Inst. Energietechnik

112 Items

Recent Submissions
Messdaten zum Honigmann-Prozess

Jahnke, Anna (2019-02-01)

Bei den beiliegenden Dateien handelt es sich um Messdaten zu Versuchen zum Honigmann-Prozess. Informationen zur Entstehung der Messwerte und deren Analyse finden sich in der dazugehörigen Dissertation "Untersuchung des Honigmann-Prozesses zur thermochemischen Energiespeicherung"

Untersuchung des Honigmann-Prozesses zur thermochemischen Energiespeicherung

Jahnke, Anna (2019)

Topic of this work is the evaluation of a thermochemical energy conversion and storage process. It can be loaded either with the input of heat or mechanical work. The stored energy can be retrieved in the form of heat, cold or mechanical work at a later point in time. The process was originally invented to drive a fireless locomotive and was patented at the end of the 19th century by Moritz Hon...

Evaluation and optimization of natural gas liquefaction process with exergy-based methods: a case study for C3MR

Primabudi, Eko (2019)

Propane pre-cooled mixed refrigerant process, known as C3MR, is the leading technology in the LNG market based on the capacity installed. In this study, exergy-based methods were implemented in order to obtain optimal operation conditions. The C3MR process is modeled with 4.5 MTPA production capacity using Aspen Plus process simulator, which is connected to the exergy and exergoeconomic analysi...

Evaluation and improvement of energy management in industrial baking ovens

Jado, Ahmed Hamdy Kamel Abdelsalam (2019)

The final step in bread making is the baking process to produce the final attributes of product quality, including texture, color, and flavor, as a result of several thermal reactions. These thermal reactions are dominated by heat and mass transfer mechanisms inside an oven chamber as well as inside the dough pieces. This research involves studying existing methods of baking bread in a common ...

Exergy-based methods applied to the processes of LNG regasification integrated into air separation units

Tesch, Stefanie Janine (2019)

The share of natural gas on the overall energy supply is among the other fossil fuels (coal and oil) the fastest growing. The market for the liquefied natural gas (LNG) has increased during the last years. In the import terminal, the LNG is regasified using direct or indirect heat transfer. Within these conventional regasification systems the low-temperature exergy of LNG is destroyed. Thus, di...

Thermische Speicher zur Optimierung des Betriebs von Heizkraftwerken in der Fernwärmeversorgung

Christidis, Andreas Christos (2019)

Der Energieversorgungssektor wird seit Anfang des Jahrtausends immer stärker von den gesellschaftspolitischen Zielen geprägt, den fossilen Primärenergieeinsatz und damit die anthropogenen Treibhausgasemissionen zu reduzieren. Wesentliche Maßnahmen um diese Ziele zu erreichen sind neben Einsparungen im Endenergieverbrauch, die Effizienzsteigerung der Energieumwandlung und die Erhöhung des Anteil...

Exergy-based analysis of aircraft environmental control systems and its integration into model-based design

Bender, Daniel (2019)

Aircraft environmental control systems are complex energy intensive systems and the most important non-propellant consumer of energy among all aircraft systems. The intense pressure on airlines to remain competitive on the global market demands more efficient aircraft greater than ever. Meaningful analysis methods for the evaluation of architectural designs and effective modeling and simulation...

Comparative evaluation of methanol production processes using natural gas

Blumberg, Timo Dominik (2018)

In the work, different processes for the production of methanol from natural gas are analysed from a thermodynamic and an economic point of view. Commercially available processes and promising future alternatives for increased thermodynamic efficiency, improved economics and reduced greenhouse gas emissions are assessed and compared. The analysed processes are based on the indirect synthesis ro...

Experimentelle und modellgestützte Charakterisierung von Adsorptionswärmeübertragern

Wittstadt, Ursula (2018)

Adsorptionsprozesse können zur Wärme- oder Kälteerzeugung genutzt werden. Dafür kommen thermisch angetriebene Wärmepumpen oder Kältemaschinen zum Einsatz. Zentrale Komponenten dieser Anlagen sind Wärmeübertrager, die mit einem Adsorptionsmaterial befüllt oder beschichtet sind. Da Wärme – und Stofftransport in solchen Adsorptionswärmeübertragern stark gekoppelt sind, ist die gezielte Entwicklung...

Theoretische Untersuchung des Wärme- und Stoffübergangs am laminaren Fallfilm

Mittermaier, Martin (2018)

In this thesis a model is presented describing a laminar film flow over a vertical isothermal plate while heat and mass transfer is occurring. Most common assumptions, such as constant property data and constant film thickness, have been cancelled. The hydrodynamic model results in longitudinal and transversal velocity components and their evolution in the entrance region. Heat and mass transfe...

