Heat transfer in upper part of electrolytic cells: Thermal circuit and sensitivity analysis

A thermal circuit representation was developed to study the heat transfer mechanisms in the top section of an aluminum smelting pot. In view of thermal management and waste heat recovery applications, the sensitivity of the off-gas temperature and of the heat content in the gas with respect to several parameters was investigated. It was found that the draft condition was the most influential parameter. Additionally, the convection coefficients on the anode cover, and on the yoke and stubs proved to have a stronger influence on exhaust gas temperature, compared with the heat transfer coefficients on the hoods and rod. The results indicate that it is conceptually possible to increase both the gas temperature and the heat content, while maintaining at the same time the current operating conditions of the cell. Variations of the potroom temperature, hood insulation and anode height were also considered and affected significantly the gas temperature.