@article{GoettscheGabryschDelahayeetal.2002,
  author    = {G{\"o}ttsche, Joachim and Gabrysch, K. and Delahaye, A. and Schwarzer, Klemens},
  title     = {Solar-Campus Juelich - Energy performance and indoor climate},
  series = {AIVC 23rd conference - EPIC 2002 AIVC (in conjunction with 3rd European Conference on Energy Performance and Indoor Climate in Buildings) - 23-26 October 2002 - Lyon - France - vol 2},
  journal   = {AIVC 23rd conference - EPIC 2002 AIVC (in conjunction with 3rd European Conference on Energy Performance and Indoor Climate in Buildings) - 23-26 October 2002 - Lyon - France - vol 2},
  pages     = {381 -- 386},
  year      = {2002},
  language  = {en}
}
@article{GoettscheHoffschmidtSchmitzetal.2009,
  author    = {G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Sauerborn, Markus},
  title     = {Solar Concentrating Systems Using Small Mirror Arrays / G{\"o}ttsche, Joachim ; Hoffschmidt, Bernhard ; Schmitz, Stefan ; Sauerborn, Markus ; Buck, Reiner ; Teufel, Edgar ; Badst{\"u}bner, Karin ; Ifland, David ; Rebholz, Christian},
  series = {Proceedings of the 2nd International Conference on Energy Sustainability - 2008 : : presented ... August 10 - 14, 2008, Jacksonville, Florida, USA / sponsored by Advanced Energy Systems Division, ASME; Solar Energy Division, ASME},
  journal   = {Proceedings of the 2nd International Conference on Energy Sustainability - 2008 : : presented ... August 10 - 14, 2008, Jacksonville, Florida, USA / sponsored by Advanced Energy Systems Division, ASME; Solar Energy Division, ASME},
  publisher = {ASME},
  address   = {New York, NY},
  isbn      = {9780791843208},
  pages     = {1 -- 5},
  year      = {2009},
  language  = {en}
}
@article{GoettscheHoffschmidtSchmitzetal.2010,
  author    = {G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Schmitz, Stefan and Sauerborn, Markus},
  title     = {Solar Concentrating Systems Using Small Mirror Arrays},
  series = {Journal of solar energy engineering},
  volume    = {Vol. 132},
  journal   = {Journal of solar energy engineering},
  number    = {Iss. 1},
  isbn      = {0199-6231},
  pages     = {4 S.},
  year      = {2010},
  language  = {en}
}
@article{WemhoenerHafnerSchwarzer2000,
  author    = {Wemh{\"o}ner, Carsten and Hafner, Bernd and Schwarzer, Klemens},
  title     = {Simulation of solar thermal systems with CARNOT blockset in the environment MATLAB-Simulink},
  pages     = {1 -- 6},
  year      = {2000},
  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{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{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{DammSauerbornFendetal.2017,
  author    = {Damm, Marc Andr{\´e} and Sauerborn, Markus and Fend, Thomas and Herrmann, Ulf},
  title     = {Optimisation of a urea selective catalytic reduction system with a coated ceramic mixing element},
  series = {Journal of ceramic science and technology},
  volume    = {8},
  journal   = {Journal of ceramic science and technology},
  number    = {1},
  publisher = {G{\"o}ller},
  address   = {Baden-Baden},
  isbn      = {2190-9385 (Print)},
  issn      = {2190-9385 (Online)},
  doi       = {10.4416/JCST2016-00056},
  pages     = {19 -- 24},
  year      = {2017},
  language  = {en}
}
@article{BlankeHagenkampDoeringetal.2021,
  author    = {Blanke, Tobias and Hagenkamp, Markus and D{\"o}ring, Bernd and G{\"o}ttsche, Joachim and Reger, Vitali and Kuhnhenne, Markus},
  title     = {Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates},
  series = {Geothermal Energy},
  volume    = {9},
  journal   = {Geothermal Energy},
  number    = {Article number: 19},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {2195-9706},
  doi       = {10.1186/s40517-021-00201-3},
  pages     = {23 Seiten},
  year      = {2021},
  abstract  = {Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellstr{\"o}m's borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54\% of the outer pipe radius for laminar fow and 60\% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth's thermal properties and the fow type. Conclusively, coaxial geothermal probes' design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics.},
  language  = {en}
}
@article{GoettscheAlexopoulosDuemmleretal.2019,
  author    = {G{\"o}ttsche, Joachim and Alexopoulos, Spiros and D{\"u}mmler, Andreas and Maddineni, S. K.},
  title     = {Multi-Mirror Array Calculations With Optical Error},
  pages     = {1 -- 6},
  year      = {2019},
  abstract  = {The optical performance of a 2-axis solar concentrator was simulated with the COMSOL Multiphysics® software. The concentrator consists of a mirror array, which was created using the application builder. The mirror facets are preconfigured to form a focal point. During tracking all mirrors are moved simultaneously in a coupled mode by 2 motors in two axes, in order to keep the system in focus with the moving sun. Optical errors on each reflecting surface were implemented in combination with the solar angular cone of ± 4.65 mrad. As a result, the intercept factor of solar radiation that is available to the receiver was calculated as a function of the transversal and longitudinal angles of incidence. In addition, the intensity distribution on the receiver plane was calculated as a function of the incidence angles.},
