@techreport{AndratschkeCeulloDawoudetal., author = {Andratschke, Christin and Ceullo, Laura and Dawoud, Belal and Draeger, Susan and Gerdes, Thorsten and Giebisch, Matthias and Grießhammer, Peter and Haas, Katharina and Haug, Sonja and Helling, Dominik and Kominis, Lena and Lang, Christian and Malz, Sebastian and Melzl, Johannes and Michlbauer, David and M{\"u}hlberger, Thomas and Nagl, Klaus and Preis, Michael and Rechenauer, Christian and Riederer, Michael and R{\"u}ckerl, Alexander and Saller, Tobias and Schnabl, Andreas and Stadler, Michael and Steffens, Oliver and Steininger, Peter and Stelzl, Andr{\´e} and Toutouly, Lovis and Trauner, Matthias and Vetter, Miriam and Walbrunn, Johannes and Weber, Karsten and Zielbauer, Lukas}, title = {MAGGIE: Energetische Modernisierung des genossenschaftlichen Wohnquartiers Margaretenau in Regensburg}, editor = {Steffens, Oliver}, address = {Regensburg}, isbn = {978-3-96256-100-0}, doi = {10.35096/othr/pub-5335}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-53354}, pages = {XVIII, 462 S.}, abstract = {Im Projekt MAGGIE wurden f{\"u}r das genossenschaftliche historische Stadtquartier „Margaretenau" in Regensburg Musterl{\"o}sungen f{\"u}r energieoptimiertes Wohnen mit innovativen Wandaufbauten aus solaraktiven Baukonstruktionen und einer vorhersagebasierten Versorgungstechnologie erforscht. Dazu wurde ein bestehendes Wohngeb{\"a}ude als Demonstrations- und Versuchsobjekt mit einem neuartigen, besonders effizienten Hybridsystem aus W{\"a}rmepumpentechnologie und Kraft- W{\"a}rme-Kopplung ausgestattet und untersucht, erg{\"a}nzt durch eine dynamische W{\"a}rmelogistik zur Verringerung von Verteilungsverlusten. Das System wurde durch ein neu entwickeltes, allgemein einsetzbares Planungs-, Optimierungs- und Steuerungstool ausgelegt und im Betrieb geregelt. Die in Echtzeit laufende Nachoptimierung des Systems w{\"a}hrend des Betriebs greift dabei auf reale Monitoringdaten zu. Die Einbindung von Nutzerbedarfsprofilen, Stromb{\"o}rse und Wetterdaten in die Steuerung gestattet einen dynamischen und perspektivischen Anlagenbetrieb zur Maximierung der Solar- und Umweltw{\"a}rme-Anteile der Energieversorgung und leistet damit einen wirksamen Beitrag zu einem emissionsarmen, klimafreundlichen Geb{\"a}udebetrieb. F{\"u}r die denkmalgerechte Modernisierung der historischen Fassaden wurde ein solaraktives und solaradaptives Außenputzsystem entwickelt und in der Realit{\"a}t getestet. Am Bestandsgeb{\"a}ude kam anstelle eines W{\"a}rmed{\"a}mmverbundsystems ein innovativer D{\"a}mmputz mit Mikrohohlglaskugeln zum Einsatz. Die Skalierbarkeit erlaubt eine abschnittsweise Modernisierung des gesamten Ensembles {\"u}ber mehrere Jahre. Durch die hohe Energieeffizienz wird die Warmmiete f{\"u}r die Bewohner der genossenschaftlichen Siedlung durch die Modernisierungsmaßnahmen nicht erh{\"o}ht, so dass auch nach der Modernisierung ein bezahlbares Wohnen sichergestellt wird.}, subject = {Altbaumodernisierung}, language = {de} } @inproceedings{Haumer, author = {Haumer, Anton}, title = {Modeling and Control Design of an Educational Magnetic Levitation System}, series = {Proceedings of the 15th International Modelica Conference 2023, Aachen, October 9-11}, booktitle = {Proceedings of the 15th International Modelica Conference 2023, Aachen, October 9-11}, publisher = {Link{\"o}ping University Electronic Press}, issn = {1650-3686}, doi = {10.3384/ecp204763}, abstract = {A magnetic levitation system is a perfect educational example of a nonlinear unstable system. Only with suitable control, a small permanent magnet can be held floating stable below a coil. After modeling and simulation of the system, control of the system can be developed. At the end, the control algorithm can be coded on a microcontroller, connected to a pilot plant.