@inproceedings{SchwagerAngeleNourietal.2022, author = {Schwager, Christian and Angele, Florian and Nouri, Bijan and Schwarzb{\"o}zl, Peter and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Impact of DNI forecast quality on performance prediction for a commercial scale solar tower: Application of nowcasting DNI maps to dynamic solar tower simulation}, series = {SolarPACES conference proceedings}, booktitle = {SolarPACES conference proceedings}, number = {Vol. 1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.675}, pages = {9 Seiten}, year = {2022}, abstract = {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.}, language = {en} } @inproceedings{SchwagerAngeleSchwarzboezletal.2023, author = {Schwager, Christian and Angele, Florian and Schwarzb{\"o}zl, Peter and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Model predictive assistance for operational decision making in molten salt receiver systems}, series = {SolarPACES: Solar Power \& Chemical Energy Systems}, booktitle = {SolarPACES: Solar Power \& Chemical Energy Systems}, number = {2815 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4623-6}, issn = {1551-7616 (online)}, doi = {10.1063/5.0151514}, pages = {8 Seiten}, year = {2023}, abstract = {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.}, language = {en} } @article{SchwagerFleschSchwarzboezletal.2022, author = {Schwager, Christian and Flesch, Robert and Schwarzb{\"o}zl, Peter and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e}}, title = {Advanced two phase flow model for transient molten salt receiver system simulation}, series = {Solar Energy}, volume = {232}, journal = {Solar Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0038-092X (print)}, doi = {10.1016/j.solener.2021.12.065}, pages = {362 -- 375}, year = {2022}, abstract = {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.}, language = {en} } @book{Schwarzer2004, author = {Schwarzer, Klemens}, title = {Lacasa : Einsatz von MATLAB-Simulink zur energetischen Analyse und Optimierung von Alt- und Neubauten inklusive Heizungs-, L{\"u}ftungs- und Klimatechnik / Hrsg.: FIA-Projekt, Forschungs-Informations-Austausch im Fachinstitut Geb{\"a}ude-Klima e.V. Projekt: Solar-Institut J{\"u}lich an der Fachhochschule Aachen}, publisher = {FIA-Projekt im Fachinst. Geb{\"a}ude-Klima}, address = {Bietigheim-Bissingen}, isbn = {3-938210-07-9}, pages = {34 S. : Ill., graph. Darst.}, year = {2004}, language = {en} } @article{SchwarzerdaSilvaHoffschmidtetal.2009, author = {Schwarzer, Klemens and da Silva, Vieira E. and Hoffschmidt, Bernhard and Schwarzer, T.}, title = {A new solar desalination system with heat recovery for decentralised drinking water production}, series = {Desalination. 248 (2009), H. 1-3}, journal = {Desalination. 248 (2009), H. 1-3}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0011-9164}, pages = {204 -- 211}, year = {2009}, language = {en} } @article{SchwarzerKrings1996, author = {Schwarzer, Klemens and Krings, T.}, title = {Dissemination of solar cookers with and without temporary storage : a report of concrete examples ; experiences from Chile, India and Mali}, series = {Proceedings / EuroSun '96 : 10. Internationales Sonnenforum. Ed. by A. Goetzberger ... - Bd. 4}, journal = {Proceedings / EuroSun '96 : 10. Internationales Sonnenforum. Ed. by A. Goetzberger ... - Bd. 4}, publisher = {DGS-Sonnenenergie-Verl.}, address = {M{\"u}nchen}, pages = {1479 -- 1482}, year = {1996}, language = {en} } @article{SchwarzerMuellerKleineHering2004, author = {Schwarzer, Klemens and M{\"u}ller, C. and Kleine-Hering, H.}, title = {Simple solar systems for heating, hot water and cooking in high altitude regions with high solar radiation / C. M{\"u}ller ; K. Schwarzer ; H. Kleine-Hering}, series = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol 1}, journal = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol 1}, publisher = {PSE}, address = {Freiburg [Breisgau]}, isbn = {3-9809656-1-9}, pages = {1-653-1-658}, year = {2004}, language = {en} } @article{SchwarzerMuellerMertes2004, author = {Schwarzer, Klemens and M{\"u}ller, C. and Mertes, C.}, title = {Solar thermal desalination systems with multi-layer heat recovery / C. M{\"u}ller ; K. Schwarzer ; C. Mertes ...}, series = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol 1}, journal = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol 1}, publisher = {PSE}, address = {Freiburg [Breisgau]}, isbn = {3-9809656-1-9}, pages = {1-647-1-652}, year = {2004}, language = {en} } @article{SchwarzerMuellerVieiradaSilva2004, author = {Schwarzer, Klemens and M{\"u}ller, C. and Vieira da Silva, E.}, title = {Solare Meerwasser-Entsalzungsanlagen mit mehrstufiger W{\"a}rmer{\"u}ckgewinnung / C. M{\"u}ller ; K. Schwarzer ; E. Vieira da Silva ...}, series = {14. Symposium Thermische Solarenergie : 12. bis 14. Mai, 2004, Kloster Banz / [Veranst.: OTTI Energie-Kolleg]}, journal = {14. Symposium Thermische Solarenergie : 12. bis 14. Mai, 2004, Kloster Banz / [Veranst.: OTTI Energie-Kolleg]}, publisher = {Ostbayerisches Technologie-Transfer-Institut}, address = {Regensburg}, isbn = {3-934681-33-6}, pages = {154 -- 159}, year = {2004}, language = {en} } @article{SchwarzerSchlenger1988, author = {Schwarzer, Klemens and Schlenger, Barbara J.}, title = {Investigation of fission product aerosol behavior in an HTR containment during severe core-heatup accidents / Barbara J. Schlenger ; K. Schwarzer}, series = {Tagungsbericht : Maritim Kongresszentrum, 17. - 19. Mai '88 Travem{\"u}nde / Kerntechnische Gesellschaft e.V.; Deutsches Atomforum e.V. [Red.: K. G. Bauer]}, journal = {Tagungsbericht : Maritim Kongresszentrum, 17. - 19. Mai '88 Travem{\"u}nde / Kerntechnische Gesellschaft e.V.; Deutsches Atomforum e.V. [Red.: K. G. Bauer]}, publisher = {Inforum}, address = {Bonn}, isbn = {0720-9207}, pages = {179 -- 182}, year = {1988}, language = {en} }