Temperature monitoring system and method in optical-grade PMMA polymerization reaction process

Abstract

The invention discloses a temperature monitoring system and method in an optical-grade PMMA polymerization reaction process, and the method comprises the steps: enabling a predicted power value outputted by a power prediction module to learn historical data based on a model through the cooperation of a data collection module, a power prediction module and a composite control module; the feed-forward control unit generates a heating / or cooling demand instruction 5-10 minutes ahead of time, foreseeable temperature fluctuation such as reaction heat release and environmental disturbance is offset, the hysteresis problem of traditional PID control is solved, meanwhile, the feedback control unit dynamically compensates for prediction errors and unmodeled disturbance of the feed-forward control unit, and the control precision of the feed-forward control unit is improved. And the fusion layer unit combines the predicted power value and the corrected power to form an execution power value, and the power of an electric heater of the reaction kettle and the opening degree of a cooling valve are accurately controlled, so that the yield of PMMA products is remarkably improved.

Description

Technical Field

[0001] This application relates to the technical field of temperature monitoring during the polymerization process of PMMA, and more particularly to a temperature monitoring system and method for the polymerization process of optical-grade PMMA. Background Technology

[0002] As a high-performance transparent plastic, optical grade PMMA's key performance indicators, such as light transmittance and molecular weight distribution, are highly dependent on the stability of the polymerization reaction temperature (which needs to be controlled within ±0.5℃).

[0003] Existing temperature control systems employ only traditional feedback control methods, relying solely on PID feedback to respond to temperature deviations, lacking the ability to anticipate process disturbances. Furthermore, due to a lack of historical process data analysis, they cannot predict future power demands based on parameters such as material flow rate and ambient temperature, making it difficult to address the strongly nonlinear exothermic characteristics of PMMA monomer polymerization. Consequently, the proportion of PMMA products failing to meet optical-grade quality standards due to inaccurate polymerization temperature control has significantly increased. Summary of the Invention

[0004] This application provides a temperature monitoring system and method for the polymerization reaction process of optical-grade PMMA, in order to solve the problem mentioned in the background art that the scrap rate of PMMA products is significantly increased due to the response temperature deviation caused by relying solely on PID feedback control.

[0005] To address the aforementioned technical problems, in a first aspect, this application provides a temperature monitoring system for the polymerization process of optical-grade PMMA, including... The data acquisition module is used to collect the current process parameters during the polymerization reaction in real time. The current process parameters include temperature data, material flow rate, cooling medium flow rate and environmental parameters inside the reactor. The power prediction module stores a heating or cooling power prediction model trained based on historical process parameter data. The model is used to output the predicted heating or cooling power value within a preset time period based on the current process parameters. The composite control module includes: a feedforward control unit, a feedback control unit, and a fusion layer unit; The feedforward control unit is used to receive the predicted power value output by the power prediction module as a feedforward control quantity; The feedback control unit is used to calculate the correction power based on the deviation between the multi-point temperature data in the reactor and the temperature setpoint, and the correction power is used as the feedback control quantity. The fusion layer unit is used to fuse the feedforward control quantity and the feedback control quantity to generate the final execution power value.

[0006] In one embodiment, the data acquisition module includes a distributed temperature sensor unit, a mass flow unit, an electromagnetic flow unit, and a temperature and humidity transmitter unit. The distributed temperature sensor unit is used to acquire the liquid phase temperature and gas phase temperature inside the reactor. The mass flow unit is used to obtain the material flow rate; The electromagnetic flow unit is used to obtain the flow rate of the cooling medium; The temperature and humidity transmitter is used to acquire environmental parameters, including ambient temperature and relative humidity.

[0007] In one embodiment, the distributed temperature sensor unit includes a liquid phase temperature array subunit, Vapor phase temperature subunit; The liquid phase temperature array subunit is used to monitor the liquid phase temperature at multiple points within the reactor. The gas phase temperature subunit is used to monitor the gas phase temperature at the top of the reactor.

[0008] In one embodiment, the composite control module further includes a power compensation unit, which is used to compensate for the predicted power value; the compensation formula is: P pred =P base +K p *ΔT,P pred Compensation power value, P base Predicted power value, K p : is the gradient compensation coefficient, ΔT: is the axial temperature gradient.

