@inproceedings{AnthrakidisHerrmannSchornetal.2015, author = {Anthrakidis, Anette and Herrmann, Ulf and Schorn, Christian and Schwarzer, Klemens and Wedding, Philipp}, title = {Weiterentwicklung und Erprobung eines neuartigen Verfahrens zur Bestimmung der Effizienz von konzentrierenden solarthermischen Kollektoren}, series = {25. OTTI Symposium Thermische Solarenergie}, booktitle = {25. OTTI Symposium Thermische Solarenergie}, pages = {15 Seiten}, year = {2015}, language = {de} } @inproceedings{HerrmannKellyPrice2002, author = {Herrmann, Ulf and Kelly, Bruce and Price, Henry}, title = {Two Tank Molten Salt Storage for Parabolic Trough Solar Power Plants}, series = {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, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich}, booktitle = {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, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich}, editor = {Steinfeld, Aldo}, publisher = {Paul Scherrer Inst.}, address = {Villingen}, isbn = {3-9521409-3-7}, pages = {517 -- 524}, year = {2002}, language = {en} } @inproceedings{DerschGeyerHerrmannetal.2002, author = {Dersch, J{\"u}rgen and Geyer, Michael and Herrmann, Ulf and Jones, Scott A. and Kelly, Bruce and Kistner, Rainer and Ortmanns, Winfried and Pitz-Paal, Robert and Price, Henry}, title = {Trough integration into power plants : a study on the performance and economy of integrated solar combined cycle systems}, series = {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, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich}, booktitle = {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, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich}, editor = {Steinfeld, Aldo}, publisher = {Paul Scherrer Inst.}, address = {Villingen}, isbn = {3-9521409-3-7}, pages = {661 -- 671}, year = {2002}, language = {en} } @inproceedings{LuepfertHerrmannPriceetal.2004, author = {L{\"u}pfert, E. and Herrmann, Ulf and Price, Henry and Zarza, E. and Kistener, R.}, title = {Towards Standard Performance Analysis for Parabolic Trough Collector Fields}, series = {12th International Symposium Solar Power and Chemical Energy Systems, October 6-8, 2004, Oaxaca Mexico ; SolarPACES International Symposium, 12}, booktitle = {12th International Symposium Solar Power and Chemical Energy Systems, October 6-8, 2004, Oaxaca Mexico ; SolarPACES International Symposium, 12}, editor = {Ramos, C.}, publisher = {Instituto de Investigaciones Electricas}, address = {[s.l.]}, isbn = {968-6114-18-1}, year = {2004}, language = {en} } @inproceedings{HerrmannWorringerGraeteretal.2006, author = {Herrmann, Ulf and Worringer, S. and Graeter, F. and Nava, P.}, title = {Three Years of Operation Experience of the SKAL-ET Collector Loop at SEGS V}, series = {13th International Symposium Concentrated Solar Power and Chemical Energy Technologies, June 20 - 23, 2006, Seville, Spain}, booktitle = {13th International Symposium Concentrated Solar Power and Chemical Energy Technologies, June 20 - 23, 2006, Seville, Spain}, editor = {Romero, Manuel}, publisher = {SolarPACES [u.a.]}, address = {[s.l.]}, isbn = {84-7834-519-1}, pages = {1 CD-ROM}, year = {2006}, language = {en} } @inproceedings{HahneHerrmannRheinlaender1997, author = {Hahne, E. and Herrmann, Ulf and Rheinl{\"a}nder, J.}, title = {The Effect of Tilt on Flow Pattern of Water/Steam Flow Through Heated Tubes}, series = {Experimental heat transfer, fluid mechanics and thermodynamics 1997 : proceedings of the 4th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Brussels, June 2 - 6, 1997. - Vol. 2}, booktitle = {Experimental heat transfer, fluid mechanics and thermodynamics 1997 : proceedings of the 4th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Brussels, June 2 - 6, 1997. - Vol. 2}, editor = {Girot, Michel}, publisher = {Ed. ETS}, address = {Pisa}, isbn = {88-467-0014-7}, pages = {925 -- 934}, year = {1997}, language = {en} } @inproceedings{MahdiDerschSchmitzetal.2022, author = {Mahdi, Zahra and Dersch, J{\"u}rgen and Schmitz, Pascal and Dieckmann, Simon and Caminos, Ricardo Alexander Chico and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf and Schwager, Christian and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and B{\"u}scher, Rauno}, title = {Technical assessment of Brayton cycle heat pumps for the integration in hybrid PV-CSP power plants}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086269}, pages = {11 Seiten}, year = {2022}, abstract = {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).}, language = {en} } @inproceedings{DerschGeyerHerrmannetal.2002, author = {Dersch, J{\"u}rgen and Geyer, Michael and Herrmann, Ulf and Jones, Scott A. and Kelly, Bruce and Kistner, Rainer and Ortmanns, Winfried and Pitz-Paal, Robert and Price, Henry}, title = {Solar Trough Integration Into Combined Cycle Systems}, series = {Solar engineering 2002 : proceedings of the International Solar Energy Conference ; presented at the 2002 International Solar Energy Conference, a part of Solar 2002 - Sunrise on the Reliable Energy Economy, June 15 - 20, 2002, Reno, Nevada}, booktitle = {Solar engineering 2002 : proceedings of the International Solar Energy Conference ; presented at the 2002 International Solar Energy Conference, a part of Solar 2002 - Sunrise on the Reliable Energy Economy, June 15 - 20, 2002, Reno, Nevada}, editor = {Pearson, J. Boise}, publisher = {ASME}, isbn = {0-7918-1689-3}, doi = {doi:10.1115/SED2002-1072}, pages = {351 -- 359}, year = {2002}, language = {en} } @inproceedings{HerrmannRheinlaenderLippke1997, author = {Herrmann, Ulf and Rheinl{\"a}nder, J. and Lippke, F.}, title = {Solar Fields for Direct Steam Generation in Parabolic Trough Collectors}, series = {Components, tools, facilities and measurement techniques. - (Solar thermal concentrating technologies : proceedings of the 8th international symposium, October, 6 - 11, 1996, K{\"o}ln, Germany ; Vol. 2)}, booktitle = {Components, tools, facilities and measurement techniques. - (Solar thermal concentrating technologies : proceedings of the 8th international symposium, October, 6 - 11, 1996, K{\"o}ln, Germany ; Vol. 2)}, editor = {Becker, Manfred}, publisher = {M{\"u}ller}, address = {Heidelberg}, isbn = {3-7880-7616-X}, pages = {815 -- 834}, year = {1997}, language = {en} } @inproceedings{KronhardtAlexopoulosReisseletal.2015, author = {Kronhardt, Valentina and Alexopoulos, Spiros and Reißel, Martin and Latzke, Markus and Rendon, C. and Sattler, Johannes, Christoph and Herrmann, Ulf}, title = {Simulation of operational management for the Solar Thermal Test and Demonstration Power Plant J{\"u}lich using optimized control strategies of the storage system}, series = {Energy procedia}, booktitle = {Energy procedia}, issn = {1876-6102}, pages = {1 -- 6}, year = {2015}, language = {en} } @inproceedings{RendonDieckmannWeidleetal.2018, author = {Rendon, Carlos and Dieckmann, Simon and Weidle, Mathias and Dersch, J{\"u}rgen and Teixeira Boura, Cristiano Jos{\´e} and Polklas, Thomas and Kuschel, Marcus and Herrmann, Ulf}, title = {Retrofitting of existing parabolic trough collector power plants with molten salt tower systems}, series = {AIP Conference Proceedings}, volume = {2033}, booktitle = {AIP Conference Proceedings}, number = {1}, doi = {10.1063/1.5067030}, pages = {030014-1 -- 030014-8}, year = {2018}, language = {en} } @inproceedings{HerrmannGraeterNava2004, author = {Herrmann, Ulf and Graeter, F. and Nava, P.}, title = {Performance of the SKAL-ET Collector Loop at KJC Operating Company}, series = {12th International Symposium Solar Power and Chemical Energy Systems, October 6-8, 2004, Oaxaca Mexico ; SolarPACES International Symposium, 12}, booktitle = {12th International Symposium Solar Power and Chemical Energy Systems, October 6-8, 2004, Oaxaca Mexico ; SolarPACES International Symposium, 12}, editor = {Ramos, C.