A composite film production line solvent concentration self-adaptive precision control system

Abstract

The application discloses a kind of composite film production line solvent concentration self-adapting precision regulation system, it is related to high polymer composite film manufacturing and industrial automation control technical field, comprising: system obtains the space mapping coordinates of virtual film element of substrate walking speed construction, combined with temperature zone environment data, estimates local solvent volatilization flux, generates multiple-component volatile state sequence;According to the feed-forward displacement amount generated by system comprehensive delay time, space feed-forward prediction is implemented to virtual film element, and air exhaust regulation instruction is generated in advance;When mixed solvent appears volatilization proportion misadjustment early warning, trigger targeted gas phase inhibition mechanism, implement single solvent steam blowing to film element surface to produce partial pressure compensation action.The system time lag of the application is converted into space addressing advance, solves the regulation misplacement problem under high-speed walking condition, significantly improves film forming quality and comprehensive energy efficiency.

Description

Technical Field

[0001] This invention relates to the field of polymer composite membrane manufacturing and industrial automation control technology, specifically to a solvent concentration adaptive and precise control system for a composite membrane production line. Background Technology

[0002] In the composite film drying process, the evaporation rate of the mixed solvent directly determines the final film quality and system energy consumption. Currently, actual production lines often face inherent defects such as localized whitening of the coating, frequent orange peel defects, and high energy consumption of the exhaust system. Essentially, this stems from a multivariate nonlinear coupling interference between multi-component fluid dynamics, the thermodynamic trajectory of polymer film formation, and concentration safety limits under high-speed, continuous dynamic conditions, leading to a comprehensive control imbalance.

[0003] To address the aforementioned issues, existing solvent concentration control technologies typically employ a total volatile organic compound (VOC) sensor installed at a single point within the exhaust duct for monitoring, relying on traditional proportional-integral-derivative (PID) closed-loop feedback logic. When the system detects that the local concentration is approaching the lower explosive limit or deviating from the set threshold, the controller passively adjusts the exhaust fan operating frequency or the opening of the inlet and exhaust dampers to maintain airflow and concentration balance inside the oven.

[0004] However, the existing solutions still face insurmountable technical bottlenecks: First, passive adjustment of the total concentration completely ignores the microscopic evaporation ratio imbalance caused by the difference in saturated vapor pressure of the mixed solvent at the gas-liquid interface, and cannot effectively suppress the microscopic phase separation of polymer adhesives; Second, due to the inherent physical lag between gas diffusion and sensor resolution, coupled with the mechanical inertia of the actuator, this time lag is amplified into a severe spatial phase misalignment under continuous roll-to-roll high-speed conveyor operation, causing the lag feedback control to be unable to accurately act on the abnormal physical film layer, thus becoming an ineffective post-hoc remedy.

[0005] Therefore, the present invention provides an adaptive and precise control system for solvent concentration in a composite membrane production line. Summary of the Invention

[0006] The purpose of this invention is to provide an adaptive and precise control system for solvent concentration in a composite membrane production line to solve the existing problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a solvent concentration adaptive and precise control system for a composite membrane production line, comprising: The spatial mapping module is configured to acquire the substrate conveyor speed and initial coating parameters of the composite film production line, divide the continuously conveying film layer into continuous virtual film elements based on the substrate conveyor speed, and construct the spatial mapping coordinates of the virtual film elements. The state prediction module is configured to extract environmental state data of each drying temperature zone in the oven, combine the environmental state data to perform local solvent evaporation flux prediction on the virtual membrane element, and generate a multi-component evaporation state sequence. The feedforward quantity generation module is configured to acquire the overall system delay time consisting of sensor response hysteresis and actuator action hysteresis, and generate a feedforward advance displacement based on the overall system delay time and the substrate conveyor speed. The concentration prediction and control module is configured to perform spatial feedforward prediction of the solvent concentration when the virtual membrane element enters the target temperature zone based on the feedforward advance displacement and the multi-component volatilization state sequence, and generate an exhaust control command for the target temperature zone. The targeted compensation module is configured to trigger a targeted gas phase suppression mechanism when the multi-component volatile state sequence indicates an imbalance in the volatile ratio of the mixed solvent. Based on the targeted gas phase suppression mechanism, a single solvent vapor is sprayed onto the surface boundary layer of the virtual membrane element to generate a partial pressure compensation action for the highly volatile component.

