@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{SchulzeBuxlohGrossUlbrich2021, author = {Schulze-Buxloh, Lina and Groß, Rolf Fritz and Ulbrich, Michelle}, title = {Digital planning using building information modelling and virtual reality: new approach for students' remote practical training under lockdown conditions in the course of smart building engineering}, series = {Proceedings of International Conference on Education in Mathematics, Science and Technology 2021}, booktitle = {Proceedings of International Conference on Education in Mathematics, Science and Technology 2021}, publisher = {ISTES Organization}, address = {San Antonio, TX}, isbn = {978-1-952092-17-6}, pages = {118 -- 123}, year = {2021}, abstract = {The worldwide Corona pandemic has severely restricted student projects in the higher semesters of engineering courses. In order not to delay the graduation, a new concept had to be developed for projects under lockdown conditions. Therefore, unused rooms at the university should be digitally recorded in order to develop a new usage concept as laboratory rooms. An inventory of the actual state of the rooms was done first by taking photos and listing up all flaws and peculiarities. After that, a digital site measuring was done with a 360° laser scanner and these recorded scans were linked to a coherent point cloud and transferred to a software for planning technical building services and supporting Building Information Modelling (BIM). In order to better illustrate the difference between the actual and target state, two virtual reality models were created for realistic demonstration. During the project, the students had to go through the entire digital planning phases. Technical specifications had to be complied with, as well as documentation, time planning and cost estimate. This project turned out to be an excellent alternative to on-site practical training under lockdown conditions and increased the students' motivation to deal with complex technical questions.}, 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} } @techreport{AyarFielenbachGrossetal.2003, author = {Ayar, A. and Fielenbach, C. and Groß, Rolf Fritz and Holfeld, T. and Lockemann, S. and Severin, C. and Thulfaut, Christian and Hillemacher, B.}, title = {Druckkohlenstaubverbrennung von rheinischer Braunkohle : Abschlussbericht}, pages = {119 Seiten}, year = {2003}, abstract = {Im Rahmen des Forschungsschwerpunkts 3 wurde experimentell und theoretisch die NO{sub x}-Bildung und -Reduktion bei der Druckkohlenstaubverbrennung untersucht. Der zuvor beschriebene Einfluss der Kohlemahlung auf die Flamme konnte auch anhand der NO{sub x}-Messungen an der DKSF-Anlage Aachen bestaetigt werden. Waehrend mit Braunkohle im Staubfeuerungsbetrieb noch keine eindeutige Druckabhaengigkeit nachgewiesen werden konnte, haben vom Lehrstuhl durchgefuehrte NO{sub x}-Messungen an der DKSF-Anlage Dorsten im Schmelzkammerfeuerungsbetrieb mit der Steinkohle Spitzbergen zwischen 9 und 13 bar ein Absinken der Stickoxidkonzentrationen mit steigendem Druck ergeben. Fuer die rheinische Braunkohle soll dieser Druckeinfluss in den naechsten Versuchsfahrten ausfuehrlicher untersucht werden. Es wurde anhand von numerischen Simulationen zu einer Braunkohleflamme der 6. Versuchsfahrt ein Vergleich zwischen der NO{sub x}-Modellierung im Standard-FLUENT-Code und in dem mit User Defined Subroutines der international flame research foundation (IFRF), Ijmuiden, erweiterten FLUENT-Code vorgenommen. Es zeigte sich, dass bei der Modellierung der Stickoxidbildung die unterschiedlich vorhergesagten Flammentemperaturen eine entscheidende Rolle spielen. Eine genauere Analyse der NO{sub x}-Modelle im Vergleich zu Messergebnissen ist bei einer Schmelzkammerfeuerung mit einer stabilen Flamme vorzunehmen. Es wurden zusaetzlich Messungen zur Untersuchung der Kinetik homogener Gasphasenreaktionen in Rauchgasen an einem Stahlreaktor durchgefuehrt. Dabei wurde sowohl der thermisch bedingte als auch der durch zudosierte Additive katalysierte Abbau nitroser Komponenten betrachtet. Vergleichend wurden mit einem am Lehrstuhl entwickelten Programm die Kinetik beschrieben. Hierbei wird mit einer Sensitivitaetsanalyse eine Reduzierung der detaillierten Darstellung der Reaktionskinetik erreicht, die es erlaubt, mit einem CFD-Code wie FLUENT zwei- und dreidimensionale Rechnungen zum Abbau verschiedener Rauchgaskomponenten durchzufuehren. Die Uebereinstimmung zwischen ein- und zweidimensionalen Rechnungen und den Messungen ist gut.