Technische Beschreibung der Versuchsanlage ALINA zur Untersuchung eines Natrium-Freistrahls. (KIT Scientific Reports ; 7570)

Im Rahmen des FAIR Projekts am GSI soll in einer Design-Studie gezeigt werden, dass es möglich ist, einen Flüssigmetall-Freistrahl zu erzeugen, der für den Beschuss mit Ionen geeignet ist. Die Experimente hierzu werden in der Testanlage ALINA am Institut für Kern- und Energietechnik (IKET) am KIT durchgeführt. Der Bericht beschreibt die zur Anlage gehörenden Kreislaufsysteme mit ihren wesentlichen Komponenten, ihrer Instrumentierung und den Anlagenbetriebszuständen

Construction of a Test Facility for Demonstration of a Liquid Lead-bismuth-cooled 10 kW Thermal Receiver in a Solar Furnace Arrangement - SOMMER

AbstractLiquid metals have been proposed in the past as high temperature heat transfer media in concentrating solar power (CSP) systems. Until the mid 80s test facilities were operated with liquid sodium-cooled central receivers. After a period of reduced interest in that approach, several new efforts have been reported recently, particularly from the US, South Africa and Australia. In addition, several recent publications have highlighted the attractive properties of liquid metals for CSP applications. A new contribution to this topic has been launched by Karlsruhe Institute of Technology (KIT) and the Solar Institute of the German Aerospace Center (DLR), combining their experience in CSP and liquid metal technology. The overall goals of this project are planning, design, construction and operation of a small concentrating solar power system in the 10kW thermal range (named SOMMER) using liquid metal as heat transfer fluid for re-gaining operation experience and validating design methodology and providing a complete design concept for a large pilot CSP plant based on liquid metal technology, up to evaluation of O&M cost and levelized cost of electricity. This paper describes the current status of the work on the design and setup of SOMMER, the research goals of this facility, first results of numerical activities in view of the liquid metal cooled receiver design and the connection to the design activities for the pilot plant

Experimental activities at KALLA on heavy-liquid metal heat transfer for fast reactors

Heavy liquid metals (HLMs), such as lead-bismuth eutectic (LBE) and pure lead are prominent candidate coolants for fast neutron systems, both critical assemblies and accelerator-driven systems. One of the key questions for the safety of these systems is the fundamental understanding of thermal-hydraulic aspects, such as the cooling of fuel assemblies under normal and accidental conditions. For several reasons, this problem is particularly challenging, compared to reactors cooled with conventional coolants. Extensive efforts are currently devoted worldwide to improving the understanding of these flows. Reliable experimental data are essential for developing advanced predicting models, but scarce. This issue has been experimentally investigated at the Karlsruhe Liquid Metal Laboratory KALLA for over a decade, in a comprehensive series of experiments of progressively increasing complexity. This contribution presents the main results from these experiments, e.g. heat transfer correlations, local temperature distributions in the fluid as well as in the rod cladding. Lessons learned in view of the experimental setup, instrumentation, procedures and usefulness of the results for development and validation of simulation codes are also presented. Finally, the main open issues which require further research are identified

Heat transfer experiments in rod bundles cooled by lead-bismuth uutectic (LBE)

Heavy liquid metals (HLMs), such as lead-bismuth eutectic (LBE) and pure lead are prominent candidate coolants for critical assemblies and accelerator-driven systems based on fast neutrons. With a strong focus on safety, key thermal-hydraulic aspects of these systems must be considered. The main challenge for modeling the heat transfer in liquid metals is given by their characteristically low Prandtl number (Pr << 1), separating the scales of turbulent transfer of momentum and heat. For that reason, specific experimental investigations are required for validating according models, particularly for complex geometries such as rod bundles. This work presents the experimental evaluation of two tests sections, both consisting of electrically-heated 19-pin hexagonal bundles, although with different characteristics. The setup #1 has grid spacers and a relatively large pitch-to-diameter ratio P/D=1.4. In this recently completed experimental campaign, extensive heat transfer and pressure drop information was obtained at typical reactor conditions of temperature (up to 450 °C), power density (up to 1.0 MW m ) and bulk velocity (2.2 m s ). With a good repeatability, these results agree well with information available in literature and are a suitable source of data for the validation of predicting models. The setup #2 is a similar bundle, with wire spacers and P/D=1.28. It is currently in the last stages of construction and commissioning. Its main characteristics, instrumentation and envisaged experiments are presented in this work

EXPERIMENTAL INVESTIGATION OF LEAD-BISMUTH-EUTECTIC FLOW AND HEAT TRANSFER IN HEXAGONAL-LATTICE ROD BUNDLES WITH GRID SPACERS

Heavy liquid metals are proposed as coolants for subcritical assemblies such as accelerator-driven systems. Particularly lead- bismuth eutectic is a superior candidate due to its low melting temperature. In that context, fluid- and geometry-specific thermal-hydraulic experiments play a major role for the design and operation of such systems. In this work a bundle with 19 rods (8.2 mm in diameter) in a hexagonal lattice with a pitch-to-diameter ratio P/D = 1.4 was tested in the existing THEADES loop at Karlsruhe Liquid Metal Laboratory of KIT. This vertical test section (870 mm heated length) includes three grid spacers, where localized instrumentation for both temperature and pressure drop is mounted. For this geometry and with reactor-representative operating conditions (temperature, velocity, heat flux) forced-convective tests applying a heat power density up to 100 W/cm2 have been performed. Based on these results, it can be concluded that within acceptable engineering accuracy, the heat transfer performance for this case can be well predicted by existing dimensionless correlations originally developed for other fluids, mainly sodium