[0009] In one embodiment, the correction power is equal to the weighted average of the deviation between the current temperature setpoint and the multi-point temperature data in the reactor, the cumulative temperature deviation from time 0 to the current time t, and the rate of temperature change.

[0010] In one embodiment, the power compensation unit further includes a data judgment subunit, which is used to determine the validity of the compensation power value. When the axial temperature gradient ΔT is greater than a preset threshold and lasts for a preset time, the compensation power value is invalid.

[0011] In one embodiment, the axial temperature gradient ΔT is calculated using the formula: ΔT = T bottom -T top / H×K adj ; T bottom : Liquid phase temperature at the bottom of the reactor, T top H: Liquid phase temperature at the top of the reactor; K: Vertical distance between temperature measuring points. adj: Correction factor for the height-to-diameter ratio of the reactor.

[0012] Secondly, this application also provides a temperature monitoring method during the polymerization reaction of optical-grade PMMA, applied to the aforementioned temperature monitoring system during the polymerization reaction of optical-grade PMMA, the method comprising: Collect current temperature data, material flow rate, cooling medium flow rate, and environmental parameters inside the reactor; Based on the current temperature data, material flow rate, cooling medium flow rate, and environmental parameters, output the predicted power value for heating or cooling within a preset time period. The predicted power value is received and used as a feedforward control variable; The correction power is calculated based on the deviation between the multi-point temperature data in the reactor and the temperature setpoint, and the correction power is used as a feedback control quantity. The feedforward control quantity and the feedback control quantity are combined to generate the final execution power value.

[0013] In one embodiment, after obtaining the predicted power value, the predicted power value is compensated by a power compensation unit.

[0014] Thirdly, this application also provides a computer device, including a processor and a memory, wherein the memory is used to store a computer program, and the computer program, when executed by the processor, implements the temperature monitoring method in the optical-grade PMMA polymerization reaction process.

[0015] Fourthly, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned method for temperature monitoring during the polymerization reaction of optical-grade PMMA.

[0016] Compared with the prior art, this application has at least the following beneficial effects: This application presents a temperature monitoring system and method for the polymerization process of optical-grade PMMA. Through the coordinated setup of a data acquisition module, a power prediction module, and a composite control module, the predicted power value output by the power prediction module is based on the model's learning from historical data. The feedforward control unit generates heating / cooling demand commands 5-10 minutes in advance to offset foreseeable temperature fluctuations such as reaction exothermics and environmental disturbances, thus solving the lag problem of traditional PID control. At the same time, the feedback control unit dynamically compensates for the prediction error and unmodeled disturbances of the feedforward control unit. The fusion layer unit combines the predicted power value and the corrected power value to form the execution power value, which precisely controls the power of the electric heater in the reactor and the opening of the cooling valve, thereby precisely controlling the polymerization reaction temperature and significantly improving the yield of PMMA products. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the structure of a temperature monitoring system during the polymerization process of optical-grade PMMA, as shown in an embodiment of this application. Figure 2 This is a schematic flowchart illustrating a temperature monitoring method during the polymerization reaction of optical-grade PMMA, as shown in an embodiment of this application. Figure 3 This is a schematic diagram of the structure of a computer device shown in an embodiment of this application.

[0018] Reference numerals: Data acquisition module 1, power prediction module 2, composite control module 3, feedforward control unit 31, feedback control unit 32, fusion layer unit 33, power compensation unit 34. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] To facilitate understanding of this application, a temperature monitoring system and method for an optical-grade PMMA polymerization process will be described more fully below with reference to the accompanying drawings. The drawings show a preferred embodiment of the temperature monitoring system and method for an optical-grade PMMA polymerization process. However, a temperature monitoring system and method for an optical-grade PMMA polymerization process can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of a temperature monitoring system and method for an optical-grade PMMA polymerization process more thorough and complete.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of a temperature monitoring system and method for an optical-grade PMMA polymerization process is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] In existing technologies, PID control only adjusts after a temperature deviation (e.g., setpoint vs. measured value) occurs. However, PMMA polymerization (especially the initiation stage) involves intense exothermic reactions with rapid temperature changes (up to 1-2°C / s). Adjusting only when the deviation becomes significant often results in overshoot (e.g., a sudden temperature rise of more than 2°C), leading to uneven molecular weight distribution (PDI > 1.8) and decreased product transmittance (< 92%). Furthermore, the exothermic rate of PMMA polymerization is strongly correlated with material flow rate and ambient temperature. For example, a 20% increase in feed flow rate may advance the exothermic peak by 5 minutes, but traditional PID control cannot predict this and can only respond passively, causing temperature fluctuations (±1.2°C).