}, language = {de} } @article{ThulfautGross2000, author = {Thulfaut, Christian and Groß, Rolf Fritz}, title = {Experimentelle Untersuchung der Luftstromvermischung in Hybridzellenk{\"u}hlt{\"u}rmen}, series = {HLH. Heizung, L{\"u}ftung/Klima, Haustechnik}, volume = {51}, journal = {HLH. Heizung, L{\"u}ftung/Klima, Haustechnik}, number = {8}, publisher = {Springer}, address = {D{\"u}sseldorf}, issn = {1436-5103}, pages = {48 -- 49}, year = {2000}, abstract = {Zwangsbel{\"u}ftete Nassk{\"u}hlt{\"u}rme haben im Gegensatz zur Trockenk{\"u}hlung bei naßkaltem Wetter Nebelschwaden zur Folge. Dagegen ist bei Naßk{\"u}hlung die spezifische K{\"u}hlleistung durch abgef{\"u}hrte Kondensationsw{\"a}rme h{\"o}her als bei der Trockenk{\"u}hlung. Hybridzellenk{\"u}hlt{\"u}rme kombinieren beide Methoden, so daß ein Mischstrom beider Abluftstr{\"o}me die Wasserdampf-S{\"a}ttigungsgrenze nicht {\"u}berschreitet. Durch das Mischungsverh{\"a}ltnis kann man den gew{\"u}nschten S{\"a}ttigungsgrad einstellen. Je dichter dieser an der S{\"a}ttigungsgrenze liegt, desto h{\"o}her ist die K{\"u}hlleistung. Der von unten zugef{\"u}hrte Luftstrom der Naßk{\"u}hlung und der seitlich zugef{\"u}hrte trockene Abluftstrom m{\"u}ssen sehr gut durchmischt werden, um {\"u}ber den gesamten Austrittsquerschnitt des K{\"u}hlturms die S{\"a}ttigungsgrenze nicht zu {\"u}berschreiten. In einem maßstabsgerechten Modell wurde der Mischungsgrad mit und ohne Einbauten untersucht. {\"U}ber ein Raster von 10 mal 10 Punkten wurde die {\"o}rtliche Temperaturverteilung ermittelt. W{\"a}rmebilanzen ergeben dann die Mischungsg{\"u}te in einer Ebene oberhalb der Zellenkrone. W{\"a}hrend ohne Mischeinbauten der Trockenluftanteil in der Mitte des Querschnitts bei unter 15 \% liegt erh{\"o}hen Einbauten den Trockenluftanteil auf 30 \% bis {\"u}ber 40 \%. Dabei wurde die Trockenluft auf jeder K{\"u}hlturmseite durch 4 konisch zulaufende, unten offene und oben geschlitzte Einbauten kanalisiert. Die Nassluft wurde durch eine im Querschnitt dreieckige Rinne in Richtung der Trockenluftausl{\"a}sse umgelenkt. Im Raster leicht zu lokalisierende Abweichungen vom gew{\"u}nschten Mittelwert zeigen Potential f{\"u}r die weitere Verbesserung der Einbauten.}, language = {de} } @incollection{GrossHeckenRenz1999, author = {Groß, Rolf Fritz and Hecken, M. and Renz, Ulrich}, title = {Hot gas filtration with ceramic filter candles: experimental and numerical investigations on fluid flow during element cleaning}, series = {High temperature gas cleaning. Vol. 2}, booktitle = {High temperature gas cleaning. Vol. 2}, editor = {Dittler, A. and Hemmer, G. and Kasper, G.}, publisher = {KIT Institut f{\"u}r Mechanische Verfahrenstechnik und Mechanik}, address = {Karlsruhe}, isbn = {3-9805220-1-6}, pages = {862 -- 873}, year = {1999}, abstract = {Ceramic hot gas filters are widely used in combined cycles based on pressurised fluidised beds. They fulfil most of the demands with respect to cleaning efficiency and long time durability, but their operation regarding the consumption of pulse gas and energy still has to be optimised. Experimental investigations were carried out to measure the flow field, the pressure and the gas temperature inside the filter candle during pulse jet cleaning. These results are compared with the results of a numerical procedure based on a solution of the two - dimensional conservation equations for momentum and energy. The observed difficulties handling different flow regimes like highly turbulent flow as well as Darcy flow simultaneously are discussed.