| This paper based on the actual industrial project waste organic solvent recovery control system as the background, it is based on SIMATIC PCS7, combined with user’s request to the function of the system, started from the PCS7 system hardware and software design and network structure, completed system hardware and software configuration, network configuration and program design automation, adopted a good open Win CC PC software to make the monitor screen. at the same time, used advanced predictive PI algorithm theory knowledge to design distillation equipment control, thus put forward the improvement plan.Waste organic solvent recovery distillation is a very important link in the process of chemical production, its purpose is to separate in the mixed solvent, the purity of reach regulation, can be used as a secondary products. The essence of the distillation process is forcing mixture of gas and liquid two phase as the reverse flow in the tower body, using the mixture of various components have different volatility, in the process of contact with each other, turn into gas phase, light component in the liquid phase and gas phase in the specific provisions of restructuring gradually into the liquid phase, so as to realize the separation of liquid mixtures. General distillation device by distillation column and reboiler, condenser, reflux drum equipment, etc. Using the control algorithm, to control the heating steam of reboiler, to maintain the rectification tower of gas phase space velocity, realize the normal operation of the distillation column.Main content of this paper is as follows:1. This paper introduces the production technology of waste organic solvent recovery control and the overall requirements. Details the framework of the whole system structure and the main equipment, as well as mentioned in the PCS7 control loop and the process control system modeling.2. In view of hardware and software design of the project, this paper introduces the PCS7 overall design thinking. Further from the beginning of the hardware design, according to the requirements of the project actual hardware configuration selection, I/O list, use hardware configuration function to the hardware design project, the field devices one-to-one correspondence with the configuration of the hardware configuration, design of network communication, all automatic control station(AS), engineer station, operator station server and client are connected by Ethernet switch, AS station,engineer station and server via a switch of the System Bus, server, engineer station and the operator of standing between Terminal Bus, forming the so-called double network structure. Last detail project system software design, from the choice of basic control circuits, third party communication, the upper unit state using Microsoft cooperate with Siemens Win CC system development, it’s simple and concise picture of the entire functionality for operator control and monitoring production process more convenient.3. The whole system is achieved in the design of software and hardware combined with PCS7, control algorithm and the controller has played a very key role. Analyzed the project of PID control and cascade control two kinds of typical control strategy, the Simulink analysis was carried out on the cascade control, and discussed in detail.4. For most of PCS7 control strategy using classical control, this paper uses the advanced control algorithm to control, introduces the advanced predictive PI control algorithm. Based on PID algorithm and the development of the predictive control, introduces the current situation of the development of predictive PI algorithm and the basic principle. This paper uses the advanced predictive PI algorithm to control the reboiler heating steam, and put forward predictive PI dynamic decoupling control of distillation tower, implement the controller model, get the specific parameters of the controller, and use the Simulink validation of advanced control algorithms and the systems. |
PDF Full Text Request