CN212016778U - Advanced process control system for methanol rectification - Google Patents
Advanced process control system for methanol rectification Download PDFInfo
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- CN212016778U CN212016778U CN202020142741.4U CN202020142741U CN212016778U CN 212016778 U CN212016778 U CN 212016778U CN 202020142741 U CN202020142741 U CN 202020142741U CN 212016778 U CN212016778 U CN 212016778U
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Abstract
The utility model relates to a methanol rectification device process control technical field especially relates to a methanol rectification advanced process control system. The methanol rectification advanced process control system comprises a DCS control device and an advanced control device; the advanced control device comprises a real-time data memory, a model prediction arithmetic unit and an optimization control component which are mutually communicated and connected; the model memory is internally stored with pre-tower model data, recovery tower model data and pressurizing tower and atmospheric tower model data; the model prediction arithmetic unit predicts the variation trend of the control variable; and the optimization control component calculates an optimal regulating quantity according to the variation trend and the preset expected value, and the DCS controller component regulates the regulating component according to the optimal regulating quantity so that the control variable works at a preset expected value. The methanol rectification advanced process control system can reduce labor intensity, control variable fluctuation range and energy consumption of the methanol rectification device, and improve automation level and system stability.
Description
Technical Field
The utility model relates to a methanol rectification device process control technical field especially relates to a methanol rectification advanced process control system.
Background
In the related art, a methanol rectification device is generally provided with a DCS (distributed control system), and the whole process of the work of the methanol rectification device is monitored by connecting detection instruments such as temperature, pressure, flow, liquid level and components into the DCS. And then the DCS control system calculates a control instruction according to a control target set by an operator according to a conventional PID (proportion, integral and differential) and cascade control schemes in the DCS control system, and finally the DCS control system sends the control instruction to an adjusting valve, a cut-off valve, a frequency converter and the like for execution so as to achieve the automatic control of the methanol rectifying device.
However, methanol distillation plants are typically multivariable, constrained and strongly coupled complex industrial processes, since they not only involve relatively complex feed and discharge relationships, but also heat integration between columns. Therefore, the conventional single-in single-out PID control scheme of the DCS control system has difficulty in solving the overall control and optimization problem of the process. Operators face complicated control objects, and are difficult to accurately predict future trends and comprehensively coordinate PID loops at each bottom layer, so that the problems of low automation level of a methanol rectification device, large fluctuation of key process parameters, unstable system operation, high device energy consumption and the like are caused.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a methanol rectification advanced process control system to solve among the prior art to a certain extent that methanol rectification device automation level is low, the fluctuation of key technological parameter is big, the system operation is not steady, the device energy consumption is high problem.
In order to achieve the above object, the present invention provides the following technical solutions;
based on the above purpose, the utility model provides a methanol rectification advanced process control system, methanol rectification device includes tower in advance, pressurized column, atmospheric tower, recovery tower and adjusting part, the adjusting part set up in tower in advance, pressurized column and recovery tower;
the methanol rectification advanced process control system comprises a DCS control device and an advanced control device, wherein the DCS control device comprises a monitor assembly and a DCS controller assembly which are in communication connection; the advanced control device comprises a real-time data memory, a model prediction arithmetic unit and an optimization control component which are mutually communicated and connected; the real-time data storage and the optimization control assembly are in communication connection with the DCS controller assembly;
historical data is stored in the real-time data storage; the model memory is internally stored with pre-tower model data, recovery tower model data and pressurizing tower and atmospheric tower model data;
the monitor component respectively acquires real-time data of control variables of the pre-tower, the pressurizing tower, the normal pressure tower and the recovery tower, and transmits and stores the real-time data into the real-time data storage;
the model prediction arithmetic unit can predict the change trend of the control variable within a preset time according to the pre-tower model data, the recovery tower model data, the pressurized tower and normal pressure tower model data, the real-time data and the historical data;
the optimization control component can calculate an optimal regulating quantity for the regulating component according to the change trend and a preset expected value and transmit the optimal regulating quantity to the DCS controller component;
and the DCS controller component adjusts the adjusting component according to the optimal adjusting quantity so as to enable the control variable to work at the preset expected value.
In any of the above technical solutions, optionally, the advanced control apparatus further includes a feedback corrector;
the feedback corrector is respectively in communication connection with the real-time data storage, the model prediction arithmetic unit and the optimization control component;
and the feedback corrector corrects the pre-tower model data, the recovery tower model data and the pressurized tower and atmospheric tower model data according to the real-time data and the change trend.
In any of the above aspects, optionally, the monitor assembly comprises a first monitor assembly, a second monitor assembly, and a third monitor assembly;
the first monitor component can acquire first real-time data of a first control variable of the pre-tower and transmit and store the first real-time data to the real-time data storage;
the second monitor assembly can acquire second real-time data of control variables of the pressurized tower and the atmospheric tower, and transmit and store the second real-time data to the real-time data storage;
the third monitor assembly can acquire third real-time data of the control variable of the recovery tower and transmit and store the third real-time data to the real-time data storage.
