Double screw devolatilization extrusion granulator synchronous area continuous flexible online devolatilization device

Abstract

The application discloses a kind of double screw devolatilization extrusion granulator synchronous area continuous flexible online devolatilization devices, and it relates to the field of polymer material processing technology, comprising: double screw extruder host, its barrel is sequentially divided into conveying zone, primary devolatilization zone, at least two multistage devolatilization zone and mixing zone along the axial direction;Feed system;With the vacuum system being communicated with each devolatilization zone;And temperature control system for independently adjusting the temperature of each zone barrel;Multi-source sensing unit, intelligent collaborative controller.The online devolatilization device described in the present application can accurately collect the data of each stage devolatilization zone, carry out intelligent collaborative control of each module, and accurately locate the disturbance source through fluctuation main disturbance factor, realize the dynamic allocation of devolatilization zone role and the synchronous flexible collaborative control of multiple parameters, solve the industry pain points of low devolatilization efficiency, pressure crosstalk, material leakage and material degradation under wide viscosity working condition, significantly improve the equipment operation stability, devolatilization efficiency and product quality, and reduce production energy consumption.

Description

Technical Field

[0001] This invention relates to the field of polymer material processing technology, and in particular to a synchronous zone continuous flexible online devolatilization device for a twin-screw devolatilization extrusion granulator. Background Technology

[0002] In the production process of polyolefin polymerization, in order to obtain pure and stable products, it is essential to efficiently remove volatile components such as unreacted monomers, oligomers, and solvents from the polymer melt. The twin-screw devolatilization extrusion granulator, as the core equipment in the post-processing section, undertakes the tasks of melt conveying, multi-stage devolatilization, mixing and homogenization, and granulation. Its devolatilization efficiency and operational stability directly affect product quality and production energy consumption.

[0003] In existing technology operations, when switching polymerization processes or producing special grades of polyolefins, the viscosity of the melt entering the devolatilization unit varies greatly, ranging from low viscosity (hundreds of Pa·s) to ultra-high viscosity (tens of thousands of Pa·s). Because the rheological properties of the melt change significantly with viscosity, the filling degree, surface renewal rate, and sensitivity to heat and shear of the melt in the screw vary greatly at different viscosities.

[0004] Existing twin-screw devouring units have significant limitations in their control methods when dealing with melts with a wide viscosity range. Specifically, the operation and control of existing equipment largely rely on operator experience, with single-loop and discrete adjustments to screw speed, barrel temperature, or vacuum level. When handling ultra-high viscosity melts, simply reducing the screw speed to prevent spillage leads to decreased output and uneven residence time distribution; conversely, simply increasing the temperature to reduce viscosity can easily trigger the degradation of heat-sensitive materials. Conversely, when handling low viscosity melts, adjusting a single parameter is insufficient to establish sufficient back pressure to maintain a vacuum seal.

[0005] The root cause of the above problems lies in the lack of a multi-parameter synchronous and coordinated adjustment mechanism in existing equipment that treats screw speed, temperature field, feed rate, and vacuum degree as an organic whole. Because it is impossible to continuously and flexibly dynamically match the real-time state of the melt in each functional area of ​​"conveyance – primary devolatilization – multi-stage devolatilization – mixing," the accuracy and stability of flow field control throughout the entire process are insufficient, severely restricting the devolatilization efficiency and operational reliability of the equipment under wide viscosity conditions.

[0006] In summary, how to provide an online devolatilization device that can sense the melt state in real time and accordingly perform synchronous and flexible coordinated control of screw speed, temperature, vacuum degree and feed rate has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] This invention provides a continuous flexible online devolatilization device for a twin-screw extrusion granulator, comprising: a twin-screw extruder main unit, a coordinated execution mechanism, a multi-source sensing unit, and an intelligent collaborative controller; wherein the barrel of the twin-screw extruder main unit is sequentially divided along the axial direction into a conveying zone, a multi-stage devolatilization zone, and a mixing zone; the coordinated execution mechanism includes a feeding system, a vacuum system, and a temperature control system; the feeding system is connected to the conveying zone of the twin-screw extruder main unit; the vacuum system is connected to the multi-stage devolatilization zone in the twin-screw extruder main unit; the temperature control system is connected to the barrel of the twin-screw extruder main unit; the multi-source sensing unit includes melt temperature sensors and melt pressure sensors installed at the inlet and outlet of the multi-stage devolatilization zone, and a vacuum degree sensor installed at the vacuum port of the multi-stage devolatilization zone; the intelligent collaborative controller is connected to the multi-source sensing unit, processes the data collected by the multi-source sensing unit, and feeds back the processing results to the twin-screw extruder main unit and the coordinated execution mechanism respectively.

[0008] The above-described twin-screw devolatilization extrusion granulator synchronous zone continuous flexible online devolatilization device, wherein the intelligent collaborative controller includes: a multi-source data processing module, a collaborative control module, and a result feedback module; The multi-source data processing module is used to calculate the main disturbance factor of each devolve zone based on the data collected by the multi-source sensing unit, dynamically allocate the role of each devolve zone in combination with the main disturbance factor, and generate a set of control strategies based on the role allocation results. The coordinated control module is used to generate coordinated control instructions that satisfy the physical constraints of each devouring zone based on the control strategy set; The results feedback module is used to issue coordinated adjustment commands to the various coordinating actuators of the devolatilization device to complete synchronous flexible control.

[0009] As described above, the synchronous zone continuous flexible online devolatilization device for a twin-screw devolatilization extrusion granulator includes a multi-source data processing module that utilizes real-time data collected by the multi-source sensing unit to calculate the sealing pressure, vacuum deviation, melt filling degree, and apparent viscosity of the current devolatilization zone; calculates the rate of change of apparent viscosity of the melt between the current sampling period and the previous sampling period; and integrates the calculated sealing pressure, vacuum deviation, and rate of change of apparent viscosity of the melt to generate the main disturbance factor of the fluctuation in the current devolatilization zone.

