On the importance of field validation in the use of cell thermal balance modeling tools

Abstract

Mathematical models have become essential for the design of modern, efficient high-amperage reduction cells, but the models are only one part of the cell design process. Since many of the inputs to a thermal balance model are difficult to evaluate, a process for validation of the predictions of the model is essential. The validation process typically includes two sources of feedback: From operational pots and from post-mortem examination. Measurements of temperatures, heat fluxes and ledge shape must be made on the operating pots. In addition, prototype pots are shut down for post-mortem examination (cell autopsy) which is the only way to evaluate transformations of materials. The transformation of materials during operation is one of the major reasons why model predictions do not match real operation. The risk of using unvalidated models to carry on design work is highlighted through the presentation of a real example from the past.