Development of a Numerical Model to Study the Electric and Thermal Behaviour of a Hall-Héroult Cell

Aluminium is one of the most widely used metals in the world. The production of primary aluminium is a complex process with high energy requirements. Climate goals have steered many countries to shift towards renewable sources for electricity production, increasing the energy costs. The transition necessitates smelters to augment the production efficiency to produce aluminium at competitive prices. Additionally, the fluctuations in the electricity price in the energy market could be utilized to benefit the smelter by achieving flexibility in the production process. A detailed understanding of the cell behaviour is necessary to realize these objectives. A numerical model provides several advantages to study the influence of various cell parameters without affecting industrial production.

The thermal balance of the cell is critical to achieving stable and efficient production. In the present work, a numerical model in OpenFOAM® is developed to study the electric and thermal behaviour of the cell.

The numerical model is validated by comparing the simulation predictions with the industrial measurements. This is followed by studying the influence of the operational parameters on the electric and thermal behaviour of the cell. The operational parameters considered in this study are the amount of aluminium and electrolyte, anode-to-cathode distance, cell current, bath composition and sidewall cooling. The influence on the cell behaviour is evaluated by analyzing the variation in the ledge thickness, the bath temperature, the ohmic voltage and the cell specific energy consumption. The results of this work provide detailed insights into the thermoelectric behaviour of the cell and identifies critical parameters, which has a high impact on the production efficiency.