A segmented temperature self-adaptive control method for a wire rod vacuum annealing furnace

Abstract

The application discloses a kind of iron wire coil vacuum annealing furnace subsection temperature self-adapting control method, specifically relates to steel wire coil vacuum annealing control technical field, for solving existing iron wire coil vacuum annealing process when furnace charging weight and stacking mode change still rely on artificial experience setting curve, temperature field in furnace is not uniform, resulting in organization and hardness batch fluctuation, energy consumption is difficult to fine control problem.Through in furnace charging after steel grade, furnace charging weight and stacking mode match annealing subsection control template, identify heat load index in vacuum extraction stage, and in the whole process of annealing based on temperature field uniformity index and thermal history index self-adapting adjustment three-temperature zone target temperature bias and cycle, strong cold fan working condition, to thereby in furnace charging condition fluctuation and stacking mode change automatically match the heat load of this furnace, keep hearth temperature field uniform, stabilize iron wire coil organization and hardness and reduce the technical effect of dependence on artificial experience test firing.

Description

Technical Field

[0001] This invention relates to the field of vacuum annealing control of steel wire rod, specifically a segmented temperature adaptive control method for a vacuum annealing furnace for steel wire rod. Background Technology

[0002] Currently, vacuum annealing production lines for low-carbon steel wire rods often employ segmented control using several "experience-based annealing curves" tailored to different steel grades. Operators typically select the appropriate curve after loading the furnace, based on the steel grade and approximate furnace weight. A programmable logic controller (PLC) executes heating, holding, and cooling according to predetermined target temperatures and holding times for each segment. Each temperature zone maintains its setpoint using a conventional closed-loop temperature control system. Process monitoring primarily focuses on alarms and recording of basic parameters such as vacuum level, temperature at each zone's measuring point, and heating power. After annealing, the process's compliance is determined solely by sampling for hardness and metallographic results. While existing technology can indeed meet basic product performance requirements under relatively stable conditions and with minimal changes in furnace loading methods, this approach is not without its limitations.

[0003] However, in actual production, factors such as furnace loading weight, wire rod stacking method, and furnace thermal inertia fluctuate significantly from batch to batch. Existing technologies often select annealing templates only based on steel grade or a rough weight range, lacking specific identification and quantification methods for the furnace loading heat load. The uniformity of the temperature field in the three temperature zones relies heavily on a few measuring points and operator experience. Throughout the annealing process, there is little use of process data to construct unified indicators that reflect the uniformity of the temperature field and the thermal history, let alone the ability to adjust the settings of each temperature zone and the operating conditions of circulating fans and forced cooling fans accordingly during segmented execution. Existing systems generally only trigger protection in extreme situations such as severe over-temperature or vacuum anomalies, making it difficult to promptly and precisely correct temperature field deviations caused by changes in furnace loading conditions. This results in insufficient consistency in microstructure and hardness between different furnace batches. Furthermore, to ensure no problems occur, the holding time is often conservatively extended as a fallback, leading to high energy consumption. The hardness and microstructure results after annealing are usually only used as a basis for qualification judgment, rarely linked to segmented execution parameters and energy consumption information systems for systematic backtracking and template parameter optimization.

[0004] Therefore, the core problem that current technology needs to solve is: in the scenario of vacuum annealing of low carbon steel wire rod, how to effectively combine batch information, furnace heat load characteristics, and temperature field and thermal history characteristics of the entire annealing process when the furnace loading conditions such as furnace weight and stacking method change, and establish a unified control strategy that can be applied to the segmented control of annealing, so that the vacuum annealing furnace can still maintain a high uniformity of furnace temperature field under multiple batches and variable operating conditions, stably obtain the required microstructure and hardness, and at the same time reduce the reliance on repeated trial firings based on human experience and conservative redundant heat preservation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods, thereby solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for segmented temperature adaptive control of a vacuum annealing furnace for iron wire rods, comprising:

[0007] S1. After loading the furnace, collect the steel type, loading weight and stacking method, and call the annealing segment control template that matches the batch information to generate the segment target temperature and holding time plan;

[0008] S2. After the vacuum is stabilized, the three temperature zones are heated with a constant heating power. During the start-up phase, the temperature changes of each temperature zone are collected, and the heat load index and temperature field uniformity index are calculated based on the heating slope and response time.

[0009] S3. During the annealing process, the temperature of the three temperature zones, heating power, and parameters of the circulating fan and the forced cooling fan are collected periodically to construct temperature field uniformity index, thermal history index and energy consumption index.

[0010] S4. Based on the heat load index, pre-correct the segment target parameters in the annealing segment control template, and use the temperature field uniformity index and thermal history index as constraints to set the start and end conditions of each segment to generate adaptive segment control targets.

[0011] S5. During the execution of each segment, the target temperature offset of each temperature zone, the working status of the circulating fan and the strong cooling fan are jointly adjusted according to the temperature field uniformity index, energy consumption index and segment control target, so that the temperature field uniformity and thermal history meet the constraints.

[0012] S6. After annealing, collect batch hardness and microstructure quality results, associate and store the heat load index, execution parameters of each segment, energy consumption index and quality results, and use them to update the annealing segment control template parameters.

[0013] Furthermore, S1 includes:

[0014] After loading into the furnace, the weight data of the loaded furnace is collected by a weighing device;

[0015] The industrial control computer selects a stable range that meets the weight fluctuation threshold and takes the average value to determine the furnace loading weight;

[0016] The industrial control computer matches templates from the annealing segment control template library that have the same steel grade, the same stacking method code, and the appropriate furnace weight based on the steel grade, furnace weight, and stacking method.

[0017] After confirming that the target temperature and holding time of each segment are within a safe range, the target temperature, holding time and allowable temperature deviation range of each segment are formed into a segment plan set, and then sent to the programmable controller with batch identifier and template version identifier.

[0018] Furthermore, S2 includes:

[0019] After the batch information collection and annealing segment control template call are completed and the segment plan is successfully registered between the industrial computer and the programmable controller, the industrial computer uses the batch identifier as the session identifier.

[0020] The programmable controller collects the vacuum level according to a fixed rhythm and sends it to the industrial control computer. The industrial control computer determines the vacuum stability state based on the vacuum fluctuation threshold and the target vacuum level threshold.

[0021] When the vacuum is not up to standard, the heating circuit is cut off by the programmable controller. After the vacuum stabilizes, the programmable controller is instructed to drive the heating circuits of the upper, middle and lower temperature zones with constant heating power and collect the temperature of the three temperature zones according to the preset sampling period.

[0022] Furthermore, the industrial control computer selects the reference temperature segment and the target temperature segment based on the three temperature zones during the startup phase, calculates the average temperature and time center of each temperature zone, and obtains the temperature rise slope.

[0023] The response time is obtained based on the time it takes for the temperature to reach the preset temperature threshold. The heating slope and response time are compared with the reference heating slope and reference response time in the reference characteristic library to generate the heat load index.

[0024] The temperature field uniformity index is generated based on the temperature rise slope difference and temperature difference of each temperature zone. The heat load index is written into the batch control context and sent to the programmable controller via industrial Ethernet.

[0025] Furthermore, S3 includes:

[0026] During the annealing process monitoring phase, the programmable controller collects the temperature of the three temperature zones, heating power, circulating fan parameters, and strong cooling fan parameters in each monitoring cycle and sends them to the industrial control computer via industrial Ethernet.

[0027] The industrial control computer monitors the alignment data of the buffer zone during the annealing process and constructs temperature field uniformity index, thermal history index and energy consumption index;

[0028] The indicators, along with the batch identifier and segment sequence number, are written into the batch control context, and monitoring messages containing the batch identifier, temperature field uniformity indicators, thermal history indicators, and cumulative specific energy consumption are sent to the programmable controller according to the monitoring cycle.

[0029] Furthermore, S4 includes:

[0030] Before the segmented annealing begins, the industrial control computer reads the heat load index from the batch control context and generates a heat load correction coefficient by combining it with the reference characteristic library. It then pre-corrects the heat preservation time of each segment template in the annealing segment control template and limits it to the range allowed by the process.

[0031] During the annealing process, thermal history indicators and temperature field uniformity indicators are used as constraints for the segment start and end conditions according to the monitoring cycle. The segment end judgment is generated by combining the modified segment target temperature and segment holding time.

[0032] The revised segmented target temperature, segmented insulation time, segmented start conditions, segmented end conditions, and actual execution results of this segment are recorded as the segmented control target execution record.

[0033] Furthermore, S5 includes:

[0034] During the segmented execution process, the industrial control computer uses batch identifiers and segment sequence numbers as indexes to read temperature field uniformity indicators, thermal history indicators, and energy consumption indicators from the annealing process monitoring buffer, and performs statistical analysis on the indicators within a preset observation window.

[0035] Based on the priority order of safety and temperature field uniformity, the target temperature offset of each temperature zone and the target parameters of the circulating fan and the forced cooling fan are generated in combination with the segmented control objectives, and then sent to the programmable controller through adjustment instruction messages.

[0036] When monitoring information and adjustment parameters are marked as abnormal, the adaptive adjustment is frozen to maintain the segmented target temperature and segmented heat preservation time.

[0037] Furthermore, S6 includes:

[0038] After receiving the quality information packet containing batch identifier, batch hardness and microstructure quality results sent by the quality inspection terminal, the industrial control computer calculates the batch hardness statistic and generates a quality grade by combining the microstructure quality results.

[0039] The quality grade is associated with the batch identifier, steel type, furnace loading weight range, stacking method code, heat load index, target and actual values ​​of holding time for each segment, thermal history index and temperature field uniformity index summary for each segment, energy consumption index, error code, and template version identifier and stored in the annealing batch operation archive.

