@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} } @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 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {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{SchulteSchwagerFrantzetal.2022, author = {Schulte, Jonas and Schwager, Christian and Frantz, Cathy and Schloms, Felix and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Control concept for a molten salt receiver in star design: Development, optimization and testing with cloud passage scenarios}, series = {SolarPACES 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.693}, pages = {9 Seiten}, year = {2022}, abstract = {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.}, language = {en} } @inproceedings{BaumannTeixeiraBouraEcksteinetal.2011, author = {Baumann, Torsten and Teixeira Boura, Cristiano Jos{\´e} and Eckstein, Julian and Felinks, Jan and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Zunft, Stefan}, title = {Air-sand heat exchanger}, series = {6th International Renewable Energy Storage Conference (IRES 2011) : November 28 - 30, 2011, bcc Berlin Congress Center, Berlin, Germany / EUROSOLAR ...}, booktitle = {6th International Renewable Energy Storage Conference (IRES 2011) : November 28 - 30, 2011, bcc Berlin Congress Center, Berlin, Germany / EUROSOLAR ...}, publisher = {Eurosolar}, address = {Bonn}, pages = {1 CD-ROM}, year = {2011}, language = {de} } @inproceedings{BaumannTeixeiraBouraGoettscheetal.2011, author = {Baumann, Torsten and Teixeira Boura, Cristiano Jos{\´e} and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Zunft, Stefan}, title = {Air-sand heat exchanger: materials and flow properties}, series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain}, booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain}, address = {Granada}, pages = {1 CD-ROM}, year = {2011}, 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} } @inproceedings{FrantzBinderBuschetal.2020, author = {Frantz, Cathy and Binder, Matthias and Busch, Konrad and Ebert, Miriam and Heinrich, Andreas and Kaczmarkiewicz, Nadine and Schl{\"o}gl-Knothe, B{\"a}rbel and Kunze, Tobias and Schuhbauer, Christian and Stetka, Markus and Schwager, Christian and Spiegel, Michael and Teixeira Boura, Cristiano Jos{\´e} and Bauer, Thomas and Bonk, Alexander and Eisen, Stefan and Funck, Bernhard}, title = {Basic Engineering of a High Performance Molten Salt Tower Receiver System}, series = {AIP Conference Proceedings}, booktitle = {AIP Conference Proceedings}, doi = {10.1063/5.0085895}, pages = {1 -- 10}, year = {2020}, abstract = {The production of dispatchable renewable energy will be one of the most important key factors of the future energy supply. Concentrated solar power (CSP) plants operated with molten salt as heat transfer and storage media are one opportunity to meet this challenge. Due to the high concentration factor of the solar tower technology the maximum process temperature can be further increased which ultimately decreases the levelized costs of electricity of the technology (LCOE). The development of an improved tubular molten salt receiver for the next generation of molten salt solar tower plants is the aim of this work. The receiver is designed for a receiver outlet temperature up to 600 °C. Together with a complete molten salt system, the receiver will be integrated into the Multi-Focus-Tower (MFT) in J{\"u}lich (Germany). The paper describes the basic engineering of the receiver, the molten salt tower system and a laboratory corrosion setup.}, language = {en} } @inproceedings{AhlbrinkAlexopoulosAnderssonetal.2009, author = {Ahlbrink, Nils and Alexopoulos, Spiros and Andersson, Joel A. E. and Belhomme, B. and Teixeira Boura, Cristiano Jos{\´e} and Gall, Jan and Hirsch, Tobias}, title = {viCERP - the Virtual Institute of Central Receiver Power Plant}, series = {MATHMOD 2009 - 6th Vienna International Conference on Mathematical Modelling : February 11 - 13, 2009, Vienna, Austria. ARGESIM Report. No. 35}, booktitle = {MATHMOD 2009 - 6th Vienna International Conference on Mathematical Modelling : February 11 - 13, 2009, Vienna, Austria. ARGESIM Report. No. 35}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-3-901608-35-3}, year = {2009}, language = {en} } @inproceedings{BaumannTeixeiraBouraEcksteinetal.2012, author = {Baumann, Torsten and Teixeira Boura, Cristiano Jos{\´e} and Eckstein, Julian and Dabrowski, Jan and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Zunft, Stefan}, title = {Properties of bulk materials for high-temperature air-sand heat exchangers}, series = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 2}, booktitle = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 2}, publisher = {Curran}, address = {Red Hook, NY}, organization = {International Solar Energy Society}, isbn = {978-1-61839-364-7}, pages = {1270 -- 1278}, year = {2012}, language = {en} } @incollection{HoffschmidtAlexopoulosRauetal.2022, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and Rau, Christoph and Sattler, Johannes Christoph and Anthrakidis, Anette and Teixeira Boura, Cristiano Jos{\´e} and O'Connor, B. and Chico Caminos, Ricardo Alexander and Rend{\´o}n, C. and Hilger, P.}, title = {Concentrating solar power}, series = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications}, booktitle = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-12-819734-9}, pages = {670 -- 724}, year = {2022}, abstract = {The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems. The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours. Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage. Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described. Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail. The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world.}, language = {en} } @inproceedings{MayBreitbachAlexopoulosetal.2019, author = {May, Martin and Breitbach, Gerd and Alexopoulos, Spiros and Latzke, Markus and B{\"a}umer, Klaus and Uhlig, Ralf and S{\"o}hn, Matthias and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Experimental facility for investigations of wire mesh absorbers for pressurized gases}, series = {AIP Conference Proceedings}, volume = {2126}, booktitle = {AIP Conference Proceedings}, issn = {0094243X}, doi = {10.1063/1.5117547}, pages = {030035-1 -- 030035-9}, year = {2019}, language = {en} } @inproceedings{SchwagerTeixeiraBouraFleschetal.2019, author = {Schwager, Christian and Teixeira Boura, Cristiano Jos{\´e} and Flesch, Robert and Alexopoulos, Spiros and Herrmann, Ulf}, title = {Improved efficiency prediction of a molten salt receiver based on dynamic cloud passage simulation}, series = {AIP Conference Proceedings}, volume = {2126}, booktitle = {AIP Conference Proceedings}, number = {1}, isbn = {978-0-7354-1866-0}, doi = {10.1063/1.5117566}, pages = {030054-1 -- 030054-8}, year = {2019}, language = {en} } @inproceedings{TeixeiraBouraNiederwestbergMcLeodetal.2016, author = {Teixeira Boura, Cristiano Jos{\´e} and Niederwestberg, Stefan and McLeod, Jacqueline and Herrmann, Ulf and Hoffschmidt, Bernhard}, title = {Development of heat exchanger for high temperature energy storage with bulk materials}, series = {AIP Conference Proceedings}, volume = {1734}, booktitle = {AIP Conference Proceedings}, number = {1}, doi = {10.1063/1.4949106}, pages = {050008-1 -- 050008-7}, year = {2016}, language = {en} } @incollection{HoffschmidtAlexopoulosRauetal.2021, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and Rau, Christoph and Sattler, Johannes Christoph and Anthrakidis, Anette and Teixeira Boura, Cristiano Jos{\´e} and O'Connor, B. and Chico Caminos, Ricardo Alexander and Rend{\´o}n, C. and Hilger, P.}, title = {Concentrating Solar Power}, series = {Earth systems and environmental sciences}, booktitle = {Earth systems and environmental sciences}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-12-409548-9}, doi = {10.1016/B978-0-12-819727-1.00089-3}, year = {2021}, abstract = {The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems. The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours. Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage. Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described. Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail. The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world.}, language = {en} } @inproceedings{SchulteSchwagerNoureldinetal.2023, author = {Schulte, Jonas and Schwager, Christian and Noureldin, Kareem and May, Martin and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Gradient controlled startup procedure of a molten-salt power-to-heat energy storage plant based on dynamic process simulation}, 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 = {10.1063/5.0148741}, pages = {9 Seiten}, year = {2023}, abstract = {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.