In any of the above technical solutions, optionally, the optimization control component includes a pre-tower controller, a pressurized tower and atmospheric tower controller, and a recovery tower controller;
the regulating assembly comprises a first regulating assembly arranged on the pre-tower, a second regulating assembly arranged on the pressurizing tower and the normal pressure tower, and a third regulating assembly arranged on the recovery tower;
the model prediction arithmetic unit can predict a first change trend of the first control variable within the preset time length according to the first real-time data, the pre-tower model and the historical data; the pre-tower controller can calculate a first optimal adjustment amount for the first adjustment assembly according to the first change trend and the preset expected value;
the model prediction arithmetic unit is also capable of predicting a second variation trend of the second control variable within the preset time length according to the second real-time data, the pressurized tower and atmospheric tower model data and the historical data; the pressurized tower and atmospheric tower controller can calculate a second optimal adjustment amount for the second adjustment assembly according to the second variation trend and the preset expected value;
the model prediction operator is further capable of predicting a third change trend of the third control variable within the predetermined time period according to the third real-time data, the recovery tower model data and the historical data; the recovery tower controller can calculate a third optimal adjustment amount for the third adjustment assembly based on the third trend of change and the predetermined desired value.
In any of the above technical solutions, optionally, the first adjusting assembly includes a pre-tower reboiler steam flow adjusting valve and a pre-tower crude methanol feed inlet adjusting valve;
the first monitor assembly comprises a pre-tower top temperature sensor, a pre-tower bottom temperature sensor, a pre-tower top pressure sensor and a pre-tower reflux ratio sensor;
the pre-tower model data is control model data of the set quantity of the first adjusting component to the monitoring quantity of the first monitor component.
In any of the above technical solutions, optionally, the second adjusting component includes a pressure tower reboiler steam flow adjusting valve, a pressure tower top return flow adjusting valve, a pressure tower feed inlet adjusting valve, a pressure tower bottom liquid level adjusting valve, an atmospheric tower top return flow adjusting valve, a pressure tower bottom steam flow adjusting valve, and a pressure tower bottom liquid level adjusting valve;
the second monitor component comprises a pressurizing tower bottom temperature sensor, a pressurizing tower top pressure sensor, a pressurizing tower bottom liquid level monitoring piece, a pressurizing tower top reflux ratio monitoring piece, an atmospheric tower top temperature sensor and an atmospheric tower bottom temperature sensor;
and the pressurized tower and atmospheric tower model data are control model data of the set value of the second adjusting component to the monitoring value of the second monitor component.
In any of the above technical solutions, optionally, the third adjusting assembly includes a recovery tower bottom steam flow adjusting valve, a recovery tower top recovery flow adjusting valve, and a recovery tower feed inlet adjusting valve;
the third monitor component comprises a recovery tower top temperature sensor, a recovery tower bottom temperature sensor and a recovery tower top pressure sensor;
the recovery tower model data is control model data of a set value of the third adjusting component on a monitoring value of the third monitor component.
In any of the above technical solutions, optionally, the DCS controller assembly further includes a DCS controller, an input device, and an output device;
the input equipment and the output equipment are both connected with the DCS controller; the input equipment is used for inputting the threshold value of the regulating quantity and the threshold value of the control variable by an operator; the output equipment is used for data monitoring of operators.
In any of the above technical solutions, optionally, the methanol rectification advanced process control system further includes a first gateway, a second gateway, and an OPC server;
the DCS control device assembly communicates with the OPC server through the first gateway, and the optimization control assembly communicates with the OPC server through the second gateway.
Adopt above-mentioned technical scheme, the beneficial effects of the utility model are that:
the utility model provides a methanol rectification advanced process control system, including DCS controlling means and advanced controlling means. By establishing the pre-tower model data, the recovery tower model data and the pressurizing tower and normal pressure tower model data, a more accurate simulation environment is provided for the model prediction arithmetic unit to predict the variation trend, so that the obtained variation trend is more fit with the actual variation trend, and the accuracy of pre-judgment is improved. Furthermore, compared with the scheme of directly obtaining a control instruction through a DCS controller component, the optimal regulating quantity obtained by comparing the change trend with the preset expected value can be more suitable for the multivariable, constrained and strongly coupled complexity of the methanol rectifying device, the working state of the methanol rectifying device can approach to an ideal state through automatic process control, the manual intervention of operators can be effectively reduced, the labor intensity of the operators can be reduced, the automation level can be improved, the fluctuation range of the control variable and the energy consumption of the methanol rectifying device are reduced, and the stability and the safety of the methanol rectifying device are greatly improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of a process flow of a methanol distillation apparatus of an advanced process control system for methanol distillation according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of an advanced process control system for methanol distillation according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an optimization control component of an advanced process control system for methanol distillation according to an embodiment of the present invention.
