TY - CHAP A1 - Fuhrmann, Thomas A1 - Niemetz, Michael T1 - Analysis and Improvement of Engineering Exams Toward Competence Orientation by Using an AI Chatbot T2 - Towards a Hybrid, Flexible and Socially Engaged Higher Education: Proceedings of the 26th International Conference on Interactive Collaborative Learning (ICL2023), Volume 1 N2 - ChatGPT is currently one of the most advanced general chatbots. This development leads to diverse challenges in higher education, like new forms of teaching and learning, additional exam methods, new possibilities for plagiarism, and many more topics. On the other side with the development of advanced AI tools, pure knowledge will be less and less important, and demands from industry will change toward graduates with higher competencies. Education has therefore to be changed from knowledge-centered toward competence centered. The goal of this article is to use ChatGPT for analyzing and improving the competence orientation of exams in engineering education. The authors use ChatGPT to analyze exams from different engineering subjects to evaluate the performance of this chatbot and draw conclusions about the competence orientation of the tested exams. The obtained information is used to develop ideas for increasing the competence orientation of exams. From this analysis, it is visible that ChatGPT gives good performance mainly where knowledge is tested. It has, however, much more problems with transfer questions or tasks where students need creativity or complex insights for finding new solutions. Based on this result, exams and also lectures can be optimized toward competence orientation. KW - Engineering education KW - Competence orientation KW - Exam analysis KW - AI chatbot KW - ChatGPT Y1 - 2024 SN - 9783031519789 U6 - https://doi.org/10.1007/978-3-031-51979-6_42 SN - 2367-3370 SP - 403 EP - 411 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Salama, Amgad A1 - Kou, Jisheng A1 - Dawoud, Belal A1 - Simonson, Carey T1 - A modeling approach for capillary-driven flow of a wetting fluid in a rectangular open microchannel of arbitrary axisymmetric width profile BT - Application to heat pipes JF - International Journal of Thermal Sciences N2 - Microchips are intensively used in almost all nowadays electronic devices. With the continuous advancement of our technologies, they get smaller in size than ever before. They generate high-intensity heat loads that need to be transported effectively such that they may function properly. Heat pipes have proven to be very effective in transporting relatively large heat loads from miniature components. They are of seamless structure that involves a working fluid capable of evaporation and condensation at the working temperature of the electronic chips. The working fluid is derived to move from the condenser to the evaporator via multiple microgrooves using capillary forces. It is important that the condensate reaches the evaporator at a proper rate such that no dry-out or flooding occur. In this work, we are particularly interested in the case of capillary-driven flows in rectangular microchannels. A generalized model is developed that works for axe-symmetric rectangular channels of arbitrary, moderately varying width profiles. It also accounts for any contrast of viscosity between the liquid and the vapor under isothermal conditions. The model shows to reduce to the special case of imbibition in straight and uniform microchannels, for which comparisons with experimental and modeling works show an excellent match. Cases representing linearly and quadratically varying converging/diverging width profiles have been explored. It is found that the viscosity ratio has a significant influence on the rate at which the meniscus advances. The model also negates the common practice found in the literature of using the formula developed for imbibition rates in capillary tubes for rectangular microchannels by replacing the diameter of the tube with the hydraulic diameter. It is also found that the channel profile has an influential effect on the imbibition rates. For tapered microchannels, the capillary force increases along the channel length while it decreases for diverging ones. It is interestingly demonstrated that, for quadratically tapered microchannel, the speed of the meniscus increases towards the end of the microchannel compared with linearly varying microchannels. On the other hand, for diverging microchannels, the speed of the meniscus decreases due to the increase in the cross-sectional area. Computational fluid dynamics (CFD) analysis has been conducted to provide a framework for confirmation and verification for which very good match has been established, which builds confidence in the modeling approach. KW - Microfluidics KW - Miniature devices KW - Capillary-driven flows KW - Microchannels KW - Heat pipes Y1 - 2024 U6 - https://doi.org/10.1016/j.ijthermalsci.2023.108622 SN - 1290-0729 VL - 195 PB - Elsevier ER - TY - INPR A1 - Schumm, Leon A1 - Abdel-Khalek, Hazem A1 - Brown, Tom A1 - Ueckerdt, Falko A1 - Sterner, Michael A1 - Fioriti, Davide A1 - Parzen, Max T1 - The impact of temporal hydrogen regulation on hydrogen exporters and their domestic energy transition N2 - As global demand for green hydrogen rises, potential hydrogen exporters move into the spotlight. However, the large-scale installation of on-grid hydrogen electrolysis for export can have profound impacts on domestic energy prices and energy-related emissions. Our investigation explores the interplay of hydrogen exports, domestic energy transition and temporal hydrogen regulation, employing a sector-coupled energy model in Morocco. We find substantial co-benets of domestic climate change mitigation and hydrogen exports, whereby exports can reduce domestic electricity prices while mitigation reduces hydrogen export prices. However, increasing hydrogen exports quickly in a system that is still dominated by fossil fuels can substantially raise domestic electricity prices, if green hydrogen production is not regulated. Surprisingly, temporal matching of hydrogen production lowers domestic electricity cost by up to 31% while the effect on exporters is minimal. This policy instrument can steer the welfare (re-)distribution between hydrogen exporting firms, hydrogen importers, and domestic electricity consumers and hereby increases acceptance among actors. KW - Energy Transition KW - Hydrogen regulation KW - Hydrogen export KW - Climate-neutral KW - Domestic prices KW - Hydrogen prices KW - Power-to-X Y1 - 2024 U6 - https://doi.org/10.21203/rs.3.rs-4285425/v1 PB - Research Square Platform LLC ER - TY - JOUR A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Achieving Optimal Reactive Power Compensation in Distribution Grids by Using Industrial Compensation Systems JF - Electricity N2 - This paper presents a method for integrating industrial consumers owning compensation systems as alternative reactive power sources into grid operating processes. In remuneration, they receive a market-based provision of reactive power. The aim is to analyze the potential of reactive power compensation systems of industrial companies connected to medium-voltage (10 kV–30 kV) AC grids in order to increase the reactive power ability of distribution grids. Measurement methods and reactive power potential results of six industrial companies are presented to characterize the amount and temporal availability of their reactive power potential. The presented approach for using the decentralized reactive power potential is a centralized reactive power control method and is based on optimal power flow (OPF) calculations. An optimization algorithm based on linear programming is used to coordinate a reactive power retrieval tuned to the actual demand. The influencing quantities are the current grid status (voltage and load flow capacity reserves at grid nodes and power lines) and the current reactive power potential of the reactive power sources. The compensation impact of six measured industrial companies on an exemplary medium-voltage grid is shown by an application example. KW - Blindleistung KW - Blindleistungsmanagement KW - Industriebetriebe KW - Optimal Power Flow KW - Reactive Power Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-59139 N1 - Corresponding author: Johannes Rauch VL - 4 IS - 1 SP - 78 EP - 95 PB - MDPI CY - Basel ER - TY - JOUR A1 - Li, Liwen A1 - Lange, Klaus W. T1 - Planning Principles for Integrating Community Empowerment into Zero-Net Carbon Transformation JF - smart cities N2 - The adoption of the UN 2030 Agenda and the Sustainable Development Goals is a landmark in international sustainability politics. For example, Europe has set ambitious targets to achieve 100 climate-neutral and smart cities by 2030. However, numerous case studies from different countries have found that accelerating the transition to net-zero carbon emissions is easily hampered by the lack of a coherent systems framework, and that implementation gaps remain at the community level. These barriers are often due to a lack of an adequate end-user (i.e., household) input and early planning participation. This work therefore aims to improve on conventional planning methods that do not reflect innovative technologies with uncertainty and may not be applicable due to the lack of community empowerment, which is a dynamic learning and intervention opportunity for end-users at different planning stages (i.e., outreach, survey, planning, implementation, management, and maintenance). Using the lessons learned from participatory action research, whereby the author was involved as a project director throughout the planning and design process, we identified a six-step cycle principle. The steps are (1) collective action commitments, (2) local values and resource identification, (3) carbon footprint inventory, (4) optimized integration of environment, economy, and energy action plans, (5) Flexible strategic energy system plans, and (6) digital performance monitoring. Ultimately, the outcomes provide application support for policymakers and planners and stimulate community engagement to contribute to the achievement of zero net carbon emissions. T2 - Planungsprinzipien für die Integration von Community Empowerment in die Zero-Net Carbon Transformation KW - social science KW - environmental planning KW - responsible research innovation KW - public–private partnerships KW - low-carbon communities KW - participatory action research KW - collective actions Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-57765 VL - 2023 IS - 6 SP - 100 EP - 122 PB - MDPI CY - Basel ER - TY - RPRT A1 - Brückl, Oliver T1 - Hemmnisse im Verteilnetzausbau und deren Überwindung N2 - Die Bundesregierung hat ambitionierte Ausbaupfade für die Windenergie und Photovoltaik festgelegt. Allerdings gefährdet vor allem der Verteilnetzausbau und der Netzanschluss der Erneuerbare-Energien-Anlagen (EE-Anlagen) die Erreichung dieser hochgesteckten Ziele. In einem Gutachten im Auftrag der Fraktion von Bündnis 90/DIE GRÜNEN im Bayerischen Landtag identifiziert Prof. Dr.