  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{GoettscheHove1999,
  author    = {G{\"o}ttsche, Joachim and Hove, T.},
  title     = {Mapping global, diffuse and beam solar radiation over Zimbabwe / T. Hove ; J. G{\"o}ttsche},
  series = {Renewable energy. 18 (1999), H. 4},
  journal   = {Renewable energy. 18 (1999), H. 4},
  isbn      = {1879-0682},
  pages     = {535 -- 556},
  year      = {1999},
  language  = {en}
}
@article{ReisgenSchleserAbdurakhmanovetal.2012,
  author    = {Reisgen, Uwe and Schleser, Markus and Abdurakhmanov, Aydemir and Turichin, Gleb and Valdaitseva, Elena and Bach, Friedrich-Wilhelm and Hassel, Thomas and Beniyashi, Alexander},
  title     = {Investigation of factors influencing the formation of weld defects in non-vacuum electron beam welding},
  series = {The Paton welding journal},
  volume    = {2012},
  journal   = {The Paton welding journal},
  number    = {2},
  publisher = {Paton Publishing House},
  address   = {Kiev},
  issn      = {0957-798X},
  pages     = {11 -- 18},
  year      = {2012},
  abstract  = {The influence of welding condition parameters and properties of material on formation of defects, such as humping and undercuts, in non-vacuum electron beam welding was investigated. The influence of separate welding parameters on the quality of welds was determined.},
  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{VelrajSeenirajHafneretal.1999,
  author    = {Velraj, R. and Seeniraj, R. V. and Hafner, B. and Faber, Christian and Schwarzer, Klemens},
  title     = {Heat transfer enhancement in a latent heat storage system},
  series = {Solar energy. Vol. 65, iss. 3},
  journal   = {Solar energy. Vol. 65, iss. 3},
  issn      = {0038-092X},
  pages     = {171 -- 180},
  year      = {1999},
  language  = {en}
}
@article{PeereBlanke2022,
  author    = {Peere, Wouter and Blanke, Tobias},
  title     = {GHEtool: An open-source tool for borefield sizing in Python},
  series = {Journal of Open Source Software},
  volume    = {7},
  journal   = {Journal of Open Source Software},
  number    = {76},
  editor    = {Vernon, Chris},
  issn      = {2475-9066},
  doi       = {10.21105/joss.04406},
  pages     = {1 -- 4, 4406},
  year      = {2022},
  abstract  = {GHEtool is a Python package that contains all the functionalities needed to deal with borefield design. It is developed for both researchers and practitioners. The core of this package is the automated sizing of borefield under different conditions. The sizing of a borefield is typically slow due to the high complexity of the mathematical background. Because this tool has a lot of precalculated data, GHEtool can size a borefield in the order of tenths of milliseconds. This sizing typically takes the order of minutes. Therefore, this tool is suited for being implemented in typical workflows where iterations are required. GHEtool also comes with a graphical user interface (GUI). This GUI is prebuilt as an exe-file because this provides access to all the functionalities without coding. A setup to install the GUI at the user-defined place is also implemented and available at: https://www.mech.kuleuven.be/en/tme/research/thermal_systems/tools/ghetool.},
  language  = {en}
}
@article{GoettscheHoffschmidtAlexopoulosetal.2008,
  author    = {G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Alexopoulos, Spiros and Funke, J. and Schwarzb{\"o}zl, P.},
  title     = {First Simulation Results for the Hybridization of Small Solar Power Tower Plants},
  series = {EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings, 2008-10-07 - 2008-10-10, Lissabon (Portugal). Vol. 1},
  journal   = {EuroSun 2008 : 1st International Conference on Solar Heating, Cooling and Buildings, 2008-10-07 - 2008-10-10, Lissabon (Portugal). Vol. 1},
  publisher = {Sociedade Portuguesa De Energia Solar (SPES)},
  address   = {Lisbon},
  isbn      = {978-1-61782-228-5},
  pages     = {1299 -- 1306},
  year      = {2008},
  language  = {en}
}
@article{SchwarzerVieiradaSilvaSchwarzer2011,
  author    = {Schwarzer, Klemens and Vieira da Silva, Maria Eugenia and Schwarzer, Tarik},
  title     = {Field results in Namibia and Brazil of the new solar desalination system for decentralised drinking water production},
  series = {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},
  journal   = {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},
  pages     = {379 -- 386},
  year      = {2011},
  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}
}
@article{AgrafiotisMavroidisKonstandopoulosetal.2007,
  author    = {Agrafiotis, Christos C. and Mavroidis, Ilias and Konstandopoulos, Athansios G. and Hoffschmidt, Bernhard and Stobbe, Per and Romero, Manuel and Fernandez-Quero, Valerio},
  title     = {Evaluation of porous silicon carbide monolithic honeycombs as volumetric receivers/collectors of concentrated solar radiation},
  series = {Solar energy materials and solar cells},
  volume    = {Vol. 91},
  journal   = {Solar energy materials and solar cells},
  number    = {Iss. 6},
  issn      = {1879-3398 (E-Journal); 0927-0248 (Print)},
  pages     = {474 -- 488},
  year      = {2007},
  language  = {en}
}