Intelligent control method of distillation tower based on industrial Internet

Abstract

The present invention provides an intelligent control method for a distillation tower based on the Industrial Internet, comprising: simultaneously inputting temperature, pressure, and other data to simulate the temperature measured by a temperature sensor installed at the top of the distillation tower; calculating the product concentration at that time based on the input temperature and pressure, comparing the product concentration at that time with the target concentration, and seeking an optimal solution that balances cost and efficiency as required and feeding it back to the control system; and controlling the concentration from two aspects: the reflux ratio and the gas flow rate. The present invention uses sensors to detect physical quantities such as temperature, pressure, and flow in the equipment, and remotely adjusts the parameters of the equipment in real time to ensure the safety of the equipment. This ensures the effective implementation of the entire separation process while avoiding the additional costs caused by equipment damage.

Description

Technical Field

[0001] The present invention relates to the field of distillation tower control, and in particular to an intelligent control method for a distillation tower based on the industrial Internet. Background Art

[0002] Distillation has been an inseparable part of chemical processes since their inception. In the information age, informatization and intelligence are the best ways to make the distillation process more efficient and accurate.

[0003] Currently, emerging information technology achievements, represented by the internet, are a crucial component of the new technological landscape. Indeed, since the birth of the modern chemical industry, information technology has been a key driver of its development. Take synthetic ammonia technology, for example. From the completion of the world's first synthetic ammonia plant in 1913 to the present day, the key technologies have remained largely unchanged. However, information technology has significantly improved the scale of equipment, promoted comprehensive energy utilization and energy conservation, and increased production from an initial 5 tons per day to a current maximum of 30,000 tons per day. It is foreseeable that the in-depth application of industrial internet and artificial intelligence technologies will further enhance the chemical industry's multi-scale energy quality optimization, as well as the stability, robustness, and economic efficiency of system operations. Due to the unique technical and economic characteristics of the chemical industry, it places unique demands on information technology.

[0004] Chemical production involves continuous or intermittent processes such as raw material preparation, chemical reactions, separation and purification, packaging, and warehousing. The complexity of these processes varies significantly. Whether to build an Industrial Internet platform and the extent of its application should be comprehensively assessed based on technological maturity and economic benefits. For some non-critical processes, traditional technologies may offer better input-output results. However, this situation is not static. As labor costs gradually rise and technology costs decrease, the advantages of Industrial Internet technology will strengthen, and its application will expand. This is a gradual process, and Industrial Internet technology can adapt to this process.

[0005] Through algorithms and monitoring systems, the distillation tower is fully monitored. Certain steps that require precision are controlled by computer output simulation parameters to achieve higher accuracy of the actuator (such as controlling the valve opening). The process is regulated through information feedback from the monitoring system, and various conditions affecting output, such as material ratio, temperature, pressure, etc., are debugged. The generation of harmful substances is monitored and the process reaction parameters are optimized. The powerful computing power of the computer is used to complete tasks that cannot be completed by human power (such as using the exhaustive method to obtain the optimal material ratio, optimal temperature and even the optimal valve angle, etc.). Summary of the Invention

[0006] The present invention provides an intelligent control method for a distillation tower based on the industrial Internet to solve at least one of the above technical problems.

[0007] To solve the above problems, as one aspect of the present invention, a method for intelligent control of a distillation column based on the Industrial Internet is provided, comprising:

[0008] Step 1, data collection:

[0009] Collect data such as the number of distillation tower plates, raw material composition temperature, pressure and flow rate, product composition, temperature, pressure and flow rate at the top of the tower, and liquid composition, temperature, pressure and flow rate at the bottom of the tower, and input the above temperature, pressure and other data into the controller;

[0010] Step 2, simulation operation:

[0011] The product concentration at that time is calculated based on the input temperature and air pressure, and compared with the target concentration. Based on the neural network model, the collected data is used as the input layer variables, and the safety control index and economic benefit index are used as the output layer variables to obtain the optimal solution for the balance between cost and efficiency and feed it back to the control system;

[0012] Step 3, feedback adjustment:

[0013] The following three methods are used: (1) controlling the heating state to regulate the flow rate of the light component gas, (2) controlling the time ratio of the two switches of the electromagnetic valve to control the reflux ratio of the product, and (3) controlling the temperature in the heat exchanger, the flow rate of condensed water and the reflux method to improve the condensation efficiency of the steam, thereby realizing the control of the concentration from the two aspects of the reflux ratio and the gas flow rate. After the controller outputs the control signal according to the difference between the given value and the measured value, the top reflux ratio control electromagnetic valve operates accordingly, outputs the signal to the controlled object, and after the adjustment is completed, the measuring transmitter is used to detect whether the target concentration, i.e., the given value, has been reached or approached. The product concentration is formed by continuously collecting data, feedback and regulating, and the trend of continuously approaching the target concentration is formed. With the target concentration as the threshold, when the product concentration (temperature) reaches the corresponding threshold concentration (temperature) during the continuous regulation process, the intelligent macro-regulation of the product yield is achieved.

[0014] Step 4: Data transfer

[0015] The distillation tower operating parameter names / parameter values are stored as JSON files, and a Socket connection is established between the server and the client for reliable data transmission.

[0016] Preferably, when controlling the time ratio of the reflux and output of the electromagnetic valve to control the reflux ratio of the product, the electromagnetic valve automatically opens and closes by electromagnetic force, controlling the ratio of the light component flowing back to the distillation tower and flowing out of the distillation tower, thereby changing the time ratio between the two. Reflux can be achieved in the tower, thereby forming a vapor-liquid two-phase contact mass transfer so that the distillation process can be carried out continuously. When the load of the distillation tower is low, a smaller reflux ratio can be used, otherwise the reflux ratio should be increased to increase the product concentration.

[0017] Preferably, when controlling the temperature in the heat exchanger, the flow rate of condensed water and the reflux mode to improve the condensation efficiency of steam, countercurrent heat exchange is adopted to obtain higher heat exchange efficiency and save heat transfer area and cooling medium, thereby increasing the reflux ratio.

[0018] While controlling product yield, the present invention significantly improves equipment safety. Regarding personnel safety, the present invention enables remote control of equipment parameters and performance, thereby preventing casualties due to on-site hazards. Furthermore, a safety threshold is set for the pressure value; when exceeded, an alarm is triggered, and safety measures are automatically implemented when the safety limit is approached. The present invention uses sensors to detect physical quantities such as temperature, pressure, and flow in the equipment, allowing for real-time remote control of equipment parameters to ensure equipment safety. This ensures the effective implementation of the entire separation process while avoiding the additional costs associated with equipment damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The control principle diagram of the present invention is schematically shown. DETAILED DESCRIPTION

[0020] The following is a detailed description of embodiments of the present invention, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0021] The present invention provides an intelligent control technology for distillation towers based on the industrial Internet, which relates to a safety monitoring technology for distillation towers, especially a safety monitoring technology for binary vapor-phase feed distillation towers. It uses algorithms and monitoring systems to conduct comprehensive monitoring of distillation towers, and uses computer output simulation parameters to control actuators for certain steps that require higher precision to achieve higher precision (such as controlling valve opening), and uses information fed back by the monitoring system to regulate the process. We use computer simulations to determine the effects that different operations may have on the control effect, and find the effect corresponding to the optimal effect, which is used as the actual operation. Debug material ratios, temperatures, pressures and other conditions that affect output, monitor the generation of harmful substances and optimize process reaction parameters, and use the powerful computing power of computers to complete tasks that cannot be completed by manpower (such as using exhaustive methods to determine the optimal material ratio, optimal temperature and even the optimal valve angle, etc.)

[0022] In one embodiment, the present invention includes the following steps:

[0023] (1) Data collection

[0024] Data such as the number of distillation tower plates, feedstock composition, temperature, pressure, and flow rate, product composition, temperature, pressure, and flow rate at the tower top, and liquid composition, temperature, pressure, and flow rate at the bottom of the tower are collected and simultaneously input into the controller. If subsequent experiments indicate that pressure has a significant impact on theoretical calculations, additional pressure parameters are added at that location to simulate the air pressure measured by a pressure sensor.