-Ing. Oliver Brückl die wesentlichen Hemmnisse für den beschleunigten Verteilnetzausbau und den Netzanschluss für EE-Anlagen und diskutiert Lösungsansätze in folgenden Bereichen: Regulierungsrahmen für die Verteilnetzbetreiber, Genehmigungsverfahren von Netzausbauprojekten, Praxis der Netzintegration von EE-An lagen, Personalkapazitäten, Beschaffung von Betriebsmitteln und Bau von Anlagen, Zertifizierungsprozess für den Netzanschluss von EE-Anlagen. Im Rahmen des Gutachtens wurden ca. 35 Interviews mit verschiedenen Stakeholdern geführt: Netzbetreiber und Stadtwerke, Projektierer*innen, Herstellerindustrie, Verbände und Behörden. KW - Netzausbau KW - Netzintegration Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-60438 PB - INA – Institut für Netz- und Anwendungstechnik GmbH CY - Waldmünchen ER - TY - JOUR A1 - Gärtner, Sebastian A1 - Marx-Schubach, Thomas A1 - Gaderer, Matthias A1 - Schmitz, Gerhard A1 - Sterner, Michael T1 - Techno-Economic Analysis of Carbon Dioxide Separation for an Innovative Energy Concept towards Low-Emission Glass Melting JF - energies N2 - The currently still high fossil energy demand is forcing the glass industry to search for innovative approaches for the reduction in CO2 emissions and the integration of renewable energy sources. In this paper, a novel power-to-methane concept is presented and discussed for this purpose. A special focus is on methods for the required CO2 capture from typical flue gases in the glass industry, which have hardly been explored to date. To close this research gap, process simulation models are developed to investigate post-combustion CO2 capture by absorption processes, followed by a techno-economic evaluation. Due to reduced flue gas volume, the designed CO2 capture plant is found to be much smaller (40 m3 absorber column volume) than absorption-based CO2 separation processes for power plants (12,560 m3 absorber column volume). As there are many options for waste heat utilization in the glass industry, the waste heat required for CO2 desorption can be generated in a particularly efficient and cost-effective way. The resulting CO2 separation costs range between 41 and 42 EUR/t CO2, depending on waste heat utilization for desorption. These costs are below the values of 50–65 EUR/t CO2 for comparable industrial applications. Despite these promising economic results, there are still some technical restrictions in terms of solvent degradation due to the high oxygen content in flue gas compositions. The results of this study point towards parametric studies for approaching these issues, such as the use of secondary and tertiary amines as solvents, or the optimization of operating conditions such as stripper pressure for further cost reductions potential. KW - economic evaluation KW - CO2-separation KW - glass industry KW - oxyfuel KW - methanation KW - power-to-gas Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-53627 N1 - Corresponding author: Sebastian Gärtner VL - 16 IS - 5 SP - 1 EP - 25 PB - MDPI CY - Basel ER - TY - CHAP A1 - Gärtner, Sebastian A1 - Rank, Daniel A1 - Heberl, Michael A1 - Gaderer, Matthias A1 - Sterner, Michael T1 - Integration of Power-To-Methane into Glass Melting Processes T2 - Proceedings of the International Renewable Energy Storage Conference (IRES 2022) N2 - The glass industry is facing increased challenges regarding climate protection targets and rising energy costs. The integration of renewable energy including conversion and storage is a key for both challenges in this energy-intensive industrial sector, which has been mainly relying on fossil gas so far. The options considered to this point for reducing CO2 emissions and switching to a renewable energy supply involve far-reaching changes of the established melting processes. This entails significant risks in terms of influences on glass quality and stable production volumes. The presented approach for the integration of a Power-to-Methane (PtM) system into the glass industry is a completely new concept and has not been considered in detail before. It allows the use of established oxyfuel melting processes, the integration of fluctuating renewable energy sources and a simultaneous reduction of CO2 emissions by more than 78%. At the same time, natural gas purchases become obsolete. A techno-economic evaluation of the complete PtM process shows, that 1,76 €/m3 or 1,26 €/kg synthetic natural gas are possible with renewable energy supply. Using electricity from the energy grid would require electricity prices < 0,126 €/kWh to allow cost competitive PtM processes in the glass industry. Such electricity prices could be achieved by electricity market-based optimization and operation of the PtM system. This operation strategy would require AI-based algorithms predicting availabilities and prices on future-based markets. KW - Power-to-Gas KW - Methanation KW - Glass Melting KW - Glass Industry KW - Decarbonisation Y1 - 2023 U6 - https://doi.org/10.2991/978-94-6463-156-2_12 SN - 2589-4943 VL - 16 SP - 147 EP - 161 PB - Atlantis Press ER - TY - JOUR A1 - Gamisch, Bernd A1 - Ettengruber, Stefan A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - Dynamic simulation of isothermal and non-isothermal reduction and oxidation reactions of iron oxide for a hydrogen storage process JF - Renewable and Sustainable Energy N2 - This work aims first to develop a dynamic lumped model for the isothermal reactions of hydrogen/steam with a single iron oxide/iron pellet inside a tubular reactor and to validate the model results against the experimental reaction kinetic data with the help of our STA device. To describe the temporal change in mass, and consequently, the temporal heat of reaction, the shrinking core model, based on the geometrical contracting sphere, is applied. It turned out that, the simulation model can reproduce the experimental, temporal concentration and temperature-dependent conversion rates with a maximum deviation of 4.6% during the oxidation reactions and 3.1% during the reduction reactions. In addition, a measured isothermal storage process comprising one reduction and one oxidation phase with a holding phase in between on a single reacting pellet could be reproduced with a maximum absolute deviation in the conversion rate of 1.5%. Moreover, a lumped, non-isothermal simulation model for a pelletized tubular redox-reactor including 2kg of iron oxide pellets has been established, in which the heat of reaction, heat transfer to the ambient and heat transfer between the solid and gas phases are considered. The temporal courses of the outlet gas concentration as well as the temperatures of the gas stream and the solid material at a constant input gas flow rate and a constant reacting gas inlet concentration but different input gas temperatures are estimated. Because of the endothermic nature of the reduction reaction, the inlet reacting gas temperature shall be kept high to prevent the severe temperature drop in the solid phase and, consequently, the significant reduction of the reaction rate. Contrary to that, the oxidation process requires lower input gas temperatures to avoid the excessive overheating of the reaction mass and, consequently, the sintering of the reacting pellets. Finally, five of the previous reactors have been connected in series to explore the influence of the changing inlet gas temperatures and concentrations on the dynamic performance of each storage mass. KW - hydrogen storage KW - iron/iron oxide KW - redox reactions KW - lumped model KW - isothermal reactions KW - non-isothermal reactions KW - kinetics of reactions KW - Aspen Custom Modeler Y1 - 2023 U6 - https://doi.org/10.55092/rse20230004 N1 - Corresponding author: Belal Dawoud VL - 1 IS - 1 PB - ELSP, International Open Science Platform ER - TY - JOUR A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Hagen, Gunter A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Moos, Ralf T1 - Soot Monitoring of Gasoline Particulate Filters Using a Radio-Frequency-Based Sensor JF - Sensors N2 - Owing to increasingly stringent emission limits, particulate filters have become mandatory for gasoline-engine vehicles. Monitoring their soot loading is necessary for error-free operation. The state-of-the-art differential pressure sensors suffer from inaccuracies due to small amounts of stored soot combined with exhaust gas conditions that lead to partial regeneration. As an alternative approach, radio-frequency-based (RF) sensors can accurately measure the soot loading, even under these conditions, by detecting soot through its dielectric properties. However, they face a different challenge as their sensitivity may depend on the engine operation conditions during soot formation. In this article, this influence is evaluated in more detail. Various soot samples were generated on an engine test bench. Their dielectric properties were measured using the microwave cavity perturbation (MCP) method and compared with the corresponding sensitivity of the RF sensor determined on a lab test bench. Both showed similar behavior. The values for the soot samples themselves, however, differed significantly from each other. A way to correct for this cross-sensitivity was found in the influence of exhaust gas humidity on the RF sensor, which can be correlated with the engine load. By evaluating this influence during significant humidity changes, such as fuel cuts, it could be used to correct the influence of the engineon the RF sensor. KW - dielectric properties KW - engine test bench KW - gasoline particulate filter (GPF) KW - microwave cavity perturbation KW - radio-frequency (RF) KW - soot mass determination Y1 - 2023 U6 - https://doi.org/10.3390/s23187861 SN - 1424-8220 N1 - This research work was funded by the Bavarian Research Foundation (Bayerische Forschungsstiftung, BFS) as part of the project “Load Sensor for GPF” (AZ-1288-17). VL - 23 IS - 18 SP - 1 EP - 19 PB - MDPI ER - TY - JOUR A1 - Rill, Georg A1 - Schuderer, Matthias T1 - A Second-Order Dynamic Friction Model Compared to Commercial Stick–Slip Models JF - Modelling N2 - Friction has long been an important issue in multibody dynamics. Static friction models apply appropriate regularization techniques to convert the stick inequality and the non-smooth stick–slip transition of Coulomb’s approach into a continuous and smooth function of the sliding velocity. However, a regularized friction force is not able to maintain long-term stick. That is why dynamic friction models were developed in recent decades. The friction force depends herein not only on the sliding velocity but also on internal states. The probably best-known representative, the LuGre friction model, is based on a fictitious bristle but realizes a too-simple approximation. The recently published second-order dynamic friction model describes the dynamics of a fictitious bristle more accurately. It is based on a regularized friction force characteristic, which is continuous and smooth but can maintain long-term stick due to an appropriate shift in the regularization. Its performance is compared here to stick–slip friction models, developed and launched not long ago by commercial multibody software packages. The results obtained by a virtual friction test-bench and by a more practical festoon cable system are very promising. Thus, the second-order dynamic friction model may serve not only as an alternative to the LuGre model but also to commercial stick–slip models. KW - commercial stick–slip friction models KW - dynamic friction model KW - long-term stick KW - multibody dynamics Y1 - 2023 U6 - https://doi.org/10.3390/modelling4030021 SN - 2673-3951 N1 - Corresponding author: Georg Rill VL - 4 IS - 3 SP - 366 EP - 381 PB - MDPI ER - TY - CHAP A1 - Rill, Georg ED - Fleury, Agenor de T. T1 - Real-Time capable Multibody Model of dual Truck Front Axles T2 - Proceedings of DINAME 2023 - Selected Papers of the XIX International Symposium on Dynamic Problems of Mechanics, 26 Feb - 03 Mar 2023, Pirenópolis, Brazil N2 - Dual front steering axles are quite common in multi-axled heavy duty trucks. In standard layouts of such axle combinations, the steer motions of the wheels depend not only on the rotation of the steering wheel but also on the movements of the axles. As a consequence, the model complexity of the steering system should match with the complexity of the suspension model. The development of new technologies like advanced driver assistance systems or autonomous driving can only be accomplished efficiently using extensive simulation methods. Such kind of applications demand for computationally efficient vehicle models. This paper presents a steering system model for dual front axles of heavy duty trucks which supplements the suspension model of the axles. The model takes the torsional compliance of the steering column as well as the stiffness of the tie rods and the coupling rod into account. A quasi-static solution provides a straight forward computation including the partial derivatives required for an efficient implicit solver. The steering system model matches perfectly with comparatively lean, but sufficiently accurate multibody suspension models. KW - Steering System KW - Dual Axles KW - Multibody Model KW - Vehicle Dynamics KW - Real-Time Y1 - 2023 UR - https://www.researchgate.net/publication/369256274_Real-Time_capable_Multibody_Model_of_dual_Truck_Front_Axles PB - Springer ER - TY - RPRT A1 - Zacherl, Florian A1 - Wopper, Christoph A1 - Mieslinger, Johann A1 - Peis, Michael A1 - Rabl, Hans-Peter T1 - Schlussbericht zum Verbundvorhaben NAMOSYN: Nachhaltige Mobilität durch synthetische Kraftstoffe BT - Cluster FC1A: OME Für Dieselmotoren - Motorische Testung; Cluster FC2: C1-O Systeme für Ottomotoren N2 - Im Labor für Verbrennungsmotoren und Abgasnachbehandlung der OTH-Regensburg sollten im Zuge des NAMOSYN-Projektes zwei Vertreter klimaneutraler Kraftstoffe an verschiedenen Systemprüfständen (Motor-, Einspritzprüfstand, optisch zugängliche Einspritzkammer, …) und mit Hilfe von Simulationsmethoden für den Einsatz in bestehenden Verbrennungsmotoren untersucht werden. Synthetische Kraftstoffe aus der Gruppe der Oxymethylenether (OME) stellen eine CO2-neutrale Alternative zu fossilem Dieselkraftstoff dar. Für Ottomotoren wurde untersucht, ob der synthetische Kraftstoff DMC/MeFo (Dimethylcarbonat & Methylformiat) einen Ersatz für Ottokraftstoff darstellen kann, bzw. eine Drop-In-Fähigkeit gegeben ist. Die OTH Regensburg bearbeitete 2 unabhängige Teilvorhaben zur motorischen Testung von synthetischen Kraftstoffen: „FC 1A: Motorische Testung von OME“ und „FC 2: Untersuchung von C1-Oxygenaten für Ottomotoren“. Die Projektlaufzeit betrug 3,5 Jahre, inkl. kostenneutraler Verlängerung um 6 Monate aufgrund der Corona-Pandemie. Im FC1A "AP2-Nachrüstung Dieselmotoren" der OTH Regensburg lag der Fokus auf der Erforschung der Potentiale und der Umrüstung eines Einzylinder-Dieselmotors mit Pumpe-Leitung-Düse-(PLD)-Einspritzsystem des Projektpartners Motorenfabrik Hatz GmbH und Co. KG für OME-Betrieb. Im AP2.1 wurden umfangreiche Daten gesammelt und Simulationsmodelle des Motors und PLD-Einspritzsystems erstellt und mit Dieselkraftstoff und OME validiert. Nachfolgend wurden Parameterstudien zur Geometrie des Einspritzsystems und der physikalischen Eigenschaften von OME durchgeführt. In AP2.2 und AP2.3 wurden umfangreiche Untersuchungen an einem Motor- und Einspritzsystemprüfstand mit Diesel und OME durchgeführt und der Steuergerätedatensatz für den OME-Betrieb optimiert. Die Ergebnisse zeigen, dass die Umstellung des Kraftstoffs auf OME, insbesondere bei einfachen Motoren mit rudimentärer Einspritztechnik und ohne Mittel zur NOx-Reduzierung (keine AGR oder SCR), ein enormes Potenzial zur Steigerung des Wirkungsgrads bei gleichzeitiger Reduzierung aller regulierten Schadstoffe (NOx, 𝑃N, 𝑃M, CO und 𝑉OC) eröffnet. Die Ergebnisse und generierten Simulationsmodelle unterstützen eine schnelle Serienentwicklung und Einführung von OME-Umrüstlösungen. In FC 2 werden die vielversprechenden Kraftstoffe Methylformiat (MeFo) und Dimethylcarbonat (DMC) motorisch getestet. Untersuchungen am Kraftstoffsystem und wichtigen Komponenten dienen als Grundlage für das AP3. Im AP3 wird die Machbarkeit der DMC/MeFo-Verbrennung am Vollmotor demonstriert und die erwarteten Emissionsvorteile gegenüber herkömmlichen Ottokraftstoffen gezeigt. Abweichend von der ursprünglichen Planung werden an der OTH Regensburg Kraftstoffblends aus Benzin und MeFo untersucht, um den Einsatzbereich des Kraftstoffs zu erweitern. In AP5 werden potentielle Mischungsverhältnisse analysiert und die Eigenschaften der ausgewählten Kraftstoffmischungen an einem Einspritzratenprüfstand, an der Einspritzkammer und am Vollmotor untersucht. Es werden Einspritzverhalten, Gemischaufbereitung und Abgasemissionen bewertet. Zudem wird eine Kraftstoffmischanlage entwickelt und ein optischer Zugang am Vollmotor ermöglicht. Eine Ölverdünnungsmesstechnik wird eingesetzt, um den Kraftstoffeintrag ins Motoröl zu untersuchen KW - Synthetische Kraftstoffe KW - OME KW - DMC KW - MeFo KW - E-Fuels Y1 - 2023 CY - Regensburg ER - TY - JOUR T1 - Energieforschung BT - geförderte Projekte 2020 bis 2022 N2 - Über uns Das Regensburg Center of Energy and Resources (RCER) bündelt seit 2012 die Aktivitäten der Ostbayerischen Technischen Hochschule Regensburg (OTH Regensburg) und der regionalen Wirtschaftsunternehmen auf dem Strategiefeld „Energie und Ressourcen“. Mission: Energieforschung: vernetzen, voranbringen, vermitteln Das RCER fördert die Vernetzung verschiedener Disziplinen der Energieforschung innerhalb der OTH Regensburg und mit externen Partnern (Firmen, Förderträgern, Forschungsinstitutionen, öffentlichen Einrichtungen). Das RCER ist Ihr Partner beim Voranbringen von Kooperationen und Forschungsvorhaben durch Unterstützung in der Antragsphase, bei der Einwerbung von Projektmitteln und Projektbegleitung im Energiebereich. Das RCER steht für die Vermittlung von Know-how, Basiswissen, aktuellen Fragen und den Technologietransfer rund um das Thema Energie zwischen Wissenschaft, Wirtschaft, Gesellschaft und Politik. Vision Wir sind Ihr erster Ansprechpartner und Motor für innovative Energieforschung. Werte Verlässlichkeit, Kompetenz, Verantwortungsbewusstsein.Regional verwurzelt und weltoffen Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-65422 PB - OTH Regensburg ET - Ausgabe 2023 ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - On the application of adsorber plate heat exchangers in thermally driven chillers BT - An experimental and analytical study JF - Applied Thermal Engineering N2 - The effect of both heat and mass transfer characteristic lengths (HTCL, MTCL) of two different adsorber plate heat exchangers (APHE), for application in an adsorption chiller, on the adsorption and desorption kinetics is investigated. Three representative test frames (TF1-TF3) are prepared to examine small-scale adsorbent samples of the microporous silica gel (Siogel of Oker-Chemie, Germany) applying the volumetric large-temperature-jump methodology at different operating conditions. Based on the obtained kinetic data, an analytical model has been developed to predict the specific cooling power (SCP) and the coefficient of performance (COP) of a single-bed adsorption chiller comprising the studied APHEs. It turned out that, within the tested range of HTCL and MTCL, it can be concluded that, the adsorption kinetics are mainly influenced by the MTCL, while the desorption kinetics are dominated by the HTCL of the adsorbent domain. Applying Siogel as loose pellets inside a newly introduced APHE results in of 423.3 and 182.7 W⋅kg−1, at the evaporator temperatures of 15 °C and 5 °C, respectively. Herein, the condenser and adsorber-end temperatures amount to 30 °C and the desorption-end temperature to 90 °C. The corresponding s amount to 0.50 and 0.40, respectively, which represent quite promising results for further design optimizations. Y1 - 2023 U6 - https://doi.org/10.1016/j.applthermaleng.2022.119713 VL - 220 PB - Elsevier ER - TY - CHAP A1 - Tremmel, Florian A1 - Nagler, O. A1 - Kutter, C. A1 - Holmer, Rainer T1 - Smart Cantilever Probe with Integrated Force and Acoustic Emission Sensor T2 - 2023 IEEE SENSORS, Vienna, Austria, 10/29/2023 - 11/1/2023 N2 - Acoustic emission (AE) testing recently found its application in the wafer testing sector of the semiconductor industry. To find out the mechanical robustness of semiconductor devices, contact pads on the chip surface are intentionally overstressed with an indenter tip and the appearing oxide cracks are detected with help of the generated AE signals. This is done in a