Dissolver negative pressure control method, system, equipment and medium

Abstract

The invention provides a dissolver negative pressure control method, system and equipment and a medium, and relates to the field of dissolver negative pressure control, the method according to the application comprises the following steps: based on a preset temperature acquisition mechanism, acquiring dissolver temperature data in real time, and adopting a preset pressure prediction mechanism to predict pressure change in a dissolver according to the temperature data; according to the predicted pressure change, a preset adjuster algorithm is adopted to adjust the pressure of an inlet of a compressed air injection pump of the dissolver so as to adjust the negative pressure of the dissolver, the adjuster algorithm maps negative pressure deviation and an operator manual intervention value into an adjusting valve opening degree instruction based on a fuzzy control rule base, and the adjusting valve opening degree instruction is used for adjusting the negative pressure of the dissolver. And negative pressure closed-loop regulation is realized through multivariable model predictive control. According to the technical scheme provided by the invention, the negative pressure of the dissolver can be automatically adjusted, and the timeliness and safety of operation are improved.

Description

Technical Field

[0001] This document relates to the technical field of dissolver negative pressure control, and in particular to a dissolver negative pressure control method, system, equipment and medium. Background Art

[0002] The dissolver's operating conditions require strict control of the dissolver's liquid temperature and negative pressure. During normal operation, sheared segments fall through a hopper and chute into a large hanging basket within the dissolver tube, achieving simultaneous dissolution. Because dissolution is an exothermic process, thermal expansion of the gas within the dissolver can affect the negative pressure. Furthermore, segments can become stuck in the hopper and chute, and excessive accumulation can cause them to flow into the dissolver, triggering a violent reaction and generating significant heat. This causes the gas to expand and contract, leading to significant fluctuations in negative pressure. If the negative pressure is not adjusted promptly, the dissolver will experience positive pressure, causing the liquid to overflow through the instrument tube.

[0003] Currently, operators use the conventional PID control algorithm built into the DCS control system to adjust the air injection pump inlet pressure to control negative pressure. Manually operating valves to pass steam or cooling water controls the dissolution temperature. This conventional PID control method, due to its overly simplistic object selection, results in large waveform peaks, large overshoot, long adjustment times, and a lack of adaptive capabilities. It is only applicable to linear time-invariant spaces and cannot automatically adjust parameters online. Large parameter changes can lead to poor system performance. Furthermore, temperature control relies on manual operation, with numerous control variables, requiring high operator experience, consuming time and effort, and posing human risk.

[0004] Therefore, it is urgent to design a control algorithm that does not require human intervention to quickly adjust the negative pressure in the dissolver to the target value and keep it stable. Summary of the Invention

[0005] The present invention provides a dissolver negative pressure control method, system, equipment and medium, which solve the problem that a conventional PID controller has a large overshoot, a long adjustment time and cannot perform online self-tuning parameters according to on-site conditions, and solves the problem that an operator needs to manually control a cylinder valve to pass steam or cooling water to the dissolver to control the dissolving temperature.

[0006] According to an embodiment of the present invention, a dissolver negative pressure control method is provided, comprising:

[0007] Based on a preset temperature acquisition mechanism, the temperature data of the dissolver is acquired in real time, and a preset pressure prediction mechanism is used to predict the pressure change in the dissolver according to the temperature data;

[0008] According to the predicted pressure change, a preset regulator algorithm is used to adjust the inlet pressure of the compressed air jet pump of the dissolver to thereby adjust the dissolver negative pressure. The regulator algorithm is based on a fuzzy control rule library, maps the negative pressure deviation and the operator's manual intervention value into a regulating valve opening instruction, and realizes negative pressure closed-loop regulation through multivariable model predictive control.

[0009] According to an embodiment of the present invention, a dissolver negative pressure control system is provided, comprising:

[0010] A prediction module, based on a preset temperature acquisition mechanism, obtains the dissolver temperature data in real time, and uses a preset pressure prediction mechanism to predict the pressure change in the dissolver according to the temperature data;

[0011] An adjustment module is used to adjust the inlet pressure of the compressed air jet pump of the dissolver using a preset regulator algorithm according to the predicted pressure change, thereby adjusting the dissolver negative pressure. The regulator algorithm is based on a fuzzy control rule library, maps the negative pressure deviation and the operator's manual intervention value into a control valve opening instruction, and realizes negative pressure closed-loop regulation through multivariable model predictive control.

[0012] According to an embodiment of the present invention, there is provided an electronic device, including:

[0013] processor; and,

[0014] A memory is arranged to store computer executable instructions, which, when executed, cause the processor to perform the steps of the dissolver negative pressure control method as described above.

[0015] According to an embodiment of the present invention, a storage medium is provided for storing computer-executable instructions, which, when executed, implement the steps of the above-mentioned dissolver negative pressure control method.

[0016] By adopting the embodiment of the present invention, the automatic control of the negative pressure of the dissolver is achieved through the pressure prediction mechanism and the regulator algorithm, which reduces the number of manual adjustments by the operator, reduces the difficulty of work, ensures the timeliness and safety of operation, and avoids safety hazards caused by improper human operation. Through the collaborative work of the predictor algorithm and the regulator algorithm, it is possible to quickly respond to temperature and pressure changes in the dissolver, effectively cope with complex operating environments, and improve the stability of the dissolver. An emergency response plan is pre-made. When the pressure of the dissolver continues to rise and cannot be automatically adjusted and lowered, the emergency interface is triggered to open the regulating valve to a safe position to ensure that the pressure in the dissolver maintains a negative pressure state, prevent danger, and enhance the safety of the system. The control process of key controlled variables is transitioned from conventional PID control to multivariable model predictive control, which improves the automation level of the company's industrial equipment, helps the company to improve quality and efficiency, and meets the development needs of modern industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 1 is a logic diagram of a dissolver negative pressure control method according to an embodiment of the present invention;

[0019] Figure 2 Flowchart of a dissolver negative pressure control method according to an embodiment of the present invention;

[0020] Figure 3 Schematic diagram of a dissolver negative pressure control system according to an embodiment of the present invention;

[0021] Figure 4 This is a dissolver parameter point diagram of an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this document.

[0023] Method Example

[0024] According to an embodiment of the present invention, a method for controlling negative pressure of a dissolver is provided. Figure 2 Flow chart of the negative pressure control method of the dissolver according to the embodiment of the present invention. Figure 2 As shown, the dissolver negative pressure control method according to the embodiment of the present invention specifically includes:

[0025] S1. Based on a preset temperature acquisition mechanism, obtain the dissolver temperature data in real time, and use a preset pressure prediction mechanism to predict the pressure change in the dissolver according to the temperature data;

[0026] The preset temperature acquisition mechanism acquires the gas phase temperature, liquid phase temperature and dissolver wall temperature by setting parameter monitoring points in the dissolver. Figure 4 The figure shows the parameter point diagram of the dissolver according to the embodiment of the present invention. Figure 4It can be seen that in the embodiment of the present invention, three parameter monitoring points are set, among which Figure 4 001 is the gas phase temperature, 002 is the liquid phase temperature, and 003 is the dissolver wall temperature.

[0027] The preset pressure prediction mechanism specifically includes: taking three temperatures as input signals of the predictor algorithm, the predictor establishes a relationship model between temperature and negative pressure through the historical temperature data and negative pressure data of the dissolver within a preset time period, and establishes a rule base to quantify the impact of temperature changes on negative pressure, thereby obtaining the pressure changes in the dissolver.

[0028] S2. According to the predicted pressure change, a preset regulator algorithm is used to adjust the inlet pressure of the compressed air jet pump of the dissolver to thereby adjust the dissolver negative pressure, wherein the regulator algorithm is based on a fuzzy control rule library, maps the negative pressure deviation and the operator's manual intervention value into a regulating valve opening instruction, and realizes negative pressure closed-loop regulation through multivariable model predictive control.

[0029] The regulator algorithm adjusts the dissolver exhaust system regulating valve based on the prediction results obtained in step S1 to control the pressure at the inlet of the compressed air jet pump, thereby adjusting the negative pressure. The predictor predicts that the pressure will increase in the next time period, and the regulator automatically adjusts the regulating valve opening to increase the pressure at the inlet of the compressed air jet pump. In this way, the heat released during the intense dissolution process will not affect the negative pressure balance in the dissolver. The specific implementation method is as follows:

[0030] In the fuzzy control rule base, the specific range of variation of the dissolver negative pressure value and the range of manual intervention values ​​collected are defined as the domain on the fuzzy set, and the valve control opening is automatically output through the preset control rules. Specifically, it includes: based on the dissolver operation experience, the predicted results are mainly based on "various operating conditions encountered by the operator during dissolution (different values ​​of negative pressure) and the manual values ​​of the operator's manual intervention" to establish a "control rule base", and the valve execution value after adjustment is automatically output. The specific range of variation of the dissolver negative pressure value and the range of manual intervention values ​​collected are defined as the domain on the fuzzy set in the rule base, such as "high", "medium", "low", "large", "small", etc., that is, pi,Man={NB,NM,NS,ZO,PS,PM,PB}; where pi is the negative pressure and Man is the manual value of human intervention. The valve control opening is automatically output through the control rules established in Table 1. The specific control rule base is shown in Table 1.

[0031] Table 1: Control rule logic table

[0032] Pi NB NM NS ZO PS PM PB Man ZO PS PM PB PB PB PB

[0033] The dissolver negative pressure control method further includes a temperature limiting algorithm, which switches to a manual control mode when the dissolver temperature deviation exceeds a preset threshold value, and starts a cooling water circulation system to reduce the dissolver temperature, specifically including: setting a temperature control deviation preset value according to the dissolver operating procedures, and the temperature control deviation preset value is the maximum temperature that the dissolver can withstand during the dissolution process minus the ideal temperature target value set for the dissolution process. When the temperature deviation value is greater than the temperature control deviation preset value, the controller changes the PID controller mode in the negative pressure automatic control algorithm to manual control according to the dissolution temperature limiting algorithm, and increases the opening of the negative pressure control regulating valve to prevent the dissolver from changing from negative pressure to positive pressure due to excessive temperature, and automatically opens the upper and lower jacket cooling valves to allow circulating water to enter the dissolver, stabilizing the temperature within the set target temperature range.

[0034] Finally, advanced control theory and fuzzy control algorithm are introduced into the control algorithm, and control strategies such as multivariable model predictive control, soft measurement, intelligent control, and performance evaluation are adopted to transition the control process of key controlled variables from the original conventional PID control to multivariable model predictive control, thereby improving the level of automatic control of the dissolver negative pressure. The fuzzy control rule tables of the three parameters of proportional Kp, integral Ki, and differential Kd are established through actual operating experience and are shown in Tables 2, 3, and 4 respectively.

[0035] Table 2: Proportional Kp fuzzy control rules table

[0036]

[0037]

[0038] Table 3: Proportional Ki fuzzy control rules table

[0039]

[0040] Table 4: Proportional Kd fuzzy control rules table

[0041]

[0042] The dissolver negative pressure control method according to the embodiment of the present invention further includes an emergency strategy, specifically including:

[0043] An emergency interface is set up. If the dissolver pressure continues to rise and cannot be automatically adjusted down, the emergency interface is triggered to open the regulating valve to a safe position to ensure that the pressure inside the dissolver remains in a negative pressure state. The dissolver negative pressure is related to the safe conditions for dissolver operation. To ensure system safety, the dissolver negative pressure control method will pre-set a safety measure. If the predictor algorithm and the adjuster algorithm do not perform according to the expected settings, if the dissolver pressure continues to rise and cannot be automatically adjusted down, press the "emergency button" on the operation screen in time. This emergency button is connected to the safety measure trigger interface of the dissolver negative pressure control method. When the button is pressed, the regulating valve is opened to a safe position (this safety valve position is set based on the maximum empirical value of the dissolver negative pressure control on site), ensuring that the pressure inside the dissolver remains in a negative pressure state and preventing danger.

[0044] Figure 1 The logic diagram of the dissolver negative pressure control method according to the embodiment of the present invention is as follows: Figure 1 The specific implementation logic of the dissolver negative pressure control method according to the embodiment of the present invention is described in detail. Figure 1 As shown, the dissolver temperature measured by the thermocouple is converted from analog-to-digital (A / D) and then fed into a predictor. The predictor, based on a relational model and rule base constructed based on historical temperature and negative pressure data, outputs a predicted negative pressure. The dissolver negative pressure measured by the pressure transmitter is converted from A / D and compared to the target negative pressure to determine the negative pressure deviation. Simultaneously, the measured temperature is compared to the target temperature to determine the temperature deviation. The predicted negative pressure is then fed into the control rule module. Simultaneously, the upper and middle jacket cylinder valves, the purge cylinder valve, and other components participate in the relevant logic processing within this module. The negative pressure deviation is fed into a PID controller, which, combined with manual control of the opening, performs proportional, integral, and differential operations to output a control signal. During this process, the negative pressure deviation and its rate of change are also fed into a fuzzy rule base to optimize the control signal. The processed control signal, after digital-to-analog conversion, controls the dissolver exhaust system regulating valve, adjusting the inlet pressure of the compressed air jet pump, and ultimately regulating the dissolver negative pressure.

[0045] Figure 1 SP is the set target value, which is the target value of the dissolver negative pressure (e.g. -50kPa) preset by the operator in the control system and serves as the reference of the control system. PV is the actual process value. The current negative pressure value PV and the values ​​of three temperature measurement points (gas phase temperature 001, liquid phase temperature 002, wall temperature 003) are collected in real time by the sensor on the dissolver. The temperature deviation e between the set target value SP and the actual process value PV is calculated. 温度 , temperature deviation e 温度As input to the subsequent control algorithm, the real-time data of the three temperature measurement points (001, 002, 003) and the historical archived temperature-negative pressure relationship model are input into the predictor. The predictor predicts the change in negative pressure in the future time period based on the current temperature change trend. If the temperature rises sharply (such as when the dissolution releases heat violently), the predictor triggers the adjuster algorithm to intervene in advance to prevent negative pressure imbalance. The predictor outputs the negative pressure change trend and key parameters, and obtains the negative pressure deviation e based on the target negative pressure and the measured negative pressure. 负压 , negative pressure deviation e 负压 The pressure change trend output by the predictor and the manual control rule base shown in Table 1 are input into the fuzzy controller, that is, the regulator algorithm in the embodiment of the present invention. The regulator algorithm is based on the negative pressure deviation e 负压 The prediction results are matched to the fuzzy control rule library (Tables 2, 3, and 4), dynamically adjusting the proportional (Kp), integral (Ki), and differential (Kd) parameters. Fuzzy logic is used to output the valve opening adjustment value (MAN). If the negative pressure deviation is large negative (NB), the valve opening remains at zero (ZO); if the negative pressure deviation is medium negative (NM), the valve opening is adjusted to small positive (PS). This outputs a control signal for regulating the valve opening, which is converted into an analog signal via a digital-to-analog converter (DA) to drive the regulating valve of the compressed air jet pump. The control signal output by the regulator adjusts the inlet pressure of the compressed air jet pump, controlling the exhaust volume of the dissolver by changing the valve opening, thereby maintaining a stable negative pressure. If the predictor detects temperature exceeding the limit or rapid fluctuations in negative pressure, the regulator automatically increases the valve opening to accelerate exhaust to offset the effects of dissolution heat. If the predictor and regulator fail to effectively control the negative pressure (e.g., if the pressure continues to rise), the system triggers the safety action interface. The operator can manually press the "emergency button" to force the regulating valve to the preset safety position (maximum opening based on experience) to ensure that the dissolver maintains negative pressure. At the same time, the upper and lower jacket cooling valves are automatically opened and circulating water is injected to cool the system to prevent positive pressure caused by excessive temperature.

[0046] By adopting the embodiments of the present invention, the following beneficial effects are achieved:

[0047] The embodiments of the present invention can effectively solve the problem of difficult control of the dissolver in complex operating environments, solve the problem of the dissolver's negative pressure control loop being unable to automatically start and requiring human intervention all year round, and realize automatic control of the dissolver's negative pressure. It improves the dynamic performance of the operating process, reduces the operating fluctuation amplitude of key variables, brings the controlled target closer to the optimized target value, improves the stability and safety of the dissolver, enhances the system's anti-interference ability, and at the same time improves the automation level of the enterprise's industrial equipment, improving quality and efficiency.

[0048] System Example

[0049] According to an embodiment of the present invention, a dissolver negative pressure control system is provided. Figure 3Schematic diagram of the negative pressure control system of the dissolver according to the embodiment of the present invention. Figure 3 The dissolver negative pressure control system according to the embodiment of the present invention specifically includes:

[0050] The prediction module 30 acquires the temperature data of the dissolver in real time based on a preset temperature acquisition mechanism, and uses a preset pressure prediction mechanism to predict the pressure change in the dissolver according to the temperature data;

[0051] The adjustment module 32 is used to adjust the inlet pressure of the compressed air jet pump of the dissolver using a preset regulator algorithm according to the predicted pressure change, thereby adjusting the dissolver negative pressure. The regulator algorithm is based on a fuzzy control rule library, maps the negative pressure deviation and the operator's manual intervention value into a control valve opening instruction, and realizes negative pressure closed-loop regulation through multivariable model predictive control.

[0052] This system embodiment is a system embodiment that corresponds one-to-one to the above-mentioned method embodiment. For its specific implementation method, please refer to the above-mentioned method embodiment, which will not be repeated here.

[0053] Device Example 1

[0054] According to an embodiment of the present invention, there is provided an electronic device, including:

[0055] processor; and,

[0056] A memory is arranged to store computer executable instructions, which, when executed, cause the processor to perform the steps of the above method embodiments.

[0057] Device Example 2

[0058] According to an embodiment of the present invention, a storage medium is provided for storing computer-executable instructions, wherein the computer-executable instructions implement the steps of the above-mentioned method embodiment when executed.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dissolver negative pressure control method, characterized in that include: Based on a preset temperature acquisition mechanism, the temperature data of the dissolver is acquired in real time, and a preset pressure prediction mechanism is used to predict the pressure change in the dissolver according to the temperature data; According to the predicted pressure change, a preset regulator algorithm is used to adjust the inlet pressure of the compressed air jet pump of the dissolver to thereby adjust the dissolver negative pressure. The regulator algorithm is based on a fuzzy control rule library, maps the negative pressure deviation and the operator's manual intervention value into a regulating valve opening instruction, and realizes negative pressure closed-loop regulation through multivariable model predictive control.

2. The method according to claim 1, characterized in that The preset temperature acquisition mechanism acquires the gas phase temperature, liquid phase temperature and dissolver wall temperature by setting parameter monitoring points in the dissolver.

3. The method according to claim 1, characterized in that The preset predictor establishes a relationship model between temperature and negative pressure through the historical temperature data and negative pressure data of the dissolver within a preset time period, establishes a rule base to quantify the impact of temperature change on negative pressure, and then obtains the pressure change in the dissolver.

4. The method according to claim 1, wherein In the fuzzy control rule base, the variation range of the specifically collected dissolver negative pressure value and the range of the manual intervention value are defined as the domain on the fuzzy set, and the valve control opening is automatically output through the preset control rules.

5. The method according to claim 1, wherein The dissolver negative pressure control method further includes a temperature limiting algorithm, which switches to a manual control mode when the dissolver temperature deviation exceeds a preset threshold, and starts a cooling water circulation system to reduce the dissolver temperature.

6. The method according to claim 1, wherein The multivariable model predictive control includes being implemented by setting a fuzzy rule table of proportional Kp, integral Ki and differential Kd parameters, and the fuzzy rule table dynamically adjusts the proportional Kp, integral Ki and differential Kd parameters according to the real-time error and the error change rate.

7. The method according to claim 1, characterized in that The method further includes an emergency response strategy, specifically including: An emergency interface is set up. When the pressure in the dissolver continues to rise and cannot be automatically adjusted and lowered, the emergency interface is triggered to open the regulating valve to a safe position to ensure that the pressure in the dissolver remains in a negative pressure state.

8. A dissolver negative pressure control system, characterized in that: include: A prediction module, based on a preset temperature acquisition mechanism, obtains the dissolver temperature data in real time, and uses a preset pressure prediction mechanism to predict the pressure change in the dissolver according to the temperature data; An adjustment module is used to adjust the inlet pressure of the compressed air jet pump of the dissolver using a preset regulator algorithm according to the predicted pressure change, thereby adjusting the dissolver negative pressure. The regulator algorithm is based on a fuzzy control rule library, maps the negative pressure deviation and the operator's manual intervention value into a control valve opening instruction, and realizes negative pressure closed-loop regulation through multivariable model predictive control.

9. An electronic device comprising: processor; as well as, A memory arranged to store computer executable instructions, which, when executed, cause the processor to perform the steps of the dissolver negative pressure control method according to any one of claims 1 to 7.

10. A storage medium for storing computer-executable instructions, wherein the computer-executable instructions, when executed, implement the steps of the dissolver negative pressure control method according to any one of claims 1 to 7.

Images