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 - 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 - Teixeira Boura, Cristiano José A1 - Flesch, Robert A1 - Alexopoulos, Spiros A1 - Herrmann, Ulf T1 - Improved efficiency prediction of a molten salt receiver based on dynamic cloud passage simulation T2 - AIP Conference Proceedings Y1 - 2019 SN - 978-0-7354-1866-0 U6 - http://dx.doi.org/10.1063/1.5117566 VL - 2126 IS - 1 SP - 030054-1 EP - 030054-8 ER - TY - CHAP A1 - Schwarzbözl, Peter A1 - Pomp, Stefan A1 - Koll, Gerrit A1 - Hennecke, Klaus A1 - Hartz, Thomas A1 - Schmitz, Mark A1 - Hoffschmidt, Bernhard T1 - The solar tower Jülich - first operational experiences and test results T2 - SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France Y1 - 2010 SP - 8 EP - 9 PB - Soc. OSC CY - Saint Maur ER - TY - CHAP A1 - Schwarzer, Klemens T1 - A new kind of efficient solar cookers with and without temporary heat storage T2 - Advances in solar cooking : proceedings of the First World Conference on Solar Cooking, Stockton, California, USA, June 19 - 20, 1992 / ed. by Edwin Pejack Y1 - 1992 SP - 107 EP - 112 PB - Solar Box Cookers International CY - Sacramento, Calif. ER - TY - CHAP A1 - Schwarzer, Klemens T1 - Desalination systems with renewable energies T2 - DME Seminar Desalination and Renewable Energies : June 19 and 20 2008, Solar Institut Jülich / Deutsche Meerwasserentsalzung e.V. Y1 - 2008 SN - 978-3-86861-017-8 PB - DME CY - Duisburg ER - TY - CHAP A1 - Schwarzer, Klemens A1 - Bieger, W. A1 - Ricking, N. A1 - Bansal, Narenda K. T1 - Solar cooker with a rock bed cum oil storage T2 - 1991 Solar World Congress : : proceedings of the Biennial Congress of the International Solar Energy Society, Denver, Colorado, USA, 19 - 23 August 1991 / ed. by M. E. Arden. Bd. 3,II Y1 - 1991 SN - 0-08-041690-x SP - 3751 EP - 3756 PB - Pergamon Pr. CY - Oxford ER - TY - CHAP A1 - Schwarzer, Klemens A1 - Faber, Christian A1 - Meliß, Michael A1 - Späte, F. T1 - Solar-Institut Jülich (SIJ), Fachhochschule Aachen, Division Jülich Germany T2 - Harmony with nature : proceedings / ISES Solar World Congress, Budapest 1993. International Solar Energy Society, Hungarian Section (H-ISES); Hungarian Solar Energy Society (HSES). Vol. 1: Energy policy, environment, education Y1 - 1993 SP - 349 EP - 354 PB - Hungarian Energy Society CY - Budapest ER - TY - CHAP A1 - Schwarzer, Klemens A1 - Hafner, B. A1 - Meer, A. von A1 - Krings, T. T1 - Simulation and dimensioning program for solar cookers with temporal heat storage and comparison with measurements T2 - Harmony with nature : : proceedings / ISES Solar World Congress, Budapest 1993. International Solar Energy Society, Hungarian Section (H-ISES); Hungarian Solar Energy Society (HSES). Bd 5: Active systems Y1 - 1993 SP - 473 EP - 478 PB - Hungarian Energy Society CY - Budapest ER - TY - CHAP A1 - Schwarzer, Klemens A1 - Kroker, Jan A1 - Rusack, Markus T1 - Technical improvement of a small modular parabolic trough collector T2 - EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings ; 7th - 10th October 2008, Lisbon, Portugal : key lectures / ISES, International Solar Energy Society. Vol. 1 Y1 - 2008 SN - 978-1-61782-228-5 SP - 1395 EP - 1402 PB - Sociedade Portuguesa De Energia Solar (SPES) CY - Lissabon ER - TY - JOUR A1 - Schwarzer, Klemens A1 - Vieira da Silva, Maria Eugenia A1 - Schwarzer, Tarik T1 - Field results in Namibia and Brazil of the new solar desalination system for decentralised drinking water production JF - Desalination and water treatment. Vol. 31 (2011), iss. 1-3: selected papers presented at EuroMed 2010 — Desalination for Clean Water and Energy: Cooperation among Mediterranean