TY - JOUR A1 - Meliß, Michael T1 - Photovoltaik bietet größtes Potential. NRW-Forschungs- und Entwicklungsarbeiten bereits heute anerkennenswert JF - Energie : das Magazin für Wirtschaft, Forschung, Technik, Umwelt. Bd. 41 (1989), H. 12 Y1 - 1989 SN - 0013-7359 SP - 32 EP - 41 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiesysteme. Teil 1 JF - Neue Deliwa-Zeitschrift. Bd. 36 (1985) Heft 12 Y1 - 1985 SN - 0369-383x SP - 568 EP - 572 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiesysteme (Teil 2) JF - Neue Deliwa-Zeitschrift. Bd. 37 (1986) Heft 1 Y1 - 1986 SN - 0369-383x SP - 14 EP - 19 ER - TY - JOUR A1 - Agrafiotis, Christos C. A1 - Mavroidis, Ilias A1 - Konstandopoulos, Athansios G. A1 - Hoffschmidt, Bernhard A1 - Stobbe, Per A1 - Romero, Manuel A1 - Fernandez-Quero, Valerio T1 - Evaluation of porous silicon carbide monolithic honeycombs as volumetric receivers/collectors of concentrated solar radiation JF - Solar energy materials and solar cells Y1 - 2007 SN - 1879-3398 (E-Journal); 0927-0248 (Print) VL - Vol. 91 IS - Iss. 6 SP - 474 EP - 488 ER - TY - JOUR A1 - Meliß, Michael A1 - Windheim, R. T1 - Energiequelle für morgen : Möglichkeiten und Grenzen der Windenergienutzung - ein Statusbericht JF - VDI-Nachrichten. Bd. 31 (1977), H. 22 Y1 - 1977 SN - 0042-1758 SP - 37 EP - 38 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiequellen JF - Brennstoff, Wärme, Kraft : BWK ; das Energie-Fachmagazin. Bd. 37 (1985), H. 4 Y1 - 1985 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) SP - 145 EP - 150 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiequellen JF - Brennstoff, Wärme, Kraft : BWK ; das Energie-Fachmagazin. Bd. 36 (1984), H. 4 Y1 - 1984 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) SP - 134 EP - 139 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiequellen JF - Brennstoff, Wärme, Kraft : BWK ; das Energie-Fachmagazin. Bd. 35 (1983), H. 4 Y1 - 1983 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) SP - 150 EP - 155 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiequellen JF - Brennstoff, Wärme, Kraft : BWK ; das Energie-Fachmagazin. Bd. 34 (1982), H. 4 Y1 - 1982 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) SP - 182 EP - 189 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiequellen JF - Brennstoff, Wärme, Kraft : BWK ; das Energie-Fachmagazin. Bd. 33 (1981), H. 4 Y1 - 1981 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) SP - 138 EP - 145 ER - TY - JOUR A1 - Stein, H. A1 - Meliß, Michael T1 - Die Bedeutung der Sonnenenergie für die zukünftige Energieversorgung der Bundesrepublik Deutschland JF - Din-Mitteilungen + Elektronorm. Bd. 59 (1980), H. 8 Y1 - 1980 SN - 0722-2912 SP - 434 EP - 440 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiequellen JF - Brennstoff, Wärme, Kraft : BWK ; das Energie-Fachmagazin. Bd. 31 (1979), H. 4 Y1 - 1979 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) SP - 147 EP - 154 ER - TY - JOUR A1 - Meliß, Michael T1 - Regenerative Energiequellen JF - Brennstoff, Wärme, Kraft : BWK Y1 - 1978 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) VL - 30 IS - 4 SP - 151 EP - 156 PB - Springer-VDI-Verlag CY - Düsseldorf ER - TY - JOUR A1 - Meliß, Michael A1 - Bünde, R. T1 - Unkonventionelle Energiequellen - Entwicklungsstudien (4) JF - Brennstoff, Wärme, Kraft : BWK Y1 - 1978 SN - 0006-9612 (Print) ; 1436-4883 (E-Journal) VL - 30 IS - 3 SP - 120 EP - 126 PB - Springer-VDI-Verlag CY - Düsseldorf ER - TY - JOUR A1 - Reisgen, Uwe A1 - Schleser, Markus A1 - Abdurakhmanov, Aydemir A1 - Turichin, Gleb A1 - Valdaitseva, Elena A1 - Bach, Friedrich-Wilhelm A1 - Hassel, Thomas A1 - Beniyashi, Alexander T1 - Investigation of factors influencing the formation of weld defects in non-vacuum electron beam welding JF - The Paton welding journal N2 - The influence of welding condition parameters and properties of material on formation of defects, such as humping and undercuts, in non-vacuum electron beam welding was investigated. The influence of separate welding parameters on the quality of welds was determined. Y1 - 2012 SN - 0957-798X VL - 2012 IS - 2 SP - 11 EP - 18 PB - Paton Publishing House CY - Kiev ER - TY - JOUR A1 - Vieira da Silva, Maria Eugenia A1 - Schwarzer, Klemens A1 - Hoffschmidt, Bernhard A1 - Pinheiro Rodrigues, Frederico A1 - Schwarzer, Tarik A1 - Costa Rocha, Paulo Alexandre T1 - Mass transfer correlation for evaporation–condensation thermal process in the range of 70 °C–95 °C JF - Renewable energy Y1 - 2013 SN - 1879-0682 (E-Journal); 0960-1481 (Print) VL - Vol. 53 SP - 174 EP - 179 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hagenkamp, Markus A1 - Blanke, Tobias A1 - Döring, Bernd T1 - Thermoelectric building temperature control: a potential assessment JF - International Journal of Energy and Environmental Engineering N2 - 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. Y1 - 2021 U6 - https://doi.org/10.1007/s40095-021-00424-x N1 - Corresponding author: Markus Hagenkamp VL - 13 SP - 241 EP - 254 PB - Springer CY - Berlin ER - TY - JOUR A1 - Wolisz, Henryk A1 - Schütz, Thomas A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Kohrn, Markus A1 - Wesseling, Mark A1 - Müller, Dirk T1 - Cost optimal sizing of smart buildings' energy system components considering changing end-consumer electricity markets JF - Energy Y1 - 2017 U6 - https://doi.org/10.1016/j.energy.2017.06.025 VL - 137 SP - 715 EP - 728 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Blanke, Tobias A1 - Hagenkamp, Markus A1 - Döring, Bernd A1 - Göttsche, Joachim A1 - Reger, Vitali A1 - Kuhnhenne, Markus T1 - Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates JF - Geothermal Energy N2 - 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 Hellström’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. Y1 - 2021 U6 - https://doi.org/10.1186/s40517-021-00201-3 SN - 2195-9706 N1 - Corresponding author: Tobias Blanke VL - 9 IS - Article number: 19 PB - Springer CY - Berlin ER - TY - JOUR A1 - Göttsche, Joachim A1 - Schwarzer, Klemens A1 - Röther, S. A1 - Jellinghaus, Sabine T1 - Efficient daylighting, heating and shading with rooflight heliostats JF - Conference Internationale Energie Solaire et Batiment Y1 - 2009 SP - 243 EP - 248 PB - EPFL CY - Lausanne ER -