The Electromagnetic Flow Coupled Model And Application Research In Aluminium Reduction Cells

Energy conservation of electrolytic aluminum industry which is high energy consumption has an important influence to the national economy development. The main route of electrolytic aluminum energy-saving technology development is reduce the slot voltage and increase current efficiency by improving the traditional aluminum electrolysis production process conditions. The fluctuations in liquid aluminum layer thickness can effectively reduced by optimizing the cathode busbar configuration, thereby reduce the slot voltage. The research object is based on160kA series pre-baked aluminum reduction cell of Chongqing Tiantai aluminium limited company, the influence of magnetic field in different process conditions and the influence of electric field, magnetic field, flow field by enhancing the electricity was researched, and the concrete prioritization scheme of busbar was proposed in the end of this dissertation.The main research content and results obtained as follows:(1) The electric-magnetic-flow coupling calculation model of aluminum reduction cell was established based on simulation software ANSYS and CFX, and simulation results of electricity at160kA and strengthen to175kA was obtained used the model, the reliability of the model was validated for the calculation results of160kA were coincide with the measured values. The calculation results of175kA show that the increases proportion of magnetic field in three direction of cell is the same as the electricity reinforcement ratio, the electricity increases9.4%, maximum and average of magnetic field is increased by9.4%.(2) The influence of magnetic field in different process conditions was researched and analyzed based on175kA pre-baked aluminum reduction cell in Chongqing Tiantai electromagnetic model:Aluminium liquid height has a big influence on horizontal magnetic field and little on vertical magnetic field, magnetic field of X direction increases approximate linearly with the increase of aluminium liquid height, Y direction increases a little and Z direction keep constant. Pole pitch has a big influence on the magnetic field of Y direction and little on X and Z direction, the magnetic field of Y direction remains unchanged after reduction first with the increase of pole pitch, but the magnetic field of X and Z direction have remained little change. Electrolyte height has a little influence on the magnetic field, the magnetic field of three directions remained constant with the increase of the electrolyte height. The shape of furnace wall issue has a big influence on magnetic field of Y direction, and little on X and Z direction. The movement of crossbeam busbar has a large influence on magnetic field, the magnetic field of three directions are on the increase when the crossbeam busbar is moving down as the anode consumption. Pole changing has a small impact on the magnetic field of X direction, but big on Y and Z direction.(3)The configuration scheme of busbar which can improve magnetic field was proposed based on low current efficiency of the reduction cell. The compensation busbar was added alone in bottom and side of the cell when the original series of busbar in the same case, and the perpendicular magnetic field was compensated by regional and subsection.(4) The magnetic field and flow field of optimized175kA reduction cell was calculated, the results show that the maximum of optimized vertical magnetic field which besides the anode projection is21.1GAUSS, with a average value of3.58GAUSS, the average value of four quadrant are within5GAUSS, aluminum liquid interface deformation up to2.6cm, the overall deformation is5.3cm, has a great margin decline relative to the fore. The current efficiency increased by4%and2.2%respectively after transformation according to Qingtongxia aluminum and Baotou aluminium, the current efficiency increased by2%under a conservative estimate in conditions of Tiantai aluminium magnetic field (the average voltage of cell at3.8v), the dc power consumption will be reduced to277kWh/t-Al, tons of aluminum can power saving178.2kWh/t*Al.A new type configuration scheme of busbar which adopted by the factory was proposed in this paper, it will bring enormous economic benefits to the aluminum industry if can comprehensive promotion, is also of great significance to the national energy conservation and emissions reduction. Pictures63,Tables14,References78.