TY - THES A1 - Abang, Roger Atini T1 - Thermodynamic modeling and experimental investigations of high temperature corrosion and oxidation due to increased power plant cycling KW - Cycling KW - Flexible generation KW - High temperature corrosion; Oxidation KW - Oxidation KW - Thermo-chemical modeling Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus4-40032 ER - TY - CHAP A1 - Abang, Roger Atini A1 - Findeisen, Alexander A1 - Krautz, Hans Joachim T1 - Corrosion Investigation of Materials under Oxyfuel Firing Conditions Y1 - 2010 ER - TY - GEN A1 - Abang, Roger Atini A1 - Lisk, Alexander A1 - Krautz, Hans Joachim T1 - Fireside corrosion of superheater materials under oxy-coal firing conditions T2 - Energy Procedia N2 - The present study investigates the fireside corrosion behavior of selected superheater materials, namely: T24, P92, VM12-SHC, A800HT, and 7RE10 under oxy-coal combustion atmospheres. Data on mass change, scale thickness, metal loss, surface morphology and micro-structural characteristics of corrosion products were obtained. The alloy specimens were analyzed by SEM-EDX, light microscopy and X-Ray diffraction techniques. The results after 2000 hours of exposure at a metal surface temperature of 600 °C indicate that metal wastage increased with decreasing Cr-content under oxy-coal conditions. Y1 - 2013 U6 - https://doi.org/10.1016/j.egypro.2013.08.035 SN - 1876-6102 VL - 40 SP - 304 EP - 311 ER - TY - GEN A1 - Abang, Roger Atini A1 - Weiß, Sabine A1 - Krautz, Hans Joachim T1 - Impact of increased power plant cycling on the oxidation and corrosion of coal-fired superheater materials T2 - Fuel N2 - As power generation from variable renewable energy sources such as wind and solar power continues to increase in the future, fewer baseload power plants will be needed. As a result, high operational flexibility is becoming a vital requirement for conventional power plants to allow for the smooth integration of the variable renewable energy sources (v-RES) into the grid. To understand the impact of high operational flexibility (increased cycling) for coal-fired power plant materials, five commercial coal boiler superheater and reheater materials were investigated under isothermal and cyclic conditions for 1000 h each. The candidate alloys investigated were: T91, VM12-SHC, TP347-HFG, DMV304 HCu and DMV310 N. The results (weight change kinetics and metallographic analysis) after exposure at a metal surface temperature of 650 °C clearly showed the impact of increased flexibility on the corrosion and oxidation of the materials. Oxide growth (weight gain), metal loss, oxide spallation, and grain boundary attack were found to be more severe under cyclic conditions than under isothermal conditions. KW - Power plant flexibility, Isothermal oxidation, Cyclic oxidation, High temperature corrosion, Superheaters Y1 - 2018 U6 - https://doi.org/10.1016/j.fuel.2018.02.047 SN - 0016-2361 VL - 2018 IS - 220 SP - 521 EP - 534 ER - TY - GEN A1 - Aha, Ulrich A1 - Findeisen, Alexander A1 - Krautz, Hans Joachim T1 - Maintenance optimization for large coal-fired power plants Y1 - 2011 ER - TY - CHAP A1 - Aha, Ulrich A1 - Koch, Alexander A1 - Krautz, Hans Joachim T1 - Finding the optimal power plant maintenance strategy with fuzzy input data T2 - 11th International Probabilistic Safety Assessment and Management Conference and the Annual European Safety and Reliability Conference 2012, (PSAM11 ESREL 2012), Helsinki, Finland 25 - 29 June 2012, Vol. 1 Y1 - 2012 SN - 978-1-62276-436-5 SP - 341 EP - 347 PB - IAPSAM & ESRA CY - Red Hook, NY ER - TY - CHAP A1 - Aha, Ulrich A1 - Manig, André A1 - Krautz, Hans Joachim T1 - Maintenance optimisation for the next generation of power plants Y1 - 2011 ER - TY - CHAP A1 - Aha, Ulrich A1 - Manig, André A1 - Krautz, Hans Joachim ED - Bérenguer, Christophe T1 - Modelling and maintenance optimisation for the next generation of power plants T2 - Advances in safety, reliability and risk management, proceedings of the European Safety and reliability Conference, ESREL 2011, Troyes, France, 18 - 22 September 2011 Y1 - 2011 SN - 978-0-415-68379-1 PB - CRC Press CY - Hoboken ER - TY - GEN A1 - Akay, Ömer A1 - Bashkatov, Aleksandr A1 - Coy, Emerson A1 - Eckert, Kerstin A1 - Einarsrud, Kristian Etienne A1 - Friedrich, Andreas A1 - Kimmel, Benjamin A1 - Loos, Stefan A1 - Mutschke, Gerd A1 - Röntzsch, Lars A1 - Symes, Mark D. A1 - Yang, Xuegeng A1 - Brinkert, Katharina T1 - Electrolysis in reduced gravitational environments: current research perspectives and future applications T2 - npj Microgravity N2 - Electrochemical energy conversion technologies play a crucial role in space missions, for example, in the Environmental Control and Life Support System (ECLSS) on the International Space Station (ISS). They are also vitally important for future long-term space travel for oxygen, fuel and chemical production, where a re-supply of resources from Earth is not possible. Here, we provide an overview of currently existing electrolytic energy conversion technologies for space applications such as proton exchange membrane (PEM) and alkaline electrolyzer systems. We discuss the governing interfacial processes in these devices influenced by reduced gravitation and provide an outlook on future applications of electrolysis systems in, e.g., in-situ resource utilization (ISRU) technologies. A perspective of computational modelling to predict the impact of the reduced gravitational environment on governing electrochemical processes is also discussed and experimental suggestions to better understand efficiency-impacting processes such as gas bubble formation and detachment in reduced gravitational environments are outlined. KW - Elektrolyse KW - electrolysis Y1 - 2022 UR - https://www.nature.com/articles/s41526-022-00239-y#citeas U6 - https://doi.org/10.1038/s41526-022-00239-y SN - 2373-8065 VL - 8 ER - TY - THES A1 - Asegehegn, Teklay Weldeabzgi T1 - Investigation of bubble hydrodynamics in gas-solid fluidized beds containing immersed horizontal tube banks for lignite drying application Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus-23578 UR - http://opus.kobv.de/btu/volltexte/2012/2357/ ER - TY - CHAP A1 - Asegehegn, Teklay Weldeabzgi A1 - Krautz, Hans Joachim T1 - Numerical study of bubble hydrodynamics for gas-solid fluidized bedswith and without horizontal