@incollection{HoffschmidtAlexopoulosGoettscheetal.2012, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and G{\"o}ttsche, Joachim and Sauerborn, Markus}, title = {High concentration solar collectors}, 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 = {978-0-08-087873-7}, doi = {10.1016/B978-0-08-087872-0.00306-1}, pages = {165 -- 209}, year = {2012}, abstract = {Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system. For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems. For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this chapter, different criteria for the choice of technology are analyzed in detail.}, 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} } @article{KronhardtAlexopoulosReisseletal.2014, author = {Kronhardt, Valentina and Alexopoulos, Spiros and Reißel, Martin and Sattler, Johannes, Christoph and Hoffschmidt, Bernhard and H{\"a}nel, Matthias and Doerbeck, Till}, title = {High-temperature thermal storage system for solar tower power plants with open-volumetric air receiver simulation and energy balancing of a discretized model}, series = {Energy procedia}, volume = {49}, journal = {Energy procedia}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102 (E-Journal) ; 1876-6102 (Print)}, doi = {10.1016/j.egypro.2014.03.094}, pages = {870 -- 877}, year = {2014}, abstract = {This paper describes the modeling of a high-temperature storage system for an existing solar tower power plant with open volumetric receiver technology, which uses air as heat transfer medium (HTF). The storage system model has been developed in the simulation environment Matlab/Simulink®. The storage type under investigation is a packed bed thermal energy storage system which has the characteristics of a regenerator. Thermal energy can be stored and discharged as required via the HTF air. The air mass flow distribution is controlled by valves, and the mass flow by two blowers. The thermal storage operation strategy has a direct and significant impact on the energetic and economic efficiency of the solar tower power plants.}, language = {en} } @article{RauAlexopoulosBreitbachetal.2014, author = {Rau, Christoph and Alexopoulos, Spiros and Breitbach, Gerd and Hoffschmidt, Bernhard and Latzke, Markus and Sattler, Johannes, Christoph}, title = {Transient simulation of a solar-hybrid tower power plant with open volumetric receiver at the location Barstow}, series = {Energy procedia : proceedings of the SolarPACES 2013 International Conference}, volume = {49}, journal = {Energy procedia : proceedings of the SolarPACES 2013 International Conference}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102}, doi = {10.1016/j.egypro.2014.03.157}, pages = {1481 -- 1490}, year = {2014}, abstract = {In this work the transient simulations of four hybrid solar tower power plant concepts with open-volumetric receiver technology for a location in Barstow-Daggett, USA, are presented. The open-volumetric receiver uses ambient air as heat transfer fluid and the hybridization is realized with a gas turbine. The Rankine cycle is heated by solar-heated air and/or by the gas turbine's flue gases. The plant can be operated in solar-only, hybrid parallel or combined cycle-only mode as well as in any intermediate load levels where the solar portion can vary between 0 to 100\%. The simulated plant is based on the configuration of a solar-hybrid power tower project, which is in planning for a site in Northern Algeria. The meteorological data for Barstow-Daggett was taken from the software meteonorm. The solar power tower simulation tool has been developed in the simulation environment MATLAB/Simulink and is validated.}, language = {en} } @article{VieiradaSilvaSchwarzerHoffschmidtetal.2013, author = {Vieira da Silva, Maria Eugenia and Schwarzer, Klemens and Hoffschmidt, Bernhard and Pinheiro Rodrigues, Frederico and Schwarzer, Tarik and Costa Rocha, Paulo Alexandre}, title = {Mass transfer correlation for evaporation-condensation thermal process in the range of 70 °C-95 °C}, series = {Renewable energy}, volume = {Vol. 53}, journal = {Renewable energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-0682 (E-Journal); 0960-1481 (Print)}, pages = {174 -- 179}, year = {2013}, language = {en} } @article{KluczkaEcksteinAlexopoulosetal.2014, author = {Kluczka, Sven and Eckstein, Julian and Alexopoulos, Spiros and Vaeßen, Christiane and Roeb, Martin}, title = {Process simulation for solar steam and dry reforming}, series = {Energy procedia : Proceedings of the SolarPACES 2013 International Conference}, volume = {49}, journal = {Energy procedia : Proceedings of the SolarPACES 2013 International Conference}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102 (E-Journal)}, doi = {10.1016/j.egypro.2014.03.092}, pages = {850 -- 859}, year = {2014}, abstract = {In co-operation with the German Aerospace Center, the Solar-Institut J{\"u}lich has been analyzing the different technologies that are available for methanol production from CO2 using solar energy. The aim of the project is to extract CO2 from industrial exhaust gases or directly from the atmosphere to recycle it by use of solar energy. Part of the study was the modeling and simulating of a methane reformer for the production of synthesis gas, which can be operated by solar or hybrid heat sources. The reformer has been simplified in such a way that the model is accurate and enables fast calculations. The developed pseudo-homogeneous one- dimensional model can be regarded as a kind of counter-current heat exchanger and is able to incorporate a steam reforming reaction as well as a dry reforming reaction.