampling period.

[0021] By adopting the above technical solution, the present invention deploys the thermal field reconstruction module, the crossflow feedforward module, the collaborative control module and the parameter update module in the collaborative control host. The collaborative control host loads and executes the processing logic corresponding to each module, thereby forming a temperature collaborative control system that can be directly applied to the roasting furnace group on site, which is convenient to use.

[0022] The present invention has the following beneficial effects: This invention reconstructs the flue temperature of adjacent furnace chambers in a roasting furnace group into a thermal field profile that unfolds with the flame segment. It identifies the pattern that the volatiles released in the upstream preheating section are carried downstream by the airflow and undergo secondary combustion and heat release. It constructs an indicator quantity of volatile release and feedforward thermal disturbance quantity that depends only on the flue temperature and the oxygen content in the flue.

[0023] Furthermore, this invention introduces a feedforward compensation term into the traditional PID control law and applies a cooperative constraint to the upstream furnace chamber, enabling the downstream furnace chamber to actively close the gas valve to reserve absorption space before the crossflow heat arrives, thus achieving effective control of the core pain point of downstream temperature pulses caused by upstream volatile crossflow. Attached Figure Description

[0024] Figure 1 This is a flowchart of a temperature-coordinated control system for a group of roasting furnaces. Figure 2 This is a comparison diagram of the temperature distribution in the thermal field profile of the roasting furnace group. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0026] This invention discloses a temperature collaborative control system for calcining furnace groups, referring to... Figure 1 It includes a thermal field reconstruction module, a crossflow feedforward module, a cooperative control module, and a parameter update module, corresponding to steps S1 to S4 respectively: The thermal field profile and current temperature deviation of each furnace chamber output by the thermal field reconstruction module are sent to the crossflow feedforward module. The crossflow thermal disturbance feedforward quantity output by the crossflow feedforward module is sent to the collaborative control module. The gas valve opening output by the collaborative control module is used to drive the gas valve actuator of each furnace chamber. The parameter update module rolls and shifts the volatile matter release indication and conversion coefficient each time the fire switching action is triggered, and feeds them back to the crossflow feedforward module and the collaborative control module respectively. The modules are connected sequentially through the data interface in the collaborative control host.

[0027] S1, Thermal Field Reconstruction Module, is used to reconstruct the thermal field profile to obtain temperature deviation.

[0028] In this embodiment, the thermal field reconstruction module includes a matrix construction unit, a profile generation unit, a front identification unit, and a deviation acquisition unit: the matrix construction unit is used to read the flue temperature and oxygen content of each furnace chamber according to a fixed sampling period, forming a two-dimensional temperature matrix with the furnace chamber number as the row and the flue depth as the column; the profile generation unit is used to treat several adjacent furnace chambers currently in the same flame system as a whole, and arrange the two-dimensional temperature matrix along the flame propagation direction in the furnace chamber dimension to obtain a thermal field profile that unfolds with the flue gas flow direction; the front identification unit is used to identify the position with the largest temperature gradient on the thermal field profile as the flame front; the deviation acquisition unit is used to compare the measured temperature of each furnace chamber upstream and downstream of the flame front with the set value of the process curve at the corresponding flame segment position point by point to obtain the current temperature deviation of each furnace chamber.

[0029] In an optional embodiment, the system arranges multiple sheathed thermocouple measuring points along the depth direction within the flue of each furnace chamber in the roasting furnace group. Simultaneously, a negative pressure sensor and a flue gas oxygen content sensor are arranged at the common flue inlet. All measuring point data are aggregated to the collaborative control host via a fieldbus. The controller reads the flue temperature, flue negative pressure, and oxygen content of each furnace chamber at a fixed sampling period, forming a two-dimensional temperature matrix with the furnace chamber number as the row and the flue depth as the column. The specific number of sheathed thermocouples arranged along the flue depth direction can be determined based on the actual length of the flues in each furnace group and the required temperature measurement resolution; for example, 3 to 5 measuring points can be arranged in each flue to ensure the spatial representativeness of the temperature profile.

