Preliminary CFD Assessment of an Experimental Test Facility Operating with Heavy Liquid Metals (original) (raw)

Status and future challenges of CFD for liquid metal cooled reactors

Liquid metal cooled reactors are envisaged to play an important role in the future of nuclear energy production because of their possibility to use natural resources efficiently and to reduce the volume and lifetime of nuclear waste. Typically, sodium and lead(-alloys) are envisaged as coolants for such reactors. Obviously, in the development of these reactors, thermal-hydraulics is recognized as a key (safety) challenge. A relatively new technique to deal with thermal-hydraulics issues is Computational Fluid Dynamics (CFD). This technique is used increasingly nowadays for design and safety evaluation purposes. This paper will discuss the development status of CFD application to liquid metal cooled reactors. In addition, the main challenges for future developments will be indicated. Firstly, the technological challenges will be discussed which ask for CFD application. Afterwards, the needs for CFD development and/or validation will be discussed. The discussion will also include the need for accompanying experiments.

CFD Methods to Nuclear Reactor Analysis

2018

Due to its ability to capture the effects of geometric details on local flow conditions, Computational Fluid Dynamics (CFD) has become a valuable tool for Framatome to design tailored products, meet customer needs, and find solutions to complex engineering problems. Framatome developed CFD methods for accurate predictions of fuel performance. These techniques were rigorously validated against measurements obtained at test facilities such as Framatome’s Technical Centers in Le Creusot, Karlstein, and Erlangen or CEA’s HERMES. CFD assessments are routinely used to define test specifications and to support the development and optimization of nuclear fuel designs with high thermal hydraulic performance. The paper focuses on a selection of typical industrial applications where CFD methods were applied to develop high performance nuclear fuels. The first part is dedicated to pre-test CFD-based evaluations and optimization of experimental setups where these CFD methods significantly reduce...

Multiphysics CFD Modelling for Design and Simulation of a Multiphase Chemical Reactor

Chemical Engineering Research and Design, 2005

T he present simulation study elaborates on a finite element (FE) computational fluid dynamics (CFD) model (Gerogiorgis and Ydstie, 2003a) developed for a candidate carbothermic aluminium reactor , aimed at industrial implementation of carbothermic Al production. Carbothermic reduction is an alternative to the conventional Hall -Héroult electrolysis process and is characterized by cost and environmental advantages as well as by a challenging complexity. Process technology encompasses a wide spectrum of phenomena (convection, diffusion, reaction, evapouration, electric field) that occur simultaneously in a multiphase configuration, the geometry of which is an open design problem and remains to be determined without prior experience or even abundance of experimental data. The strong interaction among Joule heating, endothermic reaction, natural Boussinesq convection and turbulent flow phenomena is of paramount importance for understanding reactor performance; conducting CFD simulations is an efficient way to advance with the latter goal, since reliable high-temperature measurements of state variables are remarkably laborious, uncertain and expensive. The quadruple partial differential equation (PDE) problem (electric charge, heat, momentum and gas volume balances) for the slag flow in the ARP reactor is solved via a commercial CFD software suite (FEMLAB w v. 2.3) to obtain potential, temperature, velocity and gas volume fraction distributions in a two-dimensional domain, representing in detail the complete second stage of the proposed carbothermic reactor. The new challenge is the present paper is to accurately calculate the volume fraction of the gas generated within the molten slag and understand how the proposed geometry affects production, via the instantaneous thermodynamic equilibrium assumption. The main objective of this CFD study is to extract conclusions regarding the reactive slag flow, the extent of space utilization and the existence of dead volumes, and to provide design guidelines. A steady state sensitivity analysis of state variable distributions (namely, potential, temperature, velocity and gas volume fraction) with respect to a key design variable (the imposed voltage profile) reveals the reactor heating potential, the geometry of the Al region and the nontrivial operation, design and optimization problems.

