@inproceedings{FindeisenRombrechtKrautz, author = {Findeisen, Alexander and Rombrecht, Hans-Bernd and Krautz, Hans Joachim}, title = {Qualit{\"a}tsanforderungen an alternative Biomasse-Brennstoffe}, language = {de} } @inproceedings{FindeisenKrautzHaukeetal., author = {Findeisen, Alexander and Krautz, Hans Joachim and Hauke, Th. and Kranzmann, A.}, title = {Corrosion Processes and Carbonisation of Boiler Materials under Air and Oxyfuel Process Conditions}, language = {en} } @inproceedings{FindeisenKrautz, author = {Findeisen, Alexander and Krautz, Hans Joachim}, title = {Untersuchungen zum Korrosionsverhalten ausgew{\"a}hlter Werkstoffe bei verschiedenen Betriebsbedingungen}, language = {de} } @misc{FindeisenKlattKrautz, author = {Findeisen, Alexander and Klatt, Matthias and Krautz, Hans Joachim}, title = {Examination of the corrosion behaviour of selected power plant materials under various operating conditions}, doi = {http://dx.doi.org/10.1016/j.chemer.2010.05.006}, language = {en} } @inproceedings{FindeisenCorreadaSilvaKrautz, author = {Findeisen, Alexander and Correa da Silva, Rodrigo and Krautz, Hans Joachim}, title = {Konzeptionelle und verfahrenstechnische Umsetzung eines 400 kWth-Verbrennungsversuchsstandes - erste Erfahrungen aus der Inbetriebsetzung}, language = {de} } @inproceedings{FindeisenAbangKrautz, author = {Findeisen, Alexander and Abang, Roger Atini and Krautz, Hans Joachim}, title = {Corrosion Behaviour of Selected Power Plant Materials Under Oxyfuel Combustion Conditions}, language = {en} } @inproceedings{Findeisen, author = {Findeisen, Alexander}, title = {Analysis of corrosion behaviour of materials in oxyfuel fired power plants}, language = {en} } @misc{DahashMieckOchsetal., author = {Dahash, Abdulrahman and Mieck, Sebastian and Ochs, Fabian and Krautz, Hans Joachim}, title = {A comparative study of two simulation tools for the technical feasibility in terms of modeling district heating systems: An optimization case study}, series = {Simulation Modelling Practice and Theory}, volume = {91}, journal = {Simulation Modelling Practice and Theory}, issn = {1569-190X}, doi = {10.1016/j.simpat.2018.11.008}, pages = {48 -- 68}, abstract = {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.}, language = {en} } @inproceedings{CorreadaSilvaMissagiaTappeetal., author = {Correa da Silva, Rodrigo and Missagia, Bruna and Tappe, Stephanie and Findeisen, Alexander and Krautz, Hans Joachim}, title = {Development of low CO2 technologies for oxyfuel combustion in power plants}, language = {en} } @inproceedings{CorreadaSilvaKrautz, author = {Correa da Silva, Rodrigo and Krautz, Hans Joachim}, title = {Theoretical analysis of heat transfer in a pulverized coal combustion chamber under O2/CO2 atmosphere}, language = {en} } @inproceedings{CorreadaSilvaKrautz, author = {Correa da Silva, Rodrigo and Krautz, Hans Joachim}, title = {Theoretical investigation of pulverized coal combustion in air and in O2/CO2 atmospheres}, language = {en} } @misc{CorreadaSilvaKangwanpongpanFindeisenetal., author = {Correa da Silva, Rodrigo and Kangwanpongpan, Tanin and Findeisen, Alexander and Krautz, Hans Joachim and Meyer, Marco and Roberg, Benedikt}, title = {Oxy-fuel Combustion Studies Applying a Novel Test Facility - First Numerical Results}, language = {en} } @inproceedings{CorreadaSilvaKangwanpongpanFindeisenetal., author = {Correa da Silva, Rodrigo and