Mathematical modeling for outlet temperature control in thermal storage tanks in the dairy industry

Abstract

Introduction. In Ecuador, the dairy industry at a general level represents 6.1% of the activity in agriculture and livestock in the country. Regarding the consumption of fresh unprocessed milk, it is observed that around 43.4% of production is destined for final consumption, the remaining 56% for intermediate consumption, within which the production of dairy products stands out (89% of the total consumed). Objectives. Develop the mathematical modeling of the thermal milk storage tanks of the Tunshi Experimental Station of the Polytechnic Higher School of Chimborazo in the control of the outlet temperature in the cooling and heating process. Methodology. The determination of the initial temperature of entry of the fluid to the collection center was made with a value of 19.6 °C and 8 °C for refrigeration, the heating temperature was established up to 80 °C, the process was modeled Based on the energy balance and the simulation using the Matlab program (Simulink), worked with the 875-liter capacity of a vertical-type tank in a total time of 4800 seconds. Results. For the validation, three different behaviors of curves were determined both for the energy balance of the thermal tank, its transfer function in heating the milk and the behavior of both reception, cooling and heating up to a temperature of 80 °C. Conclusion. The behavior of the curves was evidenced and verified experimentally, validating the established modeling of the two different processes.