}, 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} } @techreport{HoeflerGross2016, author = {H{\"o}fler, Matthias and Groß, Rolf Fritz}, title = {Optimierung der Oxidationskinetik von Sulfit zu Sulfat durch effiziente feinblasige Bel{\"u}ftung bei Anlagen zur Rauchgasentschwefelung fossil befeuerter Kraftwerke und Industrieanlagen mittels Seewasser ("Optiox")}, pages = {1 Seite}, year = {2016}, abstract = {Das Forschungsvorhaben Optiox besch{\"a}ftigt sich mit der Optimierung eines Bel{\"u}ftungsbeckens zur Rauchgasentschwefelung fossil befeuerter Kraftwerke mittels Seewasser. Unter Neutralisierung der entstehenden Hydroniumionen (H3O+) durch die nat{\"u}rliche Alkalit{\"a}t des Seewassers dissoziiert Schwefeldioxid aus dem Rauchgase im vorgeschalteten Absorber beim Phasen{\"u}bergang von der Gas- in die Fl{\"u}ssigphase zu Sulfiten. Im Bel{\"u}ftungsbecken werden diese Sulfite mittels eingeblasener Luft zu Sulfaten oxidiert, was zu einer geringen Erh{\"o}hung der Sulfatfracht vor Einleitung ins Meer f{\"u}hrt, die unterhalb der nat{\"u}rlichen Schwankungen liegt. Daneben dient das Bel{\"u}ftungsbecken der Konditionierung des Seewassers hinsichtlich pH-Wert und Sauerstoffgehalt und ist mit hoch effizienten Bel{\"u}ftern ausgestattet, deren Spezifikation den jeweiligen Randbedingungen, wie Abscheideleistung des Absorbers, Beckengeometrie sowie lokalen Gegebenheiten angepasst wird.}, language = {de} } @article{GrossBerger2005, author = {Groß, Rolf Fritz and Berger, J.}, title = {Quo Vadis - Ausblick in die Geb{\"a}udeleittechnik der Zukunft}, series = {HLH. Heizung, L{\"u}ftung/Klima, Haustechnik}, volume = {56}, journal = {HLH. Heizung, L{\"u}ftung/Klima, Haustechnik}, number = {1}, publisher = {Springer}, address = {D{\"u}sseldorf}, issn = {1436-5103}, pages = {39 -- 41}, year = {2005}, abstract = {Auf dem Weg zum vernetzten Haus stoßen Hersteller und Planer, insbesondere im privaten Wohnungsbau, zur Zeit noch auf erhebliche Widerst{\"a}nde bei der Durchdringung des Marktes.}, language = {de} } @article{GrossBergerGross2003, author = {Groß, Rolf Fritz and Berger, J. and Groß, H.}, title = {Geb{\"a}udeautomation - Betriebsdatenerfassung und Geb{\"a}udeleittechnik im Klartext}, series = {HLH. Heizung, L{\"u}ftung/Klima, Haustechnik}, volume = {54}, journal = {HLH. Heizung, L{\"u}ftung/Klima, Haustechnik}, number = {2}, publisher = {Springer}, address = {D{\"u}sseldorf}, issn = {1436-5103}, pages = {81}, year = {2003}, language = {de} } @phdthesis{Gross2002, author = {Groß, Rolf Fritz}, title = {Zur Kinetik homogener Gasphasenreaktionen nitroser Komponenten in Rauchgasen einer kohlebefeuerten Wirbelschicht}, publisher = {Shaker}, address = {Aachen}, isbn = {3-8322-0004-5 (softcover)}, pages = {X, 146 Seiten}, year = {2002}, language = {de} } @techreport{ChristGrossRenz1998, author = {Christ, Ansgar and Groß, Rolf Fritz and Renz, Ulrich}, title = {HGR: Untersuchung zur Minimierung von gasf{\"o}rmigen Schadstoffen aus Rauchgasen bei der Heißgasfiltration}, doi = {10.2314/GBV:504318411}, pages = {141 Seiten}, year = {1998}, abstract = {Gas- und Dampfturbinen-Kraftwerke mit Druckwirbelschicht- oder mit Druckvergasungsverfahren erm{\"o}glichen die Verstromung von Kohle mit hohem Wirkungsgrad und niedrigen Emissionen. Eine Voraussetzung f{\"u}r den Betrieb dieser Anlagen ist die Entstaubung der Rauchgase bei hohen Temperaturen und Dr{\"u}cken. Abreinigungsfilter mit keramischen Elementen werden dazu eingesetzt. Eine Reduzierung gasf{\"o}rmiger Schadstoffe unter den gleichen Bedingungen k{\"o}nnte Rauchgasw{\"a}sche ersetzen. Ziel des Gesamtvorhabens ist es, die Integration von Heißgasfiltration und katalytischem Abbau der Schadstoffe Kohlenmonoxid, Kohlenwasserstoffe und Stickoxide in einen Verfahrensschritt zu untersuchen. Die Arbeitsschwerpunkte dieses Teilvorhabens betreffen: die katalytische Wirkung eisenhaltiger Braunkohlenaschen, die Wirksamkeit des Calciumaluminat als Katalysator des Abbaus unverbrannter Kohlenwasserstoffe im Heißgasfilter, numerische Simulation der kombinierten Abscheidung von Partikeln und gasf{\"o}rmigen Schadstoffen aus Rauchgasen}, language = {de} } @inproceedings{SchulzeBuxlohGross2021, author = {Schulze-Buxloh, Lina and