Kangwanpongpan, Tanin and Findeisen, Alexander and Krautz, Hans Joachim}, title = {Aspects of Numerical Simulation of Coal Combustion under Oxyfuel Atmospheres}, language = {de} } @inproceedings{CorreadaSilvaKangwanpongpanFindeisenetal., author = {Correa da Silva, Rodrigo and Kangwanpongpan, Tanin and Findeisen, Alexander and Krautz, Hans Joachim}, title = {Description of a 0.4 MWth laboratory facility for oxy-fuel combustion studies}, language = {en} } @inproceedings{ChalupnikKrautzWirtzetal., author = {Chalupnik, Rolf W. and Krautz, Hans Joachim and Wirtz, M. and Stuhlm{\"u}ller, F.}, title = {Applied Research for a New Generation of Lignite-Fired Combined Cycle Power Plant Using Circulating Pressurized Fluidized Bed Combustion}, language = {en} } @inproceedings{ChalupnikKrautzSchulzeetal., author = {Chalupnik, Rolf W. and Krautz, Hans Joachim and Schulze, H. and Stuhlm{\"u}ller, F. and Thielen, W.}, title = {Plant studies and experiments for a lignite-fired combined-cycle power plant using circulating pressurized fluidized bed combustion}, language = {en} } @phdthesis{Chalupnik, author = {Chalupnik, Rolf W.}, title = {Druckwirbelschichtkraftwerke : Kombikraftwerke mit Druckwirbelschichtfeuerung ; Entwicklung f{\"u}r Braunkohle unter besonderer Ber{\"u}cksichtigung des Emissionsverhaltens}, publisher = {Energiewirtschaft und Technik Verlagsges.}, address = {Essen}, isbn = {3-925349-31-6}, language = {de} } @inproceedings{CarotenutoCorreadaSilvaRechetal., author = {Carotenuto, A. S. and Correa da Silva, Rodrigo and Rech, R. and Marcilio, N. R. and Smith Schneider, Paulo and Krautz, Hans Joachim}, title = {Preliminary Investigation of the Global Kinetic Parameters of low-rank coals under oxy-fuel conditions}, language = {en} } @article{BaerMuellerRost, author = {B{\"a}r, F. and M{\"u}ller, S. and Rost, M.}, title = {Effiziente Braunkohleverstromung in einer Druckwirbelschichtfeuerung mit Teilvergasung}, language = {de} } @inproceedings{AsegehegnSchreiberKrautz, author = {Asegehegn, Teklay Weldeabzgi and Schreiber, Matthias and Krautz, Hans Joachim}, title = {Influence of Horizontal Tubes, Averaging Periods and Extraction Methods on the Hydrodynamics of Bubbling Gas-Solid Fluidized Beds}, language = {en} } @misc{AsegehegnSchreiberKrautz, author = {Asegehegn, Teklay Weldeabzgi and Schreiber, Matthias and Krautz, Hans Joachim}, title = {Numerical Study of Bubbling Gas-Solid Fluidized Beds Hydrodynamics: Influence of Immersed Horizontal Tubes and Data Analysis}, language = {en} } @misc{AsegehegnSchreiberKrautz, author = {Asegehegn, Teklay Weldeabzgi and Schreiber, Matthias and Krautz, Hans Joachim}, title = {Investigation of bubble behavior in fluidized beds with and without immersed horizontal tubes using a digital image analysis technique}, doi = {http://dx.doi.org/10.1016/j.powtec.2011.03.025}, language = {en} } @misc{AsegehegnSchreiberKrautz, author = {Asegehegn, Teklay Weldeabzgi and Schreiber, Matthias and Krautz, Hans Joachim}, title = {Numerical simulation and experimental validation of bubble behavior in 2D gas-solid fluidized beds with immersed horizontal tubes}, doi = {http://dx.doi.org/10.1016/j.ces.2011.07.056}, language = {en} } @misc{AsegehegnSchreiberKrautz, author = {Asegehegn, Teklay Weldeabzgi and Schreiber, Matthias and Krautz, Hans Joachim}, title = {Influence of two- and three-dimensional simulations on bubble behaviorin