A multi-node real-time regulation industrial process temperature management system and method

Abstract

This invention provides a multi-node real-time temperature control system and method for industrial processes, relating to the field of automatic temperature control technology for industrial processes. It includes a sensor layer, a control layer, and an execution layer. The sensor layer includes a first to a seventh temperature sensor, a moisture content detection unit, and a vehicle speed detection unit. The control layer includes a central controller with a built-in temperature gradient curve planning module, a thermal hysteresis feedforward compensation module, a key node temperature window locking module, and a feedback correction module. The execution layer includes a first to a sixth actuator. The temperature gradient curve planning module generates a target temperature curve with temperature difference constraints; the thermal hysteresis feedforward compensation module predicts temperature drop based on a heat dissipation model and performs feedforward compensation; the key node temperature window locking module calculates the interface temperature using thermal weighting and locks the window; and the feedback correction module executes PID closed-loop control, achieving multi-node temperature collaborative control, improving product quality, and reducing scrap rate.

Description

Technical Field

[0001] This invention relates to the field of automatic temperature control technology for industrial processes, and specifically to a multi-node real-time control system and method for industrial process temperature management. Background Technology

[0002] In continuous production lines with multiple heating or temperature control nodes along the material conveying direction, temperature is a key process parameter affecting product forming quality. Taking a single-faced corrugated cardboard production line (referred to as a single-faced line) as an example, its process flow is as follows: the core paper is preheated by the core paper preheating roller and then enters the single-faced corrugating machine. It is pressed into a corrugated waveform between the upper and lower corrugating rollers. The glue coating roller coats the corrugated peaks with starch glue. The pressure roller presses the inner paper and the glued corrugated core paper together to form single-faced corrugated cardboard. After cooling and moisture balancing in the bridge conveyor section, it is wound up or enters the next process. The core paper preheating temperature determines the amount of moisture evaporation and the degree of fiber softening, the corrugating roller temperature determines the corrugation setting effect, the glue coating interface temperature determines the starch glue gelatinization quality, and the pressure roller temperature affects the initial tack of the composite.

[0003] Current single-unit temperature control generally adopts a mode of independent setting for each node plus single-loop PID feedback: temperature sensors are installed at the preheating roller, corrugated roller, coating roller, pressure roller, etc., and each node independently adjusts the steam valve opening according to its own set value. This mode has the following shortcomings: First, it cannot compensate for the lag in heat conduction during material transport between nodes. It takes several seconds for material to move from one temperature control node to the next, during which time it dissipates heat into the environment. The actual temperature of the material reaching the downstream end is lower than the upstream outlet temperature. Because each node only detects its own roller surface temperature and provides local feedback, the system cannot sense the temperature drop of the material during transport, causing the downstream process temperature to deviate from the target.

[0004] Secondly, the unconstrained temperature difference between adjacent nodes can easily lead to thermal stress defects. During changes in conveying speed, material specifications, or temperature fluctuations, independent adjustments at each node can cause sudden changes in temperature between adjacent nodes. The material experiences a severe temperature gradient over a short distance, resulting in warping, corrugation collapse, delamination, and wire bursting.

[0005] Third, the interface temperature at key process nodes is disconnected from the process temperature window. Taking the glue coating node as an example, starch glue gelatinization has a temperature window of approximately 58°C to 65°C, while the glue interface temperature is jointly determined by the temperature of the coating roller and the temperature of the corrugated core paper. The existing system only independently controls the water bath temperature of the coating roller, without linkage with the actual temperature of the core paper. When changes in the conveying speed cause fluctuations in the core paper temperature, the interface temperature frequently deviates from the gelatinization window.

[0006] Therefore, there is an urgent need for a real-time control system that can collaboratively plan, predict and compensate for, and lock critical windows for the temperature of multiple nodes along the material conveying direction. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-node real-time control system and method for industrial process temperature management, solving the technical problems of existing multi-node production lines where independent control of each temperature node cannot compensate for thermal hysteresis between nodes, adjacent temperature differences are unconstrained, and the interface temperature of key process nodes deviates from the process window.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A multi-node real-time control system for industrial process temperature management consists of a three-layer architecture: a sensor layer, a control layer, and an execution layer.