}, language = {en} } @article{SelmairMaurerLaietal., author = {Selmair, Maximilian and Maurer, Tobias and Lai, Chun-Han and Grant, David}, title = {Enhancing the efficiency of charging \& parking processes for Autonomous Mobile Robot fleets}, series = {Journal of Power Sources}, volume = {521}, journal = {Journal of Power Sources}, number = {3}, publisher = {Elsevier}, doi = {10.1016/j.jpowsour.2021.230894}, abstract = {The allocation of tasks to Autonomous Mobile Robots in a production setting in combination with the most efficient parking and charging processes are the focus of this paper. This study presents a simulative evaluation of the theoretical allocation methods developed in Selmair and Maurer (2020) combined with either hard or dynamic availability rules to ascertain the most efficient parameters of an Autonomous Mobile Robot System. In order to quantify this efficiency, the following Key Performance Indicator (KPI) were considered: number of delayed orders, driven fleet metres and the percentage of available Autonomous Mobile Robot as determined by their state of charge. Additionally, as an alternative energy source, a fast-charging battery developed by Battery Streak Inc. was included in this study. The results show that, in comparison to a conventional and commonly used trivial strategy, our developed strategies provide superior results in terms of the relevant KPI.}, language = {en} } @article{WalterSchwanzerSteineretal., author = {Walter, Stefanie and Schwanzer, Peter and Steiner, Carsten and Hagen, Gunter and Rabl, Hans-Peter and Dietrich, Markus and Moos, Ralf}, title = {Mixing Rules for an Exact Determination of the Dielectric Properties of Engine Soot Using the Microwave Cavity Perturbation Method and Its Application in Gasoline Particulate Filters}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {9}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/s22093311}, pages = {1 -- 17}, abstract = {In recent years, particulate filters have become mandatory in almost all gasoline-powered vehicles to comply with emission standards regarding particulate number. In contrast to diesel applications, monitoring gasoline particulate filters (GPFs) by differential pressure sensors is challenging due to lower soot masses to be deposited in the GPFs. A different approach to determine the soot loading of GPFs is a radio frequency-based sensor (RF sensor). To facilitate sensor development, in previous work, a simulation model was created to determine the RF signal at arbitrary engine operating points. To ensure accuracy, the exact dielectric properties of the soot need to be known. This work has shown how small samples of soot-loaded filter are sufficient to determine the dielectric properties of soot itself using the microwave cavity perturbation method. For this purpose, mixing rules were determined through simulation and measurement, allowing the air and substrate fraction of the sample to be considered. Due to the different geometry of filter substrates compared to crushed soot samples, a different mixing rule had to be derived to calculate the effective filter properties required for the simulation model. The accuracy of the determined mixing rules and the underlying simulation model could be verified by comparative measurements on an engine test bench.}, language = {en} } @article{MikhaeilGadererDawoud, author = {Mikhaeil, Makram and Gaderer, Matthias and Dawoud, Belal}, title = {Experimental Investigation of the Adsorption and Desorption Kinetics on an Open-Structured Asymmetric Plate Heat Exchanger; Matching Between Small-Scale and Full-Scale Results}, series = {Frontiers in Energy Research}, volume = {10}, journal = {Frontiers in Energy Research}, publisher = {Frontiers}, doi = {10.3389/fenrg.2022.818486}, pages = {1 -- 15}, abstract = {This paper introduces the results of an experimental study on the adsorption and desorption kinetics of a commercially available, open-structured asymmetric plate heat exchanger adapted to act as an adsorber/desorber for the application in adsorption heat transformation processes. In addition, a volumetric large temperature jump (V-LTJ) kinetic setup was applied to measure the adsorption and desorption kinetics of a small-scale adsorbent sample prepared dedicatedly to be representative for the adsorbent domain inside the investigated adsorber plate heat exchanger (APHE). All kinetic results of the small-scale adsorbent sample and the APHE were fitted into exponential forms with a single characteristic time constant (τ) with a coefficient of determination (R2) better than 0.9531. A very good matching between the small-scale and full-scale adsorption kinetic measurements was obtained, with an average relative deviation of 12.3\% in the obtained τ-values. In addition, the kinetic data of the small-scale adsorbent sample were utilized for estimating the expected specific instantaneous and moving average powers of the evaporator/condenser heat exchanger. The average relative deviation (ARD) between the moving average specific evaporator powers obtained from the small-scale and the full-scale measurements amounts between 5.4 and 15.1\%.