The Reactor Temperature Control System

Reactor is the important equipment in the process of chemical production,the chemical reaction accompanied by phenomenon whereby heat is liberated or absorbed,having characteristics of large time delay,time-varying,nonlinear,and the complicated reaction mechanism.Traditional PID control is a control method based on process parameter,having many advantages of a simple control principle,good stability,high reliability and easy adjustment of parameters.But the design of the object depends on the precise mathematical model and bad at tuning parameter online.The mechanism of reactor is complex and every parameter changes in the reaction process,unable to establish a precise mathematical model and it can not meet the requirements of self-tuning under different conditions.So the general PID controller can not be achieved on the precise control of reactor.Fuzzy control is a rule-based language control,the precise mathematical model does not need to be established in the design and with good robustness,the effect that interference and the changes of parameters have on the control result is greatly reduced,with effective control, However,the fuzzy controller takes error or error change for input variables and this controller has fuzzy proportion-differential control role.The accuracy is not too high,with a larger steady-state error,limited adaptive ability and easy oscillation.Predictive control is an optimal control algorithm,which determines the future control role by optimization of a performance index;having advantages of low model,good robustness, applicability to the merits of digital computer control.The predictive control of computer model has a good tracking performance,and it can effectively improve system stability and eliminate the error,has significant control result for lag process,more in line with the actual industrial temperature control requirements,so it greatly improves the performance of temperature control svstem.in this paper,the characteristics and control difficulty of reactor temperature change are analyzed,and the root causes of poor accuracy for the current temperature control system is summarized,on the basis,a technology of fuzzy self-tuning PID control based on prediction is used to achieve reactor temperature control.The main idea is to use the prediction output of system model,combined with the experience of conventional PID control,using fuzzy reasoning algorithm to improve the algorithm of controller.The experimental results show that the PID control scheme,compared to the common PID control scheme,can improve the system robustness and adaptability,with a better solution to the reactor temperature control problem.This subject completes the hardware circuit design of the reactor temperature control system,the compilers and debugging of system software.Simulation and experimental study are done for fuzzy self-tuning PID control based on prediction,compared to the PID control method. the method has more stable control performance,higher reliability and the real-time performance. adaptability,robustness are significantly increased.The control result is better.