[0040] Furthermore, the industrial control computer removes batches with abnormal start-up heating conditions, abnormal measurement signals, limited adaptive adjustment, and missing quality results from the annealing batch operation archive, and constructs a candidate sample set by encoding according to steel type, furnace weight range, and stacking method.

[0041] The heat load is divided into heat load intervals according to the heat load index. The recommended heat preservation time and suggested target temperature range are calculated based on the heat preservation time offset, quality level and energy consumption index of each segment, forming a set of template candidate parameters and generating a template version identifier.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. By matching the annealing segment control template according to steel grade, loading weight and stacking method after loading into the furnace, identifying the heat load index during the vacuum stabilization stage, constructing temperature field uniformity index and thermal history index throughout the annealing process, and combining the adaptive segment control target to adjust the target temperature offset of the three temperature zones and the working status of the circulating fan and strong cooling fan in each segment, the technical effect of automatically matching the loading heat load of the furnace, maintaining the uniformity of the furnace temperature field, ensuring the stability and consistency of the annealing structure and hardness of the iron wire rod, and reducing the reliance on repeated trial firing based on human experience can be achieved even under fluctuating loading conditions and changes in stacking method.

[0044] 2. By linking and storing the heat load index, execution parameters of each segment, temperature field uniformity and thermal history indicators, energy consumption indicators, and batch hardness and microstructure quality results after annealing, and after removing abnormal batches, statistical analysis is performed on qualified batches according to steel grade and furnace loading conditions to update the annealing segment control template parameters and lock the template version. This achieves the establishment of a closed-loop optimization and evidence chain traceability mechanism for annealing process parameters, quality results, and energy consumption performance. This ensures that subsequent batches can maintain stable annealing quality while also taking into account energy utilization level, improving process self-learning ability, and long-term operational robustness. Attached Figure Description

[0045] Figure 1 This is a schematic flowchart of a segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example: Figure 1 A flowchart illustrating a segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to the present invention is provided. The method includes:

[0048] S1. After loading the furnace, collect the steel grade, loading weight, and stacking method. Then, call the annealing segment control template matching the batch information to generate segment target temperatures and holding time plans. The specific implementation is as follows:

[0049] In one embodiment, a batch information acquisition and annealing segment control template recall function is set up on the production line for vacuum annealing of iron wire rods. The working objects are the vacuum annealing furnace and its supporting industrial control computer and programmable controller. The iron wire rods are coils formed by winding low-carbon steel wire rods as raw materials. The steel grade is the material grade name registered in the enterprise grade database. The furnace loading weight is the total weight of all iron wire rods loaded into a single annealing furnace, in kilograms, and is measured by a weighing device arranged at the bottom of the annealing furnace or on the loading trolley. The stacking method is the arrangement of the iron wire rods in the furnace chamber, which is selected by the operator from preset options on the touch screen. These include several types, such as tight stacking, gap stacking, and layered staggered stacking. Each type corresponds to a fixed code. The batch identifier is a single session marker for this annealing task. It is generated by the industrial control computer based on the date, time, and equipment number when the operator confirms the end of the furnace loading and closes the furnace door. It is used to record the entire furnace annealing process and remains unchanged within the same batch.

[0050] The annealing segment control template is a set of pre-tuned annealing segment parameters for specific steel grades, furnace weight ranges, and stacking methods. Each template contains several annealing segments arranged in chronological order. Each segment includes a target temperature and a holding time. The target temperature is the target value for furnace temperature control within that segment, expressed in degrees Celsius. The holding time is the duration for which the target temperature is maintained within that segment, expressed in minutes. During the trial production phase, the templates are compiled by process engineers based on the results of multiple furnace tests. Combined with hardness and metallographic reports, the feasible range of temperature and time for each segment is determined, and template numbers and version identifiers are assigned and stored in the non-volatile memory of the industrial control computer.

[0051] During the furnace loading operation, the operator places the iron wire rods onto the furnace loading trolley according to the predetermined stacking method. After the furnace loading is completed, the operator presses the furnace loading confirmation button on the touch screen. After receiving the furnace loading confirmation signal, the industrial control computer starts to collect batch information. Within a predetermined time window, the industrial control computer collects the electrical measurement signal of the furnace loading weight from the weighing device. This time window is preferably set to half a minute to one minute, and the sampling rhythm is preferably set to about once every half second. The industrial control computer arranges all the sampled values ​​in the time window in chronological order and calculates the difference between adjacent sampled values. The section where the difference between several consecutive sampled values ​​does not exceed the set weight fluctuation threshold is regarded as a stable area. The average of all sampled values ​​in the stable area is taken as the furnace loading weight of this batch. The weight fluctuation threshold is preferably set to one kilogram, and the number of consecutive sampling points is preferably set to about ten to ensure that the weighing reading tends to be stable after the furnace loading action stops.

[0052] The steel grade is obtained from the production task information issued by the previous process through communication with the upstream production management system. When communication fails, the operator can manually select from the steel grade list on the touch screen. The industrial control computer compares the steel grade value with the enterprise grade database. It only confirms the steel grade if it exists in the grade database and matches the production task record. Otherwise, it prompts on the touch screen that the steel grade is inconsistent and prohibits the operator from proceeding to the next step. The stacking method is selected by the operator through radio buttons on the touch screen. The industrial control computer locks the selection after the furnace loading is confirmed to prevent modification in the middle of the same batch. The steel grade, furnace loading weight, stacking method and batch identifier constitute a batch information record. The annealing furnace equipment number, furnace loading confirmation time and the current control software version identifier are added. The batch information is written into the batch information storage area in the form of key value in the industrial control computer. At the same time, a batch control context corresponding to the batch identifier is established in memory for subsequent access in each stage.

[0053] When the furnace loading weight is written, the industrial control computer compares the furnace loading weight with the upper limit of the allowable furnace loading weight on the furnace nameplate and the lower limit of the minimum furnace loading weight preset by the process. If the furnace loading weight is higher than the upper limit or lower than the lower limit, the text prompt on the touch screen indicates that the furnace loading weight exceeds the allowable range, and the batch is marked as unqualified. The annealing segment control template plan will not be generated until the unqualified status is lifted by the process engineer.

[0054] After batch information is recorded, the industrial control computer calls the annealing segment control template library for matching within the set time limit. Each template in the library records the steel type, applicable lower and upper limits of furnace loading weight, applicable stacking method code, and the segment target temperature, holding time, and allowable temperature deviation range for each segment. The industrial control computer prioritizes matching templates based on the following conditions: the steel type is exactly the same, the furnace loading weight falls between the applicable lower and upper limits of furnace loading weight, and the stacking method code is the same. Among the templates that meet the conditions, the template with the smallest difference between the applicable upper limit of furnace loading weight and the furnace loading weight of this batch is selected as the candidate template. If no template meets all three conditions, the process degenerates to matching only the steel type and stacking method code and selecting the template with an applicable upper limit of furnace loading weight greater than the furnace loading weight of this batch as the candidate template. If no candidate template is found, the batch is marked as pending configuration and a template is displayed on the touchscreen. Process engineers create a new template or copy a similar template for the steel grade and furnace weight range through the template configuration interface and adjust the parameters. The newly created or adjusted template records the template number, template version identifier, configuration personnel identity information and configuration time, and registers it as a record in the template change record for version source tracking. In one embodiment, each time the segment target temperature, holding time, upper limit of safe temperature or minimum holding time in the template is modified, the industrial control computer registers the parameter values ​​before and after the modification, along with the modification time and the identity of the modification personnel, as a parameter version record and associates it with the template version identifier to form a complete parameter version locking evidence chain.

[0055] When candidate templates exist, the industrial control computer checks segment by segment whether the target temperature and holding time of the candidate templates are within the safe range. The upper limit of the safe temperature is set according to a certain percentage of the maximum allowable temperature shown on the annealing furnace nameplate, preferably not higher than 90% of the maximum allowable temperature, and not lower than the lower limit of the recommended annealing temperature for the steel grade. The minimum holding time is set at half or more of the recommended holding time for the steel grade to ensure that the microstructure is fully formed. The allowable temperature deviation range is selected after statistical analysis of multiple furnace test firings, preferably between ±5 degrees Celsius and ±15 degrees Celsius.

[0056] If the target temperature of any segment is higher than the upper limit of the safe temperature or lower than the lower limit of the annealing temperature of the steel grade, or if any holding time is lower than the minimum holding time, the industrial control computer will refuse to use the candidate template, write the template number and template version identifier into the template parameter out-of-limit record list, and prompt on the touch screen that the template parameter exceeds the limit and needs to be modified. After the process engineer makes the modification, the system will re-execute the aforementioned matching and checking process.

[0057] When all checks pass, the industrial computer generates the segmented target temperature and holding time plan for this batch using the batch identifier and template version identifier as idempotent keys. It then copies each segment in the candidate template sequentially to the segmented plan set for this batch. In the segmented plan set, it assigns a sequence number, segmented target temperature, holding time, and allowable temperature deviation range to each segment, and attaches the batch identifier, template number, and template version identifier to the set. Finally, it stores the segmented plan set in the segmented plan storage area of ​​the industrial computer.

[0058] The industrial computer then sends a message to the programmable controller via industrial Ethernet, containing a batch identifier, template version identifier, number of segments, target temperature, holding time, and allowable temperature deviation range for each segment. After receiving the message, the programmable controller determines whether the same batch of segment plans has been registered based on the batch identifier and template version identifier. If it has been registered, the message is considered a duplicate and only the latest reception time is recorded without overwriting the registered content. If it has not been registered, the message content is written to the local storage area as the basis for the segment control of this batch.

