Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf
Numerische Untersuchungen zur Strömungsdynamik von Flüssigmetallbatterien
Due to global shortage of fossil fuels, the well known danger of nuclear-energy and the growing threats of climate change the interest in a full switch to renewable based energy-supply is still growing.
The fluctuating and unpredictable character of the power gained from renewable energy-sources, especially sun and wind, is an important fact when considering a turnaround in energy-policy. Therefore, the use of effective storage-technologies is unavoidable to ensure a stable energy-supply.
A promising candidate for cheap electro-chemical storage is the liquid-metal-battery. Coming up from a stable density-stratification of a molten salt in between an alkali metal and an alloy the battery is easy to assemble because of its fully liquid content.
The entirely liquid configuration allows the application of high current densities. By exceeding a critical total current value the so-called Tayler-instability could force a fluid movement in the cell. The instability can cause a mixing or in worst case a short-circuit of the electrodes. An experimental proof of the Tayler-instability shows also a characteristic velocity distribution below the critical current value.
Aim of the present work is a numerical analysis investigating the sub-critical fluid movement.
Possible causes are natural convection as a result of Joule heating or electro-vortex-flow induced by inhomogeneous current density distribution. Central parts of the investigation are the creation of a consistent model including the model validation and the application of the generated setup on the experimental case. An adapted in-house OpenFOAM version for the prediction of magnetohydrodynamics is available.
In a last step a multiphase system, made of a realistic material selection under the influence of electro-vortex-flow, is studied.
Each part of the study is concluded with a summary of the findings.
Keywords: Liquid Metal Battery; Electro-Vortex Flow; OpenFOAM; Rayleigh-Benard; Multiphase-Flow
TU Dresden, 2015
Mentor: Prof. Fröhlich, Martin Niemann, Tom Weier