Papers by David Jansen

Title:	A Modular Model of Reversible Heat Pumps and Chillers for System Applications
Authors:	Fabian Wüllhorst, David Jansen, Philipp Mehrfeld and Dirk Müller
Abstract:	Vapour compression machines such as heat pumps and chillers are vital for achieving climate goals. Efficiency of both depend mostly on system integration. In order to simulate coupled energy systems, fast and stable simulation models are required. Hence, we implement an open-source model for reversible vapour compression machines. The black-box based refrigeration cycle is replaceable, additional inertia and losses are optional. Furthermore, we model relevant safety controls of vapour compression machines. To show validity of the presented approach, we first calibrate two different black-box models onto measured heat pump data. The table-based model fits both measured temperature and power with minimal calibration effort. Second, we show influences of different model options onto coupled building performance simulations. Computation time increases up to 50 % when enabling all model options. Simultaneously, seasonal efficiency decreases by up to 23 % when modeling all safety controls.
Keywords:	Heat Pump, Chiller, Modular Model
Paper:	full paper / library
Bibtex:	@InProceedings{modelica.org:Wullhorst:2021, title = "{A Modular Model of Reversible Heat Pumps and Chillers for System Applications}", author = {Fabian W\"ullhorst and David Jansen and Philipp Mehrfeld and Dirk M\"uller}, pages = {561--568}, doi = {10.3384/ecp21181561}, booktitle = {Proceedings of the 14th International Modelica Conference}, location = {Link\"oping, Sweden}, editor = {Martin Sj\"olund and Lena Buffoni and Adrian Pop and Lennart Ochel}, isbn = {978-91-7929-027-6}, issn = {1650-3740}, month = sep, series = {Link\"oping Electronic Conference Proceedings}, number = {181}, publisher = {Modelica Association and Link\"oping University Electronic Press}, year = {2021} }

Title:	Examination of Reduced Order Building Models with Different Zoning Strategies to Simulate Larger Non-Residential Buildings Based on BIM as Single Source of Truth
Authors:	David Jansen, Veronika Richter, Diego Cordoba Lopez, Philipp Mehrfeld, Jérôme Frisch, Dirk Müller and Christoph van Treeck
Abstract:	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 %.
Keywords:	BEPS, BIM, zoning, low order, RC
Paper:	full paper
Bibtex:	@InProceedings{modelica.org:Jansen:2021, title = "{Examination of Reduced Order Building Models with Different Zoning Strategies to Simulate Larger Non-Residential Buildings Based on BIM as Single Source of Truth}", author = {David Jansen and Veronika Richter and Diego Cordoba Lopez and Philipp Mehrfeld and J\'er\^ome Frisch and Dirk M\"uller and Christoph van Treeck}, pages = {665--672}, doi = {10.3384/ecp21181665}, booktitle = {Proceedings of the 14th International Modelica Conference}, location = {Link\"oping, Sweden}, editor = {Martin Sj\"olund and Lena Buffoni and Adrian Pop and Lennart Ochel}, isbn = {978-91-7929-027-6}, issn = {1650-3740}, month = sep, series = {Link\"oping Electronic Conference Proceedings}, number = {181}, publisher = {Modelica Association and Link\"oping University Electronic Press}, year = {2021} }