[0059] When a message field is missing, the number of segments is zero, or the target temperature or holding time of any segment exceeds the preset check range of the programmable controller, the programmable controller generates a message containing an error identifier and returns it to the industrial control computer. The error identifier is divided into three types: furnace loading weight exceeding the limit, template missing, and illegal segmentation plan parameters. Corresponding to different error situations, the encoding values ​​are pre-defined as several fixed values ​​in the control software. In one embodiment, the error identifier uses integer encoding. Preferably, furnace loading weight exceeding the limit, template missing, and illegal segmentation plan parameters are assigned to codes number one, two, and three, respectively. Other codes are reserved for subsequent expansion. After receiving the message with the error identifier, the industrial control computer displays the specific error type on the touch screen and marks the batch identifier as a segmentation plan failure state.

[0060] During network communication, the industrial control computer waits for a reply from the programmable controller after sending a batch segmentation plan message. In the preferred case, the waiting time should not exceed a few seconds. If no reply is received within this time, the message is sent again with the same content. The number of retransmissions is preferably set to no more than three. If no reply is received from the programmable controller after the number of retransmissions exceeds the limit, the batch is marked as a communication failure and the annealing heating process is prohibited. Maintenance personnel then check the network or equipment status.

[0061] If any of the following conditions exist: furnace loading weight exceeds limit, template is missing, segmented plan parameters are illegal, or communication failure occurs, the operator is not allowed to perform the heating start operation on the touch screen. The condition must be cleared by process engineers after process adjustment, template correction, or equipment maintenance, and the batch information collection and template matching process must be completed again.

[0062] In one embodiment, each template and its version identifier are linked one-to-one with the corresponding process test furnace number, test furnace time, and quality inspection report number, forming a template source chain. This allows for tracing back to the original template parameters and formula source when a batch of annealing quality issues is subsequently discovered. Preferably, under a set of representative operating conditions, for a certain low-carbon steel grade, the single furnace loading weight is approximately 3,000 kg, and the stacking method is close stacking. The template library contains templates suitable for furnace loading weights of 2,500 kg to 3,500 kg, comprising four annealing sections. The target temperature for each section is between 500°C and 750°C, and the holding time for each section is between 30 and 90 minutes. The weight reading change of the weighing device gradually decreases within a 30-second time window. If the fluctuation is less than one kilogram within ten consecutive sampling points, the industrial control computer determines that the furnace loading weight is approximately three thousand kilograms. It then matches the aforementioned template and generates a four-segment target temperature and holding time plan. This plan is reliably transmitted to the programmable controller via industrial Ethernet, and the batch identifier and template version identifier combination key are registered as idempotent keys. In another embodiment, the furnace loading weight can be estimated by counting the number of coils loaded into the furnace and multiplying it by the theoretical weight of a single coil. The stacking method can be obtained by using a camera to capture images of the number and arrangement of coil layers during the furnace loading process, and the recognition program will provide a stacking method suggestion, which will then be confirmed by the operator on the touch screen. Both implementations can be considered equivalent replacements of the above implementation methods when they meet the requirements of weight accuracy and stacking method recognition accuracy.

[0063] S2. After the vacuum stabilizes, the three temperature zones are heated with a constant heating power. During the start-up phase, the temperature changes of each temperature zone are collected. The heat load index and temperature field uniformity index are calculated based on the heating slope and response time. The specific implementation is as follows:

[0064] After the aforementioned batch information acquisition and annealing segment control template call are completed, and the segment plan is successfully registered between the industrial control computer and the programmable controller, the industrial control computer uses the batch identifier as the current session identifier and initiates the start-up phase control for identifying the furnace loading heat load. Within the session, the programmable controller first controls the vacuum pump to operate and reads the signal from the vacuum degree measuring device located on the annealing furnace lining. The vacuum degree is the measured value of the gas pressure inside the furnace lining, measured in Pascals or kilopascals. Within a preset time period, the programmable controller acquires vacuum degree values ​​at a fixed rhythm and transmits them to the industrial control computer via industrial Ethernet. The industrial control computer arranges the vacuum degrees within this time period in chronological order and calculates the difference between adjacent sampled values, ensuring that the difference between several consecutive sampled values ​​does not exceed a certain threshold. The time period during which the vacuum level is consistently lower than the preset target vacuum level threshold is considered a stable vacuum state. The vacuum fluctuation threshold can be set to several times the pressure resolution of the vacuum measuring device, preferably two to five times that resolution. The target vacuum level threshold is set according to process requirements to ensure that the risk of decarburization and oxidation is controlled, preferably not higher than one to five percent of atmospheric pressure. If the vacuum fails to meet the above conditions within a given time window, the industrial control computer marks this batch as a vacuum failure state and cuts off the heating circuit through the programmable controller. The touch screen prompts that the vacuum system needs to be checked. After the maintenance personnel confirm that the vacuum system has recovered, the status is cleared and the control segment is re-executed.

[0065] After the vacuum stability is determined to be passed, the programmable controller drives the heating circuits of the upper, middle and lower temperature zones of the annealing furnace to work with constant heating power according to the start-up command issued by the industrial control computer. The constant heating power is a set of power settings that remain unchanged for each heating circuit during the start-up phase, in kilowatts or as a percentage of the rated power on the annealing furnace nameplate. The power can be kept basically constant for a certain period of time by controlling the thyristor firing angle or the duty cycle of the solid-state relay. In one embodiment, the setting range of the constant heating power is set with a safe upper and lower limit according to the rated power on the furnace nameplate and the power supply capacity. It is preferably set between one-third and one-half of the rated power to ensure the heating rate without overloading the heating components. During the start-up phase, the programmable controller keeps the power setting unchanged and cuts off the heating immediately only when a safety interlock signal is detected.

[0066] After a constant heating power is applied, the programmable controller collects temperature values ​​from the thermocouples in the three temperature zones according to a preset sampling period. The temperature is the furnace atmosphere or furnace wall temperature measured at each temperature zone measurement point, in degrees Celsius. The sampling period can be configured in the system parameters, preferably set to one to three seconds. The programmable controller summarizes the temperature sampling values ​​and corresponding time stamps by batch and sends them to the industrial control computer via industrial Ethernet. The industrial control computer establishes a temperature recording buffer for the start-up phase in its memory for this batch. The temperature sequence of the three temperature zones in the buffer is aligned according to the sampling time. When the time interval of individual sampling points deviates significantly from the target sampling period, interpolation or elimination of the nearest time point can be adopted to ensure that the three temperature zones have corresponding temperature values ​​at the same time point, thereby reducing the impact of sampling jitter.

[0067] During the startup phase, the industrial control computer continuously accumulates temperature records until the temperature of any temperature zone reaches the preset startup end temperature limit, or until the accumulated time from the start of constant heating power application reaches the preset maximum startup duration. The first occurrence is used as the end mark of the startup phase. The startup end temperature limit is determined by subtracting a certain temperature difference from the lower limit of the annealing temperature of the steel grade to avoid entering the actual annealing zone during the heat load identification phase. The maximum startup duration is set based on the thermal inertia of the furnace body and the maximum loading weight, preferably within the range of ten to thirty minutes, to prevent blind heating for a long time under abnormally high heat loads, which may cause safety risks.

[0068] After obtaining the complete temperature record of the startup phase, the industrial control computer analyzes the temperature changes of the three temperature zones over time. In one embodiment, the industrial control computer first selects a time interval in the early stage of startup where the temperature changes relatively slowly over time as the reference temperature interval, and selects a time interval in the late stage of startup where the temperature rise trend is close to linear as the target temperature interval. The average temperature and corresponding time center of each temperature zone in the reference temperature interval and the target temperature interval are calculated respectively. The average temperature of the target temperature is subtracted from the average temperature of the reference temperature and divided by the time difference between the two time centers to obtain the temperature rise slope value of each temperature zone in the startup phase. The temperature rise slope reflects the rate of temperature increase of the temperature zone under constant heating power, and the unit is degrees Celsius per minute. In one embodiment, in order to improve stability, the temperature curve of the entire startup phase can also be regarded as an approximate straight line. A straight line with the smallest overall deviation is sought on the time and temperature plane, and the slope of the straight line is used as the estimate of the temperature rise slope.

[0069] While obtaining the heating slope, the industrial control computer finds the time point from the temperature record when the temperature of each temperature zone rises from the reference temperature to a certain temperature threshold. The time interval from the heating start time to that time point is taken as the response time of that temperature zone. The temperature threshold can be selected as the reference temperature plus a fixed temperature difference, or it can be selected as the lower limit of the annealing temperature of the steel grade minus the fixed temperature difference. In one embodiment, the industrial control computer configures the temperature threshold to a uniform numerical range and registers this configuration in the parameter version record along with the template version identifier to ensure that the calculation caliber of the response time is consistent between different batches.

[0070] After calculating the heating slope and response time of the three temperature zones, the industrial control computer compares these quantities with the reference heating characteristics established during the trial firing stage for the current steel grade, furnace weight, and stacking method. The reference heating characteristics are stored in the industrial control computer's reference characteristic library. Each record includes the reference heating slope, reference response time, applicable conditions, a reference characteristic library maintenance version identifier, and change records. In one embodiment, the industrial control computer selects applicable records from the reference characteristic library based on the current batch of steel grade and furnace weight, calculates the ratio of the current heating slope to the reference heating slope and the ratio of the response time to the reference response time, and checks whether these ratios fall within a preset reasonable range. Within this range, the reasonable range is preferably set as a range around a certain point, for example, the lower limit is half and the upper limit is one and a half times. When the ratio of the heating slope of a certain temperature zone is significantly lower than the lower limit and the ratio of the response time is significantly higher than the upper limit, the industrial control computer determines that the heat load of that temperature zone is too heavy. When the ratio of the heating slope is significantly higher than the upper limit and the ratio of the response time is significantly lower than the lower limit, the heat load is determined to be too light. Then, according to the preset weight, the deviation of the heating slope and the deviation of the response time of each temperature zone are aggregated into a heat load index that characterizes the overall heat load of the furnace. It is preferably defined as a monotonic relationship where the heavier the heat load, the larger the value, and this definition is recorded in the parameter version record.

