TY - JOUR A1 - Sommer, F. A1 - Gerling, Ulrich A1 - Predel, Bruno T1 - Comments on 'On the evaluation of interchange energies and the equilibrium constant from mixing enthalpies of a regular associated solution' by S. Lele, G.V.S. Sastry, and P. Ramachandrarao = Kommentar zu 'Zur Berechnung der Wechselwirkungsenergien und der Gleichgewichtskonstanten aus Mischungsenthalpien in regulären assoziierten Lösungen' von S. Lele, G.V.S. Sastry und P. Ramachandrarao JF - Zeitschrift für Metallkunde : international journal of materials research and advanced techniques. Bd. 75, H. 6 Y1 - 1984 SN - 0044-3093 ; 0179-4841 SP - 449 EP - 454 ER - TY - CHAP A1 - Sirazitdinova, Y. A1 - Dulzon, A. A1 - Müller, Burghard T1 - Project management practices in engineering university T2 - 21st International Conference for Students and Young Scientists: Modern Technique and Technologies, MTT 2015; National Research Tomsk Polytechnic UniversityTomsk; Russian Federation; 5 October 2015 through 9 October 2015 Y1 - 2015 U6 - http://dx.doi.org/10.1088/1757-899X/93/1/012080 N1 - IOP Conference Series: Materials Science and Engineering Vol. 93, Issue 1 ER - TY - CHAP A1 - Sildatke, Michael A1 - Karwanni, Hendrik A1 - Kraft, Bodo A1 - Schmidts, Oliver A1 - Zündorf, Albert T1 - Automated Software Quality Monitoring in Research Collaboration Projects T2 - ICSEW'20: Proceedings of the IEEE/ACM 42nd International Conference on Software Engineering Workshops Y1 - 2020 U6 - http://dx.doi.org/10.1145/3387940.3391478 SP - 603 EP - 610 ER - TY - JOUR A1 - Schüller-Ruhl, Aaron A1 - Dinstühler, Leonard A1 - Senger, Thorsten A1 - Bergfeld, Stefan A1 - Ingenhag, Christian A1 - Fleischhaker, Robert ED - Mackenzie, Jacob T1 - Direct fabrication of arbitrary phase masks in optical glass via ultra-short pulsed laser writing of refractive index modifications JF - Applied Physics B N2 - We study the possibility to fabricate an arbitrary phase mask in a one-step laser-writing process inside the volume of an optical glass substrate. We derive the phase mask from a Gerchberg–Saxton-type algorithm as an array and create each individual phase shift using a refractive index modification of variable axial length. We realize the variable axial length by superimposing refractive index modifications induced by an ultra-short pulsed laser at different focusing depth. Each single modification is created by applying 1000 pulses with 15 μJ pulse energy at 100 kHz to a fixed spot of 25 μm diameter and the focus is then shifted axially in steps of 10 μm. With several proof-of-principle examples, we show the feasibility of our method. In particular, we identify the induced refractive index change to about a value of Δn=1.5⋅10−3. We also determine our current limitations by calculating the overlap in the form of a scalar product and we discuss possible future improvements. Y1 - 2022 U6 - http://dx.doi.org/10.1007/s00340-022-07928-2 SN - 1432-0649 (Online) SN - 0946-2171 (Print) N1 - Corresponding author: Robert Fleischhaker VL - 128 IS - Article number: 208 SP - 1 EP - 11 PB - Springer CY - Berlin ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Werner, M. A1 - Hartz, T. T1 - Lacasa - an instrument for the energy analysis and optimisation of buildings including technical equipment JF - Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft für Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 2 Y1 - 2004 SN - 3-9809656-2-7 N1 - EuroSun <5, 2004, Freiburg, Breisgau> ; Internationales Sonnenforum <14, 2004, Freiburg, Breisgau> ; Deutsche Gesellschaft für Sonnenenergie ; CD-ROM-Ausg.: ISBN 3-9809656-4-3 SP - 2-489-2-494 PB - PSE CY - Freiburg [Breisgau] ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Silva, Maria Eugênia Vieira da A1 - Faber, Christian A1 - Müller, Christoph T1 - Solar thermal desalination system with heat recovery JF - Desalination. 137 (2001), H. 1-3 Y1 - 2001 SN - 0011-9164 SP - 23 EP - 29 ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Silva, Maria Eugênia Vieira da T1 - Solar cooking system with or without heat storage for families and institutions JF - Solar energy. 75 (2003), H. 1 Y1 - 2003 SN - 0038-092x N1 - 2. ISSN: 0375-9865 SP - 34 EP - 41 ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Silva, Maria Eugenia Vieira da T1 - Characterisation and design methods of solar cookers / Schwarzer, Klemens ; Silva, Maria Eugenia Vieira da JF - Solar energy. 