Systematic modelling of flow and pressure distribution in a complex tank

This paper proposes a systematic modelling approach for flow and pressure distribution in dynamic plants. We describe a python-based software tool for design, initiation and simulation of custom models for tanks with extensive piping. The method is illustrated on a generic example, which describes the hydraulic behaviour of mixing and storage tanks as well as stirred tank reactors. The model design starts with the plant being abstracted into a topology that allows for comprehensive and precise mathematical assessment of the fundamental processes involved. The model topology is split into a dynamic and an event-dynamic one to depict the mass and pressure distribution in one concise model although both are magnitudes apart on the time scale. Subsequently, the plant's behaviour can be assessed by only a handful of algebraic equations from an ontology, covering the entirety of physical concepts, state derivatives, and conservation principles. Due to this ontology-based approach and its implementation in a largely automated modelling tool, most of the common drawbacks in equation-oriented modelling can be circumvented, thus enabling rapid, reliable, and accessible model design.