[0009] The sensor layer includes a first temperature sensor to a seventh temperature sensor, a moisture content detection unit, and a vehicle speed detection unit. A first temperature control node to a sixth temperature control node are sequentially arranged along the material conveying direction. The first to sixth temperature sensors are respectively located at each temperature control node to detect the material temperature or roller surface temperature. The seventh temperature sensor detects the ambient temperature. The moisture content detection unit is located upstream of the first temperature control node to detect the material moisture content. The vehicle speed detection unit detects the real-time material conveying speed.

[0010] The control layer includes a central controller, whose input terminals are electrically connected to the various devices in the sensor layer. The central controller incorporates a temperature gradient curve planning module, a thermal hysteresis feedforward compensation module, a critical node temperature window locking module, and a feedback correction module. The temperature gradient curve planning module generates a target temperature curve along the conveying path based on the material's moisture content, material parameters, and target conveying speed, constraining the temperature difference between adjacent nodes to no more than 15°C to 25°C. The thermal hysteresis feedforward compensation module calculates the conveying time according to the conveying time formula based on the node spacing and real-time conveying speed, using ambient temperature as an input parameter. It employs a first-order heat dissipation model to predict the material temperature reaching the downstream node and performs feedforward compensation. The measured material temperature at the upstream node outlet, ambient temperature, and heat dissipation coefficient are all model input parameters. The critical node temperature window locking module calculates the interface temperature using a thermal weighting method based on the predicted upstream material temperature and roller surface temperature, with a heat distribution coefficient ranging from 0.4 to 0.8. It adjusts the roller surface temperature to ensure the interface temperature falls within a set temperature window of 58°C to 65°C. The feedback correction module performs PID calculations on the measured temperature of each node and the corrected setpoint.

[0011] t = L / v Δ T loss =( T mat - T amb )×[1-exp(- k × t )] T int = α × T pred4 +(1- α )× T roll4 The execution layer includes a first actuator to a sixth actuator, which are respectively located on the temperature regulation pipelines of the first temperature control node to the sixth temperature control node, and the control terminal of each actuator is electrically connected to the output terminal of the central controller.

[0012] The present invention also provides a method for real-time control of industrial process temperature by multiple nodes, including steps S1 to S5, as described in claim 8.

[0013] This invention provides a multi-node real-time control system and method for industrial process temperature management, which has the following beneficial effects: (1) This invention establishes a constraint with adjacent temperature difference (Δ) T max The temperature gradient curve along the process (from 15°C to 25°C) ensures that the target temperature of each node is no longer an isolated set value but a coordinated curve that satisfies thermal stress constraints, effectively avoiding warping, deformation and delamination of materials caused by sudden temperature changes between adjacent nodes.

[0014] (2) This invention uses a first-order heat dissipation model Δ with ambient temperature as the input parameter. T loss =( T mat - T amb )×[1-exp(- k × t Predicting the temperature drop of materials during inter-node transport and feeding forward to compensate for downstream temperature transforms the traditional "post-event feedback" into "pre-event compensation," overcoming the second-level transport lag and enabling the actual material temperature to accurately track the process target.

[0015] (3) The present invention uses a thermal weighted method at key process nodes. T int = α × T pred4 +(1- α )× T roll4 The interface temperature is calculated and locked within a set temperature window of 58°C to 65°C. The roller surface temperature is adjusted in conjunction with the predicted material temperature, ensuring that the interface temperature is within the optimal process range under different conveying speeds and material specifications, thus significantly improving the bonding quality.

[0016] (4) This invention organically combines temperature gradient curve planning, thermal hysteresis feedforward compensation, and key node temperature window locking to form a closed-loop collaborative control of "planning-prediction-locking-feedback": the target temperature curve generated by the temperature gradient curve planning module serves as the benchmark for feedforward compensation and window locking; the predicted temperature output by the thermal hysteresis feedforward compensation module... T pred4 The temperature window locking module directly serves as the input for the critical node temperature window locking module, which calculates the interface temperature and adjusts the roller surface temperature accordingly. The temperature difference constraint acts simultaneously on the set value after feedforward compensation and the roller surface temperature after window locking, ensuring that the temperature of each node still meets the adjacent temperature difference limit after compensation and locking. The feedback correction module eliminates residual deviations, the feedforward overcomes conveying lag, the temperature difference constraint prevents thermal stress defects, and the window locking ensures the quality of key processes. These four elements are interconnected and indispensable, and together they produce a comprehensive technical effect of improving product molding and bonding quality and reducing scrap rate. Attached Figure Description

[0017] In the attached diagram: Figure 1 This is a three-layer architecture block diagram of the system of the present invention; Figure 2 This is a flowchart illustrating the multi-node real-time control method of the present invention.