[0008] A further improvement of this invention is that the concentration prediction and control module and the target compensation module are respectively equipped with a phase alignment spatial pre-control unit and a film-forming stability phase balance compensation unit; the phase alignment spatial pre-control unit is used to convert the time lag of the system response into the advance of spatial addressing, so that the change of exhaust intensity is synchronously aligned with the virtual membrane element carrying high-concentration solvent in spatial position; the film-forming stability phase balance compensation unit is used to suppress the differential volatilization of mixed solvent by controlling the local boundary layer partial pressure without changing the macroscopic thermodynamic parameters of the target temperature zone.

[0009] A further improvement of the present invention is that the phase alignment space pre-adjustment unit is specifically used for: The inertial response time of the exhaust system from receiving the control command to establishing a stable negative pressure field is obtained, and it is combined with the first delay parameter of the sensor response to gas diffusion and the second delay parameter of the exhaust fan reaching a stable state by frequency adjustment to obtain the total response time. The value of the feedforward advance displacement is updated in real time based on the dynamic product of the total response time and the substrate conveyor speed. Lock the specific virtual membrane element that is currently at the position of the feedforward advance displacement and mark it as the controlled target point; Within a preset time window before the controlled target point reaches the entrance of the target temperature zone, the exhaust control command is issued so that the exhaust system reaches the target exhaust intensity exactly when the controlled target point enters the temperature zone.

[0010] A further improvement of the present invention is that the film-forming stability phase balance compensation unit is specifically used for: Based on the multi-component volatile state sequence, the real-time saturation partial pressure of the highly volatile main solvent at the gas-liquid interface is calculated. Extract the compensation steam concentration output from the air curtain jet array and convert it into a compensation partial pressure value; By comparing the real-time saturated partial pressure with the compensated partial pressure value, the partial pressure compensation deviation aimed at eliminating the difference in solvent evaporation flux is calculated. The blowing rate of the air curtain jet array is adjusted in real time according to the partial pressure compensation deviation. By increasing the partial pressure concentration of the main solvent in the boundary layer, the abnormal evaporation flux of the main solvent is suppressed.

[0011] A further improvement of this invention is that the system further includes a prediction bias dynamic self-calibration module, which is used to: extract the actual solvent concentration reading detected by the sensor at the current moment; based on the residence time table of the virtual membrane element, backtrack to extract the spatial feedforward predicted concentration corresponding to the current moment and generated at historical moments; calculate the residual sequence between the actual reading and the spatial feedforward predicted concentration, and analyze the evolution trend of the residual sequence; perform adaptive correction on the mass transfer coefficient in the local solvent evaporation flux prediction model according to the evolution trend, and use the execution effect at historical moments to dynamically compensate for the prediction accuracy at future moments.

[0012] A further improvement of the present invention is that the spatial mapping module is specifically used to: perform time integration processing using the real-time linear velocity within the sampling period to obtain the unit length increment of each virtual film element; accumulate the unit length increment of each virtual film element to generate the displacement footprint of each virtual film element leaving the coating start point; establish the spatial association between the displacement footprint and the boundary coordinates of each drying temperature zone to generate the residence time table of each virtual film element in different drying temperature zones.

[0013] A further improvement of this invention is that the state prediction module is specifically used for: acquiring the vent structure parameters in each drying temperature zone and calculating the mass transfer coefficient corresponding to each temperature zone; extracting the current remaining solvent load of each virtual membrane element based on the initial coating load and historical cumulative evaporation; matching the evaporation resistance factor according to the current remaining solvent load to characterize the degree of constraint of membrane surface shrinkage on solvent removal during film formation; and performing flux calculation by combining the mass transfer coefficient, the evaporation resistance factor, and the partial pressure gradient of each solvent component to generate the multi-component evaporation state sequence.

[0014] A further improvement of the present invention is that the maximum span of the feedforward advance displacement generated by the feedforward quantity generation module is limited to not exceeding the center distance between adjacent drying temperature zones.

[0015] A further improvement of the present invention is that, when the targeted compensation module executes the volatility ratio imbalance warning, it is specifically configured as follows: extracting the current remaining mass ratio of the highly volatile main solvent to the low-volatile co-solvent from the multi-component volatility state sequence in real time; comparing the current remaining mass ratio with a preset polymer adhesive solubility threshold range; and triggering the volatility ratio imbalance warning when the current remaining mass ratio deviates from the threshold range.