customized test bench with a patented sensor-indenter system. This paper presents an improved version of the measurement setup that solves certain disadvantages of it and can be used in a standard wafer prober. The main components of the developed sensor system are a strain gauge for contact force measurement and a piezoelectric sensor element for AE signal detection. Both components are integrated on a cantilever beam which has an exchangeable indenter tip at its free end. The cantilever probe is electrically conductive to enable electrical tests via the indenter tip. This smart sensor-cantilever combination (SCC) can be mounted with several adapter components on a carrier plate to place it in a wafer prober. For both sensor elements amplifier circuits are developed to enhance their signal-to-noise ratios (SNRs). A prototype setup is shown together with simulated and experimental results to demonstrate its performance. The mechanical properties of the cantilever, as well as the force sensor and the AE crack signals, already fulfill the requirements for an implementation in a wafer prober. To further improve the sensor resolutions and detection limits, several optimizations regarding the design of the SCC are in progress. KW - Acoustic emission testing KW - piezoelectric sensor KW - strain gauge KW - operational amplifier circuit Y1 - 2023 SN - 979-8-3503-0387-2 U6 - https://doi.org/10.1109/SENSORS56945.2023.10325021 SP - 1 EP - 4 PB - IEEE ER - TY - JOUR A1 - Hofrichter, Andreas A1 - Rank, Daniel A1 - Heberl, Michael A1 - Sterner, Michael T1 - Determination of the optimal power ratio between electrolysis and renewable energy to investigate the effects on the hydrogen production costs JF - International Journal of Hydrogen Energy N2 - Green hydrogen via renewable powered electrolysis has a high relevance in decarbonization and supply security. Achieving economically competitive hydrogen production costs is a major challenge in times of an energy price crisis. Our objective is to show the economically optimal installed capacity of electrolysers in relation to wind and solar power so swift and credible statements can be made regarding the system design. The ratio between renewable generation and electrolysis power as well as scaling effects, operating behaviour and development of costs are considered. Hydrogen production costs are calculated for four exemplary real PV and wind sites and different ratios of electrolysis to renewable power for the year 2020. The ideal ratio for PV systems is between 14% and 73% and for wind between 3.3% and 143% for low and high full load hours. The lowest hydrogen production costs are identified at 2.53 €/kg for 50 MW wind power and 72 MW electrolysis power. The results provide plant constructors the possibility to create a cost-optimized design via an optimum ratio of electrolysis to renewable capacity. Therefore, the procedures for planning and dimensioning of selected systems can be drastically simplified. Y1 - 2023 U6 - https://doi.org/10.1016/j.ijhydene.2022.09.263 SN - 0360-3199 N1 - Corresponding author: Michael Heberl N1 - Corrigendum to “Determination of the optimal power ratio between electrolysis and renewable energy to investigate the effects on the hydrogen production costs” [Int J Hydrogen Energy 48 (5) (2023) 1651–1663] - https://doi.org/10.1016/j.ijhydene.2023.03.128 VL - 48 IS - 5 SP - 1651 EP - 1663 PB - Elsevier ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Nowak, Sebastian A1 - Palomba, Valeria A1 - Frazzica, Andrea A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - Experimental and analytical investigation of applying an asymmetric plate heat exchanger as an evaporator in a thermally driven adsorption appliance JF - Applied Thermal Engineering N2 - This communication presents an experimental and analytical study on the evaporation mechanism in a closed-structured asymmetric plate heat exchanger (PHE) employed as a stagnant water evaporator for the application in an adsorption heat transformation appliance. To this aim, an experimental unit is constructed, which comprises two identical PHEs, one acting as an vaporator/condenser and the second, as an adsorber/desorber. Two endoscopes are mounted inside the investigated evaporator to visualize the evaporation mechanism when performing adsorption-evaporation processes under different boundary conditions. It turned out that the evaporation mechanism is a partially covered, thin film evaporation. A heat transfer analysis is performed to evaluate the heat transfer coefficient of the thin film evaporation () inside the investigated evaporator, resulting in -values between 1330 and 160 [W∙m−2∙K−1] over the investigated adsorption-evaporation time. Correlating the obtained () to the film thickness and the wetted area results in -values between 0.34 and 0.78 [mm] and wetted to total area ratios of 0.78 to 0.16. Besides, an analytical model has been developed and introduced to correlate the overall evaporator heat transfer coefficient with the adsorption potential and the time rate of change of the water uptake. KW - Adsorption-evaporation KW - Evaporator KW - Plate heat exchanger KW - Thin film evaporation Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-61115 N1 - Corresponding author: Belal Dawoud IS - 228 PB - Elsevier ER - TY - JOUR A1 - Keiner, Dominik A1 - Thoma, Christian A1 - Bogdanov, Dmitrii A1 - Breyer, Christian T1 - Seasonal hydrogen storage for residential on- and off-grid solar photovoltaics prosumer applications: Revolutionary solution or niche market for the energy transition until 2050? JF - Applied Energy N2 - Appropriate climate change mitigation requires solutions for all actors of the energy system. The residential sector is a major part of the energy system and solutions for the implementation of a seasonal hydrogen storage system in residential houses has been increasingly discussed. A global analysis of prosumer systems including seasonal hydrogen storage with water electrolyser, hydrogen compressor, storage tank, and a fuel cell studying the role of such a seasonal household storage in the upcoming decades is not available. This study aims to close this research gap via the improved LUT-PROSUME model, which models a fully micro sector coupled residential photovoltaic prosumer system with linear optimisation for 145 regions globally. The modelling of the cost development of hydrogen storage components allows for the simulation of a residential system from 2020 until 2050 in 5-year steps in hourly resolution. The systems are cost-optimised for either on- or off-grid operation in eight scenarios including battery electric vehicles, which can act as an additional vehicle-to-home electricity storage for the system. Results show that implementation of seasonal hydrogen systems only occurs in least cost solutions in high latitude countries when the system is forced to run in off-grid mode. In general, a solar photovoltaic plus battery system including technologies that can cover the heat demand is the most economic choice and can even achieve lower cost than a full grid supply in off-grid operation for most regions until 2050. Additional parameters including the self-consumption ratio, the demand cover ratio, and the heat cover ratio can therefore not be improved by seasonal storage systems if economics is the main deciding factor for a respective system. Further research opportunities and possible limitations of the system are then identified. KW - Battery KW - Electrolyser KW - Fuel Cell KW - Hydrogen KW - ProsumerIridium KW - Residential seasonal storage KW - Rooftop solar photovoltaics Y1 - 2023 U6 - https://doi.org/10.1016/j.apenergy.2023.121009 VL - 340 PB - Elsevier ER - TY - JOUR A1 - De, Sangita A1 - Premek, Brada A1 - Mottok, Jürgen T1 - Derivation of Optimized Threshold of Semantic Alignment Metrics for Intepretation of Interoperability and Reusability of Cross-enterprise Vehicle Service Interface Models JF - Informatica N2 - Over the past decade, cars have turned gradually into real cyber physical systems. The collaboration of services between the service-oriented, cross-enterprise vehicle application frameworks has increased to generate novel, smart and complicated vehicle services. Consequently, from an interoperability perspective, semantically mapping of vehicle service component’s interface ontological models emerged as a big research interest in automotive application domain that manipulates several cross-enterprise synergy knowledge applications frameworks. The ontological metamodeling lays the foundation for building semantic bridge and exploring semantic associations between service components’ interface models based on the domain knowledge for semantic interoperability. Also, several semantic quality metrics has been defined over time for the vehicle service interface ontological metamodels. The empirically evaluated values of these metrics can be used to assess progress in cross-enterprise interoperability between the service and the clients’ APIs ontological models in vehicle domain. Despite potential benefits of semantic alignment quality metrics, the effective use of these metrics for vehicle service interface ontologies have proven elusive. Yes, such metrics can be used successfully for quantification, but then they mostly fail to provide adequate annotations in subsequent decision-making in the direction of semantic interoperability and reusability. The effective use of ontology semantic alignment quality metrics is basically hindered in the absence of the meaningful thresholds. In fact, the absence of an effective and meaningful threshold for the semantic similarity measure between various vehicle service interface ontological metamodels, motivates this research work which not only proposes a design approach to an optimized threshold for the semantic similarity metrics but also applies this threshold on few defined semantic alignment quality metrics. This paper also uses a real-world vehicle domain industrial case study to illustrate the design approach. KW - interface KW - automotive services KW - semantic KW - metrics KW - optimized threshold KW - framework KW - metamodels KW - ontologies Y1 - 2023 U6 - https://doi.org/10.31449/inf.v47i7.4739 SN - 0350-5596 VL - 47 IS - 7 PB - Slovenian Society Informatika ER - TY - JOUR A1 - Huber, Lea A1 - Heindl, Melanie A1 - Schlosser, Marc A1 - Pfitzner, Arno A1 - Dawoud, Belal T1 - On the Cycle Stability and Macroscopic Structure of Iron Oxide Pellets for Thermochemical Hydrogen Storage: Influence of Water Content during the Pelletizing Process JF - Applied Sciences N2 - Hydrogen storage based on the repeated reduction and oxidation (redox) reactions of iron oxide/iron composites represents a promising technology. This work is dedicated to studying the influence of the amount of water added during the pelletizing process on the cycle stability and structure of iron oxide pellets. The storage composites were prepared from iron oxide (Fe2O3) and 10 wt.