[0018] List of reference numerals 1. Sensor layer; 11. First temperature sensor; 12. Second temperature sensor; 13. Third temperature sensor; 14. Fourth temperature sensor; 15. Fifth temperature sensor; 16. Sixth temperature sensor; 17. Seventh temperature sensor; 18. Moisture content detection unit; 19. Vehicle speed detection unit; 2. Control layer; 21. Temperature gradient curve planning module; 22. Thermal hysteresis feedforward compensation module; 23. Key node temperature window locking module; 24. Feedback correction module; 3. Execution layer; 31. First executor; 32. Second executor; 33. Third executor; 34. Fourth executor; 35. Fifth executor; 36. Sixth executor; 4. Waste heat recovery pipeline. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0020] Example 1: Correspondence between temperature control nodes and the three-layer system architecture This embodiment uses a single-faced corrugated cardboard production line as the application object to illustrate the correspondence between temperature control nodes and single-faced corrugated cardboard production line equipment and the system architecture.

[0021] The temperature control nodes correspond as follows: The first temperature control node corresponds to the paper exit side of the core paper preheating roller in the single-faced corrugated board production line, where the material is core paper; the second temperature control node corresponds to the paper exit side of the liner paper preheating roller in the single-faced corrugated board production line, where the material is liner paper; the third temperature control node corresponds to the lower corrugating roller surface inside the single-faced corrugating machine in the single-faced corrugated board production line; the fourth temperature control node corresponds to the glue coating roller surface inside the single-faced corrugating machine in the single-faced corrugated board production line, i.e., the glue coating node; the fifth temperature control node corresponds to the pressure roller surface inside the single-faced corrugating machine in the single-faced corrugated board production line; the sixth temperature control node corresponds to the paper exit and bridge conveyor section entrance of the single-faced corrugating machine in the single-faced corrugated board production line, where the material is the formed single-faced corrugated board. Moisture content detection unit 18 is a near-infrared online moisture meter, installed on the paper feed side of the core paper preheating roller; speed detection unit 19 is an incremental photoelectric encoder, coaxially connected to the main drive motor of the production line. The set temperature window is the starch gelatinization temperature window, i.e., 58°C to 65°C.

[0022] like Figure 1 As shown, the system adopts a three-layer architecture consisting of sensor layer 1, control layer 2 (including the central controller), and execution layer 3.

[0023] Sensor Layer 1: The first temperature sensor 11 is a PT100 platinum resistance thermometer, installed 5mm above the paper web on the paper exit side of the core paper preheating roll, for non-contact detection of the paper surface temperature after core paper preheating. The second temperature sensor 12 is a PT100 platinum resistance thermometer, installed on the paper exit side of the inner paper preheating roll, for detecting the paper surface temperature after inner paper preheating. The third temperature sensor 13 is a PT100 platinum resistance thermometer, spring-loaded and attached to the non-engaging area of ​​the lower corrugated roll surface, for detecting the lower corrugated roll surface temperature. The fourth temperature sensor 14 is a PT100 platinum resistance thermometer, inserted into the water bath chamber of the coating roll, for detecting the coating roll surface temperature. The fifth temperature sensor 15 is a PT100 platinum resistance thermometer, attached to the pressure roll surface, for detecting the pressure roll surface temperature. The sixth temperature sensor 16 is an infrared thermometer, installed 10mm above the paper exit of the single-face corrugator, for detecting the paper surface temperature of the formed single-face corrugated board. The seventh temperature sensor 17 is a PT100 platinum resistance thermometer, installed in a ventilated location 1.5m above the paper surface in the production workshop to detect the ambient temperature. The moisture content detection unit 18 is a near-infrared online moisture meter, installed on the paper feed side of the core paper preheating roller, 200mm from the paper web, to detect the moisture content of the core paper base paper in real time. The speed detection unit 19 is an incremental photoelectric encoder, coaxially connected to the main drive motor, and its output pulse signal is converted into real-time conveying speed by the central controller.

