AN OPTIMIZATION APPROACH FOR ENERGY MINIMIZATION AND TEMPERATURE CONTROL OF MILK PASTEURIZATION PLANT

Milk pasteurization is a nonlinear and multivariable dynamic system that consumed a large amount of energy when temperature is not properly controlled. it is important to control the temperature of milk pasteurization plant at minimum production capital of electricity and fuel in diary industries but the effect of disturbances in the plant has affected the objective function of the pasteurization temperature. In this paper, an Extremum seeking (ES) based Proportional Integral Derivative (PID) controller is employed to eliminate the fluctuation dynamic profile of the milk and water temperature at a given set point and achieved the desired outlet milk temperature at minimum energy cost. The modelling, numerical simulation and optimization technique of ES based PID controller were formulated to minimized the consumption rate of Liquefied petroleum gas (LPG) supplied to the burner feed rate of boiler to produce steam water at the heating stage of milk pasteurization plant. The model equation of each operational units of milk pasteurization plant was developed based on general mass and energy balance principle. The simulation of the developed milk pasteurization plant model-based ESPID controller was done using MATLAB R2021a. The parameters of the PID controller are tuned using ES. The comparative analysis with PID controller and without controller was carried out to validate the observed results of the simulation model with ES-PID controller. The performance evaluation was achieved graphically and numerically analyzed in terms of rise time, settling time, peak time and percentage overshoot as the performance metrics. Hence, the developed ES-PID controller can be of significance interest to dairy industries as it gave better results compared with the conventional PID controller