Groß, Rolf Fritz}, title = {Interdisciplinary Course Smart Building Engineering: A new approach of teaching freshmen in remote teamwork project under pandemic restrictions}, series = {New Perspectives in Science Education - International Conference}, booktitle = {New Perspectives in Science Education - International Conference}, publisher = {Filodiritto}, address = {Bologna}, pages = {4 Seiten}, year = {2021}, abstract = {In the context of the Corona pandemic and its impact on teaching like digital lectures and exercises a new concept especially for freshmen in demanding courses of Smart Building Engineering became necessary. As there were hardly any face-to-face events at the university, the new teaching concept should enable a good start into engineering studies under pandemic conditions anyway and should also replace the written exam at the end. The students should become active themselves in small teams instead of listening passively to a lecture broadcast online with almost no personal contact. For this purpose, a role play was developed in which the freshmen had to work out a complete solution to the realistic problem of designing, construction planning and implementing a small guesthouse. Each student of the team had to take a certain role like architect, site manager, BIM-manager, electrician and the technitian for HVAC installations. Technical specifications must be complied with, as well as documentation, time planning and cost estimate. The final project folder had to contain technical documents like circuit diagrams for electrical components, circuit diagrams for water and heating, design calculations and components lists. On the other hand construction schedule, construction implementation plan, documentation of the construction progress and minutes of meetings between the various trades had to be submitted as well. In addition to the project folder, a model of the construction project must also be created either as a handmade model or as a digital 3D-model using Computer-aided design (CAD) software. The first steps in the field of Building information modelling (BIM) had also been taken by creating a digital model of the building showing the current planning status in real time as a digital twin. This project turned out to be an excellent training of important student competencies like teamwork, communication skills, and self -organisation and also increased motivation to work on complex technical questions. The aim of giving the student a first impression on the challenges and solutions in building projects with many different technical trades and their points of view was very well achieved and should be continued in the future.}, language = {en} } @inproceedings{MohanGrossMenzeletal.2021, author = {Mohan, Nijanthan and Groß, Rolf Fritz and Menzel, Karsten and Theis, Fabian}, title = {Opportunities and Challenges in the Implementation of Building Information Modeling for Prefabrication of Heating, Ventilation and Air Conditioning Systems in Small and Medium-Sized Contracting Companies in Germany - A Case Study}, series = {WIT Transactions on The Built Environment, Vol. 205}, booktitle = {WIT Transactions on The Built Environment, Vol. 205}, publisher = {WIT Press}, address = {Southampton}, issn = {1743-3509}, doi = {10.2495/BIM210101}, pages = {117 -- 126}, year = {2021}, abstract = {Even though BIM (Building Information Modelling) is successfully implemented in most of the world, it is still in the early stages in Germany, since the stakeholders are sceptical of its reliability and efficiency. The purpose of this paper is to analyse the opportunities and obstacles to implementing BIM for prefabrication. Among all other advantages of BIM, prefabrication is chosen for this paper because it plays a vital role in creating an impact on the time and cost factors of a construction project. The project stakeholders and participants can explicitly observe the positive impact of prefabrication, which enables the breakthrough of the scepticism factor among the small-scale construction companies. The analysis consists of the