Icon: 1-a DCS control device; 2-advanced control means; 20-real-time data storage; 21-a model memory; 22-a model prediction operator; 23-optimizing the control assembly; 230-a pre-tower controller; 231-pressurized column and atmospheric column controllers; 232-recovery column controller; 24-a feedback corrector; 30-pre-tower; 31-a pressurized column; 32-atmospheric tower; 33-a recovery column; 4-OPC server.
Detailed Description
The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Examples
The methanol rectification advanced process control system provided by the embodiment is used for a methanol rectification device.
Referring to fig. 1 to fig. 3, in the advanced process control system for methanol rectification provided in this embodiment, the methanol rectification apparatus includes a pre-tower 30, a pressurizing tower 31, an atmospheric tower 32, a recovery tower 33, and an adjusting component, and the adjusting component is disposed on the pre-tower 30, the pressurizing tower 31, the atmospheric tower 32, and the recovery tower 33.
Specifically, referring to fig. 1, crude methanol a is introduced into a preliminary column 30 to sufficiently remove low boiling components, and then introduced into a pressurizing column 31. In the pressurizing tower 31, the gas phase partial pressure and boiling point of the methanol are increased by pressurizing rectification to reduce the gas phase volatilization of the methanol.
While part of qualified refined methanol b is extracted from the top of the pressurizing tower 31, the mixture of methanol, water and the like with lower concentration flowing out from the bottom of the pressurizing tower 31 enters the atmospheric pressure rectifying tower after being decompressed.
The low concentration methanol solution completes the separation of methanol, water and higher alcohol in the atmospheric tower 32, qualified refined methanol b is extracted from the top of the atmospheric tower 32, and the residual fusel d is merged into the recovery tower 33 for concentration treatment. Wherein, alcohol-containing wastewater c in the tower bottom of the atmospheric tower 32 and the tower bottom of the recovery tower 33 is cooled and treated as sewage.
Referring to fig. 2, the methanol rectification advanced process control system comprises a DCS control device 1 and an advanced control device 2, wherein the DCS control device 1 comprises a monitor component and a DCS controller component which are in communication connection; the advanced control device 2 comprises a real-time data memory 20, a model memory 21, a model prediction arithmetic unit 22 and an optimization control component 23 which are mutually connected in a communication way; the real-time data storage 20 and the optimization control assembly 23 are both in communication connection with the DCS controller assembly.
It should be noted that the communication connection means to connect the two by wire or wirelessly so as to transmit the electrical signal therebetween.
The real-time data storage 20 stores history data; the model memory 21 stores pre-tower model data, recovery tower model data, and pressurized tower and atmospheric tower model data. The pre-tower model data is model data of a multi-input multi-output mode obtained by taking the pre-tower 30 as a modeling object, and can more accurately simulate the working mechanism in the pre-tower 30, and similarly, the recovery tower model data is model data of a multi-input multi-output mode obtained by taking the recovery tower 33 as a modeling object, and the pressurizing tower and normal pressure tower model data is model data of a multi-input multi-output mode obtained by taking the pressurizing tower 31 and normal pressure tower 32 as modeling objects, so that the working mechanism in the recovery tower 33, the pressurizing tower 31 and the normal pressure tower 32 can be more accurately simulated, and the working mechanism of the three-tower process can be more accurately simulated.
The monitor assembly acquires real-time data of control variables of the pre-tower 30, the pressurizing tower 31, the atmospheric tower 32 and the recovery tower 33 respectively, and transmits and stores the real-time data to the real-time data storage 20. It will be appreciated that the real-time data acquired, transferred and stored in the real-time data store 20 at the previous time becomes historical data for the next time. The control variables and the control variables of the preliminary tower 30, the pressurizing tower 31, the atmospheric tower 32, and the recovery tower 33 are values corresponding to control targets such as temperature, pressure, flow rate, and liquid level.
The model prediction arithmetic unit 22 can predict the variation trend of the control variable within a preset time according to the pre-tower model data, the recovery tower model data, the pressurizing tower and normal pressure tower model data, the real-time data and the historical data; the optimization control component 23 can calculate an optimal adjustment quantity for the adjustment component according to the variation trend and a preset expected value, and transmit the optimal adjustment quantity to the DCS controller component; the DCS controller component adjusts the adjusting component according to the optimal adjusting quantity so that the control variable works at a preset expected value.
Specifically, the optimization control module 23 can also perform calculation according to the high and low limit values of the control variables and the adjustment quantity, and by combining process and equipment constraints, so as to obtain the maximum economic benefit. The DCS controller component is carried by the methanol rectifying device, and stratum adjusting action is executed through the DCS controller component and the adjusting component.
