AixLib: an open-source Modelica library for compound building energy systems from component to district level with automated quality management

Maier, Laura; Jansen, David; Wüllhorst, Fabian; Kremer, Martin; Kümpel, Alexander; Blacha, Tobias; Müller, Dirk

doi:10.1080/19401493.2023.2250521

Cited by 8 publications

(7 citation statements)

References 60 publications

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“…AixLib is an open-source Modelica library for the simulation of energy systems on building to district scale developed at RWTH Aachen University [31][32][33]. It extends the Modelica IBPSA Library and has a section DistrictHeatingCooling with models specialized for the simulation of DHN.…”

Section: Aixlibmentioning

confidence: 99%

Heat Consumer Model for Robust and Fast Simulations of District Heating Networks Using Modelica

Zipplies,

Orozaliev,

Jordan

et al. 2024

Electronics

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Dynamic thermo-hydraulic simulations of district heating networks (DHN) are essential to investigate novel concepts for their sustainable design and operation. To develop solutions for a particular case study, numerous long-term simulations are required. Therefore, computational effort for simulation is critical. Heat consumers (HC) are numerous and determine the dynamics of mass flows and return temperatures in the DHN. Thus, the way in which HCs are modeled has significant impact on the computational effort and the results of the simulation. This article presents a novel Modelica-based model for HCs that builds on an existing simplified modeling approach (open-loop design). The calculation of mass flow and return temperature is improved in terms of robustness, plausible behavior and low computational effort. In particular, the model reacts to limited differential pressure and supply temperatures to ensure plausible behavior across all operating conditions, including undersupply situations. The model is successfully tested using an exemplary DHN. The analysis proves that the HC model itself requires little time to simulate. Nevertheless, it significantly influences the simulation time for the entire DHN, which varies by a factor of five for the investigated system depending on the HC model. Fast dynamics, including a bypass in the model and correction of deviations between set point and actual heat load increase the simulation time, so users should sensibly choose how to use these options. HC models triggering many state events result in high computational effort. Compared to other simple HC models, the proposed model produces more plausible results while maintaining at least equal simulation performance (for models without bypass) or even improving it (for models with bypass, CPU time is reduced by at least 35%).

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Section: Aixlibmentioning

confidence: 99%

Heat Consumer Model for Robust and Fast Simulations of District Heating Networks Using Modelica

Zipplies,

Orozaliev,

Jordan

et al. 2024

Electronics

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“…The development of MoCITempGen took place on the basis of AixLib (Maier et al 2023). A brief explanation of the application of MoCITempGen at AixLib has already been given in this previous paper.…”

Section: Aixlibmentioning

confidence: 99%

“…For instance, the wellknown modelica-buildings (Wetter et al 2014) library has an extensive CI structure based on the BuildingsPy Python library (Wetter 2019). Over the past few years, we too have built a comprehensive CI structure for the AixLib library that partially reuses functions from BuildingsPy and combines them with self developed functionality (Maier et al 2023). However, these approaches are tailored to the corresponding libraries and their application to other Modelica libraries is not straightforward.…”

Section: Introductionmentioning

confidence: 99%

MoCITempGen: Modelica Continuous Integration Template Generator

Jansen,

Wüllhorst,

Hinrichs

et al. 2023

Linköping Electronic Conference Proceedings

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Modelica enables an object-oriented approach to model complex systems in product development and research, and, thus, the development of various model libraries. Library development requires collaborative development in a team of multiple developers. A typical challenge in collaborative development, especially in the area of open source, is to create models of uniform quality despite different levels of knowledge among developers. Techniques such as Continuous Integration (CI) from the field of software development, can help to solve these challenges. However, the adaptation of CI for the area of Modelica model development currently requires the manual creation of complex templates and a high degree of manual configuration. In this paper we present MoCITempGen, an open source tool for automated generation of CI structures for the widely used modeling language Modelica. The tool is succesfully applied on two Modelica libraries to demonstrate the functionality.

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“…In the current version, bim2sim holds two Plugins for Modelica HVAC export: AixLib and HKESim. AixLib is an open source Modelica library that holds simulation models for HVAC simulation as well as BPS and is based on the IBPSA core library [20]. HKESim is a non-public library used by the ROM Technik company, who significantly contributed to the creation of bim2sim.…”

Section: Export Librariesmentioning

confidence: 99%

BIM2SIM for Hydraulic-Focussed Energy Simulations – Automatic Generation of Pre Parametrized Simulation Models

Jansen

Hering

Müller

2023

36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 20

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The construction of energy-efficient buildings is one of the most important measures to reduce the impact of buildings on our environment. The dynamic simulation of the energy systems of these buildings can improve the design and performance and thus reduce the emissions that impact the environment. However, the process of creating models for dynamic simulations is time-consuming and error-prone. By using already existing digital models from the planning process the process of model generation can partially be automated. This paper presents the tool bim2sim and its underlying methodology for the application of automatic model generation for dynamic hydraulic energy system simulation with Modelica based in Building Information Modeling models with the open exchange format IFC. The tool is applied to the use case of an example energy system and a manual comparison modeling is performed for the energy system in Modelica. The comparison shows that automatic model generation saves a significant amount of time even for comparatively simple systems.

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AixLib: an open-source Modelica library for compound building energy systems from component to district level with automated quality management

Cited by 8 publications

References 60 publications

Heat Consumer Model for Robust and Fast Simulations of District Heating Networks Using Modelica

Heat Consumer Model for Robust and Fast Simulations of District Heating Networks Using Modelica

MoCITempGen: Modelica Continuous Integration Template Generator

BIM2SIM for Hydraulic-Focussed Energy Simulations – Automatic Generation of Pre Parametrized Simulation Models

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