-% support material (cement) with different amounts of water (18 and 33 wt.-%) in a laboratory-scale pelletizing disk. To evaluate the cycle stability of the composites, the kinetics of the redox reactions were experimentally measured at 800 ∘ C in an atmosphere of 50% N2 and 50% H2 (reduction) or 50% steam (oxidation), respectively. Moreover, the structure of the pellets was analyzed by micro-computed tomography scans. It turned out that pellets with higher water contents attained faster kinetics and a higher cycle stability. The sample with the least water content (18 wt.-%) needed about 26 min and 19 min to reach a conversion rate of 80% during the reduction and oxidation reactions of the sixth redox cycle, respectively. In contrast, the sample with the highest water content (33 wt.-%) could achieve the same conversion rate after 18 min (reduction) and 13 min (oxidation) during the ninth redox cycle. KW - hydrogen storage KW - redox reactions KW - iron/iron oxide KW - pelletizing process KW - cycle stability KW - water content Y1 - 2023 U6 - https://doi.org/10.3390/app13116408 N1 - Corresponding author: Belal Dawoud VL - 13 IS - 11 PB - MDPI CY - 16 ER - TY - JOUR A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Hagen, Gunter A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Moos, Ralf T1 - Combined Ash and Soot Monitoring for Gasoline Particulate Filters Using a Radio-Frequency-Based Sensor JF - Emission Control Science and Technology N2 - Increasingly stringent emission limits have made particulate filters necessary for gasoline engines. Similar to diesel applications, gasoline particulate filters (GPFs) can be monitored by differential pressure measurement or by the radio-frequency-based filter diagnosis (RF sensor). In addition to measuring the soot loading, ash detection is critical for monitoring the GPF over the entire vehicle lifetime. Because the RF sensor detects the filter loading through a change in the dielectric properties of the GPF, it can detect not only soot but also ash. In diesel applications, the RF sensor has already demonstrated its potential for ash detection. To verify the feasibility of simultaneous ash and soot monitoring for GPFs, filters were loaded with ash on an engine test bench and measured on a lab test bench under defined synthetic exhaust gas conditions. By evaluating resonant modes, soot and ash could be clearly distinguished, as ash mainly affects the resonant frequency, while soot also changes the quality factor due to its high dielectric losses. However, higher soot loadings could not be detected by the resonant parameters, but instead by a frequency-averaged transmission signal. While the presence of ash caused an offset in this signal, its sensitivity to soot was not affected. Thus, the influence of ash can be corrected if the signal in the soot-free filter state is known, e.g., from the behavior of the resonant parameters. Therefore, even with a continuously increasing ash loading over the lifetime of a vehicle, an accurate soot detection is possible with the RF sensor. KW - Gasoline particulate flter KW - Radio-frequency KW - Soot mass determination KW - Ash detection Y1 - 2023 U6 - https://doi.org/10.1007/s40825-023-00235-y PB - Springer ER - TY - RPRT A1 - Geiss, Florian A1 - Liedl, Lucia A1 - Thalhammer, Florian A1 - Mauderer, Johannes A1 - Meier, Maximilian A1 - Geitner, Florian A1 - Bindl, Jakob A1 - Belz, Reinhold ED - Meier, Hans ED - Niemetz, Michael ED - Fuhrmann, Thomas ED - Reindl, Andrea T1 - FMS-BERICHTE WINTERSEMESTER 2022/23 BT - Seminar zu aktuellen Themen der Elektro- und Informationstechnik N2 - Dieser Bericht entstand auf Initiative der Studierenden des Masterstudiengangs „Elektro- und Informationstechnik (MEI)“, die an der Pflichtlehrveranstaltung „Forschungsmethoden und Seminar (FMS)“ im Wintersemester 2022/23 teilnahmen. Diese Lehrveranstaltung hat das Ziel, systematisch an das wissenschaftliche Arbeiten, speziell die Wissenschaftskommunikation, heranzuführen. Daher war geeignete Literatur zu einem individuellen Thema zu recherchieren, Veröffentlichungen auf ihre Relevanz hin zu beurteilen und letztendlich eine eigene Ausarbeitung basierend auf der Literaturrecherche zu erarbeiten und diese in einem Vortrag zu präsentieren. Parallel dazu erfolgte im Theorieteil die entsprechende Hinführung zu den verschiedenen Elementen der Wissenschaftskommunikation: • Bedeutung der Wissenschaftskommunikation für die Arbeit der Ingenieure in Forschung und Entwicklung • Literaturrecherche, Suchmaschinen, Sichtung und Analyse vorhandener Publikationen, Bewertung der Qualität aufgefundener Fachliteratur, Auswahl geeigneter Materialien für die eigene Arbeit • Aufbereitung und Darstellung der recherchierten technischer Inhalte in Form einer seitenanzahlbegrenzten wissenschaftlichen Ausarbeitung • Einhalten formaler Randbedingungen bzgl. Strukturierung, einschl. Bildnachweise und Zitationsstile • Peer-review-Prozess bei wertschätzender Beurteilung der Leistung anderer • Publikumsangepasstes Aufbereiten komplexer fachlicher Inhalte mit hochschulöffentlicher Präsentation der Ergebnisse • Führen mündlicher wissenschaftlicher Diskurse Nachdem die Masterstudierenden in der Regel über noch keine eigene wissenschaftliche Forschungserfahrung bzw. -inhalte verfügen, lag der wählbare Schwerpunkt der Literatursuche auf der Bearbeitung von vorgegeben aktuellen technischen oder gesellschaftspolitischen Forschungsthemen. Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-60324 PB - Ostbayerische Hochschule Regensburg CY - Regensburg ER - TY - INPR A1 - Heberl, Michael A1 - Withelm, Christian A1 - Kaul, Anja A1 - Rank, Daniel A1 - Sterner, Michael T1 - Prospective Life Cycle Assessment of Biological Methanation in a Trickle-Bed Pilot Plant and a Potential Scale-Up N2 - In this study, a pilot-scale trickle-bed reactor for biological methanation and various scale-up scenarios for 2023 and 2050 were investigated using LCA. A best- and worst-case scenario for technology development until 2050 was evolved using cross consistency analysis and morphological field, based on which the data for the ecological models were determined.The results show that the plant scale-up has a very positive effect on the ecological consequences of methanation. In the best-case scenario, the values are a factor of 23-780 lower than those of the actual plant today. A hot-spot analysis showed that especially electrolysis operation has a large impact on total emissions. The final Monte-Carlo simulation shows that the technology is likely to achieve a low GWP with a median of 104.0 kg CO2-eq / MWh CH4. Y1 - 2023 U6 - https://doi.org/10.2139/ssrn.4635066 PB - SSRN ER - TY - RPRT A1 - Sörgel, Dominika A1 - Luderer, Gunnar A1 - Emelianova, Polina A1 - Koch, Otto A1 - Timpe, Christof A1 - Bauer, Franz A1 - Sterner, Michael T1 - Kopernikus-Szenarienvergleich - Robuste Eigenschaften von Klimaschutzpfaden zur Treibhausgasneutralität 2045 und relevante Unsicherheiten N2 - Im Rahmen der vier Kopernikus-Projekte – Ariadne, ENSURE, P2X und SynErgie – wird die Transformation des deutschen Energiesystems hin zur Klimaneutralität analysiert. Im vorliegenden Bericht werden hierbei robuste Kernaussagen und relevante Unsicherheiten derjenigen Szenarien der Kopernikus-Schwesterprojekte dargestellt, die zur Zielsetzung die Klimaneutralität 2045 haben. Hierbei liegt der Fokus auf Indikatoren, die eine besonders hohe klimapolitische Relevanz haben. Y1 - 2023 UR - https://publications.pik-potsdam.de/pubman/faces/ViewItemFullPage.jsp?itemId=item_29216 PB - Kopernikus-Projekte CY - Potsdam ER - TY - RPRT A1 - Andratschke, Christin A1 - Ceullo, Laura A1 - Dawoud, Belal A1 - Draeger, Susan A1 - Gerdes, Thorsten A1 - Giebisch, Matthias A1 - Grießhammer, Peter A1 - Haas, Katharina A1 - Haug, Sonja A1 - Helling, Dominik A1 - Kominis, Lena A1 - Lang, Christian A1 - Malz, Sebastian A1 - Melzl, Johannes A1 - Michlbauer, David A1 - Mühlberger, Thomas A1 - Nagl, Klaus A1 - Preis, Michael A1 - Rechenauer, Christian A1 - Riederer, Michael A1 - Rückerl, Alexander A1 - Saller, Tobias A1 - Schnabl, Andreas A1 - Stadler, Michael A1 - Steffens, Oliver A1 - Steininger, Peter A1 - Stelzl, André A1 - Toutouly, Lovis A1 - Trauner, Matthias A1 - Vetter, Miriam A1 - Walbrunn, Johannes A1 - Weber, Karsten A1 - Zielbauer, Lukas ED - Steffens, Oliver T1 - MAGGIE: Energetische Modernisierung des genossenschaftlichen Wohnquartiers Margaretenau in Regensburg BT - Musterlösungen für solaroptimiertes Wohnen mit innovativen solaraktiven Baustoffen und einem KI-gestützten Energiemanagement für eine netzdienliche, emissionsarme Strom- und Wärmelogistik; Ergebnisbericht N2 - Im Projekt MAGGIE wurden für das genossenschaftliche historische Stadtquartier „Margaretenau“ in Regensburg Musterlösungen für energieoptimiertes Wohnen mit innovativen Wandaufbauten aus solaraktiven Baukonstruktionen und einer vorhersagebasierten Versorgungstechnologie erforscht. Dazu wurde ein bestehendes Wohngebäude als Demonstrations- und Versuchsobjekt mit einem neuartigen, besonders effizienten Hybridsystem aus Wärmepumpentechnologie und Kraft- Wärme-Kopplung ausgestattet und untersucht, ergänzt durch eine dynamische Wärmelogistik 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 während des Betriebs greift dabei auf reale Monitoringdaten zu. Die Einbindung von Nutzerbedarfsprofilen, Strombörse und Wetterdaten in die Steuerung gestattet einen dynamischen und perspektivischen Anlagenbetrieb zur Maximierung der Solar- und Umweltwärme-Anteile der Energieversorgung und leistet damit einen wirksamen Beitrag zu einem emissionsarmen, klimafreundlichen Gebäudebetrieb. Für die denkmalgerechte Modernisierung der historischen Fassaden wurde ein solaraktives und solaradaptives Außenputzsystem entwickelt und in der Realität getestet. Am Bestandsgebäude kam anstelle eines Wärmedämmverbundsystems ein innovativer Dämmputz mit Mikrohohlglaskugeln zum Einsatz. Die Skalierbarkeit erlaubt eine abschnittsweise Modernisierung des gesamten Ensembles über mehrere Jahre. Durch die hohe Energieeffizienz wird die Warmmiete für die Bewohner der genossenschaftlichen Siedlung durch die Modernisierungsmaßnahmen nicht erhöht, so dass auch nach der Modernisierung ein bezahlbares Wohnen sichergestellt wird. KW - Altbaumodernisierung KW - Energieeinsparung KW - Energiebewusstes Bauen KW - Haus Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-59011 SN - 978-3-96256-100-0 N1 - Gefördert durch einen Beschluss des Bundestages durch das Bundesministerium für Wirtschaft und Klimaschutz (BMWK); Projektlaufzeit Oktober 2017 bis Juni 2022; Förderkennzeichen 03SBE0007A–E CY - Regensburg ER - TY - CHAP A1 - Schweiberer, Philipp A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Control strategy for industrial reactive power sources depending on a specified reactive power setpoint value T2 - ETG Kongress 2023: Die Energiewende beschleunigen, 25.