[0023] The feedforward control unit of this application can generate heating or cooling demand commands 5-10 minutes in advance to offset foreseeable temperature fluctuations such as reaction exothermics and environmental disturbances, thus solving the lag problem of traditional PID control. At the same time, the feedback control unit dynamically compensates for the prediction error and unmodeled disturbances of the feedforward control unit. The fusion layer unit combines the predicted power value and the corrected power value to form the execution power value, which precisely controls the power of the electric heater of the reactor and the opening of the cooling valve, and precisely controls the polymerization reaction temperature, thus significantly improving the yield of PMMA products.

[0024] Please refer to Figure 1 This application provides a temperature monitoring system for the polymerization process of optical-grade PMMA, including... Data acquisition module 1 is used to collect the current process parameters during the polymerization reaction in real time. The current process parameters include temperature data, material flow rate, cooling medium flow rate and environmental parameters inside the reactor. The power prediction module 2 stores a heating or cooling power prediction model trained based on historical process parameter data. The model is used to output the predicted power value of heating or cooling within a preset time in the future based on the current process parameters. The composite control module 3 includes: a feedforward control unit 31, a feedback control unit 32, and a fusion layer unit 33; The feedforward control unit 31 is used to receive the predicted power value output by the power prediction module 2 as a feedforward control quantity. The feedback control unit 32 is used to calculate the correction power based on the deviation between the multi-point temperature data in the reactor and the temperature set value, and the correction power is used as the feedback control quantity. The fusion layer unit 33 is used to fuse the feedforward control quantity and the feedback control quantity to generate the final execution power value.

[0025] The feedforward control unit 31 receives the predicted power value output by the power prediction module 2 as the feedforward control quantity. The power prediction module 2 is a heating or cooling power prediction model trained based on historical process parameter data. However, in actual production, new operating conditions that have not been learned may be encountered, such as differences in raw material batches or equipment aging, causing the predicted power value to deviate from the actual demand. The feedback control unit calculates the correction amount based on the real-time temperature deviation. For example, if the feedforward control unit 31 predicts a heating power of 50kW, but the average liquid phase temperature in the reactor is still 1℃ lower than the set value, then the feedback control unit 32 outputs a +10kW correction power. The feedforward control unit 31 predicts a heating power of 50kW based on historical data to estimate the heating demand. The feedback output of +10kW correction power is necessary to make up for the energy gap because the actual liquid phase temperature is still 1℃ lower.

[0026] In one embodiment, the data acquisition module 1 includes a distributed temperature sensor unit, a mass flow unit, an electromagnetic flow unit, and a temperature and humidity transmitter unit. The distributed temperature sensor unit is used to acquire the liquid phase temperature and gas phase temperature inside the reactor. The mass flow unit is used to obtain the material flow rate; The electromagnetic flow unit is used to obtain the flow rate of the cooling medium; The temperature and humidity transmitter is used to acquire environmental parameters, including ambient temperature and relative humidity.

[0027] In one embodiment, the distributed temperature sensor unit includes a liquid phase temperature array subunit, Vapor phase temperature subunit; The liquid phase temperature array subunit is used to monitor the liquid phase temperature at multiple points within the reactor. The gas phase temperature subunit is used to monitor the gas phase temperature at the top of the reactor.

[0028] When the gas phase temperature exceeds the top liquid phase temperature by 1.5°C, the condenser power is increased by 20%. The pressure in the gas phase space is adjusted by the condensation rate to maintain a stable pressure inside the reactor (±0.1 bar) and avoid temperature runaway caused by pressure fluctuations.

[0029] Power prediction module 2 establishes a complex nonlinear relationship between multiple input parameters and power demand using a trained machine learning model (such as LSTM, random forest, etc.).