tubes Y1 - 2010 ER - TY - CHAP A1 - Asegehegn, Teklay Weldeabzgi A1 - Krautz, Hans Joachim T1 - Hydrodynamic simulation of gas-solid bubbling fluidized bed containing horizontal tubes Y1 - 2009 ER - TY - CHAP A1 - Asegehegn, Teklay Weldeabzgi A1 - Schreiber, Matthias A1 - Krautz, Hans Joachim T1 - Influence of Horizontal Tubes, Averaging Periods and Extraction Methods on the Hydrodynamics of Bubbling Gas-Solid Fluidized Beds Y1 - 2010 ER - TY - GEN A1 - Asegehegn, Teklay Weldeabzgi A1 - Schreiber, Matthias A1 - Krautz, Hans Joachim T1 - Numerical Study of Bubbling Gas-Solid Fluidized Beds Hydrodynamics: Influence of Immersed Horizontal Tubes and Data Analysis Y1 - 2011 UR - http://www.bepress.com/ijcre/vol9/A16 ER - TY - GEN A1 - Asegehegn, Teklay Weldeabzgi A1 - Schreiber, Matthias A1 - Krautz, Hans Joachim T1 - Investigation of bubble behavior in fluidized beds with and without immersed horizontal tubes using a digital image analysis technique Y1 - 2011 U6 - https://doi.org/http://dx.doi.org/10.1016/j.powtec.2011.03.025 ER - TY - GEN A1 - Asegehegn, Teklay Weldeabzgi A1 - Schreiber, Matthias A1 - Krautz, Hans Joachim T1 - Numerical simulation and experimental validation of bubble behavior in 2D gas-solid fluidized beds with immersed horizontal tubes Y1 - 2011 U6 - https://doi.org/http://dx.doi.org/10.1016/j.ces.2011.07.056 ER - TY - GEN A1 - Asegehegn, Teklay Weldeabzgi A1 - Schreiber, Matthias A1 - Krautz, Hans Joachim T1 - Influence of two- and three-dimensional simulations on bubble behaviorin gas-solid fluidized beds with and without immersed horizontal tubes Y1 - 2012 U6 - https://doi.org/10.1016/j.powtec.2011.11.050 ER - TY - CHAP A1 - Carotenuto, A. S. A1 - Correa da Silva, Rodrigo A1 - Rech, R. A1 - Marcilio, N. R. A1 - Smith Schneider, Paulo A1 - Krautz, Hans Joachim T1 - Preliminary Investigation of the Global Kinetic Parameters of low-rank coals under oxy-fuel conditions Y1 - 2011 ER - TY - CHAP A1 - Chalupnik, Rolf W. A1 - Krautz, Hans Joachim A1 - Schulze, H. A1 - Stuhlmüller, F. A1 - Thielen, W. T1 - Plant studies and experiments for a lignite-fired combined-cycle power plant using circulating pressurized fluidized bed combustion Y1 - 1999 ER - TY - CHAP A1 - Chalupnik, Rolf W. A1 - Krautz, Hans Joachim A1 - Wirtz, M. A1 - Stuhlmüller, F. T1 - Applied Research for a New Generation of Lignite-Fired Combined Cycle Power Plant Using Circulating Pressurized Fluidized Bed Combustion Y1 - 2001 ER - TY - CHAP A1 - Correa da Silva, Rodrigo A1 - Kangwanpongpan, Tanin A1 - Findeisen, Alexander A1 - Krautz, Hans Joachim T1 - Description of a 0.4 MWth laboratory facility for oxy-fuel combustion studies Y1 - 2011 ER - TY - GEN A1 - Correa da Silva, Rodrigo A1 - Kangwanpongpan, Tanin A1 - Findeisen, Alexander A1 - Krautz, Hans Joachim A1 - Meyer, Marco A1 - Roberg, Benedikt T1 - Oxy-fuel Combustion Studies Applying a Novel Test Facility - First Numerical Results Y1 - 2011 ER - TY - CHAP A1 - Correa da Silva, Rodrigo A1 - Krautz, Hans Joachim T1 - Theoretical analysis of heat transfer in a pulverized coal combustion chamber under O2/CO2 atmosphere Y1 - 2009 ER - TY - CHAP A1 - Correa da Silva, Rodrigo A1 - Krautz, Hans Joachim T1 - Theoretical investigation of pulverized coal combustion in air and in O2/CO2 atmospheres Y1 - 2009 ER - TY - CHAP A1 - Correa da Silva, Rodrigo A1 - Missagia, Bruna A1 - Tappe, Stephanie A1 - Findeisen, Alexander A1 - Krautz, Hans Joachim T1 - Development of low CO2 technologies for oxyfuel combustion in power plants Y1 - 2009 ER - TY - GEN A1 - Dahash, Abdulrahman A1 - Mieck, Sebastian A1 - Ochs, Fabian A1 - Krautz, Hans Joachim T1 - A comparative study of two simulation tools for the technical feasibility in terms of modeling district heating systems: An optimization case study T2 - Simulation Modelling Practice and Theory N2 - District heating dynamic models arise as an alternative approach to in-situ experimental investigations. The main advantage of dynamic modeling and simulation is the possibility to avoid technical and operational risks that might occur during in-situ experimental investigations (e.g. heat demand is not met, damages in the energy systems etc.). Within this study, the authors present two models for an existing district heating system in Cottbus, Germany. One model is developed using the tool EBSILON Professional, while the other one is developed using the Simscape toolbox for physical modeling in Matlab/Simulink. The models were experimentally validated against measured data from the considered district heating system. The results show that the Simscape model has a better fit and better response than the EBSILON model. Yet, some discrepancies were found between the measured and the simulated data and, therefore, the uncertainties of the models were addressed. A comparative study between both tools is presented. The EBSILON models permit only unidirectional flow, whereas the Simscape toolbox permits reverse flow. Nevertheless, the EBSILON model outperforms the Simscape model in computation time. In addition, this study presents an approach for dynamic thermo-hydraulic modeling of district heating networks. This approach is utilized to examine the role of district heating networks as heat storage as an optimization configuration. The numerical results show less start-ups for additional heat sources. Yet, higher heat losses from the network are observed due to the installation of unburied pipelines. KW - Dynamic thermo-hydraulic modeling and simulation KW - Simscape KW - EBSILON Professional KW - District heating systems KW - Heating network as heat storage Y1 - 2019 U6 - https://doi.org/10.1016/j.simpat.2018.11.008 SN - 1569-190X VL - 91 SP - 48 EP - 68 ER - TY - CHAP A1 - Findeisen, Alexander T1 - Analysis of corrosion behaviour of materials in oxyfuel fired power plants Y1 - 2008 ER - TY - CHAP A1 - Findeisen, Alexander A1 - Abang, Roger Atini A1 - Krautz, Hans Joachim T1 - Corrosion Behaviour of Selected Power Plant Materials Under Oxyfuel Combustion Conditions Y1 - 2011 ER - TY - GEN A1 - Findeisen, Alexander A1 - Klatt, Matthias A1 - Krautz, Hans Joachim T1 - Examination of the corrosion behaviour of selected power plant materials under various operating conditions KW - Korrosion KW - CCS Y1 - 2010 U6 - https://doi.org/http://dx.doi.org/10.1016/j.chemer.2010.05.006 ER - TY - CHAP A1 - Findeisen, Alexander