Numerical simulation on coupled multi-field of the perforated anode in aluminium reduction cells under low carbon operation

Abstract

Perforation on the anode block is a new way of energy conservation. The bubbles under the anode block can be eliminated from the holes, and the energy consumption is reduced. The physical and mathematical models of perforated anode and bubble layer were established, and the thickness of the anode bubble layer and temperature field, electric field and thermal stress field were simulated. The simulation results show that the thickness of the bubble layer is 1.28cm of the perforated anode, reduced by 0.72cm compared to a normal anode, of which corresponding voltage is less than 240mV; the minimum temperature of anode block is 704.3°C, and the temperature distribution in a horizontal plane presents a wave shape due to the holes; the voltage drop of the perforated anode is 379mV and the current density distribution of the perforated anode and ordinary anode are consistent; the maximum of thermal stress is 17.4MPa in the perforated anode, which is far less than the allowable stress. The perforated anode industrial was conducted on three cells. The average cell voltage of perforated anodes decreases 229mV than the traditional reduction cell after long-term operation, which is agreed with the theoretical calculation.