[0024] Control Layer 2: The central controller adopts a programmable logic controller or industrial computer. Its analog input terminals are electrically connected to the first temperature sensor 11 to the seventh temperature sensor 17, the moisture content detection unit 18, and the vehicle speed detection unit 19. The central controller has built-in temperature gradient curve planning module 21, thermal hysteresis feedforward compensation module 22, critical node temperature window locking module 23, and feedback correction module 24. Each module is stored in the central controller's memory as a software program and executed by the central processing unit.

[0025] Actuation Layer 3: The first actuator 31 is a steam regulating valve, installed in the steam heating pipeline of the core paper preheating roll; the second actuator 32 is a steam regulating valve, installed in the steam heating pipeline of the inner paper preheating roll; the third actuator 33 is a steam regulating valve, installed in the steam heating pipeline of the lower corrugated roll; the fourth actuator 34 is an electric regulating valve for the warm water circuit, installed in the warm water circulation pipeline of the glue coating roll; the fifth actuator 35 is a steam regulating valve, installed in the steam heating pipeline of the pressure roll; and the sixth actuator 36 is an air volume regulating valve, installed in the cooling air duct of the cable tray conveyor section. The control terminals of each actuator are electrically connected to the output terminal of the central controller.

[0026] Example 2: Temperature gradient curve planning and temperature difference constraint The temperature gradient curve planning module 21 generates the target temperature for each temperature control node based on the material moisture content, material parameters (grammage, specific heat capacity, heat dissipation coefficient), and target conveying speed. Taking a typical process of a single-faced corrugated board production line as an example, the benchmark target temperature curve is as follows: the first temperature control node target temperature is 90°C to 110°C (temperature after core paper preheating), the second temperature control node target temperature is 85°C to 105°C (temperature after linerboard preheating), the third temperature control node target temperature is 150°C to 170°C (temperature of the lower corrugated roll surface), the fourth temperature control node target temperature is 55°C to 70°C (temperature of the glue coating roll water bath), the fifth temperature control node target temperature is 130°C to 150°C (temperature of the pressure roll surface), and the sixth temperature control node target temperature is 70°C to 90°C (temperature of the paper surface at the paper outlet).

[0027] The target temperature difference between adjacent temperature control nodes is constrained to not exceed Δ. T max Δ T max =15°C to 25°C, in this embodiment Δ T max =20°C. When the temperature difference between adjacent nodes in the reference curve exceeds Δ... T maxWhen the temperature difference between the target temperature of the third temperature control node (160°C) and the target temperature of the fourth temperature control node (60°C) reaches 100°C, the target temperatures of the third and fourth temperature control nodes are used as fixed anchor points (these two nodes are key process nodes for corrugated forming and gluing, and their temperatures cannot be adjusted). The target temperatures of the first, second, fifth, and sixth temperature control nodes are then proportionally compressed to ensure that the temperature difference between all adjacent nodes does not exceed Δ. T max .

[0028] Moisture content bias: When the moisture content of the core paper detected by the moisture content detection unit 18 is higher than the reference moisture content (e.g., the reference moisture content is 7%), for every 1 percentage point increase in moisture content, the target temperature of each node along the process is increased by 2°C to 4°C (3°C in this embodiment) to increase the amount of water evaporation; for every 1 percentage point decrease in moisture content, the temperature is decreased by 2°C to 4°C.

[0029] Example 3: Thermal Hysteresis Feedforward Compensation The thermal hysteresis feedforward compensation module 22 calculates the conveying time based on the distance between adjacent temperature control nodes and the real-time conveying speed. Taking a single-face corrugated cardboard production line as an example, the distance between the core paper preheating roller and the lower corrugating roller is 1.5m, and the working speed is 120m / min, which is 2m / s, so the conveying time is 0.75s; the distance between the lower corrugating roller and the gluing roller is 0.3m, so the conveying time is 0.15s; the distance between the gluing roller and the pressure roller is 0.2m, so the conveying time is 0.1s; and the distance between the pressure roller and the paper outlet is 2.0m, so the conveying time is 1.0s.

[0030] The material heat dissipation model is Δ T loss =( T mat - T amb )×[1-exp(- k × t Taking the process from the first temperature control node to the second temperature control node (from the preheated core paper to the lower corrugated roll, taking the core paper path as an example), the measured material temperature at the outlet of the upstream temperature control node is 100°C, the ambient temperature detected by the seventh temperature sensor 17 is 25°C, the heat dissipation coefficient is 0.15 / s (related to paper weight and moisture content), and the conveying time is 0.75s. Therefore, the temperature drop is (100-25)×[1-exp(-0.15×0.75)]=75×[1-exp(-0.1125)]=75×0.1064≈8.0°C. That is, the core paper experiences a temperature drop of approximately 8°C during its conveying from the preheated roll to the next node.