[0071] Based on the temperature records from the same startup phase, the industrial control computer also constructs a temperature field uniformity index to reflect the degree of temperature field uniformity by calculating the differences between the heating slopes of the three temperature zones and the difference between the maximum and minimum values ​​of the average temperature of the three temperature zones over a period of time at the end of the startup phase. In one embodiment, the industrial control computer combines the differences in heating slopes and temperature differences into a single value according to the weights set in the configuration interface. The smaller the value, the more consistent the heating trend of the three temperature zones and the closer the temperatures are, thus the more uniform the temperature field. The aforementioned weights are set by process engineers in the system parameter configuration interface and recorded together with the version identifier in the parameter version record.

[0072] After the heat load index and temperature field uniformity index are calculated, the industrial control computer writes these two indices, along with the three-temperature zone temperature rise slope, response time, and statistical summary of the temperature records during the start-up phase, into the batch control context corresponding to the batch identifier. This information is then stored in the industrial control computer's segmented plan storage area for subsequent segmented control adaptive adjustment and recall. Simultaneously, the industrial control computer sends a message containing the batch identifier and heat load index to the programmable controller via industrial Ethernet to notify the programmable controller that the start-up phase of the batch has ended and heat load identification is complete. Upon receiving this message, the programmable controller sets a start-up phase completion flag based on the batch identifier. If a start-up completion message with the same batch identifier is received again within the same batch, only the time is updated, and the registration is not repeated to ensure the idempotency of start-up phase identification.

[0073] In one embodiment, if the industrial control computer detects that the temperature curve during the startup phase shows virtually no increase within a set time period, or that the temperature drops at several consecutive sampling points exceeding a preset temperature difference threshold, or that the calculated temperature rise slope is zero or negative (preferably set to a temperature drop of approximately five degrees Celsius per sampling cycle), then the batch is marked as having an abnormal startup heating condition, and a message containing an error identifier is generated and sent to the programmable controller. The error identifier is an additional category of abnormal startup heating condition, in addition to the aforementioned three categories: excessive furnace loading weight, missing template, and illegal segmented plan parameters. All error identifiers use integer codes; preferably, the abnormal startup heating condition corresponds to code number four. The code values ​​and meanings are fixed in the control software. After receiving the error identifier returned by the programmable controller, the industrial control computer displays the specific error category on the touchscreen and prohibits the start of subsequent segmented annealing control for that batch. Maintenance personnel must check the vacuum system, heating circuit, and temperature acquisition circuit to clear the status and re-execute this step.

[0074] Preferably, under a set of representative operating conditions, for a certain low-carbon steel grade, the furnace charge weight is approximately 3,000 kg, and the stacking method is close stacking. With the vacuum system stable and the vacuum level below one percent of atmospheric pressure, the constant heating power is set to approximately one-third of the rated power on the annealing furnace nameplate. The temperature sampling period is set to two seconds, and the start-up phase lasts approximately ten minutes. The industrial control computer obtains from the temperature curve the heating slope of the upper, middle, and lower temperature zones as several tens of degrees Celsius per minute. The response time is slightly longer than the recorded value under the same steel grade and weight conditions in the reference characteristic library, and the corresponding heat load index is slightly higher than the standard value. It is determined that the furnace charge heat load is too heavy, and the start-up... At the end of the dynamic stage, the temperature difference between the three temperature zones is approximately several degrees Celsius, and the temperature field uniformity index falls within a preset threshold, which is acceptable as a temperature field distribution. In another embodiment, the application of constant heating power can be achieved not by directly setting the power value, but by uniformly increasing the temperature setpoint of the three temperature zones by a fixed temperature difference and freezing the temperature closed-loop adjustment parameter for a short period of time, so that the heating element operates in an approximately constant power state during this period of time. The temperature response curves collected afterward are used to calculate the heating slope and response time in the above manner. This implementation can be regarded as an equivalent replacement of the aforementioned embodiment when the power fluctuation amplitude does not exceed a preset ratio.

[0075] S3. During the annealing process, the temperatures of the three temperature zones, heating power, and parameters of the circulating fan and forced cooling fan are collected periodically to construct temperature field uniformity indicators, thermal history indicators, and energy consumption indicators. The specific implementation is as follows:

[0076] After the heat load index and temperature field uniformity index are calculated and the start-up phase completion flag for this batch is registered in the programmable controller, the industrial control computer switches the control session to the annealing process monitoring phase. The annealing process includes the heating phase, heat preservation phase, and cooling phase executed sequentially according to the segmented plan. Throughout the segmented annealing process, the temperature of the three temperature zones, heating power, circulating fan and forced cooling fan parameters are continuously collected at a fixed rhythm, and the temperature field uniformity index, thermal history index and energy consumption index are constructed in the industrial control computer.

[0077] The three temperature zones are the temperature values ​​of the corresponding measuring points in the upper, middle, and lower temperature zones, in degrees Celsius. These values ​​are read from the thermocouple channel by the programmable controller (PLC) in each monitoring cycle. The heating power is the active power of the entire annealing furnace or the heating circuit of each temperature zone at the current moment, which can be calculated by the voltage and current acquisition device, in kilowatts. The circulating fan parameters are the fan speed or inverter output frequency and operating status indicator. The forced cooling fan parameters are the forced cooling fan speed or inverter output frequency and operating status indicator. The fan parameters are in revolutions per minute (RPM) or frequency. The operating status indicator is a logical quantity indicating on or off. In one embodiment, the PLC monitors the above quantities at a monitoring cycle that is the same as or an integer multiple of the temperature acquisition cycle. Data collection is performed, and the monitoring cycle can be configured in the system parameters, preferably set to several seconds. At the end of each monitoring cycle, the temperatures of the three temperature zones, heating power, circulating fan parameters, and forced cooling fan parameters, as well as the time stamp, are summarized by batch identifier and transmitted to the industrial control computer via industrial Ethernet. The industrial control computer establishes an annealing process monitoring buffer in its memory for this batch, arranges the received values ​​in chronological order and aligns them according to the monitoring cycle. When it is found that individual sample values ​​are missing or significantly deviate from the values ​​of previous and subsequent cycles by more than the preset deviation threshold, they can be supplemented by averaging the values ​​of previous and subsequent cycles or keeping the value of the previous cycle, so as to ensure that there is a valid value for the temperature of the three temperature zones, heating power, and fan parameters in each monitoring cycle.

[0078] The industrial control computer calculates the instantaneous temperature field uniformity index based on the aligned three temperature zones within each monitoring cycle. In one embodiment, the temperature field uniformity index is defined as a combination of the difference between the maximum and minimum temperatures in the three temperature zones and the difference between the average temperature of the three temperature zones. This combination method is set by process engineers in the system parameter configuration interface in the form of weights. The weights and calculation methods are recorded in the parameter version record to lock the version. The smaller the temperature field uniformity index value, the more uniform the current temperature field. To reduce the impact of short-term disturbances, the industrial control computer can smooth the instantaneous temperature field uniformity index of several monitoring cycles within a preset time window. For example, the average value of the temperature field uniformity index in the most recent several monitoring cycles can be taken as the temperature field uniformity index at the current moment. The length of this time window is preferably set to within a few minutes. The window length and the number of cycles participating in the smoothing are also recorded in the parameter version record.

[0079] The thermal history index is used to characterize the effective heating process experienced by this batch of iron wire rod during annealing. In one embodiment, the industrial control computer queries the target temperature range and the recommended annealing temperature range for the corresponding steel grade of the annealing segment to which the current monitoring cycle belongs in the segmented plan. The temperature of the three temperature zones is compared with the recommended range. When the temperature is within the effective range, the cycle is considered to have a positive contribution to the thermal history. When the temperature deviates from the effective range, the contribution is reduced according to the degree of deviation. Specifically, in each monitoring cycle, the length of the monitoring cycle is used as the time weight, and the degree of closeness to the effective range is used as the temperature weight. The time weight and the temperature weight are multiplied to obtain the thermal history increment of the cycle. The thermal history increments of each cycle are accumulated throughout the annealing process to form a thermal history index that changes monotonically with time. In one embodiment, process engineers can correlate the thermal history index accumulated to a certain value with the qualified range of microstructure and hardness based on the test firing data for subsequent segmented control and process evaluation.

[0080] Energy consumption indicators are used to reflect the energy consumption of the current batch of annealing process. In one embodiment, the industrial control computer uses the product of heating power and monitoring cycle length as the energy consumption increment for each monitoring cycle. The energy increments of all cycles are accumulated within the current batch to obtain the cumulative energy consumption. At the same time, the cumulative energy consumption is divided by the furnace loading weight to obtain the cumulative specific energy consumption. The sum of energy increments in the most recent monitoring cycles is divided by the time length to obtain the short-time average power, which is used to observe the recent energy consumption level. The calculation method of the above energy consumption indicators and the number of cycles involved in the statistics are set by process engineers in the system parameters and registered in the parameter version record.

