TY - CHAP A1 - Schulte, Jonas A1 - Schwager, Christian A1 - Frantz, Cathy A1 - Schloms, Felix A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Control concept for a molten salt receiver in star design: Development, optimization and testing with cloud passage scenarios T2 - SolarPACES 2022 conference proceedings N2 - A promising approach to reduce the system costs of molten salt solar receivers is to enable the irradiation of the absorber tubes on both sides. The star design is an innovative receiver design, pursuing this approach. The unconventional design leads to new challenges in controlling the system. This paper presents a control concept for a molten salt receiver system in star design. The control parameters are optimized in a defined test cycle by minimizing a cost function. The control concept is tested in realistic cloud passage scenarios based on real weather data. During these tests, the control system showed no sign of unstable behavior, but to perform sufficiently in every scenario further research and development like integrating Model Predictive Controls (MPCs) need to be done. The presented concept is a starting point to do so. KW - Molten salt receiver KW - Star design KW - Control optimization KW - Cloud passages Y1 - 2023 U6 - https://doi.org/10.52825/solarpaces.v1i.693 SN - 2751-9899 (online) N1 - SolarPACES 2022, 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA IS - 1 PB - TIB Open Publishing CY - Hannover ER - TY - CHAP A1 - Paulsen, Svea A1 - Hoffstadt, Kevin A1 - Krafft, Simone A1 - Leite, A. A1 - Zang, J. A1 - Fonseca-Zang, W. A1 - Kuperjans, Isabel T1 - Continuous biogas production from sugarcane as sole substrate T2 - Energy Reports N2 - A German–Brazilian research project investigates sugarcane as an energy plant in anaerobic digestion for biogas production. The aim of the project is a continuous, efficient, and stable biogas process with sugarcane as the substrate. Tests are carried out in a fermenter with a volume of 10 l. In order to optimize the space–time load to achieve a stable process, a continuous process in laboratory scale has been devised. The daily feed in quantity and the harvest time of the substrate sugarcane has been varied. Analyses of the digester content were conducted twice per week to monitor the process: The ratio of inorganic carbon content to volatile organic acid content (VFA/TAC), the concentration of short-chain fatty acids, the organic dry matter, the pH value, and the total nitrogen, phosphate, and ammonium concentrations were monitored. In addition, the gas quality (the percentages of CO₂, CH₄, and H₂) and the quantity of the produced gas were analyzed. The investigations have exhibited feasible and economical production of biogas in a continuous process with energy cane as substrate. With a daily feeding rate of 1.68gᵥₛ/l*d the average specific gas formation rate was 0.5 m3/kgᵥₛ. The long-term study demonstrates a surprisingly fast metabolism of short-chain fatty acids. This indicates a stable and less susceptible process compared to other substrates. Y1 - 2020 U6 - https://doi.org/10.1016/j.egyr.2019.08.035 N1 - 6th International Conference on Energy and Environment Research, ICEER 2019, 22–25 July, University of Aveiro, Portugal VL - 6 IS - Supplement 1 SP - 153 EP - 158 PB - Elsevier ER - TY - CHAP A1 - Kern, Alexander A1 - Krichel, Frank T1 - Considerations about the lightning protection system of mains independent renewable energy hybrid-systems - practical experiences N2 - In the paper a lightning protection design concept for renewable energy hybrid-systems without power mains connection is described. Based on a risk analysis protection measures against direct strikes and overvoltages are shown in an overview. The design concept is realized exemplarily for the hybrid-system VATALI on the Greek island Crete. VATALI, not lightning protected at that time, was a victim of a lightning strike in the year 2000 causing destructions and damages of some mechanical and electrical components with costs of approx. 