[0016] A further improvement of the present invention is that the system includes: A sensor array is used to collect the environmental condition data, substrate conveyor speed, and actual readings of solvent concentration. The actuator includes an adjustable damper and a variable frequency exhaust fan arranged in the temperature zone of the oven, and an air curtain jet array located above the temperature zone; The controller, connected to the sensor array and the actuator, is used to run the control program instructions corresponding to the spatial mapping module, the state prediction module, the feedforward quantity generation module, the concentration prediction and control module, and the target compensation module.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention firstly solves the problem of spatial phase misalignment caused by gas diffusion lag and mechanical inertia of actuators under continuous roll-to-roll high-speed conveyor operation by introducing feedforward predictive control logic based on virtual membrane element spatial mapping and system comprehensive delay time. This achieves high-level synchronous alignment between the dynamic peak of exhaust intensity and the controlled target point carrying high-concentration solvent in the temperature zone, greatly improving the target hit rate of concentration control and the overall energy efficiency of the oven system.

[0018] 2. By constructing a multi-component local solvent evaporation flux prediction model that couples the convective mass transfer coefficient and the diffusion resistance factor within the wet film, the problem of the sharp shrinkage of local solubility of polymer adhesives and the resulting film quality defects such as coating whitening and micro-phase separation caused by the traditional single total concentration control method neglecting the difference in evaporation of mixed solvents at the gas-liquid interface is solved. Under the premise of not disturbing the thermodynamic gradient of the oven, the dynamic balance of the extraction ratio of mixed solvents and the film quality of composite film are guaranteed. Attached Figure Description

[0019] Figure 1 This is a framework diagram of a composite membrane production line solvent concentration adaptive and precise control system according to the present invention. Detailed Implementation

[0020] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations thereof. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0021] The term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone.

[0022] Example 1 Figure 1 This embodiment illustrates a framework diagram of a solvent concentration adaptive and precise control system for a composite membrane production line, including: This control system is applied in continuous roll-to-roll coating production lines for flexible packaging composite films or optical films. Associated production equipment includes multi-temperature zone ovens, exhaust fans equipped with frequency converters, inlet regulating valves, and gas concentration detection arrays deployed along the main exhaust duct. In conventional composite film production process control, conventional control schemes often only collect the total volatile organic compound (TVOC) concentration at the exhaust vent and adjust the exhaust fan speed using feedback closed loops such as proportional-integral-derivative (PI) and differential equations.

[0023] However, this conventional operation suffers from significant transmission lag: the diffusion of the mixed gas from the membrane surface to the pipe detector requires time, and the exhaust fan also experiences mechanical inertial lag from receiving the FM signal to establishing a stable negative pressure flow field. Under conditions where the substrate conveyor speed exceeds 100 meters per minute, these time-level lags are amplified into extremely severe spatial phase misalignment. By the time the conventional method detects excessive exhaust concentration and ultimately increases the airflow, the defective membrane section causing abnormal volatilization has already moved out of the current temperature range, rendering adaptive control an ineffective post-hoc remedy.

[0024] To address this spatial phase misalignment challenge, this solution introduces a spatial mapping module and a feedforward generation module. The spatial mapping module acquires the substrate conveyor speed and initial coating parameters of the composite membrane production line. Based on the substrate conveyor speed, the continuously conveying membrane layer is divided into continuous virtual membrane elements, and the spatial mapping coordinates of these virtual membrane elements are constructed. The feedforward generation module acquires the first delay parameter corresponding to the sensor response hysteresis and the second delay parameter corresponding to the actuator frequency modulation action hysteresis, merging them into a total response time. Based on the dynamic product of the total response time and the substrate conveyor speed, the system calculates the feedforward advance displacement. The concentration prediction and control module uses this feedforward advance displacement to shift the monitoring viewport at the target temperature zone inlet to the spatial coordinates at the front of the oven by a corresponding distance, locking onto the set of membrane elements about to enter the temperature zone. This spatiotemporal transformation allows exhaust control commands to be issued with an advance of one total response time. Conventional feedback mechanisms always lag behind the objective movement of the membrane layer, while this solution uses spatial feedforward interception to achieve a high degree of synchronous alignment between the peak of the exhaust intensity and the target membrane element carrying a high concentration of solvent within the temperature range.

[0025] Example 2 In order to provide high-accuracy data support for the above-mentioned spatial feedforward prediction and to prevent the imbalance of mixed solvent evaporation, based on the inventive concept of Example 1, this embodiment presents the underlying calculation principle and error prevention and fault tolerance mechanism of the state prediction module and the target compensation module.

