@article{RegerKuhnhenneEbbertetal.2020, author = {Reger, Vitali and Kuhnhenne, Markus and Ebbert, Thiemo and Hachul, Helmut and Blanke, Tobias and D{\"o}ring, Bernd}, title = {Nutzung erneuerbarer Energien durch thermische Aktivierung von Komponenten aus Stahl}, series = {Stahlbau}, volume = {2020}, journal = {Stahlbau}, number = {Volume 89, Issue 6512-519}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1437-1049}, doi = {10.1002/stab.202000031}, pages = {512 -- 519}, year = {2020}, abstract = {Die Versorgung von Neubauten soll m{\"o}glichst weitgehend unabh{\"a}ngig von fossilen Energietr{\"a}gern erfolgen. Erneuerbare Energien spielen daf{\"u}r eine gewichtige Rolle. Eine gute M{\"o}glichkeit, erneuerbare Energien ohne viel zus{\"a}tzlichen Aufwand nutzbar zu machen, ist, bereits vorhandenen Komponenten im Geb{\"a}ude zus{\"a}tzliche Funktionen zu geben. Hier kann bspw. die Fassade oder das Dach solarthermisch aktiviert oder durch Fotovoltaikmodule erg{\"a}nzt werden. Auch Tiefgr{\"u}ndungen k{\"o}nnen neben der statischen Funktion noch eine geothermische Funktion zur Aufnahme oder Abgabe von W{\"a}rme erhalten. Neben der Erzeugung bietet sich auch f{\"u}r die Verteilung der W{\"a}rme oder K{\"a}lte im Geb{\"a}ude die Integration in Bauteile an. Hier kann bspw. der Boden durch eine Fußbodenheizung oder die Decke durch Deckenstrahlplatten aktiviert werden. Im Rahmen der Ver{\"o}ffentlichung wird auf die thermische Aktivierung von Stahlkomponenten eingegangen. Es wird eine L{\"o}sung vorgestellt, die vorgeh{\"a}ngte hinterl{\"u}ftete Stahlfassade (VHF) solarthermisch zu aktivieren. Außerdem werden zwei M{\"o}glichkeiten zur geothermischen Aktivierung von Tiefgr{\"u}ndungen mittels Stahlpf{\"a}hlen gezeigt. Zuletzt wird ein System zur thermischen Aktivierung von Stahltrapezprofilen an der Decke erl{\"a}utert, welches W{\"a}rme zuf{\"u}hren oder bei Bedarf abf{\"u}hren kann.}, language = {de} } @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{OetringerDuemmlerGoettsche2020, author = {Oetringer, Kerstin and D{\"u}mmler, Andreas and G{\"o}ttsche, Joachim}, title = {Neues Modell zur 1D-Simulation der indirekten Verdunstungsk{\"u}hlung}, series = {DKV-Tagung 2020, AA II.1}, booktitle = {DKV-Tagung 2020, AA II.1}, pages = {1 -- 13}, year = {2020}, language = {de} } @inproceedings{Meliss1995, author = {Meliß, Michael}, title = {Nettoenergie-Analysen von Energiesystemen}, series = {16. Hochschultage Energie, Tagungsberichte, Essen, 27.-28. Sept. 1995}, booktitle = {16. Hochschultage Energie, Tagungsberichte, Essen, 27.-28. Sept. 1995}, publisher = {Pomp}, address = {Bottrop}, isbn = {3-89355-900-0}, pages = {121 -- 142}, year = {1995}, language = {de} } @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} } @inproceedings{Gross2018, author = {Groß, Rolf Fritz}, title = {M{\"o}glichkeiten und Grenzen f{\"u}r Forschung an Fachhochschulen}, series = {Smart Building Convention und BIMconvention in Aachen im September}, booktitle = {Smart Building Convention und BIMconvention in Aachen im September}, pages = {19 Seiten}, year = {2018}, language = {de} } @phdthesis{Meliss1978, author = {Meliß, Michael}, title = {M{\"o}glichkeiten und Grenzen der Sonnenenergienutzung in der Bundesrepublik Deutschland mit Hilfe von Niedertemperaturkollektoren : Grundlagen - technische Systeme - Wirtschaftlichkeit. - (Spezielle Berichte der Kernforschungsanlage J{\"u}lich ; 25.)}, publisher = {Zentralbibliothek der Kernforschungsanlage J{\"u}lich}, address = {J{\"u}lich}, pages = {V, 239 S. : graph. Darst.