[0030] Its mathematical essence can be expressed as: ; The function for the trained machine learning model; P heat / P cool The predicted heating / cooling power value; T avg Reactor temperature data; T: Axial temperature gradient; Material flow rate; Q cool Cooling medium flow rate; T env Ambient temperature. The predicted power value P is obtained. base The formula for calculating the axial temperature gradient ΔT is: ΔT = T bottom -T top / H×K adj ; T bottom : Liquid phase temperature at the bottom of the reactor, T top H: Liquid phase temperature at the top of the reactor; K: Vertical distance between temperature measuring points. adj : Correction factor for the height-to-diameter ratio of the reactor.

[0031] For example, the temperature T1 at the bottom of the reactor has a range of 80℃ to 85℃ and a normalized value of 0.62. The temperature at the top of the reactor, T2, ranges from 78℃ to 82℃, with a normalized value of 0.55. Material flow rate: 100 L / min~200 L / min, normalized value: 0.73; cooling water flow rate (m³ / min) 3 / h: 50~150 m 3 / h, normalized value: 0.45; normalized value of ambient temperature: 0.21; The input vector for power prediction module 2 is [0.62, 0.55, 0.73, 0.45, 0.21]; the model output is [0.68 (heating power), 0.52 (cooling valve opening)]; corresponding to actual values: heating power = 68kW, cooling valve opening = 52%. That is, 68 kilowatts (kW) of electrical power is input to the electric heater of the reactor, and the cooling valve opening = 52%. This is to compensate for the reactor's expected heat demand. The cooling valve opening ΔV = K v * +C, Kv is the valve sensitivity coefficient, which is generally taken as 0.5~1.2, and C is the reference opening degree, which is generally 10%~20%.

[0032] In one embodiment, the composite control module 3 further includes a power compensation unit 34, which is used to compensate for the predicted power value; the compensation formula is: P pred =P base +K p *ΔT,P pred Compensation power value, P base Predicted power value, K p: This is the gradient compensation coefficient, ranging from 0.5 to 1.2. ΔT: This is the axial temperature gradient. Due to the inherent limitations of model prediction, the system's response to instantaneous temperature deviations (such as sudden heat release) is insufficient, leading to overshoot (such as a temperature surge of more than 2°C during the initiation stage), resulting in a decrease in the basic predicted value P. base There is a deviation. K p *ΔT provides an instantaneous control quantity proportional to the deviation, quickly compensating for the current error. For example, if ΔT = +1℃, K p If the output is 0.5kW / ℃, then immediately compensate with an output of +0.5kW heating power.

[0033] Furthermore, K p =K p0 *(1+α ); K p0 : Indicates the initial gain coefficient under standard operating conditions (such as axial temperature gradient ∇T=0, ambient temperature 25℃), with units of kW / ℃ or equivalent control quantity / ℃.

[0034] α = 0.3-0.8; for every 1℃ / m increase in gradient, K p Improve by 30% to 80%, and specifically strengthen the control of high-temperature areas.

[0035] In one embodiment, the correction power is equal to the weighted average of the deviation between the current temperature setpoint and the multi-point temperature data in the reactor, the cumulative temperature deviation from time 0 to the current time t, and the rate of temperature change.

[0036] The formula for calculating the corrected power is: ; The proportional, integral, and differential coefficients are respectively in units of kW / ℃, kW / (℃·s), and kW·s / ℃.

[0037] : The deviation between the current temperature setpoint and the multi-point temperature data inside the reactor; the multi-point temperature data inside the reactor here is the average value of the liquid phase multi-point temperature; : The cumulative temperature deviation from time 0 to the current time t; the cumulative temperature deviation is the cumulative liquid phase temperature at multiple points in the reactor; : Rate of temperature change.

[0038] The formula for calculating the final execution power value is as follows: Weight coefficients of fusion layer units It is negatively correlated with the absolute value of the temperature deviation. When the deviation is >1℃: =0.3 (emphasis on feedback); when the deviation is ≤0.5℃: =0.7 (emphasis on feedforward).

[0039] In this way, the temperature monitoring system in the polymerization process of optical-grade PMMA, through the coordinated setup of a data acquisition module, a power prediction module, and a composite control module, achieves this. The predicted power value output by the power prediction module is based on the model's learning from historical data. The feedforward control unit generates heating / cooling demand commands 5-10 minutes in advance to offset foreseeable temperature fluctuations such as reaction exothermics and environmental disturbances, thus solving the lag problem of traditional PID control. At the same time, the feedback control unit dynamically compensates for the prediction error and unmodeled disturbances of the feedforward control unit. The fusion layer unit combines the predicted power value and the corrected power value to form the execution power value, which precisely controls the power of the electric heater in the reactor and the opening of the cooling valve, significantly improving the yield of PMMA products.

