The accelerator of the most popular advanced contr

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Advanced control technology - the "accelerator" for enterprises to increase production and efficiency

at present, there is a large amount of secondary development of advanced control and optimization control software, and the cycle from design, testing, simulation research to the actual industrial device operation is long. Therefore, some advanced control and optimization control software with less secondary development should be developed in the future to meet the needs of the market. At the same time, it will further develop commercialized advanced control and optimization control software with strong robustness, wide adaptability (operating conditions, raw material properties, etc.) and excellent performance price ratio to meet the needs of domestic large and medium-sized enterprises

process industry process is a complex industrial process, which has a lot of characteristics, such as uncertainty, nonlinearity, multivariable coupling, large lag and state incompleteness. Therefore, there are great difficulties in the design of process industry process control system, and the traditional PID control algorithm is difficult to meet the requirements of control quality and efficiency. With the development of modern computer technology, artificial intelligence, network technology and optimization technology, advanced control technology (APC advancedprocesscontrol) has been applied in the process industry and achieved success, which has greatly promoted the production and operation level of the process industry and effectively achieved energy conservation and emission reduction. Thousands of APCs have been put into use all over the world. The input-output benefits of APCs have been recognized. The general return on investment is $10/$1. The economic benefits of optimized technology are greater, and the investment repayment period is less than 1 year. This paper expounds the application status of advanced control technology in process industry, and briefly introduces the application cases and development prospects

Since the 1970s, with the wide application of computer technology, automatic control technology has developed greatly, and advanced process control came into being. Advanced control is rich in content and covers a wide range of people living in the Netherlands, including adaptive control, robust control, predictive control, intelligent control and soft sensing technology. Advanced control technology is a general term for those control strategies that are different from conventional single loop control and have better control effect than conventional PID control

in the process of complex industrial production, a good control system should not only protect the stability of the system and the safety of the whole production, meet certain constraints, but also bring certain economic and social benefits. However, designing such a control system will encounter many difficulties, especially complex industrial processes often have uncertainties (unknown environmental structure and parameters, time-varying, randomness, mutation), nonlinearity, correlation between variables, incomplete information and large pure lag, etc., so it is very difficult to obtain accurate mathematical models. Modern complex industrial production processes, through the implementation of advanced control, can greatly improve the stability of industrial production process operation and control, improve the dynamic performance of industrial production process, reduce the fluctuation range of key variables, and make it closer to the optimization target value, so as to push the industrial production process closer to the constrained boundary conditions of the device, and finally enhance the stability and safety of industrial production process, To ensure the uniformity of product quality, improve the yield of the target product, improve the processing capacity of the production device, reduce the operation cost of the production process and reduce environmental pollution

in recent years, advanced control technology has been continuously promoted and applied in the process industry and achieved good results. At present, domestic major enterprises represented by the petrochemical industry have adopted advanced control technology. With the advantages of improving the performance of process dynamic control, reducing the fluctuation range of process variables, and making production devices operate (clamped operation) close to its constrained boundary, advanced control technology has been widely used in petrochemical, electric power and other industries. A large number of industrial devices are equipped with advanced control systems on the basis of existing DCS, Large scale model predictive control and nonlinear predictive control technology for optimization have been greatly improved. Because advanced control software packages can bring considerable economic benefits to enterprises, China has introduced advanced control software such as idcom-m, SmCA, DMCplus, and has been put into use. In addition, Honeywell profiles has cooperated with Sinopec to promote their RMPCT software in the petrochemical industry, and some of them have been put into use. In China, more and more petrochemical enterprises have also begun to try the application of advanced control, such as Maoming, Yangzi, Jinan and other refineries have applied advanced control technology, and have achieved good application results and economic benefits. However, we cannot avoid some practical problems in the application of advanced control

at present, advanced control technology has not only introduced new achievements in theory, but also made remarkable achievements in practical production and application. Now there are many excellent products to choose from at home and abroad: such as PC (profitcontroller) of Honeywell high technology execution department; Star represented by ABB; SMOC of Yokogawa agency; Connoisseur of Foxboro; DMC of Aspen, APC ADCON of Zhejiang central control, etc. At present, most production units of advanced petrochemical enterprises in the world adopt advanced control technology. According to the data of arc survey, the penetration rate in the United States has reached more than 60%, and the proportion of key units has reached 90%. To some extent, advanced control technology is more like an accelerator for enterprises to increase production and efficiency. Based on DCS, FCS and other systems, advanced control technology usually adopts multivariable predictive control, intelligent soft measurement, process calculation and other strategies to achieve the following objectives: tensile experiment (stress-strain experiment) 1. Generally, the two ends of material samples are clamped on two fixtures with a fixed distance of 1: improve the stability and safety of device operation, ensure the consistency of product quality, improve the yield of target products Increase the treatment capacity of the device, reduce the operation cost, reduce environmental pollution, etc. Therefore, more and more enterprises begin to use advanced control technology to achieve energy conservation and efficiency. At the same time, users in these industries also take advanced control technology as a breakthrough to enhance the competitiveness of enterprises

