Model predictive control design and performance analysis of a pasteurization process plant

Pasteurization is a process of heating food products at a specified temperature to eliminate micro bacteria contaminants that may endanger consumer health. In dairy food industries, the pasteurization process often set to achieve products' temperature between 70°C to 75°C during 15 seconds. This paper reports the development of control system for a lab scale pasteurization process plant Armfield PCT23MKII which is equipped with programmable logic controller (PLC) Allen Bradley SLC 5/02 and OPC KepServer5 real time interface. A MATLAB based model predictive control (MPC) algorithm is developed for the mini plant and its performance is compared to standard PID and PID cascade controllers. Based on the experimental results, it was found that the developed MPC was capable of eliminating over shoot, achieve a fast settling time with an integral absolute error (IAE) of 3884 and energy consumption 613.2 kJ. In comparison with both the PID and PID cascade controllers, it is also shown that the proposed MPC algorithm has better performance in terms of adapting to load change and mitigating disturbances.