[0010] As described above, the continuous flexible online devolatilization device for the synchronous region of the twin-screw devolatilization extrusion granulator includes a multi-source data processing module that calculates the disturbance dissipation acceptance coefficient for each devolatilization zone with an effective dominant disturbance factor; calculates the timing control synchronization factor based on the effective dominant disturbance factor and the disturbance dissipation acceptance coefficient, and constructs a pairing diagram; assigns roles to each devolatilization zone based on the constructed pairing diagram, and constructs a cooperative formation; generates a complete set of control strategies based on the role assignment results of each devolatilization zone and the constructed cooperative formation; and integrates the above subsets of control strategies to form a complete set of control strategies.

[0011] As described above, the synchronous region continuous flexible online devolatilization device for a twin-screw devolatilization extrusion granulator includes a multi-source data processing module that generates a complete set of control strategies based on the role allocation results of each devolatilization zone and the constructed collaborative formation. Specifically, this is used for: generating a subset of main-auxiliary linkage control strategies for active collaborative coupling pairs; generating a subset of balanced stabilization control strategies for balanced collaborative pairs; generating a subset of independent self-stabilization control strategies for self-dissipation zones; and directly executing emergency self-stabilization control commands for unhealthy zones. The above-mentioned subsets of control strategies are then integrated to form a complete set of control strategies.

[0012] As described above, the synchronous region continuous flexible online devolatilization device for a twin-screw devolatilization extrusion granulator includes a collaborative control module specifically used for parsing and classifying instructions to be fused; arbitrating and weighting the conflict of global instructions; verifying and limiting physical constraint boundaries; and packaging and transmitting collaborative control instructions.

[0013] The beneficial effects achieved by this invention are as follows: The online devolatilization device described in this application can accurately collect data from each level of the devolatilization zone, perform intelligent collaborative control of each module, and accurately locate the source of disturbance through the main disturbance factor of the fluctuation, realize dynamic allocation of roles in the devolatilization zone and synchronous flexible collaborative control of multiple parameters, solve the industry pain points of low devolatilization efficiency, pressure crosstalk, material overflow and material degradation under wide viscosity conditions, significantly improve equipment operation stability, devolatilization efficiency and product quality, and reduce production energy consumption. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a schematic diagram of a continuous flexible online devolatilization device in the synchronous zone of a twin-screw devolatilization extrusion granulator provided in Embodiment 1 of this application; Figure 2 This is a flowchart of a continuous flexible online devolatilization method in the synchronous zone of a twin-screw devolatilization extrusion granulator provided in Embodiment 2 of this application. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1 like Figure 1 As shown in Embodiment 1 of this application, a continuous flexible online devolatilization device for a twin-screw devolatilization extrusion granulator is provided, comprising: a twin-screw extruder main unit, a coordinated execution mechanism, a multi-source sensing unit, and an intelligent collaborative controller; wherein the barrel of the twin-screw extruder main unit is sequentially divided into a conveying zone, a multi-stage devolatilization zone, and a mixing zone along the axial direction; the coordinated execution mechanism includes a feeding system, a main drive motor, a vacuum system, and a temperature control system; the feeding system is connected to the conveying zone of the twin-screw extruder main unit; the main drive motor is connected to the twin-screw extruder main unit and is used to control the screw speed; the vacuum system is connected to the twin-screw extruder main unit. The multi-stage devolatilization zone in the twin-screw extruder main unit is used to independently control the vacuum level of each devolatilization zone; the temperature control system is connected to the barrel of the twin-screw extruder main unit and is used to independently control the temperature of each devolatilization zone; the multi-source sensing unit includes melt temperature sensors and melt pressure sensors installed at the inlet and outlet of the multi-stage devolatilization zone, and a vacuum level sensor (not shown in the figure) installed at the vacuum port of the multi-stage devolatilization zone; the intelligent collaborative controller is connected to the multi-source sensing unit, processes the data collected by the multi-source sensing unit, and feeds back the processing results to the feeding system, main drive motor, vacuum system, and temperature control system respectively.

[0018] The intelligent collaborative controller includes: a multi-source data processing module, a collaborative control module, and a result feedback module; The multi-source data processing module is used to calculate the main disturbance factor of each devolve zone based on the data collected by the multi-source sensing unit, dynamically allocate the role of each devolve zone in combination with the main disturbance factor, and generate a set of control strategies based on the role allocation results. The coordinated control module is used to generate coordinated control instructions that satisfy the physical constraints of each devouring zone based on the control strategy set; The results feedback module is used to issue coordinated adjustment commands to the various coordinating actuators of the devolatilization device to complete synchronous flexible control.

[0019] The multi-source data processing module is specifically used to calculate the sealing pressure, vacuum deviation, melt filling degree, and melt apparent viscosity of the current devolatilization zone using real-time data collected by the multi-source sensing unit; calculate the rate of change of melt apparent viscosity between the current sampling period and the previous sampling period; and generate the main disturbance factor of the fluctuation in the current devolatilization zone by fusing the calculated sealing pressure, vacuum deviation, and melt apparent viscosity change rate.

[0020] The multi-source data processing module is also used to calculate the disturbance dissipation acceptance coefficient for each de-trapping zone with an effective main disturbance factor; calculate the timing control synchronization factor based on the effective main disturbance factor and the disturbance dissipation acceptance coefficient, and construct a pairing diagram; assign roles to each de-trapping zone based on the constructed pairing diagram, and construct a cooperative formation; generate a complete set of control strategies based on the role assignment results of each de-trapping zone and the constructed cooperative formation; and integrate the above subsets of control strategies to form a complete set of control strategies.

[0021] The multi-source data processing module generates a complete set of control strategies based on the role allocation results of each decoupling zone and the constructed collaborative formation. Specifically, it generates a subset of main-auxiliary linkage control strategies for active collaborative coupling pairs; a subset of balanced stability control strategies for balanced collaborative pairs; a subset of independent self-stabilizing control strategies for self-dissipating zones; and directly executes emergency self-stabilizing control commands for unhealthy zones. The above-mentioned subsets of control strategies are integrated to form a complete set of control strategies.

[0022] The collaborative control module is specifically used for parsing and classifying instructions to be fused; arbitrating and weighted fusion of global instructions for conflicts; verifying and limiting physical constraint boundaries; and packaging and transmitting collaborative control instructions.