That is to say, by establishing the pre-tower model data, the recovery tower model data and the pressurizing tower and normal pressure tower model data, a more accurate simulation environment is provided for the model prediction arithmetic unit 22 to predict the variation trend, so that the obtained variation trend is more fit with the actual variation trend, and the accuracy of pre-judgment is improved. Furthermore, compared with the scheme of directly obtaining a control instruction through a DCS controller component, the optimal regulating quantity obtained by comparing the change trend with the preset expected value can be more suitable for the multivariable, constrained and strongly coupled complexity of the methanol rectifying device, the working state of the methanol rectifying device can approach to an ideal state through automatic process control, the manual intervention of operators can be effectively reduced, the labor intensity of the operators can be reduced, the automation level can be improved, the fluctuation range of the control variable and the energy consumption of the methanol rectifying device are reduced, and the stability and the safety of the methanol rectifying device are greatly improved.
Specifically, the methanol rectification advanced process control system can reduce the fluctuation range of key process parameters by 66.13%, reduce the steam consumption by about 3% and improve the methanol yield by 0.5%, thereby realizing the card edge control of the methanol rectification device and greatly improving the direct economic benefit.
Alternatively, the advanced control device 2 runs on a separate dedicated server, specifically a rack-mounted APC server or a tower-type APC server.
In an alternative of this embodiment, the advanced control device 2 further comprises a feedback corrector 24; the feedback corrector 24 is communicatively connected to the real-time data storage 20, the model storage 21, the model prediction operator 22 and the optimization control component 23, respectively. The feedback corrector 24 corrects the pre-tower model data, the recovery tower model data and the pressurized tower and atmospheric tower model data based on the real-time data and the variation trend.
By continuously correcting the pre-tower model data, the pressurized tower and normal pressure tower model data and the recovery tower model data, the mismatching of the model data or the excessive deviation of the working state of the methanol rectifying device from the ideal state caused by environmental interference can be prevented.
Optionally, the real-time data storage 20 is used to store all relevant information such as real-time data from the DCS control device 1 during operation of the advanced control device 2, and process data, operation records, modification records, fault and error diagnoses, etc. of the model prediction operator 22, the feedback corrector 24 and the optimization control component 23, so as to facilitate system debugging or problem analysis.
In an alternative of this embodiment, the monitor assembly includes a first monitor assembly, a second monitor assembly, and a third monitor assembly.
The first monitor assembly is capable of acquiring first real-time data of a first control variable of the pre-tower 30 and transmitting and storing the first real-time data to the real-time data storage 20. The second monitor assembly is capable of acquiring second real-time data of second control variables of the pressurized tower 31 and the atmospheric tower 32 and transmitting and storing the second real-time data to the real-time data storage 20. The third monitor assembly is capable of acquiring third real-time data of a third control variable of the recovery tower 33 and transmitting and storing the third real-time data to the real-time data storage 20.
That is, the pre-column 30, the pressurized column 31, the atmospheric column 32, and the recovery column 33 are monitored by the first monitor assembly, the second monitor assembly, and the third monitor assembly, respectively.
In an alternative to this embodiment, and as shown in fig. 3, the optimization control assembly 23 includes a pre-tower controller 230, a pressurized and atmospheric tower controller 231, and a recovery tower controller 232.
The adjusting components include a first adjusting component disposed on the pre-tower 30, a second adjusting component disposed on the pressurized tower 31 and the atmospheric tower 32, and a third adjusting component disposed on the recovery tower 33. That is, the regulation is performed by the first, second and third regulating members, the pre-tower 30, the pressurizing tower 31, the atmospheric tower 32 and the recovery tower 33, respectively.
The model prediction arithmetic unit 22 can predict a first variation trend of the first control variable within a preset time according to the first real-time data, the pre-tower model and the historical data; the pre-tower controller 230 can calculate a first optimal adjustment amount for the first adjustment assembly based on the first trend of change and a predetermined desired value. Thereby ensuring that the first control variable of the pre-tower 30 works at the preset desired value, namely that the working state of the pre-tower 30 reaches the ideal state.
The model prediction arithmetic unit 22 is also capable of predicting a second variation trend of the second control variable within the predetermined time period according to the second real-time data, the pressurized tower and atmospheric tower model data and the historical data; the pressurized tower and atmospheric tower controller 231 can calculate a second optimum adjustment amount for the second adjustment component based on the second tendency of change and a predetermined desired value. Thereby ensuring that the second control variables of the pressurized tower 31 and the atmospheric tower 32 work at the preset expected values, namely the working states of the pressurized tower 31 and the atmospheric tower 32 reach the ideal state.
