@inproceedings{AchenbachBoschBreitbachetal.2013,
  author    = {Achenbach, Timm and Bosch, Timo and Breitbach, Gerd and G{\"o}ttsche, Joachim and Sauerborn, Markus},
  title     = {Theoretical and experimental investigations regarding open volumetric receivers of CRS},
  series = {Energy procedia : proceedings of the SolarPACES 2013 International Conference},
  volume    = {Vol. 49},
  booktitle = {Energy procedia : proceedings of the SolarPACES 2013 International Conference},
  issn      = {1876-6102},
  pages     = {1259 -- 1268},
  year      = {2013},
  language  = {en}
}
@inproceedings{AchenbachGeimerGoettscheetal.2011,
  author    = {Achenbach, Timm and Geimer, K. and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and Lynen, A. and Bauer, J.},
  title     = {Simulation and flow measurements of volumetric high temperature absorbers for solar tower power plants},
  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}
}
@inproceedings{AchenbachGeimerLynenetal.2012,
  author    = {Achenbach, Timm and Geimer, Konstantin and Lynen, Arthur and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard},
  title     = {Simulation of thermo-mechanical processes in open volumetric absorber modules},
  series = {SolarPaces 2012 : concentrating solar power and chemical energy systems : Sept. 11 - 14 2012, Marrakech, Marokko},
  booktitle = {SolarPaces 2012 : concentrating solar power and chemical energy systems : Sept. 11 - 14 2012, Marrakech, Marokko},
  pages     = {1 -- 8},
  year      = {2012},
  language  = {en}
}
@inproceedings{AchenbachGoettscheKaufholdetal.2011,
  author    = {Achenbach, Timm and G{\"o}ttsche, Joachim and Kaufhold, O. and Hoffschmidt, Bernhard},
  title     = {Development of an edge module for open volumetric receiver for the use of the radiation at the receiver boundary region},
  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}
}
@inproceedings{BaumannTeixeiraBouraGoettscheetal.2010,
  author    = {Baumann, T. and Teixeira Boura, Cristiano Jos{\´e} and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and O'Connell, B. and Schmitz, S. and Zunft, S.},
  title     = {Air/Sand heat exchanger design and materials for solar thermal power plant applications},
  series = {SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France},
  booktitle = {SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France},
  publisher = {Soc. OSC},
  address   = {Saint Maur},
  pages     = {146 -- 147},
  year      = {2010},
  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}
}
@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{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{BlankeRegerDoeringetal.2021,
  author    = {Blanke, Tobias and Reger, Vitali and D{\"o}ring, Bernd and G{\"o}ttsche, Joachim and Kuhnhenne, Markus},
  title     = {Koaxiale Stahlenergiepf{\"a}hle},
  series = {Stahlbau},
  volume    = {90. 2021},
  journal   = {Stahlbau},
  number    = {6},
  publisher = {Wiley},
  address   = {Weinheim},
  pages     = {417 -- 424},
  year      = {2021},
  abstract  = {Ein entscheidender Teil der Energiewende ist die W{\"a}rmewende im Geb{\"a}udesektor. Ein Schl{\"u}sselelement sind hier W{\"a}rmepumpen. Diese ben{\"o}tigen eine W{\"a}rmequelle, der sie Energie entziehen k{\"o}nnen, um sie auf ein h{\"o}heres Temperaturniveau zu transformieren. Diese W{\"a}rmequelle kann bspw. das Erdreich sein, dessen W{\"a}rme durch Erdsonden erschlossen werden kann. In diesem Beitrag werden in Stahlpf{\"a}hle integrierte Koaxialsonden mit dem Stand der Technik von Erdsonden gleichen Durchmessers bez{\"u}glich ihrer thermischen Leistungsmerkmale verglichen. Die Stahlenergiepf{\"a}hle bieten neben der W{\"a}rmegewinnung weitere Vorteile, da sie auch eine statische Funktion {\"u}bernehmen und r{\"u}ckstandsfrei zur{\"u}ckgebaut werden k{\"o}nnen. Es werden analytische und numerische Berechnungen vorgestellt, um die thermischen Potenziale beider Systeme zu vergleichen. Außerdem wird ein Testaufbau gezeigt, bei dem Stahlenergiepf{\"a}hle in zwei verschiedenen L{\"a}ngen mit vorhandenen g{\"a}ngigen Erdsonden verglichen werden k{\"o}nnen. Die Berechnungen zeigen einen deutlichen thermischen Mehrertrag zwischen 26 \% und 148 \% der Stahlenergiepf{\"a}hle gegen{\"u}ber dem Stand der Technik abh{\"a}ngig vom Erdreich. Die Messergebnisse zeigen einen thermischen Mehrertrag von {\"u}ber 100 \%. Es l{\"a}sst sich also signifikante Erdsondenl{\"a}nge einsparen. Dabei ist zu beachten, dass sich damit der thermisch genutzte Bereich des Erdreichs reduziert, wodurch die thermische Regeneration und/oder das Langzeitverhalten des Erdreichs an Bedeutung gewinnt.},
  language  = {de}
}