CONTROL SYSTEM SYNTHESIS FOR THE ETHYLBENZENE DEHYDROGENATION PROCESS BASED ON THE PREDICTIVE FUNCTIONAL CONTROL METHOD

2021 ◽  
pp. 7-14
Author(s):  
С.Л. Подвальный ◽  
А.П. Попов ◽  
С.Г. Тихомиров ◽  
О.Г. Неизвестный
Keyword(s):  
Control System ◽  
System Analysis ◽  
Dynamic Models ◽  
Control Method ◽  
Reaction Medium ◽  
Automated System ◽  
Process Equipment ◽  
Catalytic Layer ◽  
Predictive Functional Control ◽  
Functional Control

Описывается применение метода предиктивного управления при синтезе автоматизированной системы программного управления производством стирола. На основе результатов системного анализа объекта управления обоснован способ управления технологическим процессом, проведены обзор и оценка возможности использования различных видов регулирующих устройств. В рамках концепции модельно-ориентированного проектирования синтезирована автоматизированная система, реализующая предсказательное функциональное управление (Predictive functional control (PFC)) концентрацией стирола на выходе из первой ступени реакторного блока. Выполнен структурный синтез и разработан алгоритм функционирования управляющей системы. В качестве структурного элемента, выполняющего построение прогнозной траектории изменения управляющего и управляемого параметров, использован комплекс динамических моделей, описывающих теплообменные процессы и физико-химические превращения, протекающие в исследуемой системе. Расчет оптимального значения управляющего воздействия производился с учетом инерционности технологического оборудования, параметров состояния каталитического слоя реактора, энергетических потоков и компонентов реакционной среды в соответствии со сформированным комплексным интегральным критерием энергоэффективности процесса при одновременном обеспечении максимальной производительности. Приведен сравнительный анализ результатов расчета переходных процессов по основному каналу системы управления, полученных при использовании регулятора ПИД-структуры и управляющего устройства, реализующего метод PFC-управления The article describes the application of the predictive control method in the synthesis of an automated system for software control of styrene production. Based on the results of the object system analysis, the method of process control is justified, the review and evaluation of the possibility of using various types of control devices is carried out. Within the framework of the model-oriented design concept, an automated system is synthesized that implements predictive functional control (PFC) of the concentration of styrene at the outlet of the reactor unit first stage. A structural synthesis was performed, and the control system operation algorithm was developed. A set of dynamic models describing heat exchange processes and physical and chemical transformations occurring in the system under study is used as a structural element that performs the construction of a predictive trajectory of changes in the controlling and controlled parameters. The calculation of the optimal value of the control action was carried out taking into account the inertia of the process equipment, the parameters of the state of the catalytic layer of the reactor, energy flows and components of the reaction medium in accordance with the formed complex integral criterion of the energy efficiency of the process while ensuring maximum productivity. A comparative analysis of the results of calculating transient processes for the main channel of the control system, obtained using a PID structure controller and a control device that implements the PFC control method

scholarly journals Improved predictive functional control for ethylene cracking furnace

2019 ◽  
Vol 52 (5-6) ◽  
pp. 526-539
Author(s):  
Han Song ◽  
Cheng-li Su ◽  
Hui-yuan Shi ◽  
Ping Li ◽  
Jiang-tao Cao
Keyword(s):  
Control System ◽  
State Space ◽  
Control Method ◽  
Balance Control ◽  
State Space Model ◽  
Industrial Process ◽  
Outlet Temperature ◽  
Extended State ◽  
Predictive Functional Control ◽  
Functional Control

The objective of this paper is to show the design and application of pass temperature balance control system using an improved predictive functional control method in eight 800 tone/year USC ethylene cracking furnaces. The advanced pass temperature balance controller is developed using the proposed method and implemented in proprietary APC-ISYS software, which is connected to Yokogawa distributed control system via an OPC server. The advantage of it lies in the fact that the dynamics of pass temperature with nonlinearity and time delay are described by Takagi–Sugeno model and transformed into time-varying extended state space model, and thus, the proposed controller can regulate pass temperature based on the extended state space formulation. In addition, the control law with a linear iterative form, easily applied to industrial process, is derived. The robust analysis for the set point, input disturbance and output disturbance to the output verifies the ability of tracking and disturbance rejection of the proposed method. Application results from an industrial furnace are shown to be markedly better in terms of lower variability in the outlet temperature of both the passes compared to the current proportional–integral–derivative control scheme.

