Development of a dynamics model and the study on the influence of industrial constraints on the dynamic behavior of a PID-controlled and robust MPC-controlled hybrid heat-integrated distillation system with heat and mass exchanger

The dynamic model of the apparatus used for thermal rectification of mixtures was developed, where in a channel-type exchanger the thermal separation of substances is accompanied by diaphragm heat exchange. The behavior of a PID-Controlled and Tube MPC-controlled Hybrid Heat-Integrated Distillation System (HHIDiS) with a Heat and Mass Exchanger (HME) unit is simulated using Simulink/MATLAB and the influence of industrial constraints (grow up of deposits on the heat transfer surface or hold up of liquid inside the channel of exchanger) on specific indices of quality of operation is investigated. According to the obtained results, the authors observed that when the thermal resistance of fouling and/or hold up of liquid is increased, the thermal inertia of HME, condenser and reboiler is changed, leading to changes in the dynamic behaviour of PID-control and robust MPC-control loops. Such changes were detected by studying the closed-loop HHIDiS system responses simulated at the different stages of fouling build-up and hold up of liquid.The results were generated within:the NCN OPUS research project entitled "Experimental study and numerical simulations of counter-current two-phase flow in parallel channels with simultaneous diaphragm heat exchange and thermal separation of substances".the NCN MINIATURA research project entitled “Study of the Robust MPC and PID control for the dynamic model of the integrated plate apparatus for thermal separation of substances with simultaneous diaphragm heat regeneration subjected to industrial constraints”.