gas-solid fluidized beds with and without immersed horizontal tubes}, doi = {10.1016/j.powtec.2011.11.050}, language = {en} } @misc{AsegehegnLechnerMerzschetal., author = {Asegehegn, Teklay Weldeabzgi and Lechner, Stefan and Merzsch, Matthias and Schreiber, Matthias and Silbermann, Rico and Krautz, Hans Joachim and H{\"o}hne, Olaf}, title = {Das DDWT-Verfahren als Schl{\"u}sseltechnologie zuk{\"u}nftiger Braunkohlekraftwerke}, language = {de} } @inproceedings{AsegehegnKrautz, author = {Asegehegn, Teklay Weldeabzgi and Krautz, Hans Joachim}, title = {Numerical study of bubble hydrodynamics for gas-solid fluidized bedswith and without horizontal tubes}, language = {en} } @inproceedings{AsegehegnKrautz, author = {Asegehegn, Teklay Weldeabzgi and Krautz, Hans Joachim}, title = {Numerical study of solids motion and distribution in gas-solid fluidized beds: influence of immersed horizontal tubes}, language = {de} } @inproceedings{AsegehegnKrautz, author = {Asegehegn, Teklay Weldeabzgi and Krautz, Hans Joachim}, title = {Hydrodynamic simulation of gas-solid bubbling fluidized bed containing horizontal tubes}, language = {en} } @phdthesis{Asegehegn, author = {Asegehegn, Teklay Weldeabzgi}, title = {Investigation of bubble hydrodynamics in gas-solid fluidized beds containing immersed horizontal tube banks for lignite drying application}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-23578}, language = {en} } @inproceedings{AltmannKrautz, author = {Altmann, H. and Krautz, Hans Joachim}, title = {Das CO2-freie Pilotkraftwerk von vattenfall Europe Generation}, language = {de} } @misc{AkayBashkatovCoyetal., author = {Akay, {\"O}mer and Bashkatov, Aleksandr and Coy, Emerson and Eckert, Kerstin and Einarsrud, Kristian Etienne and Friedrich, Andreas and Kimmel, Benjamin and Loos, Stefan and Mutschke, Gerd and R{\"o}ntzsch, Lars and Symes, Mark D. and Yang, Xuegeng and Brinkert, Katharina}, title = {Electrolysis in reduced gravitational environments: current research perspectives and future applications}, series = {npj Microgravity}, volume = {8}, journal = {npj Microgravity}, issn = {2373-8065}, doi = {10.1038/s41526-022-00239-y}, abstract = {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.}, language = {en} } @misc{AhmelsVossGagoetal., author = {Ahmels, Peter and Voß, Ulrike and Gago, Aldo and Lettenmeier, Philipp and Voglst{\"a}tter, Christopher and Schmitz, Steffen and Kleinickel, Cindy and Barsch, Markus and Rockmann, Rico and Pumpa, Martin and Fischer, Ulrich and Voigt, Andr{\´e}}, title = {Wasserstoff zur Windenergiespeicherung - Ergebnisse des Projektes WESpe}, series = {HZwei: das Magazin f{\"u}r Wasserstoff und Brennstoffzellen}, volume = {18}, journal = {HZwei: das Magazin f{\"u}r Wasserstoff und Brennstoffzellen}, number = {2}, issn = {1862-393X}, pages = {28 -- 30}, language = {de} } @inproceedings{AhaManigKrautz, author = {Aha, Ulrich and Manig, Andr{\´e} and Krautz, Hans Joachim}, title = {Maintenance optimisation for the next generation of power plants}, language = {en} } @incollection{AhaManigKrautz, author = {Aha, Ulrich and Manig, Andr{\´e} and Krautz, Hans Joachim}, title = {Modelling and maintenance optimisation for the next generation of power plants}, series = {Advances in safety, reliability and risk management, proceedings of the European Safety and reliability Conference, ESREL 2011, Troyes, France, 18 - 22 September 