[0026] After determining the spatial coordinates of each membrane element, its internal state must be known. Conventional prediction methods often overlook the obstruction of solvent evaporation by the macromolecular chains inside the wet membrane, leading to predictions that significantly deviate from the objective trend. The state prediction module extracts environmental state data from each drying temperature zone within the oven and combines this data to perform local solvent evaporation flux prediction for the virtual membrane element, generating a multi-component evaporation state sequence. Its core prediction calculation formula is set as follows: Among them, parameters Local surface evaporation flux calibrated as a single solvent component, expressed in grams per square meter per second, represents the solvent release intensity per unit area of ​​the film layer under transient conditions.

[0027] Parameter The calibration is set as the convective mass transfer coefficient. This variable is obtained through the empirical correlation between local wind speed and Reynolds number in the temperature zone. In a typical two-zone oven, the preferred value is a fixed constant of 0.045 m / s. The reason for choosing this fixed calibration value is that once the air nozzle structure inside the oven is installed and solidified, its airflow distribution pattern is relatively stable. Using a fixed constant can avoid the extremely high underlying computing power consumption caused by real-time flow field dynamic simulation.

[0028] Parameter The saturated vapor pressure of the solvent at the current gas-liquid interface is calibrated and obtained using the local ambient temperature and the Antoine equation; parameter The actual gas phase partial pressure above the virtual membrane element is calibrated and obtained by interpolation of the detection values ​​from the temperature zone intake and exhaust air sensors.

[0029] Parameter The volatile resistance factor, calibrated as nonlinear, characterizes the degree to which surface shrinkage of the film restricts solvent diffusion during film formation. This constraint factor is determined by the current remaining solvent loading. The mapping results show that the preferred value is 1 in the initial stage of coating, and decreases exponentially to 0.05 in the later stage of curing. The reason for choosing this exponential decay mapping scheme is that it can closely match the rapid shrinkage of free volume of polymers during the transition from solution to glass.

[0030] If, during the calculation process, a divisor parameter approaches zero due to sensor disconnection or rapid drying, the system automatically inserts a zero-prevention minimal positive number as a replacement, thereby ensuring the robust operation of the calculation program and preventing system crashes.

[0031] After addressing the feedforward estimation, if the estimated exhaust volume of a certain membrane element is too high, it will disrupt the thermodynamic equilibrium of the mixed solvent. For a composite solvent system containing ethyl acetate and methyl ethyl ketone, a sudden increase in exhaust volume will cause the highly volatile ethyl acetate to be released too quickly, resulting in a sharp contraction in the solubility of the polyurethane adhesive in the wet film state, leading to coating whitening or phase separation. To solve this problem, the system is equipped with a targeted compensation module. This module extracts the current remaining mass ratio of the main solvent to the co-solvent from the multi-component evaporation state sequence in real time. This value, denoted as the mixed solvent state monitoring ratio, is obtained by subtracting the cumulative mass release from the multi-component volatile state sequence, with a preferred control range of 2.5 to 3.0. This range is chosen because the polyurethane adhesive maintains a better spread conformation at this ratio, avoiding phase separation and gelation. When the temperature deviates from the threshold range, the air curtain jet array above the temperature zone is activated, and pure ethyl acetate saturated vapor is directionally injected into the surface boundary layer of the virtual membrane element. This operation forcibly raises the local temperature range. Concentration directly weakens the volatilization driving force of the main solvent, and the use of in-phase pressure suppression means prevents the imbalance of the ratio from the root.

[0032] Example 3 This embodiment demonstrates the evolution logic of the proposed solution in a specific complex application scenario. In some possible implementation scenarios, such as high-speed coating operations of barrier aluminum-plastic films that are extremely sensitive to moisture, fluctuations in the absolute humidity of the workshop environment can implicitly interfere with the convective mass transfer coefficient. The constancy of the parameters leads to a slow drift in the accuracy of feedforward instructions after long-term operation.

