Non-residential buildings are accountable for 11% of global energy-related CO2 emissions (United Nations Environment Programme 2018). To increase the performance in this sector, Building Energy Performance Simulation (BEPS) is one feasible approach. Therefore, there is need for reliable and fast simulation models. One feasible approach are so called Reduced Order Models (ROMs). Thus in this paper, a comparison between the results of the established BEPS tool EnergyPlus and a ROM in Modelica with a reduced number of resistances and capacities is applied at the use case of a non-residential building. A self-developed toolchain was used to create equal models for ROM and EnergyPlus based on the same Building Information Modeling (BIM) model. The comparison shows that the reduced model deviates by 10%in annual heating and cooling. To increase accuracy and decrease computational effort the zoning strategy of non-residential buildings is investigated. The investigation shows that using a suitable zoning approach can reduce the computational effort by up to 97 %.
This paper introduces the last evolution of Daccosim cosimulation environment, with Daccosim NG developed in 2018.Main features of Daccosim NG are described: enhanced Graphic User Interface and Command-Line Interface, algorithm and mechanism of co-simulation, coexecution shell, software architecture designed for both centralised and distributed architectures, aggregation of a co-simulation graph into a Matryoshka FMU, and declarative language to design large scale co-simulation graphs.A new industrial use case in simulation of energetic systems is also introduced, and first performances of Daccosim NG on multi-core architectures are analysed.
The goal is to have a flexible platform based on open standards that can be used to efficiently solve current and future engineering problems for distributed energy sources and storage systems. By basing it on a unified architecture, collaboration and efficient work flows are enabled.
Exploiting several precursor papers on specific railway modeling topics, their models have been collected and reorganized in order to propose a sound modeling framework dedicated to railway dynamics.
This paper presents a concept how a hybrid DAE of a vapor compression cycle can be initialized in steady state using the homotopy method.A simplified equation system for a vapor compression cycle is described and its computational causality explained.It is discussed how additional boundary conditions can be applied to the simplified equation system, which do not apply to the actual equation system.The robustness and CPU time for different cases is examined and discussed based on transition plots.