}, year = {1978}, language = {de} } @article{MeyerHaenelBeehetal.2020, author = {Meyer, S. and H{\"a}nel, Matthias and Beeh, B. and Dittmann-Gabriel, S{\"o}ren and Dluhosch, R. and May, Martin and Herrmann, Ulf and [und 5 weitere],}, title = {Multifunktionaler thermischer Stromspeicher f{\"u}r die Strom- und W{\"a}rmeversorgung der Industrie von morgen}, series = {ETG Journal / Energietechnische Gesellschaft im VDE (ETG)}, volume = {2020}, journal = {ETG Journal / Energietechnische Gesellschaft im VDE (ETG)}, number = {1}, issn = {2625-9907}, pages = {6 -- 9}, year = {2020}, language = {de} } @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} } @incollection{GrossMuellerHertingetal.1997, author = {Groß, Rolf Fritz and M{\"u}ller, D. and Herting, D. and Schneemann, A. and Renz, Ulrich}, title = {Modulare Messdatenerfassung in Forschung und Lehre}, series = {Virtuelle Instrumente in der Praxis : Begleitband zum Kongress VIP '97}, booktitle = {Virtuelle Instrumente in der Praxis : Begleitband zum Kongress VIP '97}, editor = {Rahman, Jamal and Jaschinski, Hans}, publisher = {H{\"u}thig}, address = {Heidelberg}, isbn = {978-3-7785-2667-5 Pp.}, pages = {282 -- 288}, year = {1997}, abstract = {The Lehrstuhl f{\"u}r W{\"a}rme{\"u}bertragung und Klimatechnik at the Aachen University of Technology operates several test facilities to investigate fundamentals of heat and mass transfer supported by the Deutsche Forschungsgemeinschaft, the Minister f{\"u}r Forschung und Technologie and the industry. In order to get high-resolution and reproselection of hardware components is as critical as the design of software routines to perform successful and accurate measurements. In the following the development of the measurement and control system for three different test facilities is presented and discussed. Special attention is given to the education of students within the framework of laboratories and scientific experiments.}, language = {de} } @inproceedings{SchwarzerVieiraMuelleretal.2003, author = {Schwarzer, Klemens and Vieira, Maria Eugenia and M{\"u}ller, Christoph and Lehmann, Harry and Coutinho, Lecimara}, title = {Modular solar thermal desalination system with flat plate collector}, series = {RIO 3 - World Climate \& Energy Event : proceedings of the international conference held in Rio de Janeiro, Brazil, 1 -5 december 2003 / chief-ed.: Stefan Krauter ...}, booktitle = {RIO 3 - World Climate \& Energy Event : proceedings of the international conference held in Rio de Janeiro, Brazil, 1 -5 december 2003 / chief-ed.: Stefan Krauter ...}, publisher = {Krauter}, address = {Rio de Janeiro}, isbn = {85-902710-2-1}, pages = {281 -- 286}, year = {2003}, language = {en} } @inproceedings{vonHeesenFaber1992, author = {von Heesen, W. and Faber, Christian}, title = {Modenfilter als Schalld{\"a}mpfer f{\"u}r axiale Turbomaschinen : M{\"o}glichkeiten und Grenzen des Einsatzes}, series = {Schalltechnik '92 : L{\"a}rmminderung durch Schalld{\"a}mpfer ; Tagung B{\"o}blingen, 19. und 20. Mai 1992 / Normenausschuß Akustik, L{\"a}rmminderung und Schwingungstechnik (NALS) im DIN und VDI. VDI-Berichte. 938}, booktitle = {Schalltechnik '92 : L{\"a}rmminderung durch Schalld{\"a}mpfer ; Tagung B{\"o}blingen, 19. und 20. Mai 1992 / Normenausschuß Akustik, L{\"a}rmminderung und Schwingungstechnik (NALS) im DIN und VDI. VDI-Berichte. 938}, publisher = {VDI-Verl.