[0030] Furthermore, existing distributed control schemes treat these temperature data as isolated time series, feeding them into independent PID loops for each furnace chamber, ignoring the spatial continuity of the flame segments. This scheme treats several adjacent furnace chambers currently within the same flame system as a whole. The specific number of chambers in each segment is determined based on the furnace group size and fire switching cycle. For example, the preheating segment can encompass 2 to 3 chambers, the heating segment 2 chambers, the insulation segment 1 chamber, and the cooling segment 2 to 3 chambers. The two-dimensional temperature matrix is ​​arranged along the flame propagation direction in the furnace chamber dimension, resulting in a thermal field profile that unfolds along the direction of the fire channel airflow. This holistic perspective is a prerequisite for all subsequent cross-furnace chamber collaborative judgments to be valid; single-furnace isolated schemes cannot support such cross-chamber comparisons from a data structure perspective.

[0031] Next, the controller identifies the location with the largest temperature gradient on the acquired thermal field profile as the flame front, and compares the measured temperature of each furnace chamber upstream and downstream of the flame front with the set value of the process curve at the corresponding flame section point by point to obtain the current temperature deviation of each furnace chamber. ,in The numbers represent the relative positions of the furnace chambers within the flame system; negative values ​​indicate the upstream preheating section, and positive values ​​indicate the downstream heating section. It should be noted that there are many other sensor configuration methods in the art capable of reconstructing the thermal field profile. Those skilled in the art can select different measurement point combinations based on the actual flue structure of the furnace group and the on-site wiring conditions. The above arrangement is merely a typical example.

[0032] In this way, by incorporating the measured temperatures of each furnace chamber within the same flame system into the thermal field profile framework, the controller obtains a complete temperature distribution map that unfolds continuously in space. This provides a complete input basis for identifying abnormal volatile precipitation in the upstream furnace chamber and transmitting thermal disturbances downstream, avoiding the blind spot where thermal disturbance signals are not perceived before being transmitted downstream from a single furnace perspective.

[0033] S2, Crossflow Feedforward Module, is used to calculate the volatile release indication to deduce the crossflow thermal disturbance feedforward.

[0034] In this embodiment, the crossflow feedforward module includes a margin calculation unit, an oxygen consumption intensity unit, an indicator generation unit, a distance acquisition unit, and a feedforward deduction unit: The margin calculation unit is used to determine whether the flue temperature of the upstream furnace chamber is within the precipitation sensitive window, and to acquire the amount by which the flue temperature exceeds the lower edge of the precipitation sensitive window as the temperature margin; the oxygen consumption intensity unit is used to calculate the amount by which the oxygen content decreases relative to the no-fire calibration baseline as the flue oxygen consumption intensity; the indicator generation unit is used to multiply the temperature margin by the flue oxygen consumption intensity to obtain the volatile matter release indicator of the upstream furnace chamber; the distance acquisition unit is used to acquire the physical distance along the flue from the upstream furnace chamber to the downstream furnace chamber; the feedforward deduction unit is used to divide the volatile matter release indicator of each upstream furnace chamber by the physical distance and perform weighted summation according to the current flue airflow direction of the flame system to obtain the crossflow thermal disturbance feedforward amount acting on the downstream furnace chamber.

[0035] In an optional embodiment, the controller anticipates the additional heat that upstream volatile matter release will inject downstream before a temperature pulse occurs in the downstream furnace chamber. The precipitation rate of pitch volatiles in carbon green billets is strongly correlated with the green billet temperature; the volatile matter precipitation rate peaks within a certain sensitive temperature range, and the precipitates undergo secondary combustion and heat release under sufficient oxygen conditions after entering the downstream flue. The controller maintains a volatile matter release indicator for each upstream preheating furnace chamber. This refers to the product of the amount by which the flue temperature exceeds the lower edge of the precipitation-sensitive window (i.e., the temperature margin) and the flue oxygen consumption intensity when the current flue temperature is within the precipitation-sensitive window. The specific definition is as follows: when hour:

[0036] otherwise:

[0037] In the formula, For the first Current flue temperature in the upstream furnace chamber; and To determine the temperatures at the lower and upper edges of the sensitive window, the values ​​were statistically derived from the flue temperature ranges corresponding to the volatile analysis peaks in the historical production log of this furnace group, rather than from manual experience. This refers to the temperature margin of the flue temperature within the precipitation sensitive window, which characterizes the trend of precipitation intensity increasing with increasing temperature. This represents the decrease in oxygen content in the corresponding flue section of the furnace chamber relative to the no-fire calibration baseline, reflecting the intensity of oxygen consumption during the secondary combustion of volatiles, i.e., the flue oxygen consumption intensity.