The model prediction arithmetic unit 22 is further capable of predicting a third variation trend of the third control variable within the predetermined time period based on the third real-time data, the recovery tower model data and the historical data; the recovery tower controller 232 can calculate a third optimal adjustment amount for the third adjustment assembly based on the third trend of change and the predetermined desired value. Thereby ensuring that the third control variable of the recovery tower 33 is operated at a predetermined desired value, i.e., the operation state of the recovery tower 33 reaches the ideal state.
Thus, the cooperative use of the pre-tower controller 230, the pressurized tower and atmospheric tower controller 231, the recovery tower controller 232, the first adjusting unit, the second adjusting unit, the third adjusting unit, the first monitor unit, the second monitor unit, and the third monitor unit can further enhance the optimal control capability of the optimal control unit 23.
Optionally, the optimization control unit 23 is a roll optimization control unit, that is, at each control cycle, the roll optimization control unit calculates an optimal adjustment amount to minimize the error of the controlled variable from a predetermined desired value within a predetermined time period. In addition, the rolling optimization control component can also take uncertainty caused by model mismatch, time variation or interference and the like into account and can make a remedy in time, so that the automatic control effect is kept in an optimal state.
Optionally, the control period of the roll optimization control assembly is 30 seconds. The rolling optimization control component is an existing controller with a rolling optimization function.
In an alternative scheme of this embodiment, the first adjusting component comprises a pre-tower reboiler steam flow adjusting valve and a pre-tower crude methanol feed inlet adjusting valve; the first monitor assembly comprises a pre-tower top temperature sensor, a pre-tower bottom temperature sensor, a pre-tower top pressure sensor and a pre-tower reflux ratio sensor; the pre-tower model data is control model data of the set quantity of the first adjusting component to the monitored quantity of the first monitor component.
That is, the control variables specifically include the pre-column top temperature, the pre-column bottom temperature, the pre-column top pressure, the pre-column reflux ratio. And correspondingly adjusting a steam flow regulating valve of the pre-tower reboiler and a pre-tower crude methanol feeding port regulating valve according to the first optimal regulating quantity calculated by the pre-tower controller 230 so as to set the steam flow of the pre-tower reboiler and the feeding quantity of the pre-tower crude methanol.
Specifically, the pre-tower model data includes: the control model of the preset value of the steam flow of the pre-tower reboiler on the temperature of the top of the pre-tower, the control model of the preset value of the steam flow of the pre-tower reboiler on the temperature of the bottom of the pre-tower, the control model of the preset value of the steam flow of the pre-tower reboiler on the pressure of the top of the pre-tower and the control model of the preset value of the steam flow of the pre-tower reboiler on the reflux ratio of the pre-tower. That is, the pre-tower model data is a multi-input multi-output control model, and can more appropriately simulate the actual operation mechanism of the pre-tower 30.
Optionally, the pre-column model data further includes a model of interference of pre-column crude methanol feed to pre-column bottoms problems.
In the alternative of this embodiment, the second adjusting component includes a pressure tower reboiler steam flow control valve, a pressure tower top return flow control valve, a pressure tower feed inlet control valve, a pressure tower bottom liquid level control valve, an atmospheric tower top return flow control valve, a pressure tower bottom steam flow control valve and a pressure tower bottom liquid level control valve. The second monitor component comprises a pressurizing tower bottom temperature sensor, a pressurizing tower top pressure sensor, a pressurizing tower bottom liquid level monitoring piece, a pressurizing tower top reflux ratio monitoring piece, an atmospheric tower top temperature sensor and an atmospheric tower bottom temperature sensor. And the model data of the pressurizing tower and the atmospheric tower are control model data of the set value of the second regulating component on the monitoring value of the second monitor component.
That is, the control variables also include the pressurized column bottoms temperature, the pressurized column top pressure, the pressurized column bottoms level, the pressurized column top reflux ratio, the atmospheric column top temperature, and the atmospheric column bottom temperature. The steam flow control valve of the reboiler of the pressurizing tower, the return flow control valve of the top of the pressurizing tower, the feed inlet control valve of the pressurizing tower, the liquid level control valve of the bottom of the pressurizing tower, the return flow control valve of the top of the atmospheric tower, the steam flow control valve of the bottom of the pressurizing tower and the liquid level control valve of the bottom of the pressurizing tower are correspondingly adjusted according to the second optimal adjustment amount calculated by the controller 231 of the pressurizing tower and the atmospheric tower so as to set the steam flow of the reboiler of the pressurizing tower, the return flow of the top of the pressurizing tower, the feed amount of the pressurizing tower, the liquid level of the bottom of the pressurizing tower, the return flow of the top of the atmospheric tower, the steam flow.