[0081] After the temperature field uniformity index, thermal history index, and energy consumption index are constructed, the industrial control computer writes the three indices, along with the batch identifier, the current segment sequence number, and the time stamp, into the batch control context at the end of each monitoring cycle. At the same time, it stores them in the annealing process monitoring buffer for subsequent segment control logic queries. In one embodiment, the industrial control computer can also summarize the time series of the above indices at a lower frequency and store them in non-volatile storage to form the batch monitoring report. To ensure information consistency with the programmable logic controller (PLC), the industrial control computer (ICC) can send a monitoring message to the PLC at a rhythm of merging multiple monitoring cycles, preferably every several monitoring cycles. This message includes at least a batch identifier, the current temperature field uniformity index, the current thermal history index, and the current cumulative specific energy consumption. After receiving the message, the PLC updates its local records according to the batch identifier for use by its local segmented control logic. When a monitoring message with the same batch identifier and a timestamp later than the previous one is received, only the old value is overwritten, and no record entry is added repeatedly to maintain the idempotency of the monitoring data update action. If the ICC does not receive confirmation from the PLC within a preset waiting time during the communication process, it can resend the same content a limited number of times. The number of resends and the waiting time are consistent with the aforementioned segmented plan message. If no confirmation is received after the number of resends, a communication fault is registered on the ICC side, but the local index calculation is not immediately interrupted to avoid the monitoring chain being interrupted due to short-term communication problems. To ensure the reliability of the collected data, if it is found that the temperatures of all three temperature zones are zero, negative, or simultaneously exceed the physical range within a certain monitoring cycle, or if the heating power value is zero and the temperature continues to rise, the industrial control computer can mark the cycle as a measurement signal abnormality cycle and add the measurement signal abnormality type to the error identifier. The error identifier adopts the aforementioned integer coding method, preferably adding the measurement signal abnormality corresponding to code number five. The touch screen will prompt maintenance personnel to check the temperature acquisition or power acquisition circuit. When multiple consecutive monitoring cycles are marked as measurement signal abnormalities, the industrial control computer can disable the adaptive segmented adjustment logic based on the index, but keep the underlying temperature closed loop and safety interlock unaffected to ensure that the annealing process still operates safely according to the basic process when a problem occurs in the monitoring chain.

[0082] During on-site inspection, process engineers can check the typical range of temperature field uniformity index, the difference of thermal history index between qualified and unqualified batches, and the fluctuation range of cumulative specific energy consumption on a certain number of batches to verify the consistency between the monitoring index and the actual annealing quality and energy consumption performance. In one embodiment, several batches with different furnace loading weights and different stacking methods can be selected as samples for statistical analysis. Preferably, the number of samples is no less than several dozen furnaces to obtain stable results. Preferably, under a set of representative working conditions, for a certain low-carbon steel grade, a furnace charge weight of approximately 3,000 kg, a close stacking method, a constant heating power of approximately one-third of the nameplate rated power, and a temperature sampling period of two seconds, the annealing process monitoring period is set to five seconds. The temperature field uniformity index remains within 10 degrees Celsius for most of the heating period, and does not exceed 20 degrees Celsius during individual disturbances. The holding period is maintained at around 5 degrees Celsius. The thermal history index reaches the lower limit of the preset qualified range near the end of the holding period and stabilizes near this range in the early cooling stage. The cumulative specific energy consumption is ultimately within a predetermined range of several hundred kilowatt-hours per ton. Based on this, the industrial control computer determines that the annealing process and energy consumption level of this batch are at a normal level. In another embodiment, the temperature field uniformity index can be changed from the maximum temperature difference form to the combination of the squared average of the deviations between the three temperature zones and the batch average temperature. Under the premise that the deviation characterizes the degree of temperature field non-uniformity and the calculation caliber is fixed through parameter version recording, this implementation can be regarded as an equivalent replacement of the above-mentioned temperature field uniformity index construction method.

[0083] S4. Based on the heat load index, pre-correct the segmented target parameters in the annealing segmented control template, and use the temperature field uniformity index and thermal history index as constraints to set the start and end conditions of each segment to generate adaptive segmented control targets. The specific implementation is as follows:

[0084] Based on the fact that the aforementioned heat load index, temperature field uniformity index, and thermal history index are continuously updated by batch on the industrial control computer side, the industrial control computer establishes a segmented control target generation unit for this batch during the annealing process monitoring stage. This unit uses the heat load index in the batch control context as the quantitative result of the furnace loading heat load level, uses the target temperature and holding time of each segment in the segmented control template as the initial segmented target parameters, and uses the real-time updated temperature field uniformity index and thermal history index as the constraint source of the start and end conditions of each segment. Based on this, an adaptive segmented control target is generated.

[0085] The heat load index is a dimensionless value representing the magnitude of the furnace heat load identified during the start-up phase. Preferably, it has been defined as a larger value for heavier heat loads, and the calculation caliber is locked in the parameter version record. The segmented control template is the set of annealing segment parameters adjusted according to steel type, furnace weight, and stacking method. It includes multiple segments arranged in sequence. Each segment has two main parameters: template target temperature and template holding time. The template target temperature is the furnace temperature level that the segment is expected to reach and maintain, in degrees Celsius. The template holding time is the length of time that the temperature is maintained near the target temperature, in minutes.

[0086] Before the batch first enters the segmented annealing stage, the industrial control computer reads the furnace heat load index from the batch control context and obtains the standard heat load index value and allowable deviation range corresponding to the steel grade and furnace weight from the reference characteristic library or parameter configuration interface. The standard heat load index and its deviation range are determined by process engineers based on multi-furnace historical data and registered in the parameter version record during the trial firing stage. The industrial control computer calculates a heat load correction coefficient according to the degree to which the current heat load index is higher or lower than the standard value. Preferably, the correction coefficient is limited to a range that is not less than a certain lower limit and not more than a certain upper limit to prevent over-adjustment caused by single-furnace identification error. In one embodiment, the heat load correction coefficient can be designed as a proportional factor that takes one when the heat load index is close to the standard value and slightly deviates from one when the heat load is too heavy or too light.

[0087] The industrial control computer then pre-corrects the heat preservation time of each segment in the segmented control template according to the heat load correction coefficient. When the heat load is too heavy, the heat preservation time of the high-temperature segment and the segment forming the key structure is increased appropriately. When the heat load is too light, the heat preservation time is shortened appropriately. After adjustment, it checks whether the heat preservation time of each segment is still within the process allowable range. The process allowable range is set in the system parameters according to the recommended annealing regime of the steel grade and included in the parameter version record. If the heat preservation time of a certain segment exceeds the maximum allowable value or falls below the minimum allowable value due to adjustment, the adjustment amount of the heat preservation time of that segment is truncated, and only the part within the allowable range is retained. At the same time, the segment number where the truncation occurred and the corresponding parameter change are recorded in the template adjustment record for subsequent traceability.

[0088] After completing the pre-correction of the template heat preservation time, the industrial control computer will form the basic segment target parameter set for this batch by the corrected segment target temperature and heat preservation time, and set segment start conditions and segment end conditions for each segment as part of the adaptive segment control target. The segment start condition includes at least the requirement that the end condition of the previous segment has been met and the current furnace temperature has reached the vicinity of the target temperature of the segment. The segment end condition considers three aspects: the heat preservation time reaches the corrected template heat preservation time requirement, the thermal history index accumulates to the preset segment thermal history threshold within this segment, and the temperature field uniformity index reaches the segment uniformity requirement.

[0089] The segmented thermal history threshold is the expected contribution of the thermal history to each segment. Process engineers break down the entire thermal history index into segments based on the test firing data and register it in the system parameters. The unit can be set consistently according to the cumulative unit of the thermal history index. The segmented uniformity requirement is the upper limit value and duration requirement of the temperature field uniformity index allowed in each segment. It is used to ensure that the furnace temperature distribution is sufficiently uniform before the end of the segment. In one embodiment, at the beginning of each segment, the industrial control computer reads the segmented thermal history threshold and segmented uniformity requirement corresponding to the steel grade and segment type from the parameter version record, and adds the minimum holding time and maximum holding time of each segment to the batch control context. The minimum holding time is used to prevent the segment from ending prematurely due to short-term fluctuations, and the maximum holding time is used to prevent the segment from being extended indefinitely if the uniformity or thermal history requirements are not met for a long time.

[0090] During the annealing process, the industrial control computer reads the latest temperature field uniformity index and thermal history index values ​​from the annealing process monitoring buffer according to the monitoring cycle, and simultaneously obtains the current segment start time, the accumulated thermal history increment of this segment, and the number of monitoring cycles in which the temperature field uniformity index has been continuously satisfied by being less than a certain segment uniformity threshold. The segment uniformity threshold and the number of cycles that need to be continuously satisfied are configured in the system parameters and included in the parameter version record. In one embodiment, the industrial control computer first determines whether the minimum heat preservation time requirement has been met in each monitoring cycle. If it has not been met, the segment end will not be triggered regardless of the thermal history index and temperature field uniformity index. Instead, the thermal history increment of this segment will continue to be accumulated and the temperature field uniformity index satisfaction status will be recorded.

[0091] When the minimum heat preservation time has been met, the industrial control computer checks whether the thermal history index of this segment has reached or exceeded the thermal history threshold of this segment, and at the same time checks whether the temperature field uniformity index has been lower than the segment uniformity threshold for several consecutive monitoring cycles. If both conditions are met, a segment end judgment is generated, the current segment is marked as completed, and the actual end time of this segment, the actual thermal history index obtained by this segment, and the temperature field uniformity index at the end of this segment are recorded in the batch control context.

[0092] If the temperature field uniformity index remains above the threshold even after the segmented thermal history threshold has been reached, and the uniformity condition is not met within the maximum holding time, the industrial control computer will terminate the segment when the maximum holding time is reached, prioritizing safety. It will record the failure of the temperature field uniformity index, mark the segment as one where the uniformity condition is not fully met, and trigger a message containing a batch identifier, segment number, and status code to be sent to the programmable controller. A new category, segment uniformity relaxation, will be added to the error identification codes, preferably code number six. The meaning of this code is fixed in the control software and used for subsequent process evaluation and possible alarm strategies. If the thermal history index still does not reach the segmented thermal history threshold within the maximum holding time, the segment will also be terminated upon reaching the maximum holding time. The segment will be marked as having insufficient thermal history, and the corresponding error code number seven will be triggered. The touchscreen will prompt the operator to check the furnace loading method or template parameter settings.