Analytische und numerische Modellbildung zur Vermeidung von Rückströmungen aufgrund von Störgrößen in Reinräumen

Brandt, Stefan (2018)

In der vorliegenden Arbeit werden Funktionen und Berechnungen von Rückströmungen aufgrund von Zustandsänderungen der Volumenstromstellglieder in Reinräumen dargestellt. Die Zustandsänderungen werden in aktive und passive Störgrößen unterteilt. Ausgehend von den Ergebnissen der Untersuchungen werden Berechnungsvorschriften zum Auftreten von Rückströmungen aufgrund von Störgrößen in Reinräumen be...

The PSS quality framework for solar home systems

Kebir, Noara Zohra ; Philipp, Daniel (2016-08)

In September 2015, the United Nations General Assembly has adopted the Sustainable Development Goals; they include SDG 7 targeting universal access to electricity by 2030. Reaching this goal implies huge investments in generation capacity, grid extension and densification. However, according to the International Energy Agency, 70% of the world's population currently excluded from electricity se...

Dampferzeugeroptimierung zur Abwärmenutzung mittels Dampfkraftprozess an mobilen Verbrennungsmotoren

Stinner, Karl (2018)

Die im Kraftstoff gespeicherte Energie wird auch bei modernsten Verbrennungsmotoren nur zu ungefähr 30% in mechanische Antriebsleistung umgewandelt. Der größere Teil geht als Abwärme an die Umgebung verloren. Der daraus resultierende mittlere Wirkungsgrad des Pkw-Verbrennungsmotors kann jedoch durch teilweise Umwandlung der thermischen Energie erhöht werden. Hierzu kann die im Abgas verbleiben...

Evaluation of an energy- and exergy-based generic modeling approach of combined heat and power plants

Mollenhauer, Eike ; Christidis, Andreas ; Tsatsaronis, George (2016-02-29)

Reduced models of combined heat and power plants are required for different applications. Among other usages, they are implemented as mixed integer linear programs (MILP) in energy market models or price-based unit commitment problems to study the economic feasibility and optimal operation strategies of different units. Generic models are particularly useful when limited information is availabl...

Advanced exergoeconomic analysis of a power plant with CO2 capture

Petrakopoulou, Fontina ; Tsatsaronis, George ; Morosuka, Tatiana (2015)

Conventional exergy-based analyses reveal options for improving energy conversion systems, but they suffer from some limitations that are addressed by advanced exergy-based analyses. Advanced exergy-based methods are capable of (1) identifying interdependencies among plant components (endogenous / exogenous values), and (2) revealing the potential for improvement (avoidable / unavoidable values...

Experimental investigation of a liquid desiccant system for air dehumidification working with ionic liquids

Zegenhagen, Mark T. ; Ricart, Cristina ; Meyer, Thomas ; Kühn, Roland ; Ziegler, Felix (2015)

Electrically-driven compression chillers are the commonly used technology for cooling and dehumidifying air. Open sorption systems driven by solar heat are an alternative to conventional air dehumidification technology and may reduce primary energy consumption. For air dehumidification, liquid desiccant systems may exhibit some process engineering and thermodynamic advantages in comparison to s...

Applicability of Drag Reducing Agents in Domestic Heating Systems

Brandt, Daniel ; Tawackolian, Karsten ; Kriegel, Martin (2017-04-05)

A special test rig was built to investigate the applicability of drag reducing agents, especially in domestic heating systems, detect problems inside the technical implementation and describe the difference between ideal characterization and application.

Additives Shear-Thinning and Turbulence Damping Influence on the Fitting Loss Coefficient of Bends

Tawackolian, Karsten ; Brandt, Daniel ; Kriegel, Martin (2017-04-05)

The flow of a drag-reducing surfactant solution in a bend with a curvature radius of 1.5 is considered, where 20 mm is the pipe inside diameter.

Transient lattice contraction in the solid-to-plasma transition

Ferguson, K. R. ; Bucher, M. ; Gorkhover, Tais ; Boutet, S. ; Fukuzawa, H. ; Koglin, J. E. ; Kumagai, Y. ; Lutman, A. ; Marinelli, A. ; Messerschmidt, M. ; Nagaya, K. ; Turner, J. ; Ueda, K. ; Williams, G. J. ; Bucksbaum, P. H. ; Bostedt, C. (2016)

In condensed matter systems, strong optical excitations can induce phonon-driven processes that alter their mechanical properties. We report on a new phenomenon where a massive electronic excitation induces a collective change in the bond character that leads to transient lattice contraction. Single large van der Waals clusters were isochorically heated to a nanoplasma state with an intense 10-...

Against the Odds: The Potential of Swarm Electrification for Small Island Development States

Koepke, Mathias ; Groh, Sebastian (2016)

The paper builds on earlier observations using system complexity theory to explain the characteristics of a swarm electrification approach using existing small, distributed renewable energy generation infrastructure integrated into a grid. The concept is based on swarm intelligence where information and electricity flow between neighbors to achieve a compounding network effect, in that they are...