The model data of the pressurized tower and the atmospheric tower comprises a control model of a set value of the steam flow of a reboiler of the pressurized tower to the tower top temperature of the pressurized tower, a control model of a set value of the steam flow of a reboiler of the pressurized tower to the tower bottom temperature of the pressurized tower, a control model of a set value of the steam flow of the reboiler of the pressurized tower to the tower top pressure of the pressurized tower, a control model of a set value of the steam flow of the reboiler of the pressurized tower to the tower bottom liquid level of the pressurized tower, a control model of a set value of the tower top reflux of the pressurized tower to the reflux ratio of the tower top of the pressurized tower, a control model of the opening of a liquid level regulating valve of the tower bottom of the pressurized tower to the tower bottom liquid level of the pressurized tower, a control model of a set value of the tower top reflux of the atmospheric tower to the tower top temperature. That is, the pressurized tower and atmospheric tower model data are multi-input multi-output control models, and can more appropriately simulate the actual operation mechanism of the pressurized tower 31 and the atmospheric tower 32.
Optionally, the pressurized and atmospheric tower model data comprises: the method comprises the following steps of (1) an interference model of the opening of a feeding valve of a pressurizing tower on the top temperature of the pressurizing tower, an interference model of the opening of the feeding valve of the pressurizing tower on the bottom temperature of the pressurizing tower, an interference model of the opening of the feeding valve of the pressurizing tower on the top pressure of the pressurizing tower, an interference model of the opening of the feeding valve of the pressurizing tower on the bottom liquid level of the pressurizing tower, an interference model of a set value of the top reflux flow of the pressurizing tower on the bottom liquid level of the pressurizing tower, an interference model of a set value of the bottom steam flow of the pressurizing tower on the top temperature of an atmospheric tower, and an interference model of the opening of a bottom liquid level.
By constructing the multi-input multi-output interference model, the influence of disturbances such as production load, feeding conditions, amount of heated steam of a reboiler at the tower bottom, temperature change and the like on the pressurizing tower 31 and the atmospheric tower 32 can be simulated, so that the simulation precision of model data of the pressurizing tower and the atmospheric tower is further improved, the fluctuation of control variables is favorably reduced, the pressurizing tower 31 and the atmospheric tower 32 operate in an optimized interval, the steam consumption is reduced, and the methanol yield and the quality of refined methanol b are improved.
In the alternative of this embodiment, the third adjusting part includes recovery tower bottom steam flow control valve, recovery tower top flow control valve and recovery tower feed inlet governing valve. The third monitor component comprises a recovery tower top temperature sensor, a recovery tower bottom temperature sensor and a recovery tower top pressure sensor. The recovery tower model data is control model data of a set value of the third regulating component to a monitored value of the third monitor component.
That is, the control variables also include the recovery column overhead temperature, the recovery column bottoms temperature, and the recovery column overhead pressure. And correspondingly adjusting a steam flow regulating valve at the bottom of the recovery tower, a steam flow regulating valve at the top of the recovery tower, a return flow regulating valve at the top of the recovery tower and a feed inlet regulating valve of the recovery tower according to the third optimal regulating quantity calculated by the recovery tower controller 232 so as to set the steam flow at the bottom of the recovery tower, the steam flow at the top of the recovery tower, the return flow at the top of the recovery tower and the feed quantity of the recovery tower.
Specifically, the recovery tower model data includes: the control model of the set value of the bottom steam flow of the recovery tower to the top temperature of the recovery tower, the control model of the set value of the bottom steam flow of the recovery tower to the bottom temperature of the recovery tower, the control model of the set value of the top steam flow of the recovery tower to the top pressure of the recovery tower and the control model of the set value of the top return flow of the recovery tower to the top temperature of the recovery tower.
Optionally, the recovery tower model data further comprises: and the interference model of the opening of the feed valve of the recovery tower on the tower top temperature of the recovery tower and the interference model of the opening of the feed valve of the recovery tower on the tower bottom temperature of the recovery tower.
By constructing the multi-input multi-output interference model, the influence of disturbances such as production load, feeding conditions, tower kettle reboiler heating steam quantity, temperature change and the like on the recovery tower 33 can be simulated, so that the simulation precision of the model data of the recovery tower is further improved, the fluctuation of control variables is favorably reduced, the recovery tower 33 operates in an optimized interval, the steam consumption is reduced, and the methanol yield and the quality of refined methanol b are improved.
That is to say, the model data of the pre-tower, the model data of the pressurizing tower and the atmospheric tower and the model data of the recovery tower can be obtained by performing model identification on the data obtained by performing step test on the methanol rectifying device.
In an optional aspect of this embodiment, the DCS controller assembly further includes a DCS controller, an input device, and an output device; the input equipment and the output equipment are both connected with the DCS controller; the input equipment is used for inputting the threshold value of the regulating variable and the threshold value of the control variable by an operator; the output equipment is used for data monitoring of operators.