}, language = {en} } @article{Alexopoulos2015, author = {Alexopoulos, Spiros}, title = {Simulation model for the transient process behaviour of solar aluminium recycling in a rotary kiln}, series = {Applied Thermal Engineering}, volume = {78}, journal = {Applied Thermal Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1359-4311}, doi = {10.1016/j.applthermaleng.2015.01.007}, pages = {387 -- 396}, year = {2015}, language = {en} } @article{WoliszSchuetzBlankeetal.2017, author = {Wolisz, Henryk and Sch{\"u}tz, Thomas and Blanke, Tobias and Hagenkamp, Markus and Kohrn, Markus and Wesseling, Mark and M{\"u}ller, Dirk}, title = {Cost optimal sizing of smart buildings' energy system components considering changing end-consumer electricity markets}, series = {Energy}, volume = {137}, journal = {Energy}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.energy.2017.06.025}, pages = {715 -- 728}, year = {2017}, language = {en} } @article{SattlerRoegerSchwarzboezletal.2020, author = {Sattler, Johannes, Christoph and R{\"o}ger, Marc and Schwarzb{\"o}zl, Peter and Buck, Reiner and Macke, Ansgar and Raeder, Christian and G{\"o}ttsche, Joachim}, title = {Review of heliostat calibration and tracking control methods}, series = {Solar Energy}, volume = {207}, journal = {Solar Energy}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.solener.2020.06.030}, pages = {110 -- 132}, year = {2020}, abstract = {Large scale central receiver systems typically deploy between thousands to more than a hundred thousand heliostats. During solar operation, each heliostat is aligned individually in such a way that the overall surface normal bisects the angle between the sun's position and the aim point coordinate on the receiver. Due to various tracking error sources, achieving accurate alignment ≤1 mrad for all the heliostats with respect to the aim points on the receiver without a calibration system can be regarded as unrealistic. Therefore, a calibration system is necessary not only to improve the aiming accuracy for achieving desired flux distributions but also to reduce or eliminate spillage. An overview of current larger-scale central receiver systems (CRS), tracking error sources and the basic requirements of an ideal calibration system is presented. Leading up to the main topic, a description of general and specific terms on the topics heliostat calibration and tracking control clarifies the terminology used in this work. Various figures illustrate the signal flows along various typical components as well as the corresponding monitoring or measuring devices that indicate or measure along the signal (or effect) chain. The numerous calibration systems are described in detail and classified in groups. Two tables allow the juxtaposition of the calibration methods for a better comparison. In an assessment, the advantages and disadvantages of individual calibration methods are presented.}, language = {en} } @article{ElMoussaouiTalbiAtmaneetal.2020, author = {El Moussaoui, Noureddine and Talbi, Sofian and Atmane, Ilyas and Kassmi, Khalil and Schwarzer, Klemens and Chayeb, Hamid and Bachiri, Najib}, title = {Feasibility of a new design of a Parabolic Trough Solar Thermal Cooker (PSTC)}, series = {Solar Energy}, volume = {201}, journal = {Solar Energy}, number = {Vol. 201 (May 2020)}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0038-092X}, doi = {10.1016/j.solener.2020.03.079}, pages = {866 -- 871}, year = {2020}, abstract = {In this article, we describe the structure, the functioning, and the tests of parabolic trough solar thermal cooker (PSTC). This oven is designed to meet the needs of rural residents, including Urban, which requires stable cooking temperatures above 200 °C. The cooking by this cooker is based on the concentration of the sun's rays on a glass vacuum tube and heating of the oil circulate in a big tube, located inside the glass tube. Through two small tubes, associated with large tube, the heated oil, rise and heats the pot of cooking pot containing the food to be cooked (capacity of 5 kg). This cooker is designed in Germany and extensively tested in Morocco for use by the inhabitants who use wood from forests. During a sunny day, having a maximum solar radiation around 720 W/m2 and temperature ambient around 26 °C, maximum temperatures recorded of the small tube, the large tube and the center of the pot are respectively: 370 °C, 270 °C and 260 °C. The cooking process with food at high (fries, ..), we show that the cooking oil temperature rises to 200 °C, after 1 h of heating, the cooking is done at a temperature of 120 °C for 20 min. These temperatures are practically stable following variations and decreases in the intensity of irradiance during the day. The comparison of these results with those of the literature shows an improvement of 30-50 \% on the maximum value of the temperature with a heat storage that could reach 60 min of autonomy. All the results obtained show the good functioning of the PSTC and the feasibility of cooking food at high temperature (>200 °C).}, language = {en} }