Model of three-tank liquid system with air bubbles in pipes

Abstract

This paper describes the process of development of a mathematical model of three-tank liquid system. The DTS200 Three-Tank-System was used as a real equipment to be modelled. This system consists of three cylindrical water tanks, six valves, two water pumps, pipes and water reservoir. The model based on ideal properties of individual components is relatively simple and is derivation using differential equations is straightforward. But the model proposed in this paper incorporates real properties and behaviour of individual parts. The main difference between ideal three-tank system and this real plant consists in presence of air bubbles in pipes. Flooding the bubbles out leads to dramatic change of plant parameters and thus the system can be considered as multi-model or multi-parametric. The effect of air bubbles is studied static. The proposed model was verified by comparison with the real DTS200 system. Described problems, which occurred during model development, are general and similar problems occur in most model-development processes.