[0031] The predicted downstream arrival temperature is equal to the measured material temperature at the upstream temperature control node outlet minus the temperature drop. The feedforward compensation is equal to the downstream target temperature minus the predicted arrival temperature. If the target temperature of the second temperature control node is 95°C and the predicted arrival temperature is 100-8=92°C, then the feedforward compensation is 95-92=3°C. This 3°C is added to the temperature setpoint of the second temperature control node, causing the second actuator 32 to open the steam valve earlier to compensate for the temperature drop during transport.

[0032] When the vehicle speed detection unit 19 detects acceleration or deceleration, it recalculates the delivery time and feedforward compensation amount based on the changed vehicle speed, and sends the compensation amount to the downstream actuator within the lead time, thereby realizing temperature prediction and adjustment during the speed change process.

[0033] Example 4: Temperature Window Locking at Critical Nodes The critical node temperature window locking module 23 performs interface temperature locking for the fourth temperature control node (adhesive application node). Interface temperature T int = α × T pred4 +(1- α )× T roll4 ,in T pred4 The temperature of the core paper when it reaches the coating roller is predicted by the thermal hysteresis feedforward compensation module 22. T roll4 The temperature of the coating roller surface detected by the fourth temperature sensor 14. α Let be the heat distribution coefficient, and take . α =0.6 (range 0.4 to 0.8).

[0034] Taking a typical operating condition as an example, the predicted core paper temperature is 80°C (the predicted temperature of the core paper after heat dissipation during its transport from the lower corrugated roll to the coating roll), and the coating roll surface temperature is 60°C. Therefore, the interface temperature is 0.6×80 + 0.4×60 = 48 + 24 = 72°C. This temperature is higher than the upper limit of the starch gelatinization window of 65°C, indicating that the coating roll temperature is too low or the core paper temperature is too high. The critical node temperature window locking module 23 outputs a temperature correction value, reducing the temperature setpoint of the third temperature control node (lower corrugated roll) or fine-tuning the water bath temperature of the fourth temperature control node (coating roll), so that the interface temperature falls back to within the 58°C to 65°C window.

[0035] When the machine speed increases from 120m / min to 150m / min, the conveying time is shortened, reducing heat dissipation from the core paper. The predicted temperature rises to approximately 85°C. If the coating roller surface temperature remains at 60°C, the interface temperature will be 0.6×85+0.4×60=51+24=75°C, exceeding the window limit. The critical node temperature window locking module 23 automatically outputs a correction amount to adjust the coating roller water bath temperature, causing the interface temperature to fall back within the window limit.

[0036] Comparative verification: Under the same operating conditions of 120m / min and 25°C ambient temperature, if thermal hysteresis feedforward compensation and critical node temperature window locking are not enabled, and only independent PID feedback control of each node is used, the interface temperature of the coating node fluctuates between 52°C and 78°C because heat dissipation during transportation is not compensated and the temperature of the coating roller is not linked with the core paper temperature. The time outside the set temperature window of 58°C to 65°C accounts for about 35%, resulting in a degumming and corrugated collapse defect rate of about 8%. After enabling the thermal hysteresis feedforward compensation and critical node temperature window locking of the present invention, the interface temperature is stabilized between 59°C and 64°C, the time within the window accounts for 100%, and the degumming and corrugated collapse defect rate is reduced to below 1%.

[0037] Example 5: Feedback Correction PID Control The feedback correction module 24 performs PID closed-loop control on each temperature control node. Taking the third temperature control node (lower corrugated roll) as an example, the deviation between the measured roll surface temperature detected by the third temperature sensor 13 and the set value after feedforward compensation correction is calculated. After PID calculation (proportional band P=5% to 15%, integral time I=20s to 60s, derivative time D=0s to 5s), a 4mA to 20mA control signal is output to the third actuator 33 (steam regulating valve). The opening of the regulating valve changes the steam flow rate, so that the roll surface temperature tracks the set value.

[0038] Feedforward compensation and PID feedback constitute a composite control: feedforward overcomes temperature deviations caused by measurable disturbances (vehicle speed changes, ambient temperature changes, moisture content fluctuations), and PID feedback eliminates residual deviations and unmeasurable disturbances. The two work together to improve temperature control accuracy.