[0023] Example 2 like Figure 2 As shown, Embodiment 2 of this application provides a continuous flexible online devolatilization method in the synchronous zone of a twin-screw devolatilization extrusion granulator, applied in the intelligent collaborative controller of Embodiment 1. The method includes: Step S10: For each devolatilization zone, calculate its main disturbance factor based on the data collected by the multi-source sensing unit; The wave principal disturbance factor for each devolatilization zone is calculated in parallel. The specific calculation process is as follows: Step S101: Calculate the sealing pressure, vacuum deviation, melt filling degree, and melt apparent viscosity of the current devolatilization zone using real-time data collected by the multi-source sensing unit. Let i be the index of the devolatilization zone. The intelligent collaborative controller first uses the multi-source sensing unit to collect the melt temperature at the inlet and outlet of the i-th stage devolatilization zone in real time during each sampling cycle (2 seconds in this embodiment, which can be adjusted according to the working conditions). , and melt pressure , Calculate the average melt temperature of the devolatilization zone. and average melt pressure And the real-time vacuum level of the vacuum port corresponding to the devolatilization zone. , which serves as a representative state parameter of the melt in this region; Subsequently, the controller invokes the built-in online rheological identification subroutine, which calculates the real-time apparent viscosity of the melt in the i-th stage devolatilization zone online based on the classic power-law fluid model. ,Right now ,in Melt temperature The consistency coefficient is expressed in units of . , Melt temperature The non-Newtonian power-law exponent is dimensionless. and All parameters are pre-fitted from historical experimental data and pre-stored in the controller database after being correlated with temperature; D is the nominal diameter of the screw. Where N is the groove depth of the i-th stage of the devouring zone, and N is the current screw speed. Let be the helix angle of the screw element in the i-th stage of the devouring zone. The calculated apparent viscosity... The data is stored in the controller's storage area in association with the current sampling period.

[0024] Then, the controller reads the melt pressure sensor data located at the inlet of the i-th stage devolatilization zone and the outlet of the (i-1)-th stage devolatilization zone, and calculates the dynamic sealing pressure of the i-th stage devolatilization zone in the current sampling period. : ,in, The measured melt pressure at the inlet of the i-th stage devolatilization zone is... This is the measured melt pressure at the outlet of the previous stage devolatilization zone; this pressure difference characterizes the effective strength of the seal element at the inlet of this stage as the melt flows from the previous stage devolatilization zone to the current stage devolatilization zone. When i=1 (corresponding to the primary devolatilization zone), This represents the measured melt pressure at the outlet of the conveying zone; when the calculated result is negative... A value of 0 indicates that there is no effective seal between adjacent areas.

[0025] Next, the controller reads the measured absolute vacuum level of the vacuum line in the i-th stage devolatilization zone. Calculate its relationship with the target vacuum level deviation and absolute value of deviation ,in The target vacuum level of the i-th stage devolatilization zone is preset and stored based on the current product brand and production process.

[0026] Simultaneously, based on the current feed rate Q (in kg / h), screw speed N, and pre-input and stored geometric parameters of each functional section of the screw (including screw groove depth, screw edge width, lead, etc.), the controller calls the filling degree prediction model to calculate the instantaneous melt filling degree of the i-th stage devolatilization zone in real time. The fill factor prediction model is based on the principle of mass conservation, and its mathematical expression is: Where 3600 is the hour-to-second conversion factor. For the i-th stage devolatilization zone melt at the average temperature The density below, , Reference temperature (The melt reference density in this embodiment is taken at 230°C.) is the temperature correction factor for melt density, determined beforehand through PVT experiments on the melt; N is the screw speed, in r / min. The theoretical conveying volume per revolution of the screw element in the i-th stage devouring zone is calculated from the screw's geometric parameters. The back pressure correction coefficient is determined in real time using a preset correction function based on the back pressure effect generated by the reverse threaded element or kneading block in this area. The correction function is as follows: , The back pressure influence coefficient is pre-calibrated based on the geometric parameters of the screw reversing element / kneading block, and its value ranges from 0.02 to 0.2. The standard atmospheric pressure is fixed at 101325 Pa.

[0027] Step S102: Calculate the rate of change of apparent melt viscosity between the current sampling period and the previous sampling period; The controller reads the apparent melt viscosity from the storage area for the current sampling period and the previous sampling period. t is the sampling period index. The viscosity change rate is calculated using the following formula. : ,in This is the time interval between two sampling periods.

[0028] When there is no historical viscosity data at t=1 (the first sampling period), the viscosity change rate is set to 0 by default and is not included in the calculation of the main disturbance factor of the fluctuation in this control period. Normal calculation will start after the second sampling period. when or In this case, the viscosity change rate is set directly to 0 to avoid errors in the domain of the logarithmic function.

[0029] Step S103: Combine the calculated sealing pressure, vacuum deviation, and melt apparent viscosity change rate to generate the main disturbance factor of the current devolatilization zone; The fusion formula is expressed as follows: ,in Let i be the wave principal disturbance factor of the i-th order devolve zone. It is the absolute value of the rate of change of apparent viscosity of the melt in the i-th stage devolatilization zone, which characterizes the degree of fluctuation in the rheological state of the melt; The instantaneous melt filling degree of the i-th stage devolatilization zone is dimensionless; The absolute deviation of the vacuum level in the i-th stage devolatilization zone is expressed in Pa. The dynamic sealing pressure of the i-th stage devolatilization zone is expressed in Pa. The maximum allowable vacuum deviation limit for the i-th stage devolatilization zone is a system preset constant. This is the lower limit of the dynamic sealing pressure allowed in the i-th stage devolatilization zone under rated steady-state conditions. This value is determined through offline experiments and stored in advance, and is also a preset constant of the system. To prevent the value from being divided by zero and reaching a minimum, a fixed value is used. This is used to avoid calculation crashes caused by a denominator of 0. The characteristic time constant is 1s. After introducing this constant, the entire molecule becomes a dimensionless quantity.

[0030] The physical meaning of this formula is as follows: the numerator quantifies the instantaneous "disturbance energy" of the melt's own state in this region—the more drastic the viscosity change, the higher the current filling degree, and the greater the vacuum deviation, the greater the intrinsic driving force for fluctuations in this region; the denominator characterizes the "tolerance capacity" of this region to maintain its own operational stability—the closer the sealing pressure is to or below the lower limit, the weaker the region's ability to tolerate fluctuations. Therefore, The higher the value of the devolatilization zone, the more unstable its state and the smaller its stability margin. It is the most likely source of pressure crosstalk and vacuum fluctuation in the entire multi-stage devolatilization system.