Optionally, the DCS controller component further includes a logic control circuit, and the logic control circuit is connected between the DCS controller and the optimization controller, so that the DCS controller communicates with the optimization control component 23 according to a communication handshake logic, a controller switching logic, a loop switching logic, an out-of-limit logic, or a card limit alarm logic.
In an alternative of this embodiment, the methanol rectification apc system further includes a first gateway, a second gateway, and an OPC server 4.
The DCS control device 1 component communicates with the OPC server 4 through a first gateway, and the optimization control component 23 communicates with the OPC server 4 through a second gateway. That is, the methanol rectification advanced process control system has an OPC client function, and communicates with the DCS controller through the OPC server 4, collects data of the DCS control device 1, and transmits the collected data to the advanced control device 2 to calculate an optimum adjustment amount.
The operator can set the control variables and the high and low limit values and the predetermined desired values of the regulating components on the dedicated operation interface of the DCS control device 1, and issue commissioning or removal instructions to the optimization control component 23. After receiving the commissioning command, the advanced control system updates the implementation data of each control variable, and then performs further calculation and control work.
Optionally, the first gateway and the second gateway are both wired communication network cards, so that the OPC server 4 can communicate with the DCS control device 1 and the optimization control component 23, respectively, through ethernet.
In an alternative of this embodiment, the methanol rectification advanced process control system further includes a system configuration, where the system configuration includes various file paths required by the operation of the optimization control component 23, an address of the OPC server 4, configuration of input/output points, operation information of the optimization control component 23, configuration of control parameters, configuration of optimization parameters, and the like.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention. Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.
Claims (9)
1. A methanol rectification advanced process control system is used for a methanol rectification device and is characterized in that the methanol rectification device comprises a pre-tower, a pressurizing tower, an atmospheric tower, a recovery tower and adjusting components, wherein the adjusting components are arranged on the pre-tower, the pressurizing tower, the atmospheric tower and the recovery tower;
the methanol rectification advanced process control system comprises a DCS control device and an advanced control device, wherein the DCS control device comprises a monitor assembly and a DCS controller assembly which are in communication connection; the advanced control device comprises a real-time data memory, a model prediction arithmetic unit and an optimization control component which are mutually communicated and connected; the real-time data storage and the optimization control assembly are in communication connection with the DCS controller assembly;
historical data is stored in the real-time data storage; the model memory is internally stored with pre-tower model data, recovery tower model data and pressurizing tower and atmospheric tower model data;
the monitor component respectively acquires real-time data of control variables of the pre-tower, the pressurizing tower, the normal pressure tower and the recovery tower, and transmits and stores the real-time data into the real-time data storage;
the model prediction arithmetic unit can predict the change trend of the control variable within a preset time according to the pre-tower model data, the recovery tower model data, the pressurized tower and normal pressure tower model data, the real-time data and the historical data;
the optimization control component can calculate an optimal regulating quantity for the regulating component according to the change trend and a preset expected value and transmit the optimal regulating quantity to the DCS controller component;
and the DCS controller component adjusts the adjusting component according to the optimal adjusting quantity so as to enable the control variable to work at the preset expected value.
2. The methanol rectification advanced process control system according to claim 1, wherein the advanced control device further comprises a feedback corrector;
the feedback corrector is respectively in communication connection with the real-time data storage, the model prediction arithmetic unit and the optimization control component;
and the feedback corrector corrects the pre-tower model data, the recovery tower model data and the pressurized tower and atmospheric tower model data according to the real-time data and the change trend.
3. The methanol rectification advanced process control system according to claim 1,
the monitor assembly comprises a first monitor assembly, a second monitor assembly, and a third monitor assembly;
the first monitor component can acquire first real-time data of a first control variable of the pre-tower and transmit and store the first real-time data to the real-time data storage;
the second monitor assembly can acquire second real-time data of second control variables of the pressurized tower and the atmospheric tower, and transmit and store the second real-time data to the real-time data storage;
the third monitor assembly is capable of acquiring third real-time data of a third control variable of the recovery tower and transmitting and storing the third real-time data to the real-time data storage.
4. The methanol rectification advanced process control system according to claim 3,
the optimization control assembly comprises a pre-tower controller, a pressurizing tower, an atmospheric tower controller and a recovery tower controller;
the regulating assembly comprises a first regulating assembly arranged on the pre-tower, a second regulating assembly arranged on the pressurizing tower and the normal pressure tower, and a third regulating assembly arranged on the recovery tower;
the model prediction arithmetic unit can predict a first change trend of the first control variable within the preset time length according to the first real-time data, the pre-tower model and the historical data; the pre-tower controller can calculate a first optimal adjustment amount for the first adjustment assembly according to the first change trend and the preset expected value;
the model prediction arithmetic unit is also capable of predicting a second variation trend of the second control variable within the preset time length according to the second real-time data, the pressurized tower and atmospheric tower model data and the historical data; the pressurized tower and atmospheric tower controller can calculate a second optimal adjustment amount for the second adjustment assembly according to the second variation trend and the preset expected value;
the model prediction operator is further capable of predicting a third change trend of the third control variable within the predetermined time period according to the third real-time data, the recovery tower model data and the historical data; the recovery tower controller can calculate a third optimal adjustment amount for the third adjustment assembly based on the third trend of change and the predetermined desired value.
