Realization Of Temperature Control Algorithm Based On Reactor With Big Delay And Nonlinearity

Reactor is a kind of important reaction vessel in chemical industry, which is dif-ficult to control. Reactor is complex inside and influenced by reaction material species and density severely with endothermic and exothermic processes. Traditional control algorithm cannot control reactor temperature effectively, and from the view of control, reactor is one of the most difficult processes.Take Reactor temperature as the controlled variable, and based on the analysis of the energy transport of reactor work process, the mathematical model of reactor tem-perature is obtained. By analyzing the step response of reactor temperature, the para-meters of reactor temperature model is measured. For traditional control theory is not suitable for system with great inertia and pure delay, combination of expert PID and feed forward-Smith control algorithm is proposed and modeled in MAT-LAB/Simulink to simulate. Simulation and the latter experiments results show the al-gorithm is effective to control system with great inertia and pure delay.Based on MCU C8051F020, the reactor control system is designed, which is composed of upper computer and lower controller, using RS-485 to implement serial communication. The lower controller is the core of the whole system, which actually runs control theory in controlling reactor temperature, whose functions are of key pressing, LCD displaying, memory expanding, temperature measuring, algorithm op-eration, tempering voltage output and serial communication with upper computer.etc; upper computer software is written by VB6.0, whose functions are of sending in-structs to controller, receiving temperature date to display and store, database man-agement and so on. With upper computer, a great deal of temperature data can be saved and by analyzing these data, effects of the control theory are shown directly. Combined work of upper and lower computer makes man-machine interaction intelli-gent. Then traditional PID control algorithm and expert PID and feed forward-Smith control algorithm are used respectively in the reactor control system to control reactor temperature, and upper computer shows these experimental data in graph. Experi- mental results show that combination of expert PID and feed forward-Smith control algorithm is efficient to control reactor temperature, quickly and accurately.