A1 - Krautz, Hans Joachim A1 - Hauke, Th. A1 - Kranzmann, A. T1 - Corrosion Processes and Carbonisation of Boiler Materials under Air and Oxyfuel Process Conditions Y1 - 2011 ER - TY - CHAP A1 - Fischer, Ulrich A1 - Krautz, Hans Joachim A1 - Wenske, Michael A1 - Tannert, Daniel A1 - Krüger, Perco A1 - Ziems, Christian A1 - Stolten, Detlef A1 - Emonts, Bernd T1 - Hydrogen Hybrid Power Plant in Prenzlau, Brandenburg T2 - Hydrogen Science and Engineering - Materials, Processes, Systems and Technology, Bd. 2 Y1 - 2016 SN - 978-3-5273323-8-0 SP - 1033 EP - 1052 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Fischer, Ulrich A1 - Tannert, Daniel A1 - Voigt, Andre A1 - Ziems, Christian A1 - Krautz, Hans Joachim A1 - Barz, Mirko A1 - Dinkler, Konstantin T1 - Renewable Energy Storage by Hydrogen Production from Water Electrolysis T2 - Technical and Economic Aspects of Renewable Energies - Know-How Transfer as Development Opportunity for Southern Europe Y1 - 2016 SN - 978-3-86387-721-7 SP - 118 EP - 126 PB - Mensch und Buch CY - Berlin ER - TY - CHAP A1 - Fischer, Ulrich A1 - Voigt, Andre A1 - Tannert, Daniel A1 - Krautz, Hans Joachim T1 - Pressure and Temperature Influence on Alkine Electrolysis Performance T2 - Proceedings of 5th European PEFC and H2 Forum, Luzern, Schweiz, June/July 2015 Y1 - 2015 SN - 978-3-905592-19-1 PB - European Fuel Cell Forum AG CY - Luzern-Adligenswil ER - TY - CHAP A1 - Fischer, Ulrich A1 - Voigt, Andre A1 - Tannert, Daniel A1 - Krautz, Hans Joachim T1 - Influence of variable operating parameters on the process of the advanced alkaline pressurised electrolysis T2 - 9th International Renewable Energy Storage Conference and Exhibition (IRES 2015), 09 - 11 March 2015, Düsseldorf, Germany Y1 - 2015 PB - EUROSOLAR [u.a.] CY - Bonn ER - TY - CHAP A1 - Griebe, Steffen A1 - Krautz, Hans Joachim T1 - Development of a cycloid combustion system for lignite and co-combustion of sewages sludge and biomass with high efficiency and low emission Y1 - 2001 ER - TY - CHAP A1 - Guerrero, Cinthya A1 - Klatt, Matthias A1 - Krautz, Hans Joachim T1 - Energy transition in Germany: a case study on renewable energy integration and its impact in the operation and efficiency of coal-fired power plants T2 - Southern African Energy Efficiency Convention (SAEEC 2017), 14th and 15th November 2017, Gauteng, Südafrika Y1 - 2017 UR - http://www.saee.org.za/cproceedings2017.aspx#K SN - 978-0-6399125-0-9 ER - TY - GEN A1 - Horsfield, B. A1 - Scheck-Wenderoth, Magdalena A1 - Krautz, Hans Joachim A1 - Mutti, M. T1 - Geoenergy: From visions to solutions KW - CCS Y1 - 2010 U6 - https://doi.org/http://dx.doi.org/10.1016/j.chemer.2010.06.002 ER - TY - GEN A1 - Höhne, Olaf A1 - Lechner, Stefan A1 - Schreiber, Matthias A1 - Krautz, Hans Joachim T1 - Drying of Lignite in a Pressurized Steam Fluidized Bed - Theory and Experiments Y1 - 2010 ER - TY - GEN A1 - Kangwanpongpan, Tanin A1 - Correa da Silva, Rodrigo A1 - Krautz, Hans Joachim T1 - Prediction of oxy-coal combustion through an optimized weighted sum of gray gases model T2 - Energy : the international journal Y1 - 2011 U6 - https://doi.org/10.1016/j.energy.2011.06.010 SN - 0360-5442 VL - 41 IS - 1 SP - 244 EP - 251 ER - TY - CHAP A1 - Kangwanpongpan, Tanin A1 - Correa da Silva, Rodrigo A1 - Krautz, Hans Joachim T1 - Prediction of oxy-coal combustion through an optimized weighted sum of gray gases model Y1 - 2010 ER - TY - GEN A1 - Kangwanpongpan, Tanin A1 - Franca, Francis H. R. A1 - Correa da Silva, Rodrigo A1 - Smith Schneider, Paulo A1 - Krautz, Hans Joachim T1 - New correlations for the weighted-sum-of-gray-gases model in oxy-fuel conditions based on HITEMP 2010 database T2 - International Journal of Heat and Mass Transfer Y1 - 2012 U6 - https://doi.org/10.1016/j.ijheatmasstransfer.2012.07.032 SN - 0017-9310 VL - 55 IS - 25-26 SP - 7419 EP - 7433 ER - TY - CHAP A1 - Kangwanpongpan, Tanin A1 - Klatt, Matthias A1 - Krautz, Hans Joachim T1 - Challenges of oxyfuel combustion modeling for carbon capture Y1 - 2012 ER - TY - CHAP A1 - Kangwanpongpan, Tanin A1 - Krautz, Hans Joachim T1 - Investigation of oxyfuel combustion by numerical simulation with different turbulent flow models Y1 - 2009 ER - TY - CHAP A1 - Kangwanpongpan, Tanin A1 - Krautz, Hans Joachim T1 - Numerical simulation of lignite combustion in O2/CO2 environment by Eddy-Dissipation Model T2 - Verbrennung und Feuerung, Tagung Bochum, 16. und 17. September 2009, 24. Deutscher Flammentag Y1 - 2009 SN - 978-3-18-092056-6 SP - 579 EP - 582 PB - VDI-Verlag CY - Düsseldorf ER - TY - CHAP A1 - Kangwanpongpan, Tanin A1 - Nimtz, Michael A1 - Klatt, Matthias A1 - Krautz, Hans Joachim T1 - Numerical Investigations for Oxy-fuel Combustion in 0.4 MWth Pilot Scale Furnace T2 - Geo-Energy International Conference Y1 - 2012 UR - http://dc-app3-13.gfz-potsdam.de/images/dokumente/kangwanpongpan-geoen-poster.pdf ER - TY - GEN A1 - Katzer, Christian A1 - Babul, Konrad A1 - Klatt, Matthias A1 - Krautz, Hans Joachim T1 - Quantitative und qualitative relationship between swirl burner operating conditions and pulverized coal flame length T2 - Fuel Processing Technology KW - Flame length KW - Flame stability KW - Swirl burner KW - Pulverized coal KW - Image processing Y1 - 2017 U6 - https://doi.org/10.1016/j.fuproc.2016.10.013 SN - 0378-3820 VL - 156 SP - 138 EP - 155 ER - TY - CHAP A1 - Katzer, Christian A1 - Babul, Konrad A1 - Klatt, Matthias A1 - Krautz, Hans Joachim T1 - Quantitative and qualitative relationship between the flame stability and flame length T2 - Proceedings of the XXII International Symposium on Combustion Processes, Polish Jurassic Highland (Jura Region), Poland, September 22-25, 2015 Y1 - 2015 SN - 978-83-61506-28-7 PB - Instytut Techniki Cieplnej Politechniki Śląskiej CY - Gliwice ER - TY - CHAP A1 - Kaß, Helge A1 - Tappe, Stephanie A1 - Krautz, Hans Joachim T1 - The combustion of dry lignite under Oxyfuel process conditions in a 0.5 MWth test plant Y1 - 2008 ER - TY - CHAP A1 - Klatt, Matthias A1 - Aha, Ulrich A1 - Krautz, Hans Joachim T1 - Maintenance optimisation of oxyfuel power plants Y1 - 2011 ER - TY - CHAP A1 - Klatt, Matthias A1 - Krautz, Hans Joachim T1 - Efficiency increase - a challenge in the context of CCS Y1 - 2009 ER - TY - CHAP A1 - Klatt, Matthias A1 - Nimtz, Michael A1 - Krautz, Hans Joachim T1 - Options for Carbon Capture Processes: Pre, Intra and