[0039] Example 6: End-node slow cooling control The sixth temperature control node (paper outlet / cable tray inlet) performs slow cooling control. The sixth temperature sensor 16 detects the paper surface temperature at the paper outlet, and the central controller calculates and controls the sixth actuator 36 (airflow regulating valve) to adjust the cooling airflow so that the cooling rate of the single-face corrugated cardboard in the cable tray conveyor section does not exceed 3°C / s, thus avoiding sudden cooling that could cause the corrugated cardboard to warp and delaminate.

[0040] Example 7: Waste Heat Recovery The system also includes a waste heat recovery pipeline 4. High-temperature condensate discharged from the steam traps of the third temperature control node (lower corrugated roll) and the fifth temperature control node (pressure roll) is fed into the flash tank via a steam trap. The secondary steam generated during flash evaporation, after pressure stabilization, is fed into the temperature regulation pipelines of the first temperature control node (core paper preheating roll) and the sixth temperature control node (bridge section) via the waste heat recovery pipeline 4, serving as an auxiliary heat source. The flash tank pressure is set to 0.1 MPa to 0.2 MPa (gauge pressure), and the secondary steam temperature is approximately 105°C to 120°C, which can reduce the steam consumption of the core paper preheating roll by approximately 15% to 20%.

[0041] Example 8: Axial zone temperature control of the roller surface The third temperature control node (lower corrugated roll) adopts axial three-zone temperature control. The third temperature sensor 13 includes an operating side temperature sensor, a middle temperature sensor, and a drive side temperature sensor arranged axially along the roll surface. The third actuator 33 includes three independent steam regulating valves corresponding to the operating side heating zone, the middle heating zone, and the drive side heating zone, respectively. The central controller adjusts the opening of the corresponding regulating valves according to the measured temperature of the three zone temperature sensors to ensure that the temperature deviation of the three heating zones does not exceed 5°C, thus eliminating uneven corrugation formation caused by the temperature difference between the two ends and the middle of the corrugated roll.

[0042] Example 9: Control Flow like Figure 2 As shown, the multi-node real-time control method of the present invention includes the following steps: S1. Data Acquisition: The material temperature or roller surface temperature and the production environment temperature are collected by the first temperature sensor 11 to the seventh temperature sensor 17 respectively from the first temperature control node to the sixth temperature control node. The material moisture content is collected by the moisture content detection unit 18 and the real-time conveying speed is collected by the vehicle speed detection unit 19.

[0043] S2. Gradient Planning: The temperature gradient curve planning module 21 generates a target temperature curve based on the material moisture content, material parameters, and target conveying speed, constraining the adjacent temperature difference to not exceed Δ. T max =15°C to 25°C; if the baseline curve exceeds the limit, the temperature of the remaining nodes is compressed proportionally with the third and fourth temperature control nodes as anchor points; and an overall bias is applied according to the moisture content deviation.

[0044] S3, Feedforward Compensation: Thermal Hysteresis Feedforward Compensation Module 22 t = L / v Calculate the transport time for each segment, according to Δ T loss =( T mat - T amb )×[1-exp(-k × t )] Calculate the temperature drop of each segment, predict the downstream arrival temperature, calculate the feedforward compensation amount and add it to the downstream set value; when changing speed, issue the compensation amount in advance.

[0045] S4, Window Lock: Key Node Temperature Window Lock Module 23 T int = α × T pred4 +(1- α )× T roll4 Calculate the interface temperature of the fourth temperature control node. α =0.4 to 0.8, adjust the roller surface temperature so that the interface temperature falls within the set temperature window of 58°C to 65°C.

[0046] S5. Feedback Correction: The feedback correction module 24 performs PID calculations on the measured temperature of each node and the corrected set value, and outputs the control quantity to the first actuator 31 to the sixth actuator 36 to adjust the temperature regulation pipeline of each node in real time.