}, address = {D{\"u}sseldorf}, isbn = {3-18-090938-2}, pages = {241 -- 260}, year = {1992}, language = {de} } @inproceedings{AlexopoulosRauHoffschmidtetal.2012, author = {Alexopoulos, Spiros and Rau, Christoph and Hoffschmidt, Bernhard and Breitbach, Gerd and Latzke, Markus}, title = {Modelling and validation of a transient heat recovery steam generator of the solar tower power plant Juelich}, series = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012}, booktitle = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012}, address = {Rijeka}, pages = {ID 97}, year = {2012}, 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} } @inproceedings{SchwagerAngeleSchwarzboezletal.2023, author = {Schwager, Christian and Angele, Florian and Schwarzb{\"o}zl, Peter and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Model predictive assistance for operational decision making in molten salt receiver systems}, series = {SolarPACES: Solar Power \& Chemical Energy Systems}, booktitle = {SolarPACES: Solar Power \& Chemical Energy Systems}, number = {2815 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4623-6}, issn = {1551-7616 (online)}, doi = {10.1063/5.0151514}, pages = {8 Seiten}, year = {2023}, abstract = {Despite the challenges of pioneering molten salt towers (MST), it remains the leading technology in central receiver power plants today, thanks to cost effective storage integration and high cost reduction potential. The limited controllability in volatile solar conditions can cause significant losses, which are difficult to estimate without comprehensive modeling [1]. This paper presents a Methodology to generate predictions of the dynamic behavior of the receiver system as part of an operating assistance system (OAS). Based on this, it delivers proposals if and when to drain and refill the receiver during a cloudy period in order maximize the net yield and quantifies the amount of net electricity gained by this. After prior analysis with a detailed dynamic two-phase model of the entire receiver system, two different reduced modeling approaches where developed and implemented in the OAS. A tailored decision algorithm utilizes both models to deliver the desired predictions efficiently and with appropriate accuracy.}, language = {en} } @inproceedings{SchulzeBuxlohGross2021, author = {Schulze-Buxloh, Lina and Groß, Rolf Fritz}, title = {Miniature urban farming plant: a complex educational "Toy" for engineering students}, series = {The Future of Education 11th Edition 2021}, booktitle = {The Future of Education 11th Edition 2021}, pages = {4 Seiten}, year = {2021}, abstract = {Urban farming is an innovative and sustainable way of food production and is becoming more and more important in smart city and quarter concepts. It also enables the production of certain foods in places where they usually dare not produced, such as production of fish or shrimps in large cities far away from the coast. Unfortunately, it is not always possible to show students such concepts and systems in real life as part of courses: visits of such industry plants are sometimes not possible because of distance or are permitted by the operator for hygienic reasons. In order to give the students the opportunity of getting into contact with such an urban farming system and its complex operation, an industrial urban farming plant was set up on a significantly smaller scale. Therefore, all needed technical components like water aeriation, biological and mechanical filtration or water circulation have been replaced either by aquarium components or by self-designed parts also using a 3D-printer. Students from different courses like mechanical engineering, smart building engineering, biology, electrical engineering, automation technology and civil engineering were involved in this project. This "miniature industrial plant" was also able to start operation and has now been running for two years successfully. Due to Corona pandemic, home office and remote online lectures, the automation of this miniature plant should be brought to a higher level in future for providing a good control over the system and water quality remotely. The aim of giving the student a chance to get to know the operation of an urban farming plant was very well achieved and the students had lots of fun in "playing" and learning with it in a realistic way.