@article{HagenkampBlankeDoering2021, author = {Hagenkamp, Markus and Blanke, Tobias and D{\"o}ring, Bernd}, title = {Thermoelectric building temperature control: a potential assessment}, series = {International Journal of Energy and Environmental Engineering}, volume = {13}, journal = {International Journal of Energy and Environmental Engineering}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/s40095-021-00424-x}, pages = {241 -- 254}, year = {2021}, abstract = {This study focuses on thermoelectric elements (TEE) as an alternative for room temperature control. TEE are semi-conductor devices that can provide heating and cooling via a heat pump effect without direct noise emissions and no refrigerant use. An efficiency evaluation of the optimal operating mode is carried out for different numbers of TEE, ambient temperatures, and heating loads. The influence of an additional heat recovery unit on system efficiency and an unevenly distributed heating demand are examined. The results show that TEE can provide heat at a coefficient of performance (COP) greater than one especially for small heating demands and high ambient temperatures. The efficiency increases with the number of elements in the system and is subject to economies of scale. The best COP exceeds six at optimal operating conditions. An additional heat recovery unit proves beneficial for low ambient temperatures and systems with few TEE. It makes COPs above one possible at ambient temperatures below 0 ∘C. The effect increases efficiency by maximal 0.81 (from 1.90 to 2.71) at ambient temperature 5 K below room temperature and heating demand Q˙h=100W but is subject to diseconomies of scale. Thermoelectric technology is a valuable option for electricity-based heat supply and can provide cooling and ventilation functions. A careful system design as well as an additional heat recovery unit significantly benefits the performance. This makes TEE superior to direct current heating systems and competitive to heat pumps for small scale applications with focus on avoiding noise and harmful refrigerants.}, 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} } @incollection{HoffschmidtAlexopoulosRauetal.2022, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and Rau, Christoph and Sattler, Johannes, Christoph and Anthrakidis, Anette and Teixeira Boura, Cristiano Jos{\´e} and O'Connor, B. and Chico Caminos, R.A. and Rend{\´o}n, C. and Hilger, P.}, title = {Concentrating solar power}, series = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications}, booktitle = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-12-819734-9}, pages = {670 -- 724}, year = {2022}, abstract = {The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems. The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours. Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage. Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described. Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail. The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world.}, language = {en} } @incollection{HoffschmidtAlexopoulosGoettscheetal.2022, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and G{\"o}ttsche, Joachim and Sauerborn, Markus and Kaufhold, O.}, title = {High Concentration Solar Collectors}, series = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications}, booktitle = {Comprehensive Renewable Energy (Second Edition) / Volume 3: Solar Thermal Systems: Components and Applications}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-12-819734-9}, doi = {10.1016/B978-0-12-819727-1.00058-3}, pages = {198 -- 245}, year = {2022}, abstract = {Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system. For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems. For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this article, different criteria for the choice of technology are analyzed in detail.}, language = {en} } @inproceedings{SchwagerTeixeiraBouraFleschetal.2019, author = {Schwager, Christian and Teixeira Boura, Cristiano Jos{\´e} and Flesch, Robert and Alexopoulos, Spiros and Herrmann, Ulf}, title = {Improved efficiency prediction of a molten salt receiver based on dynamic cloud passage simulation}, series = {AIP Conference Proceedings}, volume = {2126}, booktitle = {AIP Conference Proceedings}, number = {1}, isbn = {978-0-7354-1866-0}, doi = {10.1063/1.5117566}, pages = {030054-1 -- 030054-8}, year = {2019}, language = {en} } @article{RegerKuhnhenneHachuletal.2019, author = {Reger, Vitali and Kuhnhenne, Markus and Hachul, Helmut and D{\"o}ring, Bernd and Blanke, Tobias and G{\"o}ttsche, Joachim}, title = {Plusenergiegeb{\"a}ude 2.0 in Stahlleichtbauweise}, series = {Stahlbau}, volume = {88}, journal = {Stahlbau}, number = {6}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1437-1049 (E-journal), 0038-9145 (print)}, doi = {10.1002/stab.201900034}, pages = {522 -- 528}, year = {2019}, language = {de} } @inproceedings{GorzalkaDahlkeGoettscheetal.2018, author = {Gorzalka, Philip and Dahlke, Dennis and G{\"o}ttsche, Joachim and Israel, Martin and Patel, Dhruvkumar and Prahl, Christoph and Schmiedt, Jacob Estevam and Frommholz, Dirk and Hoffschmidt, Bernhard and Linkiewicz, Magdalena}, title = {Building Tomograph-From Remote Sensing Data of Existing Buildings to Building Energy Simulation Input}, series = {EBC, Annex 71, Fifth expert meeting, October 17-19, 2018, Innsbruck, Austria}, booktitle = {EBC, Annex 71, Fifth expert meeting, October 17-19, 2018, Innsbruck, Austria}, pages = {17 Seiten}, year = {2018}, 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{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} } @incollection{HoffschmidtAlexopoulosRauetal.2021, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and Rau, Christoph and Sattler, Johannes, Christoph and Anthrakidis, Anette and Teixeira Boura, Cristiano Jos{\´e} and O'Connor, B. and Caminos, R.A. Chico and Rend{\´o}n, C. and Hilger, P.}, title = {Concentrating Solar Power}, series = {Earth systems and environmental sciences}, booktitle = {Earth systems and environmental sciences}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-12-409548-9}, doi = {10.1016/B978-0-12-819727-1.00089-3}, year = {2021}, abstract = {The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems. The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours. Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage. Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described. Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail. The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world.}, language = {en} }