TY  - CHAP
A1  - Niederwestberg, Stefan
A1  - Schneider, Falko
A1  - Teixeira Boura, Cristiano José
A1  - Herrmann, Ulf
T1  - Introduction to a direct irradiated transparent tube particle receiver
T2  - SOLARPACES 2020
N2  - New materials often lead to innovations and advantages in technical applications. This also applies to the particle receiver proposed in this work that deploys high-temperature and scratch resistant transparent ceramics. With this receiver design, particles are heated through direct-contact concentrated solar irradiance while flowing downwards through tubular transparent ceramics from top to bottom. In this paper, the developed particle receiver as well as advantages and disadvantages are described. Investigations on the particle heat-up characteristics from solar irradiance were carried out with DEM simulations which indicate that particle temperatures can reach up to 1200 K. Additionally, a simulation model was set up for investigating the dynamic behavior. A test receiver at laboratory scale has been designed and is currently being built. In upcoming tests, the receiver test rig will be used to validate the simulation results. The design and the measurement equipment is described in this work.
KW  - Solar irradiance
KW  - Ceramics
Y1  - 2022
SN  - 978-0-7354-4195-8
U6  - https://doi.org/10.1063/5.0086735
SN  - 1551-7616 (online)
SN  - 0094-243X (print)
N1  - SOLARPACES 2020: 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  - Sattler, Johannes Christoph
A1  - Schneider, Iesse Peer
A1  - Angele, Florian
A1  - Atti, Vikrama
A1  - Teixeira Boura, Cristiano José
A1  - Herrmann, Ulf
T1  - Development of heliostat field calibration methods: Theory and experimental test results
T2  - SolarPACES 2022 conference proceedings
N2  - In this work, three patent pending calibration methods for heliostat fields of central receiver systems (CRS) developed by the Solar-Institut Jülich (SIJ) of the FH Aachen University of Applied Sciences are presented. The calibration methods can either operate in a combined mode or in stand-alone mode. The first calibration method, method A, foresees that a camera matrix is placed into the receiver plane where it is subjected to concentrated solar irradiance during a measurement process. The second calibration method, method B, uses an unmanned aerial vehicle (UAV) such as a quadrocopter to automatically fly into the reflected solar irradiance cross-section of one or more heliostats (two variants of method B were tested). The third calibration method, method C, foresees a stereo central camera or multiple stereo cameras installed e.g. on the solar tower whereby the orientations of the heliostats are calculated from the location detection of spherical red markers attached to the heliostats. The most accurate method is method A which has a mean accuracy of 0.17 mrad. The mean accuracy of method B variant 1 is 1.36 mrad and of variant 2 is 1.73 mrad. Method C has a mean accuracy of 15.07 mrad. For method B there is great potential regarding improving the measurement accuracy. For method C the collected data was not sufficient for determining whether or not there is potential for improving the accuracy.
KW  - Heliostat Field Calibration
KW  - Unmanned aerial vehicle
KW  - UAV
KW  - Quadrocopter
KW  - Camera system
Y1  - 2024
U6  - https://doi.org/10.52825/solarpaces.v1i.678
SN  - 2751-9899 (online)
N1  - SolarPACES 2022: 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA
IS  - 1
PB  - TIB Open Publishing
CY  - Hannover
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 2022 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  - https://doi.org/10.52825/solarpaces.v1i.675
SN  - 2751-9899 (online)
N1  - SolarPACES 2022, 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA
IS  - 1
PB  - TIB Open Publishing
CY  - Hannover
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 2022 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  - https://doi.org/10.52825/solarpaces.v1i.693
SN  - 2751-9899 (online)
N1  - SolarPACES 2022, 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA
IS  - 1
PB  - TIB Open Publishing
CY  - Hannover
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  - https://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  - https://doi.org/10.1063/5.0086236
SN  - 1551-7616 (online)
SN  - 0094-243X (print)
N1  - SOLARPACES 2020: 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  - Mahdi, Zahra
A1  - Dersch, Jürgen
A1  - Schmitz, Pascal
A1  - Dieckmann, Simon
A1  - Caminos, Ricardo Alexander Chico
A1  - Teixeira Boura, Cristiano José
A1  - Herrmann, Ulf
A1  - Schwager, Christian
A1  - Schmitz, Mark
A1  - Gielen, Hans
A1  - Gedle, Yibekal
A1  - Büscher, Rauno
T1  - Technical assessment of Brayton cycle heat pumps for the integration in hybrid PV-CSP power plants
T2  - SOLARPACES 2020
N2  - The hybridization of Concentrated Solar Power (CSP) and Photovoltaics (PV) systems is a promising approach to reduce costs of solar power plants, while increasing dispatchability and flexibility of power generation. High temperature heat pumps (HT HP) can be utilized to boost the salt temperature in the thermal energy storage (TES) of a Parabolic Trough Collector (PTC) system from 385 °C up to 565 °C. A PV field can supply the power for the HT HP, thus effectively storing the PV power as thermal energy. Besides cost-efficiently storing energy from the PV field, the power block efficiency of the overall system is improved due to the higher steam parameters. This paper presents a technical assessment of Brayton cycle heat pumps to be integrated in hybrid PV-CSP power plants. As a first step, a theoretical analysis was carried out to find the most suitable working fluid. The analysis included the fluids Air, Argon (Ar), Nitrogen (N2) and Carbon dioxide (CO2). N2 has been chosen as the optimal working fluid for the system. After the selection of the ideal working medium, different concepts for the arrangement of a HT HP in a PV-CSP hybrid power plant were developed and simulated in EBSILON®Professional. The concepts were evaluated technically by comparing the number of components required, pressure losses and coefficient of performance (COP).
