The Key Technology Of APC System And Its Application In Ethylene Glycol Production Process

Ethylene glycol is one of the core equipment of petrochemical enterprise.Its refining unit is composed of a plurality of distillation towers.There is strong interference between them,so how to operate stably and improve energy efficiency of distillation tower is the main target of ethylene glycol process control device.At the same time,it can achieve quality card edge,reduce product losses and improve results.The above objectives are difficult to realize by the conventional control technology of DCS,and advanced process control(APC)is a new technology to realize the process control target of ethylene glycol unit.In recent years,advanced process control technology is an important technology to maximize the efficiency of equipment output in production process.Ethylene glycol production process is using APC technology,mainly by improving level of automation of production equipment(tower),to achieve "card edge" to optimize the operation,improve product quality,improve product yield,and reduce energy consumption.With the increasingly fierce competition in the product market,the use of advanced control to enhance the level of automation and management of enterprises has become a major trend.Model identification and APC-DCS system integration technology are two key technologies of advanced process control system.Taking the key technologies as the research objects,this paper realizes the communications between the advanced process control device of ethylene glycol and the underlying DCS control system,so as to improve the control level of ethylene glycol device.The main work includes:Firstly,according to the technological characteristics of the ethylene glycol unit,discusses the technological framework of the advanced process control system of advanced ethylene glycol unit from the point of view of the advanced process control strategy,and analyses the key technologies.Secondly,through the analysis of the DMC algorithm and the hardware and software framework of APC system,it can provide the research foundation for the APC system model identification and APC-DCS system integration of the ethylene glycol unit.Thirdly,the object and purpose of model identification of ethylene glycol unit are studied,the method of model identification is expounded,and the effect of four controller model identification is analyzed.Fourthly,from the point of view of improving system safety,puts forward the integration technology of APC and DCS system of ethylene glycol unit.When the communication between the advanced control server and DCS is interrupted and the server crashes and so on,the advanced control system can be cut out and the alarm prompt is given,which is easy for the operator to process.In order to ensure the stability of the application of advanced control system,the relevant soft points for communication with APC are established on the DCS.The APC operating mode of the control system loop is modified,and the configuration of the control logic and the control interface development are carried out.Finally,implements the advanced control device of ethylene glycol,by comparison,confirms that it can enhance the optimization effect of advanced controller by virtue of its model identification accuracy,and can make the controlled process index operate more stable.By improving the operation and control level of equipment,reduce the labour intensity of operating workers,and achieve good social benefits.The integration of APC and DCS implements the operator’s direct manipulation of advanced controllers.