Design And Implementation Of Control Systems Based On S7 400 Of The Evaporator

Evaporator has been widely used in the chemical industry,food,pharmaceuticaland environmental protection industries. the accurate measurement and control of theoutlet temperature is an important precondition for the purpose of green,highquality,energy saving and safe production.Therefore,research on control systerm ofthe evaporator is of great significant.In this paper,the technological process of the evaporator is analysised entirely andthe requirement of control about evaporators is proposed.The entire control schemeabout evaporators is designed baseing on the charators of the object,the reliability andfeasibility of the control plan.The control of the evaporator can be divided by the following sections:evaporatorliquid level control, the control of evaporator’s temperature,evaporator’s outlet flowcontrol,etc.Temperature control has a big delag among the sections above.Inconclusion, simple PID controllers can’t meet the control requirement.Dynamic matrixcontrol algorithm is used to design predictive controllers in the paper.Finally, the paper takes SMPT-1000advanced multi-function process control train-ing system as the object, taking Simens PCS7as the control tools to implement theevaporator control system(completing control system configuration by CFC&SFC,com-pleting screen configuration by WinCC). At the end of this paper, a comparison is presented between PID control and predictive control of evaporator’s temperature. The res-ult indicate that predictive controller has better responding speed and robustness than ordinary PID controller. In conclusion, using predictive controller is feasible.