Post Combustion Capture Y1 - 2010 ER - TY - CHAP A1 - Kranzmann, A. A1 - Schulz, W. A1 - Neddemeyer, T. A1 - Nofz, M. A1 - Nitschke, H. A1 - Oder, G. A1 - Findeisen, Alexander A1 - Krautz, Hans Joachim T1 - Corrosion and Corrosion Protection in Oxyfuel Power Plants Y1 - 2011 ER - TY - CHAP A1 - Krause, S. A1 - Krautz, Hans Joachim A1 - Lehmann, J. A1 - Luschtinetz, Thomas A1 - Kruse, T. T1 - Operating regime of a hydrogen-storage-loop power plant of grid relevant dimensions T2 - Proceedings of the 14th International Symposium on Heat Transfer and Renewable Sources of Energy, Szczecin-Miedzyzdroje, Poland, September 06-09, 2012 Y1 - 2012 SN - 978-83-7663-121-9 PB - Wydawnistwo Uczelnianie ZUT CY - Szczecinie ER - TY - CHAP A1 - Krautz, Hans Joachim T1 - Development steps of the low CO2-power plant technology in Germany Y1 - 2008 ER - TY - CHAP A1 - Krautz, Hans Joachim T1 - Climate change and the importance of carbon management Y1 - 2009 ER - TY - GEN A1 - Krautz, Hans Joachim A1 - Corrêa da Silva, Rodrigo A1 - Kangwanpongpan, Tanin T1 - Flame pattern, temperatures and stability limits of pulverized oxy-coal combustion T2 - Fuel : the science and technology of fuel and energy N2 - The challenges in maintaining a stable oxy-coal flame have been reported in the open literature. In case of pulverized coal combustion, narrower flammable regimes arise not only of differences in the feed gas composition, but also due to changes in the flow dynamics because of reduced volume flow rate through the burners to match similar temperatures and radiative heat transfer within the furnace. The present work focuses on the study of flame structure and stability of pre-dried lignite fired by a staged feed-gas burner. Experimental runs were carried out in a 0.40 MWth laboratory facility, with the objective of investigating the effects of swirl strength and feed gas distribution in the burner registers. To assess the experimental data, a numerical study of the non-reacting flow in the near burner region is performed. Predicted flow pattern and flame images show that the primary fuel jet penetrates the internal recirculation zone, forming an annular doughnut reverse flow region for both firing conditions and resembling a type-1 flame pattern. Temperature measurements indicate that the feed gas distribution among the burner registers control the flame temperature in parallel with the swirl number in both air-fired and oxy-fired environments. The oxy-fuel cases exhibite markedly reduced temperatures on the flame axis. This difference in the core arises not just from the more pronounced penetration depth of the primary jet, but also due to reaction mechanisms including pyrolysis and gasification reactions at the higher concentrations of CO2 and water vapor. Flame stabilization is shown to be strongly dependent on an appropriate distribution of the feed gas and strength of swirling flow in the burner front. The results correlated in terms of swirl number, secondary/tertiary flow ratio and secondary/primary axial momentum point to similarities in the stability limits between air-firing and oxy-firing. KW - Oxy-fuel; Pulverized coal combustion; Flame pattern; Stability limits Y1 - 2014 U6 - https://doi.org/10.1016/j.fuel.2013.07.049 SN - 0016-2361 IS - Vol. 115 SP - 507 EP - 520 ER - TY - CHAP A1 - Krautz, Hans Joachim A1 - Guerrero Amezcua, Cinthya Larissa A1 - Ziems, Christian T1 - Future Developments of the Photovoltaic Technologies in germany and their Consequences in the Power Network stability, the System security and the demand of chemical long-term storage T2 - SASEC 2015, Third Southern African Solar Energy Conference, 11 – 13 May 2015, Kruger National Park, South Africa Y1 - 2015 UR - http://hdl.handle.net/2263/49472 SP - 383 EP - 388 ER - TY - CHAP A1 - Krautz, Hans Joachim A1 - Kirmse, Dietrich T1 - Co-Combustion of biomass in lignite-fired power plants Y1 - 2002 ER - TY - CHAP A1 - Krautz, Hans Joachim A1 - Klatt, Matthias A1 - Findeisen, Alexander T1 - CCT & CCS Technologies Y1 - 2009 ER - TY - GEN A1 - Krautz, Hans Joachim A1 - Nimtz, Michael T1 - Flexible Operation of CCS Power Plants to Match Variable Renewable Energies T2 - Energy Procedia N2 - The German Energiewende is resulting in high grid load changes caused by renewable energies. Therefore flexibility of power plants is getting more and more important. Future CCS power plants are usually equipped with more components than conventional power plants, resulting in a more complex and inert reaction on changes in power output. Additionally, due to the change in price structures and higher fixed and operational costs for CCS power plants, it is harder for them to be economically efficient. This study will show different options to increase the flexibility of CCS power plants and evaluate their benefits. KW - CCS; Flexibility; Post combustion capture; Oxyfuel; Solvent storage; Pipeline Y1 - 2013 U6 - https://doi.org/10.1016/j.egypro.2013.08.034 SN - 1876-6102 VL - 2013 IS - 40 SP - 294 EP - 303 ER - TY - CHAP A1 - Lechner, Stefan A1 - Höhne, Olaf A1 - Krautz, Hans Joachim T1 - Pressurized steam fluidized bed drying (PSFBD) of lignite: constructional and process optimization at the BTU test facility and experimental results Y1 - 2009 ER - TY - GEN A1 - Lechner, Stefan A1 - Merzsch, Matthias A1 - Krautz, Hans Joachim T1 - Heat-transfer from horizontal tube bundles into fluidized beds with Geldart A lignite particles T2 - Powder Technology N2 - This work investigates the heat transfer mechanism in fluidized beds equipped with horizontal heat exchanger surfaces such as single tubes and especially tube bundles. Previous works were performed for varying operating conditions and solids' material properties, leading to a heterogeneous and therefore not applicable spectrum of derived correlations for the influence of tube diameter and tube bundle geometry on heat transfer. Based on a wide range validation of the correlation for the influence of single tube diameter on heat transfer coefficient, tube bundles with different tube diameters and horizontal and vertical spacings and alignments were investigated. Experiments were carried out using electrical heat transfer probes in a 0.15 m2 fluidized bed test facility at ambient conditions. Geldart A lignite and Geldart D solids were used in order to distinguish between predominant