}, publisher = {Instituto de Investigaciones Electricas}, address = {[s.l.]}, isbn = {968-6114-18-1}, year = {2004}, language = {en} } @inproceedings{AnthrakidisHerrmannMirzaetal.2014, author = {Anthrakidis, Anette and Herrmann, Ulf and Mirza, M. F. and Schorn, Christian and Schwarzer, Klemens and Wedding, Philipp and Weis, Fabian}, title = {Parabolrinnenentwicklung und Qualifizierung am Solar-Institut J{\"u}lich}, series = {Thermische Solarenergie : 24. Symposium ; 7. bis 9. Mai 2014, Kloster Banz, Bad Staffelstein}, booktitle = {Thermische Solarenergie : 24. Symposium ; 7. bis 9. Mai 2014, Kloster Banz, Bad Staffelstein}, publisher = {OTTI}, address = {Regensburg}, organization = {Ostbayerisches Technologie-Transfer-Institut}, isbn = {978-3-943891-35-5}, pages = {242 -- 243}, year = {2014}, language = {de} } @inproceedings{KellyHerrmannHale2001, author = {Kelly, Bruce and Herrmann, Ulf and Hale, M.-J.}, title = {Optimization Studies for Integrated Solar Combined Cycle Systems}, series = {Solar engineering 2001 : proceedings of the International Solar Energy Conference ; presented at the 2001 International Solar Energy Conference, a part of Forum 2001 - Solar energy: the power to choose, April 21 - 25, 2001, Washington, D.C.}, booktitle = {Solar engineering 2001 : proceedings of the International Solar Energy Conference ; presented at the 2001 International Solar Energy Conference, a part of Forum 2001 - Solar energy: the power to choose, April 21 - 25, 2001, Washington, D.C.}, publisher = {ASME}, address = {New York, NY}, isbn = {0-7918-1670-2}, pages = {393 -- 398}, year = {2001}, language = {en} } @inproceedings{SattlerCaminosUerlingsetal.2020, author = {Sattler, Johannes, Christoph and Caminos, Ricardo Alexander Chico and {\"U}rlings, Nicolas and Dutta, Siddharth and Ruiz, Victor and Kalogirou, Soteris and Ktistis, Panayiotis and Agathokleous, Rafaela and Jung, Christian and Alexopoulos, Spiros and Atti, Vikrama Nagababu and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Operational experience and behaviour of a parabolic trough collector system with concrete thermal energy storage for process steam generation in Cyprus}, series = {AIP Conference Proceedings}, booktitle = {AIP Conference Proceedings}, number = {2303}, doi = {10.1063/5.0029278}, pages = {140004-1 -- 140004-10}, year = {2020}, language = {en} } @inproceedings{DuranParedesMottaghyHerrmannetal.2020, author = {Duran Paredes, Ludwin and Mottaghy, Darius and Herrmann, Ulf and Groß, Rolf Fritz}, title = {Online ground temperature and soil moisture monitoring of a shallow geothermal system with non-conventional components}, series = {EGU General Assembly 2020}, booktitle = {EGU General Assembly 2020}, year = {2020}, abstract = {We present first results from a newly developed monitoring station for a closed loop geothermal heat pump test installation at our campus, consisting of helix coils and plate heat exchangers, as well as an ice-store system. There are more than 40 temperature sensors and several soil moisture content sensors distributed around the system, allowing a detailed monitoring under different operating conditions.In the view of the modern development of renewable energies along with the newly concepts known as Internet of Things and Industry 4.0 (high-tech strategy from the German government), we created a user-friendly web application, which will connect the things (sensors) with the open network (www). Besides other advantages, this allows a continuous remote monitoring of the data from the numerous sensors at an arbitrary sampling rate.Based on the recorded data, we will also present first results from numerical simulations, taking into account all relevant heat transport processes.The aim is to improve the understanding of these processes and their influence on the thermal behavior of shallow geothermal systems in the unsaturated zone. This will in turn facilitate the prediction of the performance of these systems and therefore yield an improvement in their dimensioning when designing a specific shallow geothermal installation.