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 - Gedle, Yibekal A1 - Schmitz, Mark A1 - Gielen, Hans A1 - Schmitz, Pascal A1 - Herrmann, Ulf A1 - Teixeira Boura, Cristiano José A1 - Mahdi, Zahra A1 - Caminos, Ricardo Alexander Chico A1 - Dersch, Jürgen T1 - Analysis of an integrated CSP-PV hybrid power plant T2 - SolarPACES 2020 N2 - In the past, CSP and PV have been seen as competing technologies. Despite massive reductions in the electricity generation costs of CSP plants, PV power generation is - at least during sunshine hours - significantly cheaper. If electricity is required not only during the daytime, but around the clock, CSP with its inherent thermal energy storage gets an advantage in terms of LEC. There are a few examples of projects in which CSP plants and PV plants have been co-located, meaning that they feed into the same grid connection point and ideally optimize their operation strategy to yield an overall benefit. In the past eight years, TSK Flagsol has developed a plant concept, which merges both solar technologies into one highly Integrated CSP-PV-Hybrid (ICPH) power plant. Here, unlike in simply co-located concepts, as analyzed e.g. in [1] – [4], excess PV power that would have to be dumped is used in electric molten salt heaters to increase the storage temperature, improving storage and conversion efficiency. The authors demonstrate the electricity cost sensitivity to subsystem sizing for various market scenarios, and compare the resulting optimized ICPH plants with co-located hybrid plants. Independent of the three feed-in tariffs that have been assumed, the ICPH plant shows an electricity cost advantage of almost 20% while maintaining a high degree of flexibility in power dispatch as it is characteristic for CSP power plants. As all components of such an innovative concept are well proven, the system is ready for commercial market implementation. A first project is already contracted and in early engineering execution. KW - Hybrid energy system KW - Power plants KW - Electricity generation KW - Energy storage KW - Associated liquids Y1 - 2022 SN - 978-0-7354-4195-8 U6 - http://dx.doi.org/10.1063/5.0086236 SN - 1551-7616 (online) SN - 0094-243X (print) N1 - 26th International Conference on Concentrating Solar Power and Chemical Energy Systems 28 September–2 October 2020 Freiburg, Germany IS - 2445 / 1 PB - AIP conference proceedings / American Institute of Physics CY - Melville, NY ER - TY - CHAP A1 - Breitbach, Gerd A1 - Alexopoulos, Spiros A1 - May, Martin A1 - Teixeira Boura, Cristiano José A1 - Herrmann, Ulf T1 - Analysis of volumetric solar radiation absorbers made of wire meshes T2 - AIP Conference Proceedings Y1 - 2019 U6 - http://dx.doi.org/10.1063/1.5117521 SN - 0094243X VL - 2126 SP - 030009-1 EP - 030009-6 ER - TY - CHAP A1 - Sauerborn, Markus A1 - Liebenstund, Lena A1 - Raue, Markus A1 - Mang, Thomas A1 - Herrmann, Ulf A1 - Dueing, Andreas T1 - Analytic method for material aging and quality analyzing to forecast long time stability of plastic micro heliostat components T2 - AIP Conference Proceedings Y1 - 2017 U6 - http://dx.doi.org/10.1063/1.4984388 VL - 1850 IS - 1 SP - 030045-1 EP - 030045-8 ER - TY - CHAP A1 - Aringhoff, R. A1 - Geyer, Michael A1 - Herrmann, Ulf A1 - Kistner, Rainer A1 - Nava, P. A1 - Osuna, R. ED - Steinfeld, Aldo T1 - AndaSol : 50MW Solar Plants with 9 Hour Storage for Southern Spain T2 - Proceedings of the 11th SolarPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies : September 4 - 6, 2002, Zurich, Switzerland / Paul Scherrer Institut, PSI; ETH, Eidgenössische Technische Hochschule Zürich Y1 - 2002 SN - 3-9521409-3-7 SP - 37 EP - 42 PB - Paul Scherrer Inst. CY - Villingen ER - TY - JOUR A1 - Kearney, D. A1 - Herrmann, Ulf A1 - Nava, P. A1 - Kelly, B. A1 - Mahoney, R. A1 - Pacheco, J. A1 - Cable, R. A1 - Potrovitza, N. A1 - Blake, D. A1 - Price, H. T1 - Assessment of a Molten Salt Heat Transfer Fluid in a Parabolic Trough Solar Field JF - Journal of Solar Energy Engineering Y1 - 2003 U6 - http://dx.doi.org/10.1115/1.1565087 SN - 1528-8986 VL - 125 IS - 2 SP - 170 EP - 176 ER - TY - CHAP A1 - Herrmann, Ulf A1 - Vorbrugg, O. A1 - Nava, P. T1 - Construction and Commissioning Process of the Andasol Solar Field T2 - SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings Y1 - 2009 SN - 978-3-00-028755-8 PB - Deutsches Zentrum für Luft- u. Raumfahrt CY - Stuttgart 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 - TY - CHAP A1 - Anthrakidis, Anette A1 - Herrmann, Ulf A1 - Schorn, Christian A1 - Schwarzer, Klemens A1 - Wedding, Philipp A1 - Weis, Fabian T1 - Development and Testing of a Novel Method for the Determination of the Efficiency of Concentrating Solar Thermal Collectors T2 - Conference Proceedings Solar World Congress 2015, Daegu, Korea, 08 – 12 November 2015 Y1 - 2015 ER - TY - CHAP A1 - Caminos, Ricardo Alexander Chico A1 - Schmitz, Pascal A1 - Atti, Vikrama A1 - Mahdi, Zahra A1 - Teixeira Boura, Cristiano José A1 - Sattler, Johannes Christoph A1 - Herrmann, Ulf A1 - Hilger, Patrick A1 - Dieckmann, Simon T1 - Development of a micro heliostat and optical qualification assessment with a 3D laser scanning method T2 - SOLARPACES 2020 N2 - The Solar-Institut Jülich (SIJ) and the companies Hilger GmbH and Heliokon GmbH from Germany have developed a small-scale cost-effective heliostat, called “micro heliostat”. Micro heliostats can be deployed in small-scale concentrated solar power (CSP) plants to concentrate the sun's radiation for electricity generation, space or domestic water heating or industrial process heat. In contrast to conventional heliostats, the special feature of a micro heliostat is that it consists of dozens of parallel-moving, interconnected, rotatable mirror facets. The mirror facets array is fixed inside a box-shaped module and is protected from weathering and wind forces by a transparent glass cover. The choice of the building materials for the box, tracking mechanism and mirrors is largely dependent on the selected production process and the intended application of the micro heliostat. Special attention was paid to the material of the tracking mechanism as this has a direct influence on the accuracy of the micro heliostat. The choice of materials for the mirror support structure and the tracking mechanism is made in favor of plastic molded parts. A qualification assessment method has been developed by the SIJ in which a 3D laser scanner is used in combination with a coordinate measuring machine (CMM). For the validation of this assessment method, a single mirror facet was scanned and the slope deviation was computed. KW - Concentrated solar power KW - Electricity generation KW - Measuring instruments KW - Heliostats KW - Global change Y1 - 2022 SN - 978-0-7354-4195-8 U6 - http://dx.doi.org/10.1063/5.0086262 SN - 1551-7616 (online) SN - 0094-243X (print) N1 - 26th International Conference on Concentrating Solar Power and Chemical Energy Systems 28 September–2 October 2020 Freiburg, Germany IS - 2445 / 1 PB - AIP conference proceedings / American Institute of Physics CY - Melville, NY ER -