[0025] (2) Simulation

[0026] Because the bubble points of the light and heavy components in a solution differ, the bubble point of their mixed solution has a certain functional relationship with the product concentration and pressure. Experimental research has shown that this functional relationship is not difficult to identify. Based on the input temperature and pressure, a built-in algorithm within the application can be used to calculate the product concentration at that point. This product concentration is then compared with the target concentration. Based on the needs, the built-in algorithm comprehensively considers various factors. Based on neural network modeling, using the collected data as input variables and safety control indicators and economic benefit indicators as output variables, the optimal solution balancing cost and efficiency is obtained and fed back to the control system.

[0027] (3) Feedback regulation

[0028] The output of this system mainly focuses on three aspects of operations:

[0029] First, the flow rate of the light component gas is regulated by controlling the heating state. Changing the feed heating state increases the pressure within the tower, which in turn increases the driving force within the tower and the gas flow rate. This allows the light and heavy component states of the distillation tower feed to be adjusted to avoid low product concentrations caused by too low a gas flow rate, or flooding and entrainment caused by too high a gas flow rate. This ensures normal tower operation and increases the distillation tower product concentration.

[0030] Second, the product reflux ratio is controlled by controlling the ratio of the opening and closing times of the solenoid valve. The solenoid valve automatically opens and closes using electromagnetic force, controlling the ratio of the light fraction flowing back into the distillation column and out of it. By varying the ratio of reflux to output, reflux is achieved within the column, fostering vapor-liquid two-phase contact and mass transfer, enabling continuous distillation. Generally speaking, a lower reflux ratio is suitable when the distillation column load is low, while a higher reflux ratio is recommended to increase product concentration.

[0031] Third, the steam condensation efficiency can be improved by controlling the temperature in the heat exchanger, the flow rate of the condensed water, and the reflux method. Taking the reflux method as an example, countercurrent heat exchange can achieve higher heat transfer efficiency and save heat transfer area and cooling medium, thereby increasing the reflux ratio.

[0032] The above three methods respectively realize the control of concentration from two aspects: reflux ratio and gas flow rate. After the controller outputs a control signal according to the difference between the given value and the measured value, the tower top reflux ratio control solenoid valve will operate accordingly, output a signal to the controlled object, and after adjustment, the measuring transmitter is used to detect whether the target concentration, that is, the given value, has been reached or is approaching.

[0033] By continuously collecting data, providing feedback, and regulating, the product concentration tends to approach the target concentration. With the target concentration as the threshold, during the continuous regulation process, when the product concentration (temperature) reaches the corresponding threshold concentration (temperature), intelligent macro-regulation of the product yield is achieved.

[0034] (4) Data transmission

[0035] The distillation tower operating parameter names / parameter values are stored as JSON files, and a Socket connection is established between the server (processing equipment) and the client (chip installed on the distillation tower) for reliable data transmission.

[0036] like Figure 1 As shown in the figure, before operation, the system determines the given value (i.e., target concentration). After comparing it with the actual value, the controller outputs signals to the two major control parts, reflux ratio and gas flow rate, according to the difference between the two. Then, the concentration change is achieved by adjusting the control solenoid valve, heat exchanger, and heating state. The concentration is measured again and compared with the given value to realize the negative feedback loop control process.

[0037] For example, in the ethylene distillation process, a client program is burned into a single-chip microcomputer or other microcomputer connected to the sensors on the distillation tower to read the distillation tower's process parameters in real time. Based on Industrial Internet technology, these parameters are collected in real time and transmitted to the processor via a socket connection for calculation. This calculation feedback controls variables and sends control instructions to the distillation tower controller, such as the tower top solenoid valve to adjust the reflux ratio and the pipeline solenoid valve to adjust the valve opening to control the flow rate.

[0038] Due to the adoption of the above technical solution, this patent has the following technical effects:

[0039] (1) From a safety perspective, achieving the overall objective of the present invention requires addressing the common problem of entrainment and subsequent flooding in distillation towers. To address this problem, the present invention employs parameter feedback to simulate a solution to this problem.

[0040] (2) From the perspective of improving yield, the impact of the reflux ratio and the heat exchanger on yield is mainly considered. The present invention has conducted detailed research on the optimal reflux ratio, the heat exchanger cold liquid reflux method, the type of condensate, the heat exchanger flow rate, and the temperature.