5. The methanol rectification advanced process control system according to claim 4,
the first adjusting component comprises a steam flow adjusting valve of a pre-tower reboiler and a pre-tower crude methanol feeding port adjusting valve;
the first monitor assembly comprises a pre-tower top temperature sensor, a pre-tower bottom temperature sensor, a pre-tower top pressure sensor and a pre-tower reflux ratio sensor;
the pre-tower model data is control model data of the set quantity of the first adjusting component to the monitoring quantity of the first monitor component.
6. The methanol rectification advanced process control system according to claim 4,
the second adjusting component comprises a steam flow adjusting valve of a reboiler of the pressurizing tower, a tower top return flow adjusting valve of the pressurizing tower, a feed inlet adjusting valve of the pressurizing tower, a tower bottom liquid level adjusting valve of the pressurizing tower, a tower top return flow adjusting valve of the normal pressure tower, a tower bottom steam flow adjusting valve of the pressurizing tower and a tower bottom liquid level adjusting valve of the pressurizing tower;
the second monitor component comprises a pressurizing tower bottom temperature sensor, a pressurizing tower top pressure sensor, a pressurizing tower bottom liquid level monitoring piece, a pressurizing tower top reflux ratio monitoring piece, an atmospheric tower top temperature sensor and an atmospheric tower bottom temperature sensor;
and the pressurized tower and atmospheric tower model data are control model data of the set value of the second adjusting component to the monitoring value of the second monitor component.
7. The methanol rectification advanced process control system according to claim 4,
the third adjusting component comprises a recovery tower bottom steam flow adjusting valve, a recovery tower top return flow adjusting valve and a recovery tower feed inlet adjusting valve;
the third monitor component comprises a recovery tower top temperature sensor, a recovery tower bottom temperature sensor and a recovery tower top pressure sensor;
the recovery tower model data is control model data of a set value of the third adjusting component on a monitoring value of the third monitor component.
8. The methanol rectification advanced process control system of claim 1, wherein the DCS controller assembly further comprises a DCS controller, an input device and an output device;
the input equipment and the output equipment are both connected with the DCS controller; the input equipment is used for inputting the threshold value of the regulating quantity and the threshold value of the control variable by an operator; the output equipment is used for data monitoring of operators.
9. The methanol rectification advanced process control system according to claim 1, further comprising a first gateway, a second gateway and an OPC server:
the DCS control device assembly communicates with the OPC server through the first gateway, and the optimization control assembly communicates with the OPC server through the second gateway.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113181678A (en) * | 2021-04-13 | 2021-07-30 | 浙江毅聚新材料有限公司 | Automatic control system, method and device for separating and recycling white oil and dichloromethane mixed solution |
| CN113877231A (en) * | 2021-11-03 | 2022-01-04 | 四川泸天化创新研究院有限公司 | Automatic load increasing and decreasing intelligent control method for methanol rectification device |
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| CN117193407A (en) * | 2023-11-06 | 2023-12-08 | 万华化学集团股份有限公司 | Control method for preparing formaldehyde by oxidizing methanol, electronic equipment and storage medium |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113181678A (en) * | 2021-04-13 | 2021-07-30 | 浙江毅聚新材料有限公司 | Automatic control system, method and device for separating and recycling white oil and dichloromethane mixed solution |
| CN113877231A (en) * | 2021-11-03 | 2022-01-04 | 四川泸天化创新研究院有限公司 | Automatic load increasing and decreasing intelligent control method for methanol rectification device |
| CN114904289A (en) * | 2022-05-31 | 2022-08-16 | 浙江中智达科技有限公司 | R142b reactor heavy component zero manual steaming method and steaming device thereof |
| CN114904289B (en) * | 2022-05-31 | 2023-11-17 | 浙江中智达科技有限公司 | R142b reactor heavy component zero manual steaming method and steaming device thereof |
| CN117193407A (en) * | 2023-11-06 | 2023-12-08 | 万华化学集团股份有限公司 | Control method for preparing formaldehyde by oxidizing methanol, electronic equipment and storage medium |
| CN117193407B (en) * | 2023-11-06 | 2024-02-02 | 万华化学集团股份有限公司 | Control method for preparing formaldehyde by oxidizing methanol, electronic equipment and storage medium |
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