Numerical Study on Flow Distribution and Turbulent Flow in XT-ADS Rod Bundle Water Experiment
In the framework of accelerator driven sub-critical reactor systems (ADS), heavy liquid metals (HLM) are considered as coolant for the reactor core and the spallation target due to their efficient heat removal properties and high production rate of neutrons. The excellent heat conductivity of HLMs corresponds to a low molecular Prandtl number. Therefore, turbulence models for the heat transfer which are available in commercial CFD codes cannot be applied, since these models are restricted to Prandtl numbers of order unity. A series of experiments has been launched at the Karlsruhe Liquid metal Laboratory (KALLA) of the Karlsruhe Institute of Technology aimed to quantify turbulent heat transfer and to improve fundamental understanding. The present work is related to a water mock-up experiment of the XT-ADS rod bundle. The experiment is an isothermal 19-pin hexagonal rod-bundle assembly with the exact pin to pitch ratio and axial dimensions of the XT-ADS considered in the IP-Eurotrans. The water experiment provides detailed flow measurements for a HLM rod bundle experiment of identical dimensions which contains 19 electrically heated pins. The present study uses the Star-CCM code. Two different flow domains with one and two spacer grids are analyzed. The geometry resolves all the details of the spacer geometry which requires the use of an unstructured polyhedral mesh. A systematic grid refinement study is performed. The pressure loss along the rods is shown to be insensitive to grid refinement, while the pressure loss across the spacers requires a high resolution grid for reliable pressure loss prediction. The study shows a comparison of numerical and first experimental results for the water experiment. In the XT-ADS rod bundle the pressure losses at the spacers are shown to be dominant. Pressure losses can be predicted in good agreement with experiments. The simulations show that the pressure drop across the first and second spacer grid are near similar, so that in future simulations it is sufficient to analyse a single spacer grid with cyclic boundary conditions.
Fuel assembly spacer bundle flow ADS
A. Batta A. Class K. Litfin T. Wetzel
Karlsruhe Institute of Technology Institute for Nuclear and Energy Technologies Postfach 3640, 76021 Karlsruhe, Germany
国际会议
上海
英文
1541-1551
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）