TY - THES A1 - Betsch, Matthias T1 - Umbau einer Mikroturbine zu einer extern befeuerten Maschine mit Ankopplung an eine Stationäre-Wirbelschichtfeuerung Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?nbn:de:gbv:28-diss2009-0166-9 N1 - Diss., Univ. Rostock, 2009 PB - Univ. Rostock, Fakultät für Maschinenbau und Schiffstechnik CY - Rostock ER - TY - CHAP A1 - Birkl, Josef A1 - Diendorfer, Gerhard A1 - Kern, Alexander A1 - Thern, Stephan T1 - Extremely high lightning peak currents T2 - 34th International Conference on Ligntning Protection, 02-07 September 2018 Y1 - 2018 SN - 978-1-5386-6635-7 ER - TY - CHAP A1 - Birkl, Josef A1 - Diendorfer, Gerhard A1 - Kern, Alexander A1 - Thern, Stephan T1 - Extrem hohe Blitzströme T1 - Extremly high lightning currents T2 - 12. VDE/ABB-Blitzschutztagung : Beiträge der 12. VDE/ABB-Fachtagung, 12.-13. Oktober 2017, Aschaffenburg Y1 - 2017 SN - 978-3-8007-4459-6 SP - 146 EP - 152 ER - TY - JOUR A1 - Birkl, Josef A1 - Diendorfer, Gerhard A1 - Kern, Alexander A1 - Thern, Stephan T1 - Extrem hohe Blitzströme JF - Elektropraktiker N2 - Blitze sind nach wie vor eine enorme Schadensquelle für Personenschäden, Brände, mechanische Zerstörungen und insbesondere auch Überspannungen. Das zeigen nicht zuletzt aktuelle Statistiken der Schadensversicherer. Immer wieder gibt es Meldungen über extrem hohe Blitzströme, die natürlich auch zu großen Schäden und Zerstörungen führen können. Dabei werden Scheitelwerte von teilweise deutlich über 300 kA genannt. Dies wirft Fragen auf, da die „klassische“ Blitzstatistik (z. B. nach CIGRE und IEC [8][10]) bisher solche Werte nicht kennt. Diese extremen Blitzströme werden meist aus den Daten von Blitzortungssystemen ermittelt. Y1 - 2018 VL - 72 IS - 3 SP - 217 EP - 225 PB - Huss Medien CY - Berlin ER - TY - JOUR A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Döring, Bernd A1 - Göttsche, Joachim A1 - Reger, Vitali A1 - Kuhnhenne, Markus T1 - Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates JF - Geothermal Energy N2 - Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellström’s borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54% of the outer pipe radius for laminar fow and 60% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth’s thermal properties and the fow type. Conclusively, coaxial geothermal probes’ design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics. Y1 - 2021 U6 - http://dx.doi.org/10.1186/s40517-021-00201-3 SN - 2195-9706 N1 - Corresponding author: Tobias Blanke VL - 9 IS - Article number: 19 PB - Springer CY - Berlin ER - TY - CHAP A1 - Blanke, Tobias A1 - Schmidt, Katharina S. A1 - Göttsche, Joachim A1 - Döring, Bernd A1 - Frisch, Jérôme A1 - van Treeck, Christoph ED - Weidlich, Anke ED - Neumann, Dirk ED - Gust, Gunther ED - Staudt, Philipp ED - Schäfer, Mirko T1 - Time series aggregation for energy system design: review and extension of modelling seasonal storages T2 - Energy Informatics N2 - Using optimization to design a renewable energy system has become a computationally demanding task as the high temporal fluctuations of demand and supply arise within the considered time series. The aggregation of typical operation periods has become a popular method to reduce effort. These operation periods are modelled independently and cannot interact in most cases. Consequently, seasonal storage is not reproducible. This inability can lead to a significant error, especially for energy systems with a high share of fluctuating renewable energy. The previous paper, “Time series aggregation for energy system design: Modeling seasonal storage”, has developed a seasonal storage model to address this issue. Simultaneously, the paper “Optimal design of multi-energy systems with seasonal storage” has developed a different approach. This paper aims to review these models and extend the first model. The extension is a mathematical reformulation to decrease the number of variables and constraints. Furthermore, it aims to reduce the calculation time while achieving the same results. KW - Energy system KW - Renewable energy KW - Mixed integer linear programming (MILP) KW - Typical periods KW - Time-series aggregation Y1 - 2022 U6 - http://dx.doi.org/10.1186/s42162-022-00208-5 SN - 2520-8942 N1 - Proceedings of the 11th DACH+ Conference on Energy Informatics, 15-16 September 2022, Freiburg, Germany. VL - 5 IS - 1, Article number: 17 SP - 1 EP - 14 PB - Springer Nature ER - TY - CHAP A1 - Boesen, Niklas A1 - Rosin, Julia A1 - Butenweg, Christoph A1 - Deichsel, Anne A1 - Klinkel, Sven ED - Zabel, Volkmar ED - Beinersdorf, Silke T1 - Untersuchung vorhandenerTragreserven moderner unbewehrter Mauerwerksbauten T2 - Vortragsband der 15. D-A-CH-Tagung Erdbebeningenieurwesen und Baudynamik Y1 - 2017 SN - 978-3-930108-13-5 N1 - 21.-22. September 2017, Weimar. ISBN laut DNB falsch SP - 408 EP - 418 PB - Deutsche Gesellschaft für Erdbebeningenieurwesen und Baudynamik (DGEB) e.V. CY - Weimar ER - TY - CHAP A1 - Borchert, Jörg T1 - Der Elektrizitätsmarkt in Indonesien und Beteiligungsmöglichkeiten privater Unternehmen T2 - Investitionsführer ASEAN, Indochina, 1997 : Brunei, Indonesien, Kambodscha, Laos, Malaysia, Myanmar, Philippinen, Singapur, Thailand, Vietnam Y1 - 2015 SP - 42 EP - 52 PB - Berliner Bank AG CY - Berlin ET - Stand: Mai 1997 ER - TY - THES A1 - Borchert, Jörg T1 - Analyse von Determinanten der Großhandelspreise für Elektrizität anhand einer Systemstudie des deutschen Marktes Y1 - 2003 N1 - Berlin, Techn. Univ., Diss., 2003 ER - TY - CHAP A1 - Borchert, Jörg ED - Zenke, Ines T1 - Aufbau von Handelseinheiten T2 - Energiehandel in Europa Y1 - 2012 SN - 978-3-406-63237-2 SP - 467 EP - 479 PB - Beck CY - München ET - 3. Aufl. ER -