development of a process workflow for implementing prefabrication in building construction followed by a practical approach, which was executed with two case studies. It was planned in such a way that, the first case study gives a first-hand experience for the workers at the site on the BIM model so that they can make much use of the created BIM model, which is a better representation compared to the traditional 2D plan. The main aim of the first case study is to create a belief in the implementation of BIM Models, which was succeeded by the execution of offshore prefabrication in the second case study. Based on the case studies, the time analysis was made and it is inferred that the implementation of BIM for prefabrication can reduce construction time, ensures minimal wastes, better accuracy, less problem-solving at the construction site. It was observed that this process requires more planning time, better communication between different disciplines, which was the major obstacle for successful implementation. This paper was carried out from the perspective of small and medium-sized mechanical contracting companies for the private building sector in Germany.}, 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{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{CaminosSchmitzAttietal.2022, author = {Caminos, Ricardo Alexander Chico and Schmitz, Pascal and Atti, Vikrama and Mahdi, Zahra and Teixeira Boura, Cristiano Jos{\´e} and Sattler, Johannes Christoph and Herrmann, Ulf and Hilger, Patrick and Dieckmann, Simon}, title = {Development of a micro heliostat and optical qualification assessment with a 3D laser scanning method}, 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 = {10.1063/5.0086262}, pages = {8 Seiten}, year = {2022}, abstract = {The Solar-Institut J{\"u}lich (SIJ) and the companies Hilger GmbH and Heliokon GmbH from Germany have developed a small-scale cost-effective heliostat, called "micro heliostat". Micro heliostats can be deployed in small-scale concentrated solar power (CSP) plants to concentrate the sun's radiation for electricity generation, space or domestic water heating or industrial process heat. In contrast to conventional heliostats, the special feature of a micro heliostat is that it consists of dozens of parallel-moving, interconnected, rotatable mirror facets. The mirror facets array is fixed inside a box-shaped module and is protected from weathering and wind forces by a transparent glass cover. The choice of the building materials for the box, tracking mechanism and mirrors is largely dependent on the selected production process and the intended application of the micro heliostat. Special attention was paid to the material of the tracking mechanism as this has a direct influence on the accuracy of the micro heliostat. The choice of materials for the mirror support structure and the tracking mechanism is made in favor of plastic molded parts. A qualification assessment method has been developed by the SIJ in which a 3D laser scanner is used in combination with a coordinate measuring machine (CMM). For the validation of this assessment method, a single mirror facet was scanned and the slope deviation was computed.}, language = {en} } @inproceedings{NiederwestbergSchneiderTeixeiraBouraetal.2022, author = {Niederwestberg, Stefan and Schneider, Falko and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Introduction to a direct irradiated transparent tube particle receiver}, 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 = {10.1063/5.0086735}, pages = {9 Seiten}, year = {2022}, abstract = {New materials often lead to innovations and advantages in technical applications. This also applies to the particle receiver proposed in this work that deploys high-temperature and scratch resistant transparent ceramics. With this receiver design, particles are heated through direct-contact concentrated solar irradiance while flowing downwards through tubular transparent ceramics from top to bottom. In this paper, the developed particle receiver as well as advantages and disadvantages are described. Investigations on the particle heat-up characteristics from solar irradiance were carried out with DEM simulations which indicate that particle temperatures can reach up to 1200 K. Additionally, a simulation model was set up for investigating the dynamic behavior. A test receiver at laboratory scale has been designed and is currently being built. In upcoming tests, the receiver test rig will be used to validate the simulation results. The design and the measurement equipment is described in this work.