-26. Mai 2023, Kassel, Germany N2 - Industrial plants can provide reactive power (Q) for system- and grid-serving behavior, for which a functioning reactive power management system is essential. To make reactive power retrieval as efficient and safe as possible, the selection of reactive power sources to meet the Q-demand must consider their sensitivities and the restrictions of the industrial grid, such as operating equipment utilization or voltage limits. On this basis, a concept for a sensitivity-based control strategy that manages the reactive power retrieval of multiple reactive power sources depending on a predefined reactive power demand value is proposed. Based on the simulation of an industrial plant in the medium-voltage grid, which can provide reactive power in the form of industrial compensation systems (ICS) and generators, the operation of the algorithm is shown. Y1 - 2023 UR - https://ieeexplore.ieee.org/document/10173014/authors#authors SN - 978-3-8007-6108-1 SP - 553 EP - 558 PB - VDE VERLAG CY - Berlin ER - TY - RPRT A1 - Andratschke, Christin A1 - Ceullo, Laura A1 - Dawoud, Belal A1 - Draeger, Susan A1 - Gerdes, Thorsten A1 - Giebisch, Matthias A1 - Grießhammer, Peter A1 - Haas, Katharina A1 - Haug, Sonja A1 - Helling, Dominik A1 - Kominis, Lena A1 - Lang, Christian A1 - Malz, Sebastian A1 - Melzl, Johannes A1 - Michlbauer, David A1 - Mühlberger, Thomas A1 - Nagl, Klaus A1 - Preis, Michael A1 - Rechenauer, Christian A1 - Riederer, Michael A1 - Rückerl, Alexander A1 - Saller, Tobias A1 - Schnabl, Andreas A1 - Stadler, Michael A1 - Steffens, Oliver A1 - Steininger, Peter A1 - Stelzl, André A1 - Toutouly, Lovis A1 - Trauner, Matthias A1 - Vetter, Miriam A1 - Walbrunn, Johannes A1 - Weber, Karsten A1 - Zielbauer, Lukas ED - Steffens, Oliver T1 - MAGGIE: Energetische Modernisierung des genossenschaftlichen Wohnquartiers Margaretenau in Regensburg BT - Musterlösungen für solaroptimiertes Wohnen mit innovativen solaraktiven Baustoffen und einem KI-gestützten Energiemanagement für eine netzdienliche, emissionsarme Strom- und Wärmelogistik; Ergebnisbericht N2 - Im Projekt MAGGIE wurden für das genossenschaftliche historische Stadtquartier „Margaretenau“ in Regensburg Musterlösungen für energieoptimiertes Wohnen mit innovativen Wandaufbauten aus solaraktiven Baukonstruktionen und einer vorhersagebasierten Versorgungstechnologie erforscht. Dazu wurde ein bestehendes Wohngebäude als Demonstrations- und Versuchsobjekt mit einem neuartigen, besonders effizienten Hybridsystem aus Wärmepumpentechnologie und Kraft- Wärme-Kopplung ausgestattet und untersucht, ergänzt durch eine dynamische Wärmelogistik 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 während des Betriebs greift dabei auf reale Monitoringdaten zu. Die Einbindung von Nutzerbedarfsprofilen, Strombörse und Wetterdaten in die Steuerung gestattet einen dynamischen und perspektivischen Anlagenbetrieb zur Maximierung der Solar- und Umweltwärme-Anteile der Energieversorgung und leistet damit einen wirksamen Beitrag zu einem emissionsarmen, klimafreundlichen Gebäudebetrieb. Für die denkmalgerechte Modernisierung der historischen Fassaden wurde ein solaraktives und solaradaptives Außenputzsystem entwickelt und in der Realität getestet. Am Bestandsgebäude kam anstelle eines Wärmedämmverbundsystems ein innovativer Dämmputz mit Mikrohohlglaskugeln zum Einsatz. Die Skalierbarkeit erlaubt eine abschnittsweise Modernisierung des gesamten Ensembles über mehrere Jahre. Durch die hohe Energieeffizienz wird die Warmmiete für die Bewohner der genossenschaftlichen Siedlung durch die Modernisierungsmaßnahmen nicht erhöht, so dass auch nach der Modernisierung ein bezahlbares Wohnen sichergestellt wird. KW - Altbaumodernisierung KW - Energieeinsparung KW - Energiebewusstes Bauen KW - Haus Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-53354 SN - 978-3-96256-100-0 N1 - Gefördert durch einen Beschluss des Bundestages durch das Bundesministerium für Wirtschaft und Klimaschutz (BMWK); Projektlaufzeit Oktober 2017 bis Juni 2022; Förderkennzeichen 03SBE0007A–E N1 - korrigierte Version unter: https://doi.org/10.35096/othr/pub-5901 CY - Regensburg ER - TY - CHAP A1 - Haumer, Anton T1 - Modeling and Control Design of an Educational Magnetic Levitation System T2 - Proceedings of the 15th International Modelica Conference 2023, Aachen, October 9-11 N2 - 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. KW - mechatronics KW - magnetic levitation KW - time-discrete control KW - functional mockup interface Y1 - 2023 U6 - https://doi.org/10.3384/ecp204763 SN - 1650-3686 PB - Linköping University Electronic Press ER - TY - JOUR A1 - Selmair, Maximilian A1 - Maurer, Tobias A1 - Lai, Chun-Han A1 - Grant, David T1 - Enhancing the efficiency of charging & parking processes for Autonomous Mobile Robot fleets BT - A simulative evaluation JF - Journal of Power Sources N2 - 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. KW - AMR KW - Autonomous Mobile Robot KW - Battery charging KW - Battery management systems KW - Benchmarking KW - Fleet operations KW - Mobile robots KW - NAVIGATION KW - Secondary batteries KW - Vehicle Fleet Charging Y1 - 2022 U6 - https://doi.org/10.1016/j.jpowsour.2021.230894 VL - 521 IS - 3 PB - Elsevier ER - TY - JOUR A1 - Walter, Stefanie A1 - Schwanzer, Peter A1 - Steiner, Carsten A1 - Hagen, Gunter A1 - Rabl, Hans-Peter A1 - Dietrich, Markus A1 - Moos, Ralf T1 - 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 JF - Sensors N2 - 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. KW - mixing rule KW - dielectric properties KW - microwave cavity perturbation KW - finite element method (FEM) KW - soot mass determination KW - radio-frequency (RF) KW - gasoline particulate filter (GPF) Y1 - 2022 U6 - https://doi.org/10.3390/s22093311 VL - 22 IS - 9 SP - 1 EP - 17 PB - MDPI CY - Basel ER - TY - JOUR A1 - Mikhaeil, Makram A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - Experimental Investigation of the Adsorption and Desorption Kinetics on an Open-Structured Asymmetric Plate Heat Exchanger; Matching Between Small-Scale and Full-Scale Results JF - Frontiers in Energy Research N2 - 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%. Y1 - 2022 U6 - https://doi.org/10.3389/fenrg.2022.818486 N1 - Corresponding author: Belal Dawoud VL - 10 SP - 1 EP - 15 PB - Frontiers ER - TY - JOUR A1 - Zacherl, Florian A1 - Wopper, Christoph A1 - Schwanzer, Peter A1 - Rabl, Hans-Peter T1 - Potential of the Synthetic Fuel Oxymethylene Ether (OME) for the Usage in a Single-Cylinder Non-Road Diesel Engine: Thermodynamics and Emissions JF - Energies N2 - Non-road sectors, such as agriculture and construction machinery, require high energy densities and flexibility in use, which is why diesel engines are mainly used. The use of climate-neutral fuels, produced from renewable energies, such as Oxymethylene Ether (OME) as a diesel substitute, can significantly reduce CO2 and pollutant emissions in these sectors. In addition to CO2 neutrality, OME also offers improved combustion characteristics compared to diesel fuel, eliminating the soot–NOx trade-off and thus enabling new opportunities in engine design and calibration. In this paper, the combustion of pure OME on a close-to-production, single-cylinder non-road diesel engine with a pump–line–nozzle injection system is analyzed. A variation of the center of combustion at constant power output was performed for diesel and OME at different operating points. Two injectors were investigated with OME. A study on ignition delay and a detailed thermodynamic analysis was carried out. In addition, the exhaust emissions CO, NOx, VOC, as well as particulate-matter, -number and -size distributions were measured. With OME, a significantly shorter ignition delay as well as a shortened combustion duration could be observed, despite a longer injection duration. In addition, the maximum injection pressure increases. VOC and CO emissions are reduced. Particulate matter was reduced by more than 99% and particle number (>10 nm) was reduced by multiple orders of magnitude. The median of the particle size distribution shifts from 60 to 85 nm (diesel) into a diameter range of sub 23 nm (OME). A significant reduction of NOx emissions with OME enables new degrees of freedom in engine calibration and an efficiency advantage without hardware adaption. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-55350 N1 - Project: NAMOSYN: Nachhaltige Mobilität durch synthetische Kraftstoffe (Funding Nr. 03SF0566N0) N1 - Corresponding author: Florian Zacherl VL - 15 IS - 21 SP - 1 EP - 26 PB - MDPI ER - TY - INPR A1 - Gärtner, Sebastian A1 - Marx-Schubach, Thomas A1 - Gaderer, Matthias A1 - Schmitz, Gerhard A1 - Sterner, Michael T1 - Introduction of an Innovative Energy Concept for low Emission Glass Melting based on Carbon Capture and Usage N2 - 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. KW - glass KW - Oxyfuel KW - Methanation KW - Power-to-Gas KW - CO2 capture KW - Economic Analysis Y1 - 2022 U6 - https://doi.org/10.31224/2642 ER - TY - JOUR A1 - Kaul, Anja A1 - Boellmann, Andrea A1 - Thema, Martin A1 - Kalb, Larissa A1 - Stoeckl, Richard A1 - Huber, Harald A1 - Sterner, Michael A1 - Bellack, Annett T1 - Combining a robust thermophilic methanogen and packing material with high liquid hold-up to optimize biological methanation in trickle-bed reactors JF - Bioresource technology N2 - 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). KW - BIOCATALYTIC METHANATION KW - CARBON-DIOXIDE KW - hydrogen KW - Liquid hold-up maximization KW - MASS-TRANSFER KW - Methane production KW - Methanothermobacter KW - Methanothermococcus KW - Optimized packing-organism combination KW - THERMOAUTOTROPHICUS Y1 - 2022 U6 - https://doi.org/10.1016/j.biortech.2021.126524 VL - 345 PB - Elsevier ER - TY - CHAP A1 - Wagner, Marcus A1 - Al-Abadi, Ali A1 - Buchner, Stefan ED - López-Fernández, Xose M., T1 - A Numerical-Based Model to Determine the Resonance of the Steel Cores of Transformers T2 - ARWtr 2022 proceedings : 2022 7th Advanced Research Workshop on Transformers (ARWtr), October (23)24-26, 2022, Baiona, Spain N2 - 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. Y1 - 2022 SN - 978-84-09-45157-9 U6 - https://doi.org/https://doi.org/10.23919/ARWtr54586.2022.9959938 SP - 36 EP - 41 PB - IEEE ER - TY - CHAP A1 - Wagner, Marcus A1 - Lehrer, Tobias A1 - Franke, Markus A1 - Al-Abadi, Ali A1 - Gamil, Ahmed T1 - A Tank Resonance Model for Power Transformers T2 - ARWtr 2022 proceedings, 2022 7th Advanced Research Workshop on Transformers (ARWtr): October (23)24-26, 2022, Baiona, Spain N2 - 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. Y1 - 2022 U6 - https://doi.org/10.23919/ARWtr54586.2022.9959917 SP - 7 EP - 12 PB - IEEE ER - TY - CHAP A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Konzeptionierung netzplanerischer Prozessansätze zur Ermittlung von Blindleistungskapazitäten zum Ausgleich des Blindleistungsbedarfs in einer Netzregion T2 - Tagungsband Tagung Zukünftige Stromnetze 26./27. Januar 2022 (online) N2 - Um einen sicheren und zuverlässigen Stromnetzbetrieb zu gewährleisten, muss die Spannung im Grundfall als auch bei ungeplanten Ausfällen in definierten Bereichen gehalten werden. Im Übertragungsnetz wird hierfür bisher Blindleistung hauptsächlich aus Blindleistungskompensationsanlagen und konventionellen Großkraftwerken eingesetzt. Zukünftig wird nach §12h EnWG eine marktgestützte Beschaffung dieser Dienstleistung zur Spannungsregelung vorgeschrieben. Zugleich verändert sich der Blindleistungsbedarf der Netzbetriebsmittel durch die Integration erneuerbarer Energieanlagen und der Elektromobilität sowie durch den Netzausbau bei Übertragungs- und Verteilungsnetzbetreibern. Es bedarf somit angepasster Netzbetriebs- und Netzplanungskonzepte für ein technisch effizientes und wirtschaftlich günstiges Blindleistungsmanagement. Dieser Beitrag beschäftigt sich damit, Prozessansätze und Methodiken für ebendieses in der Netzplanung aufzuzeigen, um erforderliche Blindleistungskapazitäten unter minimalen Gesamtkostenaufwand und unter Berücksichtigung einer effizienten Blindleistungsbedarfsdeckung zu bestimmen. Dabei liegt der Fokus verstärkt in der Bedarfsanalyse. KW - Blindleistung KW - Blindleistungsmanagement KW - Netzplanungsprozesse KW - Spannungshaltung KW - Optimierungsverfahren Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-58665 SN - 978-3-948176-16-7 SP - 117 EP - 126 PB - Conexio-PSE GmbH CY - Pforzheim ER - TY - CHAP A1 - Schweiberer, Philipp A1 - Rauch, Johannes A1 - Brückl, Oliver T1 - Entwicklung eines Regelkonzeptes für einen optimierten Blindleistungsabruf auf Basis von Blindleistungspotentialanalysen bei Industriebetrieben im Mittelspannungsnetz T2 - Tagungsband Tagung Zukünftige Stromnetze 26./27. Januar 2022 (online) N2 - Im Zuge der Energiewende ergibt sich ein Wandel in der Struktur des Elektrizitätsversorgungsnetzes. Die Verschiebung der Erzeugungsleistung von konventionellen Großkraftwerken in höheren Netzebenen hin zu dezentralen erneuerbaren Energieanlagen in niedrigeren Netzebenen resultiert sowohl in bidirektionalen Lastflüssen als auch in schwankenden Einspeisecharakteristiken. Des Weiteren folgen durch den Wegfall von Großkraftwerken als Blindleistungsquellen Leistungsdefizite in der Übertragungsnetzebene, die kompensiert werden müssen. Daraus resultieren Herausforderungen an einen sicheren und zuverlässigen Betrieb der Verteil- und Übertragungsnetze. Neue Konzepte müssen für die Erbringung von Blindleistung entwickelt werden, es soll mehr Blindleistung aus dem Verteilungsnetz zur Verfügung gestellt werden, um die Systemstabilität zu wahren. Im Rahmen des Projektes Q-Integral wird das Thema „Blindleistung“ (Q) ganzheitlich untersucht. Es werden dazu verschiedene Erbringungsoptionen für Blindleistung hinsichtlich technischer und wirtschaftlicher Potentiale untersucht, die in ein funktionales und effizientes Blindleistungsmanagement eingebracht werden. Die Untersuchungsansätze dafür sind sowohl spannungsebenen-übergreifend als auch netzbetreiber-übergreifend. Ein Ansatzpunkt des Projektes ist die Betrachtung der Blindleistungsbereitstellung von Industriebetrieben. Dazu wird das Potential von Betrieben, die an das Verteilnetz angeschlossen sind und Blindleistung durch Kompensations- oder Erzeugungsanlagen bereitstellen können, untersucht. Ziel ist es, das gesicherte und maximale induktive sowie kapazitive Potential zu bestimmen. Das gesicherte kapazitive Potential kann genutzt werden, um Aussagen darüber zu treffen, wie stark dem Spannungsfall im vorgelagerten Netz zu Starklastzeiten entgegengewirkt werden kann. Anhand des gesicherten induktiven Potentials kann ein Spannungsanstieg während Schwachlastzeiten ausgeglichen werden kann. In diesem Beitrag werden Ergebnisse aus dem Projekt Q-Integral vorgestellt. Dazu werden zuerst die Berechnungsgrundlagen der induktiven und kapazitiven Blindleistungspotentiale aufgezeigt und die Ergebnisse der Berechnungen vorgestellt. Die gewonnen Ergebnisse entstammen aus Messungen an einem Industriebetrieb mit Blindleistungskompensationsanlagen (BKA), den entsprechenden Reglern der Anlagen und einer installierten Kompensationsleistung von 1600 kvar. Sowohl die Lastgänge als auch das Schaltverhalten der einzelnen Kompensationsanlagen liegen den Berechnungen zugrunde. Um den Austausch der Blindleistung an der Übergabestelle des Betriebs zum Mittelspannungsnetz netzdienlich einzustellen, bedarf es eines geeigneten Regelkonzepts, das neben den BKAs auch weitere Q-Quellen berücksichtigt. Deshalb wird abschließend ein Regelkonzept vorgestellt, das den technisch-optimierten Blindleistungsabruf unter Berücksichtigung mehrerer Blindleistungsquellen behandelt. KW - Blindleistung KW - Blindleistungsmanagement KW - Blindleistungsquellen KW - Blindleistungspotentiale KW - Industriebetriebe Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-58704 SN - 978-3-948176-16-7 SP - 224 EP - 233 PB - Conexio-PSE GmbH CY - Pforzheim ER - TY - CHAP A1 - Rauch, Johannes A1 - Brückl, Oliver A1 - Engel, Bernd ED - Schulz, Detlef T1 - Analysis and optimization of the steady state voltage deviation demand for reactive power planning using installed reactive power sources T2 - NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg N2 - 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. KW - Reactive Power KW - Reactiver Power Planning KW - Voltage Control KW - Optimal Power Flow KW - Differential Evolution Y1 - 2022 UR - https://ieeexplore.ieee.org/document/10048083 SN - 978-3-8007-5983-5 SN - 2510-6902 SP - 175 EP - 182 PB - VDE-Verlag CY - Berlin ER - TY - CHAP A1 - Schweiberer, Philipp A1 - Rauch, Johannes A1 - Brückl, Oliver ED - Schulz, Detlef T1 - Long-term analysis of industrial reactive power potentials with consideration of plant-internal grid restrictions using the example of an industrial plant in a distribution grid T2 - NEIS 2022; Conference on Sustainable Energy Supply and Energy Storage Systems, 26-27 September 2022, Hamburg N2 - Since conventional generation plants provide a considerable share of reactive power but are gradually being shut down due to energy transition, leading to power deficits at the transmission grid level, new concepts for the supply of reactive power must be developed. As one possibility for the latter, industrial plants in the distribution grid are considered suitable, as their reactive power potentials can contribute to voltage maintenance and thus to a grid- or system-serving behavior. In this paper, the determination of reactive power potentials provided by industrial compensation systems (ICS) is presented. An industrial plant in the medium voltage grid, with three installed ICSs, is investigated. The potentials are determined and described based on their time characteristics, which provide information about the occurrence and distribution of inductive and capacitive potentials. A grid simulation of the investigated industrial grid is used to analyze the effects of retrieving the reactive power potentials regarding equipment utilizations and voltage limits. KW - Reactive Power KW - Reactive Power Potentials KW - Industrial plant KW - Voltage Stability KW - Long term analysis Y1 - 2022 UR - https://ieeexplore.ieee.org/document/10048065 SN - 978-3-8007-5983-5 SN - 2510-6902 SP - 51 EP - 56 PB - VDE-Verlag CY - Berlin ER - TY - GEN A1 - Reindl, Andrea A1 - Eriksson, Lars A1 - Niemetz, Michael A1 - Sangyoung, Park A1 - Meier, Hans T1 - Control Concepts for a Decentralized Battery Management System Decentralized Battery Management System Global Control Level T2 - 16th International Renewable Energy Storage Conference (IRES2022), 20 to 22 September 2022, Düsseldorf Y1 - 2022 UR - https://www.researchgate.net/publication/363769042_Control_Concepts_for_a_Decentralized_Battery_Management_System_Decentralized_Battery_Management_System_Global_Control_Level PB - Eurosolar ER - TY - CHAP A1 - Körner, Patrick A1 - Reindl, Andrea A1 - Meier, Hans A1 - Niemetz, Michael T1 - A Theoretical Comparison of Different Virtual Synchronous Generator Implementations on Inverters T2 - 2022 24th European Conference on Power Electronics and Applications (EPE'22 ECCE Europe): 05-09 September 2022, Hannover, Germany N2 - The goal to overcome the global climate crisis leads to a rising demand for the usage of Renewable Energy Sources (RES). Decentralized control strategies are needed to allow the integration of RES into the grid. The Virtual Synchronous Generator (VSG) is proposed as a method to add virtual inertia to the grid by emulating the rotating mass of a Synchronous Generator (SG) on the control algorithm of an inverter. This paper presents the VSG control structure as well as the mathematical description in a unified form. Due to the fact that classical droop control can be seen as a special form of the VSG, their correlation is highlighted by evaluating the steady state output characteristics of the inverter. Furthermore, a theoretical comparison between different VSG topologies, including the VISMA-Method 2 and the synchronverter, is given. In order to achieve better voltage stability, principles to add virtual impedance to the inverter's output are described. Y1 - 2022 UR - https://ieeexplore.ieee.org/document/9907497 PB - IEEE ER - TY - JOUR A1 - Schächinger, J. A1 - Brückl, Oliver A1 - Becker, Mark A1 - Lechner, Raphael T1 - Results of the Research Project Optibiosy: Biogas plants as stabilizers of the power system? JF - BWK ENERGIE T2 - Biogasanlagen als Stabilisatoren des Stromsystems? Y1 - 2022 SN - 1436-4883 VL - 74 IS - 11-12 SP - 34 EP - 39 PB - VDI-Verlag CY - Düsseldorf ER - TY - RPRT A1 - Klitsman, Maksym A1 - Staudacher, Lars A1 - Brückl, Oliver A1 - Eller, Johannes A1 - Brey, Ludwig A1 - Eigenstetter, Florian T1 - neos - NetzEntwicklungsOffensive Strom - Schlussbericht BT - Projektlaufzeit: 01.09.2017 – 31.12.2021; gefördert durch Bayerisches Staatsministerium für Wirtschaft, Landesentwicklung und Energie N2 - Im Zuge der Energiewende werden die erneuerbaren Energien zur tragenden Säule unserer Stromversorgung. Bis 2025 sollen bundesweit 40-45 % des Stroms aus erneuerbaren Quellen stammen, bis 2050 sogar 80 %. Dabei wird der erzeugte Strom hauptsächlich aus Wind und Sonne stammen. Im Norden der Bundesrepublik wird Wind die Erzeugung dominieren, während im Süden, insbesondere in Bayern der Strom vornehmlich aus Photovoltaik gewonnen werden wird. Um die Ziele der Energiewende zu erreichen, wird neben den ausreichenden Erzeugungskapazitäten auch eine leistungsfähige Infrastruktur zur Verteilung und Nutzung des erneuerbaren Stroms notwendig sein. Planbarkeit und Sicherung der Versorgungsqualität bei zunehmenden Anteilen von volatiler Erzeugung werden dabei zu einer immer größeren Herausforderung. Das Projekt neos hat im engen Verbund mit den beteiligten Partnern wichtige tagesaktuelle Fragestellungen wissenschaftlich erörtert und untersucht, die sich durch die laufende Transformation des Energiesystems und den rasanten Ausbau der Anlagen zur erneuerbaren Energieerzeugung den Projektpartnern stellen. KW - Intelligentes Stromnetz KW - Energiewende KW - Netzplanung KW - Netzausbau KW - Elektromobilität KW - Spannungsqualität KW - regelbarer Ortsnetztransformator KW - Oberschwingungsbelastung KW - Netzberechnung KW - intelligente Netzbetriebsmittel Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:898-opus4-45248 ER - TY - JOUR A1 - Gamisch, Bernd A1 - Huber, Lea A1 - Gaderer, Matthias A1 - Dawoud, Belal T1 - On the Kinetic Mechanisms of the Reduction and Oxidation Reactions of Iron Oxide/Iron Pellets for a Hydrogen Storage Process JF - Energies N2 - This work aims at investigating the kinetic mechanisms of the reduction/oxidation (redox) reactions of iron oxide/iron pellets under different operating conditions. The reaction principle is the basis of a thermochemical hydrogen storage system. To simulate the charging phase, a single pellet consisting of iron oxide (90% Fe2O3, 10% stabilising cement) is reduced with different hydrogen (H2) concentrations at temperatures between 600 and 800 °C. The discharge phase is initiated by the oxidation of the previously reduced pellet by water vapour (H2O) at different concentrations in the same temperature range. In both reactions, nitrogen (N2) is used as a carrier gas. The redox reactions have been experimentally measured in a thermogravimetric analyser (TGA) at a flow rate of 250 mL/min. An extensive literature review has been conducted on the existing reactions’ kinetic mechanisms along with their applicability to describe the obtained results. It turned out that the measured kinetic results can be excellently described with the so-called shrinking core model. Using the geometrical contracting sphere reaction mechanism model, the concentration- and temperature-dependent reduction and oxidation rates can be reproduced with a maximum deviation of less than 5%. In contrast to the reduction process, the temperature has a smaller effect on the oxidation reaction kinetics, which is attributed to 71% less activation energy (Ea,Re=56.9 kJ/mol versus Ea,Ox=16.0 kJ/mol). The concentration of the reacting gas showed, however, an opposite trend: namely, to have an almost twofold impact on the oxidation reaction rate constant compared to the reduction rate constant. Y1 - 2022 U6 - https://doi.org/10.3390/en15218322 N1 - Corresponding author: Belal Dawoud VL - 15 IS - 21 PB - MDPI ER - TY - CHAP A1 - Arrieta Castro, Abel A1 - Rill, Georg ED - Orlova, Anna ED - Cole, David T1 - Kinematic Versus Elasto-Kinematic Model of a Twistbeam Suspension T2 - Advances in Dynamics of Vehicles on Roads and Tracks II, proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia N2 - The Twistbeam axle suspension is a cheap and robust layout for rear axles at front wheel driven midsize cars. Appropriate models have to take the elastic deformation of the torsion beam into account. A Finite Element approach requires detailed informations of the material properties and the shape which are usually only available in the final production stage. This paper presents a lumped mass model which can easily be integrated into a multibody vehicle model and can be used in the early stage of development. An approximation by the design kinematics further reduces the complexity of the model and considers only the kinematic properties of the Twistbeam suspension. Simulations using a nonlinear and three-dimensional vehicle model with different maneuvers, such as steady-state cornering, step steer input, and driving straight ahead on random road, demonstrate the performance and, in particular, the difference of the presented Twistbeam suspension models. KW - Design kinematics KW - Twistbeam suspension KW - Multibody model KW - Vehicle dynamics Y1 - 2022 U6 - https://doi.org/10.1007/978-3-031-07305-2_59 SP - 505 EP - 605 PB - Springer Nature ER - TY - CHAP A1 - Bünte, Tilman A1 - Rill, Georg A1 - Ruggaber, Julian A1 - Tobolář, Jakub ED - Orlova, Anna ED - Cole, David T1 - Modelling and Validation of the TMeasy Tyre Model for Extreme Parking Manoeuvres T2 - Advances in Dynamics of Vehicles on Roads and Tracks II, Proceedings of the 27th Symposium of the International Association of Vehicle System Dynamics (IAVSD 2021): August 17-19, 2021, Saint Petersburg, Russia N2 - The TMeasy is a tyre model suitable for vehicle handling analyses and enables easy parametrisation. Recently, a convenient interface to Modelica was implemented by DLR to support the TMeasy also for vehicle modelling in multi-physical domains. This paper focuses especially on the particular problem of reliable reproduction of the tyre’s bore torque which occurs during parking manoeuvres. It outlines the theory behind it, discusses the Modelica interface implementation, and presents the results of parameter identification which were achieved based on real experiments with DLR’s research platform ROboMObil. Y1 - 2022 SN - 978-3-031-07305-2 SN - 978-3-031-07304-5 U6 - https://doi.org/10.1007/978-3-031-07305-2_94 SP - 1015 EP - 1025 PB - Springer CY - Cham ER - TY - CHAP A1 - Rill, Georg T1 - A Three-Dimensional and Nonlinear Virtual Test Car T2 - ENOC 2022, book of abstracts, 10th European Nonlinear Dynamics Conference: July 17-22, 2022, Lyon, France N2 - Virtual testing procedures have become a standard in vehicle dynamics. The increasing complexity of driver assistance sys- tems demand for more and more virtual tests, which are supposed to produce reliable results even in the limit range. As a consequence, simplified vehicle models, like the classical bicycle model or 4-wheel vehicle models, have to be replaced by a fully three-dimensional and nonlinear vehicle model, which also encompasses the details of the suspension systems. This paper presents a passenger car model, where the chassis, the four knuckles, and the four wheels are described by rigid bodies, the suspension system is modeled by the generic design kinematics, and the TMeasy tire model provides the tire forces and torques in all driving situations. Y1 - 2022 UR - https://enoc2020.sciencesconf.org/data/ENOC2022_proceedings.pdf SP - 49 EP - 58 CY - Lyon ER - TY - JOUR A1 - Emberger, Peter A1 - Altmann, Robert A1 - Gebhard, Jürgen A1 - Thuneke, Klaus A1 - Winkler, Markus A1 - Töpfer, Georg A1 - Rabl, Hans-Peter A1 - Remmele, Edgar T1 - Combustion characteristics of pure rapeseed oil fuel after injection in a constant volume combustion chamber with a non-road mobile machinery engine solenoid injector JF - Fuel N2 - Pure rapeseed oil fuel (R100) according to standard DIN 51605 is a greenhouse gas saving option for the mobility sector. With its high energy density close to diesel fuel, R100 is suitable to operate non-road mobile machinery with a high power demand and long operating time, where electric drives reach their limits. Advantages are indicated for its use in environmentally sensitive areas like agriculture since R100 is highly biodegradable and non-toxic. However, R100 is characterised by differing physical and chemical properties compared to diesel. The objective of the research is to investigate the differences in the ignition and combustion behaviour of R100 compared to diesel fuel (DF). For this purpose, a constant volume combustion chamber is used, which is equipped with a modern solenoid injector for engines of non-road mobile machinery. The researched injector shows a different hydraulic behaviour when using R100 compared to DF in that the injected fuel mass is lower with R100 than with DF. In combination with the 14 % by mass lower calorific value, less energy output is determined with R100. When varying the injection pressure, the impact on the ignition delay and combustion behaviour is much higher for R100 than for DF. Specifically, an increase of the injection pressure supports mixture preparation and thus partially compensates the differing physical properties of R100. The results of ignition delay measurements and net heat release analysis are as follows: At low load conditions with low injection pressure as well as a low combustion chamber temperature and pressure, R100 ignites later and shows a further delayed combustion compared to diesel. The opposite is observed for medium and high load conditions, where R100 ignites faster and without delayed combustion in comparison to DF. Thus, an adjustment of the heat release of R100 at the same level as for DF is possible by modifying the injection strategy. The research shows that for an optimised combustion of R100 the injection settings must be adjusted for every operation point separately. The results indicate how the injection parameters should be adjusted for different load conditions to realise a high-quality engine calibration for R100. KW - Constant volume combustion chamber KW - Ignition behaviour KW - Non-road mobile machinery KW - Rapeseed oil fuel KW - Solenoid injector KW - Straight vegetable oil fuel Y1 - 2022 U6 - https://doi.org/10.1016/j.fuel.2022.123979 IS - 320 PB - Elsevier ER -