particle-convective and gas-convective heat transfer mechanisms. The tube bundle reduction factor on heat transfer coefficient was derived as a key parameter based on dimensionless geometric numbers. This factor predicts the reduction of the heat transfer coefficient compared to that of the single tube due to the particle and gas flow disturbances caused by the immersed tubes. Tube diameter as well as tube bundle geometry were successfully implemented into useful correlations for predicting tube bundles' heat transfer of gas–solid fluidized bed systems operating with fine particles. KW - Fluidized bed KW - Lignite KW - Drying KW - Heat transfer KW - Horizontal tubes KW - Tube bundle Y1 - 2014 U6 - https://doi.org/10.1016/j.powtec.2013.10.041 IS - 253 SP - 14 EP - 21 ER - TY - CHAP A1 - Menke, Dominik A1 - Krautz, Hans Joachim A1 - Mandel, Hans T1 - Modelling of availability and system dynamic of large scale fossil fuel fired power plants Y1 - 2002 ER - TY - GEN A1 - Merzsch, Matthias A1 - Lechner, Stefan A1 - Krautz, Hans Joachim T1 - Heat-transfer from single horizontal tubes in fluidized beds: Influence of tube diameter, moisture and diameter-definition by Geldart C fines content T2 - Powder Technology Y1 - 2012 U6 - https://doi.org/10.1016/j.powtec.2012.12.002 SN - 1873-328X ER - TY - GEN A1 - Mieck, Sebastian A1 - Krautz, Hans Joachim T1 - Systematic analysis and preparation of high resolution in-situ measurements for the estimation of PV module parameters T1 - Systematische Analyse und Aufbereitung von hoch-aufgelösten in-situ Messdaten für die Identifikation von Photovoltaik Modulparametern T2 - VGB PowerTech N2 - In the last two decades, a rapid expansion of photovoltaic (PV) power plants of different sizes has taken place. Along with this, the interest from science and industry is growing, exploring the strengths and weaknesses of this technology as well as further developing the efficiency in its production and operation. For planning and operating of PV power plants, valid energy yield forecasts are desirable. These forecasts are also important to draw conclusions for the monitoring of future PV technologies. The analysis, evaluation and processing of meteorological and technical measurement datasets play an essential role. In this article, high-resolution measurement data sets of a mobile, autarkic test system are analyzed firstly. The measured data are checked for plausibility and validity with the corresponding methods. After this observations and phenomena with meteorological cause are described. In a second step, a practicable procedure for the preparation of the measurement data is presented, in order to make it suitable for further calculations, e.g. identification of photovoltaic module parameters for energy yield calculations. The focus is particularly on the flexibility, adaptability and code performance of the processing procedure. Results, evaluations and outlooks on the methods used, measurement data and selected software packages are made. N2 - In den letzten zwei Dekaden ist ein rascher Zubau von Photovoltaik(PV)-Kraftwerken verschiedener Leistungsgrößen zu konstatieren. Damit einhergehend wächst das Interesse aus Wissenschaft und Wirtschaft, Stärken und Schwächen der Technologie zu ergründen sowie die Effizienz in Herstellung und Betrieb weiter zu entwickeln. Für Planung und Betrieb von PV-Kraftwerken sind z.B. valide Ertragsprognosen anzustreben, aber auch Rückschlüsse aus dem Monitoring für zukünftige PV-Technologien zu ziehen. Die Analyse, Auswertung und Verarbeitung von meteorologischen und technischen Messdatensätzen spielt dabei eine wesentliche Rolle. Im diesem Artikel werden zeitlich hoch aufgelöste Messdatensätze eines mobilen, autarken Testsystems in einem ersten Schritt analysiert. Dabei werden die Messdaten auf Plausibilität und Validität mit entsprechenden Methoden überprüft, spezielle Beobachtungen und Phänomene mit meteorologischer Ursache beschrieben. In einem zweiten Schritt wird eine praktikable Vorgehensweise für die Aufbereitung der Messdaten vorgestellt, um diese für weiterführende Berechnungen, z.B. Identifikation von Photovoltaik Modulparametern für Ertragsberechnungen, verfügbar zu machen. Im Vordergrund stehen insbesondere die Flexibilität, Adaptierbarkeit sowie Codeperformanz der Aufbereitungsprozedur. Es werden Ergebnisse, Einschätzungen und Ausblicke zu den verwendeten Methoden, Messdaten, sowie gewählter Software Pakete vorgenommen. KW - Photovoltaic KW - Data preparation Y1 - 2018 SN - 1435-3199 VL - 98 IS - 8 SP - 75 EP - 81 ER - TY - THES A1 - Missagia, Bruna T1 - Agricultural and forestry residues for decentralized energy generation in Brazil Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus-25180 ER - TY - CHAP A1 - Missagia, Bruna A1 - Guerrero, Cinthya A1 - Krautz, Hans Joachim A1 - Schluchter, Wolfgang T1 - Implications of the diffusion of biomass based energy technologies: The case of pellets from agricultural subproducts in Brazil Y1 - 2010 ER - TY - CHAP A1 - Missagia, Bruna A1 - Guerrero, Cinthya A1 - Narra, Satyanarayana A1 - Krautz, Hans Joachim A1 - Ay, Peter T1 - Physical characterization of Brazilian agricultural and forestry residues aiming the production of energy pellets Y1 - 2010 ER - TY - GEN A1 - Missagia, Bruna A1 - Guerrero, Cinthya A1 - Narra, Satyanarayana A1 - Sun, Yaoming A1 - Ay, Peter A1 - Krautz, Hans Joachim T1 - Physicomechanical properties of rice husk pellets for energy generation Y1 - 2011 ER - TY - CHAP A1 - Missagia, Bruna A1 - Krautz, Hans Joachim T1 - Comparative analysis of Brazilian residual biomass for pellet production Y1 - 2009 ER - TY - GEN A1 - Nimtz, Michael A1 - Klatt, Matthias A1 - Wiese, Bernd A1 - Kühn, Michael A1 - Krautz, Hans Joachim T1 - Modelling of the CO2 process- and transport chain in CCS systems - Examination of transport and storage processes T2 - Chemie der Erde - Geochemistry Y1 - 2010 U6 - https://doi.org/10.1016/j.chemer.2010.05.011 SN - 0009-2819 VL - 70 IS - 3 SP - 185 EP - 192 ER - TY - CHAP A1 - Nimtz, Michael A1 - Krautz, Hans Joachim T1 - Evaluation of the GERG-2008 Equation of State for the Simulation of Oxyfuel Systems Y1 - 2011 ER - TY - THES A1 - Ojong, Emile Tabu T1 - Characterization of the Performance of PEM Water Electrolysis Cells operating with and without Flow Channels, based on Experimentally Validated Semi-empirical