}, language = {en} } @inproceedings{NeumannAdamBackesetal.2021, author = {Neumann, Hannah and Adam, Mario and Backes, Klaus and B{\"o}rner, Martin and Clees, Tanja and Doetsch, Christian and Glaeser, Susanne and Herrmann, Ulf and May, Johanna and Rosenthal, Florian and Sauer, Dirk Uwe and Stadler, Ingo}, title = {Development of open educational resources for renewable energy and the energy transition process}, series = {ISES SWC 2021}, booktitle = {ISES SWC 2021}, publisher = {International Solar Energy Society}, address = {Freiburg}, doi = {10.18086/swc.2021.47.03}, pages = {6 Seiten}, year = {2021}, abstract = {The dissemination of knowledge about renewable energies is understood as a social task with the highest topicality. The transfer of teaching content on renewable energies into digital open educational resources offers the opportunity to significantly accelerate the implementation of the energy transition. Thus, in the here presented project six German universities create open educational resources for the energy transition. These materials are available to the public on the internet under a free license. So far there has been no publicly accessible, editable media that cover entire learning units about renewable energies extensively and in high technical quality. Thus, in this project, the content that remains up-to-date for a longer period is appropriately prepared in terms of media didactics. The materials enable lecturers to provide students with in-depth training about technologies for the energy transition. In a particular way, the created material is also suitable for making the general public knowledgeable about the energy transition with scientifically based material.}, language = {en} } @inproceedings{SattlerSchneiderAngeleetal.2022, author = {Sattler, Johannes Christoph and Schneider, Iesse Peer and Angele, Florian and Atti, Vikrama and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Development of heliostat field calibration methods: Theory and experimental test results}, series = {SolarPACES 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.678}, pages = {9 Seiten}, year = {2022}, abstract = {In this work, three patent pending calibration methods for heliostat fields of central receiver systems (CRS) developed by the Solar-Institut J{\"u}lich (SIJ) of the FH Aachen University of Applied Sciences are presented. The calibration methods can either operate in a combined mode or in stand-alone mode. The first calibration method, method A, foresees that a camera matrix is placed into the receiver plane where it is subjected to concentrated solar irradiance during a measurement process. The second calibration method, method B, uses an unmanned aerial vehicle (UAV) such as a quadrocopter to automatically fly into the reflected solar irradiance cross-section of one or more heliostats (two variants of method B were tested). The third calibration method, method C, foresees a stereo central camera or multiple stereo cameras installed e.g. on the solar tower whereby the orientations of the heliostats are calculated from the location detection of spherical red markers attached to the heliostats. The most accurate method is method A which has a mean accuracy of 0.17 mrad. The mean accuracy of method B variant 1 is 1.36 mrad and of variant 2 is 1.73 mrad. Method C has a mean accuracy of 15.07 mrad. For method B there is great potential regarding improving the measurement accuracy. For method C the collected data was not sufficient for determining whether or not there is potential for improving the accuracy.}, language = {en} }