Mode Coupling Analysis of Interfacial Stability and Critical Anode–Cathode Distance in a 500-kA Aluminum Electrolysis Cell

The quantitative description and theoretical research on the stability of the electromagnetic field interfacial wave in aluminum electrolysis cells are the key to achieving high energy efficiency and operational safety. The magneto-hydrodynamics equations were established based on the theory of electromagnetics and hydrodynamics and applied to a 500-kA cell. The Fourier series expansion and finite element methods were used for modeling and simulation of interfacial stability. Detailed analysis was conducted on wave mode coupling regimes by custom code in MATLAB. Based on the characteristics of total modulus, a modal analysis method was proposed to clarify how anode–cathode distance (ACD) and length-width ratio of cells affected interfacial stability. The results indicate that the stability is enhanced as the increase of ACD for a 500-kA electrolysis cell and the critical ACD is derived as 0.041 m, which is preferable for stabilizing the cell and reducing energy consumption.