[0038] Furthermore, the derivation logic of this indicator is unfolded in two layers. The first layer of conditional judgment ensures... Calculations are initiated only after the temperature enters the precipitation-sensitive window, based on the amount by which the flue temperature exceeds the lower edge of the window. This characterizes the trend that precipitation intensity increases with increasing temperature. The larger the value, the greater the excess of the current furnace temperature within the precipitation sensitive window, and the more significant the oxygen consumption in the flue, corresponding to a stronger trend of upstream volatile matter being released and heat being injected downstream; The smaller the value, or even zero, the more it indicates that the furnace chamber has not yet entered the precipitation-sensitive temperature range, or that although it is within the window, no significant oxygen consumption has been detected in the flue. In this case, the contribution to downstream thermal disturbance is considered an ineffective output. (Second layer introduction) Using objective changes in flue gas composition instead of any empirical coefficients, only when oxygen consumption is actually detected in the flue gas duct. This method generates effective output, fundamentally avoiding the misjudgment of precipitation intensity based solely on temperature conditions. The entire calculation involves only subtraction and multiplication, resulting in extremely low computational burden, making it suitable for real-time execution on a collaborative control host at a frequency synchronized with the sampling period.

[0039] Next, the controller obtains the physical distance along the fire channel from the upstream furnace chamber to the downstream furnace chamber based on the current airflow direction of the flame system, and displays the volatile matter release indication for each upstream furnace chamber. Dividing the airflow direction by the physical distance and weighting the sum according to the furnace chamber spacing, the effect on the downstream first... Feedforward of crossflow thermal disturbance in the furnace chamber:

[0040] in For the upstream furnace chamber Downstream furnace chamber The physical distance along the fire channel. This feedforward quantity characterizes the heat injection trend that is already on the airflow path at the current moment but has not yet reached the downstream measuring point. and The correlation is negative; the closer the upstream furnace chamber is, the greater the weight of the thermal disturbance to the downstream. The physical meaning is clear and can be determined by the on-site flue geometry, without any manual parameter adjustment.

[0041] In this way, by constructing indicators of volatile matter release that rely solely on two objectively measurable parameters—flue temperature and flue oxygen content—the controller can quantitatively estimate the scale of the impending crossflow heat before the downstream furnace temperature measuring point responds. This provides a physically verifiable input signal for the feedforward compensation of the subsequent control law, replacing the traditional approach of relying on preset disturbance amplitudes based on manual experience parameters.

[0042] S3, the cooperative control module, is used to construct a feedforward compensation type cascade cooperative control law to calculate the gas valve opening.

[0043] In this embodiment, the collaborative control module includes a virtual deviation unit, a control law construction unit, a regression sample unit, a coefficient update unit, a crossflow upper limit judgment unit, and a collaborative constraint unit: The virtual deviation unit is used to subtract the product of the conversion coefficient and the crossflow thermal disturbance feedforward amount from the temperature deviation to obtain the virtual positive temperature deviation; the control law construction unit is used to use the virtual positive temperature deviation as the input of the proportional and integral terms, and the original temperature deviation as the input of the differential term, to construct a feedforward compensation type cascade collaborative control law to calculate the gas valve opening of the downstream furnace chamber; the regression sample unit is used to use the paired records of the peak value of the upstream volatile matter release indication amount and the peak value of the downstream temperature deviation in the most recent multiple fire switching cycles as regression samples; the coefficient update unit is used to calculate the current regression slope using the sliding window least squares method and assign it to the conversion coefficient; the crossflow upper limit judgment unit is used to determine whether the crossflow thermal disturbance feedforward amount of the downstream furnace chamber exceeds the crossflow upper limit that the corresponding furnace chamber process can withstand; the collaborative constraint unit is used to reduce the gas increment of the upstream furnace chamber according to the recovery ratio when the crossflow upper limit is exceeded, using the ratio of the excess amount to the crossflow upper limit as the recovery ratio.