}, language = {en} } @unpublished{GaertnerMarxSchubachGadereretal., author = {G{\"a}rtner, Sebastian and Marx-Schubach, Thomas and Gaderer, Matthias and Schmitz, Gerhard and Sterner, Michael}, title = {Introduction of an Innovative Energy Concept for low Emission Glass Melting based on Carbon Capture and Usage}, doi = {10.31224/2642}, abstract = {Due to the very high fossil energy demand, the glass industry is looking for innovative approaches for the reduction of CO2 emissions and the integration of renewable energy sources. In this paper, we present a novel power-to-gas concept, which has no impact on established melting processes and discuss it for this purpose. A special focus is set on the required CO2 capture from typical flue gases in the glass industry, as this process has not been investigated in detail yet. We used a process simulation approach to investigate post-combustion CO2 capture by absorption processes, followed by a techno-economic evaluation. Our investigations found the designed CO2 capture plant to be approx. 400 times smaller than absorption based CO2 separation processes for conventional power plants. Due to the many options for waste heat utilization, the waste heat required for CO2 desorption can be generated in a particularly efficient and cost-effective way. The resulting CO2 avoidance costs range between 41-42 €/t CO2, depending on waste heat utilization for desorption, and thus offer a cost effective way of CO2 removal from glass industry melting processes. These costs are well below the values of 50-65 €/t CO2 described so far for comparable industrial applications. In addition, we describe optimization options, like solvent and process improvements, to enable further cost reductions. These results motivate further research and development on the overall process presented in this work.}, language = {en} } @article{KaulBoellmannThemaetal., author = {Kaul, Anja and Boellmann, Andrea and Thema, Martin and Kalb, Larissa and Stoeckl, Richard and Huber, Harald and Sterner, Michael and Bellack, Annett}, title = {Combining a robust thermophilic methanogen and packing material with high liquid hold-up to optimize biological methanation in trickle-bed reactors}, series = {Bioresource technology}, volume = {345}, journal = {Bioresource technology}, publisher = {Elsevier}, doi = {10.1016/j.biortech.2021.126524}, abstract = {The hydrogen gas-to-liquid mass transfer is the limiting factor in biological methanation. In trickle-bed reactors, mass transfer can be increased by high flow velocities in the liquid phase, by adding a packing material with high liquid hold-up or by using methanogenic archaea with a high methane productivity. This study developed a polyphasic approach to address all methods at once. Various methanogenic strains and packings were investigated from a microbial and hydrodynamic perspective. Analyzing the ability to produce high-quality methane and to form biofilms, pure cultures of Methanothermobacter performed better than those of the genus Methanothermococcus. Liquid and static hold-up of a packing material and its capability to facilitate attachment was not attributable to a single property. Consequently, it is recommended to carefully match organism and packing for optimized performance of trickle-bed reactors. The ideal combination for the ORBIT system was identified as Methanothermobacter thermoautotrophicus IM5 and DuraTop (R).