Coupled-Physics Models N2 - PEM water electrolysis is a clean and efficient conversion technology for hydrogen production and energy storage, especially when coupled with renewable energy sources. In spite of its many advantages, the high component and cell manufacturing costs of the conventional PEM electrolysis cell makes the PEM water electrolysis technology commercially less competitive vis-à-vis its peers. An alternative and cost effective cell design has been proposed which has up to a 25 % costs advantage over the conventional cell. In this alternative cell design, the flow channel plate which bears the most material costs in the conventional cell design has been replaced with a 3-D Porous Transport Layer (PTL) structure. While both designs perform comparably the same at low to mid current density (0 – 2 A/cm²), it has been observed that the conventional cell by far out performs the low cost cell at high current density operations, due to increased mass transport limitation in the cell without flow channels. Since industrial and commercial hydrogen production efforts are focused towards high current density operation (> 3 A/cm²), it thus becomes obvious that, in order for the cost effective alternative cell design to establish itself over the conventional cell design, the mass transport issues at high current densities have to be well understood and described. This research work seeks to understand the source of, and to eliminate the mass transport losses in the cost effective alternative cell design in order to get it performing at least as good as the conventional cell design at current densities up to 5 A/cm². To meet this objective, 2-D non-isothermal semi-empirical fully-coupled models of both cell designs have been developed and experimentally validated. The developed validated models were then used as tools to simulate and predict the best operating conditions, design parameters and micro-structural properties of the PTL at which the mass transport issues in the design without flow channels will be at its minimum, so that both cells can exhibit comparable performance even at high current densities. The models developed in this work are based on a multi-physics approach in which thermodynamic, electrochemical, thermal and mass transport sub-models are coupled and solved numerically, to predict the cell polarization and individual overpotentials, as well as address heat and water management issues. The most unique aspect of this work however, is the development of own semi-empirical equations for predicting the mass transport overpotential imposed by the gas phase (bubbles) at high current densities. Also, for the very first time, calculated PEM water electrolysis polarization curves up to 5 A/cm² have been validated by own experimental data. The results show that, the operating temperature and pressure, inlet water flowrate and thickness of the PTL are the critical parameters for mitigating mass transport limitation at high current densities. In fact, it was found that, for the size of the cells studied (25 cm² active area each), when both cells are operating at the same temperature of 60 °C, the low cost cell design will have a comparable performance to the conventional designed cell even at 5 A/cm² current density when; the operating pressure is ≥ 5 bar, the feed water flowrate is ≥ 0.024l/min∙cm², PTL porosity is 50 %, PTL pore size is ≥ 11 µm and PTL thickness is 0.5 mm. At these operating, design and micro-structural conditions, the predicted difference between the polarizations of both cells will be only ~10 mV at 5 A/cm² operating current density. N2 - Die PEM Wasser Elektrolyse gilt als effiziente Technologie zur Herstellung von sauberem Wasserstoff zur Energiespeicherung, besonders bei Kopplung mit erneuerbaren Energien. Trotz der vielen Vorteile führen hohe Kosten für die Produktion konventioneller Komponenten und Stacks zu einer nicht konkurrenzfähigen Technologie. Ein alternatives und kostengünstiges Zelldesign wurde vorgestellt, das, verglichen mit einem konventionellen Design, einen Kostenvorteil von bis zu 25 % hervorbringt. Bei diesem alternativen Zelldesign wird die Platte mit Strömungskanälen, die den größten Kostenanteil birgt, durch eine 3-D poröse Struktur (engl. Porous transport layer, PTL) ersetzt. Während beide Designs vergleichbare Leistungsdaten im niederen und mittleren Stromdichtebereich zeigen (0 – 2 A/cm2), wurde ein signifikanter Unterschied im hohen Stromdichtebereich beobachtet. Hierbei zeigt ein Design ohne Strömungskanäle niedrigere Leistungsdaten, was durch eine gesteigerte Limitierung des Massentransportes erklärt werden kann. Da sich die industrielle und kommerzielle Wasserstoffproduktion in Richtung hoher Stromdichten (> 3 A/cm²) entwickelt, scheint das erforderliche Verständnis von Massentransporteffekten offensichtlich um das kosteneffiziente Design gegenüber des konventionellen Designs voran zu treiben. Diese Forschungsarbeit versucht den Ursprung von Massentransportlimitierung des kostengünstigen Zelldesigns zu verstehen und eliminieren, um zumindest entsprechende Leistungsdaten des konventionellen Designs bis 5 A/cm² zu erreichen. Um diese Zielvorgabe zu erreichen, wurden 2-D nicht-isotherme, semi-empirische, vollstaendig gekoppelte Modelle beider Zelldesigns entwickelt und experimentell validiert. Die entwickelten und validierten Modelle wurden als Werkzeug zur Simulation und Vorhersage der geeignetsten Betriebs- und Designparameter, sowie Eigenschaften der Mikrostrukur der PTL verwendet. Dabei sind die Verluste durch Massentransport, im Design ohne Strömungskanäle, minimal, sodass beide Designs vergleichbare Leistungsdaten bei hohen Stromdichten zeigen. Die hierin entwickelten Modelle basieren auf einem multiphysikalischen Ansatz, worin thermodynamische, elektrische und thermische Effekte sowie Massentransportuntermodelle gekoppelt und gelöst wurden, um sowohl die Zellpolarisation und individuelle Überpotentiale vorherzusagen, als auch Wärme- und Wassermanagement zu adressieren. Das Alleinstellungsmerkmal dieser Arbeit ist jedoch die Entwicklung von semi-empirischen Gleichungen, um die Überpotentiale der Massentransporthemmung, ausgehend von Gasblasen, vorhersagen zu können. Ebenso wurden zum ersten Mal berechnete PEM Wasser Elektrolyse Polarisationskurven bis zu einer Stromdichte von 5 A/cm² mit eigenen