}, language = {en} } @inproceedings{MahdiRendonSchwageretal.2019, author = {Mahdi, Zahra and Rend{\´o}n, Carlos and Schwager, Christian and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Novel concept for indirect solar-heated methane reforming}, series = {AIP Conference Proceedings}, volume = {2126}, booktitle = {AIP Conference Proceedings}, publisher = {AIP Publishing}, address = {Melville, NY}, issn = {0094-243X}, doi = {10.1063/1.5117694}, pages = {180014-1 -- 180014-7}, year = {2019}, language = {en} } @inproceedings{BlakeMoensHaleetal.2002, author = {Blake, D. and Moens, L. and Hale, M.-J. and Price, Henry and Keaney, David W. and Herrmann, Ulf}, title = {New heat transfer and storage fluids for parabolic trough solar thermal electric plants}, series = {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, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich}, booktitle = {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, Eidgen{\"o}ssische Technische Hochschule Z{\"u}rich}, editor = {Steinfeld, Aldo}, publisher = {Paul Scherrer Inst.}, address = {Villingen}, isbn = {3-9521409-3-7}, pages = {63 -- 66}, year = {2002}, language = {en} } @inproceedings{ZahraPhaniSrujanCaminosetal.2022, author = {Zahra, Mahdi and Phani Srujan, Merige and Caminos, Ricardo Alexander Chico and Schmitz, Pascal and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e} and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and Dersch, J{\"u}rgen}, title = {Modeling the thermal behavior of solar salt in electrical resistance heaters for the application in PV-CSP hybrid power plants}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086268}, pages = {9 Seiten}, year = {2022}, abstract = {Concentrated Solar Power (CSP) systems are able to store energy cost-effectively in their integrated thermal energy storage (TES). By intelligently combining Photovoltaics (PV) systems with CSP, a further cost reduction of solar power plants is expected, as well as an increase in dispatchability and flexibility of power generation. PV-powered Resistance Heaters (RH) can be deployed to raise the temperature of the molten salt hot storage from 385 °C up to 565 °C in a Parabolic Trough Collector (PTC) plant. To avoid freezing and decomposition of molten salt, the temperature distribution in the electrical resistance heater is investigated in the present study. For this purpose, a RH has been modeled and CFD simulations have been performed. The simulation results show that the hottest regions occur on the electric rod surface behind the last baffle. A technical optimization was performed by adjusting three parameters: Shell-baffle clearance, electric rod-baffle clearance and number of baffles. After the technical optimization was carried out, the temperature difference between the maximum temperature and the average outlet temperature of the salt is within the acceptable limits, thus critical salt decomposition has been avoided. Additionally, the CFD simulations results were analyzed and compared with results obtained with a one-dimensional model in Modelica.}, language = {en} } @inproceedings{RendonSchwagerGhiasietal.2020, author = {Rendon, Carlos and Schwager, Christian and Ghiasi, Mona and Schmitz, Pascal and Bohang, Fakhri and Caminos, Ricardo Alexander Chico and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Modeling and upscaling of a pilot bayonettube reactor for indirect solar mixed methane reforming}, series = {AIP Conference Proceedings}, booktitle = {AIP Conference Proceedings}, number = {2303}, doi = {10.1063/5.0029974}, pages = {170012-1 -- 170012-9}, year = {2020}, language = {en} }