82 (2008), H. 2 Y1 - 2008 SN - 0038-092X SP - 157 EP - 163 ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Schlenger, Barbara J. T1 - Investigation of fission product aerosol behavior in an HTR containment during severe core-heatup accidents / Barbara J. Schlenger ; K. Schwarzer JF - Tagungsbericht : Maritim Kongresszentrum, 17. - 19. Mai '88 Travemünde / Kerntechnische Gesellschaft e.V.; Deutsches Atomforum e.V. [Red.: K. G. Bauer] Y1 - 1988 SN - 0720-9207 N1 - Jahrestagung Kerntechnik <1988, Lübeck-Travemünde> ; Annual Meeting of Nuclear Technology <1988, Lübeck-Travemünde> SP - 179 EP - 182 PB - Inforum CY - Bonn ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Müller, C. A1 - Vieira da Silva, E. T1 - Solare Meerwasser-Entsalzungsanlagen mit mehrstufiger Wärmerückgewinnung / C. Müller ; K. Schwarzer ; E. Vieira da Silva ... JF - 14. Symposium Thermische Solarenergie : 12. bis 14. Mai, 2004, Kloster Banz / [Veranst.: OTTI Energie-Kolleg] Y1 - 2004 SN - 3-934681-33-6 N1 - Symposium Thermische Solarenergie ; (14, 2004, Kloster Banz) ; Energie-Kolleg ; (Regensburg) ; OTTI-Symposium Thermische Solarenergie ; Parallel als CD-ROM-Ausg. ersch. SP - 154 EP - 159 PB - Ostbayerisches Technologie-Transfer-Institut CY - Regensburg ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Müller, C. A1 - Mertes, C. T1 - Solar thermal desalination systems with multi-layer heat recovery / C. Müller ; K. Schwarzer ; C. Mertes ... JF - Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft für Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol 1 Y1 - 2004 SN - 3-9809656-1-9 N1 - EuroSun <5, 2004, Freiburg, Breisgau> ; Internationales Sonnenforum <14, 2004, Freiburg, Breisgau> ; Deutsche Gesellschaft für Sonnenenergie ; CD-ROM-Ausg.: ISBN 3-9809656-4-3 SP - 1-647-1-652 PB - PSE CY - Freiburg [Breisgau] ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Müller, C. A1 - Kleine-Hering, H. T1 - Simple solar systems for heating, hot water and cooking in high altitude regions with high solar radiation / C. Müller ; K. Schwarzer ; H. Kleine-Hering JF - Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft für Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol 1 Y1 - 2004 SN - 3-9809656-1-9 N1 - EuroSun <5, 2004, Freiburg, Breisgau> ; Internationales Sonnenforum <14, 2004, Freiburg, Breisgau> ; Deutsche Gesellschaft für Sonnenenergie ; CD-ROM-Ausg.: ISBN 3-9809656-4-3 SP - 1-653-1-658 PB - PSE CY - Freiburg [Breisgau] ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Krings, T. T1 - Dissemination of solar cookers with and without temporary storage : a report of concrete examples ; experiences from Chile, India and Mali JF - Proceedings / EuroSun '96 : 10. Internationales Sonnenforum. Ed. by A. Goetzberger ... - Bd. 4 Y1 - 1996 N1 - EuroSun <1, 1996, Freiburg, Breisgau> SP - 1479 EP - 1482 PB - DGS-Sonnenenergie-Verl. CY - München ER - TY - JOUR A1 - Schwarzer, Klemens A1 - da Silva, Vieira E. A1 - Hoffschmidt, Bernhard A1 - Schwarzer, T. T1 - A new solar desalination system with heat recovery for decentralised drinking water production JF - Desalination. 248 (2009), H. 1-3 Y1 - 2009 SN - 0011-9164 N1 - Water and Sanitation in International Development and Disaster Relief (WSIDDR) International Workshop Edinburgh, Scotland, UK, 28–30 May 2008 SP - 204 EP - 211 PB - Elsevier CY - Amsterdam ER - TY - BOOK A1 - Schwarzer, Klemens T1 - Lacasa : Einsatz von MATLAB-Simulink zur energetischen Analyse und Optimierung von Alt- und Neubauten inklusive Heizungs-, Lüftungs- und Klimatechnik / Hrsg.: FIA-Projekt, Forschungs-Informations-Austausch im Fachinstitut Gebäude-Klima e.V. Projekt: Solar-Institut Jülich an der Fachhochschule Aachen Y1 - 2004 SN - 3-938210-07-9 PB - FIA-Projekt im Fachinst. Gebäude-Klima CY - Bietigheim-Bissingen ER - TY - JOUR A1 - Schwager, Christian A1 - Flesch, Robert A1 - Schwarzbözl, Peter A1 - Herrmann, Ulf A1 - Teixeira Boura, Cristiano José T1 - Advanced two phase flow model for transient molten salt receiver system simulation JF - Solar Energy N2 - In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed. KW - Molten salt solar tower KW - Molten salt receiver system KW - Dynamic simulation KW - Two-phase modelling KW - Transient flux distribution Y1 - 2022 U6 - http://dx.doi.org/10.1016/j.solener.2021.12.065 SN - 0038-092X (print) SN - 1471-1257 (online) VL - 232 SP - 362 EP - 375 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Schwager, Christian A1 - Angele, Florian A1 - Schwarzbözl, Peter A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Model predictive assistance for operational decision making in molten salt receiver systems T2 - SolarPACES: Solar Power & Chemical Energy Systems N2 - Despite the challenges of pioneering molten salt towers (MST), it remains the leading technology in central receiver power plants today, thanks to cost effective storage integration and high cost reduction potential. The limited controllability in volatile solar conditions can cause significant losses, which are difficult to estimate without comprehensive modeling [1]. This paper presents a Methodology to generate predictions of the dynamic behavior of the