[0041] The present invention can greatly reduce the operator's on-site operation time and reduce casualties in the event of an accident. It simulates the parameter changes of the distillation tower through data input, uses intelligent calculation to analyze the distillation tower parameters, and simulates the control of the distillation equipment through parameter output, ultimately ensuring a higher yield. While controlling the product yield, it greatly improves the safety of the equipment.

[0042] While controlling product yield, the present invention significantly improves equipment safety. Regarding personnel safety, the present invention enables remote control of equipment parameters and performance, thereby preventing casualties due to on-site hazards. Furthermore, a safety threshold is set for the pressure value; when exceeded, an alarm is triggered, and safety measures are automatically implemented when the safety limit is approached. The present invention uses sensors to detect physical quantities such as temperature, pressure, and flow in the equipment, allowing for real-time remote control of equipment parameters to ensure equipment safety. This ensures the effective implementation of the entire separation process while avoiding the additional costs associated with equipment damage.

[0043] The present invention can manually simulate signal input, and if connected to a single-chip microcomputer, it can adapt to the distillation tower; using mobile phones and on-site equipment as computing devices effectively reduces the operational delay in the process of transmitting data to the cloud; the device structure is relatively simple, and all algorithms are pre-installed in the processor, which is expected to reduce equipment costs; data transmission adopts the Socket reliable connection to transmit JSON files, which improves the reliability of data transmission.

[0044] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An intelligent control method for a distillation tower based on the industrial Internet, characterized in that: include: Step 1, data collection: Collect the number of plates in the distillation tower, the temperature, pressure and flow rate of the raw material composition, the product composition, temperature, pressure and flow rate at the top of the tower, and the liquid composition, temperature, pressure and flow rate at the bottom of the tower, and input the above temperatures and pressures into the controller at the same time; Step 2, calculation: The product concentration at that time is calculated based on the input temperature and air pressure, and compared with the target concentration. Based on the neural network model, the collected data is used as the input layer variables, and the safety control index and economic benefit index are used as the output layer variables to obtain the optimal solution for the balance between cost and efficiency and feed it back to the control system; Step 3, feedback adjustment: The following three methods are used: (1) controlling the heating state to control the flow rate of the light component gas, (2) controlling the time ratio of the two switches of the electromagnetic valve to control the reflux ratio of the product, and (3) controlling the temperature in the heat exchanger, the flow rate of condensed water and the reflux method to improve the condensation efficiency of the steam, thereby realizing the control of the concentration from the two aspects of the reflux ratio and the gas flow rate. After the controller outputs the control signal according to the difference between the given value and the measured value, the top reflux ratio control electromagnetic valve operates accordingly, outputs the signal to the controlled object, and after the adjustment is completed, the measuring transmitter is used to detect whether the target concentration, i.e., the given value, has been reached or approached. The product concentration is formed by continuously collecting data-feedback-control, and the trend of continuously approaching the target concentration is formed. With the target concentration as the threshold, when the product concentration or temperature reaches the corresponding threshold concentration or temperature during the continuous control process, the intelligent macro-control of the product yield is achieved. Among them, controlling the time ratio of the two openings and closings of the electromagnetic valve to control the reflux ratio of the product means: when controlling the time ratio of the reflux and output of the electromagnetic valve to control the reflux ratio of the product, the electromagnetic valve automatically opens and closes by electromagnetic force to control the ratio of the light component flowing back to the distillation tower and flowing out of the distillation tower, thereby changing the time ratio of the two, realizing reflux in the tower and forming vapor-liquid two-phase contact mass transfer so that the distillation process can be carried out continuously. When the load of the distillation tower is low, a smaller reflux ratio can be used, otherwise the reflux ratio should be increased to increase the product concentration; When controlling the temperature, condensate flow and reflux mode in the heat exchanger to improve the condensation efficiency of steam, countercurrent heat exchange is used to obtain higher heat transfer efficiency and save heat transfer area and cooling medium, thereby increasing the reflux ratio; Step 4: Data transfer The distillation tower operating parameter names / parameter values are stored as JSON files, and a Socket connection is established between the server and the client for reliable data transmission.

Images