[0031] Step S20: Dynamically allocate the roles of each devolve zone based on the main disturbance factor of the fluctuation, and generate a set of control strategies based on the role allocation results; specifically including the following sub-steps: Step S201: For each de-boosting zone with an effective main disturbance factor, calculate its disturbance dissipation acceptance coefficient; If a certain detachment zone If a valid calculation is not completed due to sensor failure, data link interruption, or insufficient initial sampling period, it will be marked as "invalid" and will not participate in this regulation.

[0032] The disturbance dissipation acceptance coefficient (i is the index of the devolatilization region), used to quantify the region's ability to safely convert fluctuation energy into thermal energy and micro-mixing energy through controllable viscous dissipation, thereby playing the role of an "energy buffer trap". The calculation formula is expressed as: ,in For controlled dissipation intensity factor, , is the dissipation geometry factor of the i-th stage devouring zone, which is used to quantify the geometric efficiency of the kneading block, reverse thread element and other structures in this zone in converting shear mechanical energy into melt thermal energy. The calibration method is as follows: Under offline conditions, using a polyolefin standard material with known rheological parameters, and with the screw speed and feed rate fixed, measure the melt temperature rise in this section under steady state. The temperature rise is then calculated from the energy balance relationship. If offline calibration is not performed, a conservative default value can be used. Value; N is the current screw speed; The apparent viscosity of the i-th stage devolatilization zone is the real-time viscosity. The fill factor window function is a Gaussian window function centered on the optimal fill factor, so that the dissipation and acceptance capacity reaches its maximum near the optimal fill factor, decays rapidly to both sides, and is forcibly set to zero when it exceeds the safe fill factor range. The instantaneous melt filling degree of the i-th stage devolatilization zone; The design follows the basic principle of devolatilization process: when the fill level is too low, the melt volume is insufficient and the fluctuation energy cannot be effectively dissipated; when the fill level is too high, the volatiles escape is blocked and the risk of material overflow increases dramatically. The specific rules are as follows: when the fill level is within the safe range of 0.05 to 0.90, the window function decays with the deviation from the optimal fill level in a Gaussian distribution, with the decay being faster as the deviation is greater; when the fill level is below 0.05 or above 0.90, the window function is forced to zero, indicating that the region no longer has the ability to effectively dissipate and accept disturbances; the optimal fill level is determined through offline process optimization experiments, and in this embodiment, it is set to 0.5. The window function width parameter ranges from 0.15 to 0.25, and in this embodiment, it is set to 0.2. This represents the rate of change of the apparent viscosity of the melt between the current sampling period and the previous sampling period. Here, is the critical frequency parameter for the i-th stage of devolatilization. Its physical meaning is: when the rate of change of the apparent viscosity of the melt exceeds this frequency, the dissipation process struggles to effectively follow the rapid evolution of the state, and the accepting capacity decreases accordingly. Its calibration method is: in a linear viscoelastic oscillatory shear test, the frequency of the intersection of the storage modulus and loss modulus of the polyolefin melt of this grade is measured, and 1 / 5 to 1 / 3 of this value is taken as the critical frequency. For typical polyolefins, the range of the critical frequency is approximately... to If experimental data is missing, use the conservative default value. ; To prevent the minimum value from being divided by zero, a fixed value is taken. .

[0033] Step S202: Calculate the timing control synchronization factor based on the effective fluctuation main disturbance factor and the disturbance dissipation acceptance coefficient, and construct a pairing diagram; Step 1: Screening in the health zone; The states of each devolve zone are mapped to a four-dimensional spectral space: dimension I is the effective wave principal disturbance factor. Dimension II is the perturbation dissipation acceptance coefficient. Dimension III represents the dimensionless relative deviation rate of vacuum degree. (Right now and The ratio), dimension IV is the dimensionless dynamic sealing pressure margin. (Right now and The ratio of the two values ​​of the two values ​​of the i-th detached region to the i-th detached region is used to mark it as a healthy region and allow it to participate in synchronization pairing as a candidate node only if it simultaneously meets the following two health conditions: Vacuum degree relative deviation rate The deviation from the healthy vacuum level shall not exceed the threshold value, which is preset to 0.20. Sealing pressure margin Not less than the healthy seal margin threshold, which is preset to 1.2.

[0034] Zones that do not meet the above conditions are marked as unhealthy zones and will not participate in this synchronization pairing. Instead, the emergency self-stabilizing control command in sub-step S204 will be executed directly.

[0035] Step 2: Calculate the disturbance radiation coupling coefficient ; For the i-th and j-th healthy devour regions (i is upstream of j), define the perturbation radiation coupling coefficient. The coupling strength of the disturbance propagating from the i-th region to the j-th region is calculated using the following formula: ,in , The coordinates of the axial center positions of the two regions are: The average axial spacing between adjacent devouring zones. This is the structural coupling factor (0.3 if physical sealing and isolation exist, otherwise 1.0). The dynamic sealing pressure of the j-th stage devolatilization zone. This is the minimum allowable dynamic sealing pressure lower limit for the j-th stage devolatilization zone under rated steady-state conditions; , , respectively, are the real-time apparent viscosity of the i-th and j-th devolatilization zones.

[0036] Step 3: Calculation of synchronization factor for time-controlled system and construction of pairing graph; For all healthy devitrification zones retained after screening, calculate the time-conditioning synchronization factor between any two zones. The calculation formula is expressed as: Where i and k are the indices of any two healthy devour zones. For consistency penalty items, , This is the penalty intensity coefficient, ranging from 0.5 to 2.0, with a default value of 1.0. To prevent the minimum value from being divided by zero, a fixed value is taken. .

[0037] by Construct an undirected weighted graph, i.e., a pairing graph, for the edge weights, where the nodes are healthy, discarded regions that have passed the screening process; The removal of the edge indicates that there is no substantial synergy potential between the two regions.

