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Apr 19 – 22, 2022
Vienna, Austria
Europe/Vienna timezone
FR22 starts in Vienna 19 - 22 April 2022 Online Stream: https://event.do/iaea/a/#/events/5048

Physical modeling of hydrodynamics and heat exchange in fast reactors with liquid metal coolants

Apr 20, 2022, 1:52 PM
12m
Vienna, Austria

Vienna, Austria

ORAL Track 5. Test Facilities and Experiments 5.1 Experimental Reactors and Facilities

Speaker

Mrs Julia Kuzina (SSC RF - IPPE)

Description

In order to develop numerical modeling of hydrodynamics and heat exchange for substantiation of design and safety characteristics of fast reactors planning and carrying out experiments, generalizing the experimental results according to the physical laws and to their closing relations and verification of codes are required. To solve these problems, a complex of liquid metal facilities, equipment, modeling methods, measurement techniques, sensors, etc. were created. A great number of experimental results on heat exchange for Hg, Pb, Pb-Bi, Na, Na-K, Li, Cs were obtained.
When preparing and carrying out the experiments, the most important issue is the fulfillment of the conditions for mechanical, thermal and thermodynamic similarity, which determine the dependence of the physical properties of flowing medium on the state parameters and general dependences for describing heat transfer in various liquids under various conditions of hydrodynamics and heat exchange in the objects under study. Although a lot of monographs have been written, nevertheless, the simplicity (at first view) of the foundations of this analysis and the multi-parameter nature of the modeling tasks result in misunderstandings and gross blunder.
The goal of the study was to substantiate the possibility of applying the principles of modeling of thermophysical processes in liquid-metal coolants. They are specific coolants, and the theory of similarity is used for experiments on models with other coolants to substantiate hydrodynamics and heat exchange in fast reactors and to transfer the experimental data to reactor conditions.
The results of the application of the modeling theory to the hydrodynamics and heat exchange issues in liquid metals are presented: in complex shape channels, in rod (pin) systems (core and heat exchangers of fast reactors), in a reactor vessel in various regimes, for boiling of liquid metals in the core in accidental conditions. It is shown that direct modeling can be unlimitedly applied only for such processes as hydrodynamics, for which the determined similarity numbers are the functions of the only geometric simplexes of the system and of only one determining criterion (Re).
If there are two determining criteria, for example, the Re and Pr numbers during heat exchange, the modeling is significantly complicated. And under three defining criteria (mixing chambers, collector systems), direct modeling is usually not feasible. It is necessary to carry out systematic multivariate experiments. Their objectives are the real identification of effects within the framework of a general mathematical model that cannot be reproduced either analytically or numerically.

Country/Int. organization Russian Federation
Speaker's email address ukyzina@ippe.ru
Speaker's title Ms
Affiliation/Organization State Scientific Centre of the Russian Federation – Leypunsky In

Primary authors

Mrs Julia Kuzina (SSC RF - IPPE) Mr A.P. Sorokin (IPPE JSC)

Presentation materials

Peer reviewing

Paper

Paper files: