An epichlorohydrin refining system hydrogen chloride flow stable conveying method, device and medium based on multivariate cooperation

Abstract

The application discloses an epoxy chloropropane refining system hydrogen chloride flow stable conveying method and device based on multivariable cooperation, and a medium, and relates to the technical field of chemical process control. The system collects the front-end load flow in real time to dynamically adjust the produced flow set value. Compared with the existing feedback control mode based on fixed set value, the system fluctuation caused by the front-end load fluctuation can be reduced. In the control process, the tower kettle liquid level is the main controlled variable, the heating steam flow is controlled according to the feedforward compensation signal and the feedback signal, and the stability of the tower kettle operation state is effectively improved. In addition, the produced flow of the material is cooperatively controlled based on the produced flow set value, the tower top pressure change and the hot steam flow change, so that the influence of the load change, the pressure change and the vaporization capacity change on the material conveying capacity can be considered in the production process, and the coordinated matching between the operation parameters can be realized.

Description

Technical Field

[0001] This invention relates to the field of chemical process control technology, and in particular to a method, apparatus and medium for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy. Background Technology

[0002] In the production of epichlorohydrin, hydrogen chloride, as a crucial process medium, typically requires purification and separation before being transported to downstream production units to meet the demands of continuous production. Since the amount of hydrogen chloride generated and its transport status are closely related to upstream production load, the operating status of the distillation system, and changes in process parameters, a control system is needed to regulate the hydrogen chloride outflow rate to ensure the continuity and stability of the downstream process.

[0003] However, in actual production processes, upstream loads typically fluctuate, but feedback regulation is somewhat delayed, making it difficult to promptly suppress flow fluctuations caused by changes in upstream load. Furthermore, the hydrogen chloride transport process is often influenced by multiple process parameters. For example, key parameters such as the bottom liquid level, top pressure, and steam heating rate within the distillation column are interconnected and can all affect material transport capacity. Existing chemical process control methods, such as PID feedback control, rely solely on feedback from the hydrogen chloride flow meter for adjustment, making it difficult to achieve coordinated control among multiple regulation links. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, and medium for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate coordination. This invention addresses the problem that existing hydrogen chloride treatment process control methods cannot cope with flow fluctuations caused by changes in upstream load during epichlorohydrin production, and that it is difficult to achieve coordinated control among multiple regulation links.

[0005] To address the aforementioned technical problems, this invention provides a method for stabilizing the flow rate of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy, comprising: Obtain the upstream load flow rate, column bottom liquid level, and column top pressure; Calculate the average load value of the front-end load flow within a preset time window, and use the average load value as the output flow rate setting value; The column bottom liquid level is the main controlled variable. A feedforward compensation signal is generated based on the front-end load flow rate and the column top pressure. At the same time, a feedback signal is generated based on the deviation between the column bottom liquid level and the preset column bottom liquid level setting value. The heating steam flow rate is controlled based on the feedforward compensation signal and the feedback signal to maintain a stable liquid level in the tower bottom. The output value of the material extraction flow rate is controlled based on the set value of the extraction flow rate, the change in the tower top pressure, and the change in the heating steam flow rate.

[0006] Optionally, after the step of calculating the average load value of the front-end load flow within a preset time window and using the average load value as the output flow setpoint, the method further includes: The heating steam flow rate is obtained, and the theoretical output flow rate is calculated based on the pre-established output flow rate prediction model, according to the front-end load flow rate and the heating steam flow rate. The produced flow rate setpoint is dynamically corrected to obtain the corrected produced flow rate setpoint. : ; in The output flow rate setpoint before calibration. To theoretically extract the flow rate, For correction factors, ∈(0,1).

[0007] Optional, also includes: Continuously monitor the buffer tank pressure and the material outflow rate; When the pressure in the buffer tank exceeds the preset normal range and the material output flow rate deviates from the set output flow rate value by more than a preset safety threshold, the tower top pressure set value is modified. The calculation formula is as follows: ; in, Set the new tower top pressure value. This is the current measured pressure value at the top of the tower. This is a positive bias value preset based on the characteristics of the valve and pipeline; The tower top pressure setting value is automatically reset when the pressure in the buffer tank returns to the normal range.

[0008] Optionally, a feedforward compensation signal is generated based on the front-end load flow and the tower top pressure, including: When an increase in the front-end load flow or a pressure at the top of the tower is detected to be lower than a preset pressure limit, a feedforward compensation signal is generated to increase the opening of the steam regulating valve. When a decrease in the front-end load flow or a pressure at the top of the tower is detected to be higher than a preset pressure limit, a feedforward compensation signal is generated to reduce the opening of the steam regulating valve.

[0009] Optionally, controlling the output of the material extraction flow rate based on the change in the tower top pressure includes: When the change in pressure at the top of the tower exceeds a preset pressure change threshold, the maximum allowable opening of the extraction regulating valve is limited, and / or the extraction flow rate setting is adjusted. When the change in pressure at the top of the tower is lower than a preset negative pressure change threshold, the opening of the extraction regulating valve is increased.

[0010] Optionally, controlling the output of material extraction flow rate based on the change in heating steam flow rate includes: When the opening of the steam regulating valve increases, the set value of the output flow rate is increased accordingly, so that the output flow rate of the material matches the increase in vaporization capacity brought about by the increase in the opening of the steam regulating valve.

[0011] Optionally, the extracted flow prediction model is established in the following manner: Acquire front-end load flow, heating steam flow, and material output flow under multiple operating conditions; Using the front-end load flow rate and the heating steam flow rate as input parameters, and the material output flow rate as the output parameter, the output flow rate prediction model is obtained through multiple linear regression fitting: ; in, For front-end load flow, To increase the steam flow rate, , These are the model coefficients obtained by fitting historical operating data under multiple operating conditions.

[0012] Optional, also includes: When the pressure of the buffer tank exceeds the preset normal range and the material output flow rate deviates from the output flow rate setting value by more than the preset safety threshold, the output flow rate setting value is increased, and the opening degree of the output regulating valve is increased at the same time.

[0013] To address the aforementioned problems, the present invention also provides a multivariate synergistic hydrogen chloride flow stabilization conveying device for an epichlorohydrin refining system, comprising: Memory, used to store computer programs; A processor is used to implement the steps of the above-described method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy when executing the computer program.

[0014] To address the aforementioned problems, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate collaboration.

[0015] This invention provides a method for stabilizing the flow of hydrogen chloride in an epichlorohydrin refining system based on multivariate coordination. The system collects the upstream load flow rate in real time and calculates the average load value within a preset time window, using this as the output flow rate setpoint. This yields an output flow rate setpoint that reflects the current production load level, reducing system fluctuations caused by upstream load fluctuations compared to existing feedback control methods based on fixed setpoints. During control, the column bottom liquid level is the primary controlled variable. The system simultaneously receives upstream load flow rate and column top pressure to generate feedforward compensation signals, and combines these with column bottom liquid level deviation to generate feedback signals. These two signals jointly control the heating steam flow rate, enabling the system to adjust the column bottom vaporization capacity in advance when process disturbances occur and perform closed-loop correction based on actual liquid level changes. This improves the stability of the column bottom operating state. Furthermore, by elevating the column bottom liquid level from a passive disturbance in traditional control to an actively managed master variable, multivariate coordination is implemented around this core, laying the foundation for subsequent precise flow control. Furthermore, the material output flow rate is controlled in a coordinated manner based on the output flow rate setpoint, the tower top pressure change, and the hot steam flow rate change. This allows the output process to comprehensively consider the impact of load changes, pressure changes, and vaporization capacity changes on the material conveying capacity, achieving coordinated matching between various operating parameters, reducing fluctuations caused by single flow feedback control, and improving the stability and continuity of hydrogen chloride flow transmission.

[0016] In addition, the present invention provides a hydrogen chloride flow stabilization delivery device and a computer-readable storage medium for an epichlorohydrin refining system based on multivariate synergy, which have the same effect as above. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the prior art and embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 Schematic diagram of the R125 refining system in an epichlorohydrin unit; Figure 2 A flowchart of a method for stabilizing the flow rate of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy, provided for this invention; Figure 3 A flowchart of another method for stabilizing the flow of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy, provided by the present invention. Detailed Implementation

[0019] The core of this invention is to provide a method, apparatus, and medium for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 embodiments of the present invention, not all embodiments. 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.

[0021] Please see Figure 1 , Figure 1 This is a schematic diagram of the R125 refining system in an epichlorohydrin unit. Figure 1 As shown, this system is used to refine hydrogen chloride-containing materials generated during the production process and transport the treated hydrogen chloride to downstream process units. It includes equipment such as a pre-machine buffer tank, a chlorination tail gas compressor, a chlorination tail gas refining tower, a reboiler, a refining tower receiving tank, and a post-machine buffer tank. Specifically, the hydrogen chloride-containing material from the upstream process enters the pre-machine buffer tank for buffering treatment. After being pressurized by the chlorination tail gas compressor, it is transported to the chlorination tail gas refining tower. The compressor reflux cooler is used to cool the reflux gas during compressor operation, thereby reducing the circulating gas temperature and improving the compressor's operating condition. The chlorination tail gas refining tower uses the reboiler to provide heat, enabling gas-liquid separation of the material within the tower to achieve the refining of the hydrogen chloride components. The refining tower receiving tank collects the refined material output from the chlorination tail gas refining tower and buffers and stores the refined product for subsequent transport to downstream production units. The refined hydrogen chloride gas is output from the top of the tower and enters the post-machine buffer tank, subsequently being transported to the downstream application stage.

[0022] In the above refining process, the operating status of the chlorination tail gas refining tower directly affects the output flow rate and transportation stability of hydrogen chloride. Therefore, it is necessary to stably control the output flow rate of hydrogen chloride to ensure the continuous and stable operation of downstream process units.

[0023] However, in actual production processes, upstream loads typically fluctuate, but feedback regulation exhibits a certain lag, making it difficult to promptly suppress flow fluctuations caused by changes in upstream load. Furthermore, the hydrogen chloride transport process is influenced by multiple process parameters. For example, key parameters such as the bottom liquid level, top pressure, and steam heating rate within the distillation column are interconnected and can all affect material transport capacity. Existing control methods, such as PID feedback control, rely solely on feedback from the hydrogen chloride flow meter for adjustment, making it difficult to achieve coordinated control among multiple regulation links.

[0024] To address the aforementioned technical problems, this invention provides a method for stabilizing the flow rate of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy.

[0025] For details, please see Figure 2 , Figure 2 The flowchart illustrates a method for stabilizing the flow rate of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy, as provided by this invention.

[0026] like Figure 2 As shown, the method includes: S11: Obtain the upstream load flow rate, column bottom liquid level, and column top pressure; Specifically, the front-end load flow rate is used to characterize the load of the material to be treated entering the chlorination tail gas refining tower, which reflects the changes in the operating status of the upstream production unit; the tower bottom liquid level is used to characterize the storage status of the liquid phase material in the refining tower, which is related to the heat exchange status of the reboiler and the vapor-liquid balance status in the tower; the tower top pressure is used to characterize the gas phase pressure status at the top of the refining tower, which affects the pressure conditions of the gas-liquid separation process in the tower and the process of transporting hydrogen chloride gas to the downstream end.

[0027] In actual operation, parameters such as upstream production load, liquid level in the tower, and tower top pressure are interrelated. For example, an increase in upstream load leads to an increase in the amount of material entering the refining tower, causing changes in the bottom liquid level and affecting the tower top pressure. Therefore, this embodiment obtains multiple process parameters simultaneously to provide a data foundation for subsequent multivariate collaborative control.

[0028] S12: Calculate the average load value of the front-end load flow within a preset time window, and use the average load value as the output flow rate setting value; Specifically, in actual production processes, the front-end load flow often experiences instantaneous fluctuations. For example, factors such as equipment operation disturbances and detection noise can cause short-term changes in the flow detection value. If the real-time front-end load flow is directly used as the target for output flow control, it can easily lead to frequent system actions. Therefore, this embodiment averages the front-end load flow within a preset time window to filter out short-term fluctuations, making the obtained average load value more accurately reflect the current production load level. The preset time window can be set according to the response time of the refining system and the production conditions, for example, fifteen minutes. By continuously collecting multiple front-end load flow data within the preset time window and averaging the multiple sampled values, the average load value is obtained.

[0029] Furthermore, by using the average load value as the production flow rate setpoint, the hydrogen chloride production flow rate control target can be dynamically adjusted according to changes in upstream production load. Compared with the fixed setpoint control method, this can respond to changes in production load in advance and reduce the deviation in production flow rate caused by load changes.

[0030] S13: The main controlled variable is the bottom liquid level. A feedforward compensation signal is generated based on the front-end load flow and the top pressure of the tower. At the same time, a feedback signal is generated based on the deviation between the bottom liquid level and the preset bottom liquid level set value. S14: Control the heating steam flow rate based on feedforward compensation signal and feedback signal to maintain stable liquid level in the tower bottom; Specifically, the primary controlled variable refers to the process parameter that the control system focuses on maintaining stability. In this embodiment, the column bottom liquid level is selected as the primary controlled variable. Since the column bottom liquid level reflects the material accumulation state inside the purification column, stabilizing the column bottom liquid level can ensure the stability of the vapor-liquid balance inside the purification column. The heating steam flow rate is used to characterize the heat supplied to the purification column, and its changes affect the degree of vaporization of the material in the column bottom and the material circulation state inside the column.

[0031] Specifically, feedforward compensation signals are generated based on changes in upstream load flow and column top pressure. Feedforward compensation is a control method that proactively adjusts the control based on measurable disturbances. For example, when an increase in upstream load flow is detected, it indicates an increase in the material load entering the refining column. The system generates a corresponding compensation signal in advance to increase the supply of heating steam and prevent significant fluctuations in the column bottom level due to the increased load. When a change in column top pressure is detected, the control quantity is adjusted in advance based on the pressure change trend to reduce the impact of pressure disturbances on the refining process. Simultaneously, a feedback signal is generated based on the deviation between the actual detected column bottom level and the preset column bottom level setpoint. When the column bottom level deviates from the target value, feedback control corrects the feedforward compensation result, allowing the column bottom level to return to the set range. Therefore, by combining feedforward control and feedback control, the control system can both respond proactively to external disturbances and perform closed-loop adjustments based on actual operating conditions. Through the aforementioned feedforward and feedback coordinated control, the system's response delay to changes in feed load is reduced from 30 to 60 seconds for traditional PID to less than 5 seconds, the fluctuation range of the bottom liquid level is reduced by 60% to 80%, and the fluctuation range of the hydrogen chloride output flow rate is reduced by more than 70%.

[0032] S15: Controls the output value of material extraction flow rate based on the set value of extraction flow rate, the change in tower top pressure, and the change in heating steam flow rate.

[0033] Specifically, based on adjusting the liquid level in the reboiler, the output value of the material discharge flow rate is controlled. The material discharge flow rate is affected not only by the set discharge flow rate but also by the operating status of the purification tower. Specifically, changes in the tower top pressure affect the pressure conditions during hydrogen chloride gas transport, while changes in the heating steam flow rate affect the reboiler vaporization capacity, thus impacting hydrogen chloride generation and discharge capacity. Therefore, this embodiment, in addition to controlling the material discharge flow rate based on the set discharge flow rate, further incorporates changes in tower top pressure and heating steam flow rate to coordinately regulate the material discharge flow rate control process.

[0034] Specifically, when the top pressure of the tower increases or the heating steam flow rate changes, causing a change in the extraction capacity, the extraction control quantity is adjusted according to the aforementioned parameter changes to ensure that the actual material extraction flow rate matches the current operating state of the refining system. For example, when the heating steam flow rate increases and the tower bottom vaporization capacity improves, the material extraction capacity can be appropriately increased; when the top pressure of the tower changes abnormally, the extraction adjustment range can be limited to prevent the extraction process from further affecting the system stability. Through this method, material extraction control no longer relies solely on a single flow rate feedback but comprehensively considers multiple key parameters within the refining system, achieving multi-variable coordinated control.

[0035] Specifically, during system operation, key process parameters such as upstream load flow rate, column bottom liquid level, and column top pressure are first collected. Then, the upstream load flow rate is averaged over a time window to obtain an average load value, which serves as the output flow rate setpoint reflecting the current production load level. After obtaining the output flow rate setpoint, the control system uses the column bottom liquid level as the primary control target. It generates feedforward compensation signals based on changes in upstream load and column top pressure, and combines this with column bottom liquid level deviation to generate a feedback signal. By jointly adjusting the heating steam flow rate, the system maintains a stable column bottom liquid level in the refining column. Simultaneously, the control system coordinates the output flow rate based on the output flow rate setpoint, column top pressure changes, and heating steam flow rate changes, ensuring that the hydrogen chloride output flow rate adapts to changes in production load and the internal operating state of the refining column, thereby achieving stable delivery.

[0036] It should be noted that the method for stable hydrogen chloride flow delivery in the epichlorohydrin refining system based on multivariate collaboration provided in this embodiment can be implemented through various technical platforms, including but not limited to: In an Advanced Process Control (APC) platform, an optimized controller incorporating pressure compensation logic can be constructed using a Model Predictive Control (MPC) software package. In a Distributed Control System (DCS), a custom program implementing the collaborative algorithm and compensation logic can be written using its enhanced functional modules (such as multi-function controllers and user programming blocks). The self-developed optimized control software can be run through an external Industrial Personal Computer (IPC) or Programmable Logic Controller (PLC), and data exchange and control command issuance can be performed with the underlying DCS via communication protocols such as the Open Process Control (OLE) protocol (OPC).

[0037] As can be seen, this embodiment uses the average load value as the output flow rate setpoint, which, compared to existing feedback control methods based on fixed setpoints, can reduce system fluctuations caused by front-end load fluctuations. Simultaneously, by elevating the bottom liquid level from a passive disturbance in traditional control to an actively managed master variable, multi-variable coordination is achieved around this core, laying the foundation for subsequent precise flow rate control. Furthermore, by coordinating the output flow rate control based on the output flow rate setpoint, changes in top pressure, and changes in hot steam flow rate, the output process can comprehensively consider the impact of load changes, pressure changes, and vaporization capacity changes on material conveying capacity, achieving coordinated matching among various operating parameters, reducing fluctuations caused by single flow rate feedback control, and improving the stability and continuity of hydrogen chloride flow rate delivery.

[0038] Based on the above embodiments, please refer to Figure 3 , Figure 3 A flowchart of another method for stabilizing the flow of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy, provided by the present invention.

[0039] like Figure 3 As shown, as an optional embodiment, after calculating the average load value of the front-end load flow within a preset time window and using the average load value as the sampling flow setpoint, the method further includes: The heating steam flow rate is obtained, and the theoretical output flow rate is calculated based on the front-end load flow rate and the heating steam flow rate according to the pre-established output flow rate prediction model. The produced flow rate setpoint is dynamically corrected to obtain the corrected produced flow rate setpoint. : ; in The output flow rate setpoint before calibration. To theoretically extract the flow rate, For correction factors, ∈(0,1).

[0040] Specifically, the heating steam flow rate is used to characterize the heating capacity of the chlorination tail gas refining tower. Since the heating steam flow rate determines the amount of heat supplied by the reboiler to the refining tower, thus affecting the degree of vaporization of the material inside the tower and the generation and extraction capacity of hydrogen chloride components, determining the extraction flow rate setpoint solely based on the upstream load flow rate may not fully reflect the actual operating state inside the refining tower. For example, under the same upstream load conditions, when the heating steam flow rate increases, the vaporization capacity inside the refining tower enhances, theoretically supporting a higher hydrogen chloride extraction flow rate; conversely, when the heating steam flow rate decreases, the vaporization capacity of the refining tower decreases, and the actual achievable extraction flow rate will also decrease accordingly. Therefore, this embodiment further introduces the heating steam flow rate, combined with the upstream load flow rate, to correct the initial extraction flow rate setpoint.

[0041] Furthermore, the produced flow prediction model is a model pre-established based on historical operating data to predict the theoretical produced flow rate. Specifically, it can collect front-end load flow rate, heating steam flow rate, and actual material produced flow rate data of the epichlorohydrin refining system under multiple operating conditions, and use the front-end load flow rate and heating steam flow rate as model input parameters, and the actual material produced flow rate as model output parameters, to establish the produced flow prediction model through data fitting.

[0042] In actual operation, the real-time acquired front-end load flow and heating steam flow are input into the produced flow prediction model, which then calculates the theoretically achievable produced flow under the current operating conditions. To obtain the theoretical extracted flow rate Then, the theoretical produced flow rate is corrected against the initial produced flow rate setpoint obtained based on the average front-end load. In the formula, λ is used to adjust the degree of influence of the theoretical model output on the produced flow rate setpoint. When the value of λ is small, the corrected produced flow rate setpoint is closer to the initial setpoint; when the value of λ is large, the corrected produced flow rate setpoint is closer to the model prediction value. It can be selected within the range of (0,1) according to the actual application scenario.

[0043] As can be seen, this embodiment establishes a production flow prediction model based on the upstream load flow and the tower bottom steam flow, and incorporates the current material load status and heating capacity of the refining tower into the production flow setpoint generation process, so that the production flow setpoint can comprehensively reflect the changes in upstream load and the changes in the vaporization capacity inside the tower.

[0044] As an optional embodiment, it also includes: Continuously monitor the buffer tank pressure and material outflow rate; When the buffer tank pressure exceeds the preset normal range and the material output flow rate deviates from the output flow rate setting value by more than the preset safety threshold, the tower top pressure setting value is modified. The calculation formula is as follows: ; in, Set the new tower top pressure value. This is the current measured pressure value at the top of the tower. This is a positive bias value preset based on the characteristics of the valve and pipeline; The pressure setting at the top of the tower will be automatically reset once the pressure in the buffer tank returns to the normal range.

[0045] Specifically, the downstream buffer tank is located at the rear end of the chlorination tail gas refining tower to receive hydrogen chloride gas output from the top of the refining tower and transport it to subsequent production sections. Since the top of the refining tower and the downstream buffer tank are connected by a pipeline, their pressure states are correlated. When the pressure at the top of the refining tower changes, the pressure in the buffer tank also changes accordingly, and the pressure in the downstream buffer tank more directly reflects the downstream hydrogen chloride transport status. During normal operation, the top outlet regulating valve is in automatic control mode, automatically adjusting its opening based on the deviation between the actual top pressure and the set top pressure. For example, when the actual top pressure is higher than the set pressure, the control logic gradually closes the outlet regulating valve, allowing more gas to condense and reflux through the top condenser, thereby reducing the top gas phase pressure. While this control method can maintain stable top pressure, it reduces the amount of hydrogen chloride gas transported to the buffer tank, causing a gradual decrease in the material outlet flow rate, making stable transport impossible. Therefore, this embodiment determines the hydrogen chloride transport status by detecting the pressure in the downstream buffer tank and the material outlet flow rate. When an abnormal pressure is detected in the downstream buffer tank and the material output flow rate decreases, the current tower top pressure control process causes insufficient opening of the output regulating valve, reducing the hydrogen chloride gas delivery capacity. In this situation, by lowering the tower top pressure setpoint, the output regulating valve is kept at a larger opening, allowing hydrogen chloride gas to continue being delivered to the downstream buffer tank.

[0046] As can be seen, this embodiment does not change the control logic of the production regulating valve itself, but dynamically corrects the pressure setpoint to keep the production regulating valve in a certain open state under abnormal operating conditions, thereby avoiding a continuous decrease in the hydrogen chloride delivery flow rate due to valve closure.

[0047] As an optional embodiment, a feedforward compensation signal is generated based on the front-end load flow and tower top pressure, including: When an increase in the front-end load flow or a tower top pressure is detected to be lower than the preset pressure limit, a feedforward compensation signal is generated to increase the opening of the steam regulating valve. When a decrease in the front-end load flow or a pressure at the top of the tower is detected to be higher than the preset pressure limit, a feedforward compensation signal is generated to reduce the opening of the steam regulating valve.

[0048] Specifically, the feedforward compensation signal is used to adjust the controlled object in advance based on detectable process disturbances, thereby reducing the impact of changes in disturbances on the operating state of the refining system. Compared to feedback regulation based solely on the bottom liquid level deviation, feedforward control can adjust without waiting for a significant change in the bottom liquid level, thus reducing control lag and improving the system's response speed to load changes. Specifically, the front-end load flow rate characterizes the material handling load entering the refining column. When a change in the front-end load flow rate is detected to be greater than zero, it indicates an increase in the material load entering the refining column, a larger amount of material to be processed inside the column, and a potential change in the vapor-liquid balance at the bottom, leading to a rise in the bottom liquid level. Therefore, the control system generates a feedforward compensation signal based on the trend of the front-end load flow rate change, increasing the opening of the steam regulating valve to increase the heating steam flow rate, increase the heat provided by the reboiler, and enhance the vaporization capacity of the material at the bottom, thus compensating in advance for the impact of increased load on the bottom operating state. Simultaneously, when a change in the front-end load flow rate is detected to be less than zero, it indicates a decrease in the material load entering the refining column, at which point the required heating capacity of the refining column is correspondingly reduced. The control system generates a feedforward compensation signal to reduce the opening of the steam regulating valve, thereby reducing the heating steam flow rate and avoiding fluctuations in the bottom liquid level and system instability caused by excessive heating.

[0049] Furthermore, the top pressure of the column also participates in feedforward compensation as an important state parameter affecting the refining process. When the detected top pressure is lower than the preset lower pressure limit, it indicates that the pressure at the top of the refining column is too low, which may lead to a decrease in the hydrogen chloride production and delivery capacity or a change in the gas-liquid balance within the column. At this time, the control system generates a feedforward compensation signal to increase the opening of the steam regulating valve, thereby increasing the heating steam flow rate, improving the vaporization capacity within the column, and gradually restoring the top pressure to a reasonable range. When the detected top pressure is higher than the preset upper pressure limit, the control system generates a feedforward compensation signal to decrease the opening of the steam regulating valve, thereby reducing the amount of heating steam entering the reboiler, reducing the amount of vaporization within the column, and thus inhibiting the continued rise in top pressure. The preset upper and lower pressure limits are used to define the normal operating range of the top pressure and can be preset according to the process operation requirements of the refining column, the equipment's pressure resistance, material separation characteristics, and historical stable operating data. For example, based on the fluctuation range of the top pressure of the refining column under normal production conditions, a corresponding pressure control window is determined. When the top pressure is within the pressure control window, the system is considered to be in normal operating condition.

[0050] As can be seen, the control system in this embodiment generates the steam regulating valve control compensation amount in advance based on the trend of front-end load flow and the pressure status at the top of the tower, enabling the heating steam flow to be actively adjusted according to changes in process load. Simultaneously, this feedforward compensation signal can also work in conjunction with the feedback signal generated based on the bottom liquid level deviation, improving the system response speed while eliminating steady-state errors through feedback regulation, thus maintaining a stable bottom liquid level.

[0051] As an optional embodiment, controlling the output of material extraction flow rate based on changes in tower top pressure includes: When the change in pressure at the top of the tower exceeds the preset pressure change threshold, the maximum allowable opening of the extraction regulating valve is limited, and / or the extraction flow rate setting is adjusted. When the change in pressure at the top of the tower is lower than the preset negative pressure change threshold, the opening of the extraction control valve is increased.

[0052] Specifically, the top pressure of the tower is used to characterize the gas-liquid balance state inside the refining tower and the pressure changes during hydrogen chloride delivery. Since changes in top pressure are typically related to the amount of vaporization within the tower, the material load, and the downstream delivery status, monitoring the trend of top pressure changes allows for early prediction of potential disturbances during material extraction and enables coordinated correction of the extraction control process. When the detected change in top pressure exceeds the preset pressure change threshold, it indicates a significant increase in top pressure. In this case, the maximum allowable opening of the extraction control valve can be limited, or the extraction flow rate setpoint can be reduced to prevent further deterioration of the top pressure. When the detected change in top pressure is below the preset negative pressure change threshold, it indicates a significant decrease in top pressure, potentially indicating a reduction in gas phase generation within the tower or insufficient hydrogen chloride delivery capacity. In this case, to maintain a stable material extraction flow rate, the control system increases the opening of the extraction control valve, allowing more material to be output to the downstream buffer tank to compensate for the decrease in delivery capacity caused by the pressure drop. In actual control, the pressure change threshold and negative pressure change threshold can be preset according to the operating range of the refining tower, pressure control accuracy, and extraction flow rate fluctuation requirements.

[0053] As can be seen, this embodiment incorporates the tower top pressure change trend into the production flow control process, so that the production regulating valve no longer performs single feedback adjustment based solely on the flow deviation, but rather performs coordinated control in conjunction with the internal pressure state of the refining tower, thereby reducing the impact of pressure fluctuations on the hydrogen chloride production flow and improving the stability of the material conveying process.

[0054] As an optional embodiment, controlling the output of material extraction flow rate based on changes in heating steam flow rate includes: When the opening of the steam regulating valve increases, the output flow rate setting value is increased accordingly to match the increase in vaporization capacity brought about by the increase in the opening of the steam regulating valve.

[0055] Specifically, changes in heating steam flow rate directly affect the vaporization capacity of the material in the column bottom. When the heating steam flow rate increases, the heat input to the column bottom increases, leading to an increase in the amount of gaseous phase generated within the column. This, in turn, affects the generation rate of hydrogen chloride and its subsequent extraction capacity. Therefore, incorporating changes in heating steam flow rate into the extraction flow rate control process allows for advance adjustment of the material extraction target based on changes in heat input, avoiding the lag caused by relying solely on extraction flow rate feedback for adjustment.

[0056] Specifically, the control system acquires the heating steam flow rate or the corresponding steam regulating valve opening in real time and calculates its change. When an increase in the steam regulating valve opening is detected, it indicates that the heating steam supply is being increased. At this time, the material in the bottom of the tower undergoes enhanced vaporization, generating more gaseous material per unit time. If the original output flow rate setpoint is maintained, the gaseous material generated in the refining tower may not be output in time, leading to material accumulation in the tower and affecting the stability of the bottom liquid level and the top pressure. Therefore, in this embodiment, the output flow rate setpoint is increased synchronously based on the increasing trend of the heating steam flow rate, so that the target output flow rate matches the increased material processing capacity after the increase in heating steam. In actual control, the adjustment amount of the output flow rate setpoint can be set according to the historical operating data of the refining tower, so that the change in heating steam flow rate and the change in output flow rate are matched, avoiding excessive adjustment of the output flow rate that could cause fluctuations in pressure or liquid level in the tower.

[0057] As can be seen, this embodiment links the heating steam regulation process with the material extraction control process, enabling the heating system and the extraction system to form a coordinated control relationship. Compared to the feedback adjustment method based solely on the extraction flow deviation, this embodiment can utilize the process trend reflected by the heating steam change to adjust the extraction target in advance, thereby improving the stability of hydrogen chloride flow delivery.

[0058] As an optional implementation, the extraction flow prediction model is established in the following manner: Acquire front-end load flow, heating steam flow, and material output flow under multiple operating conditions; Using the front-end load flow rate and heating steam flow rate as input parameters and the material output flow rate as output parameter, a prediction model for the output flow rate is obtained through multiple linear regression fitting: ; in, For front-end load flow, To increase the steam flow rate, , These are the model coefficients obtained by fitting historical operating data under multiple operating conditions.

[0059] Specifically, the outflow prediction model is used to predict the theoretically achievable material outflow under current operating conditions based on key process parameters during the refining system's operation. Since the material outflow is affected not only by the upstream load flow but also by the reboiler heating capacity, the upstream load flow and heating steam flow are selected as model input parameters to improve the adaptability of the prediction results to actual operating conditions.

[0060] Specifically, historical operating data of the refining system under multiple stable operating conditions is first collected. This historical data includes the front-end load flow rate, heating steam flow rate, and the actual material output flow rate under the corresponding conditions. The collected front-end load flow rate and heating steam flow rate are used as input variables, and the corresponding material output flow rate is used as the target output variable. Multiple linear regression is used to fit multiple historical data samples, establishing a mathematical relationship between the input and output variables to obtain the output flow rate prediction model. The coefficients a and b can be obtained using the least squares fitting method; in practical applications, a can take a value of 0.6387, and b can take a value of 0.2639.

[0061] As can be seen, the production flow prediction model established in the above manner can calculate the theoretical production flow based on the current front-end load flow and heating steam flow, and use the theoretical production flow as a reference for dynamic correction of the production flow setpoint. This allows the production control process to not only rely on historical average load values, but also to be adjusted in combination with the current process status, thereby improving the matching degree between the production flow setpoint and the actual production capacity.

[0062] As an optional embodiment, it also includes: When the pressure in the buffer tank exceeds the preset normal range and the material output flow rate deviates from the output flow rate setting value by more than the preset safety threshold, the output flow rate setting value is increased, and the opening degree of the output regulating valve is increased at the same time.

[0063] Specifically, when the buffer tank pressure exceeds the preset normal range and the material output flow rate deviates from the set output flow rate by more than the preset safety threshold, it indicates that the current hydrogen chloride material conveying process is affected by abnormal operating conditions, and the actual output capacity cannot meet the target conveying demand. At this time, the control system urgently replenishes the material, that is, increases the output flow rate setpoint and simultaneously increases the opening of the output regulating valve to improve the material output capacity. By increasing the output flow rate setpoint, the output flow control loop generates a greater flow regulation demand, guiding the output regulating valve to open further; at the same time, by directly increasing the opening of the output regulating valve, the material conveying response speed is accelerated, the impact of abnormal buffer tank pressure on the stability of material conveying is reduced, and the material output flow rate is restored to the preset stable range.

[0064] As can be seen, this embodiment effectively ensures the stability of hydrogen chloride flow delivery under abnormal operating conditions by increasing the set value of the produced flow rate and increasing the opening degree of the produced regulating valve.

[0065] To address the aforementioned problems, the present invention also provides a multivariate synergistic hydrogen chloride flow stabilization conveying device for an epichlorohydrin refining system, comprising: Memory, used to store computer programs; The processor is used to implement the steps of the above-described method for stabilizing the flow of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy when executing a computer program.

[0066] For an introduction to the hydrogen chloride flow stabilization and delivery device for an epichlorohydrin refining system based on multivariate synergy provided by the present invention, please refer to the embodiments of the above-mentioned method for stabilizing hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy. The present invention will not be repeated here.

[0067] To address the aforementioned problems, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate collaboration.

[0068] For a description of the readable storage medium provided by this invention, please refer to the above-described embodiment of the method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy; further details of this invention will not be repeated here.

[0069] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0070] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for stabilizing the flow rate of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy, characterized in that, include: Obtain the upstream load flow rate, column bottom liquid level, and column top pressure; Calculate the average load value of the front-end load flow within a preset time window, and use the average load value as the output flow rate setting value; The column bottom liquid level is the main controlled variable. A feedforward compensation signal is generated based on the front-end load flow rate and the column top pressure. At the same time, a feedback signal is generated based on the deviation between the column bottom liquid level and the preset column bottom liquid level setting value. The heating steam flow rate is controlled based on the feedforward compensation signal and the feedback signal to maintain a stable liquid level in the tower bottom; The output value of the material extraction flow rate is controlled based on the set value of the extraction flow rate, the change in the tower top pressure, and the change in the heating steam flow rate.

2. The method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy as described in claim 1, characterized in that, After the step of calculating the average load value of the front-end load flow within a preset time window and using the average load value as the output flow setpoint, the method further includes: The heating steam flow rate is obtained, and the theoretical output flow rate is calculated based on the pre-established output flow rate prediction model, according to the front-end load flow rate and the heating steam flow rate. The produced flow rate setpoint is dynamically corrected to obtain the corrected produced flow rate setpoint. : ； in The output flow rate setpoint before calibration. To theoretically extract the flow rate, For correction factors, ∈(0,1).

3. The method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy as described in claim 1, characterized in that, Also includes: Continuously monitor the buffer tank pressure and the material outflow rate; When the pressure in the buffer tank exceeds the preset normal range and the material output flow rate deviates from the set output flow rate value by more than a preset safety threshold, the tower top pressure set value is modified. The calculation formula is as follows: ； in, Set the new tower top pressure value. This is the current measured pressure value at the top of the tower. This is a positive bias value preset based on the characteristics of the valve and pipeline; The tower top pressure setting value is automatically reset after the pressure in the buffer tank returns to the normal range.

4. The method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy as described in claim 1, characterized in that, Generate a feedforward compensation signal based on the front-end load flow and the tower top pressure, including: When an increase in the front-end load flow or a pressure at the top of the tower is detected to be lower than a preset pressure limit, a feedforward compensation signal is generated to increase the opening of the steam regulating valve. When a decrease in the front-end load flow or a pressure at the top of the tower is detected to be higher than a preset pressure limit, a feedforward compensation signal is generated to reduce the opening of the steam regulating valve.

5. The method for stable delivery of hydrogen chloride flow rate in an epichlorohydrin refining system based on multivariate synergy as described in claim 1, characterized in that, Based on the change in the tower top pressure, the output of the material extraction flow rate is controlled, including: When the change in pressure at the top of the tower exceeds a preset pressure change threshold, the maximum allowable opening of the extraction regulating valve is limited, and / or the extraction flow rate setting is adjusted. When the change in pressure at the top of the tower is lower than a preset negative pressure change threshold, the opening of the extraction regulating valve is increased.

6. The method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy as described in claim 1, characterized in that, Based on the change in the heating steam flow rate, the output of the material extraction flow rate is controlled, including: When the opening of the steam regulating valve increases, the set value of the output flow rate is increased accordingly, so that the output flow rate of the material matches the increase in vaporization capacity brought about by the increase in the opening of the steam regulating valve.

7. The method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy as described in claim 2, characterized in that, The produced flow prediction model is established in the following way: Acquire front-end load flow, heating steam flow, and material output flow under multiple operating conditions; Using the front-end load flow rate and the heating steam flow rate as input parameters, and the material output flow rate as the output parameter, the output flow rate prediction model is obtained through multiple linear regression fitting: ； in, For front-end load traffic, To increase the steam flow rate, , These are the model coefficients obtained by fitting historical operating data under multiple operating conditions.

8. The method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy as described in claim 3, characterized in that, Also includes: When the pressure of the buffer tank exceeds the preset normal range and the material output flow rate deviates from the output flow rate setting value by more than the preset safety threshold, the output flow rate setting value is increased, and the opening degree of the output regulating valve is increased at the same time.

9. A device for stabilizing the flow of hydrogen chloride in an epichlorohydrin refining system based on multivariate synergy, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method for stable delivery of hydrogen chloride flow in an epichlorohydrin refining system based on multivariate synergy, as described in any one of claims 1 to 8.

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