}, language = {en} } @inproceedings{RendonDieckmannWeidleetal.2018, author = {Rendon, Carlos and Dieckmann, Simon and Weidle, Mathias and Dersch, J{\"u}rgen and Teixeira Boura, Cristiano Jos{\´e} and Polklas, Thomas and Kuschel, Marcus and Herrmann, Ulf}, title = {Retrofitting of existing parabolic trough collector power plants with molten salt tower systems}, series = {AIP Conference Proceedings}, volume = {2033}, booktitle = {AIP Conference Proceedings}, number = {1}, doi = {10.1063/1.5067030}, pages = {030014-1 -- 030014-8}, year = {2018}, language = {en} } @inproceedings{TeixeiraBouraEcksteinFelinksetal.2011, author = {Teixeira Boura, Cristiano Jos{\´e} and Eckstein, J. and Felinks, J. and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, S.}, title = {3-D CFD simulation of an air-sand heat exchanger}, series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain}, booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain}, address = {Granada}, pages = {1 CD-ROM}, year = {2011}, language = {en} } @incollection{HoffschmidtAlexopoulosRauetal.2012, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and Rau, Christoph and Sattler, Johannes Christoph and Anthrakidis, Anette and Teixeira Boura, Cristiano Jos{\´e} and O'Connor, P. and Hilger, Patrick}, title = {Concentrating solar power}, series = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications}, volume = {3}, booktitle = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-08-087872-0}, doi = {10.1016/B978-0-08-087872-0.00319-X}, pages = {595 -- 636}, year = {2012}, language = {en} } @inproceedings{SattlerAlexopoulosChicoCaminosetal.2019, author = {Sattler, Johannes Christoph and Alexopoulos, Spiros and Chico Caminos, Ricardo Alexander and Mitchell, John C. and Ruiz, Victor C. and Kalogirou, Soteris and Ktistis, Panayiotis K. and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Dynamic simulation model of a parabolic trough collector system with concrete thermal energy storage for process steam generation}, series = {AIP Conference Proceedings}, volume = {2126}, booktitle = {AIP Conference Proceedings}, issn = {0094243X}, doi = {10.1063/1.5117663}, pages = {150007-1 -- 150007-8}, year = {2019}, language = {en} } @article{PuppeGiulianoFrantzetal.2018, author = {Puppe, Michael and Giuliano, Stefano and Frantz, Cathy and Uhlig, Ralf and Schumacher, Ralph and Ibraheem, Wagdi and Schmalz, Stefan and Waldmann, Barbara and Guder, Christoph and Peter, Dennis and Schwager, Christian and Teixeira Boura, Cristiano Jos{\´e} and Alexopoulos, Spiros and Spiegel, Michael and Wortmann, J{\"u}rgen and Hinrichs, Matthias and Engelhard, Manfred and Aust, Michael}, title = {Techno-economic optimization of molten salt solar tower plants}, series = {AIP Conference Proceedings art.no. 040033}, volume = {2033}, journal = {AIP Conference Proceedings art.no. 040033}, number = {Issue 1}, publisher = {AIP Publishing}, address = {Melville, NY}, doi = {10.1063/1.5067069}, year = {2018}, abstract = {In this paper the results of a techno-economic analysis of improved and optimized molten salt solar tower plants (MSSTP plants) are presented. The potential improvements that were analyzed include different receiver designs, different designs of the HTF-system and plant control, increased molten salt temperatures (up to 640°C) and multi-tower systems. Detailed technological and economic models of the solar field, solar receiver and high temperature fluid system (HTF-system) were developed and used to find potential improvements compared to a reference plant based on Solar Two technology and up-to-date cost estimations. The annual yield model calculates the annual outputs and the LCOE of all variants. An improved external tubular receiver and improved HTF-system achieves a significant decrease of LCOE compared to the reference. This is caused by lower receiver cost as well as improvements of the HTF-system and plant operation strategy, significantly reducing the plant own consumption. A novel star receiver shows potential for further cost decrease. The cavity receiver concepts result in higher LCOE due to their high investment cost, despite achieving higher efficiencies. Increased molten salt temperatures seem possible with an adapted, closed loop HTF-system and achieve comparable results to the original improved system (with 565°C) under the given boundary conditions. In this analysis all multi tower systems show lower economic viability compared to single tower systems, caused by high additional cost for piping connections and higher cost of the receivers. REFERENCES}, language = {en} }