Research Outputs
Development of a Ti-doped Sodium Alanate Hydrogen Storage System
A trade-off analysis regarding power supply on satellites, which was performed for the European Space Agency (ESA), suggested that fuel cells might be an interesting candidate to replace secondary batteries on satellites. The Austrian Research Centers (ARC) decided to approach this topic by combining a fuel cell with innovative chemical hydrogen and oxygen storage as well as integrating the oxygen storage system into a form that can be used as a structural element. Also an integration of the fuel cell into the hydrogen tank, and the resulting storage of dissipation heat, results in a reduction of the necessary thermal control system. These advantages are very interesting in order to obtain higher weight efficiencies, which are especially important for space and automotive applications. The complete system includes a hydrogen storage tank based on Ti-doped sodium alanate and a novel oxygen tank based on YBaCo4O7 developed at ARC. Water tanks and a micro-fluidic system connected to the fuel cell have been considered as well in order to provide a completely reversible system, competitive to batteries. For the hydrogen storage, a finite elements model has been developed, implementing the reaction kinetics of the storage process, in order to predict the thermal mechanisms during adsorption and desorption of hydrogen in sodium alanate. The present paper discusses these simulations, the development of an experimental hydrogen storage tank and the proposed concepts of a battery replacement system.
Development of Innovative Micro Power Converter Technologies at the Austrian Institute of Technology
Waste heat is a primary source of energy loss in many aerospace and terrestrial applications. The Austrian Institute of Technology (AIT) is presently developing two different types of micro power converters, promising high efficiencies in their respective application areas. The first converter is based on an innovative thermoacoustic Stirling engine concept without moving parts. Such a maintenance-free engine system would be particularly suitable for advanced Stirling radioisotope space power systems. The second converter is based on microturbines to use exhaust-gases for improving the overall efficiency for a number of applications. This paper will summarize our efforts on micro power converter technologies.