scholarly journals System analysis of the ethylbenzene dehydrogenation reactor as a control object

2018 ◽  
Vol 80 (2) ◽  
pp. 77-85 ◽  
Author(s):  
A. P. Popov ◽  
V. K. Bityukov ◽  
S. G. Tikhomirov ◽  
O. G. Neizvestnyi ◽  
E. D. Chertov
Keyword(s):  
Control System ◽  
Temperature Regime ◽  
System Analysis ◽  
Catalyst Activity ◽  
Research Result ◽  
Control Object ◽  
Process Equipment ◽  
Main Stage ◽  
Catalytic Layer ◽  
Catalytic Dehydrogenation

Catalytic dehydrogenation of ethylbenzene charge in a two-stage continuous-action adiabatic reactor is the main stage of the styrene production process. The analysis of this technological process existing automated control systems revealed the following main drawback, that these systems require great efforts from production personnel to ensure a change of the reactor temperature regime in the stages of the reactor in accordance with styrene concentration drop, which is caused by deactivation catalytic layer deactivation. Therefore, the synthesis of the target product concentration at the reactor outlet predictive control system is actual task in the field of technical cybernetics. This article presents the system analysis results of the dehydrogenation reactor as a control object. The main research result is a method choice for controlling of the chemical transformations temperature regime in the reactor, using that, it is possible to increase the energy efficiency and productivity of this device. The general and specific tasks of the control system synthesis are formulated on the basis of the system analysis, the information and functional synthesis of the temperature regime ACS is produced, the information and functional schemes of the reactor unit process equipment control subsystems are developed. As an operating system ACS is selected, which realizes of steam-ethylbenzene mixture temperature change at the reaction zones entrances of the 1st and 2nd reactor sections in accordance with the program control algorithm on the basis of predicting models, describing the heat exchange processes occurring inside the reactor stages as well as the dynamics of changes in such parameters as the concentration of coke deposits, catalyst activity, the basic and by- products concentration of chemical reactions.

A control method to suppress the swing vibration of a hybrid excavator using sliding mode approach

2011 ◽  
Vol 226 (5) ◽  
pp. 1237-1253 ◽  
Author(s):  
K Jin ◽  
T Park ◽  
H Lee
Keyword(s):  
System Analysis ◽  
Dynamic Models ◽  
Control Method ◽  
Sliding Mode ◽  
Robust Tracking ◽  
Parameter Variations ◽  
Identification Technique ◽  
Integral Controller ◽  
System States ◽  
Hybrid Excavator

This article presents a control method for suppressing the swing vibration of a hybrid excavator. For control design, dynamic models of typical swing motions of the hybrid excavator are derived using a system identification technique. Because the system states of theobtained models are not directly measurable, a sliding mode observer is designed to estimate the system states. A sliding mode control is designed to provide robust tracking performance against the parameter variations and uncertain non-linearities caused by changes in the working conditions. A complicated mathematical model of the hybrid excavator which captures detailed mechanical, electrical, and hydraulic characteristics is developed for system analysis and simulation. The feasibility and effectiveness of the proposed control method are verified by simulations and actual tests in comparison with a conventional proportional and integral controller.

Multivariable Predictive Functional Control for the First-Order Plus Time-Delay System

2011 ◽  
Vol 282-283 ◽  
pp. 32-37
Author(s):  
Quan Ling Zhang
Keyword(s):  
Control System ◽  
Steady State ◽  
Disturbance Rejection ◽  
Delay System ◽  
Transfer Function Model ◽  
Time Delay System ◽  
Function Model ◽  
First Order ◽  
Predictive Functional Control ◽  
Functional Control

A multivariable predictive functional control (M-PFC) algorithm based on a two-inputs/two-outputs system with the transfer function model is presented in this paper. A simple and explicit solution of manipulated variables of the control system can be obtained by optimizing the objective function. Simulations of the system applying M-PFC are also provided in here, showing that the presented algorithm has good performance of tracking set-point without steady-state error, disturbance rejection and robustness. Finally, the application of temperature control for the methylamine synthesizing tower is addressed, demonstrating the effectiveness of the proposed PFC algorithm.

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