CFD initial assessment of a protrusions based experimental facility

INTERNATIONAL JOURNAL OF HEAT AND TECHNOLOGY, 2017

The design of compact heat exchangers and their mass flow distributors is still based on empirical approaches and both experimentations and numerical analyses are needed for defining the best geometries able to reduce the mass flow rate non uniformities in parallel channels. This is a cause of reduction in both thermal and fluid-dynamic performances. In this paper, a series of single-phase and two-phase CFD simulations on water and water with air injection are carried out in order to estimate the capabilities of the solvers implemented in the OpenFOAM code to reproduce (in comparison with experimental data) such kind of configurations and phenomena. The effects of different turbulence models implemented in OpenFOAM are investigated; additionally, some general considerations on the differences and analogies among different Reynolds numbers flow and turbulence model effects applied to the present configuration are discussed. Finally, by the point of view of two-phase flow, the capability of the code to reproduce the intermittent behaviour is investigated, with the aim of obtaining an acceptable simulation of the non-uniform mass flow distribution in each protrusion; the obtained results are also compared with both ANSYS-FLUENT and STARCCM+ commercial codes.

Use of CFD for applications in the oil and gas industry

Houille Blanche-Revue Internationale De L Eau, 2005

Ecoulements diphasiques Use of CFD for applications in the oil and gas industry L'utilisation de la Mécanique des Fluides Numérique (CFD) dans les applications de l'industrie pétrolière et gazières

A CFD Model for the IEA-R1 Reactor Heat Exchanger Inlet Nozzle Flow

2011

A previous preliminary model of the IEA-R1 heat exchanger inlet nozzle flow was developed and published in the International Nuclear Atlantic Conference-INAC-2009. A new model was created based on the preliminary one. It was improved concerning the actual heat exchanger tube bundle geometry. This became a very special issue. Difficulties with the size of the numerical mesh came out pointing to our computational system limits. New CFD calculations with this improved model were performed using ANSYS-CFX. In this paper, we present this model and discuss the results.

Evaluation of CFD Capability for Simulation of Energetic Flow in Light Water Reactor Containment

2015

HANNA, BOTROS NASEIF. Evaluation of CFD Capability for Simulation of Energetic Flow in Light Water Reactor Containment. (Under the direction of Dr. Igor A. Bolotnov and Dr. Nam T. Dinh.) This study is concerned with analysis of Direct Containment Heating (DCH), which is a known threat to the integrity of containment in Light Water Reactor plants during beyond design basis accident. DCH occurs in scenarios with high-pressure melt ejection (HPME) from the reactor vessel lower head to the containment. Molten corium release is followed by highly energetic steam flow, which causes melt dispersal and rapid heat up of the containment atmosphere. The present work investigates the capabilities of a computational fluid dynamics (CFD) approach for simulating high pressure steam blowdown. Evaluation Model Development and Assessment Process (EMDAP) is used to guide the investigation. Validation studies are conducted for selected flow patterns identified as important for the blowdown modeling. A ...

CFD analysis of coolant flow at bushehr nuclear reactor

The influence of fluid flow and heat transfer study within a Pressurized Water Reactor is of significant importance for the demonstration of the reactor performance and its safety in both steady and transient states. In the present pa-per, the three dimensional flow distributions in the downcomer and the lower plenum of the reactor were calculated with the computational fluid dynamics (CFD) codes. Calculations were performed for the VVER-1000, V446 reac-tor at the Bushehr nuclear power plant, Iran. Although CFD codes provide an effective tool for the calculation of flow distribution in the reactor pressure vessel (RPV), computer capacity puts restrictions on the capacity of CFD calculations. Consequently, simplified models had to be used in simulating the RPV. Nevertheless, our investigation shows a reasonable agreement between the numerical results and the measured data.

Methodology for studies of natural circulation in advanced reactors using CFD

This work presents an analysis of stability of the phenomenon of natural circulation for onedimension single-phase flow in a closed loop. The computer program uses a stabilized finite element formulation for the solution of the Navier-Stokes and energy equations in cartesian coordinates. The formulation has been developed and tested in a computer code developed at the Nuclear Engineering Institute (IEN-CNEN) and is now available either for future analysis or design of nuclear systems.