[0044] In an optional embodiment, the controller improves the traditional PID control law after acquiring the feedforward amount of crossflow thermal disturbance. The traditional PID control law only considers the temperature deviation within the furnace chamber. The original form for calculating the gas valve opening is:

[0045] In the formula For the first Furnace chamber gas valve opening, , , These are the proportional, integral, and derivative coefficients, respectively. Since this control law can only be applied until... The valve only responds passively after the temperature changes from negative to positive or even after overshooting. Its response time is naturally delayed by the actual arrival time of the crossflow heat. Under explosive precipitation conditions, it cannot complete the valve pre-closing action before the overheating occurs.

[0046] Furthermore, this scheme will incorporate feedforward thermal disturbance. The deviation calculation of the proportional and integral terms is intentionally incorporated to maintain the derivative term's relevance to the original temperature deviation. The dependency does not introduce feedforward. This is because the differential term is sensitive to high-frequency signals, and... The valve inherently contains measurement noise. Introducing the feedforward term into the derivative term simultaneously would amplify the noise interference, hindering smooth valve operation. Therefore, the derivative term maintains its original deviation to ensure uninterrupted rapid response to sudden temperature changes. The improved feedforward compensated cascade control law is as follows:

[0047] Compared to the original control law, the deviations in the proportional and integral terms are changed from the original... Replace with The virtual positive temperature deviation is obtained by subtracting the conversion factor and the feedforward amount of crossflow thermal disturbance from the temperature deviation. This is equivalent to allowing the controller to sense a virtual positive temperature deviation in advance, so that it can actively close the gas valve of the furnace chamber before the actual temperature rise pulse arrives, reserving space for the absorption of the crossflow heat that will be injected.

[0048] Next, the conversion factor. The values ​​were not assigned manually, but rather determined by the upstream values ​​in the historical fire-changing cycles of this furnace group. Peak and downstream The slope of the linear regression of the peak value is obtained through online updates. The controller uses the most recent continuous... The regression sample consists of paired records of the peak value of upstream volatile matter release indicator and the corresponding peak value of downstream temperature deviation for each completed fire-switching cycle. As a preset positive integer, the current regression slope is calculated using the sliding window least squares method and assigned to [the specified value]. In the cold start phase, when historical data accumulation is insufficient, The initial value is 1, meaning that the feedforward quantity and temperature deviation are directly proportionally converted with the same dimensions. Once sufficient historical data is available, it will automatically switch to a regression update value to ensure that the coefficient is always anchored to the actual heat transfer characteristics of this furnace group rather than human experience.

[0049] Preset positive integer The settings are based on the stability of the firing cycle of the roasting furnace group, the number of valid pairing records in the historical ledger, and the update sensitivity of the conversion factor; in one embodiment, It can be pre-configured by the collaborative control host and maintained at a fixed value in subsequent fire-swapping operations, or when the number of valid pairing records is insufficient. At this time, the conversion factor will not be updated.

[0050] Meanwhile, to prevent the upstream furnace chamber from excessively releasing volatiles and impacting the downstream in pursuit of its own heating rate, the controller applies a coordinated constraint on the gas valve opening of the upstream furnace chamber: judging the feedforward amount of crossflow thermal disturbance in the downstream furnace chamber. Does it exceed the maximum allowable crossflow limit for the corresponding furnace chamber process? If it exceeds the maximum allowable crossflow limit, then... The ratio of the excess amount exceeding the crossflow limit to the crossflow limit is used as the recovery ratio. The incremental gas flow in the upstream furnace chamber is reduced according to this recovery ratio, which actively slows down the upstream heating rate, allowing it to recover after the downstream has completed heat absorption. It should be noted that there are various control law forms in this field that can achieve feedforward compensation injection. Those skilled in the art can choose different implementation methods according to the actual controller hardware capabilities and process accuracy requirements of the furnace group.