[0040] In one embodiment, the power compensation unit 34 further includes a data judgment subunit, which is used to judge the validity of the compensation power value. When the axial temperature gradient ΔT is greater than a preset threshold and lasts for a preset time, the compensation power value is invalid.

[0041] When the axial temperature gradient ΔT=T bottom -T top / H×K adj If the temperature continues to exceed the limit, for example, ΔT>1.5℃ / m for more than 3 minutes, it may be caused by the following reasons: 1. Stirring failure: damaged blades or insufficient speed, resulting in uneven heat transfer; 2. Uneven cooling: local cooling pipe blockage, with high temperature accumulation in the high temperature zone; 3. Sensor failure: distorted data at a certain temperature measurement point, falsely triggering compensation.

[0042] When ΔT > 1.5℃ / m for more than 3 minutes, the system is deemed abnormal, the compensation power value becomes invalid, and an alarm is triggered. The system switches to pure feedback control mode and limits the heating power to ≤ 50% of the rated value. In this way, when the system detects an uncontrollable temperature gradient, it proactively abandons unreliable compensation strategies and adopts a conservative control mode, protecting equipment safety and preventing secondary quality accidents.

[0043] Please refer to Figure 2 Secondly, this application also provides a temperature monitoring method during the polymerization reaction of optical-grade PMMA, applied to the aforementioned temperature monitoring system during the polymerization reaction of optical-grade PMMA, the method comprising: S1. Collect current temperature data, material flow rate, cooling medium flow rate, and environmental parameters inside the reactor; S2. Based on the current temperature data, material flow rate, cooling medium flow rate, and environmental parameters, output the predicted power value for heating or cooling within a preset time period in the future. S3, Receive the predicted power value as the feedforward control quantity; S4. Calculate the correction power based on the deviation between the multi-point temperature data in the reactor and the temperature setpoint, and use the correction power as a feedback control quantity; S5. The feedforward control quantity and the feedback control quantity are combined to generate the final execution power value.

[0044] In one embodiment, after obtaining the predicted power value, the predicted power value is compensated by a power compensation unit.

[0045] The options described in the above system embodiments are also applicable to this embodiment, and will not be detailed here. The remaining content of this application's embodiments can be found in the above system embodiments, and will not be repeated in this embodiment.

[0046] Please refer to Figure 3 Thirdly, this application also provides a computer device 4, including a processor 40 and a memory 41, wherein the memory 41 is used to store a computer program 42, and the computer program 42, when executed by the processor 40, implements the temperature monitoring method in the optical grade PMMA polymerization reaction process.

[0047] The computer device 4 can be a computing device such as a tablet computer, desktop computer, or cloud server. This computer device may include, but is not limited to, a processor 40 and a memory 41. Those skilled in the art will understand that... Figure 3 The computer device 4 is merely an example and does not constitute a limitation on the computer device 4. It may include more or fewer components than shown, or combine certain components, or different components, such as input / output devices, network access devices, etc.

[0048] The processor 40 may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0049] In some embodiments, the memory 41 may be an internal storage unit of the computer device 4, such as a hard disk or memory of the computer device 4. In other embodiments, the memory 41 may be an external storage device of the computer device 4, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the computer device 4. Furthermore, the memory 41 may include both internal and external storage units of the computer device 4. The memory 41 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory 41 can also be used to temporarily store data that has been output or will be output.

[0050] Fourthly, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned method for temperature monitoring during the polymerization reaction of optical-grade PMMA.

[0051] This application provides a computer program product that, when run on a computer device, enables the computer device to execute the steps described in the various method embodiments above.

[0052] In the several embodiments provided in this application, it will be understood that each block in the flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the figures. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved.

[0053] 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 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.