the practice over the past few years has proved that the promotion of advanced control methods in China is not plain sailing, but has encountered many difficulties and problems. Although the benefits of advanced control system are obvious, there is always a gap between the construction and application of advanced control in domestic enterprises and abroad. The system development enterprise can ensure the normal operation of the system in the development and application process, but at the same time, the maintainer of the advanced control system is the information technology personnel of the user enterprise. They should not only be familiar with the advanced control technology itself, but also master the computer control system and process technology. Therefore, due to the lack of sufficient technical force, the long-term maintenance problem of advanced control system is becoming increasingly obvious

it should be said that China's control theorists and industrial control enterprises have achieved many successes in the application research of APC technology to varying degrees. Among them, Tsinghua University, Zhejiang University, Shanghai Jiaotong University, East China University of technology, Central South University, North China Electric Power University, China University of petroleum, Beijing University of chemical technology, Beijing University of science and technology, Zhejiang University central control company, Zhejiang Zhengtai zhongzi control company, Hollysys company, metallurgical automation Research Institute, Beijing JINZI Tianzheng intelligent company, Beijing sanbo company, etc. are all outstanding in this field

Application of APC technology in process industry

Application in chemical automation

for a long time, the technical level of China's chemical industry is low, resulting in high energy and material consumption, which limits the development of the chemical industry. To change this situation, the fundamental way out is to take the road of scientific and technological progress and adopt advanced and practical technology to transform traditional industries. As the chemical industry is increasingly developing towards integration and large-scale, the complexity of the system is increasing, which is manifested in the characteristics of strong coupling, uncertainty, nonlinearity, incomplete information and large lag of the process, and there are harsh constraints. The control objectives are diversified, the number of variables is increased and the correlation is enhanced. In this case, the traditional control strategy can no longer meet the requirements, Advanced control must be applied

for example, Guangzhou Branch of China Petroleum and Chemical Corporation (hereinafter referred to as Guangzhou Petrochemical) applied advanced control technology in the control of propylene distillation column and achieved good results. In 2007, Guangzhou Petrochemical began to cooperate with East China University of science and technology to implement the propylene distillation tower advanced control system transformation project based on the distributed control system (DCS) platform by applying the advanced control technology of the distillation tower and combining the production process characteristics of the propylene distillation tower system of Guangzhou Petrochemical. Based on the accurate and effective evaluation of the actual operation performance of the propylene distillation column and the characteristics of the previous control scheme, the project implements advanced control technology for the product quality of the propylene distillation column and the content of precious heavy components extracted from the tower kettle, so as to improve the operation stability of the propylene distillation column, reduce the loss of propylene, and then achieve the ultimate goal of improving the overall benefit of the device

for another example, based on the carbonation system of a soda plant in the State Key Laboratory of industrial control technology and the Institute of advanced control of Zhejiang University, the model predictive control software was applied to five groups of 25 carbonation towers, and a multivariable predictive controller containing hundreds of controlled variables, control variables and interference variables was developed to solve the constrained multivariable control problem of the carbonation system. The industrial application results show that the model predictive control software can ensure the carbonation system to operate in the best state for a long time, so as to reduce material consumption, improve product quality and save operating costs, and optimize production benefits

as another example, for the process control difficulties of 60kt/a organosilicon distillation unit of Zhejiang Xin'an Chemical Industry Group Co., Ltd., using APC ADCON advanced multivariable robust predictive control software of Zhejiang central control software technology Co., Ltd., an advanced control system was developed, which was successfully applied and achieved the expected control effect. The excellence rate of its key products, methyltrichlorosilane and dimethyldichlorosilane, has been increased to more than 90%, and the energy consumption per unit product has been reduced by more than 8%

large scale ethylene plant optimization operation project

with the increasingly integrated and large-scale development of China's petrochemical industry, the complexity of the system continues to increase, which is manifested in the characteristics of strong coupling, uncertainty, nonlinearity, incomplete information and large pure lag of the process, and there are harsh constraints, diversified control objectives, increased number of variables and enhanced correlation. In this case, the traditional control strategy can not fully meet the requirements, and advanced control must be applied. Ethylene plant is the core and development symbol of petrochemical industry. Although China's existing ethylene production capacity ranks second in the world and the equipment has been localized, the optimal operation still mainly depends on imported technology. The fine operation and control and optimization level of production and operation process are still poor compared with foreign advanced levels. A blow molding machine with good performance shows good market adaptability in the process of producing film. Among many advanced control technologies, multivariable predictive control technology and soft sensing technology are widely used in ethylene plant at present, and have achieved good economic benefits, and have formed the corresponding commercialized software. The cracking process technology has been developed in the domestic large-scale ethylene plant optimization operation project jointly developed by East China University of science and technology and China Petrochemical Co., Ltd

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