Design And Realization Of Control System Of Batch Process Based On PCS7

The batch process has been widely applied in many industries such as the fine chemical industry, the catalyst preparation and the dye intermediates preparation, etc. The batch process is one of the controlled objects that have the features such as long time lag, nonlinearity and the difficulties in process modeling, which make it difficult to be controlled by traditional algorithm to obtain satisfying controlling effect. The control to batch process has been considered as a difficult and challenging issue in the chemical industry.In this dissertation, a batch process in Multifunction Process and Control Experiment System (MPCE) is chosen as the controlled object, which is a chemical reaction process produces thiofide. It is considered as the most complex and representative batch process because of the characters such as the competition between main and assistant reaction, giving out the heat rapidly and pressure changing quickly along with temperature.The author deeply analyzes the manufacture process, the control task and the control difficulties. Based on the principle of rationality and feasibility, a whole control scheme is proposed. Besides, two control strategies are designed to control temperature in calefactive stage. One of the control strategies is cascade control made up of expert controller and PID controller. The other is fuzzy PID control.Based on SIMATIC PCS 7, a control system of batch process is build. This dissertation introduces the hardware and software platform of the designed control system, gives the overall network framework of the system and configures the system hardware and network. The control scheme is realized by using programming software SFC,CFC and SCL to complete the software configuration, such as the functions of the temperature controlling, the sequence control and the security control. The configuration of monitoring system is realized by using the configuration software WINCC, through which to complete the windows configuration, the distributions of the archiving systems and information systems, so the functions of real-time control and adjustment, monitoring of safety running and management are realized.The running result shows that this system can control effectively and reliably.It meets the control requirements well and brings much economic benefits.