Research On Temperature Internal Model Decoupling Control System Of Alcohol Distillation Column

Distillation is an important link in the production process of chemical industry,which has a very important impact on the production of alcohol in the alcohol distillation column.Due to the unstable temperature coupling in the tower,the output of alcohol is impure or less,which directly affects the output and quality of alcohol in the plant.As a multi input and multi output object,the distillation tower has complex internal mechanism,more control requirements and more control difficulties.The research on temperature control system of alcohol distillation column is of great significance to solve the temperature coupling phenomenon and increase alcohol output.Based on the research background of the distillation tower of COFCO bio chemical energy(Zhaodong)Co.,Ltd.,the temperature control system of the distillation tower is taken as the research object.Through the analysis of its process,the top outlet temperature and the bottom outlet temperature of the distillation tower are taken as the controlled objects.Due to the complex internal mechanism of the distillation process,there are many control requirements,and the controlled objects are nonlinear,large lag and strong It is difficult to build a precise mathematical model due to the characteristics of coupling.Therefore,the approximate mathematical model of the distillation column is established firstly,and the coupling degree of its temperature control system is analyzed.Then,the temperature cascade control system of the top tower and the kettle of the distillation column is simulated,and the temperature of the control system shows a strong coupling phenomenon.Therefore,the feedforward decoupling control method is adopted to decouple the temperature at both ends of the control system,and the results show that the control effect is obvious.Finally,the system with uncertain model is solved by internal model decoupling.The results show that the system has good stability and decoupling effect.According to the existing conditions of the laboratory,the experimental system is used as the controller and temperature object simulation unit of the system,and the single loop control module and Decoupling module are designed to realize the internal model decoupling control of temperature.Then,the monitoring configuration software is used as the upper computer monitoring configuration software of the control system to realize the real-time display of the acquisition data and the control interface,and to complete the recording of the acquisition data.The results show that the operation is stable on the experimental platform,and the decoupling effect is significant,which achieves theexpected effect.It is applied in the actual distillation tower and tested,showing good stability and robustness,and strong decoupling ability.