START-Cuve: Thermo-electro-mechanical transient simulation applied to electrical preheating of a Hall-Heroult cell

摘要

The phenomena taking place during the start-up of an aluminum reduction cell are complex and difficult to analyze. Experimental tests on industrial cells are difficult, time-consuming and expensive. Mathematical modeling offers here a good way to study the impact of design and startup methods on thermo-mechanical equilibrium in a cell. An overview of the research program, called START-Cuve, involving industrial and university researchers, will be given. The material characterization part will be briefly described. The finite element modeling approach of the research program will then be developed more thoroughly. The numerical resolution of the fully coupled thermo-electro-mechanical problem, solved with a finite element code able to cope with complex constitutive laws and multiple thermo-electro-mechanical interfaces, is a great challenge (Cross et al, 2000). In this paper, the architecture of the software is presented. The emphasis will be put on the multi-physic resolution in the context of the simulation of an electrical cell preheat, with a focus on three aspects: multi-field material constitutive laws, thermo-electro-mechanical contact between surfaces and numerical resolution of the problem. Finally, we present how the finite element analysis can advantageously be combined with experimental test results to identify specific parameters using reverse engineering approaches.