Daten validiert. Die Ergebnisse zeigen, dass Betriebstemperatur und Druck, sowie Wasserflußrate am Zelleingang und Dicke der PTL die kritischen Parameter sind, um Massentransportlimitierung bei hohen Stromdichten zu vermeiden. Es wurde sogar gezeigt, dass bei der verwendeten Zellgröße (aktive Fläche = 25 cm²) vergleichbare Leistungsdaten bei 60 °C und 5 A/cm² erreicht werden können, sofern der Betriebsdruck 5 bar übersteigt, die Flussrate des Eduktwassers größer als 0.024 l/min ist, die Porosität der PTL 50 % übersteigt, die Porendurchmesser größer als 11 µm sind und die PTL Dicke bei 0.5 mm liegt. Bei diesen Betriebsbedingungen, diesen Design- und Mikrostrukturparametern wurden Unterschiede zwischen den beiden Zelldesigns von etwa 10 mV bei 5 A/cm² vorhergesagt. KW - PEM Electrolysis KW - Porous Transport Layer KW - High Current Density KW - Mass Transport KW - Modelling KW - Experimental Validation Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus4-46504 CY - Cottbus ; Senftenberg ER - TY - CHAP A1 - Owczarek, Christian A1 - Krautz, Hans Joachim A1 - Griebe, Steffen T1 - Cycloidal combustion - a new concept for industrial combustion with low-calorific fuels Y1 - 2000 ER - TY - CHAP A1 - Owczarek, Christian A1 - Krautz, Hans Joachim A1 - Griebe, Steffen A1 - Schrader, A. A1 - Paulick, G. T1 - Progressive combustion of lignite and sludge in atmospheric cycloid combustion system Y1 - 1999 ER - TY - GEN A1 - Reimann, Ansgar A1 - Kohlenbach, Paul A1 - Röntzsch, Lars T1 - Development of a novel quasi-2D PEM Electrolyzer Model in Modelica T2 - Proceedings of the 15th International Modelica Conference 2023, Aachen, October 9-11 N2 - To increase the efficiency of PEM electrolysis, simulation models are required that accurately describe the system's electrochemical and thermal behavior in a computationally efficient manner and are thus suitable for developing control strategies. Therefore, a pseudo-2D PEM electrolyzer model is presented in this paper, which is a compromise between the previously developed models regarding their model complexity. The electrochemical behavior is described with equations commonly used in the literature and the thermal behavior with correlations for gas-liquid heat transfer. Preliminary validation indicates that the model can describe the electrochemical behavior and thermal dynamics of a PEM electrolysis stack with good accuracy. Y1 - 2023 U6 - https://doi.org/10.3384/ecp20463 SN - 1650-3686 PB - Linköping University Electronic Press ER - TY - CHAP A1 - Ristau, Herbert A1 - Mroz, Marcin A1 - Krautz, Hans Joachim T1 - Research and Development of Progressive Power Plant Techniques at the Brandenburg University of Technology Cottbus Y1 - 2000 ER - TY - CHAP A1 - Rogoll, A. A1 - Walter, E. A1 - Krautz, Hans Joachim T1 - Co-generation plant Cottbus with ABB P200- Pressurized Fluidized Bed Combustion Y1 - 2001 ER - TY - CHAP A1 - Rombrecht, Hans-Bernd A1 - Krautz, Hans Joachim T1 - Results and operation experiences of the lignite fired laboratory-scale plant with pressurized circulating fluidized bed combustion of the 2nd generation (PFBC) Y1 - 2005 ER - TY - GEN A1 - Sakkas, Nikolaos Panagiotis A1 - Roger, Abang T1 - Thermal load prediction of communal district heating systems by applying data-driven machine learning methods T2 - Energy Reports N2 - Load forecasting is an essential part of the operational management of combined heat and electrical power units, since a reliable hour- and day-ahead estimation of their thermal and electrical load can significantly improve their technical and economic performance, as well as their reliability. Among different types of prediction techniques, data-driven machine learning methods appear to be more suitable for load estimation in operational systems, compared to the classical forward approach. Research so far has been concentrated mainly on the magnitude of buildings with single load types. It has only been extended to a limited degree on the level of a district heating network where several end users with different characteristics merge into one bigger scale heat consumer (city or group of communities). In this study, artificial neural networks are utilized, to develop a load prediction model for district heating networks. A segmented analytical multi-phase approach is employed, to gradually optimize the predictor by varying the characteristics of the input variables and the structure of the neural network. The comparison against the load prediction time series generated by a local communal energy supplier using a commercial software reveals that, although the latter is enhanced by manual human corrections, the optimized fully automatic predictors developed in the present study generate a more reliable load forecast. Y1 - 2022 UR - https://www.sciencedirect.com/science/article/pii/S2352484721015213 U6 - https://doi.org/10.1016/j.egyr.2021.12.082 SN - 2352-4847 VL - 8 SP - 1883 EP - 1895 ER - TY - CHAP A1 - Sampangi, Shiva Kumar A1 - Röntzsch, Lars ED - Reedijk, Jan T1 - Electrolysis – Proton-exchange membrane electrolyzer | Proton exchange membrane water electrolysis: State-of-the-art technique and systems T2 - Reference Module in Chemistry, Molecular Sciences and Chemical Engineering Y1 - 2024 SN - 978-0-12-409547-2 U6 - https://doi.org/10.1016/B978-0-323-96022-9.00237-1 PB - Elsevier ER - TY - CHAP A1 - Schierack, Frank A1 - Krautz, Hans Joachim A1 - Griebe, Steffen T1 - Development of a new Brown coal fired Combined-Cycle Power Plant using CPFBC, 2nd Generation Y1 - 2001 ER - TY - CHAP A1 - Schierack, Frank A1 - Krautz, Hans Joachim A1 - Priesmeier, U. A1 - Nies, T. T1 - Advancement of circulating pressurized fluidized bed combustion up to plants of the 2nd Generation Y1 - 2000 SN - 3-18-091535-9 ER - TY - CHAP A1 - Schierack, Frank A1 - Krautz, Hans Joachim A1 - Ristau, Herbert T1 - Development of a new Brown coal fired Combined-Cycle Power Plant using CPFBC, 2nd Generation Y1 - 2001 ER - TY - CHAP A1 - Schreiber, Matthias A1 - Asegehegn, Teklay Weldeabzgi A1 - Krautz, Hans Joachim T1 - Numerical study of bubbling fluidized beds: Influence of immersed tubes,extraction methods and averaging periods Y1 - 2010 ER - TY - GEN A1 - Schreiber, Matthias A1 - Asegehegn, Teklay Weldeabzgi A1 - Krautz, Hans Joachim T1 - Numerical and Experimental Investigation of Bubbling Gas-Solid Fluidized Beds