“hello, (Modelica) world”: Automated documentation of complex simulation models exemplified by expansion valves

Abstract

The constantly increasing computing power enables the implementation of complex simulation models. Therefore, it is possible to create more detailed models to predict system behavior more accurately. Modelica, for example, has proven great suitability in modelling complex systems, because of its high degree of reusability. However, understanding these models is quite difficult and many simulation models are poorly documented. Consequently, it is very time-consuming to retrace given model structures especially for novice. The Unified Modeling Language (UML) provides a user-friendly and graphical structure for documentation to simplify working with existing simulation models. Hence, an algorithm (ADoCSM) is developed to automatically present the structure of a Modelica simulation model in UML. This algorithm is exemplarily applied to a refrigerant circuit expansion valve model. Thereby, we contribute to an increase of simulation model quality as well as simplifying the entry in the world of Modelica. ADoCSM and the expansion valve model are freely available on GitHub:

Open‐Source vapor compression library (VCLib): Heat pump modeling for education and research

“…Class diagrams are created with the ADoCSM software developed by Vering et al [22]. For detailed documentation of the software, refer to Vering et al [22].…”

“…Since the compressor is the heart of the heat pump, three publications are dedicated to compressor modeling as gray‐box [21] or white‐box models [7,25]. In Storek et al [18] and Vering et al [22], the focus lies on the modeling approach and the expansion valve. In Vering et al [23], parts of the VCLib were presented focusing on fluid property models and heat exchangers.…”

“…Class diagrams provide new users with an overview of the system, constituting model blocks, and their relation in one glance. Class diagrams are created with the ADoCSM software developed by Vering et al [22]. For detailed documentation of the software, refer to Vering et al [22].…”

“…BauSIM 2018 Modular modeling approach, semi-empirical compressor [21] ECOS 2018 Scalable Modeling Approach, Semi-Empirical Expansion Valve [18] Modelica Conference 2019 Automated Documentation with UML and detailed expansion valve model [22] Gustav Lorentzen 2020 Open-source library, Fluid property modeling approach, heat exchangers [23] Compressors Conference 2021 Further fluid property models and detailed reciprocating compressor [7] Compressors Conference 2021 Detailed rolling type piston compressor [25] VCLib for Education and Research This paper Abbreviation: UML, unified modeling language…”

“…The equations are defined by variables, constants, or parameters, which in turn are composed of subtypes such as “Boolean,” “String,” “Integer,” or “Real.” Equations are declared in the operator section with the keyword “equation” and are thus clearly delimited. Introduced by Vering et al [22], a parser called ADoCSM (Automated Documentation of Complex Simulation Models) can be used to interpret Modelica keywords. Thus, the parser recognizes the structure of systems, models, and submodels and can rewrite them into a syntax suitable for UML.…”