Internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback

Abstract

The invention discloses an internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback, and relates to the technical field of rubber processing equipment. The internal circulation subsystem comprises a servo driving water pump, a heating loop, a plate heat exchanger, a first temperature measuring element, a first pressure sensor, a second pressure sensor, a second temperature measuring element and a first electromagnetic flowmeter which are sequentially connected through a pipeline; the external pipeline subsystem comprises a third pressure sensor, an electric servo valve, a third temperature measuring element, a fourth temperature measuring element and a second electromagnetic flowmeter which are sequentially connected through pipelines; and the control module is electrically connected with the internal circulation subsystem and the external pipeline subsystem. The operating parameters of the servo drive water pump and the control strategy of the electric servo valve are optimized respectively, the multi-parameter coupling model is introduced, the temperature precision and the system stability are balanced through dynamic weight distribution, and the temperature fluctuation range is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of rubber processing equipment, and in particular to a temperature control system for an internal mixer with dynamic flow regulation and multi-parameter feedback. Background Art

[0002] During the mixing phase of an internal mixer, friction between the rubber compounds and the friction between the rotors cause molecular chain breakage, converting mechanical energy into heat. This phase requires the temperature control system to control the rate of temperature rise to avoid uneven temperatures, as excessive localized temperature rise can trigger premature crosslinking. During the mixing phase, as carbon black and oil are added, the temperature control system must also increase in temperature to meet process requirements. A constant temperature must be maintained for most of the time to ensure the dispersion of carbon black, oil, and compounding agents within the compound. However, during the addition of vulcanizing agents, a well-established constant temperature must be maintained to prevent scorching. After entering the discharge phase, the speed must be gradually reduced to avoid damage to the equipment from sudden temperature changes and to prevent the next batch of rubber from being fed at too high a temperature. Clearly, internal mixers and other rubber mixing equipment have different requirements for temperature control systems at different stages of production. Furthermore, temperature control requirements vary depending on the number of mixing stages and plasticizing stages.

[0003] At present, the existing internal mixer temperature control system generally adopts a dual-circuit design, and its technical defects are mainly reflected in the following three aspects:

[0004] 1. Control hysteresis: Relying on a fixed PID algorithm and on-off valve adjustment, the system response time is ≥5 seconds and the system inertia is large. Therefore, traditional PID control causes the temperature fluctuation range of the mixing stage to reach ±(5-12)°C, which is difficult to adapt to the scene of drastic temperature changes in the mixing process;

[0005] 2. Energy efficiency imbalance: The opening of the external water inlet valve is adjusted only by a single temperature signal, without considering the impact of water pressure fluctuations and flow disturbances on heat exchange efficiency. To meet cooling requirements, water pressure and power are deliberately increased, resulting in energy waste and increased equipment failure rate.

[0006] 3. Insufficient adaptability: The internal circulation water pump adopts a fixed speed drive and cannot dynamically adjust the flow rate according to the difference in heat demand in the rubber mixing stage, resulting in poor process stability. Summary of the Invention

[0007] The object of the present invention is to provide a temperature control system for an internal mixer with dynamic flow regulation and multi-parameter feedback, so as to solve the above-mentioned deficiencies in the technology.

[0008] In order to achieve the above object, the present invention provides the following technical solution: a temperature control system for an internal mixer with dynamic flow regulation and multi-parameter feedback, comprising:

[0009] An internal circulation subsystem, the internal circulation subsystem comprising a servo-driven water pump, a heating circuit, a plate heat exchanger, a first temperature measuring element, a first pressure sensor, a second pressure sensor, a second temperature measuring element, and a first electromagnetic flowmeter, which are sequentially connected through pipelines;

[0010] an external piping subsystem, the external piping subsystem comprising a third pressure sensor, an electric servo valve, a third temperature measuring element, a fourth temperature measuring element, and a second electromagnetic flowmeter connected in sequence through piping, wherein the piping between the third temperature measuring element and the fourth temperature measuring element is connected to a plate heat exchanger;