[0038] Step S203: Assign roles to each de-engagement zone based on the constructed pairing graph, and construct a collaborative formation; Mark the isolated nodes in the graph as self-dissipating regions; For the remaining connected subgraphs, pairing selection and role assignment are performed according to the following rules: For each node in the connected subgraph, select from all edges connected to it. The neighboring node with the largest value is selected as its preferred pairing candidate; if two nodes are each other's preferred pairing candidates, then the two nodes form a candidate pairing; if a node is selected as the preferred candidate by multiple other nodes, then the pairing is determined by... The values ​​are tried one by one in descending order. Each node will eventually belong to only one pair. Once a node has been selected for a pair, it will not participate in the subsequent selection. After the selection is completed, the nodes that have not been selected by any pair will be demoted to the self-dissipating zone. For each candidate pairing, the position coordinates of the two regions along the screw axis are compared, and it is stipulated that the node with the more upstream position in the axial position plays the role of disturbance amplification, and the downstream node plays the role of energy reception. This role allocation is based on the physical fact that the melt flows unidirectionally along the axial direction, and is mandatory and unchangeable.

[0039] For each candidate pairing (where i and k represent the undive zone indices in the pairing), calculate its co-fitness index under the premise of forced role assignment. The calculation formula is: ,in: The main disturbance factor is the fluctuation of the external perturbation role; The disturbance dissipation reception coefficient for the energy reception role; To prevent the minimum value from being divided by zero, take ; The flow coupling efficiency factor. ,in The perturbation radiation coupling coefficient defined for sub-step S202 is the perturbation conduction strength from the perturbation emitting role (upstream region) to its paired energy receiving role (downstream region); The coupling threshold is set to 0.4 in this embodiment. If the value is lower than this, it is considered that there is no effective disturbance conduction path between the two regions. The steepness coefficient of the coupling efficiency curve ranges from 1.5 to 3.0; in this embodiment, it is set to 2.0 to control the steepness. The rate of transition from 0 to 1; according to The status of both sides and the determination of the cooperative formation type are as follows: like If the energy receiving area is currently in a healthy state (meets the health screening criteria), then the current role allocation result is retained and it is determined to be an active collaborative coupling pair. like If the health of the energy receiving area is in a critical state (the sealing margin or vacuum deviation is close to the threshold), then the current role allocation result is retained and it is judged as a balanced cooperative pair. like ,or If the disturbance cannot be effectively propagated, the pairing is terminated, and both nodes are downgraded to self-dissipating regions.

[0040] Step S204: Generate a complete set of control strategies based on the role allocation results of each de-engagement zone and the constructed collaborative formation; Let i and k be the indexes of the devouring regions within a valid pair, where i is the devouring region that plays the role of perturbation outward and k is the devouring region that plays the role of energy reception.

[0041] For four types of objects—actively coordinating pairs, balanced coordinating pairs, self-dissipating regions, and unhealthy regions—differentiated control actions conforming to the physical constraints of the entire system are executed, forming multiple subsets of control strategies. All subsets of strategies together constitute a complete set of control strategies. All control actions are based on the core rigid constraint of "not damaging regional seals, not inducing material degradation, and not amplifying system fluctuations," achieving multi-region synchronous linkage and continuous flexible closed-loop control. Specifically, it includes the following sub-steps: Step S2041: For the active collaborative coupling pair, generate a subset of master-slave linkage control strategies; For the active collaborative coupling of internal disturbance amplification roles, the following control actions are executed in parallel: Vacuum degree closed-loop fine adjustment: Calculate the vacuum degree adjustment amount in this region. ,in The first vacuum adjustment gain coefficient is preset to a range of 0.1~0.5 (dimensionless), and is set to 0.1 in this embodiment; This is the dominant disturbance factor for the fluctuations in this region. This represents the vacuum deviation in this area; the negative sign here indicates that the adjustment direction is opposite to the vacuum deviation direction; the current vacuum setting value is compared with the calculated vacuum adjustment amount. Add them together to obtain the vacuum level setpoint for this region after adjustment; Temperature field viscosity matching control: Calculate the barrel temperature adjustment amount in this region. ,in This represents the rate of change in the apparent viscosity of the melt in the devolatilization zone. The first temperature regulation gain coefficient is preset to a range of 0.05~0.3 (dimensionless), and is set to 0.1 in this implementation; the current barrel temperature setpoint is compared with the calculated barrel temperature regulation amount. Add them together to get the barrel temperature setpoint after the adjustment of this area.

[0042] For the energy-accepting role within the proactive collaborative coupling, the following matching actions are performed synchronously: Coordinated regulation of dissipation capacity: Calculation of barrel temperature regulation in this area ,in The gain coefficient for the second temperature adjustment is preset to a range of 0.1~0.4 (dimensionless), and in this embodiment, it is set to 0.1; the gain coefficient is adjusted according to the barrel temperature. Calculate the barrel temperature setpoint after adjustment in this area; Fill degree optimization and control: Calculate the real-time fill degree deviation based on the preset optimal fill degree for this area. Calculate the feed rate adjustment amount using the following formula. Screw speed adjustment , ; ,in , The preset adjustment gain coefficient has a preset range of 0.05~0.2 (dimensionless), and in this embodiment, it is taken as 0.1. , These are the current mass feed rate and screw speed, respectively; the adjustment amount is based on the feed rate. Screw speed adjustment Calculate the feed rate setpoint and screw speed setpoint after the adjustment in this area; Vacuum gradient control: The vacuum level setpoint in this region remains unchanged by default; the vacuum level adjustment is only applied when the upstream devolatilization zone, which acts as a disturbance source, is affected. Only then is the vacuum adjustment amount calculated synchronously. To follow and adjust, avoid pressure crosstalk caused by sudden changes in the upstream and downstream vacuum gradients; adjust according to the vacuum level. Calculate the vacuum setpoint after adjustment in this area.

[0043] The calculated and adjusted production parameters are organized into a subset of the main and auxiliary linkage control strategy. The new production parameters refer to the adjusted vacuum setpoint, barrel temperature setpoint, feed rate setpoint, and screw speed setpoint calculated after the control action is executed.

