Research On Terminal Sliding Mode Control Of Interconnected Continuous Stirred Tank Reactors

Continuous stirred tank reactor(CSTR)is a complex chemical reactor,which is widely used in petrochemicals,biological fermentation,and chemical pharmaceutical industries for its advantages of low investment cost,strong heat exchange capacity,and stable product quality.It is an effective means of increasing production efficiency and ensuring product quality by precise control of reactor temperature and concentration.In actual industrial production,CSTR often exists in the form of interconnection(parallel connection,series connection,etc.).On the one hand,parallel connection of devices can effectively expand production capacity and ensure product consistency.The series connection of devices can effectively reduce backmixing and increase conversion rate.On the other hand,The mechanism of this type of equipment is characterized by strong non-linearity,multivariable coupling,etc.The interconnected system formed by the interconnection increases the difficulty of control,and it is difficult to obtain a good control effect by conventional techniques.This paper aims at this situation,based on a single CSTR,establishes a multi-pot parallel and series model,and adopts advanced control methods for controller design research.First,three sliding mode controllers are designed for a single CSTR system under certain assumptions,which there are no model uncertainties,stable bounded environmental disturbances,system temperature signals and concentration signals that can be measured and so on.The stability of the control systems are proved by using Lyapunov method,Simulation experiments are performed using MATLAB to verify the feasibility and effectiveness of the three methods,and selecting the terminal sliding mode control scheme with the best control performance by comparative analysis.Then,according to the uniqueness of the interconnected system,the synchronous control theory is proposed,that is,the synchronization process of each subsystem is maintained,and combined with the terminal sliding mode control scheme,it is applied to the parallel CSTR system and the series CSTR system,respectively.Simulation experiments show that the terminal sliding mode controller based on synchronization strategy can effectively handle the control problem of interconnected CSTR system.Finally,aiming at the characteristics that the concentration is difficult to measure in the actual process,an sliding-mode observer with filtering capability is designed.,through the state estimation of the unknown concentration signal,then using the measured temperature signal and the estimated concentration signal to carry out the terminal sliding mode controller design,the MATLAB simulation results show that the designed based on sliding mode observation The terminal sliding mode controller of the device can realize the effective control of the interconnected CSTR system,which successfully solving the problem that the system concentration signal is difficult to measure accurately.