[0011] a control module, the control module being electrically connected to the internal circulation subsystem and the external piping subsystem;

[0012] The control module includes a data acquisition layer, a decision layer and an execution layer;

[0013] The data acquisition layer collects sensor data from the internal circulation subsystem and the external pipeline subsystem every 100ms and builds a time series database;

[0014] The decision layer generates control instructions based on the fuzzy PID algorithm. The input variables include temperature difference, the ratio of external pipeline flow rate to pressure, and the temperature difference between the inlet and outlet of the plate heat exchanger. The output is the servo-driven water pump speed instruction and the electric servo valve opening instruction. The decision layer includes a segmented adaptive control algorithm unit, a multi-parameter collaborative control strategy unit, and an intelligent decision architecture unit.

[0015] The execution layer controls the servo drive actuator through PN or Modbus-TCP protocol, and the response time is less than 50ms.

[0016] Preferably, the segmented adaptive control algorithm unit dynamically adjusts the control parameters according to the rubber mixing stage, wherein:

[0017] During the heating phase, the servo-driven water pump speed is increased first;

[0018] Switch to energy-saving mode during the constant temperature stage, and give priority to adjusting the opening of the electric servo valve;

[0019] A gradient control strategy is adopted in the cooling stage. The speed of the servo-driven water pump is linearly increased to 2000-3000 rpm within 1 second, and the opening of the electric servo valve is decreased by 0.5% / s.

[0020] Preferably, the gradient temperature reduction control in the cooling stage includes:

[0021] a) After the debinding signal is triggered, the servo-driven water pump speed increases from the baseline value to 2000-3000 rpm within 1 second;

[0022] b) The heat transfer efficiency of the plate heat exchanger is dynamically corrected according to the Q_out / P_out ratio, with a correction factor k = 0.8 × ln(Q_out / P_out) + 1.2, where Q_out is the external pipeline flow rate and P_out is the pressure;

[0023] c) The opening of the electric servo valve decreases at a rate of 0.5% / s to the preset safety range.

[0024] Preferably, in the multi-parameter coordinated control strategy unit, the calculation formula for the opening degree of the electric servo valve is:

[0025]

[0026] The parameter definition is:

[0027] Q_in: internal circulation flow;

[0028] k: system characteristics;

[0029] P_0: external cooling water inlet pressure;

[0030] P_out: external cooling water return pressure;

[0031] T_out: external cooling water temperature;

[0032] T_in: internal circulating water temperature;

[0033] T_set: Set the circulation temperature.

[0034] Preferably, the rule base of the intelligent decision-making architecture unit based on the fuzzy PID algorithm includes:

[0035] Emergency mode: When ΔT>5℃, the servo-driven water pump speed and the electric servo valve opening are synchronously increased to 90% or higher of the rated value;

[0036] Thermal compensation mode: When ΔT<-8°C, the heating circuit is started and the servo-driven water pump speed is reduced to the reference speed;

[0037] Energy-saving mode: When ΔT is within the range of ±2°C, the electric servo valve opening is adjusted first and the minimum speed curve of the servo-driven water pump is maintained;

[0038] Where ΔT is the deviation between the real-time temperature of the internal circulation medium and the set value.

[0039] Preferably, the servo-driven water pump is a gear pump or a screw pump, and the speed regulation scheme is achieved through closed-loop feedback of the servo motor.

[0040] Preferably, the speed of the servo-driven water pump is preset with a multi-stage curve according to the rubber mixing process stage, including a high speed section in the mixing stage and a variable speed section in the plasticating stage, and the curve parameters are dynamically loaded through the rubber mixing process parameters.

[0041] Preferably, the speed adjustment range of the servo-driven water pump is 30%-100% of the rated speed and has a fine-tuning accuracy of ±5 rpm.

[0042] Preferably, the sensor data collected by the data collection layer includes internal circulation flow, internal circulation temperature, external flow, external return water pressure and external water temperature.