[0051] In this way, by embedding the feedforward amount of crossflow thermal disturbance into the deviation calculation of the proportional and integral terms, and simultaneously applying a cooperative constraint on the gas increment in the upstream furnace chamber, the controller achieves early suppression of crossflow thermal disturbance at the control structure level. This avoids the lag dilemma of traditional single-furnace PID being forced to respond passively only after the heat has reached the downstream measuring point, and effectively suppresses the downstream material box temperature peak before it exceeds the process limit.

[0052] S4, Parameter Update Module, is used to update collaborative parameters on a rolling basis with the fire change cycle.

[0053] In this embodiment, the parameter update module includes a window correction unit, a ledger archiving unit, and a rolling shift unit: The window correction unit is used to read the green batch and asphalt content information of the preheating section furnace chamber newly added to the flame system to retrieve the initial value of the precipitation sensitive window, and correct the lower edge of the precipitation sensitive window with the furnace chamber temperature corresponding to the start of continuous decrease in measured flue oxygen content, and correct the upper edge of the precipitation sensitive window with the furnace chamber temperature corresponding to the rate of decrease in oxygen content falling back to the judgment threshold, thus completing the adaptive correction of the window boundary; The ledger archiving unit is used to pair the recorded peak value of volatile matter release indication with the corresponding downstream temperature deviation peak value of the cooling section furnace chamber that has exited the flame system and store it in the historical ledger; The rolling shift unit is used to roll-shift the maintained volatile matter release indication and conversion coefficient along the furnace chamber number, and roll-up update the collaborative parameters with the flame replacement cycle.

[0054] In an optional embodiment, the flame system of the calcining furnace group is moved forward as a whole according to a fixed flame-changing cycle. The downstream heating section of the previous cycle becomes the insulation section of the new cycle after the flame-changing, while the new preheating section is added to the head of the flame system. The controller maintains the volatile matter release indicator amount each time a flame-changing action is triggered. and conversion factor The furnace chambers are moved along the numbering system to ensure that the coordination relationship is always anchored to the current furnace chamber combination that is actually involved in combustion, thus avoiding misalignment of the coordination parameters and the corresponding furnace chambers before and after the fire change.

[0055] Furthermore, for the preheating section furnace chamber newly added to the flame system, the controller reads the green billet batch and asphalt content information recorded in its charging logbook, and retrieves the precipitation sensitive window of the same batch of green billets from the historical production database. Initial values. Due to differences in the volatile matter characteristics of different batches of green billets, directly using the precipitation window parameters from the previous furnace chamber would lead to issues with the feedforward amount. Distortion occurs in the initial stage when the new furnace chamber enters the precipitation zone. Therefore, the controller uses the furnace temperature corresponding to the point when the oxygen content in the flue gas begins to continuously decrease as the temperature. The correction is based on the furnace temperature at which the oxygen content decreases from its peak to the judgment threshold. The correction is based on the initial value in the historical ledger, plus the incremental deviation of the measured values ​​for this batch, thereby... and The actual values ​​are consistent with the true precipitation initiation temperature and peak temperature of the batch of green billets.

[0056] Next, for the cooling section furnace chamber exiting the flame system, the controller uses the volatile matter release indication recorded during this round of operation. Peak value and corresponding downstream temperature deviation Peak pairings are stored in the historical ledger of this furnace group for continuous updating. The regression model. As peak paired samples in the historical ledger accumulate, the fitting accuracy of the sliding window least squares regression gradually improves, and the conversion coefficient... The ability to characterize the actual heat transfer characteristics of this furnace group is also enhanced, enabling the feedforward strength of the cooperative control law to continuously self-calibrate as production conditions change. It should be noted that the specific implementation method for the rolling update of cooperative parameters with the ignition cycle can be flexibly selected by those skilled in the art based on the data storage architecture of the control host and the access method of the ignition trigger signal.