2011}, booktitle = {Advances in safety, reliability and risk management, proceedings of the European Safety and reliability Conference, ESREL 2011, Troyes, France, 18 - 22 September 2011}, editor = {B{\´e}renguer, Christophe}, publisher = {CRC Press}, address = {Hoboken}, isbn = {978-0-415-68379-1}, language = {en} } @inproceedings{AhaKochKrautz, author = {Aha, Ulrich and Koch, Alexander and Krautz, Hans Joachim}, title = {Finding the optimal power plant maintenance strategy with fuzzy input data}, series = {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}, booktitle = {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}, publisher = {IAPSAM \& ESRA}, address = {Red Hook, NY}, isbn = {978-1-62276-436-5}, pages = {341 -- 347}, language = {en} } @misc{AhaFindeisenKrautzetal., author = {Aha, Ulrich and Findeisen, Alexander and Krautz, Hans Joachim and Kahlert, Joachim}, title = {Korrosion und Instandhaltungsoptimierung CO2-armer Braunkohlekraftwerke unter ge{\"a}nderten Prozessbedingungen und -parametern}, language = {de} } @misc{AhaFindeisenKrautz, author = {Aha, Ulrich and Findeisen, Alexander and Krautz, Hans Joachim}, title = {Maintenance optimization for large coal-fired power plants}, language = {en} } @inproceedings{AhaFindeisenKrautz, author = {Aha, Ulrich and Findeisen, Alexander and Krautz, Hans Joachim}, title = {Korrosion und Instandhaltungsoptimierung unter ge{\"a}nderten Prozessbedingungen und -parametern}, language = {de} } @inproceedings{AhaFindeisenKrautz, author = {Aha, Ulrich and Findeisen, Alexander and Krautz, Hans Joachim}, title = {Maintenance optimisation of large coal-fired power plants}, language = {de} } @misc{AhaFindeisenKrautz, author = {Aha, Ulrich and Findeisen, Alexander and Krautz, Hans Joachim}, title = {INSTRA - eine Software f{\"u}r die Instandhaltungsoptimierung}, language = {de} } @inproceedings{Aha, author = {Aha, Ulrich}, title = {Auswirkungen unscharfer Eingangsdaten auf Verf{\"u}gbarkeitssimulation und Instandhaltungsoptimierung}, language = {de} } @misc{AbangWeissKrautz, author = {Abang, Roger Atini and Weiß, Sabine and Krautz, Hans Joachim}, title = {Impact of increased power plant cycling on the oxidation and corrosion of coal-fired superheater materials}, series = {Fuel}, volume = {2018}, journal = {Fuel}, number = {220}, issn = {0016-2361}, doi = {10.1016/j.fuel.2018.02.047}, pages = {521 -- 534}, abstract = {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.}, language = {en} } @misc{AbangLiskKrautz, author = {Abang, Roger Atini and Lisk, Alexander and Krautz, Hans Joachim}, title = {Fireside corrosion of superheater materials under oxy-coal firing conditions}, series = {Energy Procedia}, volume = {40}, journal = {Energy Procedia}, issn = {1876-6102}, doi = {10.1016/j.egypro.2013.08.035}, pages = {304 -- 311}, abstract = {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.}, language = {en} } @inproceedings{AbangFindeisenKrautz, author = {Abang, Roger Atini and Findeisen, Alexander and Krautz, Hans Joachim}, title = {Corrosion Investigation of Materials under Oxyfuel Firing Conditions}, language = {en} } @phdthesis{Abang, author = {Abang, Roger Atini}, title = {Thermodynamic modeling and experimental investigations of high temperature corrosion and oxidation due to increased power plant cycling}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-40032}, pages = {201}, language = {en} }