[0033] To mitigate this long-term cumulative bias problem, this embodiment adds a dynamic self-calibration module for prediction bias to the system. This module extracts the objective solvent concentration reading detected by the sensor at the current time point, and then, based on the residence timetable of the virtual membrane element, back-extracts the spatial feedforward predicted concentration corresponding to the current time point and pre-generated at historical time nodes. The module calculates the residual sequence between the two. To eliminate high-frequency noise caused by airflow disturbances in the production line, the system configures an invalid point replacement scheme, replacing discrete sampling points that deviate from the mean by more than 30% with linear interpolation of the nearest valid points, and performing a moving average filtering process with a time step of five seconds on the residual sequence. Based on the evolution trend of the filtered residual, adaptive gain correction is performed on the convective mass transfer coefficient in the local solvent evaporation flux prediction model. The correction step size is preferably set to 2% of the original coefficient. The reason for choosing 2% as the step gain is that this magnitude can provide sufficient convergence speed to track slow environmental drift while suppressing measurement island noise. This calibration mechanism utilizes the objective presentation of historical actions to provide dynamic feedback compensation to the prediction engine for future moments, enabling the entire control system to track the evolution of complex fluctuations.

[0034] Example 4 This embodiment demonstrates comparative data under different variant configurations. The production line is set at a conveyor belt speed of 150 meters per minute, using polyurethane adhesive with a solids content of 30%, and a solvent mixture of ethyl acetate and methyl ethyl ketone in a 7:3 ratio. The control group uses an industry-standard closed-loop feedback control system for total volatile organic compound (TVOC) concentration in pipelines. During a continuous 72-hour high-speed operation cycle, the virtual membrane element cutting length set in this embodiment is... The preferred setting is 0.5 meters, as this discrete scale is compatible with the scanning resolution of existing thickness gauges and the operational bandwidth of programmable logic controllers.

[0035] From the perspective of final yield, the control group had a very high incidence of orange peel and microscopic whitening defects on the coating surface when experiencing sudden changes in exhaust volume caused by oven temperature zone switching or tension fluctuations; while this embodiment relies on multi-component volatilization state prediction and targeted gas phase spraying compensation, and implements partial pressure suppression with steam curtain in the early stage of detecting volatilization imbalance, so that the remaining solvent ratio is locked within a safe range throughout the process, resulting in a sharp reduction in defect rate.

[0036] Meanwhile, in terms of energy consumption, the conventional control group maintains an excessive redundant exhaust volume year-round in order to offset the potential risks of exceeding the standard caused by lag; while this solution relies on a spatial feedforward prediction mechanism, the exhaust volume is only increased synchronously when the target membrane element carrying high concentration of solvent arrives at the nozzle, which effectively reduces the heat loss of the entire oven system and forces the fluctuation range of the lower explosive limit concentration to be narrowed within the limit range.

[0037] The threshold and weight settings involved in the above embodiments can be set by default according to the present invention, or can be set by those skilled in the art.

[0038] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0039] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0040] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0041] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0042] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A solvent concentration adaptive and precise control system for a composite membrane production line, characterized in that: The system includes: The spatial mapping module is configured to acquire the substrate conveyor speed and initial coating parameters of the composite film production line, divide the continuously conveying film layer into continuous virtual film elements based on the substrate conveyor speed, and construct the spatial mapping coordinates of the virtual film elements. The state prediction module is configured to extract environmental state data of each drying temperature zone in the oven, combine the environmental state data to perform local solvent evaporation flux prediction on the virtual membrane element, and generate a multi-component evaporation state sequence. The feedforward quantity generation module is configured to acquire the overall system delay time consisting of sensor response hysteresis and actuator action hysteresis, and generate a feedforward advance displacement based on the overall system delay time and the substrate conveyor speed. The concentration prediction and control module is configured to perform spatial feedforward prediction of the solvent concentration when the virtual membrane element enters the target temperature zone based on the feedforward advance displacement and the multi-component volatilization state sequence, and generate an exhaust control command for the target temperature zone. The targeted compensation module is configured to trigger a targeted gas phase suppression mechanism when the multi-component volatile state sequence indicates an imbalance in the volatile ratio of the mixed solvent. Based on the targeted gas phase suppression mechanism, a single solvent vapor is sprayed onto the surface boundary layer of the virtual membrane element to generate a partial pressure compensation action for the highly volatile component.

2. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 1, characterized in that: The concentration prediction and control module and the target compensation module are respectively equipped with a phase alignment spatial pre-control unit and a film-forming stability phase balance compensation unit. The phase alignment spatial pre-control unit is used to convert the time lag of the system response into the advance of spatial addressing, so that the change of exhaust intensity is synchronized with the virtual membrane element carrying high-concentration solvent in spatial position. The film-forming stability phase balance compensation unit is used to suppress the differential volatilization of mixed solvent by controlling the local boundary layer partial pressure without changing the macroscopic thermodynamic parameters of the target temperature zone.

3. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 2, characterized in that: The phase alignment space pre-adjustment unit is specifically used for: The inertial response time of the exhaust system from receiving the control command to establishing a stable negative pressure field is obtained, and it is combined with the first delay parameter of the sensor response to gas diffusion and the second delay parameter of the exhaust fan reaching a stable state by frequency adjustment to obtain the total response time. The value of the feedforward advance displacement is updated in real time based on the dynamic product of the total response time and the substrate conveyor speed. Lock the specific virtual membrane element that is currently at the position of the feedforward advance displacement and mark it as the controlled target point; Within a preset time window before the controlled target point reaches the entrance of the target temperature zone, the exhaust control command is issued so that the exhaust system reaches the target exhaust intensity exactly when the controlled target point enters the temperature zone.

4. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 2, characterized in that: The film-forming stability phase balance compensation unit is specifically used for: Based on the multi-component volatile state sequence, the real-time saturation partial pressure of the highly volatile main solvent at the gas-liquid interface is calculated. Extract the compensation steam concentration output from the air curtain jet array and convert it into a compensation partial pressure value; By comparing the real-time saturated partial pressure with the compensated partial pressure value, the partial pressure compensation deviation aimed at eliminating the difference in solvent evaporation flux is calculated. The blowing rate of the air curtain jet array is adjusted in real time according to the partial pressure compensation deviation. By increasing the partial pressure concentration of the main solvent in the boundary layer, the abnormal evaporation flux of the main solvent is suppressed.

5. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 1, characterized in that: The system also includes a prediction bias dynamic self-calibration module, which is used to: extract the actual solvent concentration reading detected by the sensor at the current moment; based on the residence time table of the virtual membrane element, backtrack to extract the spatial feedforward predicted concentration generated at historical moments corresponding to the current moment; calculate the residual sequence between the actual reading and the spatial feedforward predicted concentration, and analyze the evolution trend of the residual sequence; Based on the aforementioned evolution trend, the mass transfer coefficient in the local solvent evaporation flux prediction model is adaptively corrected, and the prediction accuracy for future times is dynamically compensated using the execution results at historical moments.

6. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 1, characterized in that: The spatial mapping module is specifically used to: perform time integration processing using the real-time linear velocity within the sampling period to obtain the unit length increment of each virtual membrane element; accumulate the unit length increment of each virtual membrane element to generate the displacement footprint of each virtual membrane element leaving the coating start point; Establish a spatial correlation between the displacement footprint and the boundary coordinates of each drying temperature zone, and generate a residence time table for each virtual membrane element in different drying temperature zones.

7. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 1, characterized in that: The state prediction module is specifically used for: acquiring the vent structure parameters in each drying temperature zone and calculating the mass transfer coefficient corresponding to each temperature zone; extracting the current remaining solvent load of each virtual membrane element based on the initial coating load and historical cumulative evaporation; matching the evaporation resistance factor according to the current remaining solvent load to characterize the degree of constraint of membrane surface shrinkage on solvent removal during film formation; and performing flux calculation by combining the mass transfer coefficient, the evaporation resistance factor, and the partial pressure gradient of each solvent component to generate the multi-component evaporation state sequence.

8. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 1, characterized in that: The maximum span of the feedforward advance displacement generated by the feedforward quantity generation module is limited to not exceeding the center distance between adjacent drying temperature zones.

9. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 1, characterized in that: When the targeted compensation module executes the volatility ratio imbalance warning, it is specifically configured as follows: extract the current remaining mass ratio of the high-volatility main solvent to the low-volatility co-solvent from the multi-component volatility state sequence in real time; compare the current remaining mass ratio with a preset polymer adhesive solubility threshold range; and trigger the volatility ratio imbalance warning when the current remaining mass ratio deviates from the threshold range.

10. The adaptive and precise solvent concentration control system for a composite membrane production line according to claim 1, characterized in that: The system includes: A sensor array is used to collect the environmental condition data, substrate conveyor speed, and actual readings of solvent concentration. The actuator includes an adjustable damper and a variable frequency exhaust fan arranged in the temperature zone of the oven, and an air curtain jet array located above the temperature zone; The controller, connected to the sensor array and the actuator, is used to run the control program instructions corresponding to the spatial mapping module, the state prediction module, the feedforward quantity generation module, the concentration prediction and control module, and the target compensation module.

Images