[0044] Step S2042: For the equilibrium cooperative pair, generate a subset of equilibrium stability control strategies; For the role of externalizing disturbances within the balanced coordination mechanism, the following disturbance suppression actions are performed in parallel: Rapid closed-loop vacuum adjustment: Calculate the vacuum adjustment amount for this region. ,in This is the second vacuum adjustment gain coefficient, with a preset range of 0.4~0.8 (dimensionless). In this embodiment, it is set to 0.4. The vacuum level deviation of this area; the current vacuum level setpoint of this area and the calculated vacuum level adjustment amount. Add them together to obtain the vacuum level setpoint for this region after adjustment; Viscosity closed-loop stabilization control: Calculate the barrel temperature adjustment amount in this region. ,in The target apparent viscosity for this region under the current process (pre-set and stored). The gain coefficient for the third temperature adjustment is preset to a range of 0.2~0.5 (dimensionless), and in this embodiment it is 0.2. The apparent viscosity of the melt in this region; the current barrel temperature setpoint in this region and the calculated barrel temperature adjustment amount. Add them together to get the barrel temperature setpoint after adjustment in this area; Fill degree coordinated control: when the fill degree of this area At that time, calculate the screw speed adjustment amount. With feed rate adjustment Increase rotation speed and reduce feed rate to reduce filling density and avoid the risk of material overflow; when When , Inverting the sign executes reverse adjustment, increasing the filling degree to maintain conveying and sealing stability; whereby... , The gain coefficient for adjusting the filling degree is preset to a range of 0.1~0.3 (dimensionless), and in this embodiment, it is set to 0.2; the adjustment amount is based on the feed rate. Screw speed adjustment The feed rate setpoint and screw speed setpoint after the adjustment of the zone are calculated.

[0045] For the energy intake role within the balanced coordination mechanism, the following load control actions are performed: Dissipation capacity limiting control: Calculate the barrel temperature adjustment amount in this area. ,in The fourth temperature regulation gain coefficient is preset to a range of 0.05~0.2 (dimensionless). In this embodiment, it is set to 0.05, which is less than the adjustment range of the active cooperative coupling pair. The current barrel temperature setpoint in this region is compared with the calculated barrel temperature adjustment amount. Add them together to get the barrel temperature setpoint after adjustment in this area; Health-priority control: Real-time monitoring of the health status of this area, when the relative deviation rate of vacuum degree... or sealing pressure margin At that time, calculate the vacuum adjustment amount. The current vacuum level setpoint of the area is compared with the calculated vacuum level adjustment amount. The values ​​are added together to obtain the vacuum level setpoint for that region after adjustment, which is then used to quickly correct vacuum level deviations. The third vacuum adjustment gain coefficient has a value range of 0.6 to 1.0, and is set to 0.6 in this embodiment. Filling stiffness stability: Filling degree in this area Strictly maintain the filling level within the range of 0.3 to 0.7. If it exceeds the range, immediately perform filling level adjustment. The adjustment method is the same as the filling level optimization logic of S2042, and this adjustment has a higher priority than the coordinated dissipation control.

[0046] The calculated and adjusted production parameters are organized into a subset of equilibrium and stability control strategies.

[0047] Step S2043: Generate an independent self-stabilizing control strategy subset for the self-dissipation region; The adjustment commands for each dissipation region do not interfere with each other. The specific control actions are as follows (for any self-dissipation region, its index value is denoted as m): Independent PI closed-loop vacuum control: Calculate the vacuum control amount for this region. ,in This is the vacuum degree proportional adjustment coefficient (preset 0.3~0.8), and in this embodiment, it is set to 0.3. This is the vacuum degree integral adjustment coefficient (preset 0.05~0.2), and in this embodiment, it is set to 0.05. This refers to the vacuum level deviation in this area. This represents the cumulative vacuum deviation value of the previous three control cycles in this zone; the vacuum setpoint of the current zone is then compared with the calculated vacuum adjustment amount. Add them together to obtain the vacuum level setpoint for that region after adjustment; Temperature and viscosity adaptive PID self-stabilizing regulation: based on the target apparent viscosity in this region. The measured apparent viscosity is the set value. As the feedback value, an adaptive PID algorithm is used to output the barrel temperature regulation amount for this zone. ;PID parameters vary with real-time fill rate Adaptive adjustment: When the value is in the optimal range of 0.35 to 0.65, the PID controller uses the default parameters (proportional coefficient). Integral coefficient Differential coefficients ); When deviating from the optimal range, the proportional coefficient The temperature decreases linearly with the degree of deviation, avoiding over-adjustment that could cause further fluctuations in filling degree; the current barrel temperature setpoint for this area is compared with the calculated barrel temperature adjustment amount. Add them together to get the barrel temperature setpoint after adjustment in this area; Fill power control: when When the filling degree exceeds the safe range of 0.05~0.90, the feed rate and screw speed are immediately fine-tuned to bring the filling degree back to the safe range. The adjustment method is the same as the filling degree optimization control logic of S2042.

[0048] The adjusted vacuum setting, barrel temperature setting, feed rate setting, and screw speed setting calculated for the self-dissipation zone are organized into an independent self-stabilizing control strategy subset.

[0049] Step S2044: For unhealthy areas, directly execute emergency self-stabilization and control instructions; For any unhealthy region, its index value is denoted as 's'. When a region is marked as unhealthy, the emergency self-stabilization control command is executed directly without waiting for the generation and distribution of other regional policy subsets. If there are multiple unhealthy regions, the emergency self-stabilization control command is executed sequentially and exclusively according to the order of the initial marking time. The specific control command is as follows: like Immediately execute: ① Lock all control commands to maintain stable upstream and downstream operating conditions; ② Increase the temperature of the barrel corresponding to the sealing section before the inlet of this area by +5℃ to +10℃ (without exceeding the critical temperature for thermal degradation) to reduce the melt viscosity of the sealing section and improve conveying capacity; ③ Simultaneously and slightly increase the global screw speed, at which point the screw speed adjustment amount is... (Not exceeding the rated maximum speed), enhance the melt accumulation effect in the sealing section until... , This is the lower limit of the dynamic sealing pressure for this area; If the relative deviation rate of vacuum degree in this area Immediately execute: ① Lock the vacuum setpoint to the current measured value; ② If the vacuum level is insufficient, gradually open the vacuum pipeline valves, increasing the opening by no more than 10% each time, with an interval of one control cycle, until... ≤10%; if the vacuum is too high, gradually close the valve, with each reduction not exceeding 10%, at intervals of one control cycle, until... ≤10%; If fill degree (High risk of material overflow), take immediate action: ① Slightly reduce the overall feed rate. The feed rate adjustment amount at this time is: (Not lower than the minimum stable feed rate), simultaneously increase the screw speed slightly, at which point the screw speed adjustment amount is: (Without exceeding the rated maximum speed), rapidly reduce the filling degree; ② Simultaneously increase the vacuum degree setting value of the adjacent upstream devolatilization zone. (Absolute vacuum increases, vacuum decreases), reduce the amount of melt supplied from upstream to this area, until... The risk of counterfeit materials has been eliminated; Health recovery verification: If the area is in an unhealthy zone for 10 consecutive control cycles, the controller will trigger an audible and visual alarm to prompt the operator to intervene manually.