[0043] Preferably, the control module loads a preset servo-driven water pump speed-phase mapping table during the initialization phase, and dynamically modifies the mapping relationship according to real-time process parameters.

[0044] In the above technical solution, the technical effects and advantages provided by the present invention are:

[0045] 1. The internal circulation subsystem uses a servo-driven water pump to replace the traditional fixed-frequency pump, and the external piping subsystem uses an electric servo valve to replace the traditional on-off valve. Combined with the real-time feedback data from the electromagnetic flowmeter, temperature measuring element, and pressure sensor on the pipeline, the PID algorithm and fuzzy control are combined to dynamically adjust the servo-driven water pump speed and the electric servo valve opening to achieve precise flow control;

[0046] 2. Based on the characteristics of heating, constant temperature, and cooling in the rubber mixing stage, a segmented adaptive control algorithm was designed to optimize the operating parameters of the servo-driven water pump and the control strategy of the electric servo valve, respectively. A multi-parameter coupling model was introduced to balance temperature accuracy and system stability through dynamic weight distribution, thereby reducing the temperature fluctuation range. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0048] Figure 1 This is a system architecture diagram of the present invention;

[0049] Figure 2 It is a control structure diagram of the present invention;

[0050] Figure 3 is a control flow chart of the present invention;

[0051] Figure 4 It is the rubber mixing stage mapping table of the present invention.

[0052] Description of reference numerals:

[0053] 1. Servo-driven water pump; 2. Heating circuit; 3. Plate heat exchanger; 4. First temperature measuring element; 5. First pressure sensor; 6. Second pressure sensor; 7. Second temperature measuring element; 8. First electromagnetic flowmeter; 9. Third pressure sensor; 10. Electric servo valve; 11. Third temperature measuring element; 12. Fourth temperature measuring element; 13. Second electromagnetic flowmeter. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0055] The present invention provides Figures 1 to 4 The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback shown in FIG. includes:

[0056] Internal circulation subsystem, the internal circulation subsystem includes a servo-driven water pump 1, a heating circuit 2, a plate heat exchanger 3, a first temperature measuring element 4, a first pressure sensor 5, a second pressure sensor 6, a second temperature measuring element 7 and a first electromagnetic flowmeter 8 connected in sequence through pipelines;

[0057] The external piping subsystem includes a third pressure sensor 9, an electric servo valve 10, a third temperature measuring element 11, a fourth temperature measuring element 12, and a second electromagnetic flowmeter 13, which are sequentially connected through piping. The piping between the third temperature measuring element 11 and the fourth temperature measuring element 12 is connected to the plate heat exchanger 3.

[0058] Servo driven water pump 1 is used to dynamically adjust the flow of the internal circulation medium, with a speed regulation range of 30%-100% of the rated speed;

[0059] Heating circuit 2, integrated electric heating elements or steam pipes;

[0060] Plate heat exchanger 3, connecting the internal circulation and external pipelines to achieve heat exchange;

[0061] The first temperature measuring element 4, the first pressure sensor 5, the second pressure sensor 6, the second temperature measuring element 7 and the first electromagnetic flowmeter 8 respectively monitor the temperature, pressure and flow of the internal circulation medium;

[0062] Electric servo valve 10, used to adjust the flow of external cooling water;

[0063] The third pressure sensor 9, the third temperature measuring element 11, the fourth temperature measuring element 12 and the second electromagnetic flowmeter 13 respectively monitor the pressure, temperature and flow of the external pipeline;

[0064] A control module, the control module being electrically connected to the internal circulation subsystem and the external piping subsystem;

[0065] The control module includes data acquisition layer, decision layer and execution layer;

[0066] The data acquisition layer collects sensor data from the internal circulation subsystem and the external piping subsystem every 100ms and builds a time series database. The sensors provide real-time feedback of internal / external flow, temperature, and pressure data, eliminating the lag of traditional open-loop control and improving temperature control accuracy.

