The Mpce Experimental Device And Tube Heat Exchanger Modeling And Control Algorithm

Heat exchanger is a kind of process equipment for heat exchange which is widely used in process industry manufacturers. Under the condition that cannot recover real industrial processes, researching on typical experiment equipment with typical object model undoubtedly is a shortcut to explore control theory and algorithm into application technology. Using the multifunction process and control experiment (MPCE) device as experiment platform and tube heat exchanger as the controlled object, researches on the modeling and control algorithm of tube heat exchanger and simulation of heat transfer process are significant to improve control effect of heat exchanger system and enhance exchange thermal efficiency.Mechanism modeling and system identification methods were adopted to develop a mathematical model of heat exchanger, and determined the relationship between outlet temperature of heat fluid and inlet flow of cold fluid of heat exchanger. Step response simulation experiments and PID control experiments were conducted to verify the accuracy of the model.Based on the relatively accurate heat exchanger model,Smith predictive control experiments and feedforward-feedback experiments were realized on MPCE device.Aiming at the heat exchanger with large time delay and time-varying characteristics, all parameters adaptive Smith predictive control algorithm (APASPCA) was researched. Based on normal Smith predictor and model reference adaptive control principle, the adaptive laws of predictor gain and time constant were designed by adopting Lyapunov function method. Meanwhile the average magnitude difference function in correlation analysis technique was introduced to realize optimal estimation of time delay of controlled object which made real-time regulation of predictor parameters match with controlled object parameters. The algorithm could ensure the control effect of Smith predictor. Simulation results showed that APASPCA could get good control effect for the controlled object with large time delay and time-varying characteristics. The algorithm had good control performance and practical value.