Thermal hydraulics of liquid metals
The Karlsruhe Liquid Metal Laboratory (KALLA) performs various basic and application-oriented experiments related to the thermal-hydraulics of liquid metals. Several loop facilities with different working fluids, such as lead, lead-bismuth eutectic (LBE), sodium and indium-gallium are available. The prototypical scale of these facilities allows for example 1:1 model tests for cooling of rod bundles with LBE. Moreover, two water loop facilities are operated at KALLA. A detailed characterization of relevant thermo-hydraulic effect is possible using comprehensive instrumentation, including Laser-Doppler Anemometry (see Fig. velocity measurement in a rod bundle), Particle-Image Velocimetry, flow rate, differential pressure, local temperature and laser-aided free-surface detection.
The broad spectrum of these investigation work ranges from the development of instrumentation, fundamental experiments on flow and heat transfer in generic and complex geometries to the study of the behavior of free-surface flows . The general goal is the development of model descriptions for the investigated phenomena, which then form the basis for the design of components; e.g. for fissile-material-free neutron sources for material and medical research, and for the safety evaluation of concepts investigated in European collaborative programs for the transmutation of long-lived into short-lived fission products.
Within the framework of several pilot studies, the Karlsruhe Liquid Metal Laboratory (KALLA) investigates how components from the energy transmission chain of a concentrating solar power plant based on liquid metals can be represented. The specific focus is placed on high-temperature receivers, storage and transmission systems. Due to their excellent heat transfer properties and their heat storage capacity at high temperatures, liquid metals offer the potential to increase the time availability and efficiency of a solar thermal power plant . As part of the work, a pilot plant was built and operated.
Relevant references: more
 Pacio, J., Daubner, M., Fellmoser, F., Litfin, K. & Wetzel, T. (2016). Experimental study of heavy-liquid metal (LBE) flow and heat transfer along a hexagonal 19-rod bundle with wire spacers, Nuclear Engineering and Design 301 (2016), 111–127.
 Pacio, J., Daubner, M., Fellmoser, F., Litfin, K. & Wetzel, T. (2018). Heat transfer experiment in a partially (internally) blocked 19-rod bundle with wire spacers cooled by LBE, Nuclear Engineering and Design 330 (2018), 225–240.
Prof. Dr.-Ing. Thomas Wetzel
Tel. +49 721/608-46447