[0057] In this way, by simultaneously completing the rolling shift of collaborative parameters, batch adaptive correction of the precipitation window of the new furnace chamber, and regression sample archiving of historical data of the exiting furnace chamber during each furnace change operation, the collaborative control law always maintains a match with the current furnace chamber combination and green batch characteristics throughout the continuous production process, reducing the hidden danger that static parameter configuration gradually fails due to operating condition drift in multi-batch continuous production.

[0058] A temperature collaborative control system for a group of roasting furnaces also includes a collaborative control host, a fieldbus, multiple sheathed thermocouples, a negative pressure sensor, and a flue gas oxygen content sensor. The sheathed thermocouples are arranged along the depth of the flue in each furnace chamber, and the negative pressure sensor and the flue gas oxygen content sensor are set at the common flue inlet. The collaborative control host is connected to the sheathed thermocouples, negative pressure sensor, and flue gas oxygen content sensor via the fieldbus, and reads the flue temperature, flue negative pressure, and oxygen content of each furnace chamber according to a fixed sampling period.

[0059] The system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces, the settings and functions of which are known in the art and will not be described in detail here.

[0060] Reference Figure 2 The horizontal axis represents the furnace chamber number, and the vertical axis represents the flue temperature. Figure 2The measured flue temperatures of the existing method and the present invention are represented by bar charts. Process curve setpoints are indicated by broken lines, and sensitive areas for volatilization analysis are marked by background blocks. It can be observed that within the precipitation-sensitive areas, the measured flue temperatures of the existing method show a significant positive deviation from the setpoints. In contrast, the present invention, through coordinated control, ensures that the measured temperatures of each furnace chamber within this area closely follow the process curve, resulting in a more uniform and stable overall thermal field profile. This indicates that the present invention effectively suppresses localized temperature distortions caused by crossflow thermal disturbances in the thermal field profile.

[0061] In the description of this specification, "multiple" or "several" means at least two, such as two, three or more, unless otherwise expressly and specifically defined.

Claims

1. A temperature coordination control system for a group of roasting furnaces, characterized in that, include: The thermal field reconstruction module is used to collect the flue temperature and oxygen content of each furnace chamber in the roasting furnace group, arrange them along the flame propagation direction in the furnace chamber dimension, reconstruct the thermal field profile that unfolds with the flue airflow direction, and identify the flame front on the thermal field profile to obtain the current temperature deviation of each furnace chamber. The crossflow feedforward module is used to calculate the volatile matter release indication of the upstream furnace chamber based on the flue temperature and oxygen content of the upstream furnace chamber, and to weight and accumulate the volatile matter release indication of each upstream furnace chamber along the airflow direction according to the furnace chamber spacing to deduce the crossflow thermal disturbance feedforward amount acting on the downstream furnace chamber. The collaborative control module is used to inject the feedforward amount of crossflow thermal disturbance into the deviation calculation of the proportional and integral terms through the conversion coefficient, and maintain the dependence of the differential term on the temperature deviation to construct a feedforward compensation type cascade collaborative control law to calculate the gas valve opening degree of the downstream furnace chamber. The parameter update module is used to roll and shift the volatile matter release indication and conversion factor along the furnace chamber number each time the fire change action is triggered, so as to update the collaborative parameters in a rolling manner with the fire change cycle.

2. The system according to claim 1, characterized in that, The thermal field reconstruction module includes: The matrix construction unit is used to read the flue temperature and oxygen content of each furnace chamber at a fixed sampling period to form a two-dimensional temperature matrix with the furnace chamber number as the row and the flue depth as the column. The profile generation unit is used to treat at least two adjacent furnace chambers currently in the same flame system as a whole, arrange the two-dimensional temperature matrix along the flame propulsion direction in the furnace chamber dimension, and finally obtain the thermal field profile that unfolds along the direction of the fire channel airflow.

3. The system according to claim 1, characterized in that, The thermal field reconstruction module also includes: The front identification unit is used to identify the location with the largest temperature gradient on the thermal field profile as the flame front. The deviation acquisition unit is used to compare the measured temperature of each furnace chamber upstream and downstream of the flame front with the set value of the process curve at the corresponding flame section position point by point, and finally obtain the current temperature deviation of each furnace chamber.