}, language = {en} } @inproceedings{WagnerAlAbadiBuchner, author = {Wagner, Marcus and Al-Abadi, Ali and Buchner, Stefan}, title = {A Numerical-Based Model to Determine the Resonance of the Steel Cores of Transformers}, series = {ARWtr 2022 proceedings : 2022 7th Advanced Research Workshop on Transformers (ARWtr), October (23)24-26, 2022, Baiona, Spain}, booktitle = {ARWtr 2022 proceedings : 2022 7th Advanced Research Workshop on Transformers (ARWtr), October (23)24-26, 2022, Baiona, Spain}, editor = {L{\´o}pez-Fern{\´a}ndez, Xose M.,}, publisher = {IEEE}, isbn = {978-84-09-45157-9}, doi = {https://doi.org/10.23919/ARWtr54586.2022.9959938}, pages = {36 -- 41}, abstract = {The laminated steel core of transformers is one of the main sources of the generated sound, as it is excited by different electromagnetic effects during its normal operation. If the core is excited in its eigenfrequencies, the sound generated by a transformer will increase significantly. Therefore, knowledge of the core's eigenmodes and -frequencies in an early design stage can decrease expenses by avoiding costly modifications that might be required to avoid the sound levels exceeding the specified values after the final factory acceptance test. The current study focuses on developing a core resonance model to determine the eigenmodes and -frequencies of a transformer core. The core's geometry was simplified to a connected-beam structure and a numerical-based approach was applied. The accuracy of the developed model was validated against finite element method (FEM), using ANSYS on a reference core model.}, language = {en} } @inproceedings{WagnerLehrerFrankeetal., author = {Wagner, Marcus and Lehrer, Tobias and Franke, Markus and Al-Abadi, Ali and Gamil, Ahmed}, title = {A Tank Resonance Model for Power Transformers}, series = {ARWtr 2022 proceedings, 2022 7th Advanced Research Workshop on Transformers (ARWtr): October (23)24-26, 2022, Baiona, Spain}, booktitle = {ARWtr 2022 proceedings, 2022 7th Advanced Research Workshop on Transformers (ARWtr): October (23)24-26, 2022, Baiona, Spain}, publisher = {IEEE}, organization = {Institute of Electrical and Electronics Engineers (IEEE)}, doi = {10.23919/ARWtr54586.2022.9959917}, pages = {7 -- 12}, abstract = {During the factory acceptance test, the sound levels are measured. If the measured sound levels exceed pre-specified values, modifications on the transformer's active part and/or tank need to be conducted. Tank resonance, if occurs, at twice main power frequency and its higher harmonics is one of the main reasons of amplifying the generated sound levels. Therefore, it is preferable to know already in the design stage about the occurrence of the tank resonance and propose reliable tank solutions. The current study presents a newly developed model for calculating the mode shapes and its corresponding eigenfrequencies of the tank.}, language = {en} } @inproceedings{RauchBruecklEngel, author = {Rauch, Johannes and Br{\"u}ckl, Oliver and Engel, Bernd}, title = {Analysis and optimization of the steady state voltage deviation demand for reactive power planning using installed reactive power sources}, series = {NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg}, booktitle = {NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg}, editor = {Schulz, Detlef}, publisher = {VDE-Verlag}, address = {Berlin}, isbn = {978-3-8007-5983-5}, issn = {2510-6902}, pages = {175 -- 182}, abstract = {The provision of reactive power is one option for maintaining the grid voltage, that is defined as an ancillary service in Germany. This paper presents an approach for determining deficient voltage deviation demands within an electrical grid for long term reactive power planning investigations. In contrast to previous approaches, which evaluate the Q-behavior of extended ward elements or grid assets, voltage deviations are analyzed bus-specifically. So further reactive power planning investigations are able to scale and optimize additional reactive power sources directly on planning voltage limits using load flow sensitivity techniques. The focus lies on the analysis of the steady state demand at base case conditions. Therefore, a grid planning process is conceptualized. An optimal power flow algorithm based on Differential Evolution is used for an optimal reactive power dispatch of installed reactive power sources, e. g. reactive power compensation systems or (renewable) energy sources to minimize the total voltage deviation according to voltage limits of Transmission System Operators planning principles. Methodological and processuals specifications as well as an application use case with an exemplary transmission system are presented in this paper.}, language = {en} }