Optimization and Sliding Mode Control of Dividing-Wall Column

Abstract

The unique construction of the dividing-wall column (DWC) has the potential for both energy and capital cost conservation. A sufficiently robust control strategy is needed to handle the DWC because it is a complex multivariable system with high process nonlinearity and time lag. In this paper, the single-factor, response surface methodology (RSM), and particle swarm optimization (PSO) optimizations are applied to the DWC, and the optimal operating parameters are obtained. Then, a sliding mode control (SMC) method is proposed for DWC. Specifically, the DWC is estimated by a first-order pure lag transfer function, and the SMC controller is developed with the aid of the Interpreted MATLAB Fcn of MATLAB/Simulink. Finally, the dynamic responses of both SMC controller and proportional-integral-derivative (PID) controller are analyzed using the disturbance in the feed flow rate (F). The results show that the settling time, oscillation, and steady-state deviation of the SMC controller are less than those of the PID controller. In this way, the SMC could present a better option for control of a complex distillation process, such as the DWC.