[0054] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A temperature monitoring system for the polymerization process of optical-grade PMMA, characterized in that, include The data acquisition module is used to collect the current process parameters during the polymerization reaction in real time. The current process parameters include temperature data, material flow rate, cooling medium flow rate and environmental parameters inside the reactor. The power prediction module stores a heating or cooling power prediction model trained based on historical process parameter data. The model is used to output the predicted heating or cooling power value within a preset time period based on the current process parameters. The composite control module includes: a feedforward control unit, a feedback control unit, and a fusion layer unit; The feedforward control unit is used to receive the predicted power value output by the power prediction module as a feedforward control quantity; The feedback control unit is used to calculate the correction power based on the deviation between the multi-point temperature data in the reactor and the temperature setpoint, and the correction power is used as the feedback control quantity. The fusion layer unit is used to fuse the feedforward control quantity and the feedback control quantity to generate the final execution power value.

2. The temperature monitoring system for the polymerization process of optical-grade PMMA as described in claim 1, characterized in that, The data acquisition module includes a distributed temperature sensor unit, a mass flow unit, an electromagnetic flow unit, and a temperature and humidity transmitter unit. The distributed temperature sensor unit is used to acquire the liquid phase temperature and gas phase temperature inside the reactor. The mass flow unit is used to obtain the material flow rate; The electromagnetic flow unit is used to obtain the flow rate of the cooling medium; The temperature and humidity transmitter is used to acquire environmental parameters, including ambient temperature and relative humidity.

3. The temperature monitoring system for the polymerization process of optical-grade PMMA as described in claim 2, characterized in that, The distributed temperature sensor unit includes a liquid phase temperature array subunit and a gas phase temperature subunit; The liquid phase temperature array subunit is used to monitor the liquid phase temperature at multiple points within the reactor. The gas phase temperature subunit is used to monitor the gas phase temperature at the top of the reactor.

4. The temperature monitoring system for the polymerization process of optical-grade PMMA as described in claim 1, characterized in that, The composite control module further includes a power compensation unit, which is used to compensate for the predicted power value; the compensation formula is: P pred =P base +K p *ΔT,P pred Compensation power value, P base Predicted power value, K p : is the gradient compensation coefficient, ΔT: is the axial temperature gradient.

5. The temperature monitoring system for the polymerization process of optical-grade PMMA as described in claim 4, characterized in that, The correction power is equal to the weighted average of the deviation between the current temperature setpoint and the temperature data at multiple points in the reactor, the cumulative temperature deviation from time 0 to the current time t, and the rate of temperature change.

6. The temperature monitoring system for the polymerization process of optical-grade PMMA as described in claim 4, characterized in that, The power compensation unit further includes a data judgment subunit, which is used to judge the validity of the compensation power value. When the axial temperature gradient ΔT is greater than a preset threshold and lasts for a preset time, the compensation power value is invalid.

7. The temperature monitoring system for the polymerization process of optical-grade PMMA as described in claim 5, characterized in that, The formula for calculating the axial temperature gradient ΔT is: ΔT = T bottom -T top / H×K adj ; T bottom : Liquid phase temperature at the bottom of the reactor, T top H: Liquid phase temperature at the top of the reactor; K: Vertical distance between temperature measuring points. adj : Correction factor for the height-to-diameter ratio of the reactor.

8. A method for monitoring temperature during the polymerization reaction of optical-grade PMMA, characterized in that, A method for using a temperature monitoring system in a polymerization process of optical-grade PMMA as described in any one of claims 1 to 7, the method comprising: Collect current temperature data, material flow rate, cooling medium flow rate, and environmental parameters inside the reactor; Based on the current temperature data, material flow rate, cooling medium flow rate, and environmental parameters, output the predicted power value for heating or cooling within a preset time period. The predicted power value is received and used as a feedforward control variable; The correction power is calculated based on the deviation between the multi-point temperature data in the reactor and the temperature setpoint, and the correction power is used as a feedback control quantity. The feedforward control quantity and the feedback control quantity are combined to generate the final execution power value.

9. The temperature monitoring method during the polymerization reaction of optical-grade PMMA as described in claim 8, characterized in that, After obtaining the predicted power value, the predicted power value is compensated by a power compensation unit.

10. A computer device, characterized in that, It includes a processor and a memory, the memory being used to store a computer program, which, when executed by the processor, implements the temperature monitoring method in the polymerization process of optical-grade PMMA as described in any one of claims 8-9.

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