receiver system as part of an operating assistance system (OAS). Based on this, it delivers proposals if and when to drain and refill the receiver during a cloudy period in order maximize the net yield and quantifies the amount of net electricity gained by this. After prior analysis with a detailed dynamic two-phase model of the entire receiver system, two different reduced modeling approaches where developed and implemented in the OAS. A tailored decision algorithm utilizes both models to deliver the desired predictions efficiently and with appropriate accuracy. KW - Power plants KW - Associated liquids KW - Decision theory KW - Electrochemistry Y1 - 2023 SN - 978-0-7354-4623-6 U6 - http://dx.doi.org/10.1063/5.0151514 SN - 1551-7616 (online) SN - 0094-243X (print) N1 - 27th International Conference on Concentrating Solar Power and Chemical Energy Systems 27 September–1 October 2021 Online IS - 2815 / 1 PB - AIP conference proceedings / American Institute of Physics CY - Melville, NY ER - TY - CHAP A1 - Schwager, Christian A1 - Angele, Florian A1 - Nouri, Bijan A1 - Schwarzbözl, Peter A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Impact of DNI forecast quality on performance prediction for a commercial scale solar tower: Application of nowcasting DNI maps to dynamic solar tower simulation T2 - SolarPACES conference proceedings N2 - Concerning current efforts to improve operational efficiency and to lower overall costs of concentrating solar power (CSP) plants with prediction-based algorithms, this study investigates the quality and uncertainty of nowcasting data regarding the implications for process predictions. DNI (direct normal irradiation) maps from an all-sky imager-based nowcasting system are applied to a dynamic prediction model coupled with ray tracing. The results underline the need for high-resolution DNI maps in order to predict net yield and receiver outlet temperature realistically. Furthermore, based on a statistical uncertainty analysis, a correlation is developed, which allows for predicting the uncertainty of the net power prediction based on the corresponding DNI forecast uncertainty. However, the study reveals significant prediction errors and the demand for further improvement in the accuracy at which local shadings are forecasted. KW - Process prediction KW - DNI forecasting KW - Nowcasting KW - Uncertainty analysis KW - Molten salt receiver system, Y1 - 2024 U6 - http://dx.doi.org/10.52825/solarpaces.v1i.675 SN - 2751-9899 (online) N1 - 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA IS - Vol. 1 PB - TIB Open Publishing CY - Hannover ER - TY - CHAP A1 - Schulte, Jonas A1 - Schwager, Christian A1 - Noureldin, Kareem A1 - May, Martin A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Gradient controlled startup procedure of a molten-salt power-to-heat energy storage plant based on dynamic process simulation T2 - SolarPACES: Solar Power & Chemical Energy Systems N2 - The integration of high temperature thermal energy storages into existing conventional power plants can help to reduce the CO2 emissions of those plants and lead to lower capital expenditures for building energy storage systems, due to the use of synergy effects [1]. One possibility to implement that, is a molten salt storage system with a powerful power-to-heat unit. This paper presents two possible control concepts for the startup of the charging system of such a facility. The procedures are implemented in a detailed dynamic process model. The performance and safety regarding the film temperatures at heat transmitting surfaces are investigated in the process simulations. To improve the accuracy in predicting the film temperatures, CFD simulations of the electrical heater are carried out and the results are merged with the dynamic model. The results show that both investigated control concepts are safe regarding the temperature limits. The gradient controlled startup performed better than the temperature-controlled startup. Nevertheless, there are several uncertainties that need to be investigated further. KW - Power plants KW - Energy storage KW - Associated liquids Y1 - 2023 SN - 978-0-7354-4623-6 U6 - http://dx.doi.org/10.1063/5.0148741 SN - 1551-7616 (online) SN - 0094-243X (print) N1 - 27th International Conference on Concentrating Solar Power and Chemical Energy Systems 27 September–1 October 2021 Online IS - 2815 / 1 PB - AIP conference proceedings / American Institute of Physics CY - Melville, NY ER - 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 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 - http://dx.doi.org/10.52825/solarpaces.v1i.693 SN - 2751-9899 (online) N1 - 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA IS - Vol. 1 PB - TIB Open Publishing CY - Hannover ER -