Institute of Technical Thermodynamics

Stuttgart, Germany

Institute of Technical Thermodynamics

Stuttgart, Germany
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Roeb M.,German Aerospace Center | Sack J.-P.,German Aerospace Center | Rietbrock P.,German Aerospace Center | Prahl C.,Institute of Technical Thermodynamics | And 19 more authors.
Solar Energy | Year: 2011

The present work describes the realisation and successful test operation of a 100. kW pilot plant for two-step solar thermo-chemical water splitting on a solar tower at the Plataforma Solar de Almería, which aims at the demonstration of the feasibility of the process on a solar tower platform under real conditions. The process applies multi-valent iron based mixed metal oxides as reactive species which are coated on honeycomb absorbers inside a receiver-reactor. By the introduction of a two-chamber reactor it is possible to run both process concepts in parallel and thus, the hydrogen production process in a quasi-continuous mode. In summer 2008 an exhaustive thermal qualification of the pilot plant took place, using uncoated ceramic honeycombs as absorbers. Some main aspects of these tests were the development and validation of operational and measurement strategy, the gaining of knowledge on the dynamics of the system, in particular during thermal cycling, the determination of the controllability of the whole system, and the validation of practicability of the control concept. The thermal tests enabled to improve, to refine and finally to prove the process strategy and showed the feasibility of the control concept implemented. It could be shown that rapid changeover between the modules is a central benefit for the performance of the process. In November of 2008 the absorber was replaced and honeycombs coated with redox material were inserted. This allowed carrying out tests of hydrogen production by water splitting. Several hydrogen production cycles and metal oxide reduction cycles could be run without problems. Significant concentrations of hydrogen were produced with a conversion of steam of up to 30%. © 2010 Elsevier Ltd.

Muller-Steinhagen H.,Institute of Technical Thermodynamics | Kallo J.,German Aerospace Center
Chemical Engineer | Year: 2010

The aircraft manufacturer Airbus is working with the Institute of Technical Thermodynamics of the German Aerospace Centre (DLR) to develop fuel cell systems for aircraft. The goal is to integrate several functions and products of the fuel cell system into the aircraft architecture to demonstrate not only ecological but also economical benefits which will justify the additional costs of fuel cell technology. The primary goal of fuel cell systems in aircraft is to avoid inefficient operation phases of aircrafts. A second application could be to replace the equally inefficient ram air turbine (RAT), an emergency power system which generates hydraulic and electric power from the air stream. DLR together with Lange Aviation developed an additional flying test, the glider Antares DLR-H2, based on the commercial high-tech motor glider aircraft Antares 20E. The fuel cell system on the Antares delivers up to 25 kW of electrical power.

News Article | April 27, 2016

« LLNL 3D-printed foam outperforms standard materials | Main | SAE technical experts: fuel cell technology has advanced significantly, FC vehicle production has begun, further cost reductions & infrastructure development required » DLR is presenting the HY4—a four-seater passenger fuel cell hybrid electric aircraft prototype (earlier post)— at the 2016 Hannover Messe, along with research and development partners Hydrogenics, Pipistrel, H2FLY, the University of Ulm and Stuttgart Airport. The HY4 is due to take off for its maiden flight in the summer of 2016. The HY4’s drive train consists of a hydrogen storage unit, a low-temperature hydrogen fuel cell and a high performance battery. The DLR research team has successfully tested the drive train in the laboratory in recent months. In order to take off, the engine must reliably provide a maximum take-off output for three minutes. This has already been successfully demonstrated for more than 10 minutes. The interaction of the fuel cell and the high performance battery used as a buffer and additional safety system have also been successfully demonstrated in a simplified form in the laboratory. Hence, the road is clear for installing an initial version of this propulsion system in the four-seater HY4 passenger aircraft. The DLR Institute of Technical Thermodynamics is responsible for the overall integration of the drive train and certification of the electrochemical components for use in aeronautics. The HY4 research platform will be operated by the DLR subsidiary H2FLY. HY4 is based on an efficient battery-powered electrical aircraft concept developed by the company Pipistrel. The fuel cell stacks are supplied by the company Hydrogenics, and the electric propulsion concept, the electronic output components for the hybridization unit and the optimisation of the motor are being researched at the Institute for Energy Conversion and Storage at the University of Ulm. Der Stuttgart Airport is supporting the project as a home airport.

Schiller G.,German Aerospace Center | Schiller G.,Institute of Technical Thermodynamics | Auer C.,German Aerospace Center | Auer C.,Institute of Technical Thermodynamics | And 15 more authors.
Applied Physics B: Lasers and Optics | Year: 2013

A planar solid oxide fuel cell (SOFC) operated with hydrogen at T = 1,123 K was equipped with an optically transparent anode flow field to apply species concentration measurements by 1D laser Raman scattering. The flow channels had a cross section of 3 mm × 4 mm and a length of 40 mm. The beam from a pulsed high-power frequency-doubled Nd:YAG laser (λ = 532 nm) was directed through one channel and the Raman-scattered light from different molecular species was imaged onto an intensified CCD camera. The main goal of the study was an assessment of the potential of this experimental configuration for a quantitative determination of local gas concentrations. The paper describes the configuration of the optically accessible SOFC, the laser system and optical setup for 1D Raman spectroscopy as well as the challenges associated with the measurements. Important aspects like laser pulse shaping, signal background and signal quality are addressed. Examples of measured species concentration profiles are presented. © 2012 Springer-Verlag Berlin Heidelberg.

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