KW  - Solar thermal technologies
KW  - Hybrid energy system
KW  - Concentrated solar power
KW  - Power plants
KW  - Energy storage
Y1  - 2022
SN  - 978-0-7354-4195-8
U6  - https://doi.org/10.1063/5.0086269
SN  - 1551-7616 (online)
SN  - 0094-243X (print)
N1  - SOLARPACES 2020: 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  - Losse, Ann-Kathrin
A1  - Gehrke, Melanie
A1  - Ullrich, André
A1  - Czarnecki, Christian
A1  - Sultanow, Eldar
A1  - Breithaupt, Carsten
A1  - Koch, Christian
T1  - Entwicklung einer Open-Data-Referenzarchitektur für die Luftfahrtindustrie
T2  - INFORMATIK 2022 - Informatik in den Naturwissenschaften, Proceedings
N2  - Open Data impliziert die freie Zugänglichkeit, Verfügbarkeit und Wiederverwendbarkeit von Datensätzen. Obwohl hochwertige Datensätze öffentlich verfügbar sind, ist der Zugang zu diesen und die Transparenz über die Formate nicht immer gegeben. Dies mindert die optimale Nutzung des Potenzials zur Wertschöpfung, trotz der vorherrschenden Einigkeit über ihre Chancen. Denn Open Data ermöglicht das Vorantreiben von Compliance-Themen wie Transparenz und Rechenschaftspflicht bis hin zur Förderung von Innovationen. Die Nutzung von Open Data erfordert Mut und eine gemeinsame Anstrengung verschiedener Akteure und Branchen. Im Rahmen des vorliegenden Beitrags werden auf Grundlage des Design Science-Ansatzes eine Open Data Capability Map sowie darauf aufbauend eine Datenarchitektur für Open Data in der Luftfahrtindustrie an einem Beispiel entwickelt.
Y1  - 2022
SN  - 978-3-88579-720-3
U6  - https://doi.org/10.18420/inf2022_103
SN  - 1617-5468
N1  - INFORMATIK 2022, 26. - 30. September 2022, Hamburg
SP  - 1203
EP  - 1209
PB  - GI - Gesellschaft für Informatik
CY  - Bonn
ER  - 
TY  - GEN
A1  - Keimer, Jona
A1  - Girbig, Leo
A1  - Mayntz, Joscha
A1  - Tegtmeyer, Philipp
A1  - Wendland, Frederik
A1  - Dahman, Peter
A1  - Fisher, Alex
A1  - Dorrington, Graham
T1  - Flight mission optimization for eco-efficiency in consideration of electric regeneration and atmospheric conditions
T2  - AIAA AVIATION 2022 Forum
N2  - The development and operation of hybrid or purely electrically powered aircraft in regional air mobility is a significant challenge for the entire aviation sector. This technology is expected to lead to substantial advances in flight performance, energy efficiency, reliability, safety, noise reduction, and exhaust emissions. Nevertheless, any consumed energy results in heat or carbon dioxide emissions and limited electric energy storage capabilities suppress commercial use. Therefore, the significant challenges to achieving eco-efficient aviation are increased aircraft efficiency, the development of new energy storage technologies, and the optimization of flight operations. Two major approaches for higher eco-efficiency are identified: The first one, is to take horizontal and vertical atmospheric motion phenomena into account. Where, in particular, atmospheric waves hold exciting potential. The second one is the use of the regeneration ability of electric aircraft. The fusion of both strategies is expected to improve efficiency. The objective is to reduce energy consumption during flight while not neglecting commercial usability and convenient flight characteristics. Therefore, an optimized control problem based on a general aviation class aircraft has to be developed and validated by flight experiments. The formulated approach enables a development of detailed knowledge of the potential and limitations of optimizing flight missions, considering the capability of regeneration and atmospheric influences to increase efficiency and range.
Y1  - 2022
U6  - https://doi.org/10.2514/6.2022-4118
N1  - AIAA AVIATION 2022 Forum, June 27-July 1, 2022 Chicago, IL & Virtual
PB  - AIAA
CY  - Reston, Va.
ER  - 
TY  - CHAP
A1  - Mayntz, Joscha
A1  - Keimer, Jona
A1  - Dahmann, Peter
A1  - Hille, Sebastian
A1  - Stumpf, Eike
A1  - Fisher, Alex
A1  - Dorrington, Graham
T1  - Electrical Drive and Regeneration in General Aviation Flight with Propellers
T2  - Deutscher Luft- und Raumfahrtkongress 2020
N2  - Electric flight has the potential for a more sustainable and energy-saving way of aviation compared to fossil fuel aviation. The electric motor can be used as a generator inflight to regenerate energy during descent. Three different approaches to regenerating with electric propeller powertrains are proposed in this paper. The powertrain is to be set up in a wind tunnel to determine the propeller efficiency in both working modes as well as the noise emissions. Furthermore, the planned flight tests are discussed. In preparation for these tests, a yaw stability analysis is performed with the result that the aeroplane is controllable during flight and in the most critical failure case. The paper shows the potential for inflight regeneration and addresses the research gaps in the dual role of electric powertrains for propulsion and regeneration of general aviation aircraft.
KW  - Propeller Aerodynamics
KW  - Flight Tests
KW  - Flight Mechanics
KW  - Electrical Flight
KW  - Inflight Regeneration, Recuperation
Y1  - 2022
U6  - https://doi.org/10.25967/530100
N1  - Deutscher Luft- und Raumfahrtkongress 2020, 1. - 3. September 2020, Online
PB  - DGLR
CY  - Bonn
ER  -