}, language = {en} } @inproceedings{SauerbornHoffschmidtGoettscheetal.2009, author = {Sauerborn, Markus and Hoffschmidt, Bernhard and G{\"o}ttsche, Joachim and Schmitz, S. and Rebholz, C. and Ansorge, F. and Ifland, D.}, title = {Mini-Spiegel-Array f{\"u}r solarthermische Kraftwerke : [Vortragsfolien]}, series = {DPG-Fr{\"u}hjahrstagung, Arbeitskreis Energie, Hamburg 03.03.2009}, booktitle = {DPG-Fr{\"u}hjahrstagung, Arbeitskreis Energie, Hamburg 03.03.2009}, pages = {1 -- 10}, year = {2009}, language = {de} } @inproceedings{BeckmoellerWoltersBreitbachetal.1995, author = {Beckm{\"o}ller, S. and Wolters, J. and Breitbach, Gerd and Penkalla, H. J. and Schubert, F.}, title = {Microstructural dependent constitutive equation for inelastic analysis of internally cooled IN 738 LC turbine blades}, series = {Materials for advanced power engineering 1994 : proceedings of a conference held in Liege, Belgium, 3 - 6 Oct. 1994}, booktitle = {Materials for advanced power engineering 1994 : proceedings of a conference held in Liege, Belgium, 3 - 6 Oct. 1994}, publisher = {Kluwer}, address = {Dordrecht}, isbn = {0792330749}, pages = {829 -- 839}, year = {1995}, language = {en} } @incollection{DautzenbergGrossRenz1996, author = {Dautzenberg, H. and Groß, Rolf Fritz and Renz, Ulrich}, title = {Meßtechnik auf dem Pr{\"u}fstand: Forschung zur Heißgasfiltration}, series = {Virtuelle Instrumente in der Praxis. Begleitband zum Kongress VIP 1996}, booktitle = {Virtuelle Instrumente in der Praxis. Begleitband zum Kongress VIP 1996}, editor = {Jamal, Rahman}, publisher = {National Instruments Germany}, address = {M{\"u}nchen}, pages = {202 -- 208}, year = {1996}, abstract = {Im Rahmen von Forschungsvorhaben des BMBF und verschiedener Industriepartner betreibt der Lehrstuhl f{\"u}r W{\"a}rme{\"u}bertragung und Klimatechnik der RWTH Aachen Pilotanlagen und Pr{\"u}fst{\"a}nde f{\"u}r Untersuchungen auf dem Gebiet der Heißgasfiltration mit keramischen Filterelementen. Als wesentlicher Garant f{\"u}r den Erfolg der Forschungsarbeit muß die auf das jeweilige Projekt genau abgestimmte Meß- und Regelungstechnik angesehen werden. Hierbei z{\"a}hlt neben der Auswahl geeigneter Hardwarekomponenten auch die Softwareentwicklung unter einer leistungsstarken und zuverl{\"a}ssigen Programmierumgebung. Anhand des Aufbaus dreier Versuchsanlagen im Technikumsmaßstab soll das Anforderungsprofil an die Meßtechnik bis hin zur Umsetzung innerhalb der Anlage skizziert werden. Der Heißgasfiltrationspr{\"u}fstand im Heizkraftwerk der RWTH Aachen dient der Beobachtung des Reinigungsverhaltens keramischer Filterelemente bei der Heißgasentstaubung im Temperaturbereich bis 850 Grad C. Wesentlich f{\"u}r die Meßwerterfassung ist hierbei die Kopplung eines Orion-Datenloggers der Firma Schlumberger mit LabView 4.0. Im Hochtemperaturofen des Lehrstuhls werden instation{\"a}re Druckmessungen an einer keramischen Filterkerze w{\"a}hrend eines Abreinigungsimpulses bei 950 Grad C mit hoher Samplingrate durchgef{\"u}hrt. Hierbei {\"u}bernimmt eine durch LabView 4.0 angesteuerte E-Series Karte der Firma National Instruments die Signalaufnahme. Die katalytische Schadstoffreduktion und Entstaubung heißer Rauchgase bei 900 Grad C sind Ziele der Untersuchungen in einer erstellten Versuchsanlage mit einem Quarzglasreaktor. Die Signalerfassung und -konditionierung erfolgt {\"u}ber SCXI in Verbindung mit LabView 4.0, die Steuerung der Anlage {\"u}bernehmen zwei Multifunktionskarten (National Instruments).}, language = {de} }