60.000 €. The hardware costs for the protection measures were about 15.000 €: about 50% of the costs are due to protection measures against direct strikes, 50% are due to overvoltage protection. KW - Blitzschutz KW - Erneuerbare Energien KW - Hybridsystem KW - Photovoltaikanlage KW - Windenergieanlage KW - Lightning protection KW - renewable energy KW - hybrid system KW - photovoltaic system KW - wind turbine Y1 - 2002 ER - TY - CHAP A1 - Latzke, Markus A1 - Alexopoulos, Spiros A1 - Kronhardt, Valentina A1 - Rendón, Carlos A1 - Sattler, Johannes Christoph T1 - Comparison of Potential Sites in China for Erecting a Hybrid Solar Tower Power Plant with Air Receiver T2 - Energy Procedia Y1 - 2015 U6 - https://doi.org/10.1016/j.egypro.2015.03.142 SN - 1876-6102 N1 - International Conference on Concentrating Solar Power and Chemical Energy Systems, SolarPACES 2014, Beijing, China SP - 1327 EP - 1334 ER - TY - CHAP A1 - Höfler, M. A1 - Kneer, R. A1 - Groß, Rolf Fritz A1 - Kehrmann, K. ED - Vorobieff, P. T1 - Chemical determination of oxygen transfer rates, transfer efficiencies and interphases evoked by aeration elements for liquid flows T2 - Computational Methods in Multiphase Flow VIII. - (WIT Transactions on Engineering Sciences ; Volume 89) Y1 - 2015 SN - 978-1-84564-946-3 (Print-Ausgabe) SN - 978-1-84564-947-0 (Online-Ausgabe) SN - 1746-4471 SP - 89 EP - 101 PB - WIT Press CY - Southampton ER - TY - CHAP A1 - Kaspar, K. A1 - Groebel, Simone A1 - Kuperjans, Isabel A1 - Dielmann, Klaus-Peter A1 - Selmer, Thorsten T1 - Charakterisierung der Biozönose von Biogasfermentern in Abhängigkeit verschiedener Substrate T2 - Biogas 2013 : 6. Innovationskongress, 23. - 24.05.2013, Osnabrück, Tagungsband Y1 - 2013 SN - 978-3-9813776-3-7 SP - 69 EP - 74 PB - Profair Consult+Project CY - Hildesheim ER - TY - CHAP A1 - Butenweg, Christoph A1 - Gellert, Christoph A1 - Reindl, Lukas T1 - Capacity design of masonry buildings under cyclic loading T2 - Seismic Risk : Earthquakes in North-Western Europe ; international colloquium ; Liège on 11 and 12 September 2008 / Belgian Seismic Group (BeSeiG). Ed.: T. Camlebeeck ... Y1 - 2008 SN - 978-2-87456-063-7 SP - 201 EP - 208 PB - Editions de l'Université de Liège CY - Liège ER - TY - CHAP A1 - Kalker, Ines A1 - Toll, B. A1 - Holler, Stefan A1 - Butenweg, Christoph A1 - Topping, B. H. V. A1 - Mota Soares, C. A. T1 - Capacity analysis of textile retrofitted unreinforced masonry T2 - Proceedings of the Seventh International Conference on Computational Structures Technology : [Lisbon, Portugal, 7 - 9 September 2004] / ed. by B. H. V. Topping ... Y1 - 2004 SN - 0-948749-95-4 U6 - https://doi.org/10.4203/ccp.79.194 SP - 431 EP - 432 PB - Civil-Comp Press CY - Stirling ER - TY - CHAP A1 - Kern, Alexander A1 - Beierl, Ottmar A1 - Zischank, Wolfgang T1 - Calculation of the separation distance according to IEC 62305-3: 2006-10 - Remarks for the application and simplified methods N2 - [Paper of the X International Symposium on Lightning Protection 9th - 13th November, 2009 - Curitiba, Brazil. 6 pages] The international standard IEC 62305-3, published in 2006, requires as an integral part of the lightning protection system (LPS) the consideration of a separation distance between the conductors of the LPS and metal and electrical installations inside the structure to be protected. IEC 62305-3 gives two different methods for this calculation: a standard, simplified approach and a more detailed approach, which differ especially regarding the treatment of the current sharing effect on the LPS conductors. Hence, different results for the separation distance are possible, leading to some discrepancies in the use of the standard. The standard approach defined in the main part (Clause 6.3) and in Annex C of the standard in some cases may lead to a severe oversizing of the required separation distance. The detailed approach described in Annex E naturally gives more correct results. However, a calculation of the current sharing amongst all parts of the air-termination and downconductor network is necessary, in many cases requiring the use of network analysis programs. In this paper simplified methods for the assessment of the current sharing are presented, which are easy to use as well as sufficiently adequate. KW - Blitzschutz KW - Lightning protection Y1 - 2009 N1 - Paper in: [10. International Symposium on Lightning Protection 9. 13. November 2009, Curitiba, Brasilien. 6 Seiten] ER - TY - CHAP A1 - Pfundt, H. A1 - Vogelsang, D. A1 - Gerling, Ulrich T1 - Calculation of the crust profile in aluminium reduction cells by thermal computer modelling T2 - Light metals 1989 : 118th annual meeting of the Minerals, Metals and Materials Society, Las Vegas, NV, Feb. 27 - Mar. 03. 1989 Y1 - 1988 SP - 371 EP - 377 PB - Minerals, Metals and Materials Soc. CY - Warrendale, Pa. ER -