[0093] At the end of each segment, the industrial control computer uses the batch identifier and segment sequence number as keys to register the segment target temperature and holding time after thermal load correction, the segment start and end condition settings, and the actual execution results of this segment as the segment control target execution record of this batch, and stores it in non-volatile storage to form version locking and evidence chain traceability. This record can be used to update the reference feature library and optimize the segment control template after annealing.

[0094] In one embodiment, at the beginning of each segment, the industrial control computer sends a segment control target message to the programmable controller via industrial Ethernet. This message includes at least a batch identifier, segment sequence number, corrected segment target temperature, minimum holding time, maximum holding time, and segment thermal history threshold and segment uniformity threshold. After receiving the message, the programmable controller determines whether the segment control target has been registered based on the batch identifier and segment sequence number. If it has been registered, it only updates the timestamp without rewriting to ensure idempotency in message retransmission scenarios. When message fields are missing or parameters significantly exceed the allowable range of the device, the programmable controller reports an illegal segment control target status through an error flag. After receiving the error flag, the industrial control computer prompts process engineers to check the parameter configuration on the touch screen and can maintain the safety and controllability of the annealing process by reverting to the uncorrected template segment parameters when necessary.

[0095] Preferably, under a set of representative operating conditions, for a batch of low-carbon steel of a certain grade, with a furnace charge weight of approximately 3,000 kg and a close stacking method, the heat load index obtained during the start-up phase is slightly higher than the standard value. The industrial control computer calculates a heat load correction coefficient slightly greater than one based on the heat load index and increases the heat preservation time of the templates in the high-temperature heat preservation section by several minutes, while keeping the heat preservation time of each section within the allowable range of the recommended heat preservation time for that steel grade. During the segmented control process, the minimum heat preservation time of a certain high-temperature heat preservation section is set to several tens of minutes, and the maximum heat preservation time is set to several tens of minutes to one hour. The segmented thermal history threshold is set as a certain proportion of the total thermal history index based on the historical qualified furnace counts. The segmented uniformity threshold is set as a temperature field uniformity index less than a certain number of degrees Celsius and requires continuous monitoring for several weeks. In actual operation, after reaching the minimum holding time, the thermal history index of this segment reaches the segment thermal history threshold within a few minutes, and the temperature field uniformity index remains below the segment uniformity threshold for several consecutive monitoring cycles, thus meeting the segment termination condition. This allows for sufficient thermal history and good temperature uniformity while slightly extending the holding time. In another embodiment, the heat load pre-correction can also be applied only to the fine adjustment of the target temperature of each segment. Under the premise of ensuring that the upper limit of the safe temperature and the allowable temperature range of the steel grade are not exceeded, a similar compensation effect can be achieved by slightly increasing the target temperature of high-load furnaces and slightly decreasing the target temperature of low-load furnaces. When the corresponding adjustment of the holding time is small, this implementation can be regarded as an equivalent replacement of the above-mentioned holding time-based pre-correction method.

[0096] S5. During the execution of each segment, the target temperature offset of each temperature zone and the working status of the circulating fan and forced cooling fan are jointly adjusted according to the temperature field uniformity index, energy consumption index, and segment control target to ensure that the temperature field uniformity and thermal history meet the constraints. The specific implementation is as follows:

[0097] After the aforementioned adaptive segmented control objectives have been generated for each segment of this batch and sent to the programmable controller via segmented control objective messages, the industrial control computer uses the batch identifier and segment sequence number as session markers during the execution of each segment to jointly judge the temperature field uniformity index, energy consumption index, and segmented control objectives within each monitoring cycle of that segment, and adjusts the target temperature offset of the three temperature zones and the working status of the circulating fan and the forced cooling fan accordingly, so that the temperature field uniformity and thermal history within this segment meet the aforementioned constraints.

[0098] The target temperature offset for each temperature zone is a small increase or decrease in the target temperature of the upper, middle, and lower temperature zones based on the segmented target temperature, in degrees Celsius. A positive value indicates an increase in the base target temperature for that segment, while values ​​above zero, below zero, and equal to zero indicate a slight increase, a slight decrease, or no adjustment to the target temperature of that temperature zone, respectively. In one embodiment, the target temperature offset for each temperature zone is uniformly initialized to zero at the beginning of the segmentation. The operating status of the circulating fan and the forced cooling fan are parameters indicating the fan's start / stop and speed or frequency. The operating status includes the logic state of being on or off and the corresponding speed or frequency value, in revolutions per minute or frequency.

[0099] During the annealing process, at the end of each monitoring cycle, the programmable controller collects the temperatures of the three temperature zones, heating power, circulating fan, and forced cooling fan parameters as described above, and sends a message to the industrial control computer containing the batch identifier, the current segment sequence number, the aforementioned quantities, and the target temperature settings for each temperature zone. The industrial control computer aligns the temperature, power, and fan parameters in the message with the records in the local annealing process monitoring buffer. If the message for the current cycle is missing or incomplete, the record from the previous cycle is used as a substitute, and a communication incompleteness count is recorded in the batch control context. When the communication incompleteness count exceeds a preset threshold for several consecutive monitoring cycles, the industrial control computer marks the current batch identifier as unreliable and suspends subsequent adaptive adjustments, retaining only the basic target temperature and holding time in the segment control targets unchanged to ensure that the process is not unstable due to incorrect adjustments when communication quality deteriorates significantly.

[0100] For a normal monitoring cycle, the industrial control computer reads the temperature field uniformity index and energy consumption index corresponding to that cycle from the annealing process monitoring buffer. The temperature field uniformity index is a quantification of the degree of uneven temperature distribution in the three temperature zones. The energy consumption index includes cumulative specific energy consumption and short-time average power. In one embodiment, the industrial control computer uses a fixed-length observation window to statistically analyze the temperature field uniformity index and thermal history increment of the most recent monitoring cycles within each monitoring cycle. The length of the observation window preferably corresponds to the number of monitoring cycles within a few minutes and is recorded in the parameter version record. Within this observation window, the industrial control computer calculates the average and maximum values ​​of the temperature field uniformity index, the average value of the thermal history increment, and the average level of the short-time average power to reflect the evolution trend of the temperature field and thermal history within the current segment.

[0101] The industrial control computer executes adjustment decisions according to preset priorities in each monitoring cycle. In one embodiment, safety and temperature uniformity are given priority, followed by consideration of the degree of thermal history achievement and energy consumption level. Specifically, the average value of the temperature field uniformity index within the observation window is first compared with the uniformity threshold and allowable fluctuation range of this segment. If the average value is lower than the threshold and the maximum value does not exceed the upper limit of the threshold, the current temperature field uniformity is considered to meet the control target. In this case, the industrial control computer allows for slight adjustments to the target temperature offset and fan status of each temperature zone based on the difference between the thermal history index and the segmented thermal history threshold, as well as the energy consumption index, to improve the thermal history achievement speed or reduce energy consumption. If the average value is higher than the threshold or the maximum value significantly exceeds the upper limit of the threshold, the temperature field is considered to be significantly non-uniform. In this case, the industrial control computer prioritizes uniformity correction and no longer relaxes the temperature to pursue a faster thermal history. Instead, it improves the temperature distribution by adjusting the target temperature offset and the working status of the circulating fan in each temperature zone, and restricts further increases in heating power before the temperature field uniformity index falls back to the allowable range.

[0102] During temperature field uniformity correction, the industrial control computer identifies the highest and lowest temperature zones based on the current monitoring cycle's three temperature zones' temperature values, calculates the difference between the highest and lowest temperatures and the average temperature of the three zones, and if the highest temperature zone is higher than the average by a preset deviation threshold and the lowest temperature zone is lower than the average by a preset deviation threshold, then the target temperature offset of the highest temperature zone is adjusted by a preset step size along the cooling direction, and the target temperature offset of the lowest temperature zone is adjusted by a preset step size along the heating direction. The preset deviation threshold and the target temperature offset adjustment step size are configured in the system parameters and locked in the parameter version record. In one embodiment, the deviation threshold is preferably set within a certain range of degrees Celsius, and the target temperature offset adjustment step size is a certain number of degrees Celsius each time, limiting the cumulative value of the target temperature offset over multiple consecutive cycles. The maximum allowable offset value for each segment shall not exceed the maximum allowable offset value, which is preferably determined jointly by the allowable temperature range of the steel grade and the upper limit of the safe temperature. When only one temperature zone deviates significantly from the average value, the industrial control computer will only adjust the target temperature offset of that temperature zone in one step to avoid unnecessary disturbance to other temperature zones. When the temperature field is obviously uneven and the current speed of the circulating fan is lower than the set upper limit, the industrial control computer will simultaneously increase the target speed of the circulating fan by one step according to the preset step size to enhance the atmosphere circulation in the furnace. When the temperature field remains uniform for a long time and the energy consumption index is close to the predetermined upper limit, the industrial control computer can appropriately reduce the speed of the circulating fan to reduce energy consumption. During the adjustment process, the speed adjustment amount and the cumulative adjustment amount are limited each time to ensure that they do not exceed the allowable range on the fan nameplate.

[0103] When energy consumption and thermal history are jointly regulated, the industrial control computer compares the current cumulative thermal history of this segment with the segment's thermal history threshold. If, after a certain proportion of the expected heat preservation time has been executed in the segment, the cumulative thermal history is significantly lower than the threshold and the short-term average power is at a low level, it is determined that the thermal history of this segment is being reached too slowly. Under the premise that the temperature field uniformity index meets the conditions, the industrial control computer can slightly increase the overall target temperature offset of the three temperature zones, or appropriately reduce the speed or operating time of the strong cooling fan in the cooling segment to slow down the cooling rate, thereby increasing the thermal history increment. If the cumulative thermal history is close to or has already reached the segment's thermal history threshold, and the energy consumption index is close to the predetermined energy consumption limit for a long time, it is determined that the current segment's energy consumption pressure is high. Under the premise of ensuring that the segment's thermal history threshold can still be reached, the industrial control computer can control energy consumption by appropriately reducing the target temperature offset or adjusting the working strategy of the strong cooling fan. In one embodiment, the matching relationship between the energy consumption limit and the thermal history with time is determined by process engineers based on multi-furnace production data and recorded in the parameter version record.