[0050] Step S2045: Integrate the above subsets of control strategies to form a complete set of control strategies; The above subsets of control strategies, which include new process parameters for each devolatilization zone, are integrated to form a complete set of control strategies.

[0051] Step S30: Generate coordinated adjustment instructions that satisfy the physical constraints of each region based on the set of control strategies; This step follows the integrated control strategy set from step S2045. It should be noted that this strategy set does not include emergency control strategies for unhealthy areas—all areas marked as unhealthy have already had their emergency self-stabilizing control instructions directly generated and issued during the role allocation phase of step S20, enjoying the highest priority. This step only performs global conflict arbitration and physical constraint verification on the subset of control strategies for active cooperative coupling pairs, balanced cooperative pairs, and self-dissipating areas included in the strategy set, ultimately generating unified, conflict-free cooperative control instructions; specifically, it includes the following sub-steps: Step S301: Parse and classify the instructions to be merged; The control strategy set is divided into two categories: global instruction set: containing all the feed rate setting and screw speed setting after control strategy set; and regional independent instruction set: containing the barrel temperature setting and new vacuum setting after control strategy set for each devouring zone.

[0052] Step S302: Conflict arbitration and weighted fusion of global instructions; Following the principle of "safety first, conservative approach", the final feed rate setting is the minimum of all new feed rate settings in the global instruction set. Following the principle of "demand-oriented, weighted compromise," the new screw speed settings in the global instruction set are weighted and fused to obtain the final screw speed settings. For the different roles of the detached zone, the weighting coefficients for their screw speed settings are as follows: for the disturbance amplification role and energy reception role in the balanced cooperative pair, the weighting coefficient is 0.5; for the disturbance amplification role and energy reception role in the active cooperative coupling pair, the weighting coefficient is 0.3; and for the self-dissipating zone, the weighting coefficient is 0.2. Note that the sum of the weights of all participating regions must be normalized to 1 and allocated according to the role weight ratio. Step S303: Physical constraint boundary verification and amplitude limiting; The final feed rate setting, screw speed setting, barrel temperature setting, and vacuum setting in the region-independent instruction set are all physically boundary-checked after fusion. If they exceed the limits, they are forcibly limited to the nearest boundary. The feed rate setting must be between the minimum stable feed rate and the rated maximum feed rate of the equipment; the screw speed setting must be between the minimum stable operating speed and the rated maximum speed; the barrel temperature setting for each region must be between the melting temperature of the current material and the critical temperature for thermal degradation; and the vacuum setting for each region must be between the upper and lower limits of the vacuum unit's vacuum level.

[0053] Step S304: Packaging and transmitting coordinated adjustment instructions; The parameters after all checks and limiting are integrated into the final coordinated adjustment instruction set, with the following data structure: ,in These are the feed rate setting value and screw speed setting value after the amplitude is limited, respectively. These are the barrel temperature setpoints for each devolatilization zone after the amplitude is limited. This sets the vacuum level for each devolatilization zone after limiting. This instruction set is then transmitted to step S40, where it is uniformly distributed to each actuator.

[0054] Step S40: Issue coordinated adjustment commands to each coordinating actuator of the devolatilization device to complete the synchronous flexible control of the flow field in each functional area; First, iterate through the marked status of all devolatilization zones. If there is an unhealthy zone and its emergency self-stabilization control command has not been completed (i.e., the sealing pressure, vacuum deviation, and filling degree have not been restored to the safe range), then suspend the coordinated control command set and do not issue it to avoid interfering with the emergency response process. The execution status of emergency self-stabilizing control commands in unhealthy zones is monitored in real time. If the time between the completion of the command and the suspension time of the coordinated adjustment command set does not exceed two sampling cycles, the coordinated adjustment commands output in step S30—including the global feed rate setting value, the global screw speed setting value, the barrel temperature setting value of each zone, and the vacuum setting value of each zone—are uniformly sent to the corresponding coordinating execution mechanism (feeding system, temperature control system of barrel temperature in each zone, and vacuum system connected to each devolatilization zone) and the twin-screw extruder main unit to complete this control. If the time between the completion of the command and the suspension time of the coordinated adjustment command set exceeds two sampling cycles, a new coordinated adjustment command set is generated based on the data of the new sampling cycle.

[0055] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of the present invention should be included within the scope of protection of the present invention.

