Refine
Year of publication
- 2024 (3)
- 2023 (14)
- 2022 (37)
- 2021 (23)
- 2020 (35)
- 2019 (27)
- 2018 (22)
- 2017 (27)
- 2016 (17)
- 2015 (23)
- 2014 (40)
- 2013 (36)
- 2012 (20)
- 2011 (29)
- 2010 (35)
- 2009 (35)
- 2008 (28)
- 2007 (24)
- 2006 (29)
- 2005 (39)
- 2004 (35)
- 2003 (25)
- 2002 (33)
- 2001 (27)
- 2000 (35)
- 1999 (28)
- 1998 (28)
- 1997 (31)
- 1996 (44)
- 1995 (24)
- 1994 (30)
- 1993 (23)
- 1992 (17)
- 1991 (11)
- 1990 (11)
- 1989 (16)
- 1988 (16)
- 1987 (20)
- 1986 (20)
- 1985 (16)
- 1984 (14)
- 1983 (14)
- 1982 (10)
- 1981 (14)
- 1980 (7)
- 1979 (9)
- 1978 (3)
- 1977 (3)
- 1976 (1)
- 1975 (4)
- 1974 (1)
- 1973 (1)
- 1972 (1)
Institute
- Fachbereich Energietechnik (1115) (remove)
Language
- English (588)
- German (524)
- Multiple languages (1)
- Dutch (1)
- Spanish (1)
Document Type
- Article (609)
- Conference Proceeding (259)
- Book (125)
- Part of a Book (84)
- Doctoral Thesis (10)
- Conference: Meeting Abstract (7)
- Report (7)
- Other (4)
- Talk (3)
- Diploma Thesis (2)
Keywords
- Blitzschutz (18)
- Lightning protection (11)
- Earthquake (5)
- Diversity Management (4)
- Energy storage (4)
- Power plants (4)
- Risikomanagement (4)
- Seismic design (4)
- reinforced concrete (4)
- Associated liquids (3)
For the application of the concept of Lightning Protection Zones (LPZ), the knowledge of the magnetic fields and induced voltages inside a structure is necessary. Laboratory experiments have been conducted at a downscaled model of a building (scale factor 1:6) to determine these electromagnetic quantities in case of a direct strike to the structure. The model (3 m x 2 m x 2 m) represented a small industrial building using the reinforcement of the concrete as electromagnetic shield. The magnetic fields and magnetic field derivatives were measured at several location inside the scaled model. Further, the voltages induced on three typical cable routes inside the model was determined. The influence of the lightning current waveshape, point-of-strike, bonding of the cable routes, and bridging of an expansion joint in the middle of the building on these quantities was studied.
In IEC 61312-2 equations for the assessment of the magnetic fields inside structures due to a direct lightning strike are given. These equations are based on computer simulations for shields consisting of a single-layer steel grid of a given mesh width. Real constructions, however, contain at least two layers of reinforcement steel grids. The objective of this study was to experimentally determine the additional shielding effectiveness of a second reinforcement layer compared to a single-layer grid. To this end, simulated structures were set up in the high current laboratory. The structures consisted of cubic cages of 2 m side length with one or with two reinforcement grids, respectively. The structures were exposed to direct lightning currents representing the variety of anticipated lightning current waveforms. The magnetic fields and their derivatives at several positions inside the structure as well as the voltage between “floor” and “roof” in the center were determined for different current injection points. From these data the improvement of the shielding caused by a second reinforcement layer is derived.
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.
Technisches Zeichnen : Lösungsvorschläge für das Selbststudium. (Berichte aus dem Maschinenbau)
(2012)
Die Einleitung zur Norm DIN EN 62305-3 beschreibt klar und ein - deutig: Der vorliegende Teil der IEC 62305 behandelt den Schutz von baulichen Anlagen gegen materielle Schäden und den Schutz von Personen gegen Verletzungen durch Berührungs- und Schrittspannungen. Als das wesentlichste und effektivste Mittel zum Schutz von baulichen Anlagen gegen materielle Schäden gilt das Blitz - schutzsystem (LPS).