[0067] The decision layer generates control instructions based on the fuzzy PID algorithm. The input variables include temperature difference, the ratio of external pipeline flow rate to pressure, and the inlet and outlet temperature difference of the plate heat exchanger 3. The output is the speed instruction of the servo-driven water pump 1 and the opening instruction of the electric servo valve 10. The decision layer includes a segmented adaptive control algorithm unit, a multi-parameter collaborative control strategy unit, and an intelligent decision architecture unit.

[0068] The execution layer controls the servo drive actuator through PN or Modbus-TCP protocol, with a response time of less than 50ms;

[0069] Significantly shortens adjustment delay to meet the rapid temperature change requirements of the internal mixer.

[0070] The segmented adaptive control algorithm unit dynamically adjusts the control parameters according to the rubber mixing stage, where:

[0071] During the heating phase, the speed of servo-driven water pump 1 is increased first to quickly establish the circulation flow and shorten the heating time;

[0072] During the constant temperature stage, the energy-saving mode is switched to, and the opening of the electric servo valve 10 is adjusted first. During the constant temperature stage, the energy-saving mode is mainly used, and the speed of the electric servo valve 10 is reduced to the reference value;

[0073] A gradient control strategy is adopted in the cooling stage. The speed of the servo-driven water pump 1 is linearly increased to 2000-3000 rpm within 1 second, and the opening of the electric servo valve 10 is decreased by 0.5% / s. The gradient control in the cooling stage avoids crystallization of the rubber due to a sudden drop in temperature.

[0074] The gradient cooling control in the cooling stage includes:

[0075] a) After the binder removal signal is triggered, the servo-driven water pump 1 speed increases from the baseline value to 2000-3000 rpm within 1 second;

[0076] b) The heat exchange efficiency of the plate heat exchanger 3 is dynamically corrected based on the Q_out / P_out ratio, with a correction factor k = 0.8 × ln(Q_out / P_out) + 1.2, where Q_out is the external pipeline flow rate and P_out is the pressure. The heat exchange efficiency is corrected in real time based on Q_out / P_out to eliminate the impact of external cooling water pressure and flow fluctuations on temperature control;

[0077] c) The opening of the electric servo valve 10 decreases at a rate of 0.5% / s to a preset safety range. The opening of the electric servo valve 10 decreases at a fixed rate to prevent hydraulic shock caused by sudden changes in the valve.

[0078] In the multi-parameter coordinated control strategy unit, the calculation formula for the opening degree of the electric servo valve 10 is:

[0079]

[0080] The parameter definition is:

[0081] Q_in: internal circulation flow;

[0082] k: system characteristics;

[0083] P_0: external cooling water inlet pressure;

[0084] P_out: external cooling water return pressure;

[0085] T_out: external cooling water temperature;

[0086] T_in: internal circulating water temperature;

[0087] T_set: set the cycle temperature;

[0088] The valve opening is dynamically adjusted through the P_0 / P_out ratio to compensate for external cooling water pressure fluctuations.

[0089] The rule base of the intelligent decision-making architecture unit based on the fuzzy PID algorithm includes:

[0090] Emergency mode: When ΔT>5℃, the speed of the servo-driven water pump 1 and the opening of the electric servo valve 10 are synchronously increased to 90% of the rated value or higher to restore temperature balance and prevent the rubber from burning;

[0091] Thermal compensation mode: When ΔT < -8°C, start heating circuit 2 and reduce the speed of servo-driven water pump 1 to the reference speed;

[0092] Energy-saving mode: When ΔT is within the range of ±2°C, the opening of the electric servo valve 10 is adjusted first and the minimum speed curve of the servo-driven water pump 1 is maintained;

[0093] Where ΔT is the deviation between the real-time temperature of the internal circulation medium and the set value.

[0094] The servo-driven water pump 1 is a gear pump or a screw pump, and the speed regulation scheme is realized through the closed-loop feedback of the servo motor.