Claims

1. A continuous flexible online devolatilization device in the synchronous zone of a twin-screw devolatilization extrusion granulator, characterized in that, include: The system comprises a twin-screw extruder main unit, a coordinating actuator, a multi-source sensing unit, and an intelligent coordinating controller. The twin-screw extruder main unit's barrel is axially divided into a conveying zone, a multi-stage devolatilization zone, and a mixing zone. The coordinating actuator includes a feeding system, a vacuum system, and a temperature control system. The feeding system connects to the conveying zone of the twin-screw extruder main unit. The vacuum system connects to the multi-stage devolatilization zone within the twin-screw extruder main unit. The temperature control system connects to the barrel of the twin-screw extruder main unit. The multi-source sensing unit includes melt temperature and melt pressure sensors located at the inlet and outlet of the multi-stage devolatilization zone, and a vacuum sensor located at the vacuum port of the multi-stage devolatilization zone. The intelligent coordinating controller connects to the multi-source sensing unit, processes the data collected by the multi-source sensing unit, and feeds the processing results back to the twin-screw extruder main unit and the coordinating actuator. The intelligent collaborative controller includes: a multi-source data processing module, a collaborative control module, and a result feedback module; The multi-source data processing module is used to calculate the dominant disturbance factor of each devolatilization zone based on the data collected by the multi-source sensing unit, dynamically allocate the role of each devolatilization zone based on the dominant disturbance factor, and generate a set of control strategies according to the role allocation results. Specifically, the multi-source data processing module is used to calculate the sealing pressure, vacuum deviation, melt filling degree, and melt apparent viscosity of the current devolatilization zone using the real-time data collected by the multi-source sensing unit; calculate the rate of change of melt apparent viscosity between the current sampling period and the previous sampling period; and fuse the calculated sealing pressure, vacuum deviation, and melt apparent viscosity change rate to generate the dominant disturbance factor of the current devolatilization zone. The fusion formula is expressed as: ,in Let i be the wave principal disturbance factor of the i-th order devolve zone. is the absolute value of the rate of change of apparent viscosity of the melt in the i-th stage devolatilization zone; The instantaneous melt filling degree of the i-th stage devolatilization zone; The absolute deviation of the vacuum level in the i-th stage devolatilization zone; The dynamic sealing pressure of the i-th stage devolatilization zone; This represents the maximum allowable vacuum deviation tolerance value for the i-th stage devolatilization zone; This is the lower limit of the dynamic sealing pressure allowed in the i-th stage devolatilization zone under rated steady-state conditions; To prevent the minimum value from being divided by zero, Characteristic time constant; The coordinated control module is used to generate coordinated control instructions that satisfy the physical constraints of each devouring zone based on the control strategy set; The results feedback module is used to issue coordinated adjustment commands to the various coordinating actuators of the devolatilization device to complete synchronous flexible control.

2. The synchronous zone continuous flexible online devolatilization device for a twin-screw devolatilization extrusion granulator according to claim 1, characterized in that, The multi-source data processing module is also used to calculate the disturbance dissipation acceptance coefficient for each de-trapping zone with an effective main disturbance factor; calculate the timing control synchronization factor based on the effective main disturbance factor and the disturbance dissipation acceptance coefficient, and construct a pairing diagram; assign roles to each de-trapping zone based on the constructed pairing diagram, and construct a cooperative formation; and generate a complete set of control strategies based on the role assignment results of each de-trapping zone and the constructed cooperative formation. The disturbance dissipation acceptance coefficient is used to quantify the region's ability to safely convert fluctuation energy into thermal energy and micro-mixing energy through controllable viscous dissipation, thereby playing the role of an "energy buffer trap." The calculation formula is expressed as follows: ,in For controlled dissipation intensity factor, , is the dissipation geometry factor of the i-th stage devouring zone, used to quantify the geometric efficiency of the kneading block and reverse thread element in this zone in converting shear mechanical energy into melt thermal energy; N is the current screw speed; The apparent viscosity of the i-th stage devolatilization zone is the real-time viscosity. The fill factor window function is a Gaussian window function centered on the optimal fill factor, so that the dissipation and acceptance capacity reaches its maximum near the optimal fill factor, decays rapidly to both sides, and is forcibly set to zero when it exceeds the safe fill factor range. The instantaneous melt filling degree of the i-th stage devolatilization zone; This represents the rate of change of the apparent viscosity of the melt between the current sampling period and the previous sampling period. Let be the critical frequency parameter of the i-th stage devouring region; To prevent the value from being divided by zero and reaching a minimum; For all healthy devitrification zones retained after screening, calculate the time-conditioning synchronization factor between any two zones. The calculation formula is expressed as: Where i and k are the indices of any two healthy devour zones. For consistency penalty items, To prevent the value from being zero or a minimum.

3. The synchronous zone continuous flexible online devolatilization device for a twin-screw devolatilization extrusion granulator according to claim 2, characterized in that, The multi-source data processing module generates a complete set of control strategies based on the role allocation results of each decoupling zone and the constructed collaborative formation. Specifically, it is used to generate a subset of main-auxiliary linkage control strategies for active collaborative coupling pairs and a subset of balanced stability control strategies for balanced collaborative pairs. A subset of independent self-stabilizing control strategies is generated for the self-dissipating region; For unhealthy areas, emergency self-stabilization and control instructions are directly implemented; the above-mentioned subsets of control strategies are integrated to form a complete set of control strategies. The isolated nodes in the pairing graph are marked as self-dissipating regions; For the remaining connected subgraphs, pairing selection and role assignment are performed according to the following rules: For each node in the connected subgraph, select from all edges connected to it. The neighboring node with the largest value is selected as its preferred pairing candidate; if two nodes are each other's preferred pairing candidates, then the two nodes form a candidate pairing; if a node is selected as the preferred candidate by multiple other nodes, then the pairing is determined by... The values ​​are tried one by one in descending order. Each node will eventually belong to only one pair. Once a node has been selected for a pair, it will not participate in the subsequent selection. After the selection is completed, the nodes that have not been selected by any pair will be demoted to the self-dissipating zone. For each candidate pairing, the position coordinates of the two regions along the screw axis are compared, and it is stipulated that the node with the more upstream axial position plays the role of disturbance amplification, and the downstream node plays the role of energy reception. For each candidate pairing, let i and k represent the undive zone indices in the pairing, and calculate its cofit index. The calculation formula is: ,in: The main disturbance factor is the fluctuation of the external perturbation role; The disturbance dissipation reception coefficient for the energy reception role; To prevent the value from being divided by zero and reaching a minimum; The flow coupling efficiency factor. ,in The disturbance radiation coupling coefficient; This is the coupling threshold; This represents the steepness coefficient of the coupling efficiency curve; according to The status of both sides and the determination of the cooperative formation type are as follows: like If the energy acceptance zone is currently in a healthy state, then the current role allocation result is retained and it is determined to be an active collaborative coupling pair; like If the health of the energy acceptance zone is in a critical state, the current role allocation result is retained and it is judged as a balanced cooperation pair; like ,or If the pairing is broken, both nodes will be downgraded to self-dissipating regions.

4. The synchronous zone continuous flexible online devolatilization device for a twin-screw devolatilization extrusion granulator according to claim 1, characterized in that, The collaborative control module is specifically used for parsing and classifying instructions to be fused; arbitrating and weighted fusion of global instructions for conflicts; verifying and limiting physical constraint boundaries; and packaging and transmitting collaborative control instructions.

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