[0104] After calculating the new target temperature offsets for each temperature zone, the target speed of the circulating fan, and the start-up strategy of the forced-cooling fan, the industrial control computer sends these adjustments as a single adjustment command message to the programmable controller (PLC) via the industrial Ethernet. The message includes a batch identifier, segment sequence number, target temperature offset for each temperature zone, target speed or frequency of the circulating fan, and start / stop and target speed of the forced-cooling fan. The message also carries the current monitoring cycle number, which the PLC uses to determine the message's age. Upon receiving the message, the PLC checks each parameter against the equipment's allowable range. For parameters exceeding the allowable range, it can refuse execution and return a response. A message containing an error flag indicating that the adjustment parameter has exceeded the limit is sent. This error flag is a new type added to the aforementioned error codes, preferably corresponding to code number eight. After receiving the error flag, the industrial control computer displays "Adaptive adjustment is restricted" on the touch screen and temporarily freezes the adaptive adjustment function of this segment, keeping the target temperature offset and fan status unchanged from the last successfully issued signal until manual confirmation or the segment ends. When the programmable controller rejects the adjustment command for multiple consecutive monitoring cycles, the industrial control computer can record this batch flag as an adaptive adjustment restricted state and prompt the user to check the parameter boundary settings in the process analysis after annealing.

[0105] In one embodiment, the programmable controller superimposes the target temperature bias onto the base segment target temperature of each temperature zone in each temperature control cycle to form the current actual temperature setpoint, which is then sent to the existing temperature regulation loop. The temperature regulation loop within each segment does not undergo structural changes and only receives the adaptive bias as the setpoint adjustment amount, thereby ensuring that the present invention achieves segmented adaptive regulation without changing the underlying mature control logic.

[0106] Preferably, under a set of representative operating conditions, for a batch of a certain low-carbon steel grade, with a furnace charge weight of approximately 3,000 kg and a close-packed stacking method, after the start of a certain high-temperature insulation segment, the initial temperature field uniformity index is approximately several tens of degrees Celsius, the circulating fan speed is half of the rated speed, and the forced cooling fan is turned off. As the monitoring cycle progresses, the industrial control computer detects that the upper temperature zone temperature is several degrees Celsius higher than the average, the lower temperature zone temperature is several degrees Celsius lower than the average, and the temperature field uniformity index exceeds the segment uniformity threshold. Therefore, the target temperature offset of the upper temperature zone is lowered by several degrees Celsius, the target temperature offset of the lower temperature zone is raised by several degrees Celsius, and the circulating fan speed is increased to a certain percentage of the rated speed. After several monitoring cycles, the temperature field uniformity index drops below the threshold and the cumulative thermal history gradually approaches the segmented thermal history threshold. The energy consumption index remains below the predetermined upper limit of specific energy consumption. At the end of the segment, both the temperature field uniformity index and the thermal history index meet the segment termination conditions. In another embodiment, adaptive adjustment can only act on the fan's operating state to keep the target temperature offset of each temperature zone at zero. Temperature field adjustment is completed by increasing or decreasing the speed and start-stop time combination of the circulating fan and the strong cooling fan according to the temperature field uniformity index. Under the condition that the segmented uniformity and thermal history constraints can be met and the energy consumption is acceptable, this fan-priority adjustment mode can be regarded as an equivalent replacement of the above-mentioned temperature offset adjustment scheme.

[0107] S6. After annealing, batch hardness and microstructure quality results are collected. The heat load index, execution parameters for each segment, energy consumption index, and quality results are associated and stored, and used to update the annealing segment control template parameters. The specific implementation is as follows:

[0108] After each of the aforementioned segments is completed and the conditions for the last segment to end are met, the programmable controller sends the annealing end signal for this batch, along with the batch identifier and cooling end time, to the industrial control computer via industrial Ethernet. The industrial control computer marks the batch status as annealing complete and awaiting quality inspection in the batch control context and starts the annealing quality result acquisition and template update unit.

[0109] Batch hardness refers to the set of hardness values ​​obtained by a hardness measuring device for this batch of iron wire rods after annealing. In one embodiment, quality inspectors cut several sections of wire rod at designated sampling locations and measure the hardness at multiple points using a hardness tester. The unit can be Brinell hardness or Vickers hardness. During measurement, the loading force and holding time are determined according to the company's internal quality inspection procedures. Quality inspectors enter or scan the batch identifier at the workshop quality inspection terminal and register the hardness values ​​of each measurement point, the corresponding sampling location information, and the measurement time in the quality inspection terminal. The quality inspection terminal periodically transmits data to the factory's Ethernet or wireless network. The industrial control computer pushes an information package containing batch identifiers, a list of hardness measurement points, and the target hardness range. The microstructure quality result is a comprehensive evaluation of the microstructure level, grain size, presence of defects such as segregation, banded structure, and network structure obtained from metallographic observation or tensile testing of representative samples selected in this batch. The unit can be discrete grade or pass / fail marking. After completing the metallographic or mechanical test, the quality inspector selects the microstructure level, defect category, and overall judgment conclusion in the quality inspection terminal interface. When generating the aforementioned hardness information package, the quality inspection terminal also packages and sends the microstructure quality result.

[0110] After receiving a quality information packet from the quality inspection terminal, the industrial control computer searches for the corresponding record in the batch control context based on the batch identifier. If multiple quality information packets exist with different measurement times, the latest one is taken as the valid record, and previous records are marked as historical versions and do not participate in template updates to ensure the idempotency of quality result acquisition. If the quality information packet for this batch is not received after a preset time window from the end of annealing (preferably a range of several hours to several days, with the specific value configured in the system parameters and locked in the parameter version record), the industrial control computer marks the batch as having a missing quality result and generates a message containing the batch identifier and a missing quality result error code, which is sent to the programmable controller and the workshop upper system. This error code is a new type based on the aforementioned error identifier, preferably corresponding to code number nine, prompting the quality inspectors to supplement or retest the quality results of this batch. This batch does not participate in template parameter updates until the missing quality result status is lifted.

[0111] For the received quality information package, the industrial control computer calculates the batch hardness statistics based on the list of hardness measurement points, including the batch average hardness, maximum and minimum hardness, hardness dispersion, and deviation from the upper and lower limits of the target hardness range. The target hardness range is given in the segmented control template or steel grade process specification and registered in the parameter version record. If the batch hardness falls entirely within the target hardness range and the hardness dispersion does not exceed the preset uniformity threshold, and the microstructure quality result is rated as qualified and does not contain serious defect categories, the industrial control computer marks the overall quality grade of the batch as qualified or excellent. Otherwise, it marks it as unqualified or boundary state and records the specific hardness distribution and microstructure defect type of the unqualified batch in the quality analysis library for subsequent manual diagnosis.

[0112] After completing the quality grade determination for this batch, the industrial control computer reads the heat load index, the corrected target temperature and holding time for each segment, the actual holding time in this segment, the temperature field uniformity index and thermal history index summary in each segment, the cumulative specific energy consumption and short-time average power statistics in the energy consumption index, the typical operating state statistics of the circulating fan and forced cooling fan in each segment (such as the cumulative running time at different speed levels in each segment), and the error identification information recorded during the execution process from the batch control context and the segment control target execution record. The industrial control computer then associates the above process parameters, heat load index, energy consumption index and quality grade results with the batch identifier to form the annealing operation archive record for this batch.

[0113] The record can be represented as a combined record containing batch identifier, steel grade, furnace loading weight range, stacking method code, heat load index, target and actual holding time for each segment, thermal history and temperature field uniformity statistics for each segment, cumulative specific energy consumption, short-time average power statistics, quality grade, and a list of error codes. The industrial control computer writes it into the annealing batch operation archive in non-volatile storage and adds the current template version identifier and record generation time to the record to establish a chain of evidence between the template version and the actual operating batch.

[0114] To avoid occasional anomalies interfering with template updates, the industrial control computer filters the annealing batch operation archive before executing the template update. Batches with serious erroneous codes during operation are removed, including those with abnormal start-up heating conditions, abnormal measurement signals, limited adaptive adjustment, and missing quality results. Only batches with normal process execution and a quality level of qualified or excellent are retained as candidate samples. Sample sets are constructed by combining steel grades, furnace weight ranges, and stacking methods. In one embodiment, the industrial control computer requires that the number of samples in each combination is not less than a preset sample lower limit. The preset sample lower limit can be set to several heats in the system parameters. When the number of samples is insufficient, only the operation archive is recorded and the template update is not executed. The process engineers then perform manual analysis.

[0115] For combinations that meet the sample size requirements, the industrial control computer calls the template update algorithm. In one implementation, the candidate batch is first divided into several heat load intervals according to the heat load index, such as light, normal, and heavy intervals. Then, within each heat load interval, the offset distribution of the actual heat preservation time of each segment relative to the template heat preservation time, the corresponding quality grade distribution, and the specific energy consumption level are statistically analyzed. Within each segment, the industrial control computer finds heat preservation time intervals with lower specific energy consumption while ensuring that the quality grade pass rate is not lower than the preset pass rate threshold as candidate optimization intervals. The preset pass rate threshold is set in the system parameters as, for example, not lower than a certain percentage and the version is locked. Within the candidate optimization interval, the industrial control computer calculates the recommended heat preservation time with the sample size and energy consumption level as weights. The recommended heat preservation time is limited to the allowable variation range of the template heat preservation time. The allowable variation range is given by the steel grade process specification and registered in the parameter version record.