Countries of Europe and MENA Region, 3–7 October 2010, Tel Aviv, Israel Y1 - 2011 SP - 379 EP - 386 ER - TY - CHAP A1 - Schwarzer, Klemens A1 - Vieira, Maria Eugenia A1 - Müller, Christoph A1 - Lehmann, Harry A1 - Coutinho, Lecimara T1 - Modular solar thermal desalination system with flat plate collector T2 - RIO 3 - World Climate & Energy Event : proceedings of the international conference held in Rio de Janeiro, Brazil, 1 -5 december 2003 / chief-ed.: Stefan Krauter ... Y1 - 2003 SN - 85-902710-2-1 SP - 281 EP - 286 PB - Krauter CY - Rio de Janeiro ER - TY - CHAP A1 - Schwarzer, Klemens A1 - Wiedenfeld, M. A1 - Bansal, Narenda K. A1 - Ertl, Karl-Heinz T1 - A novel solar sterilization and water destillation system : experiment and thermodynamic analysis T2 - 1991 Solar World Congress : : proceedings of the Biennial Congress of the International Solar Energy Society, Denver, Colorado, USA, 19 - 23 August 1991 / ed. by M. E. Arden. Bd. 2,II Y1 - 1991 SN - 0-08-041690-x SP - 2276 EP - 2281 PB - Pergamon Pr. CY - Oxford ER - TY - CHAP A1 - Späte, Frank A1 - Hafner, B. A1 - Schwarzer, Klemens T1 - A system for solar process heat for decentralized applications in developing countries T2 - ISES 1999 Solar World Congress, Jerusalem, Israel, July 4-9, 1999 : conference proceedings / ed. Gershon Grossman. Vol. 3 Y1 - 2000 SN - 0-080-043895-4 SP - 236 EP - 291 PB - Elsevier CY - Oxford ER - TY - CHAP A1 - Teixeira Boura, Cristiano José A1 - Eckstein, J. A1 - Felinks, J. A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Schmitz, S. T1 - 3-D CFD simulation of an air-sand heat exchanger T2 - SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain Y1 - 2011 CY - Granada ER - TY - CHAP A1 - Teixeira Boura, Cristiano José A1 - Niederwestberg, Stefan A1 - McLeod, Jacqueline A1 - Herrmann, Ulf A1 - Hoffschmidt, Bernhard T1 - Development of heat exchanger for high temperature energy storage with bulk materials T2 - AIP Conference Proceedings Y1 - 2016 U6 - http://dx.doi.org/10.1063/1.4949106 VL - 1734 IS - 1 SP - 050008-1 EP - 050008-7 ER - TY - JOUR A1 - Velraj, R. A1 - Seeniraj, R. V. A1 - Hafner, B. A1 - Faber, Christian A1 - Schwarzer, Klemens T1 - Heat transfer enhancement in a latent heat storage system JF - Solar energy. Vol. 65, iss. 3 Y1 - 1999 SN - 0038-092X SP - 171 EP - 180 ER - TY - JOUR A1 - Vieira da Silva, Maria Eugenia A1 - Schwarzer, Klemens A1 - Hoffschmidt, Bernhard A1 - Pinheiro Rodrigues, Frederico A1 - Schwarzer, Tarik A1 - Costa Rocha, Paulo Alexandre T1 - Mass transfer correlation for evaporation–condensation thermal process in the range of 70 °C–95 °C JF - Renewable energy Y1 - 2013 SN - 1879-0682 (E-Journal); 0960-1481 (Print) VL - Vol. 53 SP - 174 EP - 179 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Warerkar, S. A1 - Schmitz, S. A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Tamme, R. T1 - Performance analysis of an air-sand heat exchanger prototype for high-temperature storage T2 - EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings ; 7th - 10th October 2008, Lisbon, Portugal : key lectures / ISES, International Solar Energy Society. Vol. 1 Y1 - 2008 SN - 978-1-61782-228-5 SP - 2215 EP - 2222 PB - Sociedade Portuguesa De Energia Solar (SPES) CY - Lissabon ER - TY - CHAP A1 - Warerkar, Shashikant A1 - Schmitz, Stefan A1 - Göttsche, Joachim A1 - Hoffschmidt, Bernhard A1 - Reißel, Martin A1 - Tamme, Rainer T1 - Air-sand heat exchanger for high-temperature storage T2 - Proceedings of the ASME 3rd International Conference on Energy Sustainability : July 19 - 23, 2009, San Francisco, California, USA. Vol. 2 Y1 - 2009 SN - 978-0-7918-4890-6 SP - 655 EP - 661 PB - ASME CY - New York, NY ER -