[0047] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-node real-time temperature control system for industrial processes, applied to a continuous production line with a first temperature control node, a second temperature control node, a third temperature control node, a fourth temperature control node, a fifth temperature control node, and a sixth temperature control node sequentially arranged along the material conveying direction, characterized in that, include: The sensor layer (1) includes: The first temperature sensor (11) is located at the first temperature control node to detect the material temperature at the first temperature control node; The second temperature sensor (12) is located at the second temperature control node to detect the material temperature at the second temperature control node; The third temperature sensor (13) is located at the third temperature control node to detect the roller surface temperature of the third temperature control node; The fourth temperature sensor (14) is located at the fourth temperature control node to detect the roller surface temperature of the fourth temperature control node; The fifth temperature sensor (15) is located at the fifth temperature control node to detect the roller surface temperature of the fifth temperature control node; The sixth temperature sensor (16) is located at the sixth temperature control node to detect the material temperature at the sixth temperature control node; The seventh temperature sensor (17) is used to detect the temperature of the production environment; A moisture content detection unit (18) is located upstream of the first temperature control node to detect the moisture content of the material. The vehicle speed detection unit (19) is used to detect the real-time conveying speed of the material; The control layer (2) includes a central controller, the input of which is electrically connected to the first temperature sensor (11) to the seventh temperature sensor (17), the moisture content detection unit (18), and the vehicle speed detection unit (19); the central controller has the following built-in: The temperature gradient curve planning module (21) is used to generate the target temperature curve of each temperature control node along the material conveying direction based on the material moisture content detected by the moisture content detection unit (18), the pre-input material parameters, and the set target conveying speed, and to constrain the target temperature difference between adjacent temperature control nodes to not exceed the set temperature difference threshold Δ. T max The Δ T max The temperature ranges from 15°C to 25°C. The thermal hysteresis feedforward compensation module (22) is used to adjust the thermal hysteresis feedforward compensation according to the distance between adjacent temperature control nodes and the real-time conveying speed detected by the vehicle speed detection unit (19). τ = L / v Calculate the material transport time between adjacent temperature control nodes, where L The conveying distance between adjacent temperature control nodes. v For real-time conveying speed; and based on the material heat dissipation model Δ T loss =( T mat - T amb )×[1-exp(- k × τ Predict the temperature of the material when it reaches the downstream temperature control node, where T mat The measured material temperature at the outlet of the upstream temperature control node. T amb The ambient temperature detected by the seventh temperature sensor (17) k The heat dissipation coefficient is related to material parameters and moisture content; the deviation between the predicted temperature and the target temperature is used as a feedforward compensation and added to the temperature setpoint of the downstream temperature control node. The critical node temperature window locking module (23) is used to determine the upstream material temperature of the fourth temperature control node based on the thermal hysteresis feedforward compensation module (22). T pred4 The roller surface temperature of the fourth temperature control node detected by the fourth temperature sensor (14) T roll4 The interface temperature between the material and the roller surface at the fourth temperature control node is calculated using a heat-weighted method. T int = α × T pred4 +(1- α )× T roll4 ,in α The heat distribution coefficient is 0.4 ≤ α ≤0.8; The output temperature correction amount ensures that the interface temperature falls within the set temperature window, which is 58°C to 65°C; The feedback correction module (24) is used to perform PID calculation on the deviation between the measured temperature of each temperature control node and the set value corrected by the thermal hysteresis feedforward compensation module (22), and output the control quantity. The execution layer (3) includes: The first actuator (31), the second actuator (32), the third actuator (33), the fourth actuator (34), the fifth actuator (35) and the sixth actuator (36) are respectively located on the temperature regulation pipeline from the first temperature control node to the sixth temperature control node. The control end of each actuator is electrically connected to the output end of the central controller. The temperature of each temperature control node is adjusted in real time according to the control quantity output by the feedback correction module (24).

2. The multi-node real-time regulated industrial process temperature management system of claim 1, wherein, When the absolute value of the target temperature difference between any two adjacent temperature control nodes in the reference temperature curve exceeds Δ T max At that time, the temperature gradient curve planning module (21) uses the target temperatures of the third and fourth temperature control nodes as fixed anchor points, and proportionally compresses the target temperatures of the first, second, fifth, and sixth temperature control nodes so that the difference in target temperature between all adjacent temperature control nodes does not exceed Δ. T max .

3. The multi-node real-time control system for industrial process temperature management according to claim 1, characterized in that, The temperature gradient curve planning module (21) also applies an overall bias to the target temperature curve based on the deviation between the material moisture content detected by the moisture content detection unit (18) and the reference moisture content: for every 1 percentage point increase in moisture content above the reference moisture content, the target temperature of each temperature control node along the process is increased by 2°C to 4°C; for every 1 percentage point decrease in moisture content below the reference moisture content, the target temperature of each temperature control node along the process is decreased by 2°C to 4°C.