with Dense Immersed Tube Bundles Y1 - 2011 ER - TY - CHAP A1 - Schreiber, Matthias A1 - Krautz, Hans Joachim T1 - Numerical and Experimental Investigation of Tube-to-Bed Heat Transfer in a Bubbling Fluidized Bed of Lignite Particles T2 - 21st International Conference on Fluidized Bed Combustion, Neapel, 2012 Y1 - 2012 ER - TY - BOOK A1 - Swat, Steffen T1 - Introduction to the simulation of power plants for EBSILON®Professional Version 15 N2 - EBSILON®Professional is a powerful modelling system developed for the simulation of thermodynamic cycles. It is suitable as a tool for plant planning, design and optimization of thermal power plants with a steam process or a gas turbine process as well as plants with renewable energies (biomass, wind energy, solar energy and geothermal energy). The introduction describes the basic principles and the working steps to create a model of the plant. Furthermore, the work with the internal programming environment EbsScript and the handling of the calculation of time series is presented. KW - power plant KW - thermodynamics KW - simulation Y1 - 2021 SN - 978-3-754142-08-0 SN - 978-3-754142-09-7 PB - Neopubli GmbH CY - Berlin ET - 1. Auflage ER - TY - CHAP A1 - Tannert, Daniel A1 - Ziems, Christian A1 - Krautz, Hans Joachim T1 - Overview and initial experiences of a 60 bar alkaline electrolyser prototype T2 - Proceedings of the 14th International Symposium on Heat Transfer and Renewable Sources of Energy, Szczecin-Miedzyzdroje, Poland, September 06-09, 2012 Y1 - 2012 SN - 978-83-7663-121-9 PB - Wydawnistwo Uczelnianie ZUT CY - Szczecinie ER - TY - CHAP A1 - Tappe, Stephanie T1 - Experimental investigations on char combustion of different lignites in O2/CO2-atmospheres Y1 - 2008 ER - TY - CHAP A1 - Tappe, Stephanie A1 - Krautz, Hans Joachim T1 - Influence of various O2/CO2-concentrations on the burning behavior of different coals Y1 - 2009 ER - TY - CHAP A1 - Tappe, Stephanie A1 - Krautz, Hans Joachim T1 - ALVA 20: a 20 kWth atmospheric laboratory test facility to investigate the combustion behaviour under "close-to-reality" conditions Y1 - 2009 ER - TY - CHAP A1 - Tappe, Stephanie A1 - Krautz, Hans Joachim T1 - Experimental investigations of combustion behaviour in various O2/CO2-atmospheres Y1 - 2009 ER - TY - GEN A1 - Thummar, Krunalkumar A1 - Abang, Roger A1 - Menzel, Katharina A1 - Groot, Matheus Theodorus de T1 - Coupling a Chlor-Alkali Membrane Electrolyzer Cell to a Wind Energy Source: Dynamic Modeling and Simulations T2 - Energies N2 - Renewable energy sources are becoming a greater component of the electrical mix, while being significantly more volatile than conventional energy sources. As a result, net stability and availability pose significant challenges. Energy-intensive processes, such as chlor-alkali electrolysis, can potentially adjust their consumption to the available power, which is known as demand side management or demand response. In this study, a dynamic model of a chlor-alkali membrane cell is developed to assess the flexible potential of the membrane cell. Several improvements to previously published models were made, making the model more representative of state-of-the-art CA plants. By coupling the model with a wind power profile, the current and potential level over the course of a day was simulated. The simulation results show that the required ramp rates are within the regular operating possibilities of the plant for most of the time and that the electrolyte concentrations in the cell can be kept at the right level by varying inlet flows and concentrations. This means that a CA plant can indeed be flexibly operated in the future energy system. Y1 - 2022 U6 - https://doi.org/10.3390/en15020606 SN - 1996-1073 VL - 15 IS - 2 SP - 1 EP - 26 ER - TY - CHAP A1 - Walter, E. A1 - Almhem, P. A1 - Krautz, Hans Joachim T1 - A Lignite Fired Combined Cycle Heat and Power Plant using Presssurized Fluidized Bed Combustion Y1 - 1997 ER - TY - CHAP A1 - Wiedemann, Philipp A1 - Krautz, Hans Joachim T1 - Numerical study of gas–solid fluidized beds: Analysis of pressure fluctuations for detection of disturbed fluidization T2 - The 14th International Conference on Fluidization – From Fundamentals to Products N2 - Numerical simulations using the Two Fluid Model are performed for gas-solid bubbling fluidized beds. The possibility to detect disturbances in the fluidization process is investigated by common analysis of pressure fluctuations and variation of the computational domain. Additionally the influences of different particle sizes and superficial gas velocities are studied. The results are compared with bubble properties obtained from a digital image analysis technique KW - Fluidisierung Y1 - 2013 UR - http://dc.engconfintl.org/fluidization_xiv/71 PB - Engineering Conferences International CY - New York ER - TY - CHAP A1 - Wiese, Bernd A1 - Nimtz, Michael A1 - Möller, Fabian A1 - Otto, Christopher A1 - Liebscher, Axel A1 - Schmidt-Hattenberger, Cornelia T1 - Determination of thermodynamics in a CO2 injection well using pressure and distributed temperature sensing T2 - Models – repositories of knowledge, proceedings of Model CARE2011 held in Leipzig, Germany, September 2011 Y1 - 2012 SN - 978-1-907161-34-6 SP - 286 EP - 290 PB - IAHS Publication CY - Wallingford ER - TY - CHAP A1 - Wiese, Bernd A1 - Nimtz, Michael A1 - Möller, Fabian A1 - Otto, Christopher A1 - Liebscher, Axel A1 - Schmidt-Hattenberger, Cornelia T1 - Determination of thermodynamics in a CO2 injection well using pressure and distributed temperature sensing Y1 - 2011 ER - TY - CHAP A1 - Ziems, Christian A1 - Fischer, Ulrich A1 - Krautz, Hans Joachim A1 - Luschtinetz, Thomas A1 - Lehmann, Jochen T1 - Project presentation-Novel 3D porous electrode materials for more efficient alkaline water electrolysis-AEL3D T2 - Nutzung regenerativer Energiequellen und Wasserstofftechnik 2016, 23. Symposium Nutzung Regenerativer Energiequellen und Wasserstofftechnik, Stralsund, 3. - 5. November 2016 Y1 - 2016 SN - 978-3-9817740-1-6 SP - 175 EP - 181 PB - Fachhochschule CY - Stralsund ER - TY - CHAP A1 - Ziems, Christian A1 - Krautz, Hans Joachim T1 - High pressure alkaline electrolyzer as a core component for power to gas applications T2 - Dena Konferenz "Power to Gas - innovative Systemlösungen für ein zukunftsfähiges Energiesystem entwickeln", Berlin, 2012 Y1 - 2012 ER -