[0116] For the target temperature parameter, the industrial control computer can calculate the average value and dispersion of the actual temperature offset in each segment. If it is confirmed that the temperature offset is biased in a certain direction for a long time and the corresponding quality performance is better and the energy consumption is not significantly increased, the recommended values ​​of the upper and lower limits of the target temperature range of the template can be adjusted appropriately. The adjustment range is also constrained by the allowable temperature range and the upper limit of the safe temperature of the steel grade.

[0117] The recommended holding time and suggested temperature range are combined into a new set of template candidate parameters. The industrial control computer generates a new template version record for the steel grade and furnace loading conditions in the template management module, assigns a new template version identifier, and records the list of batch identifiers, sample quantity, and statistical summary involved in the calculation. In one embodiment, the new template version is in a pending state by default. Process engineers need to review the statistical results and confirm its effectiveness on the engineering station interface. After confirmation, the industrial control computer will prioritize calling the latest version of the template parameters when generating segmented control templates for subsequent new batches. If the effectiveness is not confirmed, the old version of the template will still be used to ensure process stability.

[0118] The minimum feasible set of messages for the quality result interface may include batch identifier, steel grade code, upper and lower limits of target hardness range, array of hardness measurement point values, microstructure grade and defect marker, overall quality judgment, and measurement time. The message is sent by the quality inspection terminal. If the industrial control computer does not receive the message within a timeout period or if a field is missing, it generates the aforementioned error code 9 and records the reason for the incomplete quality result in the batch control context. In one embodiment, the quality inspection terminal and the industrial control computer can use a message queue or transaction mechanism to ensure that each batch quality result message is successfully processed by the industrial control computer at least once. When the same batch of quality results is sent repeatedly, the industrial control computer identifies the duplicates by combining the batch identifier and measurement time and retains only the record with the latest time to avoid multiple writes causing the same batch to be weighted repeatedly in the template update.

[0119] Preferably, under a set of representative operating conditions, for a certain low-carbon steel grade, a furnace charge weight of approximately 3,000 kg, and a product with a close stacking method, after introducing the method of this invention, the industrial control computer accumulates annealing batch operation files of dozens of qualified batches within six months. After screening and statistical analysis of these batches, it is found that when the template holding time is increased by several minutes relative to the original value in the high-temperature holding segment and the speed of the strong cooling fan is appropriately reduced in the cooling segment, the average hardness of the batch is closer to the middle of the target value and the hardness dispersion is reduced, resulting in an average energy consumption reduction of several percentage points. Thus, a new set of template candidate parameters is generated and reviewed and confirmed by process engineers. This combination is then used as a new template version for subsequent batches. In another embodiment, template updates may not automatically generate recommended holding time values, but only generate statistical results summarized in the form of charts or lists. Process engineers manually modify the segment control template parameters based on these statistical results. When the statistical scope and method are consistent with the above-described embodiments, and the modified template parameter version is also identified and the evidence chain is registered, this manual update form can be regarded as an equivalent replacement for the aforementioned automatically calculated recommended parameter form.

[0120] All calculations involved in the embodiments are dimensionless numerical calculations, and the preset parameters and thresholds in the calculations are set by those skilled in the art according to the actual situation.

[0121] It should be noted that this invention can be deployed on the device itself to realize embedded applications, or it can run on a PC or other terminal with a user interface, thereby meeting various hardware environments and usage requirements.

[0122] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wireless or wired transmission; wired transmission methods include optical fiber, twisted pair, coaxial cable, etc.; wireless transmission includes infrared, microwave, etc. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center containing one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0123] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0124] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0125] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0126] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0127] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0128] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0129] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for segmented temperature adaptive control of a vacuum annealing furnace for iron wire rods, characterized in that, include: S1. After loading the furnace, collect the steel type, loading weight and stacking method, and call the annealing segment control template that matches the batch information to generate the segment target temperature and holding time plan; S2. After the vacuum is stabilized, the three temperature zones are heated with a constant heating power. During the start-up phase, the temperature changes of each temperature zone are collected, and the heat load index and temperature field uniformity index are calculated based on the heating slope and response time. S3. During the annealing process, the temperature of the three temperature zones, heating power, and parameters of the circulating fan and the forced cooling fan are collected periodically to construct temperature field uniformity index, thermal history index and energy consumption index. S4. Based on the heat load index, the segment target parameters in the annealing segment control template are pre-corrected, and the start and end conditions of each segment are set with the temperature field uniformity index and thermal history index as constraints to generate adaptive segment control targets; before the segment annealing starts, the industrial control computer reads the heat load index from the batch control context and generates heat load correction coefficients in combination with the reference characteristic library, pre-corrects the heat preservation time of each segment template in the annealing segment control template and limits it to the process allowable range; During the annealing process, thermal history indicators and temperature field uniformity indicators are used as constraints for the segment start and end conditions according to the monitoring cycle. The segment end judgment is generated by combining the modified segment target temperature and segment holding time. The modified segment target temperature, segment holding time, segment start conditions, segment end conditions and the actual execution result of this segment are recorded as the segment control target execution record. S5. During the execution of each segment, the target temperature offset of each temperature zone, the working status of the circulating fan and the strong cooling fan are jointly adjusted according to the temperature field uniformity index, energy consumption index and segment control target, so that the temperature field uniformity and thermal history meet the constraints. S6. After annealing, collect batch hardness and microstructure quality results, associate and store the heat load index, execution parameters of each segment, energy consumption index and quality results, and use them to update the annealing segment control template parameters.

2. The segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to claim 1, characterized in that, S1 includes: After loading into the furnace, the weight data of the loaded furnace is collected by a weighing device; The industrial control computer selects a stable range that meets the weight fluctuation threshold and takes the average value to determine the furnace loading weight; The industrial control computer matches templates from the annealing segment control template library that have the same steel grade, the same stacking method code, and the appropriate furnace weight based on the steel grade, furnace weight, and stacking method. After confirming that the target temperature and holding time of each segment are within a safe range, the target temperature, holding time and allowable temperature deviation range of each segment are formed into a segment plan set, and then sent to the programmable controller with batch identifier and template version identifier.

3. The segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to claim 1, characterized in that, S2 include: After the batch information collection and annealing segment control template call are completed and the segment plan is successfully registered between the industrial computer and the programmable controller, the industrial computer uses the batch identifier as the session identifier. The programmable controller collects the vacuum level according to a fixed rhythm and sends it to the industrial control computer. The industrial control computer determines the vacuum stability state based on the vacuum fluctuation threshold and the target vacuum level threshold. When the vacuum is not up to standard, the heating circuit is cut off by the programmable controller. After the vacuum stabilizes, the programmable controller is instructed to drive the heating circuits of the upper, middle and lower temperature zones with constant heating power and collect the temperature of the three temperature zones according to the preset sampling period.

4. The segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to claim 3, characterized in that: The industrial computer selects the reference temperature range and the target temperature range based on the three temperature zones during the startup phase, calculates the average temperature and time center of each temperature zone, and obtains the temperature rise slope. The response time is obtained based on the time it takes for the temperature to reach the preset temperature threshold. The heating slope and response time are compared with the reference heating slope and reference response time in the reference characteristic library to generate the heat load index. The temperature field uniformity index is generated based on the temperature rise slope difference and temperature difference of each temperature zone. The heat load index is written into the batch control context and sent to the programmable controller via industrial Ethernet.

5. The segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to claim 1, characterized in that, S3 include: During the annealing process monitoring phase, the programmable controller collects the temperature of the three temperature zones, heating power, circulating fan parameters, and strong cooling fan parameters in each monitoring cycle and sends them to the industrial control computer via industrial Ethernet. The industrial control computer monitors the alignment data of the buffer zone during the annealing process and constructs temperature field uniformity index, thermal history index and energy consumption index; The indicators, along with the batch identifier and segment sequence number, are written into the batch control context, and monitoring messages containing the batch identifier, temperature field uniformity indicators, thermal history indicators, and cumulative specific energy consumption are sent to the programmable controller according to the monitoring cycle.

6. The segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to claim 1, characterized in that, S5 include: During the segmented execution process, the industrial control computer uses batch identifiers and segment sequence numbers as indexes to read temperature field uniformity indicators, thermal history indicators, and energy consumption indicators from the annealing process monitoring buffer, and performs statistical analysis on the indicators within a preset observation window. Based on the priority order of safety and temperature field uniformity, the target temperature offset of each temperature zone and the target parameters of the circulating fan and the forced cooling fan are generated in combination with the segmented control objectives, and then sent to the programmable controller through adjustment instruction messages. When monitoring information and adjustment parameters are marked as abnormal, the adaptive adjustment is frozen to maintain the segmented target temperature and segmented heat preservation time.

7. The segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to claim 1, characterized in that, S6 include: After receiving the quality information packet containing batch identifier, batch hardness and microstructure quality results sent by the quality inspection terminal, the industrial control computer calculates the batch hardness statistic and generates a quality grade by combining the microstructure quality results. The quality grade is associated with the batch identifier, steel type, furnace loading weight range, stacking method code, heat load index, target and actual values ​​of holding time for each segment, thermal history index and temperature field uniformity index summary for each segment, energy consumption index, error code, and template version identifier and stored in the annealing batch operation archive.

8. The segmented temperature adaptive control method for a vacuum annealing furnace for iron wire rods according to claim 7, characterized in that: The industrial control computer removes batches with abnormal startup and heating conditions, abnormal measurement signals, limited adaptive adjustment, and missing quality results from the annealing batch operation archive. It then constructs a candidate sample set by encoding according to steel type, furnace weight range, and stacking method. The heat load is divided into heat load intervals according to the heat load index. The recommended heat preservation time and suggested target temperature range are calculated based on the heat preservation time offset, quality level and energy consumption index of each segment, forming a set of template candidate parameters and generating a template version identifier.

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