4. The multi-node real-time regulated industrial process temperature management system of claim 1, wherein, When the vehicle speed detection unit (19) detects that the material conveying speed is accelerating or decelerating, the thermal hysteresis feedforward compensation module (22) recalculates the conveying time based on the changed conveying speed. τ And feedforward compensation amount, and lead time after the velocity change occurs. t a The compensation amount is then sent to the actuator of the corresponding downstream temperature control node, and the advance amount... t a Equal to the transmission time between the downstream temperature control node and the current temperature control node. τ .

5. The multi-node real-time regulated industrial process temperature management system of claim 1, wherein, The material temperature detected by the sixth temperature sensor (16) at the sixth temperature control node is processed by the central controller and output to the sixth actuator (36) to adjust the temperature regulation pipeline of the sixth temperature control node so that the cooling rate of the material at the sixth temperature control node does not exceed 3°C / s.

6. The multi-node real-time regulated industrial process temperature management system of claim 1, wherein, It also includes a waste heat recovery pipeline (4), the steam inlet of which is used to connect the drain end of the temperature regulation pipeline of the third temperature control node and the fifth temperature control node, and the steam outlet is used to connect to the temperature regulation pipeline of the first temperature control node and the sixth temperature control node. The recovered secondary steam is stabilized by the flash tank and used as an auxiliary heat source for the first temperature control node and the sixth temperature control node.

7. The multi-node real-time regulated industrial process temperature management system of claim 1, wherein, The third temperature sensor (13) includes an operating side temperature sensor, a middle temperature sensor, and a transmission side temperature sensor arranged along the axial direction of the roller surface of the third temperature control node. The third actuator (33) includes three independent regulating valves corresponding to the operating side heating zone, the middle heating zone, and the transmission side heating zone of the third temperature control node, respectively. The central controller adjusts the opening degree of the corresponding regulating valves according to the measured temperature of the operating side temperature sensor, the middle temperature sensor, and the transmission side temperature sensor, so that the temperature deviation of the three heating zones along the axial direction of the third temperature control node does not exceed 5°C.

8. A method for real-time temperature control in industrial processes using multi-node control, characterized in that, The system according to any one of claims 1 to 7 comprises the following steps: S1. The temperature and production environment temperature of the first temperature control node to the sixth temperature control node along the material conveying direction are collected by the first temperature sensor (11) to the seventh temperature sensor (17), the moisture content of the material is collected by the moisture content detection unit (18), and the real-time conveying speed of the material is collected by the vehicle speed detection unit (19). S2, Temperature Gradient Curve Planning Module (21) generates the target temperature curves for each temperature control node along the material conveying direction based on the material moisture content collected in step S1, the pre-input material parameters, and the set target conveying speed, and constrains the target temperature difference between adjacent temperature control nodes to not exceed Δ. T max =15°C to 25°C; S3, Thermal Hysteresis Feedforward Compensation Module (22) calculates the thermal hysteresis feedforward compensation based on the distance between adjacent temperature control nodes and the real-time conveying speed collected in step S1. τ = L / v Calculate the material conveying time between adjacent temperature control nodes, predict the temperature of the material when it arrives at the downstream temperature control node according to the material heat dissipation model described in claim 1, and add the deviation between the predicted temperature and the target temperature as a feedforward compensation amount to the temperature setpoint of the downstream temperature control node. S4, the critical node temperature window locking module (23) predicts the upstream material temperature of the fourth temperature control node based on the thermal hysteresis feedforward compensation module (22). T pred4 The roller surface temperature at the fourth temperature control node collected in step S1 T roll4 ,according to T int = α × T pred4 +(1- α )× T roll4 Calculate the interface temperature of the fourth temperature control node, where 0.4 ≤ α ≤0.8, the output temperature correction amount makes the interface temperature fall within the set temperature window of 58°C to 65°C; S5. The feedback correction module (24) performs a deviation PID calculation on the measured temperature of each temperature control node collected in step S1 and the set value after feedforward compensation correction in step S3, and outputs control quantities to the first actuator (31), the second actuator (32), the third actuator (33), the fourth actuator (34), the fifth actuator (35) and the sixth actuator (36) respectively, and adjusts the temperature of each temperature control node in real time.

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