4. The system according to claim 1, characterized in that, The crossflow feedforward module includes: The margin calculation unit is used to determine whether the temperature of the flue in the upstream furnace chamber is within the precipitation sensitive window, and to obtain the amount by which the flue temperature exceeds the lower edge of the precipitation sensitive window as the temperature margin. The oxygen consumption intensity unit is used to calculate the decrease in oxygen content relative to the no-fire calibration baseline as the flue oxygen consumption intensity. The indicator generation unit is used to multiply the temperature margin by the oxygen consumption intensity of the flue to obtain the volatile matter release indicator of the upstream furnace chamber.

5. The system according to claim 1, characterized in that, The crossflow feedforward module also includes: The distance acquisition unit is used to acquire the physical distance from the upstream furnace chamber to the downstream furnace chamber along the fire channel; The feedforward simulation unit is used to divide the volatile matter release indication of each upstream furnace chamber by the physical distance and accumulate them according to the current flow direction of the flame system, so as to finally obtain the feedforward amount of crossflow thermal disturbance acting on the downstream furnace chamber.

6. The system according to claim 1, characterized in that, The collaborative control module includes: The virtual deviation unit is used to subtract the product of the conversion factor and the feedforward amount of crossflow thermal disturbance from the temperature deviation to obtain the virtual positive temperature deviation. The control law construction unit is used to take the virtual positive temperature deviation as the input of the proportional and integral terms, and the original temperature deviation as the input of the derivative term, and finally construct a feedforward compensation type cascade cooperative control law.

7. The system according to claim 6, characterized in that, The collaborative control module also includes: Regression sample units are used to identify the most recent consecutive units prior to the current fire switch action. The regression sample consists of paired records of the peak value of upstream volatile matter release indicator and the corresponding peak value of downstream temperature deviation for each completed fire-switching cycle. The preset positive integer; The coefficient update unit is used to calculate the current regression slope using the sliding window least squares method and assign it to the conversion coefficient.

8. The system according to claim 1, characterized in that, The collaborative control module also includes: The crossflow upper limit judgment unit is used to determine whether the crossflow thermal disturbance feedforward amount in the downstream furnace chamber exceeds the crossflow thermal disturbance feedforward upper limit set in advance according to the process curve of the flame section where the corresponding furnace chamber is currently located. The collaborative constraint unit is used to reduce the gas increment in the upstream furnace chamber according to the recovery ratio by using the ratio of the excess amount of the crossflow thermal disturbance feedforward to the upper limit of the crossflow thermal disturbance feedforward to the upper limit of the crossflow thermal disturbance feedforward as the recovery ratio, so as to apply collaborative constraint on the gas valve opening of the upstream furnace chamber.

9. The system according to claim 1, characterized in that, The parameter update module includes: The window correction unit is used to read the green batch and asphalt content information of the preheating section furnace chamber newly added to the flame system to retrieve the initial value of the precipitation sensitive window, and correct the lower edge of the precipitation sensitive window with the furnace chamber temperature corresponding to the start of continuous decrease of the measured flue oxygen content, and correct the upper edge of the precipitation sensitive window with the furnace chamber temperature corresponding to the rate of decrease of oxygen content falling back to the judgment threshold, thus completing the adaptive correction of the window boundary. The ledger archiving unit is used to pair the recorded peak value of volatile matter release indication with the corresponding peak value of downstream temperature deviation for the cooling section furnace chamber that exits the flame system and store it in the historical ledger. The rolling shift unit is used to roll the maintained volatile matter release indicator and conversion factor along the furnace chamber number, and finally update the coordination parameters with each fire change cycle.

10. The system according to claim 1, characterized in that, It also includes a collaborative control host, fieldbus, multiple armored thermocouples, negative pressure sensor and flue gas oxygen content sensor; Armored thermocouples are arranged along the depth of the flue in each furnace chamber. Negative pressure sensors and flue gas oxygen content sensors are set at the common flue inlet. The collaborative control host is connected to the armored thermocouples, negative pressure sensors and flue gas oxygen content sensors via fieldbus, and reads the flue temperature, flue negative pressure and oxygen content of each furnace chamber according to a fixed sampling period.

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