[0095] The speed of the servo-driven water pump 1 presets a multi-stage curve according to the rubber mixing process stage, including a high speed section in the mixing stage and a variable speed section in the plasticating stage, and the curve parameters are dynamically loaded through the rubber mixing process parameters.

[0096] The speed adjustment range of the servo-driven water pump 1 is 30%-100% of the rated speed and has a fine-tuning accuracy of ±5 rpm.

[0097] The sensor data collected by the data acquisition layer include internal circulation flow, internal circulation temperature, external flow, external return water pressure and external water temperature.

[0098] The control module loads the preset servo-driven water pump 1 speed-stage mapping table during the initialization phase and dynamically modifies the mapping relationship according to real-time process parameters.

[0099] In the present invention, the initialization stage: read the rubber mixing process parameters, load the preset servo drive water pump 1 speed N_pump-stage mapping table;

[0100] Real-time adjustment stage:

[0101] Calculate ΔT every 50ms. If ΔT>5°C, the speed of the servo-driven water pump 1 and the opening of the electric servo valve 10 are increased to 90% of the rated value or higher;

[0102] When -8℃>ΔT, the heating device is started and the servo-driven water pump 1 speed is reduced to the basic speed;

[0103] If ΔT is within ±2°C, switch to energy-saving mode, give priority to adjusting the opening of electric servo valve 10 and the speed of servo-driven water pump 1;

[0104] The internal circulation subsystem and the external piping subsystem are coupled through the plate heat exchanger 3 to reduce thermal resistance and improve heat exchange efficiency;

[0105] Gradient cooling is performed during the debinding stage:

[0106] Early control of binder removal: when a binder removal signal is detected, the servo-driven water pump 1 speed is linearly increased to 2000-3000 rpm within 1 second;

[0107] In the later stage of debinding control, after reaching the target temperature, the opening of the electric servo valve 10 is reduced at a rate of 0.5% / s to a stable range.

[0108] In the internal circulation subsystem of the temperature control system of this internal mixer, a servo-driven water pump 1 is used to replace the traditional fixed-frequency pump, and the external piping subsystem uses an electric servo valve 10 to replace the traditional on-off valve. Combined with the real-time feedback data of the electromagnetic flowmeter, temperature measuring element, and pressure sensor on the pipeline, the PID algorithm and fuzzy control are combined to dynamically adjust the speed of the servo-driven water pump 1 and the opening of the electric servo valve 10 to achieve precise flow control. According to the characteristics of heating, constant temperature, and cooling in the rubber mixing stage, a segmented adaptive control algorithm is designed to optimize the operating parameters of the servo-driven water pump 1 and the control strategy of the electric servo valve 10 respectively. A multi-parameter coupling model is introduced to balance temperature accuracy and system stability through dynamic weight distribution, thereby reducing the temperature fluctuation range.

[0109] The above description is merely illustrative of certain exemplary embodiments of the present invention. It goes without saying that those skilled in the art will be able to modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims.

Claims

1. A temperature control system for an internal mixer with dynamic flow regulation and multi-parameter feedback, characterized in that: include: An internal circulation subsystem, the internal circulation subsystem comprising a servo-driven water pump (1), a heating circuit (2), a plate heat exchanger (3), a first temperature measuring element (4), a first pressure sensor (5), a second pressure sensor (6), a second temperature measuring element (7), and a first electromagnetic flowmeter (8) connected in sequence through pipelines; an external piping subsystem, the external piping subsystem comprising a third pressure sensor (9), an electric servo valve (10), a third temperature measuring element (11), a fourth temperature measuring element (12), and a second electromagnetic flowmeter (13) connected in sequence via piping, wherein the piping between the third temperature measuring element (11) and the fourth temperature measuring element (12) is connected to the plate heat exchanger (3); a control module, the control module being electrically connected to the internal circulation subsystem and the external piping subsystem; The control module includes a data acquisition layer, a decision layer and an execution layer; The data acquisition layer collects sensor data from the internal circulation subsystem and the external pipeline subsystem every 100ms and builds a time series database; The decision layer generates control instructions based on a fuzzy PID algorithm, the input variables include temperature difference, the ratio of external pipeline flow rate to pressure, and the inlet and outlet temperature difference of the plate heat exchanger (3), and the output is a servo-driven water pump (1) speed instruction and an electric servo valve (10) opening instruction. The decision layer includes a segmented adaptive control algorithm unit, a multi-parameter collaborative control strategy unit, and an intelligent decision architecture unit; The execution layer controls the servo drive actuator through PN or Modbus-TCP protocol, and the response time is less than 50ms.

2. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 1, characterized in that: The segmented adaptive control algorithm unit dynamically adjusts the control parameters according to the rubber mixing stage, wherein: During the heating phase, the rotation speed of the servo driven water pump (1) is increased first; During the constant temperature stage, the mode is switched to energy-saving mode, with priority given to adjusting the opening of the electric servo valve (10); The cooling stage adopts a gradient control strategy, the rotation speed of the servo-driven water pump (1) is linearly increased to 2000-3000 rpm within 1 second, and the opening of the electric servo valve (10) is gradually reduced at 0.5% / s.

3. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 2, characterized in that: The gradient temperature reduction control in the cooling stage includes: a) After the debinding signal is triggered, the rotation speed of the servo-driven water pump (1) is increased from the base value to 2000-3000 rpm within 1 second; b) The heat transfer efficiency of the plate heat exchanger (3) is dynamically corrected according to the ratio Q_out / P_out, with a correction factor k=0.8×ln(Q_out / P_out)+1.2, where Q_out is the external pipeline flow rate and P_out is the pressure; c) The opening of the electric servo valve (10) is gradually reduced at a rate of 0.5% / s to a preset safety range.

4. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 1, characterized in that: In the multi-parameter coordinated control strategy unit, the calculation formula for the opening degree of the electric servo valve (10) is: The parameter definition is: Q_in: internal circulation flow; k: system characteristics; P_0: external cooling water inlet pressure; P_out: external cooling water return pressure; T_out: external cooling water temperature; T_in: internal circulating water temperature; T_set: Set the circulation temperature.

5. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 1, characterized in that: The intelligent decision-making architecture unit includes the following rule base based on the fuzzy PID algorithm: Emergency mode: When ΔT>5°C, the speed of the servo-driven water pump (1) and the opening of the electric servo valve (10) are synchronously increased to 90% of the rated value or higher; Thermal compensation mode: when ΔT<-8°C, the heating circuit (2) is started and the speed of the servo-driven water pump (1) is reduced to the reference speed; Energy-saving mode: when ΔT is within the range of ±2°C, the opening of the electric servo valve (10) is adjusted first and the minimum speed curve of the servo-driven water pump (1) is maintained; Where ΔT is the deviation between the real-time temperature of the internal circulation medium and the set value.

6. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 1, characterized in that: The servo-driven water pump (1) is a gear pump or a screw pump, and the speed regulation scheme is realized through closed-loop feedback of the servo motor.

7. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 1, characterized in that: The rotation speed of the servo-driven water pump (1) is preset into a multi-stage curve according to the rubber mixing process stage, including a high rotation speed section in the mixing stage and a variable speed section in the plasticating stage, and the curve parameters are dynamically loaded through the rubber mixing process parameters.

8. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 1, characterized in that: The speed adjustment range of the servo-driven water pump (1) is 30%-100% of the rated speed and has a fine-tuning accuracy of ±5 rpm.

9. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 1, characterized in that: The sensor data collected by the data collection layer include internal circulation flow, internal circulation temperature, external flow, external return water pressure and external water temperature.

10. The internal mixer temperature control system with dynamic flow regulation and multi-parameter feedback according to claim 1, characterized in that: The control module loads a preset servo-driven water pump (1) speed-phase mapping table during the initialization phase, and dynamically modifies the mapping relationship according to real-time process parameters.

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